siRNAs from an X-linked satellite repeat promote X-chromosome recognition in Drosophila melanogaster.
Proc Natl Acad Sci U S A
; 111(46): 16460-5, 2014 Nov 18.
Article
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| MEDLINE
| ID: mdl-25368194
ABSTRACT
Highly differentiated sex chromosomes create a lethal imbalance in gene expression in one sex. To accommodate hemizygosity of the X chromosome in male fruit flies, expression of X-linked genes increases twofold. This is achieved by the male- specific lethal (MSL) complex, which modifies chromatin to increase expression. Mutations that disrupt the X localization of this complex decrease the expression of X-linked genes and reduce male survival. The mechanism that restricts the MSL complex to X chromatin is not understood. We recently reported that the siRNA pathway contributes to localization of the MSL complex, raising questions about the source of the siRNAs involved. The X-linked 1.688 g/cm(3) satellite related repeats (1.688(X) repeats) are restricted to the X chromosome and produce small RNA, making them an attractive candidate. We tested RNA from these repeats for a role in dosage compensation and found that ectopic expression of single-stranded RNAs from 1.688(X) repeats enhanced the male lethality of mutants with defective X recognition. In contrast, expression of double-stranded hairpin RNA from a 1.688(X) repeat generated abundant siRNA and dramatically increased male survival. Consistent with improved survival, X localization of the MSL complex was largely restored in these males. The striking distribution of 1.688(X) repeats, which are nearly exclusive to the X chromosome, suggests that these are cis-acting elements contributing to identification of X chromatin.
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1
Bases de datos:
MEDLINE
Asunto principal:
Cromosoma X
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Secuencias Repetitivas de Ácidos Nucleicos
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ARN Interferente Pequeño
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Drosophila melanogaster
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Año:
2014
Tipo del documento:
Article