title: Analysis of chromatin integrity and DNA damage of buffalo spermatozoa.
abstract: This study was conducted to determine chromatin integrity and DNA damage by DNA electrophoresis and comet assays of buffalo fresh and frozen semen. Semen samples were collected from four buffalo bulls and evaluated after freezing for semen motility, viability, sperm abnormalities, chromatin integrity and DNA damage. A significant variation was found in semen parameters after thawing. Highly significant differences (P<0.001) in chromatin integrity were observed between fresh and frozen semen. For the fresh semen, there was no significant difference between the bulls for chromatin integrity; however, a significant variation (P<0.05) was detected in their frozen semen. No DNA fragmentation was observed by agarose gel electrophoresis. The percentage of sperm with damaged DNA detected by comet assay differed significantly between fresh and frozen semen. A significant negative correlation was recorded between motility and DNA damage (r=-0.68, P<0.05). Sperm abnormalities and DNA fragmentation were significantly positively correlated (r=0.59, P<0.05). In conclusion, DNA damage evaluation can provide reassurance about genomic normalcy and guide the development of improved methods of selecting spermatozoa with intact DNA to be used in artificial insemination.
authors.affiliation: Department of Animal Reproduction and Artificial Insemination, National Research Center, Dokki, Giza, Egypt;
authors.forename: K Gh M
authors.initials: KG
authors.lastname: Mahmoud
authors.affiliation: General Organization for Veterinary Services, Dokki, Giza, Egypt;
authors.forename: A A E
authors.initials: AA
authors.lastname: El-Sokary
authors.affiliation: Department of Theriogenology, Faculty of Veterinary Medicine, Benha University, Kaliobia, Egypt.
authors.forename: A E
authors.initials: AE
authors.lastname: Abdel-Ghaffar
authors.affiliation: Department of Theriogenology, Faculty of Veterinary Medicine, Benha University, Kaliobia, Egypt.
authors.forename: M E A
authors.initials: ME
authors.lastname: Abou El-Roos
authors.affiliation: Department of Animal Reproduction and Artificial Insemination, National Research Center, Dokki, Giza, Egypt;
authors.forename: Y F
authors.initials: YF
authors.lastname: Ahmed
keywords: Buffalo bull; Chromatin integrity; DNA damage; Semen quality