FIG. 1.

Integration of F-MuLV into exon 13 of c-myb in the leukemia cell line 45-16. (A) Northern analysis of c-myb mRNA in a cell line derived from 45-16. Total RNAs from the myeloblast cell line, M1, and from the 45-16 cell line were electrophoresed, blotted, and hybridized with c-myb cDNA and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) probes. (B) RT-PCR analysis of 45-16. Total RNA from 45-16 was amplified following reverse transcription and electrophoresed on a 1% agarose gel containing 1 μg of ethidium bromide per ml. RNAs from M1 cells (lanes 1 to 3) or 45-16 cells (lanes 4 to 6) were reverse transcribed and amplified with an oligonucleotide primer overlapping the EcoRI site in exon 6 of c-myb in conjunction with an antisense F-MuLV LTR oligonucleotide (lanes 1 and 4), a sense LTR oligonucleotide (lanes 2 and 5), or an oligonucleotide with sequences from exons 11 and 12 (lanes 3 and 6). (C) Sequences at the c-myb exon 13–F-MuLV proviral junction in the mRNA from 45-16.