One of my (many) geeky passions is the overlap between art and science: Science as art (think of the Nikon image competition) or art inspired by science. That last category includes these lecture announcement posters from UNC Chapel Hill.

Poster for a recent lecture by Peter Wilf

The posters are designed by developmental biologist Bob Goldstein, and printed by The Merch in Carrboro, who normally print posters for dance parties rather than biology lectures!

If you’ve seen the posters online before, I may have been responsible for that as well… I wrote about them on my old blog in early 2009, and the link got picked up by BoingBoing and subsequently by The Scientist, who interviewed Bob by phone about his posters (see video below).

In an additional small world connection, Bob’s former graduate student Erin started writing for the Node, featuring pretty images from papers. That brings us full circle from “art inspired by science” to “science as art”.

(9 votes)

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Somites are the building blocks of the vertebrae, skeletal muscle and dermis…literally and figuratively.  Somites define the segmented features of vertebrate embryos, and are repeated blocks of epithelial cells formed sequentially, from anterior to posterior, and at regular intervals on either side of the neural tube.  A paper in the November 1 issue of Development helps our understanding of the signaling cascade that acts during somitogenesis.

Integrins are transmembrane proteins that function in cell adhesion, migration, signaling and proliferation, which are all important processes during development.  Previous research had demonstrated a role for integrins in the formation of somites in certain organisms, but the exact requirement or mechanism was not clear.  This month in Development, Rallis and colleagues show that β1-integrin is important for formation of all somites in chick embryos.  They also found that β1-integrin functions in “outside-inside” signaling, meaning that signals from the extracellular matrix bind to integrins and result in the activation of signaling within the cell.  Specifically, β1-integrin functions cell-autonomously to activate Wnt and Notch signaling, via ILK, which leads to compartmentalization and boundary formation of somites.

Images above show a schematic of a chick embryo (A) and β1-integrin (red) localization during somite formation (TOPRO3, in blue, stains nuclei and shows somite organization).  β1-integrin was found at the borders of both older, anterior somites (B) and newly formed somites (C).  There was also an anterior-posterior gradient of β1-integrin in the presomitic mesoderm prior to somite formation (white versus yellow arrow in D, and zoomed image in E).  Interestingly, β1-integrin was found in the core of somites (F, arrowhead), and showed a continued segmented pattern in much later embryos (G).

Reference:  Charalampos Rallis, Sheena M. Pinchin and David Ish-Horowicz (2010).  Cell-autonomous integrin control of Wnt and Notch signalling during somitogenesis.  Development 137, 3591-3601.  Paper can be found here.

(9 votes)

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From Arabidopsis to zebrafish, every species –living and extinct – is linked to every other species. Not just metaphorically, but also literally on the Tree of Life website, which ambitiously aims to create a linked database with information on every species and group of organisms.

(Image from Tree of Life, used under Attribution-NoDerivs 3.0 Unported license)

Launched in 1995 the site was originally developed for biologists who might need to find phylogenetic information, but got so many requests from students and educators that they expanded their reach and now Tree of Life also provide “treehouse” pages, featuring accessible information for a wider audience.

Incidentally, the educational aspect of Tree of Life reminded me of another project I recently heard about: Phylo is a trading card game of which the cards are produced online by volunteers. The cards can then be used to teach children about biodiversity, much like the treehouse pages on Tree of Life

Like Phylo, content on Tree of Life is also contributed by volunteers. Scientific content is peer reviewed, and contributed by scientists and science educators, but anyone can submit media (such as images) to the site.

There’s a lot to be discovered on the site, so have a look around. It’s a work in progress, as it will be a long time until they’ve filled it with complete pages for every organism!

(1 votes)

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For anyone who has never been, Cold Spring Harbor Laboratories organize some really great conferences. The axon guidance, synaptic plasticity and regeneration conference, formerly the axon guidance synaptogenesis and plasticity conference, is biannually held in September and other than occasional heavy showers you can expect some fabulous weather. The campus, with the harbor that runs alongside it, is very beautiful especially with the first hint of autumn colour.

This year axon guidance and regeneration seemed to predominate over synaptic plasticity. The first day started with an evening session and whilst the jetlag can be a problem one of the other great things about these conferences is ‘The Leading Strand’, a password protected website that allows meeting participants to re-watch talks for a limited period of time after the conference. Sadly, but perhaps understandably, this appears to be becoming less and not more popular. Perhaps people feel that it’s unnecessary since there are no parallel sessions that force you to miss something.

