Hello! Read on for some fascinating stories of stem cell treatments – proven and unproven – and find out about a new website with great information to help you tell the difference.

The Hubrecht Institute have discovered a new way of introducing molecular tools into cells – read all about it in our latest research spotlight.

Plus a new French translation of the All About Stem Cells teaching tool, a freshly updated fact sheet on stem cells and spinal cord injuries, and some interesting events coming up.

As ever, we’re keen to hear from readers of The Node – on Twitter, Facebook, or via our website. You can get involved as a writer or translator, tell us about the stem cell events you’re involved in, make comments or suggestions, or just say hello! And for regular stem cell news, why not subscribe to our monthly newsletter?

The EuroStemCell Team

Stem cell tourism: selling hope through unproven stem cell treatments – lessons from the X-Cell Center controversy

In recent years there has been a growing interest in so-called stem cell ‘tourism’ – where a person (often companied by their carer/family) travels to another country for a purported stem cell treatment that is not available in their home country. Many advertised treatments are clinically unproven, with little or no evidence for their safety and efficacy in specific conditions.

Read more

 Interview with Graziella Pellegrini – Using stem cells to cure blindness

Professor Graziella Pellegrini is one of the principal scientists on the ground breaking, corneal repair system Holoclar^®.  Working throughout Italy over the past 27 years she is now based at the Centre for Regenerative Medicine “Stefano Ferrari” at the University of Modena and Reggio Emilia.We spoke to Graziella about developing Holoclar, what it means for regenerative medicine in Europe, and what’s next.

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Interview with Michele De Luca – Epithelial cells and regrowing corneal epithelium

We spoke to Michele De Luca,director of the Centre for Regenerative Medicine “Stefano Ferrari” at the University of Modena and Reggio Emilia, about his work, the importance of collaboration, and his aspirations. He also shares some great advice for scientists starting out.

Read more

New website takes a closer look at stem cells

The International Society for Stem Cell Research (ISSCR) has launched a new website to help patients and their families make informed decisions about stem cell treatments, clinics and their health.

Stem Cells Australia’s Megan Munsie, chairperson of the ISSCR task force responsible for the website expansion, describes the revamped site as “a direct channel from researchers to the public.”

Read more

Researchers discover back door into the cell

Researchers at the Hubrecht Institute and Utrecht University have developed a revolutionary and effective way of introducing molecular tools into cells. According to Dr. Niels Geijsen, who headed the research team, this discovery brings us one step closer to treating genetic diseases:

“The difficulty of treating genetic (inherited) diseases is that we, thus far, are unable to safely transport large therapeutic compounds, for example, proteins, into cells,” explains Geijsen. “With our new technology, we’ve found that we can do this very efficiently.”

Read more

Updated: Spinal cord injuries: how could stem cells help?

There’s lots of new information in our fact sheet on stem cells and spinal cord injuries, updated this month.

Check it out.

New French translation of teaching tool: Tout sur les cellules souches

Un outil d’enseignement flexible qui introduit la recherche sur les cellules souches au moyen d’activités créatives en groupes et de discussions. Inclut des cartes d’activités imagées, des fiches de travail simples, des modèles de posters et un guide d’activités avec de nombreuses suggestions sur la façon d’utiliser le matériel.

Read more (also in EN, DE, IT, PL, ES)

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Work from Vaibhav Pai showing how manipulation of bioelectrical effects can rescue brain deficiencies caused by the introduction of Notch ICD

Trying to meet other young researchers in the Boston area interested in developmental biology can be surprisingly difficult. Despite the high density of scientists in a relatively small area, our day-to-day life exists mostly within our own labs; it’s arguable whether we interact enough with others in our own departments, never mind across departments and institutions.

After hearing about the Young Embryologist Network in the UK, it seemed that the perfect solution was to organize similar meetings this side of the pond. After lots of help from the YEN group in the UK, and kind support from Prof Marc Kirschner and the Department of Systems Biology at Harvard Medical School, on May 14th we had our first meeting, as advertised on the Node recently.

The first talk was due to be given by Dr. Stan Artap, a postdoc at Beth Israel Deaconess Medical Center in Peter Oettgen’s lab, talking about the “mouse heart” part of the meeting. However, in a great gesture that I hope will set the tone for our group going forward, Stan brought along his research assistant, Bryan Marsh, who is about to apply to graduate school in the area of developmental biology, to give the talk instead. Bryan, or our “embryological embryologist”/Very Young Embryologist, gave an excellent talk about the work he and Stan have carried out looking at the roles of the transcription factor ERG in cardiogenesis: early, in regulating BMP signaling during the specification of cardiogenic mesoderm into myocardial progenitors; and later in development, promoting endocardial-to-mesenchymal transition during cardiac cushion formation.

Left, Bryan Marsh presenting; right, an image of the eye by Vaibhav Pai.

The next talk was from Dr. Vaibhav Pai, a postdoc in Mike Levin’s Lab at Tufts University, talking about the role of membrane potentials in tissue specification in embryogenesis. Pai discussed his work in Xenopus manipulating ion flux to cause the formation of ectopic eyes in a Pax6-independent manner in all parts of the tadpole (Pai et al., 2012). He went on to show his recent work in rescuing Notch ICD-induced brain deformations by manipulating ion flux (Pai et al., 2015). His talk led to a very lively discussion, as a talk that demonstrates the role of biophysical forces in completely over-riding conventional gene regulatory network theories is wont to do!

Left, another of Vaibhav Pai’s eye images; right, Vaibhav Pai presenting.

