Transcripts of COL4A2, IRG1, MMP12 genes as potential biomarkers of bull sperm quality

Relevance . The aim of this work is to validate three sperm transcripts of candidate genes COL4A2, IRG1, MMP12 obtained using RNA-Seq and correlation analysis of their expression levels with high and low sperm quality indicators of Holstein bulls. Methods . Eighteen samples of cryopreserved sperm ejaculate were studied. The relative expression of candidate genes COL4A2, IRG1, MMP12 was analyzed, and rank correlation was analyzed using Spearman’s test. Results . The results of the study showed that the relative expression of the studied genes COL4A2, IRG1, MMP12 was predominantly lower in spermatozoa with low productivity, which confirms the results of a complete transcriptome analysis, where reduced differential expression was also observed in the group of bulls with poor productivity. Statistically significant differences in the levels of expression of total sperm RNA of the studied genes were obtained for all genes in both groups of bulls. Correlation analysis revealed a high dependence between the expression level of the studied genes COL4A2, IRG1, MMP12 and significant indicators of sperm quality. Transcripts of the genes COL4A2, IRG1 showed a high significant negative correlation with sperm motility, the content of live and normal cells and the average Ca 2 + content. A significant positive correlation was observed for undesirable traits, such as the content of dead and defective cells. The gene MMP12 transcript had the opposite effect in comparison with the genes IRG1 and COL4A2 . The expression level of the MMP12 gene showed a significantly high correlation with motility.