Citogenética de populações de Piabina argentea(Teleostei, Characiformes, Characidae) das bacias dos rios Paranapanema e Tietê
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Data
2008-09-30
Autores
Pazian, Marlon Felix [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Foi realizada a análise citogenética de duas espécies do Gênero Piabina, P. anhembi e P. argentea, utilzando-se técnicas de coloração cromossômica convencional com Giemsa, localização das Ag-RONs, coloração com CMA3, hibridação in situ com as sondas de DNAr 18S e 5S e bandamento C. Todas as quatro amostras de P. argentea apresentaram 2n=52 cromossomos e números fundamentais diferentes, com exceção de duas amostras populacionais coletadas na bacia do rio Paranapanema. Três apresentaram Ag-RONs múltiplas (Avaré, Botucatu e Bauru) e a amostra da população coletada na localidade Itatinga apresentou Ag- RONs simples e um polimorfismo de tamanho das mesmas. A hibridação in situ com o uso de sondas de DNAr 5S mostrou diferenças entre as amostras das populações. O bandamento C marcou em sua maioria as regiões terminais e centroméricas dos cromossomos. As análises evidenciaram a existência de diferenças citogenéticas entre as amostras de P. argentea coletadas, sugerindo a existência de diferenciação populacional. As diferenças citogenéticas encontradas podem ocorrer devido ao fato de que P. argentea habite apenas riachos, o que poderia levar ao isolamento destas populações. Também foi analisada a amostra de uma população de P. anhembi coletada no município de Salesópolis, que também apresentou 2n=52 cromossomos, Ag-RONs simples e polimorfismos de tamanho das Ag-RONs. A hibridação in situ com a utilização da sonda de DNAr 18S mostrou três cromossomos marcados e com a sonda de DNAr 5S mostrou dois cromossomos marcados. O Bandamento C mostrou bandas nas regiões pericentromérica de dois pares cromossômicos nos exemplares desta espécie. Considerando-se o fato deste grupo habitar geralmente regiões específicas dos ambientes de cabeceira dos riachos, isto pode constituir um fator...
Two species of the genus Piabina have been analyzed, P. argentea and P. anhembi using cytogenetic techniques (Staining of Giemsa, staining of Ag-NORs, fluorescent staining CMA3, hybridization in situ using probe of rDNA 18S and 5S and C-band). All samples of P. argentea presented 2n=52 chromosome and different fundamental numbers, with exception of the individuals of two population collected in the Paranapanema river basin. Three samples analyzed from Avaré, Botucatu and Bauru presented multiple NORs and individuals from Itatinga presented the single NOR and the polymorphic NOR. The in situ hybridization technique using the DNAr 5S probe showed differences between samples of all the populations. The technique C-banding showed marks in most of terminals and centromeric regions of the chromosomes. The existence of cytogenetic differences between the individuals of different samples collected of P. argentea, suggests a possible population differentiation. The occurrence of cytogenetic differences happened by the fact that P. argentea live only in upper stream rivers, and this can determine a process of population isolation. A sample of P.anhembi collected in the Salesópolis city was also analyzed and presented 2n=52 chromosomes, simple Ag-NORs and polymorphism of the NORs. The use of in situ hybridization technique with DNAr 18S probe revealed three labellad chromosomes, and with the rDNA 5S probe showed two labellad chromosomes. The technique of C-banding revealed the presence of heterochromatin in the pericentromeric regions of two chromosome pairs. The species Piabina argentea most of the time live in a specific environment in upper stream rivers. This possible isolation can fix spot modifications in the chromosome if it occurs. However this fact don`t change the macro structure of the chromosome in different generations.
Two species of the genus Piabina have been analyzed, P. argentea and P. anhembi using cytogenetic techniques (Staining of Giemsa, staining of Ag-NORs, fluorescent staining CMA3, hybridization in situ using probe of rDNA 18S and 5S and C-band). All samples of P. argentea presented 2n=52 chromosome and different fundamental numbers, with exception of the individuals of two population collected in the Paranapanema river basin. Three samples analyzed from Avaré, Botucatu and Bauru presented multiple NORs and individuals from Itatinga presented the single NOR and the polymorphic NOR. The in situ hybridization technique using the DNAr 5S probe showed differences between samples of all the populations. The technique C-banding showed marks in most of terminals and centromeric regions of the chromosomes. The existence of cytogenetic differences between the individuals of different samples collected of P. argentea, suggests a possible population differentiation. The occurrence of cytogenetic differences happened by the fact that P. argentea live only in upper stream rivers, and this can determine a process of population isolation. A sample of P.anhembi collected in the Salesópolis city was also analyzed and presented 2n=52 chromosomes, simple Ag-NORs and polymorphism of the NORs. The use of in situ hybridization technique with DNAr 18S probe revealed three labellad chromosomes, and with the rDNA 5S probe showed two labellad chromosomes. The technique of C-banding revealed the presence of heterochromatin in the pericentromeric regions of two chromosome pairs. The species Piabina argentea most of the time live in a specific environment in upper stream rivers. This possible isolation can fix spot modifications in the chromosome if it occurs. However this fact don`t change the macro structure of the chromosome in different generations.
Descrição
Palavras-chave
Peixe - Genética - Tietê, Rio, Piabina argentea - Citogenética, P. argentea - Cytogenetic
Como citar
PAZIAN, Marlon Felix. Citogenética de populações de Piabina argentea(Teleostei, Characiformes, Characidae) das bacias dos rios Paranapanema e Tietê. 2008. 53 f. Dissertação (mestrado) - Universidade Estadual Paulista, Instituto de Biociências de Botucatu, 2008.