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Research Technician – Cell and Developmental Biology – MRC-NIMR

Posted by , on 12 September 2012

Closing Date: 15 March 2021

Applications are invited for a Research Technician position in the research group of James Briscoe at the MRC National Institute for Medical Research, London. The lab studies the embryonic development of the vertebrate central nervous system. We combine cutting edge transgenic and genomic approaches with the latest imaging and cell biology techniques to investigate how morphogens and transcriptional networks generate spatial pattern.

http://www.nimr.mrc.ac.uk/research/james-briscoe/

Experience in molecular biology is required and experience of cell culture, mouse genetics and embryological techniques desirable. Enthusiasm, reliability and organisational skills are essential. The successful applicant will be expected to support and become engaged in specific projects aimed at elucidating the mechanisms of neural patterning. The group, which will move to the Francis Crick Institute, London, in 2015, currently comprises 11 scientists and is well supported by both MRC and external funds. The Institute provides excellent training for researchers in a multi-disciplinary environment and is equipped with state of the art facilities. Specialist training to support the development of skills will be given where necessary.

The applicant is expected to have a Degree or equivalent in a relevant subject.

This position is for 5 years in the first instance. Salary range is from £21,565 per annum inclusive of location allowance. MRC final salary pension scheme is also available.

Situated in Mill Hill, North West London, the MRC National Institute for Medical Research is the largest MRC institute, supporting 70 research groups and 500 bench scientists. Facilities include genetic modification of mice, imaging, histology, FACS and high throughput sequencing.

Applications are handled by the RCUK Shared Services Centre; to apply please visit our job board at https://ext.ssc.rcuk.ac.uk and complete an online application form.  Applicants who would like to receive this advert in an alternative format (e.g. large print, Braille, audio or hard copy), or who are unable to apply online should contact us by telephone on 01793 867003, please quote reference number

Closing date: 8th October 2012

The MRC is an Equal Opportunities Employer

Final appointments will be subject to a pre employment screening.

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Update about the Node updates

Posted by , on 12 September 2012

Have you updated your profile on the Node yet, as suggested in this post? If not, you have a few more weeks: we’re delaying the public profiles (and other updates) while we fix some existing issues with the site.

The site updates are ready to go, and we’re really excited about them, but we want to make sure everything is working perfectly without them first.

On that note, if you’re having any technical issues with the Node, please do let us know right away. You can use the email form or email us directly at thenode [at] biologists.com, or use Twitter (@the_Node).

Thanks for your understanding, and sorry to keep you waiting!

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Categories: News

World Cell Race

Posted by , on 12 September 2012

The Olympics and the Paralympics may be over, but there’s still time for sporting success this year, albeit on a rather smaller scale. The 2012 World Cell Race is on. Over the last year or so, I’ve heard both Matthieu Piel and Manuel Thery talk about the 2011 version of the race, and this morning I noticed that the results have just been published in Current Biology, officially* revealing that the fastest cell is a human mesenchymal stem cell.

Think you can beat that? They’re still accepting submissions for this year’s race, so if you have the single-celled equivalent of a Usain Bolt or an Oscar Pistorius in your freezer, send it in!

*Well, officially out of the 54 cell types they tested under the specific conditions they used…

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Grand Challenge PhD in Rihel Lab at UCL

Posted by , on 11 September 2012

Closing Date: 15 March 2021

PhD Position
University College London
Department of Cell and Developmental Biology
PhD Supervisor: Dr. Jason Rihel
Application Deadline: Oct. 15, 2012

Funding Availability:  Funding PhD Project (Grand Challenge; European/UK Students; including a stipend of £18,000 a year, Home/EU fees and £5000 per year research funds).  Non-UK/EU citizens are eligible but must have the ability to pay the difference between the Home/EU fee and the International fee for the 3 years.

