Cytogenetic divergence between two sympatric species of Characidium (Teleostei, Characiformes, Crenuchidae) from the Machado River, Minas Gerais, Brazil
Genet. mol. biol
;
29(3): 459-463, 2006. ilus
Article
in English
| LILACS
| ID: lil-450281
ABSTRACT
Cytogenetic studies were performed on two sympatric species of Characidium, C. gomesi and C. cf. zebra, from the Grande River basin, Minas Gerais State, Brazil. Although both species had a chromosome number of 50 with a karyotype exclusively consisting of meta- and submetacentric chromosomes, interspecific diversity was detected concerning the size of the two first chromosome pairs of the karyotypes. Active nucleolus organizer regions (NORs) were located at the terminal position on the long arm of the 17th pair of C. gomesi and at subterminal position on the long arm of the 23rd pair of C. cf. zebra. For both species the fluorochrome CMA3 stained only the NOR-bearing pair of chromosomes. The heterochromatin pattern also showed some differentiation between these species restricted to the centromeric or pericentromeric region of C. cf. zebra and practically absent in C. gomesi. These data are discussed concerning chromosome diversification in this fish group.
Full text:
Available
Index:
LILACS (Americas)
Main subject:
Cytogenetics
/
Fishes
/
Nucleolus Organizer Region
Limits:
Animals
Country/Region as subject:
South America
/
Brazil
Language:
English
Journal:
Genet. mol. biol
Journal subject:
Genetics
Year:
2006
Type:
Article
Affiliation country:
Brazil
Institution/Affiliation country:
Universidade Estadual Paulista/BR
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