RESUMEN
We have identified chick frizzled (Fz)-10, encoding a Wnt receptor, and examined the expression pattern during embryogenesis. Fz-10 is expressed in the region posterior to the Hensen's node at stage 6. Fz-10 expression is detected in the dorsal domain of the neural tube and the central nervous system of the developing embryo. In the developing limb, Fz-10 expression starts at stage 18 in the posterior-dorsal region of the distal mesenchyme, and gradually expands to the anterior-distal region. Fz-10 is also expressed in the feather bud and branchial arch. Implantation of Sonic hedgehog (Shh)-expressing cells into the anterior margin of the limb bud resulted in the induction of Fz-10 expression in anterior-dorsal mesenchyme.
Asunto(s)
Proteínas Aviares , Sistema Nervioso Central/embriología , Transactivadores , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Embrión de Pollo , ADN Complementario , Receptores Frizzled , Regulación del Desarrollo de la Expresión Génica , Proteínas Hedgehog , Esbozos de los Miembros/embriología , Datos de Secuencia Molecular , Proteínas/genética , Proteínas/metabolismo , Receptores de Superficie Celular/genéticaRESUMEN
Members of the frizzled (Fz) family are involved in Wnt signaling during embryogenesis in the vertebrate. We identified chicken cognates of Fz-2, Fz-3, Fz-4, Fz-6 and Fz-8, and examined spatial and temporal expression patterns in the chick embryos by whole-mount in situ hybridization. Fz-4 is intensely expressed in the apical ectodermal ridge and distal mesenchyme of the limb bud at stages 20 to 27. The transcripts are confined to the posterior-distal end of the digit-forming region at stages 25 to 27. Fz-2 is weakly expressed in the proximal limb mesenchyme at stages 25 to 27, while Fz-3 and Fz-6 expressions are uniform in the limb bud at these stages. Fz-2 is also expressed in the dermatomyotome. No expression signal for Fz-8 is detectable in the embryo at stages 20 to 27. The differential expression patterns of the Fz family, together with spatially restricted expression of the Wnt family members in the developing limb, suggest distinct but overlapping functions to transduce Wnt signal implicated in cellular interaction during embryogenesis.