Sleep is a fundamental biological process that has a major impact on human health, cognitive performance, and quality of life, yet the genetic and neural mechanisms that regulate sleep/wake behaviour are largely unknown. In the Rihel lab, we use zebrafish as a model system to study the regulation of sleep because it combines the powerful genetics of invertebrate models with the basic brain structures that regulate sleep in humans. We use high throughput behavioural assays to measure sleep behaviours in the fish and exploit genetic tools to manipulate critical regulators of sleep, such as the functionally conserved hypocretin/orexin (Hcrt) signalling system.  Recently, we have performed both small molecule and genetic screens to identify potential novel regulators of sleep in zebrafish. 

The successful PhD student will combine cutting edge techniques in molecular biology and behavioural neuroscience to explore the function of novel sleep genes and drugs.  In particular, the research will aim to map the neural circuits that are altered by small molecule and neuropeptide manipulations.       

Applicants should have a degree in molecular biology, neurobiology, or a similar field.  A 2:1 or better is normally required according to UCL eligibility criteria.

Send all enquires to Dr Jason Rihel (j.rihel@ucl.ac.uk).  Applicants should send a CV and names and contact details of two referees.

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Categories: Careers, Jobs

Vote for a Development cover – Woods Hole – Round 4

Posted by , on 5 September 2012

This is the final round of images from the 2011 Woods Hole embryology course. The students of the 2012 course have also taken some beautiful images, and you’ll see those on the Node later this year.
But for now, vote in the poll below the images for the one you would like to see on the cover of Development. (Click any of the images to see a bigger version.) Poll closes on September 26, noon GMT.

1. Alcian blue staining of a Stage 17 bat (Carollia perspicillata) embryo. This image was taken by Lingyu Wang and Ketty Lee.

2. 3D reconstruction (face on view) showing the head vasculature of a zebrafish embryo. Visualization of gata1: dsRed (red; blood cells) and flk1: EGFP (blue, endothelial cells including blood vessels). This image was taken by Meghan Morrissey and Lynn Kee.

3. Day 10.5 mouse embryo immunostained for PECAM in green, Phospho-Histone H3 in red, and DAPI (nuclei) in blue. This image was taken by Juliette Petersen and Rachel K. Miller.

4. Skeletal preparation of a turtle, the red-eared slider (Trachemys scripta elegans). This image was taken by Megan Martik, Jane Yu, John Young and Eric Brooks.


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An Interview with Haruhiko Koseki

Posted by , on 5 September 2012

This interview first appeared in Development.

Haruhiko Koseki is Director of the Developmental Genetics Research Group at the RIKEN Research Center for Allergy and Immunology in Yokohama, where he studies the epigenetic regulation of Polycomb group genes in development. He recently joined Development as an Editor, and agreed to be interviewed about his research and about science in Japan.

When did you first become interested in developmental biology?

I started university in the school of medicine, and became fascinated with comparative anatomy and embryology. In medical school in Japan, the first 4 years consist of basic classes, and the last 2 years are clinical training. I didn’t enjoy clinical training very much, and decided to move to immunology research instead of becoming a clinician. At that time, the field of immunology was exploding, and the discovery of the rearrangement of immunoglobin genes led to the study of cell differentiation in that field. My PhD research was in immunogenetics, but I discovered that immunology is not really the field to be in to study differentiation or patterning. Because of that, I made the decision to move to developmental biology. I did my postdoc with Rudi Balling in Freiburg (Germany), working on development based on mouse genetics. I really enjoyed life in Freiburg, and during my time there I published my first paper in Development.

How does research in Japan compare with research in Europe?

When I was in Germany, I learned that, in Japan, science is not fundamental science, but it’s science aimed at technology. We’re always asked about the social benefit of our discoveries. That is a natural question to ask, but I think, in Europe, people just appreciate science for the discovery.

Another difference used to be the budget invested into science. Until recently, it was much smaller in Japan compared with Europe or the USA, but in the last few decades this has changed, and at the moment it’s not very different from Europe. But I’m not sure our productivity is at the same level as that of European scientists. I think we’re not very good at sharing resources, infrastructure or ideas. It also seems that Japanese postdocs and students are not interacting much with each other. They’re relatively quiet and shy compared with European students. Traditionally, we’re educated to behave as modestly and quietly as possible. But now we have many foreign students and postdocs, and I think many students are starting to notice that this shy attitude is not ideal to get ahead in science.

