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Identifies the genetic regions in the swine genome that are responsible for economically important traits. Implementation of a quantitative trait loci (QTL) analysis by mating two female Meishan pigs with a male Gottingen pig; Effects of QTL for vertebra number on chromosomes one and two; Environmental effects included in the model of QTL analysis.

Discusses a research about the assignment of homologues of six genes located on human chromosome 8 to porcine chromosome 4 by fluorescence in situ hybridization. Suggestion that SSC4 gene encompasses several quantitative trait loci which are important in pig breeding for economic benefit; Claim that half of the SSC4 gene which are proximal to p-ter shares homology with human chromosome 8.

We performed a genome-wide association study using the porcine 60K SNP array to detect QTL regions for nine traits in a three-generational Duroc samples (n = 651), viz. generations 1, 2 and 3 from a population selected over five generations using a closed nucleus breeding scheme. We applied a linear mixed model for association mapping to detect SNP effects, adjusting for fixed effects (sex and season) and random polygenic effects (reflecting genetic relatedness), and derived a likelihood ratio statistic for each SNP using the efficient mixed-model association method. We detected a region on SSC6 for backfat thickness (BFT) and on SSC7 for cannon bone circumference (CANNON), with a genome-wide significance of P < 0.01 after Bonferroni correction. These regions had been detected previously in other pig populations. Six genes are located in the BFT-associated region, while the CANNON-associated region includes 66 genes. In the future, significantly associated SNPs, derived by sequencing the coding regions of the six genes in the BFT region, can be used in marker-assisted selection of BFT, whereas haplotypes constructed from the SSC7 region with strong LD can be used to select for the CANNON trait in our resource family., (© 2012 The Authors, Animal Genetics © 2012 Stichting International Foundation for Animal Genetics.)

Here, we analysed quantitative trait loci (QTL) for fatty acid composition, one of the factors affecting fat quality, in a Japanese wild boar x Large White cross. We found 25 significant effects for 17 traits at 13 positions at the 5% genome-wise level, of which 16 effects for 12 traits at 10 positions were significant at the 1% level. QTL for saturated fatty acids (SFA) in back fat were mapped to swine (Sus scrofa) chromosomes (SSC) 1p, 9 and 15. QTL for unsaturated fatty acids in back fat were mapped to SSC1p, 1q, 4, 5, 9, 15 and 17. Using a regression model that fits back fat thickness as a covariate, two of the QTL for linoleic acid content on SSC4 and SSC17 were not significant, but one QTL for total SFA composition was detected on SSC5 with correction for back fat thickness. Wild boar alleles at six of seven QTL tended to increase SFAs and to decrease unsaturated fatty acids. QTL for fatty acid composition in perirenal fat were mapped on SSC2, 3, 4, 5, 6, 14, 16 and X. QTL for melting point (in back fat samples) were mapped on SSC1, 2 and 15. Wild boar alleles in QTL on SSC1 and SSC15 were associated with elevated melting points whereas those on SSC2 were associated with lower melting point measurements.