Figure 6

Tg(igfbp5a:GFP) fish faithfully recapitulates the mitotic action of IGF1R-PI3K-Akt-Tor signaling. (a) Low [Ca²⁺] stress induces NaR proliferation via IGF1R signaling. Tg(igfbp5a:GFP) larvae (72 hpf) were transferred to the indicated solutions. GFP fluorescence intensity was measured at the indicated time points. NaR cell number was calculated and shown. Value are mean ± SEM, n = 10–14. * indicates significant differences (p < 0.05) between the Low [Ca²⁺] + BMS group and the Low [Ca²⁺] + DMSO group at the same time point. # indicates significant differences (p < 0.05) between the Low [Ca²⁺] + DMSO group and the normal [Ca²⁺] + DMSO group at the same time point. (b) Tg(igfbp5a:GFP) larvae (72 hpf) were treated as described in (a) and NaR cell numbers were measured at 120 hpf. Inhibitors used are BMS-754807 (BMS, 0.3 μM), NVP-AEW541 (NVP, 6 μM), LY294002 (LY, 5 μM) and wortmannin (WORT, 0.06 μM). (c) The experiment was performed as described in (a). Inhibitors used are Akti-1/2 (Akti, 5 μM), or MK2206 (MK, 2 μM). Values shown in (b) and (c) are mean ± SEM. n = 10–26. Different letters indicate statistically significant differences at p < 0.05.