A novel noncanonical Wnt pathway is involved in the regulation of the asymmetric B cell division in C. elegans.
The polarities of several cells that divide asymmetrically during Caenorhabditis elegans development are controlled by Wnt signaling. LIN-44/Wnt and LIN-17/Fz control the polarities of cells in the tail of developing C. elegans larvae, including the male-specific blast cell, B, that divides asymmetrically to generate a larger anterior daughter and a smaller posterior daughter. We determined that WRM-1 and the major canonical Wnt pathway components: BAR-1, SGG-1/GSK-3 and PRY-1/Axin were not involved in the control of B cell polarity. However, POP-1/Tcf is involved and is asymmetrically distributed to the B daughter nuclei, as it is in many cell divisions during C. elegans development. Aspects of the B cell division are reminiscent of the divisions controlled by the planar cell polarity (PCP) pathway that has been described in both Drosophila and vertebrate systems. We identified C. elegans homologs of Wnt/PCP signaling components and have determined that many of them appear to be involved in the regulation of B cell polarity. Specifically, MIG-5/Dsh, RHO-1/RhoA and LET-502/ROCK appear to play major roles, while other PCP components appear to play minor roles. We conclude that a noncanonical Wnt pathway, which is different from other Wnt pathways in C. elegans, regulates B cell polarity.
Wu
Mingfu
M
Program in Molecular, Cellular and Developmental Biology, Division of Biology, Kansas State University, Manhattan, KS 66506, USA.
Herman
Michael A
MA
D000199:Actins / Q000378:metabolism; D000818:Animals; D030801:Animals, Genetically Modified; D017173:Caenorhabditis elegans / Q000166:cytology* / Q000235:genetics / Q000502:physiology*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000502:physiology*; D002455:Cell Division; D016764:Cell Polarity; D017238:Genes, Helminth; D047908:Intracellular Signaling Peptides and Proteins; D008954:Models, Biological; D009154:Mutation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000502:physiology; D034622:RNA Interference; D015398:Signal Transduction; D051153:Wnt Proteins / Q000235:genetics / Q000502:physiology*; D054460:rho-Associated Kinases; D020742:rhoA GTP-Binding Protein / Q000235:genetics / Q000502:physiology
D000199:Actins; D029742:Caenorhabditis elegans Proteins; D047908:Intracellular Signaling Peptides and Proteins; D051153:Wnt Proteins; C515856:LET-502 protein, C elegans; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases; D020742:rhoA GTP-Binding Protein