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Sample records for artificial episomal chromosome

  1. Final report. Human artificial episomal chromosome (HAEC) for building large genomic libraries

    Energy Technology Data Exchange (ETDEWEB)

    Jean-Michael H. Vos

    1999-12-09

    Collections of human DNA fragments are maintained for research purposes as clones in bacterial host cells. However for unknown reasons, some regions of the human genome appear to be unclonable or unstable in bacteria. Their team has developed a system using episomes (extrachromosomal, autonomously replication DNA) that maintains large DNA fragments in human cells. This human artificial episomal chromosomal (HAEC) system may prove useful for coverage of these especially difficult regions. In the broader biomedical community, the HAEC system also shows promise for use in functional genomics and gene therapy. Recent improvements to the HAEC system and its application to mapping, sequencing, and functionally studying human and mouse DNA are summarized. Mapping and sequencing the human genome and model organisms are only the first steps in determining the function of various genetic units critical for gene regulation, DNA replication, chromatin packaging, chromosomal stability, and chromatid segregation. Such studies will require the ability to transfer and manipulate entire functional units into mammalian cells.

  2. Refined human artificial chromosome vectors for gene therapy and animal transgenesis

    OpenAIRE

    Kazuki, Y; Hoshiya, H.; Takiguchi, M.; S. Abe; Iida, Y; Osaki, M.; Katoh, M; Hiratsuka, M; Shirayoshi, Y; Hiramatsu, K; Ueno, E; N. Kajitani; Yoshino, T.; Kazuki, K; Ishihara, C.

    2010-01-01

    Human artificial chromosomes (HACs) have several advantages as gene therapy vectors, including stable episomal maintenance, and the ability to carry large gene inserts. We previously developed HAC vectors from the normal human chromosomes using a chromosome engineering technique. However, endogenous genes were remained in these HACs, limiting their therapeutic applications. In this study, we refined a HAC vector without endogenous genes from human chromosome 21 in homologous recombination-pro...

  3. A comparison of synthetic oligodeoxynucleotides, DNA fragments and AAV-1 for targeted episomal and chromosomal gene repair

    Directory of Open Access Journals (Sweden)

    Leclerc Xavier

    2009-04-01

    Full Text Available Abstract Background Current strategies for gene therapy of inherited diseases consist in adding functional copies of the gene that is defective. An attractive alternative to these approaches would be to correct the endogenous mutated gene in the affected individual. This study presents a quantitative comparison of the repair efficiency using different forms of donor nucleic acids, including synthetic DNA oligonucleotides, double stranded DNA fragments with sizes ranging from 200 to 2200 bp and sequences carried by a recombinant adeno-associated virus (rAAV-1. Evaluation of each gene repair strategy was carried out using two different reporter systems, a mutated eGFP gene or a dual construct with a functional eGFP and an inactive luciferase gene, in several different cell systems. Gene targeting events were scored either following transient co-transfection of reporter plasmids and donor DNAs, or in a system where a reporter construct was stably integrated into the chromosome. Results In both episomal and chromosomal assays, DNA fragments were more efficient at gene repair than oligonucleotides or rAAV-1. Furthermore, the gene targeting frequency could be significantly increased by using DNA repair stimulating drugs such as doxorubicin and phleomycin. Conclusion Our results show that it is possible to obtain repair frequencies of 1% of the transfected cell population under optimized transfection protocols when cells were pretreated with phleomycin using rAAV-1 and dsDNA fragments.

  4. Bacterial Artificial Chromosome Mutagenesis Using Recombineering

    OpenAIRE

    Kumaran Narayanan; Qingwen Chen

    2011-01-01

    Gene expression from bacterial artificial chromosome (BAC) clones has been demonstrated to facilitate physiologically relevant levels compared to viral and nonviral cDNA vectors. BACs are large enough to transfer intact genes in their native chromosomal setting together with flanking regulatory elements to provide all the signals for correct spatiotemporal gene expression. Until recently, the use of BACs for functional studies has been limited because their large size has inherently presented...

  5. Transpositionally active episomal hAT elements

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    Hice Robert H

    2009-12-01

    Full Text Available Abstract Background hAT elements and V(DJ recombination may have evolved from a common ancestral transposable element system. Extrachromosomal, circular forms of transposable elements (referred to here as episomal forms have been reported yet their biological significance remains unknown. V(DJ signal joints, which resemble episomal transposable elements, have been considered non-recombinogenic products of V(DJ recombination and a safe way to dispose of excised chromosomal sequences. V(DJ signal joints can, however, participate in recombination reactions and the purpose of this study was to determine if hobo and Hermes episomal elements are also recombinogenic. Results Up to 50% of hobo/Hermes episomes contained two intact, inverted-terminal repeats and 86% of these contained from 1-1000 bp of intercalary DNA. Episomal hobo/Hermes elements were recovered from Musca domestica (a natural host of Hermes, Drosophila melanogaster (a natural host of hobo and transgenic Drosophila melanogaster and Aedes aegypti (with autonomous Hermes elements. Episomal Hermes elements were recovered from unfertilized eggs of M. domestica and D. melanogaster demonstrating their potential for extrachromosomal, maternal transmission. Reintegration of episomal Hermes elements was observed in vitro and in vivo and the presence of Hermes episomes resulted in lower rates of canonical Hermes transposition in vivo. Conclusion Episomal hobo/Hermes elements are common products of element excision and can be maternally transmitted. Episomal forms of Hermes are capable of integration and also of influencing the transposition of canonical elements suggesting biological roles for these extrachromosomal elements in element transmission and regulation.

  6. Bacterial Artificial Chromosome Mutagenesis Using Recombineering

    Directory of Open Access Journals (Sweden)

    Kumaran Narayanan

    2011-01-01

    Full Text Available Gene expression from bacterial artificial chromosome (BAC clones has been demonstrated to facilitate physiologically relevant levels compared to viral and nonviral cDNA vectors. BACs are large enough to transfer intact genes in their native chromosomal setting together with flanking regulatory elements to provide all the signals for correct spatiotemporal gene expression. Until recently, the use of BACs for functional studies has been limited because their large size has inherently presented a major obstacle for introducing modifications using conventional genetic engineering strategies. The development of in vivo homologous recombination strategies based on recombineering in E. coli has helped resolve this problem by enabling facile engineering of high molecular weight BAC DNA without dependence on suitably placed restriction enzymes or cloning steps. These techniques have considerably expanded the possibilities for studying functional genetics using BACs in vitro and in vivo.

  7. [Cashmere goat bacterial artificial chromosome recombination and cell transfection system].

    Science.gov (United States)

    Huang, Tian; Cao, Zhongyang; Yang, Yaohui; Cao, Gengsheng

    2016-03-01

    The Cashmere goat is mainly used to produce cashmere, which is very popular for its delicate fiber, luscious softness and natural excellent warm property. Keratin associated protein (KAP) and bone morphogenetic protein (BMP) of the Cashmere goat play an important role in the proliferation and development of cashmere fiber follicle cells. Bacterial artificial chromosome containing kap6.3, kap8.1 and bmp4 genes were used to increase the production and quality of Cashmere. First, we constructed bacterial artificial chromosomes by homology recombination. Then Tol2 transposon was inserted into bacterial artificial chromosomes that were then transfected into Cashmere goat fibroblasts by Amaxa Nucleofector technology according to the manufacture's instructions. We successfully constructed the BAC-Tol2 vectors containing target genes. Each vector contained egfp report gene with UBC promoter, Neomycin resistant gene for cell screening and two loxp elements for resistance removing after transfected into cells. The bacterial artificial chromosome-Tol2 vectors showed a high efficiency of transfection that can reach 1% to 6% with a highest efficiency of 10%. We also obtained Cashmere goat fibroblasts integrated exogenous genes (kap6.3, kap8.1 and bmp4) preparing for the clone of Cashmere goat in the future. Our research demonstrates that the insertion of Tol2 transposons into bacterial artificial chromosomes improves the transfection efficiency and accuracy of bacterial artificial chromosome error-free recombination. PMID:27349114

  8. Sex Chromosome Evolution in Amniotes: Applications for Bacterial Artificial Chromosome Libraries

    OpenAIRE

    Janes, Daniel E.; Nicole Valenzuela; Tariq Ezaz; Chris Amemiya; Edwards, Scott V.

    2011-01-01

    Variability among sex chromosome pairs in amniotes denotes a dynamic history. Since amniotes diverged from a common ancestor, their sex chromosome pairs and, more broadly, sex-determining mechanisms have changed reversibly and frequently. These changes have been studied and characterized through the use of many tools and experimental approaches but perhaps most effectively through applications for bacterial artificial chromosome (BAC) libraries. Individual BAC clones carry 100–200 kb of seque...

  9. Sex Chromosome Evolution in Amniotes: Applications for Bacterial Artificial Chromosome Libraries

    Science.gov (United States)

    Janes, Daniel E.; Valenzuela, Nicole; Ezaz, Tariq; Amemiya, Chris; Edwards, Scott V.

    2011-01-01

    Variability among sex chromosome pairs in amniotes denotes a dynamic history. Since amniotes diverged from a common ancestor, their sex chromosome pairs and, more broadly, sex-determining mechanisms have changed reversibly and frequently. These changes have been studied and characterized through the use of many tools and experimental approaches but perhaps most effectively through applications for bacterial artificial chromosome (BAC) libraries. Individual BAC clones carry 100–200 kb of sequence from one individual of a target species that can be isolated by screening, mapped onto karyotypes, and sequenced. With these techniques, researchers have identified differences and similarities in sex chromosome content and organization across amniotes and have addressed hypotheses regarding the frequency and direction of past changes. Here, we review studies of sex chromosome evolution in amniotes and the ways in which the field of research has been affected by the advent of BAC libraries. PMID:20981143

  10. A Yeast Artificial Chromosome Library Database: Design Considerations

    OpenAIRE

    Frisse, Mark E.; Ge, NengJie; Langenbacher, JulieM.; Kahn, Michael G.; Brownstein, Bernard H

    1990-01-01

    This paper first describes a simple collection of HyperCard stacks created and used by genetics researchers to catalog information in a human yeast artificial chromosome (YAC) library. Although an intuitive human-computer interface made the HyperCard program easy to use, the program was neither an efficient nor a secure primary database for vital laboratory data. This paper subsequently describes a relational database implementation prototype that overcomes HyperCard's deficiencies as a datab...

  11. Integrative bacterial artificial chromosomes for DNA integration into the Bacillus subtilis chromosome.

    Science.gov (United States)

    Juhas, Mario; Ajioka, James W

    2016-06-01

    Bacillus subtilis is a well-characterized model bacterium frequently used for a number of biotechnology and synthetic biology applications. Novel strategies combining the advantages of B. subtilis with the DNA assembly and editing tools of Escherichia coli are crucial for B. subtilis engineering efforts. We combined Gibson Assembly and λ red recombineering in E. coli with RecA-mediated homologous recombination in B. subtilis for bacterial artificial chromosome-mediated DNA integration into the well-characterized amyE target locus of the B. subtilis chromosome. The engineered integrative bacterial artificial chromosome iBAC(cav) can accept any DNA fragment for integration into B. subtilis chromosome and allows rapid selection of transformants by B. subtilis-specific antibiotic resistance and the yellow fluorescent protein (mVenus) expression. We used the developed iBAC(cav)-mediated system to integrate 10kb DNA fragment from E. coli K12 MG1655 into B. subtilis chromosome. iBAC(cav)-mediated chromosomal integration approach will facilitate rational design of synthetic biology applications in B. subtilis. PMID:27033694

  12. Construction and Characterization of Three Wheat Bacterial Artificial Chromosome Libraries

    Directory of Open Access Journals (Sweden)

    Wenjin Cao

    2014-11-01

    Full Text Available We have constructed three bacterial artificial chromosome (BAC libraries of wheat cultivar Triticum aestivum Wangshuibai, germplasms T. monococcum TA2026 and TA2033. A total of 1,233,792,170,880 and 263,040 clones were picked and arrayed in 384-well plates. On the basis of genome sizes of 16.8 Gb for hexaploid wheat and 5.6 Gb for diploid wheat, the three libraries represented 9.05-, 2.60-, and 3.71-fold coverage of the haploid genomes, respectively. An improved descending pooling system for BAC libraries screening was established. This improved strategy can save 80% of the time and 68% of polymerase chain reaction (PCR with the same successful rate as the universal 6D pooling strategy.

  13. Human artificial chromosomes for Duchenne muscular dystrophy and beyond: challenges and hopes.

    OpenAIRE

    Tedesco, F. S.

    2015-01-01

    Safe and efficacious vectors able to carry large or several transgenes are of key importance for gene therapy. Human artificial chromosomes can fulfil this essential requirement; moreover, they do not integrate into the host genome. However, drawbacks such as the low efficiency of chromosome transfer and their relatively complex engineering still limit their widespread use. In this article, I summarise the key steps that brought human artificial chromosomes into preclinical research for Duche...

  14. Construction of a yeast artificial chromosome contig encompassing the chromosome 14 Alzheimer`s disease locus

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, V.; Bonnycastle, L.; Poorkai, P. [Univ. of Washington, Seattle, WA (United States)] [and others

    1994-09-01

    We have constructed a yeast artificial chromosome (YAC) contig of chromosome 14q24.3 which encompasses the chromosome 14 Alzheimer`s disease locus (AD3). Determined by linkage analysis of early-onset Alzheimer`s disease kindreds, this interval is bounded by the genetic markers D14S61-D14S63 and spans approximately 15 centimorgans. The contig consists of 29 markers and 74 YACs of which 57 are defined by one or more sequence tagged sites (STSs). The STS markers comprise 5 genes, 16 short tandem repeat polymorphisms and 8 cDNA clones. An additional number of genes, expressed sequence tags and cDNA fragments have been identified and localized to the contig by hybridization and sequence analysis of anonymous clones isolated by cDNA direct selection techniques. A minimal contig of about 15 YACs averaging 0.5-1.5 megabase in length will span this interval and is, at first approximation, in rough agreement with the genetic map. For two regions of the contig, our coverage has relied on L1/THE fingerprint and Alu-PCR hybridization data of YACs provided by CEPH/Genethon. We are currently developing sequence tagged sites from these to confirm the overlaps revealed by the fingerprint data. Among the genes which map to the contig are transforming growth factor beta 3, c-fos, and heat shock protein 2A (HSPA2). C-fos is not a candidate gene for AD3 based on the sequence analysis of affected and unaffected individuals. HSPA2 maps to the proximal edge of the contig and Calmodulin 1, a candidate gene from 4q24.3, maps outside of the region. The YAC contig is a framework physical map from which cosmid or P1 clone contigs can be constructed. As more genes and cDNAs are mapped, a highly resolved transcription map will emerge, a necessary step towards positionally cloning the AD3 gene.

  15. In Vitro Progression of HPV16 Episome-Associated Cervical Neoplasia Displays Fundamental Similarities to Integrant-Associated Carcinogenesis

    OpenAIRE

    Gray, Elizabeth; Pett, Mark R; Ward, Dawn; Winder, David M; Stanley, Margaret A; Roberts, Ian; Scarpini, Cinzia G.; Coleman, Nicholas

    2010-01-01

    An important event in the development of cervical squamous cell carcinoma (SCC) is deregulated expression of high-risk human papillomavirus (HR-HPV) oncogenes, most commonly related to viral integration into host DNA. Mechanisms of development of the ~15% of SCCs that contain extra-chromosomal (episomal) HR-HPV are poorly understood, due to limited longitudinal data. We therefore employed the W12 model to study mechanisms of cervical carcinogenesis associated with episomal HPV16. In vitro pro...

  16. Rescue of end fragments of yeast artificial chromosomes by homologous recombination in yeast.

    OpenAIRE

    Hermanson, G G; Hoekstra, M F; McElligott, D. L.; Evans, G A

    1991-01-01

    Yeast artificial chromosomes (YACs) provide a powerful tool for the isolation and mapping of large regions of mammalian chromosomes. We developed a rapid and efficient method for the isolation of DNA fragments representing the extreme ends of YAC clones by the insertion of a rescue plasmid into the YAC vector by homologous recombination. Two rescue vectors were constructed containing a yeast LYS2 selectable gene, a bacterial origin of replication, an antibiotic resistance gene, a polylinker c...

  17. A 6. 5-Mb yeast artificial chromosome contig incorporating 33 DNA markers on the human X chromosome at Xq22

    Energy Technology Data Exchange (ETDEWEB)

    Vetrie, D.; Kendall, E.; Coffey, A.; Hassock, S.; Collins, J.; Todd, C.; Bobrow, M.; Bentley, D.R. (Paediatric Research Unit, London (United Kingdom)); Lehrach, H. (Imperial Cancer Research Fund, London (United Kingdom)); Harris, A. (John Radcliffe Hospital, Oxford (United Kingdom))

    1994-01-01

    The Xq22 region of the human X chromosome contains genes for a number of inherited disorders. Sixty-nine yeast artificial chromosome clones have been isolated and assembled into a 6.5-Mb contig that contains 33 DNA markers localized to this region. This contig extends distally from DXS366 to beyond DXS87 and includes the genes involved in X-linked agammaglobulinemia (btk), Fabry disease (GLA), and Pelizaeus-Merzbacher disease (PLP). The order of markers in this contig is consistent with the known genetic and physical mapping information of Xq22. This cloned material provides a source from which to isolate other genes located in this part of the X chromosome. 45 refs., 2 figs., 2 tabs.

  18. Delineating Rearrangements in Single Yeast Artificial Chromosomes by Quantitative DNA Fiber Mapping

    OpenAIRE

    Weier, Heinz-Ulrich G.; Greulich-Bode, Karin M.; Wu, Jenny; Duell, Thomas

    2009-01-01

    Cloning of large chunks of human genomic DNA in recombinant systems such as yeast or bacterial artificial chromosomes has greatly facilitated the construction of physical maps, the positional cloning of disease genes or the preparation of patient-specific DNA probes for diagnostic purposes. For this process to work efficiently, the DNA cloning process and subsequent clone propagation need to maintain stable inserts that are neither deleted nor otherwise rearranged. Some regions of the human g...

  19. The development and characterisation of a bacterial artificial chromosome library for Fragaria vesca

    OpenAIRE

    Abbott Albert G; Monfort Amparo; Muñoz-Torres Monica C; Sargent Daniel J; Girona Elena; Bonet Julio; Arús Pere; Simpson David W; Davik Jahn

    2009-01-01

    Abstract Background The cultivated strawberry Fragaria ×ananassa is one of the most economically-important soft-fruit species. Few structural genomic resources have been reported for Fragaria and there exists an urgent need for the development of physical mapping resources for the genus. The first stage in the development of a physical map for Fragaria is the construction and characterisation of a high molecular weight bacterial artificial chromosome (BAC) library. Methods A BAC library, cons...

  20. Efficient manipulation of the human adenovirus genome as an infectious yeast artificial chromosome clone.

    OpenAIRE

    Ketner, G; Spencer, F; Tugendreich, S; C. Connelly; Hieter, P

    1994-01-01

    A yeast artificial chromosome (YAC) containing a complete human adenovirus type 2 genome was constructed, and viral DNA derived from the YAC was shown to be infectious upon introduction into mammalian cells. The adenovirus YAC could be manipulated efficiently using homologous recombination-based methods in the yeast host, and mutant viruses, including a variant that expresses the human analog of the Saccharomyces cerevisiae CDC27 gene, were readily recovered from modified derivatives of the Y...

  1. Generalized Gap Model for Bacterial Artificial Chromosome Clone Fingerprint Mapping and Shotgun Sequencing

    OpenAIRE

    Wendl, Michael C; Robert H Waterston

    2002-01-01

    We develop an extension to the Lander-Waterman theory for characterizing gaps in bacterial artificial chromosome fingerprint mapping and shotgun sequencing projects. It supports a larger set of descriptive statistics and is applicable to a wider range of project parameters. We show that previous assertions regarding inconsistency of the Lander-Waterman theory at higher coverages are incorrect and that another well-known but ostensibly different model is in fact the same. The apparent paradox ...

  2. Complete Genomes of Classical Swine Fever Virus Cloned into Bacterial Artificial Chromosomes

    OpenAIRE

    Rasmussen, Thomas Bruun; Reimann, I; Uttenthal, Åse; De Beer, M.

    2011-01-01

    Complete genome amplification of viral RNA provides a new tool for the generation of modified pestiviruses. We have used our full-genome amplification strategy for generation of amplicons representing complete genomes of classical swine fever virus. The amplicons were cloned directly into a stable single-copy bacterial artificial chromosome (BAC) generating full-length pestivirus DNAs from which infectious RNA transcripts could be also derived. Our strategy allows construction of stable infec...

  3. Bacterial Artificial Chromosome Clones of Viruses Comprising the Towne Cytomegalovirus Vaccine

    OpenAIRE

    Xiaohong Cui; Adler, Stuart P.; Davison, Andrew J.; Larry Smith; EL-Sayed E. Habib; McVoy, Michael A.

    2012-01-01

    Bacterial artificial chromosome (BAC) clones have proven invaluable for genetic manipulation of herpesvirus genomes. BAC cloning can also be useful for capturing representative genomes that comprise a viral stock or mixture. The Towne live attenuated cytomegalovirus vaccine was developed in the 1970s by serial passage in cultured fibroblasts. Although its safety, immunogenicity, and efficacy have been evaluated in nearly a thousand human subjects, the vaccine itself has been little studied. I...

  4. Generating Transgenic Mice from Bacterial Artificial Chromosomes: Transgenesis Efficiency, Integration and Expression Outcomes

    OpenAIRE

    Van Keuren, Margaret L.; Gavrilina, Galina B.; Filipiak, Wanda E.; Zeidler, Michael G.; Saunders, Thomas L.

    2009-01-01

    Transgenic mice are widely used in biomedical research to study gene expression, developmental biology, and gene therapy models. Bacterial artificial chromosome (BAC) transgenes direct gene expression at physiological levels with the same developmental timing and expression patterns as endogenous genes in transgenic animal models. We generated 707 transgenic founders from 86 BAC transgenes purified by three different methods. Transgenesis efficiency was the same for all BAC DNA purification m...

  5. In situ hybridization to cytogenetic bands of yeast artificial chromosomes covering 50% of human Xq24-Xq28 DNA

    OpenAIRE

    Montanaro, Vittorio; Casamassimi, Amelia; D'Urso, Michele; Yoon, Jae-Young; Freije, Wadiha; Schlessinger, David; Muenke, Maximilian; Nussbaum, Robert L.; Saccone, Salvatore; Maugeri, Silvana; Santoro, Anna Maria; Motta, Salvatore; Della Valle, Giuliano

    1991-01-01

    From the collection described by Abidi et al., 102 yeast artificial chromosomes (YACs) with human DNA inserts more than 300 kb in length were assigned to chromosomal band positions on early metaphase chromosomes by in situ hybridization using the biotin-avidin method. All the YACs hybridized within the Xq24-Xqter region, supporting the origin of the vast majority of the YACs from single human X-chromosomal sites. With assignments precise to ±0.5 bands, YACs were distributed among cytogenetic ...

  6. A new vector for recombination-based cloning of large DNA fragments from yeast artificial chromosomes.

    OpenAIRE

    Bradshaw, M S; Bollekens, J A; Ruddle, F H

    1995-01-01

    The functional analysis of genes frequently requires manipulation of large genomic regions embedded in yeast artificial chromosomes (YACs). We have designed a yeast-bacteria shuttle vector, pClasper, that can be used to clone specific regions of interest from YACs by homologous recombination. The important feature of pClasper is the presence of the mini-F factor replicon. This leads to a significant increase in the size of the plasmid inserts that can be maintained in bacteria after cloning b...

  7. Cloning the simian varicella virus genome in E. coli as an infectious bacterial artificial chromosome

    OpenAIRE

    Gray, Wayne L.; Zhou, Fuchun; Noffke, Juliane; Tischer, B Karsten

    2011-01-01

    Simian varicella virus (SVV) is closely related to human varicella-zoster virus and causes varicella and zoster-like disease in nonhuman primates. In this study, a mini-F replicon was inserted into a SVV cosmid and infectious SVV was generated by co-transfection of Vero cells with overlapping SVV cosmids. The entire SVV genome, cloned as a bacterial artificial chromosome (BAC), was stably propagated upon serial passage in E. coli. Transfection of pSVV-BAC DNA into Vero cells yielded infectiou...

  8. In vivo reinsertion of excised episomes by the V(DJ recombinase: a potential threat to genomic stability.

    Directory of Open Access Journals (Sweden)

    Katrina Vanura

    2007-03-01

    Full Text Available It has long been thought that signal joints, the byproducts of V(DJ recombination, are not involved in the dynamics of the rearrangement process. Evidence has now started to accumulate that this is not the case, and that signal joints play unsuspected roles in events that might compromise genomic integrity. Here we show both ex vivo and in vivo that the episomal circles excised during the normal process of receptor gene rearrangement may be reintegrated into the genome through trans-V(DJ recombination occurring between the episomal signal joint and an immunoglobulin/T-cell receptor target. We further demonstrate that cryptic recombination sites involved in T-cell acute lymphoblastic leukemia-associated chromosomal translocations constitute hotspots of insertion. Eventually, the identification of two in vivo cases associating episomal reintegration and chromosomal translocation suggests that reintegration events are linked to genomic instability. Altogether, our data suggest that V(DJ-mediated reintegration of episomal circles, an event likely eluding classical cytogenetic screenings, might represent an additional potent source of genomic instability and lymphoid cancer.

  9. Construction and characterization of a bacterial artificial chromosome library of the maize inbred line Qi319

    Directory of Open Access Journals (Sweden)

    Chun Hua Mu

    2016-03-01

    Full Text Available Zea mays L. has been the most cultivated crop and the crop with the largest yield in China since 2012. We constructed a bacterial artificial chromosome (BAC library for the maize inbred line Qi319, which may be used as a key source for disease-resistant maize breeding in China. The BAC contains 270,720 clones, with an average insert size of 90 kb. The coverage of the library is about 10.43 genome equivalents when considering a haploid genome size of 2300 Mb, providing a 99.99% likelihood of isolating any maize gene or sequence in the library. An average of 12 clones were obtained by polymerase chain reaction screening by using primer pairs linked to the genes for resistance to maize southern rust and rough dwarf. The results indicate that the library can satisfy the requirements for recovering specific sequences. The library is available to researchers to whom it may be of interest.

  10. Construction and characterization of bacterial artificial chromosomes (BACs) containing herpes simplex virus full-length genomes.

    Science.gov (United States)

    Nagel, Claus-Henning; Pohlmann, Anja; Sodeik, Beate

    2014-01-01

    Bacterial artificial chromosomes (BACs) are suitable vectors not only to maintain the large genomes of herpesviruses in Escherichia coli but also to enable the traceless introduction of any mutation using modern tools of bacterial genetics. To clone a herpes simplex virus genome, a BAC replication origin is first introduced into the viral genome by homologous recombination in eukaryotic host cells. As part of their nuclear replication cycle, genomes of herpesviruses circularize and these replication intermediates are then used to transform bacteria. After cloning, the integrity of the recombinant viral genomes is confirmed by restriction length polymorphism analysis and sequencing. The BACs may then be used to design virus mutants. Upon transfection into eukaryotic cells new herpesvirus strains harboring the desired mutations can be recovered and used for experiments in cultured cells as well as in animal infection models. PMID:24671676

  11. A Plasmid Set for Efficient Bacterial Artificial Chromosome (BAC) Transgenesis in Zebrafish.

    Science.gov (United States)

    Fuentes, Fernando; Reynolds, Eric; Lewellis, Stephen W; Venkiteswaran, Gayatri; Knaut, Holger

    2016-01-01

    Transgenesis of large DNA constructs is essential for gene function analysis. Recently, Tol2 transposase-mediated transgenesis has emerged as a powerful tool to insert bacterial artificial chromosome (BAC) DNA constructs into the genome of zebrafish. For efficient transgenesis, the genomic DNA piece in the BAC construct needs to be flanked by Tol2 transposon sites, and the constructs should contain a transgenesis marker for easy identification of transgenic animals. We report a set of plasmids that contain targeting cassettes that allow the insertion of Tol2 sites and different transgenesis markers into BACs. Using BACs containing these targeting cassettes, we show that transgenesis is as efficient as iTol2, that preselecting for expression of the transgenesis marker increases the transgenesis rate, and that BAC transgenics faithfully recapitulate the endogenous gene expression patterns and allow for the estimation of the endogenous gene expression levels. PMID:26818072

  12. Construction of bacterial artificial chromosome libraries for Zhikong Scallop Chlamys farreri

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yang; ZHANG Xiaojun; Chantel F.SCHEURING; ZHANG Hongbin; LI Fuhua; XIANG Jianhai

    2008-01-01

    Two Large-insert genomic bacterial artificial chromosome (BAC) libraries of Zhikong scallop Chlamys farreri were constructed to promote our genetic and genomic research.High-quality megabase-sized DNA was isolated from the adductor muscle of the scallop and partially digested by BamH I and Mbo I,respectively.The BamH I library consisted of 53760 clones while the Mbo I library consisted of 7680 clones.Approximately 96% of the clones in BamH I library contained nuclear DNA inserts in average size of 100 kb,providing a coverage of 5.3 haploid genome equivalents.Similarly,the Mbo I library with an average insert of 145 kb and no insert-empty clones,thus providing a genome coverage of 1.1 haploid genome equivalents.

  13. DNA immunization with a herpes simplex virus 2 bacterial artificial chromosome

    International Nuclear Information System (INIS)

    Construction of a herpes simplex virus 2 (HSV-2) bacterial artificial chromosome (BAC) is described. BAC vector sequences were inserted into the thymidine kinase gene of HSV-2 by homologous recombination. DNA from cells infected with the resulting recombinant virus was transformed into E. coli, and colonies containing the HSV-2 BAC (HSV2-BAC) were isolated and analyzed for the expected genotype. HSV2-BAC DNA was infectious when transfected back into mammalian cells and the resulting virus was thymidine kinase negative. When used to immunize mice, the HSV2-BAC DNA elicited a strong HSV-2 specific antibody response that was equal to or greater than live virus immunization. Further, HSV2-BAC immunization was protective when animals were challenged with a lethal dose of virus. The utility of the HSV2-BAC for construction of recombinant virus genomes was demonstrated by elimination of the HSV-2 glycoprotein D (gD) gene. A recombinant HSV-2 BAC with the gD gene deleted was isolated and shown to be incapable of producing infectious virus following transfection unless an HSV gD gene was expressed in a complementing cell line. Immunization of mice with the HSV2 gD-BAC also elicited an HSV-2 specific antibody response and was protective. The results demonstrate the feasibility of DNA immunization with HSV-2 bacterial artificial chromosomes for replicating and nonreplicating candidate HSV-2 vaccines, as well as the utility of BAC technology for construction and maintenance of novel HSV-2 vaccines. The results further suggest that such technology will be a powerful tool for dissecting the immune response to HSV-2

  14. Efficient assembly of de novo human artificial chromosomes from large genomic loci

    Directory of Open Access Journals (Sweden)

    Stromberg Gregory

    2005-07-01

    Full Text Available Abstract Background Human Artificial Chromosomes (HACs are potentially useful vectors for gene transfer studies and for functional annotation of the genome because of their suitability for cloning, manipulating and transferring large segments of the genome. However, development of HACs for the transfer of large genomic loci into mammalian cells has been limited by difficulties in manipulating high-molecular weight DNA, as well as by the low overall frequencies of de novo HAC formation. Indeed, to date, only a small number of large (>100 kb genomic loci have been reported to be successfully packaged into de novo HACs. Results We have developed novel methodologies to enable efficient assembly of HAC vectors containing any genomic locus of interest. We report here the creation of a novel, bimolecular system based on bacterial artificial chromosomes (BACs for the construction of HACs incorporating any defined genomic region. We have utilized this vector system to rapidly design, construct and validate multiple de novo HACs containing large (100–200 kb genomic loci including therapeutically significant genes for human growth hormone (HGH, polycystic kidney disease (PKD1 and ß-globin. We report significant differences in the ability of different genomic loci to support de novo HAC formation, suggesting possible effects of cis-acting genomic elements. Finally, as a proof of principle, we have observed sustained ß-globin gene expression from HACs incorporating the entire 200 kb ß-globin genomic locus for over 90 days in the absence of selection. Conclusion Taken together, these results are significant for the development of HAC vector technology, as they enable high-throughput assembly and functional validation of HACs containing any large genomic locus. We have evaluated the impact of different genomic loci on the frequency of HAC formation and identified segments of genomic DNA that appear to facilitate de novo HAC formation. These genomic loci

  15. Cloning of a very virulent plus, 686 strain of Marek’s disease virus as a bacterial artificial chromosome

    Science.gov (United States)

    Bacterial artificial chromosome (BAC) vectors were first developed to facilitate propagation and manipulation of large DNA fragments. This technology was later used to clone full-length genomes of large DNA viruses to study viral gene function. Marek’s disease virus (MDV) is a highly oncogenic herpe...

