Figure 6.

Jag1a Is Required Downstream of TGFβ Signaling for HSC Specification

(A) Expression of arterial markers in jag1a^MO is unaffected when compared to wild-type embryos.

(B) Expression of runx1, cmyb, and gfi1aa in wild-type and jag1a morphants (MO) at 28 hpf. All the markers analyzed are reduced or absent in jag1a morphants. Red arrowheads indicate the remaining gene expression in the floor of the DA of jag1a morphants.

(C) HSPCs (yellow arrowheads) are severely reduced in the CHT of itga2b:GFP;Kdrl:HsRas-mCherry transgenic embryos at 48 hpf injected with the jag1a^MO. Itga2b:GFP⁺ cells, magenta; Kdrl-HsRas:mCherry⁺ cells, green.

(D) Overexpression of jag1a with a Kdrl:jag1-V5 construct partially rescues the loss of runx1 and cmyb in the floor of the DA. 15 pg of the construct was used for this experiment. The numbers of embryos are shown in each panel as the number of embryos with phenotype/total number analyzed.

(E) Quantitation of the rescue effect observed in (D).

See also Figure S6.