Interações evolutivas entre borboletas da tribo troidini (Papilionidae, Papilioninae) e suas plantas hospedeiras no genero Aristolochia (Aristolochiaceae)

Orientador: Vera Nisaka Solferini, Jose Roberto TrigoTese (doutorado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo: Uma filogenia dos membros Neotropicais da tribo Troidini (Lepidoptera: Papilionidae) foi obtida a partir da seqüência de três genes codificadores de proteínas: dois mitocondriais (COI e COII) e um nuclear (EF-1?). Análises de Parcimônia e Bayesiana de 33 taxa resultaram em árvores bastante similares, independentemente do método utilizado, com os 27 Troidini sempre formando um ramo monofilético. O gênero Battus é grupo irmão dos demais Troidini, seguido pelo ramo formado pelos taxa Paleotropicais (aqui representados por três espécimes). O gênero Euryades é o próximo ramo, e grupo irmão dos Parides. O gênero Parides é monofilético, e está dividido em quatro grupos principais pela análise de Máxima Parcimônia, com o grupo mais basal composto das espécies com cauda do SE do Brasil. Otimizações de Caráter de dados ecológicos e morfológicos sobre a filogenia proposta para os troidines indicaram que o uso de várias espécies de Aristolochia é o caráter ancestral, ao invés do uso de poucas ou de uma única planta hospedeira. Para os outros três caracteres, os estados ancestrais foram ausência de uma cauda longa, floresta como habitat primário e oviposição de ovos solitários ou em grupos dispersos de vários ovos. Uma filogenia baseada no gene cloroplástico matK e na região não-codificadora entre os genes trnL-trnF, e uma relação química baseada no seu padrão de sesquiterpenos, foram propostas para as plantas do gênero Aristolochia do SE do Brasil. Aristolochia é um gênero monofilético, cujo estado ancestral é a presença de ácidos aristolóquicos (AAs) nas suas folhas. Espécies consideradas derivadas mostram apenas ácidos labdanóicos (LAs) nas folhas. A relação fenética recuperada com os sesquiterpenos não concorda com a relação filogenética para as Aristolochia, e três grupos principais podem ser reconhecidos: germacreno-D, germacreno-C e Z-cariofileno. A distribuição de AAs e LAs sobre a filogenia de Aristolochia pode ser vista como um resultado da evolução de defesas contra herbivoria de insetos fitófagos através da história evolutiva destas plantas. Por outro lado, a diferenciação das estruturas dos sesquiterpenos em espécies filogeneticamente próximas pode ser hipotetizada como resultado de adaptações relacionadas à atração de polinizadores. Análises filogenéticas foram conduzidas para se determinar relações e para investigar a evolução de caracteres na evolução da interação entre Troidini e Aristolochia, tentando responder as seguintes questões: 1) qual o padrão de utilização de Aristolochia por estas borboletas? 2) o padrão visto atualmente está relacionado à filogenia das plantas ou à sua composição química? 3) a distribuição geográfica das Aristolochia pode explicar a utilização de plantas hospedeiras observada atualmente? e 4) como a interação entre Troidini e Aristolochia evoluiu? Foi encontrada uma congruência significativa entre as filogenias de Troidini e Aristolochia e entre a filogenia dos Troidini e o quimiograma de Aristolochia quando apenas as associações com as plantas hospedeiras preferenciais de Troidini foram consideradas. No entanto, o padrão atual do uso de plantas hospedeiras não parece ser limitado pela filogenia das mesmas, nem pelos químicos secundários encontrados nestas plantas nem pela sua similaridade geográfica. O uso atual de plantas hospedeiras nestas borboletas parece ser simplesmente oportunístico, com espécies com uma ampla distribuição geográfica usando mais espécies de plantas hospedeiras do que aquelas com distribuição mais restritaAbstract: A phylogeny of the Neotropical members of the tribe Troidini (Lepidoptera: Papilionidae) was obtained with sequences of three protein-coding genes: two mitochondrial (COI and COII) and one nuclear (EF-1?). Parsimony and Bayesian analyses of 33 taxa resulted in very similar trees regardless of method used, with the 27 troidines always forming a monophyletic clade. The genus Battus is sister group to the remaining troidines, followed by a clade formed by the Paleotropical taxa (here represented by three specimens). The genus Euryades is the next branch, and sister group of Parides. The genus Parides is monophyletic, and is divided into four main groups by Maximum Parsimony analysis, with the most basal group composed of tailed species restricted to SE Brazil. Character optimization of ecological and morphological traits over the phylogeny proposed for troidines indicated that the use of several species of Aristolochia is ancestral over the use of few or a single host-plant. For the other three characters, the ancestral states were the absence of long tails, forest as the primary habitat and oviposition solitary or in loose group of several eggs. A molecular phylogeny based both on the plastid gene matK and on the non-coding region between the genes trnL-trnF, and a chemical relationship based on their sesquiterpenes pattern, were proposed for plants in the genus Aristolochia from SE Brazil. Aristolochia is a monophyletic genus, whose ancestral state is the presence of aristolochic acids (AAs) in the leaves. Species considered derived show only labdanoic acids (LAs) in leaves. The phenetic relationship recovered with sesquiterpenes does not agree with the phylogenetic relationships for Aristolochia, and three main clusters can be recognized, germacrene-D, germacrene-C and Z-caryophyllene groups. The distribution of AAs and LAs over the phylogeny of Aristolochia can be viewed as a result of the evolution of defenses against herbivory of phytophagous insects through the evolutionary history of these plants. On the other hand, the differentiation of sesquiterpene structures in species phylogenetically close can be suggested to be adaptations related to attraction of pollinators. Molecular phylogenetic analyses were conducted to determine relationships and to investigate character evolution in the Troidini/Aristolochia interaction, trying to answer the following questions: 1) what is the present pattern of use of Aristolochia by these butterflies? 2) is the pattern we see today related to the phylogeny of plants or to their chemical composition? 3) can the geographical distribution of Aristolochia explain the host-plant use observed today? and 4) how did the interaction between Troidini and Aristolochia evolve? We found a significant congruence between the phylogenies of Troidini and Aristolochia and between the phylogeny of Troidini and the chemogram of Aristolochia when only the preferred host-plant associations were considered. However, the current pattern of host-plant use of these butterflies does not seem to be constrained by the phylogeny of their food plants, neither by the secondary chemicals in these plants nor by their geographical similarity. The current host-plant use in these butterflies seems to be simply opportunistic, with species with a wide geographical range using more species of host-plants than those with a more restricted distributionDoutoradoEcologiaDoutor em Ecologi

