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1.
Genome Res ; 34(2): 286-299, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38479835

RESUMO

Genetic diversity is critical to crop breeding and improvement, and dissection of the genomic variation underlying agronomic traits can both assist breeding and give insight into basic biological mechanisms. Although recent genome analyses in plants reveal many structural variants (SVs), most current studies of crop genetic variation are dominated by single-nucleotide polymorphisms (SNPs). The extent of the impact of SVs on global trait variation, as well as their utility in genome-wide selection, is not yet understood. In this study, we built an SV data set based on whole-genome resequencing of diverse sorghum lines (n = 363), validated the correlation of photoperiod sensitivity and variety type, and identified SV hotspots underlying the divergent evolution of cellulosic and sweet sorghum. In addition, we showed the complementary contribution of SVs for heritability of traits related to sorghum adaptation. Importantly, inclusion of SV polymorphisms in association studies revealed genotype-phenotype associations not observed with SNPs alone. Three-way genome-wide association studies (GWAS) based on whole-genome SNP, SV, and integrated SNP + SV data sets showed substantial associations between SVs and sorghum traits. The addition of SVs to GWAS substantially increased heritability estimates for some traits, indicating their important contribution to functional allelic variation at the genome level. Our discovery of the widespread impacts of SVs on heritable gene expression variation could render a plausible mechanism for their disproportionate impact on phenotypic variation. This study expands our knowledge of SVs and emphasizes the extensive impacts of SVs on sorghum.


Assuntos
Variação Genética , Sorghum , Sorghum/genética , Estudo de Associação Genômica Ampla , Melhoramento Vegetal , Fenótipo , Grão Comestível/genética , Polimorfismo de Nucleotídeo Único
2.
J Virol ; 98(1): e0161823, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38174928

RESUMO

The global evolution of SARS-CoV-2 depends in part upon the evolutionary dynamics within individual hosts with varying immune histories. To characterize the within-host evolution of acute SARS-CoV-2 infection, we sequenced saliva and nasal samples collected daily from vaccinated and unvaccinated individuals early during infection. We show that longitudinal sampling facilitates high-confidence genetic variant detection and reveals evolutionary dynamics missed by less-frequent sampling strategies. Within-host dynamics in both unvaccinated and vaccinated individuals appeared largely stochastic; however, in rare cases, minor genetic variants emerged to frequencies sufficient for forward transmission. Finally, we detected significant genetic compartmentalization of viral variants between saliva and nasal swab sample sites in many individuals. Altogether, these data provide a high-resolution profile of within-host SARS-CoV-2 evolutionary dynamics.IMPORTANCEWe detail the within-host evolutionary dynamics of SARS-CoV-2 during acute infection in 31 individuals using daily longitudinal sampling. We characterized patterns of mutational accumulation for unvaccinated and vaccinated individuals, and observed that temporal variant dynamics in both groups were largely stochastic. Comparison of paired nasal and saliva samples also revealed significant genetic compartmentalization between tissue environments in multiple individuals. Our results demonstrate how selection, genetic drift, and spatial compartmentalization all play important roles in shaping the within-host evolution of SARS-CoV-2 populations during acute infection.


Assuntos
Evolução Molecular , Deriva Genética , SARS-CoV-2 , Humanos , COVID-19/virologia , Nariz/virologia , Saliva/virologia , SARS-CoV-2/genética , Masculino , Feminino , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade
3.
Proc Natl Acad Sci U S A ; 119(30): e2205068119, 2022 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-35857876

