Author
Nicolas Guilhot
Other affiliations: Institut national de la recherche agronomique, Blaise Pascal University
Bio: Nicolas Guilhot is an academic researcher from University of Auvergne. The author has contributed to research in topics: Genome & Genomics. The author has an hindex of 9, co-authored 10 publications receiving 3786 citations. Previous affiliations of Nicolas Guilhot include Institut national de la recherche agronomique & Blaise Pascal University.
Papers
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TL;DR: This annotated reference sequence of wheat is a resource that can now drive disruptive innovation in wheat improvement, as this community resource establishes the foundation for accelerating wheat research and application through improved understanding of wheat biology and genomics-assisted breeding.
Abstract: An annotated reference sequence representing the hexaploid bread wheat genome in 21 pseudomolecules has been analyzed to identify the distribution and genomic context of coding and noncoding elements across the A, B, and D subgenomes. With an estimated coverage of 94% of the genome and containing 107,891 high-confidence gene models, this assembly enabled the discovery of tissue- and developmental stage-related coexpression networks by providing a transcriptome atlas representing major stages of wheat development. Dynamics of complex gene families involved in environmental adaptation and end-use quality were revealed at subgenome resolution and contextualized to known agronomic single-gene or quantitative trait loci. This community resource establishes the foundation for accelerating wheat research and application through improved understanding of wheat biology and genomics-assisted breeding.
2,118 citations
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Academy of Sciences of the Czech Republic1, University of Saskatchewan2, Bayer3, Kansas State University4, University of California, Riverside5, Blaise Pascal University6, Kyoto University7, University of Dundee8, Punjab Agricultural University9, Indian Agricultural Research Institute10, University of Delhi11, University of Tsukuba12, Yokohama City University13, National Research Council14, Norwegian University of Life Sciences15, Sainsbury Laboratory16, Leibniz Association17, United States Department of Energy18, James Hutton Institute19, Institut national de la recherche agronomique20, University of Zurich21, Sabancı University22, Murdoch University23
TL;DR: Insight into the genome biology of a polyploid crop provide a springboard for faster gene isolation, rapid genetic marker development, and precise breeding to meet the needs of increasing food demand worldwide.
Abstract: An ordered draft sequence of the 17-gigabase hexaploid bread wheat (Triticum aestivum) genome has been produced by sequencing isolated chromosome arms. We have annotated 124,201 gene loci distributed nearly evenly across the homeologous chromosomes and subgenomes. Comparative gene analysis of wheat subgenomes and extant diploid and tetraploid wheat relatives showed that high sequence similarity and structural conservation are retained, with limited gene loss, after polyploidization. However, across the genomes there was evidence of dynamic gene gain, loss, and duplication since the divergence of the wheat lineages. A high degree of transcriptional autonomy and no global dominance was found for the subgenomes. These insights into the genome biology of a polyploid crop provide a springboard for faster gene isolation, rapid genetic marker development, and precise breeding to meet the needs of increasing food demand worldwide.
1,421 citations
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TL;DR: The distribution of structural and functional features along the chromosome revealed partitioning correlated with meiotic recombination and high wheat-specific inter- and intrachromosomal gene duplication activities that are potential sources of variability for adaption.
Abstract: We produced a reference sequence of the 1-gigabase chromosome 3B of hexaploid bread wheat. By sequencing 8452 bacterial artificial chromosomes in pools, we assembled a sequence of 774 megabases carrying 5326 protein-coding genes, 1938 pseudogenes, and 85% of transposable elements. The distribution of structural and functional features along the chromosome revealed partitioning correlated with meiotic recombination. Comparative analyses indicated high wheat-specific inter- and intrachromosomal gene duplication activities that are potential sources of variability for adaption. In addition to providing a better understanding of the organization, function, and evolution of a large and polyploid genome, the availability of a high-quality sequence anchored to genetic maps will accelerate the identification of genes underlying important agronomic traits.
522 citations
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TL;DR: It was shown that the chromosome number variation/reduction from the n = 12 common paleo-ancestor was driven by nonrandom centric double-strand break repair events, and it appeared that the centromeric/telomeric illegitimate recombination between nonhomologous chromosomes led to nested chromosome fusions (NCFs) and synteny break points (SBPs).
