| 1. |
- Grabherr, Manfred G., et al.
(author)
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Exploiting Nucleotide Composition to Engineer Promoters
- 2011
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In: PLoS One. - : Public Library of Science (PLoS). - 1932-6203. ; 6:5, s. e20136-
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Journal article (peer-reviewed)abstract
- The choice of promoter is a critical step in optimizing the efficiency and stability of recombinant protein production in mammalian cell lines. Artificial promoters that provide stable expression across cell lines and can be designed to the desired strength constitute an alternative to the use of viral promoters. Here, we show how the nucleotide characteristics of highly active human promoters can be modelled via the genome-wide frequency distribution of short motifs: by overlapping motifs that occur infrequently in the genome, we constructed contiguous sequence that is rich in GC and CpGs, both features of known promoters, but lacking homology to real promoters. We show that snippets from this sequence, at 100 base pairs or longer, drive gene expression in vitro in a number of mammalian cells, and are thus candidates for use in protein production. We further show that expression is driven by the general transcription factors TFIIB and TFIID, both being ubiquitously present across cell types, which results in less tissue-and species-specific regulation compared to the viral promoter SV40. We lastly found that the strength of a promoter can be tuned up and down by modulating the counts of GC and CpGs in localized regions. These results constitute a "proof-of-concept" for custom-designing promoters that are suitable for biotechnological and medical applications.
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| 2. |
- Alfoeldi, Jessica, et al.
(author)
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The genome of the green anole lizard and a comparative analysis with birds and mammals
- 2011
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In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 477:7366, s. 587-591
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Journal article (peer-reviewed)abstract
- The evolution of the amniotic egg was one of the great evolutionary innovations in the history of life, freeing vertebrates from an obligatory connection to water and thus permitting the conquest of terrestrial environments(1). Among amniotes, genome sequences are available for mammals and birds(2-4), but not for non-avian reptiles. Here we report the genome sequence of the North American green anole lizard, Anolis carolinensis. We find that A. carolinensis microchromosomes are highly syntenic with chicken microchromosomes, yet do not exhibit the high GC and low repeat content that are characteristic of avian microchromosomes(2). Also, A. carolinensis mobile elements are very young and diverse-more so than in any other sequenced amniote genome. The GC content of this lizard genome is also unusual in its homogeneity, unlike the regionally variable GC content found in mammals and birds(5). We describe and assign sequence to the previously unknown A. carolinensis X chromosome. Comparative gene analysis shows that amniote egg proteins have evolved significantly more rapidly than other proteins. An anole phylogeny resolves basal branches to illuminate the history of their repeated adaptive radiations.
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| 3. |
- Clark, Andrew G., et al.
(author)
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Evolution of genes and genomes on the Drosophila phylogeny
- 2007
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In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 450:7167, s. 203-218
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Journal article (peer-reviewed)abstract
- Comparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here for the first time (sechellia, simulans, yakuba, erecta, ananassae, persimilis, willistoni, mojavensis, virilis and grimshawi), illustrate how rates and patterns of sequence divergence across taxa can illuminate evolutionary processes on a genomic scale. These genome sequences augment the formidable genetic tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution. Despite remarkable similarities among these Drosophila species, we identified many putatively non-neutral changes in protein-coding genes, non-coding RNA genes, and cis-regulatory regions. These may prove to underlie differences in the ecology and behaviour of these diverse species.
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| 4. |
- Grabherr, Manfred G, et al.
