TG and thyroid gland disorder: The typical phenotypes of thyroid dyshormonogenesis were found in our tg mutant zebrafish, with significantly decreased levels of T4 and T3 production (Figure 6H–I) as well as growth retardation (Figure 8A,C–E), suggesting the poor functioning of the short TG form encoded by the tg alternative splicing form without the I1–4 region.