V-15B, AN ALLELE OF CHICKENS FOR THE PRODUCTION OF A NON-INFECTIOUS AVIAN-LEUKOSIS VIRUS

Evidence is presented that 15B chickens have a dominant allele V-15B for the expression of a noninfectious avian leukosis virus. This virus is designated 15B-ILV. In genetic crosses V-15B cosegregated with ev 7 a genetic locus which contains structural genes for virus. The expression of 15B-ILV was tightly controlled in V-15B cells. The expression of other ALV germ line and infection proviruses was not affected by V-15B. These results suggest that V-15B consists of cis-dominant control sequences as well as structural sequences for 15B-ILV. 15B cells also contain a putative allele Gr-E which codes for high levels of replication of subgroup E viruses. In genetic crosses V-15B was shown to reside at a distinct genetic locus from Gr-E. © 1979.