  16. Plant artificial chromosome technology and its potential application in genetic engineering.

    Science.gov (United States)

    Yu, Weichang; Yau, Yuan-Yeu; Birchler, James A

    2016-05-01

    Genetic engineering with just a few genes has changed agriculture in the last 20 years. The most frequently used transgenes are the herbicide resistance genes for efficient weed control and the Bt toxin genes for insect resistance. The adoption of the first-generation genetically engineered crops has been very successful in improving farming practices, reducing the application of pesticides that are harmful to both human health and the environment, and producing more profit for farmers. However, there is more potential for genetic engineering to be realized by technical advances. The recent development of plant artificial chromosome technology provides a super vector platform, which allows the management of a large number of genes for the next generation of genetic engineering. With the development of other tools such as gene assembly, genome editing, gene targeting and chromosome delivery systems, it should become possible to engineer crops with multiple genes to produce more agricultural products with less input of natural resources to meet future demands. PMID:26369910

  17. A role for MRE11, NBS1, and recombination junctions in replication and stable maintenance of EBV episomes.

    Directory of Open Access Journals (Sweden)

    Jayaraju Dheekollu

    Full Text Available Recombination-like structures formed at origins of DNA replication may contribute to replication fidelity, sister chromatid cohesion, chromosome segregation, and overall genome stability. The Epstein-Barr Virus (EBV origin of plasmid replication (OriP provides episomal genome stability through a poorly understood mechanism. We show here that recombinational repair proteins MRE11 and NBS1 are recruited to the Dyad Symmetry (DS region of OriP in a TRF2- and cell cycle-dependent manner. Depletion of MRE11 or NBS1 by siRNA inhibits OriP replication and destabilized viral episomes. OriP plasmid maintenance was defective in MRE11 and NBS1 hypomorphic fibroblast cell lines and only integrated, non-episomal forms of EBV were detected in a lympoblastoid cell line derived from an NBS1-mutated individual. Two-dimensional agarose gel analysis of OriP DNA revealed that recombination-like structures resembling Holliday-junctions form at OriP in mid S phase. MRE11 and NBS1 association with DS coincided with replication fork pausing and origin activation, which preceded the formation of recombination structures. We propose that NBS1 and MRE11 promote replication-associated recombination junctions essential for EBV episomal maintenance and genome stability.

  18. A bacterial artificial chromosome library for Biomphalaria glabrata, intermediate snail host of Schistosoma mansoni

    Directory of Open Access Journals (Sweden)

    Coen M Adema

    2006-10-01

    Full Text Available To provide a novel resource for analysis of the genome of Biomphalaria glabrata, members of the international Biomphalaria glabrata Genome Initiative (biology.unm.edu/biomphalaria-genome.html, working with the Arizona Genomics Institute (AGI and supported by the National Human Genome Research Institute (NHGRI, produced a high quality bacterial artificial chromosome (BAC library. The BB02 strain B. glabrata, a field isolate (Belo Horizonte, Minas Gerais, Brasil that is susceptible to several strains of Schistosoma mansoni, was selfed for two generations to reduce haplotype diversity in the offspring. High molecular weight DNA was isolated from ovotestes of 40 snails, partially digested with HindIII, and ligated into pAGIBAC1 vector. The resulting B. glabrata BAC library (BG_BBa consists of 61824 clones (136.3 kb average insert size and provides 9.05 × coverage of the 931 Mb genome. Probing with single/low copy number genes from B. glabrata and fingerprinting of selected BAC clones indicated that the BAC library sufficiently represents the gene complement. BAC end sequence data (514 reads, 299860 nt indicated that the genome of B. glabrata contains ~ 63% AT, and disclosed several novel genes, transposable elements, and groups of high frequency sequence elements. This BG_BBa BAC library, available from AGI at cost to the research community, gains in relevance because BB02 strain B. glabrata is targeted whole genome sequencing by NHGRI.

  19. Delineating Rearrangements in Single Yeast Artificial Chromosomes by Quantitative DNA Fiber Mapping

    Energy Technology Data Exchange (ETDEWEB)

    Weier, Heinz-Ulrich G.; Greulich-Bode, Karin M.; Wu, Jenny; Duell, Thomas

    2009-09-18

    Cloning of large chunks of human genomic DNA in recombinant systems such as yeast or bacterial artificial chromosomes has greatly facilitated the construction of physical maps, the positional cloning of disease genes or the preparation of patient-specific DNA probes for diagnostic purposes. For this process to work efficiently, the DNA cloning process and subsequent clone propagation need to maintain stable inserts that are neither deleted nor otherwise rearranged. Some regions of the human genome; however, appear to have a higher propensity than others to rearrange in any host system. Thus, techniques to detect and accurately characterize such rearrangements need to be developed. We developed a technique termed 'Quantitative DNA Fiber Mapping (QDFM)' that allows accurate tagging of sequence elements of interest with near kilobase accuracy and optimized it for delineation of rearrangements in recombinant DNA clones. This paper demonstrates the power of this microscopic approach by investigating YAC rearrangements. In our examples, high-resolution physical maps for regions within the immunoglobulin lambda variant gene cluster were constructed for three different YAC clones carrying deletions of 95 kb and more. Rearrangements within YACs could be demonstrated unambiguously by pairwise mapping of cosmids along YAC DNA molecules. When coverage by YAC clones was not available, distances between cosmid clones were estimated by hybridization of cosmids onto DNA fibers prepared from human genomic DNA. In addition, the QDFM technology provides essential information about clone stability facilitating closure of the maps of the human genome as well as those of model organisms.

  20. Construction of an infectious clone of canine herpesvirus genome as a bacterial artificial chromosome.

    Science.gov (United States)

    Arii, Jun; Hushur, Orkash; Kato, Kentaro; Kawaguchi, Yasushi; Tohya, Yukinobu; Akashi, Hiroomi

    2006-04-01

    Canine herpesvirus (CHV) is an attractive candidate not only for use as a recombinant vaccine to protect dogs from a variety of canine pathogens but also as a viral vector for gene therapy in domestic animals. However, developments in this area have been impeded by the complicated techniques used for eukaryotic homologous recombination. To overcome these problems, we used bacterial artificial chromosomes (BACs) to generate infectious BACs. Our findings may be summarized as follows: (i) the CHV genome (pCHV/BAC), in which a BAC flanked by loxP sites was inserted into the thymidine kinase gene, was maintained in Escherichia coli; (ii) transfection of pCHV/BAC into A-72 cells resulted in the production of infectious virus; (iii) the BAC vector sequence was almost perfectly excisable from the genome of the reconstituted virus CHV/BAC by co-infection with CHV/BAC and a recombinant adenovirus that expressed the Cre recombinase; and (iv) a recombinant virus in which the glycoprotein C gene was deleted was generated by lambda recombination followed by Flp recombination, which resulted in a reduction in viral titer compared with that of the wild-type virus. The infectious clone pCHV/BAC is useful for the modification of the CHV genome using bacterial genetics, and CHV/BAC should have multiple applications in the rapid generation of genetically engineered CHV recombinants and the development of CHV vectors for vaccination and gene therapy in domestic animals. PMID:16515874

  1. Multiplex sequencing of bacterial artificial chromosomes for assembling complex plant genomes.

    Science.gov (United States)

    Beier, Sebastian; Himmelbach, Axel; Schmutzer, Thomas; Felder, Marius; Taudien, Stefan; Mayer, Klaus F X; Platzer, Matthias; Stein, Nils; Scholz, Uwe; Mascher, Martin

    2016-07-01

    Hierarchical shotgun sequencing remains the method of choice for assembling high-quality reference sequences of complex plant genomes. The efficient exploitation of current high-throughput technologies and powerful computational facilities for large-insert clone sequencing necessitates the sequencing and assembly of a large number of clones in parallel. We developed a multiplexed pipeline for shotgun sequencing and assembling individual bacterial artificial chromosomes (BACs) using the Illumina sequencing platform. We illustrate our approach by sequencing 668 barley BACs (Hordeum vulgare L.) in a single Illumina HiSeq 2000 lane. Using a newly designed parallelized computational pipeline, we obtained sequence assemblies of individual BACs that consist, on average, of eight sequence scaffolds and represent >98% of the genomic inserts. Our BAC assemblies are clearly superior to a whole-genome shotgun assembly regarding contiguity, completeness and the representation of the gene space. Our methods may be employed to rapidly obtain high-quality assemblies of a large number of clones to assemble map-based reference sequences of plant and animal species with complex genomes by sequencing along a minimum tiling path. PMID:26801048

  2. Construction and Characterization of an Infectious Murine Gammaherpesivrus-68 Bacterial Artificial Chromosome

    Directory of Open Access Journals (Sweden)

    Ting-Ting Wu

    2011-01-01

    Full Text Available Here we describe the cloning of a sequenced WUMS isolate of murine gammaherpesvirus-68 (MHV-68, γHV-68, also known as MuHV-4 as a bacterial artificial chromosome (BAC. We engineered the insertion of the BAC sequence flanked by loxP sites into the left end of the viral genome before the M1 open reading frame. The infectious viruses were reconstituted following transfection of the MHV-68 BAC DNA into cells. The MHV-68 BAC-derived virus replicated indistinguishably from the wild-type virus in cultured cells. Excision of the BAC insert was efficiently achieved by coexpressing the Cre recombinase. Although the BAC insertion did not significantly affect acute productive infection in the lung, it severely compromised the ability of MHV-68 to establish splenic latency. Removal of the BAC sequence restored the wild-type level of latency. Site-specific mutagenesis was carried out by RecA-mediated recombination to demonstrate that this infectious BAC clone can be used for genetic studies of MHV-68.

  3. Utilization of a thermosensitive episome bearing transposon TN10 to isolate Hfr donor strains of Erwinia carotovora subsp. chrysanthemi.

    Science.gov (United States)

    Kotoujansky, A; Lemattre, M; Boistard, P

    1982-04-01

    A thermosensitive episome bearing the transposon Tn10, F(Ts)::Tn10 Lac+, has been successfully transferred from Escherichia coli to several wild strains of the enterobacteria Erwinia carotovora subsp. chrysanthemi, which are pathogenic on Saintpaulia ionantha. In one of these strains, all of the characters controlled by this episome (Lac+, Tetr, Tra+) were expressed, and its replication was stopped at 40 degrees C and above. At 30 degrees C, the episome was easily transferred between strains derived from E. carotovora subsp. chrysanthemi 3937j and to E coli. Hfr donor strains were obtained from a F' strain of 3937j by selecting clones which grew at 40 degrees C on plates containing tetracycline. One of these strains, Hfrq, was examined in more detail: the characters Lac+ and Tetr were stabilized and did not segregate higher than its parental F' strain. The mating was most efficient at 37 degrees C on a membrane. Hfrq transferred its chromosome to recipient strains at high frequency and in a polarized fashion, as evidenced by the gradient of transfer frequencies, the kinetics of marker entry (in interrupted mating experiments), and the analysis of linkage between different markers. The chromosome of Hfrq was most probably transferred in the following sequence: origin...met...xyl...arg...ile...leu...thr...cys...pan...ura...gal...trp...his. ..pur... Moreover, this genetic transfer system proved to be efficient in strain construction. PMID:6277860

  4. A novel method for increasing the transformation efficiency of Escherichia coli-application forbacterial artificial chromosome library construction.

    OpenAIRE

    Zhu, H; Dean, R.A.

    1999-01-01

    Bacterial artificial chromosome (BAC) libraries play a pivotal role in genomics studies. A crucial step in BAC library construction is the transformation of Escherichia coli by electroporation. Absolute efficiency (cfu/microgram DNA) is affected by a number of factors including the topological form and treatment of DNA samples. Here we report a simple new protocol using tRNA assisted precipitation that increased transformation efficiency by 70-fold for BAC ligations and up to 400-fold for pla...

  5. Visualization of lymphatic vessels by Prox1-promoter directed GFP reporter in a bacterial artificial chromosome-based transgenic mouse

    OpenAIRE

    Choi, Inho; Chung, Hee Kyoung; Ramu, Swapnika; Lee, Ha Neul; Kim, Kyu Eui; Lee, Sunju; Yoo, Jaehyuk; Choi, Dongwon; Lee, Yong Suk; Aguilar, Berenice; Hong, Young-Kwon

    2011-01-01

    Although the blood vessel-specific fluorescent transgenic mouse has been an excellent tool to study vasculogenesis and angiogenesis, a lymphatic-specific fluorescent mouse model has not been established to date. Here we report a transgenic animal model that expresses the green fluorescent protein under the promoter of Prox1, a master control gene in lymphatic development. Generated using an approximately 200-kb-long bacterial artificial chromosome harboring the entire Prox1 gene, this Prox1-g...

  6. Highly Efficient Modification of Bacterial Artificial Chromosomes (BACs) Using Novel Shuttle Vectors Containing the R6Kγ Origin of Replication

    OpenAIRE

    Gong, Shiaoching; Yang, Xiangdong William; Li, Chenjian; Heintz, Nathaniel

    2002-01-01

    Bacterial artificial chromosome (BAC) mediated transgenesis has proven to be a highly reliable way to obtain accurate transgene expression for in vivo studies of gene expression and function. A rate-limiting step in use of this technology to characterize large numbers of genes has been the process with which BACs can be modified by homologous recombination in Escherichia coli. We report here a highly efficient method for modifying BACs by using a novel set of shuttle vectors that contain the ...

  7. Incorporation of a lambda phage recombination system and EGFP detection to simplify mutagenesis of Herpes simplex virus bacterial artificial chromosomes

    OpenAIRE

    Weir Jerry P; Schmeisser Falko

    2007-01-01

    Abstract Background Targeted mutagenesis of the herpesvirus genomes has been facilitated by the use of bacterial artificial chromosome (BAC) technology. Such modified genomes have potential uses in understanding viral pathogenesis, gene identification and characterization, and the development of new viral vectors and vaccines. We have previously described the construction of a herpes simplex virus 2 (HSV-2) BAC and the use of an allele replacement strategy to construct HSV-2 recombinants. Whi...

  8. Complete Genome Sequence of Cell Culture-Attenuated Guinea Pig Cytomegalovirus Cloned as an Infectious Bacterial Artificial Chromosome

    OpenAIRE

    Yang, Dongmei; Alam, Zohaib; Cui, Xiaohong; Chen, Michael; Sherrod, Carly J.; McVoy, Michael A.; Schleiss, Mark R.; Dittmer, Dirk P

    2014-01-01

    The complete genome sequence of attenuated guinea pig cytomegalovirus cloned as bacterial artificial chromosome N13R10 was determined. Comparison to pathogenic salivary gland-derived virus revealed 13 differences, 1 of which disrupted overlapping open reading frames encoding GP129 and GP130. Attenuation of N13R10 may arise from an inability to express GP129 and/or GP130.

  9. Use of Recombination-Mediated Genetic Engineering for Construction of Rescue Human Cytomegalovirus Bacterial Artificial Chromosome Clones

    OpenAIRE

    Kalpana Dulal; Benjamin Silver; Hua Zhu

    2012-01-01

    Bacterial artificial chromosome (BAC) technology has contributed immensely to manipulation of larger genomes in many organisms including large DNA viruses like human cytomegalovirus (HCMV). The HCMV BAC clone propagated and maintained inside E. coli allows for accurate recombinant virus generation. Using this system, we have generated a panel of HCMV deletion mutants and their rescue clones. In this paper, we describe the construction of HCMV BAC mutants using a homologous recombination syste...

  10. Cloning human herpes virus 6A genome into bacterial artificial chromosomes and study of DNA replication intermediates

    OpenAIRE

    Borenstein, Ronen; Frenkel, Niza

    2009-01-01

    Cloning of large viral genomes into bacterial artificial chromosomes (BACs) facilitates analyses of viral functions and molecular mutagenesis. Previous derivations of viral BACs involved laborious recombinations within infected cells. We describe a single-step production of viral BACs by direct cloning of unit length genomes, derived from circular or head-to-tail concatemeric DNA replication intermediates. The BAC cloning is independent of intracellular recombinations and DNA packaging constr...

  11. Natural - synthetic - artificial!

    DEFF Research Database (Denmark)

    Nielsen, Peter E

    2010-01-01

    The terms "natural," "synthetic" and "artificial" are discussed in relation to synthetic and artificial chromosomes and genomes, synthetic and artificial cells and artificial life.......The terms "natural," "synthetic" and "artificial" are discussed in relation to synthetic and artificial chromosomes and genomes, synthetic and artificial cells and artificial life....

  12. CHARACTERIZATION AND CHROMOSOMAL ASSIGNMENT OF YEAST ARTIFICIAL CHROMOSOMES CONTAINING HUMAN 3P13-P21-SPECIFIC SEQUENCE-TAGGED SITES

    NARCIS (Netherlands)

    MICHAELIS, SC; BARDENHEUER, W; LUX, A; SCHRAMM, A; GOCKEL, A; SIEBERT, R; WILLERS, C; SCHMIDTKE, K; TODT, B; VANDERHOUT, AH; BUYS, CHCM; HEPPELLPARTON, AC; RABBITTS, PH; UNGAR, S; SMITH, D; LEPASLIER, D; COHEN, D; OPALKA, B; SCHUTTE, J

    1995-01-01

    Human chromosomal region 3p12-p23 is proposed to harbor at least three tumor suppressor genes involved in the development of lung cancer, renal cell carcinoma, and other neoplasias. In order to identify one of these genes we defined sequence tagged sites (STSs) specific for 3p13-p24.2 by analyzing a

  13. Quality control of the sheep bacterial artificial chromosome library, CHORI-243

    Directory of Open Access Journals (Sweden)

    Kirkness Ewen F

    2010-12-01

    Full Text Available Abstract Background The sheep CHORI-243 bacterial artificial chromosome (BAC library is being used in the construction of the virtual sheep genome, the sequencing and construction of the actual sheep genome assembly and as a source of DNA for regions of the genome of biological interest. The objective of our study is to assess the integrity of the clones and plates which make up the CHORI-243 library using the virtual sheep genome. Findings A series of analyses were undertaken based on the mapping the sheep BAC-end sequences (BESs to the virtual sheep genome. Overall, very few plate specific biases were identified, with only three of the 528 plates in the library significantly affected. The analysis of the number of tail-to-tail (concordant BACs on the plates identified a number of plates with lower than average numbers of such BACs. For plates 198 and 213 a partial swap of the BESs determined with one of the two primers appear to have occurred. A third plate, 341, also with a significant deficit in tail-to-tail BACs, appeared to contain a substantial number of sequences determined from contaminating eubacterial 16 S rRNA DNA. Additionally a small number of eubacterial 16 S rRNA DNA sequences were present on two other plates, 111 and 338, in the library. Conclusions The comparative genomic approach can be used to assess BAC library integrity in the absence of fingerprinting. The sequences of the sheep CHORI-243 library BACs have high integrity, especially with the corrections detailed above. The library represents a high quality resource for use by the sheep genomics community.

  14. Construction and characterization of the transformation-competent artificial chromosome(TAC)libraries of Leymus multicaulis

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Transformation-competent artificial chromosome system is able to clone and transfer genes efficiently in plants.In order to clone genes highly tolerant to barley yellow dwarf virus(BYDV),Aphids,drought and salt from Leymus multicaulis,the two TAC genomic libraries I and II were constructed in vector pYLTAC17 and pYLTAC747H/sacB,which contain about 165000 and 236000 recombinant clones sepa-rately.The genome coverage of the two libraries was totally estimated to be about 3―5 haploid genome equivalents,as size selection of genomic DNA fragments was approximately from 9 to 300 kb.Clones of the genomic libraries were collected as bulked pools each containing 500 clones or so,stored in twelve 96-deep-well plates and then were gridding in triplicate onto a high-density colony hybridization filter with a 3×3 pattern using a GeneTAC?G3 arraying robot after being transferred manually into three 384-well plates.Meanwhile 2501 and 2890 clones of Library in pYLTAC17 and in pYLTAC747H/sacB were stored individually in fourteen 384-well plates and then were automatically gridding in duplicate onto a high-density colony hybridization filter with a 6×6 pattern after a replication of plates.Nineteen positive clones were detected by using the probe glutahione reductase gene of L.multicaulis.TAC libraries constructed here can be used to isolate genomic clones containing target genes,and to carry out genome walking for positional cloning.Once the target TAC clones were isolated,they could be immediately transferred into plant genomes with the Agrobacterium system.

  15. Rapid construction of a Bacterial Artificial Chromosomal (BAC) expression vector using designer DNA fragments.

    Science.gov (United States)

    Chen, Chao; Zhao, Xinqing; Jin, Yingyu; Zhao, Zongbao Kent; Suh, Joo-Won

    2014-11-01

    Bacterial artificial chromosomal (BAC) vectors are increasingly being used in cloning large DNA fragments containing complex biosynthetic pathways to facilitate heterologous production of microbial metabolites for drug development. To express inserted genes using Streptomyces species as the production hosts, an integration expression cassette is required to be inserted into the BAC vector, which includes genetic elements encoding a phage-specific attachment site, an integrase, an origin of transfer, a selection marker and a promoter. Due to the large sizes of DNA inserted into the BAC vectors, it is normally inefficient and time-consuming to assemble these fragments by routine PCR amplifications and restriction-ligations. Here we present a rapid method to insert fragments to construct BAC-based expression vectors. A DNA fragment of about 130 bp was designed, which contains upstream and downstream homologous sequences of both BAC vector and pIB139 plasmid carrying the whole integration expression cassette. In-Fusion cloning was performed using the designer DNA fragment to modify pIB139, followed by λ-RED-mediated recombination to obtain the BAC-based expression vector. We demonstrated the effectiveness of this method by rapid construction of a BAC-based expression vector with an insert of about 120 kb that contains the entire gene cluster for biosynthesis of immunosuppressant FK506. The empty BAC-based expression vector constructed in this study can be conveniently used for construction of BAC libraries using either microbial pure culture or environmental DNA, and the selected BAC clones can be directly used for heterologous expression. Alternatively, if a BAC library has already been constructed using a commercial BAC vector, the selected BAC vectors can be manipulated using the method described here to get the BAC-based expression vectors with desired gene clusters for heterologous expression. The rapid construction of a BAC-based expression vector facilitates

  16. The development and characterisation of a bacterial artificial chromosome library for Fragaria vesca

    Directory of Open Access Journals (Sweden)

    Abbott Albert G

    2009-09-01

    Full Text Available Abstract Background The cultivated strawberry Fragaria ×ananassa is one of the most economically-important soft-fruit species. Few structural genomic resources have been reported for Fragaria and there exists an urgent need for the development of physical mapping resources for the genus. The first stage in the development of a physical map for Fragaria is the construction and characterisation of a high molecular weight bacterial artificial chromosome (BAC library. Methods A BAC library, consisting of 18,432 clones was constructed from Fragaria vesca f. semperflorens accession 'Ali Baba'. BAC DNA from individual library clones was pooled to create a PCR-based screening assay for the library, whereby individual clones could be identified with just 34 PCR reactions. These pools were used to screen the BAC library and anchor individual clones to the diploid Fragaria reference map (FV×FN. Findings Clones from the BAC library developed contained an average insert size of 85 kb, representing over seven genome equivalents. The pools and superpools developed were used to identify a set of BAC clones containing 70 molecular markers previously mapped to the diploid Fragaria FV×FN reference map. The number of positive colonies identified for each marker suggests the library represents between 4× and 10× coverage of the diploid Fragaria genome, which is in accordance with the estimate of library coverage based on average insert size. Conclusion This BAC library will be used for the construction of a physical map for F. vesca and the superpools will permit physical anchoring of molecular markers using PCR.

  17. Bacterial Artificial Chromosomes: A Functional Genomics Tool for the Study of Positive-strand RNA Viruses.

    Science.gov (United States)

    Yun, Sang-Im; Song, Byung-Hak; Kim, Jin-Kyoung; Lee, Young-Min

    2015-01-01

    Reverse genetics, an approach to rescue infectious virus entirely from a cloned cDNA, has revolutionized the field of positive-strand RNA viruses, whose genomes have the same polarity as cellular mRNA. The cDNA-based reverse genetics system is a seminal method that enables direct manipulation of the viral genomic RNA, thereby generating recombinant viruses for molecular and genetic studies of both viral RNA elements and gene products in viral replication and pathogenesis. It also provides a valuable platform that allows the development of genetically defined vaccines and viral vectors for the delivery of foreign genes. For many positive-strand RNA viruses such as Japanese encephalitis virus (JEV), however, the cloned cDNAs are unstable, posing a major obstacle to the construction and propagation of the functional cDNA. Here, the present report describes the strategic considerations in creating and amplifying a genetically stable full-length infectious JEV cDNA as a bacterial artificial chromosome (BAC) using the following general experimental procedures: viral RNA isolation, cDNA synthesis, cDNA subcloning and modification, assembly of a full-length cDNA, cDNA linearization, in vitro RNA synthesis, and virus recovery. This protocol provides a general methodology applicable to cloning full-length cDNA for a range of positive-strand RNA viruses, particularly those with a genome of >10 kb in length, into a BAC vector, from which infectious RNAs can be transcribed in vitro with a bacteriophage RNA polymerase. PMID:26780115

  18. Dysregulation of gene expression in the artificial human trisomy cells of chromosome 8 associated with transformed cell phenotypes.

    Directory of Open Access Journals (Sweden)

    Hisakatsu Nawata

    Full Text Available A change in chromosome number, known as aneuploidy, is a common characteristic of cancer. Aneuploidy disrupts gene expression in human cancer cells and immortalized human epithelial cells, but not in normal human cells. However, the relationship between aneuploidy and cancer remains unclear. To study the effects of aneuploidy in normal human cells, we generated artificial cells of human primary fibroblast having three chromosome 8 (trisomy 8 cells by using microcell-mediated chromosome transfer technique. In addition to decreased proliferation, the trisomy 8 cells lost contact inhibition and reproliferated after exhibiting senescence-like characteristics that are typical of transformed cells. Furthermore, the trisomy 8 cells exhibited chromosome instability, and the overall gene expression profile based on microarray analyses was significantly different from that of diploid human primary fibroblasts. Our data suggest that aneuploidy, even a single chromosome gain, can be introduced into normal human cells and causes, in some cases, a partial cancer phenotype due to a disruption in overall gene expression.

  19. Recovery of infectious virus from full-length cowpox virus (CPXV) DNA cloned as a bacterial artificial chromosome (BAC)

    OpenAIRE

    Roth Swaantje J; Höper Dirk; Beer Martin; Feineis Silke; Tischer B Karsten; Osterrieder Nikolaus

    2011-01-01

    Abstract Transmission from pet rats and cats to humans as well as severe infection in felids and other animal species have recently drawn increasing attention to cowpox virus (CPXV). We report the cloning of the entire genome of cowpox virus strain Brighton Red (BR) as a bacterial artificial chromosome (BAC) in Escherichia coli and the recovery of infectious virus from cloned DNA. Generation of a full-length CPXV DNA clone was achieved by first introducing a mini-F vector, which allows mainte...

  20. Repetitive genome elements in a European corn borer, Ostrinia nubilalis, bacterial artificial chromosome library were indicated by bacterial artificial chromosome end sequencing and development of sequence tag site markers: implications for lepidopteran genomic research.

    Science.gov (United States)

    Coates, Brad S; Sumerford, Douglas V; Hellmich, Richard L; Lewis, Leslie C

    2009-01-01

    The European corn borer, Ostrinia nubilalis, is a serious pest of food, fiber, and biofuel crops in Europe, North America, and Asia and a model system for insect olfaction and speciation. A bacterial artificial chromosome library constructed for O. nubilalis contains 36 864 clones with an estimated average insert size of >or=120 kb and genome coverage of 8.8-fold. Screening OnB1 clones comprising approximately 2.76 genome equivalents determined the physical position of 24 sequence tag site markers, including markers linked to ecologically important and Bacillus thuringiensis toxin resistance traits. OnB1 bacterial artificial chromosome end sequence reads (GenBank dbGSS accessions ET217010 to ET217273) showed homology to annotated genes or expressed sequence tags and identified repetitive genome elements, O. nubilalis miniature subterminal inverted repeat transposable elements (OnMITE01 and OnMITE02), and ezi-like long interspersed nuclear elements. Mobility of OnMITE01 was demonstrated by the presence or absence in O. nubilalis of introns at two different loci. A (GTCT)n tetranucleotide repeat at the 5' ends of OnMITE01 and OnMITE02 are evidence for transposon-mediated movement of lepidopteran microsatellite loci. The number of repetitive elements in lepidopteran genomes will affect genome assembly and marker development. Single-locus sequence tag site markers described here have downstream application for integration within linkage maps and comparative genomic studies. PMID:19132072

  1. Identification and Preliminary Analysis of Several Centromere-associated Bacterial Artificial Chromosome Clones from a Diploid Wheat Library

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Although the centromeres of some plants have been investigated previously, our knowledge of the wheat centromere is still very limited. To understand the structure and function of the wheat centromere, we used two centromeric repeats (RCS1 and CCS1-5ab) to obtain some centromere-associated bacterial artificial chromosome (BAC) clones in 32 RCS1-related BAC clones that had been screened out from a diploid wheat (Triticum boeoticum Boiss.; 2n=2x=14) BAC library. Southern hybridization results indicated that, of the 32 candidates,there were 28 RCS1-positive clones. Based on gel blot patterns, the frequency of RCS1 was approximately one copy every 69.4 kb in these 28 RCS1-positive BAC clones. More bands were detected when the same filter was probed with CCS1-5ab. Furthermore, the CCS1 bands covered all the bands detected by RCS1, which suggests that some CCS1 repeats were distributed together with RCS1. The frequency of CCS1 families was once every 35.8 kb, nearly twice that of RCS1. Fluorescence in situ hybridization (FISH) analysis indicated that the five BAC clones containing RCS1 and CCS1 sequences all detected signals at the centromeric regions in hexaploid wheat, but the signal intensities on the A-genome chromosomes were stronger than those on the B- and/or D-genome chromosomes. The FISH analysis among nine Triticeae cereals indicated that there were A-genomespecific (or rich) sequences dispersing on chromosome arms in the BAC clone TbBAC5. In addition, at the interphase cells, the centromeres of diploid species usually clustered at one pole and formed a ring-like allocation in the period before metaphase.