The first session opened with some of our favourite axon guidance molecules Slit, Robo, Ephs and Ephrins. Adam Guy from the Neuronal Growth Mechanisms Lab, RIKEN Brain Science Institute, got the dubious honour of closing the session with a late night talk showing chemorepulsion of sensory axons in the chick spinal cord by a phospholipid, suggesting a specific axon guidance role and possibly a novel group of guidance molecules.

Wednesday opened with one of the few sessions that focused on synapses and circuits. This included a very interesting talk by Nicola Allen on an astrocyte secreted factor that can induce synapse formation in vitro. Nicola went on to describe the biochemical identification of the molecule and to show that hippocampal slice cultures from the knockout mouse do have an electrophysiological phenotype. The day finished with a plenary lecture which by Peter Devreotes on chemotaxis in which he sort to bring together the many different strands of research and show how they might fit together. It was a fascinating but rapid overview of the topic and there is clearly still much left to understand.

Thursday was easily the busiest day of the conference with talks until 3.30pm, a poster session until 5.30pm and then an evening session of talks from 7.30pm. You certainly get your money’s worth of science at Cold Spring Harbor!

Friday began with the second session on stem cells, regeneration and disease. In vivo laser axotomy appears to be the tool of choice for investigating regeneration at the moment and in combination with zebrafish and C.elegans, models which are so amenable to manipulation and live imaging, will certainly yield much useful and interesting data. After lunch we were treated to two more plenary lectures, the first given by Tom Jessell on ‘The nerves and networks of spinal motor control’ and the second by Eva Marder on ‘Compensation in robust network performance’, both were truly captivating and quite humbling.

The conference dinner on Friday evening was preceded by a very impressive performance by the up and coming violinist Hahn-Bin. After such a cultured beginning it was all downhill from then on…the less said about the drunken dancing the better!

(3 votes)

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Dear Reader,

My name is Dávid Molnár, I’m a third year Ph.D. student in the Department of Human Morphology and Developmental Biology at Semmelweis University (Budapest, Hungary). I’d like to share the story of my summer internship with You!

Thanks to the generous offer of Guojun Sheng, the team leader of the Laboratory for Early Embryogenesis in RIKEN Center for Developmental Biology (Kobe, Japan), I could spend three months in his lab in a Japanese world leading institute. It changed my working progress, my view on science and the way how I got there taught me a lot.

in the front: Guojun Sheng in the background: Cantas Alev and Ruben Buys

Almost a year ago in September of 2009, I lived the ordinary life of Hungarian Ph.D. students. The preparation for the ISDB 2009 conference brought a little excitement into my days and started a series of unpredicted events. Those days were also unique for me, because that was the first time in my life when I travelled by plane.

In the charming city of Edinburgh I met many people, who had just been well known names on the headers of articles before, but there I saw the persons themselves behind the papers. In the labyrinth of the exhibitors’ stands I found the desk of RIKEN Center for Developmental Biology. I had known before that it was a melting-pot of scientists from all over the world studying developmental biology on advanced level but at that time , due to my lack of foreign research experience, I couldn’t imagine how this kind of institute worked. I took a RIKEN brochure. At the end of the conference I realized that my baggage was heavy, so I started sorting out all the papers and tearing out the useful pages. That was the moment when I saw a report of Brendan McIntyre’s work who was a post doc in Dr. Sheng’s lab. The key words “blood, hematopoiesis, CD34, chicken embryo” aroused my interest immediately.

After the conference several weeks elapsed until I read those torn pages again. That time we just started introducing in situ hybridization to our techniques. We were interested in different hematopoietic markers e.g. CD34, but there was no commercial antibody against the chicken equivalent of this protein, and we were not that experienced in molecular biology methods. I sent an e-mail to Brendan McIntyre who was really helpful. He had already left Japan but answered my questions and forwarded my e-mail to team leader Guojun Sheng. From that time we exchanged plenty of letters with Dr. Sheng in which he shared all his remarks and advice about the ideas and experiments we were planning.

Surprisingly in late February I got an e-mail form Dr. Sheng: he offered me a short time internship in his laboratory in the RIKEN Center for Developmental Biology.

Then a hurrying organization started with visa application, obtaining the certificate of eligibility, exchanging letters, photos numerous documents. Because my financial sources were limited I had to look for external funding. Coincidentally one of my collegues after a lunch break mentioned an application which supports young researchers. We checked it out together – it was the Development Travelling Fellowship. First I estimated a low chance to receive the scholarship, but I convinced myself to try it. Getting closer and closer to the 1st of June, the determined date of departure, I got more and more excited. Nearly one week before my trip I got the result: I would get support from Development. It was unbelievable how lucky I was!

