Intrauterine infusion of pathogenic bacteria persistently the transcriptome of oocytes.

To better understand the impact of infection on oocyte quality we employed global transcriptomics of oocytes collected from heifers after receiving intrauterine infusion of pathogenic Escherichia coli and Trueperella pyogenes. We hypothesized that oocyte transcriptome would be altered in response to intrauterine infection. A total of 452 differentially expressed genes were identified in oocytes collected from heifers 4 days after bacteria infusion compared to vehicle infusion, while 539 differentially expressed genes were identified in oocytes collected from heifers 60 days after bacteria infusion. Only 42 genes were differentially expressed in bacteria infused heifers at both day 4 and day 60. Interferon, HMGB1, ILK, IL-6 and TGF-beta signaling pathways were downregulated in oocytes collected at day 4 from bacteria infused heifers, while interferon, ILK and IL-6 signaling were upregulated in oocytes collected at day 60 from bacteria infused heifers. These data suggest that bacterial infusion alters the oocyte transcriptome differently at day 4 and day 60, suggesting different follicle stages are susceptible to damage. Characterizing the long-term impacts of uterine infection on oocyte transcriptome aids in our understanding of how infection causes infertility in dairy cattle. To understand the effect of uterine disease on the oocyte, we induced clinical endometritis in virgin heifers by intrauterine infusion of pathogenic E. coli and T. pyogenes. Oocytes were collected by transvaginal guided ultrasound at day 4 and day 60 post infection and subjected to global transcriptome analysis. We hypothesized that oocyte transcriptome would be altered in response to intrauterine infection. These data will enable us to better understand the consequence of uterine infection on the oocyte, and potential mechanisms by which infection reduces fertility in cattle.