Characterization of the breakpoints of a polymorphic inversion complex detects strict and broad breakpoint reuse at the molecular level.
Mol Biol Evol
; 31(9): 2331-41, 2014 Sep.
Article
em En
| MEDLINE
| ID: mdl-24881049
ABSTRACT
Inversions are an integral part of structural variation within species, and they play a leading role in genome reorganization across species. Work at both the cytological and genome sequence levels has revealed heterogeneity in the distribution of inversion breakpoints, with some regions being recurrently used. Breakpoint reuse at the molecular level has mostly been assessed for fixed inversions through genome sequence comparison, and therefore rather broadly. Here, we have identified and sequenced the breakpoints of two polymorphic inversions-E1 and E2 that share a breakpoint-in the extant Est and E1 + 2 chromosomal arrangements of Drosophila subobscura. The breakpoints are two medium-sized repeated motifs that mediated the inversions by two different mechanisms E1 via staggered breaks and subsequent repair and E2 via repeat-mediated ectopic recombination. The fine delimitation of the shared breakpoint revealed its strict reuse at the molecular level regardless of which was the intermediate arrangement. The occurrence of other rearrangements in the most proximal and distal extended breakpoint regions reveals the broad reuse of these regions. This differential degree of fragility might be related to their sharing the presence outside the inverted region of snoRNA-encoding genes.
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MEDLINE
Assunto principal:
Passeio de Cromossomo
/
Drosophila
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Pontos de Quebra do Cromossomo
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Cromossomos de Insetos
Limite:
Animals
Idioma:
En
Revista:
Mol Biol Evol
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
2014
Tipo de documento:
Article
País de afiliação:
Espanha