A position (#123028) is available immediately for a Research Technician/Faculty Specialist to contribute to our studies in neural crest and placodes. The Technician will conduct research, assist in the training of students, and take part in the management of the laboratory of Dr. Lisa Taneyhill at the University of Maryland. Laboratory skills should include the ability to perform various molecular biology and biochemical assays. Experience with microscopy, chick embryology, and tissue culture is desirable. For more information on the lab, please see http://www.ansc.umd.edu/people/lisa-taneyhill. Qualifications: A Bachelor’s degree (B.A. or B.S.) in a related field and prior laboratory research experience is essential. Fluency in spoken and written English is required. Compensation: Salaries are highly competitive, negotiable and commensurate with qualifications. Fringe benefits offered. Applicants must apply through eTerp at https://ejobs.umd.edu. Applications will be accepted until a suitable candidate is identified.
The Woods Hole Embryology Course, which will celebrate its 124th birthday this year, is a continual source of beautiful images (and videos) of development. Since 2011 the Node has run a competition for the community to pick the best images from a given year – the winning pictures become immortalised as Development covers.
Below you will find 4 images from Round 2 of the 2015 course (Round 1 was won by Theodora Koromila’s lunar chicken embryo), and a poll to vote in at the end. You can see full size versions by clicking on the images.
The poll is set up to allow only one vote per person, and closes at 13.00 BST on Wednesday 21st June.
Drosophila
Drosophila melanogaster embryo, stage 17, lateral view with anterior up, ventral to the left. Yellow – anti-HRP, all neuron cell bodies and axons; Pink – anti-Fasciclin II, motoneuron projections; Blue – anti-Tropomyosin, muscles; Green – DAPI, nuclei.
Amjad Askary
University of Southern California, USA
Longhua Guo
Stowers Institute, USA
Maike Getwan
University of Hohenheim, Germany
Nick Shikuma
Cal Tech, USA
Crab
Juvenile crab collected in a plankton tow.
Chiara Sinigaglia
Observatoire Océanologique de Villefranche sur Mer/ CNRS, France
Parhyale
Adult amphipod, Parhyale hawaiensis. Pink – DsRed expression in muscle. Yellow – FITC dextran injected into hemolymph to visualize the circulatory system. Blue – autofluorescence of cuticle.
Longhua Guo
Stowers Institute, USA
Skate
Skate (Leucoraja erinacea) embryo stained with Alcian Blue to reveal cartilage.
Like most things in life, research requires funding and scholarships. This becomes increasingly apparent as researchers progress through their career. At some point, everyone has to jump on the funding treadmill. For many researchers, the first experience of a grant application process may be applying for postgraduate scholarships for their masters/PhD. While I never pursued this option myself, as a postdoc, I now see it from the other side of the fence.
Writing a grant for your dream lab
It is a good opportunity for PIs to employ someone for 3-4 years at no cost. So if you’re an undergrad looking to apply for such a grant, expect pro forma replies from people only too happy to apply with you. If you already have funding, most PIs will happily host you even if your CV is hand written on the back of a napkin. If you are a young, clever, enthusiastic scientist make no mistake, you are a sought-after commodity so shop around.
Postdoctoral funding is a little different but the same general dynamics apply, particularly with regard to postdoctoral fellowships. What you need to be mindful of is that the application process may be a lot more gruelling and competitive. It is important that you gauge carefully what your chances of success are. Remember, a PI may agree to put their name on your application but the grant writing may be left entirely up to you. It can be a big commitment, particularly when you are in the midst of finishing up your PhD and writing your thesis.
This can be a particularly stressful and unnerving time as you don’t know what the future will hold. It can be difficult put together a competitive grant proposal under such conditions so it is not for the faint hearted. If you are lucky you might just get your dream fellowship and a flying start to your career. If you are less fortunate the PI you apply with, impressed by your efforts, might keep you in mind when they next secure funding. However, if you are unlucky, you get nothing but you learn from the experience always look at the positives.
