Freeze-thaw-induced changes of the zona pellucida explains decreased rates of fertilization in frozen-thawed mouse oocytes.

摘要: Frozen-thawed oocytes have a reduced rate of fertilization (48.8%) when compared with unfrozen controls (97%). In this study we used zona-drilling to bypass the zona pellucida and investigate whether decreased is due freezing-induced changes in which prevent sperm penetration. After drilling frozen-thawed (87.8%) was same as for zona-intact (88%), indicating that freeze-thaw-induced at level were responsible fertilization. To determine occurring during manipulations before after freezing or complete freeze-thaw cycle, exposed set normally experienced cryopreservation appropriate control groups. A small but significant decrease (82.8%) apparent (92.2%). The therefore occur primarily cycle itself not are observed oocytes.