Spatially regulated translation in embryos: asymmetric expression of maternal Wnt-11 along the dorsal-ventral axis in Xenopus.
Transition from symmetry to asymmetry is a central theme in cell and developmental biology. In Xenopus embryos, dorsal-ventral asymmetry is initiated by a microtubule-dependent cytoplasmic rotation during the first cell cycle after fertilization. Here we show that the cytoplasmic rotation initiates differential cytoplasmic polyadenylation of maternal Xwnt-11 RNA, encoding a member of the Wnt family of cell-cell signaling factors. Translational regulation of Xwnt-11 mRNA along the dorsal-ventral axis results in asymmetric accumulation of Xwnt-11 protein. These results demonstrate spatially regulated translation of a maternal cell-signaling factor along the vertebrate dorsal-ventral axis and represent a novel mechanism for Wnt gene regulation. Spatial regulation of maternal RNA translation, which has been established in invertebrates, appears to be an evolutionarily conserved mechanism in the generation of intracellular asymmetry and the consequential formation of the multicellular body pattern.
Schroeder
K E
KE
MCDBG Graduate Program, University of Minnesota, Minneapolis, Minnesota 55455, USA.
Condic
M L
ML
Eisenberg
L M
LM
Yost
H J
HJ
D000818:Animals; D019521:Body Patterning; D002453:Cell Cycle / Q000235:genetics; D003593:Cytoplasm / Q000378:metabolism; D005260:Female; D005306:Fertilization; D018507:Gene Expression Regulation, Developmental; D006023:Glycoproteins / Q000235:genetics* / Q000378:metabolism*; D008957:Models, Genetic; D011061:Poly A / Q000235:genetics; D016133:Polymerase Chain Reaction; D011132:Polyribosomes / Q000235:genetics; D014176:Protein Biosynthesis; D012313:RNA / Q000032:analysis; D012323:RNA Processing, Post-Transcriptional; D015398:Signal Transduction; D013997:Time Factors; D016212:Transforming Growth Factor beta; D051153:Wnt Proteins; D014981:Xenopus / Q000196:embryology*; D029867:Xenopus Proteins
C513103:GDF1 protein, Xenopus; D006023:Glycoproteins; D016212:Transforming Growth Factor beta; D051153:Wnt Proteins; D029867:Xenopus Proteins; C512785:wnt11b protein, Xenopus; D011061:Poly A; D012313:RNA