Figure 1.

Expression of TH components during chick development. In situ hybridizations were performed on retinal cryosections cut in the coronal plane at three different stages of chick development (Stage 26 [A-D], Stage 32 [E-H], and Stage 36 [I-L]). The probes used were Dio2 (A, E, I), Dio3 (B, F, J), TRa (C, G, K), and TRb (D, H, L). A representative scale bar is shown.