Nassar M K, Goraga Z S, Brockmann G A
Albrecht Daniel Thaer-Institut for Agricultural and Horticultural Sciences, Faculty of Life Sciences, Humboldt-Universität zu Berlin, Berlin, Germany.
Department of Animal Production, Faculty of Agriculture, Cairo University, Giza, Egypt.
Anim Genet. 2015 Aug;46(4):441-6. doi: 10.1111/age.12298. Epub 2015 Apr 23.
Reciprocal crosses between the inbred lines New Hampshire (NHI) and White Leghorn (WL77) comprising 579 F2 individuals were used to map QTL for body weight and composition. Here, we examine the growth performance until 20 weeks of age. Linkage analysis provided evidence for highly significant QTL on GGA1, 2, 4, 10 and 27 which had specific effects on early or late growth. The highest QTL effects, accounting for 4.6-25.6% of the phenotypic F2 variance, were found on the distal region of GGA4 between 142 and 170 cM (F ≥ 13.68). The NHI QTL allele increased body mass by 141.86 g at 20 weeks. Using body weight as a covariate in the analysis of body composition traits provided evidence for genes in the GGA4 QTL region affecting fat mass independently of body mass. The QTL effect size differed between sexes and depended on the direction of cross. TBC1D1, CCKAR and PPARGC1A are functional candidate genes in the QTL peak region. Our study confirmed the importance of the distal GGA4 region for chicken growth performance. The strong effect of the GGA4 QTL makes fine mapping and gene discovery feasible.
利用近交系新罕布什尔鸡（NHI）和白来航鸡（WL77）之间的正反交，共579只F2个体，对体重和体组成的QTL进行定位。在此，我们研究了直至20周龄的生长性能。连锁分析为GGA1、2、4、10和27上高度显著的QTL提供了证据，这些QTL对早期或晚期生长有特定影响。在GGA4远端区域142至170 cM之间发现了最高的QTL效应，占F2表型变异的4.6 - 25.6%（F≥13.68）。NHI QTL等位基因在20周龄时使体重增加了141.86 g。在体组成性状分析中以体重作为协变量，为GGA4 QTL区域中独立于体重影响脂肪量的基因提供了证据。QTL效应大小在性别间存在差异，且取决于杂交方向。TBC1D1、CCKAR和PPARGC1A是QTL峰值区域的功能候选基因。我们的研究证实了GGA4远端区域对鸡生长性能的重要性。GGA4 QTL的强大效应使得精细定位和基因发现成为可能。
