|Roth T L, - NATIONAL ZOO|
|Howard J G, - NATIONAL ZOO|
|Swanson W F, - NATIONAL ZOO|
|Wildt D E, - NATIONAL ZOO|
Submitted to: Journal of Reproduction and Fertility
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 28, 1995
Publication Date: N/A
Interpretive Summary: The snow leopard is one of 35 nondomestic felid species threatened or endangered by extinction. Its survival depends upon an array of conservation strategies including intensive research and captive breeding. One component of a captive breeding program involves assisted reproductive techniques to enhance propagation and maintain genetic diversity. However the potential for artificial insemination, in vitro fertilization or gamet cryopreservation depends upon understanding the fundamental biology associated with optimal sperm processing. The aim of this study was to identify culture requirements suitable to maintain snow leopard sperm viability in vitro.
Technical Abstract: Electroejaculates from 8 snow leopards were used to determine how sperm motility was influenced by: 1) media type (Ham's F10, PBS, Human tubal Fluid or RPMI-1640); 2) holding temperature (23C versus 37C); 3) sperm washing; and 4) a sperm metabolic enhancer, pentoxifylline. To assess sperm motility longevity, samples in each treatment were evaluated hourly for 6 h and a sperm motility index calculated. Sperm from the Ham's F10, PBS and PBS + pentoxifylline treatments were also co-incubated with zona- intact, domestic cat eggs that were fixed and evaluated for sperm bound to the zona pellucida, penetrating the outer and inner layers of the zona pellucida and within the perivitelline space. During the 6 h co- incubation, the sperm motility index in PBS with pentoxifylline was greater (P<0.05) than in PBS alone which, in turn, was superior (P<0.05) to the other media tested. Sperm washing enhanced (P<0.05) motility in both PBS and PBS + pentoxifylline relative to unwashed samples, but there was no effect of holding temperature. Pentoxifylline supplementation enhanced (P<0.05) the proportion of cat eggs with bound, but not penetrated, snow leopard sperm. The snow leopard appears unique among the felid species in that 1) sperm viability is sensitive to type of culture medium, 2) sperm motility and function in vitro appear enhanced by a simple rather than a complex culture medium and 3) a mechanism exists that prevents these sperm from fully penetrating heterologous, salt stored domestic cat eggs.