Effet de la cryoconservation sur les proteines des differents compartiments subcellulaires des spermatozoides bovins.

摘要

Cryopreservation is a process that induces a lot of cell damage. In fact, half spermatozoa survive following this process whereas their fertility is reduce by 10 fold. This thesis shows an evaluation of damages rely to the bovine sperm cryopreservation and explore a way to regenerate a part of damaged cells. The results show that the cryopreservation induces a loss of sperm surface protein (P25b), while other proteins localized inside bovine spermatozoa, like acrosin and calmodulin, are not affected by frozen-thawed procedures. The cryopreservation resistance is not only a genetic cause, other factors are involved as shown by andrological parameters of four identical bulls. A strategy of protein purification has been elaborated to characterize P25b, which is considered as a bull fertility marker. Finally, an increase of sperm motility parameters is observed when the cryopreserved spermatozoa are incubated with different membranous vesicles (prostasomes and epididymosomes).