An Interview With Gordon Keller

Posted by on October 19th, 2011

(This interview originally appeared in Development.)

Gordon Keller is Director of the McEwen Centre for Regenerative Medicine at the University Health Network in Toronto, Canada. His research applies concepts from developmental biology to the investigation of the lineage-specific differentiation of mouse and human embryonic stem (ES) cells. He became an Editor of Development in 2011, and recently we asked him a few questions to find out more about him and his research.

Who or what inspired you to study science?

I was always curious, and I found a scientific career to be one that allowed me to explore my curiosity.

What sparked your interest to work on the directed differentiation of stem cells?

That was a seminar by Rolf Kemler in 1984. I was in the Basel Institute for Immunology – I had arrived there about a year earlier – and Rolf came to the institute and showed us these beautiful, huge cystic embryoid bodies, in which you could see blood and vascular structures and beating heart cells. Knowing that you could make that from an ES cell piqued my interest and I decided to pursue research in this topic.

What made you return to Canada after having worked in Switzerland and the USA?

There were several things. First, there was an opportunity here to direct the McEwen Centre for Regenerative Medicine. Canada, and Toronto in particular, has a very strong scientific community but also a very strong stem cell biology community. And I am Canadian, and felt it would be a wonderful opportunity to return home and spend part of my career here.

What has been the biggest surprise that you have come across in your research?

I don’t know whether you would call it a surprise, but I have been amazed at the speed at which stem cell research has progressed. We have worked for years at differentiating mouse ES cells, and, although people were interested, it was always somewhat on the back burner. Then the discovery of human ES cells and induced pluripotent stem (iPS) cells transformed the field, and the kind of work we do has now become more mainstream. In a nutshell, I don’t know if I have been surprised by any particular finding so much, but what I find most remarkable is the evolution of the field and seeing it change almost on a weekly basis.

Given these ongoing changes, where do you see the field move next?

I think the biggest challenge that we have is to find a way to get the cells that we make in a dish to integrate into adult tissue and function. We are certainly making components of human tissues and organs, but to date there is not much evidence yet that they are functional, so I think the next hurdle – the big challenge before we can really make an argument that these are clinically relevant cells – is to find out whether in vitro differentiated cells can integrate into adult organ function.

How does developmental biology inform in vitro differentiation?

Developmental biology is the basis of all we do. For the last eight years, we have looked closely at concepts from developmental biology; for example, the pathways that control lineage specification in the early embryo. We initially applied these concepts to mouse ES cells, and more recently to human ES cells. Using knowledge from developmental biology has provided us with a very informed way to develop strategies and protocols that are both robust and efficient.

What is the role of Development within your field?

Many of the key papers that we look at to inform our work have been published in Development, and we have published a lot of our own ES cell work in the journal as well. At times, publishing our work has been challenging, I must say, because when we started it was a new system and a lot of people didn’t believe that cells in a dish could recapitulate development. But Development was very supportive and allowed us an avenue to publish our research.

Is there a particular type of in vitro differentiation paper that you would encourage people to submit to Development?

Absolutely. I would like to see ES cell differentiation papers coming to Development. This could include papers that use the system to study aspects of development that are very difficult to study in an embryo, and there are many examples of that. As we are starting to move from animal models towards human biology, ES cell differentiation is going to be the model for human developmental biology, and I would be delighted if the journal could stake a claim to human developmental biology.

If you were not a scientist, what career would you have chosen?

I have no idea. In fact I’m not sure that I had a priority to start with. I didn’t grow up saying ‘I want to be a scientist’, but rather I followed a path where my thoughts were along the lines of ‘I find this interesting, I’ll pursue it somewhat more’.
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Yukiko Yamashita, a developmental biologist at U-M, named one of this year’s MacArthur fellows

Posted by on October 13th, 2011

Photo credit: U-M Photo Services What would you do if you were given $500,000 to fund your research for five years, with no strings attached –– no proposals to write, no progress reports to submit? If you were one of the recently announced recipients of the prestigious MacArthur fellowship you would be giving this question some serious thought.

Every year since 1981 the John D. and Catherine T. MacArthur Foundation recognizes exceptionally creative individuals by awarding them with $500,000 “genius grants”. According to the press release published on September 20th “MacArthur fellowships come without stipulations or reporting requirements and offer fellows unprecedented freedom and opportunity to reflect, create, and explore. All [fellows] were selected for their creativity, originality, and potential to make important contributions in the future.”

To be considered for the MacArthur fellowship requires a nomination.  However the identities of the nominators as well as the selection process are kept in complete secrecy.  Those who are selected for the award find out through an “out of the blue” phone call from the foundation two weeks prior to the official announcement. This year’s 22 recipients include a musician, a poet, a historian, an economist, a radio producer as well as 10 scientists.  Among them is Yukiko Yamashita a developmental biologist and assistant research professor at the University of Michigan who studies the mechanisms regulating stem cell division in the context of unperturbed tissue anatomy –– adult testes.

Getting the Call

When Yukiko received the phone call informing her about being selected and asking her asking her not to discuss it with anyone except her spouse until the official announcement, she had a hard time believing that it was not a scam. “I called my husband right after I hung up my phone call with the foundation and [he] seriously warned me that ‘if you get a second phone call asking your bank account and pin number, so that they can transfer the award money, don’t give it to them.’”

They did not ask for her bank info but did want to bring a production crew to her lab to film an interview for the foundation’s website.  “I had to ask the director of my institute if the production crew can come into the building to film me before the press release. We seriously have to worry about some activists against research blowing up the building. I didn’t want to be the stupid assistant professor who believed they are awarded a MacArthur ended up with destroying the entire institute.” When the names of this years MacArthur fellows were finally announced publicly Yukiko felt more relieved than ecstatic.

Yukiko completed her undergraduate and doctoral studies in Japan, at Kyoto University, followed by postdoctoral training with Margaret Fuller in the Department of Developmental Biology at Stanford University. In 2007 she established her own lab as an assistant research professor at the University of Michigan Medical School.

Choose Your Centrosome Wisely

Her current research, which has won her the recognition from the MacArthur foundation, combines cell and developmental biology and is focused on investigating molecular and cellular mechanisms governing stem cell behavior, using the Drosophila male germline stem cells (GSCs) as a model. Her lab is investigating how stem cell division is regulated and how different stem cell populations interact to maintain tissue stability.