The meeting format was very informal; people were free to grab pizza and soda as they needed, and the “20 minute talk, 10 minute question” format worked very well for the meeting (so well, that some participants suggested they would have enjoyed hearing a third speaker). Surveys were distributed to figure out what worked and what didn’t, and the feedback was very positive; people enjoyed the ability to hear talks from various speakers, and the opportunity to meet with other researchers from other institutions. In particular, everyone seemed very keen to return for the June meeting, which will feature Siyeon Rhee, a graduate student in Kimberley Tremblay’s lab at UMass Amherst, and Sam Morris, a postdoc in George Daley’s lab at Boston Children’s Hospital.

There are still some key challenges in getting the meeting up and running; representation was very Harvard Med School-heavy, and some of the questions going forward are where to hold meetings (in one location, or rotate around a few institutions?) and how to advertise the meeting effectively (if you’re reading this, and are interested, and now others who might be, please check out the website and get in touch/spread the word!) to build up a sustainable regular meeting. However, it was great to see such enthusiasm beyond just having free pizza, and to get together and talk science with other young embryologists.

References

Pai, V., Lemire, J. M., Pare, J-F., Lin, G., Chen, Y., and Levin, M., (2015), Endogenous gradients of resting potential instructively pattern embryonic neural tissue via Notch signaling and regulation of proliferation, Journal of Neuroscience, 35(10): 4366-4385

Pai, V., Aw, S., Shomrat, T., Lemire, J. M., and Levin, M., (2012), Transmembrane voltage potential controls embryonic eye patterning in Xenopus laevis. Development, 139: 313-323

(5 votes)

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A joint Biochemical Society / FEBS Focused Meeting, held to mark the retirement of Professor Robin Irvine, FRS. It will be organized by Len Stephens, Phill Hawkins, Colin Taylor and Peter Cullen. The meeting will begin on the afternoon of Tuesday 1 September, and conclude before lunch on Friday 4 September 2015. The link with Robin Irvine’s retirement has allowed us to attract the most eminent researchers in the field. There will be poster sessions from which early career speakers will be selected. The Colworth Medal lecture will be presented by Dr Helen Walden (Dundee). Sessions will be chaired by distinguished colleagues of Robin, including Professor Sir Michael Berridge, Professors Jim Putney and Bob Michell. There will be no evening sessions, but there will be an active programme of social events.

Topics:

• Inositol phosphates
• Inositol phospholipids
• Calcium signalling
• PI kinases and phosphatases
• Intracellular trafficking
• Therapeutic opportunities and challenges

Details of the programme can be found here.

Abstract deadline: 30 June 2015.

Earlybird registration deadline: 3 August 2015.

(1 votes)

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The ‘Biennial European Fly Neurobiology Conference’ is now more commonly known by its other name, ‘Neurofly’. And as of today, it has been about 7 months since the last Neurofly, which took place in October 2014 along a shore of the island Crete. Off the top of my head, the meeting was held at the Creta Maris Convention Centre. I do not recollect exactly how many Neurofly meetings have taken place (14, 15, 16?), and I am now guessing Neurofly 2014 took place sometime between the 10th and 19th of October. I do remember there was a good approval by show-of-hands on the last day of Neurofly to have the next meeting in Greece again.

Attending Neurofly was such as pleasure, I think, but now I find myself asking why it had been such a pleasure. I mentally draw out the landscape of a welcoming sandy beach… with a relaxing 5-star resort nearby… occupied by fellow friends and colleagues… who gathered in groups for meals and poster sessions, very much engaged in catch-up and scientific discussions… We listened to lectures and short talks in an air-conditioned conference hall. It is always fun to communicate our own research and to listen to those of others, yet calling forth detailed contents of each talk purely on memory is naturally impossible. I know the opening afternoon of Neurofly was graced with 2 plenary lectures, of which the first speaker discussed the complexity of Notch signalling. The second speaker discussed the [daresay] necessary biology of forgetting, in which dopamine signalling is involved.

More accurately, there has been 15 Neurofly to date and the 15th took place on the shores of Hersonissos on Crete from Sunday, 5th October, to Thursday, 9th October 2014. A welcoming first day greeted attendees at the Creta Maris Convention Centre with two plenary lectures in the late afternoon. Spyros Artavanis-Tsakonas had expertly navigated the convoluted complexity of the Notch signaling pathway while Ron Davis, lest we forget, took us back in time to 1974, just over 40 years ago, to explore the milestones in Drosophila memory research since. The history was followed on by Davis putting forward that the biology of forgetting is necessary, being also a form of ‘homeostasis’ after a learning event, and that dopamine signaling is key in memory acquisition and forgetting.

Amongst the talks in the Development and Differentiation session, Angela Giangrande seeks to decode the molecular interactions between transcriptional fate determinants which drive stable glial cell fate. Glia depends on the glial cell missing (Gcm) transcription factor and the reverse polarity (Repo) homeodomain protein to dictate neural stem cells for choice of either neuronal or glial identity. The Giangrande research team demonstrated an existence of a temporal sequence of regulatory loops. In the earlier part of the sequence, Gcm controls its own level of expression until the threshold necessary to trigger gliogenesis is reached. As soon as this threshold is achieved, a Gcm target starts to degrade Gcm itself to allow a stable differentiation of glia. Repo acts together with Gcm such that the level of the former also ascends and reaches threshold after Gcm’s peak. Then Repo acts by inhibiting Gcm to influence the outcome of cell differentiation into glia.

Another interesting talk was given by Jean-Maurice Dura, who expanded the Wnt5/Derailed-mediated axon guidance mechanism from more familiar grounds and into fascinating new landscape with its descriptions of ligand capturing and receptor shedding during brain development. A personal highlight was the work of Adel Dunayevskyy and Adi Salzberg from the Technion-Israel Institute of Techology in Israel. Salzberg talked about examining an enigmatic phenomenon of numbers in developmental biology. A cluster of five proprioceptive chordotonal organs contains five neuron, five scolopale cells, five cap cells, five ligament cells…, but only two cap attachment (CA) cells. Indeed, it must be a case of ‘five minus three’ CA cells for proper morphogenesis. For even when developmental apoptosis is perturbed, the developing organ insists to eliminate unwanted excess cells and it does so by switching on autophagy.

