Transcriptomic analysis of key sex-differentiation genes in wild Atrina pectinata from Changdao, China

Atrina pectinata is an economically valuable bivalve, yet the molecular mechanisms underlying its sex determination and gonadal development remain unresolved. To elucidate the gonadal development pattern and to identify key sex-related genes, wild individuals were collected from the Changdao Sea area of China for histological observation and transcriptome analysis. Histological sectioning revealed that the gonadal maturation peak of A. pectinata occurs in late June. Transcriptomic screening yielded a suite of sex-biased differentially expressed genes (DEGs), whose functional enrichment indicated significant involvement in reproduction-related processes such as cell-process regulation, protein binding, and organelle organization. Notably, key regulators including Dmrt1 , Foxl2 , Nanos , Sox , CYP , β-catenin , 17β-Hsd and Fem-1 were identified among the DEGs, exhibiting pronounced sex-biased expression. These results suggest that the molecular circuitry governing sex determination and gonadal development in A. pectinata is evolutionarily conserved yet species-specific. This study provides fundamental insights into the sex-determination mechanisms of A. pectinata and offers candidate genes and key modules for future mechanistic investigations.