January 15-19, 2011
Town & Country Convention Center
San Diego, CA
Ingrid Balcells1 , Oriol Timoneda1 , Susanna Cirera2 , Rolf Søkilde3 , Thomas Litman3 , Amanda Fernández-Rodríguez4 , Jose Luís Noguera5 , Armand Sanchez1 , Anna Tomàs1
Reproductive traits, like prolificacy, are complex traits of economical interest for swine breeders. To better understand the genetic architecture of these traits, an F2 intercross was created between 18 Meishan (Me) sows and 3 Iberian (Ib) boars, breeds that show highly divergent phenotype in prolificacy traits. During pregnancy, the ovarian gene expression is controlled by epigenetic factors, like microRNAs (miRNAs), to ensure a proper synthesis of hormones essential for conceptus maintenance. The aim of this work was to study the ovarian miRNA profile of pregnant sows and to determine whether there are differences in the pattern of miRNA expression which could be attributed to the prolificacy level. Total RNA from six F2 IbxMe sows, classified into two groups according to the number of embryos (NE) at 30-32 days of gestation as high (NE≥16; n=3) or low (NE≤6; n=3) prolificacy, were hybridized on miRCURY LNA microRNA microarrays (Exiqon) contaning 1891 capture probes targeting miRNAs from human, mouse and rat registered in the miRBASE v14.0. Microarray data was quantile normalized and differential expression was analyzed by dChip software. Ten miRNAs seemed to be differentially expressed between high and low prolificacy sows when a low stringent threshold of significance was used (p-value<0.2). Among these, one miRNA was statistically significant (p-value<0.05): miR-142-3p. This is an interesting miRNA candidate since it has been associated with human endometriosis disease and targets with genes involved in reproductive processes like SLC38A4, PRLR, FMR1, HMGA2 and ARNTL. qPCR analyses are now being performed to validate and quantify these results.