165 research outputs found

    A Partitioned Likelihood Analysis of Swallowtail Butterfly Phylogeny (Lepidoptera: Papilionidae)

    Get PDF
    Although it is widely agreed that data from multiple sources are necessary to confidently resolve phylogenetic relationships, procedures for accommodating and incorporating heterogeneity in such data remained underdeveloped. We explored the use of partitioned, model-based analyses of heterogeneous molecular data in the context of a phylogenetic study of swallowtail butterflies (Lepidoptera: Papilionidae)

    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).

    Get PDF
    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

    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)

    Get PDF
    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 phi(ST) 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 differentiation85476485CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP578509/2008-3; 200942/2012-32011/00417-3Natural Sciences and Engineering Research Council of Canad

    Spatial Genetic Structure of a Symbiotic Beetle-Fungal System: Toward Multi-Taxa Integrated Landscape Genetics

    Get PDF
    Spatial patterns of genetic variation in interacting species can identify shared features that are important to gene flow and can elucidate co-evolutionary relationships. We assessed concordance in spatial genetic variation between the mountain pine beetle (Dendroctonus ponderosae) and one of its fungal symbionts, Grosmanniaclavigera, in western Canada using neutral genetic markers. We examined how spatial heterogeneity affects genetic variation within beetles and fungi and developed a novel integrated landscape genetics approach to assess reciprocal genetic influences between species using constrained ordination. We also compared landscape genetic models built using Euclidean distances based on allele frequencies to traditional pair-wise Fst. Both beetles and fungi exhibited moderate levels of genetic structure over the total study area, low levels of structure in the south, and more pronounced fungal structure in the north. Beetle genetic variation was associated with geographic location while that of the fungus was not. Pinevolume and climate explained beetle genetic variation in the northern region of recent outbreak expansion. Reciprocal genetic relationships were only detectedin the south where there has been alonger history of beetle infestations. The Euclidean distance and Fst-based analyses resulted in similar models in the north and over the entire study area, but differences between methods in the south suggest that genetic distances measures should be selected based on ecological and evolutionary contexts. The integrated landscape genetics framework we present is powerful, general, and can be applied to other systems to quantify the biotic and abiotic determinants of spatial genetic variation within and among taxa

    Systematics of the Argyrotaenia franciscana (Lepidoptera: Tortricidae) species group: evidence from mitochondrial

    Get PDF
    ABSTRACT Moths of the Argyrotaenia franciscana species group represent a challenging case of evolutionary lability and taxonomic complexity in California. We studied their evolutionary relationships using mitochondrial DNA (mtDNA) sequences from 49 specimens in 18 populations of the A. franciscana group, as well as 2 outgroup species. Most specimens were sequenced over a 799-bp segment of the cytochrome oxidase subunit I (COI) gene. Single specimens each of A. franciscana insulana Powell and A. citrana (Fernald) were sequenced over a 2.3-kb region including COI, tRNA leucine (UUR), and cytochrome oxidase subunit II (COII). mtDNA variation within and among Argyrotaenia citrana, A. franciscana (Walsingham), and A. franciscana insulana is most simply interpreted as DNA polymorphism within a single species for which the oldest name is A. franciscana. Maximal divergence among haplotypes was 3.8%, which is on the high end of the range for intraspeciÞc mtDNA variation in Lepidoptera. Argyrotaenia niscana (Kearfott) is most closely related to a new species, and this pair forms the closest outgroup to the A. franciscana-citrana complex. The status of A. isolatissima Powell remains uncertain

    Multilocus species identification and fungal DNA barcoding: insights from blue stain fungal symbionts of the mountain pine beetle.Mol

    Get PDF
    Abstract There is strong community-wide interest in applying molecular techniques to fungal species delimitation and identification, but selection of a standardized region or regions of the genome has not been finalized. A single marker, the ribosomal DNA internal transcribed spacer region, has frequently been suggested as the standard for fungi. We used a group of closely related blue stain fungi associated with the mountain pine beetle (Dendroctonus ponderosae Hopkins) to examine the success of such single-locus species identification, comparing the internal transcribed spacer with four other nuclear markers. We demonstrate that single loci varied in their utility for identifying the six fungal species examined, while use of multiple loci was consistently successful. In a literature survey of 21 similar studies, individual loci were also highly variable in their ability to provide consistent species identifications and were less successful than multilocus diagnostics. Accurate species identification is the essence of any molecular diagnostic system, and this consideration should be central to locus selection. Moreover, our study and the literature survey demonstrate the value of using closely related species as the proving ground for developing a molecular identification system. We advocate use of a multilocus barcode approach that is similar to the practice employed by the plant barcode community, rather than reliance on a single locus

    Genome-wide identification and phenotypic characterization of seizure-associated copy number variations in 741,075 individuals

    Get PDF
    Copy number variants (CNV) are established risk factors for neurodevelopmental disorders with seizures or epilepsy. With the hypothesis that seizure disorders share genetic risk factors, we pooled CNV data from 10,590 individuals with seizure disorders, 16,109 individuals with clinically validated epilepsy, and 492,324 population controls and identified 25 genome-wide significant loci, 22 of which are novel for seizure disorders, such as deletions at 1p36.33, 1q44, 2p21-p16.3, 3q29, 8p23.3-p23.2, 9p24.3, 10q26.3, 15q11.2, 15q12-q13.1, 16p12.2, 17q21.31, duplications at 2q13, 9q34.3, 16p13.3, 17q12, 19p13.3, 20q13.33, and reciprocal CNVs at 16p11.2, and 22q11.21. Using genetic data from additional 248,751 individuals with 23 neuropsychiatric phenotypes, we explored the pleiotropy of these 25 loci. Finally, in a subset of individuals with epilepsy and detailed clinical data available, we performed phenome-wide association analyses between individual CNVs and clinical annotations categorized through the Human Phenotype Ontology (HPO). For six CNVs, we identified 19 significant associations with specific HPO terms and generated, for all CNVs, phenotype signatures across 17 clinical categories relevant for epileptologists. This is the most comprehensive investigation of CNVs in epilepsy and related seizure disorders, with potential implications for clinical practice

    GWAS meta-analysis of over 29,000 people with epilepsy identifies 26 risk loci and subtype-specific genetic architecture

    Get PDF
    Epilepsy is a highly heritable disorder affecting over 50 million people worldwide, of which about one-third are resistant to current treatments. Here we report a multi-ancestry genome-wide association study including 29,944 cases, stratified into three broad categories and seven subtypes of epilepsy, and 52,538 controls. We identify 26 genome-wide significant loci, 19 of which are specific to genetic generalized epilepsy (GGE). We implicate 29 likely causal genes underlying these 26 loci. SNP-based heritability analyses show that common variants explain between 39.6% and 90% of genetic risk for GGE and its subtypes. Subtype analysis revealed markedly different genetic architectures between focal and generalized epilepsies. Gene-set analyses of GGE signals implicate synaptic processes in both excitatory and inhibitory neurons in the brain. Prioritized candidate genes overlap with monogenic epilepsy genes and with targets of current antiseizure medications. Finally, we leverage our results to identify alternate drugs with predicted efficacy if repurposed for epilepsy treatment

    COI_alignment

    No full text
    Complete COI data matrix used to construct phylogenetic tree
    corecore