During her time at Stanford, Yukiko made the discovery that the centrosomes of Drosophila male GSCs are non-randomly segregated during asymmetric division –– the older “mother” centrosome remains with the stem cell while the newly replicated “daughter” centrosome is inherited by the differentiating cell.

The GSCs in Drosophila reside in a niche composed somatic support cells called hub cells and cyst stem cells. GSCs attach to the support cells at their apical side and during cell division orient the mitotic spindle along the apical-basal axis.  The cells still attached to the hub after cell division maintain a stem fate, while the daughter cell, displaced from the hub, differentiates.

“Its been known for quite a long time in the cell biology field that mother and daughter centrosomes are a little different from each other. The newborn centriole in the centrosome takes more than one cell cycle to get fully mature,” says Yukiko. As the centriole matures it accumulates structures called subdistal appendages, which serve to anchor the microtubles forming the spindle. Mature centrosomes therefore have a stronger ability to anchor microtubules. “Because of this difference the mother centrosome always has higher microtubule nucleating capacity.” In fact Yukiko’s found that the mother centrosome is anchored by microtubules at the apical pole of the cell, near the hub. “That is why, we are guessing, the mother centrosome can stay close to the hub cells all the time.”

However this mechanism is not universal to all stem cells.  “In Drosophila neuroblasts, every single cell cycle the mother centrosome gets inactivated and the daughter centromosme gets activated and so, unconventionally, the daughter centrosome has higher [microtubule organizing center] MTOC activity. In the end the stem cell ends up inheriting the daughter centrosome all the time.” The reasoning for this switching is not known, however the trend is that the centrosome with higher MTOC activity is inherited by the stem cell.  “In one case, germ line stem cells maintain higher MTOC activity on the mother centrosome, but in the Drosophila neuroblasts they make daughter centrosome with high MTOC activity. Why this is happening we don’t know. But once you have high MTOC activity it looks like that’s going to the stem cell.”

How Do Chromosomes Fit Into the Picture?

Following Yukiko’s discovery about the non-random segregation of centrosomes other scientists in the field speculated that it might serve as a mechanism to selectively segregate chromosomes, perhaps keeping the original strands in the stem cell as proposed by the immortal strand hypothesis. Yukiko, however, was not convinced that this was the case and thought that a thorough analysis was required to prove or disprove the hypothesis –– something that she felt was lacking in some studies.

“We thought we really should address this question in our system, in which we can directly test this idea,” she says.  In early 2011 Yukiko’s group published a paper in the Journal of Cell Science reporting that the chromosomes of GSCs, unlike the centrosomes, are randomly segregated.  “I’m glad that we published this paper because I think [among] the immortal strand hypothesis papers, some are really good and the data appears really convincing, but some others are not really excluding alternative possibilities or different interpretations. I really wanted to propose some rigorous way of testing it. I’m not saying that the immortal strand [hypothesis] is not correct, but then to make it right, you have to examine every single possibility.”

Since that publication, a the graduate student pursuing this line of research in her lab has examined the segregation of each individual strand for all the chromosomes and  found that at this level of resolution only a small subset of chromosomes are selectively segregated, while the segregation of others is random.  “It looks like germline stem cells are segregating very specific strands with quite high bias only for some of  the chromosomes, but not others, so that at least suggests that cells have the machinery to distinguish one chromosome strand over the other and then segregate one into the stem cell in a biased way.”

This finding that the majority of the chromosomes are randomly segregated still leaves the question of why cells need to selectively segregate their centrosomes?  “Ultimately the question everybody is asking is: does the mother or daughter centrosome carry some information, not just microtubules?”

Yukiko doesn’t yet have the answer but can speculate about the possibilities.  “The centrosome itself [could be] associated with some sort of fate determinants. That is not unprecedented. Some fate determining mRNA is associated with just one centrosome during mollusk early embryogenesis.  [Another possibility is that] the centrosomes are used to distinguish two different sister chromatids, to segregate one strand over the other.  Why you have to distinguish one strand over the other strand of the chromosome? I don’t think its for the sake of an immortal strand, I don’t think its because of the DNA mutations or avoiding them, instead I think it’s some epigenetic information that they want to carry. It might be histone modifications or DNA methylation but we don’t have any evidence for that yet.”

Checks and Balances

In addition to their work on centrosome segregation Yukiko’s group is pursuing two other lines of research.  One is examining a novel cell cycle checkpoint, which ensures the correct orientation of centrosomes prior to cell division. “We published one paper suggesting the presence of a new checkpoint that, in GSCs, makes sure the centrosomes are correctly oriented before they get into mitosis. If the centrosomes are not oriented correctly, this checkpoint gets activated and then stalls the cell cycle before entering mitosis. We really want to identify the mechanism of how stem cells are sensing the correct orientation of the centrosome before getting into mitosis.”

The idea of a cell-cycle checkpoint is more at home with cell biologists and Yukiko thinks that it will take some time to convince developmental biologists that what they are describing is a real phenomenon. “I think its going to be a long way to really prove that this really exists, exactly how cells are sensing it, and what is the molecular mechanism, etc. It will probably take multiple papers and probably quite long time; at least five years if not 10 years.”

Yukiko also wants to understand how different stem cell populations interact in tissues and communicate to coordinate their replication and life cycles.  This is a new line of research for the lab and Yukiko wants to explore this direction in the coming years.

“[The Drosophila male gonadal] stem cell niche contains yet another type of stem cell called cyst stem cell. The germline stem cells and cyst stem cells have to coordinate their divisions somehow, we don’t know exactly how yet. Many tissues are made of cell types that are coming from different stem cell lineages. That means the decision of one single stem cell population cannot be enough to maintain the whole tissue. One stem cell population has to coordinate with another stem cell population to make sure that tissues are maintained as a whole. I’m very, very interested in how the stem cells are coordinating with each other.”

Follow Your Passion

What does getting the MacArthur fellowship mean for the future directions in the lab? Most importantly in means freedom to pursue any interesting outcomes that arise in research without the constraints of sticking to a proposed research plan.  “The whole idea of being a scientist is that you can’t really predict anything. If you’re working on something and the answer is so predictable, its quite boring.  Now I feel I do have the freedom to wander off a little bit from the original plan, because of course I didn’t propose anything for the MacArthur!”