  2. A yeast artificial chromosome contig of the critical region for cri-du-chat syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Goodart, S.A.; Rojas, K.; Overhauser, J. [Thomas Jefferson Univ., Philadelphia, PA (United States)] [and others

    1994-11-01

    Cri-du-chat is a chromosomal deletion syndrome characterized by partial deletion of the short arm of chromosome 5. The clinical symptoms include growth and mental retardation, microcephaly, hypertelorism, epicanthal folds, hyptonia, and a high-pitched monochromatic cry that is usually considered diagnostic for the syndrome. Recently, a correlation between clinical features and the extent of the chromosome 5 deletions has identified two regions of the short arm that appear to be critical for the abnormal development manifested in this syndrome. Loss of a small region in 5p15.2 correlates with all of the clinical features of cri-du-chat with the exception of the cat-like cry, which maps to 5p15.3. Here the authors report the construction of a YAC contig that spans the chromosomal region in 5p15.2 that plays a major role in the etiology of the cri-du-chat syndrome. YACs that span the 2-Mb cri-du-chat critical region have been identified and characterized. This YAC contig lays the groundwork for the construction of a transcriptional map of this region and the eventual identification of genes involved in the clinical features associated with the cri-du-chat syndrome. It also provides a new diagnostic tool for cri-du-chat in the shape of a YAC clone that may span the entire critical region. 24 refs., 4 figs., 2 tabs.

  3. Construction of an Americn mink Bacterial Artificial Chromosome (BAC) library and sequencing candidate genes important for the fur industry

    DEFF Research Database (Denmark)

    Anistoroaei, Razvan Marian; Hallers, Boudewijn ten; Nefedov, Michael;

    2011-01-01

    consisting of 18,432 clones spotted in duplicate, have been produced for hybridization screening and are publicly available. Overgo probes derived from expressed sequence tags (ESTs), representing 21 candidate genes for traits important for the mink industry, were used to screen the BAC library......BACKGROUND: Bacterial artificial chromosome (BAC) libraries continue to be invaluable tools for the genomic analysis of complex organisms. Complemented by the newly and fast growing deep sequencing technologies, they provide an excellent source of information in genomics projects. RESULTS: Here, we...... report the construction and characterization of the CHORI-231 BAC library constructed from a Danish-farmed, male American mink (Neovison vison). The library contains approximately 165,888 clones with an average insert size of 170 kb, representing approximately 10-fold coverage. High-density filters, each...

  4. Use of Recombination-Mediated Genetic Engineering for Construction of Rescue Human Cytomegalovirus Bacterial Artificial Chromosome Clones

    Directory of Open Access Journals (Sweden)

    Kalpana Dulal

    2012-01-01

    Full Text Available Bacterial artificial chromosome (BAC technology has contributed immensely to manipulation of larger genomes in many organisms including large DNA viruses like human cytomegalovirus (HCMV. The HCMV BAC clone propagated and maintained inside E. coli allows for accurate recombinant virus generation. Using this system, we have generated a panel of HCMV deletion mutants and their rescue clones. In this paper, we describe the construction of HCMV BAC mutants using a homologous recombination system. A gene capture method, or gap repair cloning, to seize large fragments of DNA from the virus BAC in order to generate rescue viruses, is described in detail. Construction of rescue clones using gap repair cloning is highly efficient and provides a novel use of the homologous recombination-based method in E. coli for molecular cloning, known colloquially as recombineering, when rescuing large BAC deletions. This method of excising large fragments of DNA provides important prospects for in vitro homologous recombination for genetic cloning.

  5. Construction and Preliminary Characterization Analysis of Wuzhishan Miniature Pig Bacterial Artificial Chromosome Library with Approximately 8-Fold Genome Equivalent Coverage

    Directory of Open Access Journals (Sweden)

    Changqing Liu

    2013-01-01

    Full Text Available Bacterial artificial chromosome (BAC libraries have been invaluable tools for the genome-wide genetic dissection of complex organisms. Here, we report the construction and characterization of a high-redundancy BAC library from a very valuable pig breed in China, Wuzhishan miniature pig (Sus scrofa, using its blood cells and fibroblasts, respectively. The library contains approximately 153,600 clones ordered in 40 superpools of 10 × 384-deep well microplates. The average insert size of BAC clones was estimated to be 152.3 kb, representing approximately 7.68 genome equivalents of the porcine haploid genome and a 99.93% statistical probability of obtaining at least one clone containing a unique DNA sequence in the library. 19 pairs of microsatellite marker primers covering porcine chromosomes were used for screening the BAC library, which showed that each of these markers was positive in the library; the positive clone number was 2 to 9, and the average number was 7.89, which was consistent with 7.68-fold coverage of the porcine genome. And there were no significant differences of genomic BAC library from blood cells and fibroblast cells. Therefore, we identified 19 microsatellite markers that could potentially be used as genetic markers. As a result, this BAC library will serve as a valuable resource for gene identification, physical mapping, and comparative genomics and large-scale genome sequencing in the porcine.

  6. The stealth episome: suppression of gene expression on the excised genomic island PPHGI-1 from Pseudomonas syringae pv. phaseolicola.

    Directory of Open Access Journals (Sweden)

    Scott A C Godfrey

    2011-03-01

    Full Text Available Pseudomonas syringae pv. phaseolicola is the causative agent of halo blight in the common bean, Phaseolus vulgaris. P. syringae pv. phaseolicola race 4 strain 1302A contains the avirulence gene avrPphB (syn. hopAR1, which resides on PPHGI-1, a 106 kb genomic island. Loss of PPHGI-1 from P. syringae pv. phaseolicola 1302A following exposure to the hypersensitive resistance response (HR leads to the evolution of strains with altered virulence. Here we have used fluorescent protein reporter systems to gain insight into the mobility of PPHGI-1. Confocal imaging of dual-labelled P. syringae pv. phaseolicola 1302A strain, F532 (dsRFP in chromosome and eGFP in PPHGI-1, revealed loss of PPHGI-1::eGFP encoded fluorescence during plant infection and when grown in vitro on extracted leaf apoplastic fluids. Fluorescence-activated cell sorting (FACS of fluorescent and non-fluorescent PPHGI-1::eGFP F532 populations showed that cells lost fluorescence not only when the GI was deleted, but also when it had excised and was present as a circular episome. In addition to reduced expression of eGFP, quantitative PCR on sub-populations separated by FACS showed that transcription of other genes on PPHGI-1 (avrPphB and xerC was also greatly reduced in F532 cells harbouring the excised PPHGI-1::eGFP episome. Our results show how virulence determinants located on mobile pathogenicity islands may be hidden from detection by host surveillance systems through the suppression of gene expression in the episomal state.

  7. Gata3 Hypomorphic Mutant Mice Rescued with a Yeast Artificial Chromosome Transgene Suffer a Glomerular Mesangial Cell Defect.

    Science.gov (United States)

    Moriguchi, Takashi; Yu, Lei; Otsuki, Akihito; Ainoya, Keiko; Lim, Kim-Chew; Yamamoto, Masayuki; Engel, James Douglas

    2016-09-01

    GATA3 is a zinc finger transcription factor that plays a crucial role in embryonic kidney development, while its precise functions in the adult kidney remain largely unexplored. Here, we demonstrate that GATA3 is specifically expressed in glomerular mesangial cells and plays a critical role in the maintenance of renal glomerular function. Newly generated Gata3 hypomorphic mutant mice exhibited neonatal lethality associated with severe renal hypoplasia. Normal kidney size was restored by breeding the hypomorphic mutant with a rescuing transgenic mouse line bearing a 662-kb Gata3 yeast artificial chromosome (YAC), and these animals (termed G3YR mice) survived to adulthood. However, most of the G3YR mice showed degenerative changes in glomerular mesangial cells, which deteriorated progressively during postnatal development. Consequently, the G3YR adult mice suffered severe renal failure. We found that the 662-kb Gata3 YAC transgene recapitulated Gata3 expression in the renal tubules but failed to direct sufficient GATA3 activity to mesangial cells. Renal glomeruli of the G3YR mice had significantly reduced amounts of platelet-derived growth factor receptor (PDGFR), which is known to participate in the development and maintenance of glomerular mesangial cells. These results demonstrate a critical role for GATA3 in the maintenance of mesangial cells and its absolute requirement for prevention of glomerular disease. PMID:27296697

  8. Incorporation of a lambda phage recombination system and EGFP detection to simplify mutagenesis of Herpes simplex virus bacterial artificial chromosomes

    Directory of Open Access Journals (Sweden)

    Weir Jerry P

    2007-05-01

    Full Text Available Abstract Background Targeted mutagenesis of the herpesvirus genomes has been facilitated by the use of bacterial artificial chromosome (BAC technology. Such modified genomes have potential uses in understanding viral pathogenesis, gene identification and characterization, and the development of new viral vectors and vaccines. We have previously described the construction of a herpes simplex virus 2 (HSV-2 BAC and the use of an allele replacement strategy to construct HSV-2 recombinants. While the BAC mutagenesis procedure is a powerful method to generate HSV-2 recombinants, particularly in the absence of selective marker in eukaryotic culture, the mutagenesis procedure is still difficult and cumbersome. Results Here we describe the incorporation of a phage lambda recombination system into an allele replacement vector. This strategy enables any DNA fragment containing the phage attL recombination sites to be efficiently inserted into the attR sites of the allele replacement vector using phage lambda clonase. We also describe how the incorporation of EGFP into the allele replacement vector can facilitate the selection of the desired cross-over recombinant BACs when the allele replacement reaction is a viral gene deletion. Finally, we incorporate the lambda phage recombination sites directly into an HSV-2 BAC vector for direct recombination of gene cassettes using the phage lambda clonase-driven recombination reaction. Conclusion Together, these improvements to the techniques of HSV BAC mutagenesis will facilitate the construction of recombinant herpes simplex viruses and viral vectors.

  9. Construction and characterization of a bacterial artificial chromosome library of thermo-sensitive genic male-sterile rice 5460S

    Institute of Scientific and Technical Information of China (English)

    邱芳; 金德敏; 伏健民; 张超良; 谢纬武; 王斌; 杨仁崔; 张洪斌

    1999-01-01

    In order to develop a detailed physical map of the thermo-sensitive genie male-sterile (TGMS) gene-encompassing region and finally clone the TGMS gene, a high-quality rice bacterial artificial chromosome (BAC) library from TGMS rice 5460S was constructed. The method of constructing BAC library was examined and optimized. The 5460S library consists of 19 584 BAC clones with an average insert size of 110 kb, which represents about 5 times rice haploid genome equivalents. Rice inserts of up to 140 kb and 250 kb were isolated and appeared stable after 100 generations of serial growth. Hybridization of BAC clones with mitochondrial and chloroplastic genes as probes demonstrated that this library has no organellar contamination. The 5460S library was screened with 3 molecular markers linked to tmsl gene as probes and at least 1 BAC clone was identified with each probe. The insert ends of positive clones were successfully isolated using thermal asymmetric interlaced PCR (TAIL-PCR) technique.

  10. Construction of a bacterial artificial chromosome library from the spikemoss Selaginella moellendorffii: a new resource for plant comparative genomics

    Directory of Open Access Journals (Sweden)

    Chapple Clint

    2005-06-01

    Full Text Available Abstract Background The lycophytes are an ancient lineage of vascular plants that diverged from the seed plant lineage about 400 Myr ago. Although the lycophytes occupy an important phylogenetic position for understanding the evolution of plants and their genomes, no genomic resources exist for this group of plants. Results Here we describe the construction of a large-insert bacterial artificial chromosome (BAC library from the lycophyte Selaginella moellendorffii. Based on cell flow cytometry, this species has the smallest genome size among the different lycophytes tested, including Huperzia lucidula, Diphaiastrum digita, Isoetes engelmanii and S. kraussiana. The arrayed BAC library consists of 9126 clones; the average insert size is estimated to be 122 kb. Inserts of chloroplast origin account for 2.3% of the clones. The BAC library contains an estimated ten genome-equivalents based on DNA hybridizations using five single-copy and two duplicated S. moellendorffii genes as probes. Conclusion The S. moellenforffii BAC library, the first to be constructed from a lycophyte, will be useful to the scientific community as a resource for comparative plant genomics and evolution.

  11. Visualization of lymphatic vessels by Prox1-promoter directed GFP reporter in a bacterial artificial chromosome-based transgenic mouse

    Science.gov (United States)

    Choi, Inho; Chung, Hee Kyoung; Ramu, Swapnika; Lee, Ha Neul; Kim, Kyu Eui; Lee, Sunju; Yoo, Jaehyuk; Choi, Dongwon; Lee, Yong Suk; Aguilar, Berenice

    2011-01-01

    Although the blood vessel-specific fluorescent transgenic mouse has been an excellent tool to study vasculogenesis and angiogenesis, a lymphatic-specific fluorescent mouse model has not been established to date. Here we report a transgenic animal model that expresses the green fluorescent protein under the promoter of Prox1, a master control gene in lymphatic development. Generated using an approximately 200-kb-long bacterial artificial chromosome harboring the entire Prox1 gene, this Prox1-green fluorescent protein mouse was found to faithfully recapitulate the expression pattern of the Prox1 gene in lymphatic endothelial cells and other Prox1-expressing organs, and enabled us to conveniently visualize detailed structure and morphology of lymphatic vessels and networks throughout development. Our data demonstrate that this novel transgenic mouse can be extremely useful for detection, imaging, and isolation of lymphatic vessels and monitoring wound-associated lymphangiogenesis. Together, this Prox1-green fluorescent protein transgenic mouse will be a great tool for the lymphatic research. PMID:20962325

  12. Functional characterization of Kaposi's sarcoma-associated herpesvirus small capsid protein by bacterial artificial chromosome-based mutagenesis

    International Nuclear Information System (INIS)

    A systematic investigation of interactions amongst KSHV capsid proteins was undertaken in this study to comprehend lesser known KSHV capsid assembly mechanisms. Interestingly the interaction patterns of the KSHV small capsid protein, ORF65 suggested its plausible role in viral capsid assembly pathways. Towards further understanding this, ORF65-null recombinant mutants (BAC-Δ65 and BAC-stop65) employing a bacterial artificial chromosome (BAC) system were generated. No significant difference was found in both overall viral gene expression and lytic DNA replication between stable monolayers of 293T-BAC36 (wild-type) and 293T-BAC-ORF65-null upon induction with 12-O-tetradecanoylphorbol-13-acetate, though the latter released 30-fold fewer virions to the medium than 293T-BAC36 cells. Sedimentation profiles of capsid proteins of ORF65-null recombinant mutants were non-reflective of their organization into the KSHV capsids and were also undetectable in cytoplasmic extracts compared to noticeable levels in nuclear extracts. These observations collectively suggested the pivotal role of ORF65 in the KSHV capsid assembly processes.

  13. A Self-Excisable Infectious Bacterial Artificial Chromosome Clone of Varicella-Zoster Virus Allows Analysis of the Essential Tegument Protein Encoded by ORF9▿

    OpenAIRE

    Tischer, B. Karsten; Kaufer, Benedikt B; Sommer, Marvin; Wussow, Felix; Ann M Arvin; Osterrieder, Nikolaus

    2007-01-01

    In order to facilitate the generation of mutant viruses of varicella-zoster virus (VZV), the agent causing varicella (chicken pox) and herpes zoster (shingles), we generated a full-length infectious bacterial artificial chromosome (BAC) clone of the P-Oka strain. First, mini-F sequences were inserted into a preexisting VZV cosmid, and the SuperCos replicon was removed. Subsequently, mini-F-containing recombinant virus was generated from overlapping cosmid clones, and full-length VZV DNA recov...

  14. Autoexcision of Bacterial Artificial Chromosome Facilitated by Terminal Repeat-Mediated Homologous Recombination: a Novel Approach for Generating Traceless Genetic Mutants of Herpesviruses ▿

    OpenAIRE

    Zhou, Fuchun; Li, Qiuhua; Wong, Scott W.; Gao, Shou-jiang

    2010-01-01

    Infectious bacterial artificial chromosomes (BACs) of herpesviruses are powerful tools for genetic manipulation. However, the presence of BAC vector sequence in the viral genomes often causes genetic and phenotypic alterations. While the excision of the BAC vector cassette can be achieved by homologous recombination between extra duplicate viral sequences or loxP site-mediated recombination, these methods either are inefficient or leave a loxP site mark in the viral genome. Here we describe t...

  15. Highly selective isolation of human DNAs from rodent–human hybrid cells as circular yeast artificial chromosomes by transformation-associated recombination cloning

    OpenAIRE

    Larionov, Vladimir; Kouprina, Natalya; Graves, Joan; Resnick, Michael A.

    1996-01-01

    Transformation-associated recombination (TAR) can be exploited in yeast to clone human DNAs. TAR cloning was previously accomplished using one or two telomere-containing vectors with a common human repeat(s) that could recombine with human DNA during transformation to generate yeast artificial chromosomes (YACs). On basis of the proposal that broken DNA ends are more recombinogenic than internal sequences, we have investigated if TAR cloning could be applied to the...

  16. Cloning of the Full-Length Rhesus Cytomegalovirus Genome as an Infectious and Self-Excisable Bacterial Artificial Chromosome for Analysis of Viral Pathogenesis

    OpenAIRE

    Chang, W. L. William; Peter A Barry

    2003-01-01

    Rigorous investigation of many functions encoded by cytomegaloviruses (CMVs) requires analysis in the context of virus-host interactions. To facilitate the construction of rhesus CMV (RhCMV) mutants for in vivo studies, a bacterial artificial chromosome (BAC) containing an enhanced green fluorescent protein (EGFP) cassette was engineered into the intergenic region between unique short 1 (US1) and US2 of the full-length viral genome by Cre/lox-mediated recombination. Infectious virions were re...

  17. A high-coverage artificial chromosome library for the genome-wide screening of drug-resistance genes in malaria parasites

    OpenAIRE

    Iwanaga, Shiroh; Kaneko, Izumi; Yuda, Masao

    2012-01-01

    The global spread of drug-resistant parasites is a serious problem for the treatment of malaria. Although identifying drug-resistance genes is crucial for the efforts against resistant parasites, an effective approach has not yet been developed. Here, we report a robust method for identifying resistance genes from parasites by using a Plasmodium artificial chromosome (PAC). Large genomic DNA fragments (10–50 kb) from the drug-resistant rodent malaria parasite Plasmodium berghei were ligated i...

  18. Construction of a bacterial artificial chromosome library from the spikemoss Selaginella moellendorffii: a new resource for plant comparative genomics

    OpenAIRE

    Chapple Clint; Carlson John; Arumuganathan K; Mueller Christopher; Kudrna Dave; Weng Jing-Ke; Kim Hye Ran; Sisneros Nicholas; Luo Meizhong; Tanurdzic Milos; Wang Wenming; de Pamphilis Claude; Mandoli Dina; Tomkins Jeff; Wing Rod A

    2005-01-01

    Abstract Background The lycophytes are an ancient lineage of vascular plants that diverged from the seed plant lineage about 400 Myr ago. Although the lycophytes occupy an important phylogenetic position for understanding the evolution of plants and their genomes, no genomic resources exist for this group of plants. Results Here we describe the construction of a large-insert bacterial artificial chromosome (BAC) library from the lycophyte Selaginella moellendorffii. Based on cell flow cytomet...

  19. A high-throughput strategy for screening of bacterial artificial chromosome libraries and anchoring of clones on a genetic map constructed with single nucleotide polymorphisms

    OpenAIRE

    Deal Karin R; Ma Yaqin; Xu Kenong; Luo Ming-Cheng; Nicolet Charles M; Dvorak Jan

    2009-01-01

    Abstract Background Current techniques of screening bacterial artificial chromosome (BAC) libraries for molecular markers during the construction of physical maps are slow, laborious and often assign multiple BAC contigs to a single locus on a genetic map. These limitations are the principal impediment in the construction of physical maps of large eukaryotic genomes. It is hypothesized that this impediment can be overcome by screening multidimensional pools of BAC clones using the highly para...

  20. Production of High-Titer Epstein-Barr Virus Recombinants Derived from Akata Cells by Using a Bacterial Artificial Chromosome System

    OpenAIRE

    Kanda, Teru; Yajima, Misako; Ahsan, Nazmul; Tanaka, Mika; Takada, Kenzo

    2004-01-01

    An Epstein-Barr virus (EBV) genome in Burkitt's lymphoma-derived cell line Akata was cloned into a bacterial artificial chromosome (BAC) vector. The BAC clone, designated AK-BAC, was rapidly and precisely modified by means of efficient homologous recombination in Escherichia coli. This system was used to produce recombinant EBVs with transgenes. An expression cassette of green fluorescent protein (GFP) was inserted into AK-BAC, and the resultant BAC clone, AK-BAC-GFP, was transfected into Aka...

  1. A high-throughput strategy for screening of bacterial artificial chromosome libraries and anchoring of clones on a genetic map constructed with single nucleotide polymorphisms

    OpenAIRE

    Luo, Ming-Cheng; Xu, Kenong; Ma, Yaqin; Karin R Deal; Nicolet, Charles M.; Dvorak, Jan

    2009-01-01

    Background Current techniques of screening bacterial artificial chromosome (BAC) libraries for molecular markers during the construction of physical maps are slow, laborious and often assign multiple BAC contigs to a single locus on a genetic map. These limitations are the principal impediment in the construction of physical maps of large eukaryotic genomes. It is hypothesized that this impediment can be overcome by screening multidimensional pools of BAC clones using the highly parallel Illu...

  2. Plasticity of DNA Replication Initiation in Epstein-Barr Virus Episomes

    Directory of Open Access Journals (Sweden)

    Norio Paolo

    2004-01-01

    Full Text Available In mammalian cells, the activity of the sites of initiation of DNA replication appears to be influenced epigenetically, but this regulation is not fully understood. Most studies of DNA replication have focused on the activity of individual initiation sites, making it difficult to evaluate the impact of changes in initiation activity on the replication of entire genomic loci. Here, we used single molecule analysis of replicated DNA (SMARD to study the latent duplication of Epstein-Barr virus (EBV episomes in human cell lines. We found that initiation sites are present throughout the EBV genome and that their utilization is not conserved in different EBV strains. In addition, SMARD shows that modifications in the utilization of multiple initiation sites occur across large genomic regions (tens of kilobases in size. These observations indicate that individual initiation sites play a limited role in determining the replication dynamics of the EBV genome. Long-range mechanisms and the genomic context appear to play much more important roles, affecting the frequency of utilization and the order of activation of multiple initiation sites. Finally, these results confirm that initiation sites are extremely redundant elements of the EBV genome. We propose that these conclusions also apply to mammalian chromosomes.

  3. Delivery of episomal vectors into primary cells by means of commercial transfection reagents.

    Science.gov (United States)

    Han, Na Rae; Lee, Hyun; Baek, Song; Yun, Jung Im; Park, Kyu Hyun; Lee, Seung Tae

    2015-05-29

    Although episomal vectors are commonly transported into cells by electroporation, a number of electroporation-derived problems have led to the search for alternative transfection protocols, such as the use of transfection reagents, which are inexpensive and easy to handle. Polyplex-mediated transport of episomal vectors into the cytoplasm has been conducted successfully in immortalized cell lines, but no report exists of successful transfection of primary cells using this method. Accordingly, we sought to optimize the conditions for polyplex-mediated transfection for effective delivery of episomal vectors into the cytoplasm of primary mouse embryonic fibroblasts. Episomal vectors were complexed with the commercially available transfection reagents Lipofectamine 2000, FuGEND HD and jetPEI. The ratio of transfection reagent to episomal vectors was varied, and the subsequent transfection efficiency and cytotoxicity of the complexes were analyzed using flow cytometry and trypan blue exclusion assay, respectively. No cytotoxicity and the highest transfection yield were observed when the ratio of transfection reagent to episomal vector was 4 (v/wt) in the cases of Lipofectamine 2000 and FuGENE HD, and 2 in the case of jetPEI. Of the three transfection reagents tested, jetPEI showed the highest transfection efficiency without any cytotoxicity. Thus, we confirmed that the transfection reagent jetPEI could be used to effectively deliver episomal vectors into primary cells without electroporation. PMID:25887802

  4. Yeast artificial chromosomes employed for random assembly of biosynthetic pathways and production of diverse compounds in Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Mitra Partha P

    2009-08-01

    Full Text Available Abstract Background Natural products are an important source of drugs and other commercially interesting compounds, however their isolation and production is often difficult. Metabolic engineering, mainly in bacteria and yeast, has sought to circumvent some of the associated problems but also this approach is impeded by technical limitations. Here we describe a novel strategy for production of diverse natural products, comprising the expression of an unprecedented large number of biosynthetic genes in a heterologous host. Results As an example, genes from different sources, representing enzymes of a seven step flavonoid pathway, were individually cloned into yeast expression cassettes, which were then randomly combined on Yeast Artificial Chromosomes and used, in a single transformation of yeast, to create a variety of flavonoid producing pathways. Randomly picked clones were analysed, and approximately half of them showed production of the flavanone naringenin, and a third of them produced the flavonol kaempferol in various amounts. This reflected the assembly of 5–7 step multi-species pathways converting the yeast metabolites phenylalanine and/or tyrosine into flavonoids, normally only produced by plants. Other flavonoids were also produced that were either direct intermediates or derivatives thereof. Feeding natural and unnatural, halogenated precursors to these recombinant clones demonstrated the potential to further diversify the type of molecules that can be produced with this technology. Conclusion The technology has many potential uses but is particularly suited for generating high numbers of structurally diverse compounds, some of which may not be amenable to chemical synthesis, thus greatly facilitating access to a huge chemical space in the search for new commercially interesting compounds

  5. Human Bacterial Artificial Chromosome (BAC) Transgenesis Fully Rescues Noradrenergic Function in Dopamine β-Hydroxylase Knockout Mice

    Science.gov (United States)

    Cubells, Joseph F.; Schroeder, Jason P.; Barrie, Elizabeth S.; Manvich, Daniel F.; Sadee, Wolfgang; Berg, Tiina; Mercer, Kristina; Stowe, Taylor A.; Liles, L. Cameron; Squires, Katherine E.; Mezher, Andrew; Curtin, Patrick; Perdomo, Dannie L.; Szot, Patricia; Weinshenker, David

    2016-01-01

    Dopamine β-hydroxylase (DBH) converts dopamine (DA) to norepinephrine (NE) in noradrenergic/adrenergic cells. DBH deficiency prevents NE production and causes sympathetic failure, hypotension and ptosis in humans and mice; DBH knockout (Dbh -/-) mice reveal other NE deficiency phenotypes including embryonic lethality, delayed growth, and behavioral defects. Furthermore, a single nucleotide polymorphism (SNP) in the human DBH gene promoter (-970C>T; rs1611115) is associated with variation in serum DBH activity and with several neurological- and neuropsychiatric-related disorders, although its impact on DBH expression is controversial. Phenotypes associated with DBH deficiency are typically treated with L-3,4-dihydroxyphenylserine (DOPS), which can be converted to NE by aromatic acid decarboxylase (AADC) in the absence of DBH. In this study, we generated transgenic mice carrying a human bacterial artificial chromosome (BAC) encompassing the DBH coding locus as well as ~45 kb of upstream and ~107 kb of downstream sequence to address two issues. First, we characterized the neuroanatomical, neurochemical, physiological, and behavioral transgenic rescue of DBH deficiency by crossing the BAC onto a Dbh -/- background. Second, we compared human DBH mRNA abundance between transgenic lines carrying either a “C” or a “T” at position -970. The BAC transgene drove human DBH mRNA expression in a pattern indistinguishable from the endogenous gene, restored normal catecholamine levels to the peripheral organs and brain of Dbh -/- mice, and fully rescued embryonic lethality, delayed growth, ptosis, reduced exploratory activity, and seizure susceptibility. In some cases, transgenic rescue was superior to DOPS. However, allelic variation at the rs1611115 SNP had no impact on mRNA levels in any tissue. These results indicate that the human BAC contains all of the genetic information required for tissue-specific, functional expression of DBH and can rescue all measured Dbh

  6. A method for producing transgenic cells using a multi-integrase system on a human artificial chromosome vector.

    Directory of Open Access Journals (Sweden)

    Shigeyuki Yamaguchi

    Full Text Available The production of cells capable of expressing gene(s of interest is important for a variety of applications in biomedicine and biotechnology, including gene therapy and animal transgenesis. The ability to insert transgenes at a precise location in the genome, using site-specific recombinases such as Cre, FLP, and ΦC31, has major benefits for the efficiency of transgenesis. Recent work on integrases from ΦC31, R4, TP901-1 and Bxb1 phages demonstrated that these recombinases catalyze site-specific recombination in mammalian cells. In the present study, we examined the activities of integrases on site-specific recombination and gene expression in mammalian cells. We designed a human artificial chromosome (HAC vector containing five recombination sites (ΦC31 attP, R4 attP, TP901-1 attP, Bxb1 attP and FRT; multi-integrase HAC vector and de novo mammalian codon-optimized integrases. The multi-integrase HAC vector has several functions, including gene integration in a precise locus and avoiding genomic position effects; therefore, it was used as a platform to investigate integrase activities. Integrases carried out site-specific recombination at frequencies ranging from 39.3-96.8%. Additionally, we observed homogenous gene expression in 77.3-87.5% of colonies obtained using the multi-integrase HAC vector. This vector is also transferable to another cell line, and is capable of accepting genes of interest in this environment. These data suggest that integrases have high DNA recombination efficiencies in mammalian cells. The multi-integrase HAC vector enables us to produce transgene-expressing cells efficiently and create platform cell lines for gene expression.

  7. Construction and Identification of Bacterial Artificial Chromosome Library for 0-613-2R in Upland Cotton

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A bacterial artificial chromosome (BAC) library containing a large genomic DNA insert is an important tool for genome physical mapping, map-based cloning, and genome sequencing. To isolate genes via a map-based cloning strategy and to perform physical mapping of the cotton genome, a high-quality BAC library containing large cotton DNA inserts is needed. We have developed a BAC library of the restoring line 0-613-2R for isolating the fertility restorer (Rf1) gene and genomic research in cotton (Gossypium hirsutum L.). The BAC library contains 97 825 clones stored in 255 pieces of a 384-well microtiter plate. Random samples of BACs digested with the Notl enzyme indicated that the average insert size is approximately 130 kb, with a range of 80-275 kb,and 95.7% of the BAC clones in the library have an average insert size larger than 100 kb. Based on a cotton genome size of 2 250 Mb, library coverage is 5.7 x haploid genome equivalents. Four clones were selected randomly from the library to determine the stability of the BAC clones. There were no different fingerprints for 0 and 100 generations of each clone digested with Notl and Hindlll enzymes. Thus, the stability of a single BAC clone can be sustained at least for 100 generations. Eight simple sequence repeat (SSR) markers flanking the Rf1 gene were chosen to screen the BAC library by pool using PCR method and 25 positive clones were identified with 3.1 positive clones per SSR marker.