RESUMO

Bifidobacterium is a commensal bacterial genus ubiquitous in the human gastrointestinal tract, which is associated with a range of health benefits. The advent of CRISPR-based genome editing technologies provides opportunities to investigate the genetics of important bacteria and transcend the lack of genetic tools in bifidobacteria to study the basis for their health-promoting attributes. Here, we repurpose the endogenous type I-G CRISPR-Cas system and adopt an exogenous CRISPR base editor for genome engineering in B. animalis subsp. lactis, demonstrating that both genomic and epigenetic contexts drive editing outcomes across strains. We reprogrammed the endogenous type I-G system to screen for naturally occurring large deletions up to 27 kb and to generate a 500-bp deletion in tetW to abolish tetracycline resistance. A CRISPR-cytosine base editor was optimized to install C•G-to-T•A amber mutations to resensitize multiple B. lactis strains to tetracycline. Remarkably, we uncovered epigenetic patterns that are distributed unevenly among B. lactis strains, despite their genomic homogeneity, that may contribute to editing efficiency variability. Insights were also expanded to Bifidobacterium longum subsp. infantis to emphasize the broad relevance of these findings. This study highlights the need to develop individualized CRISPR-based genome engineering approaches for distinct bacterial strains and opens avenues for engineering of next generation probiotics.


Assuntos
Bifidobacterium , Sistemas CRISPR-Cas , Edição de Genes , Probióticos , Bifidobacterium/genética , Edição de Genes/métodos , Genoma Bacteriano/genética , Genômica , Humanos
4.
Genome Res ; 31(7): 1203-1215, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33947700

RESUMO

In contrast to the western honey bee, Apis mellifera, other honey bee species have been largely neglected despite their importance and diversity. The genetic basis of the evolutionary diversification of honey bees remains largely unknown. Here, we provide a genome-wide comparison of three honey bee species, each representing one of the three subgenera of honey bees, namely the dwarf (Apis florea), giant (A. dorsata), and cavity-nesting (A. mellifera) honey bees with bumblebees as an outgroup. Our analyses resolve the phylogeny of honey bees with the dwarf honey bees diverging first. We find that evolution of increased eusocial complexity in Apis proceeds via increases in the complexity of gene regulation, which is in agreement with previous studies. However, this process seems to be related to pathways other than transcriptional control. Positive selection patterns across Apis reveal a trade-off between maintaining genome stability and generating genetic diversity, with a rapidly evolving piRNA pathway leading to genomes depleted of transposable elements, and a rapidly evolving DNA repair pathway associated with high recombination rates in all Apis species. Diversification within Apis is accompanied by positive selection in several genes whose putative functions present candidate mechanisms for lineage-specific adaptations, such as migration, immunity, and nesting behavior.

5.
BMC Genomics ; 24(1): 19, 2023 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-36639634

RESUMO

BACKGROUND: Adaptations by arthropod pests to host plant defenses of crops determine their impacts on agricultural production. The larval host range of western corn rootworm, Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae), is restricted to maize and a few grasses. Resistance of D. v. virgifera to crop rotation practices and multiple insecticides contributes to its status as the most damaging pest of cultivated maize in North America and Europe. The extent to which adaptations by this pest contributes to host plant specialization remains unknown. RESULTS: A 2.42 Gb draft D. v. virgifera genome, Dvir_v2.0, was assembled from short shotgun reads and scaffolded using long-insert mate-pair, transcriptome and linked read data. K-mer analysis predicted a repeat content of ≥ 61.5%. Ortholog assignments for Dvir_2.0 RefSeq models predict a greater number of species-specific gene duplications, including expansions in ATP binding cassette transporter and chemosensory gene families, than in other Coleoptera. A majority of annotated D. v. virgifera cytochrome P450s belong to CYP4, 6, and 9 clades. A total of 5,404 transcripts were differentially-expressed between D. v. virgifera larvae fed maize roots compared to alternative host (Miscanthus), a marginal host (Panicum virgatum), a poor host (Sorghum bicolor) and starvation treatments; Among differentially-expressed transcripts, 1,908 were shared across treatments and the least number were between Miscanthus compared to maize. Differentially-expressed transcripts were enriched for putative spliceosome, proteosome, and intracellular transport functions. General stress pathway functions were unique and enriched among up-regulated transcripts in marginal host, poor host, and starvation responses compared to responses on primary (maize) and alternate hosts. CONCLUSIONS: Manual annotation of D. v. virgifera Dvir_2.0 RefSeq models predicted expansion of paralogs with gene families putatively involved in insecticide resistance and chemosensory perception. Our study also suggests that adaptations of D. v. virgifera larvae to feeding on an alternate host plant invoke fewer transcriptional changes compared to marginal or poor hosts. The shared up-regulation of stress response pathways between marginal host and poor host, and starvation treatments may reflect nutrient deprivation. This study provides insight into transcriptomic responses of larval feeding on different host plants and resources for genomic research on this economically significant pest of maize.


