RT Journal Article
SR Electronic
T1 Evolutionary origin of sex differentiation system in insects
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2021.08.02.454784
DO 10.1101/2021.08.02.454784
A1 Yasuhiko Chikami
A1 Miki Okuno
A1 Atsushi Toyoda
A1 Takehiko Itoh
A1 Teruyuki Niimi
YR 2021
UL http://biorxiv.org/content/early/2021/08/05/2021.08.02.454784.abstract
AB The evolution of the functionality of genes and genetic systems is a major source of animal diversity. Its best example is insect sex differentiation systems: promoting male and female differentiation (dual-functionality) or only male differentiation (single-functionality). However, the evolutionary origin of such functional diversity is largely unknown. Here, we investigate the ancestral functions of doublesex, a key factor of insect sex differentiation system, using the apterygote insect, Thermobia domestica, and reveal that its doublesex is essential for only males at the phenotypic level, but contributes to promoting female-specific vitellogenin expression in females. This functional discordance between the phenotypic and transcription-regulatory levels in T. domestica shows a new type of functionality of animal sex differentiation systems. Then, we examine how the sex differentiation system transited from the single-functionality to the dual-functionality in phenotypes and uncover that a conserved female-specific motif of doublesex is detected in taxa with the dual-functional doublesex. It is estimated that the role of the sex differentiation system for female phenotypes may have evolved through accumulating mutations in the protein motif structures that led to the enhancement of its transcription-regulatory function.Competing Interest StatementThe authors have declared no competing interest.