The main objective of this project is to set up new strategies to improve protocols for bovine and porcine oocyte cryopreservation. Freezing of oocytes is an essencial tool for Animal Breeding because allows greater flexibility in the use of \i in vitro\i0 fertilization and related technologies (clonation, transgenic animals, etc..) by providing developmentally competent oocytes whenever needed. This project will study the effect of exposure of bovine and porcine oocytes to different cryoprotectants and freezing/thawing systems. Oocytes will be cryopreserved at different stages of oocyte maturation. Oocyte survival after freezing/thawing will be evaluated by an \i in vitro\i0 maturation, fertilization and embryo culture process. Moreover, osmotic and cytotoxic studies will be performed to know the permeability of the oolemma to water and cryoprotectant agents and the cytotoxic damage produced by a freezing/thawing process. So, we will study the relationship between ion, water and hexose channels and the functional changes in frozen/thawed oocytes. We will also analyse the effect on the distribution of chromosomes, microtubules, filamentous actina, oolemma and zona pellucida of the oocytes after a freezing/thawing process.
|Effective start/end date||28/12/01 → 27/12/04|