Dynamic morphogenesis of a pioneer axon in Drosophila and its regulation by Abl tyrosine kinase.
Mol Biol Cell
; 31(6): 452-465, 2020 03 15.
Article
en En
| MEDLINE
| ID: mdl-31967935
ABSTRACT
The fundamental problem in axon growth and guidance is to understand how cytoplasmic signaling modulates the cytoskeleton to produce directed growth cone motility. We here dissect this process using live imaging of the TSM1 axon of the developing Drosophila wing. We find that the growth cone is almost purely filopodial, and that it extends by a protrusive mode of growth. Quantitative analysis reveals two separate groups of growth cone properties that together account for growth cone structure and dynamics. The core morphological features of the growth cone are strongly correlated with one another and define two discrete morphs. Genetic manipulation of a critical mediator of axon guidance signaling, Abelson (Abl) tyrosine kinase, shows that while Abl weakly modulates the ratio of the two morphs it does not greatly change their properties. Rather, Abl primarily regulates the second group of properties, which report the organization and distribution of actin in the growth cone and are coupled to growth cone velocity. Other experiments dissect the nature of that regulation of actin organization and how it controls the spatial localization of filopodial dynamics and thus axon extension. Together, these observations suggest a novel, probabilistic mechanism by which Abl biases the stochastic fluctuations of growth cone actin to direct axon growth and guidance.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Axones
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Proteínas Tirosina Quinasas
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Proteínas de Drosophila
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Drosophila melanogaster
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Morfogénesis
Límite:
Animals
Idioma:
En
Revista:
Mol Biol Cell
Asunto de la revista:
BIOLOGIA MOLECULAR
Año:
2020
Tipo del documento:
Article