Assuntos
Besouros , Inseticidas , Animais , Zea mays/fisiologia , Besouros/genética , Larva/metabolismo , Poaceae/genética , Inseticidas/metabolismo , Controle Biológico de Vetores , Plantas Geneticamente Modificadas/genética , Endotoxinas
6.
Proc Natl Acad Sci U S A ; 117(38): 23960-23969, 2020 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-32900926

RESUMO

Many organisms enter a dormant state in their life cycle to deal with predictable changes in environments over the course of a year. The timing of dormancy is therefore a key seasonal adaptation, and it evolves rapidly with changing environments. We tested the hypothesis that differences in the timing of seasonal activity are driven by differences in the rate of development during diapause in Rhagoletis pomonella, a fly specialized to feed on fruits of seasonally limited host plants. Transcriptomes from the central nervous system across a time series during diapause show consistent and progressive changes in transcripts participating in diverse developmental processes, despite a lack of gross morphological change. Moreover, population genomic analyses suggested that many genes of small effect enriched in developmental functional categories underlie variation in dormancy timing and overlap with gene sets associated with development rate in Drosophila melanogaster Our transcriptional data also suggested that a recent evolutionary shift from a seasonally late to a seasonally early host plant drove more rapid development during diapause in the early fly population. Moreover, genetic variants that diverged during the evolutionary shift were also enriched in putative cis regulatory regions of genes differentially expressed during diapause development. Overall, our data suggest polygenic variation in the rate of developmental progression during diapause contributes to the evolution of seasonality in R. pomonella We further discuss patterns that suggest hourglass-like developmental divergence early and late in diapause development and an important role for hub genes in the evolution of transcriptional divergence.


Assuntos
Adaptação Fisiológica/genética , Diapausa/genética , Tephritidae , Transcriptoma/genética , Animais , Drosophila melanogaster/genética , Estudo de Associação Genômica Ampla , Estações do Ano , Tephritidae/genética , Tephritidae/crescimento & desenvolvimento
7.
Int J Mol Sci ; 24(8)2023 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-37108472

RESUMO

Root-lesion nematodes (genus Pratylenchus) belong to a diverse group of plant-parasitic nematodes (PPN) with a worldwide distribution. Despite being an economically important PPN group of more than 100 species, genome information related to Pratylenchus genus is scarcely available. Here, we report the draft genome assembly of Pratylenchus scribneri generated on the PacBio Sequel IIe System using the ultra-low DNA input HiFi sequencing workflow. The final assembly created using 500 nematodes consisted of 276 decontaminated contigs, with an average contig N50 of 1.72 Mb and an assembled draft genome size of 227.24 Mb consisting of 51,146 predicted protein sequences. The benchmarking universal single-copy ortholog (BUSCO) analysis with 3131 nematode BUSCO groups indicated that 65.4% of the BUSCOs were complete, whereas 24.0%, 41.4%, and 1.8% were single-copy, duplicated, and fragmented, respectively, and 32.8% were missing. The outputs from GenomeScope2 and Smudgeplots converged towards a diploid genome for P. scribneri. The data provided here will facilitate future studies on host plant-nematode interactions and crop protection at the molecular level.


