Genetic Expression of Progesterone and Oxytocin Receptors in Kari Sheep during Estrus and Early Pregnancy

Kari is a small breed of sheep found in Chitral district of Khyber Pakhtunkhwa with unique characteristics having shorter gestation length than other breeds i.e. lesser than five months. In this experiment the expression pattern of oxytocin and progesterone receptors gene in estrus cycle and early pregnancy was studied. For this experiment total seven ewes non-pregnant scanned through ultrasonography and then estrous synchronized with double PGF2α protocol. The fertile rams were allowed, and mating was observed. Blood samples was collected from ewes before and after confirmation of pregnancy. RNA was isolated from the blood and synthesized c-DNA through RT-PCR. The c-DNA was amplified using primers i.e. P4, OXTR and GABDH. No expression of OXTR was observed between 08th and 12th day in control, non-pregnant and pregnant ewes while expression of OXTR was observed on 14th day in non-pregnant and no expression in pregnant ewes. The expression of progesterone receptors was high on 10th and 12th day in pregnant ewes while low level was recorded on 16th day. In control and non-pregnant ewes the expression of P4 mRNA was lower at 08th day and highly expressed on 14th and 16th day of estrus cycle. It is concluded that early pregnancy in ewes sustained by a complex interplay between the conceptus and endometrium. This contact involves factors like IFN-t, progesterone, and growth factors, which regulate gene expression to suppress luteolysis and maintain pregnancy.