Dissecting Wnt signalling pathways and Wnt-sensitive developmental processes through transient misexpression analyses in embryos of Xenopus laevis.
We review evidence that Xenopus Wnts (Xwnts) have activities consistent with their hypothesized roles as secreted signalling factors involved in multiple developmental processes. Transient misexpression of different Xwnts has distinct effects upon early development, and upon the formation of tissues in UV-irradiated embryos. Misexpression of Xwnts also has distinct effects on the in vitro differentiation of blastula cap explants. Cellular responses to Xwnt signals include changes in gap junctional permeability, altered responsiveness to growth factors, and possibly changes in cell adhesion. Current data suggest that a maternal Xwnt- or noggin-like activity is involved in the Nieuwkoop center activity during mesoderm induction, that Xwnt-8 participates in a pathway of differentiation as ventral mesoderm, and that Xwnt-5A is a potential modulator of morphogenetic movements.
Moon
R T
RT
Department of Pharmacology, University of Washington School of Medicine, Seattle 98195.
Christian
J L
JL
Campbell
R M
RM
McGrew
L L
LL
DeMarais
A A
AA
Torres
M
M
Lai
C J
CJ
Olson
D J
DJ
Kelly
G M
GM
D000818:Animals; D004627:Embryonic Induction / Q000502:physiology*; D015870:Gene Expression / Q000235:genetics; D008648:Mesoderm / Q000502:physiology*; D009154:Mutation / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*; D014982:Xenopus laevis / Q000196:embryology* / Q000235:genetics
D011518:Proto-Oncogene Proteins