Figure 1.

CKIɛ/δ induces a secondary axis in Xenopus embryos. (a) Examples of the embryos injected with CKIɛ or β-galactosidase (β-gal) RNA. (b) Percentage of embryos with duplicated axis injected with β-gal, β-catenin, CKIɛ, CKIδ, CKIα, KN-CKIɛ, or ΔC-CKIɛ RNA as indicated. The number of the embryos with duplicated axis relative to the total number of injected embryos is indicated above each bar. (c) Axin inhibits secondary axis formation induced by CKIɛ. CKIɛ RNA was coinjected with β-gal or axin RNA (1–2 ng). (d) Induction of Siamois by CKIɛ. Siamois expression was analyzed by RT-PCR from dorsal halves of the embryos injected with XWnt-8, CKIɛ, or β-gal. EF-1 expression was a loading control.