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 Team pinpoints genes that make plant stem cells, revealing origin of beefsteak tomatoes
26.05.2015 | Cold Spring Harbor Laboratory

nachricht DNA double helix does double duty in assembling arrays of nanoparticles
26.05.2015 | DOE/Brookhaven National Laboratory

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Basel Physicists Develop Efficient Method of Signal Transmission from Nanocomponents

Physicists have developed an innovative method that could enable the efficient use of nanocomponents in electronic circuits. To achieve this, they have developed a layout in which a nanocomponent is connected to two electrical conductors, which uncouple the electrical signal in a highly efficient manner. The scientists at the Department of Physics and the Swiss Nanoscience Institute at the University of Basel have published their results in the scientific journal “Nature Communications” together with their colleagues from ETH Zurich.

Electronic components are becoming smaller and smaller. Components measuring just a few nanometers – the size of around ten atoms – are already being produced...

Im Focus: IoT-based Advanced Automobile Parking Navigation System

Development and implementation of an advanced automobile parking navigation platform for parking services

To fulfill the requirements of the industry, PolyU researchers developed the Advanced Automobile Parking Navigation Platform, which includes smart devices,...

Im Focus: First electrical car ferry in the world in operation in Norway now

  • Siemens delivers electric propulsion system and charging stations with lithium-ion batteries charged from hydro power
  • Ferry only uses 150 kilowatt hours (kWh) per route and reduces cost of fuel by 60 percent
  • Milestone on the road to operating emission-free ferries

The world's first electrical car and passenger ferry powered by batteries has entered service in Norway. The ferry only uses 150 kWh per route, which...

Im Focus: Into the ice – RV Polarstern opens the arctic season by setting course for Spitsbergen

On Tuesday, 19 May 2015 the research icebreaker Polarstern will leave its home port in Bremerhaven, setting a course for the Arctic. Led by Dr Ilka Peeken from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) a team of 53 researchers from 11 countries will investigate the effects of climate change in the Arctic, from the surface ice floes down to the seafloor.

RV Polarstern will enter the sea-ice zone north of Spitsbergen. Covering two shallow regions on their way to deeper waters, the scientists on board will focus...

Im Focus: Gel filled with nanosponges cleans up MRSA infections

Nanoengineers at the University of California, San Diego developed a gel filled with toxin-absorbing nanosponges that could lead to an effective treatment for skin and wound infections caused by MRSA (methicillin-resistant Staphylococcus aureus), an antibiotic-resistant bacteria. This "nanosponge-hydrogel" minimized the growth of skin lesions on mice infected with MRSA - without the use of antibiotics. The researchers recently published their findings online in Advanced Materials.

To make the nanosponge-hydrogel, the team mixed nanosponges, which are nanoparticles that absorb dangerous toxins produced by MRSA, E. coli and other...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International symposium: trends in spatial analysis and modelling for a more sustainable land use

20.05.2015 | Event News

15th conference of the International Association of Colloid and Interface Scientists

18.05.2015 | Event News

EHFG 2015: Securing health in Europe. Balancing priorities, sharing responsibilities

12.05.2015 | Event News

 
Latest News

Analytical lamps monitor air pollution in cities

26.05.2015 | Ecology, The Environment and Conservation

DNA double helix does double duty in assembling arrays of nanoparticles

26.05.2015 | Life Sciences

Turn That Defect Upside Down

26.05.2015 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>