Genotyping-by-sequencing Approach Indicates Geographic Distance As The Main Factor Affecting Genetic Structure And Gene Flow In Brazilian Populations Of Grapholita Molesta (lepidoptera, Tortricidae).

The oriental fruit moth Grapholita molesta is one of the major pests of stone and pome fruit species in Brazil. Here, we applied 1226 SNPs obtained by genotyping-by-sequencing to test whether host species associations or other factors such as geographic distance structured populations of this pest. Populations from the main areas of occurrence of G. molesta were sampled principally from peach and apple orchards. Three main clusters were recovered by neighbor-joining analysis, all defined by geographic proximity between sampling localities. Overall genetic structure inferred by a nonhierarchical amova resulted in a significant ΦST value = 0.19109. Here, we demonstrate for the first time that SNPs gathered by genotyping-by-sequencing can be used to infer genetic structure of a pest insect in Brazil; moreover, our results indicate that those markers are very informative even over a restricted geographic scale. We also demonstrate that host plant association has little effect on genetic structure among Brazilian populations of G. molesta; on the other hand, reduced gene flow promoted by geographic isolation has a stronger impact on population differentiation.8476-48

Seeing the forest through many trees: multi-taxon patterns of phylogenetic diversity in the Atlantic Forest hotspot

We combine phylogenetic and point locality data from selected lineages of the Atlantic Forest flora and fauna to compare spatial patterns of biodiversity sustained by the current configuration of forest remnants to a scenario of complete forest preservation. We then ask the question "how much biodiversity is likely lost, already"? Specifically, we assess how habitat loss likely impacted the climatic spaces occupied by the local species, the inferred composition of local communities and the spatial distribution of phylogenetic diversity and endemism

Transcript expression plasticity as a response to alternative larval host plants in the speciation process of corn and rice strains of Spodoptera frugiperda

