Genetics, Vol 135, 53-70, Copyright © 1993

INVESTIGATIONS

Three New Classes of Mutations in the Caenorhabditis elegans Muscle Gene sup-9

J. Z. Levin and H. R. Horvitz
Present address: California Institute of Technology, Division of Biology, Pasadena, California 91125

We are studying five interacting genes involved in the regulation or coordination of muscle contraction in Caenorhabditis elegans. A distinctive ``rubber-ban'' muscle-defective phenotype was previously shown to result from rare altered-function mutations in either of two of these genes, unc-93 and sup-10. Null mutations in sup-9, sup-10, sup-18 or unc-93 act as essentially recessive suppressors of these rubber-band mutations. In this work, we identify three new classes of sup-9 alleles: altered-function rubber-band, partial loss-of-function and dominant-suppressor. The existence of rubber-band mutations in sup-9, sup-10 and unc-93 and the suppression of these mutations by null mutations in any of these three genes suggest that these proteins are required at the same step in muscle contraction. Moreover, allele-specific interactions shown by the partial loss-of-function mutations indicate that the products of these interacting genes may physically contact each other in a multiple subunit protein complex. Finally, the phenotypes of double rubber-band mutant combinations suggest that the rubber-band mutations affect a neurogenic rather than a myogenic input in excitation-contraction coupling in muscle.

This article has been cited by other articles:

				D. M. Raizen, K. M. Cullison, A. I. Pack, and M. V. Sundaram A Novel Gain-of-Function Mutant of the Cyclic GMP-Dependent Protein Kinase egl-4 Affects Multiple Physiological Processes in Caenorhabditis elegans Genetics, May 1, 2006; 173(1): 177 - 187. [Abstract] [Full Text] [PDF]

				S. L. Hooper and J. B. Thuma Invertebrate Muscles: Muscle Specific Genes and Proteins Physiol Rev, July 1, 2005; 85(3): 1001 - 1060. [Abstract] [Full Text] [PDF]

				I. P. de la Cruz, J. Z. Levin, C. Cummins, P. Anderson, and H. R. Horvitz sup-9, sup-10, and unc-93 May Encode Components of a Two-Pore K+ Channel that Coordinates Muscle Contraction in Caenorhabditis elegans J. Neurosci., October 8, 2003; 23(27): 9133 - 9145. [Abstract] [Full Text] [PDF]