Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Study shows how the zebrafish gets his stripe

25.09.2007
Scientists have discovered how the zebrafish (Danio rerio) develops one of its four stripes.

Their findings add to the growing list of tasks carried out by an important molecule that is involved in the arrangement of everything from nerve cells to reproductive cells in the developing embryo.

The research focused on a particular zebrafish mutant known as choker, which is distinctive because one of the four stripes running down its side is missing, and it has a dark collar around its neck instead.

Dark spots and stripes in fish, amphibians and reptiles are usually caused by a type of cell, known as a melanophore, which contains high quantities of the pigment melanin.

Using time-lapse photography, the team put together movies showing how the melanophores migrate in developing embryos of both the wild-type (naturally occurring) zebrafish and the choker mutant.

At first, cells migrate through the neck region in both wild-type and choker mutant fish to generate two stripes. Then, whilst cell migration ceases in the neck region of the wild-type embryo, melanophores in the choker mutant exit from the two stripes and busily cluster around the collar region of the developing fish.

“It is as though someone has put up ‘keep off the grass’ signs in the wild-type zebrafish to keep the melanophores in separate paths (stripes),” said Dr Robert Kelsh from the University of Bath who led the study which was published in the journal Development.

“The melanophores stay on the footpath of the developing stripe in a very orderly fashion, but in choker it’s as though these signs have been knocked down, and the pigment cells run all over the grass between the footpaths.”

The breakthrough in understanding how this happens came with the discovery that a molecule, known as Sdf, appears to have some role in encouraging melanophore cell migration.

Sdf is a known cell migration guidance molecule, with roles including regulating the migration of neurones in the fish’s central nervous system and germ (reproductive) cells.

When researchers looked where the molecule was found, they could see that it appeared to line up in the same pattern as a third stripe in the wild-type zebrafish, and around the collar in choker mutants.

“The correlation of Sdf expression and melanophore pattern in wild-type and choker mutants embryos was so striking, it immediately suggested that Sdf plays a key role in dictating the pattern of at least this one stripe in zebrafish,” said Dr Kelsh.

To test the theory, researchers positioned a bead soaked in human Sdf onto the skin of zebrafish embryo. Even in the choker mutant, this bead attracted the melanophores to where it was implanted.

The researchers also used a technique known as protein knockdown to reduce the amount of Sdf produced in the embryo, and were able to partially remove the third stripe in wild types and to reduce colouring in the neck of the choker mutant.

“Sdf is really important, not just for pigmentation but also the development of neurons and germ cells,” said Dr Kelsh.

“The other three stripes must have some other mechanism controlling their development. We are still looking into how these other three stripes might form.

“Pigment pattern formation is a classic problem in developmental biology and whilst there have been lots of mathematical theories on how the fish make different patterns, the underlying genetics have been unclear.

“Similarities between animals mean that we can take what we learn about the development of these simple models, and begin applying them to more complex systems, such as humans.”

The research involved scientists from the universities of Bath (UK), Cambridge (UK), Oregon (USA) and Sheffield (UK) and the Cardiac Research Institute (Sydney, Australia).

The research is funded by the Medical Research Council (UK) and the University of Bath.

Andrew McLaughlin | alfa
Further information:
http://www.bath.ac.uk/news/2007/9/25/zebrafishstripe.html

Further reports about: Migration Mutant Sdf choker developing melanophore neck stripe wild-type zebrafish

More articles from Life Sciences:

nachricht Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>