What are you currently working on?

I’m mostly studying the epigenetic regulation underlying the maintenance of certain cell types and differentiation. When I did my postdoc in Freiburg, I was investigating how the notochord regulates somite differentiation, but when I got back to Japan in 1994, I realized that field is so competitive. I didn’t want to do similar things to what everyone else was already doing. At that time, my main interest was axial skeletal patterning. In the early 1990s, many people working on mammalian axial patterning were looking at Hox and signalling cascades. In Drosophila, Polycomb was already known to be a very important regulator for anterior/posterior specification, so I decided to work on Polycomb in the mouse. I used the system developed by Andras Nagy in Toronto (Canada) to generate many knockouts for components of mouse Polycomb complexes. Knockouts enabled us to see whether the mammalian Polycomb proteins are doing something important during development, but it’s difficult to address the underlying mechanisms by using developing embryos because of their cellular heterogeneity. To bypass this issue, we’re now focusing on ES cells as a model to study Polycomb function, to find out how various Polycomb complexes cooperate to maintain certain cell types and how their functions are modified when cells differentiate into different states. Now the critical issue is learning how catalytic activities and chromatin binding of Polycomb complexes are regulated during cell cycle progression. Ideally I’d want to get back to real embryos, but for that we need more technical breakthroughs – maybe a new device to image the chromatin status of certain loci in the living embryo, or something like that.

What are some other projects that your research group is working on?

Most of us are working on various aspects of Polycomb function. Polycomb proteins form at least a few multimeric protein complexes, but each component also interacts with many other modules, outside of Polycomb complexes, during differentiation or cell cycle progression, and approximately half of my research group is studying these interactions. For example, work with knockout mice shows that the axial skeleton phenotype of the DNA methyltransferase mutant is very similar to that of the Polycomb knockout. That suggests that there could be a functional and profound interaction between Polycomb and DNA methylation mechanisms, and that’s one of the things we’re investigating. This is a big challenge for us because of its extensive complexity and redundancy.

You also administer the mouse facility at your institute. Who uses this facility?

The mouse facility is shared by the five different institutes that make up the Yokohama RIKEN site. The animal facility is mainly used by the immunologists, but is increasingly also occupied by people from the institutes for human genetics, ‘omics’ sciences and plant sciences. This suggests that mouse genetics is becoming a more general tool to address a wide spectrum of biological and medical questions. Mouse genetics has developed in parallel with immunology, developmental biology and neurosciences, and will be further advanced by collaborating with many other fields of biomedical sciences, as well as other disciplines. It is really exciting to see with my own eyes how things are developing in this field. I am particularly interested to see the upcoming contribution of mouse genetics to the understanding of pathogenic mechanisms underlying various human diseases.

How have you experienced your first few months as a Development Editor?

It’s a great pleasure, but I’m still getting accustomed to the job, so it’s still taking up a lot of time. This is my first experience as an academic editor, and I learned a lot in the last few months, particularly from reviewers’ comments. Geographically, we’re very isolated in Japan, and not readily exposed to the way science is discussed and evaluated in the USA or Europe. Now, through reviewer comments, I get a look into how people are thinking about papers and how they express their views.

Are there any particular papers that you would really like to see people submit to Development?

Developmental biology is linked to several other fields. For example, imaging is becoming very quantitative and mathematical modelling is now used to describe developmental processes. Unfortunately, genomics is still a bit far from developmental biology, because of the heterogeneity of cells and quantitative limitations of samples. With technical breakthroughs such as chromatin immunoprecipitation, the field of genomics is moving closer to developmental biology, but many genomics researchers don’t consider their work in that context. There might eventually be a lot of genomics studies that are very interesting in terms of developmental biology, but genomics researchers might not think of submitting them to Development. The same is true, for example, for transcriptome and metabolome studies.

