The effect of zebrafish Kitlga and Kitlgb on self-renewal and proliferation of hematopoietic cells ex vivo. Quantification of the number of whole-kidney marrow cells after treatment with phosphate-buffered saline (control) or specific cytokine combinations for 3 days (A) and 7 days (B). (C) Growth curve for ex vivo culture of whole-kidney marrow cells with different cytokine combinations. Biological duplicates for every condition and time point are shown. Representative photomicrographs (right panel) of whole-kidney marrow cells isolated from transgenic gata1:DsRed fish treated with Epo, Dex, and Kitlga and cultivated for 8 days (see arrow). Images were acquired using an Olympus IX70 inverted microscope equipped with an Olympus DP72 camera. Scale bar, 100 μm. Expression heat map of Epo + Dex–treated and Epo + Dex + Kitlga–treated cells showing the top predicted differentially expressed genes (D) and representative markers of erythroid differentiation (E). *P ≤ .05, ***P ≤ .001, standard 1-way analysis of variance. n.s., not significant (P > .05).