Isoprenoids regulate RBC development in a gata1a-dependent manner. (A-F) Embryos were treated at sphere stage with Ro-48 to inhibit cholesterol, lonafarnib to inhibit isoprenoids, or vehicle control (DMSO). At 26 hpf, whole mount ISH was performed to detect hbbe1.1 (n = 45 DMSO, n = 53 Ro-48 [P = .0001], and n = 48 lonafarnib [P = .0001]) (A-C) or gata1a (D-F) expression (n = 45 DMSO, n = 39 Ro-48 [NS], and n = 51 lonafarnib; [P = .0001]). Total embryos were obtained with a minimum 3 biological replicates. Images were taken with a 10× optical lens at 6.3× objective zoom. P value designates statistical significance relative to vehicle control according to a Fisher’s exact test. Total RNA was isolated from embryos treated with vehicle control (DMSO), Ro-48, or lonafarnib; qPCR was performed to detect the expression of hbbe1.1 (G) or gata1a (H). All samples were performed in technical triplicate and error bars represent the standard deviation of technical triplicates. *P < .05. (I) Tg(gata1a:dsRed) embryos were treated at sphere stage with Ro-48 to inhibit cholesterol, lonafarnib to inhibit isoprenoids, or vehicle control (DMSO). Fluorescence was visualized using a confocal microscope. The number of cells/Z-stack was quantified using ImageJ. #P = 2.7125e-07.