Fig. 1

The signaling cascades initiated by Cxcr4a and Cxcr4b are functionally equivalent.

(A) The position of PGCs (detected by nanos3 RNA expression, yellow) relative to tissues expressing cxcl12a (magenta) and cxcl12b (green) RNAs in 12 hpf cxcr4b-/- embryos. PGCs express control RNA (cntl, left panel) or RNAs encoding for Cxcr4b (middle panel) or Cxcr4a (right panel). 20 pg of control RNA and RNA encoding for Cxcr4a and Cxcr4b were injected. (B) Epifluorescence image of transgenic sox17::gfp embryos at 8 hpf. The embryos were injected with control (cntl) morpholino and control RNA (left panel). Experimental embryos were knocked down for Cxcr4a and Cxcl12b and the effect of control RNA, cxcr4a and Cxcl12b or cxcr4b along with cxcl12a mRNAs was examined. The quantitation of the endoderm displacement with respect to the forerunner cells is presented in the graph on the right. See also Figure 1—figure supplement 1. 0.8 pmol of each morpholino was used. 100 pg of receptor and 50 pg of ligand encoding mRNA was used, as well as equimolar amounts of control RNA.