Abstract: The comparison of the chromosome numbers of today's species with common reconstructed paleo-ancestors has led to intense speculation of how chromosomes have been rearranged over time in mammals However, similar studies in plants with respect to genome evolution as well as molecular mechanisms leading to mosaic synteny blocks have been lacking due to relevant examples of evolutionary zooms from genomic sequences Such studies require genomes of species that belong to the same family but are diverged to fall into different subfamilies Our most important crops belong to the family of the grasses, where a number of genomes have now been sequenced Based on detailed paleogenomics, using inference from n = 5-12 grass ancestral karyotypes (AGKs) in terms of gene content and order, we delineated sequence intervals comprising a complete set of junction break points of orthologous regions from rice, maize, sorghum, and Brachypodium genomes, representing three different subfamilies and different polyploidization events By focusing on these sequence intervals, we could show that the chromosome number variation/reduction from the n = 12 common paleo-ancestor was driven by nonrandom centric double-strand break repair events It appeared that the centromeric/telomeric illegitimate recombination between nonhomologous chromosomes led to nested chromosome fusions (NCFs) and synteny break points (SBPs) When intervals comprising NCFs were compared in their structure, we concluded that SBPs (1) were meiotic recombination hotspots, (2) corresponded to high sequence turnover loci through repeat invasion, and (3) might be considered as hotspots of evolutionary novelty that could act as a reservoir for producing adaptive phenotypes
194 citations
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TL;DR: The Wheat@URGI portal has been developed to provide the international community of researchers and breeders with access to the bread wheat reference genome sequence produced by the International Wheat Genome Sequencing Consortium.
Abstract: The Wheat@URGI portal has been developed to provide the international community of researchers and breeders with access to the bread wheat reference genome sequence produced by the International Wheat Genome Sequencing Consortium. Genome browsers, BLAST, and InterMine tools have been established for in-depth exploration of the genome sequence together with additional linked datasets including physical maps, sequence variations, gene expression, and genetic and phenomic data from other international collaborative projects already stored in the GnpIS information system. The portal provides enhanced search and browser features that will facilitate the deployment of the latest genomics resources in wheat improvement.
171 citations
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TL;DR: The MCScanX toolkit implements an adjusted MCScan algorithm for detection of synteny and collinearity that extends the original software by incorporating 14 utility programs for visualization of results and additional downstream analyses.
Abstract: MCScan is an algorithm able to scan multiple genomes or subgenomes in order to identify putative homologous chromosomal regions, and align these regions using genes as anchors. The MCScanX toolkit implements an adjusted MCScan algorithm for detection of synteny and collinearity that extends the original software by incorporating 14 utility programs for visualization of results and additional downstream analyses. Applications of MCScanX to several sequenced plant genomes and gene families are shown as examples. MCScanX can be used to effectively analyze chromosome structural changes, and reveal the history of gene family expansions that might contribute to the adaptation of lineages and taxa. An integrated view of various modes of gene duplication can supplement the traditional gene tree analysis in specific families. The source code and documentation of MCScanX are freely available at http://chibba.pgml.uga.edu/mcscan2/.
3,388 citations
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TL;DR: This annotated reference sequence of wheat is a resource that can now drive disruptive innovation in wheat improvement, as this community resource establishes the foundation for accelerating wheat research and application through improved understanding of wheat biology and genomics-assisted breeding.
Abstract: An annotated reference sequence representing the hexaploid bread wheat genome in 21 pseudomolecules has been analyzed to identify the distribution and genomic context of coding and noncoding elements across the A, B, and D subgenomes. With an estimated coverage of 94% of the genome and containing 107,891 high-confidence gene models, this assembly enabled the discovery of tissue- and developmental stage-related coexpression networks by providing a transcriptome atlas representing major stages of wheat development. Dynamics of complex gene families involved in environmental adaptation and end-use quality were revealed at subgenome resolution and contextualized to known agronomic single-gene or quantitative trait loci. This community resource establishes the foundation for accelerating wheat research and application through improved understanding of wheat biology and genomics-assisted breeding.
