FIGURE 2

Impaired HSPC development in gata2a mutants. (A–C) Expression of runx1 by in situ hybridization in 36 hpf embryos, showing decreased expression in gata2a^um27/um27 homozygotes. (D–F) Lateral views of c-myb WISH on 36 hpf Gata2a^um27 mutants showing decreased expression in in gata2a^um27/um27 homozygotes. (G) Quantification of c-myb expression from in situ hybridization images in the AGM of 36 hpf embryos. In (H) mutant fish carrying itga2b:GFP transgene, labeling HSPCs that reside in the CHT, were used to quantify GFP^low cells in the CHT of 56 hpf embryos, showing an allele dependent decrease in GFP^low cells. (I–K) Lateral views of 4 dpf larvae showing the expression of c-myb by in situ hybridization. (L) Quantification of c-myb+ cells in the CHT of 4 dpf mutant larvae. (M–O) Lateral views of the tails of 4 dpf mutant Tg(itga2b:GFP) fish showing a decrease of GFP+ cells in gata2a^um27/um27 homozygotes. In (P), the presence (up) or absence (bottom) of blood flow in the tail of Gata2a^um27 mutant fish was monitored each day until 5 dpf. Notice the gata2a^um27/um27 homozygotes (purple triangles) gaining blood circulation at 3 and 5 dpf. (Q) Plot showing the correlation of the presence (up) or absence (bottom) of blood flow in the tail of Gata2a^um27 mutant fish and the presence (right) or absence (left) of Tg(itga2b:GFP)+ cells in 4 dpf fish. At 4 dpf, some gata2a^um27/um27 homozygotes (purple triangles) show GFP+ cells, all of which also exhibit circulation in the tail. (R–R″) Lateral views of 4 dpf mutant Tg(itga2b:GFP) fish showing a range of phenotypes of gata2a^um27/um27 homozygotes. (S–U) Lateral views of 4 dpf mutant larvae stained with SB. (V) Quantification of SB+ cells in the CHT of 4 dpf larvae shows decreased number of granulocytes in gata2a^um27/um27 homozygotes.