Comparing in vitro maturation rates in buffalo and cattle oocytes and evaluating the effect of cAMP modulators on maturation and subsequent developmental competence

Abstract

Objective: The purpose of this research was to compare the kinetics and meiotic advancement of cattle and buffalo oocytes, as well as to see how cAMP modulators affected the meiotic progression status of cattle and buffalo oocytes during the oocyte collection process.
Design: comparing maturation stages times in buffalo and cattle oocytes. Cattle and buffalo oocytes were collected, separated into two groups (standard IVM and extended IVM), and cultivated for five hours in 5% CO₂ at 39°C. The sample times for extended IVM are 8, 15, 18, 22, 24, and 30 hours. The nuclear status of each oocyte was assessed to determine how far it had matured at each time sample. Then after, study the effect of cAMP modulators on maturation rates of cattle and buffalo oocytes.
Procedures: Standard IVM samples were taken at different maturation times, commencing at 8 h and ending at 24 h, while extended IVM samples were taken at 30 h. COCs were placed in a 15-mL sterile centrifuge tube with a warmed 3 percent sodium citrate solution and vortexed at maximum speed for 4 to 8 minutes as needed to remove all cumulus cells before being placed in a warm water bath at 39°C for 5 minutes. After that, the oocytes were mounted on a slide and placed in Coplin jars with a 3:1 methanol/acetic acid solution.
Results: At any stage of sampling, the percentage of oocytes arrested at the GV stage did not differ significantly between cattle and buffalo oocytes. Furthermore, there was no significant difference between cattle and buffalo oocytes in terms of the percentage of oocytes that reached the MI stage. Moreover, the percentage of oocytes arrested at the GV stage did not differ substantially between cattle and buffalo oocytes when maturation was extended using cAMP modulators at all stages of sampling.
Conclusion and clinical relevance: Modulating cAMP during oocyte maturation can change oocyte kinetics and increase developmental competence by boosting fertilization, cleavage, and morula rates. Furthermore, there is no significant differences in maturation rates between buffalo and cattle oocytes.