Fig. 3 smp expression during zebrafish caudal fin development. Whole-mount in situ for smp in the zebrafish embryo (A), larval fin folds (B–F), juvenile fins (G and H) and regenerating larval fins (I–K). smp expression is in the head and trunk, and reduces towards the posterior at 12 hpf (A). Larval caudal fins show lack of expression at 3 dpf (B), 4 dpf (C), 5 dpf (D), 6 dpf (E) and 7 dpf (F). smp expression is not detected in developing juvenile fin at 30 dpf (G) [insert showing entire fin lobe] and 60 dpf (H) [insert showing entire fin lobe]. (I) Amputation injury at 5 dpf causes up-regulation of smp in the regenerating tissue of the larval caudal fin by 1 dpa (6 dpf). (J) Expression continues at 2 dpa (7 dpf). (K) Sense control of regenerating caudal finfold of the larva. Dashed lines show amputation plane. Scale bars equal 50 μm (A) and 100 μm (B–K). (L) Quantitative RT-PCR for smp message expression in posterior of zebrafish larvae at indicated developmental time points. smp expression is strongly upregulated upon amputation injury at the regenerating larval fin at 1 dpa.
Reprinted from Developmental Biology, 325(2), Kizil, C., Otto, G.W., Geisler, R., Nüsslein-Volhard, C., and Antos, C.L., Simplet controls cell proliferation and gene transcription during zebrafish caudal fin regeneration, 329-340, Copyright (2009) with permission from Elsevier. Full text @ Dev. Biol.