GENE EXPRESSION AND LEVELS OF DNA INTEGRITY IN RAM SEMEN TREATED WITH C-TYPE NATRIURETIC PEPTIDE (CNP)

Abstract

This study aims to evaluate the effect of CNP on DNA integrity of ram semen samples and the expression of hNPR-B gene in cooled samples. A total of 20 testicular samples were collected and processed to obtain semen samples that divided into two parts; one treated with suitable dose of CNP and the second was served as a control. Toluidine blue, acridine orange, alanine blue, protamine, mitochondrial activity and cell membrane integrity in addition to Reverse-Transcriptase- polymerase chain reaction (RT-PCR) were used. Expression of hNPR-B gene was increased significantly in prostate and seminal vesicles but not in CNP-semen compared to control semen. Also, it elevated in cooled CNP-semen at 0h, 24h, 48h and 72h compared to non-treated groups. The results of toluidine blue, acridine orange and alanin blue results revealed a gradual decrease in DNA integrity of control and CNP-semen with advancing cooling. Significant lowering in mitochondrial activity of CNP-semen seen at 0h, 24h, 48h and 72h of cooling when compared to control; while for membrane integrity, values of CNP-semen were decreased significantly at 24h, 48h and 72h but not at 0h when compared to control. However, values of CNP-semen remain significantly higher than of control groups. For protamine assessment, no significant differences were found between the values of CNP-semen and control at different cooling times. For our knowledge, this first Iraqi study targets the effect of CNP on semen of rams. However, changes occur after excessive CNP exposure remains unclear, and toxicological profile of CNP required furthermore supplements.

Keywords: Sheep fertility, hNPR-B, Mitochondrial activity and cell membrane integrity, Cryopreservation, Iraq