In less than a year I ended up with an invitation to Japan and a successful grant application, and soon after my first flight I got the chance to travel by plane again – immediately to the other half of the world. Since then I’ve been frequently thinking about what had happened if I hadn’t taken a brochure, if I hadn’t taken those torn pages, if I hadn’t been brave enough to write an e-mail to Dr. Sheng. The main conclusion of the previous year: always go with eyes wide open, because you never know what sort of chances will be served by life!

The turtle eggs have just arrived!

My experiences in Japan absolutely fit into this series of successful events. In Guojun Sheng’s lab I spent three hard-working months under the supervison of Cantas Alev. During this time I tasted a little molecular biology in the fascinating environment of RIKEN CDB. I learned how to generate in situ probes and carry out whole mount in situs. I worked on N^o1 machines in the company of great scientists. Of course I traveled around the Kansai area and I managed to visit Okinawa too, but the main advantage of my stay – beside its scientific impact- is that I got to know how life goes on in Japan. At RIKEN CDB I experienced the atmosphere of high level science outside the institute I saw a peaceful and safe country with delicious food, inspiring history, beautiful geography and I was surrounded by kind and friendly people. I really enjoyed it and it’s easy to get used to it!

Unfortunately my internship finished just when I felt the people around me were pretty close to myself and work raised the possibilities of different projects. Nowadays I usually think about my friends who I met in Japan.

This year taught me to look for the chances and to be brave enough to use them, to realize the necessity of foreign experiences and how to fit to a changed environment.

I’m really thankful to Guojun Sheng and Cantas Alev. Their support brought me one step closer to molecular biology and extended my view on other fields of developmental biology. I truly believe that this three-month internship opened new doors which may result in a long-time collaboration between the two laboratories.

At last but not least I must say thank you to each and every member in the Laboratory for Early Embryogenesis (in alphabetical order): Cantas Alev, Manjula Brahmajosyula, MengChi Lin, Hiroki Nagai, Yukiko Nakaya, Fumie Nakazawa, Kanako Ota, Guojun Sheng, Erike Sukowati, Wei Weng, Yu Ping Wu. I’m also thankful to Ms. Naoko Yamaguchi who helped arrange the visit.

Finally I’d like to express my gratitude to all those at The Company of Biologists and Development who spent time on reading my application and supported my plan to come true!

Laboratory for Early Embryogenesis – RIKEN CDB – Kobe, Japan

Developmental Biology and Immunology Lab – Department of Human Morphology and Developmental Biology, Semmelweis University – Budapest, Hungary

(5 votes)

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Here are the research highlights from the current issue of Development:

Oct1: essential for trophoblast development

Most POU family transcription factors are temporally and spatially restricted during development and play pivotal roles in specific cell fate determination events. Oct1 (Pou2f1), however, is ubiquitously expressed in embryonic and adult mouse tissues; so, does Oct1 have a developmental role? On p. 3551, Fatima Cavaleri and colleagues report that Oct1 regulates trophoblast development during mouse embryogenesis. The researchers generate Oct1-null embryos and show that they fail to develop beyond the early primitive streak stage. Analysis of the mutant embryos reveals that they lack normal maternal-embryonic interfaces because of reduced extra-embryonic ectoderm (ExE) formation and the absence of the ectoplacental cone – two extra-embryonic tissues generated from the trophectoderm cells that overlie the inner cell mass (which forms the embryo). Other experiments indicate that Oct1 loss is incompatible with the derivation of trophoblast stem cells, which normally reside in the ExE. The researchers suggest, therefore, that Oct1 is primarily required for the maintenance and differentiation of the trophoblast stem cell compartment during early post-implantation development.

Schwann cells: more than just insulators

How neurons connect to their targets during embryogenesis has been intensively studied, but what maintains the position and connections of nerves during postembryonic growth? To investigate this, William Talbot and colleagues study the development of the posterior lateral line nerve (PLLn) in zebrafish embryos and larvae (see p. 3643). Using transmission electron microscopy, the researchers show that the PLLn – a peripheral nerve that innervates sensory organs in the epidermis – initially grows in the epidermis but that shortly after axon outgrowth, the epidermal basement membrane degrades and reforms on the nerve’s opposite side, thereby repositioning the nerve into the subepidermal space. Analysis of mutant and chimeric embryos shows that Schwann cells, which myelinate peripheral nervous system axons, are required for this process; without them, the PLLn becomes severely disorganised. Thus, by remodelling tissues in the vicinity of nerves, Schwann cells, which are traditionally regarded as static insulators, could play an important role in the proper organisation of nerves that innnervate other sensory organs during postembryonic growth.

