Genetic Archaeology Finds Clues to Pregnancy in Male Pipefish, Seahorses

Dec 05, 2006
Genetic Archaeology Finds Clues to Pregnancy in Male Pipefish, Seahorses
Scientists have discovered a new function for an "old" gene in pipefish. Credit: Siam Ocean World Aquarium, Bangkok

Genetic archaeology is providing a new clue to one of the greatest gender mysteries in the fish world: how did male pregnancy evolve in a family of fish?

A gene discovered in the gulf pipefish hints that a gene already busy with kidney and liver function may have learned new tricks in the male womb, said April Harlin-Cognato, a biologist at Michigan State University, and her colleagues. Their research results, funded by the National Science Foundation (NSF), are published in this week's online edition of the journal Proceedings of the National Academy of Sciences (PNAS).

"We're interested in the evolution of novelty and how novel traits evolve," Harlin-Cognato said. "Why is this the only fish that exhibits male pregnancy? It's one of the more difficult phenomena to explain in evolutionary biology, and we're wondering if it's a matter of old genes learning new tricks."

Gulf pipefish are a member of the same family as seahorses. They look like seahorses without the curved tails. As in seahorses, male pipefish accept eggs from the females, fertilize them and carry them in pouches. These brood pouches have evolved into complex organs able to nurture and protect the eggs.

Harlin-Cognato, who conducted the research along with Eric Hoffman of the University of Central Florida, and Adam Jones of Texas A&M University, found a new type of gene that codes for a protein called astacin, which performs a variety of functions in bony fish.

Through the course of evolution, some genes are copied. The copies can take on different functions while the original continues to perform the initial functions. However, this new gene, which Harlin-Cognato's team dubbed "patristacin" in deference to its suspected fatherly functions, is not a copy. Instead, it is likely a second job for astacin.

The researchers suspect that in its early days, possibly thousands of years ago, a patristacin gene likely assisted in kidney and liver function. They think it's possible the gene was drafted into supporting the then-newfangled male brood pouch. Eventually, patristacin became productive at its second job.

"These researchers have made a strong case that this gene is not a new one, but an old gene that has taken on additional work," said Michael Beecher, a program director in NSF's Division of Integrative Organismal Biology, which funded the research.

"We think it was a case of 'genetic moonlighting,'" Harlin-Cognato said. "Genes show you ancestry. They show you the overall family tree and can tell you when things took place during the evolution of a new structure. We're looking at the endpoint and trying to figure out its origin. It's like doing genetic archaeology."

Source: NSF

Explore further: Dairy farms asked to consider breeding no-horn cows

add to favorites email to friend print save as pdf

Related Stories

New technologies for getting the most out of semen

Mar 19, 2015

For in vitro fertilization and other assisted reproductive technologies, selecting the healthiest and best swimming sperm from a sample of semen can dramatically increase success. Microfluidics—micro-scale technologies ...

Rare albino wallaroos call Aussie race track home

Mar 16, 2015

"There she is, there she is!" In the distance beyond the outstretched finger of conservation biologist Daniel Ramp stood a rare white animal, rising slowly as her ears stiffened and eyes focused on him.

Recommended for you

Dairy farms asked to consider breeding no-horn cows

16 hours ago

Food manufacturers and restaurants are taking the dairy industry by the horns on an animal welfare issue that's long bothered activists but is little known to consumers: the painful removal of budding horn ...

Italian olive tree disease stumps EU

Mar 27, 2015

EU member states are divided on how to stop the spread of a disease affecting olive trees in Italy that could result in around a million being cut down, officials said Friday.

China starts relocating endangered porpoises: Xinhua

Mar 27, 2015

Chinese authorities on Friday began relocating the country's rare finless porpoise population in a bid to revive a species threatened by pollution, overfishing and heavy traffic in their Yangtze River habitat, ...

A long-standing mystery in membrane traffic solved

Mar 27, 2015

In 2013, James E. Rothman, Randy W. Schekman, and Thomas C. Südhof won the Nobel Prize in Physiology or Medicine for their discoveries of molecular machineries for vesicle trafficking, a major transport ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.