  8. Recovery of infectious virus from full-length cowpox virus (CPXV DNA cloned as a bacterial artificial chromosome (BAC

    Directory of Open Access Journals (Sweden)

    Roth Swaantje J

    2011-01-01

    Full Text Available Abstract Transmission from pet rats and cats to humans as well as severe infection in felids and other animal species have recently drawn increasing attention to cowpox virus (CPXV. We report the cloning of the entire genome of cowpox virus strain Brighton Red (BR as a bacterial artificial chromosome (BAC in Escherichia coli and the recovery of infectious virus from cloned DNA. Generation of a full-length CPXV DNA clone was achieved by first introducing a mini-F vector, which allows maintenance of large circular DNA in E. coli, into the thymidine kinase locus of CPXV by homologous recombination. Circular replication intermediates were then electroporated into E. coli DH10B cells. Upon successful establishment of the infectious BR clone, we modified the full-length clone such that recombination-mediated excision of bacterial sequences can occur upon transfection in eukaryotic cells. This self-excision of the bacterial replicon is made possible by a sequence duplication within mini-F sequences and allows recovery of recombinant virus progeny without remaining marker or vector sequences. The in vitro growth properties of viruses derived from both BAC clones were determined and found to be virtually indistinguishable from those of parental, wild-type BR. Finally, the complete genomic sequence of the infectious clone was determined and the cloned viral genome was shown to be identical to that of the parental virus. In summary, the generated infectious clone will greatly facilitate studies on individual genes and pathogenesis of CPXV. Moreover, the vector potential of CPXV can now be more systematically explored using this newly generated tool.

  9. Construction of a nurse shark (Ginglymostoma cirratum bacterial artificial chromosome (BAC library and a preliminary genome survey

    Directory of Open Access Journals (Sweden)

    Inoko Hidetoshi

    2006-05-01

    Full Text Available Abstract Background Sharks are members of the taxonomic class Chondrichthyes, the oldest living jawed vertebrates. Genomic studies of this group, in comparison to representative species in other vertebrate taxa, will allow us to theorize about the fundamental genetic, developmental, and functional characteristics in the common ancestor of all jawed vertebrates. Aims In order to obtain mapping and sequencing data for comparative genomics, we constructed a bacterial artificial chromosome (BAC library for the nurse shark, Ginglymostoma cirratum. Results The BAC library consists of 313,344 clones with an average insert size of 144 kb, covering ~4.5 × 1010 bp and thus providing an 11-fold coverage of the haploid genome. BAC end sequence analyses revealed, in addition to LINEs and SINEs commonly found in other animal and plant genomes, two new groups of nurse shark-specific repetitive elements, NSRE1 and NSRE2 that seem to be major components of the nurse shark genome. Screening the library with single-copy or multi-copy gene probes showed 6–28 primary positive clones per probe of which 50–90% were true positives, demonstrating that the BAC library is representative of the different regions of the nurse shark genome. Furthermore, some BAC clones contained multiple genes, making physical mapping feasible. Conclusion We have constructed a deep-coverage, high-quality, large insert, and publicly available BAC library for a cartilaginous fish. It will be very useful to the scientific community interested in shark genomic structure, comparative genomics, and functional studies. We found two new groups of repetitive elements specific to the nurse shark genome, which may contribute to the architecture and evolution of the nurse shark genome.

  10. Human Bacterial Artificial Chromosome (BAC) Transgenesis Fully Rescues Noradrenergic Function in Dopamine β-Hydroxylase Knockout Mice.

    Science.gov (United States)

    Cubells, Joseph F; Schroeder, Jason P; Barrie, Elizabeth S; Manvich, Daniel F; Sadee, Wolfgang; Berg, Tiina; Mercer, Kristina; Stowe, Taylor A; Liles, L Cameron; Squires, Katherine E; Mezher, Andrew; Curtin, Patrick; Perdomo, Dannie L; Szot, Patricia; Weinshenker, David

    2016-01-01

    Dopamine β-hydroxylase (DBH) converts dopamine (DA) to norepinephrine (NE) in noradrenergic/adrenergic cells. DBH deficiency prevents NE production and causes sympathetic failure, hypotension and ptosis in humans and mice; DBH knockout (Dbh -/-) mice reveal other NE deficiency phenotypes including embryonic lethality, delayed growth, and behavioral defects. Furthermore, a single nucleotide polymorphism (SNP) in the human DBH gene promoter (-970C>T; rs1611115) is associated with variation in serum DBH activity and with several neurological- and neuropsychiatric-related disorders, although its impact on DBH expression is controversial. Phenotypes associated with DBH deficiency are typically treated with L-3,4-dihydroxyphenylserine (DOPS), which can be converted to NE by aromatic acid decarboxylase (AADC) in the absence of DBH. In this study, we generated transgenic mice carrying a human bacterial artificial chromosome (BAC) encompassing the DBH coding locus as well as ~45 kb of upstream and ~107 kb of downstream sequence to address two issues. First, we characterized the neuroanatomical, neurochemical, physiological, and behavioral transgenic rescue of DBH deficiency by crossing the BAC onto a Dbh -/- background. Second, we compared human DBH mRNA abundance between transgenic lines carrying either a "C" or a "T" at position -970. The BAC transgene drove human DBH mRNA expression in a pattern indistinguishable from the endogenous gene, restored normal catecholamine levels to the peripheral organs and brain of Dbh -/- mice, and fully rescued embryonic lethality, delayed growth, ptosis, reduced exploratory activity, and seizure susceptibility. In some cases, transgenic rescue was superior to DOPS. However, allelic variation at the rs1611115 SNP had no impact on mRNA levels in any tissue. These results indicate that the human BAC contains all of the genetic information required for tissue-specific, functional expression of DBH and can rescue all measured Dbh deficiency

  11. Construction of an American mink Bacterial Artificial Chromosome (BAC library and sequencing candidate genes important for the fur industry

    Directory of Open Access Journals (Sweden)

    Christensen Knud

    2011-07-01

    Full Text Available Abstract Background Bacterial artificial chromosome (BAC libraries continue to be invaluable tools for the genomic analysis of complex organisms. Complemented by the newly and fast growing deep sequencing technologies, they provide an excellent source of information in genomics projects. Results Here, we report the construction and characterization of the CHORI-231 BAC library constructed from a Danish-farmed, male American mink (Neovison vison. The library contains approximately 165,888 clones with an average insert size of 170 kb, representing approximately 10-fold coverage. High-density filters, each consisting of 18,432 clones spotted in duplicate, have been produced for hybridization screening and are publicly available. Overgo probes derived from expressed sequence tags (ESTs, representing 21 candidate genes for traits important for the mink industry, were used to screen the BAC library. These included candidate genes for coat coloring, hair growth and length, coarseness, and some receptors potentially involved in viral diseases in mink. The extensive screening yielded positive results for 19 of these genes. Thirty-five clones corresponding to 19 genes were sequenced using 454 Roche, and large contigs (184 kb in average were assembled. Knowing the complete sequences of these candidate genes will enable confirmation of the association with a phenotype and the finding of causative mutations for the targeted phenotypes. Additionally, 1577 BAC clones were end sequenced; 2505 BAC end sequences (80% of BACs were obtained. An excess of 2 Mb has been analyzed, thus giving a snapshot of the mink genome. Conclusions The availability of the CHORI-321 American mink BAC library will aid in identification of genes and genomic regions of interest. We have demonstrated how the library can be used to identify specific genes of interest, develop genetic markers, and for BAC end sequencing and deep sequencing of selected clones. To our knowledge, this is the

  12. First Birth after Sperm Selection through Discontinuous Gradient Centrifugation and Artificial Insemination from a Chromosomal Translocation Carrier

    OpenAIRE

    Alexandre Rouen; Capucine Hyon; Richard Balet; Nicole Joyé; Nino Guy Cassuto; Jean-Pierre Siffroi

    2014-01-01

    Introduction. Balanced chromosomal carriers, though usually healthy, are confronted with recurrent spontaneous abortions and malformations in the offspring. Those are related to the transmission of an abnormal, chromosomally unbalanced genotype. We evidenced that the proportion of unbalanced spermatozoa can be significantly decreased through a sperm preparation process called discontinuous gradient centrifugation (DGC). We therefore started offering intrauterine inseminations with this proced...

  13. Cloning of human centromeres by transformation-associated recombination in yeast and generation of functional human artificial chromosomes

    OpenAIRE

    Kouprina, N.; Ebersole, T.; Koriabine, M.; Pak, E; Rogozin, I. B.; Katoh, M; Oshimura, M; Ogi, K; Peredelchuk, M.; Solomon, G; Brown, W.; Barrett, J. C.; Larionov, V

    2003-01-01

    Human centromeres remain poorly characterized regions of the human genome despite their importance for the maintenance of chromosomes. In part this is due to the difficulty of cloning of highly repetitive DNA fragments and distinguishing chromosome-specific clones in a genomic library. In this work we report the highly selective isolation of human centromeric DNA using transformation-associated recombination (TAR) cloning. A TAR vector with alphoid DNA monomers as targeting sequences was used...

  14. Gamma-herpesvirus latency requires T cell evasion during episome maintenance.

    Directory of Open Access Journals (Sweden)

    Neil J Bennett

    2005-04-01

    Full Text Available The gamma-herpesviruses persist as latent episomes in a dynamic lymphocyte pool. Their consequent need to express a viral episome maintenance protein presents a potential immune target. The glycine-alanine repeat of the Epstein-Barr virus episome maintenance protein, EBNA-1, limits EBNA-1 epitope presentation to CD8(+ T lymphocytes (CTLs. However, CTL recognition occurs in vitro, so the significance of such evasion for viral fitness is unclear. We used the murine gamma-herpesvirus-68 (MHV-68 to define the in vivo contribution of cis-acting CTL evasion to host colonisation. Although the ORF73 episome maintenance protein of MHV-68 lacks a glycine-alanine repeat, it was equivalent to EBNA-1 in conferring limited presentation on linked epitopes. This was associated with reduced protein synthesis and reduced protein degradation. We bypassed the cis-acting evasion of ORF73 by using an internal ribosome entry site to express in trans-a CTL target from the same mRNA. This led to a severe, MHC class I-restricted and CTL-dependent reduction in viral latency. Thus, despite MHV-68 encoding at least two trans-acting CTL evasion proteins, cis-acting evasion during episome maintenance was essential for normal host colonisation.

  15. A BACTERIAL ARTIFICIAL CHROMOSOME CONTIG SPANNING THE MAJOR DOMESTICATION LOCUS Q IN WHEAT AND IDENTIFICATION OF A CANDIDATE GENE

    Science.gov (United States)

    The Q locus played a major role in the domestication of wheat because it confers the free-threshing character and influences many other agronomically important traits. We constructed a physical contig spanning the Q locus using a Triticum monococcum BAC library. Four chromosome walking steps were ...

  16. Organization of the Bacillus subtilis 168 chromosome between kdg and the attachment site of the SP beta prophage: use of Long Accurate PCR and yeast artificial chromosomes for sequencing.

    Science.gov (United States)

    Capuano, V; Galleron, N; Pujic, P; Sorokin, A; Ehrlich, S D

    1996-11-01

    Within the Bacillus subtilis genome sequencing project, the region between lysA and ilvA was assigned to our laboratory. In this report we present the sequence of the last 36 kb of this region, between the kdg operon and the attachment site of the SP beta prophage. A two-step strategy was used for the sequencing. In the first step, total chromosomal DNA was cloned in phage M13-based vectors and the clones carrying inserts from the target region were identified by hybridization with a cognate yeast artificial chromosome (YAC) from our collection. Sequencing of the clones allowed us to establish a number of contigs. In the second step the contigs were mapped by Long Accurate (LA) PCR and the remaining gaps closed by sequencing of the PCR products. The level of sequence inaccuracy due to LA PCR errors appeared to be about 1 in 10,000, which does not affect significantly the final sequence quality. This two-step strategy is efficient and we suggest that it can be applied to sequencing of longer chromosomal regions. The 36 kb sequence contains 38 coding sequences (CDSs), 19 of which encode unknown proteins. Seven genetic loci already mapped in this region, xpt, metB, ilvA, ilvD, thyB, dfrA and degR were identified. Eleven CDSs were found to display significant similarities to known proteins from the data banks, suggesting possible functions for some of the novel genes: cspD may encode a cold shock protein; bcsA, the first bacterial homologue of chalcone synthase; exol, a 5' to 3' exonuclease, similar to that of DNA polymerase I of Escherichia coli; and bsaA, a stress-response-associated protein. The protein encoded by yplP has homology with the transcriptional NifA-like regulators. The arrangement of the genes relative to possible promoters and terminators suggests 19 potential transcription units. PMID:8969496

  17. Efficient generation of recombinant RNA viruses using targeted recombination-mediated mutagenesis of bacterial artificial chromosomes containing full-length cDNA

    DEFF Research Database (Denmark)

    Rasmussen, Thomas Bruun; Risager, Peter Christian; Fahnøe, Ulrik;

    2013-01-01

    Background Infectious cDNA clones are a prerequisite for directed genetic manipulation of RNA viruses. Here, a strategy to facilitate manipulation and rescue of classical swine fever viruses (CSFVs) from full-length cDNAs present within bacterial artificial chromosomes (BACs) is described. This...... strategy allows manipulation of viral cDNA by targeted recombination-mediated mutagenesis within bacteria. Results A new CSFV-BAC (pBeloR26) derived from the Riems vaccine strain has been constructed and subsequently modified in the E2 coding sequence, using the targeted recombination strategy to enable...... rescue of chimeric pestiviruses (vR26_E2gif and vR26_TAV) with potential as new marker vaccine candidates. Sequencing of the BACs revealed a high genetic stability during passages within bacteria. The complete genome sequences of rescued viruses, after extensive passages in mammalian cells showed that...

  18. The Selection and Use of Sorghum (Sorghum propinquum Bacterial Artificial Chromosomes as Cytogenetic FISH Probes for Maize (Zea mays L.

    Directory of Open Access Journals (Sweden)

    Debbie M. Figueroa

    2011-01-01

    Full Text Available The integration of genetic and physical maps of maize is progressing rapidly, but the cytogenetic maps lag behind, with the exception of the pachytene fluorescence in situ hybridization (FISH maps of maize chromosome 9. We sought to produce integrated FISH maps of other maize chromosomes using Core Bin Marker loci. Because these 1 Kb restriction fragment length polymorphism (RFLP probes are below the FISH detection limit, we used BACs from sorghum, a small-genome relative of maize, as surrogate clones for FISH mapping. We sequenced 151 maize RFLP probes and compared in silico BAC selection methods to that of library filter hybridization and found the latter to be the best. BAC library screening, clone verification, and single-clone selection criteria are presented along with an example of transgenomic BAC FISH mapping. This strategy has been used to facilitate the integration of RFLP and FISH maps in other large-genome species.

  19. The selection and use of sorghum (Sorghum propinquum) bacterial artificial chromosomes as cytogenetic FISH probes for maize (Zea mays L.).

    Science.gov (United States)

    Figueroa, Debbie M; Davis, James D; Strobel, Cornelia; Conejo, Maria S; Beckham, Katherine D; Ring, Brian C; Bass, Hank W

    2011-01-01

    The integration of genetic and physical maps of maize is progressing rapidly, but the cytogenetic maps lag behind, with the exception of the pachytene fluorescence in situ hybridization (FISH) maps of maize chromosome 9. We sought to produce integrated FISH maps of other maize chromosomes using Core Bin Marker loci. Because these 1 Kb restriction fragment length polymorphism (RFLP) probes are below the FISH detection limit, we used BACs from sorghum, a small-genome relative of maize, as surrogate clones for FISH mapping. We sequenced 151 maize RFLP probes and compared in silico BAC selection methods to that of library filter hybridization and found the latter to be the best. BAC library screening, clone verification, and single-clone selection criteria are presented along with an example of transgenomic BAC FISH mapping. This strategy has been used to facilitate the integration of RFLP and FISH maps in other large-genome species. PMID:21234422

  20. Polymorphisms in folate-metabolizing genes, chromosome damage, and risk of Down syndrome in Italian women: identification of key factors using artificial neural networks

    Directory of Open Access Journals (Sweden)

    Migheli Francesca

    2010-09-01

    Full Text Available Abstract Background Studies in mothers of Down syndrome individuals (MDS point to a role for polymorphisms in folate metabolic genes in increasing chromosome damage and maternal risk for a Down syndrome (DS pregnancy, suggesting complex gene-gene interactions. This study aimed to analyze a dataset of genetic and cytogenetic data in an Italian group of MDS and mothers of healthy children (control mothers to assess the predictive capacity of artificial neural networks assembled in TWIST system in distinguish consistently these two different conditions and to identify the variables expressing the maximal amount of relevant information to the condition of being mother of a DS child. The dataset consisted of the following variables: the frequency of chromosome damage in peripheral lymphocytes (BNMN frequency and the genotype for 7 common polymorphisms in folate metabolic genes (MTHFR 677C>T and 1298A>C, MTRR 66A>G, MTR 2756A>G, RFC1 80G>A and TYMS 28bp repeats and 1494 6bp deletion. Data were analysed using TWIST system in combination with supervised artificial neural networks, and a semantic connectivity map. Results TWIST system selected 6 variables (BNMN frequency, MTHFR 677TT, RFC1 80AA, TYMS 1494 6bp +/+, TYMS 28bp 3R/3R and MTR 2756AA genotypes that were subsequently used to discriminate between MDS and control mothers with 90% accuracy. The semantic connectivity map provided important information on the complex biological connections between the studied variables and the two conditions (being MDS or control mother. Conclusions Overall, the study suggests a link between polymorphisms in folate metabolic genes and DS risk in Italian women.

  1. 棉花细菌人工染色体文库构建方法探讨%Studies on Construction Method of Cotton Bacterial Artificial Chromosome Library

    Institute of Scientific and Technical Information of China (English)

    高海燕; 王省芬; 刘方; 彭仁海; 张艳; 马峙英; 王坤波

    2013-01-01

    细菌人工染色体(Bacterial artificial chromosome,BAC)文库是开展基因组测序、基因图位克隆、分子标记、物理作图等研究的重要基因组资源.本文在构建了二倍体野生棉阿非利加棉(Gossypium herbaceum var.africanum)BAC文库的基础上,就棉花细菌人工染色体基因组文库构建过程中高分子量基因组DNA的提取、部分酶切片段选择、DNA的回收、连接转化以及BAC文库的保存等过程中一些细节和注意事项进行了比较详细的分析比较,希望能为棉花BAC文库的构建提供一些可供借鉴的经验.%Bacterial artificial chromosome (BAC) library is an important genome resources to such research as genome sequencing, map-based cloning, molecular markers, and physical mapping. On the base of the construction of BAC library for Gossypi-um herbaceum var. africanum, this paper presents an exhaustive analysis on details and notices of the BAC library construction process. It includes extraction of high molecular weight (HMW) nuclear DNA, determination of the optimized enzyme for partial digestion of HMW DNA, two rounds of size fractionation, recovery of large fragments DNA, ligation and transformation of large fragments of DNA and storage of BAC library. Thus being able to supply an experience for constructing high efficiency cotton BAC library.

  2. First Birth after Sperm Selection through Discontinuous Gradient Centrifugation and Artificial Insemination from a Chromosomal Translocation Carrier

    Directory of Open Access Journals (Sweden)

    Alexandre Rouen

    2014-01-01

    Full Text Available Introduction. Balanced chromosomal carriers, though usually healthy, are confronted with recurrent spontaneous abortions and malformations in the offspring. Those are related to the transmission of an abnormal, chromosomally unbalanced genotype. We evidenced that the proportion of unbalanced spermatozoa can be significantly decreased through a sperm preparation process called discontinuous gradient centrifugation (DGC. We therefore started offering intrauterine inseminations with this procedure to couples with a male translocation carriers. Case Presentation. We report the case of a 37-year-old man carrying a t(3;10(q25;p13 reciprocal translocation. He and his partner had had trouble conceiving for ten years and had four spontaneous abortions. DGC in this patient decreased the proportion of unbalanced spermatozoa from 63.6% to 52.3%. They were therefore offered intrauterine insemination with DGC, which eventually led to the birth of a healthy female child carrying the paternal translocation. Conclusion. We showed that translocation carriers could be offered intrauterine inseminations with DGC. Before this, the only two options were natural conception with prenatal diagnosis and termination of chromosomally unbalanced fetuses or preimplantation genetic diagnosis, which is a much heavier and costly procedure. We are currently offering this option through a multicentric program in France, and this is the first birth originating from it.

  3. First Birth after Sperm Selection through Discontinuous Gradient Centrifugation and Artificial Insemination from a Chromosomal Translocation Carrier.

    Science.gov (United States)

    Rouen, Alexandre; Hyon, Capucine; Balet, Richard; Joyé, Nicole; Cassuto, Nino Guy; Siffroi, Jean-Pierre

    2014-01-01

    Introduction. Balanced chromosomal carriers, though usually healthy, are confronted with recurrent spontaneous abortions and malformations in the offspring. Those are related to the transmission of an abnormal, chromosomally unbalanced genotype. We evidenced that the proportion of unbalanced spermatozoa can be significantly decreased through a sperm preparation process called discontinuous gradient centrifugation (DGC). We therefore started offering intrauterine inseminations with this procedure to couples with a male translocation carriers. Case Presentation. We report the case of a 37-year-old man carrying a t(3;10)(q25;p13) reciprocal translocation. He and his partner had had trouble conceiving for ten years and had four spontaneous abortions. DGC in this patient decreased the proportion of unbalanced spermatozoa from 63.6% to 52.3%. They were therefore offered intrauterine insemination with DGC, which eventually led to the birth of a healthy female child carrying the paternal translocation. Conclusion. We showed that translocation carriers could be offered intrauterine inseminations with DGC. Before this, the only two options were natural conception with prenatal diagnosis and termination of chromosomally unbalanced fetuses or preimplantation genetic diagnosis, which is a much heavier and costly procedure. We are currently offering this option through a multicentric program in France, and this is the first birth originating from it. PMID:24587925

  4. Variations in the association of papillomavirus E2 proteins with mitotic chromosomes

    OpenAIRE

    Jaquelline G de Oliveira; Colf, Leremy A.; Alison A McBride

    2006-01-01

    The E2 protein segregates episomal bovine papillomavirus (BPV) genomes to daughter cells by tethering them to mitotic chromosomes, thus ensuring equal distribution and retention of viral DNA. To date, only the BPV1 E2 protein has been shown to bind to mitotic chromosomes. We assessed the localization of 13 different animal and human E2 proteins from seven papillomavirus genera, and we show that most of them are stably bound to chromosomes throughout mitosis. Furthermore, in contrast to the ra...

  5. Impact of Different Promoters on Episomal Vectors Harbouring Characteristic Motifs of Matrix Attachment Regions.

    Science.gov (United States)

    Wang, Xiao-Yin; Zhang, Jun-He; Zhang, Xi; Sun, Qiu-Li; Zhao, Chun-Peng; Wang, Tian-Yun

    2016-01-01

    We previously demonstrated that the characteristic sequence of matrix attachment regions (MARs) allows transgenes to be maintained episomally in CHO cells. In the present study, six commonly used promoters from human cytomegalovirus major immediate-early (CMV), simian vacuolating virus 40 (SV40), Rous sarcoma virus, Homo sapiens ubiquitin C, phosphoglycerate kinase, and β-globin, respectively, were evaluated to determine their effects on transgene expression and stability in CHO cells stably transfected via the episomal vector harbouring characteristic MAR motifs. The CHO cells were transfected with vectors and then screened using G418, after which the stably transfected cells were split into two and further cultured either in the presence or absence of G418. Of the six promoters, the CMV promoter yielded the highest transgene expression levels and the highest transfection efficiency, whereas the SV40 promoter maintained transgene expression more stably during long-term culture than the other promoters did. The CMV and SV40 promoter-containing vectors were furthermore episomally maintained and conferred sustained eGFP expression in the cells even under nonselective conditions. On the basis of these findings, we conclude that the CMV promoter performs best in terms of yielding both high expression levels and high levels of stability using this episomal vector system. PMID:27226236

  6. Plant Artificial Chromosome:The Vector for the Next Generation of Genetic Engineering%植物人工染色体:下一代基因工程的载体

    Institute of Scientific and Technical Information of China (English)

    李晨; 闫晓红; 杨洁; 杨清; 魏文辉

    2011-01-01

    The simultaneous expression of multiple genes and genetically modified (GM) food security research have been considered as the research focus for genetic engineering in plants presently. Unlike conventional gene transformation technologies,plant artificial chromosomes provide one solution to the stable expression of multiple transgenes. As plant artificial chromosome segregation is independent of host chromosomes, they provide a platform for accelerating plant breeding and for studying the specific chromatin domains inserted into them. The generation of artificial plant chromosomes and their applications were reviewed in this article.%植物基因工程技术中的多基因转化及转基因安全已经成为其研究的2个重要方面.植物人工染色体可以在一条不含标记基因的附加染色体上提供稳定的多基因表达,是新一代的转基因载体.由于植物人工染色体独立于宿主染色体,为植物育种提供了便利,同时,也为研究染色质特殊区域的结构与功能提供了平台.本文就植物人工染色体的产生、研究现状及其应用前景等进行了综述和讨论.

  7. Rapid and efficient introduction of a foreign gene into bacterial artificial chromosome-cloned varicella vaccine by Tn7-mediated site-specific transposition

    International Nuclear Information System (INIS)

    Using a rapid and reliable system based on Tn7-mediated site-specific transposition, we have successfully constructed a recombinant Oka varicella vaccine (vOka) expressing the mumps virus (MuV) fusion protein (F). The backbone of the vector was our previously reported vOka-BAC (bacterial artificial chromosome) genome. We inserted the transposon Tn7 attachment sequence, LacZα-mini-attTn7, into the region between ORF12 and ORF13 to generate a vOka-BAC-Tn genome. The MuV-F expressing cassette was transposed into the vOka-BAC genome at the mini-attTn7 transposition site. MuV-F protein was expressed in recombinant virus, rvOka-F infected cells. In addition, the MuV-F protein was cleaved in the rvOka-F infected cells as in MuV-infected cells. The growth of rvOka-F was similar to that of the original recombinant vOka without the F gene. Thus, we show that Tn7-mediated transposition is an efficient method for introducing a foreign gene expression cassette into the vOka-BAC genome as a live virus vector.

  8. A novel system for simultaneous or sequential integration of multiple gene-loading vectors into a defined site of a human artificial chromosome.

    Directory of Open Access Journals (Sweden)

    Teruhiko Suzuki

    Full Text Available Human artificial chromosomes (HACs are gene-delivery vectors suitable for introducing large DNA fragments into mammalian cells. Although a HAC theoretically incorporates multiple gene expression cassettes of unlimited DNA size, its application has been limited because the conventional gene-loading system accepts only one gene-loading vector (GLV into a HAC. We report a novel method for the simultaneous or sequential integration of multiple GLVs into a HAC vector (designated as the SIM system via combined usage of Cre, FLP, Bxb1, and φC31 recombinase/integrase. As a proof of principle, we first attempted simultaneous integration of three GLVs encoding EGFP, Venus, and TdTomato into a gene-loading site of a HAC in CHO cells. These cells successfully expressed all three fluorescent proteins. Furthermore, microcell-mediated transfer of HACs enabled the expression of those fluorescent proteins in recipient cells. We next demonstrated that GLVs could be introduced into a HAC one-by-one via reciprocal usage of recombinase/integrase. Lastly, we introduced a fourth GLV into a HAC after simultaneous integration of three GLVs by FLP-mediated DNA recombination. The SIM system expands the applicability of HAC vectors and is useful for various biomedical studies, including cell reprogramming.

  9. HIV gene expression from intact proviruses positioned in bacterial artificial chromosomes at integration sites previously identified in latently infected T cells

    International Nuclear Information System (INIS)

    HIV integration predominantly occurs in introns of transcriptionally active genes. To study the impact of the integration site on HIV gene expression, a complete HIV-1 provirus (with GFP as a fusion with Nef) was inserted into bacterial artificial chromosomes (BACs) at three sites previously identified in latent T cells of patients: topoisomerase II (Top2A), DNA methyltransferase 1 (DNMT1), or basic leucine transcription factor 2 (BACH2). Transfection of BAC-HIV into 293 T cells resulted in a fourfold difference in production of infectious HIV-1. Cell lines were established that contained BAC-Top2A, BAC-DNMT1, or BAC-BACH2, but only BAC-DNMT1 spontaneously produced virus, albeit at a low level. Stimulation with TNF-α resulted in virus production from four of five BAC-Top2A and all BAC-DNMT1 cell lines, but not from the BAC-BACH2 lines. The results of these studies highlight differences between integration sites identified in latent T cells to support virus production and reactivation from latency.

  10. Construction of an Excisable Bacterial Artificial Chromosome Containing a Full-Length Infectious Clone of Herpes Simplex Virus Type 1: Viruses Reconstituted from the Clone Exhibit Wild-Type Properties In Vitro and In Vivo

    OpenAIRE

    Tanaka, Michiko; Kagawa, Hiroyuki; Yamanashi, Yuji; Sata, Tetsutaro; Kawaguchi, Yasushi

    2003-01-01

    In recent years, several laboratories have reported on the cloning of herpes simplex virus type 1 (HSV-1) genomes as bacterial artificial chromosomes (BACs) in Escherichia coli and on procedures to manipulate these genomes by using the bacterial recombination machinery. However, the HSV-BACs reported so far are either replication incompetent or infectious, with a deletion of one or more viral genes due to the BAC vector insertion. For use as a multipurpose clone in research on HSV-1, we attem...

  11. Cloning of the Koi Herpesvirus Genome as an Infectious Bacterial Artificial Chromosome Demonstrates That Disruption of the Thymidine Kinase Locus Induces Partial Attenuation in Cyprinus carpio koi▿

    Science.gov (United States)

    Costes, B.; Fournier, G.; Michel, B.; Delforge, C.; Raj, V. Stalin; Dewals, B.; Gillet, L.; Drion, P.; Body, A.; Schynts, F.; Lieffrig, F.; Vanderplasschen, A.

    2008-01-01

    Koi herpesvirus (KHV) is the causative agent of a lethal disease in koi and common carp. In the present study, we describe the cloning of the KHV genome as a stable and infectious bacterial artificial chromosome (BAC) clone that can be used to produce KHV recombinant strains. This goal was achieved by the insertion of a loxP-flanked BAC cassette into the thymidine kinase (TK) locus. This insertion led to a BAC plasmid that was stably maintained in bacteria and was able to regenerate virions when permissive cells were transfected with the plasmid. Reconstituted virions free of the BAC cassette but carrying a disrupted TK locus (the FL BAC-excised strain) were produced by the transfection of Cre recombinase-expressing cells with the BAC. Similarly, virions with a wild-type revertant TK sequence (the FL BAC revertant strain) were produced by the cotransfection of cells with the BAC and a DNA fragment encoding the wild-type TK sequence. Reconstituted recombinant viruses were compared to the wild-type parental virus in vitro and in vivo. The FL BAC revertant strain and the FL BAC-excised strain replicated comparably to the parental FL strain. The FL BAC revertant strain induced KHV infection in koi carp that was indistinguishable from that induced by the parental strain, while the FL BAC-excised strain exhibited a partially attenuated phenotype. Finally, the usefulness of the KHV BAC for recombination studies was demonstrated by the production of an ORF16-deleted strain by using prokaryotic recombination technology. The availability of the KHV BAC is an important advance that will allow the study of viral genes involved in KHV pathogenesis, as well as the production of attenuated recombinant candidate vaccines. PMID:18337580

  12. Human Papilloma Viral DNA Replicates as a Stable Episome in Cultured Epidermal Keratinocytes

    Science.gov (United States)

    Laporta, Robert F.; Taichman, Lorne B.