On day 3 of Neurofly, there was a window of opportunity between talks and dinner time for attendees to visit Knossos Palace, a relic from the Bronze Age and an archaeological site amidst beautiful hilly surroundings. The day eventually led to scientists and accompanying guests feeding on the gastronomic delights of Cretan dishes at the Cretan Thematic Park.

During dinner, I took interest in the history of Neurofly, specifically on how it started. This sparked a discussion on past Neurofly events at the dinner table. The scientists sitting with me on this conversation were 2 of the 4 host organisers, Efthimios Skoulakis and Maria Monastirioti, and Carsten Duch. We didn’t get to find out how and why Neurofly started, but we did gather a list of past Neurofly locations. Here is the initial list which we came up with:

1. ?
2. ?
3. 1990 – ?
4. 1992 – Glasgow, UK
5. 1994 – Regensbourg, Germany
6. 1996 – Würzburg, Germany
7. 1998 – Warwick, UK
8. 2000 – ?
9. 2002 – Alicante, Spain
10. 2004 – Dijon, France
11. 2006 – Würzburg, Germany
12. 2008 – Manchester, UK
13. 2010 – Belgium
14. 2012 – Padua, Italy
15. 2014 – Crete (Hersonissos), Greece

After the meeting, I found out that everyone was fairly good in recollecting past Neurofly locations. I refined the list through an update of the year-location pairing, and I found out that the 1st to 11th meeting were known in their time as the ‘European Meeting on the Neurogenetics of Drosophila’. Here is the updated list:

1. 1986 – Simonswald, Germany
2. 1988 – ?
3. 1990 – Saint-Rémy, France
4. 1992 – Glasgow, UK
5. 1994 – Montpellier, France
6. 1996 – Regensbourg, Germany
7. 1998 – Warwick, UK
8. 2000 – Alicante, Spain
9. 2002 – Dijon, France
10. 2004 – Neuchatel, Switzerland
11. 2006 – Leuven, Belgium
12. 2008 – Würzburg, Germany
13. 2010 – Manchester, UK
14. 2012 – Padua, Italy
15. 2014 – Crete (Hersonissos), Greece

The venue of the second Neurofly remains unknown. Should anyone uncover the mysterious location, please respond by commenting below.

It has been a pleasure for me to report on Neurofly 2014. If you’re interested in attending the next Neurofly meeting, keep an eye on the upcoming meetings webpage hosted by FlyBase.

(1 votes)

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Stem cells play crucial roles in development as well as tissue homeostasis, repair, and regeneration, and their dysregulation is involved in diseases and aging of the tissues. The stem cell is defined as a cell that has the ability to self-renew and also to produce differentiated progeny for a long-term. Yet, stem cells require other functional properties to regulate a variety of biological processes.

Epidermal keratinocyte stem cells are one of well-characterized somatic stem cells in human and successfully applied for autologous transplantation of epidermal sheets onto patients with extensive burns and genetic disorders. However, keratinocyte stem cells are eventually converted into keratinocytes with more restricted proliferative capacity. So we lose the stem cells during serial cultivation, and as a result, sometimes fail the transplantation. Therefore, a noninvasive quality control of the stem cell culture is essential for successful regenerative medicine.

We have previously found that cultured human keratinocyte stem cells and transient amplifying (TA) cells differ in their actin filament organization. This causes the two distinct modes of epidermal growth factor (EGF)-induced colony dynamics in colonies formed by keratinocyte stem cells and TA cells¹. So, we decided to explore the relationship between spontaneous cell motion and proliferative capacity in cultured human keratinocytes to identify the stem cells noninvasively and in situ.

As described in our resent paper², we found that keratinocytes with significant proliferative capacity displayed a unique rotational motion at the two-cell stage colony which is formed by a single cell division of individual keratinocytes (Figure 1). We then simulated the interaction of a hundred rotating keratinocytes with physics of multiparticle systems and proved that this rotational motion of cells gives rise to collective motion of keratinocytes in the colony (Figure 2). This in silico experiments also revealed the possibility of predicting a keratinocyte stem cell colony by only measuring cell locomotion speed. We then validated this prediction with a combination of time-lapse observation and clonal analysis with human keratinocyte stem cell culture system, and finally, we could identify human keratinocyte stem cell colonies with a noninvasive procedure.

Figure 1
Rotational motion of a two-cell colony oh human keratinocytes.
Human epidermal keratinocytes were seeded on one fourth of normal number of feeder cells. The two-cell colonies of keratinocytes (paired keratinocytes) were observed 1 day later. Bar, 20 um.

Figure 2
In silico reconstruction of keratinocyte stem cell colony dynamics.
Left panel shows that distribution of locomotion speed of keratinocytes in a growing colony after 6 days cultivation. Each color indicates different locomotion speeds that were calculated with 3 hours time-lapse observation. Bar 100 um. Right panel shows that distribution of locomotion speed of keratinocytes in a growing colony in silico. The speed of each cells was calculated by a simulation experiment based on our modeling.  Bar, 50 um.

We also found that alpha6 integrin, which is a known marker of keratinocyte stem cells, is required for rotational and collective motion of keratinocytes. alpha6 integrin is also highly expressed at the leading edge of migrating epidermis during wound repair. Although the mechanism of the rotational motion associated with growth capacity remains unclear, motile epithelial cells could retain the significant proliferative capacity, or a population of migrating cells might contain stem cells. It seems to be involved in development as well as tissue repair and regeneration.