Having a passion for science it vital for success as a scientist, but it doesn’t mean that your whole life has to be about work. Yukiko admits that she used to get worried when life’s distractions took too much time away from the bench.  What helped her to establish a career as an independent researcher and develop a life-work balance was learning “laid-back confidence” from her postdoc mentor Margaret Fuller.  “She’s a really good scientist but she is not obsessed by success. You can love science, but it doesn’t have to be your whole life. Other things enter your life that may take time away from the science, but don’t worry.  It might take you a little longer, but you will get to the point where you want to go if you just continue what you’re doing. That is something I learned from her.”

Yukiko spends her free time with her family and taking care of her six-year old daughter. I asked Yukiko if there is something people would be surprised to learn about her. “I am really obsessed with fossil hunting,” she said.  In Michigan, which used to be under tropical water millions of years ago, finding fossilized coral can be as easy as examining the pebbles on the road for a few minutes.  “It’s becoming a fun hobby for my daughter and me.”  After some thought she added: “And another thing my husband always teases me about ‘Where is this assistant professor who sleeps 8-9 hours a day?’ It’s how much I sleep every day!”

For more information:

Profile of Yukiko Yamashita on the MacArthur Foundation website

Press release from the MacArthur Foundation announcing this year’s fellows

Yukiko Yamashita’s lab webpage

References

Yadlapalli Swathi, ChengJun, YamashitaYukiko M. (2011). Drosophila male germline stem cells do not asymmetrically segregate chromosome strands. Journal of Cell Science, 124, 933-9.

Yamashita Yukiko M. (2010). A tale of mother and daughter. Molecular biology of the cell, 21, 7-8.

Yamashita Yukiko M. (2009). The centrosome and asymmetric cell division. Prion, 3, 84-8.
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A Discussion between Eric Wieschaus and Marcos González-Gaitán

Posted by on September 22nd, 2011

Eric Wieschaus is a Professor at Princeton University, USA. He was awarded the Nobel Prize in Physiology or Medicine in 1995, together with Christiane Nüsslein-Volhard and the late Edward B. Lewis, for their work “uncovering the genetic control of embryonic development”. Throughout his career, he has been interested in the mechanisms underlying patterning and morphogenesis in the early Drosophila embryo. You can find a short film featuring Eric, made at The EMBO Meeting here.


 Marcos González-Gaitán’s main interest lies in fly development as well. He started his lab at the MPI-CBG in Dresden, Germany, and in 2006, his group moved to the University of Geneva, Switzerland. Marcos has made major contributions to our understanding of how morphogen gradients are formed and regulate tissue growth. In his work, he combines cell biology and biophysics to address developmental problems in a quantitative manner.


 

I spoke to Eric and Marcos at The EMBO Meeting in Vienna last week. We talked about model systems, tackling details versus fundamentals, the future of developmental biology, and how to successfully collaborate with non-biologists. I hope you’ll enjoy reading about their experiences and thoughts!

What are currently the big scientific goals in your labs?

EW  I think I’ve always been interested in things that I can see. For me the focus is on morphological change - how cells change shape, how they move. I’m trying to do something slightly more biophysical, partially because I have this prejudice that physicists never have to remember much detail and you can get to an understanding without knowing all the details.

MG  What we are increasingly caring about is how tissues proliferate and grow, also taking a biophysical and cell biological approach. Of course I care about the details, but I try to see what can be fundamental beyond the details. I don’t know if it’s possible, because the details are contaminating the fundamentals to a large extent.

EW  Yes, and we’ve almost never done well when we don’t look at details.

MG  Exactly.

EW  I think this is actually a little frustrating about the time we’re living in, because overall in the field, we have this desire to go to a systems level, and yet at least for me how to do science is really grounded heavily in particulars. Describing something in a general, global way isn’t as helpful for me….

MG  I have very strong opinions about this, where I might be completely wrong in fact, but that’s how I think these days about this problem. We all speak about model systems, like Drosophila and I also work in fish, and with these you want to do something that can be general to other animals.

So, you start off thinking that the general description is at the level of genes. I don’t know what’s Eric’s opinion is on this, but over my career, I realised that that’s not really true – beyond saying that this gene is doing signalling, and this other one is a transcription factor. Beyond that it’s difficult to say that what Ubx does in Drosophila is the same as the homologous gene in another animal.

Then I became a cell biologist, because I thought these details might be general. I studied endosomes and endocytosis thinking that I’m going to find the principles of how endocytosis interfaces with signalling, and that’s going to be general. But, you also find out that that’s not the case, at least that’s my perception. The same endosome in the next system has totally different properties. It’s not general.

So then I moved into some biophysics and physics, thinking the universality is going to be in these physical properties, whatever they are - tension, mechanics or scaling of gradients. And now I’m getting to the point where this is probably also not true! Why is this? – I think its probably evolution; in every single system evolution has tinkered around with properties. So then where is our value?

My thinking today is that the real value is the approach. You ask questions to have solutions to these questions, and you develop tricks, assays - intelligent and elegant ways of thinking about the problem differently. In your little system, where the details are very important, you come up with a solution. I don’t think this solution is going to be universal. But the value, in my opinion, is that someone working in a different system can look at my study in flies or in fish and say, this is an interesting way of looking at the problem. You can measure degradation rates by doing FRAP, and then they can use these tricks or this way of thinking to apply to their system - the solution is probably going to be totally different.

EW  One thing that struck me was, you said that model systems are model systems because we think of them as leading to generalities. That is actually what the word means. The reality is that model systems, at least in the fields we work in, exist not because it has anything to do with generality, but because experiments were easy to do in them. We stupidly call them model systems, but we really work in them because I can go into the lab and have a chance of setting up an experiment in a way that leads to a conclusion that’s admittedly very specific. However, you’re not going to be able to do those experiments in anything other than the five or ten model organisms. So the real generality maybe is close to what you are saying, that the generality is that model systems allow the approach, allow us to pursue a scientific approach.

