Two Loci Controlling Genetic Cellular Resistance to Avian Leukosis-Sarcoma Viruses

Abstract

Female chickens known to be heterozygous for resistance to subgroups A and B of the avian leukosis-sarcoma viruses were mated to males known to be homozygously resistant to both. The progeny were assayed both on the chorioallantoic membrane (CAM) and in tissue culture for resistance to representative viruses of the A, B, and tentatively defined C subgroups. Segregation ratios of resistance to A and B subgroup viruses agreed with the previously suggested hypothesis of single-autosomal-recessive genes controlling resistance to each subgroup. Mixed infection on the CAM and replicate plate infection in tissue culture with subgroup A and B viruses showed that resistance to the A and B subgroups was inherited independently. Assays with viruses tentatively classified as subgroup C indicated that they were largely composed of a mixture of subgroup A and B viruses or of particles possessing the host range specificity of both. However, virus stocks of the subgroup C category, as well as some stocks classified as subgroup B, produced small numbers of pocks or foci on individuals known to be resistant to subgroup A and B viruses. It is suggested that these Rous sarcoma virus stocks carry between 1 and 10% of a true subgroup C virus.

Genetics, the Immune Response and Oncogenesis

“…For example: The Ah gene of mice influences carcinogenesis by 3-methylcholanthrene by affecting the inducibihty of the enzyme aryl hydrocarbon hydroxylase which converts the inert, lipid-soluble 3-MCA into oncogenic, water-soluble forms (Kouri et al 1973(Kouri et al , 1974. The chicken genes tva, tvb and tvc affect cellular resistance to avian RNA tumor viruses of subgroups A, B (and possibly E) and C, respectively (Crittenden et al 1967, Payne & Biggs 1970, Pani 1974. Susceptibility is dominant and is mediated by a gene product which allows penetration and/or uncoating of viruses of the relevant subgroup (Piraino 1967, Crittenden 1968).…”

The receptor for the subgroup A avian leukosis-sarcoma viruses binds to subgroup A but not to subgroup C envelope glycoprotein

“…Susceptibility of chickens to infection by ALSV is governed by three genetic loci, tva, tvb, and tvc (7,21). The tva and tvc susceptibility alleles are thought to encode receptors or susceptibility factors for subgroup A and C viruses, respectively, whereas different alleles of tvb may encode receptors (or factors) for subgroups B, D, and E (21).…”

Effect of the Fv‐1 gene on leukemia virus in mouse cell heterokaryons

“…The dominant character of the Fv-1 gene suggests that the non-permissive state is not due to the inability of the cell to provide a function required for virus synthesis since F-1 hybrids or heterokaryons would possess the information for the missing function. Gene loci controlling susceptibility of cells to avian tumor viruses also have been identified (Crittenden, 1967;Rubin, 1965). However, in this system, the restriction is essentially absolute; susceptibility is dominant and appears to involve an event in virus penetration (Crittenden, 1968;Piraino, 1967).…”