Evaluation of cholesterol- treated dromedary camel sperm function by heterologous IVF and AI.
Cholesterol (cholesterol-loaded cyclodextrins: CLC) treatment of dromedary camel sperm prior to freezing enhances cryosurvival. The present study first validated the efficacy of a heterologous zona-free goat oocyte assay (n=115 oocytes) to evaluate camel sperm function in vitro (Experiment 1: n=6 bulls), then examined the effects of CLC treatment (1.5mg/mL CLC; CLC+) versus no treatment (0 CLC) of fresh (Experiment 2: n=4 bulls) and frozen-thawed (Experiment 3: n=5 bulls) camel sperm to penetrate, de-condense and form pro-nuclei in in vitro-matured goat oocytes. Finally, the ability of fresh 0 CLC and CLC+ sperm to fertilize in vivo was studied by artificially inseminating super-ovulated females (n=7-9 per treatment) and examining embryo production (Experiment 4: n=4-5 bulls/treatment). Camel spermatozoa penetrated (60%) and formed pro-nuclei (33%) in goat oocytes demonstrating the utility of this heterologous system for assessing sperm function in vitro. For fresh spermatozoa, 0 CLC-treated sperm performed better than their CLC+ counterparts for all parameters measured (P<0.05). In contrast, cryopreservation resulted in a sharp decline in sperm-oocyte interaction in 0 CLC aliquots but remained unaltered in CLC+ aliquots demonstrating a protective effect of cholesterol treatment. There was no difference between treatments in the in vitro fertilizing ability of frozen-thawed sperm or in the numbers of embryos retrieved following AI with fresh 0 CLC or CLC+ sperm. We conclude that although CLC treatment of dromedary camel sperm improves sperm motility it fails to confer an advantage to them in terms of improved in vitro sperm-oocyte interaction or in vivo fertilization under the conditions tested.
Camel Reproduction Centre, PO Box 79914, Dubai, United Arab Emirates. Electronic address: bethiberg@aol.com.
Elizabeth G
EG
Crichton
Camel Reproduction Centre, PO Box 79914, Dubai, United Arab Emirates.
Clara
C
Malo
Smithsonian Conservation Biology Institute, Center for Species Survival, Front Royal, VA, USA.
Budhan S
BS
Pukazhenthi
Emirates Industries for Camel Milk and Products (EICMP), Dubai, United Arab Emirates.
Peter
P
Nagy
Camel Reproduction Centre, PO Box 79914, Dubai, United Arab Emirates.
Julian A
JA
Skidmore
D000818:Animals; D002162:Camelus / Q000502:physiology*; D002784:Cholesterol / Q000494:pharmacology*; D005260:Female; D005298:Fertility; D005307:Fertilization in Vitro / Q000662:veterinary*; D005615:Freezing; D006041:Goats; D007315:Insemination, Artificial / Q000662:veterinary*; D008297:Male; D009865:Oocytes / Q000502:physiology; D011247:Pregnancy; D018873:Pregnancy Rate; D012662:Semen Preservation / Q000662:veterinary; D013084:Sperm-Ovum Interactions / Q000502:physiology; D013094:Spermatozoa / Q000187:drug effects*
D002784:Cholesterol
AI; Cholesterol; Dromedary camel; Goat oocytes; IVF; Spermatozoa