Interactions across the future endoderm-ectoderm boundary

Inductive interactions:
Interactions across the future endoderm-ectoderm boundary

INDUCER:	Endoderm boundary
TARGET:	Ectoderm boundary
STAGE:	Mid-cleavage - mid-blastula
INDUCTION OUTCOME:	Contribution to the ectodermal state of specification above the endoderm boundary
PROOFS:	Repressive interactions that occur within certain elements of the Endo16 cis-regulatory systems prevent ectopic ectoderm expression. Two observations reveal that this repression system lies downstream of a signal trunsduction pathway: (1) the terminal transcription factor required for the function of the ectoderm repression module is of the CREB family, and (2) the spatial repression that it mediates is abrogated by introduction of a construct encoding activated Ras protein
SPECIES:	Strongylocentrotus purpuratus
COMMENTS:	It is not known wheather the signal emanates from above, below or within the veg1 ectodermal blastomeres
REFERENCE:	Yuh and Davidson, 1996, Yuh et al., 1996 (unpublished data), Montminy, 1997; Brindle et al., 1995