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Abstract: 40
Afsaneh Motamed Khorasani1 , Rajaduri Rajamahendran1 *, Chi Yu Gregory Lee2
Department of Animal Science, University of British Columbia, Vancouver, BC, Canada 1
OB/GYN Department, University of British Columbia, Vancouver, BC, Canada 2
Studies have shown that mammalian sperm acrosome reaction (AR) can be induced by progesterone (P4), whereas cholesterol (CH) inhibits P4-induced AR. The objectives of this study were to determine the effects of exogenous P4 and CH on zona-binding ability of bovine sperm and in vitro fertilization (IVF) outcome. For zona-binding assay, frozen-thawed sperm were washed in modified Tyrodes' and final concentration was set to 0.2 ×106 sperm/ml. Sperm were pre-incubated with P4 (10µg/ml, 30 min), either in the presence or absence of CH (1µg/ml) at 38.5°C, 5% CO2. Sperm were co-incubated with cumulus-free oocytes for 18 h (30 oocytes/treatment). Following washing, fixing, and staining steps, the No.of sperm attached to oocytes were counted under a fluorescent microscope. For IVF study, for 30 min prior to the addition of matured oocytes, for fertilization, sperm (0.2×106 sperm/ml) were pre-treated with P4(10µg/ml, 30 min), CH, P4+CH, and cyclodextrin (120 oocytes/treatment). Sperm exposed oocytes were then washed twice and incubated in culture medium (modified Tyrodes' supplemented with 10% serum) in a conventional incubator (38.5°C, 5% CO2). Cleavage rate was recorded after 72h. P4 increased the No. of spermatozoa bound to oocyte, 73.9±3.7 Vs 45.3±1.8, 46.2±3.3, and 45.8±3.7 for P4, CH, P4+CH, and cyclodextrin, respectively. P4 also increased cleavage rate percentage, 42.5±3.8 Vs 18.3±2.8, 17.5±1.7, and 20.8±2.0 for P4, CH, P4+CH, and cyclodextrin, respectively. It is concluded that P4 treatment of sperm prior to fertilization may improve mammalian IVF success rate.
This abstract is being presented on Sunday, August 1 at 8:00 AM to 10:15 AM at CUB 2nd Floor Ballroom.