Completed genome of platyfish may give clues to deadly skin (and scale?) cancer

Scientists have decoded the genome of platyfish, which are prone to developing melanomas (shown above) along the tail and fins. Credit: Texas State University

The platyfish (scientific name: Xiphophorus maculatus), a cousin to the guppy and a popular aquarium pet averaging about two inches in length may not seem like a spectacular organism. The small fish who likes to swim in schools may not have its own hour on the discovery channel, either.But, thanks to an international team of scientists who have successfully completed the genome of this fish, some clues regarding unknown details on cancers such as melanoma, may begin to surface.

What makes the platyfish special is that is shares many unlikely characteristics with humans–such as courting its mate and giving live birth to its young. But, scientists’ main reason for studying the organism stems from its tendency to develop melanoma, a deadly skin cancer. While platyfish come in a variety of reds, oranges, silvers and speckles, the spread of melanoma causes their scales to have dark spots that are easily seen.

“In platyfish, melanomas typically develop as black splotches along the tail and fins,” senior author Wesley Warren, PhD, a geneticist at Washington University’s Genome Institute, said. “These fish are an ideal model for exploring the many unknowns of cancer, including how, when and where it develops in the body as well as its severity.”

Just like humans, the platyfish genome consists of approximately 20,000 genes. But, unlike human chromosomes that have changed overtime, the chromosomes of platyfish and most other fishes have stayed the same for more than 200 million years.

“It’s very much a mystery as to why these chromosomes are so structurally similar among fish species over long time periods of evolution because they live in vastly different aquatic environments,” Warren.

The genome mapping project was led by scientists at Washington University, the University of Würzburg in Germany and Texas State University and the complete findings are published in Nature Genetics.

“Now that we have the genome in hand, we can tease apart the way genes interact with one another to cause melanoma,” co-lead author Manfred Schartl, PhD, of the University of Würzburg in Germany, said. “Just as in human melanoma, genes that play a role in pigment cells also influence the development of melanoma in platyfish.”

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Reference: 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, Fuerstenberg S, Boore J, Searle S, Postlethwait JH and Warren WC. The genome of the platyfish, Xiphophorus maculatus, provides insights into evolutionary adaption and several complex traits. Nature Genetics. March 31, 2013.

Tags: Amores A, Bisazza A, Boore J, Braasch I, Catchen J, Chalopin D, Fuerstenberg S, Garcia T, genome mapping, genome mapping project, health, Hillier L, Lesch K-P, melanoma, Minx P, platyfish, Postlethwait JH, RB, Schartl M, science, Searle S, Shen Y, Texas State University, University of Würzburg in Germany, Volff J-N, Walter, Warren WC, Washington University, Wilson RK, xiphophorus maculatus