    1982-06-01

    Human papilloma virus (HPV) is poorly understood because systems for its growth in tissue culture have not been developed. We report here that cultured human epidermal keratinocytes could be infected with HPV from plantar warts and that the viral DNA persisted and replicated as a stable episome. There were 50-200 copies of viral DNA per cell and there was no evidence to indicate integration of viral DNA into the cellular genome. There was also no evidence to suggest that viral DNA underwent productive replication. We conclude that cultured human epidermal keratinocytes may be a model for the study of certain aspects of HPV biology.

  13. A bacterial artificial chromosome library for the Australian saltwater crocodile (Crocodylus porosus) and its utilization in gene isolation and genome characterization

    Science.gov (United States)

    2009-01-01

    Background Crocodilians (Order Crocodylia) are an ancient vertebrate group of tremendous ecological, social, and evolutionary importance. They are the only extant reptilian members of Archosauria, a monophyletic group that also includes birds, dinosaurs, and pterosaurs. Consequently, crocodilian genomes represent a gateway through which the molecular evolution of avian lineages can be explored. To facilitate comparative genomics within Crocodylia and between crocodilians and other archosaurs, we have constructed a bacterial artificial chromosome (BAC) library for the Australian saltwater crocodile, Crocodylus porosus. This is the first BAC library for a crocodile and only the second BAC resource for a crocodilian. Results The C. porosus BAC library consists of 101,760 individually archived clones stored in 384-well microtiter plates. NotI digestion of random clones indicates an average insert size of 102 kb. Based on a genome size estimate of 2778 Mb, the library affords 3.7 fold (3.7×) coverage of the C. porosus genome. To investigate the utility of the library in studying sequence distribution, probes derived from CR1a and CR1b, two crocodilian CR1-like retrotransposon subfamilies, were hybridized to C. porosus macroarrays. The results indicate that there are a minimum of 20,000 CR1a/b elements in C. porosus and that their distribution throughout the genome is decidedly non-random. To demonstrate the utility of the library in gene isolation, we probed the C. porosus macroarrays with an overgo designed from a C-mos (oocyte maturation factor) partial cDNA. A BAC containing C-mos was identified and the C-mos locus was sequenced. Nucleotide and amino acid sequence alignment of the C. porosus C-mos coding sequence with avian and reptilian C-mos orthologs reveals greater sequence similarity between C. porosus and birds (specifically chicken and zebra finch) than between C. porosus and squamates (green anole). Conclusion We have demonstrated the utility of the

  14. 染色体多态性对供精人工授精治疗结局的影响%Influence of chromosomal polymorphism on treatment outcome of artificial insemination by donors

    Institute of Scientific and Technical Information of China (English)

    伍园园; 郑立新; 祝小丽; 舒小妹; 郑炜炜

    2013-01-01

    Objective: To investigate the relationship between the female chromosome polymorphism and the pregnancy outcome of artificial insemination by donors. Methods; The peripheral blood of patients was cultured rountinely for karotype analysis. Clinical pregnancy rate, cumulative pregnancy rate and early obortion rate were observed by treated patients with chromosomal polymorphism as the research group, and patients with normal chromosome as control group. Results: There was no significant difference in the clinical cycle pregnancy rate ( 19. 80% vs 19. 66% ) , cumulative pregnancy rate (44. 82% vs 41. 77% ) , early abortion rate ( 14. 58% vsl2. 07% ) between the two groups ( P > 0. 05 ) . Conclusion: Chromosomal polymorphism carrier status has no impact on treatment outcome of the patients receiving artificial insemination by donors.%目的 探讨女性染色体多态性与供精人工授精妊娠结局的关系.方法 对接受供精人工授精患者常规抽血行染色体检查,将发现有染色体多态的患者作为研究对象,与染色体正常群体对照,观察临床妊娠率、累积妊娠率和早期流产率.结果 染色体多态性组与正常组比较,临床周期妊娠率(19.80% vs 19.66%),累积妊娠率(44.82%vs 41.77%),早期流产率(14.58% vs12.07%),均无统计学差异(P>0.05).结论 染色体多态性携带状态不影响供精人工授精患者的治疗结局.

  15. Cloning of the Epstein-Barr Virus-Related Rhesus Lymphocryptovirus as a Bacterial Artificial Chromosome: a Loss-of-Function Mutation of the rhBARF1 Immune Evasion Gene ▿ †

    OpenAIRE

    Ohashi, Makoto; Orlova, Nina; Quink, Carol; Wang, Fred

    2010-01-01

    Rhesus macaques are naturally infected with a gammaherpesvirus which is in the same lymphocryptovirus (LCV) genus as and closely related to Epstein-Barr virus (EBV). The rhesus macaque LCV (rhLCV) contains a repertoire of genes identical to that of EBV, and experimental rhLCV infection of naive rhesus macaques accurately models acute and persistent EBV infection of humans. We cloned the LCL8664 rhLCV strain as a bacterial artificial chromosome to create recombinant rhLCV for investigation in ...

  16. Construction of a bacterial artificial chromosome (BAC) library of Lycopersicon esculentum cv. Stevens and its application to physically map the Sw-5 locus

    NARCIS (Netherlands)

    Spassova, MI; Prins, M; Stevens, MR; Hille, J; Goldbach, RW; Spassova, Mariana I.; Stevens, Mikel R.; Goldbach, Rob W.

    1999-01-01

    The Sw-5 gene is a dominantly inherited resistance gene in tomato and functional against a number of tospovirus species. The gene has been mapped on chromosome 9, tightly linked to RFLP markers CT220 and SCAR421. To analyse the Sw-5 locus, a BAC genomic library was constructed of tomato cv. Stevens,

  17. Stable transformation of an episomal protein-tagging shuttle vector in the piscine diplomonad Spironucleus vortens

    Directory of Open Access Journals (Sweden)

    Cronembold Daniela

    2008-04-01

    Full Text Available Abstract Background Diplomonads are common free-living inhabitants of anoxic aquatic environments and are also found as intestinal commensals or parasites of a wide variety of animals. Spironucleus vortens is a putatively commensal diplomonad of angelfish that grows to high cell densities in axenic culture. Genomic sequencing of S. vortens is in progress, yet little information is available regarding molecular and cellular aspects of S. vortens biology beyond descriptive ultrastructural studies. To facilitate the development of S. vortens as an additional diplomonad experimental model, we have constructed and stably transformed an episomal plasmid containing an enhanced green fluorescent protein (GFP tag, an AU1 epitope tag, and a tandem affinity purification (TAP tag. This construct also contains selectable antibiotic resistance markers for both S. vortens and E. coli. Results Stable transformants of S. vortens grew relatively rapidly (within 7 days after electroporation and were maintained under puromycin selection for over 6 months. We expressed the enhanced GFP variant, eGFP, under transcriptional control of the S. vortens histone H3 promoter, and visually confirmed diffuse GFP expression in over 50% of transformants. Next, we generated a histone H3::GFP fusion using the S. vortens conventional histone H3 gene and its native promoter. This construct was also highly expressed in the majority of S. vortens transformants, in which the H3::GFP fusion localized to the chromatin in both nuclei. Finally, we used fluorescence in situ hybridization (FISH of the episomal plasmid to show that the transformed plasmid localized to only one nucleus/cell and was present at roughly 10–20 copies per nucleus. Because S. vortens grows to high densities in laboratory culture, it is a feasible diplomonad from which to purify native protein complexes. Thus, we also included a TAP tag in the plasmid constructs to permit future tagging and subsequent purification

  18. Diagnosis and Prognostication of Ductal Adenocarcinomas of the Pancreas Based on Genome-Wide DNA Methylation Profiling by Bacterial Artificial Chromosome Array-Based Methylated CpG Island Amplification

    Directory of Open Access Journals (Sweden)

    Masahiro Gotoh

    2011-01-01

    Full Text Available To establish diagnostic criteria for ductal adenocarcinomas of the pancreas (PCs, bacterial artificial chromosome (BAC array-based methylated CpG island amplification was performed using 139 tissue samples. Twelve BAC clones, for which DNA methylation status was able to discriminate cancerous tissue (T from noncancerous pancreatic tissue in the learning cohort with a specificity of 100%, were identified. Using criteria that combined the 12 BAC clones, T-samples were diagnosed as cancers with 100% sensitivity and specificity in both the learning and validation cohorts. DNA methylation status on 11 of the BAC clones, which was able to discriminate patients showing early relapse from those with no relapse in the learning cohort with 100% specificity, was correlated with the recurrence-free and overall survival rates in the validation cohort and was an independent prognostic factor by multivariate analysis. Genome-wide DNA methylation profiling may provide optimal diagnostic markers and prognostic indicators for patients with PCs.

  19. Recombinant Adeno-Associated Virus Vector Genomes Take the Form of Long-Lived, Transcriptionally Competent Episomes in Human Muscle.

    Science.gov (United States)

    Schnepp, Bruce C; Chulay, Jeffrey D; Ye, Guo-Jie; Flotte, Terence R; Trapnell, Bruce C; Johnson, Philip R

    2016-01-01

    Gene augmentation therapy as a strategy to treat alpha-1 antitrypsin (AAT) deficiency has reached phase 2 clinical testing in humans. Sustained serum levels of AAT have been observed beyond one year after intramuscular administration of a recombinant adeno-associated virus (rAAV) vector expressing the AAT gene. In this study, sequential muscle biopsies obtained at 3 and 12 months after vector injection were examined for the presence of rAAV vector genomes. Each biopsy sample contained readily detectable vector DNA, the majority of which existed as double-stranded supercoiled and open circular episomes. Episomes persisted through 12 months, although at slightly lower levels than observed at 3 months. There was a clear dose response when comparing the low- and mid-vector-dose groups to the high-dose group. The highest absolute copy numbers were found in a high-dose subject, and serum AAT levels at 12 months confirmed that the high-dose group also had the highest sustained serum AAT levels. Sequence analysis revealed that the vast majority of episomes contained double-D inverted terminal repeats ranging from fully intact to severely deleted. Molecular clones of vector genomes derived directly from the biopsies were transcriptionally active, potentially identifying them as the source of serum AAT in the trial subjects. PMID:26650966

  20. Genetic modification of cancer cells using non-viral, episomal S/MAR vectors for in vivo tumour modelling.

    Directory of Open Access Journals (Sweden)

    Orestis Argyros

    Full Text Available The development of genetically marked animal tumour xenografts is an area of ongoing research to enable easier and more reliable testing of cancer therapies. Genetically marked tumour models have a number of advantages over conventional tumour models, including the easy longitudinal monitoring of therapies and the reduced number of animals needed for trials. Several different methods have been used in previous studies to mark tumours genetically, however all have limitations, such as genotoxicity and other artifacts related to the usage of integrating viral vectors. Recently, we have generated an episomally maintained plasmid DNA (pDNA expression system based on Scaffold/Matrix Attachment Region (S/MAR, which permits long-term luciferase transgene expression in the mouse liver. Here we describe a further usage of this pDNA vector with the human Ubiquitin C promoter to create stably transfected human hepatoma (Huh7 and human Pancreatic Carcinoma (MIA-PaCa2 cell lines, which were delivered into "immune deficient" mice and monitored longitudinally over time using a bioluminometer. Both cell lines revealed sustained episomal long-term luciferase expression and formation of a tumour showing the pathological characteristics of hepatocellular carcinoma (HCC and pancreatic carcinoma (PaCa, respectively. This is the first demonstration that a pDNA vector can confer sustained episomal luciferase transgene expression in various mouse tumour models and can thus be readily utilised to follow tumour formation without interfering with the cellular genome.

  1. Kaposi's sarcoma herpesvirus C-terminal LANA concentrates at pericentromeric and peri-telomeric regions of a subset of mitotic chromosomes

    International Nuclear Information System (INIS)

    The Kaposi's sarcoma-associated herpesvirus (KSHV) latency-associated nuclear antigen (LANA) tethers KSHV terminal repeat (TR) DNA to mitotic chromosomes to efficiently segregate episomes to progeny nuclei. LANA contains N- and C-terminal chromosome binding regions. We now show that C-terminal LANA preferentially concentrates to paired dots at pericentromeric and peri-telomeric regions of a subset of mitotic chromosomes through residues 996-1139. Deletions within C-terminal LANA abolished both self-association and chromosome binding, consistent with a requirement for self-association to bind chromosomes. A deletion abolishing TR DNA binding did not affect chromosome targeting, indicating LANA's localization is not due to binding its recognition sequence in chromosomal DNA. LANA distributed similarly on human and non-human mitotic chromosomes. These results are consistent with C-terminal LANA interacting with a cell factor that concentrates at pericentromeric and peri-telomeric regions of mitotic chromosomes

  2. pEPito: a significantly improved non-viral episomal expression vector for mammalian cells

    Directory of Open Access Journals (Sweden)

    Ogris Manfred

    2010-03-01

    Full Text Available Abstract Background The episomal replication of the prototype vector pEPI-1 depends on a transcription unit starting from the constitutively expressed Cytomegalovirus immediate early promoter (CMV-IEP and directed into a 2000 bp long matrix attachment region sequence (MARS derived from the human β-interferon gene. The original pEPI-1 vector contains two mammalian transcription units and a total of 305 CpG islands, which are located predominantly within the vector elements necessary for bacterial propagation and known to be counterproductive for persistent long-term transgene expression. Results Here, we report the development of a novel vector pEPito, which is derived from the pEPI-1 plasmid replicon but has considerably improved efficacy both in vitro and in vivo. The pEPito vector is significantly reduced in size, contains only one transcription unit and 60% less CpG motives in comparison to pEPI-1. It exhibits major advantages compared to the original pEPI-1 plasmid, including higher transgene expression levels and increased colony-forming efficiencies in vitro, as well as more persistent transgene expression profiles in vivo. The performance of pEPito-based vectors was further improved by replacing the CMV-IEP with the human CMV enhancer/human elongation factor 1 alpha promoter (hCMV/EF1P element that is known to be less affected by epigenetic silencing events. Conclusions The novel vector pEPito can be considered suitable as an improved vector for biotechnological applications in vitro and for non-viral gene delivery in vivo.

  3. [Chromosomal organization of the genomes of small-chromosome plants].

    Science.gov (United States)

    Muravenko, O V; Zelenin, A V

    2009-11-01

    An effective approach to study the chromosome organization in genomes of plants with small chromosomes and/or with low-informative C-banding patterns was developed in the course of investigation of the karyotypes of cotton plant, camomile, flax, and pea. To increase the resolving power of chromosome analysis, methods were worked out for revealing early replication patterns on chromosomes and for artificial impairment of mitotic chromosome condensation with the use of a DNA intercalator, 9-aminoacridine (9-AMA). To estimate polymorphism of the patterns of C-banding of small chromosomes on preparations obtained with the use of 9-AMA, it is necessary to choose a length interval that must not exceed three average sizes of metaphase chromosomes without the intercalator. The use of 9-AMA increases the resolution of differential C- and OR-banding and the precision of physical chromosome mapping by the FISH method. Of particular importance in studying small chromosomes is optimization of the computer-aided methods used to obtain and process chromosome images. The complex approach developed for analysis of the chromosome organization in plant genomes was used to study the karyotypes of 24 species of the genus Linum L. It permitted their chromosomes to be identified for the first time, and, in addition, B chromosomes were discovered and studied in the karyotypes of the species of the section Syllinum. By similarity of the karyotypes, the studied flax species were distributed in eight groups in agreement with the clusterization of these species according to the results of RAPD analysis performed in parallel. Systematic positions and phylogenetic relationships of the studied flax species were verified. Out results can serve as an important argument in favour of the proposal to develop a special program for sequencing the genome of cultivated flax (L. usitatissimum L.), which is a major representative of small-chromosome species. PMID:20058798

  4. Isolation and characterization of purine regulatory mutants of Salmonella typhimurium with an episomal purE-lac fusion.

    OpenAIRE

    Thomulka, K W; Gots, J S

    1982-01-01

    Expression of the purE operon of Salmonella typhimurium was analyzed by using an Escherichia coli F' episome containing a purE-lac fusion. The fusion removes the lacOP and part of the lacZ genes of the lac operon and places the intact lacY and lacA genes under control of the purE operon as shown by inhibition of growth on melibiose (lacY) and repression of thiogalactoside transacetylase (lacA) by various purines. Two classes of regulatory-deficient mutants were found among those resistant to ...

  5. Beyond the chromosome: the prevalence of unique extra-chromosomal bacteriophages with integrated virulence genes in pathogenic Staphylococcus aureus.

    Directory of Open Access Journals (Sweden)

    Bryan Utter

    Full Text Available In Staphylococcus aureus, the disease impact of chromosomally integrated prophages on virulence is well described. However, the existence of extra-chromosomal prophages, both plasmidial and episomal, remains obscure. Despite the recent explosion in bacterial and bacteriophage genomic sequencing, studies have failed to specifically focus on extra-chromosomal elements. We selectively enriched and sequenced extra-chromosomal DNA from S. aureus isolates using Roche-454 technology and uncovered evidence for the widespread distribution of multiple extra-chromosomal prophages (ExPΦs throughout both antibiotic-sensitive and -resistant strains. We completely sequenced one such element comprised of a 43.8 kbp, circular ExPΦ (designated ФBU01 from a vancomycin-intermediate S. aureus (VISA strain. Assembly and annotation of ФBU01 revealed a number of putative virulence determinants encoded within a bacteriophage immune evasion cluster (IEC. Our identification of several potential ExPΦs and mobile genetic elements (MGEs also revealed numerous putative virulence factors and antibiotic resistance genes. We describe here a previously unidentified level of genetic diversity of stealth extra-chromosomal elements in S. aureus, including phages with a larger presence outside the chromosome that likely play a prominent role in pathogenesis and strain diversity driven by horizontal gene transfer (HGT.

  6. A Sequence-Independent Strategy for Amplification and Characterisation of Episomal Badnavirus Sequences Reveals Three Previously Uncharacterised Yam Badnaviruses.

    Science.gov (United States)

    Bömer, Moritz; Turaki, Aliyu A; Silva, Gonçalo; Kumar, P Lava; Seal, Susan E

    2016-01-01

    Yam (Dioscorea spp.) plants are potentially hosts to a diverse range of badnavirus species (genus Badnavirus, family Caulimoviridae), but their detection is complicated by the existence of integrated badnavirus sequences in some yam genomes. To date, only two badnavirus genomes have been characterised, namely, Dioscorea bacilliform AL virus (DBALV) and Dioscorea bacilliform SN virus (DBSNV). A further 10 tentative species in yam have been described based on their partial reverse transcriptase (RT)-ribonuclease H (RNaseH) sequences, generically referred to here as Dioscorea bacilliform viruses (DBVs). Further characterisation of DBV species is necessary to determine which represent episomal viruses and which are only present as integrated badnavirus sequences in some yam genomes. In this study, a sequence-independent multiply-primed rolling circle amplification (RCA) method was evaluated for selective amplification of episomal DBV genomes. This resulted in the identification and characterisation of nine complete genomic sequences (7.4-7.7 kbp) of existing and previously undescribed DBV phylogenetic groups from Dioscorea alata and Dioscorea rotundata accessions. These new yam badnavirus genomes expand our understanding of the diversity and genomic organisation of DBVs, and assist the development of improved diagnostic tools. Our findings also suggest that mixed badnavirus infections occur relatively often in West African yam germplasm. PMID:27399761

  7. Isolation and characterization of bovine herpesvirus 4 (BoHV-4 from a cow affected by post partum metritis and cloning of the genome as a bacterial artificial chromosome

    Directory of Open Access Journals (Sweden)

    Cavirani Sandro

    2009-08-01

    Full Text Available Abstract Background Bovine herpesvirus 4 (BoHV-4 is a gammaherpesvirus with a Worldwide distribution in cattle and is often isolated from the uterus of animals with postpartum metritis or pelvic inflammatory disease. Virus strain adaptation to an organ, tissue or cell type is an important issue for the pathogenesis of disease. To explore the mechanistic role of viral strain variation for uterine disease, the present study aimed to develop a tool enabling precise genetic discrimination between strains of BoHV-4 and to easily manipulate the viral genome. Methods A strain of BoHV-4 was isolated from the uterus of a persistently infected cow and designated BoHV-4-U. The authenticity of the isolate was confirmed by RFLP-PCR and sequencing using the TK and IE2 loci as genetic marker regions for the BoHV-4 genome. The isolated genome was cloned as a Bacterial Artificial Chromosome (BAC and manipulated through recombineering technology Results The BoHV-4-U genome was successfully cloned as a BAC, and the stability of the pBAC-BoHV-4-U clone was confirmed over twenty passages, with viral growth similar to the wild type virus. The feasibility of using BoHV-4-U for mutagenesis was demonstrated using the BAC recombineering system. Conclusion The analysis of genome strain variation is a key method for investigating genes associated with disease. A resource for dissection of the interactions between BoHV-4 and host endometrial cells was generated by cloning the genome of BoHV-4 as a BAC.

  8. Integration sites of Epstein-Barr virus genome on chromosomes of human lymphoblastoid cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Wuu, K.D.; Chen, Y.J.; Wang-Wuu, S. [Institute of Genetics, Taipei (Taiwan, Province of China)

    1994-09-01

    Epstein-Barr virus (EBV) is the pathogen of infectious mononucleosis. The viral genome is present in more than 95% of the African cases of Burkitt lymphoma and it is usually maintained in episomal form in the tumor cells. Viral integration has been described only for Nanalwa which is a Burkitt lymphoma cell line lacking episomes. In order to examine the role of EBV in the immortalization of human Blymphocytes, we investigated whether the EBV integration into the human genome is essential. If the integration does occur, we would like to know whether the integration is randomly distributed or whether the viral DNA integrates preferentially at certain sites. Fourteen in vitro immortalized human lymphoblastoid cell lines (LCLs) were examined by fluorescence in situ hybridization (FISH) with a biotinylated EBV BamHI w DNA fragment as probe. The episomal form of EBV DNA was found in all cells of these cell lines, while only about 65% of the cells have the integrated viral DNA. This might suggest that integration is not a pre-requisite for cell immortalization. Although all chromosomes, except Y, have been found with integrated viral genome, chromsomes 1 and 5 are the most frequent EBV DNA carrier (p<0.05). Nine chromosome bands, namely, 1p31, 1q31, 2q32, 3q13, 3q26, 5q14, 6q24, 7q31 and 12q21, are preferential targets for EBV integration (p<0.001). Eighty percent of the total 938 EBV hybridization signals were found to be at G-band-positive area. This suggests that the mechanism of EBV integration might be different from that of the retroviruses, which specifically integrate to G-band-negative areas. Thus, we conclude that the integration of EBV to host genome is non-random and it may have something to do with the structure of chromosome and DNA sequences.

  9. Artificial intelligence

    CERN Document Server

    Hunt, Earl B

    1975-01-01

    Artificial Intelligence provides information pertinent to the fundamental aspects of artificial intelligence. This book presents the basic mathematical and computational approaches to problems in the artificial intelligence field.Organized into four parts encompassing 16 chapters, this book begins with an overview of the various fields of artificial intelligence. This text then attempts to connect artificial intelligence problems to some of the notions of computability and abstract computing devices. Other chapters consider the general notion of computability, with focus on the interaction bet

  10. Chromosomal aberration

    International Nuclear Information System (INIS)

    Chromosomal aberrations are classified into two types, chromosome-type and chromatid-type. Chromosom-type aberrations include terminal deletion, dicentric, ring and interstitial deletion, and chromatid-type aberrations include achromatic lesion, chromatid deletion, isochromatid deletion and chromatid exchange. Clastogens which induce chromosomal aberration are divided into ''S-dependent'' agents and ''S-independent''. It might mean whether they can induce double strand breaks independent of the S phase or not. Double strand breaks may be the ultimate lesions to induce chromosomal aberrations. Caffeine added even in the G2 phase appeared to modify the frequency of chromatid aberrations induced by X-rays and mitomycin C. Those might suggest that the G2 phase involves in the chromatid aberration formation. The double strand breaks might be repaired by ''G2 repair system'', the error of which might yield breakage types of chromatid aberrations and the by-pass of which might yield chromatid exchanges. Chromosome-type aberrations might be formed in the G1 phase. (author)

  11. Original Research: Generation of non-deletional hereditary persistence of fetal hemoglobin β-globin locus yeast artificial chromosome transgenic mouse models: -175 Black HPFH and -195 Brazilian HPFH.

    Science.gov (United States)

    Braghini, Carolina A; Costa, Flavia C; Fedosyuk, Halyna; Neades, Renee Y; Novikova, Lesya V; Parker, Matthew P; Winefield, Robert D; Peterson, Kenneth R

    2016-04-01

    Fetal hemoglobin is a major genetic modifier of the phenotypic heterogeneity in patients with sickle cell disease and certain β-thalassemias. Normal levels of fetal hemoglobin postnatally are approximately 1% of total hemoglobin. Patients who have hereditary persistence of fetal hemoglobin, characterized by elevated synthesis of γ-globin in adulthood, show reduced disease pathophysiology. Hereditary persistence of fetal hemoglobin is caused by β-globin locus deletions (deletional hereditary persistence of fetal hemoglobin) or γ-globin gene promoter point mutations (non-deletional hereditary persistence of fetal hemoglobin). Current research has focused on elucidating the pathways involved in the maintenance/reactivation of γ-globin in adult life. To better understand these pathways, we generated new β-globin locus yeast artificial chromosome transgenic mice bearing the (A)γ-globin -175 T > C or -195 C > G hereditary persistence of fetal hemoglobin mutations to model naturally occurring hereditary persistence of fetal hemoglobin. Adult -175 and -195 mutant β-YAC mice displayed a hereditary persistence of fetal hemoglobin phenotype, as measured at the mRNA and protein levels. The molecular basis for these phenotypes was examined by chromatin immunoprecipitation of transcription factor/co-factor binding, including YY1, PAX1, TAL1, LMO2, and LDB1. In -175 HPFH versus wild-type samples, the occupancy of LMO2, TAL1 and LDB1 proteins was enriched in HPFH mice (5.8-fold, 5.2-fold and 2.7-fold, respectively), a result that concurs with a recent study in cell lines showing that these proteins form a complex with GATA-1 to mediate long-range interactions between the locus control region and the (A)γ-globin gene. Both hereditary persistence of fetal hemoglobin mutations result in a gain of (A)γ-globin activation, in contrast to other hereditary persistence of fetal hemoglobin mutations that result in a loss of repression. The mice provide additional tools to

  12. Generation of non-deletional hereditary persistence of fetal hemoglobin β-globin locus yeast artificial chromosome transgenic mouse models: −175 Black HPFH and −195 Brazilian HPFH

    Science.gov (United States)

    Braghini, Carolina A; Costa, Flavia C; Fedosyuk, Halyna; Neades, Renee Y; Novikova, Lesya V; Parker, Matthew P; Winefield, Robert D; Peterson, Kenneth R

    2016-01-01

    Fetal hemoglobin is a major genetic modifier of the phenotypic heterogeneity in patients with sickle cell disease and certain β-thalassemias. Normal levels of fetal hemoglobin postnatally are approximately 1% of total hemoglobin. Patients who have hereditary persistence of fetal hemoglobin, characterized by elevated synthesis of γ-globin in adulthood, show reduced disease pathophysiology. Hereditary persistence of fetal hemoglobin is caused by β-globin locus deletions (deletional hereditary persistence of fetal hemoglobin) or γ-globin gene promoter point mutations (non-deletional hereditary persistence of fetal hemoglobin). Current research has focused on elucidating the pathways involved in the maintenance/reactivation of γ-globin in adult life. To better understand these pathways, we generated new β-globin locus yeast artificial chromosome transgenic mice bearing the Aγ-globin −175 T >C or −195 C >G hereditary persistence of fetal hemoglobin mutations to model naturally occurring hereditary persistence of fetal hemoglobin. Adult −175 and −195 mutant β-YAC mice displayed a hereditary persistence of fetal hemoglobin phenotype, as measured at the mRNA and protein levels. The molecular basis for these phenotypes was examined by chromatin immunoprecipitation of transcription factor/co-factor binding, including YY1, PAX1, TAL1, LMO2, and LDB1. In −175 HPFH versus wild-type samples, the occupancy of LMO2, TAL1 and LDB1 proteins was enriched in HPFH mice (5.8-fold, 5.2-fold and 2.7-fold, respectively), a result that concurs with a recent study in cell lines showing that these proteins form a complex with GATA-1 to mediate long-range interactions between the locus control region and the Aγ-globin gene. Both hereditary persistence of fetal hemoglobin mutations result in a gain of Aγ-globin activation, in contrast to other hereditary persistence of fetal hemoglobin mutations that result in a loss of repression. The mice provide additional tools to study

  13. 大白菜细菌人工染色体文库的构建及鉴定%Construction and Characterization of a Bacterial Artificial Chromosome Library from Chinese Cabbage

    Institute of Scientific and Technical Information of China (English)

    冯大领; 石学萍; 杨煜; 王彦华; 轩淑欣; 赵建军; 申书兴

    2011-01-01

    以我国优良的大白菜自交系'85-1'为材料,利用 pIndigoBAC-5 为载体,通过对高分子量DNA 的制备、大片段 DNA 的选择、连接转化条件等几个方面的优化,构建了大白菜细菌人工染色体文库.该文库由 57 600个克隆组成,平均大小为98.4 kb,空载率为1.5%;覆盖大白菜基因组 10.3 倍;挑取 6 个克隆培养5 d 后,经HindⅢ完全酶切检测,其指纹图谱稳定一致.大白菜细菌人工染色体文库的构建为重要功能基因的克隆和定位及比较基因组研究奠定了基础.%A bacterial artificial chromosome library of Brassica campestris L. ssp. pekinensis ( Lour.)Olsson (Chinese cabbage) was constructed from inbred line‘ 85-1’ with the vector pIndigoBAC-5. The key processes of the construction, such as preparation of high molecular weight DNA, selection of digested fragments, condition of ligation and transformation, were studied. The library consists of 57 600 clones in which the average insert size is about 98.4 kb and the empty clones are about 1.5%. The library represents an equivalent of 10.3 fold size of Chinese cabbage genome. Six clones randomly picked from this library show no HindⅢ fingerprint changes after 5 days' successive culture, which indicates that the clones in the library are stable. The library will lay the foundation for gene clone, location and comparative genomics research of Brassica.

  14. Artificial Limbs

    Science.gov (United States)

    ... you are missing an arm or leg, an artificial limb can sometimes replace it. The device, which ... activities such as walking, eating, or dressing. Some artificial limbs let you function nearly as well as ...

