Abstract
Chicken cell DNA contains sequences which are homologous to the avian erythroblastosis virus oncogene v-erb. These cellular sequences (c-erb) have been isolated from a library of chicken cell DNA fragments generated by partial digestion with AluI and HaeIII and shown to be shared by at least two loci in the chicken DNA. One of them, denoted c-erbB, contains approximately 1.8 kilobase pairs of chicken DNA homologous to the 3' part of the v-erb oncogene (v-erbB). Restriction mapping studies show that the c-erbB DNA sequences homologous to v-erbB are distributed among six EcoRI fragments located in a single genomic region. Heteroduplexes between v-erbB in viral RNA and cloned c-erbB DNA show that the chicken DNA sequences homologous to v-erbB are interrupted by 11 DNA sequences not present in the v-erb oncogene. We conclude from our data that the c-erbB locus might represent the cellular progenitor for the v-erbB domain of the v-erb oncogene.