Transcriptome analysis of glyptosternum maculatum (sisoridae: siluriformes) provided insights into sexual dimorphism, Xizang, China.

Abstract

Glyptosternum maculatum, designated as a second-class nationally protected aquatic species in Xizang, China, has been categorized as critically endangered on the Red List of China's Vertebrates. This species exhibits significant sexual dimorphism. The primary objective of this research was to explore and analyze the genetic components underlying sexual variations in G. maculatum. In this investigation, transcriptomic methodologies were utilized to identify potential genes contributing to sexual dimorphism in G. maculatum. The transcriptomic analysis yielded 9788 differentially expressed genes (DEGs) between males and females, with 5490 upregulated and 4157 downregulated. Enrichment analysis via the KEGG pathway identified substantial enrichment of DEGs in six pathways central to sex determination, sexual differentiation, and gonadal development. These pathways were grouped into three primary signaling pathways: P450 pigment synthesis, steroid biosynthesis, and energy metabolism. Functional annotation additionally pinpointed 16 genes exhibiting high expression levels during sexual differentiation, including cyp19a, dmrtX1, SOX9, kiss2, and FSHR. These genes, previously substantiated in other teleost species, were confirmed to play crucial roles in sex determination. This study offers substantial theoretical foundation and empirical data, thereby facilitating future endeavors in identifying sex-determining genes, dissecting their functional aspects, and advancing the development of all-male offspring in G. maculatum.