The DMRT gene family in amphioxus

Area of Science:

• Evolutionary Developmental Biology
• Genomics
• Zoology

Background:

• The Doublesex and Mab-3-related transcription factor (DMRT) gene family plays a crucial role in sexual development across diverse species.
• Amphioxus, a protochordate, occupies a vital phylogenetic position for understanding vertebrate evolution.

Purpose of the Study:

• To identify and characterize DMRT genes in amphioxus.
• To investigate the evolutionary origins and relationships of DMRT genes between invertebrates and vertebrates.

Main Methods:

• Gene identification and classification based on conserved domains (DM and DMA).
• Comparative genomic structure analysis.
• Phylogenetic analysis of DMRT gene family using DM domain sequences.

Main Results:

• Eight DMRT genes were identified in amphioxus, categorized into two groups based on domain composition.
• Phylogenetic analysis revealed that amphioxus DMRT genes cluster with vertebrate DMRT genes, suggesting common ancestry.
• A distinct cluster for the second group of amphioxus DMRT genes indicates divergence from vertebrate lineages.
• Gene duplication events are proposed as a mechanism for DMRT gene expansion in amphioxus and potentially other species.

Conclusions:

• Amphioxus DMRT genes provide insights into the evolution of sex determination and differentiation pathways.
• The findings support the hypothesis that several vertebrate DMRT genes originated from invertebrate homologs.
• Gene duplication likely played a significant role in the diversification of the DMRT gene family across phyla.