Prognostic value of various spermatological attributes as predictors of zona binding and zona penetration of buffalo (Bubalus bubalis) semen.
Twenty-four ejaculates from six (four ejaculates each) Surti buffalo bulls aged 4-8 years were used to assess various attributes of spermatozoa influencing the zona-binding and zona-penetration tests. Ejaculates from each bulls were subjected to in vitro sperm--zona binding and sperm--zona penetration tests (four replicates per bull) using immature buffalo oocytes. The average number of spermatozoa bound per oocyte was 27.79 +/- 5.90. The average number of spermatozoa penetrated per oocyte was 3.35 +/- 0.64. The average number of zona-bound and -penetrated spermatozoa differed significantly between animals. Significant difference (p < 0.05) was observed between the plasmalemma integrity as assessed by eosin--nigrosin stain and hypo-osmotic swelling (HOS) test. Furthermore, the percentage of cells positive for the HOS test, i.e. functional membrane integrity (51.25 +/- 2.32) was significantly (p < 0.05) higher than hypo-osmotic swelling-Giemsa (HOS-G) test, i.e. the subpopulation of spermatozoa positive for functional membrane and acrosomal integrities (42.87 +/- 4.56). The HOS test had significant correlations with plasmalemma integrity as measured by the vital stain, eosin--nigrosin (r = 0.85, p < 0.05). The HOS-G test also had significant correlation with plasmalemma integrity measured by vital stains such as eosin--nigrosin (r = 0.90, p < 0.05) and fluorogenic stains [carboxyfluorescein diacetate (CFDA) and propidium iodide (PI); r = 0.92, p < 0.01] and HOS test (r = 0.93), acrosomal integrity (r = 0.86, p < 0.05) and mitochondrial membrane potential (r = 0.99, p < 0.01). The plasmalemma integrity (fluorogenic stain), functional membrane integrity (HOS test), subpopulation of spermatozoa positive for functional membrane and acrosomal integrities (HOS-G test) and mitochondrial membrane potential had significant (p < 0.05) correlation with sperm zona binding and penetration. The present study indicates that these parameters could represent important determinants of sperm quality influencing zona binding and penetration.
Selvaraju
S
S
Reproductive Physiology Laboratory, Animal Physiology Division, National Institute of Animal Nutrition and Physiology, Bangalore, India. selvarajuars@rediffmail.com
Ghosh
J
J
Ravindra
J P
JP
D000177:Acrosome / Q000502:physiology; D000818:Animals; D002020:Buffaloes / Q000502:physiology*; D002462:Cell Membrane / Q000502:physiology; D005260:Female; D005298:Fertility; D007315:Insemination, Artificial / Q000662:veterinary; D008297:Male; D053078:Membrane Potential, Mitochondrial; D008856:Microscopy, Fluorescence; D009865:Oocytes / Q000502:physiology; D009997:Osmotic Pressure; D011379:Prognosis; D012661:Semen / Q000502:physiology; D013081:Sperm Motility; D013084:Sperm-Ovum Interactions / Q000502:physiology*; D013094:Spermatozoa / Q000502:physiology* / Q000648:ultrastructure