Post-Doc and PhD student grant writing tips and advice
It is, admittedly, a lot easier to focus on writing a research proposal when you know where the next paycheque is coming from. For this reason, many choose to secure a postdoctoral position before pursuing fellowship funding – a bird in the hand is worth two in the bush. This is probably a less stressful approach than applying for funding during the latter stages of your PhD. However, don’t forget that the clock is ticking from the moment you finish your viva – you will not be eligible for certain early stage’ fellowships after you clock up certain amount of experience e.g. Sir Henry Wellcome Postdoctoral Fellowships (ineligible after one year of postdoctoral experience).
My first postdoc was in the same lab where I did my PhD. In reality, this was more of a mop-up’ period for my doctoral work; several manuscripts were submitted, all of which were eventually published, so paper-wise it was a productive time. My advice to anyone considering this option is don’t do it for too long – identify short-term achievable goals and make sure you have an exit strategy. Unless there is something truly amazing happening in the lab, there are a number of reasons you should probably move on after your PhD. Firstly, moving to a different lab is a new experience and will force you outside of your comfort zone, to meet new people, learn new skills and develop fresh ideas. Secondly, if you want to apply for a fellowship, there are often mobility clauses written into fellowship grants which preclude staying in the same lab where you completed your PhD e.g. Marie Curie Intra-European Fellowships for career development (IEF).
Early stage researcher grants
Aside from fellowships, there are several other funding opportunities for postdoctoral researchers. These generally take the form of larger collaborative grants where you, as an early stage researcher, may not be the lead applicant. If successful, these grants may cover your costs for a number of years so success can buy you breathing room and time to focus on your research. These grants can effectively represent a fellowship from your perspective although their raison d’etre is likely to be delivery of a research goal rather than a postdoc’s career development.
After a six month stint, I waved goodbye to my old lab in 2011. As I was finishing up, finished my ELISAs I applied with my current PI for a postdoctoral fellowship but was unsuccessful. In spite of this I moved to this lab in 2012 as funding became available and so began my first postdoctoral post outside my alma mater. The first couple of months were given to setting up the lab – things like ordering equipment and organising paper work, getting to know people in the department/university, supervising undergrads and then (eventually) getting on with my experiments. However, aside from research, the main focus has been on grant writing.
Drafting scientific grants
I have written eight grants and am currently drafting my ninth; one was successful, another three are still under review and five were unsuccessful. It’s a learning process. There is no magic formula for writing grants and even if you write the best proposal imaginable, success can be decided by factors beyond your control. Nevertheless, to begin with, the guidelines and eligibility criteria need to be gone over with a fine-tooth comb. Read the notes from the funding bodies as carefully as possible and check out the success rates to see exactly what your chances are before you even begin writing. Make sure you know exactly who you are applying to and what their mandate is. You may need to tailor your research aims to fit the call but remember that if successful you’ll have to deliver, so your aims must be genuinely achievable. You might have to consider drafting in a collaborator who has a strong track record in a particular field to strengthen your proposal. I would also advise getting in contact with researchers who have written successful grant applications (sometimes they are listed online or you might know somebody who has been successful). If you want to see some examples of high quality proposals, check out the NIH website where you can download some successful R01 grant applications. These are high-quality applications and a good benchmark for any proposal.
Importantly, don’t forget that there are no marks for effort if you are unsuccessful. Aside from grant writing you need to be generating quality research and clocking up the publications. You can’t spend all your time writing grants it’s a question of balance. For what it’s worth, I suggest using grant writing as a vehicle to develop your ideas and plan your research. It’s amazing how great an idea can seem until you put it down on paper. Writing really helps crystallise your thoughts.
Successful grant applications
While grant applications may seem a lottery at times, don’t forget that chance favours only the prepared mind. This is as true of funding applications as it is of science. Although grant writing takes time and includes elements which are not purely scientific, it is probably the best chance you have of taking control of your career and driving your research in the direction you want.
