Cytogeography and the evolutionary significance of B chromosomes in relation to inverted rearrangements in a grasshopper species.
Cytogenet Genome Res
; 106(2-4): 351-8, 2004.
Article
em En
| MEDLINE
| ID: mdl-15292616
The analysis of geographic distribution of polymorphic cytological markers, briefly termed as cytogeography, can be considered an important tool to be applied when studying the evolutionary significance of chromosome variability within a species, either to unravel the adaptive significance of chromosome polymorphisms or to investigate the parasitic nature of some genomic elements. In this article we review cytogeographical studies in Trimerotropis pallidipennis, a grasshopper species whose South American populations display geographical patterns of distribution of inversion and B chromosome polymorphisms. Several lines of evidence that issue from the analysis of the geographic distribution of polymorphic markers suggest that inverted chromosomes are special sequences that are maintained by deterministic forces. On the other hand, the pattern of distribution of B chromosome polymorphism clearly demonstrates its selfish nature, being more frequent in those populations in central environments. We also present the analysis of 272 individuals of T. pallidipennis from Uspallata, and demonstrate that Bs in this population have some influence on body size, enlarging many of the morphometric characters of individuals and we propose it could be the consequence of its genotypic disequilibrium with one inversion. These investigations are finally discussed with regard to the models proposed for the maintenance of B chromosomes in natural populations and in relation to the possible interactions with chromosome inversions.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Cromossomos
/
Evolução Molecular
/
Gafanhotos
/
Inversão Cromossômica
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Cytogenet Genome Res
Assunto da revista:
GENETICA
Ano de publicação:
2004
Tipo de documento:
Article
País de afiliação:
Argentina
País de publicação:
Suíça