Topological constraints on transvection between white genes within the transposing element TE35B in Drosophila melanogaster.
Genetics
; 146(3): 919-37, 1997 Jul.
Article
en En
| MEDLINE
| ID: mdl-9215897
The transposable element TE35B carries two copies of the white (w) gene at 35B1.2 on the second chromosome. These w genes are suppressed in zeste-1 (z1) mutant background in a synapsis-dependent manner. Single-copy derivatives of the original TE35B stock give red eyes when heterozygous, but zeste eyes when homozygous. TE35B derivatives carrying single, double or triple copies of w were crossed to generate flies carrying from two to five ectopic w genes. Within this range, z1-mediated suppression is insensitive to copynumber and does not distinguish between w genes that are in cis or in trans. Suppression does not require the juxtaposition of even numbers of w genes, but is extremely sensitive to chromosomal topology. When arranged in a tight cluster, in triple-copy TE derivatives, w genes are nonsuppressible. Breakpoints falling within TE35B and separating two functional w genes act as partial suppressors of z1. Similarly, breakpoints immediately proximal or distal to both w genes give partial suppression. This transvection-dependent downregulation of w genes may result from mis-activation of the X-chromosome dosage compensation mechanism.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Elementos Transponibles de ADN
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Transfección
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Genes de Insecto
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Transportadoras de Casetes de Unión a ATP
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Proteínas de Insectos
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Proteínas de Drosophila
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Drosophila melanogaster
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Proteínas del Ojo
Límite:
Animals
Idioma:
En
Revista:
Genetics
Año:
1997
Tipo del documento:
Article
País de afiliación:
Reino Unido
Pais de publicación:
Estados Unidos