Cloning and characterization of different human sequences related to the onc gene (v-myc) of avian myelocytomatosis virus (MC29)

Abstract

We have studied the genomic organization of human cellular sequences (c-myc) homologous to the transforming gene (v-myc) of avian myelocytomatosis virus (MC29). Southern blotting experiments using v-myc probes showed that several fragments of the human genome contain sequences related to the central part of v-myc but only few of them are homologous to the 3' portion of the viral gene. Several recombinant phages which represent different regions of the genome containing c-myc-related sequences were isolated from a human DNA library. Two clones (lambda-LMC-12 and -41) overlap over approximately 17 kilobases of DNA where a sequence homologous to that of the entire v-myc is present. Restriction mapping experiments and heteroduplex analysis show that c-myc sequences of this locus are interrupted by one intron, suggesting that lambda-LMC-12 and -41 contain the complete functional c-myc gene. Three other clones (lambda-LMC-3, -4, and -26) do not overlap and contain sequences related to only approximately 0.3 kilobase of v-myc but lack 5' and 3' portions of the gene. These sequences are not interrupted by introns and are more divergent from v-myc than is the complete gene, suggesting that they may represent either pseudogenes or parts of distantly related genes.