References
1. Nanba, D., Toki, F., Matsushita, N., Matsushita, S., Higashiyama, S., & Barrandon, Y. (2013). Actin filament dynamics impacts keratinocyte stem cell maintenance EMBO Molecular Medicine, 5 (4), 640-653 DOI: 10.1002/emmm.201201839

2. Nanba, D., Toki, F., Tate, S., Imai, M., Matsushita, N., Shiraishi, K., Sayama, K., Toki, H., Higashiyama, S., & Barrandon, Y. (2015). Cell motion predicts human epidermal stemness The Journal of Cell Biology, 209 (2), 305-315 DOI: 10.1083/jcb.201409024

(4 votes)

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This is a news item which was first posted on the bsdb.org site. Please, note that not all items will be duplicated on The Node. To ensure you stay informed, please, take a minute to subscribe for email notifications on the bsdb.org site: simply enter your email address in the 3rd item of the side bar. Be ensured that the amount of emails sent to you will usually not exceed one per week or fortnight.

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(2 votes)

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Cecilia Lara-Mondragón and Mario Arteaga-Vázquez

Hello, my name is Cecilia Lara. I am an undergrad student working under the supervision of Dr. Mario Arteaga-Vazquez at the Laboratory of Epigenetics and Developmental Biology. Our lab is part of the Institute for Biotechnology and Applied Ecology at the University of Veracruz (INBIOTECA-UV). The INBIOTECA-UV is located in Xalapa, a rainy, damp, green and beautiful city in the heart of the state of Veracruz, Mexico. Its foggy nights remind you of those in horror movies where a huge guy with an axe can jump out of the bushes and chase you at any time! Right there in the south of the city is our little institute and our second home- the epilab (as we call it). At the epilab we study an emerging model, a liverwort called Marchantia polymorpha (Marchantia), which is a non-vascular plant that belongs to the most basal lineages of land plants.

Marchantia polymorpha is descendant of the first plants that colonized terrestrial environments 

Plants are fundamental for life in our planet. A major event in earth’s history was the colonization of the terrestrial environment by plants. Land plants (embryophytes) colonized terrestrial environments about 480 millions years ago. Bryophytes include the oldest extant land plant lineages (liverworts, mosses, and hornworts).There is an intense debate over the phylogenetic relationships between different bryophytes, mainly regarding which group is sister to either land plants or vascular plants, but evidence from the fossil record, molecular, systematic and phylogenomic data strongly suggests that liverworts were some of the first plants that colonized the landscape. This makes Marchantia a very interesting model to address many questions from an evolutionary perspective. For example: How did plants evolve from an aquatic ancestor? What kind of molecular and developmental innovations played an essential role during the evolution of embryophytes, resulting in the extraordinary radiation of land plants? What has been the contribution of epigenetic regulation during the evolution of land plants? This and many more questions can make more than one biologist lucubrate night after night!

Evolutionary developmental biology of paramutation and RNA-based gene silencing pathways

The main goal of our lab is trying to understand the molecular basis, evolution and developmental implications of paramutation. Paramutation is the most amazing and extreme example of transgenerational epigenetic inheritance. Paramutation is an interaction between alleles (or homologous sequences) that leads to mitotically and meiotically heritable changes in gene expression. During the last decade we started to gain insight into the genetic and molecular mechanisms of paramutation. We now know that in plants, paramutation is mediated by components of an RNA-directed DNA methylation pathway that is involved in the epigenetic regulation of transposable elements. In our lab, we are studying the function and evolution of RNA-directed gene regulation in both Marchantia and maize. Our adventure in Marchantia started in 2009 when Dr. Arteaga visited Dr. John Bowman’s laboratory in Australia. Three years later he attended a Marchantia Workshop in Kyoto, where he officially established a collaboration with Dr. Takayuki Kohchi and Dr. Bowman, both pioneers of Marchantia research and leading the Marchantia genome sequencing initiative. This collaboration has extended to many other labs in Japan, including Dr. Kimitsune Ishizaki’s group in Kobe University and Dr. Katsuyuki T. Yamato’s group in Kinki University.

General anatomy of Marchantia polymorpha

Marchantia plants are morphologically simple. They grow as a thallus (flat-sheet tissue reminiscent of leaves) (Figure 1) with rhizoids (single cell root-like filaments) growing on the lower surface and repetitive units adapted for photosyntesis on the upper surface. Marchantia reproduces both sexually and asexually. Asexual propagules (gemmae) are formed inside specialized structures (gemmae cups) (Figure 1) which are dispered by abiotic mechanical factors (e.g raindrops).

Figure 1. Marchantia thallus. A mature thallus of M. polymorpha showing gemmae cups and gemmae.

Sex in Marchantia is determined by the presence of cytologically distinct sex chromosomes, males having one very small Y chromosome while females have one X chromosome. The male and female thalli look alike, but they can be easily distinguished based on the morphology of the sexual structures they produce (Figure 2). Male antheridiophores (Figure 2A and Figure 3) or female archegoniophores (Figure 2B and Figure 4) arise from the upper surface of the thallus. Antheridiophores produce sperm-forming antheridia and archegoniophores produce egg-forming archegonia. In contrast to what is observed in angiosperms, sperm in Marchantia consist of a single motile cell capable of traveling in an aqueous environment towards the egg cell. The embryo resulting from a cross is enclosed in the gametophyte. It lacks an indeterminate meristem but grows a number of different cell types, including a sub-epidermal population of cells on the apical pole that correspond to the precursors of the germ cells that will undergo meiosis to form the spores.

Figure 2. Marchantia male and female strains. Populations of male (A) and female (B) plants with reproductive structures already induced and ready to be crossed.

