235 research outputs found

    High Level of Structural Polymorphism Driven by Mobile Elements in the Hox Genomic Region of the Chaetognath Spadella cephaloptera

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    Little is known about the relationships between genome polymorphism, mobile element dynamics, and population size among animal populations. The chaetognath species Spadella cephaloptera offers a unique perspective to examine this issue because they display a high level of genetic polymorphism at the population level. Here, we have investigated in detail the extent of nucleotide and structural polymorphism in a region harboring Hox1 and several coding genes and presumptive functional elements. Sequencing of several bacterial artificial chromosome inserts representative of this nuclear region uncovered a high level of structural heterogeneity, which is mainly caused by the polymorphic insertion of a diversity of genetic mobile elements. By anchoring this variation through individual genotyping, we demonstrated that sequence diversity could be attributed to the allelic pool of a single population, which was confirmed by detection of extensive recombination within the genomic region studied. The high average level of nucleotide heterozygosity provides clues of selection in both coding and noncoding domains. This pattern stresses how selective processes remarkably cope with intense sequence turnover due to substitutions, mobile element insertions, and recombination to preserve the integrity of functional landscape. These findings suggest that genome polymorphism could provide pivotal information for future functional annotation of genomes

    Chætognath transcriptome reveals ancestral and unique features among bilaterians

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    Background: The chætognaths (arrow worms) have puzzled zoologists for years because of their astonishing morphological and developmental characteristics. Despite their deuterostome-like development, phylogenomic studies recently positioned the chætognath phylum in protostomes, most likely in an early branching. This key phylogenetic position and the peculiar characteristics of chætognaths prompted further investigation of their genomic features. / Results: Transcriptomic and genomic data were collected from the chætognath Spadella cephaloptera through the sequencing of expressed sequence tags and genomic bacterial artificial chromosome clones. Transcript comparisons at various taxonomic scales emphasized the conservation of a core gene set and phylogenomic analysis confirmed the basal position of chætognaths among protostomes. A detailed survey of transcript diversity and individual genotyping revealed a past genome duplication event in the chætognath lineage, which was, surprisingly, followed by a high retention rate of duplicated genes. Moreover, striking genetic heterogeneity was detected within the sampled population at the nuclear and mitochondrial levels but cannot be explained by cryptic speciation. Finally, we found evidence for trans-splicing maturation of transcripts through splice-leader addition in the chætognath phylum and we further report that this processing is associated with operonic transcription. / Conclusion: These findings reveal both shared ancestral and unique derived characteristics of the chætognath genome, which suggests that this genome is likely the product of a very original evolutionary history. These features promote chætognaths as a pivotal model for comparative genomics, which could provide new clues for the investigation of the evolution of animal genomes

    Kölcsey Ferenc minden munkái (kritikai kiadás) = The Complete Works of Ferenc Kölcsey (critical edition)

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    A Kölcsey Ferenc minden munkáinak kritikai kiadását képező, a tervezett időszakra vállalt kötetekből egy megjelent a Levelezés II. (Szabó G. Zoltán), megjelenés előtt az Erkölcsi, pedagógiai írások (Onder Csaba), más kötetek lektorálás, ill. tervezett megjelenés előtt: Esztétikai és kritikai írások II. (Gyapay László), Kölcsey-bibliográfia (Csécs Teréz), Kölcsey családi iratai és. dokumentumai (Csorba Sándor), több kötet különböző készültségi állapotban: Országgyűlési beszédek (Gángó G.-Ratzky R.) átdolgozás alatt, Wesselényi védőbeszéd (Pajkossy Gábor) esetében a főszöveg tisztázása, az előszó, keletkezéstörténet után a jegyzetek elkészítése következik, Kölcsey országgyűlési teevékenységével kapcsolatos szövegek (Völgyesi Orsolya) az anyagggyűjtés befejezése és a jegyzetek elkészítése szakaszában van. Eredménytelen volt Jászberényi József munkája: a Kölcsey filozófiai írásai (meghaladta a kutató szakmai, ill. nyelvi kompetenciáját), ugyancsak eredményetelen lett Lakner Lajos Kölcsey-kronológia c. vállalkozása, mely a koncepció kidolgozása után más elfoglaltságok miatt abbamaradt. | In the critical edition of Ferenc Kölcsey's Complete Works the second volume of Correspondence (edited by Zoltán G. Szabó) has been relased as planned for this term. The volume of Moral and Pedagogic Writings (edited by Csaba Onder) is to be published, as well as Kölcsey's Aesthetical and Critical writtings (by László Gyapay), his Bibliography (by Teréz Csécs) and his Domestical and Official Documents (by Sándor Csorba). Several volumes are respectively on different levels of readiness. Kölcsey's Parliamentary Speeches (by Gábor Gángó and Rita Ratzky) currently is under revision. In the case of Wesselényi's Plea (by Gábor Pajkossy) after textological investigations, writing off an introduction and revealing their background, the texts are still to be annotated. The volume considering the documents of Kölcsey's parliamentary activity (by Orsolya Völgyesi) is also in the phase of annotating. József Jászberényi's work remained inefficient: elaborating Kölcsey's philosophical works has proved to be beyond his abilities. After developing the conceptual framework, Lajos Lakner has also given up his venture of accomplishing a Kölcsey-Chronology

