Gilmour D G, Collins W M, Fredericksen T L, Auclair B, Clark K K, Urban W E
Immunogenetics. 1983;17(1):43-54. doi: 10.1007/BF00364288.
Chickens of Regional Poultry Research Laboratory (RPRL) inbred line 6(3) regress sarcomas induced by Bryan high-titer Rous sarcoma virus to a greater extent than chickens of line 7(2), although these lines are identical for the major histocompatibility complex (MHC, B complex). They differ, however, at two independent autosomal loci, Ly-4 and Th-1, which determine surface alloantigens of partly overlapping subsets of T lymphocytes. Association of genotypes at these loci with quantitative variation in ability to regress Rous sarcomas was tested in segregating progeny derived from crosses of lines 6(3) and 7(2). In the F4 generation chickens of the Ly-4a/Ly-4a, Th-1a/Th-1a genotype (symbolized aa/aa) had significantly higher regressor ability than any of the other three double homozygous genotypes. In F5, all nine genotypes formed by combinations of homozygotes and heterozygotes were tested, and higher regressor ability was shown by the aa/aa, ab/aa, and aa/ab genotypes. These results indicate that higher regression is associated with: (1) interaction between the line 6(3) Ly-4a and Th-1a alleles in homozygous form; and (2) dominance x dominance interaction, in that the a allele at each locus is dominant for higher regression only within the homozygous aa genotype at the other locus.
区域家禽研究实验室（RPRL）近交系6(3)的鸡，比7(2)系的鸡能更显著地使由布莱恩高滴度劳氏肉瘤病毒诱导的肉瘤发生消退，尽管这两个品系在主要组织相容性复合体（MHC，B复合体）方面是相同的。然而，它们在两个独立的常染色体位点Ly-4和Th-1上存在差异，这两个位点决定了T淋巴细胞部分重叠亚群的表面同种异体抗原。在6(3)系和7(2)系杂交产生的分离后代中，测试了这些位点的基因型与劳氏肉瘤消退能力的数量变异之间的关联。在F4代中，Ly-4a/Ly-4a、Th-1a/Th-1a基因型（表示为aa/aa）的鸡比其他三种双纯合基因型中的任何一种都具有显著更高的消退能力。在F5代中，对由纯合子和杂合子组合形成的所有九种基因型进行了测试，aa/aa、ab/aa和aa/ab基因型表现出更高的消退能力。这些结果表明，更高的消退能力与以下因素有关：（1）纯合形式的6(3)系Ly-4a和Th-1a等位基因之间的相互作用；（2）显性×显性相互作用，即每个位点的a等位基因仅在另一个位点的纯合aa基因型内对更高的消退能力具有显性作用。