The programme (http://www.grc.org/programs.aspx?id=11170) covers a wide a range of exciting subjects such gene regulatory networks, mechanics, stem cells, regeneration, organoids, and evolution. The conference will be preceded by a two-day symposium designed exclusively for students and post-docs.
As some readers will already be aware, we have recently introduced a new ‘format-free’ submission policy. We’ve been delighted by the early feedback on this – from what we’re hearing, this has been a popular move and will help make life easier for authors submitting to Development. But what do we mean by format-free and how does it differ from our earlier policy?
Now, when you submit your paper to Development, you don’t need to worry about specific formatting requirements for the journal – we don’t care if your references are not in Development style (they can even be numbered), whether your materials and methods section comes after the introduction or the discussion, or whether you’ve provided the figures in the format that we need for final publication. We hope this should make things easier for all authors, but particularly for those submitting to Development after their paper has been considered elsewhere; while we like to believe that all our authors select Development as their first choice of venue for publication of their work, we are realistic and recognise that at least a few of you might already have tried another journal first! In general, we don’t see the value in asking you to reformat (or just format) your paper in our house style before you know whether it is likely to be accepted for publication with us. Instead, we want to remove as many of the hurdles to submission as we can and make the whole process as quick and smooth as possible.
So what do we need at initial submission? The most important requirement we still retain, and one that we recognise will not be universally popular, is a length restriction. Research articles over 7000 words and Research reports over 3000 words (excluding title page, abstract, reference list and, now, materials and methods – more on which below) will be returned to authors with a request to shorten the paper to within this limit. We make this a requirement because we believe that length limits serve a valuable purpose – to ensure that a paper remains relatively concise and accessible to the reader. And we have chosen to enforce this guideline at initial submission because, in our experience, papers tend only to get longer during the revision process, meaning that it will become even more difficult to meet these limits at a later stage in the process. In exceptional cases, and following consultation with the handling editor, we may be able to consider papers that exceed this length, but we generally believe that it should be possible to write your paper in a way that does not run over this limit – and that this will make the paper a better read upon eventual publication.
We will also return your paper before sending it to the editor if text or figures are unreadable following conversion to PDF (although this is rare), and we may also ask you for a smaller PDF if the file is too large to be easily handled by editors and referees. In addition, we may have to delay assigning your paper to an editor if we can’t confirm the identity of your co-authors. You might be aware that a few journals (fortunately not us) have encountered problems with corresponding authors submitting papers with fake email addresses for their co-authors, allowing them to circumvent the normal checks that ensure that all co-authors are aware of and approve the paper and its submission. Therefore, where non-institutional (e.g. Gmail) addresses are provided, we will query these with the corresponding author and request either institutional email addresses and/or ORCID IDs. We are sure you understand that it is important we make sure all authors are kept fully informed of the status of their work, and hence why this is an essential check to keep at first submission.
With these changes, we hope to make initial submission to Development as easy as we can. In fact, we were already operating on a largely format-free basis before the announcement of this policy, but we have further relaxed our guidelines with this latest set of changes. We will, however, ask that you ensure your paper complies with our formatting guidelines at revision stage – should your work meet with positive assessment from our editors and referees. At this point, we will also require you to fill in our submission checklist – confirming that your paper complies with various policies and best practise guidelines – to provide high-resolution versions of the figures that our graphics team can process for publication, and to tell us about your funding bodies. Given that, according to recent statistics, we accept over 95% of papers where we have invited a revision, we hope that you won’t mind taking the extra time to format your paper at this stage, when you know the chances of eventual acceptance are very high.
