Figure 3.

Distribution of alternatively spliced gephyrin sequences in murine non-neuronal tissues and brain. Oligonucleotide probes specific for the alternatively spliced exons 3 (C2: A), 13 (C5: B), 19 (C6: C), and the invariant 3′ region of the murine gephyrin mRNA (T1: D Upper) as well as for β actin transcripts (D Lower) were hybridized to a multiple tissue Northern blot. The exon 3 probe revealed a predominant 3.8-kb transcript in liver in addition to differentially spliced mRNAs in heart, brain, liver, kidney, and testis (A). The exon 13 probe hybridized to a mRNA of 6.5 kb in muscle and heart (B). Expression of transcripts containing exon 19 (C) was seen in liver (3.8 and 2.2 kb), skeletal muscle (6.5 and 3.6 kb), and possibly testis (≈9 kb and 2.2 kb). In addition, higher molecular weight mRNAs were detected in heart (6.5 kb). In brain, heterogeneous bands 5–9 kb were labeled. The T1 probe detected 3.6- to 3.8-kb RNAs in all tissues examined except spleen (D Upper). Control hybridizations obtained with a probe specific for β actin transcripts also are shown (D Lower).