Figure 4.

pfkp knockdown disrupts right-sided coco bias. (a) Representative images of coco expression at the gastrocoel roof plate (GRP) in st. 20–21 embryos. (b) Schematic depicting right-sided coco bias during post-flow stages. Reduced coco expression on the left-side permits initiation of the Nodal signalling cascade by alleviating inhibition of Xenopus Nodal related-1 (Xnr-1). Downstream transcription factors (Pitx2) important for initiating asymmetric organ morphogenesis are activated. High levels of right-sided coco expression repress similar activation of Nodal signalling on the right side. (c) Relative to control embryos, significantly fewer pfkp morphants exhibited right-sided bias of coco expression (p = 0.0058, two-tailed Fisher's Exact test). (Online version in colour.)