The curious thing, as biologists, we worry a little about generality, but one of the accusations the physicists make about biologists is that we don’t see the forest for the trees. We see trees all the time, it’s all we see, we see little specific trees. And my physicist friends worry a lot about whether what we’re doing is important, or generalisable? They always ask that question, and my reaction with time has become: Oh yes, it’s going to be generalisable, and somebody really smart some time down the road is going to see all of this, it’s all going to fit together in some picture - maybe! But right now I’m happy with trees, I’m happy that I can go into the lab and get something that is admittedly specific about flies, but at least is probably true, and measurable.

MG  The question is whether the problems we are addressing now, are comparable to trying to understand the double helix etc. We have the tendency to believe that it’s not, because we’re so much into our thing. But then, very often when people look back, they say, “These guys were doing absolutely fundamental research!”, but at the time they were just looking into this very particular thing. I ask this question all the time, are we looking at something fundamental or just the details. Because when I started to do developmental biology, I thought all my colleagues who did botany were completely boring, because they were just describing petals and sepals, while I was doing something fundamental. But with age, I’m not sure that I’m not just looking at petals and sepals, I’m not sure…

EW  Well you know, some day, somebody will know, but we will fortunately not be around!

In your view, what will be the future of developmental biology?

MG  I organise retreats in my lab, which often have this question - What is going to be the future in 5, 10 years. And it’s funny, my students and postdocs in the lab would say that the future is physics and to measure things. I think that’s not the future, that’s now! I have the feeling that we are neglecting some other things that might be the future, and that is chemistry. We think of proteins and genes, but there are all also lipids and sugars, and we are ignoring them completely! Maybe the future could be to measure them, find out where they are and how they influence things. Chemistry could be the future.

EW  Maybe the future is ignorance! Meaning where the future is, is where we’re ignorant today. So, in a way, asking where the future is, is to ask what are the things that we don’t know. That’s the question I never ask because if I would make a list of all the things I don’t know, I’d just spend all my time making that list. Beyond the idea that it’s just in the things we don’t know today, your job as a scientist is to find something you don’t know and figure it out.

MG  I think the future is determined by new ways of looking at things and then you can just ask different questions. For example, when I started my PhD with Garcia-Bellído, I was looking at work that he was proposing, and that Eric was proposing, which back then, meant to look at cells. At that time, developmental biology was not looking at cells at all - I’m talking 1985. So I thought the future is in cells, single cells, and it became the future in the 90s and 2000s. The same now with physics, people started to do this, so that can change the way we look at things and we will find things that we don’t know now. In this sense the new way of looking at it is maybe chemistry, but perhaps other things that my students may see one day, but not me.

EW  I suppose if you were an administrator at a university deciding where you’re going to throw money, clearly one of the places that you could decide to throw money is in re-vamping chemistry departments, which many places now do. And that might be another test of where the future is - it’s where the people who have money are throwing it!

So they might set the future by throwing money there, because money usually makes things possible?

EW  Yes, and when things become possible, unless people are cruelly incompetent, something good comes out of… going to the moon.

How did you start your collaborations with physicists, and do you have advice for others who are trying to do this?

EW  I’m totally dependent on proximity. I don’t like talking on the phone, I type badly, I don’t write - I have to have people who are next to me, and I have to get along personally with them. What helps me a lot is that I’m at a university that has a very strong commitment to undergraduate teaching. It’s a great university with a lot of very smart people, but we all teach undergraduates, and we all often teach together. And so a lot of my contacts with physicists or with computer scientists are through my teaching. It’s odd, because you think, “God if I didn’t have to do so much teaching I could be really, really good and accomplish all kinds of stuff!”, but for me, teaching has been a very important part of my scientific development over the past 30 years. It’s brought me into contact with colleagues and people that I wouldn’t necessarily have found common ground with.

MG  First, I think that very often biologists, when they go into these quantitative things have an agenda. They want to be proved right, and then they use these guys to prove them right. That is a short-term agenda. I think doesn’t work. In my case, I probably started in this way, but my main collaborator, Frank Jülicher, he’s a very deep person, and we have had to take our time to understand each other. Fortunately, we never had time pressure - we saw a problem and stepped back to the fundamentals. And we went slowly. It takes time; to me not rushing is something important. Second, I’m discovering that there is a component of personal chemistry and respect that is very important. The physicist needs to respect, appreciate and value, and want to understand the experiment and the details of it. And you need to do the same with their science; you need to understand how they solve the differential equations at some point because there is value in that.

What career advice do you give to your students and postdocs?

EW  Work hard! Really, work hard, and be successful. Meaning that make choices always based on “Is this going to be successful?”, and be able to make that judgement. Be able to change, be flexible. You have to work really hard; you have to work on the weekends and all these things. But it’s not an excuse after a year or two to say, “Well, I worked really hard, somebody should hire me.” They’re not going to hire you because you work really hard; they’re going to hire you because you’ve actually accomplished something. And it’s impossible to accomplish something unless you work hard, and you have to finish stuff. You have to bring things to conclusions.

MG  I’m more of a dreamer, I’m not so pragmatic. What I tell them is, value your career of course, but be beyond that, you want to understand something, and that is the uncompromisable thing. Do what is important to you, do work hard indeed, but go for a problem, understand something. I think that is the fuel to work hard and to improve your career. It allows you to relax a little bit about this pressure that everybody is feeling now, about crises, problems; you just focus on your problem. If you cannot do this, it does not work.

EW  Yes, it’s really hard to work hard if you’re not passionate. It is the passion I guess that allows you to believe that if you work hard, you’ll accomplish something.
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An Interview with Janet Rossant

Posted by on September 13th, 2011

I arranged to talk to Professor Janet Rossant after her talk at The EMBO Meeting here in Vienna. Janet is Chief of Research at The Hospital for Sick Children in Toronto, besides being a University Professor at the University of Toronto. Throughout her career she has been and still is making major contributions to the understanding of early development of the mouse embryo.

During the interview I took the opportunity to ask her about her career, her thoughts on the future of developmental biology and for some advice for young scientists. I hope you enjoy reading it as much as I did talking to Janet!

Why did you become a developmental biologist?

When I was an undergraduate many years ago in Oxford, I was taught by John Gurdon. John Gurdon is one of the world’s famous developmental biologists, still active and he did all the early work on Xenopus embryos, nuclear transfer embryos. He really got me excited about this idea of how it is that a single cell develops into a whole organism, and how you can begin to manipulate embryos, understand particularly the early stages. So I found that really exciting.

