The SSC15 QTL-Rich Region Mutations Affecting Intramuscular Fat and Production Traits in Pigs

One of the more interesting regions in the pig genome is on chromosome 15 (115,800,000-122,100,000, SSC15, Sus scrofa 11.1) that has high quantitative trait locus (QTL) density associated with fattening, slaughter and meat quality characteristics. The SSC15 region encodes over 80 genes and a few miRNA sequences where potential genetic markers can be found. The goal of the study was to evaluate the effects of SSC15 mutations associated with villin 1 (VIL1), tensin 1 (TNS1), obscurin-like 1 (OBSL1) genes and with one long non-coding RNA (lncRNA) on productive pig traits and to enrich the genetic marker pool in further selection purpose. The potential genetic markers were identified using the targeted enrichment DNA sequencing (TEDNA-seq) of chromosome 15 region. The selected mutations were genotyped by using HRM, PCR and PCRRFLP methods. The association study was performed using the general linear model (GLM) in the sas program that included over 600 pigs of 5 Polish populations. The rs332253419 VIL1 mutation shows a significant effect on intramuscular fat (IMF) content in Duroc population where AA pigs had a 16% higher level than heterozygotes. The IMF content is also affected by the OBSL1 mutation, and the differences between groups are even up to 30%, but it is strongly dependent on breed factor. The OBSL1 mutation also significantly influences the meat yellowness, backfat thickness and pH level. The performed study delivers valuable information that could be highly useful during the development of the high-throughput genotyping method for further selection purposes in pigs. The OBSL1 and VIL1 mutations seem to be the most promising DNA marker showing a high effect on IMF level.