May 10^th 2010 marked the second anniversary of a very young but promising scientific meeting, the Young Embryologist Meeting (YEM). This meeting was organised by a group of PhD students and young post-docs from London interested in developmental biology but open to everyone. Researchers at this level are just beginning to make decisions on what direction they would like their career to take. By bringing together young developmental biologists in an informal setting it was hoped to create research links that will outlast the time spent together in London. Also the idea was to create a network where exchange of ideas, support and even collaborations can occur. The outcome was a complete success with a packed seminar room full of students, post-docs and PI’s mostly from London but also from places like Barcelona, East Anglia and Cambridge. This massive attendance and the fact that already people are volunteering for next year’s meeting show how much an event like this was needed.

The meeting was held in the Wilkins room buried within the cloisters of University College London and its capacity was certainly stretched. It was opened by a keynote lecture by Peter Lawrence, who travelled down from Cambridge to talk to us about ‘Moments of discovery in a scientists life’. Everyone commented on how this talk was exactly what the conference needed. We were reminded about how it is the moment when one sees something new in nature that is the ultimate goal of research, and that these moments are a highly personal thing that once given to us can not be taken away again. It is this what drives us to keep experimenting and deal with all the frustrations that that can bring.

The meeting itself, an excellent series of short talks from young embryologists, was organised into four separate sessions. Each of session was named after the title of a classic embryological work that set the basis of the work presented in the corresponding session. This was to remind us of the importance in a continual re-appraisal of the core questions in embryology and to ask to what extent they have been answered, and how are we to address them in light of our recent knowledge and new techniques. The talks for each session were then selected with the aim of presenting a wide variety of different systems in which those core questions are being addressed. Through this and the subsequent discussion, it is hoped that ideas on the optimal experimental system in which to propose a particular research objective can be revealed. The talks covered areas ranging from de-novo centriole formation in mouse embryos, through to neurulation in zebrafish, mouse limb development, primary neurogenesis in Xenopus and the isolation of a novel organiser in the chick. Finally we had a series of talks focussing on neural crest development following by substantial amounts of wine and discussion.

The speakers and audience came form all places in London including the Department of Craniofacial Development and the MRC Developmental Neurobiology Department from KCL. In addition, we had talks from the institute of Women’s health and the Institute of Child Health, the NIMR at Mill Hill and the Department of Cell and Developmental Biology (CDB) at UCL. The CDB requires special thanks, as this was the sponsor of this event. The number of departments involved already, the people coming from outside London and the clear interest in organising new versions of the meeting will make the YEM a yearly and larger event. Thank you to everyone who helped to make this years meeting a success, we are sure everyone will agree on at least one thing; next year we will need a bigger room.

The 2010 YEM organising committee

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If you are a plant developmental biologist studying the Selaginella spikemosses, you might be interested in this beautiful animation that shows the life cycle of the Selaginella, Selaginella apoda

Life Cycle: Selaginella apoda from Ciaran Moloney on Vimeo.

And if you are captured by the simple beauty of this plant, you might also like a Development cover we published three years ago featuring the lycophyte Selaginella kraussiana.

The image shows the small dorsal leaves, large ventral leaves and the shoot branching pattern of this plant and was submitted by Harrison et al. to accompany their paper on how the growth of leaves from the meristem of S. kraussiana differs to that of flowering plants; a study that provided a framework for future comparative studies of meristem and leaf development in land plants.

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Here are the research highlights from the current issue of Development. You can find these on the Development site but we thought it would be useful to have them posted on the Node, too.

Brainy signals for actin dynamics

During brain development, neurite outgrowth and neuronal migration establish the brain architecture needed for brain function. Now, Eric Olson and colleagues reveal a regulatory feedback loop that links the cytoskeletal changes that provide the mechanical force needed for neurite outgrowth and migration to nuclear gene transcription during mouse brain development (see p. 2365). Myocardin-related transcription factors (MRTFs), the expression of which is forebrain enriched, translocate to the nucleus in response to actin polymerisation and cooperate with serum response factor (Srf) to regulate the expression of cytoskeletal genes. The researchers show that either Mrtfa orMrtfb is sufficient to support brain development but that the brain-specific deletion of both produces brain abnormalities similar to those caused by Srf deletion. These abnormalities, they report, are accompanied by dysregulation of the actin-severing protein gelsolin and of the kinase Pctaire1, which cooperates with Cdk5 to initiate a kinase cascade that governs cytoskeletal rearrangements. The researchers suggest, therefore, that MRTFs couple two signalling pathways that modulate cytoskeletal dynamics during neurite outgrowth and neuronal development.

