Author
David G. Heckel
Other affiliations: Clemson University, Spanish National Research Council
Bio: David G. Heckel is an academic researcher from Max Planck Society. The author has contributed to research in topics: Helicoverpa armigera & Bacillus thuringiensis. The author has an hindex of 68, co-authored 249 publications receiving 17767 citations. Previous affiliations of David G. Heckel include Clemson University & Spanish National Research Council.
Papers published on a yearly basis
Papers
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Stephen Richards1, Richard A. Gibbs1, Nicole M. Gerardo2, Nancy A. Moran3 +220 more•Institutions (58)
TL;DR: The genome of the pea aphid shows remarkable levels of gene duplication and equally remarkable gene absences that shed light on aspects of aphid biology, most especially its symbiosis with Buchnera.
Abstract: Aphids are important agricultural pests and also biological models for studies of insect-plant interactions, symbiosis, virus vectoring, and the developmental causes of extreme phenotypic plasticity. Here we present the 464 Mb draft genome assembly of the pea aphid Acyrthosiphon pisum. This first published whole genome sequence of a basal hemimetabolous insect provides an outgroup to the multiple published genomes of holometabolous insects. Pea aphids are host-plant specialists, they can reproduce both sexually and asexually, and they have coevolved with an obligate bacterial symbiont. Here we highlight findings from whole genome analysis that may be related to these unusual biological features. These findings include discovery of extensive gene duplication in more than 2000 gene families as well as loss of evolutionarily conserved genes. Gene family expansions relative to other published genomes include genes involved in chromatin modification, miRNA synthesis, and sugar transport. Gene losses include genes central to the IMD immune pathway, selenoprotein utilization, purine salvage, and the entire urea cycle. The pea aphid genome reveals that only a limited number of genes have been acquired from bacteria; thus the reduced gene count of Buchnera does not reflect gene transfer to the host genome. The inventory of metabolic genes in the pea aphid genome suggests that there is extensive metabolite exchange between the aphid and Buchnera, including sharing of amino acid biosynthesis between the aphid and Buchnera. The pea aphid genome provides a foundation for post-genomic studies of fundamental biological questions and applied agricultural problems.
1,271 citations
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University College London1, University of Cambridge2, University of California, Irvine3, University of Maryland, College Park4, University of Oxford5, Smithsonian Institution6, University of Greifswald7, Max Planck Society8, Imperial College London9, Harvard University10, University of East Anglia11, Mississippi State University12, University of Texas at Austin13, Commonwealth Scientific and Industrial Research Organisation14, University of Paris15, University of Hawaii16, California Academy of Sciences17, Williams College18, Yale University19, University of Puerto Rico20, Johns Hopkins University21, North Carolina State University22, University of Bristol23, University of Edinburgh24, Baylor College of Medicine25, Del Rosario University26, University of Exeter27, Boston University28
TL;DR: It is inferred that closely related Heliconius species exchange protective colour-pattern genes promiscuously, implying that hybridization has an important role in adaptive radiation.
Abstract: Sequencing of the genome of the butterfly Heliconius melpomene shows that closely related Heliconius species exchange protective colour-pattern genes promiscuously.
1,103 citations
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TL;DR: Microarray analysis of all P450s in Drosophila melanogaster shows that DDT-R, a gene conferring resistance to DDT, is associated with overtranscription of a single cytochrome P450 gene, Cyp6g1, which has spread globally.
Abstract: Insecticide resistance is one of the most widespread genetic changes caused by human activity, but we still understand little about the origins and spread of resistant alleles in global populations of insects. Here, via microarray analysis of all P450s in Drosophila melanogaster, we show that DDT-R, a gene conferring resistance to DDT, is associated with overtranscription of a single cytochrome P450 gene, Cyp6g1. Transgenic analysis of Cyp6g1 shows that overtranscription of this gene alone is both necessary and sufficient for resistance. Resistance and up-regulation in Drosophila populations are associated with a single Cyp6g1 allele that has spread globally. This allele is characterized by the insertion of an Accord transposable element into the 5' end of the Cyp6g1 gene.
819 citations
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Swedish University of Agricultural Sciences1, University of Exeter2, Commonwealth Scientific and Industrial Research Organisation3, University of Bath4, George Washington University5, Ghent University6, Centre for DNA Fingerprinting and Diagnostics7, University of Copenhagen8, Kansas State University9, University of Montpellier10, Max Planck Society11, University of Warsaw12, University of Georgia13, National Autonomous University of Mexico14, Australian National University15, University of Valencia16, Wageningen University and Research Centre17, Agriculture and Agri-Food Canada18, University of Saskatchewan19, Stockholm University20, Eötvös Loránd University21, University of Tokyo22, National Institute of Advanced Industrial Science and Technology23, Plant & Food Research24, Oregon State University25, Agricultural Research Service26, Leiden University27, University of Manitoba28
TL;DR: Despite a large variation in the data, trends that are found are that RNAi is particularly successful in the family Saturniidae and in genes involved in immunity and that gene expression in epidermal tissues seems to be most difficult to silence.
