FIG. 1.

(A) Abl oncogenes transduced by retrovirus infection. cDNAs carrying bcr-abl (b3a2), bcr-abl (b3a3), and ΔSH3 c-abl were ligated into the EcoRI site of the retroviral vector MSCV-IRES-gfp. Retroviral vectors were transfected into the packaging cell line Bosc23, to create viral stocks. The hatched region of ΔSH3 c-abl encodes the amino-terminal sequence of c-Abl type IV. MCSV, murine stem cell virus vector; IRES, internal ribosome entry site; LTR, long terminal repeat. (B) Transient expression of Abl oncoproteins in NIH 3T3 cells. Viral stocks produced from Bosc23 cells with the GFP vector (MSCV-IRES-gfp) or GFP vector containing the indicated abl oncogene were normalized to equivalent titers and used to infect NIH 3T3 cells. Two days after infection, cell lysates were prepared, run on 6 to 15% polyacrylamide gradient gels, transferred to nitrocellulose filters, and probed with anti-Abl (Ab-3), antiphosphotyrosine (PY20), or antiactin (AC-40) antibodies, as indicated. WB, Western blot.