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: Keep dogs and cats safe during winter

add to favorites email to friend print save as pdf

Related Stories

DNA sheds light on why largest lemurs disappeared

Dec 16, 2014

Ancient DNA extracted from the bones and teeth of giant lemurs that lived thousands of years ago in Madagascar may help explain why the giant lemurs went extinct. It also explains what factors make some surviving ...

How fast you age depends on your parents

Dec 11, 2014

In the hunt for better knowledge on the aging process, researchers from Lund University have now enlisted the help of small birds. A new study investigates various factors which affect whether chicks are ...

Recommended for you

Keep dogs and cats safe during winter

7 hours ago

(HealthDay)—Winter can be tough on dogs and cats, but there are a number of safe and effective ways you can help them get through the cold season, an expert says.

Scientists target mess from Christmas tree needles

Dec 26, 2014

The presents are unwrapped. The children's shrieks of delight are just a memory. Now it's time for another Yuletide tradition: cleaning up the needles that are falling off your Christmas tree.

Top Japan lab dismisses ground-breaking stem cell study

Dec 26, 2014

Japan's top research institute on Friday hammered the final nail in the coffin of what was once billed as a ground-breaking stem cell study, dismissing it as flawed and saying the work could have been fabricated.

Research sheds light on what causes cells to divide

Dec 24, 2014

When a rapidly-growing cell divides into two smaller cells, what triggers the split? Is it the size the growing cell eventually reaches? Or is the real trigger the time period over which the cell keeps growing ...

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.