Figure 4

HnRNP A2/B1 expression in tissues and cells from 1B4 homozygous and wild type mice. (A) Analysis of hnRNP A2/B1 expression in wild type (+/+) and homozygous mutant (-/-) mice. Approximately 20 μg of total RNA was fractionated on a 1% formaldehyde agarose gel and hybridized to a ³²P labelled probe corresponding to the flanking sequence isolated by inverse PCR. The migration of the 18S ribosomal RNA is indicated. (B) Analysis of hnRNP A2/B1 expression in embryonic fibroblast cell lines derived from wild type (+/+), heterozygous (+/-), and homozygous mutant (-/-) mice. Approximately 20 μg of total RNA was fractionated on a 1% formaldehyde agarose gel and hybridized to a ³²P labelled probe corresponding to hnRNP A2/B1 exons located 3' of the site of provirus integration. Levels of GAPDH transcripts were used as an internal control for RNA loading. Homozygous mutant cells displayed a two-fold reduction in hnRNPA2/B1 transcript levels, as determined by phosphoimager analysis.