Genome-wide mapping of Quantitative Trait Loci for fatness, fat cell characteristics and fat metabolism in three porcine F2 crosses

Abstract

BackgroundQTL affecting fat deposition related performance traits have been considered in several studies and mapped on numerous porcine chromosomes. However, activity of specific enzymes, protein content and cell structure in fat tissue probably depend on a smaller number of genes than traits related to fat content in carcass. Thus, in this work traits related to metabolic and cytological features of back fat tissue and fat related performance traits were investigated in a genome-wide QTL analysis. QTL similarities and differences were examined between three F2 crosses, and between male and female animals.MethodsA total of 966 F2 animals originating from crosses between Meishan (M), Pietrain (P) and European wild boar (W) were analysed for traits related to fat performance (11), enzymatic activity (9) and number and volume of fat cells (20). Per cross, 216 (M × P), 169 (W × P) and 195 (W × M) genome-wide distributed marker loci were genotyped. QTL mapping was performed separately for each cross in steps of 1 cM and steps were reduced when the distance between loci was shorter. The additive and dominant components of QTL positions were detected stepwise by using a multiple position model.ResultsA total of 147 genome-wide significant QTL (76 at P < 0.05 and 71 at P < 0.01) were detected for the three crosses. Most of the QTL were identified on SSC1 (between 76-78 and 87-90 cM), SSC7 (predominantly in the MHC region) and SSCX (in the vicinity of the gene CAPN6). Additional genome-wide significant QTL were found on SSC8, 12, 13, 14, 16, and 18. In many cases, the QTL are mainly additive and differ between F2 crosses. Many of the QTL profiles possess multiple peaks especially in regions with a high marker density. Sex specific analyses, performed for example on SSC6, SSC7 and SSCX, show that for some traits the positions differ between male and female animals. For the selected traits, the additive and dominant components that were analysed for QTL positions on different chromosomes, explain in combination up to 23% of the total trait variance.ConclusionsOur results reveal specific and partly new QTL positions across genetically diverse pig crosses. For some of the traits associated with specific enzymes, protein content and cell structure in fat tissue, it is the first time that they are included in a QTL analysis. They provide large-scale information to analyse causative genes and useful data for the pig industry.

Tissue expression, association analysis between three novel SNPs of the RXRα gene and growth traits in Chinese indigenous cattle

“…edu/cgi-bin/QTLdb/BT/index), we only found milk traits in this region, however, some QTLs about growth and meat quality traits were found on the animals that were usually used to study the growth and meat quality traits, such as the swine and chicken RXR gene. The swine RXR gene located on chromosome 1 about from 288.83 to 288.86 Mb, in this region some QTLs associated with production and meat quality traits was mapped, such as abdominal fat weight [29], backfat [30,31], body weight [32] and average daily gain [32,33]. The chicken RXR gene was located on chromosome 17 about from 7.27 to 7.35 Mb, and we found some QTLs associated with meat quality traits located in this region, such as abdominal fat percentage and drumstick weight [34], bone mineral content and tibia length [35], abdominal fat weight [36], body weight [37].…”

Polymorphism, linkage mapping, and association analysis with carcass traits of four porcine candidate genes selected from gene-expression profiles of Czech Large White and Wild Boar muscles

“…in the PN × (CZL × CZLW) population, which had significantly higher values in genotype CC (and In a Wild Boar × Pietrain F 2 cross, significant QTL for ham meat weight, dressing B and shoulder meat weight were found in this chromosome interval of SSC4 (Cepica et al, 2003b). No significant QTL were detected in this chromosome interval in Meishan × Pietrain and Wild Boar × Meishan crosses (Cepica et al, 2003b;Geldermann et al, 2010). In a Berkshire × Yorkshire F 2 cross, the position of SORT1 is expected to be in the chromosome interval for QTL for loin eye area, carcass weight, last rib back fat, and average daily gain (Malek et al, 2001).…”

Preadipocyte and Adipose Tissue Differentiation in Meat Animals: Influence of Species and Anatomical Location

“…Distribution of adipocyte cell diameters determined by histological preparations of adipose tissue and collagenase-isolated adipocyte showed genotype-specific differences and a lower proportion of large adipocytes in LWQTL7/MSQTL7 pigs (162). Several other studies detected QTL that influence fat cell size and relative fat cell number through genome-wide mapping of QTL of F2 animals originating from crosses between Meishan, Pietrain, and European wild boar (163). Of the 41 QTL detected for fat cell traits, 73% were found on SSC7, of which 34% were for relative fat cell number and 39% were for relative fat cell size.…”