BioProject

The equine endometrium exhibits characteristic morphological and functional changes during the estrous cycle controlled by the interplay of progesterone and estradiol. More...

The equine endometrium exhibits characteristic morphological and functional changes during the estrous cycle controlled by the interplay of progesterone and estradiol. A microarray analysis of endometrial tissue samples derived from 5 time points of the estrous cycle (D0, D3, D8, D12, and D16) was performed to study the dynamics of endometrial gene expression. Endometrial biopsies were collected from five mares (Bavarian Warmblood) at the respective time points. Samples were divided and subjected to isolation of RNA for microarray analysis and analysis of tissue composition. Blood samples were collected to determine serum progesterone levels for every sample. Statistical analysis of microarray data revealed almost 10,000 differential probes corresponding to 4,996 differentially expressed genes. A cluster analysis based on gene expression profiles during the estrous cycle revealed 8 major gene expression profiles: mRNAs with highest levels 1) at D0, 2) from D0 to D3, 3) at D3, 4) from D3 to D8, 5) at D8, 6) from D8 to D12, 7) from D12 to D16, and 8) at D16. DAVID Functional Annotation Clustering revealed overrepresentation of distinct functional terms in different phases of the cycle, e.g. ‘extracellular matrix’ and ‘protein transport’ during estrus, ‘DNA replication and ‘cell cycle’ during early luteal phase, ‘endoplasmic reticulum’ and ‘protein transport’ in the luteal phase, and ‘inflammatory response’ in the late luteal and follicular phase. Expression of selected genes of the expression clusters was validated by quantitative Real-time PCR (qPCR). This study provides new insights into global changes of equine endometrial gene expression during the estrous cycle. Overall design: Equine endometrial tissue samples were collected at 5 time points during the sexual (estrous) cycle from 5 mares (5 biological replicates per time point) and analyzed with Agilent microarrays. Less...