The other significant change we have made, as alluded to above, is to remove the materials and methods section from our word count. The aim here is twofold. First, we want to give you a little more flexibility with article length – the total word limit remains the same even though we now exclude the materials and methods. Second, and more importantly, we recognise the importance of this section of the paper and want to encourage authors to provide appropriate details of all experimental protocols. Length limits often mean that methods sections simply cite previous papers, which cite even earlier papers, so that a reader can find it impossible to figure out how an experiment has been conducted. We would prefer that methods be provided in greater detail, allowing readers to fully understand the protocols. Where materials and methods are particularly lengthy, we will still encourage some of this information – additional details that are primarily of interest to the real expert in the field or to those wishing to replicate the experiments – to be provided in the supplementary information, but again we will not enforce this at initial submission and can work with the authors to make appropriate changes at revision stages.
Together, we hope these changes will make the submission process for authors – whether you are submitting to Development as first choice (which of course we hope most of you do!), or have already been elsewhere – a quicker and easier process. As always, we will continue to review these policies as we go forwards, and we welcome your feedback.
Here are the highlights from the current issue of Development:
Getting MAD in meiosis
In meiosis I, homologous chromosomes must pair and form crossovers to ensure appropriate chromosome alignment and segregation. During this process, as in mitosis, the spindle assembly checkpoint (SAC) functions to detect misaligned chromosomes at metaphase. This delays anaphase to enable error correction and induces apoptosis when errors cannot be corrected. Surprisingly, previous studies have suggested that the core SAC component MAD2 might be dispensable during spermatogenesis in mice, but Imrul Faisal and Liisa Kauppi now re-investigate the role of MAD2 in male meiosis (p. 1988). Using mouse models in which either all chromosomes (Mlh1 mutants) or just the sex chromosomes (Spo11β-only mice) show defective crossover formation, the authors look at the consequences of Mad2 heterozygosity on spermatocyte apoptosis and aneuploidy. While Mad2 heterozygosity does not rescue sterility of Mlh1 mutants, suggesting that the checkpoint is still active in this context, it does partially rescue apoptosis in the Spo11β-only mouse, resulting in low-level sperm aneuploidy. These data provide the first evidence that MAD2 is important for efficient SAC activation in spermatocytes, and suggest that cells with relatively mild chromosome crossover defects are more sensitive to MAD2 levels than those with severe defects.
Growing a labyrinth with G9a
Defects in placental growth and patterning can have severe consequences for foetal health, and can cause intrauterine growth restriction (IUGR). However, relatively little is understood about the mechanisms regulating placental development, particularly the later phase of maturation when the blood vessels of the so-called labyrinth elongate and elaborate. On p. 1976, Paul Delgado-Olguin and colleagues show that the histone methyltransferase G9a is required for placental maturation. Endothelial-specific knockout of G9a in mice has no effect on early placental development, but mutants show severe defects in labyrinth size and structure after mid-gestation, owing to reduced proliferation of endothelial cells. Intriguingly, the authors provide evidence for non-autonomous regulation of trophoblast cell proliferation, which is upregulated in the endothelial-specific knockout. G9a conditional mutants show reduced expression of Notch pathway effectors (previously implicated in regulation of placental maturation), and the placental vessel phenotype can be rescued by activation of the Notch pathway. Thus, G9a is a key regulator of placental maturation in mice, regulating the balance of endothelial versus trophoblast proliferation. Notably, this mechanism may also apply in human, since G9a and Notch pathway components show altered expression in samples from IUGR pregnancies.
Wheat domestication: Q is the answer
Domestication of wheat has involved a number of phenotypic changes from wild isolates. Notably, domesticated varieties possess a subcompact spike and a loss of the tough glumes that protect the grain, leading to a free-threshing phenotype. Several genetic determinants of these characteristics have been identified, including the Q gene, which encodes an AP2-like transcription factor. Cultivated wheats generally have the hypermorphic Q allele, whereas wild varieties have the q variant, associated with lower AP2 activity. It is known that AP2 factors can be regulated by the miR172 miRNA, and that Q bears a mutation in the miR172 binding site, but how this putative regulation affects the phenotypes associated with domestication has been unclear.