After I finished my undergraduate degree I thought I’d do research. So I talked to John, who suggested that I might talk to Chris Graham, who had started to do the same things in mouse embryos. Chris sent me to Richard Gardner, who was starting to make mouse chimeras, and I switched into mouse. I’m still interested in the fundamental question how the embryo develops, using the mouse system. And I must say that in the time - I switched to the mouse system in the late 70s, because I thought the Xenopus system was passé! Well, I was right about the mouse being an important system, but I was wrong about Xenopus, I apologise. I’ve stuck with the mouse ever since. Occasionally we’ve played a little with fish and various other organisms, and now of course we’re doing some stuff with human embryonic stem cells. Really that’s a direction we’re moving into, taking mouse development and trying to understand human development.

You’ve been involved in the public debate on the ethics of stem cell research and studying human development in Canada. What role did you have there and did you enjoy doing it?

Well, yes and no. There have been some very educational parts of that. As the human stem cell debate started to rage it became very clear to me that as developmental biologists and stem cell biologists we had to get involved. You can’t sit back and let the right wing politicians and lobby groups try to succeed.

I got involved through the CIHR, the funding agency for health research. They set up a panel to look at guidelines for human embryonic stem cell research, and I chaired that. So that would have been my first entree. With that we also had to appear before parliament and parliamentary committees. I’ve done quite a lot of public lectures in this area, to try to put forward the science, without necessarily getting into the ethical debate. At the end of the day, when people believe that a human embryo from the time of conception is worthy of all protection, you cannot argue against that. All I can argue is that we are in a situation where human embryos through IVF programmes are discarded, and isn’t it more ethically acceptable to use those discarded embryos to help save human lives in the future? I think that’s, the overall societal consensus pretty well worldwide and most people actually believe that that’s a doable thing.

You do have to educate people, and of course there are extreme groups who will not change their mind, but society can’t respond to extreme groups. Society as a whole has to come up with a consensus and we need public debate, and we need forums in which to do that. So I think it’s very important for scientists to get involved. Nowadays the CIHR guidelines exist, we have a regulatory environment, and human embryonic stem cell research is certainly proceeding in Canada. We also can undertake some forms of human embryo research, again with all the right conditions and approvals, unlike the States, where with federal funding you can work with existing cells, but you cannot use embryos or make new cells. In Canada we can, if approved, so it is a big advantage.

You’re British, but you ended up in Canada. Why, and have you ever considered coming back?

It’s simple, I married a Canadian. But it’s turned out to be very good; I’m still married to him, and I really enjoy having a career in Canada, it’s been great. I certainly looked occasionally and I obviously have a lot of colleagues and family still in the UK, associations I’d like to keep up. I don’t think at this stage I’m likely to move back in any major scientific role, but never say never, we’ll see!

What were the most exciting moments during your career?

First of all, we were very early involved in doing knockout mice. Oliver Smithies and Mario Capecchi had just shown that homologous recombination was possible in ES cells. My colleague Alex Joyner and myself knew that if we wanted to study genetics in the mouse, we needed to be able to knock out genes. So we got really excited, and she and I together worked on making our first knock out. Getting the first PCR to see that we had actually knocked out the gene was very exciting. It was Engrailed-2, a homeobox gene that Alex had worked on. In retrospect, we were lucky because the frequency we got was quite high - Alex had a postdoc working for months after that to knock out Engrailed-1, who could not do that at all! It turned out to be because there were some genetic variations between the clones, so eventually it worked. So we were very lucky. At the time it was so exciting, you could give a seminar and say you’ve managed to make a knock out and they’d be falling out the door and try to find out how you did it.

The other one was whole-mount in situ hybridisation in embryos. Today everyone knows all the beautiful pictures, we can do movies, we can do everything. But being able to actually see patterns of gene expression in embryos, as opposed to even sectioned materials, where it’s hard to reconstruct the complexity of the embryo, was fascinating. People had done whole-mount in situs in Drosophila, but in the mammalian system, we were having a lot of trouble. One of my postdocs worked very hard to get whole-mount in situs working in the mouse embryo - everybody does it with Brachyury first because it’s so easy to see, but we cranked it up to see other genes.

I remember Siew-Lan Ang, who was working at the time on looking for novel orthologues of Drosophila genes. She cloned Otx2, an orthologue of Orthodenticle, involved in anterior function in the fly. She took me to the microscope one day, and said, “What do you think of that?” I looked down the microscope and there was a late gastrula, early neural fold embryo in the mouse where you can’t really see anything, it all looks the same and there it was, front to end Otx2 positive, a strict boundary, nothing behind, amazing. Those kinds of things, they really grab you.

What advice do you give to your students and postdocs today?

First of all, you have to follow your passion, because at the end of the day you have to be grabbed by a question and by your research if you really want to drive it through. If the passion isn’t there, then you’re probably not in the right game.

Secondly, I think today life is complicated, and there are so many opportunities. So I really encourage people to think about the different kinds of tools that one can apply to a question. Try to combine, as we’ve heard it in these talks today, precision of looking at a question, or a stage, or a process with some of the tools of systems biology to try to get out an integrated model. I think that to me is the biggest challenge, whether it’s in the embryo, in stem cells or anywhere else. You don’t even always have to do the data yourself, there’s a lot of in silico data out there that you can capture.

Where do you think developmental biology as a field is heading?

It’s a mature field, interestingly. You see that at meetings. We certainly don’t have all the details, but we do have a good fundamental understanding of how to put a fly embryo together, a mouse embryo, a frog embryo. We do know the main players, and when I look back, we didn’t! Hox genes were cloned; nobody knew they were going to be conserved across evolution, and nobody believed they were really doing the same things if they were conserved. It’s hard to put your brain back at that time. Conservation of function across development has opened up our ability to look at the systems, and the similarities and the differences have really been worked out.

So I think that we are getting into the details of developmental pathways. It’s going to go in the systems approach, it’s going to go down into the cell biology - how cells are behaving in embryos. The area we’ve been trying to move into is to use it perhaps more directly in a translational sense. To me, the exciting things around embryonic stem cells and iPS cells is trying to combine developmental biology to drive embryonic stem cells to look at human development and model disease. And I really start to think can we use that for new drugs and new therapies.