What would people be surprised to find out about you?

I have played volleyball since I was a high school student. I didn’t have a lot of opportunity to play when I was in Germany, unfortunately, but except for these 3 years in Freiburg, I have kept playing. I’m now 50, and that’s old in terms of playing volleyball. Ten years ago, I had a fracture on my right ankle and it took almost half a year to recover. Recently, I’m a bit cautious of getting injured. But I still join in competitive games and sometimes go to the other side of Japan for competitions.

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In Development this week (Vol. 139, Issue 19)

Posted by , on 4 September 2012

Here are the highlights from the current issue of Development:

Stem cells get cut loose

During tissue maintenance and regeneration, stem cells (SCs) are mobilised and migrate towards sites of tissue turnover or repair. However, owing to the inaccessible nature of most in vivo SC populations, very little is known about the molecular factors that regulate SC mobilisation. Otto Guedelhoefer and Alejandro Sánchez Alvarado tackle this problem by studying SC mobilisation during tissue homeostasis and regeneration in the planarian flatworm Schmidtea mediterranea (p. 3510). They show that planarian SCs migrate minimally in the absence of wounding; in partially irradiated animals, SCs do not migrate from the areas that were shielded from radiation to populate irradiated areas. Importantly, the researchers report, amputation increases SC dispersal and induces directional recruitment of SCs to sites of tissue repair, suggesting that factors capable of directing SCs are activated upon amputation. These findings highlight that, in planaria, SC depletion alone is not sufficient to trigger SC migration and that loss of tissue integrity is required to promote the directional migration of SCs.

Coupling genome defence to epigenetic reprogramming

DNA methylation plays an important role in gene silencing and repressing transposable elements (TEs). During primordial germ cell (PGC) development, DNA methylation marks are erased during extensive epigenetic reprogramming, so how does this demethylation impact gene expression and TE repression in PGCs? Richard Meehan and co-workers (p. 3623) show that DNA methylation at the promoters of germline-specific genes couples genome-defence mechanisms to epigenetic reprogramming in mouse PGCs. The researchers identify a set of germline-specific genes that are dependent exclusively on promoter DNA methylation for their silencing; their promoters possess specialised chromatin in somatic cells that does not acquire additional repressive histone modifications. This set, they discover, is enriched in genes involved in suppressing TE activity in germ cells, and the expression of these genes is activated during two phases of DNA demethylation in PGCs. These findings suggest that unique reliance on promoter DNA methylation acts as a highly tuned sensor of global DNA demethylation and allows PGCs to be primed to suppress TEs.

Stan points the way in planar polarity

Many epithelial tissues display planar cell polarity (PCP). This phenomenon has been best studied in Drosophila in which most epidermal cells produce hairs at one side that all point in the same direction. The molecular mechanisms underlying PCP establishment remain controversial. Key players are the transmembrane proteins Starry night (Stan; also known as Flamingo), Frizzled (Fz) and Vang Gogh (Vang, also known as Strabismus). Stan, a protocadherin, forms homodimeric bridges between cells. These bridges appear to link Fz and Vang on the abutting distal and proximal faces of adjacent cells, and their resulting asymmetric distributions polarise both cells to point the same way. Now, Struhl, Casal and Lawrence (p. 3665) report the surprising finding that Vang is not essential for cell polarisation. Instead, asymmetric interactions between Stan and Stan/Fz are sufficient to define polarity, and Vang plays an accessory role, probably by enhancing the capacity of Stan to interact with Stan/Fz. These results challenge current models of PCP, although the authors propose an alternative that may reconcile the data.

