Abasht Behnam, Pitel Frédérique, Lagarrigue Sandrine, Le Bihan-Duval Elisabeth, Le Roy Pascale, Demeure Olivier, Vignoles Florence, Simon Jean, Cogburn Larry, Aggrey Sammy, Vignal Alain, Douaire Madeleine
UMR Inra-Agrocampus Génétique animale, 35042 Rennes, France.
Genet Sel Evol. 2006 May-Jun;38(3):297-311. doi: 10.1186/1297-9686-38-3-297. Epub 2006 Apr 26.
Quantitative trait loci (QTL) affecting fatness in male chickens were previously identified on chromosome 5 (GGA5) in a three-generation design derived from two experimental chicken lines divergently selected for abdominal fat weight. A new design, established from the same pure lines, produced 407 F2 progenies (males and females) from 4 F1-sire families. Body weight and abdominal fat were measured on the F2 at 9 wk of age. In each sire family, selective genotyping was carried out for 48 extreme individuals for abdominal fat using seven microsatellite markers from GGA5. QTL analyses confirmed the presence of QTL for fatness on GGA5 and identified a QTL by sex interaction. By crossing one F1 sire heterozygous at the QTL with lean line dams, three recombinant backcross 1 (BC1) males were produced and their QTL genotypes were assessed in backcross 2 (BC2) progenies. These results confirmed the QTL by sex interaction identified in the F2 generation and they allow mapping of the female QTL to less than 8 Mb at the distal part of the GGA5. They also indicate that fat QTL alleles were segregating in both fat and lean lines.
先前在一个三代设计中，从两个针对腹脂重量进行了反向选择的实验鸡系衍生而来，在5号染色体（GGA5）上鉴定出了影响雄性鸡脂肪含量的数量性状基因座（QTL）。基于相同的纯系建立了一个新设计，从4个F1父本家系产生了407个F2后代（雄性和雌性）。在9周龄时对F2代的体重和腹脂进行了测量。在每个父本家系中，使用来自GGA5的7个微卫星标记对48个腹脂极端个体进行了选择性基因分型。QTL分析证实了GGA5上存在脂肪含量的QTL，并通过性别互作鉴定出一个QTL。通过将一个在该QTL处杂合的F1父本与瘦肉系母本杂交，产生了3个重组回交1（BC1）雄性，并在回交2（BC2）后代中评估了它们的QTL基因型。这些结果证实了在F2代中鉴定出的通过性别互作的QTL，并将雌性QTL定位到GGA5远端小于8 Mb的区域。它们还表明脂肪QTL等位基因在脂肪系和瘦肉系中均发生了分离。
