Fig. 3

Mutations of both pku300 and fbn2b contributed to sco^te382 mutant phenotypes. The endocardium in the atrium, ventricle and CCV were labeled by the Tg(kdrl:EGFP) transgene. The endocardium was projected by red pseudocolor with Imaris software. (A-C) 2341 offspring from heterozygous sco^te382 mutant crosses produced 25.5% mutants that had defects in the atrial endocardium and CCV (B), 6.7% mutants that had only reduced atrial endocardium (C), and 67.8% siblings that were phenotypically normal (A), suggesting more than one gene mutated in the sco^te382 locus. Sequencing confirmed that the mutants (group II) with defects in the heart (endocardium and CCV) and tail (caudal vein) (supplementary material Fig. S3) were fbn2b^-/- and pku300^-/- (B), and the mutants (group I) with defects only in the heart (endocardium) were fbn2b^+/- and pku300^+/- (C). (D–F) 297 offspring from heterozygous sco^pku300 mutant crosses produced 25.5% mutants with defects in the atrial endocardium and CCV (E) and 74.6% normal siblings (D), which was supported by morpholino knockdown of pku300 with 9.6ng pku300MO (F). (G–I) A fbn2bMO (1.6ng) morphant showed reduced atrial endocardium but had normal CCV (I), compared with the control (H) and a pku300 morphant (G). a, atrium; v, ventricle. Scale bars: 50μm.