Fig. 5

SFPQ Protein Is Found in Axons, with Unprocessed RNA Targets and Spliceosome Component U1 snRNP70

Transverse single confocal sections of 24 hpf (A, N, and O) and 48 hpf (B–M) forebrain (A and I–K) or spinal cord dorsal to the top (G, H, L, and M) or to the left (B–D), and lateral view of head, anterior to the left (E and F).

(A–F) SFPQ protein expression shown by antibody staining (A–D) or GFP-tagged ectopically expressed protein (E and F). Identity of red, green, and blue staining is labeled on bottom right corner of each picture. Arrow shows axonal localization.

(G–K) Localization of first alternative introns (in red) of SFPQ-dependent transcripts, bcas3 (G and H), and gnao1a (I–K). Axons are stained by acetylated tubulin antibody in green.

(L and M) High-resolution imaging of bcas3 intron detection (L; red) in motor axons stained with acetylated tubulin antibody (M; green).

(N and O) Double antibody staining of U1 snRNP70 proteins (N) with acetylated tubulin (O; merged channels) in spinal axons. Arrows are pointing to motor axons. Scale bar, 25 μm.