(author)
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Full-length transcriptome assembly from RNA-Seq data without a reference genome
- 2011
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In: Nature Biotechnology. - : Springer Science and Business Media LLC. - 1087-0156 .- 1546-1696. ; 29:7, s. 644-652
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Journal article (peer-reviewed)abstract
- Massively parallel sequencing of cDNA has enabled deep and efficient probing of transcriptomes. Current approaches for transcript reconstruction from such data often rely on aligning reads to a reference genome, and are thus unsuitable for samples with a partial or missing reference genome. Here we present the Trinity method for de novo assembly of full-length transcripts and evaluate it on samples from fission yeast, mouse and whitefly, whose reference genome is not yet available. By efficiently constructing and analyzing sets of de Bruijn graphs, Trinity fully reconstructs a large fraction of transcripts, including alternatively spliced isoforms and transcripts from recently duplicated genes. Compared with other de novo transcriptome assemblers, Trinity recovers more full-length transcripts across a broad range of expression levels, with a sensitivity similar to methods that rely on genome alignments. Our approach provides a unified solution for transcriptome reconstruction in any sample, especially in the absence of a reference genome.
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| 5. |
- Grabherr, Manfred G, et al.
(author)
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Genome-wide synteny through highly sensitive sequence alignment : Satsuma
- 2010
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In: Bioinformatics. - : Oxford University Press (OUP). - 1367-4803 .- 1367-4811. ; 26:9, s. 1145-1151
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Journal article (peer-reviewed)abstract
- MOTIVATION: Comparative genomics heavily relies on alignments of large and often complex DNA sequences. From an engineering perspective, the problem here is to provide maximum sensitivity (to find all there is to find), specificity (to only find real homology) and speed (to accommodate the billions of base pairs of vertebrate genomes). RESULTS: Satsuma addresses all three issues through novel strategies: (i) cross-correlation, implemented via fast Fourier transform; (ii) a match scoring scheme that eliminates almost all false hits; and (iii) an asynchronous 'battleship'-like search that allows for aligning two entire fish genomes (470 and 217 Mb) in 120 CPU hours using 15 processors on a single machine. AVAILABILITY: Satsuma is part of the Spines software package, implemented in C++ on Linux. The latest version of Spines can be freely downloaded under the LGPL license from http://www.broadinstitute.org/science/programs/genome-biology/spines/.
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| 6. |
- Höppner, Marc P., et al.
(author)
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An Improved Canine Genome and a Comprehensive Catalogue of Coding Genes and Non-Coding Transcripts
- 2014
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In: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:3, s. e91172-
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Journal article (peer-reviewed)abstract
- The domestic dog, Canis familiaris, is a well-established model system for mapping trait and disease loci. While the original draft sequence was of good quality, gaps were abundant particularly in promoter regions of the genome, negatively impacting the annotation and study of candidate genes. Here, we present an improved genome build, canFam3.1, which includes 85 MB of novel sequence and now covers 99.8% of the euchromatic portion of the genome. We also present multiple RNA-Sequencing data sets from 10 different canine tissues to catalog similar to 175,000 expressed loci. While about 90% of the coding genes previously annotated by EnsEMBL have measurable expression in at least one sample, the number of transcript isoforms detected by our data expands the EnsEMBL annotations by a factor of four. Syntenic comparison with the human genome revealed an additional similar to 3,000 loci that are characterized as protein coding in human and were also expressed in the dog, suggesting that those were previously not annotated in the EnsEMBL canine gene set. In addition to,20,700 high-confidence protein coding loci, we found,4,600 antisense transcripts overlapping exons of protein coding genes, similar to 7,200 intergenic multi-exon transcripts without coding potential, likely candidates for long intergenic non-coding RNAs (lincRNAs) and,11,000 transcripts were reported by two different library construction methods but did not fit any of the above categories. Of the lincRNAs, about 6,000 have no annotated orthologs in human or mouse. Functional analysis of two novel transcripts with shRNA in a mouse kidney cell line altered cell morphology and motility. All in all, we provide a much-improved annotation of the canine genome and suggest regulatory functions for several of the novel non-coding transcripts.
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| 7. |
- Jones, Felicity C., et al.
