Molecular analysis of chromosomal polymorphism in the South American cricetid, Graomys griseoflavus.
Chromosome Res
; 3(6): 361-7, 1995 Sep.
Article
em En
| MEDLINE
| ID: mdl-7551551
Graomys griseoflavus is a South American phyllotine rodent widespread in Argentina that shows a high frequency of Robertsonian fusions (RFs). DNA restriction with EcoRI produced a 250-bp repeated family (EG250) specific for the genus. Southern hybridization and sequencing analysis indicate that the EG250 family is heterogeneous, comprising at least two subfamilies. In situ hybridized EG250 probe showed a centromere location in almost all chromosomes. In all karyomorphs C-banding was negative, but restriction enzyme banding (Re-banding) with Alul and Mbol showed centromeric blocks in the autosomes that will generate Robertsonian fusions. Thus, we found three groups of chromosomes: (a) EG250 and Re-banding negative; (b) EG250 positive and Re-banding negative; and (c) EG250 and Re-banding positive. We consider that group (b) is more the result of chromatin condensation state than that of the frequency of recognition sites for the enzymes used. Restriction enzyme blocks would appear in regions with heterochromatic EG250 subfamilies, while lack of banding would be due to decondensed EG250 subfamilies becoming an easier target for chromosomal restriction. It is suggested that heterochromatic EG250 DNA provides a favourable molecular environment for Robertsonian fusion occurrence.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Polimorfismo Genético
/
Arvicolinae
/
Cromossomos
Limite:
Animals
País/Região como assunto:
America do sul
Idioma:
En
Revista:
Chromosome Res
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
1995
Tipo de documento:
Article
País de afiliação:
Argentina