Abstract Background Our main purpose was to evaluate the expression of plastic and evolved genes involved in ecological speciation in the noctuid moth Spodoptera frugiperda, the fall armyworm (FAW); and to demonstrate how host plants might influence lineage differentiation in this polyphagous insect. FAW is an important pest of several crops worldwide, and it is differentiated into host plant-related strains, corn (CS) and rice strains (RS). RNA-Seq and transcriptome characterization were applied to evaluate unbiased genetic expression differences in larvae from the two strains, fed on primary (corn) and alternative (rice) host plants. We consider that genes that are differently regulated by the same FAW strain, as a response to different hosts, are “plastic”. Otherwise, differences in gene expression between the two strains fed on the same host are considered constitutive differences. Results Individual performance parameters (larval and pupal weight) varied among conditions (strains vs. hosts). A total of 3657 contigs was related to plastic response, and 2395 contigs were differentially regulated in the two strains feeding on preferential and alternative hosts (constitutive contigs). Three molecular functions were present in all comparisons, both down- and up-regulated: oxidoreductase activity, metal-ion binding, and hydrolase activity. Conclusions Metabolization of foreign chemicals is among the key functions involved in the phenotypic variation of FAW strains. From an agricultural perspective, high plasticity in families of detoxifying genes indicates the capacity for a rapid response to control compounds such as insecticides

Genetic Differentiation of a New World Screwworm Fly Population from Uruguay Detected by SNPs, Mitochondrial DNA and Microsatellites in Two Consecutive Years

The New World screwworm (NWS) fly, Cochliomyia hominivorax (Diptera: Calliphoridae), is an economically important ectoparasite currently distributed in South America and in the Caribbean basin. The successful eradication of this species in USA, Mexico and continental Central America was achieved by a control program based on the sterile insect technique (SIT). In order to implement a genetic control strategy over the NWS fly’s current area of occurrence, first, it is necessary to understand the species dynamics and population structure. In order to address this objective, the spatial genetic structure of the NWS fly was previously reported in South America based on different genetic markers; however, to date, no study has investigated temporal changes in the genetic composition of its populations. In the current study, the temporal genetic structure of a NWS fly population from Uruguay was investigated through two consecutive samplings from the same locality over an interval of approximately 18 generations. The genetic structure was accessed with neutral and under selection SNPs obtained with genotyping-by-sequencing. The results gathered with these data were compared to estimates achieved with mitochondrial DNA sequences and eight microsatellite markers. Temporal changes in the genetic composition were revealed by all three molecular markers, which may be attributed to seasonal changes in the NWS fly’s southern distribution. SNPs were employed for the first time for estimating the genetic structure in a NWS fly population; these results provide new clues and perspectives on its population genetic structure. This approach could have significant implications for the planning and implementation of management programs

Phylogenetic Relationships Of Butterflies Of The Tribe Acraeini (lepidoptera, Nymphalidae, Heliconiinae) And The Evolution Of Host Plant Use.

The tribe Acraeini (Nymphalidae, Heliconiinae) is believed to comprise between one and seven genera, with the greatest diversity in Africa. The genera Abananote, Altinote, and Actinote (s. str.) are distributed in the Neotropics, while the genera Acraea, Bematistes, Miyana, and Pardopsis have a Palaeotropical distribution. The monotypic Pardopsis use herbaceous plants of the family Violaceae, Acraea and Bematistes feed selectively on plants with cyanoglycosides belonging to many plant families, but preferentially to Passifloraceae, and all Neotropical species with a known life cycle feed on Asteraceae only. Here, a molecular phylogeny is proposed for the butterflies of the tribe Acraeini based on sequences of COI, EF-1alpha and wgl. Both Maximum Parsimony and Bayesian analyses showed that the tribe is monophyletic, once the genus Pardopsis is excluded, since it appears to be related to Argynnini. The existing genus Acraea is a paraphyletic group with regard to the South American genera, and the species of Acraea belonging to the group of Old World Actinote is the sister group of the Neotropical genera. The monophyly of South American clade is strongly supported, suggesting a single colonization event of South America. The New World Actinote (s. str.) is monophyletic, and sister to Abananote+Altinote (polyphyletic). Based on the present results it was possible to propose a scenario for the evolution in host plant use within Acraeini, mainly concerning the use of Asteraceae by the South American genera.46515-3

Network.

<p>Network of Brazilian populations of <i>S</i>. <i>frugiperda</i> (FAW) at <i>k</i> = 10 with minimum-spanning tree (MST), based on 7664 SNPs. A) Colors represent each population sampled in the field; B) Colors represent corn- (red) and rice- (blue) strains of FAW.</p