Caracterização citogenética e molecular das espécies pintado (Pseudoplatystoma corruscans), cachara (Pseudoplatystoma reticulatum) e seus híbridos utilizados na piscicultura brasileira
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Data
2010-02-26
Autores
Prado, Fernanda Dotti do [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A hibridação artificial interespecífica de peixes é utilizada em diversos estabelecimentos voltados à piscicultura no país, com a finalidade de produzir indivíduos mais vantajosos e favoráveis para o cultivo. Porém, devido principalmente às dificuldades encontradas na identificação dos híbridos, esta prática pode determinar o surgimento de sérios problemas como a contaminação genética dos estoques de cultivo, a comercialização de produtos híbridos como espécies puras, a introdução de espécies exóticas e escapes de produtos de piscicultura para o ambiente natural e até eventos de introgressão genética e extinção das espécies nativas. Neste contexto, o presente trabalho teve por objetivo analisar geneticamente exemplares das linhagens parentais de Pseudoplatystoma corruscans (pintado) e Pseudoplatystoma reticulatum (cachara) e seus híbridos interespecíficos pintachara (macho de pintado x fêmea de cachara) e cachapinta (fêmea de cachara x macho de pintado), provenientes dos estoques de cultivo do CEPTAlICMBio, Pirassununga, SP, a fim de identificar e estabelecer marcadores genéticos para possibilitar sua identificação e diferenciação. Também foram analisadas geneticamente amostras de P. corruscans e P. reticulatum coletadas no Rio Paraguai, MS (bacia do Paraguai) e de P. corruscans capturados do rio Mogi- Guaçu, SP (bacia do Alto Paraná), a fim de identificar a possível ocorrência de híbridos entre estas espécies na natureza. As análises citogenéticas revelaram um número diploide de 2n=56 cromossomos para ambas as espécies parentais, com cariótipos caracterizados por cromossomos dos tipos 20m+12am+12st+12a e número fundamental (NF) igual a 100, indicando uma fórmula cariotípica conservada entre estas espécies. A análise dos padrões de heterocromatina pelo bandamento C revelou blocos heterocromáticos localizados nas porções...
Artificial interspecific hybridization of fish is used in various establishments linked to fish farming in the country, in order to produce individuais more advantageous and favorable for cultivation. However, due mainly to difficulties in the hybrid products identification, this practice may determine the onset of serious problems such as genetic contamination of the breeder stocks, marketing of hybrids as pure species, introduction of exotic species and escapes of farmed products to the natural environment and sometimes leading to events of genetic introgression and extinction of native species. In such context, the present study aimed to analyze genetically copies of the parental lines of Pseudoplatystoma corruscans (pintado) and Pseudoplatystoma reticulatum (cachara) and their interspecific hybrids pintachara (female of pintado x male of cachara) and cachapinta (female of cachara x male of pintado), from the stocks manteined in CEPTAlICMBio, Pirassununga, SP, in order to characterize and establish genetic markers to allow their identification and differentiation. Samples of P. corruscans and P. reticulatum collected in the Paraguay river, MS (Paraguay basin) and P. corruscans captured in Mogi-Guaçu river, SP (Alto Paraná basin), also were genetically analyzed in order to identify the possible occurrence of hybrids between these species in nature. The cytogenetic analysis revealed a diploid number of 2n = 56 chromosomes for both parental species with karyotypes characterized by the formula 20m+12am+12st+12a and fundamental number (NF) of 100, indicating a karyotypic formula conserved among these species. The analysis of the heterochromatin C-banding patterns revealed heterochromatic blocks located in the pericentromeric and terminal portions of some chromosomes, the NOR was sim pie and located in one chromosome pai r and 5S ribosomal genes located on two different subtelocentric... (Complete abstract click electronic access below)
Artificial interspecific hybridization of fish is used in various establishments linked to fish farming in the country, in order to produce individuais more advantageous and favorable for cultivation. However, due mainly to difficulties in the hybrid products identification, this practice may determine the onset of serious problems such as genetic contamination of the breeder stocks, marketing of hybrids as pure species, introduction of exotic species and escapes of farmed products to the natural environment and sometimes leading to events of genetic introgression and extinction of native species. In such context, the present study aimed to analyze genetically copies of the parental lines of Pseudoplatystoma corruscans (pintado) and Pseudoplatystoma reticulatum (cachara) and their interspecific hybrids pintachara (female of pintado x male of cachara) and cachapinta (female of cachara x male of pintado), from the stocks manteined in CEPTAlICMBio, Pirassununga, SP, in order to characterize and establish genetic markers to allow their identification and differentiation. Samples of P. corruscans and P. reticulatum collected in the Paraguay river, MS (Paraguay basin) and P. corruscans captured in Mogi-Guaçu river, SP (Alto Paraná basin), also were genetically analyzed in order to identify the possible occurrence of hybrids between these species in nature. The cytogenetic analysis revealed a diploid number of 2n = 56 chromosomes for both parental species with karyotypes characterized by the formula 20m+12am+12st+12a and fundamental number (NF) of 100, indicating a karyotypic formula conserved among these species. The analysis of the heterochromatin C-banding patterns revealed heterochromatic blocks located in the pericentromeric and terminal portions of some chromosomes, the NOR was sim pie and located in one chromosome pai r and 5S ribosomal genes located on two different subtelocentric... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Peixe - Genetica, Genetica molecular, Fish cytogenetics, Molecular markers, Genetic conservation
Como citar
PRADO, Fernanda Dotti do. Caracterização citogenética e molecular das espécies pintado (Pseudoplatystoma corruscans), cachara (Pseudoplatystoma reticulatum) e seus híbridos utilizados na piscicultura brasileira. 2010. 107 f. Dissertação (mestrado) - Universidade Estadual Paulista, Instituto de Biociências de Botucatu, 2010.