Figure 3. Marchantia anteridiophores. A. Anteridiophores primordia. B. Young developing anteridiophores. C. Mature anteridiophore with sperms ready to be collected (note the cloudiness in the droplet of water).

Figure 4. Marchantia archegoniophores. A. Archegoniophores primordia. B. Young developing archegoniophores. C. Mature archegoniophore 

Figure 5. Marchantia growth room. Shelves with Marchantia growing on rockwool under white and far-red lights (top). Both lights are required to induce reproductive structures.

Figure 6. Marchantia sporangium. A-C. Developmental series of early sporogenesis. D. Mature sporangium. E. Close up of spores from panel D. F. Archegoniophore with closed sporangia. G. Open sporangium showing recently released spores. H. Archegoniophore with open sporangia.

 Confocal 3D reconstruction of DAPI stained Marchantia sperms, archegonium and egg-cell.

Genetic crosses in Marchantia polymorpha

Genetic crosses are very easy to perform. A drop of water is incubated on top of an antheridiophore and after a couple of minutes the water will become cloudy. This is the sign to collect the drop of water (loaded with sperm) which can now be added on top of a developing archegoniophore. That’s it! You just made a genetic cross that will produce thousands of spores per sporangium.

How to perform genetic crosses in Marchantia?

A typical day at the epilab

A typical day in the lab starts with a 30 minutes walk from my house to the lab. Then I check on the plants, making sure they have enough water and that the AC unit is working properly. Xalapa is hot and humid most of the year so it is extremely important to keep the plants in an optimal temperature range from 20 to 22 °C. Marchantia grows nicely on a number of substrates including, vermiculite, turface (baked clay), ground brick, rockwool and it can also be grown in vitro in both solid and liquid media. Marchantia protocols including in vitro plant growth, induction of reproductive structures, cryopreservation and genetic transformation of spores have been developed by Dr. Kohchi’s group over decades of work. Recently, new protocols for genetic transformation of gemmae and thalli were developed by Dr. Yutaka Kodama’s group at the Utsunomiya University. This might sound like a cliché, but it is true, we are standing on the shoulders of giants.

During the last couple of months I have spent nights and days doing molecular biology benchwork, cloning genes and making all sorts of genetic constructs for my B.S. thesis. My thesis is part of a large scale comparative genomics project that involves the molecular characterization of small RNA-based gene silencing mechanisms in Marchantia. I am particularly focused on the characterization of the Argonaute gene family and the miRNA repertoire of Marchantia. One of the greatest features of Marchantia is that it is very easy to grow and to handle. You can grow large populations of Marchantia in very little space (Figure 2 and 5). My own special assignment in the lab is to keep our spore stocks safe and sound. For this, I select the most promising young antheridiophores and archegoniophores for crossing, and three or four weeks later I collect sporangia with thousands of spores that I dry and keep at either 4° C (if we plan to use them within a couple of months) or -80° C (for long term storage) (Figure 6).

I came to the epilab two years ago as a scholar of the Research Summer Program of the Mexican Academy of Science. I was and still am extremely excited to work with Marchantia. I have had the opportunity to learn a lot of things about plant biology, genomics, evolution and developmental biology. In spite of the ever changing weather and the ferocious population of arthropods (mostly mosquitoes) that populate Xalapa during the summer, this experience has been one of the most frutiful times in my life both academically and personally.

Marchantia polymorpha is rapidly developing into a remarkable experimental model with a powerful toolkit for comparative studies, molecular genetics and functional genomics thanks to the hard work of a number of pioneer scientists.

If you are interested in our work just visit the epilab webpage: epilab.weebly.com

Acknowledgements

We would like to thank all friends and colleagues who helped us start the epilab in Mexico. We are particularly in debt with Ana Dorantes-Acosta, Liliana Arteaga-Dorantes, Elena Arteaga-Dorantes, Vicki Chandler, Xuemei Chen, Daniel Grimanelli, Hervé Vaucheret, John Bowman, Takayuki Kohchi, Kimitsune Ishizaki, Katsuyuki Yamato, Eduardo Flores, Rebecca Mosher, Blake Meyers, Efraín de Luna, Luis Herrera-Estrella, Félix Recillas-Targa, Alfredo Cruz-Ramírez, Juan Caballero-Pérez, Alfredo Herrera-Estrella, Patricia León-Mejía, Mario Zurita-Ortega, Alejandra Covarrubias-Robles, Federico Sánchez-Rodríguez, José Reyes-Taboada, Noé Duran-Figueroa, Andrés Cruz-Hernández, Shih-Shun Lin and Francisco Díaz-Fleischer. We thank past and current members of the epilab and the INBIOTECA-UV. We also thank our friend Luis Alberto Cruz Silva, Research Specialist of the Microscopy Unit in Biomimic^TM at the Institute of Ecology A.C. (INECOL). We are grateful to the University of Veracruz (Cuerpo Académico CA-UVER-234) and the following funding agencies: UC MEXUS Collaborative program (Grant 2011-UCMEXUS-19941-44-OAC7), Consejo Nacional de Ciencia y Tecnología (CONACYT) (Grants: CB-158550 and CB-158561), JEAI- Institut de Recherche pour le Développement (IRD) (Grant: COSEAMX1- EPIMAIZE).

This post is part of a series on a day in the life of developmental biology labs working on different model organisms. You can read the introduction to the series here and read other posts in this series here.

(9 votes)

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This interview first appeared in Development.

Juergen Knoblich is a senior scientist and deputy scientific director of the Institute of Molecular Biotechnology of the Austrian Academy of Sciences in Vienna. We met Juergen at the 56th Annual Drosophila Research Conference, where we asked him about his work in this model system and, more recently, on human cerebral organoids, and about his thoughts on recent technological developments and the funding situation.

