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

## TL;DR

This study identifies eight Dmrt transcription factors in the centipede Scolopendra mutilans and explores their roles in sexual dimorphism and sex determination.

## Contribution

The study reveals the structural and functional diversity of Dmrt genes and their regulatory mechanisms in a myriapod species.

## Key findings

- Eight Dmrt transcription factors were identified, including five Dsx-related genes and three Dmrt-related genes.
- Dsx2 showed tandem duplication on chromosome 4, and Dsx5 was female-biased while Dsx2, Dsx3, and Dsx4 were male-biased.
- Sxl and Fem-1C were linked to the regulation of Dsx isoforms, indicating a conserved upstream regulatory cascade.

## Abstract

In this study, we identified eight Dmrt transcription factors in the genome of the centipede Scolopendra mutilans. Phylogenetic analysis revealed evolutionary conservation across arthropods, and structural analysis confirmed conserved DM domains and sex-specific motifs, with tan-dem duplication of Dsx2 on chromosome 4. 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.

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.