(author)
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The genomic basis of adaptive evolution in threespine sticklebacks
- 2012
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In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 484:7392, s. 55-61
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Journal article (peer-reviewed)abstract
- Marine stickleback fish have colonized and adapted to thousands of streams and lakes formed since the last ice age, providing an exceptional opportunity to characterize genomic mechanisms underlying repeated ecological adaptation in nature. Here we develop a high-quality reference genome assembly for threespine sticklebacks. By sequencing the genomes of twenty additional individuals from a global set of marine and freshwater populations, we identify a genome-wide set of loci that are consistently associated with marine-freshwater divergence. Our results indicate that reuse of globally shared standing genetic variation, including chromosomal inversions, has an important role in repeated evolution of distinct marine and freshwater sticklebacks, and in the maintenance of divergent ecotypes during early stages of reproductive isolation. Both coding and regulatory changes occur in the set of loci underlying marine-freshwater evolution, but regulatory changes appear to predominate in this well known example of repeated adaptive evolution in nature.
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| 8. |
- Lindblad-Toh, Kerstin, et al.
(author)
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Genome sequence, comparative analysis and haplotype structure of the domestic dog.
- 2005
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In: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 438:7069, s. 803-19
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Journal article (peer-reviewed)abstract
- Here we report a high-quality draft genome sequence of the domestic dog (Canis familiaris), together with a dense map of single nucleotide polymorphisms (SNPs) across breeds. The dog is of particular interest because it provides important evolutionary information and because existing breeds show great phenotypic diversity for morphological, physiological and behavioural traits. We use sequence comparison with the primate and rodent lineages to shed light on the structure and evolution of genomes and genes. Notably, the majority of the most highly conserved non-coding sequences in mammalian genomes are clustered near a small subset of genes with important roles in development. Analysis of SNPs reveals long-range haplotypes across the entire dog genome, and defines the nature of genetic diversity within and across breeds. The current SNP map now makes it possible for genome-wide association studies to identify genes responsible for diseases and traits, with important consequences for human and companion animal health.
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| 9. |
- Mikkelsen, Tarjei S, et al.
(author)
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Genome of the marsupial Monodelphis domestica reveals innovation in non-coding sequences
- 2007
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In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 447:7141, s. 167-177
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Journal article (peer-reviewed)abstract
- We report a high-quality draft of the genome sequence of the grey, short-tailed opossum (Monodelphis domestica). As the first metatherian ('marsupial') species to be sequenced, the opossum provides a unique perspective on the organization and evolution of mammalian genomes. Distinctive features of the opossum chromosomes provide support for recent theories about genome evolution and function, including a strong influence of biased gene conversion on nucleotide sequence composition, and a relationship between chromosomal characteristics and X chromosome inactivation. Comparison of opossum and eutherian genomes also reveals a sharp difference in evolutionary innovation between protein-coding and non-coding functional elements. True innovation in protein-coding genes seems to be relatively rare, with lineage-specific differences being largely due to diversification and rapid turnover in gene families involved in environmental interactions. In contrast, about 20% of eutherian conserved non-coding elements (CNEs) are recent inventions that postdate the divergence of Eutheria and Metatheria. A substantial proportion of these eutherian-specific CNEs arose from sequence inserted by transposable elements, pointing to transposons as a major creative force in the evolution of mammalian gene regulation.
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| 10. |
- Pielberg, Gerli Rosengren, et al.
(author)
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A cis-acting regulatory mutation causes premature hair graying and susceptibility to melanoma in the horse
- 2008
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In: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 40:8, s. 1004-1009
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Journal article (peer-reviewed)abstract
- In horses, graying with age is an autosomal dominant trait associated with a high incidence of melanoma and vitiligo-like depigmentation. Here we show that the Gray phenotype is caused by a 4.6-kb duplication in intron 6 of STX17 (syntaxin-17) that constitutes a cis-acting regulatory mutation. Both STX17 and the neighboring NR4A3 gene are overexpressed in melanomas from Gray horses. Gray horses carrying a loss-of-function mutation in ASIP (agouti signaling protein) had a higher incidence of melanoma, implying that increased melanocortin-1 receptor signaling promotes melanoma development in Gray horses. The Gray horse provides a notable example of how humans have cherry-picked mutations with favorable phenotypic effects in domestic animals.
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