Drosophila duplication hotspots are associated with late-replicating regions of the genome.

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Margarida Cardoso-Moreira

2011-11-01

Full Text Available Duplications play a significant role in both extremes of the phenotypic spectrum of newly arising mutations: they can have severe deleterious effects (e.g. duplications underlie a variety of diseases but can also be highly advantageous. The phenotypic potential of newly arisen duplications has stimulated wide interest in both the mutational and selective processes shaping these variants in the genome. Here we take advantage of the Drosophila simulans-Drosophila melanogaster genetic system to further our understanding of both processes. Regarding mutational processes, the study of two closely related species allows investigation of the potential existence of shared duplication hotspots, and the similarities and differences between the two genomes can be used to dissect its underlying causes. Regarding selection, the difference in the effective population size between the two species can be leveraged to ask questions about the strength of selection acting on different classes of duplications. In this study, we conducted a survey of duplication polymorphisms in 14 different lines of D. simulans using tiling microarrays and combined it with an analogous survey for the D. melanogaster genome. By integrating the two datasets, we identified duplication hotspots conserved between the two species. However, unlike the duplication hotspots identified in mammalian genomes, Drosophila duplication hotspots are not associated with sequences of high sequence identity capable of mediating non-allelic homologous recombination. Instead, Drosophila duplication hotspots are associated with late-replicating regions of the genome, suggesting a link between DNA replication and duplication rates. We also found evidence supporting a higher effectiveness of selection on duplications in D. simulans than in D. melanogaster. This is also true for duplications segregating at high frequency, where we find evidence in D. simulans that a sizeable fraction of these mutations is

Analysis of high-identity segmental duplications in the grapevine genome

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Carelli Francesco N

2011-08-01

Full Text Available Abstract Background Segmental duplications (SDs are blocks of genomic sequence of 1-200 kb that map to different loci in a genome and share a sequence identity > 90%. SDs show at the sequence level the same characteristics as other regions of the human genome: they contain both high-copy repeats and gene sequences. SDs play an important role in genome plasticity by creating new genes and modeling genome structure. Although data is plentiful for mammals, not much was known about the representation of SDs in plant genomes. In this regard, we performed a genome-wide analysis of high-identity SDs on the sequenced grapevine (Vitis vinifera genome (PN40024. Results We demonstrate that recent SDs (> 94% identity and >= 10 kb in size are a relevant component of the grapevine genome (85 Mb, 17% of the genome sequence. We detected mitochondrial and plastid DNA and genes (10% of gene annotation in segmentally duplicated regions of the nuclear genome. In particular, the nine highest copy number genes have a copy in either or both organelle genomes. Further we showed that several duplicated genes take part in the biosynthesis of compounds involved in plant response to environmental stress. Conclusions These data show the great influence of SDs and organelle DNA transfers in modeling the Vitis vinifera nuclear DNA structure as well as the impact of SDs in contributing to the adaptive capacity of grapevine and the nutritional content of grape products through genome variation. This study represents a step forward in the full characterization of duplicated genes important for grapevine cultural needs and human health.

The house spider genome reveals an ancient whole-genome duplication during arachnid evolution.

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Schwager, Evelyn E; Sharma, Prashant P; Clarke, Thomas; Leite, Daniel J; Wierschin, Torsten; Pechmann, Matthias; Akiyama-Oda, Yasuko; Esposito, Lauren; Bechsgaard, Jesper; Bilde, Trine; Buffry, Alexandra D; Chao, Hsu; Dinh, Huyen; Doddapaneni, HarshaVardhan; Dugan, Shannon; Eibner, Cornelius; Extavour, Cassandra G; Funch, Peter; Garb, Jessica; Gonzalez, Luis B; Gonzalez, Vanessa L; Griffiths-Jones, Sam; Han, Yi; Hayashi, Cheryl; Hilbrant, Maarten; Hughes, Daniel S T; Janssen, Ralf; Lee, Sandra L; Maeso, Ignacio; Murali, Shwetha C; Muzny, Donna M; Nunes da Fonseca, Rodrigo; Paese, Christian L B; Qu, Jiaxin; Ronshaugen, Matthew; Schomburg, Christoph; Schönauer, Anna; Stollewerk, Angelika; Torres-Oliva, Montserrat; Turetzek, Natascha; Vanthournout, Bram; Werren, John H; Wolff, Carsten; Worley, Kim C; Bucher, Gregor; Gibbs, Richard A; Coddington, Jonathan; Oda, Hiroki; Stanke, Mario; Ayoub, Nadia A; Prpic, Nikola-Michael; Flot, Jean-François; Posnien, Nico; Richards, Stephen; McGregor, Alistair P

2017-07-31

The duplication of genes can occur through various mechanisms and is thought to make a major contribution to the evolutionary diversification of organisms. There is increasing evidence for a large-scale duplication of genes in some chelicerate lineages including two rounds of whole genome duplication (WGD) in horseshoe crabs. To investigate this further, we sequenced and analyzed the genome of the common house spider Parasteatoda tepidariorum. We found pervasive duplication of both coding and non-coding genes in this spider, including two clusters of Hox genes. Analysis of synteny conservation across the P. tepidariorum genome suggests that there has been an ancient WGD in spiders. Comparison with the genomes of other chelicerates, including that of the newly sequenced bark scorpion Centruroides sculpturatus, suggests that this event occurred in the common ancestor of spiders and scorpions, and is probably independent of the WGDs in horseshoe crabs. Furthermore, characterization of the sequence and expression of the Hox paralogs in P. tepidariorum suggests that many have been subject to neo-functionalization and/or sub-functionalization since their duplication. Our results reveal that spiders and scorpions are likely the descendants of a polyploid ancestor that lived more than 450 MYA. Given the extensive morphological diversity and ecological adaptations found among these animals, rivaling those of vertebrates, our study of the ancient WGD event in Arachnopulmonata provides a new comparative platform to explore common and divergent evolutionary outcomes of polyploidization events across eukaryotes.

MSOAR 2.0: Incorporating tandem duplications into ortholog assignment based on genome rearrangement

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Zhang Liqing

2010-01-01

Full Text Available Abstract Background Ortholog assignment is a critical and fundamental problem in comparative genomics, since orthologs are considered to be functional counterparts in different species and can be used to infer molecular functions of one species from those of other species. MSOAR is a recently developed high-throughput system for assigning one-to-one orthologs between closely related species on a genome scale. It attempts to reconstruct the evolutionary history of input genomes in terms of genome rearrangement and gene duplication events. It assumes that a gene duplication event inserts a duplicated gene into the genome of interest at a random location (i.e., the random duplication model. However, in practice, biologists believe that genes are often duplicated by tandem duplications, where a duplicated gene is located next to the original copy (i.e., the tandem duplication model. Results In this paper, we develop MSOAR 2.0, an improved system for one-to-one ortholog assignment. For a pair of input genomes, the system first focuses on the tandemly duplicated genes of each genome and tries to identify among them those that were duplicated after the speciation (i.e., the so-called inparalogs, using a simple phylogenetic tree reconciliation method. For each such set of tandemly duplicated inparalogs, all but one gene will be deleted from the concerned genome (because they cannot possibly appear in any one-to-one ortholog pairs, and MSOAR is invoked. Using both simulated and real data experiments, we show that MSOAR 2.0 is able to achieve a better sensitivity and specificity than MSOAR. In comparison with the well-known genome-scale ortholog assignment tool InParanoid, Ensembl ortholog database, and the orthology information extracted from the well-known whole-genome multiple alignment program MultiZ, MSOAR 2.0 shows the highest sensitivity. Although the specificity of MSOAR 2.0 is slightly worse than that of InParanoid in the real data experiments

Discovery of previously unidentified genomic disorders from the duplication architecture of the human genome.

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Sharp, Andrew J; Hansen, Sierra; Selzer, Rebecca R; Cheng, Ze; Regan, Regina; Hurst, Jane A; Stewart, Helen; Price, Sue M; Blair, Edward; Hennekam, Raoul C; Fitzpatrick, Carrie A; Segraves, Rick; Richmond, Todd A; Guiver, Cheryl; Albertson, Donna G; Pinkel, Daniel; Eis, Peggy S; Schwartz, Stuart; Knight, Samantha J L; Eichler, Evan E

2006-09-01

Genomic disorders are characterized by the presence of flanking segmental duplications that predispose these regions to recurrent rearrangement. Based on the duplication architecture of the genome, we investigated 130 regions that we hypothesized as candidates for previously undescribed genomic disorders. We tested 290 individuals with mental retardation by BAC array comparative genomic hybridization and identified 16 pathogenic rearrangements, including de novo microdeletions of 17q21.31 found in four individuals. Using oligonucleotide arrays, we refined the breakpoints of this microdeletion, defining a 478-kb critical region containing six genes that were deleted in all four individuals. We mapped the breakpoints of this deletion and of four other pathogenic rearrangements in 1q21.1, 15q13, 15q24 and 17q12 to flanking segmental duplications, suggesting that these are also sites of recurrent rearrangement. In common with the 17q21.31 deletion, these breakpoint regions are sites of copy number polymorphism in controls, indicating that these may be inherently unstable genomic regions.

Detection and correction of false segmental duplications caused by genome mis-assembly

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2010-01-01

Diploid genomes with divergent chromosomes present special problems for assembly software as two copies of especially polymorphic regions may be mistakenly constructed, creating the appearance of a recent segmental duplication. We developed a method for identifying such false duplications and applied it to four vertebrate genomes. For each genome, we corrected mis-assemblies, improved estimates of the amount of duplicated sequence, and recovered polymorphisms between the sequenced chromosomes. PMID:20219098

Supervised Learning for Detection of Duplicates in Genomic Sequence Databases.

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Qingyu Chen

Full Text Available First identified as an issue in 1996, duplication in biological databases introduces redundancy and even leads to inconsistency when contradictory information appears. The amount of data makes purely manual de-duplication impractical, and existing automatic systems cannot detect duplicates as precisely as can experts. Supervised learning has the potential to address such problems by building automatic systems that learn from expert curation to detect duplicates precisely and efficiently. While machine learning is a mature approach in other duplicate detection contexts, it has seen only preliminary application in genomic sequence databases.We developed and evaluated a supervised duplicate detection method based on an expert curated dataset of duplicates, containing over one million pairs across five organisms derived from genomic sequence databases. We selected 22 features to represent distinct attributes of the database records, and developed a binary model and a multi-class model. Both models achieve promising performance; under cross-validation, the binary model had over 90% accuracy in each of the five organisms, while the multi-class model maintains high accuracy and is more robust in generalisation. We performed an ablation study to quantify the impact of different sequence record features, finding that features derived from meta-data, sequence identity, and alignment quality impact performance most strongly. The study demonstrates machine learning can be an effective additional tool for de-duplication of genomic sequence databases. All Data are available as described in the supplementary material.

Supervised Learning for Detection of Duplicates in Genomic Sequence Databases.

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Chen, Qingyu; Zobel, Justin; Zhang, Xiuzhen; Verspoor, Karin

2016-01-01

First identified as an issue in 1996, duplication in biological databases introduces redundancy and even leads to inconsistency when contradictory information appears. The amount of data makes purely manual de-duplication impractical, and existing automatic systems cannot detect duplicates as precisely as can experts. Supervised learning has the potential to address such problems by building automatic systems that learn from expert curation to detect duplicates precisely and efficiently. While machine learning is a mature approach in other duplicate detection contexts, it has seen only preliminary application in genomic sequence databases. We developed and evaluated a supervised duplicate detection method based on an expert curated dataset of duplicates, containing over one million pairs across five organisms derived from genomic sequence databases. We selected 22 features to represent distinct attributes of the database records, and developed a binary model and a multi-class model. Both models achieve promising performance; under cross-validation, the binary model had over 90% accuracy in each of the five organisms, while the multi-class model maintains high accuracy and is more robust in generalisation. We performed an ablation study to quantify the impact of different sequence record features, finding that features derived from meta-data, sequence identity, and alignment quality impact performance most strongly. The study demonstrates machine learning can be an effective additional tool for de-duplication of genomic sequence databases. All Data are available as described in the supplementary material.

The sea lamprey meiotic map improves resolution of ancient vertebrate genome duplications.

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Smith, Jeramiah J; Keinath, Melissa C

2015-08-01

It is generally accepted that many genes present in vertebrate genomes owe their origin to two whole-genome duplications that occurred deep in the ancestry of the vertebrate lineage. However, details regarding the timing and outcome of these duplications are not well resolved. We present high-density meiotic and comparative genomic maps for the sea lamprey (Petromyzon marinus), a representative of an ancient lineage that diverged from all other vertebrates ∼550 million years ago. Linkage analyses yielded a total of 95 linkage groups, similar to the estimated number of germline chromosomes (1n ∼ 99), spanning a total of 5570.25 cM. Comparative mapping data yield strong support for the hypothesis that a single whole-genome duplication occurred in the basal vertebrate lineage, but do not strongly support a hypothetical second event. Rather, these comparative maps reveal several evolutionarily independent segmental duplications occurring over the last 600+ million years of chordate evolution. This refined history of vertebrate genome duplication should permit more precise investigations of vertebrate evolution. © 2015 Smith and Keinath; Published by Cold Spring Harbor Laboratory Press.

Decoding Synteny Blocks and Large-Scale Duplications in Mammalian and Plant Genomes

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Peng, Qian; Alekseyev, Max A.; Tesler, Glenn; Pevzner, Pavel A.

The existing synteny block reconstruction algorithms use anchors (e.g., orthologous genes) shared over all genomes to construct the synteny blocks for multiple genomes. This approach, while efficient for a few genomes, cannot be scaled to address the need to construct synteny blocks in many mammalian genomes that are currently being sequenced. The problem is that the number of anchors shared among all genomes quickly decreases with the increase in the number of genomes. Another problem is that many genomes (plant genomes in particular) had extensive duplications, which makes decoding of genomic architecture and rearrangement analysis in plants difficult. The existing synteny block generation algorithms in plants do not address the issue of generating non-overlapping synteny blocks suitable for analyzing rearrangements and evolution history of duplications. We present a new algorithm based on the A-Bruijn graph framework that overcomes these difficulties and provides a unified approach to synteny block reconstruction for multiple genomes, and for genomes with large duplications.

Analysis Of Segmental Duplications In The Pig Genome Based On Next-Generation Sequencing

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Fadista, João; Bendixen, Christian

Segmental duplications are >1kb segments of duplicated DNA present in a genome with high sequence identity (>90%). They are associated with genomic rearrangements and provide a significant source of gene and genome evolution within mammalian genomes. Although segmental duplications have been...... extensively studied in other organisms, its analysis in pig has been hampered by the lack of a complete pig genome assembly. By measuring the depth of coverage of Illumina whole-genome shotgun sequencing reads of the Tabasco animal aligned to the latest pig genome assembly (Sus scrofa 10 – based also...... and their associated copy number alterations, focusing on the global organization of these segments and their possible functional significance in porcine phenotypes. This work provides insights into mammalian genome evolution and generates a valuable resource for porcine genomics research...

Whole genome duplications and expansion of the vertebrate GATA transcription factor gene family

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Bowerman Bruce

2009-08-01

Full Text Available Abstract Background GATA transcription factors influence many developmental processes, including the specification of embryonic germ layers. The GATA gene family has significantly expanded in many animal lineages: whereas diverse cnidarians have only one GATA transcription factor, six GATA genes have been identified in many vertebrates, five in many insects, and eleven to thirteen in Caenorhabditis nematodes. All bilaterian animal genomes have at least one member each of two classes, GATA123 and GATA456. Results We have identified one GATA123 gene and one GATA456 gene from the genomic sequence of two invertebrate deuterostomes, a cephalochordate (Branchiostoma floridae and a hemichordate (Saccoglossus kowalevskii. We also have confirmed the presence of six GATA genes in all vertebrate genomes, as well as additional GATA genes in teleost fish. Analyses of conserved sequence motifs and of changes to the exon-intron structure, and molecular phylogenetic analyses of these deuterostome GATA genes support their origin from two ancestral deuterostome genes, one GATA 123 and one GATA456. Comparison of the conserved genomic organization across vertebrates identified eighteen paralogous gene families linked to multiple vertebrate GATA genes (GATA paralogons, providing the strongest evidence yet for expansion of vertebrate GATA gene families via genome duplication events. Conclusion From our analysis, we infer the evolutionary birth order and relationships among vertebrate GATA transcription factors, and define their expansion via multiple rounds of whole genome duplication events. As the genomes of four independent invertebrate deuterostome lineages contain single copy GATA123 and GATA456 genes, we infer that the 0R (pre-genome duplication invertebrate deuterostome ancestor also had two GATA genes, one of each class. Synteny analyses identify duplications of paralogous chromosomal regions (paralogons, from single ancestral vertebrate GATA123 and GATA456

Whole Genome and Tandem Duplicate Retention facilitated Glucosinolate Pathway Diversification in the Mustard Family.

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Hofberger, J.A.; Lyons, E.; Edger, P.P.; Pires, J.C.; Schranz, M.E.

2013-01-01

Plants share a common history of successive whole genome duplication (WGD) events retaining genomic patterns of duplicate gene copies (ohnologs) organized in conserved syntenic blocks. Duplication was often proposed to affect the origin of novel traits during evolution. However, genetic evidence

"Tandem duplication-random loss" is not a real feature of oyster mitochondrial genomes

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Zhang Guofan

2009-02-01

Full Text Available Abstract Duplications and rearrangements of coding genes are major themes in the evolution of mitochondrial genomes, bearing important consequences in the function of mitochondria and the fitness of organisms. Yu et al. (BMC Genomics 2008, 9:477 reported the complete mt genome sequence of the oyster Crassostrea hongkongensis (16,475 bp and found that a DNA segment containing four tRNA genes (trnK1, trnC, trnQ1 and trnN, a duplicated (rrnS and a split rRNA gene (rrnL5' was absent compared with that of two other Crassostrea species. It was suggested that the absence was a novel case of "tandem duplication-random loss" with evolutionary significance. We independently sequenced the complete mt genome of three C. hongkongensis individuals, all of which were 18,622 bp and contained the segment that was missing in Yu et al.'s sequence. Further, we designed primers, verified sequences and demonstrated that the sequence loss in Yu et al.'s study was an artifact caused by placing primers in a duplicated region. The duplication and split of ribosomal RNA genes are unique for Crassostrea oysters and not lost in C. hongkongensis. Our study highlights the need for caution when amplifying and sequencing through duplicated regions of the genome.

Genome-wide signatures of 'rearrangement hotspots' within segmental duplications in humans.

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Mohammed Uddin

Full Text Available The primary objective of this study was to create a genome-wide high resolution map (i.e., >100 bp of 'rearrangement hotspots' which can facilitate the identification of regions capable of mediating de novo deletions or duplications in humans. A hierarchical method was employed to fragment segmental duplications (SDs into multiple smaller SD units. Combining an end space free pairwise alignment algorithm with a 'seed and extend' approach, we have exhaustively searched 409 million alignments to detect complex structural rearrangements within the reference-guided assembly of the NA18507 human genome (18× coverage, including the previously identified novel 4.8 Mb sequence from de novo assembly within this genome. We have identified 1,963 rearrangement hotspots within SDs which encompass 166 genes and display an enrichment of duplicated gene nucleotide variants (DNVs. These regions are correlated with increased non-allelic homologous recombination (NAHR event frequency which presumably represents the origin of copy number variations (CNVs and pathogenic duplications/deletions. Analysis revealed that 20% of the detected hotspots are clustered within the proximal and distal SD breakpoints flanked by the pathogenic deletions/duplications that have been mapped for 24 NAHR-mediated genomic disorders. FISH Validation of selected complex regions revealed 94% concordance with in silico localization of the highly homologous derivatives. Other results from this study indicate that intra-chromosomal recombination is enhanced in genic compared with agenic duplicated regions, and that gene desert regions comprising SDs may represent reservoirs for creation of novel genes. The generation of genome-wide signatures of 'rearrangement hotspots', which likely serve as templates for NAHR, may provide a powerful approach towards understanding the underlying mutational mechanism(s for development of constitutional and acquired diseases.

Small homologous blocks in phytophthora genomes do not point to an ancient whole-genome duplication.

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van Hooff, Jolien J E; Snel, Berend; Seidl, Michael F

2014-05-01

Genomes of the plant-pathogenic genus Phytophthora are characterized by small duplicated blocks consisting of two consecutive genes (2HOM blocks) and by an elevated abundance of similarly aged gene duplicates. Both properties, in particular the presence of 2HOM blocks, have been attributed to a whole-genome duplication (WGD) at the last common ancestor of Phytophthora. However, large intraspecies synteny-compelling evidence for a WGD-has not been detected. Here, we revisited the WGD hypothesis by deducing the age of 2HOM blocks. Two independent timing methods reveal that the majority of 2HOM blocks arose after divergence of the Phytophthora lineages. In addition, a large proportion of the 2HOM block copies colocalize on the same scaffold. Therefore, the presence of 2HOM blocks does not support a WGD at the last common ancestor of Phytophthora. Thus, genome evolution of Phytophthora is likely driven by alternative mechanisms, such as bursts of transposon activity.

A salmonid EST genomic study: genes, duplications, phylogeny and microarrays

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Brahmbhatt Sonal

2008-11-01

Full Text Available Abstract Background Salmonids are of interest because of their relatively recent genome duplication, and their extensive use in wild fisheries and aquaculture. A comprehensive gene list and a comparison of genes in some of the different species provide valuable genomic information for one of the most widely studied groups of fish. Results 298,304 expressed sequence tags (ESTs from Atlantic salmon (69% of the total, 11,664 chinook, 10,813 sockeye, 10,051 brook trout, 10,975 grayling, 8,630 lake whitefish, and 3,624 northern pike ESTs were obtained in this study and have been deposited into the public databases. Contigs were built and putative full-length Atlantic salmon clones have been identified. A database containing ESTs, assemblies, consensus sequences, open reading frames, gene predictions and putative annotation is available. The overall similarity between Atlantic salmon ESTs and those of rainbow trout, chinook, sockeye, brook trout, grayling, lake whitefish, northern pike and rainbow smelt is 93.4, 94.2, 94.6, 94.4, 92.5, 91.7, 89.6, and 86.2% respectively. An analysis of 78 transcript sets show Salmo as a sister group to Oncorhynchus and Salvelinus within Salmoninae, and Thymallinae as a sister group to Salmoninae and Coregoninae within Salmonidae. Extensive gene duplication is consistent with a genome duplication in the common ancestor of salmonids. Using all of the available EST data, a new expanded salmonid cDNA microarray of 32,000 features was created. Cross-species hybridizations to this cDNA microarray indicate that this resource will be useful for studies of all 68 salmonid species. Conclusion An extensive collection and analysis of salmonid RNA putative transcripts indicate that Pacific salmon, Atlantic salmon and charr are 94–96% similar while the more distant whitefish, grayling, pike and smelt are 93, 92, 89 and 86% similar to salmon. The salmonid transcriptome reveals a complex history of gene duplication that is

On Computing Breakpoint Distances for Genomes with Duplicate Genes.

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Shao, Mingfu; Moret, Bernard M E

2017-06-01

A fundamental problem in comparative genomics is to compute the distance between two genomes in terms of its higher level organization (given by genes or syntenic blocks). For two genomes without duplicate genes, we can easily define (and almost always efficiently compute) a variety of distance measures, but the problem is NP-hard under most models when genomes contain duplicate genes. To tackle duplicate genes, three formulations (exemplar, maximum matching, and any matching) have been proposed, all of which aim to build a matching between homologous genes so as to minimize some distance measure. Of the many distance measures, the breakpoint distance (the number of nonconserved adjacencies) was the first one to be studied and remains of significant interest because of its simplicity and model-free property. The three breakpoint distance problems corresponding to the three formulations have been widely studied. Although we provided last year a solution for the exemplar problem that runs very fast on full genomes, computing optimal solutions for the other two problems has remained challenging. In this article, we describe very fast, exact algorithms for these two problems. Our algorithms rely on a compact integer-linear program that we further simplify by developing an algorithm to remove variables, based on new results on the structure of adjacencies and matchings. Through extensive experiments using both simulations and biological data sets, we show that our algorithms run very fast (in seconds) on mammalian genomes and scale well beyond. We also apply these algorithms (as well as the classic orthology tool MSOAR) to create orthology assignment, then compare their quality in terms of both accuracy and coverage. We find that our algorithm for the "any matching" formulation significantly outperforms other methods in terms of accuracy while achieving nearly maximum coverage.

Insights into three whole-genome duplications gleaned from the Paramecium caudatum genome sequence.

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McGrath, Casey L; Gout, Jean-Francois; Doak, Thomas G; Yanagi, Akira; Lynch, Michael

2014-08-01

Paramecium has long been a model eukaryote. The sequence of the Paramecium tetraurelia genome reveals a history of three successive whole-genome duplications (WGDs), and the sequences of P. biaurelia and P. sexaurelia suggest that these WGDs are shared by all members of the aurelia species complex. Here, we present the genome sequence of P. caudatum, a species closely related to the P. aurelia species group. P. caudatum shares only the most ancient of the three WGDs with the aurelia complex. We found that P. caudatum maintains twice as many paralogs from this early event as the P. aurelia species, suggesting that post-WGD gene retention is influenced by subsequent WGDs and supporting the importance of selection for dosage in gene retention. The availability of P. caudatum as an outgroup allows an expanded analysis of the aurelia intermediate and recent WGD events. Both the Guanine+Cytosine (GC) content and the expression level of preduplication genes are significant predictors of duplicate retention. We find widespread asymmetrical evolution among aurelia paralogs, which is likely caused by gradual pseudogenization rather than by neofunctionalization. Finally, cases of divergent resolution of intermediate WGD duplicates between aurelia species implicate this process acts as an ongoing reinforcement mechanism of reproductive isolation long after a WGD event. Copyright © 2014 by the Genetics Society of America.

Development of genome- and transcriptome-derived microsatellites in related species of snapping shrimps with highly duplicated genomes.

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Gaynor, Kaitlyn M; Solomon, Joseph W; Siller, Stefanie; Jessell, Linnet; Duffy, J Emmett; Rubenstein, Dustin R

2017-11-01

Molecular markers are powerful tools for studying patterns of relatedness and parentage within populations and for making inferences about social evolution. However, the development of molecular markers for simultaneous study of multiple species presents challenges, particularly when species exhibit genome duplication or polyploidy. We developed microsatellite markers for Synalpheus shrimp, a genus in which species exhibit not only great variation in social organization, but also interspecific variation in genome size and partial genome duplication. From the four primary clades within Synalpheus, we identified microsatellites in the genomes of four species and in the consensus transcriptome of two species. Ultimately, we designed and tested primers for 143 microsatellite markers across 25 species. Although the majority of markers were disomic, many markers were polysomic for certain species. Surprisingly, we found no relationship between genome size and the number of polysomic markers. As expected, markers developed for a given species amplified better for closely related species than for more distant relatives. Finally, the markers developed from the transcriptome were more likely to work successfully and to be disomic than those developed from the genome, suggesting that consensus transcriptomes are likely to be conserved across species. Our findings suggest that the transcriptome, particularly consensus sequences from multiple species, can be a valuable source of molecular markers for taxa with complex, duplicated genomes. © 2017 John Wiley & Sons Ltd.

Whole genome duplication of intra- and inter-chromosomes in the tomato genome.

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Song, Chi; Guo, Juan; Sun, Wei; Wang, Ying

2012-07-20

Whole genome duplication (WGD) events have been proven to occur in the evolutionary history of most angiosperms. Tomato is considered a model species of the Solanaceae family. In this study, we describe the details of the evolutionary process of the tomato genome by detecting collinearity blocks and dating the WGD events on the tree of life by combining two different methods: synonymous substitution rates (Ks) and phylogenetic trees. In total, 593 collinearity blocks were discovered out of 12 pseudo-chromosomes constructed. It was evident that chromosome 2 had experienced an intra-chromosomal duplication event. Major inter-chromosomal duplication occurred among all the pseudo-chromosome. We calculated the Ks value of these collinearity blocks. Two peaks of Ks distribution were found, corresponding to two WGD events occurring approximately 36-82 million years ago (MYA) and 148-205 MYA. Additionally, the results of phylogenetic trees suggested that the more recent WGD event may have occurred after the divergence of the rosid-asterid clade, but before the major diversification in Solanaceae. The older WGD event was shown to have occurred before the divergence of the rosid-asterid clade and after the divergence of rice-Arabidopsis (monocot-dicot). Copyright © 2012. Published by Elsevier Ltd.

Transcriptome analysis reveals the time of the fourth round of genome duplication in common carp (Cyprinus carpio)

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2012-01-01

Background Common carp (Cyprinus carpio) is thought to have undergone one extra round of genome duplication compared to zebrafish. Transcriptome analysis has been used to study the existence and timing of genome duplication in species for which genome sequences are incomplete. Large-scale transcriptome data for the common carp genome should help reveal the timing of the additional duplication event. Results We have sequenced the transcriptome of common carp using 454 pyrosequencing. After assembling the 454 contigs and the published common carp sequences together, we obtained 49,669 contigs and identified genes using homology searches and an ab initio method. We identified 4,651 orthologous pairs between common carp and zebrafish and found 129,984 paralogous pairs within the common carp. An estimation of the synonymous substitution rate in the orthologous pairs indicated that common carp and zebrafish diverged 120 million years ago (MYA). We identified one round of genome duplication in common carp and estimated that it had occurred 5.6 to 11.3 MYA. In zebrafish, no genome duplication event after speciation was observed, suggesting that, compared to zebrafish, common carp had undergone an additional genome duplication event. We annotated the common carp contigs with Gene Ontology terms and KEGG pathways. Compared with zebrafish gene annotations, we found that a set of biological processes and pathways were enriched in common carp. Conclusions The assembled contigs helped us to estimate the time of the fourth-round of genome duplication in common carp. The resource that we have built as part of this study will help advance functional genomics and genome annotation studies in the future. PMID:22424280

The detection of large deletions or duplications in genomic DNA.

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Armour, J A L; Barton, D E; Cockburn, D J; Taylor, G R

2002-11-01

While methods for the detection of point mutations and small insertions or deletions in genomic DNA are well established, the detection of larger (>100 bp) genomic duplications or deletions can be more difficult. Most mutation scanning methods use PCR as a first step, but the subsequent analyses are usually qualitative rather than quantitative. Gene dosage methods based on PCR need to be quantitative (i.e., they should report molar quantities of starting material) or semi-quantitative (i.e., they should report gene dosage relative to an internal standard). Without some sort of quantitation, heterozygous deletions and duplications may be overlooked and therefore be under-ascertained. Gene dosage methods provide the additional benefit of reporting allele drop-out in the PCR. This could impact on SNP surveys, where large-scale genotyping may miss null alleles. Here we review recent developments in techniques for the detection of this type of mutation and compare their relative strengths and weaknesses. We emphasize that comprehensive mutation analysis should include scanning for large insertions and deletions and duplications. Copyright 2002 Wiley-Liss, Inc.

Whole genome duplication affects evolvability of flowering time in an autotetraploid plant.

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Sara L Martin

Full Text Available Whole genome duplications have occurred recurrently throughout the evolutionary history of eukaryotes. The resulting genetic and phenotypic changes can influence physiological and ecological responses to the environment; however, the impact of genome copy number on evolvability has rarely been examined experimentally. Here, we evaluate the effect of genome duplication on the ability to respond to selection for early flowering time in lines drawn from naturally occurring diploid and autotetraploid populations of the plant Chamerion angustifolium (fireweed. We contrast this with the result of four generations of selection on synthesized neoautotetraploids, whose genic variability is similar to diploids but genome copy number is similar to autotetraploids. In addition, we examine correlated responses to selection in all three groups. Diploid and both extant tetraploid and neoautotetraploid lines responded to selection with significant reductions in time to flowering. Evolvability, measured as realized heritability, was significantly lower in extant tetraploids (^b(T =  0.31 than diploids (^b(T =  0.40. Neotetraploids exhibited the highest evolutionary response (^b(T  =  0.55. The rapid shift in flowering time in neotetraploids was associated with an increase in phenotypic variability across generations, but not with change in genome size or phenotypic correlations among traits. Our results suggest that whole genome duplications, without hybridization, may initially alter evolutionary rate, and that the dynamic nature of neoautopolyploids may contribute to the prevalence of polyploidy throughout eukaryotes.

Predictions of Gene Family Distributions in Microbial Genomes: Evolution by Gene Duplication and Modification

International Nuclear Information System (INIS)

Yanai, Itai; Camacho, Carlos J.; DeLisi, Charles

2000-01-01

A universal property of microbial genomes is the considerable fraction of genes that are homologous to other genes within the same genome. The process by which these homologues are generated is not well understood, but sequence analysis of 20 microbial genomes unveils a recurrent distribution of gene family sizes. We show that a simple evolutionary model based on random gene duplication and point mutations fully accounts for these distributions and permits predictions for the number of gene families in genomes not yet complete. Our findings are consistent with the notion that a genome evolves from a set of precursor genes to a mature size by gene duplications and increasing modifications. (c) 2000 The American Physical Society

Predictions of Gene Family Distributions in Microbial Genomes: Evolution by Gene Duplication and Modification

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Yanai, Itai; Camacho, Carlos J.; DeLisi, Charles

2000-09-18

A universal property of microbial genomes is the considerable fraction of genes that are homologous to other genes within the same genome. The process by which these homologues are generated is not well understood, but sequence analysis of 20 microbial genomes unveils a recurrent distribution of gene family sizes. We show that a simple evolutionary model based on random gene duplication and point mutations fully accounts for these distributions and permits predictions for the number of gene families in genomes not yet complete. Our findings are consistent with the notion that a genome evolves from a set of precursor genes to a mature size by gene duplications and increasing modifications. (c) 2000 The American Physical Society.

Approximating the edit distance for genomes with duplicate genes under DCJ, insertion and deletion

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Shao Mingfu

2012-12-01

Full Text Available Abstract Computing the edit distance between two genomes under certain operations is a basic problem in the study of genome evolution. The double-cut-and-join (DCJ model has formed the basis for most algorithmic research on rearrangements over the last few years. The edit distance under the DCJ model can be easily computed for genomes without duplicate genes. In this paper, we study the edit distance for genomes with duplicate genes under a model that includes DCJ operations, insertions and deletions. We prove that computing the edit distance is equivalent to finding the optimal cycle decomposition of the corresponding adjacency graph, and give an approximation algorithm with an approximation ratio of 1.5 + ∈.

Prevalent Role of Gene Features in Determining Evolutionary Fates of Whole-Genome Duplication Duplicated Genes in Flowering Plants1[W][OA

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Jiang, Wen-kai; Liu, Yun-long; Xia, En-hua; Gao, Li-zhi

2013-01-01

The evolution of genes and genomes after polyploidization has been the subject of extensive studies in evolutionary biology and plant sciences. While a significant number of duplicated genes are rapidly removed during a process called fractionation, which operates after the whole-genome duplication (WGD), another considerable number of genes are retained preferentially, leading to the phenomenon of biased gene retention. However, the evolutionary mechanisms underlying gene retention after WGD remain largely unknown. Through genome-wide analyses of sequence and functional data, we comprehensively investigated the relationships between gene features and the retention probability of duplicated genes after WGDs in six plant genomes, Arabidopsis (Arabidopsis thaliana), poplar (Populus trichocarpa), soybean (Glycine max), rice (Oryza sativa), sorghum (Sorghum bicolor), and maize (Zea mays). The results showed that multiple gene features were correlated with the probability of gene retention. Using a logistic regression model based on principal component analysis, we resolved evolutionary rate, structural complexity, and GC3 content as the three major contributors to gene retention. Cluster analysis of these features further classified retained genes into three distinct groups in terms of gene features and evolutionary behaviors. Type I genes are more prone to be selected by dosage balance; type II genes are possibly subject to subfunctionalization; and type III genes may serve as potential targets for neofunctionalization. This study highlights that gene features are able to act jointly as primary forces when determining the retention and evolution of WGD-derived duplicated genes in flowering plants. These findings thus may help to provide a resolution to the debate on different evolutionary models of gene fates after WGDs. PMID:23396833

p53 protects against genome instability following centriole duplication failure

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Lambrus, Bramwell G.; Uetake, Yumi; Clutario, Kevin M.; Daggubati, Vikas; Snyder, Michael; Sluder, Greenfield

2015-01-01

Centriole function has been difficult to study because of a lack of specific tools that allow persistent and reversible centriole depletion. Here we combined gene targeting with an auxin-inducible degradation system to achieve rapid, titratable, and reversible control of Polo-like kinase 4 (Plk4), a master regulator of centriole biogenesis. Depletion of Plk4 led to a failure of centriole duplication that produced an irreversible cell cycle arrest within a few divisions. This arrest was not a result of a prolonged mitosis, chromosome segregation errors, or cytokinesis failure. Depleting p53 allowed cells that fail centriole duplication to proliferate indefinitely. Washout of auxin and restoration of endogenous Plk4 levels in cells that lack centrioles led to the penetrant formation of de novo centrioles that gained the ability to organize microtubules and duplicate. In summary, we uncover a p53-dependent surveillance mechanism that protects against genome instability by preventing cell growth after centriole duplication failure. PMID:26150389

Mitochondrial Genomes of Kinorhyncha: trnM Duplication and New Gene Orders within Animals.

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Popova, Olga V; Mikhailov, Kirill V; Nikitin, Mikhail A; Logacheva, Maria D; Penin, Aleksey A; Muntyan, Maria S; Kedrova, Olga S; Petrov, Nikolai B; Panchin, Yuri V; Aleoshin, Vladimir V

2016-01-01

Many features of mitochondrial genomes of animals, such as patterns of gene arrangement, nucleotide content and substitution rate variation are extensively used in evolutionary and phylogenetic studies. Nearly 6,000 mitochondrial genomes of animals have already been sequenced, covering the majority of animal phyla. One of the groups that escaped mitogenome sequencing is phylum Kinorhyncha-an isolated taxon of microscopic worm-like ecdysozoans. The kinorhynchs are thought to be one of the early-branching lineages of Ecdysozoa, and their mitochondrial genomes may be important for resolving evolutionary relations between major animal taxa. Here we present the results of sequencing and analysis of mitochondrial genomes from two members of Kinorhyncha, Echinoderes svetlanae (Cyclorhagida) and Pycnophyes kielensis (Allomalorhagida). Their mitochondrial genomes are circular molecules approximately 15 Kbp in size. The kinorhynch mitochondrial gene sequences are highly divergent, which precludes accurate phylogenetic inference. The mitogenomes of both species encode a typical metazoan complement of 37 genes, which are all positioned on the major strand, but the gene order is distinct and unique among Ecdysozoa or animals as a whole. We predict four types of start codons for protein-coding genes in E. svetlanae and five in P. kielensis with a consensus DTD in single letter code. The mitochondrial genomes of E. svetlanae and P. kielensis encode duplicated methionine tRNA genes that display compensatory nucleotide substitutions. Two distant species of Kinorhyncha demonstrate similar patterns of gene arrangements in their mitogenomes. Both genomes have duplicated methionine tRNA genes; the duplication predates the divergence of two species. The kinorhynchs share a few features pertaining to gene order that align them with Priapulida. Gene order analysis reveals that gene arrangement specific of Priapulida may be ancestral for Scalidophora, Ecdysozoa, and even Protostomia.

Mitochondrial Genomes of Kinorhyncha: trnM Duplication and New Gene Orders within Animals.

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Olga V Popova

Full Text Available Many features of mitochondrial genomes of animals, such as patterns of gene arrangement, nucleotide content and substitution rate variation are extensively used in evolutionary and phylogenetic studies. Nearly 6,000 mitochondrial genomes of animals have already been sequenced, covering the majority of animal phyla. One of the groups that escaped mitogenome sequencing is phylum Kinorhyncha-an isolated taxon of microscopic worm-like ecdysozoans. The kinorhynchs are thought to be one of the early-branching lineages of Ecdysozoa, and their mitochondrial genomes may be important for resolving evolutionary relations between major animal taxa. Here we present the results of sequencing and analysis of mitochondrial genomes from two members of Kinorhyncha, Echinoderes svetlanae (Cyclorhagida and Pycnophyes kielensis (Allomalorhagida. Their mitochondrial genomes are circular molecules approximately 15 Kbp in size. The kinorhynch mitochondrial gene sequences are highly divergent, which precludes accurate phylogenetic inference. The mitogenomes of both species encode a typical metazoan complement of 37 genes, which are all positioned on the major strand, but the gene order is distinct and unique among Ecdysozoa or animals as a whole. We predict four types of start codons for protein-coding genes in E. svetlanae and five in P. kielensis with a consensus DTD in single letter code. The mitochondrial genomes of E. svetlanae and P. kielensis encode duplicated methionine tRNA genes that display compensatory nucleotide substitutions. Two distant species of Kinorhyncha demonstrate similar patterns of gene arrangements in their mitogenomes. Both genomes have duplicated methionine tRNA genes; the duplication predates the divergence of two species. The kinorhynchs share a few features pertaining to gene order that align them with Priapulida. Gene order analysis reveals that gene arrangement specific of Priapulida may be ancestral for Scalidophora, Ecdysozoa, and even

Selective Constraints on Coding Sequences of Nervous System Genes Are a Major Determinant of Duplicate Gene Retention in Vertebrates.

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Roux, Julien; Liu, Jialin; Robinson-Rechavi, Marc

2017-11-01

The evolutionary history of vertebrates is marked by three ancient whole-genome duplications: two successive rounds in the ancestor of vertebrates, and a third one specific to teleost fishes. Biased loss of most duplicates enriched the genome for specific genes, such as slow evolving genes, but this selective retention process is not well understood. To understand what drives the long-term preservation of duplicate genes, we characterized duplicated genes in terms of their expression patterns. We used a new method of expression enrichment analysis, TopAnat, applied to in situ hybridization data from thousands of genes from zebrafish and mouse. We showed that the presence of expression in the nervous system is a good predictor of a higher rate of retention of duplicate genes after whole-genome duplication. Further analyses suggest that purifying selection against the toxic effects of misfolded or misinteracting proteins, which is particularly strong in nonrenewing neural tissues, likely constrains the evolution of coding sequences of nervous system genes, leading indirectly to the preservation of duplicate genes after whole-genome duplication. Whole-genome duplications thus greatly contributed to the expansion of the toolkit of genes available for the evolution of profound novelties of the nervous system at the base of the vertebrate radiation. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Recombination facilitates neofunctionalization of duplicate genes via originalization

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Huang Ren

2010-06-01

Full Text Available Abstract Background Recently originalization was proposed to be an effective way of duplicate-gene preservation, in which recombination provokes the high frequency of original (or wild-type allele on both duplicated loci. Because the high frequency of wild-type allele might drive the arising and accumulating of advantageous mutation, it is hypothesized that recombination might enlarge the probability of neofunctionalization (Pneo of duplicate genes. In this article this hypothesis has been tested theoretically. Results Results show that through originalization recombination might not only shorten mean time to neofunctionalizaiton, but also enlarge Pneo. Conclusions Therefore, recombination might facilitate neofunctionalization via originalization. Several extensive applications of these results on genomic evolution have been discussed: 1. Time to nonfunctionalization can be much longer than a few million generations expected before; 2. Homogenization on duplicated loci results from not only gene conversion, but also originalization; 3. Although the rate of advantageous mutation is much small compared with that of degenerative mutation, Pneo cannot be expected to be small.

Rapid genome reshaping by multiple-gene loss after whole-genome duplication in teleost fish suggested by mathematical modeling

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Sato, Yukuto; Tsukamoto, Katsumi; Nishida, Mutsumi

2015-01-01

Whole-genome duplication (WGD) is believed to be a significant source of major evolutionary innovation. Redundant genes resulting from WGD are thought to be lost or acquire new functions. However, the rates of gene loss and thus temporal process of genome reshaping after WGD remain unclear. The WGD shared by all teleost fish, one-half of all jawed vertebrates, was more recent than the two ancient WGDs that occurred before the origin of jawed vertebrates, and thus lends itself to analysis of gene loss and genome reshaping. Using a newly developed orthology identification pipeline, we inferred the post–teleost-specific WGD evolutionary histories of 6,892 protein-coding genes from nine phylogenetically representative teleost genomes on a time-calibrated tree. We found that rapid gene loss did occur in the first 60 My, with a loss of more than 70–80% of duplicated genes, and produced similar genomic gene arrangements within teleosts in that relatively short time. Mathematical modeling suggests that rapid gene loss occurred mainly by events involving simultaneous loss of multiple genes. We found that the subsequent 250 My were characterized by slow and steady loss of individual genes. Our pipeline also identified about 1,100 shared single-copy genes that are inferred to have become singletons before the divergence of clupeocephalan teleosts. Therefore, our comparative genome analysis suggests that rapid gene loss just after the WGD reshaped teleost genomes before the major divergence, and provides a useful set of marker genes for future phylogenetic analysis. PMID:26578810

Biological consequences of ancient gene acquisition and duplication in the large genome soil bacterium, ""solibacter usitatus"" strain Ellin6076

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Challacombe, Jean F [Los Alamos National Laboratory; Eichorst, Stephanie A [Los Alamos National Laboratory; Xie, Gary [Los Alamos National Laboratory; Kuske, Cheryl R [Los Alamos National Laboratory; Hauser, Loren [ORNL; Land, Miriam [ORNL

2009-01-01

Bacterial genome sizes range from ca. 0.5 to 10Mb and are influenced by gene duplication, horizontal gene transfer, gene loss and other evolutionary processes. Sequenced genomes of strains in the phylum Acidobacteria revealed that 'Solibacter usistatus' strain Ellin6076 harbors a 9.9 Mb genome. This large genome appears to have arisen by horizontal gene transfer via ancient bacteriophage and plasmid-mediated transduction, as well as widespread small-scale gene duplications. This has resulted in an increased number of paralogs that are potentially ecologically important (ecoparalogs). Low amino acid sequence identities among functional group members and lack of conserved gene order and orientation in the regions containing similar groups of paralogs suggest that most of the paralogs were not the result of recent duplication events. The genome sizes of cultured subdivision 1 and 3 strains in the phylum Acidobacteria were estimated using pulsed-field gel electrophoresis to determine the prevalence of the large genome trait within the phylum. Members of subdivision 1 were estimated to have smaller genome sizes ranging from ca. 2.0 to 4.8 Mb, whereas members of subdivision 3 had slightly larger genomes, from ca. 5.8 to 9.9 Mb. It is hypothesized that the large genome of strain Ellin6076 encodes traits that provide a selective metabolic, defensive and regulatory advantage in the variable soil environment.

Sorting duplicated loci disentangles complexities of polyploid genomes masked by genotyping by sequencing

DEFF Research Database (Denmark)

Limborg, Morten; Seeb, Lisa W.; Seeb, J. E.

2016-01-01

Many plants and animals of polyploid origin are currently enjoying a genomics explosion enabled by modern sequencing and genotyping technologies. However, routine filtering of duplicated loci in most studies using genotyping by sequencing introduces an unacceptable, but often overlooked, bias when...... particularly stress the sometimes overlooked fact that basing genomic studies on dense maps provides value added in the form of locating and annotating outlier loci or colocating outliers into islands of divergenc...

Exploiting a Reference Genome in Terms of Duplications: The Network of Paralogs and Single Copy Genes in Arabidopsis thaliana

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Mara Sangiovanni

2013-12-01

Full Text Available Arabidopsis thaliana became the model organism for plant studies because of its small diploid genome, rapid lifecycle and short adult size. Its genome was the first among plants to be sequenced, becoming the reference in plant genomics. However, the Arabidopsis genome is characterized by an inherently complex organization, since it has undergone ancient whole genome duplications, followed by gene reduction, diploidization events and extended rearrangements, which relocated and split up the retained portions. These events, together with probable chromosome reductions, dramatically increased the genome complexity, limiting its role as a reference. The identification of paralogs and single copy genes within a highly duplicated genome is a prerequisite to understand its organization and evolution and to improve its exploitation in comparative genomics. This is still controversial, even in the widely studied Arabidopsis genome. This is also due to the lack of a reference bioinformatics pipeline that could exhaustively identify paralogs and singleton genes. We describe here a complete computational strategy to detect both duplicated and single copy genes in a genome, discussing all the methodological issues that may strongly affect the results, their quality and their reliability. This approach was used to analyze the organization of Arabidopsis nuclear protein coding genes, and besides classifying computationally defined paralogs into networks and single copy genes into different classes, it unraveled further intriguing aspects concerning the genome annotation and the gene relationships in this reference plant species. Since our results may be useful for comparative genomics and genome functional analyses, we organized a dedicated web interface to make them accessible to the scientific community.

Duplicability of self-interacting human genes.

LENUS (Irish Health Repository)

Pérez-Bercoff, Asa

2010-01-01

BACKGROUND: There is increasing interest in the evolution of protein-protein interactions because this should ultimately be informative of the patterns of evolution of new protein functions within the cell. One model proposes that the evolution of new protein-protein interactions and protein complexes proceeds through the duplication of self-interacting genes. This model is supported by data from yeast. We examined the relationship between gene duplication and self-interaction in the human genome. RESULTS: We investigated the patterns of self-interaction and duplication among 34808 interactions encoded by 8881 human genes, and show that self-interacting proteins are encoded by genes with higher duplicability than genes whose proteins lack this type of interaction. We show that this result is robust against the system used to define duplicate genes. Finally we compared the presence of self-interactions amongst proteins whose genes have duplicated either through whole-genome duplication (WGD) or small-scale duplication (SSD), and show that the former tend to have more interactions in general. After controlling for age differences between the two sets of duplicates this result can be explained by the time since the gene duplication. CONCLUSIONS: Genes encoding self-interacting proteins tend to have higher duplicability than proteins lacking self-interactions. Moreover these duplicate genes have more often arisen through whole-genome rather than small-scale duplication. Finally, self-interacting WGD genes tend to have more interaction partners in general in the PIN, which can be explained by their overall greater age. This work adds to our growing knowledge of the importance of contextual factors in gene duplicability.

Duplicate retention in signalling proteins and constraints from network dynamics.

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Soyer, O S; Creevey, C J

2010-11-01

Duplications are a major driving force behind evolution. Most duplicates are believed to fix through genetic drift, but it is not clear whether this process affects all duplications equally or whether there are certain gene families that are expected to show neutral expansions under certain circumstances. Here, we analyse the neutrality of duplications in different functional classes of signalling proteins based on their effects on response dynamics. We find that duplications involving intermediary proteins in a signalling network are neutral more often than those involving receptors. Although the fraction of neutral duplications in all functional classes increase with decreasing population size and selective pressure on dynamics, this effect is most pronounced for receptors, indicating a possible expansion of receptors in species with small population size. In line with such an expectation, we found a statistically significant increase in the number of receptors as a fraction of genome size in eukaryotes compared with prokaryotes. Although not confirmative, these results indicate that neutral processes can be a significant factor in shaping signalling networks and affect proteins from different functional classes differently. © 2010 The Authors. Journal Compilation © 2010 European Society For Evolutionary Biology.

Genetic diversity and population structure inferred from the partially duplicated genome of domesticated carp, Cyprinus carpio L.

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Feldman Marcus W

2007-04-01

Full Text Available Abstract Genetic relationships among eight populations of domesticated carp (Cyprinus carpio L., a species with a partially duplicated genome, were studied using 12 microsatellites and 505 AFLP bands. The populations included three aquacultured carp strains and five ornamental carp (koi variants. Grass carp (Ctenopharyngodon idella was used as an outgroup. AFLP-based gene diversity varied from 5% (grass carp to 32% (koi and reflected the reasonably well understood histories and breeding practices of the populations. A large fraction of the molecular variance was due to differences between aquacultured and ornamental carps. Further analyses based on microsatellite data, including cluster analysis and neighbor-joining trees, supported the genetic distinctiveness of aquacultured and ornamental carps, despite the recent divergence of the two groups. In contrast to what was observed for AFLP-based diversity, the frequency of heterozygotes based on microsatellites was comparable among all populations. This discrepancy can potentially be explained by duplication of some loci in Cyprinus carpio L., and a model that shows how duplication can increase heterozygosity estimates for microsatellites but not for AFLP loci is discussed. Our analyses in carp can help in understanding the consequences of genotyping duplicated loci and in interpreting discrepancies between dominant and co-dominant markers in species with recent genome duplication.

De novo assembly of the zucchini genome reveals a whole-genome duplication associated with the origin of the Cucurbita genus.

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Montero-Pau, Javier; Blanca, José; Bombarely, Aureliano; Ziarsolo, Peio; Esteras, Cristina; Martí-Gómez, Carlos; Ferriol, María; Gómez, Pedro; Jamilena, Manuel; Mueller, Lukas; Picó, Belén; Cañizares, Joaquín

2017-11-07

The Cucurbita genus (squashes, pumpkins and gourds) includes important domesticated species such as C. pepo, C. maxima and C. moschata. In this study, we present a high-quality draft of the zucchini (C. pepo) genome. The assembly has a size of 263 Mb, a scaffold N50 of 1.8 Mb and 34 240 gene models. It includes 92% of the conserved BUSCO core gene set, and it is estimated to cover 93.0% of the genome. The genome is organized in 20 pseudomolecules that represent 81.4% of the assembly, and it is integrated with a genetic map of 7718 SNPs. Despite the small genome size, three independent lines of evidence support that the C. pepo genome is the result of a whole-genome duplication: the topology of the gene family phylogenies, the karyotype organization and the distribution of 4DTv distances. Additionally, 40 transcriptomes of 12 species of the genus were assembled and analysed together with all the other published genomes of the Cucurbitaceae family. The duplication was detected in all the Cucurbita species analysed, including C. maxima and C. moschata, but not in the more distant cucurbits belonging to the Cucumis and Citrullus genera, and it is likely to have occurred 30 ± 4 Mya in the ancestral species that gave rise to the genus. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

Detection and analysis of ancient segmental duplications in mammalian genomes.

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Pu, Lianrong; Lin, Yu; Pevzner, Pavel A

2018-05-07

Although segmental duplications (SDs) represent hotbeds for genomic rearrangements and emergence of new genes, there are still no easy-to-use tools for identifying SDs. Moreover, while most previous studies focused on recently emerged SDs, detection of ancient SDs remains an open problem. We developed an SDquest algorithm for SD finding and applied it to analyzing SDs in human, gorilla, and mouse genomes. Our results demonstrate that previous studies missed many SDs in these genomes and show that SDs account for at least 6.05% of the human genome (version hg19), a 17% increase as compared to the previous estimate. Moreover, SDquest classified 6.42% of the latest GRCh38 version of the human genome as SDs, a large increase as compared to previous studies. We thus propose to re-evaluate evolution of SDs based on their accurate representation across multiple genomes. Toward this goal, we analyzed the complex mosaic structure of SDs and decomposed mosaic SDs into elementary SDs, a prerequisite for follow-up evolutionary analysis. We also introduced the concept of the breakpoint graph of mosaic SDs that revealed SD hotspots and suggested that some SDs may have originated from circular extrachromosomal DNA (ecDNA), not unlike ecDNA that contributes to accelerated evolution in cancer. © 2018 Pu et al.; Published by Cold Spring Harbor Laboratory Press.

A genome-wide RNAi screen to dissect centriole duplication and centrosome maturation in Drosophila.

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Jeroen Dobbelaere

2008-09-01

Full Text Available Centrosomes comprise a pair of centrioles surrounded by an amorphous pericentriolar material (PCM. Here, we have performed a microscopy-based genome-wide RNA interference (RNAi screen in Drosophila cells to identify proteins required for centriole duplication and mitotic PCM recruitment. We analysed 92% of the Drosophila genome (13,059 genes and identified 32 genes involved in centrosome function. An extensive series of secondary screens classified these genes into four categories: (1 nine are required for centriole duplication, (2 11 are required for centrosome maturation, (3 nine are required for both functions, and (4 three genes regulate centrosome separation. These 32 hits include several new centrosomal components, some of which have human homologs. In addition, we find that the individual depletion of only two proteins, Polo and Centrosomin (Cnn can completely block centrosome maturation. Cnn is phosphorylated during mitosis in a Polo-dependent manner, suggesting that the Polo-dependent phosphorylation of Cnn initiates centrosome maturation in flies.

Gene Conversion in Angiosperm Genomes with an Emphasis on Genes Duplicated by Polyploidization

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Xi-Yin Wang

2011-01-01

Full Text Available Angiosperm genomes differ from those of mammals by extensive and recursive polyploidizations. The resulting gene duplication provides opportunities both for genetic innovation, and for concerted evolution. Though most genes may escape conversion by their homologs, concerted evolution of duplicated genes can last for millions of years or longer after their origin. Indeed, paralogous genes on two rice chromosomes duplicated an estimated 60–70 million years ago have experienced gene conversion in the past 400,000 years. Gene conversion preserves similarity of paralogous genes, but appears to accelerate their divergence from orthologous genes in other species. The mutagenic nature of recombination coupled with the buffering effect provided by gene redundancy, may facilitate the evolution of novel alleles that confer functional innovations while insulating biological fitness of affected plants. A mixed evolutionary model, characterized by a primary birth-and-death process and occasional homoeologous recombination and gene conversion, may best explain the evolution of multigene families.

Evolution of the duplicated intracellular lipid-binding protein genes of teleost fishes.

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Venkatachalam, Ananda B; Parmar, Manoj B; Wright, Jonathan M

2017-08-01

Increasing organismal complexity during the evolution of life has been attributed to the duplication of genes and entire genomes. More recently, theoretical models have been proposed that postulate the fate of duplicated genes, among them the duplication-degeneration-complementation (DDC) model. In the DDC model, the common fate of a duplicated gene is lost from the genome owing to nonfunctionalization. Duplicated genes are retained in the genome either by subfunctionalization, where the functions of the ancestral gene are sub-divided between the sister duplicate genes, or by neofunctionalization, where one of the duplicate genes acquires a new function. Both processes occur either by loss or gain of regulatory elements in the promoters of duplicated genes. Here, we review the genomic organization, evolution, and transcriptional regulation of the multigene family of intracellular lipid-binding protein (iLBP) genes from teleost fishes. Teleost fishes possess many copies of iLBP genes owing to a whole genome duplication (WGD) early in the teleost fish radiation. Moreover, the retention of duplicated iLBP genes is substantially higher than the retention of all other genes duplicated in the teleost genome. The fatty acid-binding protein genes, a subfamily of the iLBP multigene family in zebrafish, are differentially regulated by peroxisome proliferator-activated receptor (PPAR) isoforms, which may account for the retention of iLBP genes in the zebrafish genome by the process of subfunctionalization of cis-acting regulatory elements in iLBP gene promoters.

Genome specific PPARαB duplicates in salmonids and insights into estrogenic regulation in brown trout.

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Madureira, Tânia Vieira; Pinheiro, Ivone; de Paula Freire, Rafaelle; Rocha, Eduardo; Castro, Luis Filipe; Urbatzka, Ralph

2017-06-01

Peroxisome proliferator-activated receptors (PPARs) are key regulators of many processes in vertebrates, such as carbohydrate and lipid metabolism. PPARα, a member of the PPAR nuclear receptor gene subfamily (NR1C1), is involved in fatty acid metabolism, namely in peroxisomal β-oxidation. Two gene paralogues, pparαA and pparαB, were described in several teleost species with their origin dating back to the teleost-specific genome duplication (3R). Given the additional salmonid-specific genome duplication (4R), four genes could be theoretically anticipated for this gene subfamily. In this work, we examined the pparα gene repertoire in brown trout, Salmo trutta f. fario. Data disclosed two pparα-like sequences in brown trout. Phylogenetic analyses further revealed that the isolated genes are most likely genome pparαB duplicates, pparαBa and pparαBb, while pparαA is apparently absent in salmonids. Both genes showed a ubiquitous mRNA expression across a panel of 11 different organs. In vitro exposed primary brown trout hepatocytes strongly suggest that pparα gene paralogues are differently regulated by ethinylestradiol (EE2). PparαBb mRNA expression significantly decreased with dosage, reaching significance after exposure to 50μM EE2, while pparαBa mRNA increased, significant at 1μM EE2. The present data enhances the understanding of pparα function and evolution in teleost, and reinforces the evidence of a potential crosstalk between estrogenic and pparα signaling pathways. Copyright © 2017 Elsevier Inc. All rights reserved.

Sorting by Cuts, Joins, and Whole Chromosome Duplications.

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Zeira, Ron; Shamir, Ron

2017-02-01

Genome rearrangement problems have been extensively studied due to their importance in biology. Most studied models assumed a single copy per gene. However, in reality, duplicated genes are common, most notably in cancer. In this study, we make a step toward handling duplicated genes by considering a model that allows the atomic operations of cut, join, and whole chromosome duplication. Given two linear genomes, [Formula: see text] with one copy per gene and [Formula: see text] with two copies per gene, we give a linear time algorithm for computing a shortest sequence of operations transforming [Formula: see text] into [Formula: see text] such that all intermediate genomes are linear. We also show that computing an optimal sequence with fewest duplications is NP-hard.

Evolutionary restoration of fertility in an interspecies hybrid yeast, by whole-genome duplication after a failed mating-type switch.

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Raúl A Ortiz-Merino

2017-05-01

Full Text Available Many interspecies hybrids have been discovered in yeasts, but most of these hybrids are asexual and can replicate only mitotically. Whole-genome duplication has been proposed as a mechanism by which interspecies hybrids can regain fertility, restoring their ability to perform meiosis and sporulate. Here, we show that this process occurred naturally during the evolution of Zygosaccharomyces parabailii, an interspecies hybrid that was formed by mating between 2 parents that differed by 7% in genome sequence and by many interchromosomal rearrangements. Surprisingly, Z. parabailii has a full sexual cycle and is genetically haploid. It goes through mating-type switching and autodiploidization, followed by immediate sporulation. We identified the key evolutionary event that enabled Z. parabailii to regain fertility, which was breakage of 1 of the 2 homeologous copies of the mating-type (MAT locus in the hybrid, resulting in a chromosomal rearrangement and irreparable damage to 1 MAT locus. This rearrangement was caused by HO endonuclease, which normally functions in mating-type switching. With 1 copy of MAT inactivated, the interspecies hybrid now behaves as a haploid. Our results provide the first demonstration that MAT locus damage is a naturally occurring evolutionary mechanism for whole-genome duplication and restoration of fertility to interspecies hybrids. The events that occurred in Z. parabailii strongly resemble those postulated to have caused ancient whole-genome duplication in an ancestor of Saccharomyces cerevisiae.

