Fig. 6. SoxB1 functions in a negative-feedback loop. Zygotes were injected with glycerol as a control (A) or with SoxB1 MO (B) and allowed to develop to the mesenchyme blastula stage or its temporal equivalent. They were then subjected to whole-mount in situ hybridization with a SoxB1 probe. In order to observe the spatial pattern of expression, the enzymatic signal development was 4-fold longer for controls than for experimental embryos. Signals were consistently and significantly elevated in SoxB1 MO embryos, but only in presumptive ectoderm. Scale bar: 20 µm.