Regulation of Spermatogenesis by Different Alternative Splicing Events of MEI1 Gene in Mongolian Horse

Abstract The Mongolian horse has the characteristics of cold resistance, rough feeding resistance, good endurance, strong disease resistance and strong gregariousness. The normal production of sperm in male mammals is the basis of reproduction, and spermatogenesis includes a mitosis, meiosis twice and metamorphosis of sperm cells. The MEI1 gene is involved in the meiosis cycle and is required for normal meiosis chromosome association. Previous studies have shown that alternative splicing of MEI1 gene can promote spermatogenesis in Mongolian horses. In this study, the expression of MEI1 gene was determined by immunofluorescence in the third generation Mongolian horse testicular sertoli cells. Two overexpressed lentiviral vectors with MXE and SE events of MEI1 gene were constructed and successfully infected into sertoli cells. CCK-8 was used to detect the proliferation and activity of infected cells, transcripomics and metabolomics were used to screen and annotate differential genes and differential metabolites in the two sertoli cells with MXE and SE events. After 72 h of virus infection, 193 differentially expressed genes and 11360 differentially expressed metabolites were screened, 109 up-regulated genes including MEI1 and 84 down-regulated genes, 7494 up-regulated metabolites and 3866 down-regulated metabolites. Differential genes and differential metabolites were mainly enriched in several pathways related to spermatogenesis. Differential genes such as IL31RA, ATP2B3, CASQ2 were highly expressed in SE events, IL11, PRLR, CCR7 were highly expressed in MXE events. Metabolites such as folic acid and spermine were highly expressed in SE events, citric acid and glutathione were highly expressed in MXE events. This suggested that both MXE and SE events of MEI1 gene can promote the activity of spermatogenesis signaling pathway, and the gene influences spermatogenesis by regulating the expression of metabolites. In summary, MXE and SE events of MEI1 gene can promote the expression of spermatogen-related genes and metabolites, and genes affect spermatogenesis by regulating the expression of metabolites. The results of this study laid a theoretical foundation for exploring the regulatory mechanism of different alternative splicing events on spermatogenesis in Mongolian horse.