We have used antisense morpholino oligos to establish the developmental roles of three Xsox17 proteins in Xenopus development (Xsox17α1, α2 and β). We show that their synthesis can be inhibited with modest amounts of oligo. The inhibition of each individually produces defects in late midgut development. Loss of activity of the Xsox17α proteins additionally inhibits hindgut formation, and inhibiting Xsox17α1 disrupts foregut development with variable penetrance. When all Xsox17 activity is inhibited cell movements are halted during late gastrulation and the transcription of several endodermally expressed genes is reduced. Thus the Xsox17 proteins have redundant roles in early development of the endoderm and partly distinct roles during later organogenesis.