WUSCHEL robustly plants stem cell homeostasis

Plant stem cell populations are maintained by the precise coordination of stem cell division and the rates of cell division and differentiation among stem cell progenitors. In the growing tips of higher plants (shoot apical meristems, SAMs), stem cell daughters produced by infrequent stem cell division in the central zone (CZ) are displaced towards the surrounding peripheral zone (PZ), where they divide faster and their progeny differentiate into leaves or flowers. Now, Venugopala Reddy and co-workers report that the homeodomain transcription factor WUSCHEL (WUS) mediates stem cell homeostasis in Arabidopsis (see p. 3581). The researchers use transient manipulation of WUS expression and live imaging to show that elevated WUS levels in the CZ induce CZ expansion and increase PZ cell division rates. Conversely, decreased WUS levels lead to a smaller CZ, reduced PZ cell division rates and increased responsiveness of PZ cells to the plant hormone auxin, which leads to enlarged organ primordia. Thus, by regulating stem cell numbers and growth and differentiation patterns, a single transcription factor robustly mediates plant stem cell homeostasis.

Haematopoietic cluster locations made transparent

Haematopoietic clusters – cell aggregates that are associated with endothelium in the large blood vessels of midgestation vertebrate embryos – play a pivotal but poorly understood role in the formation of the adult blood system. To date, the opaqueness of whole embryos has prevented the systematic quantitation or mapping of all the haematopoietic clusters in mouse embryos but, on p. 3651, Tomomasa Yokomizo and Elaine Dzierzak remedy this situation. Using a technique to make whole mouse embryos transparent, combined with immunostaining and three-dimensional confocal microscopy, they show that the number of clusters peaks at embryonic day 10.5. Clusters are heterogeneous, they report, and localise to specific vascular subregions, such as the middle subregion of the aorta near to its junction with the vitelline artery. Finally, by combining flow cytometry and functional studies, the authors demonstrate that haematopoietic progenitor and stem cells are enriched within the cluster population. Together, these results provide novel insights into the spatial development of the adult blood system in mice.

Chordin downregulation waves on aortae fusion

During development, extensive remodelling of the embryonic vasculature, the first organ to develop, ensures that the embryo’s cells are constantly supplied with oxygen and nutrients. The first major vascular remodelling event in mammalian and avian embryos is fusion of the bilateral dorsal aortae at the midline to form the dorsal aorta. Takashi Mikawa and co-workers now show that a developmental switch in notochord activity signals this fusion in chick and quail embryos (see p. 3697). Prior to fusion, the researchers report, the notochord secretes positive and negative factors that together block the initiation of aortae fusion. Notably, whereas the expression of positive vascular regulators is maintained during fusion, the expression of negative regulators such as chordin, an antagonist of the positive regulator BMP, is downregulated along the anteroposterior axis. The discovery of this novel mechanism for modifying vascular pattern – modulation of vascular inhibitors without changes in positive vascular regulator levels – could aid the development of treatments for vascular injury.

Cut to fly airway remodelling

In insects that completely metamorphose, such as Drosophila, embryonically specified imaginal cells remain dormant until the larval stages when their coordinated proliferation and differentiation generates various adult organs. Now, on p. 3615, Chrysoula Pitsouli and Norbert Perrimon describe how embryonic cells – spiracular branch (SB) tracheoblasts – remodel the Drosophila abdominal airways during metamorphosis. The adult fly tracheal system consists of branched tracheal tubes (which transport air into the insect’s body) and spiracles (the external respiratory organs, which are surrounded by epidermal cells). The researchers show that embryonic SB tracheoblasts are multipotent cells that express the homeobox transcription factor Cut, which is necessary for their survival and normal development. SB tracheoblasts, they report, give rise to three distinct cell populations at the end of larval development, which generate the two components of the adult tracheal system and the surrounding epidermis. This dissection of the molecular events that underlie the formation of an adult tubular structure in Drosophila might shed light on mammalian tubular organ development, suggest the researchers.

Also…

In the first of our new Evolutionary crossroads in developmental biology series, Prigge and Bezanilla introduce Physcomitrella patens, a moss from this ancient, non-vascular plant lineage, studies of which are distinguishing ancestral developmental mechanisms from those that are novel innovations in flowering plants. See the Primer on page 3535.