  15. Synthetic chromosomes.

    Science.gov (United States)

    Schindler, Daniel; Waldminghaus, Torsten

    2015-11-01

    What a living organism looks like and how it works and what are its components-all this is encoded on DNA, the genetic blueprint. Consequently, the way to change an organism is to change its genetic information. Since the first pieces of recombinant DNA have been used to transform cells in the 1970s, this approach has been enormously extended. Bigger and bigger parts of the genetic information have been exchanged or added over the years. Now we are at a point where the construction of entire chromosomes becomes a reachable goal and first examples appear. This development leads to fundamental new questions, for example, about what is possible and desirable to build or what construction rules one needs to follow when building synthetic chromosomes. Here we review the recent progress in the field, discuss current challenges and speculate on the appearance of future synthetic chromosomes. PMID:26111960

  16. Genetic reprogramming of human amniotic cells with episomal vectors: neural rosettes as sentinels in candidate selection for validation assays

    Directory of Open Access Journals (Sweden)

    Patricia G. Wilson

    2014-11-01

    Full Text Available The promise of genetic reprogramming has prompted initiatives to develop banks of induced pluripotent stem cells (iPSCs from diverse sources. Sentinel assays for pluripotency could maximize available resources for generating iPSCs. Neural rosettes represent a primitive neural tissue that is unique to differentiating PSCs and commonly used to identify derivative neural/stem progenitors. Here, neural rosettes were used as a sentinel assay for pluripotency in selection of candidates to advance to validation assays. Candidate iPSCs were generated from independent populations of amniotic cells with episomal vectors. Phase imaging of living back up cultures showed neural rosettes in 2 of the 5 candidate populations. Rosettes were immunopositive for the Sox1, Sox2, Pax6 and Pax7 transcription factors that govern neural development in the earliest stage of development and for the Isl1/2 and Otx2 transcription factors that are expressed in the dorsal and ventral domains, respectively, of the neural tube in vivo. Dissociation of rosettes produced cultures of differentiation competent neural/stem progenitors that generated immature neurons that were immunopositive for βIII-tubulin and glia that were immunopositive for GFAP. Subsequent validation assays of selected candidates showed induced expression of endogenous pluripotency genes, epigenetic modification of chromatin and formation of teratomas in immunodeficient mice that contained derivatives of the 3 embryonic germ layers. Validated lines were vector-free and maintained a normal karyotype for more than 60 passages. The credibility of rosette assembly as a sentinel assay for PSCs is supported by coordinate loss of nuclear-localized pluripotency factors Oct4 and Nanog in neural rosettes that emerge spontaneously in cultures of self-renewing validated lines. Taken together, these findings demonstrate value in neural rosettes as sentinels for pluripotency and selection of promising candidates for advance

  17. Chromosome Microarray.

    Science.gov (United States)

    Anderson, Sharon

    2016-01-01

    Over the last half century, knowledge about genetics, genetic testing, and its complexity has flourished. Completion of the Human Genome Project provided a foundation upon which the accuracy of genetics, genomics, and integration of bioinformatics knowledge and testing has grown exponentially. What is lagging, however, are efforts to reach and engage nurses about this rapidly changing field. The purpose of this article is to familiarize nurses with several frequently ordered genetic tests including chromosomes and fluorescence in situ hybridization followed by a comprehensive review of chromosome microarray. It shares the complexity of microarray including how testing is performed and results analyzed. A case report demonstrates how this technology is applied in clinical practice and reveals benefits and limitations of this scientific and bioinformatics genetic technology. Clinical implications for maternal-child nurses across practice levels are discussed. PMID:27276104

  18. Association Between Pachytene Chromosomes and Linkage Groups in Carrot

    Science.gov (United States)

    The genome of carrot (Daucus carota L.) consists of ~ 480 Mb/1C organized in 9 chromosome pairs. The importance of carrots in human nutrition is triggering the development of genomic resources, including carrot linkage maps, a bacterial artificial chromosome (BAC) clone library and BAC end sequence...

  19. Artificial blood

    Directory of Open Access Journals (Sweden)

    Sarkar Suman

    2008-01-01

    Full Text Available Artificial blood is a product made to act as a substitute for red blood cells. While true blood serves many different functions, artificial blood is designed for the sole purpose of transporting oxygen and carbon dioxide throughout the body. Depending on the type of artificial blood, it can be produced in different ways using synthetic production, chemical isolation, or recombinant biochemical technology. Development of the first blood substitutes dates back to the early 1600s, and the search for the ideal blood substitute continues. Various manufacturers have products in clinical trials; however, no truly safe and effective artificial blood product is currently marketed. It is anticipated that when an artificial blood product is available, it will have annual sales of over $7.6 billion in the United States alone.

  20. A high-resolution physical map integrating an anchored chromosome with the BAC physical maps of wheat chromosome 6B

    OpenAIRE

    Kobayashi, F; Wu, J. Z.; Kanamori, H; Tanaka, T.; Katagiri, S.; Karasawa, W.; Kaneko, S.; Watanabe, S; Sakaguchi, T; Šafář, J. (Jan); Šimková, H. (Hana); Mukai, Y.; M. Hamada; Saito, M; Hayakawa, K

    2015-01-01

    Background: A complete genome sequence is an essential tool for the genetic improvement of wheat. Because the wheat genome is large, highly repetitive and complex due to its allohexaploid nature, the International Wheat Genome Sequencing Consortium (IWGSC) chose a strategy that involves constructing bacterial artificial chromosome (BAC)-based physical maps of individual chromosomes and performing BAC-by-BAC sequencing. Here, we report the construction of a physical map of chromosome 6B with t...

  1. Artificial intelligence

    CERN Document Server

    Ennals, J R

    1987-01-01

    Artificial Intelligence: State of the Art Report is a two-part report consisting of the invited papers and the analysis. The editor first gives an introduction to the invited papers before presenting each paper and the analysis, and then concludes with the list of references related to the study. The invited papers explore the various aspects of artificial intelligence. The analysis part assesses the major advances in artificial intelligence and provides a balanced analysis of the state of the art in this field. The Bibliography compiles the most important published material on the subject of

  2. Artificial urushi.

    Science.gov (United States)

    Kobayashi, S; Uyama, H; Ikeda, R

    2001-11-19

    A new concept for the design and laccase-catalyzed preparation of "artificial urushi" from new urushiol analogues is described. The curing proceeded under mild reaction conditions to produce the very hard cross-linked film (artificial urushi) with a high gloss surface. A new cross-linkable polyphenol was synthesized by oxidative polymerization of cardanol, a phenol derivative from cashew-nut-shell liquid, by enzyme-related catalysts. The polyphenol was readily cured to produce the film (also artificial urushi) showing excellent dynamic viscoelasticity. PMID:11763444

  3. Artificial Reefs

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — An artificial reef is a human-made underwater structure, typically built to promote marine life in areas with a generally featureless bottom, control erosion, block...

  4. Enhanced Generation of Integration-free iPSCs from Human Adult Peripheral Blood Mononuclear Cells with an Optimal Combination of Episomal Vectors

    Directory of Open Access Journals (Sweden)

    Wei Wen

    2016-06-01

    Full Text Available We previously reported the generation of integration-free induced pluripotent stem cells from adult peripheral blood (PB with an improved episomal vector (EV system, which uses the spleen focus-forming virus U3 promoter and an extra factor BCL-XL (B. Here we show an ∼100-fold increase in efficiency by optimizing the vector combination. The two most critical factors are: (1 equimolar expression of OCT4 (O and SOX2 (S, by using a 2A linker; (2 a higher and gradual increase in the MYC (M to KLF4 (K ratio during the course of reprogramming, by using two individual vectors to express M and K instead of one. The combination of EV plasmids (OS + M + K + B is comparable with Sendai virus in reprogramming efficiency but at a fraction of the cost. The generated iPSCs are indistinguishable from those from our previous approach in pluripotency and phenotype. This improvement lays the foundation for broad applications of episomal vectors in PB reprogramming.

  5. Artificial noses.

    Science.gov (United States)

    Stitzel, Shannon E; Aernecke, Matthew J; Walt, David R

    2011-08-15

    The mammalian olfactory system is able to detect many more odorants than the number of receptors it has by utilizing cross-reactive odorant receptors that generate unique response patterns for each odorant. Mimicking the mammalian system, artificial noses combine cross-reactive sensor arrays with pattern recognition algorithms to create robust odor-discrimination systems. The first artificial nose reported in 1982 utilized a tin-oxide sensor array. Since then, however, a wide range of sensor technologies have been developed and commercialized. This review highlights the most commonly employed sensor types in artificial noses: electrical, gravimetric, and optical sensors. The applications of nose systems are also reviewed, covering areas such as food and beverage quality control, chemical warfare agent detection, and medical diagnostics. A brief discussion of future trends for the technology is also provided. PMID:21417721

  6. Artificial intelligence

    International Nuclear Information System (INIS)

    A vivid example of the growing need for frontier physics experiments to make use of frontier technology is in the field of artificial intelligence and related themes. This was reflected in the second international workshop on 'Software Engineering, Artificial Intelligence and Expert Systems in High Energy and Nuclear Physics' which took place from 13-18 January at France Telecom's Agelonde site at La Londe des Maures, Provence. It was the second in a series, the first having been held at Lyon in 1990

  7. Artificial Intelligence

    CERN Document Server

    Warwick, Kevin

    2011-01-01

    if AI is outside your field, or you know something of the subject and would like to know more then Artificial Intelligence: The Basics is a brilliant primer.' - Nick Smith, Engineering and Technology Magazine November 2011 Artificial Intelligence: The Basics is a concise and cutting-edge introduction to the fast moving world of AI. The author Kevin Warwick, a pioneer in the field, examines issues of what it means to be man or machine and looks at advances in robotics which have blurred the boundaries. Topics covered include: how intelligence can be defined whether machines can 'think' sensory

  8. Caracterização citogenética, viabilidade de pólen e hibridação artificial em gérbera Chromosome number, pollen viability and gerbera hybridization

    Directory of Open Access Journals (Sweden)

    Raquel DL Cardoso

    2009-03-01

    Full Text Available Este trabalho foi conduzido com o objetivo de confirmar o número de cromossomos em cultivares de Gerbera hybrida Hort., determinar o número de cromossomos em acessos não comerciais de Gerbera sp., avaliar a viabilidade de pólen e a possibilidade de cruzamentos entre cultivares e acessos não comerciais. Foram coletados ápices de raízes e pólen de seis cultivares e de sete acessos não comerciais. O material coletado foi corado com carmim acético a 45%. A contagem dos cromossomos foi realizada em células metafásicas intactas e a estimativa de viabilidade de pólen realizada por meio da contagem do número de grãos de pólen viáveis e não viáveis. A possibilidade de cruzamento entre as cultivares e entre as cultivares e acessos não comerciais foi avaliada por meio da hibridação entre os genitores femininos, cv. Terra Fame e acesso A8, e masculinos, cvs. Cariba e Azteca. Todos os acessos contiveram cinqüenta cromossomos, indicando que a variação morfológica nos capítulos (simples, semidobrado e dobrado não é devida a mutações cromossômicas numéricas ou a poliploidia. A viabilidade do pólen variou de 87,67% a 99,27%. A formação de sementes foi de 4,46% nos cruzamentos entre cultivares, e de 50% entre o A8 e as cultivares. A compatibilidade genômica entre os acessos, a alta viabilidade do pólen e o sucesso na obtenção de sementes entre acessos comercias e não comerciais, revela a possibilidade de produção de híbridos com novas combinações alélicas e transferência de caracteres desejáveis dos acessos não comerciais para os comerciaisThis work was conducted to confirm the chromosomes number of Gerbera hybrida Hort. cultivars, to determine the chromosomes number in the non commercial accessions of Gerbera sp., and to estimate the pollen viability and the possibility of crossings among different accessions. Root-tip and pollen were collected from six cultivars and seven non commercial accessions. The collected

  9. Mitotic chromosome structure

    International Nuclear Information System (INIS)

    Mounting evidence is compiling linking the physical organizational structure of chromosomes and the nuclear structure to biological function. At the base of the physical organizational structure of both is the concept of loop formation. This implies that physical proximity within chromosomes is provided for otherwise distal genomic regions and thus hierarchically organizing the chromosomes. Together with entropy many experimental observations can be explained with these two concepts. Among the observations that can be explained are the measured physical extent of the chromosomes, their shape, mechanical behavior, the segregation into territories (chromosomal and territories within chromosomes), the results from chromosome conformation capture experiments, as well as linking gene expression to structural organization.

  10. Artificial sweeteners

    DEFF Research Database (Denmark)

    Raben, Anne Birgitte; Richelsen, Bjørn

    2012-01-01

    Artificial sweeteners can be a helpful tool to reduce energy intake and body weight and thereby risk for diabetes and cardiovascular diseases (CVD). Considering the prevailing diabesity (obesity and diabetes) epidemic, this can, therefore, be an important alternative to natural, calorie-containin...

  11. Artificial photosynthesis

    OpenAIRE

    Andrew C. Benniston; Anthony Harriman

    2008-01-01

    We raise here a series of critical issues regarding artificial photosynthesis with the intention of increasing awareness about what needs to be done to bring about a working prototype. Factors under consideration include energy and electron transfers, coupled redox reactions, repair mechanisms, and integrated photosystems.

  12. Comparative metabolism of benzo[a]pyrene by human keratinocytes infected with high-risk human papillomavirus types 16 and 18 as episomal or integrated genomes

    Directory of Open Access Journals (Sweden)

    Neil Trushin

    2012-01-01

    Full Text Available Background: Infection with human papillomavirus (HPV is a critical factor in the development of cervical cancer. Smoking is an additional risk factor. Tobacco smoke carcinogens, such as benzo[a]pyrene (B[a]P, and their cytochrome P450-related metabolites are present in significantly higher levels in the cervical mucus of women smokers than in nonsmokers. We determined the metabolism and P450 expression of B[a]P-treated human keratinocytes infected with HPV-16 or -18. Materials and Methods: Monolayer cultures of uninfected primary human foreskin keratinocytes, human vaginal and cervical keratinocytes carrying episomal genomes of HPV-16 and -18, respectively, and invasive cervical carcinoma cell lines carrying either HPV-16 or -18 genomes integrated into the host DNA, were incubated with 0.1 μM [3H]B[a]P. The resulting oxidative metabolites were analyzed and quantified by radioflow high-performance liquid chromatography. Additionally, all cell lines were incubated with unlabeled 0.1 μM B[a]P for Western blot analysis of cytochrome P450 1A1 and 1B1. Results: Significant enhancement in levels of both detoxification and activation metabolites was found in incubations with all types of HPV-infected cells compared with control incubations (P < 0.05. The highest capacity to metabolize B[a]P was observed with cells containing integrated HPV-18 genomes. Induction of cytochrome 1B1 was observed in HPV-16 and -18 integrated, and in HPV-16 episomal cell types. Conclusions: Both viral genotype and genomic status in the host cell affect B[a]P metabolism and cytochrome P450 1B1 expression. An increase of DNA-damaging metabolites might result from exposure of HPV-infected women to cigarette smoke carcinogens.

  13. Fetal chromosome analysis: screening for chromosome disease?

    DEFF Research Database (Denmark)

    Philip, J; Tabor, Ann; Bang, J;

    1983-01-01

    A + B). Pregnant women 35 years of age, women who previously had a chromosomally abnormal child, families with translocation carriers or other heritable chromosomal disease, families where the father was 50 years or more and women in families with a history of Down's syndrome (group A), were...... unbalanced chromosome abnormality in group A (women with elevated risk) is significantly higher than in group B + C (women without elevated risk) (relative risk 2.4). Women with a known familial translocation and women 40 years or more have a relative risk of 5.7 of having an unbalanced chromosome......The aim of the study was to investigate the rationale of the current indications for fetal chromosome analysis. 5372 women had 5423 amniocentesis performed, this group constituting a consecutive sample at the chromosome laboratory, Rigshospitalet, Copenhagen from March 1973 to September 1980 (Group...

  14. Chromatin structure and ionizing-radiation-induced chromosome aberrations

    International Nuclear Information System (INIS)

    The possible influence of chromatic structure or activity on chromosomal radiosensitivity was studied. A cell line was isolated which contained some 105 copies of an amplified plasmid in a single large mosquito artificial chromosome (MAC). This chromosome was hypersensitive to DNase I. Its radiosensitivity was some three fold greater than normal mosquito chromosomes in the same cell. In cultured human cells irradiated during G0, the initial breakage frequency in chromosome 4, 19 and the euchromatic and heterochromatic portions of the Y chromosome were measured over a wide range of doses by inducing Premature Chromosome Condensation (PCC) immediately after irradiation with Cs-137 gamma rays. No evidence was seen that Y heterochromatin or large fragments of it remained unbroken. The only significant deviation from the expected initial breakage frequency per Gy per unit length of chromosome was that observed for the euchromatic portion of the Y chromosome, with breakage nearly twice that expected. The development of aberrations involving X and Y chromosomes at the first mitosis after irradation was also studied. Normal female cells sustained about twice the frequency of aberrations involving X chromosomes for a dose of 7.3 Gy than the corresponding male cells. Fibroblasts from individuals with supernumerary X chromosomes did not show any further increase in X aberrations for this dos. The frequency of aberrations involving the heterochromatic portion of the long arm of the Y chromosome was about what would be expected for a similar length of autosome, but the euchromatic portion of the Y was about 3 times more radiosensitive per unit length. 5-Azacytidine treatment of cultured human female fibroblasts or fibroblasts from a 49,XXXXY individual, reduced the methylation of cytosine residues in DNA, and resulted in an increased chromosomal radiosensitivity in general, but it did not increase the frequency of aberrations involving the X chromosomes

  15. Artificial Intelligence.

    Science.gov (United States)

    Lawrence, David R; Palacios-González, César; Harris, John

    2016-04-01

    It seems natural to think that the same prudential and ethical reasons for mutual respect and tolerance that one has vis-à-vis other human persons would hold toward newly encountered paradigmatic but nonhuman biological persons. One also tends to think that they would have similar reasons for treating we humans as creatures that count morally in our own right. This line of thought transcends biological boundaries-namely, with regard to artificially (super)intelligent persons-but is this a safe assumption? The issue concerns ultimate moral significance: the significance possessed by human persons, persons from other planets, and hypothetical nonorganic persons in the form of artificial intelligence (AI). This article investigates why our possible relations to AI persons could be more complicated than they first might appear, given that they might possess a radically different nature to us, to the point that civilized or peaceful coexistence in a determinate geographical space could be impossible to achieve. PMID:26957450

  16. Artificial intelligence

    OpenAIRE

    Duda, Antonín

    2009-01-01

    Abstract : Issue of this work is to acquaint the reader with the history of artificial inteligence, esspecialy branch of chess computing. Main attention is given to progress from fifties to the present. The work also deals with fighting chess programs against each other, and against human opponents. The greatest attention is focused on 1997 and duel Garry Kasparov against chess program Deep Blue. The work is divided into chapters according to chronological order.

  17. Chromosome painting in plants.

    NARCIS (Netherlands)

    Schubert, I.; Fransz, P.F.; Fuchs, J.; Jong, de J.H.

    2001-01-01

    The current 'state-of-art' as to chromosome painting in plants is reviewed. We define different situations described as painting so far: i) Genomic in situ hybridisation (GISH) with total genomic DNA to distinguish alien chromosomes on the basis of divergent dispersed repeats, ii) 'Chromosomal in si

  18. Chromosomal Islands of Streptococcus pyogenes and related streptococci: Molecular Switches for Survival and Virulence

    Directory of Open Access Journals (Sweden)

    Scott Van Nguyen

    2014-08-01

    Full Text Available Streptococcus pyogenes is a significant pathogen of humans, annually causing over 700,000,000 infections and 500,000 deaths. Virulence in S. pyogenes is closely linked to mobile genetic elements like phages and chromosomal islands (CI. S. pyogenes phage-like chromosomal islands (SpyCI confer a complex mutator phenotype on their host. SpyCI integrate into the 5’ end of DNA mismatch repair (MMR gene mutL, which also disrupts downstream operon genes lmrP, ruvA, and tag. During early logarithmic growth, SpyCI excise from the bacterial chromosome and replicate as episomes, relieving the mutator phenotype. As growth slows and the cells enter stationary phase, SpyCI reintegrate into the chromosome, again silencing the MMR operon. This system creates a unique growth-dependent and reversible mutator phenotype. Additional CI using the identical attachment site in mutL have been identified in related species, including Streptococcus dysgalactiae subsp. equisimilis, Streptococcus anginosus, Streptococcus intermedius, Streptococcus parauberis, and Streptococcus canis. These CI have small genomes, which range from 13-20 kB, conserved integrase and DNA replication genes, and no identifiable genes encoding capsid proteins. SpyCI may employ a helper phage for packaging and dissemination in a fashion similar to the Staphylococcus aureus pathogenicity islands (SaPI. Outside of the core replication and integration genes, SpyCI and related CI show considerable diversity with the presence of many indels that may contribute to the host cell phenotype or fitness. SpyCI are a subset of a larger family of streptococcal CI who potentially regulate the expression of other host genes. The biological and phylogenetic analysis of streptococcal chromosomal islands provides important clues as to how these chromosomal islands help S. pyogenes and other streptococcal species persist in human populations in spite of antibiotic therapy and immune challenges.

  19. Chromosomal islands of Streptococcus pyogenes and related streptococci: molecular switches for survival and virulence.

    Science.gov (United States)

    Nguyen, Scott V; McShan, William M

    2014-01-01

    Streptococcus pyogenes is a significant pathogen of humans, annually causing over 700,000,000 infections and 500,000 deaths. Virulence in S. pyogenes is closely linked to mobile genetic elements like phages and chromosomal islands (CI). S. pyogenes phage-like chromosomal islands (SpyCI) confer a complex mutator phenotype on their host. SpyCI integrate into the 5' end of DNA mismatch repair (MMR) gene mutL, which also disrupts downstream operon genes lmrP, ruvA, and tag. During early logarithmic growth, SpyCI excise from the bacterial chromosome and replicate as episomes, relieving the mutator phenotype. As growth slows and the cells enter stationary phase, SpyCI reintegrate into the chromosome, again silencing the MMR operon. This system creates a unique growth-dependent and reversible mutator phenotype. Additional CI using the identical attachment site in mutL have been identified in related species, including Streptococcus dysgalactiae subsp. equisimilis, Streptococcus anginosus, Streptococcus intermedius, Streptococcus parauberis, and Streptococcus canis. These CI have small genomes, which range from 13 to 20 kB, conserved integrase and DNA replication genes, and no identifiable genes encoding capsid proteins. SpyCI may employ a helper phage for packaging and dissemination in a fashion similar to the Staphylococcus aureus pathogenicity islands (SaPI). Outside of the core replication and integration genes, SpyCI and related CI show considerable diversity with the presence of many indels that may contribute to the host cell phenotype or fitness. SpyCI are a subset of a larger family of streptococcal CI who potentially regulate the expression of other host genes. The biological and phylogenetic analysis of streptococcal chromosomal islands provides important clues as to how these chromosomal islands help S. pyogenes and other streptococcal species persist in human populations in spite of antibiotic therapy and immune challenges. PMID:25161960

  20. Compositional discordance between prokaryotic plasmids and host chromosomes

    Directory of Open Access Journals (Sweden)

    van Kampen Antoine HC

    2006-02-01

    Full Text Available Abstract Background Most plasmids depend on the host replication machinery and possess partitioning genes. These properties confine plasmids to a limited range of hosts, yielding a close and presumably stable relationship between plasmid and host. Hence, it is anticipated that due to amelioration the dinucleotide composition of plasmids is similar to that of the genome of their hosts. However, plasmids are also thought to play a major role in horizontal gene transfer and thus are frequently exchanged between hosts, suggesting dinucleotide composition dissimilarity between plasmid and host genome. We compared the dinucleotide composition of a large collection of plasmids with that of their host genomes to shed more light on this enigma. Results The dinucleotide frequency, coined the genome signature, facilitates the identification of putative horizontally transferred DNA in complete genome sequences, since it was found to be typical for a certain genome, and similar between related species. By comparison of the genome signature of 230 plasmid sequences with that of the genome of each respective host, we found that in general the genome signature of plasmids is dissimilar from that of their host genome. Conclusion Our results show that the genome signature of plasmids does not resemble that of their host genome. This indicates either absence of amelioration or a less stable relationship between plasmids and their host. We propose an indiscriminate lifestyle for plasmids preserving the genome signature discordance between these episomes and host chromosomes.

  1. Chromosome-specific DNA Repeat Probes

    Energy Technology Data Exchange (ETDEWEB)

    Baumgartner, Adolf; Weier, Jingly Fung; Weier, Heinz-Ulrich G.

    2006-03-16

    In research as well as in clinical applications, fluorescence in situ hybridization (FISH) has gained increasing popularity as a highly sensitive technique to study cytogenetic changes. Today, hundreds of commercially available DNA probes serve the basic needs of the biomedical research community. Widespread applications, however, are often limited by the lack of appropriately labeled, specific nucleic acid probes. We describe two approaches for an expeditious preparation of chromosome-specific DNAs and the subsequent probe labeling with reporter molecules of choice. The described techniques allow the preparation of highly specific DNA repeat probes suitable for enumeration of chromosomes in interphase cell nuclei or tissue sections. In addition, there is no need for chromosome enrichment by flow cytometry and sorting or molecular cloning. Our PCR-based method uses either bacterial artificial chromosomes or human genomic DNA as templates with {alpha}-satellite-specific primers. Here we demonstrate the production of fluorochrome-labeled DNA repeat probes specific for human chromosomes 17 and 18 in just a few days without the need for highly specialized equipment and without the limitation to only a few fluorochrome labels.

  2. Chimpanzee chromosome 12 is homologous to human chromosome 2q

    Energy Technology Data Exchange (ETDEWEB)

    Sun, N. C.; Sun, C. R.Y.; Ho, T.

    1977-01-01

    Most of the 46 human chromosomes find their counterparts in the 48 chimpanzee chromosomes except for chromosome 2 which has been hypothesized to have been derived from a centric fusion of two chimpanzee acrocentric chromosomes. These two chromosomes correspond to the human chromosomes 2p and 2g. This conclusion is based primarily on chromosome banding techniques, and the somatic cell hybridization technique has also been used. (HLW)

  3. Evolution of Chromosome 6 of Solanum Species Revealed by Comparative Fluorescence in Situ Hybridization Mapping

    Science.gov (United States)

    Comparative genome mapping is an important tool in evolutionary research. Here we demonstrate a comparative fluorescent in situ hybridization (FISH) mapping strategy. A set of 13 bacterial artificial chromosome (BAC) clones derived from potato chromosome 6 was used for FISH mapping in seven differen...

  4. Physical Map and Organization of Chromosome 7 in the Rice Blast Fungus, Magnaporthe grisea

    OpenAIRE

    Zhu, Heng; Blackmon, Barbara P.; Sasinowski, Maciek; Dean, Ralph A.

    1999-01-01

    The rice blast fungus Magnaporthe grisea is a highly destructive plant pathogen and one of the most important for studying various aspects of host-plant interactions. It has been widely adopted as a model organism because it is ideally suited for genetic and biological studies. To facilitate map-based cloning, chromosome walking, and genome organization studies of M. grisea, a complete physical map of chromosome 7 was constructed using a large-insert (130 kb) bacterial artificial chromosome (...

  5. Artificial Economy

    Directory of Open Access Journals (Sweden)

    Alexandru JIVAN

    2011-08-01

    Full Text Available This paper proposes to eliminate, a routine in the economic thinking, claimed to be responsible for the negative essence of economic developments, from the point of view, of the ecological implications (employment in the planetary ecosystem. The methodological foundations start from the natural origins of the functionality of the human economic society according to the originary physiocrat liberalism, and from specific natural characteristics of the humankind. This paper begins with a comment-analysis of the difference between natural and artificial within the economy, and then explains some of the most serious diversions from the natural essence of economic liberalism. It shall be explained the original (heterodox interpretation of the Classical political economy (economics, by making calls to the Romanian economic thinking from aggravating past century. Highlighting the destructive impact of the economy - which, under the invoked doctrines, we call unnatural - allows an intuitive presentation of a logical extension of Marshall's market price, based on previous research. Besides the doctrinal arguments presented, the economic realities inventoried along the way (major deficiencies and effects, determined demonstrate the validity of the hypothesis of the unnatural character and therefore necessarily to be corrected, of the concept and of the mechanisms of the current economy.The results of this paper consist of original heterodox methodspresented, intuitive or developed that can be found conclusively within the key proposals for education and regulation.

  6. Plant sex chromosome evolution.

    Science.gov (United States)

    Charlesworth, Deborah

    2013-01-01

    It is now well established that plants have an important place in studies of sex chromosome evolution because of the repeated independent evolution of separate sexes and sex chromosomes. There has been considerable recent progress in studying plant sex chromosomes. In this review, I focus on how these recent studies have helped clarify or answer several important questions about sex chromosome evolution, and I shall also try to clarify some common misconceptions. I also outline future work that will be needed to make further progress, including testing some important ideas by genetic, molecular, and developmental approaches. Systems with different ages can clearly help show the time course of events during changes from an ancestral co-sexual state (hermaphroditism or monoecy), and I will also explain how different questions can be studied in lineages whose dioecy or sex chromosomes evolved at different times in the past. PMID:23125359

  7. Ectopic expression of AID in a non-B cell line triggers A:T and G:C point mutations in non-replicating episomal vectors.

    Directory of Open Access Journals (Sweden)

    Tihana Jovanic

    Full Text Available Somatic hypermutation (SHM of immunoglobulin genes is currently viewed as a two step process initiated by the deamination of deoxycytidine (C to deoxyuridine (U, catalysed by the activation induced deaminase (AID. Phase 1 mutations arise from DNA replication across the uracil residue or the abasic site, generated by the uracil-DNA glycosylase, yielding transitions or transversions at G:C pairs. Phase 2 mutations result from the recognition of the U:G mismatch by the Msh2/Msh6 complex (MutS Homologue, followed by the excision of the mismatched nucleotide and the repair, by the low fidelity DNA polymerase eta, of the gap generated by the exonuclease I. These mutations are mainly focused at A:T pairs. Whereas in activated B cells both G:C and A:T pairs are equally targeted, ectopic expression of AID was shown to trigger only G:C mutations on a stably integrated reporter gene. Here we show that when using non-replicative episomal vectors containing a GFP gene, inactivated by the introduction of stop codons at various positions, a high level of EGFP positive cells was obtained after transient expression in Jurkat cells constitutively expressing AID. We show that mutations at G:C and A:T pairs are produced. EGFP positive cells are obtained in the absence of vector replication demonstrating that the mutations are dependent only on the mismatch repair (MMR pathway. This implies that the generation of phase 1 mutations is not a prerequisite for the expression of phase 2 mutations.

  8. Vibrio chromosomes share common history

    OpenAIRE

    Gevers Dirk; Chang Sarah; Chang LeeAnn; Kirkup Benjamin C; Polz Martin F

    2010-01-01

    Abstract Background While most gamma proteobacteria have a single circular chromosome, Vibrionales have two circular chromosomes. Horizontal gene transfer is common among Vibrios, and in light of this genetic mobility, it is an open question to what extent the two chromosomes themselves share a common history since their formation. Results Single copy genes from each chromosome (142 genes from chromosome I and 42 genes from chromosome II) were identified from 19 sequenced Vibrionales genomes ...