Assuntos
Parasitos , Tylenchoidea , Animais , Anotação de Sequência Molecular , Análise de Sequência de DNA , Genoma , Sequência de Bases , Tylenchoidea/genética , Parasitos/genética
8.
Syst Biol ; 70(4): 719-738, 2021 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-32979270

RESUMO

The insect order Psocodea is a diverse lineage comprising both parasitic (Phthiraptera) and nonparasitic members (Psocoptera). The extreme age and ecological diversity of the group may be associated with major genomic changes, such as base compositional biases expected to affect phylogenetic inference. Divergent morphology between parasitic and nonparasitic members has also obscured the origins of parasitism within the order. We conducted a phylogenomic analysis on the order Psocodea utilizing both transcriptome and genome sequencing to obtain a data set of 2370 orthologous genes. All phylogenomic analyses, including both concatenated and coalescent methods suggest a single origin of parasitism within the order Psocodea, resolving conflicting results from previous studies. This phylogeny allows us to propose a stable ordinal level classification scheme that retains significant taxonomic names present in historical scientific literature and reflects the evolution of the group as a whole. A dating analysis, with internal nodes calibrated by fossil evidence, suggests an origin of parasitism that predates the K-Pg boundary. Nucleotide compositional biases are detected in third and first codon positions and result in the anomalous placement of the Amphientometae as sister to Psocomorpha when all nucleotide sites are analyzed. Likelihood-mapping and quartet sampling methods demonstrate that base compositional biases can also have an effect on quartet-based methods.[Illumina; Phthiraptera; Psocoptera; quartet sampling; recoding methods.].


Assuntos
Anoplura , Insetos , Animais , Sequência de Bases , Viés , Insetos/genética , Filogenia
9.
Proc Natl Acad Sci U S A ; 115(50): 12775-12780, 2018 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-30478043

RESUMO

Hemipteroid insects (Paraneoptera), with over 10% of all known insect diversity, are a major component of terrestrial and aquatic ecosystems. Previous phylogenetic analyses have not consistently resolved the relationships among major hemipteroid lineages. We provide maximum likelihood-based phylogenomic analyses of a taxonomically comprehensive dataset comprising sequences of 2,395 single-copy, protein-coding genes for 193 samples of hemipteroid insects and outgroups. These analyses yield a well-supported phylogeny for hemipteroid insects. Monophyly of each of the three hemipteroid orders (Psocodea, Thysanoptera, and Hemiptera) is strongly supported, as are most relationships among suborders and families. Thysanoptera (thrips) is strongly supported as sister to Hemiptera. However, as in a recent large-scale analysis sampling all insect orders, trees from our data matrices support Psocodea (bark lice and parasitic lice) as the sister group to the holometabolous insects (those with complete metamorphosis). In contrast, four-cluster likelihood mapping of these data does not support this result. A molecular dating analysis using 23 fossil calibration points suggests hemipteroid insects began diversifying before the Carboniferous, over 365 million years ago. We also explore implications for understanding the timing of diversification, the evolution of morphological traits, and the evolution of mitochondrial genome organization. These results provide a phylogenetic framework for future studies of the group.


Assuntos
Insetos/genética , Animais , Calibragem , Ecossistema , Fósseis , Genoma Mitocondrial/genética , Filogenia
10.
Proc Biol Sci ; 287(1921): 20193005, 2020 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-32070251

RESUMO

Tinamous host the highest generic diversity of lice of any group of birds, as well as hosting representatives of all four avian feather louse ecomorphs. Although the generic diversity of tinamou feather lice is well documented, few attempts have been made to reconstruct the phylogenetic relationships among these lice. To test whether tinamou feather lice form a monophyletic group as a whole, we used whole-genome sequencing to estimate a higher-level phylogeny of tinamou feather lice, together with a broad diversity of other avian feather louse groups. In total, we analysed sequences from over 1000 genes for 48 genera of avian lice using both concatenated and coalescent approaches to estimate the phylogeny of this diverse group of avian feather lice. Although the body louse ecomorph of tinamou feather lice formed a monophyletic group, they did not strictly form a monophyletic group together with the other three ecomorphs of tinamou feather lice. In particular, a clade comprised of several feather louse genera, mainly from South America, is nested phylogenetically within tinamou lice, which also have their main centre of diversity in South America. These results suggest in situ radiation of these parasites in South America.


