EV-3, A STRUCTURAL GENE LOCUS FOR ENDOGENOUS VIRUS, SEGREGATES WITH THE GS+CHF+ PHENOTYPE IN MATINGS OF LINE 6-3 CHICKENS

ev 3 is one of seven recently described genetic loci of the chicken which contain structural genes for endogenous virus (S. M. Astrin, 1978, Proc. Nat. Acad. Sci. USA75, 5941-5945). ev 3 is present exclusively in chickens of the gs+chf+ phenotype, that is, chickens whose cells produce endogenous viral group-specific antigen (gs) and viral envelope protein (chf). The segregation of ev 3 was followed in a genetic cross in which the gs+chf+ phenotype was also segregating. The progeny of the cross were analyzed for endogenous viral loci by cleavage of embryo DNA with restriction endonuclease Sst 1, electrophoretic separation of the resulting fragments, and detection of bands containing viral sequences by hybridization of the DNA to radiolabeled viral RNA. Four endogenous viral loci, ev 1, ev 3, ev 4, and ev 5, were identified in the progeny of the cross. ev 1 was present in all of the progeny. ev 4 and ev 5 were present in progeny of both the gs+chf+ and gs- chf- phenotypes and were observed to be genetically linked. ev 3 was present exclusively in progeny of the gs+chf+ phenotype and all progeny of this phenotype contained ev 3. From these data, we suggest that ev 3 codes for gs and chf in the cells of gs+chf+ chickens. © 1979.