Proliferation’s not over ’til the Fat-Hippo sings

During development, transitions from proliferating, undifferentiated cells to quiescent, differentiated cells are tightly regulated to ensure that organs reach the correct size. Kenneth Irvine and colleagues now reveal that Fat-Hippo and Notch signalling influence this important transition during optic lobe development in Drosophila (see p. 2397). Like the vertebrate nervous system, the Drosophilaoptic lobe develops from neuroepithelial cells, which function as symmetrically dividing neural progenitors. The Fat-Hippo signalling pathway, which contains the large cadherin Fat and the serine/threonine kinase Hippo, regulates the transcription of cell proliferation and survival genes. The researchers report that neuroepithelial cells in the Drosophila optic lobe undergo a cell-cycle arrest that is regulated by Fat-Hippo signalling before converting to neuroblasts. They also identify a role for Notch signalling in committing neuroepithelial cells to become neuroblasts. These and other results suggest that, by arresting the cell cycle, Fat-Hippo signalling contributes to the accumulation of Delta, which modulates Notch signalling and triggers neuroepithelial differentiation. A similar mechanism might be involved in vertebrate neural development.

Pluripotent stem cell derivation gets a (2i-)LIFt

Pluripotent mouse embryonic stem (ES) cells are obtained directly from the mouse epiblast, while pluripotent embryonic germ (EG) cells can be derived from unipotent mouse primordial germ cells (PGCs) by epigenetic reprogramming. But how similar are EG and ES cells? On p. 2279, Azim Surani, Austin Smith and colleagues report that these cells share a conserved molecular and developmental ‘ground state’. ES cells can be established using the cytokine LIF combined with the inhibition of GSK3 and of mitogen-activated protein kinase signalling (so-called 2i-LIF culture). The researchers show that pluripotent mouse EG cells can also be efficiently established using 2i-LIF culture. Then, using the same conditions, they derive rat EG cells for the first time. These cells express similar markers to rat and mouse ES cells, they report, and can contribute extensively to chimeric rats. Together, these findings raise the possibility that 2i-LIF culture could be used to derive EG cell lines with pluripotent ground state properties from other species, including humans.

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As announced in my last post, here is part two of the BSDB-BSCB Spring Meeting Report. It deals with two presentations on networks of transcription factors (TFs). During development, such dynamic networks of TFs and signaling molecules establish and maintain the spatio-temporal patterns of gene expression characteristic for the developing tissue. Using high throughput approaches in this post-genomics era, we now have the opportunity to comprehensively analyze and model these networks and try to link network features to function.

Part 2: Transcription Factor Networks

Eileen Furlong (EMBL, Heidelberg, Germany) presented her lab’s approach to globally decipher the combinatorial action of TFs in cis-regulatory modules (CRM). Using ChIP-on-chip with antibodies against five TFs required for mesoderm development in Drosophila, they generated a high-resolution, genome-wide dataset, describing TF occupancy during 10 hours of early embryonic development. They then used a subset of this data along with the corresponding in vivo activity data of characterized enhancers to train a machine learning algorithm. Using this approach, they were able to correctly predict the spatio-temporal expression of CRMs not included in the training set, based solely on their combinatorial TF binding profiles, in 80% of the tested cases.

Marion Walhout (University of Massachusetts Medical School, Worcester, USA) presented her team’s global analysis of 34 basic helix-loop-helix (bHLH) TFs in C. elegans. They set out to measure all the parameters describing a bHLH TF’s function: which bHLH partner it dimerizes with; where and when the TF is expressed; which DNA sequences it predominantly binds to; and whether it might preferentially regulate genes involved in certain processes. They then combined all of these parameters for every bHLH TF in an integrated network, from which they predicted and experimentally confirmed the function of a specific bHLH, and systematically compared the parameters among all possible bHLH pairs. These analyses linked certain TF dimers to specific processes and interlinked a subset of dimers with each other, uncovering overlapping and specific functions.

I found these presentations inspiring as they combined both previously and newly generated data to try to move beyond merely looking for patterns towards attempting to predict the behavior of the system. However, since these data sets and models are highly complex, it is not always possible to uncover clear-cut trends or rules of behavior.

