Tissue-specific expression of neurexophilins in rats, mice, and humans. RNA blots are hybridized with neurexophilin 1 (Nph 1; A, E,I), neurexophilin 2 (Nph 2;B, F, J), neurexophilin 3 (Nph 3; C,G, K), and neurexophilin 4 (Nph 4; D, H,L) probes. RNA blots from mouse (A–D), rat (E–H), and human (I–L) tissues contained total RNA from heart (H; lane 1), brain (B; lane 2), spleen (S;lane 3), lung (Lu; lane 4), liver (Li; lane 5), skeletal muscle (Sk; lane 6), kidney (K; lane 7), and testis (T; lane 8). A single multitissue RNA blot (obtained from Clontech) from each species was consecutively hybridized with probes for each neurexophilin. Rat probes were used for all hybridizations except for the blots for human neurexophilins 3 and 4 (K and L) that were hybridized with human probes. Arrowheads for D andH mark the position of the 28S RNA that cross-hybridizes with the glycine- and cysteine-rich rat neurexophilin 4 probe. Positions of molecular size markers are indicated on theleft.