Figure 6
Lhx9 and Lhx1 cross-repress each other. (A, C) Lhx9 and (B, D) Lhx1, cloned in pCIG plasmid, were electroporated at stage 19 into the chick neural tube. At E4, embryos were fixed and stained with antibodies (Ab) to the cognate Lim-HD proteins. A vast reduction in Lhx1/5 (A) is evident after Lhx9 ectopic expression. Lhx1 ectopic expression resulted in a reduction of Lhx2/9 (B). For quantification (C, D), the ratio between dIx-specific neurons expressing ectopic Lim-HD (Limecto) plus their own Lim-HD (Limx) and the total number of electroporated dIx neurons is presented. Neurons co expressing Limecto and Limx are nuclear GFP (nGFP)+/Limx+. For estimating the total number of electroporated dIx neurons, the number of nGFP-/Limx+ neurons at the electroporated side was subtracted from the number of Limx+ neurons at the control side. The quotient plus the number of nGFP+/Limx+ equals the number of electroporated dIx neurons. Scale bar: 200 μm.