title: Differential gene expression in cumulus oocyte complexes collected by ovum pick up from repeat breeder and normally fertile Holstein Friesian heifers.
abstract: The aim of this study was to establish whether perturbed gene expression during cumulus oocyte development causes repeat breeding in cattle. In this study, a repeat breeder was defined as a normal estrous cycling animal that did not become pregnant after three inseminations despite the absence of clinically detectable reproductive disorders. Transcripts of genes extracted from cumulus oocyte complexes (COC) that were collected from three repeat breeder and three normally fertile Holstein Friesian heifers were compared. Up to 40 COC were collected from each heifer by means of repeated sessions of ovum pick up in the absence of hormonal stimulation; immediately plunged into liquid nitrogen; and stored at -80°C until analysis. For each heifer, RNA was extracted from the pooled COC and hybridized on GeneChip(®) Bovine Gene Array (Affymetrix). Analysis of gene expression profiles of repeat breeder and control COC showed that 178 genes were differentially expressed (log2 fold change>1.5). Of these genes, 43 (24%) were up-regulated and 135 (76%) were down-regulated in repeat breeder relative to control heifers. This altered pattern of expression occurred in genes involved in several cellular biological processes and cellular components such as metabolism, angiogenesis, substrate/ion transport, regulation/signaling, cell adhesion and cytoskeleton. From these, 13 genes potentially involved in cumulus oocyte growth were subjected to validation by qRT-PCR and nine genes (annexin A1, ANXA1; lactoferrin, LTF; interferon stimulated exonuclease 20kDa, ISG20/HEM45; oxidized low density lipoprotein receptor 1, OLR1; fatty acid desaturase 2, FADS2; glutathione S-transferase A2 and A4, GSTA2 and GSTA4; glutathione peroxidase 1, GPX1; endothelin receptor type A, EDNRA) were confirmed to be differentially expressed. This study identified potential marker genes for fertility in dairy cattle.
authors.affiliation: Istituto Sperimentale Italiano Lazzaro Spallanzani, Loc. La Quercia, 26027 Rivolta d'Adda (CR), Italy. roberto.puglisi@istitutospallanzani.it
authors.forename: Roberto
authors.initials: R
authors.lastname: Puglisi
authors.forename: Caterina
authors.initials: C
authors.lastname: Cambuli
authors.forename: Rossana
authors.initials: R
authors.lastname: Capoferri
authors.forename: Laura
authors.initials: L
authors.lastname: Giannino
authors.forename: Aleksander
authors.initials: A
authors.lastname: Lukaj
authors.forename: Roberto
authors.initials: R
authors.lastname: Duchi
authors.forename: Giovanna
authors.initials: G
authors.lastname: Lazzari
authors.forename: Cesare
authors.initials: C
authors.lastname: Galli
authors.forename: Maria
authors.initials: M
authors.lastname: Feligini
authors.forename: Andrea
authors.initials: A
authors.lastname: Galli
authors.forename: Graziella
authors.initials: G
authors.lastname: Bongioni
mesh_terms: D000818:Animals; D002417:Cattle / Q000502:physiology*; D054885:Cumulus Cells / Q000378:metabolism*; D005260:Female; D005298:Fertility / Q000502:physiology*; D005786:Gene Expression Regulation / Q000502:physiology*; D054315:Oocyte Retrieval / Q000662:veterinary*; D011247:Pregnancy
keywords: Bovine; Fertility; Microarray; Ovarian follicle; Transcriptome