So, developmental biology, as ever, sits in a very interesting convergence area, where you can move into many different directions. My personal direction is two-fold: Get into the details of that blastocyst, and the other is to move towards human development and disease.

But developmental biology still is fundamentally interesting. The other thing that people do, and I don’t really recommend my people to do it, is of course Evo-Devo - it’s fascinating, but it cannot easily get funded. Unless you’re a Howard Hughes investigator, it’s very hard. If that’s what people care about and want to do, that’s fine. I think it’s very important and exciting, but in the broadest sense it’s hard if you want to get forward, since it’s hard to get funded.

What were the biggest challenges you had to face during your career, and how did you deal with them?

When I started in Canada in 1977, there were not many jobs anywhere at the time, since a lot of the universities in the UK, US and in Canada had done a big expansion in the 1960s, so all those professors were sitting in their positions. I ended up at a small university, Brock University, teaching biology and doing research. So the biggest challenge I had was to go from Oxford and Cambridge to a small university in a country I didn’t know, trying to make contacts and all the rest of it.

The way I took on that challenge was to stick at it and to network, network, network! So I went out from Brock and I found people to collaborate with. I did a lot of collaborations with Verne Chapman in Buffalo and I collaborated with people in Toronto, so that’s how I ended up in Toronto. You can’t sit and feel sorry for yourself, you have to go out and do something about it. In those days I had to actually get in the car and drive around, these days you’d probably skype with people all over the world and stay in your lab. But actually, I think it can’t work exclusively that way, you still need that personal contact.

If you weren’t a scientist, what would you like to do?

I don’t ask myself that so much anymore, because I’m getting to the end of my career. So if I’d lost all my grants now I could just stop doing anything. But in the middle of your career, when things are looking rough, you ask yourself, “What would I do?” - I honestly don’t know. I certainly enjoyed teaching when I was at Brock; this is again a piece of advice to researchers, do some teaching! It’s awfully good practice for learning how to give talks and communication, because it’s all about communication.

However, I did get a bit tired of teaching first-year biology and sit on the exams and all that. So I’m not sure I’d have the patience to do that forever. I like to cook, but starting a restaurant - forget that! Maybe I could have a small catering company. I also do quite a lot of administration, since I run a big research institute, so I always got involved in science policy and science administration. So I guess fallback, that’s what I would end up doing. But at the end of the day, although I actually enjoy that, I can’t leave the research behind, it has to be part of the equation.

What would we be surprised to know about you?

That I like watching Top Gear!
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An interview with Magdalena Götz

Posted by on August 1st, 2011

(This interview originally appeared in Development.)

Magdalena Götz is the Director of the Institute for Stem Cell Research at the Helmholtz Center and Professor at the Ludwig-Maximilians-University in Munich, Germany. Her developmental work in neurogenesis has identified radial glial cells as the source of neurons in the developing brain. Magdalena joined Development as Editor in 2010, and she agreed to be interviewed about her scientific inspirations and about finding a place for adult stem and progenitor cells within developmental biology.

When did you first become interested in science?

I have always loved biology, and in school I was truly inspired by my biology teacher. In our rather non-innovative school system, we had a young American biology teacher who made us actually think and do things, and I was simply fascinated.

What was your PhD about and how did it inform your subsequent career choices?

My PhD was on development of the cerebral cortex and investigated how specific cell types develop and form their specific connections. This work laid the basis for many research questions, which I continued to pursue into much later stages. For example, it led to the isolation of specific progenitor subtypes in order to understand stem cell and progenitor heterogeneity, and the molecular specification of these subtypes. The new questions that arose from my PhD project also determined how I chose my postdoc lab, and many of the basic questions from this time still keep us busy now.

Did you have a mentor or someone who inspired you in your early career?

After my inspiring biology teacher in school, my PhD supervisor, Jürgen Bolz, was also key in shaping my way. His readiness to discuss science at any time was certainly very important to further fuel my enthusiasm for understanding how the cerebral cortex develops. My interest in developmental biology was originally inspired by a course at the Max-Planck Institute for Developmental Biology in Tübingen and by the fascinating questions of axon growth and regeneration studied by Friedrich Bonhoeffer and Claudia Stürmer.

Typically, I have always been inspired by people we call `Querdenker’ in German – i.e. people whose thoughts and ideas are contrary to common beliefs and who follow their own ideas entirely independent of the field. Therefore, people like Nils Birbaumer in Tübingen and Rüdiger Wehner in Zürich were important for me to see that following your own way and ideas is the way to go.

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An interview with Elisabeth Knust: President of the German Society for Developmental Biology

Posted by on May 27th, 2011

(This interview originally appeared in Development)

Every two years, the German Society for Developmental Biology (GfE – Gesellschaft für Entwicklungsbiologie) holds a scientific meeting for their members. This year, from 23 to 26 March, their meeting was held in Dresden, jointly with the Japanese Society of Developmental Biologists (JSDB). At this meeting, we sat down with GfE President Elisabeth Knust to learn more about her and about the society’s role in connecting developmental biologists in Germany.

What is your lab working on?

My lab is working on major questions in cell polarity, in particular on the elucidation of the mechanisms that maintain cell polarity, and we are concentrating specifically on polarity in epithelial cells. Some years ago, we identified what is now called the Crumbs complex. We’re now trying to understand how this complex controls cell polarity. For the past few years we have also been working on photoreceptor cells. We know that the Crumbs complex is involved in the function and development of these cells by controlling shape and morphogenesis. Flies that do not have Crumbs in their photoreceptor cells become blind when they’re exposed to constant light, a phenotype reminiscent of a human disease, retinitis pigmentosa 12. Indeed, some of these patients have mutations in one of the homologues of the Crumbs gene, CRB1. Given these different aspects of the function of Crumbs – control of cell polarity, control of cell morphogenesis and prevention of light-dependent degeneration – we are asking what the complex is doing at a cell biological level. I expect that the function is the same but that the readout of each cell is slightly different. However, this is what we have to figure out.

You’re also the current President of the GfE. How long have you been president of the society?

I’ve been president since 2010 and presidency is always a two-year period. The main task of the President is to organise the meeting, which we are currently holding here in Dresden. The society also runs the GfE school, a symposium particularly for young scientists – graduate students, postdocs – to present their work. This school also takes place every other year and is organised by Ulrich Nauber, the treasurer of the society, and one or two additional scientists, who determine the topic.

