Dmrt1 Undergoes Sex-Specific Functional Evolution in Xenopus

Kukoly et al. (PLOS Genetics, Jan. 2, 2026) generated knockout lines of dmrt1 homeologs in allotetraploid Xenopus laevis and diploid X. tropicalis and profiled mesonephros/gonad transcriptomes during sexual differentiation. They show loss of female-essential function in dmrt1.S and gain of male-essential function in dmrt1.L following allotetraploidization. The results indicate developmental tipping points where gene duplication drives subfunctionalization and neofunctionalization of sex-determination.