Fig. 3.

(A) Thyroid hormone (TH) receptor α (TRα) knockdown tadpoles have faster growth during premetamorphosis in Xenopus tropicalis. Tadpoles with different TALEN mRNA injections as in Figure 2 were classified in three categories: large size, medium size, and small size (top panel), at the age of 20 days post-fertilization and the percentage in each category is shown in a bar graph (bottom panel). (B) TRα knockdown tadpoles are smaller than the wild type siblings at the onset of prometamorphosis (stage 54). Top: Representative photos of stage 54 (the onset of metamorphosis) tadpoles. Tadpoles were staged based on hindlimb morphology. All animals are at the same stage but are of different ages. Bottom: The average size (body length) of the animals at stage 54 for different groups. The letter n indicates the number of tadpoles for each group. Tadpole body length was measured from jaw to tail tips. **Indicates significant difference between the TRα knockdown group compared to all three other groups (P < 0.05). See Fig. 2 and (Wen & Shi 2015) for details.