Smith E J, Fadly A M
USDA, Agricultural Research Service, East Lansing, Michigan 48823.
Poult Sci. 1988 Dec;67(12):1674-9. doi: 10.3382/ps.0671674.
After contact exposure to Strain RPL-40 avian leukosis virus-infected hatchmates, a dilatory neutralizing antibody response and prolonged RPL-40 viremia was found among most pullets that were congenitally infected with endogenous virus 21 (EV21). Conversely, most of the hatchmates that were not congenitally infected seroconverted within 10 wk after exposure to Strain RPL-40 virus. Compared with noncongenitally infected hatchmates, EV-21 infection-induced tolerance to pathogenic avian leukosis viruses was reflected in a significantly higher incidence of lymphomas in congenitally infected hens. The rate of seroconversion and the incidence of RPL-40 virus-induced tumors among noncongenitally infected daughters from slow-feathering dams homozygous resistant to EV were similar to those found among daughters of rapid-feathering dams that lacked genetic locus ev21. Results suggest that selection for resistance to EV may eliminate tolerance toward oncogenic field strains of avian leukosis viruses and may improve the performance of progeny from a feather-sex cross.
在与感染RPL - 40株禽白血病病毒的同窝雏鸡接触后，发现大多数先天性感染内源性病毒21（EV21）的小母鸡存在延迟的中和抗体反应以及持续时间较长的RPL - 40病毒血症。相反，大多数未先天性感染的同窝雏鸡在接触RPL - 40株病毒后10周内血清转化。与未先天性感染的同窝雏鸡相比，EV - 21感染诱导的对致病性禽白血病病毒的耐受性表现为先天性感染母鸡中淋巴瘤的发生率显著更高。对EV纯合抗性的慢羽母鸡所产未先天性感染的子代中，血清转化率和RPL - 40病毒诱导肿瘤的发生率与缺乏ev21基因座的快羽母鸡所产子代相似。结果表明，选择对EV的抗性可能消除对禽白血病病毒致癌野毒株的耐受性，并可能改善羽速性别杂交后代的性能。
