Boa-Amponsem K, Larsen C T, Dunnington E A, Price S E, Yang A, Siegel P B
Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, 24061-0306, USA.
Poult Sci. 1998 Aug;77(8):1073-80. doi: 10.1093/ps/77.8.1073.
Two lines of White Leghorns that had undergone long-term selection for high (HH) or low (LL) antibody response to sheep red blood cell antigen(s) formed the nuclear lines for this experiment. Matings were made in a full diallel cross to produce in a single hatch from age-contemporary breeders the parental lines, reciprocal F1 and F2 crosses, and backcrosses for 16 progeny types. For males and females, there were parental line differences in BW to 42 d of age, after which there was decline between lines for males. Differences in BW between reciprocal F1 crosses and maternal heterosis declined with age, primarily reflecting dissipation of effects of egg weight. Heterosis of BW was dependent on the particular F1 cross and recombination effects were not important. At 50 d of age chicks were inoculated with either a 1 or 10% suspension of spleen extract from chickens infected with marble spleen disease virus (MSDV). A third group served as uninjected controls. Response to MSDV was evaluated by spleen weight 6 d after inoculation. Spleen weights relative to BW of control chicks were heavier for the HH than LL line with evidence from the crosses of sexlinkage and negative heterosis. Line LL chicks were more resistant to MSDV than Line HH chicks was F1 crosses intermediate to and different from either parental line with no evidence of heterosis.
两个对白血细胞抗原产生高（HH）或低（LL）抗体反应经过长期选择的白来航鸡品系构成了本实验的核心品系。进行完全双列杂交交配，以便从年龄相当的育种鸡中在同一批孵化中产生亲本品系、正反交F1和F2杂交后代以及回交后代，共16种后代类型。对于雄性和雌性，42日龄前体重存在亲本品系差异，之后雄性品系间体重出现下降。正反交F1杂交后代间的体重差异和母体杂种优势随年龄下降，主要反映了蛋重效应的消散。体重杂种优势取决于特定的F1杂交组合，重组效应并不重要。50日龄时，给雏鸡接种感染大理石脾病病毒（MSDV）的鸡脾脏提取物1%或10%的悬液。第三组作为未注射对照。接种后6天通过脾脏重量评估对MSDV的反应。与对照雏鸡体重相比，HH品系的脾脏重量比LL品系重，杂交后代有性连锁和负杂种优势的证据。LL品系雏鸡比HH品系雏鸡对MSDV更具抗性，F1杂交后代介于两个亲本品系之间且与二者不同，没有杂种优势的证据。
