Zaprionus indianus: uma visão da espécie invasora sob o aspecto genético e evolutivo
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Data
2011-03-04
Autores
Commar, Leliane Silva [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Zaprionus indianus é uma espécie de mosca de origem africana que se dispersou pelas regiões tropicais da Ásia e das Américas. Grande interesse tem sido despertado sobre essa espécie, principalmente pela recente expansão da sua área de distribuição com a invasão do continente americano, ocorrida na década de 90. Hoje, indivíduos dessa espécie são encontrados em uma larga amplitude latitudinal, do Uruguai a Belém (Brasil), além do Panamá (América Central) e Flórida (Estados Unidos). Tem sido proposta que a introdução de Z. indianus no Brasil ocorreu no Estado de São Paulo e de lá a espécie se propagou para outros estados brasileiros por meio do comércio de frutas. Entretanto, a rota de dispersão dessa espécie não foi ainda completamente estabelecida. Na tentativa de esclarecer essa questão, avaliamos a variabilidade genética de dois marcadores, um fragmento do gene COI (citocromo oxidase I), de 612 pb, e do gene ortólogo ao Est-6 de Drosophila melanogaster, de 747 pb, em 19 populações de Z. indianus, de diversas regiões geográficas, englobando África, Ásia e Américas. A análise do polimorfismo do gene ortólogo ao Est–6 mostrou uma elevada diversidade nucleotídica, resultado de substituições sinônimas, indicando seleção purificadora atuando neste gene, tanto nas populações ancestrais como nas invasoras. Para o propósito de estabelecer a rota de dispersão de Z. indianus, foi construída uma rede de haplótipos por meio do método “median-joning network” para os dois marcadores. Os resultados são inéditos, pois indicam a ocorrência de duas invasões no Brasil, ao contrário de estudos anteriores que sugeriram apenas uma. Esses resultados também sugerem que a invasão de Z. indianus na América do Norte se deu a partir de migrantes de populações brasileiras, e não africanas ou asiáticas. Essa invasão pode estar diretamente...
Zaprionus indianus is a species of an African origin which has dispersed through tropical Asian as well as South and North America regions. Great interest has been taken at this species, mainly for the fact that recently its distribution has been expanded to American continent due to the invasion probably occurred in the nineties. Nowadays individuals from this species are found in wide latitudinal extent, from Uruguay to Belem (Brazil), besides Panama (Central America) and Florida (The United States). It has been proposed that Z. indianus introduction in Brazil happened from the São Paulo to other Brazilian states through fruit trading, though this species’ dispersion route has not been completely established. In order to clarify this issue we evaluated genetic variability of two markers, a sequence of the gene COI (cytochrome oxidase I), 612 bp long and of the ortholog to Est-6 gene from Drosophila melanogaster, 747 bp long, in 19 populations of Z. indianus from several geographic regions, covering Africa, Asia and America. Polymorphism analysis of ortholog to Est-6 gene showed an elevated nucleotide diversity, resulting from synonym substitutions, indicating a purifying selection acting on this gene, which occurred in ancestral populations, as well as in the invader ones. Aiming at establishing the Z. indianus dispersion route, a haplotype network was built, using median-joining network method for the two markers. The results are unreleased, for they indicate the occurrence of two invasions in Brazil, in opposition to previous studies that have indicated just one. They also demonstrate that Z. indianus’ invasion in North America has happened from Brazilian population migrants, not African or Asian ones. This invasion can be directly related to the fact that Brazil is currently the third largest world fruit producer and exports over... (Complete abstract click electronic access below)
Zaprionus indianus is a species of an African origin which has dispersed through tropical Asian as well as South and North America regions. Great interest has been taken at this species, mainly for the fact that recently its distribution has been expanded to American continent due to the invasion probably occurred in the nineties. Nowadays individuals from this species are found in wide latitudinal extent, from Uruguay to Belem (Brazil), besides Panama (Central America) and Florida (The United States). It has been proposed that Z. indianus introduction in Brazil happened from the São Paulo to other Brazilian states through fruit trading, though this species’ dispersion route has not been completely established. In order to clarify this issue we evaluated genetic variability of two markers, a sequence of the gene COI (cytochrome oxidase I), 612 bp long and of the ortholog to Est-6 gene from Drosophila melanogaster, 747 bp long, in 19 populations of Z. indianus from several geographic regions, covering Africa, Asia and America. Polymorphism analysis of ortholog to Est-6 gene showed an elevated nucleotide diversity, resulting from synonym substitutions, indicating a purifying selection acting on this gene, which occurred in ancestral populations, as well as in the invader ones. Aiming at establishing the Z. indianus dispersion route, a haplotype network was built, using median-joining network method for the two markers. The results are unreleased, for they indicate the occurrence of two invasions in Brazil, in opposition to previous studies that have indicated just one. They also demonstrate that Z. indianus’ invasion in North America has happened from Brazilian population migrants, not African or Asian ones. This invasion can be directly related to the fact that Brazil is currently the third largest world fruit producer and exports over... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Genetica molecular, Evolução molecular, Drosofila - Evolução, Drosófila - Genética, Drosophila melanogaster, Zaprionus indianus, Bioinvasion, Polymorphism, Molecular markers
Como citar
COMMAR, Leliane Silva. Zaprionus indianus: uma visão da espécie invasora sob o aspecto genético e evolutivo. 2011. 115 f. Tese (doutorado) - Universidade Estadual Paulista Júlio de Mesquita Filho, Instituto de Biociências, Letras e Ciências Exatas de São José do Rio Preto, 2011.