Comprehensive Genome-Wide Analysis of Dmrt Transcription Factors Reveals Their Roles in Sexual Dimorphism in Scolopendra mutilans

Abstract

The double-sex and mab-3-related transcription factors (Dmrt) are widely distributed in the animal kingdom and play a crucial role in sex determination and differentiation. In this study, we identified eight Dmrt transcription factors in the genome of the centipede Scolopendra mutilans, including five Dsx-related genes (as Dsx1, Dsx2 (five splice variants), Dsx3, Dsx4 and Dsx5) and three Dmrt-related genes (as Dmrt11E, Dmrt99B, and Dmrt93B). Phylogenetic analysis revealed evolutionary conservation across arthropods, with Dsx genes clustered into class-specific clades (Chilopoda, Insecta, Crustacea, Arachnida). Structural analysis confirmed conserved DM domains and sex-specific motifs, with tandem duplication of Dsx2 on chromosome 4. Expression profiling demonstrated significant sexual dimorphism: Dsx5 was female-biased, whereas Dsx2, Dsx3, and Dsx4 were male-biased, suggesting their functional divergence in sexual differentiation. Correlation analysis linked the expression of Sxl and Fem-1C to the regulation of Dsx isoforms, suggesting the presence of a conserved upstream regulatory cascade for sex-specific splicing. These findings elucidate the structural and functional landscape of Dmrts in S. mutilans, and provide insights into how sex-determination mechanisms evolved in Myriapoda.