106 research outputs found

    Genome-wide introgression among distantly related Heliconius butterfly species

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    Background: Although hybridization is thought to be relatively rare in animals, the raw genetic material introduced via introgression may play an important role in fueling adaptation and adaptive radiation. The butterfly genus Heliconius is an excellent system to study hybridization and introgression but most studies have focused on closely related species such as H. cydno and H. melpomene. Here we characterize genome-wide patterns of introgression between H. besckei, the only species with a red and yellow banded 'postman' wing pattern in the tiger-striped silvaniform clade, and co-mimetic H. melpomene nanna. Results: We find a pronounced signature of putative introgression from H. melpomene into H. besckei in the genomic region upstream of the gene optix, known to control red wing patterning, suggesting adaptive introgression of wing pattern mimicry between these two distantly related species. At least 39 additional genomic regions show signals of introgression as strong or stronger than this mimicry locus. Gene flow has been on-going, with evidence of gene exchange at multiple time points, and bidirectional, moving from the melpomene to the silvaniform clade and vice versa. The history of gene exchange has also been complex, with contributions from multiple silvaniform species in addition to H. besckei. We also detect a signature of ancient introgression of the entire Z chromosome between the silvaniform and melpomene/cydno clades. Conclusions: Our study provides a genome-wide portrait of introgression between distantly related butterfly species. We further propose a comprehensive and efficient workflow for gene flow identification in genomic data sets

    Overlooked gall-inducing moths revisited, with the description of Andescecidium parrai gen. et sp. n. and Oliera saizi sp. n. from Chile (Lepidoptera, Cecidosidae)

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    There are still many gall systems associated with larvae of Lepidoptera in which the true gall-inducers have not been identified to species. Reports on misidentification of gall inducers have been recurrent for these galls, particularly in complex gall-systems that may include inquilines, kleptoparasites, and cecidophages, among other feeding guilds such as predators and parasitoid wasps. Here we describe and illustrate the adults, larvae, pupae and galls, based on light and scanning microscopy, of Andescecidium parrai gen. et sp. n. and Oliera saizi sp. n., two sympatric cecidosid moths that are associated with Schinus polygamus (Cav.) Cabrera (Anacardiaceae) in central Chile. Adults, immatures, and galls of the former did not conform to any known cecidosid genus. Galls of A. parrai are external, spherical, and conspicuous, being known for more than one century. However, their induction has been mistakenly associated with either unidentified Coleoptera (original description) or Oliera argentinana Br糨es (recently), a distinct cecidosid species with distribution restricted to the eastern Andes. Galls of O. saizi had been undetected, as they are inconspicuous. They occur under the bark within swollen stems, and may occur on the same plant, adjacent to those of A. parrai. We also propose a time-calibrated phylogeny using sequences from mitochondrial and nuclear loci, including specimens of the new proposed taxa. Thus in addition to clarifying the taxonomy of the Chilean cecidosid species we also tested their monophyly in comparison to congeneric species and putative specimens of all genera of Neotropical and African cecidosids.Fil: Silva, Gabriela T.. Universidade Federal do Rio Grande do Sul; BrasilFil: Moreira, Gilson R. P.. Universidade Federal do Rio Grande do Sul; BrasilFil: Vargas, Héctor A.. Universidad de Tarapacá de Arica; ChileFil: Gonçalves, Gislene L.. Universidade Federal do Rio Grande do Sul; Brasil. Universidad de Tarapacá de Arica; ChileFil: Mainardi, Marina D.. Universidade Federal do Rio Grande do Sul; BrasilFil: San Blas, Diego German. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Pampa; ArgentinaFil: Davis, Donald. National Museum of Natural History; Estados Unido

    External morphology of the immature stages of Neotropical heliconines: VI. Dione moneta moneta Hübner (Lepidoptera, Nymphalidae, Heliconiini)

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    The external features of the egg, larva and pupa of Dione moneta moneta Hübner, 1825 are described and illustrated, based upon light and scanning electron microscopy.As estruturas externas do ovo, larva e pupa de Dione moneta moneta Hübner, 1825 são descritas e ilustradas, baseadas em microscopia óptica e eletrônica de varredura.1323Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Selective sweeps on novel and introgressed variation shape mimicry loci in a butterfly adaptive radiation.