Assuntos
Paleógnatas/parasitologia , Animais , Evolução Biológica , Aves/parasitologia , Plumas/parasitologia , Interações Hospedeiro-Parasita , Ftirápteros , Filogenia , América do Sul
11.
J Exp Zool B Mol Dev Evol ; 330(5): 265-278, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29566459

RESUMO

The acquisition of genome sequences from a wide range of insects and other arthropods has revealed a broad positive correlation between the complexity of their chemical ecology and the size of their chemosensory gene repertoire. The German cockroach Blattella germanica is an extreme omnivore and has the largest chemosensory gene repertoire known for an arthropod, exceeding even the highly polyphagous spider mite Tetranychus urticae. While the Odorant Receptor family is not particularly large, with 123 genes potentially encoding 134 receptors (105 intact), the Gustatory Receptor family is greatly expanded to 431 genes potentially encoding 545 receptors (483 intact), the largest known for insects and second only to the spider mite. The Ionotropic Receptor family of olfactory and gustatory receptors is vastly expanded to at least 897 genes (604 intact), the largest size known in arthropods, far surpassing the 150 known from the dampwood termite Zootermopsis nevadensis. Commensurately, the Odorant Binding Protein family is expanded to the largest known for insects at 109 genes (all intact). Comparison with the far more specialized, but phylogenetically related termite, within the Dictyoptera, reveals considerable gene losses from the termite, and massive species-specific gene expansions in the cockroach. The cockroach has lost function of 11%-41% of these three chemoreceptor gene families to pseudogenization, and most of these are young events, implying rapid turnover of genes along with these major expansions, presumably in response to changes in its chemical ecology.


Assuntos
Blattellidae/genética , Proteínas de Insetos/genética , Receptores de Superfície Celular/genética , Animais , Evolução Molecular , Comportamento Alimentar , Isópteros/genética , Família Multigênica/genética , Filogenia , Especificidade da Espécie , Paladar
12.
Mol Ecol ; 26(21): 6021-6035, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28921805

RESUMO

Across insect genomes, the size of the cytochrome P450 monooxygenase (CYP) gene superfamily varies widely. CYPome size variation has been attributed to reciprocal adaptive radiations in insect detoxification genes in response to plant biosynthetic gene radiations driven by co-evolution between herbivores and their chemically defended hostplants. Alternatively, variation in CYPome size may be due to random "birth-and-death" processes, whereby exponential increase via gene duplications is limited by random decay via gene death or transition via divergence. We examined CYPome diversification in the genomes of seven Lepidoptera species varying in host breadth from monophagous (Bombyx mori) to highly polyphagous (Amyelois transitella). CYPome size largely reflects the size of Clan 3, the clan associated with xenobiotic detoxification, and to some extent phylogenetic age. Consistently across genomes, families CYP6, CYP9 and CYP321 are most diverse and CYP6AB, CYP6AE, CYP6B, CYP9A and CYP9G are most diverse among subfamilies. Higher gene number in subfamilies is due to duplications occurring primarily after speciation and specialization ("P450 blooms"), and the genes are arranged in clusters, indicative of active duplicating loci. In the parsnip webworm, Depressaria pastinacella, gene expression levels in large subfamilies are high relative to smaller subfamilies. Functional and phylogenetic data suggest a correlation between highly dynamic loci (reflective of extensive gene duplication, functionalization and in some cases loss) and the ability of enzymes encoded by these genes to metabolize hostplant defences, consistent with an adaptive, nonrandom process driven by ecological interactions.


