Transcriptional profiling of bovine endometrial tissue at day 17 of the reproductive cycle

Over the past three decades, there has been a significant decline in dairy cattle fertility. A large proportion of pregnancy losses are believed to occur during the pre-implantation period, when the developing embryo is elongating rapidly and signaling its presence to the maternal system. The molecular mechanisms that prevent progression of the estrous cycle and allow the allogenic embryo to survive within the maternal environment are not well understood. To gain a more complete picture of these molecular events, global transcriptional profiling was performed using endometrial tissues from reproductive day 17 pregnant and non-pregnant (cycling) Holstein-Friesian dairy cattle. 22 animals were enrolled in this study, 2 samples from each animal were used for microarray analysis consisting of caruncular and intercaruncular endometrium. A reference design was used for hybridisation, whereby each of the 44 samples were hybridised to individual microarrays along with a pooled reference sample. The reference sample was generated by taking equal concentrations of each of the experimental samples.