Differential expression of ten candidate genes regulating prostaglandin action in reproductive tissues of buffalo during estrous cycle and pregnancy

- Several studies in different species showed that the PLA2G4A, PGT, COX-2, PGFS, PGES, FP, EP1, EP2, EP3 and EP4 genes are involved in the PG biosynthesis pathway and effector mechanisms for maintenance of pregnancy.
- This is the first study ever in case of buffaloes, in which we have elucidated the regulation of these genes during different stages of pregnancy.
- The basic information generated in our study will present the way forward on specific pathways involved in understanding the faeto-maternal communication during early pregnancy in buffaloes.
- Besides, further studies are needed to be carried out on the global genes expression profiling in different reproductive stages to understand the gene network pathway involved during the pregnancy.

Prostaglandins (PGs) are the key mediators of several female reproductive functions, including luteolysis, ovulation, fertilization, implantation, pregnancy, and parturition. The present study was conducted in buffalo endometrial and luteal tissues between nonpregnant and two stages of pregnancy (29-38 days of pregnancy, 48-56 days of pregnancy) tissue samples. The genes involved from synthesis upto receptor level effect of PGs (PGF2α and PGE2) were studied for their relative mRNA expression. We have collected the endometrial and luteal tissues from slaughtered animals and confirmed the stages by external examination and crown vertebral rump length measurement of the foetus. The mRNA expression of COX-2 and PGFS genes revealed high significant rise in the transcript at pregnancy stage I as compared to the late luteal phase of nonpregnant. However, EP2 and EP3 genes were highly upregulated in pregnancy stage II. The expression of PLA2G4A and PGT genes showed difference in their transcripts in pregnancy, however, the difference was nonsignificant as compared to the nonpregnant stage. The findings emerged from this study also suggested the strict regulation at COX-2 mRNA level than at synthase enzyme's level. Among the four subtypes of EP gene, we have observed highly significant expression difference in EP2 followed by EP3 after implantation.