Constructs for transfection. A 1.4-kb Sst I (S) fragment of the human β-actin promoter plus β-actin IVS-I was fused to various 3′ ends at the EcoRI (R) site:βAPr-Bcl-2 contains the normal genomic Bcl-2 3′ end, including the Bcl-2 poly(A) sites and 3′ flanking regions;βAPr-Ig contains a translocated allele cloned from SU-DHL-6, including the Bcl-2 mbr as well as the JH-CHand CH introns and the Cγ1 poly(A) sites and flanking regions; βAPr-Ig▵Introns contains a translocated cDNA from SU-DHL-6 and the genomic Cγ1 membrane (M) poly(A) signal and flanking regions; βApr-IgςIntron corresponds toβAPr-Ig▵Introns with the exception that a nonlymphoid intron (IVS-II of β-actin) is inserted as a substitute for the JH-CH intron. The transcriptional start site is indicated by an arrow. The EcoRI (R) and Xba I (X) sites were used for the S1 protections and primer extensions on the β-actin promoter.
