Acrosomal Changes and Survivability of Following Preservation of Dog Spermatozoa I. The Effects of Different Chilling Duration

개 정자의 보존방법에 따른 첨체 및 생존성의 변화 1. 저온보존에 따른 효과

  • 정정란 (경상대학교 수의과대학 동물의학연구소) ;
  • 유재규 (경상대학교 수의과대학 동물의학연구소) ;
  • 양성렬 (경상대학교 수의과대학 동물의학연구소) ;
  • 여현진 (경상대학교 수의과대학 동물의학연구소) ;
  • 박종식 (경상대학교 수의과대학 동물의학연구소) ;
  • 예은하 (경상대학교 수의과대학 동물의학연구소) ;
  • 노규진 (경상대학교 수의과대학 동물의학연구소) ;
  • 최상용 (경상대학교 수의과대학 동물의학연구소)
  • Published : 2001.04.01

Abstract

Artificial insemination (AI) with frozen or cooled semen is widely used in commercial fields of cattle and pig. Little is known about characteristics of canine sperm after freezing or cooling. For both practical and commercial goal, the canine semen treated with cooling and freezing should be carried out to exam the fundamentals, including sperm motility, survivability and fertilizing capacity. The aim of this study, thus, was to identify the effects of extended exposure to 4$0^{\circ}C$ on canine semen by motility, survivability, acrosomal changes following different duration. Fifteen ejaculates collected by digital manipulation twice per week from 3 dogs (Shih-Tzu) were divided to 16 aliquots after adding Tris-egg yolk (TE) buffer formulated by our laboratory, and cooled from 37 to 4$^{\circ}C$, by ramp rate of 0.6$^{\circ}C$/min. Each sample was evaluated by their motility, survivability and the acrosomal status at 0h (control), 2h, 12h and 1 d~10 d, respectively. The motility of spermatozoa was graded to 6 levels using the modified method of Seager. The survivability of sperm was assessed using an epifluorescence microscope after Fert/Light (Mole-cular Probes Inc.) staining. To estimate the proportion of the spermatozoa of intact acrosome, 200 spermatozoa were assessed in randomly selected fields, using epifluorescence microscope after FITC/PSA (Sigma) staining. At 2 h after cooling, the motility of most spermatozoa were assessed to be grade 0 and 1. At 12 h, high number of sperm were in grade 0 to 1, however, it was significantly (P<0.05) lower than that of 2 h. From 1 d to 4 d, ~50% of sperm was assessed to grade 0 to 1. On day 7, a little sperm were in grade 0 to 1. No sperm showed motility on day 10. Sperm motility was rapidly reduced by the percent of 10% of grade 0 to 1. From 2 h to 6 h, the number of live sperm was 90% and the sperm chilled for 10 days lived>50%. Acrosomal intact of spermatozoa exposed to 4$^{\circ}C$ for 2 h was 51%, supposed the sperm of control was 100%. Our results suggest that 1) this is easy to transfer and preservation for short periods 2) AI can be used by semen chilled for 6-Day.

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