Heteroduplex DNA in meiotic recombination in Drosophila mei-9 mutants.
Genetics
; 176(1): 63-72, 2007 May.
Article
en En
| MEDLINE
| ID: mdl-17339219
ABSTRACT
Meiotic recombination gives rise to crossovers, which are required in most organisms for the faithful segregation of homologous chromosomes during meiotic cell division. Characterization of crossover-defective mutants has contributed much to our understanding of the molecular mechanism of crossover formation. We report here a molecular analysis of recombination in a Drosophila melanogaster crossover-defective mutant, mei-9. In the absence of mei-9 activity, postmeiotic segregation associated with noncrossovers occurs at the expense of crossover products, suggesting that the underlying meiotic function for MEI-9 is in crossover formation rather than mismatch repair. In support of this, analysis of the arrangement of heteroduplex DNA in the postmeiotic segregation products reveals different patterns from those observed in Drosophila Msh6 mutants, which are mismatch-repair defective. This analysis also provides evidence that the double-strand break repair model applies to meiotic recombination in Drosophila. Our results support a model in which MEI-9 nicks Holliday junctions to generate crossovers during meiotic recombination, and, in the absence of MEI-9 activity, the double Holliday junction intermediate instead undergoes dissolution to generate noncrossover products in which heteroduplex is unrepaired.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Proteínas Nucleares
/
Intercambio Genético
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Proteínas de Drosophila
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Drosophila melanogaster
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Meiosis
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Mutación
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Ácidos Nucleicos Heterodúplex
Límite:
Animals
Idioma:
En
Revista:
Genetics
Año:
2007
Tipo del documento:
Article
País de afiliación:
Estados Unidos