    Lightweight Testing of Communication Networks with e-Motions

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    This paper illustrates the use of high-level domain specific models to specify and test some performance properties of complex systems, in particular Communication Networks, using a light-weight approach. By following a Model-Driven Engineering (MDE) approach, we show the benefits of constructing very abstract models of the systems under test, which can then be easily prototyped and analysed to explore their properties. For this purpose we use e-Motions, a language and its supporting toolkit that allows end-user modelling of real-time systems and their analysis in a graphical manner.Junta de Andalucía P07-TIC-03184Ministerio de Ciencia e Innovación TIN2008-0310

    Detailed deletion mapping of chromosome band 14q32 in human neuroblastoma defines a 1.1-Mb region of common allelic loss

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    Neuroblastoma (NB) is a well-known malignant disease in infants, but its molecular mechanisms have not yet been fully elucidated. To investigate the genetic contribution of abnormalities on the long arm of chromosome 14 (14q) in NB, we analysed loss of heterozygosity (LOH) in 54 primary NB samples using 12 microsatellite markers on 14q32. Seventeen (31%) of 54 tumours showed LOH at one or more of the markers analysed, and the smallest common region of allelic loss was identified between D14S62 and D14S987. This region was estimated to be 1-cM long from the linkage map. Fluorescence in situ hybridization also confirmed the loss. There was no statistical correlation between LOH and any clinicopathologic features, including age, stage, amplification of MYCN and ploidy. We further constructed a contig spanning the lost region using bacterial artificial chromosome and estimated this region to be approximately 1.1-Mb by pulsed-field gel electrophoresis. Our results will contribute to cloning and characterizing the putative tumour-associated gene(s) in 14q32 in NB. © 2000 Cancer Research Campaig

    Enhanced genetic maps from family-based disease studies: population-specific comparisons

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    Abstract Background Accurate genetic maps are required for successful and efficient linkage mapping of disease genes. However, most available genome-wide genetic maps were built using only small collections of pedigrees, and therefore have large sampling errors. A large set of genetic studies genotyped by the NHLBI Mammalian Genotyping Service (MGS) provide appropriate data for generating more accurate maps. Results We collected a large sample of uncleaned genotype data for 461 markers generated by the MGS using the Weber screening sets 9 and 10. This collection includes genotypes for over 4,400 pedigrees containing over 17,000 genotyped individuals from different populations. We identified and cleaned numerous relationship and genotyping errors, as well as verified the marker orders. We used this dataset to test for population-specific genetic maps, and to re-estimate the genetic map distances with greater precision; standard errors for all intervals are provided. The map-interval sizes from the European (or European descent), Chinese, and Hispanic samples are in quite good agreement with each other. We found one map interval on chromosome 8p with a statistically significant size difference between the European and Chinese samples, and several map intervals with significant size differences between the African American and Chinese samples. When comparing Palauan with European samples, a statistically significant difference was detected at the telomeric region of chromosome 11p. Several significant differences were also identified between populations in chromosomal and genome lengths. Conclusions Our new population-specific screening set maps can be used to improve the accuracy of disease-mapping studies. As a result of the large sample size, the average length of the 95% confidence interval (CI) for a 10 cM map interval is only 2.4 cM, which is considerably smaller than on previously published maps.http://deepblue.lib.umich.edu/bitstream/2027.42/112826/1/12881_2010_Article_748.pd

    Genetic aberrations in glioblastoma multiforme: translocation of chromosome 10 in an O-2A-like cell line

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    We have examined the genetic aberrations in two near-diploid glioblastoma multiforme cell lines that appear to have arisen from different glial lineages. One cell line, Hu-O-2A/Gb1, expresses antigens and metabolic profiles characteristic of the oligodendrocyte-type-2 astrocyte (0-2A) lineage of the rat central nervous system. This line generates, in vitro, cells with characteristics of 0-2A progenitor cells, oligodendrocytes and astrocytes. The second cell line, IN1434, is derived from an astrocyte or a precursor cell restricted to astrocytic differentiation. In Hu-O-2A/Gb1 the sole homologue of chromosome 10 is disrupted at band 10p11–12.1 by translocation with chromosomes X and 15. The translocation breakpoint is localized between genetic markers D10S2103 and [D10S637, D10S1962, D10S355]. Other aberrations include a 5;14 translocation, deletion of the long and short arms of chromosome 16 and loss of one copy of the CDKN2 gene. IN1434 cells share some cytogenetic abnormalities with Hu-O-2A/Gb1 cells, despite their apparent derivation from a different biological origin, but also have translocations involving the long and short arms of chromosome 1 and the long arm of chromosome 7, and deletion of chromosome 13 at bands 13q12–21. © 1999 Cancer Research Campaig

    Analysis of the 10q23 chromosomal region and the PTEN gene in human sporadic breast carcinoma

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    We examined a panel of sporadic breast carcinomas for loss of heterozygosity (LOH) in a 10-cM interval on chromosome 10 known to encompass the PTEN gene. We detected allele loss in 27 of 70 breast tumour DNAs. Fifteen of these showed loss limited to a subregion of the area studied. The most commonly deleted region was flanked by D10S215 and D10S541 and encompasses the PTEN locus. We used a combination of denaturing gradient gel electrophoresis and single-strand conformation polymorphism analyses to investigate the presence of PTEN mutations in tumours with LOH in this region. We did not detect mutations of PTEN in any of these tumours. Our data show that, in sporadic breast carcinoma, loss of heterozygosity of the PTEN locus is frequent, but mutation of PTEN is not. These results are consistent with loss of another unidentified tumour suppressor in this region in sporadic breast carcinoma. © 1999 Cancer Research Campaig

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
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