SPERM DNA INTEGRITY IN BUFFALO, BULL AND STALLION
Creators: name: Serafini, Rosanna
Publisher: name: Università degli Studi di Napoli Federico II
Year: 2015

description: The interest in sperm DNA integrity evaluation and its relationship to subfertility and infertility loaded to development of several sperm DNA assays. The aim of this study was to compare several sperm DNA assays in buffaloes, bulls and stallions, and to identify the relationships between those DNA assays and traditional sperm features. In Italian Mediterranean Buffalo (IMB) bulls traditional sperm features (motility, viability, acrosome integrity and morphology), sperm DNA integrity (neutral Comet assay, Sperm Bos Halomax-SBH, and Sperm Chromatin Structure Assay-SCSA), fertility in vivo and their relationships, were evaluated. The neutral Comet assay was correlated to sperm motility, viability, coiled tails and presence of epithelial cells. The SCSA measures were correlated to sperm viability, bent midpieces and distal droplets. SBH was correlated to Non-Viable Acrosome Damaged-NVAD (r= 0.60; P&lt;0.05) and to Viable Acrosome Damaged-VAD (r= -0.63; P&lt;0.05). Sperm DNA assays were not correlated to each other (P&gt;0.05). Pregnancy rate at 30 d, 45 d and calving rate were 57%, 55% and 45%, respectively. Receiver Operating Characteristic (ROC) Curve evidenced significant values  for sperm motility, distal droplets, Non-Viable Acrosome Damaged, Standard Deviation-αt (SD-αt) and neutral comet measures of Olive Tail moment and tail moment, %DNA in head (and tail) and tail area (P&lt;0.05). In bulls sperm DNA integrity was examined in two groups selected on sperm motility and morphology (higher and lower). The aims of this study were to: 1) describe Comet assay measures and examine their repeatability (inter- and intra-assay); 2) compare sperm DNA quality assays (i.e., SCSA, alkaline and neutral Comet assays and SBH); 3) determine the relationship among DNA assays and sperm motility and morphology. Inter-assay repeatability was higher for the neutral Comet assay as compared to the alkaline Comet assay. Intra-assay repeatability was higher than inter-assay repeatability for both Comet assays. Comet assay dimension measures and % tail DNA were the most repeatable for both Comet assays. Among sperm DNA quality assays, only SCSA measures and neutral Comet assay Ghosts (% Ghosts), head diameter and area, and comet area were different between high and low sperm quality groups (P&lt;0.05). The SCSA measures were correlated with neutral Comet head measures (diameter, area, and intensity) and % Ghosts (P&lt;0.05). The %Ghosts and COMP-αt were correlated with some measures of sperm morphology and sperm motility. The neutral Comet assay was more appropriate for sperm evaluation than the alkaline Comet assay for distinguishing between groups with different sperm quality. In stallions sperm DNA integrity was assessed following the induction of a mild stress to the scrotum (unilateral orchiectomy-UO), using the Comet assay and the SCSA, and compared at pre-UO (0 d) and at 14, 30, 60 days post-UO. The %DNA in the comet tail was higher at 14 and 60 d compared to 0 d (P&lt;0.05). Comet tail length, moment and migration were higher at all time periods post-UO compared to 0 d (P&lt;0.05). Two SCSA measures (Mean-αt, Mode-αt) increased at 14 d post-UO (P&lt;0.05), while two measures (SD-αt and COMP-αt) did not change (P&gt;0.05). This study identified a decrease in sperm DNA quality using both the neutral Comet assay and the SCSA, which was not identified using traditional measures of sperm quality.