Nucleotide sequence analysis of the proviral genome of avian myelocytomatosis virus (MC29).

The nucleotide sequence of the integrated proviral genome of avian myelocytomatosis virus (MC29) coding for gag-myc protein has been determined. By comparison of this nucleotide sequence with the helper virus as well as the c-myc region, it was possible to localize the junction points between helper viral and v-myc sequences. These studies demonstrate that (i) the large terminal repeat sequence of MC29 is very similar to that of Rous sarcoma virus, (ii) the viral genome has suffered extensive deletions in the gag, pol, and env genes, (iii) the gag region can code for p19, p10, and part of p27, (iv) the recombination between viral and cellular sequences occurred in the coding region of p27 such that the open reading frame extends for an additional stretch of 1,266 base pairs, resulting in a gag-myc hybrid protein, (v) the open reading frame terminated within the v-myc region 300 bases upstream of v-myc-helper viral junction, and (vi) the v-myc helper-viral junction at the 3' end occurred in the middle of env gene, rendering it defective.