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: GMO mosquito plan sparks outcry in Florida

add to favorites email to friend print save as pdf

Related Stories

GMO mosquito plan sparks outcry in Florida

3 hours ago

A British company's plan to unleash hordes of genetically modified mosquitoes in Florida to reduce the threat of dengue fever and other diseases has sparked an outcry from fearful residents.

Cichlid sisters swim together in order to reach the goal

Jan 23, 2015

The manner and routes of dispersal vary with the species and the ecological conditions. Many fish form shoals to avoid predation. Shoaling with familiar conspecifics affords the fish an even greater advantage ...

Men want commitment when women are scarce

Jan 13, 2015

The sexual stereotype, in line with evolutionary theory, is that women want commitment and men want lots of flings. But a study of the Makushi people in Guyana shows the truth is more complex, with men more ...

Recommended for you

GMO mosquito plan sparks outcry in Florida

18 hours ago

A British company's plan to unleash hordes of genetically modified mosquitoes in Florida to reduce the threat of dengue fever and other diseases has sparked an outcry from fearful residents.

Population genomics unveil seahorse domain

Jan 30, 2015

In a finding vital to effective species management, a team including City College of New York biologists has determined that the lined seahorse (Hippocampus erectus) is more a permanent resident of the we ...

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.