  9. Sequential cloning of chromosomes

    Energy Technology Data Exchange (ETDEWEB)

    Lacks, S.A.

    1991-12-31

    A method for sequential cloning of chromosomal DNA and chromosomal DNA cloned by this method are disclosed. The method includes the selection of a target organism having a segment of chromosomal DNA to be sequentially cloned. A first DNA segment, having a first restriction enzyme site on either side. homologous to the chromosomal DNA to be sequentially cloned is isolated. A first vector product is formed by ligating the homologous segment into a suitably designed vector. The first vector product is circularly integrated into the target organism`s chromosomal DNA. The resulting integrated chromosomal DNA segment includes the homologous DNA segment at either end of the integrated vector segment. The integrated chromosomal DNA is cleaved with a second restriction enzyme and ligated to form a vector-containing plasmid, which is replicated in a host organism. The replicated plasmid is then cleaved with the first restriction enzyme. Next, a DNA segment containing the vector and a segment of DNA homologous to a distal portion of the previously isolated DNA segment is isolated. This segment is then ligated to form a plasmid which is replicated within a suitable host. This plasmid is then circularly integrated into the target chromosomal DNA. The chromosomal DNA containing the circularly integrated vector is treated with a third, retrorestriction enzyme. The cleaved DNA is ligated to give a plasmid that is used to transform a host permissive for replication of its vector. The sequential cloning process continues by repeated cycles of circular integration and excision. The excision is carried out alternately with the second and third enzymes.

  10. A new chromosome was born: comparative chromosome painting in Boechera.

    Science.gov (United States)

    Koch, Marcus A

    2015-09-01

    Comparative chromosome painting is a powerful tool to study the evolution of chromosomes and genomes. Analyzing karyotype evolution in cruciferous plants highlights the origin of aberrant chromosomes in apomictic Boechera and further establishes the cruciferous plants as important model system for our understanding of plant chromosome and genome evolution. PMID:26228436

  11. Evolutionary Design of Rule Changing Artificial Society Using Genetic Algorithms

    Science.gov (United States)

    Wu, Yun; Kanoh, Hitoshi

    Socioeconomic phenomena, cultural progress and political organization have recently been studied by creating artificial societies consisting of simulated agents. In this paper we propose a new method to design action rules of agents in artificial society that can realize given requests using genetic algorithms (GAs). In this paper we propose an efficient method for designing the action rules of agents that will constitute an artificial society that meets a specified demand by using a GAs. In the proposed method, each chromosome in the GA population represents a candidate set of action rules and the number of rule iterations. While a conventional method applies distinct rules in order of precedence, the present method applies a set of rules repeatedly for a certain period. The present method is aiming at both firm evolution of agent population and continuous action by that. Experimental results using the artificial society proved that the present method can generate artificial society which fills a demand in high probability.

  12. Chimpanzee chromosome 13 is homologous to human chromosome 2p

    Energy Technology Data Exchange (ETDEWEB)

    Sun, N. C.; Sun, C. R.Y.; Ho, T.

    1977-01-01

    Similarities between human and chimpanzee chromosomes are shown by chromosome banding techniques and somatic cell hybridization techniques. Cell hybrids were obtained from the chimpanzee lymphocyte LE-7, and the Chinese hamster mutant cell, Gal-2. Experiments showed that the ACPL, MDHs, and Gal-Act genes could be assigned to chimpanzee chromosome 13, and since these genes have been assigned to human chromosme 2p, it is suggested that chimpanzee chromosome 13 is homologous to human chromosome 2p. (HLW)

  13. Chromosome condensation and segmentation

    International Nuclear Information System (INIS)

    Some aspects of chromosome condensation in mammalians -humans especially- were studied by means of cytogenetic techniques of chromosome banding. Two further approaches were adopted: a study of normal condensation as early as prophase, and an analysis of chromosome segmentation induced by physical (temperature and γ-rays) or chemical agents (base analogues, antibiotics, ...) in order to show out the factors liable to affect condensation. Here 'segmentation' means an abnormal chromosome condensation appearing systematically and being reproducible. The study of normal condensation was made possible by the development of a technique based on cell synchronization by thymidine and giving prophasic and prometaphasic cells. Besides, the possibility of inducing R-banding segmentations on these cells by BrdU (5-bromodeoxyuridine) allowed a much finer analysis of karyotypes. Another technique was developed using 5-ACR (5-azacytidine), it allowed to induce a segmentation similar to the one obtained using BrdU and identify heterochromatic areas rich in G-C bases pairs

  14. Chromosomal abnormalities and autism

    Directory of Open Access Journals (Sweden)

    Farida El-Baz

    2016-01-01

    Conclusion: Chromosomal abnormalities were not detected in the studied autistic children, and so the relation between the genetics and autism still needs further work up with different study methods and techniques.

  15. Chromosome numbers in Bromeliaceae

    OpenAIRE

    2000-01-01

    The present study reports chromosome numbers of 17 species of Bromeliaceae, belonging to the genera Encholirium, Bromelia, Orthophytum, Hohenbergia, Billbergia, Neoglaziovia, Aechmea, Cryptanthus and Ananas. Most species present 2n = 50, however, Bromelia laciniosa, Orthophytum burle-marxii and O. maracasense are polyploids with 2n = 150, 2n = 100 and 2n = 150, respectively, while for Cryptanthus bahianus, 2n = 34 + 1-4B. B chromosomes were observed in Bromelia plumieri and Hohenbergia aff. u...

  16. Micromechanics of human mitotic chromosomes

    International Nuclear Information System (INIS)

    Eukaryote cells dramatically reorganize their long chromosomal DNAs to facilitate their physical segregation during mitosis. The internal organization of folded mitotic chromosomes remains a basic mystery of cell biology; its understanding would likely shed light on how chromosomes are separated from one another as well as into chromosome structure between cell divisions. We report biophysical experiments on single mitotic chromosomes from human cells, where we combine micromanipulation, nano-Newton-scale force measurement and biochemical treatments to study chromosome connectivity and topology. Results are in accord with previous experiments on amphibian chromosomes and support the 'chromatin network' model of mitotic chromosome structure. Prospects for studies of chromosome-organizing proteins using siRNA expression knockdowns, as well as for differential studies of chromosomes with and without mutations associated with genetic diseases, are also discussed

  17. Vibrio chromosomes share common history

    Directory of Open Access Journals (Sweden)

    Gevers Dirk

    2010-05-01

    Full Text Available Abstract Background While most gamma proteobacteria have a single circular chromosome, Vibrionales have two circular chromosomes. Horizontal gene transfer is common among Vibrios, and in light of this genetic mobility, it is an open question to what extent the two chromosomes themselves share a common history since their formation. Results Single copy genes from each chromosome (142 genes from chromosome I and 42 genes from chromosome II were identified from 19 sequenced Vibrionales genomes and their phylogenetic comparison suggests consistent phylogenies for each chromosome. Additionally, study of the gene organization and phylogeny of the respective origins of replication confirmed the shared history. Conclusions Thus, while elements within the chromosomes may have experienced significant genetic mobility, the backbones share a common history. This allows conclusions based on multilocus sequence analysis (MLSA for one chromosome to be applied equally to both chromosomes.

  18. Artificial Inteligence and Law

    OpenAIRE

    Fuková, Kateřina

    2012-01-01

    Submitted diploma work Artificial Intelligence and Law deals with the rule of law and its position in the process of new advanced technologies in computer cybernetics and further scientific disciplines related with artificial intelligence and its creation. The first part of the work introduces the history of the first imagines about artificial intelligence and concerns with its birth. This chapter presents main theoretical knowledge and hypotheses defined artificial intelligence and progre...

  19. Artificial Skin in Robotics

    OpenAIRE

    Strohmayr, Michael

    2012-01-01

    Artificial Skin - A comprehensive interface for system-environment interaction - This thesis investigates a multifunctional artificial skin as touch sensitive whole-body cover for robotic systems. To further the evolution from tactile sensors to an implementable artificial skin a general concept for the design process is derived. A standard test procedure is proposed to evaluate the performance. The artificial skin contributes to a safe and intuitive physical human robot interaction.

  20. Development of a novel HAC-based "gain of signal" quantitative assay for measuring chromosome instability (CIN) in cancer cells

    OpenAIRE

    Kim, Jung Hyun; Lee, Hee Sheung; Lee, Nicholas C.O.; Goncharov, Nikolay V.; Kumeiko, Vadim; Masumoto, Hiroshi; Earnshaw, William C.; Kouprina, Natalay; Larionov, Vladimir

    2016-01-01

    Accumulating data indicates that chromosome instability (CIN) common to cancer cells can be used as a target for cancer therapy. At present the rate of chromosome mis-segregation is quantified by laborious techniques such as coupling clonal cell analysis with karyotyping or fluorescence in situ hybridization (FISH). Recently, a novel assay was developed based on the loss of a non-essential human artificial chromosome (HAC) carrying a constitutively expressed EGFP transgene ("loss of signal" a...

  1. Chromosome duplication in Lolium multiflorum Lam.

    Directory of Open Access Journals (Sweden)

    Roselaine Cristina Pereira

    2014-11-01

    Full Text Available Artificial chromosome duplication of diploid genotypes of Lolium multiflorum (2n=2x=14 is worthy to breeding, and aims to increase the expression of traits with agronomic interest. The purpose of this study was to obtain polyploid plants of L. multiflorum from local diploid populations in order to exploit adaptation and future verification of the effects of polyploidy in agronomic traits. Seedlings were immersed in different colchicine solutions for an exposure time of 3h and 24h. Ploidy determination was made by the DNA content and certified by chromosomes counts. The plants confirmed as tetraploids were placed in a greenhouse, and, at flowering, pollen viability was evaluated, and seeds were harvested to assess the stability of the progenies. The percentage of polyploids obtained was 20%. Pollen viability of the tetraploids generated ranged from 58% to 69%. The tetraploid plants obtained in the experiment generated 164 progenies, of which 109 presented DNA content compatible with the tetraploid level, showing stability of chromosome duplication in the filial generation.

  2. Sex determination by chromosome manipulation in fish

    International Nuclear Information System (INIS)

    Since it is impossible to artificially remove only sex chromosomes in sperm, gamma- or UV-irradiation has been used in destroying all chromosomes without loss of abilities of sperm movement and egg activation. It has been shown that a dose of gamma rays required for this purpose is 105 rad in any species of fish. For UV-irradiation, a 15 W lamp is used and irradiation for 60 to 120 seconds is required. With such an irradiation technique, gynogenetic haploid embryogenesis is induced. In developing normal diploid embryos of eggs inseminated with irradiated sperm (gynogenetic diploid embryogenesis with XX type), it is furthermore necessary to use physical procedures, such as low or high temperature and hydrostatic pressure. Irradiated sperm of different species of fish has also been used in inducing gynogenesis. As the most desirable technique, it is proposed to physiologically convert the sex of gynogenetic diploid embryos into males and to use sperm from those physiological males with XX chromosomes. Theoretical possibility of developing androgenetic haploid embryogenesis has been suggested. (Namekawa, K.)

  3. Chromosome numbers in Bromeliaceae

    Directory of Open Access Journals (Sweden)

    Cotias-de-Oliveira Ana Lúcia Pires

    2000-01-01

    Full Text Available The present study reports chromosome numbers of 17 species of Bromeliaceae, belonging to the genera Encholirium, Bromelia, Orthophytum, Hohenbergia, Billbergia, Neoglaziovia, Aechmea, Cryptanthus and Ananas. Most species present 2n = 50, however, Bromelia laciniosa, Orthophytum burle-marxii and O. maracasense are polyploids with 2n = 150, 2n = 100 and 2n = 150, respectively, while for Cryptanthus bahianus, 2n = 34 + 1-4B. B chromosomes were observed in Bromelia plumieri and Hohenbergia aff. utriculosa. The chromosome number of all species was determined for the first time, except for Billbergia chlorosticta and Cryptanthus bahianus. Our data supports the hypothesis of a basic number of x = 25 for the Bromeliaceae family and decreasing aneuploidy in the genus Cryptanthus.

  4. Those amazing dinoflagellate chromosomes

    Institute of Scientific and Technical Information of China (English)

    PETER J RIZZO

    2003-01-01

    Dinoflagellates are a very large and diverse group of eukaryotic algae that play a major role in aquatic food webs of both fresh water and marine habitats. Moreover, the toxic members of this group pose a health threat in the form of red tides. Finally, dinoflagellates are of great evolutionary importance,because of their taxonomic position, and their unusual chromosome structure and composition. While the cytoplasm of dinoflagellates is typically eukaryotic, the nucleus is unique when compared to the nucleus of other eukaryotes. More specifically, while the chromosomes of all other eukaryotes contain histones,dinoflagellate chromosomes lack histones completely. There are no known exceptions to this observation: all dinoflagellates lack histones, and all other eukaryotes contain histones. Nevertheless, dinoflagellates remain a relatively unstudied group of eukaryotes.

  5. Chromosomal rearrangements in cattle and pigs revealed by chromosome microdissection and chromosome painting

    Directory of Open Access Journals (Sweden)

    Yerle Martine

    2003-11-01

    Full Text Available Abstract A pericentric inversion of chromosome 4 in a boar, as well as a case of (2q-;5p+ translocation mosaicism in a bull were analysed by chromosome painting using probes generated by conventional microdissection. For the porcine inversion, probes specific for p arms and q arms were produced and hybridised simultaneously on metaphases of a heterozygote carrier. In the case of the bovine translocation, two whole chromosome probes (chromosome 5, and derived chromosome 5 were elaborated and hybridised independently on chromosomal preparations of the bull who was a carrier of the mosaic translocation. The impossibility of differentiating chromosomes 2 and der(2 from other chromosomes of the metaphases did not allow the production of painting probes for these chromosomes. For all experiments, the quality of painting was comparable to that usually observed with probes obtained from flow-sorted chromosomes. The results obtained allowed confirmation of the interpretations proposed with G-banding karyotype analyses. In the bovine case, however, the reciprocity of the translocation could not be proven. The results presented in this paper show the usefulness of the microdissection technique for characterising chromosomal rearrangements in species for which commercial probes are not available. They also confirmed that the main limiting factor of the technique is the quality of the chromosomal preparations, which does not allow the identification of target chromosomes or chromosome fragments in all cases.

  6. Speeding up chromosome evolution in Phaseolus: multiple rearrangements associated with a one-step descending dysploidy.

    Science.gov (United States)

    Fonsêca, Artur; Ferraz, Maria Eduarda; Pedrosa-Harand, Andrea

    2016-06-01

    The genus Phaseolus L. has been subject of extensive cytogenetic studies due to its global economic importance. It is considered karyotypically stable, with most of its ca. 75 species having 2n = 22 chromosomes, and only three species (Phaseolus leptostachyus, Phaseolus macvaughii, and Phaseolus micranthus), which form the Leptostachyus clade, having 2n = 20. To test whether a simple chromosomal fusion was the cause of this descending dysploidy, mitotic chromosomes of P. leptostachyus (2n = 20) were comparatively mapped by fluorescent in situ hybridization (FISH) using bacterial artificial chromosomes (BACs) and ribosomal DNA (rDNA) probes. Our results corroborated the conservation of the 5S and 45S rDNA sites on ancestral chromosomes 10 and 6, respectively. The reduction from x = 11 to x = 10 was the result of the insertion of chromosome 10 into the centromeric region of chromosome 11, supporting a nested chromosome fusion (NCF) as the main cause of this dysploidy. Additionally, the terminal region of the long arm of chromosome 6 was translocated to this larger chromosome. Surprisingly, the NCF was accompanied by several additional translocations and inversions previously unknown for the genus, suggesting that the dysploidy may have been associated to a burst of genome reorganization in this otherwise stable, diploid plant genus. PMID:26490170

  7. Identification of Chromosomes from Multiple Rice Genomes Using a Universal Molecular Cytogenetic Marker System

    Institute of Scientific and Technical Information of China (English)

    Xiaomin Tang; Weidong Bao; Wenli Zhang; Zhukuan Cheng

    2007-01-01

    To develop reliable techniques for chromosome identification is critical for cytogenetic research, especially for genomes with a large number and smaller-sized chromosomes. An efficient approach using bacterial artificial chromosome (BAG) clones as molecular cytological markers has been developed for many organisms. Herein, we present a set of chromosomal arm-specific molecular cytological markers derived from the gene-enriched regions of the sequenced rice genome. All these markers are able to generate very strong signals on the pachytene chromosomes of Oryza satlva L. (AA genome) when used as fluorescence in situ hybridization (FISH) probes. We further probed those markers to the pachytene chromosomes of O. punctata (BB genome) and O. officinalis (CC genome) and also got very strong signals on the relevant pachytene chromosomes. The signal position of each marker on the related chromosomes from the three different rice genomes was pretty much stable, which enabled us to identify different chromosomes among various rice genomes. We also constructed the karyotype for both O. punctata and O. officinalis with the BB and CC genomes, respectively, by analysis of 10 pachytene cells anchored by these chromosomal arm-specific markers.

  8. Construction of BAC Libraries from Flow-Sorted Chromosomes.

    Science.gov (United States)

    Šafář, Jan; Šimková, Hana; Doležel, Jaroslav

    2016-01-01

    Cloned DNA libraries in bacterial artificial chromosome (BAC) are the most widely used form of large-insert DNA libraries. BAC libraries are typically represented by ordered clones derived from genomic DNA of a particular organism. In the case of large eukaryotic genomes, whole-genome libraries consist of a hundred thousand to a million clones, which make their handling and screening a daunting task. The labor and cost of working with whole-genome libraries can be greatly reduced by constructing a library derived from a smaller part of the genome. Here we describe construction of BAC libraries from mitotic chromosomes purified by flow cytometric sorting. Chromosome-specific BAC libraries facilitate positional gene cloning, physical mapping, and sequencing in complex plant genomes. PMID:27511172

  9. Linked genetic variants on chromosome 10 control ear morphology and body mass among dog breeds

    OpenAIRE

    Webster, Matthew T.; Kamgari, Nona; Perloski, Michele; Höppner, Marc P.; Axelsson, Erik; Hedhammar, Ake; Pielberg, Gerli; Lindblad-Toh, Kerstin

    2015-01-01

    Background The domestic dog is a rich resource for mapping the genetic components of phenotypic variation due to its unique population history involving strong artificial selection. Genome-wide association studies have revealed a number of chromosomal regions where genetic variation associates with morphological characters that typify dog breeds. A region on chromosome 10 is among those with the highest levels of genetic differentiation between dog breeds and is associated with body mass and ...

  10. Quo Vadis, Artificial Intelligence?

    OpenAIRE

    Alfons Schuster; Daniel Berrar; Naoyuki Sato

    2010-01-01

    Since its conception in the mid 1950s, artificial intelligence with its great ambition to understand and emulate intelligence in natural and artificial environments alike is now a truly multidisciplinary field that reaches out and is inspired by a great diversity of other fields. Rapid advances in research and technology in various fields have created environments into which artificial intelligence could embed itself naturally and comfortably. Neuroscience with its desire to understand nervou...

  11. Anticipatory Artificial Autopoiesis

    OpenAIRE

    DuBois, Daniel; Holmberg, Stig C.

    2010-01-01

    In examining relationships between autopoiesis and anticipation in artificial life (Alife) systems it is demonstrated that anticipation may increase efficiency and viability in artificial autopoietic living systems. This paper, firstly, gives a review of the Varela et al [1974] automata algorithm of an autopoietic living cell. Some problems in this algorithm must be corrected. Secondly, a new and original anticipatory artificial autopoiesis algorithm for automata is presented. ...

  12. Artificial cognition architectures

    CERN Document Server

    Crowder, James A; Friess, Shelli A

    2013-01-01

    The goal of this book is to establish the foundation, principles, theory, and concepts that are the backbone of real, autonomous Artificial Intelligence. Presented here are some basic human intelligence concepts framed for Artificial Intelligence systems. These include concepts like Metacognition and Metamemory, along with architectural constructs for Artificial Intelligence versions of human brain functions like the prefrontal cortex. Also presented are possible hardware and software architectures that lend themselves to learning, reasoning, and self-evolution

  13. Doped Colloidal Artificial Ice

    OpenAIRE

    Libal, A.; Reichhardt, C. J. Olson; Reichhardt, C.

    2015-01-01

    We examine square and kagome artificial spin ice for colloids confined in arrays of double-well traps. Unlike magnetic artificial spin ices, colloidal and vortex artificial spin ice realizations allow creation of doping sites through double occupation of individual traps. We find that doping square and kagome ice geometries produces opposite effects. For square ice, doping creates local excitations in the ground state configuration that produce a local melting effect as the temperature is rai...

  14. Inteligencia artificial en vehiculo

    OpenAIRE

    Amador Díaz, Pedro

    2012-01-01

    Desarrollo de un robot seguidor de líneas, en el que se implementan diversas soluciones de las áreas de sistemas embebidos e inteligencia artificial. Desenvolupament d'un robot seguidor de línies, en el qual s'implementen diverses solucions de les àrees de sistemes encastats i intel·ligència artificial. Follower robot development of lines, in which various solutions are implemented in the areas of artificial intelligence embedded systems.

  15. Ring chromosome 13

    DEFF Research Database (Denmark)

    Brandt, C A; Hertz, Jens Michael; Petersen, M B; Vogel, F; Noer, H; Mikkelsen, M

    1992-01-01

    A stillborn male child with anencephaly and multiple malformations was found to have the karyotype 46,XY,r(13) (p11q21.1). The breakpoint at 13q21.1, determined by high resolution banding, is the most proximal breakpoint ever reported in patients with ring chromosome 13. In situ hybridisation with...

  16. The Y Chromosome

    Science.gov (United States)

    Offner, Susan

    2010-01-01

    The Y chromosome is of great interest to students and can be used to teach about many important biological concepts in addition to sex determination. This paper discusses mutation, recombination, mammalian sex determination, sex determination in general, and the evolution of sex determination in mammals. It includes a student activity that…

  17. Chromosomes, cancer and radiosensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Samouhos, E.

    1983-08-01

    Some specific chromosomal abnormalities are associated with certain cancers. The earliest description of such a specific association is the one of the Philadelphia chromosome and myelogenous leukemia (1960). Other congenital karyotype abnormalities are associated with specific cancers. Examples of these are Down's syndrome with leukemia and Klinefelter's syndrome with male breast cancer. Genetic diseases of increased chromosome breakage, or of defective chromosome repair, are associated with greatly increased cancer incidence. Three such diseases have been recognized: 1) Fanconi's anemia, associated with leukemias and lymphomas, 2) Bloom's syndrome, associated with acute leukemias and lymphosarcoma, and 3) ataxia telangiectasia, associated with Hodgkin's disease, leukemia, and lymphosarcomas. Ten percent of individuals with ataxia telangiectasia will develop one of these neoplasms. Individuals with certain of these syndromes display an unusually high radiosensitivity. Radiation therapy for cancers has been fatal in patients who received as low as 3000 rad. This remarkable radiosensitivity has been quantitated in cell cultures from such cases. Evidence suggests that the apparent sensitivity may reflect subnormal ability to repair radiation damage. The rapid proliferation of information in this field stems from the interdigitation of many disciplines and specialties, including cytogenetics, cell biology, molecular biology, epidemiology, radiobiology, and several others. This paper is intended for clinicians; it presents a structured analytic scheme for correlating and classifying this multidisciplinary information as it becomes available.

  18. Chromosomes, cancer and radiosensitivity

    International Nuclear Information System (INIS)

    Some specific chromosomal abnormalities are associated with certain cancers. The earliest description of such a specific association is the one of the Philadelphia chromosome and myelogenous leukemia (1960). Other congenital karyotype abnormalities are associated with specific cancers. Examples of these are Down's syndrome with leukemia and Klinefelter's syndrome with male breast cancer. Genetic diseases of increased chromosome breakage, or of defective chromosome repair, are associated with greatly increased cancer incidence. Three such diseases have been recognized: 1) Fanconi's anemia, associated with leukemias and lymphomas, 2) Bloom's syndrome, associated with acute leukemias and lymphosarcoma, and 3) ataxia telangiectasia, associated with Hodgkin's disease, leukemia, and lymphosarcomas. Ten percent of individuals with ataxia telangiectasia will develop one of these neoplasms. Individuals with certain of these syndromes display an unusually high radiosensitivity. Radiation therapy for cancers has been fatal in patients who received as low as 3000 rad. This remarkable radiosensitivity has been quantitated in cell cultures from such cases. Evidence suggests that the apparent sensitivity may reflect subnormal ability to repair radiation damage. The rapid proliferation of information in this field stems from the interdigitation of many disciplines and specialties, including cytogenetics, cell biology, molecular biology, epidemiology, radiobiology, and several others. This paper is intended for clinicians; it presents a structured analytic scheme for correlating and classifying this multidisciplinary information as it becomes available

  19. Chromosome Morphology in Kniphofia.

    Directory of Open Access Journals (Sweden)

    J. M. J de Wet

    1960-12-01

    Full Text Available A number of species and varieties of the genus  Kniphofia (Liliaceae were studied cytologically. The somatic chromosome number is  2n = 12 in all the species. This is also true in  Notosceptrum natalense Baker.

  20. Genetic and physical mapping of the bovine X chromosome

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, Chen Chen; Taylor, J.F.; Sanders, J. O. [Texas A& M Univ., College Station, TX (United States)] [and others

    1996-03-01

    Three hundred eighty reciprocal backcross and F{sub 2} full sib progeny from 33 families produced by embryo transfer from 77 Angus (Bos taurus), Brahman (Bos indicus), and F{sub 1} parents and grandparents were used to construct genetic maps of the bovine X and Y chromosomes. All individuals were scored for 15 microsatellite loci, with an average of 608 informative meioses per locus. The length of the bovine X chromosome genetic map was 118.7 cM (female only) and of the pseudoautosomal region was 13.0 cM (male only). The 15-marker framework map in Kosambi centimorgans is (BM6017-6.1-TGLA89-35.8-TEXAN13-3.4-TGLA128-1.3-BM2713-21.1-BM4604-2.4-BR215-12.9-TGLA68-10.0-BM4321-1.0-HEL14-4.9-TGLA15-2.3-INRA120-12.5-TGLA325-1.6-MAF45-3.2-INRA30), with an average interval of 7.91 cM. Clones containing pseudoautosomal or sex-linked microsatellites were isolated from a bovine bacterial artificial chromosome library and were physically mapped to bovine metaphase chromosomes by fluorescence in situ hybridization to orient the X and Y chromosome maps. BAC57, containing the pseudoautosomal microsatellite INRA30, mapped to the distal end of the long arm of the X chromosome at q42-ter and to the short arm of the Y chromosome at p13-ter. This confirms the published assignment of this region to Yp12-ter, but challenges the published assignment of Xp14-ter and thus reorients the X chromosome physical map. BAC204, containing the X-linked microsatellite BM4604, mapped to the middle of the long arm of the X chromosome at q26-q31. The position of the physically mapped to the middle of the long arm of the X chromosome at q26-q31. The position of the physically mapped markers indicates either a lack of microsatellite markers for a large (30 to 50 cM) region of the short arm of the X chromosome or heterogeneity of recombination along the X chromosome. 46 refs., 2 figs., 3 tabs.

  1. Telomere dysfunction and chromosome instability

    Energy Technology Data Exchange (ETDEWEB)

    Murnane, John P., E-mail: jmurnane@radonc.ucsf.edu [Department of Radiation Oncology, University of California San Francisco, 2340 Sutter Street, San Francisco, CA 94143-1331 (United States)

    2012-02-01

    The ends of chromosomes are composed of a short repeat sequence and associated proteins that together form a cap, called a telomere, that keeps the ends from appearing as double-strand breaks (DSBs) and prevents chromosome fusion. The loss of telomeric repeat sequences or deficiencies in telomeric proteins can result in chromosome fusion and lead to chromosome instability. The similarity between chromosome rearrangements resulting from telomere loss and those found in cancer cells implicates telomere loss as an important mechanism for the chromosome instability contributing to human cancer. Telomere loss in cancer cells can occur through gradual shortening due to insufficient telomerase, the protein that maintains telomeres. However, cancer cells often have a high rate of spontaneous telomere loss despite the expression of telomerase, which has been proposed to result from a combination of oncogene-mediated replication stress and a deficiency in DSB repair in telomeric regions. Chromosome fusion in mammalian cells primarily involves nonhomologous end joining (NHEJ), which is the major form of DSB repair. Chromosome fusion initiates chromosome instability involving breakage-fusion-bridge (B/F/B) cycles, in which dicentric chromosomes form bridges and break as the cell attempts to divide, repeating the process in subsequent cell cycles. Fusion between sister chromatids results in large inverted repeats on the end of the chromosome, which amplify further following additional B/F/B cycles. B/F/B cycles continue until the chromosome acquires a new telomere, most often by translocation of the end of another chromosome. The instability is not confined to a chromosome that loses its telomere, because the instability is transferred to the chromosome donating a translocation. Moreover, the amplified regions are unstable and form extrachromosomal DNA that can reintegrate at new locations. Knowledge concerning the factors promoting telomere loss and its consequences is

  2. Organization of the bacterial chromosome.

    OpenAIRE

    Krawiec, S.; Riley, M

    1990-01-01

    Recent progress in studies on the bacterial chromosome is summarized. Although the greatest amount of information comes from studies on Escherichia coli, reports on studies of many other bacteria are also included. A compilation of the sizes of chromosomal DNAs as determined by pulsed-field electrophoresis is given, as well as a discussion of factors that affect gene dosage, including redundancy of chromosomes on the one hand and inactivation of chromosomes on the other hand. The distinction ...

  3. The B chromosomes of the African cichlid fish Haplochromis obliquidens harbour 18S rRNA gene copies

    Directory of Open Access Journals (Sweden)

    Martins Cesar

    2010-01-01

    Full Text Available Abstract Background Diverse plant and animal species have B chromosomes, also known as accessory, extra or supernumerary chromosomes. Despite being widely distributed among different taxa, the genomic nature and genetic behavior of B chromosomes are still poorly understood. Results In this study we describe the occurrence of B chromosomes in the African cichlid fish Haplochromis obliquidens. One or two large B chromosome(s occurring in 39.6% of the analyzed individuals (both male and female were identified. To better characterize the karyotype and assess the nature of the B chromosomes, fluorescence in situ hybridization (FISH was performed using probes for telomeric DNA repeats, 18S and 5S rRNA genes, SATA centromeric satellites, and bacterial artificial chromosomes (BACs enriched in repeated DNA sequences. The B chromosomes are enriched in repeated DNAs, especially non-active 18S rRNA gene-like sequences. Conclusion Our results suggest that the B chromosome could have originated from rDNA bearing subtelo/acrocentric A chromosomes through formation of an isochromosome, or by accumulation of repeated DNAs and rRNA gene-like sequences in a small proto-B chromosome derived from the A complement.

  4. Artificial life and life artificialization in Tron

    Directory of Open Access Journals (Sweden)

    Carolina Dantas Figueiredo

    2012-12-01

    Full Text Available Cinema constantly shows the struggle between the men and artificial intelligences. Fiction, and more specifically fiction films, lends itself to explore possibilities asking “what if?”. “What if”, in this case, is related to the eventual rebellion of artificial intelligences, theme explored in the movies Tron (1982 and Tron Legacy (2010 trat portray the conflict between programs and users. The present paper examines these films, observing particularly the possibility programs empowering. Finally, is briefly mentioned the concept of cyborg as a possibility of response to human concerns.