The odds of duplicate gene persistence after polyploidization

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Chain Frédéric JJ

2011-12-01

Full Text Available Abstract Background Gene duplication is an important biological phenomenon associated with genomic redundancy, degeneration, specialization, innovation, and speciation. After duplication, both copies continue functioning when natural selection favors duplicated protein function or expression, or when mutations make them functionally distinct before one copy is silenced. Results Here we quantify the degree to which genetic parameters related to gene expression, molecular evolution, and gene structure in a diploid frog - Silurana tropicalis - influence the odds of functional persistence of orthologous duplicate genes in a closely related tetraploid species - Xenopus laevis. Using public databases and 454 pyrosequencing, we obtained genetic and expression data from S. tropicalis orthologs of 3,387 X. laevis paralogs and 4,746 X. laevis singletons - the most comprehensive dataset for African clawed frogs yet analyzed. Using logistic regression, we demonstrate that the most important predictors of the odds of duplicate gene persistence in the tetraploid species are the total gene expression level and evenness of expression across tissues and development in the diploid species. Slow protein evolution and information density (fewer exons, shorter introns in the diploid are also positively correlated with duplicate gene persistence in the tetraploid. Conclusions Our findings suggest that a combination of factors contribute to duplicate gene persistence following whole genome duplication, but that the total expression level and evenness of expression across tissues and through development before duplication are most important. We speculate that these parameters are useful predictors of duplicate gene longevity after whole genome duplication in other taxa.

Functional diversification upon leader protease domain duplication in the Citrus tristeza virus genome: Role of RNA sequences and the encoded proteins.

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Kang, Sung-Hwan; Atallah, Osama O; Sun, Yong-Duo; Folimonova, Svetlana Y

2018-01-15

Viruses from the family Closteroviridae show an example of intra-genome duplications of more than one gene. In addition to the hallmark coat protein gene duplication, several members possess a tandem duplication of papain-like leader proteases. In this study, we demonstrate that domains encoding the L1 and L2 proteases in the Citrus tristeza virus genome underwent a significant functional divergence at the RNA and protein levels. We show that the L1 protease is crucial for viral accumulation and establishment of initial infection, whereas its coding region is vital for virus transport. On the other hand, the second protease is indispensable for virus infection of its natural citrus host, suggesting that L2 has evolved an important adaptive function that mediates virus interaction with the woody host. Copyright © 2017 Elsevier Inc. All rights reserved.

Neofunctionalization of Duplicated P450 Genes Drives the Evolution of Insecticide Resistance in the Brown Planthopper.

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Zimmer, Christoph T; Garrood, William T; Singh, Kumar Saurabh; Randall, Emma; Lueke, Bettina; Gutbrod, Oliver; Matthiesen, Svend; Kohler, Maxie; Nauen, Ralf; Davies, T G Emyr; Bass, Chris

2018-01-22

Gene duplication is a major source of genetic variation that has been shown to underpin the evolution of a wide range of adaptive traits [1, 2]. For example, duplication or amplification of genes encoding detoxification enzymes has been shown to play an important role in the evolution of insecticide resistance [3-5]. In this context, gene duplication performs an adaptive function as a result of its effects on gene dosage and not as a source of functional novelty [3, 6-8]. Here, we show that duplication and neofunctionalization of a cytochrome P450, CYP6ER1, led to the evolution of insecticide resistance in the brown planthopper. Considerable genetic variation was observed in the coding sequence of CYP6ER1 in populations of brown planthopper collected from across Asia, but just two sequence variants are highly overexpressed in resistant strains and metabolize imidacloprid. Both variants are characterized by profound amino-acid alterations in substrate recognition sites, and the introduction of these mutations into a susceptible P450 sequence is sufficient to confer resistance. CYP6ER1 is duplicated in resistant strains with individuals carrying paralogs with and without the gain-of-function mutations. Despite numerical parity in the genome, the susceptible and mutant copies exhibit marked asymmetry in their expression with the resistant paralogs overexpressed. In the primary resistance-conferring CYP6ER1 variant, this results from an extended region of novel sequence upstream of the gene that provides enhanced expression. Our findings illustrate the versatility of gene duplication in providing opportunities for functional and regulatory innovation during the evolution of an adaptive trait. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Independent Evolution of Winner Traits without Whole Genome Duplication in Dekkera Yeasts.

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Yi-Cheng Guo

Full Text Available Dekkera yeasts have often been considered as alternative sources of ethanol production that could compete with S. cerevisiae. The two lineages of yeasts independently evolved traits that include high glucose and ethanol tolerance, aerobic fermentation, and a rapid ethanol fermentation rate. The Saccharomyces yeasts attained these traits mainly through whole genome duplication approximately 100 million years ago (Mya. However, the Dekkera yeasts, which were separated from S. cerevisiae approximately 200 Mya, did not undergo whole genome duplication (WGD but still occupy a niche similar to S. cerevisiae. Upon analysis of two Dekkera yeasts and five closely related non-WGD yeasts, we found that a massive loss of cis-regulatory elements occurred in an ancestor of the Dekkera yeasts, which led to improved mitochondrial functions similar to the S. cerevisiae yeasts. The evolutionary analysis indicated that genes involved in the transcription and translation process exhibited faster evolution in the Dekkera yeasts. We detected 90 positively selected genes, suggesting that the Dekkera yeasts evolved an efficient translation system to facilitate adaptive evolution. Moreover, we identified that 12 vacuolar H+-ATPase (V-ATPase function genes that were under positive selection, which assists in developing tolerance to high alcohol and high sugar stress. We also revealed that the enzyme PGK1 is responsible for the increased rate of glycolysis in the Dekkera yeasts. These results provide important insights to understand the independent adaptive evolution of the Dekkera yeasts and provide tools for genetic modification promoting industrial usage.

Genome-wide analysis of the Dof transcription factor gene family reveals soybean-specific duplicable and functional characteristics.

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Yong Guo

Full Text Available The Dof domain protein family is a classic plant-specific zinc-finger transcription factor family involved in a variety of biological processes. There is great diversity in the number of Dof genes in different plants. However, there are only very limited reports on the characterization of Dof transcription factors in soybean (Glycine max. In the present study, 78 putative Dof genes were identified from the whole-genome sequence of soybean. The predicted GmDof genes were non-randomly distributed within and across 19 out of 20 chromosomes and 97.4% (38 pairs were preferentially retained duplicate paralogous genes located in duplicated regions of the genome. Soybean-specific segmental duplications contributed significantly to the expansion of the soybean Dof gene family. These Dof proteins were phylogenetically clustered into nine distinct subgroups among which the gene structure and motif compositions were considerably conserved. Comparative phylogenetic analysis of these Dof proteins revealed four major groups, similar to those reported for Arabidopsis and rice. Most of the GmDofs showed specific expression patterns based on RNA-seq data analyses. The expression patterns of some duplicate genes were partially redundant while others showed functional diversity, suggesting the occurrence of sub-functionalization during subsequent evolution. Comprehensive expression profile analysis also provided insights into the soybean-specific functional divergence among members of the Dof gene family. Cis-regulatory element analysis of these GmDof genes suggested diverse functions associated with different processes. Taken together, our results provide useful information for the functional characterization of soybean Dof genes by combining phylogenetic analysis with global gene-expression profiling.

Gene Duplicability of Core Genes Is Highly Consistent across All Angiosperms.

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Li, Zhen; Defoort, Jonas; Tasdighian, Setareh; Maere, Steven; Van de Peer, Yves; De Smet, Riet

2016-02-01

Gene duplication is an important mechanism for adding to genomic novelty. Hence, which genes undergo duplication and are preserved following duplication is an important question. It has been observed that gene duplicability, or the ability of genes to be retained following duplication, is a nonrandom process, with certain genes being more amenable to survive duplication events than others. Primarily, gene essentiality and the type of duplication (small-scale versus large-scale) have been shown in different species to influence the (long-term) survival of novel genes. However, an overarching view of "gene duplicability" is lacking, mainly due to the fact that previous studies usually focused on individual species and did not account for the influence of genomic context and the time of duplication. Here, we present a large-scale study in which we investigated duplicate retention for 9178 gene families shared between 37 flowering plant species, referred to as angiosperm core gene families. For most gene families, we observe a strikingly consistent pattern of gene duplicability across species, with gene families being either primarily single-copy or multicopy in all species. An intermediate class contains gene families that are often retained in duplicate for periods extending to tens of millions of years after whole-genome duplication, but ultimately appear to be largely restored to singleton status, suggesting that these genes may be dosage balance sensitive. The distinction between single-copy and multicopy gene families is reflected in their functional annotation, with single-copy genes being mainly involved in the maintenance of genome stability and organelle function and multicopy genes in signaling, transport, and metabolism. The intermediate class was overrepresented in regulatory genes, further suggesting that these represent putative dosage-balance-sensitive genes. © 2016 American Society of Plant Biologists. All rights reserved.

Differential transcriptional modulation of duplicated fatty acid-binding protein genes by dietary fatty acids in zebrafish (Danio rerio: evidence for subfunctionalization or neofunctionalization of duplicated genes

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Denovan-Wright Eileen M

2009-09-01

Full Text Available Abstract Background In the Duplication-Degeneration-Complementation (DDC model, subfunctionalization and neofunctionalization have been proposed as important processes driving the retention of duplicated genes in the genome. These processes are thought to occur by gain or loss of regulatory elements in the promoters of duplicated genes. We tested the DDC model by determining the transcriptional induction of fatty acid-binding proteins (Fabps genes by dietary fatty acids (FAs in zebrafish. We chose zebrafish for this study for two reasons: extensive bioinformatics resources are available for zebrafish at zfin.org and zebrafish contains many duplicated genes owing to a whole genome duplication event that occurred early in the ray-finned fish lineage approximately 230-400 million years ago. Adult zebrafish were fed diets containing either fish oil (12% lipid, rich in highly unsaturated fatty acid, sunflower oil (12% lipid, rich in linoleic acid, linseed oil (12% lipid, rich in linolenic acid, or low fat (4% lipid, low fat diet for 10 weeks. FA profiles and the steady-state levels of fabp mRNA and heterogeneous nuclear RNA in intestine, liver, muscle and brain of zebrafish were determined. Result FA profiles assayed by gas chromatography differed in the intestine, brain, muscle and liver depending on diet. The steady-state level of mRNA for three sets of duplicated genes, fabp1a/fabp1b.1/fabp1b.2, fabp7a/fabp7b, and fabp11a/fabp11b, was determined by reverse transcription, quantitative polymerase chain reaction (RT-qPCR. In brain, the steady-state level of fabp7b mRNAs was induced in fish fed the linoleic acid-rich diet; in intestine, the transcript level of fabp1b.1 and fabp7b were elevated in fish fed the linolenic acid-rich diet; in liver, the level of fabp7a mRNAs was elevated in fish fed the low fat diet; and in muscle, the level of fabp7a and fabp11a mRNAs were elevated in fish fed the linolenic acid-rich or the low fat diets. In all cases

Universal features in the genome-level evolution of protein domains.

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Cosentino Lagomarsino, Marco; Sellerio, Alessandro L; Heijning, Philip D; Bassetti, Bruno

2009-01-01

Protein domains can be used to study proteome evolution at a coarse scale. In particular, they are found on genomes with notable statistical distributions. It is known that the distribution of domains with a given topology follows a power law. We focus on a further aspect: these distributions, and the number of distinct topologies, follow collective trends, or scaling laws, depending on the total number of domains only, and not on genome-specific features. We present a stochastic duplication/innovation model, in the class of the so-called 'Chinese restaurant processes', that explains this observation with two universal parameters, representing a minimal number of domains and the relative weight of innovation to duplication. Furthermore, we study a model variant where new topologies are related to occurrence in genomic data, accounting for fold specificity. Both models have general quantitative agreement with data from hundreds of genomes, which indicates that the domains of a genome are built with a combination of specificity and robust self-organizing phenomena. The latter are related to the basic evolutionary 'moves' of duplication and innovation, and give rise to the observed scaling laws, a priori of the specific evolutionary history of a genome. We interpret this as the concurrent effect of neutral and selective drives, which increase duplication and decrease innovation in larger and more complex genomes. The validity of our model would imply that the empirical observation of a small number of folds in nature may be a consequence of their evolution.

Sox genes in grass carp (Ctenopharyngodon idella with their implications for genome duplication and evolution

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Tong Jingou

2006-11-01

Full Text Available Abstract The Sox gene family is found in a broad range of animal taxa and encodes important gene regulatory proteins involved in a variety of developmental processes. We have obtained clones representing the HMG boxes of twelve Sox genes from grass carp (Ctenopharyngodon idella, one of the four major domestic carps in China. The cloned Sox genes belong to group B1, B2 and C. Our analyses show that whereas the human genome contains a single copy of Sox4, Sox11 and Sox14, each of these genes has two co-orthologs in grass carp, and the duplication of Sox4 and Sox11 occurred before the divergence of grass carp and zebrafish, which support the "fish-specific whole-genome duplication" theory. An estimation for the origin of grass carp based on the molecular clock using Sox1, Sox3 and Sox11 genes as markers indicates that grass carp (subfamily Leuciscinae and zebrafish (subfamily Danioninae diverged approximately 60 million years ago. The potential uses of Sox genes as markers in revealing the evolutionary history of grass carp are discussed.

The vertebrate ancestral repertoire of visual opsins, transducin alpha subunits and oxytocin/vasopressin receptors was established by duplication of their shared genomic region in the two rounds of early vertebrate genome duplications.

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Lagman, David; Ocampo Daza, Daniel; Widmark, Jenny; Abalo, Xesús M; Sundström, Görel; Larhammar, Dan

2013-11-02

Vertebrate color vision is dependent on four major color opsin subtypes: RH2 (green opsin), SWS1 (ultraviolet opsin), SWS2 (blue opsin), and LWS (red opsin). Together with the dim-light receptor rhodopsin (RH1), these form the family of vertebrate visual opsins. Vertebrate genomes contain many multi-membered gene families that can largely be explained by the two rounds of whole genome duplication (WGD) in the vertebrate ancestor (2R) followed by a third round in the teleost ancestor (3R). Related chromosome regions resulting from WGD or block duplications are said to form a paralogon. We describe here a paralogon containing the genes for visual opsins, the G-protein alpha subunit families for transducin (GNAT) and adenylyl cyclase inhibition (GNAI), the oxytocin and vasopressin receptors (OT/VP-R), and the L-type voltage-gated calcium channels (CACNA1-L). Sequence-based phylogenies and analyses of conserved synteny show that the above-mentioned gene families, and many neighboring gene families, expanded in the early vertebrate WGDs. This allows us to deduce the following evolutionary scenario: The vertebrate ancestor had a chromosome containing the genes for two visual opsins, one GNAT, one GNAI, two OT/VP-Rs and one CACNA1-L gene. This chromosome was quadrupled in 2R. Subsequent gene losses resulted in a set of five visual opsin genes, three GNAT and GNAI genes, six OT/VP-R genes and four CACNA1-L genes. These regions were duplicated again in 3R resulting in additional teleost genes for some of the families. Major chromosomal rearrangements have taken place in the teleost genomes. By comparison with the corresponding chromosomal regions in the spotted gar, which diverged prior to 3R, we could time these rearrangements to post-3R. We present an extensive analysis of the paralogon housing the visual opsin, GNAT and GNAI, OT/VP-R, and CACNA1-L gene families. The combined data imply that the early vertebrate WGD events contributed to the evolution of vision and the

Comparative study of human mitochondrial proteome reveals extensive protein subcellular relocalization after gene duplications

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Huang Yong

2009-11-01

Full Text Available Abstract Background Gene and genome duplication is the principle creative force in evolution. Recently, protein subcellular relocalization, or neolocalization was proposed as one of the mechanisms responsible for the retention of duplicated genes. This hypothesis received support from the analysis of yeast genomes, but has not been tested thoroughly on animal genomes. In order to evaluate the importance of subcellular relocalizations for retention of duplicated genes in animal genomes, we systematically analyzed nuclear encoded mitochondrial proteins in the human genome by reconstructing phylogenies of mitochondrial multigene families. Results The 456 human mitochondrial proteins selected for this study were clustered into 305 gene families including 92 multigene families. Among the multigene families, 59 (64% consisted of both mitochondrial and cytosolic (non-mitochondrial proteins (mt-cy families while the remaining 33 (36% were composed of mitochondrial proteins (mt-mt families. Phylogenetic analyses of mt-cy families revealed three different scenarios of their neolocalization following gene duplication: 1 relocalization from mitochondria to cytosol, 2 from cytosol to mitochondria and 3 multiple subcellular relocalizations. The neolocalizations were most commonly enabled by the gain or loss of N-terminal mitochondrial targeting signals. The majority of detected subcellular relocalization events occurred early in animal evolution, preceding the evolution of tetrapods. Mt-mt protein families showed a somewhat different pattern, where gene duplication occurred more evenly in time. However, for both types of protein families, most duplication events appear to roughly coincide with two rounds of genome duplications early in vertebrate evolution. Finally, we evaluated the effects of inaccurate and incomplete annotation of mitochondrial proteins and found that our conclusion of the importance of subcellular relocalization after gene duplication on

The hidden duplication past of the plant pathogen Phytophthora and its consequences for infection

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Martens Cindy

2010-06-01

Full Text Available Abstract Background Oomycetes of the genus Phytophthora are pathogens that infect a wide range of plant species. For dicot hosts such as tomato, potato and soybean, Phytophthora is even the most important pathogen. Previous analyses of Phytophthora genomes uncovered many genes, large gene families and large genome sizes that can partially be explained by significant repeat expansion patterns. Results Analysis of the complete genomes of three different Phytophthora species, using a newly developed approach, unveiled a large number of small duplicated blocks, mainly consisting of two or three consecutive genes. Further analysis of these duplicated genes and comparison with the known gene and genome duplication history of ten other eukaryotes including parasites, algae, plants, fungi, vertebrates and invertebrates, suggests that the ancestor of P. infestans, P. sojae and P. ramorum most likely underwent a whole genome duplication (WGD. Genes that have survived in duplicate are mainly genes that are known to be preferentially retained following WGDs, but also genes important for pathogenicity and infection of the different hosts seem to have been retained in excess. As a result, the WGD might have contributed to the evolutionary and pathogenic success of Phytophthora. Conclusions The fact that we find many small blocks of duplicated genes indicates that the genomes of Phytophthora species have been heavily rearranged following the WGD. Most likely, the high repeat content in these genomes have played an important role in this rearrangement process. As a consequence, the paucity of retained larger duplicated blocks has greatly complicated previous attempts to detect remnants of a large-scale duplication event in Phytophthora. However, as we show here, our newly developed strategy to identify very small duplicated blocks might be a useful approach to uncover ancient polyploidy events, in particular for heavily rearranged genomes.

A conserved segmental duplication within ELA.

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Brinkmeyer-Langford, C L; Murphy, W J; Childers, C P; Skow, L C

2010-12-01

The assembled genomic sequence of the horse major histocompatibility complex (MHC) (equine lymphocyte antigen, ELA) is very similar to the homologous human HLA, with the notable exception of a large segmental duplication at the boundary of ELA class I and class III that is absent in HLA. The segmental duplication consists of a ∼ 710 kb region of at least 11 repeated blocks: 10 blocks each contain an MHC class I-like sequence and the helicase domain portion of a BAT1-like sequence, and the remaining unit contains the full-length BAT1 gene. Similar genomic features were found in other Perissodactyls, indicating an ancient origin, which is consistent with phylogenetic analyses. Reverse-transcriptase PCR (RT-PCR) of mRNA from peripheral white blood cells of healthy and chronically or acutely infected horses detected transcription from predicted open reading frames in several of the duplicated blocks. This duplication is not present in the sequenced MHCs of most other mammals, although a similar feature at the same relative position is present in the feline MHC (FLA). Striking sequence conservation throughout Perissodactyl evolution is consistent with a functional role for at least some of the genes included within this segmental duplication. © 2010 The Authors, Journal compilation © 2010 Stichting International Foundation for Animal Genetics.

Gene Duplicability of Core Genes Is Highly Consistent across All Angiosperms[OPEN

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Li, Zhen; Van de Peer, Yves; De Smet, Riet

2016-01-01

Gene duplication is an important mechanism for adding to genomic novelty. Hence, which genes undergo duplication and are preserved following duplication is an important question. It has been observed that gene duplicability, or the ability of genes to be retained following duplication, is a nonrandom process, with certain genes being more amenable to survive duplication events than others. Primarily, gene essentiality and the type of duplication (small-scale versus large-scale) have been shown in different species to influence the (long-term) survival of novel genes. However, an overarching view of “gene duplicability” is lacking, mainly due to the fact that previous studies usually focused on individual species and did not account for the influence of genomic context and the time of duplication. Here, we present a large-scale study in which we investigated duplicate retention for 9178 gene families shared between 37 flowering plant species, referred to as angiosperm core gene families. For most gene families, we observe a strikingly consistent pattern of gene duplicability across species, with gene families being either primarily single-copy or multicopy in all species. An intermediate class contains gene families that are often retained in duplicate for periods extending to tens of millions of years after whole-genome duplication, but ultimately appear to be largely restored to singleton status, suggesting that these genes may be dosage balance sensitive. The distinction between single-copy and multicopy gene families is reflected in their functional annotation, with single-copy genes being mainly involved in the maintenance of genome stability and organelle function and multicopy genes in signaling, transport, and metabolism. The intermediate class was overrepresented in regulatory genes, further suggesting that these represent putative dosage-balance-sensitive genes. PMID:26744215

Genetics Home Reference: 17q12 duplication

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... J, Li C, Roeder E, Cox S, Karaviti L, Pearson M, Kang SH, Sahoo T, Lalani SR, Stankiewicz ... genomic disorders from the duplication architecture of the human genome. Nat Genet. 2006 Sep;38(9):1038- ...

Annelid Distal-less/Dlx duplications reveal varied post-duplication fates

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Korchagina Natalia

2011-08-01

Full Text Available Abstract Background Dlx (Distal-less genes have various developmental roles and are widespread throughout the animal kingdom, usually occurring as single copy genes in non-chordates and as multiple copies in most chordate genomes. While the genomic arrangement and function of these genes is well known in vertebrates and arthropods, information about Dlx genes in other organisms is scarce. We investigate the presence of Dlx genes in several annelid species and examine Dlx gene expression in the polychaete Pomatoceros lamarckii. Results Two Dlx genes are present in P. lamarckii, Capitella teleta and Helobdella robusta. The C. teleta Dlx genes are closely linked in an inverted tail-to-tail orientation, reminiscent of the arrangement of vertebrate Dlx pairs, and gene conversion appears to have had a role in their evolution. The H. robusta Dlx genes, however, are not on the same genomic scaffold and display divergent sequences, while, if the P. lamarckii genes are linked in a tail-to-tail orientation they are a minimum of 41 kilobases apart and show no sign of gene conversion. No expression in P. lamarckii appendage development has been observed, which conflicts with the supposed conserved role of these genes in animal appendage development. These Dlx duplications do not appear to be annelid-wide, as the polychaete Platynereis dumerilii likely possesses only one Dlx gene. Conclusions On the basis of the currently accepted annelid phylogeny, we hypothesise that one Dlx duplication occurred in the annelid lineage after the divergence of P. dumerilii from the other lineages and these duplicates then had varied evolutionary fates in different species. We also propose that the ancestral role of Dlx genes is not related to appendage development.

A SNP Based Linkage Map of the Arctic Charr (Salvelinus alpinus Genome Provides Insights into the Diploidization Process After Whole Genome Duplication

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Cameron M. Nugent

2017-02-01

Full Text Available Diploidization, which follows whole genome duplication events, does not occur evenly across the genome. In salmonid fishes, certain pairs of homeologous chromosomes preserve tetraploid loci in higher frequencies toward the telomeres due to residual tetrasomic inheritance. Research suggests this occurs only in homeologous pairs where one chromosome arm has undergone a fusion event. We present a linkage map for Arctic charr (Salvelinus alpinus, a salmonid species with relatively fewer chromosome fusions. Genotype by sequencing identified 19,418 SNPs, and a linkage map consisting of 4508 markers was constructed from a subset of high quality SNPs and microsatellite markers that were used to anchor the new map to previous versions. Both male- and female-specific linkage maps contained the expected number of 39 linkage groups. The chromosome type associated with each linkage group was determined, and 10 stable metacentric chromosomes were identified, along with a chromosome polymorphism involving the sex chromosome AC04. Two instances of a weak form of pseudolinkage were detected in the telomeric regions of homeologous chromosome arms in both female and male linkage maps. Chromosome arm homologies within the Atlantic salmon (Salmo salar and rainbow trout (Oncorhynchus mykiss genomes were determined. Paralogous sequence variants (PSVs were identified, and their comparative BLASTn hit locations showed that duplicate markers exist in higher numbers on seven pairs of homeologous arms, previously identified as preserving tetrasomy in salmonid species. Homeologous arm pairs where neither arm has been part of a fusion event in Arctic charr had fewer PSVs, suggesting faster diploidization rates in these regions.

Identification of Ohnolog Genes Originating from Whole Genome Duplication in Early Vertebrates, Based on Synteny Comparison across Multiple Genomes.

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Singh, Param Priya; Arora, Jatin; Isambert, Hervé

2015-07-01

Whole genome duplications (WGD) have now been firmly established in all major eukaryotic kingdoms. In particular, all vertebrates descend from two rounds of WGDs, that occurred in their jawless ancestor some 500 MY ago. Paralogs retained from WGD, also coined 'ohnologs' after Susumu Ohno, have been shown to be typically associated with development, signaling and gene regulation. Ohnologs, which amount to about 20 to 35% of genes in the human genome, have also been shown to be prone to dominant deleterious mutations and frequently implicated in cancer and genetic diseases. Hence, identifying ohnologs is central to better understand the evolution of vertebrates and their susceptibility to genetic diseases. Early computational analyses to identify vertebrate ohnologs relied on content-based synteny comparisons between the human genome and a single invertebrate outgroup genome or within the human genome itself. These approaches are thus limited by lineage specific rearrangements in individual genomes. We report, in this study, the identification of vertebrate ohnologs based on the quantitative assessment and integration of synteny conservation between six amniote vertebrates and six invertebrate outgroups. Such a synteny comparison across multiple genomes is shown to enhance the statistical power of ohnolog identification in vertebrates compared to earlier approaches, by overcoming lineage specific genome rearrangements. Ohnolog gene families can be browsed and downloaded for three statistical confidence levels or recompiled for specific, user-defined, significance criteria at http://ohnologs.curie.fr/. In the light of the importance of WGD on the genetic makeup of vertebrates, our analysis provides a useful resource for researchers interested in gaining further insights on vertebrate evolution and genetic diseases.

Conservation of the abscission signaling peptide IDA during Angiosperm evolution: withstanding genome duplications and gain and loss of the receptors HAE/HSL2

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Ida M. Stø

2015-10-01

Full Text Available The peptide INFLORESCENCE DEFICIENT IN ABSCISSION (IDA, which signals through the leucine-rich repeat receptor-like kinases HAESA (HAE and HAESA-LIKE2 (HSL2, controls different cell separation events in Arabidopsis thaliana. We hypothesize the involvement of this signaling module in abscission processes in other plant species even though they may shed other organs than A. thaliana. As the first step towards testing this hypothesis from an evolutionarily perspective we have identified genes encoding putative orthologues of IDA and its receptors by BLAST searches of publically available protein, nucleotide and genome databases for angiosperms. Genes encoding IDA or IDA-LIKE (IDL peptides and HSL proteins were found in all investigated species, which were selected as to represent each angiosperm order with available genomic sequences. The 12 amino acids representing the bioactive peptide in A. thaliana have virtually been unchanged throughout the evolution of the angiosperms; however, the number of IDL and HSL genes varies between different orders and species. The phylogenetic analyses suggest that IDA, HSL2 and the related HSL1 gene, were present in the species that gave rise to the angiosperms. HAE has arisen from HSL1 after a genome duplication that took place after the monocot - eudicots split. HSL1 has also independently been duplicated in the monocots, while HSL2 has been lost in gingers (Zingiberales and grasses (Poales. IDA has been duplicated in eudicots to give rise to functionally divergent IDL peptides. We postulate that the high number of IDL homologs present in the core eudicots is a result of multiple whole genome duplications. We substantiate the involvement of IDA and HAE/HSL2 homologs in abscission by providing gene expression data of different organ separation events from various species.

Array comparative genomic hybridisation analysis of boys with X linked hypopituitarism identifies a 3.9 Mb duplicated critical region at Xq27 containing SOX3.

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Solomon, N.M.; Ross, S.; Morgan, T.; Belsky, J.L.; Hol, F.A.; Karnes, P.; Hopwood, N.J.; Myers, S.E.; Tan, A.; Warne, G.L.; Forrest, S.M.; Thomas, P.Q.

2004-01-01

INTRODUCTION: Array comparative genomic hybridisation (array CGH) is a powerful method that detects alteration of gene copy number with greater resolution and efficiency than traditional methods. However, its ability to detect disease causing duplications in constitutional genomic DNA has not been

Genome duplication and mutations in ACE2 cause multicellular, fast-sedimenting phenotypes in evolved Saccharomyces cerevisiae.

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Oud, Bart; Guadalupe-Medina, Victor; Nijkamp, Jurgen F; de Ridder, Dick; Pronk, Jack T; van Maris, Antonius J A; Daran, Jean-Marc

2013-11-05

Laboratory evolution of the yeast Saccharomyces cerevisiae in bioreactor batch cultures yielded variants that grow as multicellular, fast-sedimenting clusters. Knowledge of the molecular basis of this phenomenon may contribute to the understanding of natural evolution of multicellularity and to manipulating cell sedimentation in laboratory and industrial applications of S. cerevisiae. Multicellular, fast-sedimenting lineages obtained from a haploid S. cerevisiae strain in two independent evolution experiments were analyzed by whole genome resequencing. The two evolved cell lines showed different frameshift mutations in a stretch of eight adenosines in ACE2, which encodes a transcriptional regulator involved in cell cycle control and mother-daughter cell separation. Introduction of the two ace2 mutant alleles into the haploid parental strain led to slow-sedimenting cell clusters that consisted of just a few cells, thus representing only a partial reconstruction of the evolved phenotype. In addition to single-nucleotide mutations, a whole-genome duplication event had occurred in both evolved multicellular strains. Construction of a diploid reference strain with two mutant ace2 alleles led to complete reconstruction of the multicellular-fast sedimenting phenotype. This study shows that whole-genome duplication and a frameshift mutation in ACE2 are sufficient to generate a fast-sedimenting, multicellular phenotype in S. cerevisiae. The nature of the ace2 mutations and their occurrence in two independent evolution experiments encompassing fewer than 500 generations of selective growth suggest that switching between unicellular and multicellular phenotypes may be relevant for competitiveness of S. cerevisiae in natural environments.

Signals of historical interlocus gene conversion in human segmental duplications.

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Beth L Dumont

Full Text Available Standard methods of DNA sequence analysis assume that sequences evolve independently, yet this assumption may not be appropriate for segmental duplications that exchange variants via interlocus gene conversion (IGC. Here, we use high quality multiple sequence alignments from well-annotated segmental duplications to systematically identify IGC signals in the human reference genome. Our analysis combines two complementary methods: (i a paralog quartet method that uses DNA sequence simulations to identify a statistical excess of sites consistent with inter-paralog exchange, and (ii the alignment-based method implemented in the GENECONV program. One-quarter (25.4% of the paralog families in our analysis harbor clear IGC signals by the quartet approach. Using GENECONV, we identify 1477 gene conversion tracks that cumulatively span 1.54 Mb of the genome. Our analyses confirm the previously reported high rates of IGC in subtelomeric regions and Y-chromosome palindromes, and identify multiple novel IGC hotspots, including the pregnancy specific glycoproteins and the neuroblastoma breakpoint gene families. Although the duplication history of a paralog family is described by a single tree, we show that IGC has introduced incredible site-to-site variation in the evolutionary relationships among paralogs in the human genome. Our findings indicate that IGC has left significant footprints in patterns of sequence diversity across segmental duplications in the human genome, out-pacing the contributions of single base mutation by orders of magnitude. Collectively, the IGC signals we report comprise a catalog that will provide a critical reference for interpreting observed patterns of DNA sequence variation across duplicated genomic regions, including targets of recent adaptive evolution in humans.

Recombination and evolution of duplicate control regions in the mitochondrial genome of the Asian big-headed turtle, Platysternon megacephalum.

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Chenfei Zheng

Full Text Available Complete mitochondrial (mt genome sequences with duplicate control regions (CRs have been detected in various animal species. In Testudines, duplicate mtCRs have been reported in the mtDNA of the Asian big-headed turtle, Platysternon megacephalum, which has three living subspecies. However, the evolutionary pattern of these CRs remains unclear. In this study, we report the completed sequences of duplicate CRs from 20 individuals belonging to three subspecies of this turtle and discuss the micro-evolutionary analysis of the evolution of duplicate CRs. Genetic distances calculated with MEGA 4.1 using the complete duplicate CR sequences revealed that within turtle subspecies, genetic distances between orthologous copies from different individuals were 0.63% for CR1 and 1.2% for CR2app:addword:respectively, and the average distance between paralogous copies of CR1 and CR2 was 4.8%. Phylogenetic relationships were reconstructed from the CR sequences, excluding the variable number of tandem repeats (VNTRs at the 3' end using three methods: neighbor-joining, maximum likelihood algorithm, and Bayesian inference. These data show that any two CRs within individuals were more genetically distant from orthologous genes in different individuals within the same subspecies. This suggests independent evolution of the two mtCRs within each P. megacephalum subspecies. Reconstruction of separate phylogenetic trees using different CR components (TAS, CD, CSB, and VNTRs suggested the role of recombination in the evolution of duplicate CRs. Consequently, recombination events were detected using RDP software with break points at ≈290 bp and ≈1,080 bp. Based on these results, we hypothesize that duplicate CRs in P. megacephalum originated from heterological ancestral recombination of mtDNA. Subsequent recombination could have resulted in homogenization during independent evolutionary events, thus maintaining the functions of duplicate CRs in the mtDNA of P

Molecular cytogenetic differentiation of paralogs of Hox paralogs in duplicated and re-diploidized genome of the North American paddlefish (Polyodon spathula)

Czech Academy of Sciences Publication Activity Database

Symonová, Radka; Havelka, M.; Amemiya, C. T.; Howell, M. W.; Kořínková, Tereza; Flajšhans, M.; Gela, D.; Ráb, Petr

2017-01-01

Roč. 18, č. 1 (2017), č. článku 19. ISSN 1471-2156 R&D Projects: GA ČR GA14-02940S; GA MŠk EF15_003/0000460 Institutional support: RVO:67985904 Keywords : hoxA/D paralogs mapping * sturgeon whole genome duplication * ancient fish genome * rediploidization Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Genetics and heredity (medical genetics to be 3) Impact factor: 2.266, year: 2016

Age distribution of human gene families shows significant roles of both large- and small-scale duplications in vertebrate evolution.

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Gu, Xun; Wang, Yufeng; Gu, Jianying

2002-06-01

The classical (two-round) hypothesis of vertebrate genome duplication proposes two successive whole-genome duplication(s) (polyploidizations) predating the origin of fishes, a view now being seriously challenged. As the debate largely concerns the relative merits of the 'big-bang mode' theory (large-scale duplication) and the 'continuous mode' theory (constant creation by small-scale duplications), we tested whether a significant proportion of paralogous genes in the contemporary human genome was indeed generated in the early stage of vertebrate evolution. After an extensive search of major databases, we dated 1,739 gene duplication events from the phylogenetic analysis of 749 vertebrate gene families. We found a pattern characterized by two waves (I, II) and an ancient component. Wave I represents a recent gene family expansion by tandem or segmental duplications, whereas wave II, a rapid paralogous gene increase in the early stage of vertebrate evolution, supports the idea of genome duplication(s) (the big-bang mode). Further analysis indicated that large- and small-scale gene duplications both make a significant contribution during the early stage of vertebrate evolution to build the current hierarchy of the human proteome.

Balanced gene losses, duplications and intensive rearrangements led to an unusual regularly sized genome in Arbutus unedo chloroplasts.

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Martínez-Alberola, Fernando; Del Campo, Eva M; Lázaro-Gimeno, David; Mezquita-Claramonte, Sergio; Molins, Arantxa; Mateu-Andrés, Isabel; Pedrola-Monfort, Joan; Casano, Leonardo M; Barreno, Eva

2013-01-01

Completely sequenced plastomes provide a valuable source of information about the duplication, loss, and transfer events of chloroplast genes and phylogenetic data for resolving relationships among major groups of plants. Moreover, they can also be useful for exploiting chloroplast genetic engineering technology. Ericales account for approximately six per cent of eudicot diversity with 11,545 species from which only three complete plastome sequences are currently available. With the aim of increasing the number of ericalean complete plastome sequences, and to open new perspectives in understanding Mediterranean plant adaptations, a genomic study on the basis of the complete chloroplast genome sequencing of Arbutus unedo and an updated phylogenomic analysis of Asteridae was implemented. The chloroplast genome of A. unedo shows extensive rearrangements but a medium size (150,897 nt) in comparison to most of angiosperms. A number of remarkable distinct features characterize the plastome of A. unedo: five-fold dismissing of the SSC region in relation to most angiosperms; complete loss or pseudogenization of a number of essential genes; duplication of the ndhH-D operon and its location within the two IRs; presence of large tandem repeats located near highly re-arranged regions and pseudogenes. All these features outline the primary evolutionary split between Ericaceae and other ericalean families. The newly sequenced plastome of A. unedo with the available asterid sequences allowed the resolution of some uncertainties in previous phylogenies of Asteridae.

Balanced gene losses, duplications and intensive rearrangements led to an unusual regularly sized genome in Arbutus unedo chloroplasts.

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Fernando Martínez-Alberola

Full Text Available Completely sequenced plastomes provide a valuable source of information about the duplication, loss, and transfer events of chloroplast genes and phylogenetic data for resolving relationships among major groups of plants. Moreover, they can also be useful for exploiting chloroplast genetic engineering technology. Ericales account for approximately six per cent of eudicot diversity with 11,545 species from which only three complete plastome sequences are currently available. With the aim of increasing the number of ericalean complete plastome sequences, and to open new perspectives in understanding Mediterranean plant adaptations, a genomic study on the basis of the complete chloroplast genome sequencing of Arbutus unedo and an updated phylogenomic analysis of Asteridae was implemented. The chloroplast genome of A. unedo shows extensive rearrangements but a medium size (150,897 nt in comparison to most of angiosperms. A number of remarkable distinct features characterize the plastome of A. unedo: five-fold dismissing of the SSC region in relation to most angiosperms; complete loss or pseudogenization of a number of essential genes; duplication of the ndhH-D operon and its location within the two IRs; presence of large tandem repeats located near highly re-arranged regions and pseudogenes. All these features outline the primary evolutionary split between Ericaceae and other ericalean families. The newly sequenced plastome of A. unedo with the available asterid sequences allowed the resolution of some uncertainties in previous phylogenies of Asteridae.

Gene duplication as a major force in evolution

Indian Academy of Sciences (India)

Based on whole-genome analysis of Arabidopsis thaliana, there is compelling evidence that angiosperms underwent two whole-genome duplication events early during their evolutionary history. Recent studies have shown that these events were crucial for creation of many important developmental and regulatory genes ...

Expansion of banana (Musa acuminata) gene families involved in ethylene biosynthesis and signalling after lineage-specific whole-genome duplications.

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Jourda, Cyril; Cardi, Céline; Mbéguié-A-Mbéguié, Didier; Bocs, Stéphanie; Garsmeur, Olivier; D'Hont, Angélique; Yahiaoui, Nabila

2014-05-01

Whole-genome duplications (WGDs) are widespread in plants, and three lineage-specific WGDs occurred in the banana (Musa acuminata) genome. Here, we analysed the impact of WGDs on the evolution of banana gene families involved in ethylene biosynthesis and signalling, a key pathway for banana fruit ripening. Banana ethylene pathway genes were identified using comparative genomics approaches and their duplication modes and expression profiles were analysed. Seven out of 10 banana ethylene gene families evolved through WGD and four of them (1-aminocyclopropane-1-carboxylate synthase (ACS), ethylene-insensitive 3-like (EIL), ethylene-insensitive 3-binding F-box (EBF) and ethylene response factor (ERF)) were preferentially retained. Banana orthologues of AtEIN3 and AtEIL1, two major genes for ethylene signalling in Arabidopsis, were particularly expanded. This expansion was paralleled by that of EBF genes which are responsible for control of EIL protein levels. Gene expression profiles in banana fruits suggested functional redundancy for several MaEBF and MaEIL genes derived from WGD and subfunctionalization for some of them. We propose that EIL and EBF genes were co-retained after WGD in banana to maintain balanced control of EIL protein levels and thus avoid detrimental effects of constitutive ethylene signalling. In the course of evolution, subfunctionalization was favoured to promote finer control of ethylene signalling. © 2014 CIRAD New Phytologist © 2014 New Phytologist Trust.

Spotting and validation of a genome wide oligonucleotide chip with duplicate measurement of each gene

International Nuclear Information System (INIS)

Thomassen, Mads; Skov, Vibe; Eiriksdottir, Freyja; Tan, Qihua; Jochumsen, Kirsten; Fritzner, Niels; Brusgaard, Klaus; Dahlgaard, Jesper; Kruse, Torben A.

2006-01-01

The quality of DNA microarray based gene expression data relies on the reproducibility of several steps in a microarray experiment. We have developed a spotted genome wide microarray chip with oligonucleotides printed in duplicate in order to minimise undesirable biases, thereby optimising detection of true differential expression. The validation study design consisted of an assessment of the microarray chip performance using the MessageAmp and FairPlay labelling kits. Intraclass correlation coefficient (ICC) was used to demonstrate that MessageAmp was significantly more reproducible than FairPlay. Further examinations with MessageAmp revealed the applicability of the system. The linear range of the chips was three orders of magnitude, the precision was high, as 95% of measurements deviated less than 1.24-fold from the expected value, and the coefficient of variation for relative expression was 13.6%. Relative quantitation was more reproducible than absolute quantitation and substantial reduction of variance was attained with duplicate spotting. An analysis of variance (ANOVA) demonstrated no significant day-to-day variation

Evolution of Cis-Regulatory Elements and Regulatory Networks in Duplicated Genes of Arabidopsis.

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Arsovski, Andrej A; Pradinuk, Julian; Guo, Xu Qiu; Wang, Sishuo; Adams, Keith L

2015-12-01

Plant genomes contain large numbers of duplicated genes that contribute to the evolution of new functions. Following duplication, genes can exhibit divergence in their coding sequence and their expression patterns. Changes in the cis-regulatory element landscape can result in changes in gene expression patterns. High-throughput methods developed recently can identify potential cis-regulatory elements on a genome-wide scale. Here, we use a recent comprehensive data set of DNase I sequencing-identified cis-regulatory binding sites (footprints) at single-base-pair resolution to compare binding sites and network connectivity in duplicated gene pairs in Arabidopsis (Arabidopsis thaliana). We found that duplicated gene pairs vary greatly in their cis-regulatory element architecture, resulting in changes in regulatory network connectivity. Whole-genome duplicates (WGDs) have approximately twice as many footprints in their promoters left by potential regulatory proteins than do tandem duplicates (TDs). The WGDs have a greater average number of footprint differences between paralogs than TDs. The footprints, in turn, result in more regulatory network connections between WGDs and other genes, forming denser, more complex regulatory networks than shown by TDs. When comparing regulatory connections between duplicates, WGDs had more pairs in which the two genes are either partially or fully diverged in their network connections, but fewer genes with no network connections than the TDs. There is evidence of younger TDs and WGDs having fewer unique connections compared with older duplicates. This study provides insights into cis-regulatory element evolution and network divergence in duplicated genes. © 2015 American Society of Plant Biologists. All Rights Reserved.

Molecular genetic features of polyploidization and aneuploidization reveal unique patterns for genome duplication in diploid Malus.

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Michael J Considine

Full Text Available Polyploidization results in genome duplication and is an important step in evolution and speciation. The Malus genome confirmed that this genus was derived through auto-polyploidization, yet the genetic and meiotic mechanisms for polyploidization, particularly for aneuploidization, are unclear in this genus or other woody perennials. In fact the contribution of aneuploidization remains poorly understood throughout Plantae. We add to this knowledge by characterization of eupolyploidization and aneuploidization in 27,542 F₁ seedlings from seven diploid Malus populations using cytology and microsatellite markers. We provide the first evidence that aneuploidy exceeds eupolyploidy in the diploid crosses, suggesting aneuploidization is a leading cause of genome duplication. Gametes from diploid Malus had a unique combinational pattern; ova preserved euploidy exclusively, while spermatozoa presented both euploidy and aneuploidy. All non-reduced gametes were genetically heterozygous, indicating first-division restitution was the exclusive mode for Malus eupolyploidization and aneuploidization. Chromosome segregation pattern among aneuploids was non-uniform, however, certain chromosomes were associated for aneuploidization. This study is the first to provide molecular evidence for the contribution of heterozygous non-reduced gametes to fitness in polyploids and aneuploids. Aneuploidization can increase, while eupolyploidization may decrease genetic diversity in their newly established populations. Auto-triploidization is important for speciation in the extant Malus. The features of Malus polyploidization confer genetic stability and diversity, and present heterozygosity, heterosis and adaptability for evolutionary selection. A protocol using co-dominant markers was proposed for accelerating apple triploid breeding program. A path was postulated for evolution of numerically odd basic chromosomes. The model for Malus derivation was considerably revised

Molecular genetic features of polyploidization and aneuploidization reveal unique patterns for genome duplication in diploid Malus.

Science.gov (United States)

Considine, Michael J; Wan, Yizhen; D'Antuono, Mario F; Zhou, Qian; Han, Mingyu; Gao, Hua; Wang, Man

2012-01-01

Polyploidization results in genome duplication and is an important step in evolution and speciation. The Malus genome confirmed that this genus was derived through auto-polyploidization, yet the genetic and meiotic mechanisms for polyploidization, particularly for aneuploidization, are unclear in this genus or other woody perennials. In fact the contribution of aneuploidization remains poorly understood throughout Plantae. We add to this knowledge by characterization of eupolyploidization and aneuploidization in 27,542 F₁ seedlings from seven diploid Malus populations using cytology and microsatellite markers. We provide the first evidence that aneuploidy exceeds eupolyploidy in the diploid crosses, suggesting aneuploidization is a leading cause of genome duplication. Gametes from diploid Malus had a unique combinational pattern; ova preserved euploidy exclusively, while spermatozoa presented both euploidy and aneuploidy. All non-reduced gametes were genetically heterozygous, indicating first-division restitution was the exclusive mode for Malus eupolyploidization and aneuploidization. Chromosome segregation pattern among aneuploids was non-uniform, however, certain chromosomes were associated for aneuploidization. This study is the first to provide molecular evidence for the contribution of heterozygous non-reduced gametes to fitness in polyploids and aneuploids. Aneuploidization can increase, while eupolyploidization may decrease genetic diversity in their newly established populations. Auto-triploidization is important for speciation in the extant Malus. The features of Malus polyploidization confer genetic stability and diversity, and present heterozygosity, heterosis and adaptability for evolutionary selection. A protocol using co-dominant markers was proposed for accelerating apple triploid breeding program. A path was postulated for evolution of numerically odd basic chromosomes. The model for Malus derivation was considerably revised. Impacts of

Genetic Competence Drives Genome Diversity in Bacillus subtilis

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Chevreux, Bastien; Serra, Cláudia R; Schyns, Ghislain; Henriques, Adriano O

2018-01-01

Abstract Prokaryote genomes are the result of a dynamic flux of genes, with increases achieved via horizontal gene transfer and reductions occurring through gene loss. The ecological and selective forces that drive this genomic flexibility vary across species. Bacillus subtilis is a naturally competent bacterium that occupies various environments, including plant-associated, soil, and marine niches, and the gut of both invertebrates and vertebrates. Here, we quantify the genomic diversity of B. subtilis and infer the genome dynamics that explain the high genetic and phenotypic diversity observed. Phylogenomic and comparative genomic analyses of 42 B. subtilis genomes uncover a remarkable genome diversity that translates into a core genome of 1,659 genes and an asymptotic pangenome growth rate of 57 new genes per new genome added. This diversity is due to a large proportion of low-frequency genes that are acquired from closely related species. We find no gene-loss bias among wild isolates, which explains why the cloud genome, 43% of the species pangenome, represents only a small proportion of each genome. We show that B. subtilis can acquire xenologous copies of core genes that propagate laterally among strains within a niche. While not excluding the contributions of other mechanisms, our results strongly suggest a process of gene acquisition that is largely driven by competence, where the long-term maintenance of acquired genes depends on local and global fitness effects. This competence-driven genomic diversity provides B. subtilis with its generalist character, enabling it to occupy a wide range of ecological niches and cycle through them. PMID:29272410

Differential retention of metabolic genes following whole-genome duplication.

Science.gov (United States)

Gout, Jean-François; Duret, Laurent; Kahn, Daniel

2009-05-01

Classical studies in Metabolic Control Theory have shown that metabolic fluxes usually exhibit little sensitivity to changes in individual enzyme activity, yet remain sensitive to global changes of all enzymes in a pathway. Therefore, little selective pressure is expected on the dosage or expression of individual metabolic genes, yet entire pathways should still be constrained. However, a direct estimate of this selective pressure had not been evaluated. Whole-genome duplications (WGDs) offer a good opportunity to address this question by analyzing the fates of metabolic genes during the massive gene losses that follow. Here, we take advantage of the successive rounds of WGD that occurred in the Paramecium lineage. We show that metabolic genes exhibit different gene retention patterns than nonmetabolic genes. Contrary to what was expected for individual genes, metabolic genes appeared more retained than other genes after the recent WGD, which was best explained by selection for gene expression operating on entire pathways. Metabolic genes also tend to be less retained when present at high copy number before WGD, contrary to other genes that show a positive correlation between gene retention and preduplication copy number. This is rationalized on the basis of the classical concave relationship relating metabolic fluxes with enzyme expression.

FUNCTIONAL SPECIALIZATION OF DUPLICATED FLAVONOID BIOSYNTHESIS GENES IN WHEAT

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Khlestkina E.

2012-08-01

Full Text Available Gene duplication followed by subfunctionalization and neofunctionalization is of a great evolutionary importance. In plant genomes, duplicated genes may result from either polyploidization (homoeologous genes or segmental chromosome duplications (paralogous genes. In allohexaploid wheat Triticum aestivum L. (2n=6x=42, genome BBAADD, both homoeologous and paralogous copies were found for the regulatory gene Myc encoding MYC-like transcriptional factor in the biosynthesis of flavonoid pigments, anthocyanins, and for the structural gene F3h encoding one of the key enzymes of flavonoid biosynthesis, flavanone 3-hydroxylase. From the 5 copies (3 homoeologous and 2 paralogous of the Myc gene found in T. aestivum, only one plays a regulatory role in anthocyanin biosynthesis, interacting complementary with another transcriptional factor (MYB-like to confer purple pigmentation of grain pericarp in wheat. The role and functionality of the other 4 copies of the Myc gene remain unknown. From the 4 functional copies of the F3h gene in T. aestivum, three homoeologues have similar function. They are expressed in wheat organs colored with anthocyanins or in the endosperm, participating there in biosynthesis of uncolored flavonoid substances. The fourth copy (the B-genomic paralogue is transcribed neither in wheat organs colored with anthocyanins nor in seeds, however, it’s expression has been noticed in roots of aluminium-stressed plants, where the three homoeologous copies are not active. Functional diversification of the duplicated flavonoid biosynthesis genes in wheat may be a reason for maintenance of the duplicated copies and preventing them from pseudogenization.The study was supported by RFBR (11-04-92707. We also thank Ms. Galina Generalova for technical assistance.

Multiple independent origins of mitochondrial control region duplications in the order Psittaciformes

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Schirtzinger, Erin E.; Tavares, Erika S.; Gonzales, Lauren A.; Eberhard, Jessica R.; Miyaki, Cristina Y.; Sanchez, Juan J.; Hernandez, Alexis; Müeller, Heinrich; Graves, Gary R.; Fleischer, Robert C.; Wright, Timothy F.

2012-01-01

Mitochondrial genomes are generally thought to be under selection for compactness, due to their small size, consistent gene content, and a lack of introns or intergenic spacers. As more animal mitochondrial genomes are fully sequenced, rearrangements and partial duplications are being identified with increasing frequency, particularly in birds (Class Aves). In this study, we investigate the evolutionary history of mitochondrial control region states within the avian order Psittaciformes (parrots and cockatoos). To this aim, we reconstructed a comprehensive multi-locus phylogeny of parrots, used PCR of three diagnostic fragments to classify the mitochondrial control region state as single or duplicated, and mapped these states onto the phylogeny. We further sequenced 44 selected species to validate these inferences of control region state. Ancestral state reconstruction using a range of weighting schemes identified six independent origins of mitochondrial control region duplications within Psittaciformes. Analysis of sequence data showed that varying levels of mitochondrial gene and tRNA homology and degradation were present within a given clade exhibiting duplications. Levels of divergence between control regions within an individual varied from 0–10.9% with the differences occurring mainly between 51 and 225 nucleotides 3′ of the goose hairpin in domain I. Further investigations into the fates of duplicated mitochondrial genes, the potential costs and benefits of having a second control region, and the complex relationship between evolutionary rates, selection, and time since duplication are needed to fully explain these patterns in the mitochondrial genome. PMID:22543055

The roles of segmental and tandem gene duplication in the evolution of large gene families in Arabidopsis thaliana

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Baumgarten Andrew

2004-06-01

Full Text Available Abstract Background Most genes in Arabidopsis thaliana are members of gene families. How do the members of gene families arise, and how are gene family copy numbers maintained? Some gene families may evolve primarily through tandem duplication and high rates of birth and death in clusters, and others through infrequent polyploidy or large-scale segmental duplications and subsequent losses. Results Our approach to understanding the mechanisms of gene family evolution was to construct phylogenies for 50 large gene families in Arabidopsis thaliana, identify large internal segmental duplications in Arabidopsis, map gene duplications onto the segmental duplications, and use this information to identify which nodes in each phylogeny arose due to segmental or tandem duplication. Examples of six gene families exemplifying characteristic modes are described. Distributions of gene family sizes and patterns of duplication by genomic distance are also described in order to characterize patterns of local duplication and copy number for large gene families. Both gene family size and duplication by distance closely follow power-law distributions. Conclusions Combining information about genomic segmental duplications, gene family phylogenies, and gene positions provides a method to evaluate contributions of tandem duplication and segmental genome duplication in the generation and maintenance of gene families. These differences appear to correspond meaningfully to differences in functional roles of the members of the gene families.

Circular DNA Intermediate in the Duplication of Nile Tilapia vasa Genes

Science.gov (United States)

Fujimura, Koji; Conte, Matthew A.; Kocher, Thomas D.

2011-01-01

vasa is a highly conserved RNA helicase involved in animal germ cell development. Among vertebrate species, it is typically present as a single copy per genome. Here we report the isolation and sequencing of BAC clones for Nile tilapia vasa genes. Contrary to a previous report that Nile tilapia have a single copy of the vasa gene, we find evidence for at least three vasa gene loci. The vasa gene locus was duplicated from the original site and integrated into two distant novel sites. For one of these insertions we find evidence that the duplication was mediated by a circular DNA intermediate. This mechanism of gene duplication may explain the origin of isolated gene duplicates during the evolution of fish genomes. These data provide a foundation for studying the role of multiple vasa genes in the development of tilapia gonads, and will contribute to investigations of the molecular mechanisms of sex determination and evolution in cichlid fishes. PMID:22216289

Effect of Duplicate Genes on Mouse Genetic Robustness: An Update

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Zhixi Su

2014-01-01

Full Text Available In contrast to S. cerevisiae and C. elegans, analyses based on the current knockout (KO mouse phenotypes led to the conclusion that duplicate genes had almost no role in mouse genetic robustness. It has been suggested that the bias of mouse KO database toward ancient duplicates may possibly cause this knockout duplicate puzzle, that is, a very similar proportion of essential genes (PE between duplicate genes and singletons. In this paper, we conducted an extensive and careful analysis for the mouse KO phenotype data and corroborated a strong effect of duplicate genes on mouse genetics robustness. Moreover, the effect of duplicate genes on mouse genetic robustness is duplication-age dependent, which holds after ruling out the potential confounding effect from coding-sequence conservation, protein-protein connectivity, functional bias, or the bias of duplicates generated by whole genome duplication (WGD. Our findings suggest that two factors, the sampling bias toward ancient duplicates and very ancient duplicates with a proportion of essential genes higher than that of singletons, have caused the mouse knockout duplicate puzzle; meanwhile, the effect of genetic buffering may be correlated with sequence conservation as well as protein-protein interactivity.

Recurrent duplications of 17q12 associated with variable phenotypes

DEFF Research Database (Denmark)

Mitchell, Elyse; Douglas, Andrew; Kjaegaard, Susanne

2015-01-01

The ability to identify the clinical nature of the recurrent duplication of chromosome 17q12 has been limited by its rarity and the diverse range of phenotypes associated with this genomic change. In order to further define the clinical features of affected patients, detailed clinical information......, potentially contributory copy number changes in a subset of patients, including one patient each with 16p11.2 deletion and 15q13.3 deletion. Our data further define and expand the clinical spectrum associated with duplications of 17q12 and provide support for the role of genomic modifiers contributing...... to phenotypic variability....

Independent Origin and Global Distribution of Distinct Plasmodium vivax Duffy Binding Protein Gene Duplications.

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Jessica B Hostetler

2016-10-01

Full Text Available Plasmodium vivax causes the majority of malaria episodes outside Africa, but remains a relatively understudied pathogen. The pathology of P. vivax infection depends critically on the parasite's ability to recognize and invade human erythrocytes. This invasion process involves an interaction between P. vivax Duffy Binding Protein (PvDBP in merozoites and the Duffy antigen receptor for chemokines (DARC on the erythrocyte surface. Whole-genome sequencing of clinical isolates recently established that some P. vivax genomes contain two copies of the PvDBP gene. The frequency of this duplication is particularly high in Madagascar, where there is also evidence for P. vivax infection in DARC-negative individuals. The functional significance and global prevalence of this duplication, and whether there are other copy number variations at the PvDBP locus, is unknown.Using whole-genome sequencing and PCR to study the PvDBP locus in P. vivax clinical isolates, we found that PvDBP duplication is widespread in Cambodia. The boundaries of the Cambodian PvDBP duplication differ from those previously identified in Madagascar, meaning that current molecular assays were unable to detect it. The Cambodian PvDBP duplication did not associate with parasite density or DARC genotype, and ranged in prevalence from 20% to 38% over four annual transmission seasons in Cambodia. This duplication was also present in P. vivax isolates from Brazil and Ethiopia, but not India.PvDBP duplications are much more widespread and complex than previously thought, and at least two distinct duplications are circulating globally. The same duplication boundaries were identified in parasites from three continents, and were found at high prevalence in human populations where DARC-negativity is essentially absent. It is therefore unlikely that PvDBP duplication is associated with infection of DARC-negative individuals, but functional tests will be required to confirm this hypothesis.

Phylogenetic detection of numerous gene duplications shared by animals, fungi and plants

OpenAIRE

Zhou, Xiaofan; Lin, Zhenguo; Ma, Hong

2010-01-01

Background Gene duplication is considered a major driving force for evolution of genetic novelty, thereby facilitating functional divergence and organismal diversity, including the process of speciation. Animals, fungi and plants are major eukaryotic kingdoms and the divergences between them are some of the most significant evolutionary events. Although gene duplications in each lineage have been studied extensively in various contexts, the extent of gene duplication prior to the split of pla...

Sorting cancer karyotypes using double-cut-and-joins, duplications and deletions.

Science.gov (United States)

Zeira, Ron; Shamir, Ron

2018-05-03

Problems of genome rearrangement are central in both evolution and cancer research. Most genome rearrangement models assume that the genome contains a single copy of each gene and the only changes in the genome are structural, i.e., reordering of segments. In contrast, tumor genomes also undergo numerical changes such as deletions and duplications, and thus the number of copies of genes varies. Dealing with unequal gene content is a very challenging task, addressed by few algorithms to date. More realistic models are needed to help trace genome evolution during tumorigenesis. Here we present a model for the evolution of genomes with multiple gene copies using the operation types double-cut-and-joins, duplications and deletions. The events supported by the model are reversals, translocations, tandem duplications, segmental deletions, and chromosomal amplifications and deletions, covering most types of structural and numerical changes observed in tumor samples. Our goal is to find a series of operations of minimum length that transform one karyotype into the other. We show that the problem is NP-hard and give an integer linear programming formulation that solves the problem exactly under some mild assumptions. We test our method on simulated genomes and on ovarian cancer genomes. Our study advances the state of the art in two ways: It allows a broader set of operations than extant models, thus being more realistic, and it is the first study attempting to reconstruct the full sequence of structural and numerical events during cancer evolution. Code and data are available in https://github.com/Shamir-Lab/Sorting-Cancer-Karyotypes. ronzeira@post.tau.ac.il, rshamir@tau.ac.il. Supplementary data are available at Bioinformatics online.

Early vertebrate chromosome duplications and the evolution of the neuropeptide Y receptor gene regions

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Brenner Sydney

2008-06-01

Full Text Available Abstract Background One of the many gene families that expanded in early vertebrate evolution is the neuropeptide (NPY receptor family of G-protein coupled receptors. Earlier work by our lab suggested that several of the NPY receptor genes found in extant vertebrates resulted from two genome duplications before the origin of jawed vertebrates (gnathostomes and one additional genome duplication in the actinopterygian lineage, based on their location on chromosomes sharing several gene families. In this study we have investigated, in five vertebrate genomes, 45 gene families with members close to the NPY receptor genes in the compact genomes of the teleost fishes Tetraodon nigroviridis and Takifugu rubripes. These correspond to Homo sapiens chromosomes 4, 5, 8 and 10. Results Chromosome regions with conserved synteny were identified and confirmed by phylogenetic analyses in H. sapiens, M. musculus, D. rerio, T. rubripes and T. nigroviridis. 26 gene families, including the NPY receptor genes, (plus 3 described recently by other labs showed a tree topology consistent with duplications in early vertebrate evolution and in the actinopterygian lineage, thereby supporting expansion through block duplications. Eight gene families had complications that precluded analysis (such as short sequence length or variable number of repeated domains and another eight families did not support block duplications (because the paralogs in these families seem to have originated in another time window than the proposed genome duplication events. RT-PCR carried out with several tissues in T. rubripes revealed that all five NPY receptors were expressed in the brain and subtypes Y2, Y4 and Y8 were also expressed in peripheral organs. Conclusion We conclude that the phylogenetic analyses and chromosomal locations of these gene families support duplications of large blocks of genes or even entire chromosomes. Thus, these results are consistent with two early vertebrate

Positive Selection Driving Cytoplasmic Genome Evolution of the Medicinally Important Ginseng Plant Genus Panax.