In part three, my final post on this meeting, I will cover talks on several topics: Stem cells, limb development and evo-devo.

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I am employed as a graduate teaching assistant for a first year biomedical sciences course at Auckland University in New Zealand. The class is called Cellular and Developmental Biology and my job is to help with tutoring the laboratory classes. For my lab streams I’m the one who stands at the front and gives instructions, works with the demonstrators to assist and instruct the students, then grades the assignments afterwards.

With the word ‘developmental’ in the title, as you can imagine, there are lectures about embryology as part of the course. As the aim of the lab section is to support and extend what is taught within the lectures we naturally include an embryology class too. During the three hour session each student constructs a three dimensional model of a human four week old embryo (“today we’re making babies!”). Details are given here on the Auckland Uni website and the instructions are copyright to Colin Quilter 2003.

Each embryo is made of modelling clay called Du Kit and are baked before being returned to the students, giving everyone something to take home and keep. Teaching the class is a lot easier when you’ve been through it before so all demonstrators and tutors are given a modelling clay kit and the instructions then sent home to have a go. Here is the clay sitting on my dining room table ready for me to start.

The clay comes in different colours so that each germ layer or type of blood vessel can be colour coded. Normally we’d use dissecting instruments to help with the modelling but I don’t have a dissection kit at home so I raided the kitchen drawers.

The first section to make, and one of the hardest, was the neural tube. It takes a bit of playing for the clay to warm up and also I was still getting the hang of how to work it at this point. The instructions are to scale at this point so the best method is to lay the clay on the page to see if it matches, but it’s easy to make the embryo flat on one side while doing this whereas an embryo should, of course, be rounded and somewhat smooth.

Then the notocord and gut sections are attached, giving the main internal structure of the model. It’s kind of cool how putting on the auditory and optic vesicles make it look more like a human.

At this point I discovered that my home has a hazard we don’t usually face in the lab:

After shutting the cat out of the room I started putting on blood vessels. The colour coding really helps here, purple for mixed blood, red for oxygenated and blue for deoxygenated. The next picture has the aortic arches and other arteries attached.

Since the embryo is getting oxygen from the mother rather than the lungs the blood flow is different to what I’m used to having studied mainly adult physiology. I found this all a bit confusing at first but being able to trace the different vessels with their colour coding to and from the heart to the various other places they go really helped clarify what was happening. I would never have figured this out so well from just pictures, there’s something about physically laying the tubes down in the right place that sticks it into my brain.

Then I just needed to add somites along the back and the mesonephros and trigeminal ganglion. An actual embryo will have 43 somite pairs but we accepted any number as long as they were correctly paired and positioned and the sizes were appropriate. Mine has 14 pairs.

So there’s the end product, a beautiful four week old embryo. There are a few tissue types missing from this model to make it easier to see what’s going on, so it’s not technically a complete embryo. However after looking at the marking schedule and checking everything over I think I’ve done a good job, I’d give myself ten out of ten for this effort.

The students on the whole do seem to enjoy this lab, particularly when they get the finished product back at the end. And I was actually surprised at how much I learnt about how everything fits together and what turns into what after both making my version and teaching it to the students, so I think it’s an effective method for teaching this stage of human development.

(18 votes)

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(Originally posted in Development)

Development editors Liz Robertson (Professor of Developmental Biology at the Sir William Dunn School of Pathology in Oxford) and Alexandra Joyner (Courtney Steel Chair in Pediatric Cancer Research and Professor in the Department of Developmental Biology at Memorial Sloan-Kettering Cancer Center in New York) are not only actively involved in research and editorial work but, as of this summer, they will both be in charge of national developmental biology societies. Liz is Chair of the British Society for Developmental Biology (BSDB), and in August 2010, Alex will become President of the Society for Developmental Biology (SDB) in North America. We caught up with both of them at the annual BSDB Spring meeting that took place at the University of Warwick in April 2010.

Liz, you’re currently Chair of the British Society for Developmental Biology (BSDB). How long have you held this position?

Liz: Only for the last six months. I took over the reins when Matt Freeman stepped down last autumn. Matt had a very big job during his tenure as the BSDB Chair because the Society was fortunate to host the 2009 ISDB [International Society for Developmental Biology] conference in Edinburgh. This is the major event in the developmental biologists’ calendar as it’s only held every 4 years. The ISDB attracts around 1300 delegates and it’s a very challenging and time-consuming task to organize a meeting of this size.