Is the GfE school just open to members or can anyone attend?

In principle, anyone can attend. For GfE members, at least for member students, participation and accommodation is free. The invited speakers also get free accommodation but they are supposed to pay for their travel themselves. I think that’s a good way to keep this meeting affordable while still getting good scientists to present their work. But a major function of this GfE school is also to provide the opportunity for students and postdocs to present their own work.

How old is the society?


The society was founded in 1975 with the goal of fostering developmental biology in Germany. Initially, it was meant to be the society for all German-speaking countries, including Austria and Switzerland, but the number of members in Austria and Switzerland has gone down with time: currently there are only eleven members from these countries.

When the society was founded in 1975, was that just for West Germany at the time?

Yes, it was only for West Germany, because at that time everything was separated. After the unification of East and West Germany, it was not difficult to merge GfE membership because there was very little developmental biology in the eastern part of Germany. There was one Drosophila group in Halle – the group of Gunter Reuter, whose work on position-effect variegation made major contributions to what is now known as epigenetic regulation of chromatin. Today, only about 12% of the members come from the former east, e.g. from Dresden, Berlin, Halle and Rostock.
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Interview with Beddington Medal winner Carlos Carmona-Fontaine

Posted by on May 11th, 2011

Each year, the British Society for Developmental Biology awards the Beddington Medal for the best PhD thesis in developmental biology. At the 2011 BSDB meeting, this award went to Carlos Carmona-Fontaine, who completed his PhD in Roberto Mayor’s lab at UCL. Now a postdoc at Sloan-Kettering Institute in New York, Carlos returned to the UK to present his thesis work at the BSDB meeting. He gave a brilliant talk that included comparisons between insect migration and neural crest cell movement, as well as an auditory interpretation of the effect of chemo-attractants on harmonic collective cellular movement. Everyone in the audience (including Carlos’ parents!) enjoyed the talk immensely. I caught up with Carlos at the end of the conference to talk a bit more about locusts, music, and the trick to a successful PhD thesis.

Congratulations on the Beddington Medal. What was your thesis about?

Thank you. My thesis was about neural crest migration. Neural crest cells are a cell population in the embryo that can differentiate into different kinds of cells. But before differentiating, they have to migrate, and the way they do that is as a group of cells. This is called collective migration. What was interesting to me was that neural crest cells seem to be able to self-organise in order to get this coherent, co-ordinated movement, so I studied which kinds of cell-cell interaction allow for these coherent group movements.

Your Beddington talk yesterday covered a lot of ground. You were even talking about locust migration. What do locusts have to do with cells?

I had found a paper in Current Biology, by the group of Iain Couzin, about locust collective movement. I noticed that the kind of interactions they described were so similar to the interactions I was finding in neural crest cells, that I thought similar rules may apply, and we started collaborating.
Obviously locusts are very different to cells, but in mathematical terms the interactions between locusts or between migrating cells are very, very similar. If you look at attraction and repulsion, for example, “attraction” in insects could be a visual cue, whereas in cells it could be a chemo-attractant, but at the end of the day, mathematically speaking, they are the same thing: simple interactions that allow collective movement.

Besides locusts and cells, you also included some music in your talk. Can you explain what that was about?

One of the striking things of collective movement is not only that the cells remain together, but that they move in a coordinated way. I considered this to be harmonic movements, and was thinking of a way to represent that.
Then I heard a concert by Steve Reich. He’s a 21st century composer – one of my favourites. He has this piece called “Drumming”, which is only percussion. There’s a specific moment with a lot of xylophones and some drums, and they all seem to coordinate in this very random pattern. I was just amazed by this piece.
This gave me the idea of representing cell coordination in a similar way. It ended up as something a lot less musically pleasing than what Steve Reich does, but the idea came from there.

What are you doing now? Are you still working on neural crest cells?

No. I started a postdoc in New York about a month ago, and there I will eventually work on computer models of tumour growth. But the project is not entirely defined yet, and the idea is to explore a little bit at this point.

Do you have any advice for new PhD students?

Don’t stress, have fun – and pay attention to mathematical, and more quantitative means of biology. Even if you’re not an expert in mathematics, you can still try to get some inspiration from more physical and mathematical points of view. And have fun.


Read more:
ResearchBlogging.orgCarmona-Fontaine, C., Matthews, H., Kuriyama, S., Moreno, M., Dunn, G., Parsons, M., Stern, C., & Mayor, R. (2008). Contact inhibition of locomotion in vivo controls neural crest directional migration Nature, 456 (7224), 957-961 DOI: 10.1038/nature07441

Bazazi, S., Buhl, J., Hale, J., Anstey, M., Sword, G., Simpson, S., & Couzin, I. (2008). Collective Motion and Cannibalism in Locust Migratory Bands Current Biology, 18 (10), 735-739 DOI: 10.1016/j.cub.2008.04.035
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Marion Silies wins GfE thesis award

Posted by on March 31st, 2011

Every two years, the German society for developmental biology (Gesellschaft für Entwicklungsbiologie - GfE) hands out an award for the best PhD thesis of the previous two years. At their society meeting last week, this award went to Marion Silies, for her PhD thesis on glial cell migration.

I met up with Marion after her talk and asked a few questions about her PhD work in Christian Klämbt’s lab, and whether she had any tips for graduate students.


Congratulations on your award. What was your thesis about?
I worked on glial cell migration in the fly peripheral nervous system. I looked at how neurons and glial cells co-regulate their development. In a screen we found a cell cycle regulator with strong phenotypes in the migration of glial cells, but I showed that it has a post-mitotic function, so a function outside of its function in cell cycle: it controls glial cell migration from the neuron, by regulating distribution of a cell adhesion molecule.

What are you doing now? Are you still working on the nervous system?
For my PhD I studied developmental processes, but for my postdoc I moved on to understand how the nervous system functions. I’m in the lab of Tom Clandinin now, at Stanford University.

Did you have to come back to Germany just to pick up your award?
I would have loved to come just for this meeting, but I was actually in Germany anyway for another meeting, so this just fit very well.