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Jiang, Peng; Shi, Feng-Xue; Li, Ming-Rui; Liu, Bao; Wen, Jun; Xiao, Hong-Xing; Li, Lin-Feng

2018-01-01

Panax L. (the ginseng genus) is a shade-demanding group within the family Araliaceae and all of its species are of crucial significance in traditional Chinese medicine. Phylogenetic and biogeographic analyses demonstrated that two rounds of whole genome duplications accompanying with geographic and ecological isolations promoted the diversification of Panax species. However, contributions of the cytoplasmic genomes to the adaptive evolution of Panax species remained largely uninvestigated. In this study, we sequenced the chloroplast and mitochondrial genomes of 11 accessions belonging to seven Panax species. Our results show that heterogeneity in nucleotide substitution rate is abundant in both of the two cytoplasmic genomes, with the mitochondrial genome possessing more variants at the total level but the chloroplast showing higher sequence polymorphisms at the genic regions. Genome-wide scanning of positive selection identified five and 12 genes from the chloroplast and mitochondrial genomes, respectively. Functional analyses further revealed that these selected genes play important roles in plant development, cellular metabolism and adaptation. We therefore conclude that positive selection might be one of the potential evolutionary forces that shaped nucleotide variation pattern of these Panax species. In particular, the mitochondrial genes evolved under stronger selective pressure compared to the chloroplast genes.

Divergence of recently duplicated M{gamma}-type MADS-box genes in Petunia.

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Bemer, Marian; Gordon, Jonathan; Weterings, Koen; Angenent, Gerco C

2010-02-01

The MADS-box transcription factor family has expanded considerably in plants via gene and genome duplications and can be subdivided into type I and MIKC-type genes. The two gene classes show a different evolutionary history. Whereas the MIKC-type genes originated during ancient genome duplications, as well as during more recent events, the type I loci appear to experience high turnover with many recent duplications. This different mode of origin also suggests a different fate for the type I duplicates, which are thought to have a higher chance to become silenced or lost from the genome. To get more insight into the evolution of the type I MADS-box genes, we isolated nine type I genes from Petunia, which belong to the Mgamma subclass, and investigated the divergence of their coding and regulatory regions. The isolated genes could be subdivided into two categories: two genes were highly similar to Arabidopsis Mgamma-type genes, whereas the other seven genes showed less similarity to Arabidopsis genes and originated more recently. Two of the recently duplicated genes were found to contain deleterious mutations in their coding regions, and expression analysis revealed that a third paralog was silenced by mutations in its regulatory region. However, in addition to the three genes that were subjected to nonfunctionalization, we also found evidence for neofunctionalization of one of the Petunia Mgamma-type genes. Our study shows a rapid divergence of recently duplicated Mgamma-type MADS-box genes and suggests that redundancy among type I paralogs may be less common than expected.

Inference of the ancestral vertebrate phenotype through vestiges of the whole-genome duplications.

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Onimaru, Koh; Kuraku, Shigehiro

2018-03-16

Inferring the phenotype of the last common ancestor of living vertebrates is a challenging problem because of several unresolvable factors. They include the lack of reliable out-groups of living vertebrates, poor information about less fossilizable organs and specialized traits of phylogenetically important species, such as lampreys and hagfishes (e.g. secondary loss of vertebrae in adult hagfishes). These factors undermine the reliability of ancestral reconstruction by traditional character mapping approaches based on maximum parsimony. In this article, we formulate an approach to hypothesizing ancestral vertebrate phenotypes using information from the phylogenetic and functional properties of genes duplicated by genome expansions in early vertebrate evolution. We named the conjecture as 'chronological reconstruction of ohnolog functions (CHROF)'. This CHROF conjecture raises the possibility that the last common ancestor of living vertebrates may have had more complex traits than currently thought.

Evolutionary patterns of RNA-based duplication in non-mammalian chordates.

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Ming Chen

Full Text Available The role of RNA-based duplication, or retroposition, in the evolution of new gene functions in mammals, plants, and Drosophila has been widely reported. However, little is known about RNA-based duplication in non-mammalian chordates. In this study, we screened ten non-mammalian chordate genomes for retrocopies and investigated their evolutionary patterns. We identified numerous retrocopies in these species. Examination of the age distribution of these retrocopies revealed no burst of young retrocopies in ancient chordate species. Upon comparing these non-mammalian chordate species to the mammalian species, we observed that a larger fraction of the non-mammalian retrocopies was under strong evolutionary constraints than mammalian retrocopies are, as evidenced by signals of purifying selection and expression profiles. For the Western clawed frog, Medaka, and Sea squirt, many retrogenes have evolved gonad and brain expression patterns, similar to what was observed in human. Testing of retrogene movement in the Medaka genome, where the nascent sex chrosomes have been well assembled, did not reveal any significant gene movement. Taken together, our analyses demonstrate that RNA-based duplication generates many functional genes and can make a significant contribution to the evolution of non-mammalian genomes.

The genomic distribution of intraspecific and interspecific sequence divergence of human segmental duplications relative to human/chimpanzee chromosomal rearrangements

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Eichler Evan E

2008-08-01

Full Text Available Abstract Background It has been suggested that chromosomal rearrangements harbor the molecular footprint of the biological phenomena which they induce, in the form, for instance, of changes in the sequence divergence rates of linked genes. So far, all the studies of these potential associations have focused on the relationship between structural changes and the rates of evolution of single-copy DNA and have tried to exclude segmental duplications (SDs. This is paradoxical, since SDs are one of the primary forces driving the evolution of structure and function in our genomes and have been linked not only with novel genes acquiring new functions, but also with overall higher DNA sequence divergence and major chromosomal rearrangements. Results Here we take the opposite view and focus on SDs. We analyze several of the features of SDs, including the rates of intraspecific divergence between paralogous copies of human SDs and of interspecific divergence between human SDs and chimpanzee DNA. We study how divergence measures relate to chromosomal rearrangements, while considering other factors that affect evolutionary rates in single copy DNA. Conclusion We find that interspecific SD divergence behaves similarly to divergence of single-copy DNA. In contrast, old and recent paralogous copies of SDs do present different patterns of intraspecific divergence. Also, we show that some relatively recent SDs accumulate in regions that carry inversions in sister lineages.

Persistence drives gene clustering in bacterial genomes

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Rocha Eduardo PC

2008-01-01

Full Text Available Abstract Background Gene clustering plays an important role in the organization of the bacterial chromosome and several mechanisms have been proposed to explain its extent. However, the controversies raised about the validity of each of these mechanisms remind us that the cause of this gene organization remains an open question. Models proposed to explain clustering did not take into account the function of the gene products nor the likely presence or absence of a given gene in a genome. However, genomes harbor two very different categories of genes: those genes present in a majority of organisms – persistent genes – and those present in very few organisms – rare genes. Results We show that two classes of genes are significantly clustered in bacterial genomes: the highly persistent and the rare genes. The clustering of rare genes is readily explained by the selfish operon theory. Yet, genes persistently present in bacterial genomes are also clustered and we try to understand why. We propose a model accounting specifically for such clustering, and show that indispensability in a genome with frequent gene deletion and insertion leads to the transient clustering of these genes. The model describes how clusters are created via the gene flux that continuously introduces new genes while deleting others. We then test if known selective processes, such as co-transcription, physical interaction or functional neighborhood, account for the stabilization of these clusters. Conclusion We show that the strong selective pressure acting on the function of persistent genes, in a permanent state of flux of genes in bacterial genomes, maintaining their size fairly constant, that drives persistent genes clustering. A further selective stabilization process might contribute to maintaining the clustering.

Dissecting a hidden gene duplication: the Arabidopsis thaliana SEC10 locus.

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Nemanja Vukašinović

Full Text Available Repetitive sequences present a challenge for genome sequence assembly, and highly similar segmental duplications may disappear from assembled genome sequences. Having found a surprising lack of observable phenotypic deviations and non-Mendelian segregation in Arabidopsis thaliana mutants in SEC10, a gene encoding a core subunit of the exocyst tethering complex, we examined whether this could be explained by a hidden gene duplication. Re-sequencing and manual assembly of the Arabidopsis thaliana SEC10 (At5g12370 locus revealed that this locus, comprising a single gene in the reference genome assembly, indeed contains two paralogous genes in tandem, SEC10a and SEC10b, and that a sequence segment of 7 kb in length is missing from the reference genome sequence. Differences between the two paralogs are concentrated in non-coding regions, while the predicted protein sequences exhibit 99% identity, differing only by substitution of five amino acid residues and an indel of four residues. Both SEC10 genes are expressed, although varying transcript levels suggest differential regulation. Homozygous T-DNA insertion mutants in either paralog exhibit a wild-type phenotype, consistent with proposed extensive functional redundancy of the two genes. By these observations we demonstrate that recently duplicated genes may remain hidden even in well-characterized genomes, such as that of A. thaliana. Moreover, we show that the use of the existing A. thaliana reference genome sequence as a guide for sequence assembly of new Arabidopsis accessions or related species has at least in some cases led to error propagation.

The prevalence of gene duplications and their ancient origin in Rhodobacter sphaeroides 2.4.1

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Cho Hyuk

2010-12-01

Full Text Available Abstract Background Rhodobacter sphaeroides 2.4.1 is a metabolically versatile organism that belongs to α-3 subdivision of Proteobacteria. The present study was to identify the extent, history, and role of gene duplications in R. sphaeroides 2.4.1, an organism that possesses two chromosomes. Results A protein similarity search (BLASTP identified 1247 orfs (~29.4% of the total protein coding orfs that are present in 2 or more copies, 37.5% (234 gene-pairs of which exist in duplicate copies. The distribution of the duplicate gene-pairs in all Clusters of Orthologous Groups (COGs differed significantly when compared to the COG distribution across the whole genome. Location plots revealed clusters of gene duplications that possessed the same COG classification. Phylogenetic analyses were performed to determine a tree topology predicting either a Type-A or Type-B phylogenetic relationship. A Type-A phylogenetic relationship shows that a copy of the protein-pair matches more with an ortholog from a species closely related to R. sphaeroides while a Type-B relationship predicts the highest match between both copies of the R. sphaeroides protein-pair. The results revealed that ~77% of the proteins exhibited a Type-A phylogenetic relationship demonstrating the ancient origin of these gene duplications. Additional analyses on three other strains of R. sphaeroides revealed varying levels of gene loss and retention in these strains. Also, analyses on common gene pairs among the four strains revealed that these genes experience similar functional constraints and undergo purifying selection. Conclusions Although the results suggest that the level of gene duplication in organisms with complex genome structuring (more than one chromosome seems to be not markedly different from that in organisms with only a single chromosome, these duplications may have aided in genome reorganization in this group of eubacteria prior to the formation of R. sphaeroides as gene

Using paleogenomics to study the evolution of gene families: origin and duplication history of the relaxin family hormones and their receptors.

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Sergey Yegorov

Full Text Available Recent progress in the analysis of whole genome sequencing data has resulted in the emergence of paleogenomics, a field devoted to the reconstruction of ancestral genomes. Ancestral karyotype reconstructions have been used primarily to illustrate the dynamic nature of genome evolution. In this paper, we demonstrate how they can also be used to study individual gene families by examining the evolutionary history of relaxin hormones (RLN/INSL and relaxin family peptide receptors (RXFP. Relaxin family hormones are members of the insulin superfamily, and are implicated in the regulation of a variety of primarily reproductive and neuroendocrine processes. Their receptors are G-protein coupled receptors (GPCR's and include members of two distinct evolutionary groups, an unusual characteristic. Although several studies have tried to elucidate the origins of the relaxin peptide family, the evolutionary origin of their receptors and the mechanisms driving the diversification of the RLN/INSL-RXFP signaling systems in non-placental vertebrates has remained elusive. Here we show that the numerous vertebrate RLN/INSL and RXFP genes are products of an ancestral receptor-ligand system that originally consisted of three genes, two of which apparently trace their origins to invertebrates. Subsequently, diversification of the system was driven primarily by whole genome duplications (WGD, 2R and 3R followed by almost complete retention of the ligand duplicates in most vertebrates but massive loss of receptor genes in tetrapods. Interestingly, the majority of 3R duplicates retained in teleosts are potentially involved in neuroendocrine regulation. Furthermore, we infer that the ancestral AncRxfp3/4 receptor may have been syntenically linked to the AncRln-like ligand in the pre-2R genome, and show that syntenic linkages among ligands and receptors have changed dynamically in different lineages. This study ultimately shows the broad utility, with some caveats, of

Characterization of the past and current duplication activities in the human 22q11.2 region

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Morrow Bernice

2011-01-01

Full Text Available Abstract Background Segmental duplications (SDs on 22q11.2 (LCR22, serve as substrates for meiotic non-allelic homologous recombination (NAHR events resulting in several clinically significant genomic disorders. Results To understand the duplication activity leading to the complicated SD structure of this region, we have applied the A-Bruijn graph algorithm to decompose the 22q11.2 SDs to 523 fundamental duplication sequences, termed subunits. Cross-species syntenic analysis of primate genomes demonstrates that many of these LCR22 subunits emerged very recently, especially those implicated in human genomic disorders. Some subunits have expanded more actively than others, and young Alu SINEs, are associated much more frequently with duplicated sequences that have undergone active expansion, confirming their role in mediating recombination events. Many copy number variations (CNVs exist on 22q11.2, some flanked by SDs. Interestingly, two chromosome breakpoints for 13 CNVs (mean length 65 kb are located in paralogous subunits, providing direct evidence that SD subunits could contribute to CNV formation. Sequence analysis of PACs or BACs identified extra CNVs, specifically, 10 insertions and 18 deletions within 22q11.2; four were more than 10 kb in size and most contained young AluYs at their breakpoints. Conclusions Our study indicates that AluYs are implicated in the past and current duplication events, and moreover suggests that DNA rearrangements in 22q11.2 genomic disorders perhaps do not occur randomly but involve both actively expanded duplication subunits and Alu elements.

Ascorbate peroxidase-related (APx-R) is not a duplicable gene.

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Dunand, Christophe; Mathé, Catherine; Lazzarotto, Fernanda; Margis, Rogério; Margis-Pinheiro, Marcia

2011-12-01

Phylogenetic, genomic and functional analyses have allowed the identification of a new class of putative heme peroxidases, so called APx-R (APx-Related). These new class, mainly present in the green lineage (including green algae and land plants), can also be detected in other unicellular chloroplastic organisms. Except for recent polyploid organisms, only single-copy of APx-R gene was detected in each genome, suggesting that the majority of the APx-R extra-copies were lost after chromosomal or segmental duplications. In a similar way, most APx-R co-expressed genes in Arabidopsis genome do not have conserved extra-copies after chromosomal duplications and are predicted to be localized in organelles, as are the APx-R. The member of this gene network can be considered as unique gene, well conserved through the evolution due to a strong negative selection pressure and a low evolution rate. © 2011 Landes Bioscience

The zebrafish maternal-effect gene cellular atoll encodes the centriolar component sas-6 and defects in its paternal function promote whole genome duplication.

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Yabe, Taijiro; Ge, Xiaoyan; Pelegri, Francisco

2007-12-01

A female-sterile zebrafish maternal-effect mutation in cellular atoll (cea) results in defects in the initiation of cell division starting at the second cell division cycle. This phenomenon is caused by defects in centrosome duplication, which in turn affect the formation of a bipolar spindle. We show that cea encodes the centriolar coiled-coil protein Sas-6, and that zebrafish Cea/Sas-6 protein localizes to centrosomes. cea also has a genetic paternal contribution, which when mutated results in an arrested first cell division followed by normal cleavage. Our data supports the idea that, in zebrafish, paternally inherited centrosomes are required for the first cell division while maternally derived factors are required for centrosomal duplication and cell divisions in subsequent cell cycles. DNA synthesis ensues in the absence of centrosome duplication, and the one-cycle delay in the first cell division caused by cea mutant sperm leads to whole genome duplication. We discuss the potential implications of these findings with regards to the origin of polyploidization in animal species. In addition, the uncoupling of developmental time and cell division count caused by the cea mutation suggests the presence of a time window, normally corresponding to the first two cell cycles, which is permissive for germ plasm recruitment.

Teleost Fish-Specific Preferential Retention of Pigmentation Gene-Containing Families After Whole Genome Duplications in Vertebrates

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Lorin, Thibault; Brunet, Frédéric G.; Laudet, Vincent; Volff, Jean-Nicolas

2018-01-01

Vertebrate pigmentation is a highly diverse trait mainly determined by neural crest cell derivatives. It has been suggested that two rounds (1R/2R) of whole-genome duplications (WGDs) at the basis of vertebrates allowed changes in gene regulation associated with neural crest evolution. Subsequently, the teleost fish lineage experienced other WGDs, including the teleost-specific Ts3R before teleost radiation and the more recent Ss4R at the basis of salmonids. As the teleost lineage harbors the highest number of pigment cell types and pigmentation diversity in vertebrates, WGDs might have contributed to the evolution and diversification of the pigmentation gene repertoire in teleosts. We have compared the impact of the basal vertebrate 1R/2R duplications with that of the teleost-specific Ts3R and salmonid-specific Ss4R WGDs on 181 gene families containing genes involved in pigmentation. We show that pigmentation genes (PGs) have been globally more frequently retained as duplicates than other genes after Ts3R and Ss4R but not after the early 1R/2R. This is also true for non-pigmentary paralogs of PGs, suggesting that the function in pigmentation is not the sole key driver of gene retention after WGDs. On the long-term, specific categories of PGs have been repeatedly preferentially retained after ancient 1R/2R and Ts3R WGDs, possibly linked to the molecular nature of their proteins (e.g., DNA binding transcriptional regulators) and their central position in protein-protein interaction networks. Taken together, our results support a major role of WGDs in the diversification of the pigmentation gene repertoire in the teleost lineage, with a possible link with the diversity of pigment cell lineages observed in these animals compared to other vertebrates. PMID:29599177

Yeast "make-accumulate-consume" life strategy evolved as a multi-step process that predates the whole genome duplication.

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Hagman, Arne; Säll, Torbjörn; Compagno, Concetta; Piskur, Jure

2013-01-01

When fruits ripen, microbial communities start a fierce competition for the freely available fruit sugars. Three yeast lineages, including baker's yeast Saccharomyces cerevisiae, have independently developed the metabolic activity to convert simple sugars into ethanol even under fully aerobic conditions. This fermentation capacity, named Crabtree effect, reduces the cell-biomass production but provides in nature a tool to out-compete other microorganisms. Here, we analyzed over forty Saccharomycetaceae yeasts, covering over 200 million years of the evolutionary history, for their carbon metabolism. The experiments were done under strictly controlled and uniform conditions, which has not been done before. We show that the origin of Crabtree effect in Saccharomycetaceae predates the whole genome duplication and became a settled metabolic trait after the split of the S. cerevisiae and Kluyveromyces lineages, and coincided with the origin of modern fruit bearing plants. Our results suggest that ethanol fermentation evolved progressively, involving several successive molecular events that have gradually remodeled the yeast carbon metabolism. While some of the final evolutionary events, like gene duplications of glucose transporters and glycolytic enzymes, have been deduced, the earliest molecular events initiating Crabtree effect are still to be determined.

Conservation, duplication, and loss of the Tor signaling pathway in the fungal kingdom

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Heitman Joseph

2010-09-01

Full Text Available Abstract Background The nutrient-sensing Tor pathway governs cell growth and is conserved in nearly all eukaryotic organisms from unicellular yeasts to multicellular organisms, including humans. Tor is the target of the immunosuppressive drug rapamycin, which in complex with the prolyl isomerase FKBP12 inhibits Tor functions. Rapamycin is a gold standard drug for organ transplant recipients that was approved by the FDA in 1999 and is finding additional clinical indications as a chemotherapeutic and antiproliferative agent. Capitalizing on the plethora of recently sequenced genomes we have conducted comparative genomic studies to annotate the Tor pathway throughout the fungal kingdom and related unicellular opisthokonts, including Monosiga brevicollis, Salpingoeca rosetta, and Capsaspora owczarzaki. Results Interestingly, the Tor signaling cascade is absent in three microsporidian species with available genome sequences, the only known instance of a eukaryotic group lacking this conserved pathway. The microsporidia are obligate intracellular pathogens with highly reduced genomes, and we hypothesize that they lost the Tor pathway as they adapted and streamlined their genomes for intracellular growth in a nutrient-rich environment. Two TOR paralogs are present in several fungal species as a result of either a whole genome duplication or independent gene/segmental duplication events. One such event was identified in the amphibian pathogen Batrachochytrium dendrobatidis, a chytrid responsible for worldwide global amphibian declines and extinctions. Conclusions The repeated independent duplications of the TOR gene in the fungal kingdom might reflect selective pressure acting upon this kinase that populates two proteinaceous complexes with different cellular roles. These comparative genomic analyses illustrate the evolutionary trajectory of a central nutrient-sensing cascade that enables diverse eukaryotic organisms to respond to their natural

Quantitative measure of randomness and order for complete genomes

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Kong, Sing-Guan; Fan, Wen-Lang; Chen, Hong-Da; Wigger, Jan; Torda, Andrew E.; Lee, H. C.

2009-06-01

We propose an order index, ϕ , which gives a quantitative measure of randomness and order of complete genomic sequences. It maps genomes to a number from 0 (random and of infinite length) to 1 (fully ordered) and applies regardless of sequence length. The 786 complete genomic sequences in GenBank were found to have ϕ values in a very narrow range, ϕg=0.031-0.015+0.028 . We show this implies that genomes are halfway toward being completely random, or, at the “edge of chaos.” We further show that artificial “genomes” converted from literary classics have ϕ ’s that almost exactly coincide with ϕg , but sequences of low information content do not. We infer that ϕg represents a high information-capacity “fixed point” in sequence space, and that genomes are driven to it by the dynamics of a robust growth and evolution process. We show that a growth process characterized by random segmental duplication can robustly drive genomes to the fixed point.

Tandemly Arrayed Genes in Vertebrate Genomes

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Deng Pan

2008-01-01

Full Text Available Tandemly arrayed genes (TAGs are duplicated genes that are linked as neighbors on a chromosome, many of which have important physiological and biochemical functions. Here we performed a survey of these genes in 11 available vertebrate genomes. TAGs account for an average of about 14% of all genes in these vertebrate genomes, and about 25% of all duplications. The majority of TAGs (72–94% have parallel transcription orientation (i.e., they are encoded on the same strand in contrast to the genome, which has about 50% of its genes in parallel transcription orientation. The majority of tandem arrays have only two members. In all species, the proportion of genes that belong to TAGs tends to be higher in large gene families than in small ones; together with our recent finding that tandem duplication played a more important role than retroposition in large families, this fact suggests that among all types of duplication mechanisms, tandem duplication is the predominant mechanism of duplication, especially in large families. Finally, several species have a higher proportion of large tandem arrays that are species-specific than random expectation.

Ultra Large Gene Families: A Matter of Adaptation or Genomic Parasites?

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Philipp H. Schiffer

2016-08-01

Full Text Available Gene duplication is an important mechanism of molecular evolution. It offers a fast track to modification, diversification, redundancy or rescue of gene function. However, duplication may also be neutral or (slightly deleterious, and often ends in pseudo-geneisation. Here, we investigate the phylogenetic distribution of ultra large gene families on long and short evolutionary time scales. In particular, we focus on a family of NACHT-domain and leucine-rich-repeat-containing (NLR-genes, which we previously found in large numbers to occupy one chromosome arm of the zebrafish genome. We were interested to see whether such a tight clustering is characteristic for ultra large gene families. Our data reconfirm that most gene family inflations are lineage-specific, but we can only identify very few gene clusters. Based on our observations we hypothesise that, beyond a certain size threshold, ultra large gene families continue to proliferate in a mechanism we term “run-away evolution”. This process might ultimately lead to the failure of genomic integrity and drive species to extinction.

A role for gene duplication and natural variation of gene expression in the evolution of metabolism.

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Daniel J Kliebenstein

Full Text Available BACKGROUND: Most eukaryotic genomes have undergone whole genome duplications during their evolutionary history. Recent studies have shown that the function of these duplicated genes can diverge from the ancestral gene via neo- or sub-functionalization within single genotypes. An additional possibility is that gene duplicates may also undergo partitioning of function among different genotypes of a species leading to genetic differentiation. Finally, the ability of gene duplicates to diverge may be limited by their biological function. METHODOLOGY/PRINCIPAL FINDINGS: To test these hypotheses, I estimated the impact of gene duplication and metabolic function upon intraspecific gene expression variation of segmental and tandem duplicated genes within Arabidopsis thaliana. In all instances, the younger tandem duplicated genes showed higher intraspecific gene expression variation than the average Arabidopsis gene. Surprisingly, the older segmental duplicates also showed evidence of elevated intraspecific gene expression variation albeit typically lower than for the tandem duplicates. The specific biological function of the gene as defined by metabolic pathway also modulated the level of intraspecific gene expression variation. The major energy metabolism and biosynthetic pathways showed decreased variation, suggesting that they are constrained in their ability to accumulate gene expression variation. In contrast, a major herbivory defense pathway showed significantly elevated intraspecific variation suggesting that it may be under pressure to maintain and/or generate diversity in response to fluctuating insect herbivory pressures. CONCLUSION: These data show that intraspecific variation in gene expression is facilitated by an interaction of gene duplication and biological activity. Further, this plays a role in controlling diversity of plant metabolism.

Microevolution of Duplications and Deletions and Their Impact on Gene Expression in the Nematode Pristionchus pacificus.

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Praveen Baskaran

Full Text Available The evolution of diversity across the animal kingdom has been accompanied by tremendous gene loss and gain. While comparative genomics has been fruitful to characterize differences in gene content across highly diverged species, little is known about the microevolution of structural variations that cause these differences in the first place. In order to investigate the genomic impact of structural variations, we made use of genomic and transcriptomic data from the nematode Pristionchus pacificus, which has been established as a satellite model to Caenorhabditis elegans for comparative biology. We exploit the fact that P. pacificus is a highly diverse species for which various genomic data including the draft genome of a sister species P. exspectatus is available. Based on resequencing coverage data for two natural isolates we identified large (> 2 kb deletions and duplications relative to the reference strain. By restriction to completely syntenic regions between P. pacificus and P. exspectatus, we were able to polarize the comparison and to assess the impact of structural variations on expression levels. We found that while loss of genes correlates with lack of expression, duplication of genes has virtually no effect on gene expression. Further investigating expression of individual copies at sites that segregate between the duplicates, we found in the majority of cases only one of the copies to be expressed. Nevertheless, we still find that certain gene classes are strongly depleted in deletions as well as duplications, suggesting evolutionary constraint acting on synteny. In summary, our results are consistent with a model, where most structural variations are either deleterious or neutral and provide first insights into the microevolution of structural variations in the P. pacificus genome.

Rapid bursts of androgen-binding protein (Abp) gene duplication occurred independently in diverse mammals.

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Laukaitis, Christina M; Heger, Andreas; Blakley, Tyler D; Munclinger, Pavel; Ponting, Chris P; Karn, Robert C

2008-02-12

The draft mouse (Mus musculus) genome sequence revealed an unexpected proliferation of gene duplicates encoding a family of secretoglobin proteins including the androgen-binding protein (ABP) alpha, beta and gamma subunits. Further investigation of 14 alpha-like (Abpa) and 13 beta- or gamma-like (Abpbg) undisrupted gene sequences revealed a rich diversity of developmental stage-, sex- and tissue-specific expression. Despite these studies, our understanding of the evolution of this gene family remains incomplete. Questions arise from imperfections in the initial mouse genome assembly and a dearth of information about the gene family structure in other rodents and mammals. Here, we interrogate the latest 'finished' mouse (Mus musculus) genome sequence assembly to show that the Abp gene repertoire is, in fact, twice as large as reported previously, with 30 Abpa and 34 Abpbg genes and pseudogenes. All of these have arisen since the last common ancestor with rat (Rattus norvegicus). We then demonstrate, by sequencing homologs from species within the Mus genus, that this burst of gene duplication occurred very recently, within the past seven million years. Finally, we survey Abp orthologs in genomes from across the mammalian clade and show that bursts of Abp gene duplications are not specific to the murid rodents; they also occurred recently in the lagomorph (rabbit, Oryctolagus cuniculus) and ruminant (cattle, Bos taurus) lineages, although not in other mammalian taxa. We conclude that Abp genes have undergone repeated bursts of gene duplication and adaptive sequence diversification driven by these genes' participation in chemosensation and/or sexual identification.

A Genome-Wide Landscape of Retrocopies in Primate Genomes.

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Navarro, Fábio C P; Galante, Pedro A F

2015-07-29

Gene duplication is a key factor contributing to phenotype diversity across and within species. Although the availability of complete genomes has led to the extensive study of genomic duplications, the dynamics and variability of gene duplications mediated by retrotransposition are not well understood. Here, we predict mRNA retrotransposition and use comparative genomics to investigate their origin and variability across primates. Analyzing seven anthropoid primate genomes, we found a similar number of mRNA retrotranspositions (∼7,500 retrocopies) in Catarrhini (Old Word Monkeys, including humans), but a surprising large number of retrocopies (∼10,000) in Platyrrhini (New World Monkeys), which may be a by-product of higher long interspersed nuclear element 1 activity in these genomes. By inferring retrocopy orthology, we dated most of the primate retrocopy origins, and estimated a decrease in the fixation rate in recent primate history, implying a smaller number of species-specific retrocopies. Moreover, using RNA-Seq data, we identified approximately 3,600 expressed retrocopies. As expected, most of these retrocopies are located near or within known genes, present tissue-specific and even species-specific expression patterns, and no expression correlation to their parental genes. Taken together, our results provide further evidence that mRNA retrotransposition is an active mechanism in primate evolution and suggest that retrocopies may not only introduce great genetic variability between lineages but also create a large reservoir of potentially functional new genomic loci in primate genomes. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Early stages of functional diversification in the Rab GTPase gene family revealed by genomic and localization studies in Paramecium species.

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Bright, Lydia J; Gout, Jean-Francois; Lynch, Michael

2017-04-15

New gene functions arise within existing gene families as a result of gene duplication and subsequent diversification. To gain insight into the steps that led to the functional diversification of paralogues, we tracked duplicate retention patterns, expression-level divergence, and subcellular markers of functional diversification in the Rab GTPase gene family in three Paramecium aurelia species. After whole-genome duplication, Rab GTPase duplicates are more highly retained than other genes in the genome but appear to be diverging more rapidly in expression levels, consistent with early steps in functional diversification. However, by localizing specific Rab proteins in Paramecium cells, we found that paralogues from the two most recent whole-genome duplications had virtually identical localization patterns, and that less closely related paralogues showed evidence of both conservation and diversification. The functionally conserved paralogues appear to target to compartments associated with both endocytic and phagocytic recycling functions, confirming evolutionary and functional links between the two pathways in a divergent eukaryotic lineage. Because the functionally diversifying paralogues are still closely related to and derived from a clade of functionally conserved Rab11 genes, we were able to pinpoint three specific amino acid residues that may be driving the change in the localization and thus the function in these proteins. © 2017 Bright et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Dose effect of the uvsA+ gene product in duplication strains of Aspergillus nidulans

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Majerfeld, I.H.; Roper, J.A.

1978-01-01

Strains of Aspergillus nidulans which carry a particular segment of chromosome I in duplicate - one segment in normal position, the other translocated to chromosome II - are more resistant to uv light than are strains with a balanced haploid genome. A double dose of the uvsA + allele, carried on the duplicate segment, determines this enhanced resistance; this is shown by the descending order of resistance of duplication haploids uvsA + /uvsA + , uvsA1/uvsA + and uvsA1/uvsA1. An unbalanced diploid with three doses of the uvsA + allele also shows greater resistance than a balanced uvsA + //uvsA + diploid. However, in balanced diploids the uvsA1 allele appears to be completely recessive; uvsA + //uvsA + and uvsA + //uvsA1 diploids produce indistinguishable survival curves after uv irradiation. Thus, the uvsA + gene product is not rate-limiting in repair processes in strains with a balanced genome. The rate-limiting effect observed in these unbalanced strains presumably reflects an interaction of the uvsA + product and other functions determined by the rest of the genome. Duplication haploids and normal haploids lose photorepairable lesions at similar rates. This observation may be interpreted to indicate that differences in survival are not due to differences in the efficiency of excision of uv-induced pyrimidime dimers

Divergence of gene body DNA methylation and evolution of plant duplicate genes.

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Jun Wang

Full Text Available It has been shown that gene body DNA methylation is associated with gene expression. However, whether and how deviation of gene body DNA methylation between duplicate genes can influence their divergence remains largely unexplored. Here, we aim to elucidate the potential role of gene body DNA methylation in the fate of duplicate genes. We identified paralogous gene pairs from Arabidopsis and rice (Oryza sativa ssp. japonica genomes and reprocessed their single-base resolution methylome data. We show that methylation in paralogous genes nonlinearly correlates with several gene properties including exon number/gene length, expression level and mutation rate. Further, we demonstrated that divergence of methylation level and pattern in paralogs indeed positively correlate with their sequence and expression divergences. This result held even after controlling for other confounding factors known to influence the divergence of paralogs. We observed that methylation level divergence might be more relevant to the expression divergence of paralogs than methylation pattern divergence. Finally, we explored the mechanisms that might give rise to the divergence of gene body methylation in paralogs. We found that exonic methylation divergence more closely correlates with expression divergence than intronic methylation divergence. We show that genomic environments (e.g., flanked by transposable elements and repetitive sequences of paralogs generated by various duplication mechanisms are associated with the methylation divergence of paralogs. Overall, our results suggest that the changes in gene body DNA methylation could provide another avenue for duplicate genes to develop differential expression patterns and undergo different evolutionary fates in plant genomes.

Rapid sequence divergence rates in the 5 prime regulatory regions of young Drosophila melanogaster duplicate gene pairs

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Michael H. Kohn

2008-01-01

Full Text Available While it remains a matter of some debate, rapid sequence evolution of the coding sequences of duplicate genes is characteristic for early phases past duplication, but long established duplicates generally evolve under constraint, much like the rest of the coding genome. As for coding sequences, it may be possible to infer evolutionary rate, selection, and constraint via contrasts between duplicate gene divergence in the 5 prime regions and in the corresponding synonymous site divergence in the coding regions. Finding elevated rates for the 5 prime regions of duplicated genes, in addition to the coding regions, would enable statements regarding the early processes of duplicate gene evolution. Here, 1 kb of each of the 5 prime regulatory regions of Drosophila melanogaster duplicate gene pairs were mapped onto one another to isolate shared sequence blocks. Genetic distances within shared sequence blocks (d5’ were found to increase as a function of synonymous (dS, and to a lesser extend, amino-acid (dA site divergence between duplicates. The rate d5’/dS was found to rapidly decay from values > 1 in young duplicate pairs (dS 0.8. Such rapid rates of 5 prime evolution exceeding 1 (~neutral predominantly were found to occur in duplicate pairs with low amino-acid site divergence and that tended to be co-regulated when assayed on microarrays. Conceivably, functional redundancy and relaxation of selective constraint facilitates subsequent positive selection on the 5 prime regions of young duplicate genes. This might promote the evolution of new functions (neofunctionalization or division of labor among duplicate genes (subfunctionalization. In contrast, similar to the vast portion of the non-coding genome, the 5 prime regions of long-established gene duplicates appear to evolve under selective constraint, indicating that these long-established gene duplicates have assumed critical functions.

Enteric and rectal duplications and duplication cysts in the adult.

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Simsek, Abdurrahman; Zeybek, Nazif; Yagci, Gokhan; Kaymakcioglu, Nihat; Tas, Huseyin; Saglam, Mutlu; Cetiner, Sadettin

2005-03-01

Alimentary tract duplication and duplication cysts are rare congenital malformations. The ileum is the most frequently affected site. However, alimentary tract duplication and duplication cysts can occur at any point along the gastrointestinal tract. Early diagnosis and prompt surgical treatment is the best way to prevent associated morbidity. This article presents the cases of three patients admitted to Gulhane Military Medical Academy with signs of acute abdomen, intra-abdominal mass and chronic abdominal pain. These patients were found to have enteric duplication, duplication cyst and/or retro-rectal cyst. The literature on alimentary tract duplications is reviewed.

The fate of the duplicated androgen receptor in fishes: a late neofunctionalization event?

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Haendler Bernard

2008-12-01

Full Text Available Abstract Background Based on the observation of an increased number of paralogous genes in teleost fishes compared with other vertebrates and on the conserved synteny between duplicated copies, it has been shown that a whole genome duplication (WGD occurred during the evolution of Actinopterygian fish. Comparative phylogenetic dating of this duplication event suggests that it occurred early on, specifically in teleosts. It has been proposed that this event might have facilitated the evolutionary radiation and the phenotypic diversification of the teleost fish, notably by allowing the sub- or neo-functionalization of many duplicated genes. Results In this paper, we studied in a wide range of Actinopterygians the duplication and fate of the androgen receptor (AR, NR3C4, a nuclear receptor known to play a key role in sex-determination in vertebrates. The pattern of AR gene duplication is consistent with an early WGD event: it has been duplicated into two genes AR-A and AR-B after the split of the Acipenseriformes from the lineage leading to teleost fish but before the divergence of Osteoglossiformes. Genomic and syntenic analyses in addition to lack of PCR amplification show that one of the duplicated copies, AR-B, was lost in several basal Clupeocephala such as Cypriniformes (including the model species zebrafish, Siluriformes, Characiformes and Salmoniformes. Interestingly, we also found that, in basal teleost fish (Osteoglossiformes and Anguilliformes, the two copies remain very similar, whereas, specifically in Percomorphs, one of the copies, AR-B, has accumulated substitutions in both the ligand binding domain (LBD and the DNA binding domain (DBD. Conclusion The comparison of the mutations present in these divergent AR-B with those known in human to be implicated in complete, partial or mild androgen insensitivity syndrome suggests that the existence of two distinct AR duplicates may be correlated to specific functional differences that may be

The Brassica oleracea genome reveals the asymmetrical evolution of polyploid genomes

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Liu, Shengyi; Liu, Yumei; Yang, Xinhua; Tong, Chaobo; Edwards, David; Parkin, Isobel A. P.; Zhao, Meixia; Ma, Jianxin; Yu, Jingyin; Huang, Shunmou; Wang, Xiyin; Wang, Junyi; Lu, Kun; Fang, Zhiyuan; Bancroft, Ian; Yang, Tae-Jin; Hu, Qiong; Wang, Xinfa; Yue, Zhen; Li, Haojie; Yang, Linfeng; Wu, Jian; Zhou, Qing; Wang, Wanxin; King, Graham J; Pires, J. Chris; Lu, Changxin; Wu, Zhangyan; Sampath, Perumal; Wang, Zhuo; Guo, Hui; Pan, Shengkai; Yang, Limei; Min, Jiumeng; Zhang, Dong; Jin, Dianchuan; Li, Wanshun; Belcram, Harry; Tu, Jinxing; Guan, Mei; Qi, Cunkou; Du, Dezhi; Li, Jiana; Jiang, Liangcai; Batley, Jacqueline; Sharpe, Andrew G; Park, Beom-Seok; Ruperao, Pradeep; Cheng, Feng; Waminal, Nomar Espinosa; Huang, Yin; Dong, Caihua; Wang, Li; Li, Jingping; Hu, Zhiyong; Zhuang, Mu; Huang, Yi; Huang, Junyan; Shi, Jiaqin; Mei, Desheng; Liu, Jing; Lee, Tae-Ho; Wang, Jinpeng; Jin, Huizhe; Li, Zaiyun; Li, Xun; Zhang, Jiefu; Xiao, Lu; Zhou, Yongming; Liu, Zhongsong; Liu, Xuequn; Qin, Rui; Tang, Xu; Liu, Wenbin; Wang, Yupeng; Zhang, Yangyong; Lee, Jonghoon; Kim, Hyun Hee; Denoeud, France; Xu, Xun; Liang, Xinming; Hua, Wei; Wang, Xiaowu; Wang, Jun; Chalhoub, Boulos; Paterson, Andrew H

2014-01-01

Polyploidization has provided much genetic variation for plant adaptive evolution, but the mechanisms by which the molecular evolution of polyploid genomes establishes genetic architecture underlying species differentiation are unclear. Brassica is an ideal model to increase knowledge of polyploid evolution. Here we describe a draft genome sequence of Brassica oleracea, comparing it with that of its sister species B. rapa to reveal numerous chromosome rearrangements and asymmetrical gene loss in duplicated genomic blocks, asymmetrical amplification of transposable elements, differential gene co-retention for specific pathways and variation in gene expression, including alternative splicing, among a large number of paralogous and orthologous genes. Genes related to the production of anticancer phytochemicals and morphological variations illustrate consequences of genome duplication and gene divergence, imparting biochemical and morphological variation to B. oleracea. This study provides insights into Brassica genome evolution and will underpin research into the many important crops in this genus. PMID:24852848

Genome Sequence of the Palaeopolyploid soybean

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Schmutz, Jeremy; Cannon, Steven B.; Schlueter, Jessica; Ma, Jianxin; Mitros, Therese; Nelson, William; Hyten, David L.; Song, Qijian; Thelen, Jay J.; Cheng, Jianlin; Xu, Dong; Hellsten, Uffe; May, Gregory D.; Yu, Yeisoo; Sakura, Tetsuya; Umezawa, Taishi; Bhattacharyya, Madan K.; Sandhu, Devinder; Valliyodan, Babu; Lindquist, Erika; Peto, Myron; Grant, David; Shu, Shengqiang; Goodstein, David; Barry, Kerrie; Futrell-Griggs, Montona; Abernathy, Brian; Du, Jianchang; Tian, Zhixi; Zhu, Liucun; Gill, Navdeep; Joshi, Trupti; Libault, Marc; Sethuraman, Anand; Zhang, Xue-Cheng; Shinozaki, Kazuo; Nguyen, Henry T.; Wing, Rod A.; Cregan, Perry; Specht, James; Grimwood, Jane; Rokhsar, Dan; Stacey, Gary; Shoemaker, Randy C.; Jackson, Scott A.

2009-08-03

Soybean (Glycine max) is one of the most important crop plants for seed protein and oil content, and for its capacity to fix atmospheric nitrogen through symbioses with soil-borne microorganisms. We sequenced the 1.1-gigabase genome by a whole-genome shotgun approach and integrated it with physical and high-density genetic maps to create a chromosome-scale draft sequence assembly. We predict 46,430 protein-coding genes, 70percent more than Arabidopsis and similar to the poplar genome which, like soybean, is an ancient polyploid (palaeopolyploid). About 78percent of the predicted genes occur in chromosome ends, which comprise less than one-half of the genome but account for nearly all of the genetic recombination. Genome duplications occurred at approximately 59 and 13 million years ago, resulting in a highly duplicated genome with nearly 75percent of the genes present in multiple copies. The two duplication events were followed by gene diversification and loss, and numerous chromosome rearrangements. An accurate soybean genome sequence will facilitate the identification of the genetic basis of many soybean traits, and accelerate the creation of improved soybean varieties.

Evolutionary history of glucose-6-phosphatase encoding genes in vertebrate lineages: towards a better understanding of the functions of multiple duplicates.

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Marandel, Lucie; Panserat, Stéphane; Plagnes-Juan, Elisabeth; Arbenoits, Eva; Soengas, José Luis; Bobe, Julien

2017-05-02

Glucose-6-phosphate (G6pc) is a key enzyme involved in the regulation of the glucose homeostasis. The present study aims at revisiting and clarifying the evolutionary history of g6pc genes in vertebrates. g6pc duplications happened by successive rounds of whole genome duplication that occurred during vertebrate evolution. g6pc duplicated before or around Osteichthyes/Chondrichthyes radiation, giving rise to g6pca and g6pcb as a consequence of the second vertebrate whole genome duplication. g6pca was lost after this duplication in Sarcopterygii whereas both g6pca and g6pcb then duplicated as a consequence of the teleost-specific whole genome duplication. One g6pca duplicate was lost after this duplication in teleosts. Similarly one g6pcb2 duplicate was lost at least in the ancestor of percomorpha. The analysis of the evolution of spatial expression patterns of g6pc genes in vertebrates showed that all g6pc were mainly expressed in intestine and liver whereas teleost-specific g6pcb2 genes were mainly and surprisingly expressed in brain and heart. g6pcb2b, one gene previously hypothesised to be involved in the glucose intolerant phenotype in trout, was unexpectedly up-regulated (as it was in liver) by carbohydrates in trout telencephalon without showing significant changes in other brain regions. This up-regulation is in striking contrast with expected glucosensing mechanisms suggesting that its positive response to glucose relates to specific unknown processes in this brain area. Our results suggested that the fixation and the divergence of g6pc duplicated genes during vertebrates' evolution may lead to adaptive novelty and probably to the emergence of novel phenotypes related to glucose homeostasis.

Biased exonization of transposed elements in duplicated genes: A lesson from the TIF-IA gene

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Shomron Noam

2007-11-01

Full Text Available Abstract Background Gene duplication and exonization of intronic transposed elements are two mechanisms that enhance genomic diversity. We examined whether there is less selection against exonization of transposed elements in duplicated genes than in single-copy genes. Results Genome-wide analysis of exonization of transposed elements revealed a higher rate of exonization within duplicated genes relative to single-copy genes. The gene for TIF-IA, an RNA polymerase I transcription initiation factor, underwent a humanoid-specific triplication, all three copies of the gene are active transcriptionally, although only one copy retains the ability to generate the TIF-IA protein. Prior to TIF-IA triplication, an Alu element was inserted into the first intron. In one of the non-protein coding copies, this Alu is exonized. We identified a single point mutation leading to exonization in one of the gene duplicates. When this mutation was introduced into the TIF-IA coding copy, exonization was activated and the level of the protein-coding mRNA was reduced substantially. A very low level of exonization was detected in normal human cells. However, this exonization was abundant in most leukemia cell lines evaluated, although the genomic sequence is unchanged in these cancerous cells compared to normal cells. Conclusion The definition of the Alu element within the TIF-IA gene as an exon is restricted to certain types of cancers; the element is not exonized in normal human cells. These results further our understanding of the delicate interplay between gene duplication and alternative splicing and of the molecular evolutionary mechanisms leading to genetic innovations. This implies the existence of purifying selection against exonization in single copy genes, with duplicate genes free from such constrains.

THE STUDY OF SELF-BALANCED POTATO SORTING MACHINE WITH LINEAR INDUCTION DRIVE

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Linenko A. V.; Baynazarov V. G.; Kamalov T. I.

2016-01-01

In the article we have considered the self-balanced potato sorting machine differing from existing designs of self-balanced potato sorting machines with an oscillatory electric drive. That drive uses a linear induction motor. As the counterbalancing device, the method of the duplicating mechanism is applied. The duplicating mechanism is a specular reflection of the main working body, and also participates in technological process. Its application in the drive of machine allows not only to inc...

The presence of two rare genomic syndromes, 1q21 deletion and Xq28 duplication, segregating independently in a family with intellectual disability.

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Ha, Kyungsoo; Shen, Yiping; Graves, Tyler; Kim, Cheol-Hee; Kim, Hyung-Goo

2016-01-01

1q21 microdeletion syndrome is a rare contiguous gene deletion disorder with de novo or autosomal dominant inheritance patterns and its phenotypic features include intellectual disability, distinctive facial dysmorphism, microcephaly, cardiac abnormalities, and cataracts. MECP2 duplication syndrome is an X-linked recessive neurodevelopmental disorder characterized by intellectual disability, global developmental delay, and other neurological complications including late-onset seizures. Previously, these two different genetic syndromes have not been reported segregating independently in a same family. Here we describe two siblings carrying either a chromosome 1q21 microdeletion or a chromosome Xq28 duplication. Using a comparative genomic hybridization (CGH) array, we identified a 1.24 Mb heterozygous deletion at 1q21 resulting in the loss of 9 genes in a girl with learning disability, hypothyroidism, short stature, sensory integration disorder, and soft dysmorphic features including cupped ears and a unilateral ear pit. We also characterized a 508 kb Xq28 duplication encompassing MECP2 in her younger brother with hypotonia, poor speech, cognitive and motor impairment. The parental CGH and quantitative PCR (qPCR) analyses revealed that the 1q21 deletion in the elder sister is de novo , but the Xq28 duplication in the younger brother was originally inherited from the maternal grandmother through the mother, both of whom are asymptomatic carriers. RT-qPCR assays revealed that the affected brother has almost double the amount of MECP2 mRNA expression compared to other family members of both genders including maternal grandmother and mother who have the same Xq28 duplication with no phenotype. This suggests the X chromosome with an Xq28 duplication in the carrier females is preferentially silenced. From our understanding, this would be the first report showing the independent segregation of two genetically unrelated syndromes, 1q21 microdeletion and Xq28 duplication

External cystic rectal duplication: an unusual presentation of rectal duplication cyst.

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Karaman, I; Karaman, A; Arda, N; Cakmak, O

2007-11-01

Duplications of gastrointestinal tract are rare anomalies, and rectal duplications account for five percent of the alimentary tract duplications. We present an unusual case of rectal duplication, which was located externally in a newborn female, and discuss the types of distal hindgut duplications.

Local synteny and codon usage contribute to asymmetric sequence divergence of Saccharomyces cerevisiae gene duplicates

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Bergthorsson Ulfar

2011-09-01

Full Text Available Abstract Background Duplicated genes frequently experience asymmetric rates of sequence evolution. Relaxed selective constraints and positive selection have both been invoked to explain the observation that one paralog within a gene-duplicate pair exhibits an accelerated rate of sequence evolution. In the majority of studies where asymmetric divergence has been established, there is no indication as to which gene copy, ancestral or derived, is evolving more rapidly. In this study we investigated the effect of local synteny (gene-neighborhood conservation and codon usage on the sequence evolution of gene duplicates in the S. cerevisiae genome. We further distinguish the gene duplicates into those that originated from a whole-genome duplication (WGD event (ohnologs versus small-scale duplications (SSD to determine if there exist any differences in their patterns of sequence evolution. Results For SSD pairs, the derived copy evolves faster than the ancestral copy. However, there is no relationship between rate asymmetry and synteny conservation (ancestral-like versus derived-like in ohnologs. mRNA abundance and optimal codon usage as measured by the CAI is lower in the derived SSD copies relative to ancestral paralogs. Moreover, in the case of ohnologs, the faster-evolving copy has lower CAI and lowered expression. Conclusions Together, these results suggest that relaxation of selection for codon usage and gene expression contribute to rate asymmetry in the evolution of duplicated genes and that in SSD pairs, the relaxation of selection stems from the loss of ancestral regulatory information in the derived copy.

Maintenance and Loss of Duplicated Genes by Dosage Subfunctionalization.

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Gout, Jean-Francois; Lynch, Michael

2015-08-01

Whole-genome duplications (WGDs) have contributed to gene-repertoire enrichment in many eukaryotic lineages. However, most duplicated genes are eventually lost and it is still unclear why some duplicated genes are evolutionary successful whereas others quickly turn to pseudogenes. Here, we show that dosage constraints are major factors opposing post-WGD gene loss in several Paramecium species that share a common ancestral WGD. We propose a model where a majority of WGD-derived duplicates preserve their ancestral function and are retained to produce enough of the proteins performing this same ancestral function. Under this model, the expression level of individual duplicated genes can evolve neutrally as long as they maintain a roughly constant summed expression, and this allows random genetic drift toward uneven contributions of the two copies to total expression. Our analysis suggests that once a high level of imbalance is reached, which can require substantial lengths of time, the copy with the lowest expression level contributes a small enough fraction of the total expression that selection no longer opposes its loss. Extension of our analysis to yeast species sharing a common ancestral WGD yields similar results, suggesting that duplicated-gene retention for dosage constraints followed by divergence in expression level and eventual deterministic gene loss might be a universal feature of post-WGD evolution. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Concomitant duplications of opioid peptide and receptor genes before the origin of jawed vertebrates.

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Görel Sundström

Full Text Available BACKGROUND: The opioid system is involved in reward and pain mechanisms and consists in mammals of four receptors and several peptides. The peptides are derived from four prepropeptide genes, PENK, PDYN, PNOC and POMC, encoding enkephalins, dynorphins, orphanin/nociceptin and beta-endorphin, respectively. Previously we have described how two rounds of genome doubling (2R before the origin of jawed vertebrates formed the receptor family. METHODOLOGY/PRINCIPAL FINDINGS: Opioid peptide gene family members were investigated using a combination of sequence-based phylogeny and chromosomal locations of the peptide genes in various vertebrates. Several adjacent gene families were investigated similarly. The results show that the ancestral peptide gene gave rise to two additional copies in the genome doublings. The fourth member was generated by a local gene duplication, as the genes encoding POMC and PNOC are located on the same chromosome in the chicken genome and all three teleost genomes that we have studied. A translocation has disrupted this synteny in mammals. The PDYN gene seems to have been lost in chicken, but not in zebra finch. Duplicates of some peptide genes have arisen in the teleost fishes. Within the prepropeptide precursors, peptides have been lost or gained in different lineages. CONCLUSIONS/SIGNIFICANCE: The ancestral peptide and receptor genes were located on the same chromosome and were thus duplicated concomitantly. However, subsequently genetic linkage has been lost. In conclusion, the system of opioid peptides and receptors was largely formed by the genome doublings that took place early in vertebrate evolution.

A search for RNA insertions and NS3 gene duplication in the genome of cytopathic isolates of bovine viral diarrhea virus

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V.L. Quadros

2006-07-01

Full Text Available Calves born persistently infected with non-cytopathic bovine viral diarrhea virus (ncpBVDV frequently develop a fatal gastroenteric illness called mucosal disease. Both the original virus (ncpBVDV and an antigenically identical but cytopathic virus (cpBVDV can be isolated from animals affected by mucosal disease. Cytopathic BVDVs originate from their ncp counterparts by diverse genetic mechanisms, all leading to the expression of the non-structural polypeptide NS3 as a discrete protein. In contrast, ncpBVDVs express only the large precursor polypeptide, NS2-3, which contains the NS3 sequence within its carboxy-terminal half. We report here the investigation of the mechanism leading to NS3 expression in 41 cpBVDV isolates. An RT-PCR strategy was employed to detect RNA insertions within the NS2-3 gene and/or duplication of the NS3 gene, two common mechanisms of NS3 expression. RT-PCR amplification revealed insertions in the NS2-3 gene of three cp isolates, with the inserts being similar in size to that present in the cpBVDV NADL strain. Sequencing of one such insert revealed a 296-nucleotide sequence with a central core of 270 nucleotides coding for an amino acid sequence highly homologous (98% to the NADL insert, a sequence corresponding to part of the cellular J-Domain gene. One cpBVDV isolate contained a duplication of the NS3 gene downstream from the original locus. In contrast, no detectable NS2-3 insertions or NS3 gene duplications were observed in the genome of 37 cp isolates. These results demonstrate that processing of NS2-3 without bulk mRNA insertions or NS3 gene duplications seems to be a frequent mechanism leading to NS3 expression and BVDV cytopathology.

Hominoid chromosomal rearrangements on 17q map to complex regions of segmental duplication.

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Cardone, Maria Francesca; Jiang, Zhaoshi; D'Addabbo, Pietro; Archidiacono, Nicoletta; Rocchi, Mariano; Eichler, Evan E; Ventura, Mario

2008-01-01

Chromosomal rearrangements, such as translocations and inversions, are recurrent phenomena during evolution, and both of them are involved in reproductive isolation and speciation. To better understand the molecular basis of chromosome rearrangements and their part in karyotype evolution, we have investigated the history of human chromosome 17 by comparative fluorescence in situ hybridization (FISH) and sequence analysis. Human bacterial artificial chromosome/p1 artificial chromosome probes spanning the length of chromosome 17 were used in FISH experiments on great apes, Old World monkeys and New World monkeys to study the evolutionary history of this chromosome. We observed that the macaque marker order represents the ancestral organization. Human, chimpanzee and gorilla homologous chromosomes differ by a paracentric inversion that occurred specifically in the Homo sapiens/Pan troglodytes/Gorilla gorilla ancestor. Detailed analyses of the paracentric inversion revealed that the breakpoints mapped to two regions syntenic to human 17q12/21 and 17q23, both rich in segmental duplications. Sequence analyses of the human and macaque organization suggest that the duplication events occurred in the catarrhine ancestor with the duplication blocks continuing to duplicate or undergo gene conversion during evolution of the hominoid lineage. We propose that the presence of these duplicons has mediated the inversion in the H. sapiens/P. troglodytes/G. gorilla ancestor. Recently, the same duplication blocks have been shown to be polymorphic in the human population and to be involved in triggering microdeletion and duplication in human. These results further support a model where genomic architecture has a direct role in both rearrangement involved in karyotype evolution and genomic instability in human.

Enteric Duplication.

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Jeziorczak, Paul M; Warner, Brad W

2018-03-01

Enteric duplications have been described throughout the entire gastrointestinal tract. The usual perinatal presentation is an abdominal mass. Duplications associated with the foregut have associated respiratory symptoms, whereas duplications in the midgut and hindgut can present with obstructive symptoms, perforation, nausea, emesis, hemorrhage, or be asymptomatic, and identified as an incidental finding. These are differentiated from other cystic lesions by the presence of a normal gastrointestinal mucosal epithelium. Enteric duplications are located on the mesenteric side of the native structures and are often singular with tubular or cystic characteristics. Management of enteric duplications often requires operative intervention with preservation of the native blood supply and intestine. These procedures are usually very well tolerated with low morbidity.

Polyploidy can drive rapid adaptation in yeast

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Selmecki, Anna M.; Maruvka, Yosef E.; Richmond, Phillip A.; Guillet, Marie; Shoresh, Noam; Sorenson, Amber L.; de, Subhajyoti; Kishony, Roy; Michor, Franziska; Dowell, Robin; Pellman, David

2015-03-01

Polyploidy is observed across the tree of life, yet its influence on evolution remains incompletely understood. Polyploidy, usually whole-genome duplication, is proposed to alter the rate of evolutionary adaptation. This could occur through complex effects on the frequency or fitness of beneficial mutations. For example, in diverse cell types and organisms, immediately after a whole-genome duplication, newly formed polyploids missegregate chromosomes and undergo genetic instability. The instability following whole-genome duplications is thought to provide adaptive mutations in microorganisms and can promote tumorigenesis in mammalian cells. Polyploidy may also affect adaptation independently of beneficial mutations through ploidy-specific changes in cell physiology. Here we perform in vitro evolution experiments to test directly whether polyploidy can accelerate evolutionary adaptation. Compared with haploids and diploids, tetraploids undergo significantly faster adaptation. Mathematical modelling suggests that rapid adaptation of tetraploids is driven by higher rates of beneficial mutations with stronger fitness effects, which is supported by whole-genome sequencing and phenotypic analyses of evolved clones. Chromosome aneuploidy, concerted chromosome loss, and point mutations all provide large fitness gains. We identify several mutations whose beneficial effects are manifest specifically in the tetraploid strains. Together, these results provide direct quantitative evidence that in some environments polyploidy can accelerate evolutionary adaptation.

Evolutionary mechanisms driving the evolution of a large polydnavirus gene family coding for protein tyrosine phosphatases

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Serbielle Céline

2012-12-01

Full Text Available Abstract Background Gene duplications have been proposed to be the main mechanism involved in genome evolution and in acquisition of new functions. Polydnaviruses (PDVs, symbiotic viruses associated with parasitoid wasps, are ideal model systems to study mechanisms of gene duplications given that PDV genomes consist of virulence genes organized into multigene families. In these systems the viral genome is integrated in a wasp chromosome as a provirus and virus particles containing circular double-stranded DNA are injected into the parasitoids’ hosts and are essential for parasitism success. The viral virulence factors, organized in gene families, are required collectively to induce host immune suppression and developmental arrest. The gene family which encodes protein tyrosine phosphatases (PTPs has undergone spectacular expansion in several PDV genomes with up to 42 genes. Results Here, we present strong indications that PTP gene family expansion occurred via classical mechanisms: by duplication of large segments of the chromosomally integrated form of the virus sequences (segmental duplication, by tandem duplications within this form and by dispersed duplications. We also propose a novel duplication mechanism specific to PDVs that involves viral circle reintegration into the wasp genome. The PTP copies produced were shown to undergo conservative evolution along with episodes of adaptive evolution. In particular recently produced copies have undergone positive selection in sites most likely involved in defining substrate selectivity. Conclusion The results provide evidence about the dynamic nature of polydnavirus proviral genomes. Classical and PDV-specific duplication mechanisms have been involved in the production of new gene copies. Selection pressures associated with antagonistic interactions with parasitized hosts have shaped these genes used to manipulate lepidopteran physiology with evidence for positive selection involved in

Comparative genomic analysis reveals occurrence of genetic recombination in virulent Cryptosporidium hominis subtypes and telomeric gene duplications in Cryptosporidium parvum.

Science.gov (United States)

Guo, Yaqiong; Tang, Kevin; Rowe, Lori A; Li, Na; Roellig, Dawn M; Knipe, Kristine; Frace, Michael; Yang, Chunfu; Feng, Yaoyu; Xiao, Lihua

2015-04-18

Cryptosporidium hominis is a dominant species for human cryptosporidiosis. Within the species, IbA10G2 is the most virulent subtype responsible for all C. hominis-associated outbreaks in Europe and Australia, and is a dominant outbreak subtype in the United States. In recent yearsIaA28R4 is becoming a major new subtype in the United States. In this study, we sequenced the genomes of two field specimens from each of the two subtypes and conducted a comparative genomic analysis of the obtained sequences with those from the only fully sequenced Cryptosporidium parvum genome. Altogether, 8.59-9.05 Mb of Cryptosporidium sequences in 45-767 assembled contigs were obtained from the four specimens, representing 94.36-99.47% coverage of the expected genome. These genomes had complete synteny in gene organization and 96.86-97.0% and 99.72-99.83% nucleotide sequence similarities to the published genomes of C. parvum and C. hominis, respectively. Several major insertions and deletions were seen between C. hominis and C. parvum genomes, involving mostly members of multicopy gene families near telomeres. The four C. hominis genomes were highly similar to each other and divergent from the reference IaA25R3 genome in some highly polymorphic regions. Major sequence differences among the four specimens sequenced in this study were in the 5' and 3' ends of chromosome 6 and the gp60 region, largely the result of genetic recombination. The sequence similarity among specimens of the two dominant outbreak subtypes and genetic recombination in chromosome 6, especially around the putative virulence determinant gp60 region, suggest that genetic recombination plays a potential role in the emergence of hyper-transmissible C. hominis subtypes. The high sequence conservation between C. parvum and C. hominis genomes and significant differences in copy numbers of MEDLE family secreted proteins and insulinase-like proteases indicate that telomeric gene duplications could potentially contribute to

Molecular cytogenetic characterization and origin of two de novo duplication 9p cases.

Science.gov (United States)

Tsezou, A; Kitsiou, S; Galla, A; Petersen, M B; Karadima, G; Syrrou, M; Sahlèn, S; Blennow, E

2000-03-13

We report on two additional cases with duplication of 9p, minor with facial anomalies and developmental delay. Using fluorescence in situ hybridization and single-copy probes, we showed that the first case was a direct duplication, whereas the second case was inverted. The extent of the direct duplication was defined as 9p12 --> p24 by microdissection and microcloning of the aberrant chromosome and subsequent chromosome-specific comparative genomic hybridization. DNA polymorphism analysis with eight microsatellite markers revealed that the origin of the dup(9p) was maternal in the first case, whereas it was paternal in the second. Copyright 2000 Wiley-Liss, Inc.

Parasitism drives host genome evolution: Insights from the Pasteuria ramosa-Daphnia magna system.

