Effect of fixed-time artificial insemination on corpus luteum gene expression at the day 16 and 25 pregnancy of gilt.

Utilization of female livestock can be optimized by application of Fixed-Time Artificial Insemination (FTAI), which plays an important role in large-scale livestock production. However, molecular mechanism of FTAI affecting reproductive performance remains unclear. To investigate the effects of FTAI on corpus luteum in 16 and 25 days of pregnancy gilts, 12 pregnancy gilts were selected from Altrenogest + PMSG + GnRH (APG) group and control group. The number of left and right CL in APG group were significantly higher than control (p < 0.05). Furthermore, result showed the number of differentially expressed genes between 16APG group and 16 C group was obviously larger than that between 25APG and 25 C group (2394 vs. 1476). Up regulated genes in APG were mainly associated with cytokine production and secretion, cell communication and transport (day 16) and angiogenesis, cell cycle and cell-cell signaling (day 25). The expression of differentially expressed genes (RPL10, CYP17A1, DCN, IL18, LDLR and PRLR) in luteal tissue were verified by real-time PCR. In summary, APG program significantly improve reproductive efficiency of gilts through up regulation of cytokine production/secretion, cell communication and transport in Day 16 pregnancy and angiogenesis, cell cycle and cell-cell signaling at Day 25 pregnancy in porcine.