Oviductal transcriptional profiling of a bovine fertility model by next-generation sequencing

Abstract

In cattle, the oviduct plays a fundamental role in the reproductive process. Oviductal functions are controlled by the ovarian sex steroids: estradiol and progesterone. Here, we tested the hypothesis that the exposure to contrasting sex steroid milieus differentially impacts the oviductal transcriptional profile. We manipulated growth of the pre-ovulatory follicle to obtain cows that ovulated a larger (LF group) or a smaller (SF group) follicle. The LF group presented greater proestrus/estrus concentrations of estradiol and metaestrus concentrations of progesterone (Gonella-Diaza et al. 2015 [1], Mesquita et al. 2014 [2]). Also, the LF group was associated with greater fertility in timed-artificial insemination programs (Pugliesi et al. 2016 [3]). Cows were slaughtered on day 4 of the estrous cycle and total RNA was extracted from ampulla and isthmus fragments and analyzed by RNAseq. The resulting reads were mapped to the bovine genome (Bos taurus UMD 3.1, NCBI). The differential expression analyses revealed that 325 and 367 genes in ampulla and 274 and 316 genes in the isthmus were up-regulated and down-regulated in LF samples, respectively. To validate the RNAseq results, transcript abundance of 23 genes was assessed by qPCR and expression patterns were consistent between the two techniques. A functional enrichment analysis was performed using Database for Annotation, Visualization and Integrated Discovery (DAVID) software. Processes enriched in the LF group included tissue morphology changes (extracellular matrix remodeling), cellular changes (proliferation), and secretion changes (growth factors, ions and metal transporters). An overview of the gene expression data was deposited in the NCBI's Gene Expression Omnibus (GEO) and is accessible through the accession number GSE65681. In conclusion, differences in the peri-ovulatory sex steroid milieu modify the oviductal gene expression profiles. Such differences may be associated with the greater fertility of the LF cows. This dataset is useful for further investigations of the oviductal biology and the impact of sex-steroid on the female reproductive tract.

Steroidal Regulation of Oviductal microRNAs Is Associated with microRNA-Processing in Beef Cows

“…Results from the animal model used here have been reported previously [ 8 , 9 , 10 , 21 ]. Growth of the preovulatory follicle was controlled with the aim to obtain cows that ovulated a small follicle and subsequently bore a small corpus luteum (CL; SF-SCL group) or a large follicle and large CL (LF-LCL).…”

“…A comprehensive analysis of the ampulla and isthmus transcriptome of cows in the LF-LCL and SF-SCL groups was reported previously [ 9 , 21 ]. In the ampulla region, a total of 692 genes showed differential expression, of which 325 and 367 were up-regulated in LF-LCL and SF-SCL samples, respectively.…”

“…In cattle, lower concentrations of estradiol during proestrus and lower concentrations of progesterone during early diestrus dysregulate oviductal and endometrial function to result in decreased fertility [ 7 , 8 , 9 , 26 ]. In the oviduct, dysregulation is manifested through tissue, cellular and molecular alterations associated with altered patterns of transcription, that are regionally specific [ 9 , 10 , 21 ]. Because a key regulation of transcript abundance is via miRNAs, here we tested the hypothesis that the periovulatory sex-steroid milieu affects the miRNA processing machinery and the expression of specific miRNA levels in bovine oviductal tissues.…”

“…Methods and general results from a transcriptomic analysis of tissues were published previously [ 9 , 21 ]. Briefly, ampulla and isthmus samples from three animals of each group were selected for individual RNA-Seq (please see details in the Statistical Analyses section).…”

Equine chorionic gonadotropin increases estradiol levels in the bovine oviduct and drives the transcription of genes related to fertilization in superstimulated cows

“…Temporal changes in steroid concentrations during the estrous cycle induce modulation of the oviductal transcriptional profile (Bauersachs et al, ; Binelli et al, ; Cerny, Garrett, Walton, Anderson, & Bridges, ). In general, E2 activity is associated with the stimulation of oviductal secretory cells, and cell proliferation, whereas P4 exhibits a suppressive effect (Binelli et al, ; Gonella‐Diaza et al, ). A detrimental effect of supra‐physiological P4 concentrations in the female reproductive tract as a result of ovarian superstimulation (OVS) protocols has been reported in cows (Forde et al, ; Gad et al, ; Roque et al, ).…”