Alex, when do you start as President of the Society for Developmental Biology?

Alex: I’ll take up the position of SDB President after our yearly meeting this August.

For how long does the Chair or President occupy their position in these different developmental biology societies?

Liz: All of the officers of the BSDB, which includes the Chair, the Secretary, the Treasurer and the Meetings Officer, hold office for five years.

Alex: At the SDB, the President’s position is just one year, as the main responsibility of the President is to organize the annual meeting. However, the President makes a three-year commitment because they are President-Elect for one year before being President and Past President the year after being President. There are also representatives for seven regions in the United States, a Canada representative and one junior faculty representative. These are all three-year positions, with the possibility for re-election once.

What is the role of the British and the North American societies for developmental biology in their respective geographic regions?

Liz: The primary goal of the BSDB is to bring together developmental biologists in the UK and Europe through networking activities. We have two yearly meetings: the spring meeting, which we’re at at the moment, is the largest meeting and is usually jointly held with the British Society for Cell Biology. We also have an autumn workshop, which is at a smaller venue and on a more focused topic. We also join with other developmental biology societies to organize meetings. For example, in 2011 we’re holding a meeting with the French Society for Developmental Biology in Nice.

Alex: The SDB holds an annual meeting each summer attended by developmental biologists from North America, as well as the rest of the world, and all the local regions also have a smaller meeting in the spring or the fall. The regional meetings are focused on giving an opportunity for junior faculty and students and post-docs to give talks, whereas at the larger annual meeting, the main talks are often given by more-established scientists. In addition, the SDB spearheads a number of educational initiatives throughout the year and during the SDB meeting. For example, we have a bi-yearly course, called boot camp, for new investigators to help them get their lab up and running and make them aware of the promotion process. In the alternate year, we have a reboot camp for senior faculty to reinvigorate their research and teaching approaches. There are also workshops for postdoctoral fellows and students.

Liz: We also aim to have an educational component within the BSDB. It takes a couple of forms: first, at this meeting there are two workshops scheduled during the lunch breaks that aim to provide help and careers advice for our junior colleagues. Second, owing to a very generous block grant from The Company of Biologists [the publishers of Development] we’re also able to award a lot of travel grants to students who are BSDB members, which facilitates their ability to attend this meeting as well as international meetings. Our goal is to underwrite their costs so that they can get out there, network and meet people from other countries and working in other disciplines.

Alex: Similarly, the SDB receives money from the journal Developmental Biology, which is used for a variety of initiatives, including student travel and support for meetings that have a developmental biology component to them. In such cases, we encourage the organizers to use the funds for travel for young people and to have an even gender balance.

How do you see the future of your societies in their respective communities?
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I am from Chile, a country located along the extreme southwestern coast of South America, a beautiful land of happy and courageous people, with an admirable geography however from time to time, some naturally events remind us how small is  our human scale compared with the Mother Earth that gave us life, (“we are children of rigor” as well-said JM, a famous Chilean reporter).

I tell this because my scientific visit in Germany coincided, for better or for worse, with the huge earthquake that hit my country last February, I came to Germany only two days before this catastrophe !, thus my first actions in this new country were trying to get news of my family, friends and colleagues. Meanwile, one of the major casualties of the earthquake was Science. Specifically, the laboratory of the Dr. Miguel Allende (CGC, Universidad de Chile) where I am making my PhD thesis, lost nearly all equipment and suffered substantial damages to the structure of the building. More serously, irreplaceable reagents, stocks, samples and experiments were lost. For me, it is very hard as a Chilean scientist to see my colleagues and friends, who are helpless in all of this, forced to star from square again,… it was very sad for me.

