Abstract
ABSTRACTBiological systems are organized into well-ordered structures and can evolve new patterns when perturbed. To identify principles underlying biological order, we turned to C. elegans for its simple anatomy and powerful genetics. We developed a method to quantify the arrangement of three dendrites in the main sensory nerve bundle, and found that they exhibit a stereotyped arrangement throughout larval growth. Dendrite order does not require prominent features including sensory cilia and glial junctions. In contrast, loss of the cell adhesion molecule (CAM) CDH-4/Fat-like cadherin causes dendrites to be ordered randomly, despite remaining bundled. Loss of the CAMs PTP-3/LAR or SAX-7/L1CAM causes dendrites to adopt an altered order, which becomes increasingly random as animals grow. Misexpression of SAX-7 leads to subtle but reproducible changes in dendrite order. Our results suggest that differential expression of CAMs allows dendrites to self-organize into a stereotyped arrangement that readily gives rise to new patterns when perturbed.
Publisher
Cold Spring Harbor Laboratory
Reference91 articles.
1. The Two Isoforms of the Caenorhabditis elegans Leukocyte-Common Antigen Related Receptor Tyrosine Phosphatase PTP-3 Function Independently in Axon Guidance and Synapse Formation
2. Altun, Z. F. , Herndon, L. A. , Wolkow, C. A. , Crocker, C. , Lints, R. , and Hall, D. H. (2002). Wormatlas
3. Altun, Z. F. , and Hall, D. H. (2005). SW-Worm Viewer, Slice No. 18 and 50. www.WormAtlas.org
4. Ephaptic coupling of cortical neurons
5. daf-12 encodes a nuclear receptor that regulates the dauer diapause and developmental age in C. elegans;Genes Dev,2000