Fig. 4. Szl affects VBI development in whole embryos, but has no effect on blood differentiation in isolated animal caps. (A) BMP4-induced blood differentiation in animal caps. Embryos were injected in the animal pole at the two-cell stage; caps were explanted at stage 8 to 9 and incubated in saline until sibling embryos reached stage 30 to 35. Erythroid markers xGata1 and T3 globin were analyzed by radioactive, semi-quantitative RT-PCR. EF1 was used as an internal control for RNA levels. Where indicated, 50 ng/ml bFGF were added to the medium. When no bFGF was added (left panel), embryos were injected with 1 ng BMP4 RNA. When explants were treated with bFGF (right panel), embryos were injected with 200 pg of a BMP4 expression plasmid (pCS2-BMP4). Where indicated, embryos were also injected with 20 ng of the morpholino oligo MOSZL or with 1 ng of wSzl RNA. (B) Blood differentiation in whole embryos. 20 ng of MOSZL or increasing amounts of wSzl RNA were injected, respectively, into two- or four-cell stage embryos; expression of erythroid markers was assessed by semi quantitative RT-PCR at stage 30 to 35 as above.

Return to article