In vitro fertilization with in vitro developed oocytes: the impact of heparin on the viability of frozen-thawed bull sperm

Abstract

In-vitro-matured oocytes were fertilized with bull sperm that had been frozen and thawed in-vitro.Swim up
separation was performed on thawed, frozen sperm in a Ca++-free variant of Tyrode's medium for a total
of 20 minutes. The cleaned sperm were then diluted (1:1) with identical medium containing heparin so as
to yield final concentration of 0, 10, 50 and 100 ug/ml. For 15 or 30 minutes, we incubated heparin-treated
sperm at 39 degrees Celsius in 5% carbon dioxide.and checked for signs of development and fertilization
by fixing, staining, and examining them. The data demonstrate that almost all Oocytes (96%) enter
metaphase II by the end of the 28th hour. Heparin was also shown to be quite useful in facilitating sperm
penetration of Oocytes. The percentage of fertilized Oocytes rose dramatically with increasing heparin
content in the capacitation medium (4.8% for 0 g/ml, 50.9% for 10 g/ml, 69.3% for 50 g/ml, and 83.6% for
100 g/ml; P0.01). Cow serum resulted in a considerably higher rate of oocyte development to 2-4 cells
(63.3% vs. 32.1%; P0.01) than BSA.