Figure 2.

SNURF-specific mRNA analyses. (a) Extended exposure of a human multitissue Northern blot probed with SNURF exons 1–3. A major 1.6-kb product is present in all tissues, and a minor 0.5-kb species is seen in a subset of tissues. Only the 1.6-kb product is seen with probes from SNRPN exons 4–10 (8). Tissue types are: H, heart; B, brain; Pl, placenta; Lu, lung; Li, liver; SM, skeletal muscle; K, kidney; Pa, pancreas. (b) SNURF exon 3b. The exon is shown as boxed, capital letters, with flanking genomic sequence shown as lower case. Consensus sequences for polyadenylation (white letters in a black box) and splice acceptor (splice consensus, conformity indicated by a vertical line; y, pyrimidine) also are shown. An alignment of the homologous mouse genomic sequence is shown below; ∗ marks a point mutation of the splice acceptor consensus in mice. (c) Extended exposure of a mouse multitissue Northern blot probed with mouse Snurf exons 1–3. The 1.6-kb product is present in most tissues, but a 0.5-kb band is not observed in any tissue. Identical results are obtained for probes from Snrpn exons 4–10 (data not shown). Tissue types are as for a. S, spleen; T, testis.