As you may suspect, the beginning of my stay was full of worry and anguish, but at the same time, with the fascination of being in a country like Germany, where the lifestyle and the organization of things is quite different from those known to me in Chile and other South American countries. My first internship was in the laboratory of Dr. Clemens Grabher, at the Institute of Toxicology and Genetics (ITG), Karlsruhe Institute of Technology (http://www-itg.fzk.de/itg/itg_home.html ), where I had an excellent welcome. Moreover, I had the opportunity to collaborate with other groups such as the the laboratory of Dr. Urban Liebel (http://liebel-lab.fzk.de/liebelwiki/index.php/Main_Page ), where I used “first-class” equipment for my experiments, being a major contribution to my scientific experience. Finished in Karlsruhe, a stay was generated in the laboratory of Dra. Virginie Lecaudey, in the University of Freiburg (http://www.biologie.uni-freiburg.de/data/bio1/lecaudey/), a beautiful city from which I was delighted to come. The welcome here has been spectacular, coinciding with the celebration of my birthday for first time in Europe; and also, allowing me to continue with important experiments for my thesis. Next in my scientific journey through Germany,  I`m now in the laboratory of Dr. Joachim Wittbrodt at the University of Heidelberg (http://www.izn.uni-heidelberg.de/index.php?option=com_content&task=view&id=63&Itemid=261), where I will be able to make relevant experiments for my work in a great zebrafish lab, living in other beautiful German city and enjoying the FIFA World Cup, where I hope that Chile (and my host country Germany) have a good participation !.

For me, making these visits is an unforgettable experience in both the professional and personal sense. First, I could test and compare “in situ” and “in vivo” how the science is in developed countries, and get to know the availability of the resources and the high level of organization that these laboratories have. However, this experience also made me notice the large differences in sciences between countries like Chile and Germany, in the level of resources, the proper use of them and the full support of the scientific career. Personally, this has been a culture and scientific learning experience, even being out of my country in difficult times.  But over time I realized increasingly the importance of my stay here, because I understood how much I can learn and then apply it in my country, by helping in the education and development of it.

Finally, I want to thank all the institutions that helped me, either to fund my trip, as well as the research and their laboratories, who hosted me and gave me the opportunity to live this experience, and do things that in my country I could not have done.

I would like to finish this story, with greetings to my lab partners and my tutor Miguel Allende in Chile (my full support) and give them the strength and encouragement in the rebuilding of our lab !…for them and the chilean people, an extract of Pablo Neruda`s Poem “Hymn and return”:

…y mirando tu ilustre y solitaria espuma
un ramo litoral tejeré a tu belleza.

Patria, mi patria
toda rodeada de agua combatiente
y nieve combatida,
en ti se junta el águila al azufre,
y en tu antártica mano de armiño y de zafiro
una gota de pura luz humana
brilla encendiendo el enemigo cielo.

Guarda tu luz, oh patria!,
mantén
tu dura espiga de esperanza
en medio
del ciego aire temible.
En tu remota tierra ha caído toda esta luz difícil,
este destino de los hombres
que te hace defender una flor misteriosa
sola, en la inmensidad de América dormida.

…and looking your illustrious and lonely foam
a coastal bouquet I`ll knit to your beauty.

Homeland, my homeland
all sorrounded by combatant water
and fought snow,
in your eagle and sulfur combines,
and in your Antartic hand of mink and  sapphire
a drop of pure human light
shine lighting the enemy sky.

Save your light, oh homeland!
keep your hard spike of hope
in the midst of the fearsome blind air.
In your remote land all this difficult light has dropped,
this fate of men
that make you defend a mysterious flower
alone, in the vastness of America asleep.

Cristian A. Undurraga S.
A curious man by nature…and
PhD student in Molecular/Celular Biology and Neurosciences
Center for Genomics of the Cell
Laboratorio de Biología del Desarrollo
Facultad de Ciencias
Universidad de Chile
http://www.mileniocgc.cl/
Twitter: @cundurraga

(3 votes)

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On one of the walls of the Royal Institution in London is the following quote:

“Science may never come up with a better office communication system than the coffee break” – Earl Wilson

Coffee breaks are not just a good source of information in office communication, but also in science communication. In the mid-nineties, Swiss art curator Hans Ulrich Obrist organized a conference for artists and scientists in which the entire conference program was replaced with one big coffee break. He had noticed that at a conference, the interesting discussion happen during the coffee breaks – not necessarily at the presentations themselves.

We’d like you to think of the Node as a way to spend your coffee breaks. As you’re reading papers or doing experiments, you learn a lot about the science of developmental biology, but not so much about the scientists. To get the latest news about funding or hear which meeting you might want to attend next, to find out the day-to-day practices of other labs or hear some entertaining stories from the field, you need to get up from behind the bench and talk to people. With the Node, you don’t even have to get up anymore: you can roll your chair over to your laptop, and visit the site. Once you’re all caught up and ready to get back to work, you can catch up on recent papers using the table of contents of developmental biology journals listed in the sidebar.

