| |
Fig. 6. Knock down of the BMP pathway results in repression of Hox
expression. We used a dominant negative BMP receptor (tBR), a BMP
antagonist [chordin (chd)] and two different morpholinos against BMP-4
(BMP4MO1, BMP4MO2), to repress the BMP-4 pathway. Arrowheads
point to the side of injection. (A–F) Vegetal views (organiser is up) of
embryos stained for Hoxd-1. Noninjected (ni) embryos (A) and embryos
injected with a control morpholino (conMO, D) show the characteristic
horseshoe-shaped expression domain. Injection of tBR or chordin mRNAs
on the non-organiser side resulted in a repression of Hoxd-1 (B, C), as did
the injection of the two different BMP-4 morpholinos (E, F). (G–J)
Experiments with the BMP4MO1 demonstrate that the expression of Hoxc-
6 (H) and Hoxa-7 (J) are repressed compared to control morpholino
injection (G, I). (K–N) To ensure that the BMP-4 morpholino really affects
the BMP-4 pathway, the known downstream target Xvent-2 was analysed
for changes in its expression after injection of BMP4MO1 and was seen to
be downregulated (K, L). The organiser gene Xlim-1 is upregulated (M, N). |