698 citations
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TL;DR: This work shows that disruption of a cadherin-superfamily gene by retrotransposon-mediated insertion was linked to high levels of resistance to the Bt toxin Cry1Ac in the cotton pest Heliothis virescens, enabling efficient DNA-based screening for resistant heterozygotes by directly detecting the recessive allele.
Abstract: Transgenic crops producing insecticidal toxins from Bacillus thuringiensis (Bt) are widely used for pest control. Bt-resistant insect strains have been studied, but the molecular basis of resistance has remained elusive. Here, we show that disruption of a cadherin-superfamily gene by retrotransposon-mediated insertion was linked to high levels of resistance to the Bt toxin Cry1Ac in the cotton pest Heliothis virescens. Monitoring the early phases of Bt resistance evolution in the field has been viewed as crucial but extremely difficult, especially when resistance is recessive. Our findings enable efficient DNA-based screening for resistant heterozygotes by directly detecting the recessive allele.
600 citations
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28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。
18,940 citations
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TL;DR: It is suggested that the natural selection against large insertion/deletion is so weak that a large amount of variation is maintained in a population.
11,521 citations
01 Jun 2012
TL;DR: SPAdes as mentioned in this paper is a new assembler for both single-cell and standard (multicell) assembly, and demonstrate that it improves on the recently released E+V-SC assembler and on popular assemblers Velvet and SoapDeNovo (for multicell data).
Abstract: The lion's share of bacteria in various environments cannot be cloned in the laboratory and thus cannot be sequenced using existing technologies. A major goal of single-cell genomics is to complement gene-centric metagenomic data with whole-genome assemblies of uncultivated organisms. Assembly of single-cell data is challenging because of highly non-uniform read coverage as well as elevated levels of sequencing errors and chimeric reads. We describe SPAdes, a new assembler for both single-cell and standard (multicell) assembly, and demonstrate that it improves on the recently released E+V-SC assembler (specialized for single-cell data) and on popular assemblers Velvet and SoapDeNovo (for multicell data). SPAdes generates single-cell assemblies, providing information about genomes of uncultivatable bacteria that vastly exceeds what may be obtained via traditional metagenomics studies. SPAdes is available online ( http://bioinf.spbau.ru/spades ). It is distributed as open source software.
10,124 citations
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Broad Institute1, Commonwealth Scientific and Industrial Research Organisation2, Massachusetts Institute of Technology3, Hebrew University of Jerusalem4, Science for Life Laboratory5, Pittsburgh Supercomputing Center6, Oklahoma State University–Stillwater7, Griffith University8, University of Wisconsin-Madison9, Dresden University of Technology10, California Institute for Quantitative Biosciences11, Flanders Institute for Biotechnology12, Parco Tecnologico Padano13, United States Department of Agriculture14, Purdue University15, Indiana University16
TL;DR: This protocol provides a workflow for genome-independent transcriptome analysis leveraging the Trinity platform and presents Trinity-supported companion utilities for downstream applications, including RSEM for transcript abundance estimation, R/Bioconductor packages for identifying differentially expressed transcripts across samples and approaches to identify protein-coding genes.
Abstract: De novo assembly of RNA-seq data enables researchers to study transcriptomes without the need for a genome sequence; this approach can be usefully applied, for instance, in research on 'non-model organisms' of ecological and evolutionary importance, cancer samples or the microbiome. In this protocol we describe the use of the Trinity platform for de novo transcriptome assembly from RNA-seq data in non-model organisms. We also present Trinity-supported companion utilities for downstream applications, including RSEM for transcript abundance estimation, R/Bioconductor packages for identifying differentially expressed transcripts across samples and approaches to identify protein-coding genes. In the procedure, we provide a workflow for genome-independent transcriptome analysis leveraging the Trinity platform. The software, documentation and demonstrations are freely available from http://trinityrnaseq.sourceforge.net. The run time of this protocol is highly dependent on the size and complexity of data to be analyzed. The example data set analyzed in the procedure detailed herein can be processed in less than 5 h.
6,369 citations
01 Aug 2000
TL;DR: Assessment of medical technology in the context of commercialization with Bioentrepreneur course, which addresses many issues unique to biomedical products.
Abstract: BIOE 402. Medical Technology Assessment. 2 or 3 hours. Bioentrepreneur course. Assessment of medical technology in the context of commercialization. Objectives, competition, market share, funding, pricing, manufacturing, growth, and intellectual property; many issues unique to biomedical products. Course Information: 2 undergraduate hours. 3 graduate hours. Prerequisite(s): Junior standing or above and consent of the instructor.
4,833 citations