This article is the first in a series of Primers on organisms and phyla that have been particularly informative for studying the evolution of developmental mechanisms and morphology. Other articles in this series will be published over the next 12 months.

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The FASEB Excellence in Science Award is awarded annually to a woman whose research has made an exceptional contribution to the field of biological sciences. In 2011, this award will go to developmental biologist Gail Martin, of the University of California, San Francisco.

Martin’s current work focuses mainly on the role of FGF signalling in organ development, but in 1981 she was the first  to isolate embryonic stem cells from mouse blastocysts grown in vitro, and in fact coined the term “embryonic stem cell”.

The Society for Developmental Biology (SDB) has written a profile of Gail Martin that is currently in press at Developmental Biology. Martin was president of the SDB in 2006-2007, and in her interview she addresses her passion for mentoring students and postdocs, and her interest in sharing unpublished results. She will receive her award at the 2011 SDB meeting, to be held in Chicago in July.

(3 votes)

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In the US, basic plant research is relatively underfunded compared to other fields, with most of the available money going directly towards the development of practical agricultural applications.

Last year, the Howard Hughes Medical Institute (HHMI) organized a meeting called “Future Horizons in Plant Science”, where select scientists in the field concluded that there was a need for a funding boost in plant science. Now, the HHMI, together with the Gordon and Betty Moore Foundation (GBMF) is providing this boost in the form of $75 million for 15 researchers over the next five years.

This is a one-time competition to specifically target plant researchers at a time when they are not receiving as much funding as their colleagues working on animal organisms. To qualify, scientists need to currently be working as tenured or tenure-track researcher at a US institution. Applications for the new grants are due on November 9.

See HHMI press release for full details, including a link to the application website with even more information.

(Arabidopsis painting by Emmanuel Boutet through CC-BY-SA license on Wikimedia commons.)

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Hello to all of you Node readers!  My name is Erin Campbell and I’m the blogger behind HighMag Blog, a blog that features cell biology images a few times a week.  The great Eva Amsen contacted me about featuring some images on The Node, so I’m excited to be part of this growing community forum.  The first image I’m blogging about is from a paper in the October 1 issue of Development, and features the biologically complex and visually stunning Drosophila ovary.

Ovarian cyst development begins in the germarium, with a stem division that produces the cystoblast, which then divides 4 more times.  One cell in this 16-cell mass eventually becomes the oocyte, and the remaining cells serve as nurse cells to support the growth of the oocyte.  This 16-cell cyst then becomes a separate egg chamber after being surrounded by follicle cells and budding off of the germarium.  The hierarchy of signals and events that allow the differentiation of the cyst has been well studied, and a recent paper fills in the gaps in our understanding of this process.

Tastan and colleagues report that the Drosophila homolog of the human ataxin 2-binding protein 1 (A2BP1) gene functions in the intermediate stages of cyst differentiation, bridging the expression of early and terminal differentiation markers.  Mutations in A2BP1 cause defects in cyst differentiation, as shown in the images above.  Germline cells are labeled in green using anti-VASA antibodies, membranes are labeled in red using an anti-1B1 antibody, and DNA is labeled in blue.  Compared with control ovaries, mutants exhibit a range of phenotypes:  A2BP1^CC00511 cysts have extra nurse cells, A2BP1^f02600 cysts exhibit a mildly tumorous phenotype, and A2BP1^f01889 cysts have an extreme tumorous phenotype.

Reference: Ömür Y. Tastan, Jean Z. Maines, Yun Li, Dennis M. Mckearin and Michael Buszczak (2010). Drosophila Ataxin 2-binding protein 1 marks an intermediate step in the molecular differentiation of female germline cysts. Development 137, 3167-3176. Paper can be found here.

(10 votes)

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Robert Edwards has just been announced as winner of the 2010 Nobel Prize in Physiology or Medicine, for his work on in vitro fertilization (IVF)

We speculated about the winners a few weeks ago, and he was not among anyone’s guesses, but this is a very exciting and timely choice. Just last Friday I mentioned that the Human Fertilisation and Embryology Authority will likely be cut. This is the body that regulates all IVF research in the UK, where Edwards work took place. Hopefully this award will bring the relevance of such regulatory bodies in the spotlight again.

Edwards worked together with gynecologist Patrick Steptoe, who died in 1988. Nobel Prizes are not awarded posthumously, which explains why he’s not included in the award.

The Nobel Prize website will be livestreaming all announcements of Nobel Prize winners this week. The Chemistry prize – which has predominantly been awarded to biology-related research the past decade – is announced on Wednesday.

(6 votes)

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