Science.gov (United States)

Bourgeois, Yann; Roulin, Anne C; Müller, Kristina; Ebert, Dieter

2017-04-01

Because parasitism is thought to play a major role in shaping host genomes, it has been predicted that genomic regions associated with resistance to parasites should stand out in genome scans, revealing signals of selection above the genomic background. To test whether parasitism is indeed such a major factor in host evolution and to better understand host-parasite interaction at the molecular level, we studied genome-wide polymorphisms in 97 genotypes of the planktonic crustacean Daphnia magna originating from three localities across Europe. Daphnia magna is known to coevolve with the bacterial pathogen Pasteuria ramosa for which host genotypes (clonal lines) are either resistant or susceptible. Using association mapping, we identified two genomic regions involved in resistance to P. ramosa, one of which was already known from a previous QTL analysis. We then performed a naïve genome scan to test for signatures of positive selection and found that the two regions identified with the association mapping further stood out as outliers. Several other regions with evidence for selection were also found, but no link between these regions and phenotypic variation could be established. Our results are consistent with the hypothesis that parasitism is driving host genome evolution. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

Convergent evolution of gene networks by single-gene duplications in higher eukaryotes.

Science.gov (United States)

Amoutzias, Gregory D; Robertson, David L; Oliver, Stephen G; Bornberg-Bauer, Erich

2004-03-01

By combining phylogenetic, proteomic and structural information, we have elucidated the evolutionary driving forces for the gene-regulatory interaction networks of basic helix-loop-helix transcription factors. We infer that recurrent events of single-gene duplication and domain rearrangement repeatedly gave rise to distinct networks with almost identical hub-based topologies, and multiple activators and repressors. We thus provide the first empirical evidence for scale-free protein networks emerging through single-gene duplications, the dominant importance of molecular modularity in the bottom-up construction of complex biological entities, and the convergent evolution of networks.

Duplications and losses in gene families of rust pathogens highlight putative effectors.

Science.gov (United States)

Pendleton, Amanda L; Smith, Katherine E; Feau, Nicolas; Martin, Francis M; Grigoriev, Igor V; Hamelin, Richard; Nelson, C Dana; Burleigh, J Gordon; Davis, John M

2014-01-01

Rust fungi are a group of fungal pathogens that cause some of the world's most destructive diseases of trees and crops. A shared characteristic among rust fungi is obligate biotrophy, the inability to complete a lifecycle without a host. This dependence on a host species likely affects patterns of gene expansion, contraction, and innovation within rust pathogen genomes. The establishment of disease by biotrophic pathogens is reliant upon effector proteins that are encoded in the fungal genome and secreted from the pathogen into the host's cell apoplast or within the cells. This study uses a comparative genomic approach to elucidate putative effectors and determine their evolutionary histories. We used OrthoMCL to identify nearly 20,000 gene families in proteomes of 16 diverse fungal species, which include 15 basidiomycetes and one ascomycete. We inferred patterns of duplication and loss for each gene family and identified families with distinctive patterns of expansion/contraction associated with the evolution of rust fungal genomes. To recognize potential contributors for the unique features of rust pathogens, we identified families harboring secreted proteins that: (i) arose or expanded in rust pathogens relative to other fungi, or (ii) contracted or were lost in rust fungal genomes. While the origin of rust fungi appears to be associated with considerable gene loss, there are many gene duplications associated with each sampled rust fungal genome. We also highlight two putative effector gene families that have expanded in Cqf that we hypothesize have roles in pathogenicity.

Segmental Duplication, Microinversion, and Gene Loss Associated with a Complex Inversion Breakpoint Region in Drosophila

Science.gov (United States)

Calvete, Oriol; González, Josefa; Betrán, Esther; Ruiz, Alfredo

2012-01-01

Chromosomal inversions are usually portrayed as simple two-breakpoint rearrangements changing gene order but not gene number or structure. However, increasing evidence suggests that inversion breakpoints may often have a complex structure and entail gene duplications with potential functional consequences. Here, we used a combination of different techniques to investigate the breakpoint structure and the functional consequences of a complex rearrangement fixed in Drosophila buzzatii and comprising two tandemly arranged inversions sharing the middle breakpoint: 2m and 2n. By comparing the sequence in the breakpoint regions between D. buzzatii (inverted chromosome) and D. mojavensis (noninverted chromosome), we corroborate the breakpoint reuse at the molecular level and infer that inversion 2m was associated with a duplication of a ∼13 kb segment and likely generated by staggered breaks plus repair by nonhomologous end joining. The duplicated segment contained the gene CG4673, involved in nuclear transport, and its two nested genes CG5071 and CG5079. Interestingly, we found that other than the inversion and the associated duplication, both breakpoints suffered additional rearrangements, that is, the proximal breakpoint experienced a microinversion event associated at both ends with a 121-bp long duplication that contains a promoter. As a consequence of all these different rearrangements, CG5079 has been lost from the genome, CG5071 is now a single copy nonnested gene, and CG4673 has a transcript ∼9 kb shorter and seems to have acquired a more complex gene regulation. Our results illustrate the complex effects of chromosomal rearrangements and highlight the need of complementing genomic approaches with detailed sequence-level and functional analyses of breakpoint regions if we are to fully understand genome structure, function, and evolutionary dynamics. PMID:22328714

Increments and duplication events of enzymes and transcription factors influence metabolic and regulatory diversity in prokaryotes.

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Mario Alberto Martínez-Núñez

Full Text Available In this work, the content of enzymes and DNA-binding transcription factors (TFs in 794 non-redundant prokaryotic genomes was evaluated. The identification of enzymes was based on annotations deposited in the KEGG database as well as in databases of functional domains (COG and PFAM and structural domains (Superfamily. For identifications of the TFs, hidden Markov profiles were constructed based on well-known transcriptional regulatory families. From these analyses, we obtained diverse and interesting results, such as the negative rate of incremental changes in the number of detected enzymes with respect to the genome size. On the contrary, for TFs the rate incremented as the complexity of genome increased. This inverse related performance shapes the diversity of metabolic and regulatory networks and impacts the availability of enzymes and TFs. Furthermore, the intersection of the derivatives between enzymes and TFs was identified at 9,659 genes, after this point, the regulatory complexity grows faster than metabolic complexity. In addition, TFs have a low number of duplications, in contrast to the apparent high number of duplications associated with enzymes. Despite the greater number of duplicated enzymes versus TFs, the increment by which duplicates appear is higher in TFs. A lower proportion of enzymes among archaeal genomes (22% than in the bacterial ones (27% was also found. This low proportion might be compensated by the interconnection between the metabolic pathways in Archaea. A similar proportion was also found for the archaeal TFs, for which the formation of regulatory complexes has been proposed. Finally, an enrichment of multifunctional enzymes in Bacteria, as a mechanism of ecological adaptation, was detected.

Radiological findings of male urethral duplication associated with bladder duplication: case report

International Nuclear Information System (INIS)

Kim, Hyoung Jung; Lim, Joo Won; Lee, Dong Ho; Ko, Young Tae

2004-01-01

Urethral duplication or accessory urethra is a rare congenital anomaly. Even rarer, is its association with bladder duplication. We report a case of urethral duplication associated with bladder duplication in a seven-year-old boy who underwent retrograde urethrography, sonography and magnetic resonance (MR) imaging. WhiIe retrograde urethrography can demonstrate the extent of the duplicated urethra, MR imaging and sonography can provide detailed information on the anatomy of the adjacent tissues as well as urethral duplication

Promotion and Suppression of Centriole Duplication Are Catalytically Coupled through PLK4 to Ensure Centriole Homeostasis

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Minhee Kim

2016-08-01

Full Text Available PLK4 is the major kinase driving centriole duplication. Duplication occurs only once per cell cycle, forming one new (or daughter centriole that is tightly engaged to the preexisting (or mother centriole. Centriole engagement is known to block the reduplication of mother centrioles, but the molecular identity responsible for the block remains unclear. Here, we show that the centriolar cartwheel, the geometric scaffold for centriole assembly, forms the identity of daughter centrioles essential for the block, ceasing further duplication of the mother centriole to which it is engaged. To ensure a steady block, we found that the cartwheel requires constant maintenance by PLK4 through phosphorylation of the same substrate that drives centriole assembly, revealing a parsimonious control in which “assembly” and “block for new assembly” are linked through the same catalytic reaction to achieve homeostasis. Our results support a recently deduced model that the cartwheel-bound PLK4 directly suppresses centriole reduplication.

Inter-genomic DNA Exchanges and Homeologous Gene Silencing Shaped the Nascent Allopolyploid Coffee Genome (Coffea arabica L.

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Philippe Lashermes

2016-09-01

Full Text Available Allopolyploidization is a biological process that has played a major role in plant speciation and evolution. Genomic changes are common consequences of polyploidization, but their dynamics over time are still poorly understood. Coffea arabica, a recently formed allotetraploid, was chosen to study genetic changes that accompany allopolyploid formation. Both RNA-seq and DNA-seq data were generated from two genetically distant C. arabica accessions. Genomic structural variation was investigated using C. canephora, one of its diploid progenitors, as reference genome. The fate of 9047 duplicate homeologous genes was inferred and compared between the accessions. The pattern of SNP density along the reference genome was consistent with the allopolyploid structure. Large genomic duplications or deletions were not detected. Two homeologous copies were retained and expressed in 96% of the genes analyzed. Nevertheless, duplicated genes were found to be affected by various genomic changes leading to homeolog loss or silencing. Genetic and epigenetic changes were evidenced that could have played a major role in the stabilization of the unique ancestral allotetraploid and its subsequent diversification. While the early evolution of C. arabica mainly involved homeologous crossover exchanges, the later stage appears to have relied on more gradual evolution involving gene conversion and homeolog silencing.

Impact of whole-genome duplication events on diversification rates in angiosperms.

Science.gov (United States)

Landis, Jacob B; Soltis, Douglas E; Li, Zheng; Marx, Hannah E; Barker, Michael S; Tank, David C; Soltis, Pamela S

2018-03-01

Polyploidy or whole-genome duplication (WGD) pervades the evolutionary history of angiosperms. Despite extensive progress in our understanding of WGD, the role of these events in promoting diversification is still not well understood. We seek to clarify the possible association between WGD and diversification rates in flowering plants. Using a previously published phylogeny spanning all land plants (31,749 tips) and WGD events inferred from analyses of the 1000 Plants (1KP) transcriptome data, we analyzed the association of WGDs and diversification rates following numerous WGD events across the angiosperms. We used a stepwise AIC approach (MEDUSA), a Bayesian mixture model approach (BAMM), and state-dependent diversification analyses (MuSSE) to investigate patterns of diversification. Sister-clade comparisons were used to investigate species richness after WGDs. Based on the density of 1KP taxon sampling, 106 WGDs were unambiguously placed on the angiosperm phylogeny. We identified 334-530 shifts in diversification rates. We found that 61 WGD events were tightly linked to changes in diversification rates, and state-dependent diversification analyses indicated higher speciation rates for subsequent rounds of WGD. Additionally, 70 of 99 WGD events showed an increase in species richness compared to the sister clade. Forty-six of the 106 WGDs analyzed appear to be closely associated with upshifts in the rate of diversification in angiosperms. Shifts in diversification do not appear more likely than random within a four-node lag phase following a WGD; however, younger WGD events are more likely to be followed by an upshift in diversification than older WGD events. © 2018 Botanical Society of America.

Gene duplication, tissue-specific gene expression and sexual conflict in stalk-eyed flies (Diopsidae).

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Baker, Richard H; Narechania, Apurva; Johns, Philip M; Wilkinson, Gerald S

2012-08-19

Gene duplication provides an essential source of novel genetic material to facilitate rapid morphological evolution. Traits involved in reproduction and sexual dimorphism represent some of the fastest evolving traits in nature, and gene duplication is intricately involved in the origin and evolution of these traits. Here, we review genomic research on stalk-eyed flies (Diopsidae) that has been used to examine the extent of gene duplication and its role in the genetic architecture of sexual dimorphism. Stalk-eyed flies are remarkable because of the elongation of the head into long stalks, with the eyes and antenna laterally displaced at the ends of these stalks. Many species are strongly sexually dimorphic for eyespan, and these flies have become a model system for studying sexual selection. Using both expressed sequence tag and next-generation sequencing, we have established an extensive database of gene expression in the developing eye-antennal imaginal disc, the adult head and testes. Duplicated genes exhibit narrower expression patterns than non-duplicated genes, and the testes, in particular, provide an abundant source of gene duplication. Within somatic tissue, duplicated genes are more likely to be differentially expressed between the sexes, suggesting gene duplication may provide a mechanism for resolving sexual conflict.

Comparative genomic analysis of the MHC: the evolution of class I duplication blocks, diversity and complexity from shark to man.

Science.gov (United States)

Kulski, Jerzy K; Shiina, Takashi; Anzai, Tatsuya; Kohara, Sakae; Inoko, Hidetoshi

2002-12-01

The major histocompatibility complex (MHC) genomic region is composed of a group of linked genes involved functionally with the adaptive and innate immune systems. The class I and class II genes are intrinsic features of the MHC and have been found in all the jawed vertebrates studied so far. The MHC genomic regions of the human and the chicken (B locus) have been fully sequenced and mapped, and the mouse MHC sequence is almost finished. Information on the MHC genomic structures (size, complexity, genic and intergenic composition and organization, gene order and number) of other vertebrates is largely limited or nonexistent. Therefore, we are mapping, sequencing and analyzing the MHC genomic regions of different human haplotypes and at least eight nonhuman species. Here, we review our progress with these sequences and compare the human MHC structure with that of the nonhuman primates (chimpanzee and rhesus macaque), other mammals (pigs, mice and rats) and nonmammalian vertebrates such as birds (chicken and quail), bony fish (medaka, pufferfish and zebrafish) and cartilaginous fish (nurse shark). This comparison reveals a complex MHC structure for mammals and a relatively simpler design for nonmammalian animals with a hypothetical prototypic structure for the shark. In the mammalian MHC, there are two to five different class I duplication blocks embedded within a framework of conserved nonclass I and/or nonclass II genes. With a few exceptions, the class I framework genes are absent from the MHC of birds, bony fish and sharks. Comparative genomics of the MHC reveal a highly plastic region with major structural differences between the mammalian and nonmammalian vertebrates. Additional genomic data are needed on animals of the reptilia, crocodilia and marsupial classes to find the origins of the class I framework genes and examples of structures that may be intermediate between the simple and complex MHC organizations of birds and mammals, respectively.

Genome-wide identification and evolution of the PIN-FORMED (PIN) gene family in Glycine max.

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Liu, Yuan; Wei, Haichao

2017-07-01

Soybean (Glycine max) is one of the most important crop plants. Wild and cultivated soybean varieties have significant differences worth further investigation, such as plant morphology, seed size, and seed coat development; these characters may be related to auxin biology. The PIN gene family encodes essential transport proteins in cell-to-cell auxin transport, but little research on soybean PIN genes (GmPIN genes) has been done, especially with respect to the evolution and differences between wild and cultivated soybean. In this study, we retrieved 23 GmPIN genes from the latest updated G. max genome database; six GmPIN protein sequences were changed compared with the previous database. Based on the Plant Genome Duplication Database, 18 GmPIN genes have been involved in segment duplication. Three pairs of GmPIN genes arose after the second soybean genome duplication, and six occurred after the first genome duplication. The duplicated GmPIN genes retained similar expression patterns. All the duplicated GmPIN genes experienced purifying selection (K a /K s genome sequence of 17 wild and 14 cultivated soybean varieties. Our research provides useful and comprehensive basic information for understanding GmPIN genes.

Gene conversion in the rice genome

DEFF Research Database (Denmark)

Xu, Shuqing; Clark, Terry; Zheng, Hongkun

2008-01-01

-chromosomal conversions distributed between chromosome 1 and 5, 2 and 6, and 3 and 5 are more frequent than genome average (Z-test, P ... is not tightly linked to natural selection in the rice genome. To assess the contribution of segmental duplication on gene conversion statistics, we determined locations of conversion partners with respect to inter-chromosomal segment duplication. The number of conversions associated with segmentation is less...... involved in conversion events. CONCLUSION: The evolution of gene families in the rice genome may have been accelerated by conversion with pseudogenes. Our analysis suggests a possible role for gene conversion in the evolution of pathogen-response genes....

Telomere maintenance through recruitment of internal genomic regions.

Science.gov (United States)

Seo, Beomseok; Kim, Chuna; Hills, Mark; Sung, Sanghyun; Kim, Hyesook; Kim, Eunkyeong; Lim, Daisy S; Oh, Hyun-Seok; Choi, Rachael Mi Jung; Chun, Jongsik; Shim, Jaegal; Lee, Junho

2015-09-18

Cells surviving crisis are often tumorigenic and their telomeres are commonly maintained through the reactivation of telomerase. However, surviving cells occasionally activate a recombination-based mechanism called alternative lengthening of telomeres (ALT). Here we establish stably maintained survivors in telomerase-deleted Caenorhabditis elegans that escape from sterility by activating ALT. ALT survivors trans-duplicate an internal genomic region, which is already cis-duplicated to chromosome ends, across the telomeres of all chromosomes. These 'Template for ALT' (TALT) regions consist of a block of genomic DNA flanked by telomere-like sequences, and are different between two genetic background. We establish a model that an ancestral duplication of a donor TALT region to a proximal telomere region forms a genomic reservoir ready to be incorporated into telomeres on ALT activation.

The zebrafish genome: a review and msx gene case study.

Science.gov (United States)

Postlethwait, J H

2006-01-01

Zebrafish is one of several important teleost models for understanding principles of vertebrate developmental, molecular, organismal, genetic, evolutionary, and genomic biology. Efficient investigation of the molecular genetic basis of induced mutations depends on knowledge of the zebrafish genome. Principles of zebrafish genomic analysis, including gene mapping, ortholog identification, conservation of syntenies, genome duplication, and evolution of duplicate gene function are discussed here using as a case study the zebrafish msxa, msxb, msxc, msxd, and msxe genes, which together constitute zebrafish orthologs of tetrapod Msx1, Msx2, and Msx3. Genomic analysis suggests orthologs for this difficult to understand group of paralogs.

Duplications and losses in gene families of rust pathogens highlight putative effectors

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Amanda L. Pendleton

2014-06-01

Full Text Available Rust fungi are a group of fungal pathogens that cause some of the world’s most destructive diseases of trees and crops. A shared characteristic among rust fungi is obligate biotrophy, the inability to complete a lifecycle without a host. This dependence on a host species likely affects patterns of gene expansion, contraction, and innovation within rust pathogen genomes. The establishment of disease by biotrophic pathogens is reliant upon effector proteins that are encoded in the fungal genome and secreted from the pathogen into the host’s cell apoplast or within the cells. This study uses a comparative genomic approach to elucidate putative effectors and determine their evolutionary histories. We used OrthoMCL to identify nearly 20,000 gene families in proteomes of sixteen diverse fungal species, which include fifteen basidiomycetes and one ascomycete. We inferred patterns of duplication and loss for each gene family and identified families with distinctive patterns of expansion/contraction associated with the evolution of rust fungal genomes. To recognize potential contributors for the unique features of rust pathogens, we identified families harboring secreted proteins that: i arose or expanded in rust pathogens relative to other fungi, or ii contracted or were lost in rust fungal genomes. While the origin of rust fungi appears to be associated with considerable gene loss, there are many gene duplications associated with each sampled rust fungal genome. We also highlight two putative effector gene families that have expanded in Cqf that we hypothesize have roles in pathogenicity.

Genome-wide analysis of SSR and ILP markers in trees: diversity profiling, alternate distribution, and applications in duplication.

Science.gov (United States)

Xia, Xinyao; Luan, Lin Lin; Qin, Guanghua; Yu, Li Fang; Wang, Zhi Wei; Dong, Wan Chen; Song, Yumin; Qiao, Yuling; Zhang, Xian Sheng; Sang, Ya Lin; Yang, Long

2017-12-20

Molecular markers are efficient tools for breeding and genetic studies. However, despite their ecological and economic importance, their development and application have long been hampered. In this study, we identified 524,170 simple sequence repeat (SSR), 267,636 intron length polymorphism (ILP), and 11,872 potential intron polymorphism (PIP) markers from 16 tree species based on recently available genome sequences. Larger motifs, including hexamers and heptamers, accounted for most of the seven different types of SSR loci. Within these loci, A/T bases comprised a significantly larger proportion of sequence than G/C. SSR and ILP markers exhibited an alternative distribution pattern. Most SSRs were monomorphic markers, and the proportions of polymorphic markers were positively correlated with genome size. By verifying with all 16 tree species, 54 SSR, 418 ILP, and four PIP universal markers were obtained, and their efficiency was examined by PCR. A combination of five SSR and six ILP markers were used for the phylogenetic analysis of 30 willow samples, revealing a positive correlation between genetic diversity and geographic distance. We also found that SSRs can be used as tools for duplication analysis. Our findings provide important foundations for the development of breeding and genetic studies in tree species.

Ultrafast comparison of personal genomes

OpenAIRE

Mauldin, Denise; Hood, Leroy; Robinson, Max; Glusman, Gustavo

2017-01-01

We present an ultra-fast method for comparing personal genomes. We transform the standard genome representation (lists of variants relative to a reference) into 'genome fingerprints' that can be readily compared across sequencing technologies and reference versions. Because of their reduced size, computation on the genome fingerprints is fast and requires little memory. This enables scaling up a variety of important genome analyses, including quantifying relatedness, recognizing duplicative s...

The spotted gar genome illuminates vertebrate evolution and facilitates human-teleost comparisons.

Science.gov (United States)

Braasch, Ingo; Gehrke, Andrew R; Smith, Jeramiah J; Kawasaki, Kazuhiko; Manousaki, Tereza; Pasquier, Jeremy; Amores, Angel; Desvignes, Thomas; Batzel, Peter; Catchen, Julian; Berlin, Aaron M; Campbell, Michael S; Barrell, Daniel; Martin, Kyle J; Mulley, John F; Ravi, Vydianathan; Lee, Alison P; Nakamura, Tetsuya; Chalopin, Domitille; Fan, Shaohua; Wcisel, Dustin; Cañestro, Cristian; Sydes, Jason; Beaudry, Felix E G; Sun, Yi; Hertel, Jana; Beam, Michael J; Fasold, Mario; Ishiyama, Mikio; Johnson, Jeremy; Kehr, Steffi; Lara, Marcia; Letaw, John H; Litman, Gary W; Litman, Ronda T; Mikami, Masato; Ota, Tatsuya; Saha, Nil Ratan; Williams, Louise; Stadler, Peter F; Wang, Han; Taylor, John S; Fontenot, Quenton; Ferrara, Allyse; Searle, Stephen M J; Aken, Bronwen; Yandell, Mark; Schneider, Igor; Yoder, Jeffrey A; Volff, Jean-Nicolas; Meyer, Axel; Amemiya, Chris T; Venkatesh, Byrappa; Holland, Peter W H; Guiguen, Yann; Bobe, Julien; Shubin, Neil H; Di Palma, Federica; Alföldi, Jessica; Lindblad-Toh, Kerstin; Postlethwait, John H

2016-04-01

To connect human biology to fish biomedical models, we sequenced the genome of spotted gar (Lepisosteus oculatus), whose lineage diverged from teleosts before teleost genome duplication (TGD). The slowly evolving gar genome has conserved in content and size many entire chromosomes from bony vertebrate ancestors. Gar bridges teleosts to tetrapods by illuminating the evolution of immunity, mineralization and development (mediated, for example, by Hox, ParaHox and microRNA genes). Numerous conserved noncoding elements (CNEs; often cis regulatory) undetectable in direct human-teleost comparisons become apparent using gar: functional studies uncovered conserved roles for such cryptic CNEs, facilitating annotation of sequences identified in human genome-wide association studies. Transcriptomic analyses showed that the sums of expression domains and expression levels for duplicated teleost genes often approximate the patterns and levels of expression for gar genes, consistent with subfunctionalization. The gar genome provides a resource for understanding evolution after genome duplication, the origin of vertebrate genomes and the function of human regulatory sequences.

The enrichment of TATA box and the scarcity of depleted proximal nucleosome in the promoters of duplicated yeast genes.

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Kim, Yuseob; Lee, Jang H; Babbitt, Gregory A

2010-01-01

Population genetic theory of gene duplication suggests that the preservation of duplicate copies requires functional divergence upon duplication. Genes that can be readily modified to produce new gene expression patterns may thus be duplicated often. In yeast, genes exhibit dichotomous expression patterns based on their promoter architectures. The expression of genes that contain TATA box or occupied proximal nucleosome (OPN) tends to be variable and respond to external signals. On the other hand, genes without TATA box or with depleted proximal nucleosome (DPN) are expressed constitutively. We find that recent duplicates in the yeast genome are heavily biased to be TATA box containing genes and not to be DPN genes. This suggests that variably expressed genes, due to the functional organization in their promoters, have higher duplicability than constitutively expressed genes.

Processes of fungal proteome evolution and gain of function: gene duplication and domain rearrangement

International Nuclear Information System (INIS)

Cohen-Gihon, Inbar; Nussinov, Ruth; Sharan, Roded

2011-01-01

During evolution, organisms have gained functional complexity mainly by modifying and improving existing functioning systems rather than creating new ones ab initio. Here we explore the interplay between two processes which during evolution have had major roles in the acquisition of new functions: gene duplication and protein domain rearrangements. We consider four possible evolutionary scenarios: gene families that have undergone none of these event types; only gene duplication; only domain rearrangement, or both events. We characterize each of the four evolutionary scenarios by functional attributes. Our analysis of ten fungal genomes indicates that at least for the fungi clade, species significantly appear to gain complexity by gene duplication accompanied by the expansion of existing domain architectures via rearrangements. We show that paralogs gaining new domain architectures via duplication tend to adopt new functions compared to paralogs that preserve their domain architectures. We conclude that evolution of protein families through gene duplication and domain rearrangement is correlated with their functional properties. We suggest that in general, new functions are acquired via the integration of gene duplication and domain rearrangements rather than each process acting independently

Duplication and relocation of the functional DPY19L2 gene within low copy repeats

Directory of Open Access Journals (Sweden)

Cheung Joseph

2006-03-01

Full Text Available Abstract Background Low copy repeats (LCRs are thought to play an important role in recent gene evolution, especially when they facilitate gene duplications. Duplicate genes are fundamental to adaptive evolution, providing substrates for the development of new or shared gene functions. Moreover, silencing of duplicate genes can have an indirect effect on adaptive evolution by causing genomic relocation of functional genes. These changes are theorized to have been a major factor in speciation. Results Here we present a novel example showing functional gene relocation within a LCR. We characterize the genomic structure and gene content of eight related LCRs on human Chromosomes 7 and 12. Two members of a novel transmembrane gene family, DPY19L, were identified in these regions, along with six transcribed pseudogenes. One of these genes, DPY19L2, is found on Chromosome 12 and is not syntenic with its mouse orthologue. Instead, the human locus syntenic to mouse Dpy19l2 contains a pseudogene, DPY19L2P1. This indicates that the ancestral copy of this gene has been silenced, while the descendant copy has remained active. Thus, the functional copy of this gene has been relocated to a new genomic locus. We then describe the expansion and evolution of the DPY19L gene family from a single gene found in invertebrate animals. Ancient duplications have led to multiple homologues in different lineages, with three in fish, frogs and birds and four in mammals. Conclusion Our results show that the DPY19L family has expanded throughout the vertebrate lineage and has undergone recent primate-specific evolution within LCRs.

Somatic mosaicism of an intragenic FANCB duplication in both fibroblast and peripheral blood cells observed in a Fanconi anemia patient leads to milder phenotype.

Science.gov (United States)

Asur, Rajalakshmi S; Kimble, Danielle C; Lach, Francis P; Jung, Moonjung; Donovan, Frank X; Kamat, Aparna; Noonan, Raymond J; Thomas, James W; Park, Morgan; Chines, Peter; Vlachos, Adrianna; Auerbach, Arleen D; Smogorzewska, Agata; Chandrasekharappa, Settara C

2018-01-01

Fanconi anemia (FA) is a rare disorder characterized by congenital malformations, progressive bone marrow failure, and predisposition to cancer. Patients harboring X-linked FANCB pathogenic variants usually present with severe congenital malformations resembling VACTERL syndrome with hydrocephalus. We employed the diepoxybutane (DEB) test for FA diagnosis, arrayCGH for detection of duplication, targeted capture and next-gen sequencing for defining the duplication breakpoint, PacBio sequencing of full-length FANCB aberrant transcript, FANCD2 ubiquitination and foci formation assays for the evaluation of FANCB protein function by viral transduction of FANCB-null cells with lentiviral FANCB WT and mutant expression constructs, and droplet digital PCR for quantitation of the duplication in the genomic DNA and cDNA. We describe here an FA-B patient with a mild phenotype. The DEB diagnostic test for FA revealed somatic mosaicism. We identified a 9154 bp intragenic duplication in FANCB, covering the first coding exon 3 and the flanking regions. A four bp homology (GTAG) present at both ends of the breakpoint is consistent with microhomology-mediated duplication mechanism. The duplicated allele gives rise to an aberrant transcript containing exon 3 duplication, predicted to introduce a stop codon in FANCB protein (p.A319*). Duplication levels in the peripheral blood DNA declined from 93% to 7.9% in the span of eleven years. Moreover, the patient fibroblasts have shown 8% of wild-type (WT) allele and his carrier mother showed higher than expected levels of WT allele (79% vs. 50%) in peripheral blood, suggesting that the duplication was highly unstable. Unlike sequence point variants, intragenic duplications are difficult to precisely define, accurately quantify, and may be very unstable, challenging the proper diagnosis. The reversion of genomic duplication to the WT allele results in somatic mosaicism and may explain the relatively milder phenotype displayed by the FA

A molecularly defined duplication set for the X chromosome of Drosophila melanogaster

Energy Technology Data Exchange (ETDEWEB)

Venken, Koen J. T.; Popodi, Ellen; Holtzman, Stacy L.; Schulze, Karen L.; Park, Soo; Carlson, Joseph W.; Hoskins, Roger A.; Bellen, Hugo J.; Kaufman, Thomas C.

2010-07-22

We describe a molecularly defined duplication kit for the X chromosome of Drosophila melanogaster. A set of 408 overlapping P[acman] BAC clones was used to create small duplications (average length 88 kb) covering the 22-Mb sequenced portion of the chromosome. The BAC clones were inserted into an attP docking site on chromosome 3L using C31 integrase, allowing direct comparison of different transgenes. The insertions complement 92% of the essential and viable mutations and deletions tested, demonstrating that almost all Drosophila genes are compact and that the current annotations of the genome are reasonably accurate. Moreover, almost all genes are tolerated at twice the normal dosage. Finally, we more precisely mapped two regions at which duplications cause diplo-lethality in males. This collection comprises the first molecularly defined duplication set to cover a whole chromosome in a multicellular organism. The work presented removes a long-standing barrier to genetic analysis of the Drosophila X chromosome, will greatly facilitate functional assays of X-linked genes in vivo, and provides a model for functional analyses of entire chromosomes in other species.

Global Metabolic Reconstruction and Metabolic Gene Evolution in the Cattle Genome

Science.gov (United States)

Kim, Woonsu; Park, Hyesun; Seo, Seongwon

2016-01-01

The sequence of cattle genome provided a valuable opportunity to systematically link genetic and metabolic traits of cattle. The objectives of this study were 1) to reconstruct genome-scale cattle-specific metabolic pathways based on the most recent and updated cattle genome build and 2) to identify duplicated metabolic genes in the cattle genome for better understanding of metabolic adaptations in cattle. A bioinformatic pipeline of an organism for amalgamating genomic annotations from multiple sources was updated. Using this, an amalgamated cattle genome database based on UMD_3.1, was created. The amalgamated cattle genome database is composed of a total of 33,292 genes: 19,123 consensus genes between NCBI and Ensembl databases, 8,410 and 5,493 genes only found in NCBI or Ensembl, respectively, and 266 genes from NCBI scaffolds. A metabolic reconstruction of the cattle genome and cattle pathway genome database (PGDB) was also developed using Pathway Tools, followed by an intensive manual curation. The manual curation filled or revised 68 pathway holes, deleted 36 metabolic pathways, and added 23 metabolic pathways. Consequently, the curated cattle PGDB contains 304 metabolic pathways, 2,460 reactions including 2,371 enzymatic reactions, and 4,012 enzymes. Furthermore, this study identified eight duplicated genes in 12 metabolic pathways in the cattle genome compared to human and mouse. Some of these duplicated genes are related with specific hormone biosynthesis and detoxifications. The updated genome-scale metabolic reconstruction is a useful tool for understanding biology and metabolic characteristics in cattle. There has been significant improvements in the quality of cattle genome annotations and the MetaCyc database. The duplicated metabolic genes in the cattle genome compared to human and mouse implies evolutionary changes in the cattle genome and provides a useful information for further research on understanding metabolic adaptations of cattle. PMID

The pineapple genome and the evolution of CAM photosynthesis.

Science.gov (United States)

Ming, Ray; VanBuren, Robert; Wai, Ching Man; Tang, Haibao; Schatz, Michael C; Bowers, John E; Lyons, Eric; Wang, Ming-Li; Chen, Jung; Biggers, Eric; Zhang, Jisen; Huang, Lixian; Zhang, Lingmao; Miao, Wenjing; Zhang, Jian; Ye, Zhangyao; Miao, Chenyong; Lin, Zhicong; Wang, Hao; Zhou, Hongye; Yim, Won C; Priest, Henry D; Zheng, Chunfang; Woodhouse, Margaret; Edger, Patrick P; Guyot, Romain; Guo, Hao-Bo; Guo, Hong; Zheng, Guangyong; Singh, Ratnesh; Sharma, Anupma; Min, Xiangjia; Zheng, Yun; Lee, Hayan; Gurtowski, James; Sedlazeck, Fritz J; Harkess, Alex; McKain, Michael R; Liao, Zhenyang; Fang, Jingping; Liu, Juan; Zhang, Xiaodan; Zhang, Qing; Hu, Weichang; Qin, Yuan; Wang, Kai; Chen, Li-Yu; Shirley, Neil; Lin, Yann-Rong; Liu, Li-Yu; Hernandez, Alvaro G; Wright, Chris L; Bulone, Vincent; Tuskan, Gerald A; Heath, Katy; Zee, Francis; Moore, Paul H; Sunkar, Ramanjulu; Leebens-Mack, James H; Mockler, Todd; Bennetzen, Jeffrey L; Freeling, Michael; Sankoff, David; Paterson, Andrew H; Zhu, Xinguang; Yang, Xiaohan; Smith, J Andrew C; Cushman, John C; Paull, Robert E; Yu, Qingyi

2015-12-01

Pineapple (Ananas comosus (L.) Merr.) is the most economically valuable crop possessing crassulacean acid metabolism (CAM), a photosynthetic carbon assimilation pathway with high water-use efficiency, and the second most important tropical fruit. We sequenced the genomes of pineapple varieties F153 and MD2 and a wild pineapple relative, Ananas bracteatus accession CB5. The pineapple genome has one fewer ancient whole-genome duplication event than sequenced grass genomes and a conserved karyotype with seven chromosomes from before the ρ duplication event. The pineapple lineage has transitioned from C3 photosynthesis to CAM, with CAM-related genes exhibiting a diel expression pattern in photosynthetic tissues. CAM pathway genes were enriched with cis-regulatory elements associated with the regulation of circadian clock genes, providing the first cis-regulatory link between CAM and circadian clock regulation. Pineapple CAM photosynthesis evolved by the reconfiguration of pathways in C3 plants, through the regulatory neofunctionalization of preexisting genes and not through the acquisition of neofunctionalized genes via whole-genome or tandem gene duplication.

DB2: a probabilistic approach for accurate detection of tandem duplication breakpoints using paired-end reads.

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Yavaş, Gökhan; Koyutürk, Mehmet; Gould, Meetha P; McMahon, Sarah; LaFramboise, Thomas

2014-03-05

With the advent of paired-end high throughput sequencing, it is now possible to identify various types of structural variation on a genome-wide scale. Although many methods have been proposed for structural variation detection, most do not provide precise boundaries for identified variants. In this paper, we propose a new method, Distribution Based detection of Duplication Boundaries (DB2), for accurate detection of tandem duplication breakpoints, an important class of structural variation, with high precision and recall. Our computational experiments on simulated data show that DB2 outperforms state-of-the-art methods in terms of finding breakpoints of tandem duplications, with a higher positive predictive value (precision) in calling the duplications' presence. In particular, DB2's prediction of tandem duplications is correct 99% of the time even for very noisy data, while narrowing down the space of possible breakpoints within a margin of 15 to 20 bps on the average. Most of the existing methods provide boundaries in ranges that extend to hundreds of bases with lower precision values. Our method is also highly robust to varying properties of the sequencing library and to the sizes of the tandem duplications, as shown by its stable precision, recall and mean boundary mismatch performance. We demonstrate our method's efficacy using both simulated paired-end reads, and those generated from a melanoma sample and two ovarian cancer samples. Newly discovered tandem duplications are validated using PCR and Sanger sequencing. Our method, DB2, uses discordantly aligned reads, taking into account the distribution of fragment length to predict tandem duplications along with their breakpoints on a donor genome. The proposed method fine tunes the breakpoint calls by applying a novel probabilistic framework that incorporates the empirical fragment length distribution to score each feasible breakpoint. DB2 is implemented in Java programming language and is freely available

Population Genomics of Infectious and Integrated Wolbachia pipientis Genomes in Drosophila ananassae

Science.gov (United States)

Choi, Jae Young; Bubnell, Jaclyn E.; Aquadro, Charles F.

2015-01-01

Coevolution between Drosophila and its endosymbiont Wolbachia pipientis has many intriguing aspects. For example, Drosophila ananassae hosts two forms of W. pipientis genomes: One being the infectious bacterial genome and the other integrated into the host nuclear genome. Here, we characterize the infectious and integrated genomes of W. pipientis infecting D. ananassae (wAna), by genome sequencing 15 strains of D. ananassae that have either the infectious or integrated wAna genomes. Results indicate evolutionarily stable maternal transmission for the infectious wAna genome suggesting a relatively long-term coevolution with its host. In contrast, the integrated wAna genome showed pseudogene-like characteristics accumulating many variants that are predicted to have deleterious effects if present in an infectious bacterial genome. Phylogenomic analysis of sequence variation together with genotyping by polymerase chain reaction of large structural variations indicated several wAna variants among the eight infectious wAna genomes. In contrast, only a single wAna variant was found among the seven integrated wAna genomes examined in lines from Africa, south Asia, and south Pacific islands suggesting that the integration occurred once from a single infectious wAna genome and then spread geographically. Further analysis revealed that for all D. ananassae we examined with the integrated wAna genomes, the majority of the integrated wAna genomic regions is represented in at least two copies suggesting a double integration or single integration followed by an integrated genome duplication. The possible evolutionary mechanism underlying the widespread geographical presence of the duplicate integration of the wAna genome is an intriguing question remaining to be answered. PMID:26254486

The evolution of the tape measure protein: units, duplications and losses

Directory of Open Access Journals (Sweden)

Poisson Guylaine

2011-10-01

Full Text Available Abstract Background A large family of viruses that infect bacteria, called phages, is characterized by long tails used to inject DNA into their victims' cells. The tape measure protein got its name because the length of the corresponding gene is proportional to the length of the phage's tail: a fact shown by actually copying or splicing out parts of DNA in exemplar species. A natural question is whether there exist units for these tape measures, and if different tape measures have different units and lengths. Such units would allow us to retrace the evolution of tape measure proteins using their duplication/loss history. The vast number of sequenced phages genomes allows us to attack this problem with a comparative genomics approach. Results Here we describe a subset of phages whose tape measure proteins contain variable numbers of an 11 amino acids sequence repeat, aligned with sequence similarity, structural properties, and simple arithmetics. This subset provides a unique opportunity for the combinatorial study of phage evolution, without the added uncertainties of multiple alignments, which are trivial in this case, or of protein functions, that are well established. We give a heuristic that reconstructs the duplication history of these sequences, using divergent strains to discriminate between mutations that occurred before and after speciation, or lineage divergence. The heuristic is based on an efficient algorithm that gives an exhaustive enumeration of all possible parsimonious reconstructions of the duplication/speciation history of a single nucleotide. Finally, we present a method that allows, when possible, to discriminate between duplication and loss events. Conclusions Establishing the evolutionary history of viruses is difficult, in part due to extensive recombinations and gene transfers, and high mutation rates that often erase detectable similarity between homologous genes. In this paper, we introduce new tools to address this

Reciprocal duplication of the Williams-Beuren syndrome deletion on chromosome 7q11.23 is associated with schizophrenia.

Science.gov (United States)

Mulle, Jennifer Gladys; Pulver, Ann E; McGrath, John A; Wolyniec, Paula S; Dodd, Anne F; Cutler, David J; Sebat, Jonathan; Malhotra, Dheeraj; Nestadt, Gerald; Conrad, Donald F; Hurles, Matthew; Barnes, Chris P; Ikeda, Masashi; Iwata, Nakao; Levinson, Douglas F; Gejman, Pablo V; Sanders, Alan R; Duan, Jubao; Mitchell, Adele A; Peter, Inga; Sklar, Pamela; O'Dushlaine, Colm T; Grozeva, Detelina; O'Donovan, Michael C; Owen, Michael J; Hultman, Christina M; Kähler, Anna K; Sullivan, Patrick F; Kirov, George; Warren, Stephen T

2014-03-01

Several copy number variants (CNVs) have been implicated as susceptibility factors for schizophrenia (SZ). Some of these same CNVs also increase risk for autism spectrum disorders, suggesting an etiologic overlap between these conditions. Recently, de novo duplications of a region on chromosome 7q11.23 were associated with autism spectrum disorders. The reciprocal deletion of this region causes Williams-Beuren syndrome. We assayed an Ashkenazi Jewish cohort of 554 SZ cases and 1014 controls for genome-wide CNV. An excess of large rare and de novo CNVs were observed, including a 1.4 Mb duplication on chromosome 7q11.23 identified in two unrelated patients. To test whether this 7q11.23 duplication is also associated with SZ, we obtained data for 14,387 SZ cases and 28,139 controls from seven additional studies with high-resolution genome-wide CNV detection. We performed a meta-analysis, correcting for study population of origin, to assess whether the duplication is associated with SZ. We found duplications at 7q11.23 in 11 of 14,387 SZ cases with only 1 in 28,139 control subjects (unadjusted odds ratio 21.52, 95% confidence interval: 3.13-922.6, p value 5.5 × 10(-5); adjusted odds ratio 10.8, 95% confidence interval: 1.46-79.62, p value .007). Of three SZ duplication carriers with detailed retrospective data, all showed social anxiety and language delay premorbid to SZ onset, consistent with both human studies and animal models of the 7q11.23 duplication. We have identified a new CNV associated with SZ. Reciprocal duplication of the Williams-Beuren syndrome deletion at chromosome 7q11.23 confers an approximately tenfold increase in risk for SZ. Copyright © 2014 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

The spotted gar genome illuminates vertebrate evolution and facilitates human-to-teleost comparisons

Science.gov (United States)

Braasch, Ingo; Gehrke, Andrew R.; Smith, Jeramiah J.; Kawasaki, Kazuhiko; Manousaki, Tereza; Pasquier, Jeremy; Amores, Angel; Desvignes, Thomas; Batzel, Peter; Catchen, Julian; Berlin, Aaron M.; Campbell, Michael S.; Barrell, Daniel; Martin, Kyle J.; Mulley, John F.; Ravi, Vydianathan; Lee, Alison P.; Nakamura, Tetsuya; Chalopin, Domitille; Fan, Shaohua; Wcisel, Dustin; Cañestro, Cristian; Sydes, Jason; Beaudry, Felix E. G.; Sun, Yi; Hertel, Jana; Beam, Michael J.; Fasold, Mario; Ishiyama, Mikio; Johnson, Jeremy; Kehr, Steffi; Lara, Marcia; Letaw, John H.; Litman, Gary W.; Litman, Ronda T.; Mikami, Masato; Ota, Tatsuya; Saha, Nil Ratan; Williams, Louise; Stadler, Peter F.; Wang, Han; Taylor, John S.; Fontenot, Quenton; Ferrara, Allyse; Searle, Stephen M. J.; Aken, Bronwen; Yandell, Mark; Schneider, Igor; Yoder, Jeffrey A.; Volff, Jean-Nicolas; Meyer, Axel; Amemiya, Chris T.; Venkatesh, Byrappa; Holland, Peter W. H.; Guiguen, Yann; Bobe, Julien; Shubin, Neil H.; Di Palma, Federica; Alföldi, Jessica; Lindblad-Toh, Kerstin; Postlethwait, John H.

2016-01-01

To connect human biology to fish biomedical models, we sequenced the genome of spotted gar (Lepisosteus oculatus), whose lineage diverged from teleosts before the teleost genome duplication (TGD). The slowly evolving gar genome conserved in content and size many entire chromosomes from bony vertebrate ancestors. Gar bridges teleosts to tetrapods by illuminating the evolution of immunity, mineralization, and development (e.g., Hox, ParaHox, and miRNA genes). Numerous conserved non-coding elements (CNEs, often cis-regulatory) undetectable in direct human-teleost comparisons become apparent using gar: functional studies uncovered conserved roles of such cryptic CNEs, facilitating annotation of sequences identified in human genome-wide association studies. Transcriptomic analyses revealed that the sum of expression domains and levels from duplicated teleost genes often approximate patterns and levels of gar genes, consistent with subfunctionalization. The gar genome provides a resource for understanding evolution after genome duplication, the origin of vertebrate genomes, and the function of human regulatory sequences. PMID:26950095

Co-expression network analysis of duplicate genes in maize (Zea mays L.) reveals no subgenome bias.

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Li, Lin; Briskine, Roman; Schaefer, Robert; Schnable, Patrick S; Myers, Chad L; Flagel, Lex E; Springer, Nathan M; Muehlbauer, Gary J

2016-11-04

Gene duplication is prevalent in many species and can result in coding and regulatory divergence. Gene duplications can be classified as whole genome duplication (WGD), tandem and inserted (non-syntenic). In maize, WGD resulted in the subgenomes maize1 and maize2, of which maize1 is considered the dominant subgenome. However, the landscape of co-expression network divergence of duplicate genes in maize is still largely uncharacterized. To address the consequence of gene duplication on co-expression network divergence, we developed a gene co-expression network from RNA-seq data derived from 64 different tissues/stages of the maize reference inbred-B73. WGD, tandem and inserted gene duplications exhibited distinct regulatory divergence. Inserted duplicate genes were more likely to be singletons in the co-expression networks, while WGD duplicate genes were likely to be co-expressed with other genes. Tandem duplicate genes were enriched in the co-expression pattern where co-expressed genes were nearly identical for the duplicates in the network. Older gene duplications exhibit more extensive co-expression variation than younger duplications. Overall, non-syntenic genes primarily from inserted duplications show more co-expression divergence. Also, such enlarged co-expression divergence is significantly related to duplication age. Moreover, subgenome dominance was not observed in the co-expression networks - maize1 and maize2 exhibit similar levels of intra subgenome correlations. Intriguingly, the level of inter subgenome co-expression was similar to the level of intra subgenome correlations, and genes from specific subgenomes were not likely to be the enriched in co-expression network modules and the hub genes were not predominantly from any specific subgenomes in maize. Our work provides a comprehensive analysis of maize co-expression network divergence for three different types of gene duplications and identifies potential relationships between duplication types

Polyploidy: adaptation to the genomic environment.

Science.gov (United States)

Hollister, Jesse D

2015-02-01

Genomic evidence of ancestral whole genome duplication (WGD) and polyploidy is widespread among eukaryotic species, and especially among plants. WGD is thought to provide the raw material for adaptation in the form of duplicated genes, and polyploids are thought to benefit from both physiological and genetic buffering. Comparatively little attention has focused on the genomic challenge of polyploidy, however, although much evidence exists that polyploidy severely perturbs important cellular functions. Here, I review recent progress in the study of the re-establishment of stable meiosis in recently evolved polyploids, focusing on four plant species. This work has yielded an insight into the mechanisms underlying stabilization of genome transmission in polyploids, and is revealing remarkable parallels among diverse taxa. Importantly, these studies also provide a road map for investigating how polyploids respond to the challenge of WGD.

The mitochondrial genomes of the acoelomorph worms Paratomella rubra, Isodiametra pulchra and Archaphanostoma ylvae.

Science.gov (United States)

Robertson, Helen E; Lapraz, François; Egger, Bernhard; Telford, Maximilian J; Schiffer, Philipp H

2017-05-12

Acoels are small, ubiquitous - but understudied - marine worms with a very simple body plan. Their internal phylogeny is still not fully resolved, and the position of their proposed phylum Xenacoelomorpha remains debated. Here we describe mitochondrial genome sequences from the acoels Paratomella rubra and Isodiametra pulchra, and the complete mitochondrial genome of the acoel Archaphanostoma ylvae. The P. rubra and A. ylvae sequences are typical for metazoans in size and gene content. The larger I. pulchra  mitochondrial genome contains both ribosomal genes, 21 tRNAs, but only 11 protein-coding genes. We find evidence suggesting a duplicated sequence in the I. pulchra mitochondrial genome. The P. rubra, I. pulchra and A. ylvae mitochondria have a unique genome organisation in comparison to other metazoan mitochondrial genomes. We found a large degree of protein-coding gene and tRNA overlap with little non-coding sequence in the compact P. rubra genome. Conversely, the A. ylvae and I. pulchra genomes have many long non-coding sequences between genes, likely driving genome size expansion in the latter. Phylogenetic trees inferred from mitochondrial genes retrieve Xenacoelomorpha as an early branching taxon in the deuterostomes. Sequence divergence analysis between P. rubra sampled in England and Spain indicates cryptic diversity.

The impact of genome triplication on tandem gene evolution in Brassica rapa

Directory of Open Access Journals (Sweden)

Lu eFang

2012-11-01

Full Text Available Whole genome duplication (WGD and tandem duplication (TD are both important modes of gene expansion. However, how whole genome duplication influences tandemly duplicated genes is not well studied. We used Brassica rapa, which has undergone an additional genome triplication (WGT and shares a common ancestor with Arabidopsis thaliana, Arabidopsis lyrata and Thellungiella parvula, to investigate the impact of genome triplication on tandem gene evolution. We identified 2,137, 1,569, 1,751 and 1,135 tandem gene arrays in B. rapa, A. thaliana, A. lyrata and T. parvula respectively. Among them, 414 conserved tandem arrays are shared by the 3 species without WGT, which were also considered as existing in the diploid ancestor of B. rapa. Thus, after genome triplication, B. rapa should have 1,242 tandem arrays according to the 414 conserved tandems. Here, we found 400 out of the 414 tandems had at least one syntenic ortholog in the genome of B. rapa. Furthermore, 294 out of the 400 shared syntenic orthologs maintain tandem arrays (more than one gene for each syntenic hit in B. rapa. For the 294 tandem arrays, we obtained 426 copies of syntenic paralogous tandems in the triplicated genome of B. rapa. In this study, we demonstrated that tandem arrays in B. rapa were dramatically fractionated after WGT when compared either to non-tandem genes in the B. rapa genome or to the tandem arrays in closely related species that have not experienced a recent whole-genome polyploidization event.

Dissecting a Hidden Gene Duplication: The Arabidopsis thaliana SEC10 Locus

Czech Academy of Sciences Publication Activity Database

Vukašinović, Nemanja; Cvrčková, F.; Eliáš, M.; Cole, R.; Fowler, J.E.; Žárský, Viktor; Synek, Lukáš

2014-01-01

Roč. 9, č. 4 (2014) E-ISSN 1932-6203 R&D Projects: GA ČR GPP501/11/P853; GA ČR(CZ) GAP305/11/1629 Grant - others:GA MŠk ME10033 Institutional support: RVO:61389030 Keywords : WHOLE-GENOME * ARABIDOPSIS-THALIANA * RECENT SEGMENTAL DUPLICATIONS Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.234, year: 2014

A molecularly defined duplication set for the X chromosome of Drosophila melanogaster.

Science.gov (United States)

Venken, Koen J T; Popodi, Ellen; Holtzman, Stacy L; Schulze, Karen L; Park, Soo; Carlson, Joseph W; Hoskins, Roger A; Bellen, Hugo J; Kaufman, Thomas C

2010-12-01

We describe a molecularly defined duplication kit for the X chromosome of Drosophila melanogaster. A set of 408 overlapping P[acman] BAC clones was used to create small duplications (average length 88 kb) covering the 22-Mb sequenced portion of the chromosome. The BAC clones were inserted into an attP docking site on chromosome 3L using ΦC31 integrase, allowing direct comparison of different transgenes. The insertions complement 92% of the essential and viable mutations and deletions tested, demonstrating that almost all Drosophila genes are compact and that the current annotations of the genome are reasonably accurate. Moreover, almost all genes are tolerated at twice the normal dosage. Finally, we more precisely mapped two regions at which duplications cause diplo-lethality in males. This collection comprises the first molecularly defined duplication set to cover a whole chromosome in a multicellular organism. The work presented removes a long-standing barrier to genetic analysis of the Drosophila X chromosome, will greatly facilitate functional assays of X-linked genes in vivo, and provides a model for functional analyses of entire chromosomes in other species.

The Sorghum bicolor genome and the diversification of grasses

Energy Technology Data Exchange (ETDEWEB)

Paterson, Andrew H.; Bowers, John E.; Bruggmann, Remy; dubchak, Inna; Grimwood, Jane; Gundlach, Heidrun; Haberer, Georg; Hellsten, Uffe; Mitros, Therese; Poliakov, Alexander; Schmutz, Jeremy; Spannagl, Manuel; Tang, Haibo; Wang, Xiyin; Wicker, Thomas; Bharti, Arvind K.; Chapman, Jarrod; Feltus, F. Alex; Gowik, Udo; Grigoriev, Igor V.; Lyons, Eric; Maher, Christopher A.; Martis, Mihaela; Marechania, Apurva; Otillar, Robert P.; Penning, Bryan W.; Salamov, Asaf. A.; Wang, Yu; Zhang, Lifang; Carpita, Nicholas C.; Freeling, Michael; Gingle, Alan R.; hash, C. Thomas; Keller, Beat; Klein, Patricia; Kresovich, Stephen; McCann, Maureen C.; Ming, Ray; Peterson, Daniel G.; ur-Rahman, Mehboob-; Ware, Doreen; Westhoff, Peter; Mayer, Klaus F. X.; Messing, Joachim; Rokhsar, Daniel S.

2008-08-20

Sorghum, an African grass related to sugar cane and maize, is grown for food, feed, fibre and fuel. We present an initial analysis of the approx730-megabase Sorghum bicolor (L.) Moench genome, placing approx98percent of genes in their chromosomal context using whole-genome shotgun sequence validated by genetic, physical and syntenic information. Genetic recombination is largely confined to about one-third of the sorghum genome with gene order and density similar to those of rice. Retrotransposon accumulation in recombinationally recalcitrant heterochromatin explains the approx75percent larger genome size of sorghum compared with rice. Although gene and repetitive DNA distributions have been preserved since palaeopolyploidization approx70 million years ago, most duplicated gene sets lost one member before the sorghum rice divergence. Concerted evolution makes one duplicated chromosomal segment appear to be only a few million years old. About 24percent of genes are grass-specific and 7percent are sorghum-specific. Recent gene and microRNA duplications may contribute to sorghum's drought tolerance.

Duplicate editorial on duplicate publication.

Science.gov (United States)

Corson, Stephen L; Decherney, Alan H

2005-04-01

The authors define and discuss the various forms taken by duplicate publications, and provide suggested remedies to help authors, editors, reviewers, and readers avoid this form of internal plagiarism.

An ancient history of gene duplications, fusions and losses in the evolution of APOBEC3 mutators in mammals

Science.gov (United States)

2012-01-01

Background The APOBEC3 (A3) genes play a key role in innate antiviral defense in mammals by introducing directed mutations in the DNA. The human genome encodes for seven A3 genes, with multiple splice alternatives. Different A3 proteins display different substrate specificity, but the very basic question on how discerning self from non-self still remains unresolved. Further, the expression of A3 activity/ies shapes the way both viral and host genomes evolve. Results We present here a detailed temporal analysis of the origin and expansion of the A3 repertoire in mammals. Our data support an evolutionary scenario where the genome of the mammalian ancestor encoded for at least one ancestral A3 gene, and where the genome of the ancestor of placental mammals (and possibly of the ancestor of all mammals) already encoded for an A3Z1-A3Z2-A3Z3 arrangement. Duplication events of the A3 genes have occurred independently in different lineages: humans, cats and horses. In all of them, gene duplication has resulted in changes in enzyme activity and/or substrate specificity, in a paradigmatic example of convergent adaptive evolution at the genomic level. Finally, our results show that evolutionary rates for the three A3Z1, A3Z2 and A3Z3 motifs have significantly decreased in the last 100 Mya. The analysis constitutes a textbook example of the evolution of a gene locus by duplication and sub/neofunctionalization in the context of virus-host arms race. Conclusions Our results provide a time framework for identifying ancestral and derived genomic arrangements in the APOBEC loci, and to date the expansion of this gene family for different lineages through time, as a response to changes in viral/retroviral/retrotransposon pressure. PMID:22640020

Nested radiations and the pulse of angiosperm diversification: increased diversification rates often follow whole genome duplications.

Science.gov (United States)

Tank, David C; Eastman, Jonathan M; Pennell, Matthew W; Soltis, Pamela S; Soltis, Douglas E; Hinchliff, Cody E; Brown, Joseph W; Sessa, Emily B; Harmon, Luke J

2015-07-01

Our growing understanding of the plant tree of life provides a novel opportunity to uncover the major drivers of angiosperm diversity. Using a time-calibrated phylogeny, we characterized hot and cold spots of lineage diversification across the angiosperm tree of life by modeling evolutionary diversification using stepwise AIC (MEDUSA). We also tested the whole-genome duplication (WGD) radiation lag-time model, which postulates that increases in diversification tend to lag behind established WGD events. Diversification rates have been incredibly heterogeneous throughout the evolutionary history of angiosperms and reveal a pattern of 'nested radiations' - increases in net diversification nested within other radiations. This pattern in turn generates a negative relationship between clade age and diversity across both families and orders. We suggest that stochastically changing diversification rates across the phylogeny explain these patterns. Finally, we demonstrate significant statistical support for the WGD radiation lag-time model. Across angiosperms, nested shifts in diversification led to an overall increasing rate of net diversification and declining relative extinction rates through time. These diversification shifts are only rarely perfectly associated with WGD events, but commonly follow them after a lag period. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Fine mapping of a de novo interstitial 10q22-q23 duplication in a patient with congenital heart disease and microcephaly

DEFF Research Database (Denmark)

Erdogan, F; Belloso, J M; Gabau, E

2008-01-01

deletions or duplications elsewhere in the genome. The main clinical features of the patient are microcephaly and congenital heart disease, which are likely to be caused by dosage effect of one or several genes in the duplicated region. Similar phenotypes have been found in other patients with 10q11-q22...

FGF: A web tool for Fishing Gene Family in a whole genome database

DEFF Research Database (Denmark)

Zheng, Hongkun; Shi, Junjie; Fang, Xiaodong

2007-01-01

Gene duplication is an important process in evolution. The availability of genome sequences of a number of organisms has made it possible to conduct comprehensive searches for duplicated genes enabling informative studies of their evolution. We have established the FGF (Fishing Gene Family) progr...... is freely available on a web server at http://fgf.genomics.org.cn/...

Genome plasticity and systems evolution in Streptomyces

Science.gov (United States)

2012-01-01

Background Streptomycetes are filamentous soil-dwelling bacteria. They are best known as the producers of a great variety of natural products such as antibiotics, antifungals, antiparasitics, and anticancer agents and the decomposers of organic substances for carbon recycling. They are also model organisms for the studies of gene regulatory networks, morphological differentiation, and stress response. The availability of sets of genomes from closely related Streptomyces strains makes it possible to assess the mechanisms underlying genome plasticity and systems adaptation. Results We present the results of a comprehensive analysis of the genomes of five Streptomyces species with distinct phenotypes. These streptomycetes have a pan-genome comprised of 17,362 orthologous families which includes 3,096 components in the core genome, 5,066 components in the dispensable genome, and 9,200 components that are uniquely present in only one species. The core genome makes up about 33%-45% of each genome repertoire. It contains important genes for Streptomyces biology including those involved in gene regulation, secretion, secondary metabolism and morphological differentiation. Abundant duplicate genes have been identified, with 4%-11% of the whole genomes composed of lineage-specific expansions (LSEs), suggesting that frequent gene duplication or lateral gene transfer events play a role in shaping the genome diversification within this genus. Two patterns of expansion, single gene expansion and chromosome block expansion are observed, representing different scales of duplication. Conclusions Our results provide a catalog of genome components and their potential functional roles in gene regulatory networks and metabolic networks. The core genome components reveal the minimum requirement for streptomycetes to sustain a successful lifecycle in the soil environment, reflecting the effects of both genome evolution and environmental stress acting upon the expressed phenotypes. A

Duplication in DNA Sequences

Science.gov (United States)

Ito, Masami; Kari, Lila; Kincaid, Zachary; Seki, Shinnosuke

The duplication and repeat-deletion operations are the basis of a formal language theoretic model of errors that can occur during DNA replication. During DNA replication, subsequences of a strand of DNA may be copied several times (resulting in duplications) or skipped (resulting in repeat-deletions). As formal language operations, iterated duplication and repeat-deletion of words and languages have been well studied in the literature. However, little is known about single-step duplications and repeat-deletions. In this paper, we investigate several properties of these operations, including closure properties of language families in the Chomsky hierarchy and equations involving these operations. We also make progress toward a characterization of regular languages that are generated by duplicating a regular language.

Cep63 and cep152 cooperate to ensure centriole duplication.

Directory of Open Access Journals (Sweden)

Nicola J Brown

Full Text Available Centrosomes consist of two centrioles embedded in pericentriolar material and function as the main microtubule organising centres in dividing animal cells. They ensure proper formation and orientation of the mitotic spindle and are therefore essential for the maintenance of genome stability. Centrosome function is crucial during embryonic development, highlighted by the discovery of mutations in genes encoding centrosome or spindle pole proteins that cause autosomal recessive primary microcephaly, including Cep63 and Cep152. In this study we show that Cep63 functions to ensure that centriole duplication occurs reliably in dividing mammalian cells. We show that the interaction between Cep63 and Cep152 can occur independently of centrosome localisation and that the two proteins are dependent on one another for centrosomal localisation. Further, both mouse and human Cep63 and Cep152 cooperate to ensure efficient centriole duplication by promoting the accumulation of essential centriole duplication factors upstream of SAS-6 recruitment and procentriole formation. These observations describe the requirement for Cep63 in maintaining centriole number in dividing mammalian cells and further establish the order of events in centriole formation.

