Filogeografia de Nasutitermes corniger (Isoptera: Termitidae: Nasutitermitinae) na região Neotropical
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Data
2016-03-04
Autores
Santos, Amanda de Faria [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
Cupins são insetos eussociais da infraordem Isoptera, que, atualmente, é composta por nove famílias com representantes vivos. Ecologicamente, os cupins desempenham um importante papel na ciclagem de nutrientes do solo, e são conhecidos como "super decompositores". A região Neotropical é a terceira em número de espécies de cupins conhecidas, com aproximadamente 600 descritas, que são divididas em cinco famílias, incluindo Termitidae, que abriga a espécie deste trabalho, Nasutitermes corniger. O presente trabalho se propôs a estudar as populações de N. corniger sob a perspectiva da genética de populações e da filogeografia. Essas duas áreas de estudo, aliadas, permitem que se trace a história evolutiva dos processos responsáveis pelo surgimento de padrões encontrados atualmente. De modo geral, esse foi o objetivo deste trabalho: encontrar e compreender os padrões e os processos que permitem traçar a história evolutiva da espécie N. corniger, distribuída ao longo da região Neotropical, utilizando-se o marcador molecular mitocondrial 16S rDNA. Foram utilizados 230 espécimes de N. corniger, provenientes de mais de 15 estados brasileiros, de países da América do Sul, América Central e Ilhas do Caribe. Após sequenciamento dos fragmentos de 16S rDNA, obteve-se 45 haplótipos, que puderam ser divididos em 6 agrupamentos. Com exceção de alguns haplótipos do agrupamento 1, considerado o mais antigo, os agrupamentos estão distribuídos de modo a relacionar áreas geográficas proximamente localizadas. A observação desse padrão, junto aos resultados da Análise de Variância Molecular (AMOVA), permitiu que se inferisse que as populações analisadas estão estruturadas ao longo da área amostrada. Os resultados da Nested Clade Phylogeografic Analysis (NCPA) frequentemente indicaram isolamento por distância como causa do padrão de distribuição de haplótipos encontrado, inferência corroborada pelo teste de Mantel. A partir dos agrupamentos observados na rede haplotípica e do padrão de distribuição dos haplótipos ao longo da região Neotropical, ainda foi possível inferir uma provável rota de dispersão para a espécie, que parte da América Central em direção à América do Sul, adentrando o território brasileiro. Além disso, foi possível observar que a distribuição dos haplótipos ao longo da área amostrada está associada a eventos biogeográficos que ocorreram na América do Sul e à distribuição das biotas encontradas no continente, como é o caso dos haplótipos encontrados na Mata Atlântica, e nas regiões de vegetação aberta do Cerrado, Caatinga e Chaco.
Termites are eusocial insects of the infraorder Isoptera, which is currently composed of nine families with living representatives. Ecologically, termites have an important role in nutrient cycling of the soil, and are known as "super decomposers". The Neotropical region is the third in number of known species, with about 600 described species, that are divided in five families, including Termitidae, which involving the specie of this work, Nasutitermes corniger. This work proposed to study the populations of N. corniger by the approach of Populations Genetics and Phylogeography. Both study areas, together, allow to trace the evolutionary history of the processes responsible for the origin of currently found patterns. Overall, this was the aim of this work: to find and understand the patterns and processes which allow to trace the evolutionary history of the specie N. corniger, distributed along the Neotropics, using the mitochondrial molecular marker 16S rDNA. Have been used 230 specimens of N. corniger, from more than 15 Brazilian states, South and Central America countries and Caribbean Islands. After sequencing of 16S rDNA fragments, 45 haplotypes were obtained, which could be divided into six groupings. Except some haplotypes of grouping 1, considered oldest, the groupings are distributed to relate geographical areas most closely located. The observation of this pattern, together with the results of Analysis of Molecular Variance (AMOVA), allowed it to be deduced that populations are structured along sampled area. The results of Nested Clade Phylogeografic Analysis (NCPA) indicate, frequently, isolation by distance as cause of distribution pattern found, inference supported by Mantel’s test. From the groupings which were observed at haplotypic network and the haplotype distribution pattern throughout the sampled region, it was still possible to infer a probable expansion route for the specie, which goes from Central America in direction to South America, entering in the Brazilian territory. Furthermore, it was possible to observe that the haplotype distribution along sampled area is associated with biogeographic events which occurred in South America and with the biotas’ distribution found in the continent, as the case of haplotypes found in Atlantic Forest, and in the regions of opened vegetation of Cerrado and Caatinga.
Termites are eusocial insects of the infraorder Isoptera, which is currently composed of nine families with living representatives. Ecologically, termites have an important role in nutrient cycling of the soil, and are known as "super decomposers". The Neotropical region is the third in number of known species, with about 600 described species, that are divided in five families, including Termitidae, which involving the specie of this work, Nasutitermes corniger. This work proposed to study the populations of N. corniger by the approach of Populations Genetics and Phylogeography. Both study areas, together, allow to trace the evolutionary history of the processes responsible for the origin of currently found patterns. Overall, this was the aim of this work: to find and understand the patterns and processes which allow to trace the evolutionary history of the specie N. corniger, distributed along the Neotropics, using the mitochondrial molecular marker 16S rDNA. Have been used 230 specimens of N. corniger, from more than 15 Brazilian states, South and Central America countries and Caribbean Islands. After sequencing of 16S rDNA fragments, 45 haplotypes were obtained, which could be divided into six groupings. Except some haplotypes of grouping 1, considered oldest, the groupings are distributed to relate geographical areas most closely located. The observation of this pattern, together with the results of Analysis of Molecular Variance (AMOVA), allowed it to be deduced that populations are structured along sampled area. The results of Nested Clade Phylogeografic Analysis (NCPA) indicate, frequently, isolation by distance as cause of distribution pattern found, inference supported by Mantel’s test. From the groupings which were observed at haplotypic network and the haplotype distribution pattern throughout the sampled region, it was still possible to infer a probable expansion route for the specie, which goes from Central America in direction to South America, entering in the Brazilian territory. Furthermore, it was possible to observe that the haplotype distribution along sampled area is associated with biogeographic events which occurred in South America and with the biotas’ distribution found in the continent, as the case of haplotypes found in Atlantic Forest, and in the regions of opened vegetation of Cerrado and Caatinga.
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Palavras-chave
Cupins, Genética de populações, DNA mitocondrial, Haplótipos, 16S rDNA, Termites, Population Genetics, Mitochondrial DNA, Haplotypes