Two papers in this issue of Development address the regulation of Q by miR172. Steve Swain and colleagues (p. 1959) isolate a new allele of Q, Q’, which results in higher protein abundance due to impaired miR172-mediated targeting. Through analysis of Q’ and induced revertants, the authors show that higher levels of AP2 activity are associated with the formation of ectopic florets in place of glumes – an apparent homeotic transformation in the spike. Similar results are also presented by Jorge Dubcovsky and co-workers (p. 1966), who further demonstrate that reduced miR172-mediated degradation of Q is largely responsible for the free-threshing and other phenotypes associated with domesticated varieties. The relative levels of miR172 and Q define spikelet morphology, with higher Q or lower miR172 activity being associated with glume-to-floret transition and free-threshing character, and lower Q activity with the opposite changes. Moreover, a gradient of miR172:Q levels along the spike is associated with a gradient of homeotic changes.
Together, these two papers convincingly demonstrate that tight regulation of Q by miR172 is important for the acquisition of free-threshing character in domesticated wheat varieties, and help to resolve prior controversies as to the mechanism underlying the Q phenotype. These studies also add to our understanding of how AP2 factors regulate floral patterning in plants.
Video Highlight
On p2070, Brant Weinstein and colleagues describe generation of a zebrafish transgenic line expressing GFP in lymphatic vessels allows visualization of the developing lymphatic network, demonstrating a stereotyped, stepwise assembly.
Hiroshi Hamada, director of the RIKEN Center for Developmental Biology, talks about his career in Japan and North America, his fascination with left-right axis determination and his love of Irish music.
This Review discusses the diverse epithelial cell behaviours involved in small neurosensory organ development, using dental placodes, hair follicles, taste buds, lung neuroendocrine cells and lateral line neuromasts as examples.
How do we perceive sounds, gravity or head movements? It all starts during development, when sensory cells in the inner ear acquire a crown of motion detectors known as the stereocilia bundle. The Tarchini laboratory investigates the molecular mechanisms that corral and layer stereocilia into a functional bundle, a highly polarized architectural process that, when defective, results in deafness. (http://tarchini-lab.org).
We are seeking a Postdoctoral Associate interested in dissecting how G protein signaling controls and coordinates two features essential for hearing and balance ability: 1) the striking alignment of hair cells along the epithelial plane (planar polarity), and 2) the staircase-like architecture of the motion-sensor compartment of hair cells, the stereocilia bundle.
Required qualifications include a recently obtained PhD in Developmental or Cell Biology, Neuroscience or a related field. Expertise with inner ear Biology and mouse genetics is desired but not required
The Jackson Laboratory (http://www.jax.org) in Bar Harbor, Maine, USA, is recognized internationally for its excellence in research, unparalleled mouse resources, outstanding training environment, and exceptional core services – all within a spectacular setting adjacent to Acadia National Park. The Tarchini lab is currently funded with an R01 grant from the National Institute on Deafness and Other Communication Disorders (NIH NIDCD; https://www.nidcd.nih.gov) and support from The Jackson Laboratory.
Each year, the British and US societies for Developmental Biology have their annual meeting, the BSDB‘s usually in April, the SDB‘s usually in July. The winner of the student poster prize in each of the meetings gets the chance to go to the other society’s meeting the following year. Beginning in 2012, the Node began getting the winners together for an interview chain, and the tradition is continued here with the SDB’s 2016 poster winner Yusuff Abdu (from Jeremy Nance’s lab, NYU; Yusuff was interviewed last year in Boston by Mathew Tata) interviewing the BSDB’s 2017 winner Claire Bromley (Jon Clarke’s lab, Kings College London).
What’s your favorite model embryo other than zebrafish and why?
I would have to say Drosophila. Their genetic tractability and possibilities for live imaging during embryogenesis make them an excellent system to understand many things, including early development – a topic that I am fascinated by.
Tell us more about the work in your lab.
