A genome scan reveals QTL for growth, fatness, leanness and meat quality in a Duroc‐Pietrain resource population

Abstract

We performed a genome-wide QTL scan for production traits in a line cross between Duroc and Pietrain breeds of pigs, which included 585 F(2) progeny produced from 31 full-sib families genotyped with 106 informative microsatellites. A linkage map covering all 18 autosomes and spanning 1987 Kosambi cM was constructed. Thirty-five phenotypic traits including body weight, growth, carcass composition and meat quality traits were analysed using least square regression interval mapping. Twenty-four QTL exceeded the genome-wide significance threshold, while 47 QTL reached the suggestive threshold. These QTL were located at 28 genomic regions on 16 autosomal chromosomes and QTL in 11 regions were significant at the genome-wide level. A QTL affecting pH value in loin was detected on SSC1 between marker-interval S0312-S0113 with strong statistical support (P < 3.0 x 10(-14)); this QTL was also associated with meat colour and conductivity. QTL for carcass composition and average daily gain was also found on SSC1, suggesting multiple QTL. Seventeen genomic segments had only a single QTL that reached at least suggestive significance. Forty QTL exhibited additive inheritance whereas 31 QTL showed (over-) dominance effects. Two QTL for trait backfat thickness were detected on SSC2; a significant paternal effect was found for a QTL in the IGF2 region while another QTL in the middle of SSC2 showed Mendelian expression.

Detecção de locos de características quantitativas nos cromossomos 1, 2, 3, 12, 14, 15 e X de suínos: características de desempenho

“…Beeckmann et al (2003) encontraram QTL para CR a 117,2cM e 74,3cM e para GPD a 59,7cM, no SSC1 de suínos selvagens europeus x Pietrain. Liu et al (2007) encontraram QTL para GPD entre os marcadores SW1824 e SW1301, a 88,9cM no SSC1, o qual segregou em uma população Duroc x Pietrain.…”

“…Segundo Benevenudo Júnior (2001), ao estudar a presente população, os suínos Piau atingiram peso ao abate de 65kg após sete meses de idade, enquanto os suínos da linhagem comercial atingiram o peso ao abate entre quatro e cinco meses. Outros estudos encontraram na região proximal do SSC3, região do presente QTL para idade ao abate, QTL para peso ao nascimento (Malek et al, 2001;Quintanilla et al, 2002;Liu et al, 2007).…”

“…Na região central do SSC15 (64cM), entre os marcadores SW1989 e SW1119, encontrou-se QTL cromossômico a 5% de probabilidade para CR, associado aos alelos da linhagem comercial, o qual explicou apenas 0,10% da variação fenotípica. Resultado semelhante foi encontrado por Liu et al (2007), que detectaram QTL para consumo de ração no SSC15 com IC = 88,5 -119,9, o qual segregou em uma população Duroc x Pietrain, entre os marcadores SW936-SW1119, e explicou 2,0% da variação fenotípica. Já Houston et al (2005) encontraram QTL para consumo de ração dos 35 aos 55kg a 94,4cM e QTL para CR dos 35 aos 80kg a 83,1cM, o qual segregou em uma população Meishan x Large White.…”

Identification of pleiotropic genes and gene sets underlying growth and immunity traits: a case study on Meishan pigs

“…We should note that many QTL mapping designs used families that were developed by crossing European Wild Boar with a commercial breed or crossing the Chinese Meishan breed with a commercial breed (Rothschild et al, 2007). For example, an overlap could be formed by a growth-related QTL identified in a family generated by cross-breeding of Duroc and Pietrain (Liu et al, 2007) and an immunity-related QTL in a family generated by cross-breeding of Pietrain and Meishan (Reiner et al, 2008). Therefore, to decrease false-positive findings, we set the threshold to be a conservative value -10 kb.…”

Microsatellite mapping of quantitative trait loci affecting meat quality, stress hormones and production traits in Duroc × Large White F2 pigs

“…When QTL are detected in such populations, they cannot be directly used in selection programmes and additional studies are required to confirm the existence of these QTL in commercial populations. Nevertheless, genome scans are carried out on an increasing -E-mail: marie-pierre.sanchez@jouy.inra.fr number of crosses of commercial populations: Yorkshire 3 Berkshire (Malek et al, 2001a and2001b), Piétrain 3 Large White (Nezer et al, 2002), Iberian 3 Landrace (Varona et al, 2002), Hampshire 3 Landrace (Karlskov-Mortensen et al, 2005) or Duroc 3 Piétrain populations (Liu et al, 2007;Edwards et al, 2008a and2008b) and even on purebred commercial populations (Evans et al, 2003;Vidal et al, 2005;Tribout et al, 2008). All these studies revealed a large number of QTL, suggesting that different alleles are fixed in distinct commercial populations or that QTL are still segregating in purebred populations after many generations of selection.…”