Predicting embryonic axes

In many animals, the polarised transport of maternal factors by the microtubule cytoskeleton is required for setting up embryonic axes. Now, Karuna Sampath and colleagues show that microtubules at the vegetal cortex of early zebrafish embryos are dynamically remodelled and predict the future embryonic axis (p. 3644). Using live imaging, they find that two transient populations of microtubules – perpendicular bundles and parallel arrays – are detected exclusively at the vegetal cortex of fertilised embryos before the first cell division. The perpendicular bundles, which are likely to transport maternal factors via the yolk to the blastoderm, extend from the vegetal cortex and orient along the animal-vegetal axis. The parallel arrays form autonomously even in the absence of sperm entry and fertilisation. Importantly, the asymmetric orientation of parallel arrays shortly after fertilisation predicts where the zebrafish dorsal structures will form. Finally, the authors provide in vivo evidence for cortical rotation-like movements of cytoplasmic granules, similar to those occurring in Xenopus, suggesting that such movements might be more common in development than previously thought.

Potassium channels and patterning

Mutations that disrupt the function of the inwardly rectifying Kir2.1 potassium channel cause developmental defects in both humans and mice, but the mechanisms underlying these abnormalities remain unclear. Now, on p. 3653, Emily Bates and co-workers show that disruption of a homologous Drosophila potassium channel, Irk2, causes developmental defects by modulating signalling of Decapentaplegic (Dpp), a bone morphogenetic protein (BMP) homologue. The authors find that compromised Irk2 function causes wing patterning defects similar to those observed when Dpp signalling is disrupted. The phenotypes of Irk2 mutant flies are enhanced by reducing Dpp function. Importantly, the researchers demonstrate that aberrant Irk2 function leads to a decrease in Dpp signalling within the wing: phosphorylation of Mad (a downstream effector of Dpp signalling) and the expression of spalt (a transcriptional target of Dpp) are decreased in Irk2 mutant wing discs. Collectively, these findings identify a novel mechanism by which potassium channels act during development and suggest that BMP pathways might somehow sense alterations in membrane potential.

Insights into the origins of HSCs

In mice, haematopoietic stem cells (HSCs) are first found in the dorsal aorta of early embryos shortly after 10.5 days post coitus (dpc) and in the foetal liver at 11 dpc. However, multipotent haematopoietic progenitors can also be detected in the dorsal aorta from 9 dpc. Do these cells contribute to adult haematopoiesis? Here, Ana Cumano and co-workers address this question by characterising this population of cells (p. 3521). The researchers show that multipotent progenitors detected in the dorsal aorta at 9 dpc, which they term immature HSCs (imHSCs), are endowed with long-term reconstitution capacity. Furthermore, they report, these cells are capable of evolving into HSCs under appropriate culture conditions and are able to colonise the mouse foetal liver. Of note, the early colonisation of the foetal liver by imHSCs precedes that of HSCs. Moreover, organ culture experiments suggest that, in the liver environment, imHSCs are able to mature into HSCs, thus identifying a novel stage in HSC development.

Plus…

An interview with Haruhiko Koseki

Primer: Epithelial-mesenchymal transitions: insights from development

Review: Tooth shape formation and tooth renewal: evolving with the same signals

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This Month on the Node – August 2012

Posted by , on 31 August 2012

A detailed view of mice and fish

Michael Wong wrote about the 3D mouse embryo atlas he has worked on. The high-resolution atlas of an E15.5 mouse embryo allows for easier phenotyping of mutant strains, which can then be compared to the wildtype.

“If you have two groups of mouse embryos, one wild-type and one mutant, with a single gene knockout, how do you find out what’s different about them? How do you get clues to the function of the knocked out gene and its role in mouse embryo development? The most intuitive answer would be to look at the two groups of mouse embryos with a microscope and see if you can find any gross differences in morphology in the mutant group. You could hypothesize that the organ or structure that shows an aberration in comparison with the wild-type group is an area where that particular gene function is important and carry on with more focused phenotyping assays from there. This is the exact premise of our recent paper in Development.”

Mice were not the only animals that we’ve looked at in high-resolution detail. A recent paper in JCB described “virtual nanoscopy”, a method to collate multiple EM images to create a detailed map of a zebrafish embryo.

