Fig. 2
Insulin signaling blockade increases embryonic β cell formation. (A) Schematic of a dominant negative IRS2 construct designed to block transmission of insulin signaling; C-terminal effector binding domains are replaced with GFP. (B,C) 5 hpf embryo injected with dnIRS2-GFP mRNA (B) Photomicrograph of epifluorescence shows ubiquitous distribution of GFP. (C) Confocal plane shows the localization of dnIRS2-GFP to the plasma membrane while co-injected H2B-RFP mRNA labels cell nuclei red. (D,E) Confocal projections of control (D) and dnIRS2-GFP mRNA-injected islets in 24 hpf Tg(ins:dsRed) embryos. (F) Quantification of insa:dsRed+ β cells in 24 hpf control (n=12) and dnIRS2-GFPmRNA injected embryos (n=10). (G,H) Confocal projections of DMSO-treated control (G) and 1 µM wortmannin-treated islets in 30 hpf Tg(ins:CFP-NTR) embryos. (I) Quantification of β cells in DMSO-treated control (n=18) and 1 µM wortmannin-treated (n=17) islets in 30 hpf embryos. Student t-test was used to determine significance in F and I.
Reprinted from Developmental Biology, 409(2), Ye, L., Robertson, M.A., Mastracci, T.L., Anderson, R.M., An insulin signaling feedback loop regulates pancreas progenitor cell differentiation during islet development and regeneration, 354-69, Copyright (2016) with permission from Elsevier. Full text @ Dev. Biol.