Unleashing the genome of Brassica rapa

Directory of Open Access Journals (Sweden)

Haibao eTang

2012-07-01

Full Text Available The completion and release of the Brassica rapa genome is of great benefit to researchers of the Brassicas, Arabidopsis, and genome evolution. While its lineage is closely related to the model organism Arabidopsis thaliana, the Brassicas experienced a whole genome triplication subsequent to their divergence. This event contemporaneously created three copies of its ancestral genome, which had diploidized through the process of homeologous gene loss known as fractionation. By the fractionation of homeologous gene content and genetic regulatory binding sites, Brassica’s genome is well placed to use comparative genomic techniques to identify syntenic regions, homeologous gene duplications, and putative regulatory sequences. Here, we use the comparative genomics platform CoGe to perform several different genomic analyses with which to study structural changes of its genome and dynamics of various genetic elements. Starting with whole genome comparisons, the Brassica paleohexaploidy is characterized, syntenic regions with Arabidopsis thaliana are identified, and the TOC1 gene in the circadian rhythm pathway from Arabidopsis thaliana is used to find duplicated orthologs in Brassica rapa. These TOC1 genes are further analyzed to identify conserved noncoding sequences that contain cis-acting regulatory elements and promoter sequences previously implicated in circadian rhythmicity. Each 'cookbook style' analysis includes a step-by-step walkthrough with links to CoGe to quickly reproduce each step of the analytical process.

Wild tobacco genomes reveal the evolution of nicotine biosynthesis.

Science.gov (United States)

Xu, Shuqing; Brockmöller, Thomas; Navarro-Quezada, Aura; Kuhl, Heiner; Gase, Klaus; Ling, Zhihao; Zhou, Wenwu; Kreitzer, Christoph; Stanke, Mario; Tang, Haibao; Lyons, Eric; Pandey, Priyanka; Pandey, Shree P; Timmermann, Bernd; Gaquerel, Emmanuel; Baldwin, Ian T

2017-06-06

Nicotine, the signature alkaloid of Nicotiana species responsible for the addictive properties of human tobacco smoking, functions as a defensive neurotoxin against attacking herbivores. However, the evolution of the genetic features that contributed to the assembly of the nicotine biosynthetic pathway remains unknown. We sequenced and assembled genomes of two wild tobaccos, Nicotiana attenuata (2.5 Gb) and Nicotiana obtusifolia (1.5 Gb), two ecological models for investigating adaptive traits in nature. We show that after the Solanaceae whole-genome triplication event, a repertoire of rapidly expanding transposable elements (TEs) bloated these Nicotiana genomes, promoted expression divergences among duplicated genes, and contributed to the evolution of herbivory-induced signaling and defenses, including nicotine biosynthesis. The biosynthetic machinery that allows for nicotine synthesis in the roots evolved from the stepwise duplications of two ancient primary metabolic pathways: the polyamine and nicotinamide adenine dinucleotide (NAD) pathways. In contrast to the duplication of the polyamine pathway that is shared among several solanaceous genera producing polyamine-derived tropane alkaloids, we found that lineage-specific duplications within the NAD pathway and the evolution of root-specific expression of the duplicated Solanaceae-specific ethylene response factor that activates the expression of all nicotine biosynthetic genes resulted in the innovative and efficient production of nicotine in the genus Nicotiana Transcription factor binding motifs derived from TEs may have contributed to the coexpression of nicotine biosynthetic pathway genes and coordinated the metabolic flux. Together, these results provide evidence that TEs and gene duplications facilitated the emergence of a key metabolic innovation relevant to plant fitness.

Multiple Whole Genome Alignments Without a Reference Organism

Energy Technology Data Exchange (ETDEWEB)

Dubchak, Inna; Poliakov, Alexander; Kislyuk, Andrey; Brudno, Michael

2009-01-16

Multiple sequence alignments have become one of the most commonly used resources in genomics research. Most algorithms for multiple alignment of whole genomes rely either on a reference genome, against which all of the other sequences are laid out, or require a one-to-one mapping between the nucleotides of the genomes, preventing the alignment of recently duplicated regions. Both approaches have drawbacks for whole-genome comparisons. In this paper we present a novel symmetric alignment algorithm. The resulting alignments not only represent all of the genomes equally well, but also include all relevant duplications that occurred since the divergence from the last common ancestor. Our algorithm, implemented as a part of the VISTA Genome Pipeline (VGP), was used to align seven vertebrate and sixDrosophila genomes. The resulting whole-genome alignments demonstrate a higher sensitivity and specificity than the pairwise alignments previously available through the VGP and have higher exon alignment accuracy than comparable public whole-genome alignments. Of the multiple alignment methods tested, ours performed the best at aligning genes from multigene families?perhaps the most challenging test for whole-genome alignments. Our whole-genome multiple alignments are available through the VISTA Browser at http://genome.lbl.gov/vista/index.shtml.

JGI Plant Genomics Gene Annotation Pipeline

Energy Technology Data Exchange (ETDEWEB)

Shu, Shengqiang; Rokhsar, Dan; Goodstein, David; Hayes, David; Mitros, Therese

2014-07-14

Plant genomes vary in size and are highly complex with a high amount of repeats, genome duplication and tandem duplication. Gene encodes a wealth of information useful in studying organism and it is critical to have high quality and stable gene annotation. Thanks to advancement of sequencing technology, many plant species genomes have been sequenced and transcriptomes are also sequenced. To use these vastly large amounts of sequence data to make gene annotation or re-annotation in a timely fashion, an automatic pipeline is needed. JGI plant genomics gene annotation pipeline, called integrated gene call (IGC), is our effort toward this aim with aid of a RNA-seq transcriptome assembly pipeline. It utilizes several gene predictors based on homolog peptides and transcript ORFs. See Methods for detail. Here we present genome annotation of JGI flagship green plants produced by this pipeline plus Arabidopsis and rice except for chlamy which is done by a third party. The genome annotations of these species and others are used in our gene family build pipeline and accessible via JGI Phytozome portal whose URL and front page snapshot are shown below.

Duplication of 20p12.3 associated with familial Wolff-Parkinson-White syndrome.

Science.gov (United States)

Mills, Kimberly I; Anderson, Jacqueline; Levy, Philip T; Cole, F Sessions; Silva, Jennifer N A; Kulkarni, Shashikant; Shinawi, Marwan

2013-01-01

Wolff-Parkinson-White (WPW) syndrome is caused by preexcitation of the ventricular myocardium via an accessory pathway which increases the risk for paroxysmal supraventricular tachycardia. The condition is often sporadic and of unknown etiology in the majority of cases. Autosomal dominant inheritance and association with congenital heart defects or ventricular hypertrophy were described. Microdeletions of 20p12.3 have been associated with WPW syndrome with either cognitive dysfunction or Alagille syndrome. Here, we describe the association of 20p12.3 duplication with WPW syndrome in a patient who presented with non-immune hydrops. Her paternal uncle carries the duplication and has attention-deficit hyperactivity disorder and electrocardiographic findings consistent with WPW. The 769 kb duplication was detected by the Affymetrix Whole Genome-Human SNP Array 6.0 and encompasses two genes and the first two exons of a third gene. We discuss the potential role of the genes in the duplicated region in the pathogenesis of WPW and possible neurobehavioral abnormalities. Our data provide additional support for a significant role of 20p12.3 chromosomal rearrangements in the etiology of WPW syndrome. Copyright © 2012 Wiley Periodicals, Inc.

Split photosystem protein, linear-mapping topology, and growth of structural complexity in the plastid genome of chromera velia

KAUST Repository

Janouškovec, Jan

2013-08-22

The canonical photosynthetic plastid genomes consist of a single circular-mapping chromosome that encodes a highly conserved protein core, involved in photosynthesis and ATP generation. Here, we demonstrate that the plastid genome of the photosynthetic relative of apicomplexans, Chromera velia, departs from this view in several unique ways. Core photosynthesis proteins PsaA and AtpB have been broken into two fragments, which we show are independently transcribed, oligoU-tailed, translated, and assembled into functional photosystem I and ATP synthase complexes. Genome-wide transcription profiles support expression of many other highly modified proteins, including several that contain extensions amounting to hundreds of amino acids in length. Canonical gene clusters and operons have been fragmented and reshuffled into novel putative transcriptional units. Massive genomic coverage by paired-end reads, coupled with pulsed-field gel electrophoresis and polymerase chain reaction, consistently indicate that the C. velia plastid genome is linear-mapping, a unique state among all plastids. Abundant intragenomic duplication probably mediated by recombination can explain protein splits, extensions, and genome linearization and is perhaps the key driving force behind the many features that defy the conventional ways of plastid genome architecture and function. © The Author 2013.

A universal genomic coordinate translator for comparative genomics.

Science.gov (United States)

Zamani, Neda; Sundström, Görel; Meadows, Jennifer R S; Höppner, Marc P; Dainat, Jacques; Lantz, Henrik; Haas, Brian J; Grabherr, Manfred G

2014-06-30

Genomic duplications constitute major events in the evolution of species, allowing paralogous copies of genes to take on fine-tuned biological roles. Unambiguously identifying the orthology relationship between copies across multiple genomes can be resolved by synteny, i.e. the conserved order of genomic sequences. However, a comprehensive analysis of duplication events and their contributions to evolution would require all-to-all genome alignments, which increases at N2 with the number of available genomes, N. Here, we introduce Kraken, software that omits the all-to-all requirement by recursively traversing a graph of pairwise alignments and dynamically re-computing orthology. Kraken scales linearly with the number of targeted genomes, N, which allows for including large numbers of genomes in analyses. We first evaluated the method on the set of 12 Drosophila genomes, finding that orthologous correspondence computed indirectly through a graph of multiple synteny maps comes at minimal cost in terms of sensitivity, but reduces overall computational runtime by an order of magnitude. We then used the method on three well-annotated mammalian genomes, human, mouse, and rat, and show that up to 93% of protein coding transcripts have unambiguous pairwise orthologous relationships across the genomes. On a nucleotide level, 70 to 83% of exons match exactly at both splice junctions, and up to 97% on at least one junction. We last applied Kraken to an RNA-sequencing dataset from multiple vertebrates and diverse tissues, where we confirmed that brain-specific gene family members, i.e. one-to-many or many-to-many homologs, are more highly correlated across species than single-copy (i.e. one-to-one homologous) genes. Not limited to protein coding genes, Kraken also identifies thousands of newly identified transcribed loci, likely non-coding RNAs that are consistently transcribed in human, chimpanzee and gorilla, and maintain significant correlation of expression levels across

Spider Transcriptomes Identify Ancient Large-Scale Gene Duplication Event Potentially Important in Silk Gland Evolution.

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Clarke, Thomas H; Garb, Jessica E; Hayashi, Cheryl Y; Arensburger, Peter; Ayoub, Nadia A

2015-06-08

The evolution of specialized tissues with novel functions, such as the silk synthesizing glands in spiders, is likely an influential driver of adaptive success. Large-scale gene duplication events and subsequent paralog divergence are thought to be required for generating evolutionary novelty. Such an event has been proposed for spiders, but not tested. We de novo assembled transcriptomes from three cobweb weaving spider species. Based on phylogenetic analyses of gene families with representatives from each of the three species, we found numerous duplication events indicative of a whole genome or segmental duplication. We estimated the age of the gene duplications relative to several speciation events within spiders and arachnids and found that the duplications likely occurred after the divergence of scorpions (order Scorpionida) and spiders (order Araneae), but before the divergence of the spider suborders Mygalomorphae and Araneomorphae, near the evolutionary origin of spider silk glands. Transcripts that are expressed exclusively or primarily within black widow silk glands are more likely to have a paralog descended from the ancient duplication event and have elevated amino acid replacement rates compared with other transcripts. Thus, an ancient large-scale gene duplication event within the spider lineage was likely an important source of molecular novelty during the evolution of silk gland-specific expression. This duplication event may have provided genetic material for subsequent silk gland diversification in the true spiders (Araneomorphae). © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Genomic Imprinting Was Evolutionarily Conserved during Wheat Polyploidization.

Science.gov (United States)

Yang, Guanghui; Liu, Zhenshan; Gao, Lulu; Yu, Kuohai; Feng, Man; Yao, Yingyin; Peng, Huiru; Hu, Zhaorong; Sun, Qixin; Ni, Zhongfu; Xin, Mingming

2018-01-01

Genomic imprinting is an epigenetic phenomenon that causes genes to be differentially expressed depending on their parent of origin. To evaluate the evolutionary conservation of genomic imprinting and the effects of ploidy on this process, we investigated parent-of-origin-specific gene expression patterns in the endosperm of diploid ( Aegilops spp), tetraploid, and hexaploid wheat ( Triticum spp) at various stages of development via high-throughput transcriptome sequencing. We identified 91, 135, and 146 maternally or paternally expressed genes (MEGs or PEGs, respectively) in diploid, tetraploid, and hexaploid wheat, respectively, 52.7% of which exhibited dynamic expression patterns at different developmental stages. Gene Ontology enrichment analysis suggested that MEGs and PEGs were involved in metabolic processes and DNA-dependent transcription, respectively. Nearly half of the imprinted genes exhibited conserved expression patterns during wheat hexaploidization. In addition, 40% of the homoeolog pairs originating from whole-genome duplication were consistently maternally or paternally biased in the different subgenomes of hexaploid wheat. Furthermore, imprinted expression was found for 41.2% and 50.0% of homolog pairs that evolved by tandem duplication after genome duplication in tetraploid and hexaploid wheat, respectively. These results suggest that genomic imprinting was evolutionarily conserved between closely related Triticum and Aegilops species and in the face of polyploid hybridization between species in these genera. © 2018 American Society of Plant Biologists. All rights reserved.

A Distinct Class of Genome Rearrangements Driven by Heterologous Recombination.

Science.gov (United States)

León-Ortiz, Ana María; Panier, Stephanie; Sarek, Grzegorz; Vannier, Jean-Baptiste; Patel, Harshil; Campbell, Peter J; Boulton, Simon J

2018-01-18

Erroneous DNA repair by heterologous recombination (Ht-REC) is a potential threat to genome stability, but evidence supporting its prevalence is lacking. Here we demonstrate that recombination is possible between heterologous sequences and that it is a source of chromosomal alterations in mitotic and meiotic cells. Mechanistically, we find that the RTEL1 and HIM-6/BLM helicases and the BRCA1 homolog BRC-1 counteract Ht-REC in Caenorhabditis elegans, whereas mismatch repair does not. Instead, MSH-2/6 drives Ht-REC events in rtel-1 and brc-1 mutants and excessive crossovers in rtel-1 mutant meioses. Loss of vertebrate Rtel1 also causes a variety of unusually large and complex structural variations, including chromothripsis, breakage-fusion-bridge events, and tandem duplications with distant intra-chromosomal insertions, whose structure are consistent with a role for RTEL1 in preventing Ht-REC during break-induced replication. Our data establish Ht-REC as an unappreciated source of genome instability that underpins a novel class of complex genome rearrangements that likely arise during replication stress. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Facial duplication: case, review, and embryogenesis.

Science.gov (United States)

Barr, M

1982-04-01

The craniofacial anatomy of an infant with facial duplication is described. There were four eyes, two noses, two maxillae, and one mandible. Anterior to the single pituitary the brain was duplicated and there was bilateral arhinencephaly. Portions of the brain were extruded into a large frontal encephalocele. Cases of symmetrical facial duplication reported in the literature range from two complete faces on a single head (diprosopus) to simple nasal duplication. The variety of patterns of duplication suggests that the doubling of facial components arises in several different ways: Forking of the notochord, duplication of the prosencephalon, duplication of the olfactory placodes, and duplication of maxillary and/or mandibular growth centers around the margins of the stomatodeal plate. Among reported cases, the female:male ratio is 2:1.

Step-wise and punctuated genome evolution drive phenotype changes of tumor cells

International Nuclear Information System (INIS)

Stepanenko, Aleksei; Andreieva, Svitlana; Korets, Kateryna; Mykytenko, Dmytro; Huleyuk, Nataliya; Vassetzky, Yegor; Kavsan, Vadym

2015-01-01

genome context. Temozolomide treatment of 293-pcDNA3.1 cells intensified the stochastic punctuated genome changes and CNAs, and significantly reduced viability and CFE. In contrast, temozolomide treatment of HeLa-CHI3L1 cells promoted the step-wise genome changes, CNAs, and increased viability and CFE, which did not correlate with the ectopic CHI3L1 production. Thus, consistent coevolution of karyotypes and phenotypes was observed. CIN as a driving force of genome evolution significantly influences growth characteristics of tumor cells and should be always taken into consideration during the different experimental manipulations

Step-wise and punctuated genome evolution drive phenotype changes of tumor cells

Energy Technology Data Exchange (ETDEWEB)

Stepanenko, Aleksei, E-mail: a.a.stepanenko@gmail.com [Department of Biosynthesis of Nucleic Acids, Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Kyiv 03680 (Ukraine); Andreieva, Svitlana; Korets, Kateryna; Mykytenko, Dmytro [Department of Biosynthesis of Nucleic Acids, Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Kyiv 03680 (Ukraine); Huleyuk, Nataliya [Institute of Hereditary Pathology, National Academy of Medical Sciences of Ukraine, Lviv 79008 (Ukraine); Vassetzky, Yegor [CNRS UMR8126, Université Paris-Sud 11, Institut de Cancérologie Gustave Roussy, Villejuif 94805 (France); Kavsan, Vadym [Department of Biosynthesis of Nucleic Acids, Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Kyiv 03680 (Ukraine)

2015-01-15

genome context. Temozolomide treatment of 293-pcDNA3.1 cells intensified the stochastic punctuated genome changes and CNAs, and significantly reduced viability and CFE. In contrast, temozolomide treatment of HeLa-CHI3L1 cells promoted the step-wise genome changes, CNAs, and increased viability and CFE, which did not correlate with the ectopic CHI3L1 production. Thus, consistent coevolution of karyotypes and phenotypes was observed. CIN as a driving force of genome evolution significantly influences growth characteristics of tumor cells and should be always taken into consideration during the different experimental manipulations.

Gene duplication, modularity and adaptation in the evolution of the aflatoxin gene cluster

Directory of Open Access Journals (Sweden)

Jakobek Judy L

2007-07-01

Full Text Available Abstract Background The biosynthesis of aflatoxin (AF involves over 20 enzymatic reactions in a complex polyketide pathway that converts acetate and malonate to the intermediates sterigmatocystin (ST and O-methylsterigmatocystin (OMST, the respective penultimate and ultimate precursors of AF. Although these precursors are chemically and structurally very similar, their accumulation differs at the species level for Aspergilli. Notable examples are A. nidulans that synthesizes only ST, A. flavus that makes predominantly AF, and A. parasiticus that generally produces either AF or OMST. Whether these differences are important in the evolutionary/ecological processes of species adaptation and diversification is unknown. Equally unknown are the specific genomic mechanisms responsible for ordering and clustering of genes in the AF pathway of Aspergillus. Results To elucidate the mechanisms that have driven formation of these clusters, we performed systematic searches of aflatoxin cluster homologs across five Aspergillus genomes. We found a high level of gene duplication and identified seven modules consisting of highly correlated gene pairs (aflA/aflB, aflR/aflS, aflX/aflY, aflF/aflE, aflT/aflQ, aflC/aflW, and aflG/aflL. With the exception of A. nomius, contrasts of mean Ka/Ks values across all cluster genes showed significant differences in selective pressure between section Flavi and non-section Flavi species. A. nomius mean Ka/Ks values were more similar to partial clusters in A. fumigatus and A. terreus. Overall, mean Ka/Ks values were significantly higher for section Flavi than for non-section Flavi species. Conclusion Our results implicate several genomic mechanisms in the evolution of ST, OMST and AF cluster genes. Gene modules may arise from duplications of a single gene, whereby the function of the pre-duplication gene is retained in the copy (aflF/aflE or the copies may partition the ancestral function (aflA/aflB. In some gene modules, the

Genome-wide identification and comparative expression analysis reveal a rapid expansion and functional divergence of duplicated genes in the WRKY gene family of cabbage, Brassica oleracea var. capitata.

Science.gov (United States)

Yao, Qiu-Yang; Xia, En-Hua; Liu, Fei-Hu; Gao, Li-Zhi

2015-02-15

WRKY transcription factors (TFs), one of the ten largest TF families in higher plants, play important roles in regulating plant development and resistance. To date, little is known about the WRKY TF family in Brassica oleracea. Recently, the completed genome sequence of cabbage (B. oleracea var. capitata) allows us to systematically analyze WRKY genes in this species. A total of 148 WRKY genes were characterized and classified into seven subgroups that belong to three major groups. Phylogenetic and synteny analyses revealed that the repertoire of cabbage WRKY genes was derived from a common ancestor shared with Arabidopsis thaliana. The B. oleracea WRKY genes were found to be preferentially retained after the whole-genome triplication (WGT) event in its recent ancestor, suggesting that the WGT event had largely contributed to a rapid expansion of the WRKY gene family in B. oleracea. The analysis of RNA-Seq data from various tissues (i.e., roots, stems, leaves, buds, flowers and siliques) revealed that most of the identified WRKY genes were positively expressed in cabbage, and a large portion of them exhibited patterns of differential and tissue-specific expression, demonstrating that these gene members might play essential roles in plant developmental processes. Comparative analysis of the expression level among duplicated genes showed that gene expression divergence was evidently presented among cabbage WRKY paralogs, indicating functional divergence of these duplicated WRKY genes. Copyright © 2014 Elsevier B.V. All rights reserved.

Mitochondrial genome sequencing helps show the evolutionary mechanism of mitochondrial genome formation in Brassica

Science.gov (United States)

2011-01-01

Background Angiosperm mitochondrial genomes are more complex than those of other organisms. Analyses of the mitochondrial genome sequences of at least 11 angiosperm species have showed several common properties; these cannot easily explain, however, how the diverse mitotypes evolved within each genus or species. We analyzed the evolutionary relationships of Brassica mitotypes by sequencing. Results We sequenced the mitotypes of cam (Brassica rapa), ole (B. oleracea), jun (B. juncea), and car (B. carinata) and analyzed them together with two previously sequenced mitotypes of B. napus (pol and nap). The sizes of whole single circular genomes of cam, jun, ole, and car are 219,747 bp, 219,766 bp, 360,271 bp, and 232,241 bp, respectively. The mitochondrial genome of ole is largest as a resulting of the duplication of a 141.8 kb segment. The jun mitotype is the result of an inherited cam mitotype, and pol is also derived from the cam mitotype with evolutionary modifications. Genes with known functions are conserved in all mitotypes, but clear variation in open reading frames (ORFs) with unknown functions among the six mitotypes was observed. Sequence relationship analysis showed that there has been genome compaction and inheritance in the course of Brassica mitotype evolution. Conclusions We have sequenced four Brassica mitotypes, compared six Brassica mitotypes and suggested a mechanism for mitochondrial genome formation in Brassica, including evolutionary events such as inheritance, duplication, rearrangement, genome compaction, and mutation. PMID:21988783

Rectal duplication with sciatic hernia.

Science.gov (United States)

Nosek, Marzena; Golonka, Anna; Kalińska-Lipert, Anita; Nachulewicz, Paweł

2015-07-01

Rectal duplications represent 5% of all duplications in the alimentary tract, and they are very rarely diagnosed during the neonatal period. The authors present the method of investigation and the results of surgical treatment of a full-term neonate with a sciatic hernia containing a rectal duplication. The procedure started with three-port laparoscopy, but excision of the tubular duplication of the rectum was possible only by a transanal endorectal pull-through approach. The sciatic hernia was closed, and plastic sutures on the buttock finished the procedure. The coincidence of sciatic hernia with rectal duplication is extremely rare, and the method of treatment depends exclusively on the anatomical conditions.

Craniofacial duplication: a case report.

Science.gov (United States)

Suryawanshi, Pradeep; Deshpande, Mandar; Verma, Nitin; Mahendrakar, Vivek; Mahendrakar, Sandhya

2013-09-01

A craniofacial duplication or diprosopus is an unusual variant of conjoined twinning. The reported incidence is one in 180,000-15 million births and 35 cases have been reported till date. The phenotype is wide, with the partial duplication of a few facial structures to complete dicephalus. A complete duplication is associated with a high incidence of anomalies in the central nervous system, cardiovascular system, gastrointestinal system and the respiratory system, whereas no major anomalies are found in the infants with a partial duplication. A term baby with the features of a craniofacial duplication has been described, with the proposed theories on embryogenesis and a brief review of the literature.

Evaluation of contrast in duplicated radiographs

International Nuclear Information System (INIS)

Thunthy, K.H.; Weinberg, R.

1982-01-01

This investigation evaluated changes in the contrast of duplicated radiographs made at different ultraviolet light exposures. Increasing ultraviolet light exposure had different effects on the duplicates of originals of different background densities. When correctly exposed, a duplicate radiograph enhanced contrast. When originals had the same contrast but different background densities, their duplicates did not have the same contrast. It was not possible to duplicate accurately all the different contrasts measured on an original. It was possible, however, to produce duplicates with all contrasts greater than those of the original

Convergent evolution of gene networks by single-gene duplications in higher eukaryotes

OpenAIRE

Amoutzias, Gregory D; Robertson, David L; Oliver, Stephen G; Bornberg-Bauer, Erich

2004-01-01

By combining phylogenetic, proteomic and structural information, we have elucidated the evolutionary driving forces for the gene-regulatory interaction networks of basic helix–loop–helix transcription factors. We infer that recurrent events of single-gene duplication and domain rearrangement repeatedly gave rise to distinct networks with almost identical hub-based topologies, and multiple activators and repressors. We thus provide the first empirical evidence for scale-free protein networks e...

Gene duplication and fragmentation in the zebra finch major histocompatibility complex.

Science.gov (United States)

Balakrishnan, Christopher N; Ekblom, Robert; Völker, Martin; Westerdahl, Helena; Godinez, Ricardo; Kotkiewicz, Holly; Burt, David W; Graves, Tina; Griffin, Darren K; Warren, Wesley C; Edwards, Scott V

2010-04-01

Due to its high polymorphism and importance for disease resistance, the major histocompatibility complex (MHC) has been an important focus of many vertebrate genome projects. Avian MHC organization is of particular interest because the chicken Gallus gallus, the avian species with the best characterized MHC, possesses a highly streamlined minimal essential MHC, which is linked to resistance against specific pathogens. It remains unclear the extent to which this organization describes the situation in other birds and whether it represents a derived or ancestral condition. The sequencing of the zebra finch Taeniopygia guttata genome, in combination with targeted bacterial artificial chromosome (BAC) sequencing, has allowed us to characterize an MHC from a highly divergent and diverse avian lineage, the passerines. The zebra finch MHC exhibits a complex structure and history involving gene duplication and fragmentation. The zebra finch MHC includes multiple Class I and Class II genes, some of which appear to be pseudogenes, and spans a much more extensive genomic region than the chicken MHC, as evidenced by the presence of MHC genes on each of seven BACs spanning 739 kb. Cytogenetic (FISH) evidence and the genome assembly itself place core MHC genes on as many as four chromosomes with TAP and Class I genes mapping to different chromosomes. MHC Class II regions are further characterized by high endogenous retroviral content. Lastly, we find strong evidence of selection acting on sites within passerine MHC Class I and Class II genes. The zebra finch MHC differs markedly from that of the chicken, the only other bird species with a complete genome sequence. The apparent lack of synteny between TAP and the expressed MHC Class I locus is in fact reminiscent of a pattern seen in some mammalian lineages and may represent convergent evolution. Our analyses of the zebra finch MHC suggest a complex history involving chromosomal fission, gene duplication and translocation in the

Gene duplication and fragmentation in the zebra finch major histocompatibility complex

Directory of Open Access Journals (Sweden)

Burt David W

2010-04-01

Full Text Available Abstract Background Due to its high polymorphism and importance for disease resistance, the major histocompatibility complex (MHC has been an important focus of many vertebrate genome projects. Avian MHC organization is of particular interest because the chicken Gallus gallus, the avian species with the best characterized MHC, possesses a highly streamlined minimal essential MHC, which is linked to resistance against specific pathogens. It remains unclear the extent to which this organization describes the situation in other birds and whether it represents a derived or ancestral condition. The sequencing of the zebra finch Taeniopygia guttata genome, in combination with targeted bacterial artificial chromosome (BAC sequencing, has allowed us to characterize an MHC from a highly divergent and diverse avian lineage, the passerines. Results The zebra finch MHC exhibits a complex structure and history involving gene duplication and fragmentation. The zebra finch MHC includes multiple Class I and Class II genes, some of which appear to be pseudogenes, and spans a much more extensive genomic region than the chicken MHC, as evidenced by the presence of MHC genes on each of seven BACs spanning 739 kb. Cytogenetic (FISH evidence and the genome assembly itself place core MHC genes on as many as four chromosomes with TAP and Class I genes mapping to different chromosomes. MHC Class II regions are further characterized by high endogenous retroviral content. Lastly, we find strong evidence of selection acting on sites within passerine MHC Class I and Class II genes. Conclusion The zebra finch MHC differs markedly from that of the chicken, the only other bird species with a complete genome sequence. The apparent lack of synteny between TAP and the expressed MHC Class I locus is in fact reminiscent of a pattern seen in some mammalian lineages and may represent convergent evolution. Our analyses of the zebra finch MHC suggest a complex history involving

The genome of the extremophile crucifer Thellungiella parvula

KAUST Repository

Dassanayake, Maheshi; Oh, Dongha; Haas, Jeffrey S.; Herná ndez, Á lvaro Gonzalez; Hong, Hyewon; Ali, Shahjahan; Yun, Daejin; Bressan, Ray Anthony; Zhu, Jian-Kang; Bohnert, Hans Jü rgen; Cheeseman, John McP

2011-01-01

Thellungiella parvula is related to Arabidopsis thaliana and is endemic to saline, resource-poor habitats, making it a model for the evolution of plant adaptation to extreme environments. Here we present the draft genome for this extremophile species. Exclusively by next generation sequencing, we obtained the de novo assembled genome in 1,496 gap-free contigs, closely approximating the estimated genome size of 140 Mb. We anchored these contigs to seven pseudo chromosomes without the use of maps. We show that short reads can be assembled to a near-complete chromosome level for a eukaryotic species lacking prior genetic information. The sequence identifies a number of tandem duplications that, by the nature of the duplicated genes, suggest a possible basis for T. parvula's extremophile lifestyle. Our results provide essential background for developing genomically influenced testable hypotheses for the evolution of environmental stress tolerance. © 2011 Nature America, Inc. All rights reserved.

Genome of Plant Maca (Lepidium meyenii) Illuminates Genomic Basis for High-Altitude Adaptation in the Central Andes.

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Zhang, Jing; Tian, Yang; Yan, Liang; Zhang, Guanghui; Wang, Xiao; Zeng, Yan; Zhang, Jiajin; Ma, Xiao; Tan, Yuntao; Long, Ni; Wang, Yangzi; Ma, Yujin; He, Yuqi; Xue, Yu; Hao, Shumei; Yang, Shengchao; Wang, Wen; Zhang, Liangsheng; Dong, Yang; Chen, Wei; Sheng, Jun

2016-07-06

Maca (Lepidium meyenii Walp, 2n = 8x = 64), belonging to the Brassicaceae family, is an economic plant cultivated in the central Andes sierra in Peru (4000-4500 m). Considering that the rapid uplift of the central Andes occurred 5-10 million years ago (Ma), an evolutionary question arises regarding how plants such as maca acquire high-altitude adaptation within a short geological period. Here, we report the high-quality genome assembly of maca, in which two closely spaced maca-specific whole-genome duplications (WGDs; ∼6.7 Ma) were identified. Comparative genomic analysis between maca and closely related Brassicaceae species revealed expansions of maca genes and gene families involved in abiotic stress response, hormone signaling pathway, and secondary metabolite biosynthesis via WGDs. The retention and subsequent functional divergence of many duplicated genes may account for the morphological and physiological changes (i.e., small leaf shape and self-fertility) in maca in a high-altitude environment. In addition, some duplicated maca genes were identified with functions in morphological adaptation (i.e., LEAF CURLING RESPONSIVENESS) and abiotic stress response (i.e., GLYCINE-RICH RNA-BINDING PROTEINS and DNA-DAMAGE-REPAIR/TOLERATION 2) under positive selection. Collectively, the maca genome provides useful information to understand the important roles of WGDs in the high-altitude adaptation of plants in the Andes. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Evolution of the Largest Mammalian Genome.

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Evans, Ben J; Upham, Nathan S; Golding, Goeffrey B; Ojeda, Ricardo A; Ojeda, Agustina A

2017-06-01

The genome of the red vizcacha rat (Rodentia, Octodontidae, Tympanoctomys barrerae) is the largest of all mammals, and about double the size of their close relative, the mountain vizcacha rat Octomys mimax, even though the lineages that gave rise to these species diverged from each other only about 5 Ma. The mechanism for this rapid genome expansion is controversial, and hypothesized to be a consequence of whole genome duplication or accumulation of repetitive elements. To test these alternative but nonexclusive hypotheses, we gathered and evaluated evidence from whole transcriptome and whole genome sequences of T. barrerae and O. mimax. We recovered support for genome expansion due to accumulation of a diverse assemblage of repetitive elements, which represent about one half and one fifth of the genomes of T. barrerae and O. mimax, respectively, but we found no strong signal of whole genome duplication. In both species, repetitive sequences were rare in transcribed regions as compared with the rest of the genome, and mostly had no close match to annotated repetitive sequences from other rodents. These findings raise new questions about the genomic dynamics of these repetitive elements, their connection to widespread chromosomal fissions that occurred in the T. barrerae ancestor, and their fitness effects-including during the evolution of hypersaline dietary tolerance in T. barrerae. ©The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Complete colonic duplication in children.

Science.gov (United States)

Khaleghnejad Tabari, Ahmad; Mirshemirani, Alireza; Khaleghnejad Tabari, Nasibeh

2012-01-01

Complete colonic duplication is a very rare congenital anomaly that may have different presentations according to its location and size. Complete colonic duplication can occur in 15% of gastrointestinal duplication. We report two cases of complete colonic duplications, and their characteristics. We present two patients with complete colonic duplication with different types and presentations. Case 1: A 2- year old boy presented to the clinic with abdominal protrusion, difficulty to defecate, chronic constipation and mucosal prolaps covered bulging (rectocele) since he was 6 months old. The patient had palpable pelvic mass with doughy consistency. Rectal exam confirmed perirectal mass with soft consistency. The patient underwent a surgical operation that had total tubular colorectal duplication with one blind end and was treated with simple fenestration of distal end, and was discharged without complication. After two years follow up, he had normal defecation and good weight gain. Case 2: A 2 -day old infant was referred with imperforate anus and complete duplication of recto-sigmoid colon, diphallus, double bladder, and hypospadiasis. After clinical and paraclinical investigations, he underwent operations in several stages in different periods, and was discharged without complications. After four years follow up, he led a normal life. The patients with complete duplication have to be examined carefully because of the high incidence of other systemic anomalies. Treatment includes simple resection of distal common wall, fenestration, and repair other associated anomalies.

A case of de novo duplication of 15q24-q26.3

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Hye Ran Kim

2011-06-01

Full Text Available Distal duplication, or trisomy 15q, is an extremely rare chromosomal disorder characterized by prenatal and postnatal overgrowth, mental retardation, and craniofacial malformations. Additional abnormalities typically include an unusually short neck, malformations of the fingers and toes, scoliosis and skeletal malformations, genital abnormalities, particularly in affected males, and, in some cases, cardiac defects. The range and severity of symptoms and physical findings may vary from case to case, depending upon the length and location of the duplicated portion of chromosome 15q. Most reported cases of duplication of the long arm of chromosome 15 frequently have more than one segmental imbalance resulting from unbalanced translocations involving chromosome 15 and deletions in another chromosome, as well as other structural chromosomal abnormalities. We report a female newborn with a de novo duplication, 15q24- q26.3, showing intrauterine overgrowth, a narrow asymmetric face with down-slanting palpebral fissures, a large, prominent nose, and micrognathia, arachnodactyly, camptodactyly, congenital heart disease, hydronephrosis, and hydroureter. Chromosomal analysis showed a 46,XX,inv(9(p12q13,dup(15(q24q26.3. Array comparative genomic hybridization analysis revealed a gain of 42 clones on 15q24-q26.3. This case represents the only reported patient with a de novo 15q24-q26.3 duplication that did not result from an unbalanced translocation and did not have a concomitant monosomic component in Korea.

Divergence of the bZIP Gene Family in Strawberry, Peach, and Apple Suggests Multiple Modes of Gene Evolution after Duplication

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Xiao-Long Wang

2015-01-01

Full Text Available The basic leucine zipper (bZIP transcription factors are the most diverse members of dimerizing transcription factors. In the present study, 50, 116, and 47 bZIP genes were identified in Malus domestica (apple, Prunus persica (peach, and Fragaria vesca (strawberry, respectively. Species-specific duplication was the main contributor to the large number of bZIPs observed in apple. After WGD in apple genome, orthologous bZIP genes corresponding to strawberry on duplicated regions in apple genome were retained. However, in peach ancestor, these syntenic regions were quickly lost or deleted. Maybe the positive selection contributed to the expansion of clade S to adapt to the development and environment stresses. In addition, purifying selection was mainly responsible for bZIP sequence-specific DNA binding. The analysis of orthologous pairs between chromosomes indicates that these orthologs derived from one gene duplication located on one of the nine ancient chromosomes in the Rosaceae. The comparative analysis of bZIP genes in three species provides information on the evolutionary fate of bZIP genes in apple and peach after they diverged from strawberry.

Genome-Wide Identification and Expression Analysis of WRKY Transcription Factors under Multiple Stresses in Brassica napus.

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He, Yajun; Mao, Shaoshuai; Gao, Yulong; Zhu, Liying; Wu, Daoming; Cui, Yixin; Li, Jiana; Qian, Wei

2016-01-01

WRKY transcription factors play important roles in responses to environmental stress stimuli. Using a genome-wide domain analysis, we identified 287 WRKY genes with 343 WRKY domains in the sequenced genome of Brassica napus, 139 in the A sub-genome and 148 in the C sub-genome. These genes were classified into eight groups based on phylogenetic analysis. In the 343 WRKY domains, a total of 26 members showed divergence in the WRKY domain, and 21 belonged to group I. This finding suggested that WRKY genes in group I are more active and variable compared with genes in other groups. Using genome-wide identification and analysis of the WRKY gene family in Brassica napus, we observed genome duplication, chromosomal/segmental duplications and tandem duplication. All of these duplications contributed to the expansion of the WRKY gene family. The duplicate segments that were detected indicated that genome duplication events occurred in the two diploid progenitors B. rapa and B. olearecea before they combined to form B. napus. Analysis of the public microarray database and EST database for B. napus indicated that 74 WRKY genes were induced or preferentially expressed under stress conditions. According to the public QTL data, we identified 77 WRKY genes in 31 QTL regions related to various stress tolerance. We further evaluated the expression of 26 BnaWRKY genes under multiple stresses by qRT-PCR. Most of the genes were induced by low temperature, salinity and drought stress, indicating that the WRKYs play important roles in B. napus stress responses. Further, three BnaWRKY genes were strongly responsive to the three multiple stresses simultaneously, which suggests that these 3 WRKY may have multi-functional roles in stress tolerance and can potentially be used in breeding new rapeseed cultivars. We also found six tandem repeat pairs exhibiting similar expression profiles under the various stress conditions, and three pairs were mapped in the stress related QTL regions

Genome-Wide Identification and Expression Analysis of WRKY Transcription Factors under Multiple Stresses in Brassica napus.

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Yajun He

Full Text Available WRKY transcription factors play important roles in responses to environmental stress stimuli. Using a genome-wide domain analysis, we identified 287 WRKY genes with 343 WRKY domains in the sequenced genome of Brassica napus, 139 in the A sub-genome and 148 in the C sub-genome. These genes were classified into eight groups based on phylogenetic analysis. In the 343 WRKY domains, a total of 26 members showed divergence in the WRKY domain, and 21 belonged to group I. This finding suggested that WRKY genes in group I are more active and variable compared with genes in other groups. Using genome-wide identification and analysis of the WRKY gene family in Brassica napus, we observed genome duplication, chromosomal/segmental duplications and tandem duplication. All of these duplications contributed to the expansion of the WRKY gene family. The duplicate segments that were detected indicated that genome duplication events occurred in the two diploid progenitors B. rapa and B. olearecea before they combined to form B. napus. Analysis of the public microarray database and EST database for B. napus indicated that 74 WRKY genes were induced or preferentially expressed under stress conditions. According to the public QTL data, we identified 77 WRKY genes in 31 QTL regions related to various stress tolerance. We further evaluated the expression of 26 BnaWRKY genes under multiple stresses by qRT-PCR. Most of the genes were induced by low temperature, salinity and drought stress, indicating that the WRKYs play important roles in B. napus stress responses. Further, three BnaWRKY genes were strongly responsive to the three multiple stresses simultaneously, which suggests that these 3 WRKY may have multi-functional roles in stress tolerance and can potentially be used in breeding new rapeseed cultivars. We also found six tandem repeat pairs exhibiting similar expression profiles under the various stress conditions, and three pairs were mapped in the stress related

Mitochondrial genome of the Komodo dragon: efficient sequencing method with reptile-oriented primers and novel gene rearrangements.

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Kumazawa, Yoshinori; Endo, Hideki

2004-04-30

The mitochondrial genome of the Komodo dragon (Varanus komodoensis) was nearly completely sequenced, except for two highly repetitive noncoding regions. An efficient sequencing method for squamate mitochondrial genomes was established by combining the long polymerase chain reaction (PCR) technology and a set of reptile-oriented primers designed for nested PCR amplifications. It was found that the mitochondrial genome had novel gene arrangements in which genes from NADH dehydrogenase subunit 6 to proline tRNA were extensively shuffled with duplicate control regions. These control regions had 99% sequence similarity over 700 bp. Although snake mitochondrial genomes are also known to possess duplicate control regions with nearly identical sequences, the location of the second control region suggested independent occurrence of the duplication on lineages leading to snakes and the Komodo dragon. Another feature of the mitochondrial genome of the Komodo dragon was the considerable number of tandem repeats, including sequences with a strong secondary structure, as a possible site for the slipped-strand mispairing in replication. These observations are consistent with hypotheses that tandem duplications via the slipped-strand mispairing may induce mitochondrial gene rearrangements and may serve to maintain similar copies of the control region.

Deletions, Inversions, Duplications: Engineering of Structural Variants using CRISPR/Cas in Mice

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Katerina Kraft

2015-02-01

Full Text Available Structural variations (SVs contribute to the variability of our genome and are often associated with disease. Their study in model systems was hampered until now by labor-intensive genetic targeting procedures and multiple mouse crossing steps. Here we present the use of CRISPR/Cas for the fast (10 weeks and efficient generation of SVs in mice. We specifically produced deletions, inversions, and also duplications at six different genomic loci ranging from 1.1 kb to 1.6 Mb with efficiencies up to 42%. After PCR-based selection, clones were successfully used to create mice via aggregation. To test the practicability of the method, we reproduced a human 500 kb disease-associated deletion and were able to recapitulate the human phenotype in mice. Furthermore, we evaluated the regulatory potential of a large genomic interval by deleting a 1.5 Mb fragment. The method presented permits rapid in vivo modeling of genomic rearrangements.

Remembrance of things past retrieved from the Paramecium genome.

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Sperling, Linda

2011-01-01

Paramecium and other ciliates are the only unicellular eukaryotes that separate germinal and somatic functions. A germline micronucleus transmits the genetic information to sexual progeny, while a somatic macronucleus expresses the genetic information during vegetative growth to determine the phenotype. At each sexual generation, a new macronucleus develops from the zygotic nucleus through programmed rearrangements of the germline genome. Paramecium tetraurelia somatic genome sequencing, reviewed here, has provided insight into the organization and evolution of the genome. A series of at least 3 whole genome duplications was detected in the Paramecium lineage and selective pressures that determine the fate of the gene duplicates analyzed. Variability in the somatic DNA was characterized and could be attributed to the genome rearrangement processes. Since, in Paramecium, alternative genome rearrangement patterns can be inherited across sexual generations by homology-dependent epigenetic mechanisms and can affect phenotype, I discuss the possibility that ciliate nuclear dimorphism buffers genetic variation hidden in the germline. Copyright © 2011 Institut Pasteur. Published by Elsevier SAS. All rights reserved.

The complete chloroplast genome sequences of Lychnis wilfordii and Silene capitata and comparative analyses with other Caryophyllaceae genomes.

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Kang, Jong-Soo; Lee, Byoung Yoon; Kwak, Myounghai

2017-01-01

The complete chloroplast genomes of Lychnis wilfordii and Silene capitata were determined and compared with ten previously reported Caryophyllaceae chloroplast genomes. The chloroplast genome sequences of L. wilfordii and S. capitata contain 152,320 bp and 150,224 bp, respectively. The gene contents and orders among 12 Caryophyllaceae species are consistent, but several microstructural changes have occurred. Expansion of the inverted repeat (IR) regions at the large single copy (LSC)/IRb and small single copy (SSC)/IR boundaries led to partial or entire gene duplications. Additionally, rearrangements of the LSC region were caused by gene inversions and/or transpositions. The 18 kb inversions, which occurred three times in different lineages of tribe Sileneae, were thought to be facilitated by the intermolecular duplicated sequences. Sequence analyses of the L. wilfordii and S. capitata genomes revealed 39 and 43 repeats, respectively, including forward, palindromic, and reverse repeats. In addition, a total of 67 and 56 simple sequence repeats were discovered in the L. wilfordii and S. capitata chloroplast genomes, respectively. Finally, we constructed phylogenetic trees of the 12 Caryophyllaceae species and two Amaranthaceae species based on 73 protein-coding genes using both maximum parsimony and likelihood methods.

Restriction and Recruitment—Gene Duplication and the Origin and Evolution of Snake Venom Toxins

Science.gov (United States)

Hargreaves, Adam D.; Swain, Martin T.; Hegarty, Matthew J.; Logan, Darren W.; Mulley, John F.

2014-01-01

Snake venom has been hypothesized to have originated and diversified through a process that involves duplication of genes encoding body proteins with subsequent recruitment of the copy to the venom gland, where natural selection acts to develop or increase toxicity. However, gene duplication is known to be a rare event in vertebrate genomes, and the recruitment of duplicated genes to a novel expression domain (neofunctionalization) is an even rarer process that requires the evolution of novel combinations of transcription factor binding sites in upstream regulatory regions. Therefore, although this hypothesis concerning the evolution of snake venom is very unlikely and should be regarded with caution, it is nonetheless often assumed to be established fact, hindering research into the true origins of snake venom toxins. To critically evaluate this hypothesis, we have generated transcriptomic data for body tissues and salivary and venom glands from five species of venomous and nonvenomous reptiles. Our comparative transcriptomic analysis of these data reveals that snake venom does not evolve through the hypothesized process of duplication and recruitment of genes encoding body proteins. Indeed, our results show that many proposed venom toxins are in fact expressed in a wide variety of body tissues, including the salivary gland of nonvenomous reptiles and that these genes have therefore been restricted to the venom gland following duplication, not recruited. Thus, snake venom evolves through the duplication and subfunctionalization of genes encoding existing salivary proteins. These results highlight the danger of the elegant and intuitive “just-so story” in evolutionary biology. PMID:25079342

Full mitochondrial genome sequences of two endemic Philippine hornbill species (Aves: Bucerotidae) provide evidence for pervasive mitochondrial DNA recombination.

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Sammler, Svenja; Bleidorn, Christoph; Tiedemann, Ralph

2011-01-14

Although nowaday it is broadly accepted that mitochondrial DNA (mtDNA) may undergo recombination, the frequency of such recombination remains controversial. Its estimation is not straightforward, as recombination under homoplasmy (i.e., among identical mt genomes) is likely to be overlooked. In species with tandem duplications of large mtDNA fragments the detection of recombination can be facilitated, as it can lead to gene conversion among duplicates. Although the mechanisms for concerted evolution in mtDNA are not fully understood yet, recombination rates have been estimated from "one per speciation event" down to 850 years or even "during every replication cycle". Here we present the first complete mt genome of the avian family Bucerotidae, i.e., that of two Philippine hornbills, Aceros waldeni and Penelopides panini. The mt genomes are characterized by a tandemly duplicated region encompassing part of cytochrome b, 3 tRNAs, NADH6, and the control region. The duplicated fragments are identical to each other except for a short section in domain I and for the length of repeat motifs in domain III of the control region. Due to the heteroplasmy with regard to the number of these repeat motifs, there is some size variation in both genomes; with around 21,657 bp (A. waldeni) and 22,737 bp (P. panini), they significantly exceed the hitherto longest known avian mt genomes, that of the albatrosses. We discovered concerted evolution between the duplicated fragments within individuals. The existence of differences between individuals in coding genes as well as in the control region, which are maintained between duplicates, indicates that recombination apparently occurs frequently, i.e., in every generation. The homogenised duplicates are interspersed by a short fragment which shows no sign of recombination. We hypothesize that this region corresponds to the so-called Replication Fork Barrier (RFB), which has been described from the chicken mitochondrial genome. As this RFB

Full mitochondrial genome sequences of two endemic Philippine hornbill species (Aves: Bucerotidae provide evidence for pervasive mitochondrial DNA recombination

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Bleidorn Christoph

2011-01-01

Full Text Available Abstract Background Although nowaday it is broadly accepted that mitochondrial DNA (mtDNA may undergo recombination, the frequency of such recombination remains controversial. Its estimation is not straightforward, as recombination under homoplasmy (i.e., among identical mt genomes is likely to be overlooked. In species with tandem duplications of large mtDNA fragments the detection of recombination can be facilitated, as it can lead to gene conversion among duplicates. Although the mechanisms for concerted evolution in mtDNA are not fully understood yet, recombination rates have been estimated from "one per speciation event" down to 850 years or even "during every replication cycle". Results Here we present the first complete mt genome of the avian family Bucerotidae, i.e., that of two Philippine hornbills, Aceros waldeni and Penelopides panini. The mt genomes are characterized by a tandemly duplicated region encompassing part of cytochrome b, 3 tRNAs, NADH6, and the control region. The duplicated fragments are identical to each other except for a short section in domain I and for the length of repeat motifs in domain III of the control region. Due to the heteroplasmy with regard to the number of these repeat motifs, there is some size variation in both genomes; with around 21,657 bp (A. waldeni and 22,737 bp (P. panini, they significantly exceed the hitherto longest known avian mt genomes, that of the albatrosses. We discovered concerted evolution between the duplicated fragments within individuals. The existence of differences between individuals in coding genes as well as in the control region, which are maintained between duplicates, indicates that recombination apparently occurs frequently, i.e., in every generation. Conclusions The homogenised duplicates are interspersed by a short fragment which shows no sign of recombination. We hypothesize that this region corresponds to the so-called Replication Fork Barrier (RFB, which has been

The genome of the extremophile crucifer Thellungiella parvula

KAUST Repository

Dassanayake, Maheshi

2011-08-07

Thellungiella parvula is related to Arabidopsis thaliana and is endemic to saline, resource-poor habitats, making it a model for the evolution of plant adaptation to extreme environments. Here we present the draft genome for this extremophile species. Exclusively by next generation sequencing, we obtained the de novo assembled genome in 1,496 gap-free contigs, closely approximating the estimated genome size of 140 Mb. We anchored these contigs to seven pseudo chromosomes without the use of maps. We show that short reads can be assembled to a near-complete chromosome level for a eukaryotic species lacking prior genetic information. The sequence identifies a number of tandem duplications that, by the nature of the duplicated genes, suggest a possible basis for T. parvula\\'s extremophile lifestyle. Our results provide essential background for developing genomically influenced testable hypotheses for the evolution of environmental stress tolerance. © 2011 Nature America, Inc. All rights reserved.

Effects of chemical and physical mutagens on the frequency of a large genetic duplication in Salmonella typhimurium. II

International Nuclear Information System (INIS)

Hoffman, G.R.; Morgan, R.W.; Kirven, R.

1978-01-01

Strains of Salmonella typhimurium which contain a duplication of approximately 30% of the genome may be obtained by a simple selective procedure. These strains are highly unstable, losing the duplication when grown on non-selective medium. In this paper the authors report that treatment of merodiploid bacteria with mutagenic agents stimulates the rate at which haploid segregants are obtained from merodiploid strains. The mutagens which have been tested for this effect are X-rays, ultraviolet light (UV), ethyl methanesulfonate (EMS), and the azaacridine half-mustard ICR-372. (Auth.)

Microarray Analysis of Copy Number Variants on the Human Y Chromosome Reveals Novel and Frequent Duplications Overrepresented in Specific Haplogroups.

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Martin M Johansson

Full Text Available The human Y chromosome is almost always excluded from genome-wide investigations of copy number variants (CNVs due to its highly repetitive structure. This chromosome should not be forgotten, not only for its well-known relevance in male fertility, but also for its involvement in clinical phenotypes such as cancers, heart failure and sex specific effects on brain and behaviour.We analysed Y chromosome data from Affymetrix 6.0 SNP arrays and found that the signal intensities for most of 8179 SNP/CN probes in the male specific region (MSY discriminated between a male, background signals in a female and an isodicentric male containing a large deletion of the q-arm and a duplication of the p-arm of the Y chromosome. Therefore, this SNP/CN platform is suitable for identification of gain and loss of Y chromosome sequences. In a set of 1718 males, we found 25 different CNV patterns, many of which are novel. We confirmed some of these variants by PCR or qPCR. The total frequency of individuals with CNVs was 14.7%, including 9.5% with duplications, 4.5% with deletions and 0.7% exhibiting both. Hence, a novel observation is that the frequency of duplications was more than twice the frequency of deletions. Another striking result was that 10 of the 25 detected variants were significantly overrepresented in one or more haplogroups, demonstrating the importance to control for haplogroups in genome-wide investigations to avoid stratification. NO-M214(xM175 individuals presented the highest percentage (95% of CNVs. If they were not counted, 12.4% of the rest included CNVs, and the difference between duplications (8.9% and deletions (2.8% was even larger.Our results demonstrate that currently available genome-wide SNP platforms can be used to identify duplications and deletions in the human Y chromosome. Future association studies of the full spectrum of Y chromosome variants will demonstrate the potential involvement of gain or loss of Y chromosome sequence in

Parallel origins of duplications and the formation of pseudogenes in mitochondrial DNA from parthenogenetic lizards (Heteronotia binoei; Gekkonidae).

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Zevering, C E; Moritz, C; Heideman, A; Sturm, R A

1991-11-01

Analysis of mitochondrial DNAs (mtDNAs) from parthenogenetic lizards of the Heteronotia binoei complex with restriction enzymes revealed an approximately 5-kb addition present in all 77 individuals. Cleavage site mapping suggested the presence of a direct tandem duplication spanning the 16S and 12S rRNA genes, the control region and most, if not all, of the gene for the subunit 1 of NADH dehydrogenase (ND1). The location of the duplication was confirmed by Southern hybridization. A restriction enzyme survey provided evidence for modifications to each copy of the duplicated sequence, including four large deletions. Each gene affected by a deletion was complemented by an intact version in the other copy of the sequence, although for one gene the functional copy was heteroplasmic for another deletion. Sequencing of a fragment from one copy of the duplication which encompassed the tRNA(leu)(UUR) and parts of the 16S rRNA and ND1 genes, revealed mutations expected to disrupt function. Thus, evolution subsequent to the duplication event has resulted in mitochondrial pseudogenes. The presence of duplications in all of these parthenogens, but not among representatives of their maternal sexual ancestors, suggests that the duplications arose in the parthenogenetic form. This provides the second instance in H. binoei of mtDNA duplication associated with the transition from sexual to parthenogenetic reproduction. The increased incidence of duplications in parthenogenetic lizards may be caused by errors in mtDNA replication due to either polyploidy or hybridity of their nuclear genomes.

Analysis of the 9p21.3 sequence associated with coronary artery disease reveals a tendency for duplication in a CAD patient

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Kouprina, Natalay; Noskov, Vladimir N.; Waterfall, Joshua J.; Walker, Robert L.; Meltzer, Paul S.; Topol, Eric J.; Larionov, Vladimir

2018-01-01

Tandem segmental duplications (SDs) greater than 10 kb are widespread in complex genomes. They provide material for gene divergence and evolutionary adaptation, while formation of specific de novo SDs is a hallmark of cancer and some human diseases. Most SDs map to distinct genomic regions termed ‘duplication blocks’. SDs organization within these blocks is often poorly characterized as they are mosaics of ancestral duplicons juxtaposed with younger duplicons arising from more recent duplication events. Structural and functional analysis of SDs is further hampered as long repetitive DNA structures are underrepresented in existing BAC and YAC libraries. We applied Transformation-Associated Recombination (TAR) cloning, a versatile technique for large DNA manipulation, to selectively isolate the coronary artery disease (CAD) interval sequence within the 9p21.3 chromosome locus from a patient with coronary artery disease and normal individuals. Four tandem head-to-tail duplicons, each ∼50 kb long, were recovered in the patient but not in normal individuals. Sequence analysis revealed that the repeats varied by 10-15 SNPs between each other and by 82 SNPs between the human genome sequence (version hg19). SNPs polymorphism within the junctions between repeats allowed two junction types to be distinguished, Type 1 and Type 2, which were found at a 2:1 ratio. The junction sequences contained an Alu element, a sequence previously shown to play a role in duplication. Knowledge of structural variation in the CAD interval from more patients could help link this locus to cardiovascular diseases susceptibility, and maybe relevant to other cases of regional amplification, including cancer. PMID:29632643

Switches in Genomic GC Content Drive Shifts of Optimal Codons under Sustained Selection on Synonymous Sites

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Sun, Yu; Tamarit, Daniel

2017-01-01

Abstract The major codon preference model suggests that codons read by tRNAs in high concentrations are preferentially utilized in highly expressed genes. However, the identity of the optimal codons differs between species although the forces driving such changes are poorly understood. We suggest that these questions can be tackled by placing codon usage studies in a phylogenetic framework and that bacterial genomes with extreme nucleotide composition biases provide informative model systems. Switches in the background substitution biases from GC to AT have occurred in Gardnerella vaginalis (GC = 32%), and from AT to GC in Lactobacillus delbrueckii (GC = 62%) and Lactobacillus fermentum (GC = 63%). We show that despite the large effects on codon usage patterns by these switches, all three species evolve under selection on synonymous sites. In G. vaginalis, the dramatic codon frequency changes coincide with shifts of optimal codons. In contrast, the optimal codons have not shifted in the two Lactobacillus genomes despite an increased fraction of GC-ending codons. We suggest that all three species are in different phases of an on-going shift of optimal codons, and attribute the difference to a stronger background substitution bias and/or longer time since the switch in G. vaginalis. We show that comparative and correlative methods for optimal codon identification yield conflicting results for genomes in flux and discuss possible reasons for the mispredictions. We conclude that switches in the direction of the background substitution biases can drive major shifts in codon preference patterns even under sustained selection on synonymous codon sites. PMID:27540085

Evolution of Rosaceae Fruit Types Based on Nuclear Phylogeny in the Context of Geological Times and Genome Duplication.

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Xiang, Yezi; Huang, Chien-Hsun; Hu, Yi; Wen, Jun; Li, Shisheng; Yi, Tingshuang; Chen, Hongyi; Xiang, Jun; Ma, Hong

2017-02-01

Fruits are the defining feature of angiosperms, likely have contributed to angiosperm successes by protecting and dispersing seeds, and provide foods to humans and other animals, with many morphological types and important ecological and agricultural implications. Rosaceae is a family with ∼3000 species and an extraordinary spectrum of distinct fruits, including fleshy peach, apple, and strawberry prized by their consumers, as well as dry achenetum and follicetum with features facilitating seed dispersal, excellent for studying fruit evolution. To address Rosaceae fruit evolution and other questions, we generated 125 new transcriptomic and genomic datasets and identified hundreds of nuclear genes to reconstruct a well-resolved Rosaceae phylogeny with highly supported monophyly of all subfamilies and tribes. Molecular clock analysis revealed an estimated age of ∼101.6 Ma for crown Rosaceae and divergence times of tribes and genera, providing a geological and climate context for fruit evolution. Phylogenomic analysis yielded strong evidence for numerous whole genome duplications (WGDs), supporting the hypothesis that the apple tribe had a WGD and revealing another one shared by fleshy fruit-bearing members of this tribe, with moderate support for WGDs in the peach tribe and other groups. Ancestral character reconstruction for fruit types supports independent origins of fleshy fruits from dry-fruit ancestors, including the evolution of drupes (e.g., peach) and pomes (e.g., apple) from follicetum, and drupetum (raspberry and blackberry) from achenetum. We propose that WGDs and environmental factors, including animals, contributed to the evolution of the many fruits in Rosaceae, which provide a foundation for understanding fruit evolution. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

SINEs as driving forces in genome evolution.

Science.gov (United States)

Schmitz, J

2012-01-01

SINEs are short interspersed elements derived from cellular RNAs that repetitively retropose via RNA intermediates and integrate more or less randomly back into the genome. SINEs propagate almost entirely vertically within their host cells and, once established in the germline, are passed on from generation to generation. As non-autonomous elements, their reverse transcription (from RNA to cDNA) and genomic integration depends on the activity of the enzymatic machinery of autonomous retrotransposons, such as long interspersed elements (LINEs). SINEs are widely distributed in eukaryotes, but are especially effectively propagated in mammalian species. For example, more than a million Alu-SINE copies populate the human genome (approximately 13% of genomic space), and few master copies of them are still active. In the organisms where they occur, SINEs are a challenge to genomic integrity, but in the long term also can serve as beneficial building blocks for evolution, contributing to phenotypic heterogeneity and modifying gene regulatory networks. They substantially expand the genomic space and introduce structural variation to the genome. SINEs have the potential to mutate genes, to alter gene expression, and to generate new parts of genes. A balanced distribution and controlled activity of such properties is crucial to maintaining the organism's dynamic and thriving evolution. Copyright © 2012 S. Karger AG, Basel.

The complex jujube genome provides insights into fruit tree biology.

Science.gov (United States)

Liu, Meng-Jun; Zhao, Jin; Cai, Qing-Le; Liu, Guo-Cheng; Wang, Jiu-Rui; Zhao, Zhi-Hui; Liu, Ping; Dai, Li; Yan, Guijun; Wang, Wen-Jiang; Li, Xian-Song; Chen, Yan; Sun, Yu-Dong; Liu, Zhi-Guo; Lin, Min-Juan; Xiao, Jing; Chen, Ying-Ying; Li, Xiao-Feng; Wu, Bin; Ma, Yong; Jian, Jian-Bo; Yang, Wei; Yuan, Zan; Sun, Xue-Chao; Wei, Yan-Li; Yu, Li-Li; Zhang, Chi; Liao, Sheng-Guang; He, Rong-Jun; Guang, Xuan-Min; Wang, Zhuo; Zhang, Yue-Yang; Luo, Long-Hai

2014-10-28

The jujube (Ziziphus jujuba Mill.), a member of family Rhamnaceae, is a major dry fruit and a traditional herbal medicine for more than one billion people. Here we present a high-quality sequence for the complex jujube genome, the first genome sequence of Rhamnaceae, using an integrated strategy. The final assembly spans 437.65 Mb (98.6% of the estimated) with 321.45 Mb anchored to the 12 pseudo-chromosomes and contains 32,808 genes. The jujube genome has undergone frequent inter-chromosome fusions and segmental duplications, but no recent whole-genome duplication. Further analyses of the jujube-specific genes and transcriptome data from 15 tissues reveal the molecular mechanisms underlying some specific properties of the jujube. Its high vitamin C content can be attributed to a unique high level expression of genes involved in both biosynthesis and regeneration. Our study provides insights into jujube-specific biology and valuable genomic resources for the improvement of Rhamnaceae plants and other fruit trees.