2,118 citations
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Academy of Sciences of the Czech Republic1, University of Saskatchewan2, Bayer3, Kansas State University4, University of California, Riverside5, Blaise Pascal University6, Kyoto University7, University of Dundee8, Punjab Agricultural University9, Indian Agricultural Research Institute10, University of Delhi11, University of Tsukuba12, Yokohama City University13, National Research Council14, Norwegian University of Life Sciences15, Sainsbury Laboratory16, Leibniz Association17, United States Department of Energy18, James Hutton Institute19, Institut national de la recherche agronomique20, University of Zurich21, Sabancı University22, Murdoch University23
TL;DR: Insight into the genome biology of a polyploid crop provide a springboard for faster gene isolation, rapid genetic marker development, and precise breeding to meet the needs of increasing food demand worldwide.
Abstract: An ordered draft sequence of the 17-gigabase hexaploid bread wheat (Triticum aestivum) genome has been produced by sequencing isolated chromosome arms. We have annotated 124,201 gene loci distributed nearly evenly across the homeologous chromosomes and subgenomes. Comparative gene analysis of wheat subgenomes and extant diploid and tetraploid wheat relatives showed that high sequence similarity and structural conservation are retained, with limited gene loss, after polyploidization. However, across the genomes there was evidence of dynamic gene gain, loss, and duplication since the divergence of the wheat lineages. A high degree of transcriptional autonomy and no global dominance was found for the subgenomes. These insights into the genome biology of a polyploid crop provide a springboard for faster gene isolation, rapid genetic marker development, and precise breeding to meet the needs of increasing food demand worldwide.
1,421 citations
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TL;DR: Genomic signatures of selection and domestication are associated with positively selected genes (PSGs) for fiber improvement in the A subgenome and for stress tolerance in the D subgenomes, suggesting asymmetric evolution.
Abstract: Upland cotton is a model for polyploid crop domestication and transgenic improvement. Here we sequenced the allotetraploid Gossypium hirsutum L. acc. TM-1 genome by integrating whole-genome shotgun reads, bacterial artificial chromosome (BAC)-end sequences and genotype-by-sequencing genetic maps. We assembled and annotated 32,032 A-subgenome genes and 34,402 D-subgenome genes. Structural rearrangements, gene loss, disrupted genes and sequence divergence were more common in the A subgenome than in the D subgenome, suggesting asymmetric evolution. However, no genome-wide expression dominance was found between the subgenomes. Genomic signatures of selection and domestication are associated with positively selected genes (PSGs) for fiber improvement in the A subgenome and for stress tolerance in the D subgenome. This draft genome sequence provides a resource for engineering superior cotton lines.
1,221 citations
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Leibniz Association1, University of Zurich2, James Hutton Institute3, Murdoch University4, University of Minnesota5, National Institutes of Health6, University of California, Riverside7, European Bioinformatics Institute8, University of Udine9, University of Helsinki10, Norwich University11, Zhejiang University12, Kansas State University13, University of Adelaide14, University of East Anglia15, National Institute of Agricultural Botany16, Technische Universität München17, Lund University18, Government of Western Australia19, Yangtze University20, University of Dundee21, University of Western Australia22
TL;DR: The importance of the barley reference sequence for breeding is demonstrated by inspecting the genomic partitioning of sequence variation in modern elite germplasm, highlighting regions vulnerable to genetic erosion.
Abstract: Cereal grasses of the Triticeae tribe have been the major food source in temperate regions since the dawn of agriculture. Their large genomes are characterized by a high content of repetitive elements and large pericentromeric regions that are virtually devoid of meiotic recombination. Here we present a high-quality reference genome assembly for barley (Hordeum vulgare L.). We use chromosome conformation capture mapping to derive the linear order of sequences across the pericentromeric space and to investigate the spatial organization of chromatin in the nucleus at megabase resolution. The composition of genes and repetitive elements differs between distal and proximal regions. Gene family analyses reveal lineage-specific duplications of genes involved in the transport of nutrients to developing seeds and the mobilization of carbohydrates in grains. We demonstrate the importance of the barley reference sequence for breeding by inspecting the genomic partitioning of sequence variation in modern elite germplasm, highlighting regions vulnerable to genetic erosion.
1,105 citations