The Genetics Behind Sexual Dimorphism Unraveled By Scientists

Sexual dimorphism is a very complex topic that has intrigued biologists ever since. The differences in the morphological and anatomical characteristics of every species are what is responsible for their continual survival and existence. Therefore, understanding the modus operandi of the genes that determine differential expression of the genome is highly crucial.

Previously held notion about sexual dimorphism was based on the perception that the expression of genes is either switched on or off, based on the gender of the organism. However, recent findings of a study conducted by a group of scientists from Indiana University indicate that there exists a "master gene" that controls the differential expression of similar genes in males and females of every species. The findings of the study were published in the Nature Communications journal on Feb. 27, 2017, WBOI reported.

The said study characterized the role of the "doublesex" or dsx gene, in the expression of the gene responsible for the presence of horns in the males of Onthophagus taurus beetles. It is already known that male beetles have these horns, which help them in battling other male opponents over females. However, females of the species are completely devoid of these horns, since the presence of these would have a significant negative impact on their ability to dig tunnels and nest their offsprings.

In order to understand the role of dsx gene in regulating the genetic mechanism behind this differential expression, the scientists produced a dsx gene-suppressed beetle population and compared it with that of the normal ones.

According to Lab Manager, the scientists observed that both males and females of beetles of the dsx-suppressed population had horns on their heads. This is a clear indication that the gene responsible for horn formation is present and functional in both males and females. It is in fact the dsx master gene that determines its expression depending on the gender of the beetle.

Further understanding of the role of the dsx gene could provide new insights into the role of sexual dimorphism in evolution and diversification of other species.