Structural chromosome polymorphism in a Pimelodus maculatus La Cepède, 1803 population (Siluriformes, Pimelodidae) from the Paranapanema River basin, PR, Brazil
Braz. j. biol
;
67(4,supl): 935-937, Dec. 2007. ilus
Article
in English
| LILACS
| ID: lil-474234
ABSTRACT
In the present cytogenetic study of Pimelodus maculatus, 13 specimens (8 males and 5 females) from the Congonhas Stream in Paraná State, Brazil, were examined using conventional staining. All of them showed a karyotype of 2n = 56, with a chromosome distribution of 20m + 20sm + 10st + 6a. However, four individuals (2 males and 2 females) were found to have a variant karyotype (cytotype) with two heteromorphic chromosomes in the group of submetacentric chromosomes - one of them corresponds to the second largest chromosome of this group and the other is a chromosome of small size. This variation suggests the existence of a structural polymorphism in the studied population.
RESUMO
No presente estudo citogenético, foram analisados, mediante coloração convencional, 13 exemplares de Pimelodus maculatus, (8 machos e 5 fêmeas), do ribeirão Congonhas, PR, Brasil. Todos apresentaram um cariótipo com 2n = 56, distribuídos em 20 cromossomos metacêntricos (m), 20 submetacêntricos (sm), 10 subtelocêntricos (st) e 6 acrocêntricos (a). Entretanto, 4 indivíduos (2 machos e 2 fêmeas) apresentaram um cariótipo variante (citótipo) com dois cromossomos heteromórficos no grupo dos submetacêntricos, sendo um deles o segundo maior deste grupo e o outro de tamanho pequeno. Esta variação sugere a ocorrência de um polimorfismo estrutural na população estudada.
Full text:
Available
Index:
LILACS (Americas)
Main subject:
Polymorphism, Genetic
/
Cytogenetic Analysis
/
Fishes
Limits:
Animals
Country/Region as subject:
South America
/
Brazil
Language:
English
Journal:
Braz. j. biol
Journal subject:
Biology
Year:
2007
Type:
Article
Affiliation country:
Brazil
Institution/Affiliation country:
Universidade Estadual de Londrina/BR
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