mec-7 is a beta-tubulin gene required for the production of 15-protofilament microtubules in Caenorhabditis elegans.
In the nematode Caenorhabditis elegans, microtubules with 15 protofilaments are a specialized feature of six touch-receptor neurons; microtubules found in other C. elegans neurons have 11 protofilaments. Mutations in the gene mec-7 result in touch-insensitive animals whose touch cells lack the 15-protofilament microtubules. We have characterized 54 mutations in the mec-7 gene. The absence of mec-7 activity results selectively in the recessive loss of touch sensitivity. Partial loss-of-function alleles result in a partial loss of touch sensitivity. Dominant mutations, which are isolated at an unusually high proportion, may encode abnormal products. We have cloned the mec-7 gene; it encodes a beta-tubulin which is 90-93% identical to vertebrate beta-tubulin. Our results are consistent with the hypothesis that tubulin heterogeneity contributes to the formation of structurally and functionally distinct sets of microtubules.
Savage
C
C
Department of Biological Sciences, Columbia University, New York, New York 10027.
Hamelin
M
M
Culotti
J G
JG
Coulson
A
A
Albertson
D G
DG
Chalfie
M
M
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002107:Caenorhabditis / Q000235:genetics* / Q000502:physiology / Q000648:ultrastructure; D029742:Caenorhabditis elegans Proteins; D008870:Microtubules / Q000502:physiology / Q000648:ultrastructure*; D008969:Molecular Sequence Data; D009474:Neurons / Q000648:ultrastructure; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity; D014110:Touch; D014404:Tubulin / Q000235:genetics* / Q000502:physiology
D029742:Caenorhabditis elegans Proteins; C115872:Mec-7 protein, C elegans; D014404:Tubulin