Endometrial transcriptome changes in comparison of equine endometrium samples collected on Day 12 of pregnancy and Day 12 of the estrous cycle

Establishment and maintenance of pregnancy in equids is only partially understood. To provide new insights into early events of this process, we performed a systematic analysis of transcriptome changes in the endometrium at days 8 and 12 of pregnancy. Endometrial biopsy samples from pregnant and non-pregnant (Day 12) stages were taken from the same mares. Composition of the collected biopsy samples was analyzed using quantitative stereological techniques to determine proportions of surface and glandular epithelium and blood vessels. RNA-seq analysis was performed and differentially expressed genes were identified. The samples used for RNA-seq were already analyzed before by the use of Agilent microarrays (GSE21046). Messenger RNA profiles of equine endometrial biopsies collected on Day 12 of pregnancy and Day 12 of estrous cycle, respectively, from in total 4 healthy mares were generated by RNA-sequencing using Illumina Genome Analyzer IIx, one pregnant and one control (non-pregnant) sample were taken from every mare by random order