Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Surprising Findings in Fish Genome

09.04.2013
It is a popular aquarium fish: the platyfish, Xiphophorus maculatus. It is valued by researchers as an important model organism in the search for genetic trigger factors of skin cancer. Together with colleagues from the USA, University of Würzburg biochemist Manfred Schartl has decoded the genome of this fish species.
It varies in color from cornflower blue to orange, red or silver with a broad range of color patterns. The platyfish, also known as platy, is one of the most popular species of aquarium fish today. Besides its striking coloration, it has another characteristic: While the females of most fish species lay eggs, which are fertilized afterwards, the platy species is a livebearer. It can give birth to up to 100 young at a time.

An animal model of skin cancer

The fish species Xiphophorus maculatus is of interest to scientists for another reason: If you cross certain strains of this species with each other, their progeny always develops skin tumors. Due to the cross-breeding, the finely adjusted regulatory system of genes gets out of control, leading to the formation of cancer. The tumors produced in this way correspond to malignant melanoma in humans.

A few years ago, Manfred Schartl identified one of these oncogenes and described its properties. Together with researchers from Washington University St. Louis and Texas State University/USA, the head of the Department for Physiological Chemistry at the Biocenter of the University of Würzburg has now deciphered the complete genome of this fish species. The research is published in the current issue of the journal Nature Genetics.

"With our knowledge of the genome, we can now trace the participation and interplay of individual genes in the development of skin cancer. Even in the initial analysis, we have found several interesting candidates," says Schartl. This knowledge about the fish can be readily applied to humans: "The very genes that trigger skin cancer in human pigment cells are responsible for the development of melanoma in Xiphophorus," the geneticist explains.

20,000 genes – and some surprises

The research team identified 20,000 genes in the genome of Xiphophorus – about as many as are contained in the human genome. The comparison with related species of fish brought some surprises.

Like many other fish species, Xiphophorus exhibits complex behavioral patterns, e.g. with regard to the courtship of females, parental care of offspring, foraging and fighting behavior or the avoidance of threats. With respect to behavioral complexity, the fish greatly surpass the other so-called lower vertebrates, such as frogs, salamanders, snakes, turtles and lizards – although the latter are much more closely related to birds and mammals in the evolutionary tree.

Gene copies make complex behavior possible

Why this is the case remained a mystery for a long time. A possible explanation can be found in the genes that are associated with perception and cognition. Klaus-Peter Lesch, the head of the Department for Molecular Psychiatry at the University of Würzburg, has studied such genes in humans and in laboratory mice for several years. Schartl and Lesch found that many of the genes responsible for these areas exist in the platyfish as well.

This finding led the researchers to analyze the genomes of other fish in this respect as well. "To our surprise, we discovered that many of these genes do not only exist as a single copy in the genome of the fish as is the case in terrestrial vertebrates, but even in duplicate," says Schartl. They are relics of a whole genome duplication event in an ancestor of today's modern fish. According to the scientists, the additional second copy is now free to take on new responsibilities in brain function. Thus, the fish had a larger set of tools available for the development of complex behavioral patterns as compared to other vertebrates.

The same traits developed independently

The fact that Xiphophorus females give birth to live young was also of interest to the scientists. When they compared the fish genome with that of mice and other mammals in this respect, they came across a series of further surprises: Although the trait of giving birth to live young developed in mammals and fish independently in the course of evolution, you can find identical genes in their genome.

It is true that the genes important for placenta function, yolk formation or ovum maturation exhibit "unique molecular changes", but they also possess commonalities in the molecular detail. "If the same biological characteristics evolve completely independently of each other, this obviously requires the same or at least very similar changes down to the molecular level of proteins and genes," says Schartl.

The genome is the "blueprint" of life. The sequencing of the platyfish genome provides cancer researchers, ethologists and all biologists interested in this organism with new opportunities to better understand the genes and their complex interactions in many important biological processes or in cancer development.

The genome of the platyfish, Xiphophorus maculatus, provides insights into evolutionary adaption and several complex traits. Schartl M, Walter, RB, Shen Y, Garcia T, Catchen J, Amores A, Braasch I, Chalopin D, Volff J-N, Lesch K-P, Bisazza A, Minx P, Hillier L, Wilson RK, Fuerstenber S, Boore J, Searle S, Postlethwait JH and Warren W. Nature Genetics. March 31, 2013. doi:10.1038/ng.2604

Contact person

Prof. Dr. Manfred Schartl, Department of Physiological Chemistry I, T: +49 (0)931 31-84149, email:Opens window for sending email phch1@biozentrum.uni-wuerzburg.de

Gunnar Bartsch | idw
Further information:
http://www.uni-wuerzburg.de

More articles from Life Sciences:

nachricht Cancer diagnosis: no more needles?
25.05.2018 | Christian-Albrechts-Universität zu Kiel

nachricht Less is more? Gene switch for healthy aging found
25.05.2018 | Leibniz-Institut für Alternsforschung - Fritz-Lipmann-Institut e.V. (FLI)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Powerful IT security for the car of the future – research alliance develops new approaches

The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.

Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...

Im Focus: Molecular switch will facilitate the development of pioneering electro-optical devices

A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.

The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

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...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

In focus: Climate adapted plants

25.05.2018 | Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

 
Latest News

In focus: Climate adapted plants

25.05.2018 | Event News

Flow probes from the 3D printer

25.05.2018 | Machine Engineering

Less is more? Gene switch for healthy aging found

25.05.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>