Fig. 1

Phenotype of whitesnake/sfpq mutants. A-Q: Brain ventricles were visualized by microinjecting a fluorescent dye, Rhodamine-dextran, into the hindbrain ventricle of living anesthetized embryos at 24 hours postfertilization (hpf, A-F), 28 hpf (G-I), and 2 dpf (J-Q). A-F: At 24 hpf, the wis^tr241 mutant has reduced brain ventricles and abnormal curvature of the tail (B,E), as compared with wild-type (A,D), and the sfpq^hi1779 mutant phenotype is similar (C,F). G-I: At 28 hpf, both wis^tr241 and sfpq^hi1779 show variable reduction in brain ventricle size and reduced pigmentation. J-Q: By 48 hpf, the wis brain ventricle reduction becomes more severe compared with wild-type, especially in the midbrain. A-C,G-I,N-Q: Dorsal views. D-F,J-M: Side views. F, forebrain; M, midbrain; H, hindbrain. Scale bar = 100 μm. R:sfpq gene/PSF protein and corresponding mutations. wis^tr241 has a C to T mutation at position 491 of coding sequence, which results in an early stop codon at amino acid 167. sfpq^hi1779 has a 6-kb retroviral insertion (which has a stop codon early in the insertion sequence). wis^m427 mRNA has aberrant splicing resulting in 200 base pairs of intronic sequence inserted before the last exon. Both sfpq^hi1779 and wis^tr241 are truncated near the end of P/Q-rich region, and wis^m427 lacks the last NLS. P/Q, proline/glutamine-rich region; RRMs, RNA recognition motifs; NLS, nuclear localization sequence.