Fig. 1

Identification of hgfa and met mutations from three zebrafish lines with abnormal thyroid morphology by whole-exome sequencing and positional cloning.

A–C Three lines with abnormal thyroid morphology were screened by ENU. Thyroid marked by tg in 5 dpf larvae using WISH. Nearly 25% of the progeny from intercrossed heterozygotes exhibited an abnormal small thyroid morphology. Siblings contained wild-type and heterozygous larvae. Three independent experiments were carried for A–C. D–F Three mutants from the three zebrafish lines had mutations in hgfa and met that caused by K80X, E217K, and I284N amino acid substitutions, respectively. Verification by Sanger sequencing. G Diagram of the HGF/Met axis showing the mutations of Met localized in the Sema α domain. H Structures of the wild-type and mutant hgfa proteins. I, J Embryos injected with translation-blocking hgfa morpholinos (MO-hgfa) or met morpholinos (MO-met) to knock down hgfa or met induced the phenotype of abnormal small thyroid morphology at 5 dpf, as detected by in situ hybridization using tg as a probe. Three independent experiments were carried for I, J. MO-Con, embryos injected with standard control morpholino. Scale bars: 100 μm.