Do you have any tips for current or new PhD students?
My tip for students about to start their PhD would be to pick something that they’re really excited about. I think this is the most important thing: A PhD takes a long time, and you put in a lot of work, so try to find something that you really like. A lot of people think that they have to be at a very prestigious university, or at a very well-known institute. I would say: go wherever you want – just find something that you really like to do, and find a nice boss.
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A walk in the park is a walk amongst development

Posted by on March 10th, 2011

[updated 25/3/2011] Video was temporarily removed from Vimeo. Will repost it when it’s back up.
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Interview with Wellcome Image Award Winners

Posted by on March 9th, 2011

The 2011 Wellcome Image Awards were announced a few weeks ago, and developmental biology is well-represented in this year’s gallery, with images featuring cell division in plants, fish eye development, blastocysts, a developing mouse kidney, chromatin density in chromosomes, caterpillar prolegs, and a mouse embryo animation.

On February 23rd, the awards were announced at an official ceremony in London. “The awards ceremony was absolutely delightful”, according to Agnieszka Jedrusik, whose blastocyst image was amongst the winners, “Dr Laura Pastorelli should be congratulated on her amazing organizational skills. There were over 200 guests invited, yet, she still made an effort to greet all guests in person and made sure they felt welcomed.” Monica Folgueira, who is behind the winning cavefish image, also enjoyed the ceremony: “Everything went very quick for me. What I liked the most was having the opportunity of meeting the organizers and other creators.” Monica’s former lab mate Kara Cerveny was also amongst the winners, but she, unfortunately, couldn’t attend: “I’m now working at Cell as a scientific editor”, Kara writes, “and couldn’t make it back to London, but I heard that the ceremony was lots of fun.”

The Node spoke to Monica, Agnieszka and Kara to find out a bit more about them and their winning images. Click any of the thumbnail images to go to the high-resolution image in the Wellcome Image database.

Monica Folgueira
“I’m a lecturer at University of A Coruña (Spain). I just moved back to Spain last September after a postdoc at Steve Wilson’s lab (UCL). Now that I’m back in Spain, I will try to continue studying different aspects of the development and anatomy of neuronal circuits in the zebrafish brain, in collaboration with Steve’s lab. In addition, I’m interested in brain diversity and evolution. So I plan to perform studies of comparative neuroanatomy in a few species of fish, including cavefish.

My image is a confocal micrograph of a cavefish embryo at around five days post-fertilisation. The embryo has been stained with an antibody against a calcium-binding protein (in green) to show different neuronal types and their processes in the nervous system, and with an antibody against a component of tight junctions (zona occludens- 1, in red)

I produced this image during my postdoc at Steve’s lab (UCL). This image was produced after a set of experiments whose aim was to compare the morphology of the telencephalon between various teleost fishes (including zebrafish, cavefish and medaka).

I decided to submit this image because for me it brings together some kind of beauty and drama. I find it striking that, although it is an embryo, the combination of small eyes and strong jaws makes it look more like an adult fish. The image also reveals interesting characteristics of the anatomy in fishes, like the presence of taste buds outside the oral cavity.”

Agnieszka Jedrusik
“I gained my first degree (BSc in 2004 followed by MSc degree in 2006) in Developmental Biology from Warsaw University, in professor Marek Maleszewski group, investigating the nature of sperm activating factor during fertilization of the mouse oocyte. In 2006 I moved to Cambridge, to professor Magdalena Zernicka-Goetz’s group at the Wellcome Trust/Cancer Research UK Gurdon Institute, where I have just completed my PhD. Here, I am investigating the molecular and cellular mechanisms behind the first cell fate decision that generates pluripotent ICM and the differentiated extra-embryonic lineage, the trophectoderm.

My image shows a three-dimensional reconstruction of a mouse blastocyst. Blastocyst is an outcome of a pre-implantation development, a unique developmental phase characteristic for placental mammals such as mouse or human. In mouse, this phase encompasses a period of approximately 4.5 days and leads to formation of the first tissue types: outer epithelium, called the trophectoderm (TE; in white) and pluripotent group of inner cells, the inner cell mass (ICM; in red). Following implantation into the uterus wall, the ICM will form the fetus, differentiating into all tissue types of the body. TE, on the other hand, will give rise to extra-embryonic structures that support embryo development by mediating nutrients exchange between mother and the fetus and providing signals to pattern the embryo and segregate germ cell lineage. Understanding how these first tissue types emerge during early development becomes increasingly important in modern world, given growing interest in assisted reproductive technology (ART) and associated with it the need for optimizing culture conditions and assessing quality of the obtained embryos.

This image was produced by scanning the embryo with a confocal microscope to create multiple virtual sections, which were then reconstructed using 3D computer software.

I submitted it to the Wellcome Image Awards because I believe it is important that the general public realizes that the pre-implantation embryo is not just a group of pluripotent cells that will build the body of the future individual. In fact, approximately two-thirds of embryos’ cells at that stage are differentiated (the trophectoderm) and will build the extra-embryonic structures. It is important to realize that, given the fierce discussion on the moral aspects of the research on the embryo derived ESc.”

Kara Cerveny
“I’m a cell and developmental biologist with an interest in the developing nervous system. Up until a few months ago, I was a post-doc in Steve Wilson’s lab at the University College London where I studied the transition from proliferation to differentiation in the zebrafish retina.

This image highlights two separate populations within the zebrafish retinal stem cell zone, an area found in the region of the retina closest to the lens. The undifferentiated retinal stem cells are highlighted in red, while the cells that are beginning to differentiate are highlighted in purple. The central yellow region is the lens.

I took this image relatively early in my post-doc (nearly 5 years ago now) when I was working out the protocol of double in situ staining for fish eyes. This particular sample worked beautifully, and to be a bit creative and make a pretty picture to hang next to my computer, I cropped the original image so that only the top half was visible and then reflected it across the absissa to make the image you now see. Eventually, unmodified images similar to this one were used for a paper that was published in Development.

When I presented my work at the Fall 2010 BSDB sensory biology meeting last September, Laura Pastorelli, the image curator for the Wellcome Trust, asked me if I would be willing to submit this image to the Wellcome Image collection. I was surprised and very happy when I learned that my image had been chosen to be part of this year’s award series. I later learned that the judges had been captivated by the kaleidoscope effect created by the elongated retinal progenitor cells seeming to radiate from the lens (just like I had been several years before).”
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