Analysis of mRNA expression profiles in bovine endometrium during the pre-attachment period using monocygotic twin pairs

To get new insights into molecular mechanisms underlying the embryo-maternal communication during the pre-implantation period endometrium samples from Day 18 pregnant vs. non-pregnant twin cows were analyzed using a combination of subtracted cDNA libraries and cDNA array hybridization. Keywords: Comparison of endometrium of pregnant versus control animals Endometrial tissue samples of day 18 pregnant cows (ET, n=5) were compared to non-pregnant controls (ST, n=5). Pair wise comparison was done within twin pairs (one pregnant twin versus the corresponding control twin). First, subtracted cDNA libraries were produced enriched for cDNAs of genes upregulated in pregnant animals starting from endometrial tissue samples of one twin pair (405/406). Overall 4608 clones of every library were picked and PCR-amplified cDNA fragments were spotted on three arrays. These three arrays were then simultaneously hybridized with P-33 labeled probes derived from the 10 tissue samples. cDNA clones with an upregulation of 2-fold or higher in at least 4 out of five twin pairs were set as interesting. Signals of these cDNA clones were manually evaluated to eliminate false-positive signal differences. These cDNA clones and some additional interesting cDNA clones were sequenced.