Assuntos
Evolução Biológica , Sistema Enzimático do Citocromo P-450/genética , Mariposas/enzimologia , Filogenia , Animais , Genoma de Inseto , Mariposas/classificação , Mariposas/genética , Transcriptoma
13.
PLoS Genet ; 10(9): e1004660, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25232843

RESUMO

The family Polydnaviridae is of interest because it provides the best example of viruses that have evolved a mutualistic association with their animal hosts. Polydnaviruses in the genus Bracovirus are strictly associated with parasitoid wasps in the family Braconidae, and evolved ∼100 million years ago from a nudivirus. Each wasp species relies on its associated bracovirus to parasitize hosts, while each bracovirus relies on its wasp for vertical transmission. Prior studies establish that bracovirus genomes consist of proviral segments and nudivirus-like replication genes, but how these components are organized in the genomes of wasps is unknown. Here, we sequenced the genome of the wasp Microplitis demolitor to characterize the proviral genome of M. demolitor bracovirus (MdBV). Unlike nudiviruses, bracoviruses produce virions that package multiple circular, double-stranded DNAs. DNA segments packaged into MdBV virions resided in eight dispersed loci in the M. demolitor genome. Each proviral segment was bounded by homologous motifs that guide processing to form mature viral DNAs. Rapid evolution of proviral segments obscured homology between other bracovirus-carrying wasps and MdBV. However, some domains flanking MdBV proviral loci were shared with other species. All MdBV genes previously identified to encode proteins required for replication were identified. Some of these genes resided in a multigene cluster but others, including subunits of the RNA polymerase that transcribes structural genes and integrases that process proviral segments, were widely dispersed in the M. demolitor genome. Overall, our results indicate that genome dispersal is a key feature in the evolution of bracoviruses into mutualists.


Assuntos
Genoma Viral , Genômica , Interações Hospedeiro-Patógeno , Mutação , Sequência de Aminoácidos , Animais , Sequência Conservada , DNA Intergênico , Feminino , Duplicação Gênica , Ligação Genética , Loci Gênicos , Genoma de Inseto , Sequenciamento de Nucleotídeos em Larga Escala , Interações Hospedeiro-Patógeno/genética , Masculino , Dados de Sequência Molecular , Família Multigênica , Polydnaviridae/genética , Regiões Promotoras Genéticas , Provírus/genética , Sequências de Repetição em Tandem , Integração Viral , Vespas/genética , Vespas/virologia
14.
J Exp Biol ; 219(Pt 17): 2613-22, 2016 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-27312473

RESUMO

The duration of dormancy regulates seasonal timing in many organisms and may be modulated by day length and temperature. Though photoperiodic modulation has been well studied, temperature modulation of dormancy has received less attention. Here, we leverage genetic variation in diapause in the apple maggot fly, Rhagoletis pomonella, to test whether gene expression during winter or following spring warming regulates diapause duration. We used RNAseq to compare transcript abundance during and after simulated winter between an apple-infesting population and a hawthorn-infesting population where the apple population ends pupal diapause earlier than the hawthorn-infesting population. Marked differences in transcription between the two populations during winter suggests that the 'early' apple population is developmentally advanced compared with the 'late' hawthorn population prior to spring warming, with transcripts participating in growth and developmental processes relatively up-regulated in apple pupae during the winter cold period. Thus, regulatory differences during winter ultimately drive phenological differences that manifest themselves in the following summer. Expression and polymorphism analysis identify candidate genes in the Wnt and insulin signaling pathways that contribute to population differences in seasonality. Both populations remained in diapause and displayed a pattern of up- and then down-regulation (or vice versa) of growth-related transcripts following warming, consistent with transcriptional repression. The ability to repress growth stimulated by permissive temperatures is likely critical to avoid mismatched phenology and excessive metabolic demand. Compared with diapause studies in other insects, our results suggest some overlap in candidate genes/pathways, though the timing and direction of changes in transcription are likely species specific.


