EFFECT OF NON-SURGICAL REMOVAL OF CONCEPTUS ON ESTROUS CYCLE LENGTH AND INTERFERON TAU (IFNT) GENE EXPRESSION PROFILE IN WATER BUFFALO (Bubalus bubalis)

The physiology of maternal recognition of pregnancy (MRP) in cattle is well explored and a better understanding of phenomenon of MRP is needed in order to improve reproductive efficiency in buffaloes. The present work was conducted to study the effect of non-surgical removal of conceptus and expression profile of interferon tau (IFNT) in the conceptus after post insemination in buffaloes. In the experiment I, 15 female buffaloes in estrus were inseminated using frozen semen of Murrah buffalo and the uterine flushing by non-surgical method was carried out on days 12, 14, 16, 18 and 20 of post insemination for collection of conceptus. Under experiment II, conceptus tissue collected on different days in the experiment I and conceptus tissue collected from slaughter house pregnant reproductive tracts were used for RNA isolation to study real time expression pattern of IFNT on day 12, 14, 16, 18, 20, 30, 40 and 50 of pregnancy by using specific primers (F5’-GCCCTGGTGCTGGTCAGCTA -3’ and R5’-CATCTTAGTCAGCGAGAGTC -3’). The estrous cycle length following non- surgical removal of conceptus on day 12, 14, 16, 18 and 20 post-insemination was 23.50±0.96, 36.60±3.35, 41.25±2.67, 42.73 ±2.61 and 45.20±7.03 days, respectively. The mean cycle length increased significantly by 8-47 days following removal of conceptus on day 14, 16, 18 and 20 post-insemination when compared to day 12. The expression of IFNT was found low but at detectable levels as early as on day 12 of gestation. The level of expression increased significantly (P<0.01) on day 14 of pregnancy and remains elevated up to day 16 and  It, thereafter, started reducing significantly (P<0.01) on day 20, 30, 40 and reached undetectable level on day 50 of pregnancy. It may, therefore, be concluded that non- surgical removal of conceptus on day 14, 16, 18 and 20 of pregnancy extended the cycle length up to 8-47 days and strong expression of IFNT during day 14-16 of pregnancy indicating embryonic signal to dam and establishment of Maternal Recognition Pregnancy (MRP) in buffalo.