Growth cone navigation in substrate-bound ephrin gradients.
Development
; 133(13): 2487-95, 2006 Jul.
Article
em En
| MEDLINE
| ID: mdl-16763203
ABSTRACT
Graded distributions of ephrin ligands are involved in the formation of topographic maps. However, it is still poorly understood how growth cones read gradients of membrane-bound guidance molecules. We used microcontact printing to produce discontinuous gradients of substrate-bound ephrinA5. These consist of submicron-sized protein-covered spots, which vary with respect to their sizes and spacings. Growth cones of chick temporal retinal axons are able to integrate these discontinuous ephrin distributions and stop at a distinct zone in the gradient while still undergoing filopodial activity. The position of this stop zone depends on both the steepness of the gradient and on the amount of substrate-bound ephrin per unit surface area. Quantitative analysis of axon outgrowth shows that the stop reaction is controlled by a combination of the local ephrin concentration and the total amount of encountered ephrin, but cannot be attributed to one of these parameters alone.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Células Ganglionares da Retina
/
Axônios
/
Cones de Crescimento
/
Efrinas
/
Efrina-A5
Limite:
Animals
Idioma:
En
Ano de publicação:
2006
Tipo de documento:
Article