Assuntos
Malus/parasitologia , Estações do Ano , Tephritidae/genética , Tephritidae/fisiologia , Transcriptoma/genética , Animais , Diapausa de Inseto/genética , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Insulina/metabolismo , Larva/genética , Polimorfismo de Nucleotídeo Único/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução de Sinais/genética , Fatores de Tempo , Transcrição Gênica
15.
BMC Genomics ; 15: 501, 2014 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-24948464

RESUMO

BACKGROUND: The chemical senses of insects mediate behaviors that are closely linked to survival and reproduction. The order Diptera contains two model organisms, the vinegar fly Drosophila melanogaster and the mosquito Anopheles gambiae, whose chemosensory genes have been extensively studied. Representing a third dipteran lineage with an interesting phylogenetic position, and being ecologically distinct by feeding on plants, the Hessian fly (Mayetiola destructor Say, Diptera: Cecidomyiidae) genome sequence has recently become available. Among plant-feeding insects, the Hessian fly is unusual in 'reprogramming' the plant to create a superior food and in being the target of plant resistance genes, a feature shared by plant pathogens. Chemoreception is essential for reproductive success, including detection of sex pheromone and plant-produced chemicals by males and females, respectively. RESULTS: We identified genes encoding 122 odorant receptors (OR), 28 gustatory receptors (GR), 39 ionotropic receptors (IR), 32 odorant binding proteins, and 7 sensory neuron membrane proteins in the Hessian fly genome. We then mapped Illumina-sequenced transcriptome reads to the genome to explore gene expression in male and female antennae and terminal abdominal segments. Our results reveal that a large number of chemosensory genes have up-regulated expression in the antennae, and the expression is in many cases sex-specific. Sex-specific expression is particularly evident among the Or genes, consistent with the sex-divergent olfactory-mediated behaviors of the adults. In addition, the large number of Ors in the genome but the reduced set of Grs and divergent Irs suggest that the short-lived adults rely more on long-range olfaction than on short-range gustation. We also report up-regulated expression of some genes from all chemosensory gene families in the terminal segments of the abdomen, which play important roles in reproduction. CONCLUSIONS: We show that a large number of the chemosensory genes in the Hessian fly genome have sex- and tissue-specific expression profiles. Our findings provide the first insights into the molecular basis of chemoreception in plant-feeding flies, representing an important advance toward a more complete understanding of olfaction in Diptera and its links to ecological specialization.


Assuntos
Dípteros/genética , Dípteros/metabolismo , Perfilação da Expressão Gênica , Herbivoria/genética , Animais , Mapeamento Cromossômico , Feminino , Ontologia Genética , Masculino , Proteínas de Membrana/genética , Anotação de Sequência Molecular , Especificidade de Órgãos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores Odorantes/genética , Células Receptoras Sensoriais/metabolismo
16.
Proc Natl Acad Sci U S A ; 108(14): 5673-8, 2011 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-21282631

RESUMO

Ants are some of the most abundant and familiar animals on Earth, and they play vital roles in most terrestrial ecosystems. Although all ants are eusocial, and display a variety of complex and fascinating behaviors, few genomic resources exist for them. Here, we report the draft genome sequence of a particularly widespread and well-studied species, the invasive Argentine ant (Linepithema humile), which was accomplished using a combination of 454 (Roche) and Illumina sequencing and community-based funding rather than federal grant support. Manual annotation of >1,000 genes from a variety of different gene families and functional classes reveals unique features of the Argentine ant's biology, as well as similarities to Apis mellifera and Nasonia vitripennis. Distinctive features of the Argentine ant genome include remarkable expansions of gustatory (116 genes) and odorant receptors (367 genes), an abundance of cytochrome P450 genes (>110), lineage-specific expansions of yellow/major royal jelly proteins and desaturases, and complete CpG DNA methylation and RNAi toolkits. The Argentine ant genome contains fewer immune genes than Drosophila and Tribolium, which may reflect the prominent role played by behavioral and chemical suppression of pathogens. Analysis of the ratio of observed to expected CpG nucleotides for genes in the reproductive development and apoptosis pathways suggests higher levels of methylation than in the genome overall. The resources provided by this genome sequence will offer an abundance of tools for researchers seeking to illuminate the fascinating biology of this emerging model organism.