In Jon’s lab we are working to understand the processes that make and shape a neuroepithelium and make and shape neurons. We use the zebrafish neural tube as our model. I’m working on how you shape the neuroepithelium. There are many complex cell rearrangements that occur. For example, cells from each side of the neural primordium initially interdigitate before rearranging to meet at a distinct, straight left-right interface. I’m currently investigating the role of biomechanical forces during this process. We hypothesise that there is a ‘tug-of-war’ between these two columns of neighbouring cells that acts to position the cell interfaces at the tissue midline. By cutting the ‘rope’ between cells we can measure how far they ‘fall back’. This gives us an idea of how hard they were pulling on each other, allowing us to reveal intrinsic forces. I’m now trying to use light to interfere with these forces to understand their function.
Imaging must be an important part of your project. What challenges have you faced and how did you solve this problem?
To be able to perform laser cuts in the densely packed neural rod, we had to trial a variety of techniques to find one that gave reproducible cuts coupled with rapid imaging post-cut. I found collaborating with Conny Schwayer and Carl-Philipp Heisenberg who have a UV laser on a spinning disk scope the best way to go. This also gave me several trips to Vienna! We optimised UV laser cuts and have been able to gain interesting insights into the forces present in this complex 3D structure.
What questions in brain development do you find most intriguing?
I am intrigued by the early formation of shapes and patterns during development – and not just in the brain! It’s amazing how single cells go on to form functional organisms in a highly reproducible fashion. All the research projects that I have worked on so far have focused on understanding early events during embryogenesis, whether through the lens of symmetry breaking or shape changes.
Along the same line, what do you plan to work on in the future?
I am most excited by work at the interface of biology and physics. Morphogenesis is intrinsically a mechanical process in many ways, and I feel that important discoveries in this area can be made through collaborations between biologists and physicists. As a biologist I have learnt a lot from physicists – and I hope to continue to do so in the future.
Cell sorting is a critical process during development, as differently specified cells are segregated to the right parts of the embryo. Differences in cell adhesion and cortical tension are thought to be crucial to this process, but the mechanics have been difficult to probe in vivo. This week’s paper, published in the current issue of Development, argues that directed migration – rather than differential tissue surface tension – drives cell sorting during zebrafish gastrulation. We caught up with lead author S.F. Gabriel Krens and his supervisor Carl-Philipp Heisenberg, Professor in the Institute of Science and Technology in Klosterneuburg, Austria.
Gabriel (left) and Carl-Phillip (right)
Carl-Philipp, can give us your scientific biography and the key questions your lab is interested in?
CPH I studied Biology in Munich, did my PhD in the lab of Christiane Nüsslein-Volhard, in Tübingen/Germany and worked as a postdoctoral fellow in the lab of Steve Wilson in London/UK. I started my own lab at the MPI-CBG in Dresden/Germany in 2001 and moved from there to the newly founded IST Austria in Klosterneuburg/Austria a few years ago.
And Gabriel, how did you come to join the Heisenberg lab?
During my PhD I was introduced to work with zebrafish in the research group of Prof. Herman Spaink and my supervisor Dr. Ewa Snaar-Jagalska at the University of Leiden (NL). The focus of my work was more to understand the role of MAPKs in development. Since the importance of these proteins in early embryonic processes, I was also soon exposed to the work of Carl-Philipp and I got very much interested in the multi-disciplinary approach that he was taking.
I met him for the first time in person at ‘the zebrafish conference’ in Dresden, and after a second visit later to the MPI-CBG in Dresden, I knew that this was the place I wanted to go to, to do my postdoctoral research. After finishing my PhD, I joined his lab for my postdoctoral studies, and later also moved with him to I.S.T. Austria.
Mesoderm internalisation at the onset of gastrulation from Figure 1, Krens, et al. 2017
Can you give us the key results of the paper in a paragraph?
