Clownfish Change Sex For Survival

Posted: Dec 19 2016, 11:02am CST | by , in News | Latest Science News

 

Clownfish Change Sex for Survival
Photo Credit: Getty Images
 

New study identifies changes in gene expression that drive the process of sex change

Clownfish has made many adaptations during its evolution. The most unusual is perhaps the transition from male to female in the absence of a mature female. This adaptation restores their gender balance and ensures the survival of the clownfish species that might otherwise result in decline in population or even lead to their demise.

“Several species of fish, and in particular coral reef fish, are able to swap their sex during their lifespan” said study researcher Timothy Ravasi from KAUST's Environmental Epigenetic Program. “This is known as sequential hermaphroditism.”

Clownfish, also known as anemonefish, carry both male and female reproductive organs. If the female dies, the male can turn into a female to adjust the gender ratio of its population. However, until now, researchers were never been able to identify the genes that trigger the process of sex change. 

To find out, researchers analyzed genetic activity of fully developed males as well as females at multiple stages of the process and detected clear changes in gene expressions within the brains of males two weeks after being separated from female. These changes in gene expression activated gender transition which became evident in gonadal gene expression few weeks later.

“Our analysis has highlighted the rapid and complex genomic response of the brain associated with sex change, which is subsequently transmitted to the gonads, identifying a large number of candidate genes, some well-known and some novel, involved in the process.” Authors wrote in the study.

One important candidate gene is aromatase, which is known to be involved in the production of estrogen. The enzyme was found in both the brain and gonads of the fish adapting to gender ratio alterations.

Researchers know very little about the factors influencing male to female transition. Understanding molecular pathways underlying this sex change can allow researchers to explore environmental factors involved in the process.

“We are not sure whether the ocean’s warming and acidification can influence the tightly controlled regulation of gender ratio changes,” said Ravasi. “We are systemically exploring the fish to end-of-century predicted ocean conditions and trying to understand whether climate change alters their molecular pathways.”

This story may contain affiliate links.

Comments

The Author


Hira Bashir covers daily affairs around the world.

 

 

Advertisement

comments powered by Disqus