110 Temporal Changes in Endometrial Gene Expression Between Ipsi- and Contralateral Uterine Horns in Cattle

J. M. Sánchez; C. Passaro; N. Forde; S. Behura; J. A. Browne; D. J. Mathew; S. T. Butler; T. E. Spencer; P. Lonergan

doi:10.1071/RDv30n1Ab110

RESEARCH ARTICLE

110 Temporal Changes in Endometrial Gene Expression Between Ipsi- and Contralateral Uterine Horns in Cattle

J. M. Sánchez ^A , C. Passaro ^A , N. Forde ^B , S. Behura ^D , J. A. Browne ^A , D. J. Mathew ^A , S. T. Butler ^C , T. E. Spencer ^D and P. Lonergan ^A

+ Author Affiliations

- Author Affiliations

^A School of Agriculture and Food Science, University College Dublin, Dublin, Ireland;

^B School of Medicine, University of Leeds, Leeds, United Kingdom;

^C Animal and Grassland Research and Innovation Centre, Teagasc, Moorepark, Fermoy, Co. Cork, Ireland;

^D Division of Animal Sciences, University of Missouri, Columbia, MO, USA

Reproduction, Fertility and Development 30(1) 194-195 https://doi.org/10.1071/RDv30n1Ab110
Published: 4 December 2017

Abstract

The transfer of an embryo into the uterine horn contralateral to the ovary bearing the corpus luteum has been associated with a decreased pregnancy rate in cattle compared with transfer into the ipsilateral horn. These findings suggest that the environment in the contralateral horn is less conducive to supporting conceptus development than that of the ipsilateral horn. Therefore, this study compared the endometrial transcriptome of the ipsi- and contralateral uterine horns during the luteal phase. Endometrial samples from the ipsi- (IPSI) and contralateral (CONTRA) horns were collected from synchronized nonpregnant beef heifers on Days 5, 7, 13 or 16 post-oestrus (n = 5 heifers per time point). Total RNA was isolated and sequenced. Differences in the transcriptome were determined by edgeR-robust analysis. Principal component analysis found that IPSI and CONTRA have distinct patterns of gene expression on each day, with Day 5 exhibiting the most variation and Day 16 being least variable. Further, the 2 uterine horns had distinct expression patterns on Day 5, with IPSI exhibiting significantly higher variation in gene expression compared twitho CONTRA. EdgeR-robust analysis found 217 (201 up- and 16 down-regulated), 54 (44 up- and 10 down-regulated), 14 (13 up- and 1 down-regulated), and 18 (14 up- and 4 down-regulated) differentially expressed genes (DEG; >2-fold change, false discovery rate P < 0.05) between IPSI and CONTRA endometria on Days 5, 7, 13, and 16 of the oestrous cycle, respectively. The top 5 canonical pathways associated with DEG between IPSI and CONTRA during the luteal phase of the oestrous cycle were involved in signalling pathways regulating pluripotency of stem cells (73/138), progesterone-mediated oocyte maturation (55/89), endometrial cancer (31/51), ErbB signalling pathway (50/87), and mTOR signalling pathway (36/61). The impact of DEG on signalling pathways was assessed using a pathway perturbation algorithm called Signalling Pathway Impact Analysis (SPIA). This topology-based pathway analysis was conducted using the Bioconductor ToPAseq package (https://bioconductor.org/packages/release/bioc/html/ToPASeq.html) and revealed that signalling pathways regulating pluripotency of stem cells showed the highest perturbation score when IPSI was compared with CONTRA irrespective of day. Discovering and cataloguing which pathways are perturbed in each uterine horn throughout the oestrous cycle may contribute to our understanding of the mechanisms underlying early embryonic loss.

Ths study was supported by Science Foundation Ireland (13/IA/1983) and the Irish Department of Agriculture, Food and The Marine (13S528).