T.K. DATTAKRITI AHUJA2023-11-172023-11-172020https://krishikosh.egranth.ac.in/handle/1/5810201440Development ability of oocytes ultimately determines its ability to participate in the process of fertilisation and its subsequentfate to grow as an embryo. It still remains poorly understood on what makes only a few oocytes, out of many, to become eligible for making a normal embryo. Wnt pathway has been reported as one of the most salient pathway which affects the competence of the oocytes by regulating the events in TGF Beta cascade. The next generation sequencing data from our lab showed Wnt as significantly differentially affected signaling pathways in the BCB- buffalo oocytes and its overactivity can be attributed to lower embryo production in BCB- oocytes. In the present study efforts were made to improve the overall in vitro oocyte maturation and embryo development in buffalo oocytes by modulating the Wnt signaling pathway in BCB- oocytes during IVM. Expression analysis of key molecules of Wnt revealed a significantover activity of the pathway in BCB- oocytesat mRNA and protein during initial 8 hours of the IVM. The overactive Wnt pathway could be successfully inhibited by 100ng/ml of DKK1 while JW74 was found to be ineffective. There was no effect on percentage cleavage, 8- 16 cell but a significant improvement was seen in morula and blastocyst percentage compared to BCB- control. The group of oocytes supplemented with 100ng/ml of DKK1 showed a significant increase in the expression of GVBD and MET genes compared to BCB- control signifying occurrence of this event at correct time and in correct frequency in Wnt suppressed cases. Also the genes GDF9, HAS2 and PTGS2and nuclear maturation rate showed significant increase in BCB- oocytes with 100ng/ml DKK1 compared to BCBcontrol. Our work concludes that inhibition of Wnt pathway under optimum dose and duration can prove useful for embryonic development in buffaloes.EnglishThesis