How did you first become interested in biology? Was there someone who inspired you?

I was always very interested in chemistry, but at some point my chemistry teacher told me that there was not much more to be discovered in chemistry, and that the new trend was to study biochemistry – which is what I did at university. It was really during my master’s thesis research that I became interested in genetics, and I got my training as a scientist during my PhD in the lab of Christian Lehner. He essentially taught me everything that I know about flies.

The Drosophila neuroblast has been the focus of your research for many years. Why did you choose this system?

I started my Drosophila career looking at cell cycle progression. As a PhD student I worked on cyclins and the transcriptional regulation of cell cycle exit. The logical next step for me was to look at the cell biology of mitosis itself. It so happened that my postdoc lab, the lab of Yuh Nung Jan at the University of California, San Francisco (UCSF), had just discovered the phenomenon of asymmetric cell division, which I then studied, mostly in the peripheral nervous system. The honest reason why I shifted to neuroblasts was that it allowed me to connect my cell biological research with something that is of very great medical relevance, i.e. stem cell biology. It is a fantastic cell biological system and you learn things from it that you can use and translate into higher organisms.

How do you feel that Drosophila research has changed over the course of your career?

Drosophila research over the past 10, 15 years has changed dramatically. If I had, as a PhD student, the technological tools available in flies now, I would have been the happiest person on Earth! Things are so much faster now. It started with the sequencing of the fly genome, which changed things completely. And now we have CRISPR-Cas, which is another revolution.

What is also very good about Drosophila as a model system is that there are a lot of people in the community who are fascinated by technology. They generate these absolutely fantastic collections, the latest being the MiMIC collection (http://flypush.imgen.bcm.tmc.edu/pscreen/index.php), that are available to the entire fly community and speed up our research so much.

Do you think that Drosophila as a genetic model system is being threatened by other model systems catching up with genomic tools?

I don’t think so. My lab uses not only Drosophila, but also mouse and human systems. So I honestly think that it is not just the technology that is better in Drosophila. There is a fundamental design difference between Drosophila and vertebrates. The enormous optimization of Drosophila development has eliminated many redundancies in the genome, and that comes in very handy for a geneticist. So when you make a certain mutation in Drosophila you typically get a very clear answer, and that is not usually the case in the mouse.

What is a threat to Drosophila research is that the interest of funding organizations and young scientists is starting to shift. Funding organizations are much more interested in direct medical translation. This is reflected in the interest of students. Drosophila as a system needs to switch to more disease-oriented research, and a lot
of groups are actually doing this. I think this enormous trend towards application is the real threat to Drosophila research. But it will survive.

Drosophila is famous as a genetic model, but you have been quite involved in RNAi screening efforts in this organism. What do you think is the relationship between knockout versus knockdown approaches, especially in the context of the recent developments in genome technology?

My lab makes extensive use of the genome-wide RNAi collection at the Vienna Drosophila Research Centre (VDRC). The collection was originally made by Barry Dickson and it is an absolutely invaluable resource for my lab. However, in some of the recent VDRC board meetings we discussed whether we have to prepare ourselves to stop maintaining this resource. Personally, I do not think RNAi will be replaced by CRISPR, and the reason for this is that RNAi is very versatile. You can make tissue-specific knockdowns, you can control them over time, you can make RNAi lines that have different knockdown levels, and they are a very successful tool to perform genome-wide screens.

CRISPR is a very interesting phenomenon. The technology is less than two years old and there has never been, to my knowledge, a technology that has so quickly transformed the entire field of genetics. It has effectively replaced other techniques to generate gene knockouts in flies, which were always difficult to use. In Drosophila, CRISPR is a great technology to generate stable loss-of-function point mutations, or for making insertions and tagging genes. But it cannot generate genome-wide loss-of-function resources that have the same versatility as the RNAi collection. Genome-wide loss-of-function screens using CRISPR-Cas will be possible at some point but will have their own problems, namely the fact that you do not have complete control over all the mutations that you make. So I think CRISPR and RNAi are complementary
techniques.

More recently, your lab has been making important contributions to the field of organogenesis, generating cerebral organoids in vitro. This is a shift away from the core focus of what your lab has been doing for many years…

It is quite an adventure for a Drosophila lab to all of a sudden work on human genetics, but I have a lot of fun trying out new things. We actually started shifting to the mouse a few years ago, and my lab now has almost five to six years of research experience in mouse brain development. The work of my lab is very much driven by the interest of the postdocs, and I typically develop projects with them, rather than telling them what to do. The organoid system was the project of Madeline Lancaster, who joined my lab as a postdoc initially to work on two-dimensional culture in mouse. We both then decided that it might actually be a really good idea to shift to humans, and to a three-dimensional culture. But she should take all the credit for the actual experimental protocol.

There was also a specific scientific question behind this project. As a postdoc I characterized a gene in Drosophila called inscuteable. Inscuteable is a molecular switch for spindle orientation. In mouse, changing the orientation of the mitotic spindle can change the number of neurons that are generated in the cortex, and a number of recent findings make inscuteable a really good candidate for the cortical enlargement you see as you go from the mouse to human. The one critical experiment that is missing is to
make a human inscuteable mutant. That was for me the real reason for developing this organoid system, and I hope that we will have this mutant very soon.

The cerebral organoids have a range of potential applications, from trying to understand how the brain develops at a more basic level to model human disease. Where would you like your lab to go next?

The core interest of my lab is lineage specification in stem cells. Recent findings have shown that there is a very strong difference in the cortical lineage between rodents and primates. Understanding this lineage change in evolution is one of the key questions that fascinate me, and I would like to address this question in my lab. However, modelling disease in organoids is not something that I want to neglect, and we have started to set up a translational research unit. But this is not going to be the core interest of my lab.

