New York: A joint research team from the US and Japan has identified a thermosensor protein which is associated with temperature-dependent sex determination (TSD) among American alligators.
It has been observed that in the American alligator's eggs, incubation at 33 degree Celsius produces mostly males, while incubation at 30 degree Celsius produces mostly females.
The research team found that a thermosensitive protein called TRPV4 is present within the developing alligator gonad inside the egg.
This protein is responsive to warm temperatures near mid-30s, and can activate cell signalling by inducing calcium ion influx.
The study showed that by specific pharmacological inhibition of TPRV4 protein function in the developing egg, genes important for male development are influenced, and partial feminisation at male producing temperatures have been observed.
According to study authors, their study demonstrates that TRPV4 may significantly influence the male gonadal sex determination pathway at a molecular level during TSD in the alligator.
"Reptiles can be difficult to study at times, but we were delighted to obtain such an interesting result and elucidate part of the alligator TSD mechanism. We still have much to research, but we are interested in how our results relate with other TSD species diversity and evolution," said PhD student Ryohei Yatsu of SOKENDAI (the Graduate University for Advanced Studies), who was part of the research team.
Professor Taisen Iguchi of Japan's National Institute for Basic Biology, who headed the team, said: "Organisms that have adopted TSD systems may be more susceptible to the risks of environmental change, such as global warming. In future, we would like to know how an unstable environmental factor such as incubation temperature was able to establish itself as a sex determination factor."
The study findings were published in the journal Scientific Reports.