Fig. 5.

kcnh2a is expressed ectopically in lof^t2 intra-ray mesenchyme lineage cells during fin regeneration. (A,B) kcnh2a mRNA localization (in green) detected by RNAscope in longitudinal caudal fin sections from 4 days post-amputation (dpa) TL (lof^t2/t2, A) and AB (B) animals. The green arrow indicates proximal intra-ray cells expressing high levels of kcnh2a, which is also detected in medial mesenchyme (yellow arrow) and distal cells (magenta arrow) of TL fish. The dashed yellow line indicates the site of amputation. Hoechst stained nuclei are in gray. Scale bars: 50 µm. (C,D) Double kcnh2a RNAscope (green) and Msx immunostaining (magenta) of 4 dpa caudal fin sections from TL (C) and AB (D) fish. (E,F) Combination kcnh2a RNAscope (green) and mCherry immunostaining (magenta) of 4 dpa fin sections from (E) tph1b:mCherry; lof^t2/+ and (F) tph1b:mCherry; lof^+/+ fish. For C-F, green arrows highlight Msx⁺ or tph1b:mCherry⁺ cells with overlapping kcnh2a mRNA in proximal regenerating lof tissue. White arrows indicate Msx⁺ or tph1b:mCherry⁺ nuclei in corresponding regions from control fins lacking kcnh2a expression. Fin rays are outlined with a dashed orange line. Hoechst-stained nuclei are in gray. Scale bars: 50 µm.