Gene rearrangement

Kalin Narov introduced us to recent work on gene rearrangement in the lamprey.

“…according to the authors, it is the first known example of a genome rearrangement of such scale in vertebrates, which makes it especially important for better understanding the evolution and mechanisms of vertebrate gene regulation.”

Conferences:

The Santa Cruz Developmental Biology Meeting took place earlier this month, and Katherine Brown wrote a summary for the Node.

Last month, at the SDB meeting, we continued our chain of poster winner interviews, as BSDB poster award winner Stephen Fleenor interviewed SDB poster award winner John Young.

Also on the Node:

We’re going to make author biographies public on the Node. Make sure to check that yours is up to date!

– The culture medium used for preimplantation cultures in IVF labs may have long-term effects on development.

– Several new jobs have been posted on the site.

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The in silico metamorphosis of the best known metazoan GRN

Posted by , on 31 August 2012

This rather lengthy summary describes a fascinating progress in the field of GRN modeling; it is a review of the article “Predictive computation of genomic logic processing functions in embryonic development”, which appeared few days ago in PNAS.

Gene regulatory networks (GRNs) are complex systems of interacting genes that deploy in both space and time and are the main regulatory logic behind the specification of cell fates during embryogenesis (Li et Davidson, 2009). Gene networks can be derived for any developmental process or structure and, in simple terms, consist of nodes (the genes themselves) connected by lines, which represent the causal relationships between the different genes. More or less, the GRNs unfold in time in a hierarchical mode where the products of earlier genes serve as regulatory factors (inputs), controlling the expression (output) of downstream targets. Provided that sufficiently detailed knowledge about the gene expression pattern and interactions for a given process is available, a computational model of the respective GRN can be constructed. The main objective of constructing a GRN model is to be able to causally explain each regulatory event in the system and, most importantly, to be able to predict the outcomes of experimental perturbations.

One of the the most complete, if not the best for any developmental process to date, is the GRN behind endomesoderm specification in the embryo of a sea urchin with the lovely name Strongylocentrotus purpuratus, famous for being the favorite model organism in Eric H. Davidson’s lab. Eric’s lab has been instrumental in establishing the endomesoderm network, which currenty contains some 50 genes, and their recent article describes the generation of a Boolean computational model, which beautifully and correctly reconstructs the spatiotemporal expression pattern of the interacting genes and allows for predictions to be made about the effects of changes in the system (Peter et al, 2012).

The computational model has been created by the incorporation of several sources of data: observations on the expression patterns of regulatory genes in space and time and results from trans and cis perturbation experiments. There are four spatial domains in the sea urchin embryo, based on differential gene expression, concerned with the endomesoderm specification -skeletogenic and non-skeletogenic mesoderm, and anterior and the future posterior endoderm. The data was used to construct an abstract representation of the interactions using Boolean logic. At the core of the model are the vector equations – one for every gene in the model. Each equation captures all inputs that sum at a respective node and give its output in Boolean terms, 1 – “on” or 0 – “off”. Understandably, the inputs are the outputs of other genes in the system and the relevant maternal inputs provide the initial triggers – the starting regulatory state.

A strong feature of the model is the incorporation of several other characteristics of the developing embryo, like the notion of intercellular signalling, embryonic geometry (which is the relative position of the four spatial domains in the embryo) and real-time kinetics of gene expression. Including such parametres in the model is important for the configuration of the spatial domains relative to each other changes with time and the kinetics of target gene transcription is a function of the temporal expression features of its regulators (like kinetics of RNA and protein synthesis and turnover). As for the latter, an earlier investigation by the same group has revealed a rather surprising phenomenon, that the step time (this is the “interval between activation of a given regulatory gene and the activation of an immediate downstream target…”) is rather uniform for most genes operating during early sea urchin development, and is approximately 3 hours. This characteristic was included in the model.