As with any coffee break conversation, you’re not just listening to others speaking, but you can have your say as well. If you create an account on the Node, we’ll then make you an author of the site, and you can add you own posts. Have a look at the help page for more information, and feel free to ask us any questions.

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(This was essentially written by Dr. Chris Gordon – see bottom for details, though “Heather” posted it here.)

Approximately 320 participants attended the second joint meeting of both the Japanese and French societies for developmental biology at the Institut Pasteur on May 26^th to 28^th, 2010. Of these, sixty Japanese developmental biologists made the voyage to mingle with their French colleagues, drawing on a long-standing and fruitful exchange of scientific trainees and expertise. The Sasakawa Fondation and the Riken Center for Developmental Biology provided lodging for the Japanese participants in Paris, which probably helped with the numbers.

Margaret Buckingham (Institut Pasteur, Paris) and Shinichi Aizawa (Riken Center for Developmental Biology, Kobe), two of the organizers, welcomed all attendees to the conference, entitled “From Cells to Organs”. Each day was divided into two non-concurrent major sessions which were grouped loosely according to theme, and for the first two days, interspersed with two alternate poster sessions. These were so many (168) that even the ample time allotted during coffee breaks, daily catered buffet lunches and evening wine and cheese did not seem to be enough to do them justice. Full presentation abstracts for both talks and posters are found here.

The oral presentations represented an even balance of junior and senior scientists from near and far, all of whom presented in a perfectly comprehensible, transcultural English.

Overall, diverse models were represented. For the posters, the technical approaches were even more diverse and impressive, but too numerous to summarize. Among the talks, models ranged from engineering (Yoshihiro Morishita [Kyushu University, Fukuoaka]) and mathematical approaches (Kenji Matsuno [Tokyo University of Science, Tokyo] ; Hiroki Nishida [Osaka University, Osaka]; Aki Kimura [National Institute of Genetics, Mishima])  to plants (Alexis Peaucelle [INRA, Versailles]) to a broad variety of invertebrate and vertebrate animal systems. For example, Masaaki Yamaguchi (Kanazawa University, Kanazawa) and Julien Behague (Institut Jacques Monod, Paris)  spoke about highly conserved transcription factors in the sand dollar Peronella japonica and the annelid Platynereis dumerilii respectively, the study of which uncover evolutionary implications for body plan homologies among Bilaterian clades. Reiko Kuroda (University of Tokyo, Tokyo) presented work on blastomeric symmetry-breaking in the chiral snail, Lymnaeia stagnalis.

Other highlights from the talks, which were all of an excellent standard and most of which presented at least some unpublished work, are summarized below in no particular order, to represent the flavour of the conference.

Atsuo Kawahara (National Cardiovascular Center Research Institute, Osaka) reported his work on the role of sphingosine-1-phosphate (S1P) signalling in zebrafish heart morphogenesis. From a mutagenesis screen, a mutation was identified in spns2, an S1P transporter, in animals with bifid hearts – a phenotype resembling that previously described for an S1P receptor. Knockdown of spns2, or of a sphingosine kinase, specifically in the extraembryonic yolk syncytial layer, also produced cardia bifida. Kawahara’s elegant genetic manipulations suggest that S1P, released by the yolk, signals to migrating cardiac cells in the embryonic tissue above, ensuring coalescence of cardiac progenitors in the midline. For background, see this publication.

Yuuta Moriyama (University of Tokyo, Tokyo) presented data suggesting that in the medaka mutant Double anal fin (Da), in which externally visible dorsal trunk structures become ventralized, a transposon insertion adjacent to zic1 and zic4 disrupts the function of a somitic enhancer for the zic gene pair. Moriyama’s work indicates that via zic genes, the somite plays a key role in patterning a range of tissues in the dorsoventral trunk axis.

Otoliths are biomineralized crystals attached to cilia within the zebrafish inner ear. Their mass contributes to ciliary deflection, leading to transduction of signals for hearing and balance. Julien Vermot (Institut de Genetique et de Biologie Moleculaire et Cellulaire, Illkirch) has used advanced imaging techniques to shed light on how precursor particles of the otolith accumulate within the cavity of the inner ear. Although random diffusion predominates in the central portion of the cavity, local currents are created by beating cilia near the otoliths at the poles of the cavity, thereby attracting particles to the growing crystal. Also, Vermot demonstrated that normal otolith formation is dependent on these cilia, by laser ablation of cilia or knockdown of their components. For background, see this publication.

