Study On Expression Profiles Of Protamine In Main Reproductive Organs Of Bucks

The protamines are a family of arginine-rich proteins that are synthesized in the late-stage spermatids of many animals and plants and bind to DNA by replacing histons, condensing the spermatid genome into a genetically inactive state, which plays special roles in maintaining the sperm stabilization and function.Three 2-,3-,5-,6-,9-,12-month-old Jinlan Cashmere Goats were selected as experiment animals. In this experiment, mRNA expression was detected by real-time fluorescent quantitative PCR in testis and sperm, cellular localization of Protamine was examined by immunohistochemistry, qualitative protein expression was examined by the analysis of optical density of immunohistochemistry. The objective of this study was to evaluate the expression of Protamine in testis and sperm of bucks, explore the influence on sperm structure and function and its mechanism.1. The coding sequence of Protamine gene was obtained by PCR, then analysed the bioinformatic function of Protamine protein. The ORF of protamine was 156 bp long and encoded a 51 amino acid protein. The estimated molecular weight was 6.8432 kDa and the Isoelectric point (pI) was 12.23 according to the predicted amino acid sequences. There were 27 arginine and lysine,7 cysteine in the goat protamine, two phosphorylation sites(serine and threonine) were predicted. In the present study, the protamine contained β turn and turn region.2. The expression of Protamine gene was gradually increased with the growth and development of animals, the mRNA expression in 9- and 12-month-old testis were significantly higher than that in 2-,3-, 5- and 6-month-old; the mRNA expression in high motility rate semen of goat was significantly higher than that in low motility rate semen.3. Protamine proteins were expressed in elongating spermatids and sperm, there was no positive signals in other cells of testis, the similar results were obtained in the protein expression of Protamine.This study indicated Protamine played an important role in reproduction and spermatogenesis, and its exact functional mechanisms need further study.