Axonal guidance mutants of Caenorhabditis elegans identified by filling sensory neurons with fluorescein dyes

• Published in: Developmental biology Vol. 111; no. 1; pp. 158 - 170
• Main Authors: Hedgecock, Edward M., Culotti, Joseph G., Thomson, J.Nichol, Perkins, Lizabeth A.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.01.1985; Elsevier
• Subjects: Animals; Axons - physiology; Axons - ultrastructure; Biological and medical sciences; Caenorhabditis - genetics; Caenorhabditis - ultrastructure; Caenorhabditis elegans; Classical genetics, quantitative genetics, hybrids; Fluorescein-5-isothiocyanate; Fluoresceins - metabolism; Fundamental and applied biological sciences. Psychology; Genes; Genetics of eukaryotes. Biological and molecular evolution; Invertebrata; Locomotion; Microscopy, Electron; Microscopy, Fluorescence; Microtubules - ultrastructure; Mutation; Neurons, Afferent - physiology; Neurons, Afferent - ultrastructure; Phenotype; Space life sciences; Thiocyanates - metabolism; Neuron; Helmintha; Axon; Nemathelminthia; Mutation; Invertebrata; Nematoda
• ISSN: 0012-1606; 1095-564X
• DOI: 10.1016/0012-1606(85)90443-9

Eight pairs of chemosensory neurons in Caenorhabditis elegans take up fluorescein dyes entering through the chemosensory organs. These are amphid neurons ADF, ASH, ASI, ASJ, ASK, and ADL and phasmid neurons PHA and PHB. When filled with dye, the processes and cell bodies of these neurons can be examined in live animals by fluorescence microscopy. Using this technique, we have identified five genes, unc-33, unc-44, unc-51, unc-76, and unc-106, that affect the growth of the amphid and phasmid axons. These genes were found to affect the axons of the mechanosensory PDE neurons as well. The unc-33 mutation specifically affects neuronal microtubules. Sensory dendrites in this mutant have a superabundance of microtubules. Moreover, many of these microtubules are abnormal in diameter, and some form hooks or multiple tubules.