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Figure 1. Fli1 Is Required Upstream of Gata2 for the Primitive Hemangioblast Program(A–L) Fli1 requirement for the primitive hemangioblast. Xenopus embryos injected with Fli1 MO in the DMZ at the 4-cell stage were processed for in situ hybridization at stage 17, either as whole mounts (WISH) (A–H, J, K) or as sections (I, L).(M–X) Gata2 morphants and rescue experiments confirm that Fli1 is at the top of the primitive hemangioblast hierarchy. Gata2 MOs were injected into the DMZ at the 4-cell stage and embryos were processd for WISH at stages 16/17. Expression of SpiB (S–U) and Runx1 (V–X) was partially rescued by coinjection of mRNA for Scl, Lmo2, and Gata2.Arrows mark the primitive hemangioblast population. Proportion of embryos with phenotype shown indicated in top right corner. |
