Seminal PDC-109 protein vis-a vis cholesterol content and freezability of buffalo Spermatozoa

Abstract

tAdvancements in reproductive technologies have shown seminal plasma (SP) as a nutritive-protective medium for spermatozoa metabolism, function and transport. At the same timequality variables and thus freezability of spermatozoa are influenced by SP proteins origi-nating from male reproductive tract. One such protein, viz. PDC-109 is reported to influencefreezability of spermatozoa in cattle. Thus the present investigation was designed to eval-uate effect of seminal PDC-109 protein concentration on post-thaw cholesterol contentand semen quality variables (SQP) as an indicator of membrane integrity and freezability,respectively of buffalo spermatozoa. Ejaculates (n = 42) selected on the basis of mass activ-ity and individual motility were divided into three parts, first part for SP proteins isolation,second for cholesterol estimation and third part was cryo-preserved to evaluate freezabil-ity based on post-thaw SQP, viz. individual progressive motility, viability and acrosomeintegrity of spermatozoa. A total of 28 (66.7%) and 14 (33.3%) ejaculates from four bullswere found as freezable or non-freezable, respectively. Though total seminal plasma pro-tein (TSPP) concentration was found similar in freezable and non-freezable ejaculates, theheparin binding proteins (HBP) content in non-freezable semen was greater (P < 0.01) thanfreezable ejaculates. There was a similar trend for the PDC-109 protein content in respec-tive ejaculates. Cholesterol content of spermatozoa and SQP were greater (P < 0.05 and 0.01,respectively) in freezable as compared to non-freezable ejaculates of each bull at post-thawstage. This study showed that concentrations of HBP and PDC-109 in non-freezable semenmight be responsible for greater cryo-damage reflecting in poor freezability of buffalospermatozoa.