title: Ability of thawed tiger (Panthera tigris) spermatozoa to fertilize conspecific eggs and bind and penetrate domestic cat eggs in vitro.
abstract: Electroejaculates from tigers were collected and half was used fresh to inseminate tiger eggs in vitro and domestic cat eggs stored in a hypertonic salt solution. The remainder was pelleted, frozen in a solution of 20% egg yolk, 11% lactose and 4% glycerol, thawed and cultured with tiger and domestic cat eggs. The motility index ((sperm % motility)+(status rating x 20))/2 for thawed spermatozoa was about 86% of that in fresh aliquots. Of the 49 tiger oocytes inseminated in vitro with fresh spermatozoa, 34 (69.4%) cleaved, compared with 33 of 47 oocytes (70.2%) cultured with thawed spermatozoa (P > 0.05). Embryos generated by either sperm treatment could develop in vitro to the 16-cell or morula stage. Fresh and thawed tiger spermatozoa were equally capable (P > 0.05) of binding and penetrating the outer and inner zona pellucida of domestic cat eggs. These results demonstrate the ability of frozen-thawed tiger spermatozoa to (i) penetrate homologous and heterologous eggs and (ii) result in conspecific, advanced development of preimplantation embryos in vitro.
authors.affiliation: National Zoological Park, Smithsonian Institution, Washington DC 20008.
authors.forename: A M
authors.initials: AM
authors.lastname: Donoghue
authors.forename: L A
authors.initials: LA
authors.lastname: Johnston
authors.forename: U S
authors.initials: US
authors.lastname: Seal
authors.forename: D L
authors.initials: DL
authors.lastname: Armstrong
authors.forename: L G
authors.initials: LG
authors.lastname: Simmons
authors.forename: T
authors.initials: T
authors.lastname: Gross
authors.forename: R L
authors.initials: RL
authors.lastname: Tilson
authors.forename: D E
authors.initials: DE
authors.lastname: Wildt
mesh_terms: D000818:Animals; D001947:Breeding / Q000379:methods; D002335:Carnivora / Q000196:embryology / Q000502:physiology*; D002415:Cats; D016009:Chi-Square Distribution; D015925:Cryopreservation / Q000662:veterinary*; D005260:Female; D005307:Fertilization in Vitro; D007315:Insemination, Artificial; D008297:Male; D012662:Semen Preservation / Q000009:adverse effects / Q000662:veterinary*; D013081:Sperm Motility; D013084:Sperm-Ovum Interactions; D013997:Time Factors