Study of the expression level influence of aquaporin genes on the quality of semen of Holstein bulls

The aim of the study is to assess the influence of candidate genes encoding aquaporins (AQPs): AQP3, AQP7 and AQP11, associated with indicators of bull semen quality, for their further use as transcriptional biomarkers. Methods. Using quantitative reverse transcription polymerase chain reaction (RT-qPCR), we assessed the expression of selected genes in native and frozen-thawed sperm of 7 Holstein bulls and analyzed the correlations between the expression level of the studied genes with indicators of sperm quality that are significant for survival and fertilization. The following biochemical parameters of native and deconserved bull spermatozoa were assessed: motility, cell morphology, membrane integrity, viability, mitochondrial membrane potential, level of generation of reactive oxygen species (ROS). The scientific novelty of the study lies in the fact that for the first time in our country the relationship between the expression level of the AQP3, AQP7 and AQP11 genes and the quality of sperm of Holstein bulls was assessed. Results. The AQP11 gene can be recommended as a reliable transcriptional biomarker, since it had a high positive correlation with the content of living (0.821, p = 0.0145), normal (0.750, p = 0.0384) cells, and a negative correlation with the content of defective (–0.679, p = 0.0735), dead cells (–0.821, p = 0.0145) and ROS content (-0.821 p=0.0145) in frozen-thawed and native sperm. The AQP7 gene transcript of frozen-thawed sperm had an average negative correlation with indicators of dead sperm content (–0.727, p = 0.0545) and acrosome defects (–0.667, p = 0.0735) at a level close to significant. The AQP3 gene transcript had a significant positive correlation with the content of dead cells (0.786, p = 0.0251) in frozen-thawed sperm and a negative correlation with the content of defective, dead cells and ROS content in frozen-thawed and native sperm.