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
Flow of cerebrospinal fluid regulates neural stem cell division
21.05.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt
Chemists at FAU successfully demonstrate imine hydrogenation with inexpensive main group metal
21.05.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.
The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...
Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.
Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...
A team of scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg investigated optically-induced superconductivity in the alkali-doped fulleride K3C60under high external pressures. This study allowed, on one hand, to uniquely assess the nature of the transient state as a superconducting phase. In addition, it unveiled the possibility to induce superconductivity in K3C60 at temperatures far above the -170 degrees Celsius hypothesized previously, and rather all the way to room temperature. The paper by Cantaluppi et al has been published in Nature Physics.
Unlike ordinary metals, superconductors have the unique capability of transporting electrical currents without any loss. Nowadays, their technological...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
18.05.2018 | Power and Electrical Engineering
18.05.2018 | Information Technology
18.05.2018 | Information Technology