Abstract
The exc mutations of Caenorhabditis elegans alter the position and shape of the apical cytoskeleton in polarized epithelial cells. Mutants in exc-7 form small cysts throughout the tubular excretory canals that regulate organismal osmolarity. We have cloned the exc-7 gene, the closest nematode homologue to the neural RNA-binding protein ELAV. EXC-7 is expressed in the canal for a short time midway through embryogenesis. Cysts in exc-7 mutants do not develop until several hours later, beginning at the time of hatching. We find that the first larval period is when the canal completes the majority of its outgrowth, and adds new apical cytoskeleton at a rapid rate. Ultrastructural studies show that exc-7 mutant defects resemble loss of βH-spectrin (encoded by sma-1) at the distal ends of the excretory canals. In addition, exc-7 mutants exhibit synergistic excretory canal defects with mutations in sma-1, and EXC-7 binds sma-1 mRNA. These data imply that EXC-7 protein may affect expression of sma-1 and other genes to effect proper development of the excretory canals.
Original language | English (US) |
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Pages (from-to) | 290-301 |
Number of pages | 12 |
Journal | Developmental Biology |
Volume | 256 |
Issue number | 2 |
DOIs | |
State | Published - Apr 15 2003 |
Keywords
- Apical cytoskeleton
- ELAV
- Epithelial polarity
- Excretory canals
- RNA-binding
- Spectrin
ASJC Scopus subject areas
- Molecular Biology
- Developmental Biology
- Cell Biology