Mutations in RPGRIP1L, a gene encoding a ciliary protein, have previously been detected in patients with Joubert and Meckel syndromes. Sylvie Schneider-Maunoury (Université Pierre et Marie Curie, Paris) described her recent analysis of olfactory bulb and telencephalic defects in Rpgrip1l-null mice. Concomitant with ciliary defects in forebrain neuroepithelial cells, the mutant mice display a dorsal expansion of ventral telencephalon domains. Gli3, an effector of Hedgehog signalling, regulates dorsoventral patterning of the anterior telencephalon. Schneider-Maunoury presented data suggesting that the Rpgrip1l-null forebrain phenotype is mediated by a reduction of the repressor form of Gli3.

Another layer of complexity in the transmission of Hedgehog signals was discussed by Pascal Thérond (Institut de Biologie du Developpement et du Cancer, Nice). Using the Drosophila epithelial wing disc as a model, Thérond showed that there are apically- and basolaterally-secreted pools of Hedgehog, with Hedgehog activity from the apical pool extending further into the anterior compartment of the disc than that of the basolateral pool. This long-range apical activity is enhanced by the glypican Dally, an extracellular matrix protein, and by Notum, a hydrolase that releases Dally into the apical lumen. The specific readout in cells receiving Hedgehog may be the result of integration of both apical and basolateral inputs. For more information, see this recent publication.

These last presentations were timely in the light of feature articles from that particular issue of Development and also tied in well with a number of other talks and posters concerning Hedgehog signalling effects.

Among these, Koji Tamura (Tohoku University, Sendai) revisited the contribution of the zone of polarizing activity (ZPA) to digit cartilage. As shown by chick-quail chimera fate-mapping, hindlimb digit IV cartilage is directly derived from the Sonic hedgehog-producing ZPA, whereas in the forelimb, no cartilage comes directly from ZPA cells. Heterotopic grafting experiments demonstrated that hindlimb posterior digit identity can be imposed in the forelimb, but not the converse, and only during a restricted time window. A discussion ensued about digit homologies between theropod dinosaurs and birds, and during the questions, amphibians and mammals.

Yoshiko Takahashi (Nara Institute of Science and Technology, Nara) also used the chick embryo to explore the responsiveness of sub-populations of neural crest cells to environmental signals during their dissemination through the body, using the sympatho-adrenal (SA) sublineage as a model. Takahashi reported that SA cells respond to environmental signals that act first on guidepost tissues which thereby attract the neural crest. Subsequently, while sympathetic precursors remain behind to form ganglia, the adrenal precursors must carry on. SA progenitors are electroporated first with an elegant Tol2 transposon construction that mediates stable transgenesis of GFP expression, a helper plasmid with a transposase, and a tet-on inducible dominant-negative receptor. Upon judicious doxycycline stimulation, signal transduction is interrupted only after the labelled cells arrive at the level of the sympathetic ganglion, and the adrenal precursors no longer colonize their target.

Philippe Herbomel (Institut Pasteur, Paris) presented some exquisite examples of in vivo imaging in zebrafish embryos. Using embryos in which vascular cells were labelled with GFP, Herbomel demonstrated how hematopoietic stem cells arise within the aortic endothelium of the fish, in contrast with amniotes. Individual stem cells bend out from the endothelium, away from the lumen of the aorta, and pinch off. They subsequently pass through the underlying mesenchyme to enter the axial vein and go on to seed caudal hematopoietic tissue. Runx1, a key regulator of the emergence of hematopoietic stem cells, is required for this endothelial to hematopoietic transition. Further details can be found in this recent publication.

On the second day, during the general assembly meeting of the SFBD, its new website (http://www.sfbd.fr/) was launched and introduced by Stephan Zaffran. Douglas Sipp, representing the International Society for Developmental Biology also took the stage to encourage the contribution or support of new ideas relative to improving meeting attendance and participation by developmental biologists around the world, before the next ISDB conference in Cancun, Mexico, in 2013.

