Gonadal transcriptomic analysis and differentially expressed genes between the testes and ovaries in Trachinotus ovatus

Abstract

The Trachinotus ovatus is a popular aquaculture species in China. There are no obvious morphological differences between male and female fish, even during maturity, prompting research studies on sex-related features of this fish. To examine sex determination- and gonadal development-related genes, we conducted transcriptome analysis of the ovaries and testes of T. ovatus. A total of 345,972,132 high-quality clean reads were obtained from 12 libraries. In addition, 28,137 gonad-expressed unigenes were obtained by mapping the clean reads to the T. ovatus reference genome. A total of 8,237 differentially expressed genes (DEGs) were identified between stage I ovaries and testes, including 3,235 testicular upregulated and 5,002 ovarian upregulated genes. Furthermore, 13,448 DEGs were obtained between stage III ovarian and testicular libraries, including 7,576 testicular upregulated and 5,872 ovarian upregulated genes. The DEGs included some sex-determining genes such as sry, dmrt1, and amh. DEGs between ovarian and testicular libraries were significantly enriched with KEGG pathways that are involved in gonadal development, sex determination, and gonadal function. Then, 10 DEGs (seven testicular upregulated and three ovarian upregulated unigenes) were selected for quantitative real-time PCR analysis. Four genes (zinc-binding protein A33-like, pro-opiomelanocortin-like, leucine-rich repeat and transmembrane domain-containing protein 2-like, and forkhead boxC1) showed a specific testicular expression pattern. The gonadally expressed as well as testicular and ovarian DEGs provide useful information for further research on the reproductive biology of T. ovatus.

Keywords

• Transcriptome
• Trachinotus ovatus
• Gonad
• High-throughput sequencing
• RT-qPCR