GK One of the key results in my opinion is there was only very little known about the role of the interstitial fluid – in particular in early development. Many interpretations therefore have been drawn on the interaction that different cells display toward each other, without taking into account their direct ‘liquid’ environment of their physiological context: the developing embryo. This notion only appeared to me after performing quite a number of experiments in vitro and trying to understand the differences of germ layer organization between the in vitro data and in vivo gastrulation processes. In addition, I got the chance from Carl-Philipp to visit Wayne Brodland in Waterloo (Canada) and Wayne told me back then that he knew how to extract interfacial tensions from images based on his DITH hypothesis, but that he lacked the experimental data to do so. I had been optimizing the imaging of our cell sorting assay in vitro to the point that we could record on a cell-membrane resolution that would allow us to extract interfacial tensions. After obtaining our first results on experiments performed in culture, I was excited to test the CellFIT-3D in vivo, but we were missing this 3rd ‘liquid’ interface. I noticed that there were gaps between cells in the developing embryo. It did not take us long to consider that these cavities were not empty, but rather fluid-filled (IF), and that we should take this additional fluid interface into consideration too for our tension analysis. Ever since, we have been tightly collaborating with Jim and Wayne to develop the technology, improve image quality and to get to a level of biological understanding of the differences in interfacial tension relationships in vitro and in vivo to the point that we thought was ready to be published.
What made you decide to look at osmolarity in the first place? Is it an underappreciated variable in culture experiments?
GK We already knew for quite some time that the interfacial tension distributions that we found in vitro were not able to explain the behaviour of what we see in vivo. We tried many approached to find out what was different, and one of them was to use the poky mutant fish line from Daniel Wagner. These fish have a defective enveloping layer and are therefore quite susceptible to osmotic variation of the embryo culture medium. By experimenting with this, we discovered that we could actually influence the germ layer organization in these fish by only altering the embryo medium. So far, we were not able to extract tensions in these fish, as the dye to label the IF diffused out at the moment of gastrulation initiation, but this was the main motivation to try to characterise the osmolarity of IF of early zebrafish embryos.
Cell sorting in heterotypic cultures of ectoderm and mesoderm progenitors. Movie 1 from Krens, et al. 2017
And how do you think osmolarity might influence cell behaviour in your experiments?
GK It is well known that cells respond to osmolarity, and that there is an immediate / short-term response and a long-term response. Changing the osmolarity will change the osmotic pressure and subsequently the hydrostatic pressure in the cells. This hydrostatic pressure needs to be compensated, which can occur by an increase of contractility of the actomyosin cortex and by changing the composition of the cytoplasm / metabolism. On long term – it is likely that also regulators of cytoplasmic composition, such as ion-channels, aquaporins and metabolic regulators, are involved in the process. This would be a nice area to follow up on.
Do you have an idea about the cues that direct the mesendoderm progenitor migration during internalisation?
GK I think that this is an open question in the zebrafish that stands out already for a long time. I find it more and more difficult to believe that we have missed out on that one components in all previous molecular and genetic screens that have been performed so far. On top of that, there as been numerous attempts, and so did we, to find THE cue that directs mesendoderm progenitor cells to the embryonic interior. Therefore, I am starting to believe that this might be more a generic factor, such as the embryonic layout, rather than one single guidance molecule. As we discuss at the end of our manuscript, this could also distribution of IF, as this seems to form gradient at the onset of gastrulation. At this moment this hypothesis goes more toward speculation that anything that is build on data!
GFP-expressing ppl progenitors in wild type and DN-Rac conditions, from Figure 4, Krens, et al. 2017
When doing the research, was there a particularly exciting result or eureka moment that has stayed with you?
GK During this work, there were quite some eureka results, as we had to overcome a significant amount of technical and intellectual difficulties. But we definitely had a couple of very good moments: The matching simulations output with the CellFIT found to the experiment; the osmolarity rescue experiments in vitro; the DN-Rac data I still find rather stunning as this was an experiment with low hope and a surprisingly awesome result; but most special is the moment that we managed to both extract and measure IF osmolarites, as this is a rather challenging set of experiments that need to come together perfectly to get it to work.
And what about the flipside: any moments of frustration or despair?