The cerebral organoids, often called minibrains, attracted a lot of media attention.What was your experience interacting with the press?

I should first say that the term ‘minibrains’ was not invented by us, but we were not surprised that they gained this name!

Nothing I did before ever generated such a high degree of media attention. I was quite well-prepared for it, and the press conference that was organized by Nature helped a lot in thinking about what the message was that I wanted to get across and how to best do that. I think that preparation for this kind of discussions is very important. Talking to the high-level news channels (such as the BBC or CNN) is very easy. It becomes more difficult when the tabloid press gets interested, but by taking the journalists seriously, and by preparing how to get the core of our message across, it can also work. Overall, it was a very good experience, and the press coverage was generally very positive. Everyone realized the enormous potential of what we did, and we addressed well the understandable concerns regarding what could be done with this system.

So you would encourage other scientists to interact with journalists?

I should say that for the organoids I had no choice! But in general, yes. Our research is funded by the public, and the public has a right to know what we are doing and why we are doing it. It is absolutely essential if we want to continue to be funded. This of course means going to the media. It also means accepting the rules of the media, and accepting that they have a different understanding of what is true or is not true. Conversely, we should also have a certain level of tolerance towards our colleagues when they explain things to the media or the lay public and deliberately use less accurate language.

How do you feel about the funding situation in Europe at the moment, particularly with the recent threat to the European Research Council (ERC) budget? Do we have reasons to worry?

Yes, I do think we have reasons to worry. For a long time there was a dogma that, even in times of reduced financial prosperity, the one thing that would not be touched were the long-term future investments, such as science and education. All of a sudden that changed, and I do not really understand why. The recent threat to the ERC project is, in my view, nothing less than a scandal. The ERC is one of the success stories of Europe; for once something in which the European Union has become a role model for other funding organizations. It has united European sciences. To cut the budget of this organization in favour of short-term investments is the wrong decision. Although I think the ERC will survive, any minor cut threatens the whole system, given the very low acceptance rate for ERC grants. There is no final decision on this yet, and I still hope the European Union will reconsider its decision.

In this context of funding difficulties, what is your advice for young scientists?

I think what is happening at the moment is a transient phase, and as such we must distinguish between those whowant to go into science and those who are currently young scientists. Science funding, particularly for the biological sciences, grew strongly for a long time, but we have now reached a point where funding rates are constant, or even going down. There are a number of reasons for this. One of the reasons is that you cannot grow forever. The other is that biological sciences have made all sorts of promises, such as cures for a variety of diseases. At some point the public got impatient and said “now really deliver those cures”. This is why there is a strong shift towards translational research at the moment. This is, I think, a bit short-sighted, as we all know that the great discoveries in science do not come from a direct targeted discovery, but are to some degree serendipitous.

When you ask me what my advice is to young scientists, whether they should go into science, I think yes, by all means. They should pick the area by their interests, and not by the funding situation. My feeling is that we are undergoing a shrinking process, but this is a transient period. Indeed,when I started my PhD the situation was very similar. There was even a whole department dedicated to biologists at the Stuttgart unemployment office, because, among the natural scientists, biologists were the ones with the highest unemployment rate. This changed dramatically afterwards. On the other hand, if you ask me about the advice to give to people who are about to start their own lab, then it is tough at the moment and one really has to be very dedicated to being a scientist. But most of the people I know who really wanted to become a scientist succeeded in the end.

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Here are the highlights from the current issue of Development:

Capping off sesamoid bone development

Sesamoid bones are small, flat bones that are embedded within tendons. To date, it has been thought that these bones develop within tendons in response to mechanical signals, but now (on p. 1831) Elazar Zelzer and colleagues challenge this assumption, focussing on the patella (the kneecap), which is the largest sesamoid bone in the human body. They show that that, in mice, the patella initially develops as a bony process that is part of the adjacent femur bone. Subsequently, they report, the patella is separated from the femur during the process of joint formation. This process is regulated by mechanical load; patella separation is perturbed in mutant embryos that are devoid of contracting muscle. The authors further demonstrate that, similar to bone eminences – superstructures that mediate bone-tendon attachment – the patella arises from progenitors that express the chondrocyte marker Sox9 and the tendon marker scleraxis (Scx) and that are regulated by TGFβ/BMP signalling. Together, these findings provide a new model for patella development and highlight that a high degree of plasticity exists during skeletal patterning and development.

FGF receptors sculpt synaptogenesis

A balanced network of excitatory and inhibitory synapses is required for correct brain function, and any perturbations to this balance can give rise to neurological and psychiatric disorders. It has been shown previously that FGF22 and FGF7 promote excitatory or inhibitory synapse formation, respectively, in the hippocampus, but how do these ligands mediate their synaptogenic effects? Here, Hisashi Umemori and co-workers use various FGF receptor knockout mice to address this question (p. 1818). They first show that excitatory presynaptic differentiation is impaired inFgfr2b and Fgfr1b mutant mice. Following on from this, they reveal that both FGFR2b and FGFR1b act downstream of FGF22 and are required for FGF22-dependent excitatory presynaptic differentiation. The authors further show that the kinase activity of FGFR2b as well as its ability to bind to FRS2 and PI3K is required for it to respond to FGF22. By contrast, they report, inhibitory presynaptic differentiation is defective only in Fgfr2b, and not Fgfr1b, mutants. In line with this, they demonstrate that FGF7 requires FGFR2b and not FGFR1b to mediate its effect on inhibitory presynaptic differentiation. Together, these findings indicate that distinct but overlapping sets of FGF receptors sculpt excitatory and inhibitory synapse formation in the mammalian brain.

