Fig. 4. Participation of CheWnt3 in Wnt pathway regulatory interactions. (A) CheWnt3-MO injection into Clytia eggs did not affect the graded distribution of CheFz1 and CheFz3 RNAs at the early blastula stage (4.5 hpf; essentially maternally derived RNA). However, by the early gastrula stage (10 hpf), both RNAs were found strongly expressed throughout the embryo. This shows that CheWnt3 is required for mutual negative regulation of the receptors during the intervening period, probably at the transcriptional level. (B) The oral territory of zygotic Wnt3 expression was not greatly affected by treatments that upregulate (dnGSK3, Fz3-MO) or downregulate (Fz1-MO) the canonical Wnt pathway.