GK As mentioned before, we have tried quite some approaches, which all had their challenges. The whole study took pretty long and that means that there were also times that things did not go so smoothly of course and that many things failed or that we got quite some experiments to work with nice supportive data, but that did not make it in the manuscript. We also moved labs in between – which also did not simplify matters – but I am really glad with the final result of the work.
Finite Element simulations of progenitor cell sorting using relative interfacial tension distributions determined in vitro and in vivo. Movie 4 in Krens, et al. 2017.
What next for you following this work?
GK Momentarily I am turning my focus to the more technical part of the lab-work that I have been doing. We needed to do quite some ‘expert experiments’, which also demanded quite some manual annotation of image data. Automation of the (image-)analysis of these experiments will be beneficial to a lot of my colleagues. I will also find it really interesting to further get to know if there is a specific component in the IF that might effect cells to have physical properties: what is the composition of IF, how is the composition regulated and I remain curious to find out why mesendodermal germ layer progenitor cells actually end up at the inside of the zebrafish gastrula.
And where will this paper take the Hesienberg lab?
We got particularly interested in understanding how interstitial fluid is accumulating within the early zebrafish blastula, and whether this accumulation is important for cell/tissue morphogenesis and cell fate specification during gastrulation. Our preliminary data clearly support a model where differences in the osmolarity between the inside and outside of the embryo trigger interstitial fluid accumulation and we are currently trying to find out how this affects gastrulation.
Finally – what do you get up to when you are not in the lab?
GK People who know me, know that I do not have to think long to give a reply to this question: I am a passionate mountain biker. The fact that we moved closer to the mountains is a big bonus for someone that come from a country that is know to be extremely flat and below sea level. Besides that, I do some running and drawing.
A postdoctoral H2020 funded position is available, to develop a deeper understanding of the relevance of in vivo Drosophila models to study pathologies of disease, within Acies Bio – a research driven biotech company based in Slovenia.
We welcome applicants who hold a PhD in a relevant subject, or are nearing completion. A successful candidate would be an independent researcher, experienced in disease model development: particularly in vivo models in the fruit fly Drosophila melanogaster. Expertise in molecular biology model development, phenotypic characterisation, and candidate compound efficacy evaluation is desirable. The Innovation Associate will be responsible for developing and implementing phenotypic assays on existing disease models as well as generating new models for disease.
The researcher will have access to state-of-the-art facilities and work in an international and interdisciplinary setting. The candidate can expect to maintain an active international research profile through publications, academic partnerships and attendance at conferences (including the EDRC 2017). They will also gain insight into commercial aspects of drug discovery research programmes and receive mentorship in the area of intellectual property protection and IP-driven experimental design strategies. This 1 year fixed post will commence on 01/09/17, however there would be a strong, realistic desire towards continuing employment.
This position must comply with MSCA mobility criteria (<12 months work in Slovenia since Sept 2014), and relocation expenses would be covered. The Associate will have the benefit of working in a lively European capital (integration fully supported with afternoon language lessons), and living in an ideally located Central European country with access to the Mediterranean, the Julian Alps, and 4 neighbouring countries. Slovenia has an MSCA country correction coefficient of 86% – reflecting the low cost of living.
For further information and to submit an application for this vacancy visit
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Surprisingly, previous studies have suggested that the core SAC component MAD2 might be dispensable during spermatogenesis in mice, but Imrul Faisal and Liisa Kauppi now re-investigate the role of MAD2 in male meiosis (p. 
On p. 
Several genetic determinants of these characteristics have been identified, including the Q gene, which encodes an AP2-like transcription factor. Cultivated wheats generally have the hypermorphic Q allele, whereas wild varieties have the q variant, associated with lower AP2 activity. It is known that AP2 factors can be regulated by the miR172 miRNA, and that Q bears a mutation in the miR172 binding site, but how this putative regulation affects the phenotypes associated with domestication has been unclear.
(4 votes)