Bates P, Rong L, Varmus H E, Young J A, Crittenden L B
Department of Microbiology, University of Pennsylvania School of Medicine, Philadelphia 19104-6076, USA.
J Virol. 1998 Mar;72(3):2505-8. doi: 10.1128/JVI.72.3.2505-2508.1998.
A chicken gene conferring susceptibility to subgroup A avian sarcoma and leukosis viruses (ASLV-A) was recently identified by a gene transfer strategy. Classical genetic approaches had previously identified a locus, TVA, that controls susceptibility to ASLV-A. Using restriction fragment length polymorphism (RFLP) mapping in inbred susceptible (TVAS) and resistant (TVAR) chicken lines, we demonstrate that in 93 F2 progeny an RFLP for the cloned receptor gene segregates with TVA. From these analyses we calculate that the cloned receptor gene lies within 5 centimorgans of TVA, making it highly probable that the cloned gene is the previously identified locus TVA. The polymorphism that distinguishes the two alleles of TVA in these inbred lines affects the encoded amino acid sequence of the region of Tva that encompasses the viral binding domain. However, analysis of the genomic sequence encoding this region of Tva in randomly bred chickens suggests that the altered virus binding domain is not the basis for genetic resistance in the chicken lines analyzed.
最近通过基因转移策略鉴定出了一个使鸡对A亚群禽肉瘤和白血病病毒（ASLV-A）易感的基因。经典遗传学方法先前已鉴定出一个控制对ASLV-A易感性的基因座TVA。利用近交易感（TVAS）和抗性（TVAR）鸡系中的限制性片段长度多态性（RFLP）图谱，我们证明在93个F2后代中，克隆受体基因的RFLP与TVA共分离。通过这些分析我们计算出克隆的受体基因位于TVA的5厘摩范围内，这使得克隆基因极有可能就是先前鉴定出的基因座TVA。在这些近交系中区分TVA两个等位基因的多态性影响了Tva中包含病毒结合域区域的编码氨基酸序列。然而，对随机交配鸡中编码Tva该区域的基因组序列分析表明，在分析的鸡系中，改变的病毒结合域并非遗传抗性的基础。