The First Complete Chloroplast Genome Sequences in Actinidiaceae: Genome Structure and Comparative Analysis.

Science.gov (United States)

Yao, Xiaohong; Tang, Ping; Li, Zuozhou; Li, Dawei; Liu, Yifei; Huang, Hongwen

2015-01-01

Actinidia chinensis is an important economic plant belonging to the basal lineage of the asterids. Availability of a complete Actinidia chloroplast genome sequence is crucial to understanding phylogenetic relationships among major lineages of angiosperms and facilitates kiwifruit genetic improvement. We report here the complete nucleotide sequences of the chloroplast genomes for Actinidia chinensis and A. chinensis var deliciosa obtained through de novo assembly of Illumina paired-end reads produced by total DNA sequencing. The total genome size ranges from 155,446 to 157,557 bp, with an inverted repeat (IR) of 24,013 to 24,391 bp, a large single copy region (LSC) of 87,984 to 88,337 bp and a small single copy region (SSC) of 20,332 to 20,336 bp. The genome encodes 113 different genes, including 79 unique protein-coding genes, 30 tRNA genes and 4 ribosomal RNA genes, with 16 duplicated in the inverted repeats, and a tRNA gene (trnfM-CAU) duplicated once in the LSC region. Comparisons of IR boundaries among four asterid species showed that IR/LSC borders were extended into the 5' portion of the psbA gene and IR contraction occurred in Actinidia. The clap gene has been lost from the chloroplast genome in Actinidia, and may have been transferred to the nucleus during chloroplast evolution. Twenty-seven polymorphic simple sequence repeat (SSR) loci were identified in the Actinidia chloroplast genome. Maximum parsimony analyses of a 72-gene, 16 taxa angiosperm dataset strongly support the placement of Actinidiaceae in Ericales within the basal asterids.

Comparative genomics analysis of rice and pineapple contributes to understand the chromosome number reduction and genomic changes in grasses

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Jinpeng Wang

2016-10-01

Full Text Available Rice is one of the most researched model plant, and has a genome structure most resembling that of the grass common ancestor after a grass common tetraploidization ~100 million years ago. There has been a standing controversy whether there had been 5 or 7 basic chromosomes, before the tetraploidization, which were tackled but could not be well solved for the lacking of a sequenced and assembled outgroup plant to have a conservative genome structure. Recently, the availability of pineapple genome, which has not been subjected to the grass-common tetraploidization, provides a precious opportunity to solve the above controversy and to research into genome changes of rice and other grasses. Here, we performed a comparative genomics analysis of pineapple and rice, and found solid evidence that grass-common ancestor had 2n =2x =14 basic chromosomes before the tetraploidization and duplicated to 2n = 4x = 28 after the event. Moreover, we proposed that enormous gene missing from duplicated regions in rice should be explained by an allotetraploid produced by prominently divergent parental lines, rather than gene losses after their divergence. This means that genome fractionation might have occurred before the formation of the allotetraploid grass ancestor.

Rectal duplication: a case report.

Science.gov (United States)

Didden, K; Masereel, B; Geyskens, P

2013-01-01

Gastrointestinal tract duplications are uncommon congenital abnormalities, that may occur anywhere along the alimentary tract. Most frequently they occur at the level of the small bowel tract and are symptomatic before the age of two. In our case we report the history of a 68-years old women with a colon duplication, especially a rectal duplication. This is very exceptional.

Genome-wide Comparative Analyses Reveal the Dynamic Evolution of Nucleotide-Binding Leucine-Rich Repeat Gene Family among Solanaceae Plants

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Eunyoung Seo

2016-08-01

Full Text Available Plants have evolved an elaborate innate immune system against invading pathogens. Within this system, intracellular nucleotide-binding leucine-rich repeat (NLR immune receptors are known play critical roles in effector-triggered immunity (ETI plant defense. We performed genome-wide identification and classification of NLR-coding sequences from the genomes of pepper, tomato, and potato using fixed criteria. We then compared genomic duplication and evolution features. We identified intact 267, 443, and 755 NLR-encoding genes in tomato, potato, and pepper genomes, respectively. Phylogenetic analyses and classification of Solanaceae NLRs revealed that the majority of NLR super family members fell into 14 subgroups, including a TIR-NLR (TNL subgroup and 13 non-TNL subgroups. Specific subgroups have expanded in each genome, with the expansion in pepper showing subgroup-specific physical clusters. Comparative analysis of duplications showed distinct duplication patterns within pepper and among Solanaceae plants suggesting subgroup- or species-specific gene duplication events after speciation, resulting in divergent evolution. Taken together, genome-wide analyses of NLR family members provide insights into their evolutionary history in Solanaceae. These findings also provide important foundational knowledge for understanding NLR evolution and will empower broader characterization of disease resistance genes to be used for crop breeding.

Duplication of 17(p11.2p11.2) in a male child with autism and severe language delay.

Science.gov (United States)

Nakamine, Alisa; Ouchanov, Leonid; Jiménez, Patricia; Manghi, Elina R; Esquivel, Marcela; Monge, Silvia; Fallas, Marietha; Burton, Barbara K; Szomju, Barbara; Elsea, Sarah H; Marshall, Christian R; Scherer, Stephen W; McInnes, L Alison

2008-03-01

Duplications of 17(p11.2p11.2) have been associated with various behavioral manifestations including attention deficits, obsessive-compulsive symptoms, autistic traits, and language delay. We are conducting a genetic study of autism and are screening all cases for submicroscopic chromosomal abnormalities, in addition to standard karyotyping, and fragile X testing. Using array-based comparative genomic hybridization analysis of data from the Affymetrix GeneChip(R) Human Mapping Array set, we detected a duplication of approximately 3.3 Mb on chromosome 17p11.2 in a male child with autism and severe expressive language delay. The duplication was confirmed by measuring the copy number of genomic DNA using quantitative polymerase chain reaction. Gene expression analyses revealed increased expression of three candidate genes for the Smith-Magenis neurobehavioral phenotype, RAI1, DRG2, and RASD1, in transformed lymphocytes from Case 81A, suggesting gene dosage effects. Our results add to a growing body of evidence suggesting that duplications of 17(p11.2p11.2) result in language delay as well as autism and related phenotypes. As Smith-Magenis syndrome is also associated with language delay, a gene involved in acquisition of language may lie within this interval. Whether a parent of origin effect, gender of the case, the presence of allelic variation, or changes in expression of genes outside the breakpoints influence the resultant phenotype remains to be determined. (c) 2007 Wiley-Liss, Inc.

Rectal duplication.

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Kulkarni B

1995-04-01

Full Text Available Duplications of the alimentary tract are of a great rarity, particularly so in the rectum. Because of its rarity, the difficulty of making a correct diagnosis and of selection of proper approach for treatment, this entity bears a special significance. The present case report deals with a female newborn who presented with imperforate anus and a rectovestibular fistula and a mass prolapsing at the introitus. Complete excision of the mass was carried out through the perineal approach and the child then underwent, a PSARP for the correction of the rectal anomaly. Histology confirmed the mass to be a rectal duplication.

Genome sequence and genetic diversity of European ash trees

DEFF Research Database (Denmark)

Sollars, Elizabeth S A; Harper, Andrea L; Kelly, Laura J

2017-01-01

-heterozygosity Fraxinus excelsior tree from Gloucestershire, UK, annotating 38,852 protein-coding genes of which 25% appear ash specific when compared with the genomes of ten other plant species. Analyses of paralogous genes suggest a whole-genome duplication shared with olive (Olea europaea, Oleaceae). We also re...

Duplication of the oesophagus

Energy Technology Data Exchange (ETDEWEB)

Lingg, G; Nebel, G

1981-08-01

The article reports on the authors' own observation of a patient with duplication of the oesophagus. Basing on this case, the possibilities of the evolutionary origin are discussed briefly. The significance and decisive importance of X-ray film diagnosis in gastro-intestinal duplications is underlined.

Recent Duplication and Functional Divergence in Parasitic Nematode Levamisole-Sensitive Acetylcholine Receptors.

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Thomas B Duguet

2016-07-01

Full Text Available Helminth parasites rely on fast-synaptic transmission in their neuromusculature to experience the outside world and respond to it. Acetylcholine plays a pivotal role in this and its receptors are targeted by a wide variety of both natural and synthetic compounds used in human health and for the control of parasitic disease. The model, Caenorhabditis elegans is characterized by a large number of acetylcholine receptor subunit genes, a feature shared across the nematodes. This dynamic family is characterized by both gene duplication and loss between species. The pentameric levamisole-sensitive acetylcholine receptor has been characterized from C. elegans, comprised of five different subunits. More recently, cognate receptors have been reconstituted from multiple parasitic nematodes that are found to vary in subunit composition. In order to understand the implications of receptor composition change and the origins of potentially novel drug targets, we investigated a specific example of subunit duplication based on analysis of genome data for 25 species from the 50 helminth genome initiative. We found multiple independent duplications of the unc-29, acetylcholine receptor subunit, where codon substitution rate analysis identified positive, directional selection acting on amino acid positions associated with subunit assembly. Characterization of four gene copies from a model parasitic nematode, Haemonchus contortus, demonstrated that each copy has acquired unique functional characteristics based on phenotype rescue of transgenic C. elegans and electrophysiology of receptors reconstituted in Xenopus oocytes. We found evidence that a specific incompatibility has evolved for two subunits co-expressed in muscle. We demonstrated that functional divergence of acetylcholine receptors, driven by directional selection, can occur more rapidly than previously thought and may be mediated by alteration of receptor assembly. This phenomenon is common among the

Genomic organization and evolution of the Atlantic salmon hemoglobin repertoire

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Phillips Ruth B

2010-10-01

Full Text Available Abstract Background The genomes of salmonids are considered pseudo-tetraploid undergoing reversion to a stable diploid state. Given the genome duplication and extensive biological data available for salmonids, they are excellent model organisms for studying comparative genomics, evolutionary processes, fates of duplicated genes and the genetic and physiological processes associated with complex behavioral phenotypes. The evolution of the tetrapod hemoglobin genes is well studied; however, little is known about the genomic organization and evolution of teleost hemoglobin genes, particularly those of salmonids. The Atlantic salmon serves as a representative salmonid species for genomics studies. Given the well documented role of hemoglobin in adaptation to varied environmental conditions as well as its use as a model protein for evolutionary analyses, an understanding of the genomic structure and organization of the Atlantic salmon α and β hemoglobin genes is of great interest. Results We identified four bacterial artificial chromosomes (BACs comprising two hemoglobin gene clusters spanning the entire α and β hemoglobin gene repertoire of the Atlantic salmon genome. Their chromosomal locations were established using fluorescence in situ hybridization (FISH analysis and linkage mapping, demonstrating that the two clusters are located on separate chromosomes. The BACs were sequenced and assembled into scaffolds, which were annotated for putatively functional and pseudogenized hemoglobin-like genes. This revealed that the tail-to-tail organization and alternating pattern of the α and β hemoglobin genes are well conserved in both clusters, as well as that the Atlantic salmon genome houses substantially more hemoglobin genes, including non-Bohr β globin genes, than the genomes of other teleosts that have been sequenced. Conclusions We suggest that the most parsimonious evolutionary path leading to the present organization of the Atlantic salmon

Genomic organization and evolution of the Atlantic salmon hemoglobin repertoire

Science.gov (United States)

2010-01-01

Background The genomes of salmonids are considered pseudo-tetraploid undergoing reversion to a stable diploid state. Given the genome duplication and extensive biological data available for salmonids, they are excellent model organisms for studying comparative genomics, evolutionary processes, fates of duplicated genes and the genetic and physiological processes associated with complex behavioral phenotypes. The evolution of the tetrapod hemoglobin genes is well studied; however, little is known about the genomic organization and evolution of teleost hemoglobin genes, particularly those of salmonids. The Atlantic salmon serves as a representative salmonid species for genomics studies. Given the well documented role of hemoglobin in adaptation to varied environmental conditions as well as its use as a model protein for evolutionary analyses, an understanding of the genomic structure and organization of the Atlantic salmon α and β hemoglobin genes is of great interest. Results We identified four bacterial artificial chromosomes (BACs) comprising two hemoglobin gene clusters spanning the entire α and β hemoglobin gene repertoire of the Atlantic salmon genome. Their chromosomal locations were established using fluorescence in situ hybridization (FISH) analysis and linkage mapping, demonstrating that the two clusters are located on separate chromosomes. The BACs were sequenced and assembled into scaffolds, which were annotated for putatively functional and pseudogenized hemoglobin-like genes. This revealed that the tail-to-tail organization and alternating pattern of the α and β hemoglobin genes are well conserved in both clusters, as well as that the Atlantic salmon genome houses substantially more hemoglobin genes, including non-Bohr β globin genes, than the genomes of other teleosts that have been sequenced. Conclusions We suggest that the most parsimonious evolutionary path leading to the present organization of the Atlantic salmon hemoglobin genes involves

Genetic, genomic, and molecular tools for studying the protoploid yeast, L. waltii.

Science.gov (United States)

Di Rienzi, Sara C; Lindstrom, Kimberly C; Lancaster, Ragina; Rolczynski, Lisa; Raghuraman, M K; Brewer, Bonita J

2011-02-01

Sequencing of the yeast Kluyveromyces waltii (recently renamed Lachancea waltii) provided evidence of a whole genome duplication event in the lineage leading to the well-studied Saccharomyces cerevisiae. While comparative genomic analyses of these yeasts have proven to be extremely instructive in modeling the loss or maintenance of gene duplicates, experimental tests of the ramifications following such genome alterations remain difficult. To transform L. waltii from an organism of the computational comparative genomic literature into an organism of the functional comparative genomic literature, we have developed genetic, molecular and genomic tools for working with L. waltii. In particular, we have characterized basic properties of L. waltii (growth, ploidy, molecular karyotype, mating type and the sexual cycle), developed transformation, cell cycle arrest and synchronization protocols, and have created centromeric and non-centromeric vectors as well as a genome browser for L. waltii. We hope that these tools will be used by the community to follow up on the ideas generated by sequence data and lead to a greater understanding of eukaryotic biology and genome evolution. 2010 John Wiley & Sons, Ltd.

Universal global imprints of genome growth and evolution--equivalent length and cumulative mutation density.

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Hong-Da Chen

Full Text Available BACKGROUND: Segmental duplication is widely held to be an important mode of genome growth and evolution. Yet how this would affect the global structure of genomes has been little discussed. METHODS/PRINCIPAL FINDINGS: Here, we show that equivalent length, or L(e, a quantity determined by the variance of fluctuating part of the distribution of the k-mer frequencies in a genome, characterizes the latter's global structure. We computed the L(es of 865 complete chromosomes and found that they have nearly universal but (k-dependent values. The differences among the L(e of a chromosome and those of its coding and non-coding parts were found to be slight. CONCLUSIONS: We verified that these non-trivial results are natural consequences of a genome growth model characterized by random segmental duplication and random point mutation, but not of any model whose dominant growth mechanism is not segmental duplication. Our study also indicates that genomes have a nearly universal cumulative "point" mutation density of about 0.73 mutations per site that is compatible with the relatively low mutation rates of (1-5 x 10(-3/site/Mya previously determined by sequence comparison for the human and E. coli genomes.

Williams syndrome deletions and duplications: Genetic windows to understanding anxiety, sociality, autism, and schizophrenia.

Science.gov (United States)

Crespi, Bernard J; Procyshyn, Tanya L

2017-08-01

We describe and evaluate an integrative hypothesis for helping to explain the major neurocognitive features of individuals with Williams syndrome region deletions and duplications. First, we demonstrate how the cognitive differences between Williams syndrome individuals, individuals with duplications of this region, and healthy individuals parallel the differences between individuals subject to effects of increased or decreased oxytocin. Second, we synthesize evidence showing that variation in expression of the gene GTF2I (General Transcription Factor II-I) underlies the primary social phenotypes of Williams syndrome and that common genetic variation in GTF2I mediates oxytocin reactivity, and its correlates, in healthy populations. Third, we describe findings relevant to the hypothesis that the GTF2I gene is subject to parent of origin effects whose behavioral expression fits with predictions from the kinship theory of genomic imprinting. Fourth, we describe how Williams syndrome can be considered, in part, as an autistic syndrome of Lorna Wing's 'active-but-odd' autism subtype, in contrast to associations of duplications with both schizophrenia and autism. Copyright © 2017 Elsevier Ltd. All rights reserved.

The ecoresponsive genome of Daphnia pulex

Energy Technology Data Exchange (ETDEWEB)

Colbourne, John K.; Pfrender, Michael E.; Gilbert, Donald; Thomas, W. Kelley; Tucker, Abraham; Oakley, Todd H.; Tokishita, Shinichi; Aerts, Andrea; Arnold, Georg J.; Basu, Malay Kumar; Bauer, Darren J.; Caceres, Carla E.; Carmel, Liran; Casola, Claudio; Choi, Jeong-Hyeon; Detter, John C.; Dong, Qunfeng; Dusheyko, Serge; Eads, Brian D.; Frohlich, Thomas; Geiler-Samerotte, Kerry A.; Gerlach, Daniel; Hatcher, Phil; Jogdeo, Sanjuro; Krijgsveld, Jeroen; Kriventseva, Evgenia V; Kültz, Dietmar; Laforsch, Christian; Lindquist, Erika; Lopez, Jacqueline; Manak, Robert; Muller, Jean; Pangilinan, Jasmyn; Patwardhan, Rupali P.; Pitluck, Samuel; Pritham, Ellen J.; Rechtsteiner, Andreas; Rho, Mina; Rogozin, Igor B.; Sakarya, Onur; Salamov, Asaf; Schaack, Sarah; Shapiro, Harris; Shiga, Yasuhiro; Skalitzky, Courtney; Smith, Zachary; Souvorov, Alexander; Sung, Way; Tang, Zuojian; Tsuchiya, Dai; Tu, Hank; Vos, Harmjan; Wang, Mei; Wolf, Yuri I.; Yamagata, Hideo; Yamada, Takuji; Ye, Yuzhen; Shaw, Joseph R.; Andrews, Justen; Crease, Teresa J.; Tang, Haixu; Lucas, Susan M.; Robertson, Hugh M.; Bork, Peer; Koonin, Eugene V.; Zdobnov, Evgeny M.; Grigoriev, Igor V.; Lynch, Michael; Boore, Jeffrey L.

2011-02-04

This document provides supporting material related to the sequencing of the ecoresponsive genome of Daphnia pulex. This material includes information on materials and methods and supporting text, as well as supplemental figures, tables, and references. The coverage of materials and methods addresses genome sequence, assembly, and mapping to chromosomes, gene inventory, attributes of a compact genome, the origin and preservation of Daphnia pulex genes, implications of Daphnia's genome structure, evolutionary diversification of duplicated genes, functional significance of expanded gene families, and ecoresponsive genes. Supporting text covers chromosome studies, gene homology among Daphnia genomes, micro-RNA and transposable elements and the 46 Daphnia pulex opsins. 36 figures, 50 tables, 183 references.

Duplication of the oesophagus

International Nuclear Information System (INIS)

Lingg, G.; Nebel, G.

1981-01-01

The article reports on the authors' own observation of a patient with duplication of the oesophagus. Basing on this case, the possibilities of the evolutionary origin are discussed briefly. The significance and decisive importance of X-ray film diagnosis in gastro-intestinal duplications is underlined. (orig.) [de

Extensive lineage-specific gene duplication and evolution of the spiggin multi-gene family in stickleback

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Nishida Mutsumi

2007-11-01

Full Text Available Abstract Background The threespine stickleback (Gasterosteus aculeatus has a characteristic reproductive mode; mature males build nests using a secreted glue-like protein called spiggin. Although recent studies reported multiple occurrences of genes that encode this glue-like protein spiggin in threespine and ninespine sticklebacks, it is still unclear how many genes compose the spiggin multi-gene family. Results Genome sequence analysis of threespine stickleback showed that there are at least five spiggin genes and two pseudogenes, whereas a single spiggin homolog occurs in the genomes of other fishes. Comparative genome sequence analysis demonstrated that Muc19, a single-copy mucous gene in human and mouse, is an ortholog of spiggin. Phylogenetic and molecular evolutionary analyses of these sequences suggested that an ancestral spiggin gene originated from a member of the mucin gene family as a single gene in the common ancestor of teleosts, and gene duplications of spiggin have occurred in the stickleback lineage. There was inter-population variation in the copy number of spiggin genes and positive selection on some codons, indicating that additional gene duplication/deletion events and adaptive evolution at some amino acid sites may have occurred in each stickleback population. Conclusion A number of spiggin genes exist in the threespine stickleback genome. Our results provide insight into the origin and dynamic evolutionary process of the spiggin multi-gene family in the threespine stickleback lineage. The dramatic evolution of genes for mucous substrates may have contributed to the generation of distinct characteristics such as "bio-glue" in vertebrates.

The bipartite mitochondrial genome of Ruizia karukerae (Rhigonematomorpha, Nematoda).

Science.gov (United States)

Kim, Taeho; Kern, Elizabeth; Park, Chungoo; Nadler, Steven A; Bae, Yeon Jae; Park, Joong-Ki

2018-05-10

Mitochondrial genes and whole mitochondrial genome sequences are widely used as molecular markers in studying population genetics and resolving both deep and shallow nodes in phylogenetics. In animals the mitochondrial genome is generally composed of a single chromosome, but mystifying exceptions sometimes occur. We determined the complete mitochondrial genome of the millipede-parasitic nematode Ruizia karukerae and found its mitochondrial genome consists of two circular chromosomes, which is highly unusual in bilateral animals. Chromosome I is 7,659 bp and includes six protein-coding genes, two rRNA genes and nine tRNA genes. Chromosome II comprises 7,647 bp, with seven protein-coding genes and 16 tRNA genes. Interestingly, both chromosomes share a 1,010 bp sequence containing duplicate copies of cox2 and three tRNA genes (trnD, trnG and trnH), and the nucleotide sequences between the duplicated homologous gene copies are nearly identical, suggesting a possible recent genesis for this bipartite mitochondrial genome. Given that little is known about the formation, maintenance or evolution of abnormal mitochondrial genome structures, R. karukerae mtDNA may provide an important early glimpse into this process.

Anterior colorectal duplication presenting as rectal prolapse.

Science.gov (United States)

Ramirez-Resendiz, Amador; Asz, Jose; Medina-Vega, F Antonio; Ortega-Salgado, J Arturo

2007-09-01

Duplications of the gastrointestinal (GI) tract are rare. Only 5% of them are rectal and there are very few reports of rectal prolapse (RP) caused by a duplication. An 11 month-old female presented with a RP caused by a blind-ended anterior tubular colorectal duplication. The duplication was successfully opened and connected to the normal rectum without complications. Although infrequent, a rectal duplication should be considered in the differential diagnosis of RP.

The infinite sites model of genome evolution.

Science.gov (United States)

Ma, Jian; Ratan, Aakrosh; Raney, Brian J; Suh, Bernard B; Miller, Webb; Haussler, David

2008-09-23

We formalize the problem of recovering the evolutionary history of a set of genomes that are related to an unseen common ancestor genome by operations of speciation, deletion, insertion, duplication, and rearrangement of segments of bases. The problem is examined in the limit as the number of bases in each genome goes to infinity. In this limit, the chromosomes are represented by continuous circles or line segments. For such an infinite-sites model, we present a polynomial-time algorithm to find the most parsimonious evolutionary history of any set of related present-day genomes.

Neutral Evolution of Duplicated DNA: An Evolutionary Stick-Breaking Process Causes Scale-Invariant Behavior

Science.gov (United States)

Massip, Florian; Arndt, Peter F.

2013-04-01

Recently, an enrichment of identical matching sequences has been found in many eukaryotic genomes. Their length distribution exhibits a power law tail raising the question of what evolutionary mechanism or functional constraints would be able to shape this distribution. Here we introduce a simple and evolutionarily neutral model, which involves only point mutations and segmental duplications, and produces the same statistical features as observed for genomic data. Further, we extend a mathematical model for random stick breaking to analytically show that the exponent of the power law tail is -3 and universal as it does not depend on the microscopic details of the model.

Genome Organization Drives Chromosome Fragility.

Science.gov (United States)

Canela, Andres; Maman, Yaakov; Jung, Seolkyoung; Wong, Nancy; Callen, Elsa; Day, Amanda; Kieffer-Kwon, Kyong-Rim; Pekowska, Aleksandra; Zhang, Hongliang; Rao, Suhas S P; Huang, Su-Chen; Mckinnon, Peter J; Aplan, Peter D; Pommier, Yves; Aiden, Erez Lieberman; Casellas, Rafael; Nussenzweig, André

2017-07-27

In this study, we show that evolutionarily conserved chromosome loop anchors bound by CCCTC-binding factor (CTCF) and cohesin are vulnerable to DNA double strand breaks (DSBs) mediated by topoisomerase 2B (TOP2B). Polymorphisms in the genome that redistribute CTCF/cohesin occupancy rewire DNA cleavage sites to novel loop anchors. While transcription- and replication-coupled genomic rearrangements have been well documented, we demonstrate that DSBs formed at loop anchors are largely transcription-, replication-, and cell-type-independent. DSBs are continuously formed throughout interphase, are enriched on both sides of strong topological domain borders, and frequently occur at breakpoint clusters commonly translocated in cancer. Thus, loop anchors serve as fragile sites that generate DSBs and chromosomal rearrangements. VIDEO ABSTRACT. Published by Elsevier Inc.

Genomic islands predict functional adaptation in marine actinobacteria

Energy Technology Data Exchange (ETDEWEB)

Penn, Kevin; Jenkins, Caroline; Nett, Markus; Udwary, Daniel; Gontang, Erin; McGlinchey, Ryan; Foster, Brian; Lapidus, Alla; Podell, Sheila; Allen, Eric; Moore, Bradley; Jensen, Paul

2009-04-01

Linking functional traits to bacterial phylogeny remains a fundamental but elusive goal of microbial ecology 1. Without this information, it becomes impossible to resolve meaningful units of diversity and the mechanisms by which bacteria interact with each other and adapt to environmental change. Ecological adaptations among bacterial populations have been linked to genomic islands, strain-specific regions of DNA that house functionally adaptive traits 2. In the case of environmental bacteria, these traits are largely inferred from bioinformatic or gene expression analyses 2, thus leaving few examples in which the functions of island genes have been experimentally characterized. Here we report the complete genome sequences of Salinispora tropica and S. arenicola, the first cultured, obligate marine Actinobacteria 3. These two species inhabit benthic marine environments and dedicate 8-10percent of their genomes to the biosynthesis of secondary metabolites. Despite a close phylogenetic relationship, 25 of 37 secondary metabolic pathways are species-specific and located within 21 genomic islands, thus providing new evidence linking secondary metabolism to ecological adaptation. Species-specific differences are also observed in CRISPR sequences, suggesting that variations in phage immunity provide fitness advantages that contribute to the cosmopolitan distribution of S. arenicola 4. The two Salinispora genomes have evolved by complex processes that include the duplication and acquisition of secondary metabolite genes, the products of which provide immediate opportunities for molecular diversification and ecological adaptation. Evidence that secondary metabolic pathways are exchanged by Horizontal Gene Transfer (HGT) yet are fixed among globally distributed populations 5 supports a functional role for their products and suggests that pathway acquisition represents a previously unrecognized force driving bacterial diversification

Genome Wide Identification, Phylogeny, and Expression of Aquaporin Genes in Common Carp (Cyprinus carpio.

Directory of Open Access Journals (Sweden)

Chuanju Dong

Full Text Available Aquaporins (Aqps are integral membrane proteins that facilitate the transport of water and small solutes across cell membranes. Among vertebrate species, Aqps are highly conserved in both gene structure and amino acid sequence. These proteins are vital for maintaining water homeostasis in living organisms, especially for aquatic animals such as teleost fish. Studies on teleost Aqps are mainly limited to several model species with diploid genomes. Common carp, which has a tetraploidized genome, is one of the most common aquaculture species being adapted to a wide range of aquatic environments. The complete common carp genome has recently been released, providing us the possibility for gene evolution of aqp gene family after whole genome duplication.In this study, we identified a total of 37 aqp genes from common carp genome. Phylogenetic analysis revealed that most of aqps are highly conserved. Comparative analysis was performed across five typical vertebrate genomes. We found that almost all of the aqp genes in common carp were duplicated in the evolution of the gene family. We postulated that the expansion of the aqp gene family in common carp was the result of an additional whole genome duplication event and that the aqp gene family in other teleosts has been lost in their evolution history with the reason that the functions of genes are redundant and conservation. Expression patterns were assessed in various tissues, including brain, heart, spleen, liver, intestine, gill, muscle, and skin, which demonstrated the comprehensive expression profiles of aqp genes in the tetraploidized genome. Significant gene expression divergences have been observed, revealing substantial expression divergences or functional divergences in those duplicated aqp genes post the latest WGD event.To some extent, the gene families are also considered as a unique source for evolutionary studies. Moreover, the whole set of common carp aqp gene family provides an

Neurodevelopmental and neurobehavioral characteristics in males and females with CDKL5 duplications.

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Szafranski, Przemyslaw; Golla, Sailaja; Jin, Weihong; Fang, Ping; Hixson, Patricia; Matalon, Reuben; Kinney, Daniel; Bock, Hans-Georg; Craigen, William; Smith, Janice L; Bi, Weimin; Patel, Ankita; Wai Cheung, Sau; Bacino, Carlos A; Stankiewicz, Paweł

2015-07-01

Point mutations and genomic deletions of the CDKL5 (STK9) gene on chromosome Xp22 have been reported in patients with severe neurodevelopmental abnormalities, including Rett-like disorders. To date, only larger-sized (8-21 Mb) duplications harboring CDKL5 have been described. We report seven females and four males from seven unrelated families with CDKL5 duplications 540-935 kb in size. Three families of different ethnicities had identical 667kb duplications containing only the shorter CDKL5 isoform. Four affected boys, 8-14 years of age, and three affected girls, 6-8 years of age, manifested autistic behavior, developmental delay, language impairment, and hyperactivity. Of note, two boys and one girl had macrocephaly. Two carrier mothers of the affected boys reported a history of problems with learning and mathematics while at school. None of the patients had epilepsy. Similarly to CDKL5 mutations and deletions, the X-inactivation pattern in all six studied females was random. We hypothesize that the increased dosage of CDKL5 might have affected interactions of this kinase with its substrates, leading to perturbation of synaptic plasticity and learning, and resulting in autistic behavior, developmental and speech delay, hyperactivity, and macrocephaly.

Sex drives intracellular conflict in yeast.

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Harrison, E; MacLean, R C; Koufopanou, V; Burt, A

2014-08-01

Theory predicts that sex can drive the evolution of conflict within the cell. During asexual reproduction, genetic material within the cell is inherited as a single unit, selecting for cooperation both within the genome as well as between the extra-genomic elements within the cell (e.g. plasmids and endosymbionts). Under sexual reproduction, this unity is broken down as parental genomes are distributed between meiotic progeny. Genetic elements able to transmit to more than 50% of meiotic progeny have a transmission advantage over the rest of the genome and are able to spread, even where they reduce the fitness of the individual as a whole. Sexual reproduction is therefore expected to drive the evolution of selfish genetic elements (SGEs). Here, we directly test this hypothesis by studying the evolution of two independent SGEs, the 2-μm plasmid and selfish mitochondria, in populations of Saccharomyces cerevisiae. Following 22 rounds of sexual reproduction, 2-μm copy number increased by approximately 13.2 (±5.6) copies per cell, whereas in asexual populations copy number decreased by approximately 5.1 (±1.5) copies per cell. Given that the burden imposed by this parasite increases with copy number, these results support the idea that sex drives the evolution of increased SGE virulence. Moreover, we found that mitochondria that are respiratory-deficient rapidly invaded sexual but not asexual populations, demonstrating that frequent outcrossed sex can drive the de novo evolution of genetic parasites. Our study highlights the genomic perils of sex and suggests that SGEs may play a key role in driving major evolutionary transitions, such as uniparental inheritance. © 2014 The Authors. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

Partial duplication of the APBA2 gene in chromosome 15q13 corresponds to duplicon structures

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Kesterson Robert A

2003-04-01

Full Text Available Abstract Background Chromosomal abnormalities affecting human chromosome 15q11-q13 underlie multiple genomic disorders caused by deletion, duplication and triplication of intervals in this region. These events are mediated by highly homologous segments of DNA, or duplicons, that facilitate mispairing and unequal cross-over in meiosis. The gene encoding an amyloid precursor protein-binding protein (APBA2 was previously mapped to the distal portion of the interval commonly deleted in Prader-Willi and Angelman syndromes and duplicated in cases of autism. Results We show that this gene actually maps to a more telomeric location and is partially duplicated within the broader region. Two highly homologous copies of an interval containing a large 5' exon and downstream sequence are located ~5 Mb distal to the intact locus. The duplicated copies, containing the first coding exon of APBA2, can be distinguished by single nucleotide sequence differences and are transcriptionally inactive. Adjacent to APBA2 maps a gene termed KIAA0574. The protein encoded by this gene is weakly homologous to a protein termed X123 that in turn maps adjacent to APBA1 on 9q21.12; APBA1 is highly homologous to APBA2 in the C-terminal region and is distinguished from APBA2 by the N-terminal region encoded by this duplicated exon. Conclusion The duplication of APBA2 sequences in this region adds to a complex picture of different low copy repeats present across this region and elsewhere on the chromosome.

Submicroscopic duplication of the Wolf-Hirschhorn critical region with a 4p terminal deletion.

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Roselló, M; Monfort, S; Orellana, C; Ferrer-Bolufer, I; Quiroga, R; Oltra, S; Martínez, F

2009-01-01

Chromosomal rearrangements in the short arm of chromosome 4 can result in 2 different clinical entities: Wolf-Hirschhorn syndrome (WHS), characterized by severe growth delay, mental retardation, microcephaly, 'Greek helmet' facies, and closure defects, or partial 4p trisomy, associated with multiple congenital anomalies, mental retardation, and facial dysmorphisms. We present clinical and laboratory findings in a patient who showed a small duplication in 4p16.3 associated with a subtle terminal deletion in the same chromosomal region. GTG-banding analyses, multiplex ligation-dependent probe amplification analyses, and studies by array-based comparative genomic hybridization were performed. The results of the analyses revealed a de novo 1.3 Mb deletion of the terminal 4p and a 1.1 Mb duplication in our patient, encompassing the WHS critical region. Interestingly, this unusual duplication/deletion rearrangement results in an intermediate phenotype that shares characteristics of the WHS and the 4p trisomy syndrome. The use of novel technologies in the genetic diagnosis leads to the description of new clinical syndromes; there is a growing list of microduplication syndromes. Therefore, we propose that overexpression of candidate genes in WHS (WHSC1, WHSC2 and LETM1) due to a duplication causes a clinical entity different to both the WHS and 4p trisomy syndrome. (c) 2009 S. Karger AG, Basel.

Salmo salar and Esox lucius full-length cDNA sequences reveal changes in evolutionary pressures on a post-tetraploidization genome

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Holt Robert A

2010-04-01

Full Text Available Abstract Background Salmonids are one of the most intensely studied fish, in part due to their economic and environmental importance, and in part due to a recent whole genome duplication in the common ancestor of salmonids. This duplication greatly impacts species diversification, functional specialization, and adaptation. Extensive new genomic resources have recently become available for Atlantic salmon (Salmo salar, but documentation of allelic versus duplicate reference genes remains a major uncertainty in the complete characterization of its genome and its evolution. Results From existing expressed sequence tag (EST resources and three new full-length cDNA libraries, 9,057 reference quality full-length gene insert clones were identified for Atlantic salmon. A further 1,365 reference full-length clones were annotated from 29,221 northern pike (Esox lucius ESTs. Pairwise dN/dS comparisons within each of 408 sets of duplicated salmon genes using northern pike as a diploid out-group show asymmetric relaxation of selection on salmon duplicates. Conclusions 9,057 full-length reference genes were characterized in S. salar and can be used to identify alleles and gene family members. Comparisons of duplicated genes show that while purifying selection is the predominant force acting on both duplicates, consistent with retention of functionality in both copies, some relaxation of pressure on gene duplicates can be identified. In addition, there is evidence that evolution has acted asymmetrically on paralogs, allowing one of the pair to diverge at a faster rate.

Yeast genome sequencing:

DEFF Research Database (Denmark)

Piskur, Jure; Langkjær, Rikke Breinhold

2004-01-01

For decades, unicellular yeasts have been general models to help understand the eukaryotic cell and also our own biology. Recently, over a dozen yeast genomes have been sequenced, providing the basis to resolve several complex biological questions. Analysis of the novel sequence data has shown...... of closely related species helps in gene annotation and to answer how many genes there really are within the genomes. Analysis of non-coding regions among closely related species has provided an example of how to determine novel gene regulatory sequences, which were previously difficult to analyse because...... they are short and degenerate and occupy different positions. Comparative genomics helps to understand the origin of yeasts and points out crucial molecular events in yeast evolutionary history, such as whole-genome duplication and horizontal gene transfer(s). In addition, the accumulating sequence data provide...

The large soybean (Glycine max) WRKY TF family expanded by segmental duplication events and subsequent divergent selection among subgroups.

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Yin, Guangjun; Xu, Hongliang; Xiao, Shuyang; Qin, Yajuan; Li, Yaxuan; Yan, Yueming; Hu, Yingkao

2013-10-03

WRKY genes encode one of the most abundant groups of transcription factors in higher plants, and its members regulate important biological process such as growth, development, and responses to biotic and abiotic stresses. Although the soybean genome sequence has been published, functional studies on soybean genes still lag behind those of other species. We identified a total of 133 WRKY members in the soybean genome. According to structural features of their encoded proteins and to the phylogenetic tree, the soybean WRKY family could be classified into three groups (groups I, II, and III). A majority of WRKY genes (76.7%; 102 of 133) were segmentally duplicated and 13.5% (18 of 133) of the genes were tandemly duplicated. This pattern was not apparent in Arabidopsis or rice. The transcriptome atlas revealed notable differential expression in either transcript abundance or in expression patterns under normal growth conditions, which indicated wide functional divergence in this family. Furthermore, some critical amino acids were detected using DIVERGE v2.0 in specific comparisons, suggesting that these sites have contributed to functional divergence among groups or subgroups. In addition, site model and branch-site model analyses of positive Darwinian selection (PDS) showed that different selection regimes could have affected the evolution of these groups. Sites with high probabilities of having been under PDS were found in groups I, II c, II e, and III. Together, these results contribute to a detailed understanding of the molecular evolution of the WRKY gene family in soybean. In this work, all the WRKY genes, which were generated mainly through segmental duplication, were identified in the soybean genome. Moreover, differential expression and functional divergence of the duplicated WRKY genes were two major features of this family throughout their evolutionary history. Positive selection analysis revealed that the different groups have different evolutionary rates

The evolution of pepsinogen C genes in vertebrates: duplication, loss and functional diversification.

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Luís Filipe Costa Castro

Full Text Available BACKGROUND: Aspartic proteases comprise a large group of enzymes involved in peptide proteolysis. This collection includes prominent enzymes globally categorized as pepsins, which are derived from pepsinogen precursors. Pepsins are involved in gastric digestion, a hallmark of vertebrate physiology. An important member among the pepsinogens is pepsinogen C (Pgc. A particular aspect of Pgc is its apparent single copy status, which contrasts with the numerous gene copies found for example in pepsinogen A (Pga. Although gene sequences with similarity to Pgc have been described in some vertebrate groups, no exhaustive evolutionary framework has been considered so far. METHODOLOGY/PRINCIPAL FINDINGS: By combining phylogenetics and genomic analysis, we find an unexpected Pgc diversity in the vertebrate sub-phylum. We were able to reconstruct gene duplication timings relative to the divergence of major vertebrate clades. Before tetrapod divergence, a single Pgc gene tandemly expanded to produce two gene lineages (Pgbc and Pgc2. These have been differentially retained in various classes. Accordingly, we find Pgc2 in sauropsids, amphibians and marsupials, but not in eutherian mammals. Pgbc was retained in amphibians, but duplicated in the ancestor of amniotes giving rise to Pgb and Pgc1. The latter was retained in mammals and probably in reptiles and marsupials but not in birds. Pgb was kept in all of the amniote clade with independent episodes of loss in some mammalian species. Lineage specific expansions of Pgc2 and Pgbc have also occurred in marsupials and amphibians respectively. We find that teleost and tetrapod Pgc genes reside in distinct genomic regions hinting at a possible translocation. CONCLUSIONS: We conclude that the repertoire of Pgc genes is larger than previously reported, and that tandem duplications have modelled the history of Pgc genes. We hypothesize that gene expansion lead to functional divergence in tetrapods, coincident with the

Screening synteny blocks in pairwise genome comparisons through integer programming.

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Tang, Haibao; Lyons, Eric; Pedersen, Brent; Schnable, James C; Paterson, Andrew H; Freeling, Michael

2011-04-18

It is difficult to accurately interpret chromosomal correspondences such as true orthology and paralogy due to significant divergence of genomes from a common ancestor. Analyses are particularly problematic among lineages that have repeatedly experienced whole genome duplication (WGD) events. To compare multiple "subgenomes" derived from genome duplications, we need to relax the traditional requirements of "one-to-one" syntenic matchings of genomic regions in order to reflect "one-to-many" or more generally "many-to-many" matchings. However this relaxation may result in the identification of synteny blocks that are derived from ancient shared WGDs that are not of interest. For many downstream analyses, we need to eliminate weak, low scoring alignments from pairwise genome comparisons. Our goal is to objectively select subset of synteny blocks whose total scores are maximized while respecting the duplication history of the genomes in comparison. We call this "quota-based" screening of synteny blocks in order to appropriately fill a quota of syntenic relationships within one genome or between two genomes having WGD events. We have formulated the synteny block screening as an optimization problem known as "Binary Integer Programming" (BIP), which is solved using existing linear programming solvers. The computer program QUOTA-ALIGN performs this task by creating a clear objective function that maximizes the compatible set of synteny blocks under given constraints on overlaps and depths (corresponding to the duplication history in respective genomes). Such a procedure is useful for any pairwise synteny alignments, but is most useful in lineages affected by multiple WGDs, like plants or fish lineages. For example, there should be a 1:2 ploidy relationship between genome A and B if genome B had an independent WGD subsequent to the divergence of the two genomes. We show through simulations and real examples using plant genomes in the rosid superorder that the quota

The complete mitochondrial genome of the enigmatic bigheadedturtle (Platysternon): description of unusual genomic features and thereconciliation of phylogenetic hypotheses based on mitochondrial andnuclear DNA

Energy Technology Data Exchange (ETDEWEB)

Parham, James F.; Feldman, Chris R.; Boore, Jeffrey L.

2005-12-28

The big-headed turtle (Platysternon megacephalum) from east Asia is the sole living representative of a poorly-studied turtle lineage (Platysternidae). It has no close living relatives, and its phylogenetic position within turtles is one of the outstanding controversies in turtle systematics. Platysternon was traditionally considered to be close to snapping turtles (Chelydridae) based on some studies of its morphology and mitochondrial (mt) DNA, however, other studies of morphology and nuclear (nu) DNA do not support that hypothesis. We sequenced the complete mt genome of Platysternon and the nearly complete mt genomes of two other relevant turtles and compared them to turtle mt genomes from the literature to form the largest molecular dataset used to date to address this issue. The resulting phylogeny robustly rejects the placement of Platysternon with Chelydridae, but instead shows that it is a member of the Testudinoidea, a diverse, nearly globally-distributed group that includes pond turtles and tortoises. We also discovered that Platysternon mtDNA has large-scale gene rearrangements and possesses two, nearly identical, control regions, features that distinguish it from all other studied turtles. Our study robustly determines the phylogenetic placement of Platysternon and provides a well-resolved outline of major turtle lineages, while demonstrating the significantly greater resolving power of comparing large amounts of mt sequence over that of short fragments. Earlier phylogenies placing Platysternon with chelydrids required a temporal gap in the fossil record that is now unnecessary. The duplicated control regions and gene rearrangements of the Platysternon mt DNA probably resulted from the duplication of part of the genome and then the subsequent loss of redundant genes. Although it is possible that having two control regions may provide some advantage, explaining why the control regions would be maintained while some of the duplicated genes were eroded

PBX1 Genomic Pioneer Function Drives ERα Signaling Underlying Progression in Breast Cancer

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Magnani, Luca; Ballantyne, Elizabeth B.; Zhang, Xiaoyang; Lupien, Mathieu

2011-01-01

Altered transcriptional programs are a hallmark of diseases, yet how these are established is still ill-defined. PBX1 is a TALE homeodomain protein involved in the development of different types of cancers. The estrogen receptor alpha (ERα) is central to the development of two-thirds of all breast cancers. Here we demonstrate that PBX1 acts as a pioneer factor and is essential for the ERα-mediated transcriptional response driving aggressive tumors in breast cancer. Indeed, PBX1 expression correlates with ERα in primary breast tumors, and breast cancer cells depleted of PBX1 no longer proliferate following estrogen stimulation. Profiling PBX1 recruitment and chromatin accessibility across the genome of breast cancer cells through ChIP-seq and FAIRE-seq reveals that PBX1 is loaded and promotes chromatin openness at specific genomic locations through its capacity to read specific epigenetic signatures. Accordingly, PBX1 guides ERα recruitment to a specific subset of sites. Expression profiling studies demonstrate that PBX1 controls over 70% of the estrogen response. More importantly, the PBX1-dependent transcriptional program is associated with poor-outcome in breast cancer patients. Correspondingly, PBX1 expression alone can discriminate a priori the outcome in ERα-positive breast cancer patients. These features are markedly different from the previously characterized ERα-associated pioneer factor FoxA1. Indeed, PBX1 is the only pioneer factor identified to date that discriminates outcome such as metastasis in ERα-positive breast cancer patients. Together our results reveal that PBX1 is a novel pioneer factor defining aggressive ERα-positive breast tumors, as it guides ERα genomic activity to unique genomic regions promoting a transcriptional program favorable to breast cancer progression. PMID:22125492

Comprehensive genome-wide survey, genomic constitution and expression profiling of the NAC transcription factor family in foxtail millet (Setaria italica L..

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Swati Puranik

Full Text Available The NAC proteins represent a major plant-specific transcription factor family that has established enormously diverse roles in various plant processes. Aided by the availability of complete genomes, several members of this family have been identified in Arabidopsis, rice, soybean and poplar. However, no comprehensive investigation has been presented for the recently sequenced, naturally stress tolerant crop, Setaria italica (foxtail millet that is famed as a model crop for bioenergy research. In this study, we identified 147 putative NAC domain-encoding genes from foxtail millet by systematic sequence analysis and physically mapped them onto nine chromosomes. Genomic organization suggested that inter-chromosomal duplications may have been responsible for expansion of this gene family in foxtail millet. Phylogenetically, they were arranged into 11 distinct sub-families (I-XI, with duplicated genes fitting into one cluster and possessing conserved motif compositions. Comparative mapping with other grass species revealed some orthologous relationships and chromosomal rearrangements including duplication, inversion and deletion of genes. The evolutionary significance as duplication and divergence of NAC genes based on their amino acid substitution rates was understood. Expression profiling against various stresses and phytohormones provides novel insights into specific and/or overlapping expression patterns of SiNAC genes, which may be responsible for functional divergence among individual members in this crop. Further, we performed structure modeling and molecular simulation of a stress-responsive protein, SiNAC128, proffering an initial framework for understanding its molecular function. Taken together, this genome-wide identification and expression profiling unlocks new avenues for systematic functional analysis of novel NAC gene family candidates which may be applied for improvising stress adaption in plants.

Comprehensive genome-wide survey, genomic constitution and expression profiling of the NAC transcription factor family in foxtail millet (Setaria italica L.).

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Puranik, Swati; Sahu, Pranav Pankaj; Mandal, Sambhu Nath; B, Venkata Suresh; Parida, Swarup Kumar; Prasad, Manoj

2013-01-01

The NAC proteins represent a major plant-specific transcription factor family that has established enormously diverse roles in various plant processes. Aided by the availability of complete genomes, several members of this family have been identified in Arabidopsis, rice, soybean and poplar. However, no comprehensive investigation has been presented for the recently sequenced, naturally stress tolerant crop, Setaria italica (foxtail millet) that is famed as a model crop for bioenergy research. In this study, we identified 147 putative NAC domain-encoding genes from foxtail millet by systematic sequence analysis and physically mapped them onto nine chromosomes. Genomic organization suggested that inter-chromosomal duplications may have been responsible for expansion of this gene family in foxtail millet. Phylogenetically, they were arranged into 11 distinct sub-families (I-XI), with duplicated genes fitting into one cluster and possessing conserved motif compositions. Comparative mapping with other grass species revealed some orthologous relationships and chromosomal rearrangements including duplication, inversion and deletion of genes. The evolutionary significance as duplication and divergence of NAC genes based on their amino acid substitution rates was understood. Expression profiling against various stresses and phytohormones provides novel insights into specific and/or overlapping expression patterns of SiNAC genes, which may be responsible for functional divergence among individual members in this crop. Further, we performed structure modeling and molecular simulation of a stress-responsive protein, SiNAC128, proffering an initial framework for understanding its molecular function. Taken together, this genome-wide identification and expression profiling unlocks new avenues for systematic functional analysis of novel NAC gene family candidates which may be applied for improvising stress adaption in plants.

Genome-wide patterns of copy number variation in the diversified chicken genomes using next-generation sequencing.

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Yi, Guoqiang; Qu, Lujiang; Liu, Jianfeng; Yan, Yiyuan; Xu, Guiyun; Yang, Ning

2014-11-07

Copy number variation (CNV) is important and widespread in the genome, and is a major cause of disease and phenotypic diversity. Herein, we performed a genome-wide CNV analysis in 12 diversified chicken genomes based on whole genome sequencing. A total of 8,840 CNV regions (CNVRs) covering 98.2 Mb and representing 9.4% of the chicken genome were identified, ranging in size from 1.1 to 268.8 kb with an average of 11.1 kb. Sequencing-based predictions were confirmed at a high validation rate by two independent approaches, including array comparative genomic hybridization (aCGH) and quantitative PCR (qPCR). The Pearson's correlation coefficients between sequencing and aCGH results ranged from 0.435 to 0.755, and qPCR experiments revealed a positive validation rate of 91.71% and a false negative rate of 22.43%. In total, 2,214 (25.0%) predicted CNVRs span 2,216 (36.4%) RefSeq genes associated with specific biological functions. Besides two previously reported copy number variable genes EDN3 and PRLR, we also found some promising genes with potential in phenotypic variation. Two genes, FZD6 and LIMS1, related to disease susceptibility/resistance are covered by CNVRs. The highly duplicated SOCS2 may lead to higher bone mineral density. Entire or partial duplication of some genes like POPDC3 may have great economic importance in poultry breeding. Our results based on extensive genetic diversity provide a more refined chicken CNV map and genome-wide gene copy number estimates, and warrant future CNV association studies for important traits in chickens.

19q12q13.2 duplication syndrome: neuropsychiatric long-term follow-up of a new case and literature update

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Nacinovich R

2017-10-01

Full Text Available Renata Nacinovich,1,2 Nicoletta Villa,3 Fiorenza Broggi,1,2 Cristina Tavaniello,1 Monica Bomba,1 Donatella Conconi,2 Serena Redaelli,2 Elena Sala,3 Marialuisa Lavitrano,2 Francesca Neri1,2 1Childhood and Adolescence Neuropsychiatric Unit, San Gerardo Hospital, 2School of Medicine and Surgery, University of Milano Bicocca, 3Medical Genetics Laboratory, Clinical Pathology Department, San Gerardo Hospital, Monza, Italy Abstract: Genetic syndromes are well characterized by the phenotypic point of view, but little is known about their progression and patients’ quality of life. We report a 10-year neuropsychiatric follow-up of a boy with duplication of chromosome 19. Cytogenetic investigation was requested at the age of 5 years for psychomotor and speech delay. The genomic study identified an 8.17 Mb duplication on chromosome 19q12q13.2. We propose that the long-term follow-up of our patient would help to delineate the neuropsychiatric phenotype associated with 19q duplication. This study could be a model for further long-term research in the neuropsychiatric follow-up of patients with 19q duplication syndrome. Keywords: 19q duplication, neuropsychiatric follow-up, array-CGH

Syntenic block overlap multiplicities with a panel of reference genomes provide a signature of ancient polyploidization events.

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Zheng, Chunfang; Santos Muñoz, Daniella; Albert, Victor A; Sankoff, David

2015-01-01

Following whole genome duplication (WGD), there is a compact distribution of gene similarities within the genome reflecting duplicate pairs of all the genes in the genome. With time, the distribution broadens and loses volume due to variable decay of duplicate gene similarity and to the process of duplicate gene loss. If there are two WGD, the older one becomes so reduced and broad that it merges with the tail of the distributions resulting from more recent events, and it becomes difficult to distinguish them. The goal of this paper is to advance statistical methods of identifying, or at least counting, the WGD events in the lineage of a given genome. For a set of 15 angiosperm genomes, we analyze all 15 × 14 = 210 ordered pairs of target genome versus reference genome, using SynMap to find syntenic blocks. We consider all sets of B ≥ 2 syntenic blocks in the target genome that overlap in the reference genome as evidence of WGD activity in the target, whether it be one event or several. We hypothesize that in fitting an exponential function to the tail of the empirical distribution f (B) of block multiplicities, the size of the exponent will reflect the amount of WGD in the history of the target genome. By amalgamating the results from all reference genomes, a range of values of SynMap parameters, and alternative cutoff points for the tail, we find a clear pattern whereby multiple-WGD core eudicots have the smallest (negative) exponents, followed by core eudicots with only the single "γ" triplication in their history, followed by a non-core eudicot with a single WGD, followed by the monocots, with a basal angiosperm, the WGD-free Amborella having the largest exponent. The hypothesis that the exponent of the fit to the tail of the multiplicity distribution is a signature of the amount of WGD is verified, but there is also a clear complicating factor in the monocot clade, where a history of multiple WGD is not reflected in a small exponent.

Biliary tract duplication cyst with gastric heterotopia

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Grumbach, K.; Baker, D.H.; Weigert, J.; Altman, R.P.

1988-05-01

Cystic duplications of the biliary tract are rare anomalies, easily mistaken for choledochal cysts. Surgical drainage is the preferred therapy for choledochal cyst, but cystic duplication necessitates surgical excision as duplications may contain heterotopic gastric mucosa leading to peptic ulceration of the biliary tract. We report a case of biliary tract duplication cyst containing heterotopic alimentary mucosa which had initially been diagnosed and surgically treated as a choledochal cyst.

Biliary tract duplication cyst with gastric heterotopia

International Nuclear Information System (INIS)

Grumbach, K.; Baker, D.H.; Weigert, J.; Altman, R.P.

1988-01-01

Cystic duplications of the biliary tract are rare anomalies, easily mistaken for choledochal cysts. Surgical drainage is the preferred therapy for choledochal cyst, but cystic duplication necessitates surgical excision as duplications may contain heterotopic gastric mucosa leading to peptic ulceration of the biliary tract. We report a case of biliary tract duplication cyst containing heterotopic alimentary mucosa which had initially been diagnosed and surgically treated as a choledochal cyst. (orig.)

The centriole duplication cycle

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Fırat-Karalar, Elif Nur; Stearns, Tim

2014-01-01

Centrosomes are the main microtubule-organizing centre of animal cells and are important for many critical cellular and developmental processes from cell polarization to cell division. At the core of the centrosome are centrioles, which recruit pericentriolar material to form the centrosome and act as basal bodies to nucleate formation of cilia and flagella. Defects in centriole structure, function and number are associated with a variety of human diseases, including cancer, brain diseases and ciliopathies. In this review, we discuss recent advances in our understanding of how new centrioles are assembled and how centriole number is controlled. We propose a general model for centriole duplication control in which cooperative binding of duplication factors defines a centriole ‘origin of duplication’ that initiates duplication, and passage through mitosis effects changes that license the centriole for a new round of duplication in the next cell cycle. We also focus on variations on the general theme in which many centrioles are created in a single cell cycle, including the specialized structures associated with these variations, the deuterosome in animal cells and the blepharoplast in lower plant cells. PMID:25047614

Current incidence of duplicate publication in otolaryngology.

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Cheung, Veronique Wan Fook; Lam, Gilbert O A; Wang, Yun Fan; Chadha, Neil K

2014-03-01

Duplicate publication--deemed highly unethical--is the reproduction of substantial content in another article by the same authors. In 1999, Rosenthal et al. identified an 8.5% incidence of duplicate articles in two otolaryngology journals. We explored the current incidence in three otolaryngology journals in North America and Europe. Retrospective literature review. Index articles in 2008 in Archives of Otolaryngology-Head and Neck Surgery, Laryngoscope, and Clinical Otolaryngology were searched using MEDLINE. Potential duplicate publications in 2006 through 2010 were identified using the first, second, and last authors' names. Three authors independently investigated suspected duplicate publications--classifying them by degree of duplication. Of 358 index articles screened, 75 (20.9%) had 119 potential duplicates from 2006 to 2010. Full review of these 119 potential duplicates revealed a total of 40 articles with some form of redundancy (33.6% of the potential duplicates) involving 27 index articles (7.5% of 358 index articles); one (0.8%) "dual" publication (identical or nearly identical data and conclusions to the index article); three (2.5%) "suspected" dual publications (less than 50% new data and same conclusions); and 36 (30.3%) publications with "salami-slicing" (portion of the index article data repeated) were obtained. Further analysis compared the likelihood of duplicate publication by study source and subspecialty within otolaryngology. The incidence of duplicate publication has not significantly changed over 10 years. "Salami-slicing" was a concerning practice, with no cross-referencing in 61% of these cases. Detecting and eliminating redundant publications is a laborious task, but it is essential in upholding the journal quality and research integrity. © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

Array comparative genomic hybridization analysis of a familial duplication of chromosome 13q: A recognizable syndrome

NARCIS (Netherlands)

Mathijssen, Inge B.; Hoovers, Jan M. N.; Mul, Adri N. P. M.; Man, Hai-Yen; Ket, Jan L.; Hennekam, Raoul C. M.

2005-01-01

We report on a family with six persons in three generations who have mild mental retardation, behavioral problems, seizures, hearing loss, strabismus, dental anomalies, hypermobility, juvenile hallux valgus, and mild dysmorphic features. Classical cytogenetic analysis showed a partial duplication of

Expression Pattern Similarities Support the Prediction of Orthologs Retaining Common Functions after Gene Duplication Events1[OPEN

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Haberer, Georg; Panda, Arup; Das Laha, Shayani; Ghosh, Tapas Chandra; Schäffner, Anton R.

2016-01-01

The identification of functionally equivalent, orthologous genes (functional orthologs) across genomes is necessary for accurate transfer of experimental knowledge from well-characterized organisms to others. This frequently relies on automated, coding sequence-based approaches such as OrthoMCL, Inparanoid, and KOG, which usually work well for one-to-one homologous states. However, this strategy does not reliably work for plants due to the occurrence of extensive gene/genome duplication. Frequently, for one query gene, multiple orthologous genes are predicted in the other genome, and it is not clear a priori from sequence comparison and similarity which one preserves the ancestral function. We have studied 11 organ-dependent and stress-induced gene expression patterns of 286 Arabidopsis lyrata duplicated gene groups and compared them with the respective Arabidopsis (Arabidopsis thaliana) genes to predict putative expressologs and nonexpressologs based on gene expression similarity. Promoter sequence divergence as an additional tool to substantiate functional orthology only partially overlapped with expressolog classification. By cloning eight A. lyrata homologs and complementing them in the respective four Arabidopsis loss-of-function mutants, we experimentally proved that predicted expressologs are indeed functional orthologs, while nonexpressologs or nonfunctionalized orthologs are not. Our study demonstrates that even a small set of gene expression data in addition to sequence homologies are instrumental in the assignment of functional orthologs in the presence of multiple orthologs. PMID:27303025

Highly syntenic regions in the genomes of soybean, Medicago truncatula, and Arabidopsis thaliana

Directory of Open Access Journals (Sweden)

Roe Bruce A

2005-08-01

Full Text Available Abstract Background Recent genome sequencing enables mega-base scale comparisons between related genomes. Comparisons between animals, plants, fungi, and bacteria demonstrate extensive synteny tempered by rearrangements. Within the legume plant family, glimpses of synteny have also been observed. Characterizing syntenic relationships in legumes is important in transferring knowledge from model legumes to crops that are important sources of protein, fixed nitrogen, and health-promoting compounds. Results We have uncovered two large soybean regions exhibiting synteny with M. truncatula and with a network of segmentally duplicated regions in Arabidopsis. In all, syntenic regions comprise over 500 predicted genes spanning 3 Mb. Up to 75% of soybean genes are colinear with M. truncatula, including one region in which 33 of 35 soybean predicted genes with database support are colinear to M. truncatula. In some regions, 60% of soybean genes share colinearity with a network of A. thaliana duplications. One region is especially interesting because this 500 kbp segment of soybean is syntenic to two paralogous regions in M. truncatula on different chromosomes. Phylogenetic analysis of individual genes within these regions demonstrates that one is orthologous to the soybean region, with which it also shows substantially denser synteny and significantly lower levels of synonymous nucleotide substitutions. The other M. truncatula region is inferred to be paralogous, presumably resulting from a duplication event preceding speciation. Conclusion The presence of well-defined M. truncatula segments showing orthologous and paralogous relationships with soybean allows us to explore the evolution of contiguous genomic regions in the context of ancient genome duplication and speciation events.

Duplicated Enhancer Region Increases Expression of CTSB and Segregates with Keratolytic Winter Erythema in South African and Norwegian Families.

