Estudos citogenéticos em populações de Bryconamericus stramines, Eigenmann, 1908(Teleostei, Characidae) em rios das bacias do Tietê e Paranapanema
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Data
2008-09-30
Autores
Pescatori, Gustavo Luiz Rossetto [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
A família Characidae é a maior e mais complexa dentre as famílias de peixes da ordem Characiformes e grande parte dos peixes do Brasil encontra-se na família Characidae. A maioria dos peixes desta família é conhecida popularmente como lambaris, piracanjubas, peixes-cachorros, pacus, piranhas e dourados. Distribuemse no continente americano – desde a fronteira do México com os Estados Unidos até o sul da Argentina. O gênero Bryconamericus possui aproximadamente 51 espécies identificadas e destas, cerca de 30 que vivem em distintas regiões do Brasil, possuem um número diplóide relativamente estável de 2n=52 cromossomos, mas há muito pouca informação citogenética sobre os representantes deste. No presente projeto, foi realizada a análise citogenética em representantes de cinco populações de Bryconamericus stramineus, Eigenmann, 1908, em rios das bacias do Tietê e Paranapanema, região de Botucatu, SP. Para tanto, foram caracterizados seus cariótipos através de coloração convencional com Giemsa, a qual evidenciou um cariótipo padrão de 2n=52 cromossomos; foram identificados os padrões de distribuição de heterocromatina constitutiva (Bandas C) que revelaram blocos heterocromáticos centroméricos, intersticiais e teloméricos; foram identificadas as regiões organizadoras de nucléolos (RONs) através de impregnação com nitrato de prata, evidenciando-se RONs simple e múltiplas; foram identificadas as regiões cromossômicas ricas em GC através de coloração com o fluorocromo cromomicina (CMA3) que também se mostraram simples e múltiplas, mostrando correspondência com as Ag-RONs; foram identificados ainda os cístrons ribossômicos através de hibridação in situ fluorescente (FISH) com a sonda de DNAr 18S, que revelou de duas e seis marcações e com a sonda de DNAr 5S que revelou de três...
The Characidae family is the largest and more complex among the fish families of Characiform order and most part of Brazilian fishes are in this family. The majority of fishes from this family are popularly known as lambaris, piracanjubas, peixes-cachorros, pacus, piranhas e dourados. They are spread over great part of the American continent - since the border of Mexico with United 8tates until the southern limit of Argentina. The gender Bryconamericus has proximately 51 identified species and about 30 of them live in distinct regions of Brazil. There are very few cytogenetic information about them beyond the relatively stable diploid number of 2n=52 chromosomes. In the present project cytogenetic analysis were accomplished in representative species of five populations of Bryconamericus stramineus, Eigenmann, 1908, from rivers that belong to Tietê and Parapanema basins, in the Botucatu town, state of 8ão Paulo. For that, the karyotypes were characterized by conventional Giemsa staining, which showed a karyotype of 2n= 52 chromosomes; the pattern of distribution of the constitutive heterochromatin were identified by C Banding and revealed centromeric, interstitial and telomeric heterochromatic blocks; the nucleoli organizer regions (NORs) were identified through silver nitrate impregnation and evidenced simple and multiple RONs; the GC rich chromosomic regions were identified through the f1uorochrome chromomycin (CMAJ) which appeared as simple and multiple marks, showing correspondence to Ag-NORs; the ribosomal cistrons were identified through f1uorescentin situ hybridization (FI8H) with 188 rDNA as probe, which revealed from two to six marks and, with 58 rDNA as probe, revealed from two to five marks. The obtained data, besides revealing... (Complete abstract click electronic access below)
The Characidae family is the largest and more complex among the fish families of Characiform order and most part of Brazilian fishes are in this family. The majority of fishes from this family are popularly known as lambaris, piracanjubas, peixes-cachorros, pacus, piranhas e dourados. They are spread over great part of the American continent - since the border of Mexico with United 8tates until the southern limit of Argentina. The gender Bryconamericus has proximately 51 identified species and about 30 of them live in distinct regions of Brazil. There are very few cytogenetic information about them beyond the relatively stable diploid number of 2n=52 chromosomes. In the present project cytogenetic analysis were accomplished in representative species of five populations of Bryconamericus stramineus, Eigenmann, 1908, from rivers that belong to Tietê and Parapanema basins, in the Botucatu town, state of 8ão Paulo. For that, the karyotypes were characterized by conventional Giemsa staining, which showed a karyotype of 2n= 52 chromosomes; the pattern of distribution of the constitutive heterochromatin were identified by C Banding and revealed centromeric, interstitial and telomeric heterochromatic blocks; the nucleoli organizer regions (NORs) were identified through silver nitrate impregnation and evidenced simple and multiple RONs; the GC rich chromosomic regions were identified through the f1uorochrome chromomycin (CMAJ) which appeared as simple and multiple marks, showing correspondence to Ag-NORs; the ribosomal cistrons were identified through f1uorescentin situ hybridization (FI8H) with 188 rDNA as probe, which revealed from two to six marks and, with 58 rDNA as probe, revealed from two to five marks. The obtained data, besides revealing... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Peixe - Genética - Paranapanema, Rio, Peixe - Genética - Tietê, Rio, Bryconamericus - Citogenética
Como citar
PESCATORI, Gustavo Luiz Rossetto. Estudos citogenéticos em populações de Bryconamericus stramines, Eigenmann, 1908(Teleostei, Characidae) em rios das bacias do Tietê e Paranapanema. 2008. 92 f. Dissertação (mestrado) - Universidade Estadual Paulista, Instituto de Biociências de Botucatu, 2008.