Genetic Susceptibility of Chicken x Quail Hybrid Embryos to Avian RNA Tumour Viruses

An attempt was made to hybridize the chicken (Gallus domesticus) male with Japanese quail (Coturnix coturnix japonica) female in order to study the genetic susceptibility of hybrid embryos to avian RNA tumour viruses of subgroups, A, B, D and E. In the hybrids the results supported the prevailing concept that susceptibility is dominant over resistance regardless of the dominant trait contributed by either parent. It was also observed that the Ie gene of the chicken was unable to suppress the 'quail-coded' susceptibility to subgroup E virus in the hybrid system, suggesting the lack of penetrance of the Ie gene. Despite the fact that some hybrids were resistant to viruses of subgroups B and D, they were susceptible to subgroup E virus, which was not expected on the basis of the concept that subgroup B-resistant cells cannot be E-susceptible. Also, the hybrids were susceptible to E virus regardless of gs antigen expression and presence of the Ie gene in the genome. This indicates that our earlier suggestion that the Ie gene is another expression of the gs antigen-determining gene is inconsistent.