CRYOGENIC PROTECTION OF OOCYTES WITH ANTIFREEZE PROTEINS

Proteins belonging to a family of compounds known as ''antifreeze prot eins'' interact with occytes and protect the oolemma from damage at cr yogenic temperatures. Experiments were performed with pig oocytes rapi dly cooled to cryogenic temperatures in vitrifying solutions with and without antifreeze proteins. Four different types of antifreeze polype ptides and glycoproteins were tested. The integrity of the oolemma was examined with Fluoroscein Diacetate (FDA) staining and morphological examinations. Results show that the pig oocyte oolemma is a primary si te of injury during exposure to low temperatures and that all the diff erent proteins have a similar ability to interact with and protect the oolemma. Our results may be important in developing solutions for lon g-term preservation of oocytes at cryogenic temperatures (cryopreserva tion). (C) 1993 Wiley-Liss, Inc.