ATRX: keeping quiet in the embryo

Human embryos are particularly susceptible to chromosome instability (CIN) and errors in chromosome segregation, but the molecular mechanisms that regulate and sense CIN in mammalian embryos are unclear. Here, on p. 1806, Maria Viveiros and colleagues investigate the role of the chromatin remodelling protein ATRX in early mouse embryos. They first show that ATRX, which is transmitted to the early zygote through the maternal germ line, localises to pericentric heterochromatin (PCH) within the maternal pronucleus, where it is required for the transcriptional repression of major satellite transcripts. The loss of ATRX hence leads to the abnormal expression of maternal satellite transcripts. The authors also demonstrate that the maternal inheritance of ATRX helps to set up an epigenetic asymmetry between the maternal and paternal chromosomes, which might be implicated in facilitating chromosome segregation. In line with this, ATRX loss, they report, causes abnormal centromeric mitotic recombination and an increase in double-strand DNA breaks. Overall, these data highlight an important role for ATRX in the early mouse embryo and provide new insights into how CIN is controlled in early mammalian development.

Divide but stay together: cytokinesis in tubes

During development, epithelial tubes often need to grow while still maintaining their barrier properties. How can cells divide without disrupting the integrity of the tubular epithelium? On p. 1794, Markus Affolter and colleagues address this question in the Drosophila larval tracheal system. In a particular subset of tracheal tubes, there is extensive remodelling during the early third instar, such that unicellular tubes, in which a single cell encircles the lumen and creates junctions with itself, transform into multicellular tubes, a process accompanied by proliferation. The authors demonstrate that this transition involves cell intercalation to replace the autocellular junctions with intercellular ones. Depending on cell length, mitosis may occur either before or after this junctional remodelling is complete, thus generating two major classes of cytokinesis events. In both cases, cytokinesis is asymmetric, with the new membrane extending from the side of the cell where the nucleus is located. In rare cases, this can lead to the formation of a binucleate and an anucleate daughter. The authors further find that Dpp signalling is required for appropriate junctional remodelling and cell division. Together, these data provide insights into how barrier integrity can be maintained through cell division in these tubular structures.

A double take on the segmentation clock

The segmentation clock, which controls the periodic formation of somites along the vertebrate body axis, involves the oscillating expression of clock genes in presomitic mesoderm (PSM) cells. Oscillations are synchronised between cells, giving rise to a sweeping wave of gene expression throughout the PSM. This cyclic wave of gene expression is known to slow as it moves anteriorly, but the causes and implications of this slowing have remained unclear. Here, Sharon Amacher and co-workers investigate segmentation clock dynamics in zebrafish embryos (p. 1785). Using a her1:her1-venus reporter to visualise clock gene oscillations in real-time, the authors show that the periodicity of oscillations slows as PSM cells become displaced anteriorly. This slowing gives rise to a situation in which cells that are one somite apart are actually in opposite phases of the clock. Thus, they report, a one-segment periodicity is observed in the posterior of the embryo, whereas a two-segment spatial periodicity is seen in the anterior. The researchers further demonstrate that neighbouring cells oscillate synchronously in both the posterior and anterior PSM until they are incorporated into somites. Based on these findings, the authors propose an updated model of the segmentation clock.

PLUS:

An interview with Juergen Knoblich

Juergen Knoblich is a senior scientist and deputy scientific director of the Institute of Molecular Biotechnology of the Austrian Academy of Sciences in Vienna. We met Juergen at the 56^th Annual Drosophila Research Conference, where we asked him about his work in this model system and, more recently, on human cerebral organoids, and about his thoughts on recent technological developments and the funding situation.

Hematopoietic development at high altitude: blood stem cells put to the test

In February 2015, scientists gathered for the Keystone Hematopoiesis meeting, which was held at the scenic Keystone Resort in Colorado, USA.  During the exciting program, field leaders and new investigators presented discoveries that spanned developmental and adult hematopoiesis within both physiologic and pathologic contexts.  See the Meeting Review on p. 1728

Building the backbone: the development and evolution of vertebral patterning

The segmented vertebral column comprises a repeat series of vertebrae, each consisting of the vertebral body and the vertebral arches. Despite being a defining feature of vertebrates, much remains to be understood about vertebral development and evolution. Particular controversy surrounds whether vertebral structures are homologous across vertebrates, how somite and vertebral patterning are connected, and the developmental origin of vertebral bone-mineralizing cells. Here, Roger Keynes and colleagues consider these issues. See the Review on p. 1733

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This week I have the pleasure of attending the “Getting Into and Out of Mitosis” Workshop organised by The Company of Biologists. On Sunday, renowned experts and early-career scientists alike travelled to Wiston House in West Sussex, UK, to listen to the latest research, ask questions and discuss results in the field of cell division.

It is certainly unlike any meeting I have attended in the past. Due to the small size of the Workshop, all participants get to know each other from the very first day. Here, early-career scientists have a unique opportunity to interact closely with leaders in the field. There are many opportunities for such interactions during meals and coffee breaks, whilst admiring the beautiful period house where the meeting is held and during the organised walk through the stunning English countryside.

Another unique and much appreciated feature of the Workshop is the generous 15-minute question period after each talk. Combined with inclusive atmosphere, these have stimulated some great discussions involving not only the senior scientists, but also the students, postdocs and junior group leaders. There are also general discussions built into the programme about the open questions in the field. Even though I’ve left the bench, I can feel a contagious research energy that is sure to spark many collaborations.

A meeting report, with more details of topics covered, will soon be published in Journal of Cell Science. For now, I look forward to another day and a half of exciting talks about mitosis!

By Anna Bobrowska, Editorial Intern, Journal of Cell Science

The next Company of Biologists workshop will be on Transgenerational Epigenetic Inheritance. For more details click here.

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