Figure 4.

Effect of the ROSA26 mutation on expression of the three transcripts. (A) Multiple adult tissue RNAs from wild-type and ROSA26 homozygous mutant mice were used on a Northern blot that was probed first for transcript 1 and then for transcript AS. He, heart; Ki, kidney; Li, liver; Lu, lung; Mu, muscle; Sp, spleen; Te, testis. (B) RT–PCR assays were done on adult kidney RNA samples obtained from wild-type or ROSA26 homozygous mutants as indicated. The RT reaction was carried out in the presence (+) or absence (−) of reverse transcriptase and with three different sets of primers that could specifically detect transcripts 1 (lanes 2–5), 2 (lanes 6–9), or 3 (lanes 10–13). The molecular size marker in lane 1 is the 1-kb ladder (GIBCO/BRL).