The effect of vitrification after warming on the expressions of p38, CDK1, and cyclin B in immature goat oocytes followed by maturation.

BACKGROUND AND AIM

The combination of vitrification techniques and maturation can reduce oocyte competence. Mitogen-activated protein kinase and maturation-promoting factor are significant in oocyte meiotic maturation regulation. This study aimed to analyze vitrification's effect, after warming followed by maturation, on the expressions of protein 38 (p38), cyclin-dependent kinase 1 (CDK1), and cyclin B and oocyte maturation level.

MATERIALS AND METHODS

Immature goat oocytes were soaked in vitrification and warming solutions. The procedure was followed by maturation and maturation without post-warming vitrification as a control. These oocytes, along with their cumulus, were vitrified using in liquid nitrogen. Oocyte maturation was carried out in a maturation medium that was added with 10 μg/mL of FSH, 10 μg/mL of LH, and 1 μg/mL E for 22 h. The expressions of p38, CDK1, and cyclin B were observed using immunocytochemical methods, which were assessed semiquantitatively according to the modified Remmele method. The oocyte maturation level was observed using the aceto-orcein staining method based on the achievement of chromosomes up to the metaphase II stage and/or the formation of the polar body I.

RESULTS

p38 expression in vitrified oocytes after warming, followed by maturation, increased insignificantly (p≥0.05), with the acquisition of 3.91±2.69 and 2.69±0.50 in the control oocytes. CDK1 expression in vitrified oocytes decreased significantly (p≤0.05) after warming, followed by maturation, with the acquisition of 2.73±1.24 and 7.27±4.39 in the control oocytes. Cyclin B expression in vitrified oocytes decreased insignificantly (p≥0.05) after warming, followed by maturation, with the acquisition of 3.09±1.4 and 4.18±2.61 in the control oocytes. The proportion of vitrified oocyte maturation levels after warming, followed by maturation, decreased significantly (p≤0.05), with the acquisition of 45.45% and 77.27% in the control oocytes.

CONCLUSION

This study concluded that vitrification after warming resulted in an insignificant increase in p38 expression, a significant decrease in CDK1 expression, an insignificant decrease in cyclin B expression, and a significant reduction in oocyte maturation levels.