The involvement of lethal giant larvae and Wnt signaling in bottle cell formation in Xenopus embryos.
Lethal giant larvae (Lgl) plays a critical role in establishment of cell polarity in epithelial cells. While Frizzled/Dsh signaling has been implicated in the regulation of the localization and activity of Lgl, it remains unclear whether specific Wnt ligands are involved. Here we show that Wnt5a triggers the release of Lgl from the cell cortex into the cytoplasm with the concomitant decrease in Lgl stability. The observed changes in Lgl localization were independent of atypical PKC (aPKC), which is known to influence Lgl distribution. In ectodermal cells, both Wnt5a and Lgl triggered morphological and molecular changes characteristic of apical constriction, whereas depletion of their functions prevented endogenous and ectopic bottle cell formation. Furthermore, Lgl RNA partially rescued bottle cell formation in embryos injected with a dominant negative Wnt5a construct. These results suggest a molecular link between Wnt5a and Lgl that is essential for apical constriction during vertebrate gastrulation.
Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY 10029, USA.
Sun-Cheol
SC
Choi
Sergei Y
SY
Sokol
D000818:Animals; D015153:Blotting, Western; D016764:Cell Polarity; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D008856:Microscopy, Fluorescence; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D051153:Wnt Proteins / Q000235:genetics / Q000378:metabolism*; D000071818:Wnt-5a Protein; D029867:Xenopus Proteins / Q000235:genetics / Q000378:metabolism*; D014982:Xenopus laevis / Q000196:embryology / Q000235:genetics / Q000378:metabolism
C505294:LLGL1 protein, Xenopus; D051153:Wnt Proteins; D000071818:Wnt-5a Protein; C085096:Wnt5a protein, Xenopus; D029867:Xenopus Proteins; D049452:Green Fluorescent Proteins