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    Natural selection leaves distinct signatures in the genome that can reveal the targets and history of adaptive evolution. By analysing high-coverage genome sequence data from 4 major colour pattern loci sampled from nearly 600 individuals in 53 populations, we show pervasive selection on wing patterns in the Heliconius adaptive radiation. The strongest signatures correspond to loci with the greatest phenotypic effects, consistent with visual selection by predators, and are found in colour patterns with geographically restricted distributions. These recent sweeps are similar between co-mimics and indicate colour pattern turn-over events despite strong stabilising selection. Using simulations, we compare sweep signatures expected under classic hard sweeps with those resulting from adaptive introgression, an important aspect of mimicry evolution in Heliconius butterflies. Simulated recipient populations show a distinct 'volcano' pattern with peaks of increased genetic diversity around the selected target, characteristic of sweeps of introgressed variation and consistent with diversity patterns found in some populations. Our genomic data reveal a surprisingly dynamic history of colour pattern selection and co-evolution in this adaptive radiation

    I Diretrizes do Grupo de Estudos em Cardiogeriatria da Sociedade Brasileira de Cardiologia

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    O idoso apresenta características próprias na manifestação das doenças, na resposta à terapêutica e no efeito colateral dos medicamentos. Constitui um grupo de maior risco para o aparecimento das doenças degenerativas, em geral, e cardiovasculares, em particular, além de apresentar maior número de comorbidades

    The Genome of Anopheles darlingi, the main neotropical malaria vector

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    Anopheles darlingi is the principal neotropical malaria vector, responsible for more than a million cases of malaria per year on the American continent. Anopheles darlingi diverged from the African and Asian malaria vectors ∼100 million years ago (mya) and successfully adapted to the New World environment. Here we present an annotated reference A. darlingi genome, sequenced from a wild population of males and females collected in the Brazilian Amazon. A total of 10 481 predicted protein-coding genes were annotated, 72% of which have their closest counterpart in Anopheles gambiae and 21% have highest similarity with other mosquito species. In spite of a long period of divergent evolution, conserved gene synteny was observed between A. darlingi and A. gambiae. More than 10 million single nucleotide polymorphisms and short indels with potential use as genetic markers were identified. Transposable elements correspond to 2.3% of the A. darlingi genome. Genes associated with hematophagy, immunity and insecticide resistance, directly involved in vectorhuman and vectorparasite interactions, were identified and discussed. This study represents the first effort to sequence the genome of a neotropical malaria vector, and opens a new window through which we can contemplate the evolutionary history of anopheline mosquitoes. It also provides valuable information that may lead to novel strategies to reduce malaria transmission on the South American continent. The A. darlingi genome is accessible at www.labinfo.lncc.br/index.php/anopheles- darlingi. © 2013 The Author(s)

    The complete genome sequence of Chromobacterium violaceum reveals remarkable and exploitable bacterial adaptability

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    Chromobacterium violaceum is one of millions of species of free-living microorganisms that populate the soil and water in the extant areas of tropical biodiversity around the world. Its complete genome sequence reveals (i) extensive alternative pathways for energy generation, (ii) ≈500 ORFs for transport-related proteins, (iii) complex and extensive systems for stress adaptation and motility, and (iv) wide-spread utilization of quorum sensing for control of inducible systems, all of which underpin the versatility and adaptability of the organism. The genome also contains extensive but incomplete arrays of ORFs coding for proteins associated with mammalian pathogenicity, possibly involved in the occasional but often fatal cases of human C. violaceum infection. There is, in addition, a series of previously unknown but important enzymes and secondary metabolites including paraquat-inducible proteins, drug and heavy-metal-resistance proteins, multiple chitinases, and proteins for the detoxification of xenobiotics that may have biotechnological applications

    31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

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    Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival
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