The usefulness of the computational model was first revealed by testing its ability to reproduce the regulatory state (the sum of all known regulatory genes expressed at a particular time interval) for each domain. Remarkably, there was a perfect match between the experimentally observed and computed patterns of expression of 33 genes, with only two exceptions – the bm1/2/4 and wnt8 genes. For these genes, the model resulted into a novel expression domain or prolonged expression, respectively, which is most likely due to the lack of knowledge about additional inputs operating in the embryo. Second, the incorporation of a uniform time step in the model successfully reproduced the observed dynamics of spatial gene expression, which is rather surprising, and further supports the idea that the regulatory genes of the S. purpuratus embryo operate with similar kinetics. Curiously, when the model was run with a different step time ( of 4 hours instead) the result was a catastrophic discrepancy in the expression kinetics of many genes.

The next task, and a most daunting one, was to challenge the model’s explanatory power by manually changing selected initial parameters (“removing” or “expressing ectopically” selected genes) and comparing the computational results with data derived from previous experimental perturbations of those same genes. For instance, in one of the settings the authors extinguished delta expression from the skeletogenic mesoderm, which in the model resulted in the loss of gatae and gcm  expression in the non-skeletogenic mesoderm and the ectopic expression of V2 endoderm genes, like blimpb1, foxa and hox11/13b. So far so good – this was exactly in agreement with the experimental observations. However, the real predictive power of the model was revealed when the expression of additional genes appeared perturbed, genes that have not yet been tested experimentally! For example, the GRN model predicted that the absence of delta affects not only gatae and gcm, but also genex and j(suh). It would be interesting to experimentally investigate the expression profile of the latter two genes in embryos injected with delta morpholinos, to check whether their patterns conform to the model’s predictions. If they do, then “Hail The Model!”; if they do not, it would simply mean that there exist regulatory inputs beyond our current knowledge.

In a final and rather challenging test, the authors computationally mimicked an experiment from the classic days of transplantation studies by Hoerstadius, when donor skeletogenic micromeres were transplanted on the animal pole of a host embryo, which resulted in a complete second gut and associated mesodermal tissues. In modern terms, this implies that the donor micromeres were sufficient to induce the downstream GRN required for endomesoderm development. However, in their model the authors computationally endowed the animal pole cells (which normally do not form skeletogenic micromeres) with maternal factors sufficient to induce the micromere cell fate. Then, remarkably, the surrounding cells formed three successive spatial domains – ring 1, 2 and 3, which expressed the regulatory states of the mesoderm, veg1 and veg2 endoderm, respectively, precisely mimicking the experimental results.

In conclusion, this study demonstrates the great predictive importance of GRN modeling but also its usefulness for further in silico evaluation of current GRNs structure and discovery of knowledge gaps, or lacunae, as described by the authors. One type of lacunae appear as discrepancies between what is observed and what is computationally generated but, as this study reveals, their frequency is low. In fact, what seems as a rare “failure” of the model could potentially guide future investigations.

 

References:

 

Peter IS, Faure E and Davidson EH, Predictive computation of genomic logic processing functions in embryonic development, PNAS Early Edition, Aug 27th 2012

 

Li E and Davidson EH, Building developmental gene regulatory networks, Birth Defects Research (Part C) 87:123–130, 2009

 

 

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Public profiles on the Node

Posted by , on 30 August 2012

When you click on an author’s name on a Node post, you are currently shown a page with all of the posts by that author. You can try it on this post.

In a few weeks, this is going to change! We will soon have profile pages for everyone who has written (or will write) on the Node. The profile page will list biography information that you can edit yourself. We’ve created a page that describes how to do that.

If you currently have a post anywhere on the Node, whether it’s a job ad or a two-year-old conference report, I recommend checking what you have filled out in your profile, because it will soon be public!

We have a few other changes in the works for the Node, and we hope to have the redesign up in the third week of September. If you can find a minute to update your profile before September 13, that would be very helpful.

You can always edit your profile later, but please just be aware that in a few weeks the biography section from your profile will become public.

The information page clearly describes what part of your profile will become public, and how to edit it.

If you have any questions, let us know via email, or leave a comment below.

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Categories: News