Figure 6.
Dose-dependent effect of local delivery of T3 on gross morphology and body length. A, Photomicrographs of tadpoles from four designated treatment groups. Tadpoles were treated with T3 (50 mm) in the bath or injected in the brain ventricle with T3CO at three different concentrations. Control animals were reared in control bath or injected with coconut oil without T3 (ControlCO). The inset image at bottom left shows coconut oil droplet (arrow) in the ventricle. B, Bath application of T3 affected the whole tadpole, quantified here as a decrease in body length. The two highest concentrations of T3 CO also significantly decreased body length (2-way ANOVA, effect of treatment, p < 0.001) and changed craniofacial features (see arrowheads in photomicrographs in A). Tadpoles injected with 500 μg/ml T3CO had body length and overall appearance comparable with control groups. n = 8–16 tadpoles per treatment and time point.