Assuntos
Formigas/genética , Genoma de Inseto/genética , Genômica/métodos , Filogenia , Animais , Formigas/fisiologia , Sequência de Bases , California , Metilação de DNA , Biblioteca Gênica , Genética Populacional , Hierarquia Social , Dados de Sequência Molecular , Polimorfismo de Nucleotídeo Único/genética , Receptores Odorantes/genética , Análise de Sequência de DNA
17.
Mol Phylogenet Evol ; 66(1): 417-22, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23000819

RESUMO

Next-generation sequencing technologies are revolutionizing the field of phylogenetics by making available genome scale data for a fraction of the cost of traditional targeted sequencing. One challenge will be to make use of these genomic level data without necessarily resorting to full-scale genome assembly and annotation, which is often time and labor intensive. Here we describe a technique, the Target Restricted Assembly Method (TRAM), in which the typical process of genome assembly and annotation is in essence reversed. Protein sequences of phylogenetically useful genes from a species within the group of interest are used as targets in tblastn searches of a data set from a lane of Illumina reads for a related species. Resulting blast hits are then assembled locally into contigs and these contigs are then aligned against the reference "cDNA" sequence to remove portions of the sequences that include introns. We illustrate the Target Restricted Assembly Method using genomic scale datasets for 20 species of lice (Insecta: Psocodea) to produce a test phylogenetic data set of 10 nuclear protein coding gene sequences. Given the advantages of using DNA instead of RNA, this technique is very cost effective and feasible given current technologies.


Assuntos
Genômica/métodos , Filogenia , Análise de Sequência de DNA/métodos , Animais , Teorema de Bayes , Genes de Insetos , Funções Verossimilhança , Modelos Genéticos , Ftirápteros/classificação , Ftirápteros/genética , Alinhamento de Sequência
18.
Ecol Evol ; 13(10): e10572, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37791294

RESUMO

Extensive transformation of natural land cover into urbanized areas enhances accumulation of phenotypic differences between animals from urban and nonurban populations, but there is little information on whether these changes, especially in terms of animal behaviour and circadian rhythm, have a genetic basis. The aim of this study was to investigate genetic background of behavioural differences between four pairs of urban and nonurban populations of a common waterbird, the Eurasian coot Fulica atra. For this purpose, we quantified polymorphisms in personality-related candidate genes, previously reported to be associated with avian circadian rhythms and behavioural traits that may be crucial for urban life. We found general associations between landscape urbanization level and polymorphisms in 3'UTR region of CREB1 gene encoding transcriptional factor, which participates in development of cognitive functions and regulation of circadian rhythm. We also found significant differentiation between urban and nonurban populations in the intronic region of CKIɛ gene responsible for regulation of circadian clock. Although we lacked evidence for linkage of this intronic variation with coding polymorphisms, genetic differentiation between urban populations was significantly stronger at CKIɛ intron compared with neutral microsatellite markers, suggesting possible local adaptations of CKIɛ expression regulation to specific urban sites. Our results indicate that behavioural differentiation between urban and nonurban coot populations may be the effect of habitat-specific selective pressure resulting in genetic adaptations to urban environment and supporting the microevolutionary scenario. These adaptations, however, prevailed in non-coding regulatory rather than coding gene regions and showed either general or local patterns, revealing high complexity of associations between behaviour and landscape urbanization in birds.

19.
Microbiol Resour Announc ; 12(10): e0059623, 2023 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-37772887

RESUMO

Pacific Biosciences long-read sequencing was used to improve the genome assembly for Lodderomyces elongisporus strain NRRL YB-4239 (ATCC 11503). The new assembly included eight chromosomes that were substantiated by the electrophoretic karyotype. The nuclear genome was 16.1 Mb (37.2% GC) with 5,740 genes predicted.

20.
Microbiol Resour Announc ; 12(6): e0021323, 2023 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-37227286

RESUMO

Pacific Biosciences (PacBio) long-read sequencing was used to generate a chromosome-level genome assembly for Yamadazyma tenuis strain ATCC 10573. The assembly featured 7 chromosomes that matched the electrophoretic karyotype and a 26.5-kb circular mitochondrial genome. The nuclear genome was 10.8 Mb, with a GC content of 43%, and 5,340 predicted genes.

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