Science.gov (United States)

Ngcungcu, Thandiswa; Oti, Martin; Sitek, Jan C; Haukanes, Bjørn I; Linghu, Bolan; Bruccoleri, Robert; Stokowy, Tomasz; Oakeley, Edward J; Yang, Fan; Zhu, Jiang; Sultan, Marc; Schalkwijk, Joost; van Vlijmen-Willems, Ivonne M J J; von der Lippe, Charlotte; Brunner, Han G; Ersland, Kari M; Grayson, Wayne; Buechmann-Moller, Stine; Sundnes, Olav; Nirmala, Nanguneri; Morgan, Thomas M; van Bokhoven, Hans; Steen, Vidar M; Hull, Peter R; Szustakowski, Joseph; Staedtler, Frank; Zhou, Huiqing; Fiskerstrand, Torunn; Ramsay, Michele

2017-05-04

Keratolytic winter erythema (KWE) is a rare autosomal-dominant skin disorder characterized by recurrent episodes of palmoplantar erythema and epidermal peeling. KWE was previously mapped to 8p23.1-p22 (KWE critical region) in South African families. Using targeted resequencing of the KWE critical region in five South African families and SNP array and whole-genome sequencing in two Norwegian families, we identified two overlapping tandem duplications of 7.67 kb (South Africans) and 15.93 kb (Norwegians). The duplications segregated with the disease and were located upstream of CTSB, a gene encoding cathepsin B, a cysteine protease involved in keratinocyte homeostasis. Included in the 2.62 kb overlapping region of these duplications is an enhancer element that is active in epidermal keratinocytes. The activity of this enhancer correlated with CTSB expression in normal differentiating keratinocytes and other cell lines, but not with FDFT1 or NEIL2 expression. Gene expression (qPCR) analysis and immunohistochemistry of the palmar epidermis demonstrated significantly increased expression of CTSB, as well as stronger staining of cathepsin B in the stratum granulosum of affected individuals than in that of control individuals. Analysis of higher-order chromatin structure data and RNA polymerase II ChIA-PET data from MCF-7 cells did not suggest remote effects of the enhancer. In conclusion, KWE in South African and Norwegian families is caused by tandem duplications in a non-coding genomic region containing an active enhancer element for CTSB, resulting in upregulation of this gene in affected individuals. Copyright © 2017 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Molecular evolution of a Y chromosome to autosome gene duplication in Drosophila.

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Dyer, Kelly A; White, Brooke E; Bray, Michael J; Piqué, Daniel G; Betancourt, Andrea J

2011-03-01

In contrast to the rest of the genome, the Y chromosome is restricted to males and lacks recombination. As a result, Y chromosomes are unable to respond efficiently to selection, and newly formed Y chromosomes degenerate until few genes remain. The rapid loss of genes from newly formed Y chromosomes has been well studied, but gene loss from highly degenerate Y chromosomes has only recently received attention. Here, we identify and characterize a Y to autosome duplication of the male fertility gene kl-5 that occurred during the evolution of the testacea group species of Drosophila. The duplication was likely DNA based, as other Y-linked genes remain on the Y chromosome, the locations of introns are conserved, and expression analyses suggest that regulatory elements remain linked. Genetic mapping reveals that the autosomal copy of kl-5 resides on the dot chromosome, a tiny autosome with strongly suppressed recombination. Molecular evolutionary analyses show that autosomal copies of kl-5 have reduced polymorphism and little recombination. Importantly, the rate of protein evolution of kl-5 has increased significantly in lineages where it is on the dot versus Y linked. Further analyses suggest this pattern is a consequence of relaxed purifying selection, rather than adaptive evolution. Thus, although the initial fixation of the kl-5 duplication may have been advantageous, slightly deleterious mutations have accumulated in the dot-linked copies of kl-5 faster than in the Y-linked copies. Because the dot chromosome contains seven times more genes than the Y and is exposed to selection in both males and females, these results suggest that the dot suffers the deleterious effects of genetic linkage to more selective targets compared with the Y chromosome. Thus, a highly degenerate Y chromosome may not be the worst environment in the genome, as is generally thought, but may in fact be protected from the accumulation of deleterious mutations relative to other nonrecombining

Guided genome halving: hardness, heuristics and the history of the Hemiascomycetes.

Science.gov (United States)

Zheng, Chunfang; Zhu, Qian; Adam, Zaky; Sankoff, David

2008-07-01

Some present day species have incurred a whole genome doubling event in their evolutionary history, and this is reflected today in patterns of duplicated segments scattered throughout their chromosomes. These duplications may be used as data to 'halve' the genome, i.e. to reconstruct the ancestral genome at the moment of doubling, but the solution is often highly nonunique. To resolve this problem, we take account of outgroups, external reference genomes, to guide and narrow down the search. We improve on a previous, computationally costly, 'brute force' method by adapting the genome halving algorithm of El-Mabrouk and Sankoff so that it rapidly and accurately constructs an ancestor close the outgroups, prior to a local optimization heuristic. We apply this to reconstruct the predoubling ancestor of Saccharomyces cerevisiae and Candida glabrata, guided by the genomes of three other yeasts that diverged before the genome doubling event. We analyze the results in terms (1) of the minimum evolution criterion, (2) how close the genome halving result is to the final (local) minimum and (3) how close the final result is to an ancestor manually constructed by an expert with access to additional information. We also visualize the set of reconstructed ancestors using classic multidimensional scaling to see what aspects of the two doubled and three unduplicated genomes influence the differences among the reconstructions. The experimental software is available on request.

Maximum likelihood phylogenetic reconstruction from high-resolution whole-genome data and a tree of 68 eukaryotes.

Science.gov (United States)

Lin, Yu; Hu, Fei; Tang, Jijun; Moret, Bernard M E

2013-01-01

The rapid accumulation of whole-genome data has renewed interest in the study of the evolution of genomic architecture, under such events as rearrangements, duplications, losses. Comparative genomics, evolutionary biology, and cancer research all require tools to elucidate the mechanisms, history, and consequences of those evolutionary events, while phylogenetics could use whole-genome data to enhance its picture of the Tree of Life. Current approaches in the area of phylogenetic analysis are limited to very small collections of closely related genomes using low-resolution data (typically a few hundred syntenic blocks); moreover, these approaches typically do not include duplication and loss events. We describe a maximum likelihood (ML) approach for phylogenetic analysis that takes into account genome rearrangements as well as duplications, insertions, and losses. Our approach can handle high-resolution genomes (with 40,000 or more markers) and can use in the same analysis genomes with very different numbers of markers. Because our approach uses a standard ML reconstruction program (RAxML), it scales up to large trees. We present the results of extensive testing on both simulated and real data showing that our approach returns very accurate results very quickly. In particular, we analyze a dataset of 68 high-resolution eukaryotic genomes, with from 3,000 to 42,000 genes, from the eGOB database; the analysis, including bootstrapping, takes just 3 hours on a desktop system and returns a tree in agreement with all well supported branches, while also suggesting resolutions for some disputed placements.

Colonic duplication in an adult

International Nuclear Information System (INIS)

Baro, P.; Dario Casas, J.; Sanchez, D.

1988-01-01

A case of colonic duplication that was diagnosed radiologically in an adult is reported. A long duplicated segment below the normal transverse colon, with a wide anastomosis at the hepatic flexure level, was observed on barium enema. The rarity of this anomaly unassociated with other malformations is emphasized. (orig.)

Clinical Fact of Rectal Duplication with gastric heterotopy | Atmani ...

African Journals Online (AJOL)

Enteric duplication could occur through the entire alimentary tract. A case of rectal duplication cyst with heterotopic gastric mucosa in a chid is described. MRI scan is shown useful in the diagnosis of the duplication. The treatment is the complete local resection of the rectal duplication. Keywords: duplication, rectal, MRI, ...

Noncommunicating Isolated Enteric Duplication Cyst in the ...

African Journals Online (AJOL)

Noncommunicating isolated enteric duplications in the abdomen are an extremely rare variant of enteric duplications with their own blood supply. We report a case of a noncommunicating isolated ileal duplication in a 10-month-old boy. He was admitted because of severe abdominal distension and developed irritability ...

Laparoscopic excision of a newborn rectal duplication cyst.

Science.gov (United States)

Hartin, Charles W; Lau, Stanley T; Escobar, Mauricio A; Glick, Philip L

2008-08-01

Congenital rectal duplication cyst is a rare entity treated with surgical excision. Without treatment, a rectal duplication cyst may cause a variety of complications, most notably, transforming into a malignancy. We report on a 7-week-old girl who was found to have a rectal duplication cyst. The rectal duplication cyst was successfully excised laparoscopically. Rectal duplication cysts are rare alimentary tract anomalies generally discovered during childhood. Complications include symptoms arising from the cyst and the possibility of malignant degeneration. They are typically managed by surgical excision.

Distribution of segmental duplications in the context of higher order chromatin organisation of human chromosome 7

DEFF Research Database (Denmark)

Ebert, Grit; Steininger, Anne; Weißmann, Robert

2014-01-01

of the Williams-Beuren syndrome locus we demonstrate by cross-species comparison that these SDs have inserted at the borders of a topological domain and that they flank regions with distinct DNA conformation. CONCLUSIONS: Our study suggests a link of nuclear architecture and the propagation of SDs across......BACKGROUND: Segmental duplications (SDs) are not evenly distributed along chromosomes. The reasons for this biased susceptibility to SD insertion are poorly understood. Accumulation of SDs is associated with increased genomic instability, which can lead to structural variants and genomic disorders...... chromosome 7, either by promoting regional SD insertion or by contributing to the establishment of higher order chromatin organisation themselves. The latter could compensate for the high risk of structural rearrangements and thus may have contributed to their evolutionary fixation in the human genome....

The complete chloroplast genome sequence of Pelargonium xhortorum: Or ganization and evolution of the largest and most highlyrearranged chloroplast genome of land plants

Energy Technology Data Exchange (ETDEWEB)

Chumley, Timothy W.; Palmer, Jeffrey D.; Mower, Jeffrey P.; Fourcade, H. Matthew; Calie, Patrick J.; Boore, Jeffrey L.; Jansen,Robert K.

2006-01-20

The chloroplast genome of Pelargonium e hortorum has beencompletely sequenced. It maps as a circular molecule of 217,942 bp, andis both the largest and most rearranged land plant chloroplast genome yetsequenced. It features two copies of a greatly expanded inverted repeat(IR) of 75,741 bp each, and consequently diminished single copy regionsof 59,710 bp and 6,750 bp. It also contains two different associations ofrepeated elements that contribute about 10 percent to the overall sizeand account for the majority of repeats found in the genome. Theyrepresent hotspots for rearrangements and gene duplications and include alarge number of pseudogenes. We propose simple models that account forthe major rearrangements with a minimum of eight IR boundary changes and12 inversions in addition to a several insertions of duplicated sequence.The major processes at work (duplication, IR expansion, and inversion)have disrupted at least one and possibly two or three transcriptionaloperons, and the genes involved in these disruptions form the core of thetwo major repeat associations. Despite the vast increase in size andcomplexity of the genome, the gene content is similar to that of otherangiosperms, with the exceptions of a large number of pseudogenes as partof the repeat associations, the recognition of two open reading frames(ORF56 and ORF42) in the trnA intron with similarities to previouslyidentified mitochondrial products (ACRS and pvs-trnA), the loss of accDand trnT-GGU, and in particular, the lack of a recognizably functionalrpoA. One or all of three similar open reading frames may possibly encodethe latter, however.

Our experience with unusual gastrointestinal tract duplications in infants

Directory of Open Access Journals (Sweden)

Bilal Mirza

2014-01-01

Full Text Available Background: Classical duplications may present along any part of gastrointestinal tract (GIT from mouth to anus. Atypical or unusual rare varieties of GIT duplications may also occur, but with different anatomical features. Materials and Methods: We reviewed our 5-year record (February 2008-January 2013 to describe clinical profile of unusual GIT duplications in neonates and small infants. Results: Three patients with atypical variety of GIT duplications were managed in our department during this tenure. Two were females and one male. Age was ranged between 11 days and 2 months. All patients presented with massive abdominal distension causing respiratory embarrassment in two of them. In all patients, the pre-operative differential diagnoses also included GIT duplication cysts. Computerized tomography (CT scan showed single huge cyst in one and multiple cysts in two patients. In one patient the CT scan also depicted a thoracic cyst in relation to posterior mediastinum. At operation, one patient had colonic tubular duplication cyst along with another isolated duplication cyst, the second case had a tubular duplication cyst of ileum with its segmental dilatation, and in the third case two isolated duplications were found. Duplication cysts were excised along with mucosal stripping in one patient, cyst excision and intestinal resection and anastomosis in one patient, and only cysts excision in one. All patients did well post-operatively. Conclusion: We presented unusual GIT duplications. These duplications are managed on similar lines as classical duplications with good prognosis when dealt early.

The evolution of genome size in ants

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Spagna Joseph C

2008-02-01

Full Text Available Abstract Background Despite the economic and ecological importance of ants, genomic tools for this family (Formicidae remain woefully scarce. Knowledge of genome size, for example, is a useful and necessary prerequisite for the development of many genomic resources, yet it has been reported for only one ant species (Solenopsis invicta, and the two published estimates for this species differ by 146.7 Mb (0.15 pg. Results Here, we report the genome size for 40 species of ants distributed across 10 of the 20 currently recognized subfamilies, thus making Formicidae the 4th most surveyed insect family and elevating the Hymenoptera to the 5th most surveyed insect order. Our analysis spans much of the ant phylogeny, from the less derived Amblyoponinae and Ponerinae to the more derived Myrmicinae, Formicinae and Dolichoderinae. We include a number of interesting and important taxa, including the invasive Argentine ant (Linepithema humile, Neotropical army ants (genera Eciton and Labidus, trapjaw ants (Odontomachus, fungus-growing ants (Apterostigma, Atta and Sericomyrmex, harvester ants (Messor, Pheidole and Pogonomyrmex, carpenter ants (Camponotus, a fire ant (Solenopsis, and a bulldog ant (Myrmecia. Our results show that ants possess small genomes relative to most other insects, yet genome size varies three-fold across this insect family. Moreover, our data suggest that two whole-genome duplications may have occurred in the ancestors of the modern Ectatomma and Apterostigma. Although some previous studies of other taxa have revealed a relationship between genome size and body size, our phylogenetically-controlled analysis of this correlation did not reveal a significant relationship. Conclusion This is the first analysis of genome size in ants (Formicidae and the first across multiple species of social insects. We show that genome size is a variable trait that can evolve gradually over long time spans, as well as rapidly, through processes that may

A 380-kb Duplication in 7p22.3 Encompassing the LFNG Gene in a Boy with Asperger Syndrome

NARCIS (Netherlands)

Vulto-van Silfhout, A.T.; de Brouwer, A.F.; de Leeuw, N.; Obihara, C.C.; Brunner, H.G.; Vries, L.B.A. de

2012-01-01

De novo genomic aberrations are considered an important cause of autism spectrum disorders. We describe a de novo 380-kb gain in band p22.3 of chromosome 7 in a patient with Asperger syndrome. This duplicated region contains 9 genes including the LNFG gene that is an important regulator of NOTCH

Bacterial niche-specific genome expansion is coupled with highly frequent gene disruptions in deep-sea sediments

KAUST Repository

Wang, Yong; Yang, Jiang Ke; Lee, On On; Li, Tie Gang; Al-Suwailem, Abdulaziz M.; Danchin, Antoine; Qian, Pei-Yuan

2011-01-01

The complexity and dynamics of microbial metagenomes may be evaluated by genome size, gene duplication and the disruption rate between lineages. In this study, we pyrosequenced the metagenomes of microbes obtained from the brine and sediment of a deep-sea brine pool in the Red Sea to explore the possible genomic adaptations of the microbes in response to environmental changes. The microbes from the brine and sediments (both surface and deep layers) of the Atlantis II Deep brine pool had similar communities whereas the effective genome size varied from 7.4 Mb in the brine to more than 9 Mb in the sediment. This genome expansion in the sediment samples was due to gene duplication as evidenced by enrichment of the homologs. The duplicated genes were highly disrupted, on average by 47.6% and 70% for the surface and deep layers of the Atlantis II Deep sediment samples, respectively. The disruptive effects appeared to be mainly due to point mutations and frameshifts. In contrast, the homologs from the Atlantis II Deep brine sample were highly conserved and they maintained relatively small copy numbers. Likely, the adaptation of the microbes in the sediments was coupled with pseudogenizations and possibly functional diversifications of the paralogs in the expanded genomes. The maintenance of the pseudogenes in the large genomes is discussed. © 2011 Wang et al.

Bacterial niche-specific genome expansion is coupled with highly frequent gene disruptions in deep-sea sediments

KAUST Repository

Wang, Yong

2011-12-21

The complexity and dynamics of microbial metagenomes may be evaluated by genome size, gene duplication and the disruption rate between lineages. In this study, we pyrosequenced the metagenomes of microbes obtained from the brine and sediment of a deep-sea brine pool in the Red Sea to explore the possible genomic adaptations of the microbes in response to environmental changes. The microbes from the brine and sediments (both surface and deep layers) of the Atlantis II Deep brine pool had similar communities whereas the effective genome size varied from 7.4 Mb in the brine to more than 9 Mb in the sediment. This genome expansion in the sediment samples was due to gene duplication as evidenced by enrichment of the homologs. The duplicated genes were highly disrupted, on average by 47.6% and 70% for the surface and deep layers of the Atlantis II Deep sediment samples, respectively. The disruptive effects appeared to be mainly due to point mutations and frameshifts. In contrast, the homologs from the Atlantis II Deep brine sample were highly conserved and they maintained relatively small copy numbers. Likely, the adaptation of the microbes in the sediments was coupled with pseudogenizations and possibly functional diversifications of the paralogs in the expanded genomes. The maintenance of the pseudogenes in the large genomes is discussed. © 2011 Wang et al.

Bacterial niche-specific genome expansion is coupled with highly frequent gene disruptions in deep-sea sediments.

Directory of Open Access Journals (Sweden)

Yong Wang

Full Text Available The complexity and dynamics of microbial metagenomes may be evaluated by genome size, gene duplication and the disruption rate between lineages. In this study, we pyrosequenced the metagenomes of microbes obtained from the brine and sediment of a deep-sea brine pool in the Red Sea to explore the possible genomic adaptations of the microbes in response to environmental changes. The microbes from the brine and sediments (both surface and deep layers of the Atlantis II Deep brine pool had similar communities whereas the effective genome size varied from 7.4 Mb in the brine to more than 9 Mb in the sediment. This genome expansion in the sediment samples was due to gene duplication as evidenced by enrichment of the homologs. The duplicated genes were highly disrupted, on average by 47.6% and 70% for the surface and deep layers of the Atlantis II Deep sediment samples, respectively. The disruptive effects appeared to be mainly due to point mutations and frameshifts. In contrast, the homologs from the Atlantis II Deep brine sample were highly conserved and they maintained relatively small copy numbers. Likely, the adaptation of the microbes in the sediments was coupled with pseudogenizations and possibly functional diversifications of the paralogs in the expanded genomes. The maintenance of the pseudogenes in the large genomes is discussed.

Duplication of the dystroglycan gene in most branches of teleost fish

Directory of Open Access Journals (Sweden)

Giardina Bruno

2007-05-01

Full Text Available Abstract Background The dystroglycan (DG complex is a major non-integrin cell adhesion system whose multiple biological roles involve, among others, skeletal muscle stability, embryonic development and synapse maturation. DG is composed of two subunits: α-DG, extracellular and highly glycosylated, and the transmembrane β-DG, linking the cytoskeleton to the surrounding basement membrane in a wide variety of tissues. A single copy of the DG gene (DAG1 has been identified so far in humans and other mammals, encoding for a precursor protein which is post-translationally cleaved to liberate the two DG subunits. Similarly, D. rerio (zebrafish seems to have a single copy of DAG1, whose removal was shown to cause a severe dystrophic phenotype in adult animals, although it is known that during evolution, due to a whole genome duplication (WGD event, many teleost fish acquired multiple copies of several genes (paralogues. Results Data mining of pufferfish (T. nigroviridis and T. rubripes and other teleost fish (O. latipes and G. aculeatus available nucleotide sequences revealed the presence of two functional paralogous DG sequences. RT-PCR analysis proved that both the DG sequences are transcribed in T. nigroviridis. One of the two DG sequences harbours an additional mini-intronic sequence, 137 bp long, interrupting the uncomplicated exon-intron-exon pattern displayed by DAG1 in mammals and D. rerio. A similar scenario emerged also in D. labrax (sea bass, from whose genome we have cloned and sequenced a new DG sequence that also harbours a shorter additional intronic sequence of 116 bp. Western blot analysis confirmed the presence of DG protein products in all the species analysed including two teleost Antarctic species (T. bernacchii and C. hamatus. Conclusion Our evolutionary analysis has shown that the whole-genome duplication event in the Class Actinopterygii (ray-finned fish involved also DAG1. We unravelled new important molecular genetic details

Ancestral genomic duplication of the insulin gene in tilapia: An analysis of possible implications for clinical islet xenotransplantation using donor islets from transgenic tilapia expressing a humanized insulin gene.

Science.gov (United States)

Hrytsenko, Olga; Pohajdak, Bill; Wright, James R

2016-07-03

Tilapia, a teleost fish, have multiple large anatomically discrete islets which are easy to harvest, and when transplanted into diabetic murine recipients, provide normoglycemia and mammalian-like glucose tolerance profiles. Tilapia insulin differs structurally from human insulin which could preclude their use as islet donors for xenotransplantation. Therefore, we produced transgenic tilapia with islets expressing a humanized insulin gene. It is now known that fish genomes may possess an ancestral duplication and so tilapia may have a second insulin gene. Therefore, we cloned, sequenced, and characterized the tilapia insulin 2 transcript and found that its expression is negligible in islets, is not islet-specific, and would not likely need to be silenced in our transgenic fish.

X-linked congenital ptosis and associated intellectual disability, short stature, microcephaly, cleft palate, digital and genital abnormalities define novel Xq25q26 duplication syndrome

DEFF Research Database (Denmark)

Møller, R S; Jensen, L R; Maas, S M

2014-01-01

, hypogonadism and feeding difficulties. Female carriers are often phenotypically normal or show a similar but milder phenotype, as in most cases the X-chromosome harbouring the duplication is subject to inactivation. Xq28, which includes MECP2 is the major locus for submicroscopic X-chromosome duplications......, whereas duplications in Xq25 and Xq26 have been reported in only a few cases. Using genome-wide array platforms we identified overlapping interstitial Xq25q26 duplications ranging from 0.2 to 4.76 Mb in eight unrelated families with in total five affected males and seven affected females. All affected...... males shared a common phenotype with intrauterine- and postnatal growth retardation and feeding difficulties in childhood. Three had microcephaly and two out of five suffered from epilepsy. In addition, three males had a distinct facial appearance with congenital bilateral ptosis and large protruding...

RNA-seq in grain unveils fate of neo- and paleopolyploidization events in bread wheat (Triticum aestivum L.).

Science.gov (United States)

Pont, Caroline; Murat, Florent; Confolent, Carole; Balzergue, Sandrine; Salse, Jérôme

2011-12-02

Whole genome duplication is a common evolutionary event in plants. Bread wheat (Triticum aestivum L.) is a good model to investigate the impact of paleo- and neoduplications on the organization and function of modern plant genomes. We performed an RNA sequencing-based inference of the grain filling gene network in bread wheat and identified a set of 37,695 non-redundant sequence clusters, which is an unprecedented resolution corresponding to an estimated half of the wheat genome unigene repertoire. Using the Brachypodium distachyon genome as a reference for the Triticeae, we classified gene clusters into orthologous, paralogous, and homoeologous relationships. Based on this wheat gene evolutionary classification, older duplicated copies (dating back 50 to 70 million years) exhibit more than 80% gene loss and expression divergence while recent duplicates (dating back 1.5 to 3 million years) show only 54% gene loss and 36 to 49% expression divergence. We suggest that structural shuffling due to duplicated gene loss is a rapid process, whereas functional shuffling due to neo- and/or subfunctionalization of duplicates is a longer process, and that both shuffling mechanisms drive functional redundancy erosion. We conclude that, as a result of these mechanisms, half the gene duplicates in plants are structurally and functionally altered within 10 million years of evolution, and the diploidization process is completed after 45 to 50 million years following polyploidization.

De novo duplication of 17p13.1-p13.2 in a patient with intellectual disability and obesity.

Science.gov (United States)

Kuroda, Yukiko; Ohashi, Ikuko; Tominaga, Makiko; Saito, Toshiyuki; Nagai, Jun-Ichi; Ida, Kazumi; Naruto, Takuya; Masuno, Mitsuo; Kurosawa, Kenji

2014-06-01

17p13.1 Deletion encompassing TP53 has been described as a syndrome characterized by intellectual disability and dysmorphic features. Only one case with a 17p13.1 duplication encompassing TP53 has been reported in a patient with intellectual disability, seizures, obesity, and diabetes mellitus. Here, we present a patient with a 17p13.1 duplication who exhibited obesity and intellectual disability, similar to the previous report. The 9-year-old proposita was referred for the evaluation of intellectual disability and obesity. She also exhibited insulin resistance and liver dysfunction. She had wide palpebral fissures, upturned nostrils, a long mandible, short and slender fingers, and skin hyperpigmentation. Array comparative genomic hybridization (array CGH) detected a 3.2 Mb duplication of 17p13.1-p13.2 encompassing TP53, FXR2, NLGN2, and SLC2A4, which encodes the insulin-responsive glucose transporter 4 (GLUT4) associated with insulin-stimulated glucose uptake in adipocytes and muscle. We suggest that 17p13.1 duplication may represent a clinically recognizable condition characterized partially by a characteristic facial phenotype, developmental delay, and obesity. © 2014 Wiley Periodicals, Inc.

Perforated ileal duplication cyst with haemorrhagic pseudocyst formation

International Nuclear Information System (INIS)

Hwang, Im Kyung; Kim, Bong Soo; Kim, Heung Chul; Lee, In Sun; Hwang, Woo Chul; Namkung, Sook

2003-01-01

Duplication cysts of the gastrointestinal tract are rare congenital abnormalities. Ectopic gastric mucosa, which can be found in duplications, may cause peptic ulceration, gastrointestinal bleeding or perforation. We report a 1-year-old boy with a perforated ileal duplication cyst with haemorrhagic pseudocyst formation caused by peptic ulceration of the duplication cyst. It presented a snowman-like appearance consisting of a small, thick-walled, true enteric cyst and a large, thin-walled haemorrhagic pseudocyst on US and CT. It is an unusual manifestation of a duplication cyst, which has not been reported in the English language literature. (orig.)

11p15 duplication and 13q34 deletion with Beckwith-Wiedemann syndrome and factor VII deficiency.

Science.gov (United States)

Jurkiewicz, Dorota; Kugaudo, Monika; Tańska, Anna; Wawrzkiewicz-Witkowska, Angelika; Tomaszewska, Agnieszka; Kucharczyk, Marzena; Cieślikowska, Agata; Ciara, Elżbieta; Krajewska-Walasek, Małgorzata

2015-06-01

Here we report a patient with 11p15.4p15.5 duplication and 13q34 deletion presenting with Beckwith-Wiedemann syndrome (BWS) and moderate deficiency of factor VII (FVII). The duplication was initially diagnosed on methylation-sensitive multiplex ligation-dependent probe amplification. Array comparative genome hybridization confirmed its presence and indicated a 13q34 distal deletion. The patient's clinical symptoms, including developmental delay and facial dysmorphism, were typical of BWS with paternal 11p15 trisomy. Partial 13q monosomy in this patient is associated with moderate deficiency of FVII and may also overlap with a few symptoms of paternal 11p15 trisomy such as developmental delay and some facial features. To our knowledge this is the first report of 11p15.4p15.5 duplication associated with deletion of 13q34 and FVII deficiency. Moreover, this report emphasizes the importance of detailed clinical as well as molecular examinations in patients with BWS features and developmental delay. © 2015 Japan Pediatric Society.

A case with concurrent duplication, triplication, and uniparental isodisomy at 1q42.12-qter supporting microhomology-mediated break-induced replication model for replicative rearrangements.

Science.gov (United States)

Kohmoto, Tomohiro; Okamoto, Nana; Naruto, Takuya; Murata, Chie; Ouchi, Yuya; Fujita, Naoko; Inagaki, Hidehito; Satomura, Shigeko; Okamoto, Nobuhiko; Saito, Masako; Masuda, Kiyoshi; Kurahashi, Hiroki; Imoto, Issei

2017-01-01

Complex genomic rearrangements (CGRs) consisting of interstitial triplications in conjunction with uniparental isodisomy (isoUPD) have rarely been reported in patients with multiple congenital anomalies (MCA)/intellectual disability (ID). One-ended DNA break repair coupled with microhomology-mediated break-induced replication (MMBIR) has been recently proposed as a possible mechanism giving rise to interstitial copy number gains and distal isoUPD, although only a few cases providing supportive evidence in human congenital diseases with MCA have been documented. Here, we report on the chromosomal microarray (CMA)-based identification of the first known case with concurrent interstitial duplication at 1q42.12-q42.2 and triplication at 1q42.2-q43 followed by isoUPD for the remainder of chromosome 1q (at 1q43-qter). In distal 1q duplication/triplication overlapping with 1q42.12-q43, variable clinical features have been reported, and our 25-year-old patient with MCA/ID presented with some of these frequently described features. Further analyses including the precise mapping of breakpoint junctions within the CGR in a sequence level suggested that the CGR found in association with isoUPD in our case is a triplication with flanking duplications, characterized as a triplication with a particularly long duplication-inverted triplication-duplication (DUP-TRP/INV-DUP) structure. Because microhomology was observed in both junctions between the triplicated region and the flanking duplicated regions, our case provides supportive evidence for recently proposed replication-based mechanisms, such as MMBIR, underlying the formation of CGRs + isoUPD implicated in chromosomal disorders. To the best of our knowledge, this is the first case of CGRs + isoUPD observed in 1q and having DUP-TRP/INV-DUP structure with a long proximal duplication, which supports MMBIR-based model for genomic rearrangements. Molecular cytogenetic analyses using CMA containing single

Gallbladder duplication

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Yagan Pillay

2015-01-01

Conclusion: Duplication of the gallbladder is a rare congenital abnormality, which requires special attention to the biliary ductal and arterial anatomy. Laparoscopic cholecystectomy with intraoperative cholangiography is the appropriate treatment in a symptomatic gallbladder. The removal of an asymptomatic double gallbladder remains controversial.

Maintaining Genome Stability: The Role of Helicases and Deaminases

Science.gov (United States)

2008-07-01

Errors in duplicating DNA can result in genomic instability, leading to various human diseases, such as cancer, immune system disorder, muscle dystrophy ...as cancer, immune system disorder, muscle dystrophy , and neurodegenerations. Thus, maintaining genomic integrity is vital to the normal growth of...31–38. Eberharter, A., R. Ferreira and P. Becker , 2005 Dynamic chro- matin: concerted nucleosome remodelling and acetylation. Biol. Chem. 386: 745

Implications of duplicated cis-regulatory elements in the evolution of metazoans: the DDI model or how simplicity begets novelty.

Science.gov (United States)

Jiménez-Delgado, Senda; Pascual-Anaya, Juan; Garcia-Fernàndez, Jordi

2009-07-01

The discovery that most regulatory genes were conserved among animals from distant phyla challenged the ideas that gene duplication and divergence of homologous coding sequences were the basis for major morphological changes in metazoan evolution. In recent years, however, the interest for the roles, conservation and changes of non-coding sequences grew-up in parallel with genome sequencing projects. Presently, many independent studies are highlighting the importance that subtle changes in cis-regulatory regions had in the evolution of morphology trough the Animal Kingdom. Here we will show and discuss some of these studies, and underscore the future of cis-Evo-Devo research. Nevertheless, we would also explore how gene duplication, which includes duplication of regulatory regions, may have been critical for spatial or temporal co-option of new regulatory networks, causing the deployment of new transcriptome scenarios, and how these induced morphological changes were critical for the evolution of new forms. Forty years after Susumu Ohno famous sentence 'natural selection merely modifies, while redundancy creates', we suggest the alternative: 'natural selection modifies, while redundancy of cis-regulatory elements innovates', and propose the Duplication-Degeneration-Innovation model to explain the increased evolvability of duplicated cis-regulatory regions. Paradoxically, making regulation simpler by subfunctionalization paved the path for future complexity or, in other words, 'to make it simple to make it complex'.

On Sorting Genomes with DCJ and Indels

Science.gov (United States)

Braga, Marília D. V.

A previous work of Braga, Willing and Stoye compared two genomes with unequal content, but without duplications, and presented a new linear time algorithm to compute the genomic distance, considering double cut and join (DCJ) operations, insertions and deletions. Here we derive from this approach an algorithm to sort one genome into another one also using DCJ, insertions and deletions. The optimal sorting scenarios can have different compositions and we compare two types of sorting scenarios: one that maximizes and one that minimizes the number of DCJ operations with respect to the number of insertions and deletions.

Presentation and Surgical Management of Duodenal Duplication in Adults

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Caroline C. Jadlowiec

2015-01-01

Full Text Available Duodenal duplications in adults are exceedingly rare and their diagnosis remains difficult as symptoms are largely nonspecific. Clinical presentations include pancreatitis, biliary obstruction, gastrointestinal bleeding from ectopic gastric mucosa, and malignancy. A case of duodenal duplication in a 59-year-old female is presented, and her treatment course is reviewed with description of combined surgical and endoscopic approach to repair, along with a review of historic and current recommendations for management. Traditionally, gastrointestinal duplications have been treated with surgical resection; however, for duodenal duplications, the anatomic proximity to the biliopancreatic ampulla makes surgical management challenging. Recently, advances in endoscopy have improved the clinical success of cystic intraluminal duodenal duplications. Despite these advances, surgical resection is still recommended for extraluminal tubular duplications although combined techniques may be necessary for long tubular duplications. For duodenal duplications, a combined approach of partial excision combined with mucosal stripping may offer advantage.

Rectal Duplication%直肠重复畸形

Institute of Scientific and Technical Information of China (English)

张道荣; 牟弦琴; 李振东; 李恭才; 王修忠; 代蕊霜

1983-01-01

@@ 我们两院近10年来共收治先天性直肠重复畸形17例(其中河北医学院11例,西安医学院6例).均经手术及病理证实.现总结如下:临床资料本组男性6例,女性11例,最小年龄4天,最大年龄14岁.%This paper reports 17 cases of rectal duplication. There were 6 males and 11rectal duplications were divided into three bordered by a common wall.9 patients in this series were found to have this condition.a rectovestitubular fistula.B.Pararectal duplication.The duplicated bowel lies near elliptical in shape and filled with fluid.In Complicated rectal duplication.The dupticated bowel is located at the perineum near the abnormal anus and is usually associated with hypospadia.Two cases were of this type.between the duplicated bowel and normal rectum must be partially resected at the distal end.The rectovestitubular fistula should be repaired at the same time.Pararectal duplication can be completely resected.resect the duplicated bowel from perineum but leave the genital anomaly for later treatment.

Rectal duplication cyst in a cat.

Science.gov (United States)

Kook, Peter H; Hagen, Regine; Willi, Barbara; Ruetten, Maja; Venzin, Claudio

2010-12-01

Enteric duplication is a rare developmental malformation in people, dogs and cats. The purpose of the present report is to describe the first case of a rectal duplication cyst in a 7-year-old domestic shorthair cat presenting for acute constipation and tenesmus. On rectal palpation a spherical mass compressing the lumen of the rectum could be felt in the dorsal wall of the rectum. A computed tomography (CT) scan confirmed the presence of a well demarcated cystic lesion in the pelvic canal, dorsal to the rectum. The cyst was surgically removed via a perineal approach. No communication with the rectal lumen could be demonstrated. Histopathological examination was consistent with a rectal duplication cyst. Clinical signs resolved completely after excision of this conjoined non-communicating cystic rectal duplicate. Copyright © 2010 ISFM and AAFP. Published by Elsevier Ltd. All rights reserved.

Genome-Wide Distribution, Organisation and Functional Characterization of Disease Resistance and Defence Response Genes across Rice Species

Science.gov (United States)

Singh, Sangeeta; Chand, Suresh; Singh, N. K.; Sharma, Tilak Raj

2015-01-01

The resistance (R) genes and defense response (DR) genes have become very important resources for the development of disease resistant cultivars. In the present investigation, genome-wide identification, expression, phylogenetic and synteny analysis was done for R and DR-genes across three species of rice viz: Oryza sativa ssp indica cv 93-11, Oryza sativa ssp japonica and wild rice species, Oryza brachyantha. We used the in silico approach to identify and map 786 R -genes and 167 DR-genes, 672 R-genes and 142 DR-genes, 251 R-genes and 86 DR-genes in the japonica, indica and O. brachyanth a genomes, respectively. Our analysis showed that 60.5% and 55.6% of the R-genes are tandemly repeated within clusters and distributed over all the rice chromosomes in indica and japonica genomes, respectively. The phylogenetic analysis along with motif distribution shows high degree of conservation of R- and DR-genes in clusters. In silico expression analysis of R-genes and DR-genes showed more than 85% were expressed genes showing corresponding EST matches in the databases. This study gave special emphasis on mechanisms of gene evolution and duplication for R and DR genes across species. Analysis of paralogs across rice species indicated 17% and 4.38% R-genes, 29% and 11.63% DR-genes duplication in indica and Oryza brachyantha, as compared to 20% and 26% duplication of R-genes and DR-genes in japonica respectively. We found that during the course of duplication only 9.5% of R- and DR-genes changed their function and rest of the genes have maintained their identity. Syntenic relationship across three genomes inferred that more orthology is shared between indica and japonica genomes as compared to brachyantha genome. Genome wide identification of R-genes and DR-genes in the rice genome will help in allele mining and functional validation of these genes, and to understand molecular mechanism of disease resistance and their evolution in rice and related species. PMID:25902056

Mapping copy number variation by population-scale genome sequencing

DEFF Research Database (Denmark)

Mills, Ryan E.; Walter, Klaudia; Stewart, Chip

2011-01-01

Genomic structural variants (SVs) are abundant in humans, differing from other forms of variation in extent, origin and functional impact. Despite progress in SV characterization, the nucleotide resolution architecture of most SVs remains unknown. We constructed a map of unbalanced SVs (that is......, copy number variants) based on whole genome DNA sequencing data from 185 human genomes, integrating evidence from complementary SV discovery approaches with extensive experimental validations. Our map encompassed 22,025 deletions and 6,000 additional SVs, including insertions and tandem duplications...

Genome-Wide Identification and Evolution of HECT Genes in Soybean

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Xianwen Meng

2015-04-01

Full Text Available Proteins containing domains homologous to the E6-associated protein (E6-AP carboxyl terminus (HECT are an important class of E3 ubiquitin ligases involved in the ubiquitin proteasome pathway. HECT-type E3s play crucial roles in plant growth and development. However, current understanding of plant HECT genes and their evolution is very limited. In this study, we performed a genome-wide analysis of the HECT domain-containing genes in soybean. Using high-quality genome sequences, we identified 19 soybean HECT genes. The predicted HECT genes were distributed unevenly across 15 of 20 chromosomes. Nineteen of these genes were inferred to be segmentally duplicated gene pairs, suggesting that in soybean, segmental duplications have made a significant contribution to the expansion of the HECT gene family. Phylogenetic analysis showed that these HECT genes can be divided into seven groups, among which gene structure and domain architecture was relatively well-conserved. The Ka/Ks ratios show that after the duplication events, duplicated HECT genes underwent purifying selection. Moreover, expression analysis reveals that 15 of the HECT genes in soybean are differentially expressed in 14 tissues, and are often highly expressed in the flowers and roots. In summary, this work provides useful information on which further functional studies of soybean HECT genes can be based.

Exon duplications in the ATP7A gene

DEFF Research Database (Denmark)

Mogensen, Mie; Skjørringe, Tina; Kodama, Hiroko

2011-01-01

the identified duplicated fragments originated from a single or from two different X-chromosomes, polymorphic markers located in the duplicated fragments were analyzed. RESULTS: Partial ATP7A gene duplication was identified in 20 unrelated patients including one patient with Occipital Horn Syndrome (OHS...

Long segment ileal duplication with extensive gastric heterotopia

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Jacob Sunitha

2009-07-01

Full Text Available Duplications of the alimentary tract are rare congenital anomalies which can be found at all levels of the alimentary tract. Majority of the duplications present as spherical cysts and usually range from a few millimeters to less than ten centimeters in size. Duplications produce complications such as intestinal obstruction or hemorrhage. A two-month-old infant presented with recurrent episodes of bleeding per rectum. Laparotomy revealed a giant ileal duplicated bowel segment which exhibited extensive gastric heterotopia with focal ulceration.

Genomic evidence of gene duplication and adaptive evolution of Toll like receptors (TLR2 and TLR4) in reptiles.

Science.gov (United States)

Shang, Shuai; Zhong, Huaming; Wu, Xiaoyang; Wei, Qinguo; Zhang, Huanxin; Chen, Jun; Chen, Yao; Tang, Xuexi; Zhang, Honghai

2018-04-01

Toll-like receptors (TLRs) encoded by the TLR multigene family play an important role in initial pathogen recognition in vertebrates. Among the TLRs, TLR2 and TLR4 may be of particular importance to reptiles. In order to study the evolutionary patterns and structural characteristics of TLRs, we explored the available genomes of several representative members of reptiles. 25 TLR2 genes and 19 TLR4 genes from reptiles were obtained in this study. Phylogenetic results showed that the TLR2 gene duplication occurred in several species. Evolutionary analysis by at least two methods identified 30 and 13 common positively selected codons in TLR2 and TLR4, respectively. Most positively selected sites of TLR2 and TLR4 were located in the Leucine-rich repeat (LRRs). Branch model analysis showed that TLR2 genes were under different evolutionary forces in reptiles, while the TLR4 genes showed no significant selection pressure. The different evolutionary adaptation of TLR2 and TLR4 among the reptiles might be due to their different function in recognizing bacteria. Overall, we explored the structure and evolution of TLR2 and TLR4 genes in reptiles for the first time. Our study revealed valuable information regarding TLR2 and TLR4 in reptiles, and provided novel insights into the conservation concern of natural populations. Copyright © 2017 Elsevier B.V. All rights reserved.

Genome Sequences of Marine Shrimp Exopalaemon carinicauda Holthuis Provide Insights into Genome Size Evolution of Caridea.

Science.gov (United States)

Yuan, Jianbo; Gao, Yi; Zhang, Xiaojun; Wei, Jiankai; Liu, Chengzhang; Li, Fuhua; Xiang, Jianhai

2017-07-05

Crustacea, particularly Decapoda, contains many economically important species, such as shrimps and crabs. Crustaceans exhibit enormous (nearly 500-fold) variability in genome size. However, limited genome resources are available for investigating these species. Exopalaemon carinicauda Holthuis, an economical caridean shrimp, is a potential ideal experimental animal for research on crustaceans. In this study, we performed low-coverage sequencing and de novo assembly of the E. carinicauda genome. The assembly covers more than 95% of coding regions. E. carinicauda possesses a large complex genome (5.73 Gb), with size twice higher than those of many decapod shrimps. As such, comparative genomic analyses were implied to investigate factors affecting genome size evolution of decapods. However, clues associated with genome duplication were not identified, and few horizontally transferred sequences were detected. Ultimately, the burst of transposable elements, especially retrotransposons, was determined as the major factor influencing genome expansion. A total of 2 Gb repeats were identified, and RTE-BovB, Jockey, Gypsy, and DIRS were the four major retrotransposons that significantly expanded. Both recent (Jockey and Gypsy) and ancestral (DIRS) originated retrotransposons responsible for the genome evolution. The E. carinicauda genome also exhibited potential for the genomic and experimental research of shrimps.

Finding all sorting tandem duplication random loss operations

DEFF Research Database (Denmark)

Bernt, Matthias; Chen, Kuan Yu; Chen, Ming Chiang

2011-01-01

A tandem duplication random loss (TDRL) operation duplicates a contiguous segment of genes, followed by the random loss of one copy of each of the duplicated genes. Although the importance of this operation is founded by several recent biological studies, it has been investigated only rarely from...

The natural history of class I primate alcohol dehydrogenases includes gene duplication, gene loss, and gene conversion.

Directory of Open Access Journals (Sweden)

Matthew A Carrigan

Full Text Available Gene duplication is a source of molecular innovation throughout evolution. However, even with massive amounts of genome sequence data, correlating gene duplication with speciation and other events in natural history can be difficult. This is especially true in its most interesting cases, where rapid and multiple duplications are likely to reflect adaptation to rapidly changing environments and life styles. This may be so for Class I of alcohol dehydrogenases (ADH1s, where multiple duplications occurred in primate lineages in Old and New World monkeys (OWMs and NWMs and hominoids.To build a preferred model for the natural history of ADH1s, we determined the sequences of nine new ADH1 genes, finding for the first time multiple paralogs in various prosimians (lemurs, strepsirhines. Database mining then identified novel ADH1 paralogs in both macaque (an OWM and marmoset (a NWM. These were used with the previously identified human paralogs to resolve controversies relating to dates of duplication and gene conversion in the ADH1 family. Central to these controversies are differences in the topologies of trees generated from exonic (coding sequences and intronic sequences.We provide evidence that gene conversions are the primary source of difference, using molecular clock dating of duplications and analyses of microinsertions and deletions (micro-indels. The tree topology inferred from intron sequences appear to more correctly represent the natural history of ADH1s, with the ADH1 paralogs in platyrrhines (NWMs and catarrhines (OWMs and hominoids having arisen by duplications shortly predating the divergence of OWMs and NWMs. We also conclude that paralogs in lemurs arose independently. Finally, we identify errors in database interpretation as the source of controversies concerning gene conversion. These analyses provide a model for the natural history of ADH1s that posits four ADH1 paralogs in the ancestor of Catarrhine and Platyrrhine primates

Whole genome resequencing reveals natural target site preferences of transposable elements in Drosophila melanogaster.

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Raquel S Linheiro

Full Text Available Transposable elements are mobile DNA sequences that integrate into host genomes using diverse mechanisms with varying degrees of target site specificity. While the target site preferences of some engineered transposable elements are well studied, the natural target preferences of most transposable elements are poorly characterized. Using population genomic resequencing data from 166 strains of Drosophila melanogaster, we identified over 8,000 new insertion sites not present in the reference genome sequence that we used to decode the natural target preferences of 22 families of transposable element in this species. We found that terminal inverted repeat transposon and long terminal repeat retrotransposon families present clade-specific target site duplications and target site sequence motifs. Additionally, we found that the sequence motifs at transposable element target sites are always palindromes that extend beyond the target site duplication. Our results demonstrate the utility of population genomics data for high-throughput inference of transposable element targeting preferences in the wild and establish general rules for terminal inverted repeat transposon and long terminal repeat retrotransposon target site selection in eukaryotic genomes.

Embryonic duplications in sheep.

Science.gov (United States)

Dennis, S M

1975-02-01

Twenty-seven embryonic duplications were examined during a 3-year investigation into the causes of perinatal lamb mortality. Twenty of the 27 were anomalous twins with 19 being conjoined (diplopagus 9 and heteropagus 10). The various duplications were: haloacardius acephalus 1, diprosopus 2, dicephalus 2, dipypus 3, diprosopus dipygus 1, syncephalus dipygus 1, pygopagus parasiticus 1, heteropagus dipygus 3, melodidymus 6, polyury 4, penile duplication 2, and bilateral otognathia 1. Four lambs were living and the time of death of the others was: parturient 8, and post-parturient 15. Average dry weight of the lambs was 3.35 kg (range 1.59 to 5.45 kg). Breed distribution was: Merino 77.8%, Crossbred 14.8%, Dorset Horn 3.7%, and Corriedale 3.7%. The caudal region was involved in 10 of the conjoined twins (52.6%), anterior region in 7 (36.9%), and both anterior and caudal regions in 2 (10.5%). Associated defects were present in 70.4% of the 27 lambs, the most common being atresia ani.

The genome of Prunus mume.

Science.gov (United States)

Zhang, Qixiang; Chen, Wenbin; Sun, Lidan; Zhao, Fangying; Huang, Bangqing; Yang, Weiru; Tao, Ye; Wang, Jia; Yuan, Zhiqiong; Fan, Guangyi; Xing, Zhen; Han, Changlei; Pan, Huitang; Zhong, Xiao; Shi, Wenfang; Liang, Xinming; Du, Dongliang; Sun, Fengming; Xu, Zongda; Hao, Ruijie; Lv, Tian; Lv, Yingmin; Zheng, Zequn; Sun, Ming; Luo, Le; Cai, Ming; Gao, Yike; Wang, Junyi; Yin, Ye; Xu, Xun; Cheng, Tangren; Wang, Jun

2012-01-01

Prunus mume (mei), which was domesticated in China more than 3,000 years ago as ornamental plant and fruit, is one of the first genomes among Prunus subfamilies of Rosaceae been sequenced. Here, we assemble a 280M genome by combining 101-fold next-generation sequencing and optical mapping data. We further anchor 83.9% of scaffolds to eight chromosomes with genetic map constructed by restriction-site-associated DNA sequencing. Combining P. mume genome with available data, we succeed in reconstructing nine ancestral chromosomes of Rosaceae family, as well as depicting chromosome fusion, fission and duplication history in three major subfamilies. We sequence the transcriptome of various tissues and perform genome-wide analysis to reveal the characteristics of P. mume, including its regulation of early blooming in endodormancy, immune response against bacterial infection and biosynthesis of flower scent. The P. mume genome sequence adds to our understanding of Rosaceae evolution and provides important data for improvement of fruit trees.

Metabolic 'engines' of flight drive genome size reduction in birds.

Science.gov (United States)

Wright, Natalie A; Gregory, T Ryan; Witt, Christopher C

2014-03-22

The tendency for flying organisms to possess small genomes has been interpreted as evidence of natural selection acting on the physical size of the genome. Nonetheless, the flight-genome link and its mechanistic basis have yet to be well established by comparative studies within a volant clade. Is there a particular functional aspect of flight such as brisk metabolism, lift production or maneuverability that impinges on the physical genome? We measured genome sizes, wing dimensions and heart, flight muscle and body masses from a phylogenetically diverse set of bird species. In phylogenetically controlled analyses, we found that genome size was negatively correlated with relative flight muscle size and heart index (i.e. ratio of heart to body mass), but positively correlated with body mass and wing loading. The proportional masses of the flight muscles and heart were the most important parameters explaining variation in genome size in multivariate models. Hence, the metabolic intensity of powered flight appears to have driven genome size reduction in birds.

The duplication 17p13.3 phenotype

DEFF Research Database (Denmark)

Curry, Cynthia J; Rosenfeld, Jill A; Grant, Erica

2013-01-01

. Older patients were often overweight. Three variant phenotypes included cleft lip/palate (CLP), split hand/foot with long bone deficiency (SHFLD), and a connective tissue phenotype resembling Marfan syndrome. The duplications in patients with clefts appear to disrupt ABR, while the SHFLD phenotype......Chromosome 17p13.3 is a gene rich region that when deleted is associated with the well-known Miller-Dieker syndrome. A recently described duplication syndrome involving this region has been associated with intellectual impairment, autism and occasional brain MRI abnormalities. We report 34...... was associated with duplication of BHLHA9 as noted in two recent reports. The connective tissue phenotype did not have a convincing critical region. Our experience with this large cohort expands knowledge of this diverse duplication syndrome....

Prevalence of lower extremity venous duplication

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Simpson William

2010-01-01

Full Text Available Purpose: This retrospective study was performed to determine the prevalence of lower extremity venous duplication using duplex ultrasound in the patient population of a large urban medical center. Materials and Methods: The reports of all lower extremity venous ultrasound examinations performed at our institution between January 1, 2002 and December 31, 2002 were reviewed. Ultrasound examinations that were performed for purposes other than the detection of lower extremity deep vein thrombosis were excluded. The prevalence of duplication and its specific location were recorded. In addition, the prevalence of thrombus and its specific location were also recorded. Results: A total of 3118 exams were performed in 2664 patients. Of the 2664 patients, 2311 had only one examination performed during the study period; 353 patients had more than one examination performed. We found that 10.1% of patients (270/2664 had at least one venous segment duplicated and 5.4% of patients (143/2664 had a thrombus in at least one venous segment. There was a statistically significant difference in the prevalence of both duplication and thrombus with a change in venous segment. Only 0.4% of patients (11/2664 had thrombus within a duplicated segment. Of those who had more than one examination performed, 15.3% (54/353 had the same venous segment(s seen on one examination but not another. Conclusion: Lower extremity venous duplication is a frequent anatomic variant that is seen in 10.1% of patients, but it may not be as common as is generally believed. It can result in a false negative result for deep vein thrombosis.

Insertional translocation leading to a 4q13 duplication including the EPHA5 gene in two siblings with attention-deficit hyperactivity disorder.

Science.gov (United States)

Matoso, Eunice; Melo, Joana B; Ferreira, Susana I; Jardim, Ana; Castelo, Teresa M; Weise, Anja; Carreira, Isabel M

2013-08-01

An insertional translocation (IT) can result in pure segmental aneusomy for the inserted genomic segment allowing to define a more accurate clinical phenotype. Here, we report on two siblings sharing an unbalanced IT inherited from the mother with a history of learning difficulty. An 8-year-old girl with developmental delay, speech disability, and attention-deficit hyperactivity disorder (ADHD), showed by GTG banding analysis a subtle interstitial alteration in 21q21. Oligonucleotide array comparative genomic hybridization (array-CGH) analysis showed a 4q13.1-q13.3 duplication spanning 8.6 Mb. Fluorescence in situ hybridization (FISH) with bacterial artificial chromosome (BAC) clones confirmed the rearrangement, a der(21)ins(21;4)(q21;q13.1q13.3). The duplication described involves 50 RefSeq genes including the EPHA5 gene that encodes for the EphA5 receptor involved in embryonic development of the brain and also in synaptic remodeling and plasticity thought to underlie learning and memory. The same rearrangement was observed in a younger brother with behavioral problems and also exhibiting ADHD. ADHD is among the most heritable of neuropsychiatric disorders. There are few reports of patients with duplications involving the proximal region of 4q and a mild phenotype. To the best of our knowledge this is the first report of a duplication restricted to band 4q13. This abnormality could be easily missed in children who have nonspecific cognitive impairment. The presence of this behavioral disorder in the two siblings reinforces the hypothesis that the region involved could include genes involved in ADHD. Copyright © 2013 Wiley Periodicals, Inc.

Complete cloacal duplication imaged before and during pregnancy.

Science.gov (United States)

Ragab, Omar; Landay, Melanie; Shriki, Jabi

2009-01-01

The authors describe a 31 year-old female who presented emergently with abdominal pain and was found at CT to have complete genitourinary duplication including separate urinary bladders, uteri, cervices, and vaginas, and also duplication of the rectum. No etiology for abdominal pain was identified. The patient was referred to urology for further evaluation, and an intravenous urographic study was obtained, which confirmed complete lower urinary tract duplication. The patient presented emergently 9 months later during a subsequent pregnancy for further evaluation of abdominal pain. A second CT scan was ordered to rule out appendicitis. Findings consistent with cloacal duplication were again noted. There was also dilatation of the urinary collecting systems, more prominently on the right side. A Cesarean section was performed and confirmed total genitourinary and rectal duplication.

Mitochondrial mutations drive prostate cancer aggression

DEFF Research Database (Denmark)

Hopkins, Julia F.; Sabelnykova, Veronica Y.; Weischenfeldt, Joachim

2017-01-01

Nuclear mutations are well known to drive tumor incidence, aggression and response to therapy. By contrast, the frequency and roles of mutations in the maternally inherited mitochondrial genome are poorly understood. Here we sequence the mitochondrial genomes of 384 localized prostate cancer...... in prostate cancer, and suggest interplay between nuclear and mitochondrial mutational profiles in prostate cancer....

An unusual presentation of a rectal duplication cyst.

Science.gov (United States)

Jackson, Katharine L; Peche, William J; Rollins, Michael D

2012-01-01

Intestinal duplications are rare developmental anomalies that can occur anywhere along the gastrointestinal tract. Rectal duplication cysts account for approximately 4% of all duplication cysts. They usually present in childhood with symptoms of mass effect, local infection or more rarely with rectal bleeding from ectopic gastric mucosa. A 26year old male presented with a history of bright red blood per rectum. On examination a mucosal defect with an associated cavity adjacent to the rectum was identified. This was confirmed with rigid proctoscopy and CT scan imaging. A complete transanal excision was performed. Rectal duplication cysts are more common in pediatric patients. They more frequently present with symptoms of mass effect or local infection than with rectal bleeding. In adult patients they are a rare cause of rectal bleeding. Definitive treatment is with surgical excision. A transanal, transcoccygeal, posterior sagittal or a combined abdominoperineal approach may be used depending on anatomic characteristics of the duplication cyst. We present a rare case of a rectal duplication cyst presenting in adulthood with rectal bleeding, managed with transanal excision. Published by Elsevier Ltd.

[Rectal duplication cyst--case report].

Science.gov (United States)

Turyna, R; Horák, L; Kucera, E; Hejda, V; Krofta, L; Feyereisl, J

2009-06-01

The authors demonstrate a rare case of duplication anomaly of the rectum. Case report. Institute for the Care of Mother and Child, Prague. We present a rare case of cystic rectal duplication in adult, completely removed and histologically confirmed. A literature review was summarized. The case was complicated by delay in diagnosis, multiple operations, and by the association with endometriosis, as well. Mentioned anomaly is published in the Czech literature for the very first time.

Genome-Wide Analysis of Syntenic Gene Deletion in the Grasses

Science.gov (United States)

Schnable, James C.; Freeling, Michael; Lyons, Eric

2012-01-01

The grasses, Poaceae, are one of the largest and most successful angiosperm families. Like many radiations of flowering plants, the divergence of the major grass lineages was preceded by a whole-genome duplication (WGD), although these events are not rare for flowering plants. By combining identification of syntenic gene blocks with measures of gene pair divergence and different frequencies of ancient gene loss, we have separated the two subgenomes present in modern grasses. Reciprocal loss of duplicated genes or genomic regions has been hypothesized to reproductively isolate populations and, thus, speciation. However, in contrast to previous studies in yeast and teleost fishes, we found very little evidence of reciprocal loss of homeologous genes between the grasses, suggesting that post-WGD gene loss may not be the cause of the grass radiation. The sets of homeologous and orthologous genes and predicted locations of deleted genes identified in this study, as well as links to the CoGe comparative genomics web platform for analyzing pan-grass syntenic regions, are provided along with this paper as a resource for the grass genetics community. PMID:22275519

Evolutionary Genomics of Life in (and from) the Sea

Energy Technology Data Exchange (ETDEWEB)

Boore, Jeffrey L.; Dehal, Paramvir; Fuerstenberg, Susan I.

2006-01-09

High throughput genome sequencing centers that were originally built for the Human Genome Project (Lander et al., 2001; Venter et al., 2001) have now become an engine for comparative genomics. The six largest centers alone are now producing over 150 billion nucleotides per year, more than 50 times the amount of DNA in the human genome, and nearly all of this is directed at projects that promise great insights into the pattern and processes of evolution. Unfortunately, this data is being produced at a pace far exceeding the capacity of the scientific community to provide insightful analysis, and few scientists with training and experience in evolutionary biology have played prominent roles to date. One of the consequences is that poor quality analyses are typical; for example, orthology among genes is generally determined by simple measures of sequence similarity, when this has been discredited by molecular evolutionary biologists decades ago. Here we discuss the how genomes are chosen for sequencing and how the scientific community can have input. We describe the PhIGs database and web tools (Dehal and Boore 2005a; http://PhIGs.org), which provide phylogenetic analysis of all gene families for all completely sequenced genomes and the associated 'Synteny Viewer', which allows comparisons of the relative positions of orthologous genes. This is the best tool available for inferring gene function across multiple genomes. We also describe how we have used the PhIGs methods with the whole genome sequences of a tunicate, fish, mouse, and human to conclusively demonstrate that two rounds of whole genome duplication occurred at the base of vertebrates (Dehal and Boore 2005b). This evidence is found in the large scale structure of the positions of paralogous genes that arose from duplications inferred by evolutionary analysis to have occurred at the base of vertebrates.

Duplicate Record Elimination in Large Data Files.

Science.gov (United States)

1981-08-01

UNCLASSIFIJED CSTR -445 NL LmEE~hhE - I1.0 . 111112----5 1.~4 __112 ___IL25_ 1.4 111111.6 EI24 COMPUTER SCIENCES DEPARTMENT oUniversity of Wisconsin...we propose a combinatorial model for the use in the analysis of algorithms for duplicate elimination. We contend that this model can serve as a...duplicates in a multiset of records, knowing the size of the multiset and the number of distinct records in it. 3. Algorithms for Duplicate Elimination

Cattle genomics and its implications for future nutritional strategies for dairy cattle.

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Seo, S; Larkin, D M; Loor, J J

2013-03-01

The recently sequenced cattle (Bos taurus) genome unraveled the unique genomic features of the species and provided the molecular basis for applying a systemic approach to systematically link genomic information to metabolic traits. Comparative analysis has identified a variety of evolutionary adaptive features in the cattle genome, such as an expansion of the gene families related to the rumen function, large number of chromosomal rearrangements affecting regulation of genes for lactation, and chromosomal rearrangements that are associated with segmental duplications and copy number variations. Metabolic reconstruction of the cattle genome has revealed that core metabolic pathways are highly conserved among mammals although five metabolic genes are deleted or highly diverged and seven metabolic genes are present in duplicate in the cattle genome compared to their human counter parts. The evolutionary loss and gain of metabolic genes in the cattle genome may reflect metabolic adaptations of cattle. Metabolic reconstruction also provides a platform for better understanding of metabolic regulation in cattle and ruminants. A substantial body of transcriptomics data from dairy and beef cattle under different nutritional management and across different stages of growth and lactation are already available and will aid in linking the genome with metabolism and nutritional physiology of cattle. Application of cattle genomics has great potential for future development of nutritional strategies to improve efficiency and sustainability of beef and milk production. One of the biggest challenges is to integrate genomic and phenotypic data and interpret them in a biological and practical platform. Systems biology, a holistic and systemic approach, will be very useful in overcoming this challenge.

Comparative analysis of the genomes of two field isolates of the rice blast fungus Magnaporthe oryzae.

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Minfeng Xue

Full Text Available Rice blast caused by Magnaporthe oryzae is one of the most destructive diseases of rice worldwide. The fungal pathogen is notorious for its ability to overcome host resistance. To better understand its genetic variation in nature, we sequenced the genomes of two field isolates, Y34 and P131. In comparison with the previously sequenced laboratory strain 70-15, both field isolates had a similar genome size but slightly more genes. Sequences from the field isolates were used to improve genome assembly and gene prediction of 70-15. Although the overall genome structure is similar, a number of gene families that are likely involved in plant-fungal interactions are expanded in the field isolates. Genome-wide analysis on asynonymous to synonymous nucleotide substitution rates revealed that many infection-related genes underwent diversifying selection. The field isolates also have hundreds of isolate-specific genes and a number of isolate-specific gene duplication events. Functional characterization of randomly selected isolate-specific genes revealed that they play diverse roles, some of which affect virulence. Furthermore, each genome contains thousands of loci of transposon-like elements, but less than 30% of them are conserved among different isolates, suggesting active transposition events in M. oryzae. A total of approximately 200 genes were disrupted in these three strains by transposable elements. Interestingly, transposon-like elements tend to be associated with isolate-specific or duplicated sequences. Overall, our results indicate that gain or loss of unique genes, DNA duplication, gene family expansion, and frequent translocation of transposon-like elements are important factors in genome variation of the rice blast fungus.

