Technical Note: Bovine Oviduct and Endometrium Array Version 1: A Tailored Tool for Studying Bovine Endometrium Biology and Pathophysiology

Abstract

Fertility problems are the main reason for slaughter of high-performance milk cows, because elongated calving intervals result in financial losses for the farmer and retard genetic progress. Genetic improvement of fertility would be of great benefit, but functional traits for effective selection are missing. Recent advances in functional genomics tools like DNA microarrays could be the key to identify gene expression patterns in the endometrium that correlate with maternal fertility. Therefore, a first version of a bovine oviduct and endometrium cDNA array was established that contains a set of 1,440 cDNA clones and long oligonucleotides representing 950 different genes. The major part of these genes has been identified in a series of differential gene expression studies in endometrium (different stages of the estrous cycle, d 18 pregnant vs. nonpregnant) and in oviduct epithelial cells (different stages of the estrous cycle) using a combination of subtracted cDNA libraries and cDNA array hybridization. Furthermore, cDNA clones of genes, which showed no changes in their mRNA levels in the analyzed tissues, were added as controls. Reproducibility of the array hybridization, a comparison with the Affymetrix bovine genome array, and confirmation of differential gene expression with reverse transcription-quantitative PCR is shown. Potential future applications include systematic studies of interactions between metabolic status and functionality of the endometrium to identify genes that could be used for differential diagnosis of fertility problems. Further, endometrium transcriptome profiles may serve as novel traits to improve fertility by genetic selection.

The endometrium responds differently to cloned versus fertilized embryos

“…Total RNA was isolated from intercaruncular endometrium samples (10 IVF pregnancies and 9 SCNT pregnancies with embryos from 4 different genotypes) and was used for gene expression profiling with a custom cDNA microarray, the Bovine Oviduct and Endometrium (BOE) array, that contains 950 different transcripts, most of which are differentially expressed in bovine endometrium and/or oviduct epithelium during the estrous cycle or early pregnancy (18). Overall, the variation of gene expression levels in the endometrial samples was greater for SCNT than for IVF pregnancies (P Ͻ 0.00001); the mean coefficient of variation of normalized signal values for the differentially expressed genes was 1.87% in the IVF group and 2.74% in the SCNT group.…”

Dynamic changes in messenger RNA profiles of bovine endometrium during the oestrous cycle

“…To analyse gene expression changes in the bovine intercaruncular endometrium during the oestrus cycle at the level of the mRNA, a custom-made cDNA array (BOE array) was used (Bauersachs et al 2007). This array contains 1344 cDNA fragments and 96 oligonucleotides representing 950 different genes.…”

“…The generation of the BOE array has been described previously (Bauersachs et al 2007). Fifteen microlitres of the PCR products of the cDNA fragments and 15 ml long oligonucleotides (50 ng/ml; Operon, Cologne, Germany) were transferred to 384-well microtitre plates (Abgene, Epsom, Surrey, UK) containing 15 ml twofold spotting buffer (40 mM Tris-HCl (pH 8.0), 2 M NaCl, 2 mM EDTA, bromophenol blue).…”

“…In the present study, a custom-made bovine oviduct and endometrium (BOE) cDNA array (Bauersachs et al 2007) was used to generate mRNA expression profiles of the bovine endometrium during the oestrous cycle. Molecular pathways were identified as related to the biological functions of the endometrium in the context of recognition and establishment of early pregnancy.…”

Genes involved in conceptus–endometrial interactions in ruminants: insights from reductionism and thoughts on holistic approaches

“…Further, custom arrays from the endometrium have been made for transcriptional profiling experiments in sheep (Chen et al 2006, Gray et al 2006 and cattle (Bauersachs et al 2007). The advent of commercially available bovine arrays from the bovine oligo microarray consortium (www.bovineoligo.org) and commercial companies should enhance research profiling gene expression in ruminant embryos and endometria.…”