Cytoskeleton Genes Expression and Survival Rate Comparison Between Immature and Mature Yak Oocyte After OPS Vitrification.

This study was conducted to investigate the effect of vitrification on survival rate and cytoskeleton gene expression during yak oocyte maturation. The yak oocytes were incubated for 0h [germinal vesicle (GV) stage] and in vitro matured for 24h [metaphase II (MII) stage] to obtain immature and mature oocytes. Survival rate after vitrification were compared between immature and mature yak oocytes and cytoskeleton-related genes [cytokeratin 8 (CK8), -actin (ACTB), and gap junction protein, alpha 1 (GJA1)] were tested by real-time PCR. Our results showed that MII stage survival rate after open pulled straw vitrification (35.60%) is significantly higher than GV stage (25.90%) oocytes. Furthermore, expression of CK8, ACTB, and GJA1 in MII stage oocytes are also significantly higher than GV stage oocytes. In conclusion, our study demonstrated that higher expression of GJA1, CK8, and ACTB in vitrify-warmed MII stage oocytes when compared with GV stage oocytes and such discrepancy might result in higher survival rate in vitrify-warmed MII stage oocytes.