|
|
|
|
|
|
|
||
J. Cell Biol.,
Volume 143, Number 5, November 30, 1998 1283-1294
* Department of Zoology and The lethal mutation l(2)CA4 causes specific
defects in local growth of neuronal processes. We uncovered four alleles of l(2)CA4 and mapped it to bands
50A-C on the polytene chromosomes and found it to be
allelic to kakapo (. Genetics. 146:275- 285). In embryos carrying our kakapo mutant alleles,
motorneurons form correct nerve branches, showing
that long distance growth of neuronal processes is unaffected. However, neuromuscular junctions (NMJs) fail
to form normal local arbors on their target muscles and
are significantly reduced in size. In agreement with this finding, antibodies against kakapo (Gregory and
Brown. 1998. J. Cell Biol. 143:1271-1282) detect a specific epitope at all or most Drosophila NMJs. Within
the central nervous system of kakapo mutant embryos,
neuronal dendrites of the RP3 motorneuron form at
correct positions, but are significantly reduced in size.
At the subcellular level we demonstrate two phenotypes potentially responsible for the defects in neuronal
branching: first, transmembrane proteins, which can
play important roles in neuronal growth regulation, are
incorrectly localized along neuronal processes. Second,
microtubules play an important role in neuronal
growth, and kakapo appears to be required for their organization in certain ectodermal cells: On the one hand,
kakapo mutant embryos exhibit impaired microtubule organization within epidermal cells leading to detachment of muscles from the cuticle. On the other, a specific type of sensory neuron (scolopidial neurons)
shows defects in microtubule organization and detaches
from its support cells.
Department of Genetics, University of Cambridge, Cambridge CB2 3EH, United Kingdom
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
This article has been cited by other articles:
|
|
