Glucose enhances HSC formation in the zebrafish AGM region. Zebrafish were exposed to 1% glucose from 10 somites to 36 hpf and analyzed at 36 hpf. (A) D-glucose enhanced runx1/cmyb expression by in situ hybridization (560 increased/652 scored [85.9%↑]). The metabolically inactive enantiomer, L-glucose, had no effect (n > 100 embryos/treatment [tx]). Top panels show whole embryos, while bottom panels depict AGM regions. Numbers in lower right of panels, here and following, indicate embryos with altered HSC expression (as depicted) over the total number scored. (B) Glucose exposure increased HSC number as determined by in vivo fluorescent microscopy of runx1:eGFP, cmyb:eGFP, and CD41:eGFP transgenic reporter embryos (n = 60/tx). (C) Quantification of fluorescent cell number by FACS analysis of reporter embryos supported the effects of observed by microscopy (t test, runx1: *P < .0001; cmyb/lmo2: **P < .05; CD41: ***P < .01, n = 6-9). (D) qPCR confirmed significantly enhanced expression of HSC markers following glucose exposure (20 embryos/cohort, t test, runx1, cmyb: *P < .0001; CD41: **P < .05, n = 3).