The meeting ended on a cheerful note with the distribution of poster awards, chosen with some difficulty among the many worthy possibilities by the members of the organizing committee. Meeting sponsors enabled these prizes to not only be a public honour, but to be attached to some prize money. These went to the following presentations:

Glenda Comai (Schedl group, Nice): Functional study of the role of the novel tumor suppressor gene WTX during mouse embryonic development

Mathieu Gouzi (Grapin-Botton group, Lausanne): Role of Neurogenin3 in migration of pancreatic endocrine cells during development

Benjamin Bonneau (Gillet group, Lyon): Member of Bcl2 family Nrz controls yolk cytoskeleton dynamics via regulation of calcium fluxes during zebrafish early development

Toshihiro Banjo (Ogura group, Sendai): MicroRNA-21 expression triggered by heartbeat contributes to zebrafish cardiac valve formation.

Finally, and importantly, the 2^nd joint meeting of the British and French Societies for Developmental Biology will be in Nice, France, (yes, that’s the Côte d’Azur) from 3-6 septembre 2011. (The first was in 2003.) Hope to see you there!

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About the authors:

Chris Gordon is a postdoc in the “Embryology and genetic architecture of human neural crest malformations” group, INSERM unit 781, in Paris, France.

Heather Etchevers is not quite sure what she is when it’s translated into English, but she’s tenured with the INSERM and they let her carry out research. She worked in the same group as Chris until June, 2010, when she moved to the INSERM unit 910 in Marseille, France.

(2 votes)

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It is close to three years since my first visit to the ‘Land of the royal kings and gold, tigers, cobras and elephants’ – INCREDIBLE INDIA!! Yes, incredible in every way with its friendly people, deep-rooted culture, heritage and history, natural beauty and scientific accomplishments, the most recent being in the area of space research with the discovery of water on Mars.

In the south of India in the State of Karnataka is the city of Bangalore, a bustling metropolis often called the IT capital or silicon valley of India. To the north of the city, is the famous Tata Institute of Fundamental Research (TIFR), one of the oldest research institutions in the country. It houses the National Centre for Biological Sciences (NCBS), a premier research unit supported by the Government of India and situated on a beautiful, sprawling campus spread over an attractive 20-acre plot surrounded by forests and green fields. NCBS is known for its advanced research on biochemistry, biophysics and bioinformatics, genetics and development, cellular organization and signaling, neurobiology, theory and modeling of biological systems, ecology and evolution.

NCBS has excellent facilities for academics and modern research. There are more than 20 well-equipped laboratories and a separate Central Imaging and Flow Facility. Each laboratory functions as an independent, self-sufficient community or unit with its own traditional approach, although the overall strategy is highly integrated and collaborative. It also supports recreational activities with a well equipped sports complex and swimming pool that ensures a pleasant and healthy environment for research.

Since autumn 2007, I worked as a visiting student at the laboratory of Prof. Gaiti Hasan, a reputed research scientist with range of international publications to credit, whose focus of work addresses the role of inositol-1,4,5-trisphosphate receptor signaling in cellular and systematic physiology. This past experience and moreover the encouragement and support offered to international candidates convinced me to pursue my first Post-Doctoral training at this reputed institution.  Moreover, the Journal of Development has kindly supported my visit to India by awarding a Travelling Fellowship. Currently, I hold a full-time position as a ‘Post-Doctoral Visiting Fellow’ under the supervision of Prof. Hasan. Typically, new lab entrants receive a warm welcome and are considered members of what is known as ‘our unique family”. This is more than apt since for many researchers it’s a second home that supports advanced research and at the same time helps balance family life which is equally important.

The lab hosts several weekly events: Lab-meets on Saturdays to report individual research data, Journal Scientific Club on Tuesdays to understand the latest achievements of the specific research area in question such as, molecular aspects and genetics of neurodegeneration, role of Ins1,4,5-trisphosphate receptors in this phenomenon, Ca²⁺-signalling via STIM and Orai proteins in excitable cells, etc. NCBS also hosts weekly research seminars by outstanding scientists representing premier research institutions worldwide. I have been fortunate to participate in some of these sessions that have helped provide me with a broader perspective to the multi-disciplinary nuances of research.

Amidst all this serious work is the fun side of lab-life with team outings, lunch get-togethers and the ‘Bollywood’ specials noted for its colourful song and dance routines!

The overall experience has been truly enriching and I look forward to the year ahead. I hope to share with you in the coming weeks and months more interesting snippets from my research life at NCBS and India.

Cheers

Tetyana

(2 votes)

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