Improved methods and resources for paramecium genomics: transcription units, gene annotation and gene expression.

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Arnaiz, Olivier; Van Dijk, Erwin; Bétermier, Mireille; Lhuillier-Akakpo, Maoussi; de Vanssay, Augustin; Duharcourt, Sandra; Sallet, Erika; Gouzy, Jérôme; Sperling, Linda

2017-06-26

The 15 sibling species of the Paramecium aurelia cryptic species complex emerged after a whole genome duplication that occurred tens of millions of years ago. Given extensive knowledge of the genetics and epigenetics of Paramecium acquired over the last century, this species complex offers a uniquely powerful system to investigate the consequences of whole genome duplication in a unicellular eukaryote as well as the genetic and epigenetic mechanisms that drive speciation. High quality Paramecium gene models are important for research using this system. The major aim of the work reported here was to build an improved gene annotation pipeline for the Paramecium lineage. We generated oriented RNA-Seq transcriptome data across the sexual process of autogamy for the model species Paramecium tetraurelia. We determined, for the first time in a ciliate, candidate P. tetraurelia transcription start sites using an adapted Cap-Seq protocol. We developed TrUC, multi-threaded Perl software that in conjunction with TopHat mapping of RNA-Seq data to a reference genome, predicts transcription units for the annotation pipeline. We used EuGene software to combine annotation evidence. The high quality gene structural annotations obtained for P. tetraurelia were used as evidence to improve published annotations for 3 other Paramecium species. The RNA-Seq data were also used for differential gene expression analysis, providing a gene expression atlas that is more sensitive than the previously established microarray resource. We have developed a gene annotation pipeline tailored for the compact genomes and tiny introns of Paramecium species. A novel component of this pipeline, TrUC, predicts transcription units using Cap-Seq and oriented RNA-Seq data. TrUC could prove useful beyond Paramecium, especially in the case of high gene density. Accurate predictions of 3' and 5' UTR will be particularly valuable for studies of gene expression (e.g. nucleosome positioning, identification of cis

Cis-acting mutation and duplication: History of molecular evolution in a P450 haplotype responsible for insecticide resistance in Culex quinquefasciatus.

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Itokawa, Kentaro; Komagata, Osamu; Kasai, Shinji; Masada, Masahiro; Tomita, Takashi

2011-07-01

A cytochrome P450 gene, Cyp9m10, is more than 200-fold overexpressed in a pyrethroid resistant strain of Culex quinquefasciatus, JPal-per. The haplotype of this strain contains two copies of Cyp9m10 resulted from recent tandem duplication. In this study, we discovered and isolated a Cyp9m10 haplotype closely related to this duplicated Cyp9m10 haplotype from JHB, a strain used for the recent genome project for this mosquito species. The isolated haplotype (JHB-NIID-B haplotype) shared the same insertion of a transposable element upstream of the coding region with JPal-per strain but not duplicated. The JHB-NIID-B haplotype was considered to have diverged from the JPal-per lineage just before the duplication event. Cyp9m10 was moderately overexpressed in larvae with the JHB-NIID-B haplotype. The overexpressions in JHB-NIID-B and JPal-per haplotypes were developmentally regulated in similar pattern indicating both haplotypes share a common cis-acting mutation responsible for the overexpressions. The isolated moderately overexpressed haplotype conferred resistance, however, its efficacy was relatively small. We hypothesized that the first cis-acting mutation modified the consequence of the subsequent duplication in JPal-per lineage to confer stronger phenotypic effect than that if it occurred before the first cis-acting mutation. Copyright © 2011 Elsevier Ltd. All rights reserved.

A novel genome-wide microsatellite resource for species of Eucalyptus with linkage-to-physical correspondence on the reference genome sequence.

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Grattapaglia, Dario; Mamani, Eva M C; Silva-Junior, Orzenil B; Faria, Danielle A

2015-03-01

Keystone species in their native ranges, eucalypts, are ecologically and genetically very diverse, growing naturally along extensive latitudinal and altitudinal ranges and variable environments. Besides their ecological importance, eucalypts are also the most widely planted trees for sustainable forestry in the world. We report the development of a novel collection of 535 microsatellites for species of Eucalyptus, 494 designed from ESTs and 41 from genomic libraries. A selected subset of 223 was evaluated for individual identification, parentage testing, and ancestral information content in the two most extensively studied species, Eucalyptus grandis and Eucalyptus globulus. Microsatellites showed high transferability and overlapping allele size range, suggesting they have arisen still in their common ancestor and confirming the extensive genome conservation between these two species. A consensus linkage map with 437 microsatellites, the most comprehensive microsatellite-only genetic map for Eucalyptus, was built by assembling segregation data from three mapping populations and anchored to the Eucalyptus genome. An overall colinearity between recombination-based and physical positioning of 84% of the mapped microsatellites was observed, with some ordering discrepancies and sporadic locus duplications, consistent with the recently described whole genome duplication events in Eucalyptus. The linkage map covered 95.2% of the 605.8-Mbp assembled genome sequence, placing one microsatellite every 1.55 Mbp on average, and an overall estimate of physical to recombination distance of 618 kbp/cM. The genetic parameters estimates together with linkage and physical position data for this large set of microsatellites should assist marker choice for genome-wide population genetics and comparative mapping in Eucalyptus. © 2014 John Wiley & Sons Ltd.

The sunflower genome provides insights into oil metabolism, flowering and Asterid evolution.

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Badouin, Hélène; Gouzy, Jérôme; Grassa, Christopher J; Murat, Florent; Staton, S Evan; Cottret, Ludovic; Lelandais-Brière, Christine; Owens, Gregory L; Carrère, Sébastien; Mayjonade, Baptiste; Legrand, Ludovic; Gill, Navdeep; Kane, Nolan C; Bowers, John E; Hubner, Sariel; Bellec, Arnaud; Bérard, Aurélie; Bergès, Hélène; Blanchet, Nicolas; Boniface, Marie-Claude; Brunel, Dominique; Catrice, Olivier; Chaidir, Nadia; Claudel, Clotilde; Donnadieu, Cécile; Faraut, Thomas; Fievet, Ghislain; Helmstetter, Nicolas; King, Matthew; Knapp, Steven J; Lai, Zhao; Le Paslier, Marie-Christine; Lippi, Yannick; Lorenzon, Lolita; Mandel, Jennifer R; Marage, Gwenola; Marchand, Gwenaëlle; Marquand, Elodie; Bret-Mestries, Emmanuelle; Morien, Evan; Nambeesan, Savithri; Nguyen, Thuy; Pegot-Espagnet, Prune; Pouilly, Nicolas; Raftis, Frances; Sallet, Erika; Schiex, Thomas; Thomas, Justine; Vandecasteele, Céline; Varès, Didier; Vear, Felicity; Vautrin, Sonia; Crespi, Martin; Mangin, Brigitte; Burke, John M; Salse, Jérôme; Muños, Stéphane; Vincourt, Patrick; Rieseberg, Loren H; Langlade, Nicolas B

2017-06-01

The domesticated sunflower, Helianthus annuus L., is a global oil crop that has promise for climate change adaptation, because it can maintain stable yields across a wide variety of environmental conditions, including drought. Even greater resilience is achievable through the mining of resistance alleles from compatible wild sunflower relatives, including numerous extremophile species. Here we report a high-quality reference for the sunflower genome (3.6 gigabases), together with extensive transcriptomic data from vegetative and floral organs. The genome mostly consists of highly similar, related sequences and required single-molecule real-time sequencing technologies for successful assembly. Genome analyses enabled the reconstruction of the evolutionary history of the Asterids, further establishing the existence of a whole-genome triplication at the base of the Asterids II clade and a sunflower-specific whole-genome duplication around 29 million years ago. An integrative approach combining quantitative genetics, expression and diversity data permitted development of comprehensive gene networks for two major breeding traits, flowering time and oil metabolism, and revealed new candidate genes in these networks. We found that the genomic architecture of flowering time has been shaped by the most recent whole-genome duplication, which suggests that ancient paralogues can remain in the same regulatory networks for dozens of millions of years. This genome represents a cornerstone for future research programs aiming to exploit genetic diversity to improve biotic and abiotic stress resistance and oil production, while also considering agricultural constraints and human nutritional needs.

Cumulative Impact of Polychlorinated Biphenyl and Large Chromosomal Duplications on DNA Methylation, Chromatin, and Expression of Autism Candidate Genes.

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Dunaway, Keith W; Islam, M Saharul; Coulson, Rochelle L; Lopez, S Jesse; Vogel Ciernia, Annie; Chu, Roy G; Yasui, Dag H; Pessah, Isaac N; Lott, Paul; Mordaunt, Charles; Meguro-Horike, Makiko; Horike, Shin-Ichi; Korf, Ian; LaSalle, Janine M

2016-12-13

Rare variants enriched for functions in chromatin regulation and neuronal synapses have been linked to autism. How chromatin and DNA methylation interact with environmental exposures at synaptic genes in autism etiologies is currently unclear. Using whole-genome bisulfite sequencing in brain tissue and a neuronal cell culture model carrying a 15q11.2-q13.3 maternal duplication, we find that significant global DNA hypomethylation is enriched over autism candidate genes and affects gene expression. The cumulative effect of multiple chromosomal duplications and exposure to the pervasive persistent organic pollutant PCB 95 altered methylation of more than 1,000 genes. Hypomethylated genes were enriched for H2A.Z, increased maternal UBE3A in Dup15q corresponded to reduced levels of RING1B, and bivalently modified H2A.Z was altered by PCB 95 and duplication. These results demonstrate the compounding effects of genetic and environmental insults on the neuronal methylome that converge upon dysregulation of chromatin and synaptic genes. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

A case report of Ileal duplication

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Oh, K K; Suh, J H; Choi, B S [Yonsei University College of Medicine, Seoul (Korea, Republic of)

1971-10-15

Since Frankel reported the congenital anomalous intestinal duplication incidentally during autopsy in 1883, about 228 cases has been reported on the literatures. In our severance hospital, one case of ileal duplication was found, and was confirmed by pathology and surgery. This patient of duplication usually reveals the symptoms of abnormal distension, pain and palpable abdominal mass, and sometimes the symptoms of intestinal obstruction. On x-ray flate abdomen, huge occupying mass displaces intestinal gas pattern to left side. Barium enema study reveals elongation and displacement of ileum by large extrinsic mass. And cecum is also displaced upward. On the IVP, this extrinsic mass is not related to kidneys. Also, the literature was reviewed.

Duplication of Key Frames of Video Streams in Wireless Networks

OpenAIRE

Sagatov, Evgeny S.; Sukhov, Andrei M.

2011-01-01

In this paper technological solutions for improving the quality of video transfer along wireless networks are investigated. Tools have been developed to allow packets to be duplicated with key frames data. In the paper we tested video streams with duplication of all frames, with duplication of key frames, and without duplication. The experiments showed that the best results are obtained by duplication of packages which contain key frames. The paper also provides an overview of the coefficient...

Partial craniofacial duplication: a review of the literature and case report.

Science.gov (United States)

Costa, Melinda A; Borzabadi-Farahani, Ali; Lara-Sanchez, Pedro A; Schweitzer, Daniela; Jacobson, Lia; Clarke, Noreen; Hammoudeh, Jeffery; Urata, Mark M; Magee, William P

2014-06-01

Diprosopus (Greek; di-, "two" + prosopon, "face"), or craniofacial duplication, is a rare craniofacial anomaly referring to the complete duplication of facial structures. Partial craniofacial duplication describes a broad spectrum of congenital anomalies, including duplications of the oral cavity. This paper describes a 15 month-old female with a duplicated oral cavity, mandible, and maxilla. A Tessier type 7 cleft, midline meningocele, and duplicated hypophysis were also present. The preoperative evaluation, surgical approach, postoperative results, and a review of the literature are presented. The surgical approach was designed to preserve facial nerve innervation to the reconstructed cheek and mouth. The duplicated mandible and maxilla were excised and the remaining left maxilla was bone grafted. Soft tissue repair included closure of the Tessier type VII cleft. Craniofacial duplication remains a rare entity that is more common in females. The pathophysiology remains incompletely characterized, but is postulated to be due to duplication of the notochord, as well as duplication of mandibular growth centres. While diprosopus is a severe deformity often associated with anencephaly, patients with partial duplication typically benefit from surgical treatment. Managing craniofacial duplication requires a detailed preoperative evaluation as well as a comprehensive, staged treatment plan. Long-term follow up is needed appropriately to address ongoing craniofacial deformity. Published by Elsevier Ltd.

Rectal duplication cyst presenting as rectal prolapse in an infant

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Maher Zaiem

2018-05-01

Full Text Available Rectal duplication is a rare variety of gastrointestinal duplication. It accounts 4% of the total gastrointestinal duplications.In this paper, we are reporting a case of an 8 months old male who presented with rectal prolapse. Digital rectal examination revealed a soft mass bulging through the posterior wall of rectum. Computed tomography (CT scan showed a cystic mass compressing the posterior wall of the rectum. The mass was excised using a Muscle Complex Saving Posterior Sagittal approach (MCS-PSA. The pathology report confirmed the diagnosis of the rectal duplication cyst. The postoperative recovery was uneventful. Keywords: Intestinal duplication, Cystic rectal duplication, Rectal prolapse

The Genome Sequence of Taurine Cattle: A Window to Ruminant Biology and Evolution

OpenAIRE

Elsik, Christine G.; Tellam, Ross L.; Worley, Kim C.; Gibbs, Richard A.; Abatepaulo, Antonio R. R.; Abbey, Colette A.; Adelson, David L.; Aerts, Jan; Ahola, Virpi; Alexander, Lee; Alioto, Tyler; Almeida, Iassudara G.; Amadio, Ariel F.; Anatriello, Elen; Antonarakis, Stylianos E.

2009-01-01

To understand the biology and evolution of ruminants, the cattle genome was sequenced to about sevenfold coverage. The cattle genome contains a minimum of 22,000 genes, with a core set of 14,345 orthologs shared among seven mammalian species of which 1217 are absent or undetected in noneutherian (marsupial or monotreme) genomes. Cattle-specific evolutionary breakpoint regions in chromosomes have a higher density of segmental duplications, enrichment of repetitive elements, and species-specifi...

The complete chloroplast genome sequence of Curcuma flaviflora (Curcuma).

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Zhang, Yan; Deng, Jiabin; Li, Yangyi; Gao, Gang; Ding, Chunbang; Zhang, Li; Zhou, Yonghong; Yang, Ruiwu

2016-09-01

The complete chloroplast (cp) genome of Curcuma flaviflora, a medicinal plant in Southeast Asia, was sequenced. The genome size was 160 478 bp in length, with 36.3% GC content. A pair of inverted repeats (IRs) of 26 946 bp were separated by a large single copy (LSC) of 88 008 bp and a small single copy (SSC) of 18 578 bp, respectively. The cp genome contained 132 annotated genes, including 79 protein coding genes, 30 tRNA genes, and four rRNA genes. And 19 of these genes were duplicated in inverted repeat regions.

[Intestinal volvulus due to yeyunal duplication].

Science.gov (United States)

Rodríguez Iglesias, P; Carazo Palacios, M E; Lluna González, J; Ibáñez Pradas, V; Rodríguez Caraballo, L

2014-10-01

Duplications of the alimentary tract are congenital malformations. The ileum is the most commonly affected organ. A lot of duplications are incidentally diagnosed but most of patients present a combination of pain or complications such as obstructive symptoms, intestinal intussusception, perforation or volvulus. We report the case of a 6-years-old girl, with intermittent abdominal pain and vomits for two months long. Laboratory work was completely normal and in the radiology analysis (abdominal sonography and magnetic resonance) a cystic image with intestinal volvulus was observed. The patient underwent laparotomy, Ladd's procedure was done and the cyst was resected. In conclusion, if a patient is admitted with abdominal pain and obstructive symptoms, it is important to consider duplication of the alimentary tract as a possible diagnosis.

Surgical management of complete penile duplication accompanied by multiple anomalies.

Science.gov (United States)

Karaca, Irfan; Turk, Erdal; Ucan, A Basak; Yayla, Derya; Itirli, Gulcin; Ercal, Derya

2014-09-01

Diphallus (penile duplication) is very rare and seen once every 5.5 million births. It can be isolated, but is usually accompanied by other congenital anomalies. Previous studies have reported many concurrent anomalies, such as bladder extrophy, cloacal extrophy, duplicated bladder, scrotal abnormalities, hypospadias, separated symphysis pubis, intestinal anomalies and imperforate anus; no penile duplication case accompanied by omphalocele has been reported. We present the surgical management of a patient with multiple anomalies, including complete penile duplication, hypo-gastric omphalocele and extrophic rectal duplication.

Mitochondrial Genomes of Kinorhyncha: trnM Duplication and New Gene Orders within Animals

OpenAIRE

Popova, Olga V.; Mikhailov, Kirill V.; Nikitin, Mikhail A.; Logacheva, Maria D.; Penin, Aleksey A.; Muntyan, Maria S.; Kedrova, Olga S.; Petrov, Nikolai B.; Panchin, Yuri V.; Aleoshin, Vladimir V.

2016-01-01

Many features of mitochondrial genomes of animals, such as patterns of gene arrangement, nucleotide content and substitution rate variation are extensively used in evolutionary and phylogenetic studies. Nearly 6,000 mitochondrial genomes of animals have already been sequenced, covering the majority of animal phyla. One of the groups that escaped mitogenome sequencing is phylum Kinorhyncha-an isolated taxon of microscopic worm-like ecdysozoans. The kinorhynchs are thought to be one of the earl...

A new resource for characterizing X-linked genes in Drosophila melanogaster: systematic coverage and subdivision of the X chromosome with nested, Y-linked duplications.

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Cook, R Kimberley; Deal, Megan E; Deal, Jennifer A; Garton, Russell D; Brown, C Adam; Ward, Megan E; Andrade, Rachel S; Spana, Eric P; Kaufman, Thomas C; Cook, Kevin R

2010-12-01

Interchromosomal duplications are especially important for the study of X-linked genes. Males inheriting a mutation in a vital X-linked gene cannot survive unless there is a wild-type copy of the gene duplicated elsewhere in the genome. Rescuing the lethality of an X-linked mutation with a duplication allows the mutation to be used experimentally in complementation tests and other genetic crosses and it maps the mutated gene to a defined chromosomal region. Duplications can also be used to screen for dosage-dependent enhancers and suppressors of mutant phenotypes as a way to identify genes involved in the same biological process. We describe an ongoing project in Drosophila melanogaster to generate comprehensive coverage and extensive breakpoint subdivision of the X chromosome with megabase-scale X segments borne on Y chromosomes. The in vivo method involves the creation of X inversions on attached-XY chromosomes by FLP-FRT site-specific recombination technology followed by irradiation to induce large internal X deletions. The resulting chromosomes consist of the X tip, a medial X segment placed near the tip by an inversion, and a full Y. A nested set of medial duplicated segments is derived from each inversion precursor. We have constructed a set of inversions on attached-XY chromosomes that enable us to isolate nested duplicated segments from all X regions. To date, our screens have provided a minimum of 78% X coverage with duplication breakpoints spaced a median of nine genes apart. These duplication chromosomes will be valuable resources for rescuing and mapping X-linked mutations and identifying dosage-dependent modifiers of mutant phenotypes.

Endoscopic ultrasonography and rectal duplication cyst in an adult.

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Castro-Poças, Fernando M; Araújo, Tarcísio P; Silva, Jorge D; Gonçalves, Vicente S

2017-01-01

Rectal duplication cysts account for 4% of all duplications of the alimentary tract. Presentation in adulthood is rare. An asymptomatic 54-year-old man was referred for endoscopic colorectal cancer screening. A bulging mass covered by normal mucosa was identified in the rectum. Endoscopic ultrasonography (EUS) with fine needle aspiration (FNA) was made for a diagnosis of rectal duplication cyst. The patient was operated and the diagnosis was confirmed. The diagnosis of the rectal duplication cyst is a challenge. EUS may have a singular role when identifying a muscular layer, because this is the only absolutely necessary criterion for the diagnosis. FNA by EUS may eventually identify colorectal and/or heterotypic epithelium that are the other diagnostic criteria of the duplication cyst.

Duplication and independent selection of cell-wall invertase genes GIF1 and OsCIN1 during rice evolution and domestication

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Ge Song

2010-04-01

Full Text Available Abstract Background Various evolutionary models have been proposed to interpret the fate of paralogous duplicates, which provides substrates on which evolution selection could act. In particular, domestication, as a special selection, has played important role in crop cultivation with divergence of many genes controlling important agronomic traits. Recent studies have indicated that a pair of duplicate genes was often sub-functionalized from their ancestral functions held by the parental genes. We previously demonstrated that the rice cell-wall invertase (CWI gene GIF1 that plays an important role in the grain-filling process was most likely subjected to domestication selection in the promoter region. Here, we report that GIF1 and another CWI gene OsCIN1 constitute a pair of duplicate genes with differentiated expression and function through independent selection. Results Through synteny analysis, we show that GIF1 and another cell-wall invertase gene OsCIN1 were paralogues derived from a segmental duplication originated during genome duplication of grasses. Results based on analyses of population genetics and gene phylogenetic tree of 25 cultivars and 25 wild rice sequences demonstrated that OsCIN1 was also artificially selected during rice domestication with a fixed mutation in the coding region, in contrast to GIF1 that was selected in the promoter region. GIF1 and OsCIN1 have evolved into different expression patterns and probable different kinetics parameters of enzymatic activity with the latter displaying less enzymatic activity. Overexpression of GIF1 and OsCIN1 also resulted in different phenotypes, suggesting that OsCIN1 might regulate other unrecognized biological process. Conclusion How gene duplication and divergence contribute to genetic novelty and morphological adaptation has been an interesting issue to geneticists and biologists. Our discovery that the duplicated pair of GIF1 and OsCIN1 has experienced sub

Targeted tandem duplication of a large chromosomal segment in Aspergillus oryzae.

Science.gov (United States)

Takahashi, Tadashi; Sato, Atsushi; Ogawa, Masahiro; Hanya, Yoshiki; Oguma, Tetsuya

2014-08-01

We describe here the first successful construction of a targeted tandem duplication of a large chromosomal segment in Aspergillus oryzae. The targeted tandem chromosomal duplication was achieved by using strains that had a 5'-deleted pyrG upstream of the region targeted for tandem chromosomal duplication and a 3'-deleted pyrG downstream of the target region. Consequently,strains bearing a 210-kb targeted tandem chromosomal duplication near the centromeric region of chromosome 8 and strains bearing a targeted tandem chromosomal duplication of a 700-kb region of chromosome 2 were successfully constructed. The strains bearing the tandem chromosomal duplication were efficiently obtained from the regenerated protoplast of the parental strains. However, the generation of the chromosomal duplication did not depend on the introduction of double-stranded breaks(DSBs) by I-SceI. The chromosomal duplications of these strains were stably maintained after five generations of culture under nonselective conditions. The strains bearing the tandem chromosomal duplication in the 700-kb region of chromosome 2 showed highly increased protease activity in solid-state culture, indicating that the duplication of large chromosomal segments could be a useful new breeding technology and gene analysis method.

Genome-Wide Identification, Characterization and Phylogenetic Analysis of ATP-Binding Cassette (ABC) Transporter Genes in Common Carp (Cyprinus carpio).

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Liu, Xiang; Li, Shangqi; Peng, Wenzhu; Feng, Shuaisheng; Feng, Jianxin; Mahboob, Shahid; Al-Ghanim, Khalid A; Xu, Peng

2016-01-01

The ATP-binding cassette (ABC) gene family is considered to be one of the largest gene families in all forms of prokaryotic and eukaryotic life. Although the ABC transporter genes have been annotated in some species, detailed information about the ABC superfamily and the evolutionary characterization of ABC genes in common carp (Cyprinus carpio) are still unclear. In this research, we identified 61 ABC transporter genes in the common carp genome. Phylogenetic analysis revealed that they could be classified into seven subfamilies, namely 11 ABCAs, six ABCBs, 19 ABCCs, eight ABCDs, two ABCEs, four ABCFs, and 11 ABCGs. Comparative analysis of the ABC genes in seven vertebrate species including common carp, showed that at least 10 common carp genes were retained from the third round of whole genome duplication, while 12 duplicated ABC genes may have come from the fourth round of whole genome duplication. Gene losses were also observed for 14 ABC genes. Expression profiles of the 61 ABC genes in six common carp tissues (brain, heart, spleen, kidney, intestine, and gill) revealed extensive functional divergence among the ABC genes. Different copies of some genes had tissue-specific expression patterns, which may indicate some gene function specialization. This study provides essential genomic resources for future studies in common carp.

Genome-Wide Identification, Characterization and Phylogenetic Analysis of ATP-Binding Cassette (ABC) Transporter Genes in Common Carp (Cyprinus carpio)

Science.gov (United States)

Peng, Wenzhu; Feng, Shuaisheng; Feng, Jianxin; Mahboob, Shahid; Al-Ghanim, Khalid A.

2016-01-01

The ATP-binding cassette (ABC) gene family is considered to be one of the largest gene families in all forms of prokaryotic and eukaryotic life. Although the ABC transporter genes have been annotated in some species, detailed information about the ABC superfamily and the evolutionary characterization of ABC genes in common carp (Cyprinus carpio) are still unclear. In this research, we identified 61 ABC transporter genes in the common carp genome. Phylogenetic analysis revealed that they could be classified into seven subfamilies, namely 11 ABCAs, six ABCBs, 19 ABCCs, eight ABCDs, two ABCEs, four ABCFs, and 11 ABCGs. Comparative analysis of the ABC genes in seven vertebrate species including common carp, showed that at least 10 common carp genes were retained from the third round of whole genome duplication, while 12 duplicated ABC genes may have come from the fourth round of whole genome duplication. Gene losses were also observed for 14 ABC genes. Expression profiles of the 61 ABC genes in six common carp tissues (brain, heart, spleen, kidney, intestine, and gill) revealed extensive functional divergence among the ABC genes. Different copies of some genes had tissue-specific expression patterns, which may indicate some gene function specialization. This study provides essential genomic resources for future studies in common carp. PMID:27058731

Genome-Wide Identification, Characterization and Phylogenetic Analysis of ATP-Binding Cassette (ABC Transporter Genes in Common Carp (Cyprinus carpio.

Directory of Open Access Journals (Sweden)

Xiang Liu

Full Text Available The ATP-binding cassette (ABC gene family is considered to be one of the largest gene families in all forms of prokaryotic and eukaryotic life. Although the ABC transporter genes have been annotated in some species, detailed information about the ABC superfamily and the evolutionary characterization of ABC genes in common carp (Cyprinus carpio are still unclear. In this research, we identified 61 ABC transporter genes in the common carp genome. Phylogenetic analysis revealed that they could be classified into seven subfamilies, namely 11 ABCAs, six ABCBs, 19 ABCCs, eight ABCDs, two ABCEs, four ABCFs, and 11 ABCGs. Comparative analysis of the ABC genes in seven vertebrate species including common carp, showed that at least 10 common carp genes were retained from the third round of whole genome duplication, while 12 duplicated ABC genes may have come from the fourth round of whole genome duplication. Gene losses were also observed for 14 ABC genes. Expression profiles of the 61 ABC genes in six common carp tissues (brain, heart, spleen, kidney, intestine, and gill revealed extensive functional divergence among the ABC genes. Different copies of some genes had tissue-specific expression patterns, which may indicate some gene function specialization. This study provides essential genomic resources for future studies in common carp.

Immunohistochemical findings in rectal duplication mimicking rectal prolapse.

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Cortese, M G; Pucci, A; Macchieraldo, R; Sacco Casamassima, M G; Canavese, F

2008-08-01

Alimentary tract duplications represent rare anomalies, with only 5 % occurring in the rectum. The variety in clinical presentation may lead to a delay in diagnosis or to incorrect and multiple surgical procedures. We report the clinical, histological and immunohistochemical characteristics of a rectal duplication occurring in a 3-month-old male with an unusual clinical presentation. Using routine histology and immunohistochemistry, the rectal duplication showed the diffuse presence of gastric mucosa with a characteristic immunophenotype (i.e., diffuse cytokeratin 7 positivity and scattered chromogranin immunoreactivity). As far as we know, this is the first report showing an immunohistochemical differentiation pattern of gastric lining in a rectal duplication. Our results, showing the presence of gastric mucosa, are suggestive of a possible origin from the embryonic foregut.

Alignment of whole genomes.

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Delcher, A L; Kasif, S; Fleischmann, R D; Peterson, J; White, O; Salzberg, S L

1999-01-01

A new system for aligning whole genome sequences is described. Using an efficient data structure called a suffix tree, the system is able to rapidly align sequences containing millions of nucleotides. Its use is demonstrated on two strains of Mycoplasma tuberculosis, on two less similar species of Mycoplasma bacteria and on two syntenic sequences from human chromosome 12 and mouse chromosome 6. In each case it found an alignment of the input sequences, using between 30 s and 2 min of computation time. From the system output, information on single nucleotide changes, translocations and homologous genes can easily be extracted. Use of the algorithm should facilitate analysis of syntenic chromosomal regions, strain-to-strain comparisons, evolutionary comparisons and genomic duplications. PMID:10325427

Bilateral duplication of the internal auditory canal

International Nuclear Information System (INIS)

Weon, Young Cheol; Kim, Jae Hyoung; Choi, Sung Kyu; Koo, Ja-Won

2007-01-01

Duplication of the internal auditory canal is an extremely rare temporal bone anomaly that is believed to result from aplasia or hypoplasia of the vestibulocochlear nerve. We report bilateral duplication of the internal auditory canal in a 28-month-old boy with developmental delay and sensorineural hearing loss. (orig.)

Genome analysis of multiple pathogenic isolates of Streptococcus agalactiae : Implications for the microbial "pan-genome"

NARCIS (Netherlands)

Tettelin, H; Masignani, [No Value; Cieslewicz, MJ; Donati, C; Medini, D; Ward, NL; Angiuoli, SV; Crabtree, J; Jones, AL; Durkin, AS; DeBoy, RT; Davidsen, TM; Mora, M; Scarselli, M; Ros, IMY; Peterson, JD; Hauser, CR; Sundaram, JP; Nelson, WC; Madupu, R; Brinkac, LM; Dodson, RJ; Rosovitz, MJ; Sullivan, SA; Daugherty, SC; Haft, DH; Selengut, J; Gwinn, ML; Zhou, LW; Zafar, N; Khouri, H; Radune, D; Dimitrov, G; Watkins, K; O'Connor, KJB; Smith, S; Utterback, TR; White, O; Rubens, CE; Grandi, G; Madoff, LC; Kasper, DL; Telford, JL; Wessels, MR; Rappuoli, R; Fraser, CM

2005-01-01

The development of efficient and inexpensive genome sequencing methods has revolutionized the study of human bacterial pathogens and improved vaccine design. Unfortunately, the sequence of a single genome does not reflect how genetic variability drives pathogenesis within a bacterial species and

The amphioxus genome and the evolution of the chordate karyotype

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Putnam, Nicholas H.; Butts, Thomas; Ferrier, David E.K.; Furlong, Rebecca F.; Hellsten, Uffe; Kawashima, Takeshi; Robinson-Rechavi, Marc; Shoguchi, Eiichi; Terry, Astrid; Yu, Jr-Kai; Benito-Gutierrez, Elia; Dubchak, Inna; Garcia-Fernandez, Jordi; Gibson-Brown, Jeremy J.; Grigoriev, Igor V.; Horton, Amy C.; de Jong, Pieter J.; Jurka, Jerzy; Kapitonov, Vladimir; Kohara, Yuji; Kuroki, Yoko; Lindquist, Erika; Lucas, Susan; Osoegawa, Kazutoyo; Pennacchio, Len A.; Salamov, Asaf A.; Satou, Yutaka; Sauka-Spengler, Tatjana; Schmutz[, Jeremy; Shin-I, Tadasu; Toyoda, Atsushi; Bronner-Fraser, Marianne; Fujiyama, Asao; Holland, Linda Z.; Holland, Peter W. H.; Satoh, Nori; Rokhsar, Daniel S.

2008-04-01

Lancelets ('amphioxus') are the modern survivors of an ancient chordate lineage with a fossil record dating back to the Cambrian. We describe the structure and gene content of the highly polymorphic {approx}520 million base pair genome of the Florida lancelet Branchiostoma floridae, and analyze it in the context of chordate evolution. Whole genome comparisons illuminate the murky relationships among the three chordate groups (tunicates, lancelets, and vertebrates), and allow reconstruction of not only the gene complement of the last common chordate ancestor, but also a partial reconstruction of its genomic organization, as well as a description of two genome-wide duplications and subsequent reorganizations in the vertebrate lineage. These genome-scale events shaped the vertebrate genome and provided additional genetic variation for exploitation during vertebrate evolution.

Evolutionary history and functional divergence of the cytochrome P450 gene superfamily between Arabidopsis thaliana and Brassica species uncover effects of whole genome and tandem duplications.

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Yu, Jingyin; Tehrim, Sadia; Wang, Linhai; Dossa, Komivi; Zhang, Xiurong; Ke, Tao; Liao, Boshou

2017-09-18

The cytochrome P450 monooxygenase (P450) superfamily is involved in the biosynthesis of various primary and secondary metabolites. However, little is known about the effects of whole genome duplication (WGD) and tandem duplication (TD) events on the evolutionary history and functional divergence of P450s in Brassica after splitting from a common ancestor with Arabidopsis thaliana. Using Hidden Markov Model search and manual curation, we detected that Brassica species have nearly 1.4-fold as many P450 members as A. thaliana. Most P450s in A. thaliana and Brassica species were located on pseudo-chromosomes. The inferred phylogeny indicated that all P450s were clustered into two different subgroups. Analysis of WGD event revealed that different P450 gene families had appeared after evolutionary events of species. For the TD event analyses, the P450s from TD events in Brassica species can be divided into ancient and recent parts. Our comparison of influence of WGD and TD events on the P450 gene superfamily between A. thaliana and Brassica species indicated that the family-specific evolution in the Brassica lineage can be attributed to both WGD and TD, whereas WGD was recognized as the major mechanism for the recent evolution of the P450 super gene family. Expression analysis of P450s from A. thaliana and Brassica species indicated that WGD-type P450s showed the same expression pattern but completely different expression with TD-type P450s across different tissues in Brassica species. Selection force analysis suggested that P450 orthologous gene pairs between A. thaliana and Brassica species underwent negative selection, but no significant differences were found between P450 orthologous gene pairs in A. thaliana-B. rapa and A. thaliana-B. oleracea lineages, as well as in different subgenomes in B. rapa or B. oleracea compared with A. thaliana. This study is the first to investigate the effects of WGD and TD on the evolutionary history and functional divergence of P450

New pillars of evolutionary theory in the light of genomics

International Nuclear Information System (INIS)

Lopez Carrascal, Camilo Ernesto

2011-01-01

The evolutionist theory proposed by Darwin is one of the fundamental pillars in biology. Darwin's theory was solidified with the modern synthesis of evolutionary biology thanks to the rediscovery of Mendel's work, which laid the genetic basis of heredity. In recent years, great progress has been acquired in the sequencing and analyses of complete genomes, which have provided several elements to discuss some Darwinists tenets of evolution. The evidence of gene duplication and whole-genome duplication, the horizontal gene transfer and the endosymbiosis process question the idea that evolution proceeds through the gradual accumulation of infinitesimally small random changes. The new evidence of neutral selection on the genomics context reveals other mechanisms of evolution not necessarily related with the idea of progress or with an adaptationist program as was originally stated by the Darwin's theory. in this paper, I present these and other concepts such as gene regulation, molecular mechanisms of development and some environmental aspects (epigenesis and phenotypic plasticity) as starting points to think in the necessity to update the evolutionary theory which in my opinion should be more inclusive, pluralistic and consistent with our current knowledge.

[Colonic duplication revealed by intestinal obstruction due to fecal impaction].

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Azahouani, A; Hida, M; Benhaddou, H

2015-12-01

Colonic duplications are very rare in children. With rectal duplications, they are the rarest locations of alimentary tract duplications, most often diagnosed in the first years of life. We report an unusual case of colic duplication with fecal impaction in a 9-month-old boy revealed by intestinal obstruction. We discuss the main diagnostic and therapeutic aspects of this malformation. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

A Mitochondrial Genome of Rhyparochromidae (Hemiptera: Heteroptera) and a Comparative Analysis of Related Mitochondrial Genomes.

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Li, Teng; Yang, Jie; Li, Yinwan; Cui, Ying; Xie, Qiang; Bu, Wenjun; Hillis, David M

2016-10-19

The Rhyparochromidae, the largest family of Lygaeoidea, encompasses more than 1,850 described species, but no mitochondrial genome has been sequenced to date. Here we describe the first mitochondrial genome for Rhyparochromidae: a complete mitochondrial genome of Panaorus albomaculatus (Scott, 1874). This mitochondrial genome is comprised of 16,345 bp, and contains the expected 37 genes and control region. The majority of the control region is made up of a large tandem-repeat region, which has a novel pattern not previously observed in other insects. The tandem-repeats region of P. albomaculatus consists of 53 tandem duplications (including one partial repeat), which is the largest number of tandem repeats among all the known insect mitochondrial genomes. Slipped-strand mispairing during replication is likely to have generated this novel pattern of tandem repeats. Comparative analysis of tRNA gene families in sequenced Pentatomomorpha and Lygaeoidea species shows that the pattern of nucleotide conservation is markedly higher on the J-strand. Phylogenetic reconstruction based on mitochondrial genomes suggests that Rhyparochromidae is not the sister group to all the remaining Lygaeoidea, and supports the monophyly of Lygaeoidea.

Craniofacial duplication (diprosopus).

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Turpin, I M; Furnas, D W; Amlie, R N

1981-02-01

No congenital malformation in infants is more profound than anterior craniofacial duplication. The precise term for this rare anomaly is diprosopus, referring to a fetus with a single trunk, normal limbs, and varying degrees of facial duplication. A search of the world literature produced only 16 cases of diprosopus since 1864. Despite the rarity of this anomaly, three such infants were born in the Southern California area during the past year, making this the largest reported series to date. The three infants were born with two distinctly formed faces. Each had four separate eyes, two mouths, two noses, and two ears with a primitive ear or sinus tract at the plane of fusion. In addition, multiple congenital aberrations existed which involved a variety of internal organs. The pathogenesis of diprosopus is not well understood, but environmental stress early in embryologic development has been suggested as a possible factor. The apparent mechanism is a slowing of pregastrulation oxidation with resultant focal developmental arrests.

Plant STAND P-loop NTPases: a current perspective of genome distribution, evolution, and function : Plant STAND P-loop NTPases: genomic organization, evolution, and molecular mechanism models contribute broadly to plant pathogen defense.

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Arya, Preeti; Acharya, Vishal

2018-02-01

STAND P-loop NTPase is the common weapon used by plant and other organisms from all three kingdoms of life to defend themselves against pathogen invasion. The purpose of this study is to review comprehensively the latest finding of plant STAND P-loop NTPase related to their genomic distribution, evolution, and their mechanism of action. Earlier, the plant STAND P-loop NTPase known to be comprised of only NBS-LRRs/AP-ATPase/NB-ARC ATPase. However, recent finding suggests that genome of early green plants comprised of two types of STAND P-loop NTPases: (1) mammalian NACHT NTPases and (2) NBS-LRRs. Moreover, YchF (unconventional G protein and members of P-loop NTPase) subfamily has been reported to be exceptionally involved in biotic stress (in case of Oryza sativa), thereby a novel member of STAND P-loop NTPase in green plants. The lineage-specific expansion and genome duplication events are responsible for abundance of plant STAND P-loop NTPases; where "moderate tandem and low segmental duplication" trajectory followed in majority of plant species with few exception (equal contribution of tandem and segmental duplication). Since the past decades, systematic research is being investigated into NBS-LRR function supported the direct recognition of pathogen or pathogen effectors by the latest models proposed via 'integrated decoy' or 'sensor domains' model. Here, we integrate the recently published findings together with the previous literature on the genomic distribution, evolution, and distinct models proposed for functional molecular mechanism of plant STAND P-loop NTPases.

Insights into the Musa genome: Syntenic relationships to rice and between Musa species

Directory of Open Access Journals (Sweden)

Althoff Ryan

2008-01-01

Full Text Available Abstract Background Musa species (Zingiberaceae, Zingiberales including bananas and plantains are collectively the fourth most important crop in developing countries. Knowledge concerning Musa genome structure and the origin of distinct cultivars has greatly increased over the last few years. Until now, however, no large-scale analyses of Musa genomic sequence have been conducted. This study compares genomic sequence in two Musa species with orthologous regions in the rice genome. Results We produced 1.4 Mb of Musa sequence from 13 BAC clones, annotated and analyzed them along with 4 previously sequenced BACs. The 443 predicted genes revealed that Zingiberales genes share GC content and distribution characteristics with eudicot and Poaceae genomes. Comparison with rice revealed microsynteny regions that have persisted since the divergence of the Commelinid orders Poales and Zingiberales at least 117 Mya. The previously hypothesized large-scale duplication event in the common ancestor of major cereal lineages within the Poaceae was verified. The divergence time distributions for Musa-Zingiber (Zingiberaceae, Zingiberales orthologs and paralogs provide strong evidence for a large-scale duplication event in the Musa lineage after its divergence from the Zingiberaceae approximately 61 Mya. Comparisons of genomic regions from M. acuminata and M. balbisiana revealed highly conserved genome structure, and indicated that these genomes diverged circa 4.6 Mya. Conclusion These results point to the utility of comparative analyses between distantly-related monocot species such as rice and Musa for improving our understanding of monocot genome evolution. Sequencing the genome of M. acuminata would provide a strong foundation for comparative genomics in the monocots. In addition a genome sequence would aid genomic and genetic analyses of cultivated Musa polyploid genotypes in research aimed at localizing and cloning genes controlling important agronomic

Duplication of the Portal Vein: A Case Report

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Kim, Sang Won; Shin, Hyeong Cheol; Jou, Sung Shick; Han, Jong Kyu; Kim, Il Young [Soonchunhyang University Cheonan Hospital, Cheonan (Korea, Republic of)

2009-12-15

The duplication of the portal vein is an uncommon congenital anomaly. To date, only four cases have been reported in the medical literature. This anomaly can cause portal hypertension in pediatric patients. In addition, duplication of the portal vein has various patterns of connection with a splenic vein or mesenteric veins, and it can lie anterior or posterior to the duodenum. We report the MDCT findings of an adult patient with duplication of the portal vein that was found incidentally

Genome-wide identification, functional and evolutionary analysis of terpene synthases in pineapple.

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Chen, Xiaoe; Yang, Wei; Zhang, Liqin; Wu, Xianmiao; Cheng, Tian; Li, Guanglin

2017-10-01

Terpene synthases (TPSs) are vital for the biosynthesis of active terpenoids, which have important physiological, ecological and medicinal value. Although terpenoids have been reported in pineapple (Ananas comosus), genome-wide investigations of the TPS genes responsible for pineapple terpenoid synthesis are still lacking. By integrating pineapple genome and proteome data, twenty-one putative terpene synthase genes were found in pineapple and divided into five subfamilies. Tandem duplication is the cause of TPS gene family duplication. Furthermore, functional differentiation between each TPS subfamily may have occurred for several reasons. Sixty-two key amino acid sites were identified as being type-II functionally divergence between TPS-a and TPS-c subfamily. Finally, coevolution analysis indicated that multiple amino acid residues are involved in coevolutionary processes. In addition, the enzyme activity of two TPSs were tested. This genome-wide identification, functional and evolutionary analysis of pineapple TPS genes provide a new insight into understanding the roles of TPS family and lay the basis for further characterizing the function and evolution of TPS gene family. Copyright © 2017 Elsevier Ltd. All rights reserved.

Yeast Interspecies Comparative Proteomics Reveals Divergence in Expression Profiles and Provides Insights into Proteome Resource Allocation and Evolutionary Roles of Gene Duplication*

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Kito, Keiji; Ito, Haruka; Nohara, Takehiro; Ohnishi, Mihoko; Ishibashi, Yuko; Takeda, Daisuke

2016-01-01

Omics analysis is a versatile approach for understanding the conservation and diversity of molecular systems across multiple taxa. In this study, we compared the proteome expression profiles of four yeast species (Saccharomyces cerevisiae, Saccharomyces mikatae, Kluyveromyces waltii, and Kluyveromyces lactis) grown on glucose- or glycerol-containing media. Conserved expression changes across all species were observed only for a small proportion of all proteins differentially expressed between the two growth conditions. Two Kluyveromyces species, both of which exhibited a high growth rate on glycerol, a nonfermentative carbon source, showed distinct species-specific expression profiles. In K. waltii grown on glycerol, proteins involved in the glyoxylate cycle and gluconeogenesis were expressed in high abundance. In K. lactis grown on glycerol, the expression of glycolytic and ethanol metabolic enzymes was unexpectedly low, whereas proteins involved in cytoplasmic translation, including ribosomal proteins and elongation factors, were highly expressed. These marked differences in the types of predominantly expressed proteins suggest that K. lactis optimizes the balance of proteome resource allocation between metabolism and protein synthesis giving priority to cellular growth. In S. cerevisiae, about 450 duplicate gene pairs were retained after whole-genome duplication. Intriguingly, we found that in the case of duplicates with conserved sequences, the total abundance of proteins encoded by a duplicate pair in S. cerevisiae was similar to that of protein encoded by nonduplicated ortholog in Kluyveromyces yeast. Given the frequency of haploinsufficiency, this observation suggests that conserved duplicate genes, even though minor cases of retained duplicates, do not exhibit a dosage effect in yeast, except for ribosomal proteins. Thus, comparative proteomic analyses across multiple species may reveal not only species-specific characteristics of metabolic processes under

Sexually antagonistic "zygotic drive" of the sex chromosomes.

Directory of Open Access Journals (Sweden)

William R Rice

2008-12-01

Full Text Available Genomic conflict is perplexing because it causes the fitness of a species to decline rather than improve. Many diverse forms of genomic conflict have been identified, but this extant tally may be incomplete. Here, we show that the unusual characteristics of the sex chromosomes can, in principle, lead to a previously unappreciated form of sexual genomic conflict. The phenomenon occurs because there is selection in the heterogametic sex for sex-linked mutations that harm the sex of offspring that does not carry them, whenever there is competition among siblings. This harmful phenotype can be expressed as an antagonistic green-beard effect that is mediated by epigenetic parental effects, parental investment, and/or interactions among siblings. We call this form of genomic conflict sexually antagonistic "zygotic drive", because it is functionally equivalent to meiotic drive, except that it operates during the zygotic and postzygotic stages of the life cycle rather than the meiotic and gametic stages. A combination of mathematical modeling and a survey of empirical studies is used to show that sexually antagonistic zygotic drive is feasible, likely to be widespread in nature, and that it can promote a genetic "arms race" between the homo- and heteromorphic sex chromosomes. This new category of genomic conflict has the potential to strongly influence other fundamental evolutionary processes, such as speciation and the degeneration of the Y and W sex chromosomes. It also fosters a new genetic hypothesis for the evolution of enigmatic fitness-reducing traits like the high frequency of spontaneous abortion, sterility, and homosexuality observed in humans.

Phylogenetic signal from rearrangements in 18 Anopheles species by joint scaffolding extant and ancestral genomes.

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Anselmetti, Yoann; Duchemin, Wandrille; Tannier, Eric; Chauve, Cedric; Bérard, Sèverine

2018-05-09

Genomes rearrangements carry valuable information for phylogenetic inference or the elucidation of molecular mechanisms of adaptation. However, the detection of genome rearrangements is often hampered by current deficiencies in data and methods: Genomes obtained from short sequence reads have generally very fragmented assemblies, and comparing multiple gene orders generally leads to computationally intractable algorithmic questions. We present a computational method, ADSEQ, which, by combining ancestral gene order reconstruction, comparative scaffolding and de novo scaffolding methods, overcomes these two caveats. ADSEQ provides simultaneously improved assemblies and ancestral genomes, with statistical supports on all local features. Compared to previous comparative methods, it runs in polynomial time, it samples solutions in a probabilistic space, and it can handle a significantly larger gene complement from the considered extant genomes, with complex histories including gene duplications and losses. We use ADSEQ to provide improved assemblies and a genome history made of duplications, losses, gene translocations, rearrangements, of 18 complete Anopheles genomes, including several important malaria vectors. We also provide additional support for a differentiated mode of evolution of the sex chromosome and of the autosomes in these mosquito genomes. We demonstrate the method's ability to improve extant assemblies accurately through a procedure simulating realistic assembly fragmentation. We study a debated issue regarding the phylogeny of the Gambiae complex group of Anopheles genomes in the light of the evolution of chromosomal rearrangements, suggesting that the phylogenetic signal they carry can differ from the phylogenetic signal carried by gene sequences, more prone to introgression.

The complete chloroplast genome of Sinopodophyllum hexandrum (Berberidaceae).

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Li, Huie; Guo, Qiqiang

2016-07-01

The complete chloroplast (cp) genome of the Sinopodophyllum hexandrum (Berberidaceae) was determined in this study. The circular genome is 157,940 bp in size, and comprises a pair of inverted repeat (IR) regions of 26,077 bp each, a large single-copy (LSC) region of 86,460 bp and a small single-copy (SSC) region of 19,326 bp. The GC content of the whole cp genome was 38.5%. A total of 133 genes were identified, including 88 protein-coding genes, 37 tRNA genes and eight rRNA genes. The whole cp genome consists of 114 unique genes, and 19 genes are duplicated in the IR regions. The phylogenetic analysis revealed that S. hexandrum is closely related to Nandina domestica within the family Berberidaceae.

Genomic and Functional Approaches to Understanding Cancer Aneuploidy.

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Taylor, Alison M; Shih, Juliann; Ha, Gavin; Gao, Galen F; Zhang, Xiaoyang; Berger, Ashton C; Schumacher, Steven E; Wang, Chen; Hu, Hai; Liu, Jianfang; Lazar, Alexander J; Cherniack, Andrew D; Beroukhim, Rameen; Meyerson, Matthew

2018-04-09

Aneuploidy, whole chromosome or chromosome arm imbalance, is a near-universal characteristic of human cancers. In 10,522 cancer genomes from The Cancer Genome Atlas, aneuploidy was correlated with TP53 mutation, somatic mutation rate, and expression of proliferation genes. Aneuploidy was anti-correlated with expression of immune signaling genes, due to decreased leukocyte infiltrates in high-aneuploidy samples. Chromosome arm-level alterations show cancer-specific patterns, including loss of chromosome arm 3p in squamous cancers. We applied genome engineering to delete 3p in lung cells, causing decreased proliferation rescued in part by chromosome 3 duplication. This study defines genomic and phenotypic correlates of cancer aneuploidy and provides an experimental approach to study chromosome arm aneuploidy. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

The genome of Eucalyptus grandis

Energy Technology Data Exchange (ETDEWEB)

Myburg, Alexander A.; Grattapaglia, Dario; Tuskan, Gerald A.; Hellsten, Uffe; Hayes, Richard D.; Grimwood, Jane; Jenkins, Jerry; Lindquist, Erika; Tice, Hope; Bauer, Diane; Goodstein, David M.; Dubchak, Inna; Poliakov, Alexandre; Mizrachi, Eshchar; Kullan, Anand R. K.; Hussey, Steven G.; Pinard, Desre; van der Merwe, Karen; Singh, Pooja; van Jaarsveld, Ida; Silva-Junior, Orzenil B.; Togawa, Roberto C.; Pappas, Marilia R.; Faria, Danielle A.; Sansaloni, Carolina P.; Petroli, Cesar D.; Yang, Xiaohan; Ranjan, Priya; Tschaplinski, Timothy J.; Ye, Chu-Yu; Li, Ting; Sterck, Lieven; Vanneste, Kevin; Murat, Florent; Soler, Marçal; Clemente, Hélène San; Saidi, Naijib; Cassan-Wang, Hua; Dunand, Christophe; Hefer, Charles A.; Bornberg-Bauer, Erich; Kersting, Anna R.; Vining, Kelly; Amarasinghe, Vindhya; Ranik, Martin; Naithani, Sushma; Elser, Justin; Boyd, Alexander E.; Liston, Aaron; Spatafora, Joseph W.; Dharmwardhana, Palitha; Raja, Rajani; Sullivan, Christopher; Romanel, Elisson; Alves-Ferreira, Marcio; Külheim, Carsten; Foley, William; Carocha, Victor; Paiva, Jorge; Kudrna, David; Brommonschenkel, Sergio H.; Pasquali, Giancarlo; Byrne, Margaret; Rigault, Philippe; Tibbits, Josquin; Spokevicius, Antanas; Jones, Rebecca C.; Steane, Dorothy A.; Vaillancourt, René E.; Potts, Brad M.; Joubert, Fourie; Barry, Kerrie; Pappas, Georgios J.; Strauss, Steven H.; Jaiswal, Pankaj; Grima-Pettenati, Jacqueline; Salse, Jérôme; Van de Peer, Yves; Rokhsar, Daniel S.; Schmutz, Jeremy

2014-06-11

Eucalypts are the world s most widely planted hardwood trees. Their broad adaptability, rich species diversity, fast growth and superior multipurpose wood, have made them a global renewable resource of fiber and energy that mitigates human pressures on natural forests. We sequenced and assembled >94% of the 640 Mbp genome of Eucalyptus grandis into its 11 chromosomes. A set of 36,376 protein coding genes were predicted revealing that 34% occur in tandem duplications, the largest proportion found thus far in any plant genome. Eucalypts also show the highest diversity of genes for plant specialized metabolism that act as chemical defence against biotic agents and provide unique pharmaceutical oils. Resequencing of a set of inbred tree genomes revealed regions of strongly conserved heterozygosity, likely hotspots of inbreeding depression. The resequenced genome of the sister species E. globulus underscored the high inter-specific genome colinearity despite substantial genome size variation in the genus. The genome of E. grandis is the first reference for the early diverging Rosid order Myrtales and is placed here basal to the Eurosids. This resource expands knowledge on the unique biology of large woody perennials and provides a powerful tool to accelerate comparative biology, breeding and biotechnology.

Typewriting: Toward Duplicating Success

Science.gov (United States)

Orsborn, Karen J.

1977-01-01

A description of two projects (secretarial handbook and memo pad and personalized stationery) for use in teaching the duplication process that will capture the interests of students in an advanced typewriting class. (HD)

Identification of approximately duplicate material records in ERP systems

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Zong, Wei; Wu, Feng; Chu, Lap-Keung; Sculli, Domenic

2017-03-01

The quality of master data is crucial for the accurate functioning of the various modules of an enterprise resource planning (ERP) system. This study addresses specific data problems arising from the generation of approximately duplicate material records in ERP databases. Such problems are mainly due to the firm's lack of unique and global identifiers for the material records, and to the arbitrary assignment of alternative names for the same material by various users. Traditional duplicate detection methods are ineffective in identifying such approximately duplicate material records because these methods typically rely on string comparisons of each field. To address this problem, a machine learning-based framework is developed to recognise semantic similarity between strings and to further identify and reunify approximately duplicate material records - a process referred to as de-duplication in this article. First, the keywords of the material records are extracted to form vectors of discriminating words. Second, a machine learning method using a probabilistic neural network is applied to determine the semantic similarity between these material records. The approach was evaluated using data from a real case study. The test results indicate that the proposed method outperforms traditional algorithms in identifying approximately duplicate material records.

Genomic and transcriptomic approaches to study immunology in cyprinids: What is next?

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Petit, Jules; David, Lior; Dirks, Ron; Wiegertjes, Geert F

2017-10-01

Accelerated by the introduction of Next-Generation Sequencing (NGS), a number of genomes of cyprinid fish species have been drafted, leading to a highly valuable collective resource of comparative genome information on cyprinids (Cyprinidae). In addition, NGS-based transcriptome analyses of different developmental stages, organs, or cell types, increasingly contribute to the understanding of complex physiological processes, including immune responses. Cyprinids are a highly interesting family because they comprise one of the most-diversified families of teleosts and because of their variation in ploidy level, with diploid, triploid, tetraploid, hexaploid and sometimes even octoploid species. The wealth of data obtained from NGS technologies provides both challenges and opportunities for immunological research, which will be discussed here. Correct interpretation of ploidy effects on immune responses requires knowledge of the degree of functional divergence between duplicated genes, which can differ even between closely-related cyprinid fish species. We summarize NGS-based progress in analysing immune responses and discuss the importance of respecting the presence of (multiple) duplicated gene sequences when performing transcriptome analyses for detailed understanding of complex physiological processes. Progressively, advances in NGS technology are providing workable methods to further elucidate the implications of gene duplication events and functional divergence of duplicates genes and proteins involved in immune responses in cyprinids. We conclude with discussing how future applications of NGS technologies and analysis methods could enhance immunological research and understanding. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Multiple independent structural dynamic events in the evolution of snake mitochondrial genomes.

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Qian, Lifu; Wang, Hui; Yan, Jie; Pan, Tao; Jiang, Shanqun; Rao, Dingqi; Zhang, Baowei

2018-05-10

Mitochondrial DNA sequences have long been used in phylogenetic studies. However, little attention has been paid to the changes in gene arrangement patterns in the snake's mitogenome. Here, we analyzed the complete mitogenome sequences and structures of 65 snake species from 14 families and examined their structural patterns, organization and evolution. Our purpose was to further investigate the evolutionary implications and possible rearrangement mechanisms of the mitogenome within snakes. In total, eleven types of mitochondrial gene arrangement patterns were detected (Type I, II, III, III-A, III-B, III-B1, III-C, III-D, III-E, III-F, III-G), with mitochondrial genome rearrangements being a major trend in snakes, especially in Alethinophidia. In snake mitogenomes, the rearrangements mainly involved three processes, gene loss, translocation and duplication. Within Scolecophidia, the O L was lost several times in Typhlopidae and Leptotyphlopidae, but persisted as a plesiomorphy in the Alethinophidia. Duplication of the control region and translocation of the tRNA Leu gene are two visible features in Alethinophidian mitochondrial genomes. Independently and stochastically, the duplication of pseudo-Pro (P*) emerged in seven different lineages of unequal size in three families, indicating that the presence of P* was a polytopic event in the mitogenome. The WANCY tRNA gene cluster and the control regions and their adjacent segments were hotspots for mitogenome rearrangement. Maintenance of duplicate control regions may be the source for snake mitogenome structural diversity.

Chromosomal duplication strains of Aspergillus nidulans and their instability

International Nuclear Information System (INIS)

Azevedo, J.L. de; Almeida Okino, L.M. de

1981-01-01

Strains of Aspergillus nidulans with chromosomal duplication were obtained after gamma irradiation followed by crossing of the translocated strains with normal strains. From 20 analysed colonies, 12 have shown translocations induced by irradiation. Segregants from four of these translocation strains crossed to normal strains have shown to be unstable although presenting normal morphology. Two segregants were genetically analysed. The first one has shown a duplication of part of linkage groups VIII and the second one presented a duplication of a segment of linkage group V. These new duplication strains in A. nidulans open new perspectives of a more detailed study of the instability phenomenon in this fungus. (Author) [pt

Soybean (Glycine max) SWEET gene family: insights through comparative genomics, transcriptome profiling and whole genome re-sequence analysis.

Science.gov (United States)

Patil, Gunvant; Valliyodan, Babu; Deshmukh, Rupesh; Prince, Silvas; Nicander, Bjorn; Zhao, Mingzhe; Sonah, Humira; Song, Li; Lin, Li; Chaudhary, Juhi; Liu, Yang; Joshi, Trupti; Xu, Dong; Nguyen, Henry T

2015-07-11

SWEET (MtN3_saliva) domain proteins, a recently identified group of efflux transporters, play an indispensable role in sugar efflux, phloem loading, plant-pathogen interaction and reproductive tissue development. The SWEET gene family is predominantly studied in Arabidopsis and members of the family are being investigated in rice. To date, no transcriptome or genomics analysis of soybean SWEET genes has been reported. In the present investigation, we explored the evolutionary aspect of the SWEET gene family in diverse plant species including primitive single cell algae to angiosperms with a major emphasis on Glycine max. Evolutionary features showed expansion and duplication of the SWEET gene family in land plants. Homology searches with BLAST tools and Hidden Markov Model-directed sequence alignments identified 52 SWEET genes that were mapped to 15 chromosomes in the soybean genome as tandem duplication events. Soybean SWEET (GmSWEET) genes showed a wide range of expression profiles in different tissues and developmental stages. Analysis of public transcriptome data and expression profiling using quantitative real time PCR (qRT-PCR) showed that a majority of the GmSWEET genes were confined to reproductive tissue development. Several natural genetic variants (non-synonymous SNPs, premature stop codons and haplotype) were identified in the GmSWEET genes using whole genome re-sequencing data analysis of 106 soybean genotypes. A significant association was observed between SNP-haplogroup and seed sucrose content in three gene clusters on chromosome 6. Present investigation utilized comparative genomics, transcriptome profiling and whole genome re-sequencing approaches and provided a systematic description of soybean SWEET genes and identified putative candidates with probable roles in the reproductive tissue development. Gene expression profiling at different developmental stages and genomic variation data will aid as an important resource for the soybean research

Genome rearrangements detected by SNP microarrays in individuals with intellectual disability referred with possible Williams syndrome.

Directory of Open Access Journals (Sweden)

Ariel M Pani

2010-08-01

Full Text Available Intellectual disability (ID affects 2-3% of the population and may occur with or without multiple congenital anomalies (MCA or other medical conditions. Established genetic syndromes and visible chromosome abnormalities account for a substantial percentage of ID diagnoses, although for approximately 50% the molecular etiology is unknown. Individuals with features suggestive of various syndromes but lacking their associated genetic anomalies pose a formidable clinical challenge. With the advent of microarray techniques, submicroscopic genome alterations not associated with known syndromes are emerging as a significant cause of ID and MCA.High-density SNP microarrays were used to determine genome wide copy number in 42 individuals: 7 with confirmed alterations in the WS region but atypical clinical phenotypes, 31 with ID and/or MCA, and 4 controls. One individual from the first group had the most telomeric gene in the WS critical region deleted along with 2 Mb of flanking sequence. A second person had the classic WS deletion and a rearrangement on chromosome 5p within the Cri du Chat syndrome (OMIM:123450 region. Six individuals from the ID/MCA group had large rearrangements (3 deletions, 3 duplications, one of whom had a large inversion associated with a deletion that was not detected by the SNP arrays.Combining SNP microarray analyses and qPCR allowed us to clone and sequence 21 deletion breakpoints in individuals with atypical deletions in the WS region and/or ID or MCA. Comparison of these breakpoints to databases of genomic variation revealed that 52% occurred in regions harboring structural variants in the general population. For two probands the genomic alterations were flanked by segmental duplications, which frequently mediate recurrent genome rearrangements; these may represent new genomic disorders. While SNP arrays and related technologies can identify potentially pathogenic deletions and duplications, obtaining sequence information