  5. Artificial insemination in poultry

    Science.gov (United States)

    Artificial insemination is a relative simple yet powerful tool geneticists can employ for the propagation of economically important traits in livestock and poultry. In this chapter, we address the fundamental methods of the artificial insemination of poultry, including semen collection, semen evalu...

  6. Chromosome 19 International Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Pericak-Vance, M.A. (Duke Univ., Durham, NC (United States). Medical Center); Ropers, H.H. (Univ. Hospital Nijmegen, (The Netherlands). Dept. of Human Genetics); Carrano, A.J. (Lawrence Livermore National Lab., CA (United States))

    1993-01-04

    The Second International Workshop on Human Chromosome 19 was hosted on January 25 and 26, 1992, by the Department of Human Genetics, University Hospital Nijmegen, The Netherlands, at the 'Meerdal Conference Center'. The workshop was supported by a grant from the European Community obtained through HUGO, the Dutch Research Organization (NWO) and the Muscular Dystrophy Association (MDA). Travel support for American participants was provided by the Department of Energy. The goals of this workshop were to produce genetic, physical and integrated maps of chromosome 19, to identify inconsistencies and gaps, and to discuss and exchange resources and techniques available for the completion of these maps. The second day of the meeting was largely devoted to region or disease specific efforts. In particular, the meeting served as a platform for assessing and discussing the recent progress made into the molecular elucidation of myotonic dystrophy.

  7. Genetic and physical mapping of the bovine X chromosome.

    Science.gov (United States)

    Yeh, C C; Taylor, J F; Gallagher, D S; Sanders, J O; Turner, J W; Davis, S K

    1996-03-01

    Three hundred eighty reciprocal backcross and F(2) full sib progeny from 33 families produced by embryo transfer from 77 Angus (Bos taurus), Brahman (Bos indicus), and F1 parents and grandparents were used to construct genetic maps of the bovine X and Y chromosomes. Ml individuals were scored for 15 microsatellite loci, with an average of 608 informative meioses per locus. The length of the bovine X chromosome genetic map was 118.7 cM (female only) and of the pseudoautosomal region was 13.0 cM (male only). The 15-marker framework map in Kosambi centimorgans is [BM6017-6.1 -TGLA89-35.8-TEXAN13-3.4-TGLA128-1.3 -BM2713 -21.1 -BM4604-2.4-BR215 - 12.9-TGLA68-10.0-BM4321 - 1.0-HEL14-4.9-TGLA15-2.3-INRA12O- 12.5-TGLA325- 1.6-MAF45-3.2-INRA3O], with an average interval of 7.91 cM. Clones containing pseudoautosomal or sex-linked microsatellites were isolated from a bovine bacterial artificial chromosome library and were physically mapped to bovine metaphase chromosomes by fluorescence in situ hybridization to orient the X and Y chromosome maps. BAC57, containing the pseudoautosomal microsatellite INRA3O, mapped to the distal end of the long arm of the X chromosome at q42-ter and to the short arm of the Y chromosome at p13-ter. This confirms the published assignment of this region to Ypl2-ter, but challenges the published assignment of Xpl4-ter and thus reorients the X chromosome physical map. BAC2O4, containing the X-linked microsatellite BM4604, mapped to the middle of the long arm of the X chromosome at q26-q31. The position of the physically mapped markers indicates either a lack of microsatellite markers for a large (30 to 50 cM) region of the short arm of the X chromosome or heterogeneity of recombination along the X chromosome. PMID:8833151

  8. Chromosome numbers and meiotic analysis in the pre-breeding of Brachiaria decumbens (Poaceae)

    Indian Academy of Sciences (India)

    Gléia Cristina Laverde Ricci; Alice Maria De Souza-Kaneshima; Mariana Ferrari Felismino; Andrea Beatriz Mendes-Bonato; Maria Suely Pagliarini; Cacilda Borges Do Valle

    2011-08-01

    A total of 44 accessions of Brachiaria decumbens were analysed for chromosome count and meiotic behaviour in order to identify potential progenitors for crosses. Among them, 15 accessions presented $2n = 18$; 27 accessions, $2n = 36$; and 2 accessions, $2n = 45$ chromosomes. Among the diploid accessions, the rate of meiotic abnormalities was low, ranging from 0.82% to 7.93%. In the 27 tetraploid accessions, the rate of meiotic abnormalities ranged from 18.41% to 65.83%. The most common meiotic abnormalities were related to irregular chromosome segregation, but chromosome stickiness and abnormal cytokinesis were observed in low frequency. All abnormalities can compromise pollen viability by generating unbalanced gametes. Based on the chromosome number and meiotic stability, the present study indicates the apomictic tetraploid accessions that can act as male genitor to produce interspecific hybrids with B. ruziziensis or intraspecific hybrids with recently artificially tetraploidized accessions.

  9. Chromosome Evolution in African Cichlid Fish: Contributions from the Physical Mapping of Repeated DNAs

    Science.gov (United States)

    Ferreira, I.A.; Poletto, A.B.; Kocher, T.D.; Mota-Velasco, J.C.; Penman, D.J.; Martins, C.

    2010-01-01

    Cichlid fishes have been the subject of increasing scientific interest because of their rapid adaptive radiation that has led to extensive ecological diversity and because of their enormous importance to tropical and subtropical aquaculture. To further understanding of chromosome evolution among cichlid species, we have comparatively mapped the SATA satellite DNA, the transposable element ROn-1, and repeated sequences in the bacterial artificial chromosome clone BAC-C4E09 on the chromosomes of a range of African species of Cichlidae, using fluorescence in situ hybridization. The SATA satellite DNA was mapped in almost all the centromeres of all tilapiine and haplochromine species studied. The maintenance and centromeric distribution of the SATA satellite DNA in African cichlids suggest that this sequence plays an important role in the organization and function of the centromere in these species. Furthermore, analysis of SATA element distribution clarifies that chromosome fusions occurred independently in Oreochromis and Tilapia genera, and led to the reduced chromosome number detected in O. karongae and T. mariae. The comparative chromosome mapping of the ROn-1 SINE-like element and BAC-C4E09 shows that the repeated sequences have been maintained among tilapiine, haplochromine and hemichromine fishes and has demonstrated the homology of the largest chromosomes among these groups. Furthermore, the mapping of ROn-1 suggested that different chromosomal rearrangements could have occurred in the origin of the largest chromosome pairs of tilapiines and non-tilapiines. PMID:20606399

  10. A FISH-based chromosome map for the European corn borer yields insights into ancient chromosomal fusions in the silkworm.

    Science.gov (United States)

    Yasukochi, Y; Ohno, M; Shibata, F; Jouraku, A; Nakano, R; Ishikawa, Y; Sahara, K

    2016-01-01

    A significant feature of the genomes of Lepidoptera, butterflies and moths, is the high conservation of chromosome organization. Recent remarkable progress in genome sequencing of Lepidoptera has revealed that syntenic gene order is extensively conserved across phylogenetically distant species. The ancestral karyotype of Lepidoptera is thought to be n=31; however, that of the most well-studied moth, Bombyx mori, is n=28, and diverse studies suggest that three chromosomal fusion events occurred in this lineage. To identify the boundaries between predicted ancient fusions involving B. mori chromosomes 11, 23 and 24, we constructed fluorescence in situ hybridization (FISH)-based chromosome maps of the European corn borer, Ostrinia nubilalis (n=31). We first determined a 511 Mb genomic sequence of the Asian corn borer, O. furnacalis, a congener of O. nubilalis, and isolated bacterial artificial chromosomes and fosmid clones that were expected to localize in candidate regions for the boundaries using these sequences. Combined with FISH and genetic analysis, we narrowed down the candidate regions to 40 kb-1.5 Mb, in strong agreement with a previous estimate based on the genome of a butterfly, Melitaea cinxia. The significant difference in the lengths of the candidate regions where no functional genes were observed may reflect the evolutionary time after fusion events. PMID:26264548

  11. Artificial ecosystem selection.

    Science.gov (United States)

    Swenson, W; Wilson, D S; Elias, R

    2000-08-01

    Artificial selection has been practiced for centuries to shape the properties of individual organisms, providing Darwin with a powerful argument for his theory of natural selection. We show that the properties of whole ecosystems can also be shaped by artificial selection procedures. Ecosystems initiated in the laboratory vary phenotypically and a proportion of the variation is heritable, despite the fact that the ecosystems initially are composed of thousands of species and millions of individuals. Artificial ecosystem selection can be used for practical purposes, illustrates an important role for complex interactions in evolution, and challenges a widespread belief that selection is most effective at lower levels of the biological hierarchy. PMID:10890915

  12. Developing Creativity: Artificial Barriers in Artificial Intelligence

    OpenAIRE

    Jennings, Kyle E.

    2010-01-01

    The greatest rhetorical challenge to developers of creative artificial intelligence systems is convincingly arguing that their software is more than just an extension of their own creativity. This paper suggests that “creative autonomy,” which exists when a system not only evaluates creations on its own, but also changes its standards without explicit direction, is a necessary condition for making this argument. Rather than requiring that the system be hermetically sealed to avoid perceptions...

  13. Molecular fundamentals of chromosomal mutagenesis

    International Nuclear Information System (INIS)

    Precise quantitative correlation between the yield of chromosome structure damages and the yield of DNA damages is shown when comparing data on molecular and cytogenetic investigations carried out in cultural Mammalia cells. As the chromosome structure damage is to be connected with the damage of its carcass structure, then it is natural that DNA damage in loop regions is not to affect considerably the structure, while DNA damage lying on the loop base and connected with the chromosome carcass is to play a determining role in chromosomal mutagenesis. This DNA constitutes 1-2% from the total quantity of nuclear DNA. If one accepts that damages of these regions of DNA are ''hot'' points of chromosomal mutagenesis, then it becomes clear why 1-2% of preparation damages in a cell are realized in chromosome structural damages

  14. Electochemical detection of chromosome translocation

    DEFF Research Database (Denmark)

    Kwasny, Dorota; Dimaki, Maria; Silahtaroglu, Asli;

    2014-01-01

    Cytogenetics is a study of the cell structure with a main focus on chromosomes content and their structure. Chromosome abnormalities, such as translocations may cause various genetic disorders and heametological malignancies. Chromosome translocations are structural rearrangements of two...... hybridization approach developed for label-free detection of the chromosome translocations. For specific translocation detection it is necessary to determine that the two DNA sequences forming a derivative chromosome are connected, which is achieved by two subsequent hybridization steps. The electrochemical...... impedance spectroscopy was selected as the sensing method on a microfabricated chip with array of 12 electrode sets. Two independent chips (Chip1 and Chip2) were used for targeting the chromosomal fragments involved in the translocation. Each chip was differentially functionalized with DNA probes matching...

  15. Assignment of genetic linkage maps to diploid Solanum tuberosum pachytene chromosomes by BAC-FISH technology

    NARCIS (Netherlands)

    Tang, X.; Boer, de J.M.; Eck, van H.J.; Bachem, C.W.B.; Visser, R.G.F.; Jong, de J.H.

    2009-01-01

    A cytogenetic map has been developed for diploid potato (Solanum tuberosum), in which the arms of the 12 potato bivalents can be identified in pachytene complements using multicolor fluorescence in situ hybridization (FISH) with a set of 60 genetically anchored bacterial artificial chromosome (BAC)

  16. Intraspecific chromosome variability

    Directory of Open Access Journals (Sweden)

    N Dubinin

    2010-12-01

    Full Text Available (Editorial preface. The publication is presented in order to remind us of one of dramatic pages of the history of genetics. It re-opens for the contemporary reader a comprehensive work marking the priority change from plant cytogenetics to animal cytogenetics led by wide population studies which were conducted on Drosophila polytene chromosomes. The year of the publication (1937 became the point of irretrievable branching between the directions of Old World and New World genetics connected with the problems of chromosome variability and its significance for the evolution of the species. The famous book of T. Dobzhansky (1937 was published by Columbia University in the US under the title “Genetics and the origin of species”, and in the shadow of this American ‘skybuilding’ all other works grew dim. It is remarkable that both Dobzhansky and Dubinin come to similar conclusions about the role of chromosomes in speciation. This is not surprising given that they both might be considered as representatives of the Russian genetic school, by their birth and education. Interestingly, Dobzhansky had never referred to the full paper of Dubinin et al. (1937, though a previous short communication in Nature (1936 was included together with all former papers on the related subject. In full, the volume of the original publication printed in the Biological Journal in Moscow comprised 47 pages, in that number 41 pages of the Russian text accompanied by 16 Figs, a table and reference list, and, above all, 6 pages of the English summary. This final part in English is now reproduced in the authors’ version with the only addition being the reference list in the originally printed form.

  17. Reference-assisted chromosome assembly

    OpenAIRE

    Kim, Jaebum; Larkin, Denis M; Cai, Qingle; Asan,; Zhang, Yongfen; Ge, Ri-Li; Auvil, Loretta; Capitanu, Boris; Zhang, Guojie; Lewin, Harris A.; Ma, Jian

    2013-01-01

    One of the most difficult problems in modern genomics is the assembly of full-length chromosomes using next generation sequencing (NGS) data. To address this problem, we developed “reference-assisted chromosome assembly” (RACA), an algorithm to reliably order and orient sequence scaffolds generated by NGS and assemblers into longer chromosomal fragments using comparative genome information and paired-end reads. Evaluation of results using simulated and real genome assemblies indicates that ou...

  18. Principles of artificial intelligence

    CERN Document Server

    Nilsson, Nils J

    1980-01-01

    A classic introduction to artificial intelligence intended to bridge the gap between theory and practice, Principles of Artificial Intelligence describes fundamental AI ideas that underlie applications such as natural language processing, automatic programming, robotics, machine vision, automatic theorem proving, and intelligent data retrieval. Rather than focusing on the subject matter of the applications, the book is organized around general computational concepts involving the kinds of data structures used, the types of operations performed on the data structures, and the properties of th

  19. Intelligence: Real or artificial?

    OpenAIRE

    Schlinger, Henry D

    1992-01-01

    Throughout the history of the artificial intelligence movement, researchers have strived to create computers that could simulate general human intelligence. This paper argues that workers in artificial intelligence have failed to achieve this goal because they adopted the wrong model of human behavior and intelligence, namely a cognitive essentialist model with origins in the traditional philosophies of natural intelligence. An analysis of the word “intelligence” suggests that it originally r...

  20. Artificial Personality and Disfluency

    OpenAIRE

    Wester, Mirjam; Aylett, Matthew; Tomalin, Marcus; Dall, Rasmus

    2015-01-01

    The focus of this paper is artificial voices with different personalities. Previous studies have shown links between an individual's use of disfluencies in their speech and their perceived personality. Here, filled pauses (uh and um) and discourse markers (like, you know, I mean) have been included in synthetic speech as a way of creating an artificial voice with different personalities. We discuss the automatic insertion of filled pauses and discourse markers (i.e., fillers) into otherwise f...

  1. The Artificial Anal Sphincter

    OpenAIRE

    Christiansen, John

    2000-01-01

    The artificial anal sphincter as treatment for end stage anal incontinence was first described in 1987. Published series concern a total of 42 patients, with a success rate of approximately 80%. Infection has been the most serious complication, but a number of technical complications related to the device have also occurred and required revisional procedures in 40% to 60% of the patients. The artificial anal sphincter may be used for the same indications as dynamic graciloplasty except in pat...

  2. Artificial skin. Jinko hifu

    Energy Technology Data Exchange (ETDEWEB)

    Kifune, K. (Unitika Ltd., Osaka (Japan))

    1993-06-15

    In order to restore the human skin wounds, the transplantation is only one measure. The transplantation can take only when own skin is used, and there is no successful example by using other person's skin. When the own skin is not sufficient due to the too vast damage, the artificial skin, which can be regenerated as it is, is required. The artificial skin is said to be the most difficult organ among the artificial organs, even though its function is quite simple. Although there are the pig skin, the collagen membrane and the synthetic materials such as the polyurethane and so forth, as the materials similar to the artificial skin, they cover the wounds just until the cuticle is formed. Recently there is a cultivated skin. Firstly the normal skin with a size of the stamp is cut off, and then the cuticle cells are taken to pieces and cultivated, and consequently it is possible to increase the area by several 10 times. In addition, there is also a trial to make the artificial skin synthetically. Its upper layer is composed of the silicon, and the lower layer is the collagen membrane with a sponge structure. The silicon, membrane can be said to be an ideal artificial skin, because it detaches naturally. The chitin, which has recently appeared as the wound protection material, is also the promising material. 3 figs.

  3. Chromosome Connections: Compelling Clues to Common Ancestry

    Science.gov (United States)

    Flammer, Larry

    2013-01-01

    Students compare banding patterns on hominid chromosomes and see striking evidence of their common ancestry. To test this, human chromosome no. 2 is matched with two shorter chimpanzee chromosomes, leading to the hypothesis that human chromosome 2 resulted from the fusion of the two shorter chromosomes. Students test that hypothesis by looking for…

  4. X-chromosome workshop.

    Science.gov (United States)

    Paterson, A D

    1998-01-01

    Researchers presented results of ongoing research to the X-chromosome workshop of the Fifth World Congress on Psychiatric Genetics, covering a wide range of disorders: X-linked infantile spasms; a complex phenotype associated with deletions of Xp11; male homosexuality; degree of handedness; bipolar affective disorder; schizophrenia; childhood onset psychosis; and autism. This report summarizes the presentations, as well as reviewing previous studies. The focus of this report is on linkage findings for schizophrenia and bipolar disorder from a number of groups. For schizophrenia, low positive lod scores were obtained for markers DXS991 and DXS993 from two studies, although the sharing of alleles was greatest from brother-brother pairs in one study, and sister-sister in the other. Data from the Irish schizophrenia study was also submitted, with no strong evidence for linkage on the X chromosome. For bipolar disease, following the report of a Finnish family linked to Xq24-q27, the Columbia group reported some positive results for this region from 57 families, however, another group found no evidence for linkage to this region. Of interest, is the clustering of low positive linkage results that point to regions for possible further study. PMID:9686435

  5. Chromosome analysis and sorting

    Czech Academy of Sciences Publication Activity Database

    Doležel, Jaroslav; Kubaláková, Marie; Suchánková, Pavla; Kovářová, Pavlína; Bartoš, Jan; Šimková, Hana

    Weinheim : Wiley-VCH, 2007 - (Doležel, J.; Greilhuber, J.; Suda, J.), s. 373-403 ISBN 978-3-527-31487-4 R&D Projects: GA ČR GA521/04/0607; GA ČR GP521/05/P257; GA ČR GD521/05/H013; GA MŠk(CZ) LC06004 Grant ostatní: Mendelova zemědělská a lesnická univerzita v Brně / Agronomická fakulta(CZ) ME 844 Institutional research plan: CEZ:AV0Z5038910 Source of funding: V - iné verejné zdroje ; V - iné verejné zdroje ; V - iné verejné zdroje ; V - iné verejné zdroje ; V - iné verejné zdroje Keywords : Plant flow cytometry * chromosome sorting * flow cytogenetics Subject RIV: EB - Genetics ; Molecular Biology http://books. google .com/books?id=3cwakORieqUC&pg=PA373&lpg=PA373&dq=Chromosome+analysis+and+sorting&source=web&ots=8IyvJlBQyq&sig=_NlXyQQgBCwpj1pTC9YITvvVZqU

  6. Chromothripsis-like chromosomal rearrangements induced by ionizing radiation using proton microbeam irradiation system.

    Science.gov (United States)

    Morishita, Maki; Muramatsu, Tomoki; Suto, Yumiko; Hirai, Momoki; Konishi, Teruaki; Hayashi, Shin; Shigemizu, Daichi; Tsunoda, Tatsuhiko; Moriyama, Keiji; Inazawa, Johji

    2016-03-01

    Chromothripsis is the massive but highly localized chromosomal rearrangement in response to a one-step catastrophic event, rather than an accumulation of a series of subsequent and random alterations. Chromothripsis occurs commonly in various human cancers and is thought to be associated with increased malignancy and carcinogenesis. However, the causes and consequences of chromothripsis remain unclear. Therefore, to identify the mechanism underlying the generation of chromothripsis, we investigated whether chromothripsis could be artificially induced by ionizing radiation. We first elicited DNA double-strand breaks in an oral squamous cell carcinoma cell line HOC313-P and its highly metastatic subline HOC313-LM, using Single Particle Irradiation system to Cell (SPICE), a focused vertical microbeam system designed to irradiate a spot within the nuclei of adhesive cells, and then established irradiated monoclonal sublines from them, respectively. SNP array analysis detected a number of chromosomal copy number alterations (CNAs) in these sublines, and one HOC313-LM-derived monoclonal subline irradiated with 200 protons by the microbeam displayed multiple CNAs involved locally in chromosome 7. Multi-color FISH showed a complex translocation of chromosome 7 involving chromosomes 11 and 12. Furthermore, whole genome sequencing analysis revealed multiple de novo complex chromosomal rearrangements localized in chromosomes 2, 5, 7, and 20, resembling chromothripsis. These findings suggested that localized ionizing irradiation within the nucleus may induce chromothripsis-like complex chromosomal alterations via local DNA damage in the nucleus. PMID:26862731

  7. Physical map and organization of chromosome 7 in the rice blast fungus, Magnaporthe grisea.

    Science.gov (United States)

    Zhu, H; Blackmon, B P; Sasinowski, M; Dean, R A

    1999-08-01

    The rice blast fungus Magnaporthe grisea is a highly destructive plant pathogen and one of the most important for studying various aspects of host-plant interactions. It has been widely adopted as a model organism because it is ideally suited for genetic and biological studies. To facilitate map-based cloning, chromosome walking, and genome organization studies of M. grisea, a complete physical map of chromosome 7 was constructed using a large-insert (130 kb) bacterial artificial chromosome (BAC) library. Using 147 chromosome 7-specific single-copy BAC clones and 20 RFLP markers on chromosome 7, 625 BAC clones were identified by hybridization. BAC clones were digested with HindIII, and fragments were size separated on analytical agarose gels to create DNA fingerprints. Hybridization contigs were constructed using a random cost algorithm, whereas fingerprinting contigs were constructed using the software package FPC. Results from both methods were generally in agreement, but numerous anomalies were observed. The combined data produced five robust anchored contigs after gap closure by chromosomal walking. The genetic and physical maps agreed closely. The final physical map was estimated to cover >95% of the 4.2 Mb of chromosome 7. Based on the contig maps, a minimum BAC tile containing 42 BAC clones was created, and organization of repetitive elements and expressed genes of the chromosome was investigated. PMID:10447509

  8. Cohesin in determining chromosome architecture

    Energy Technology Data Exchange (ETDEWEB)

    Haering, Christian H., E-mail: christian.haering@embl.de [Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Heidelberg (Germany); Jessberger, Rolf, E-mail: rolf.jessberger@tu-dresden.de [Institute of Physiological Chemistry, Dresden University of Technology, Dresden (Germany)

    2012-07-15

    Cells use ring-like structured protein complexes for various tasks in DNA dynamics. The tripartite cohesin ring is particularly suited to determine chromosome architecture, for it is large and dynamic, may acquire different forms, and is involved in several distinct nuclear processes. This review focuses on cohesin's role in structuring chromosomes during mitotic and meiotic cell divisions and during interphase.

  9. Causes of oncogenic chromosomal translocation

    OpenAIRE

    Aplan, Peter D.

    2005-01-01

    Non-random chromosomal translocations are frequently associated with a variety of cancers, especially hematologic malignancies and childhood sarcomas In addition to their diagnostic utility, chromosomal translocations are increasingly being used in the clinic to guide therapeutic decisions. However, the mechanisms which cause these translocations remain poorly understood. Illegit...

  10. An integrated linkage, chromosome, and genome map for the yellow fever mosquito Aedes aegypti.

    Directory of Open Access Journals (Sweden)

    Vladimir A Timoshevskiy

    Full Text Available BACKGROUND: Aedes aegypti, the yellow fever mosquito, is an efficient vector of arboviruses and a convenient model system for laboratory research. Extensive linkage mapping of morphological and molecular markers localized a number of quantitative trait loci (QTLs related to the mosquito's ability to transmit various pathogens. However, linking the QTLs to Ae. aegypti chromosomes and genomic sequences has been challenging because of the poor quality of polytene chromosomes and the highly fragmented genome assembly for this species. METHODOLOGY/PRINCIPAL FINDINGS: Based on the approach developed in our previous study, we constructed idiograms for mitotic chromosomes of Ae. aegypti based on their banding patterns at early metaphase. These idiograms represent the first cytogenetic map developed for mitotic chromosomes of Ae. aegypti. One hundred bacterial artificial chromosome clones carrying major genetic markers were hybridized to the chromosomes using fluorescent in situ hybridization. As a result, QTLs related to the transmission of the filarioid nematode Brugia malayi, the avian malaria parasite Plasmodium gallinaceum, and the dengue virus, as well as sex determination locus and 183 Mbp of genomic sequences were anchored to the exact positions on Ae. aegypti chromosomes. A linear regression analysis demonstrated a good correlation between positions of the markers on the physical and linkage maps. As a result of the recombination rate variation along the chromosomes, 12 QTLs on the linkage map were combined into five major clusters of QTLs on the chromosome map. CONCLUSION: This study developed an integrated linkage, chromosome, and genome map-iMap-for the yellow fever mosquito. Our discovery of the localization of multiple QTLs in a few major chromosome clusters suggests a possibility that the transmission of various pathogens is controlled by the same genomic loci. Thus, the iMap will facilitate the identification of genomic determinants of

  11. Genetics Home Reference: ring chromosome 20 syndrome

    Science.gov (United States)

    ... 3 links) Encyclopedia: Chromosome Encyclopedia: Epilepsy Health Topic: Epilepsy Genetic and Rare Diseases Information Center (1 link) Ring chromosome 20 Additional NIH Resources (2 links) National Human Genome Research Institute: Chromosome Abnormalities National Institute of ...

  12. Genetics Home Reference: ring chromosome 14 syndrome

    Science.gov (United States)

    ... Encyclopedia: Chromosome Health Topic: Developmental Disabilities Health Topic: Epilepsy Genetic and Rare Diseases Information Center (1 link) Ring chromosome 14 Additional NIH Resources (2 links) National Human Genome Research Institute: Chromosome Abnormalities National Institute of ...

  13. Bacterial chromosome organization and segregation.

    Science.gov (United States)

    Badrinarayanan, Anjana; Le, Tung B K; Laub, Michael T

    2015-01-01

    If fully stretched out, a typical bacterial chromosome would be nearly 1 mm long, approximately 1,000 times the length of a cell. Not only must cells massively compact their genetic material, but they must also organize their DNA in a manner that is compatible with a range of cellular processes, including DNA replication, DNA repair, homologous recombination, and horizontal gene transfer. Recent work, driven in part by technological advances, has begun to reveal the general principles of chromosome organization in bacteria. Here, drawing on studies of many different organisms, we review the emerging picture of how bacterial chromosomes are structured at multiple length scales, highlighting the functions of various DNA-binding proteins and the impact of physical forces. Additionally, we discuss the spatial dynamics of chromosomes, particularly during their segregation to daughter cells. Although there has been tremendous progress, we also highlight gaps that remain in understanding chromosome organization and segregation. PMID:26566111

  14. ADN et chromosomes

    OpenAIRE

    Hayes, Hélène

    2000-01-01

    Chaque chromosome contient une seule molécule d’ADN. L’ADN déroulé d’un noyau de cellule humaine mesurerait environ 1,8 m : chaque molécule d’ADN est enroulée et compactée en plusieurs étapes, grâce à l’association de différentes protéines, et loge dans le noyau de 6 µm de diamètre. Le degré de condensation de l’ADN est variable selon les régions chromosomiques et les régions les moins condensées sont les plus riches en gènes. L’ADN est composé d’une variété de séquences codantes ou non et ré...

  15. X-Chromosome dosage compensation.

    Science.gov (United States)

    Meyer, Barbara J

    2005-01-01

    In mammals, flies, and worms, sex is determined by distinctive regulatory mechanisms that cause males (XO or XY) and females (XX) to differ in their dose of X chromosomes. In each species, an essential X chromosome-wide process called dosage compensation ensures that somatic cells of either sex express equal levels of X-linked gene products. The strategies used to achieve dosage compensation are diverse, but in all cases, specialized complexes are targeted specifically to the X chromosome(s) of only one sex to regulate transcript levels. In C. elegans, this sex-specific targeting of the dosage compensation complex (DCC) is controlled by the same developmental signal that establishes sex, the ratio of X chromosomes to sets of autosomes (X:A signal). Molecular components of this chromosome counting process have been defined. Following a common step of regulation, sex determination and dosage compensation are controlled by distinct genetic pathways. C. elegans dosage compensation is implemented by a protein complex that binds both X chromosomes of hermaphrodites to reduce transcript levels by one-half. The dosage compensation complex resembles the conserved 13S condensin complex required for both mitotic and meiotic chromosome resolution and condensation, implying the recruitment of ancient proteins to the new task of regulating gene expression. Within each C. elegans somatic cell, one of the DCC components also participates in the separate mitotic/meiotic condensin complex. Other DCC components play pivotal roles in regulating the number and distribution of crossovers during meiosis. The strategy by which C. elegans X chromosomes attract the condensin-like DCC is known. Small, well-dispersed X-recognition elements act as entry sites to recruit the dosage compensation complex and to nucleate spreading of the complex to X regions that lack recruitment sites. In this manner, a repressed chromatin state is spread in cis over short or long distances, thus establishing the

  16. Artificial intelligence in nanotechnology

    International Nuclear Information System (INIS)

    During the last decade there has been increasing use of artificial intelligence tools in nanotechnology research. In this paper we review some of these efforts in the context of interpreting scanning probe microscopy, the study of biological nanosystems, the classification of material properties at the nanoscale, theoretical approaches and simulations in nanoscience, and generally in the design of nanodevices. Current trends and future perspectives in the development of nanocomputing hardware that can boost artificial-intelligence-based applications are also discussed. Convergence between artificial intelligence and nanotechnology can shape the path for many technological developments in the field of information sciences that will rely on new computer architectures and data representations, hybrid technologies that use biological entities and nanotechnological devices, bioengineering, neuroscience and a large variety of related disciplines. (topical review)

  17. Chromatid Painting for Chromosomal Inversion Detection Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose the continued development of a novel approach to the detection of chromosomal inversions. Transmissible chromosome aberrations (translocations and...

  18. Chromatid Painting for Chromosomal Inversion Detection Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose a novel approach to the detection of chromosomal inversions. Transmissible chromosome aberrations (translocations and inversions) have profound genetic...

  19. Artificial ionospheric turbulence (review)

    International Nuclear Information System (INIS)

    This study is an analysis of artificial ionospheric turbulence (AIT) arising near the level at which a powerful wave is reflected with ordinary polarization. AIT is an inhomogeneous structure in the ionosphere with a size on the order of centimeters or tens of kilometers and with characteristic frequencies from a fraction of a hertz (aperiodic inhomogeneity) to several megahertz (plasma waves). The authors are primarily concerned with small-scale artificial ionospheric turbulence (SAIT), i.e., with inhomogeneities that are greatly extended along the geomagnetic field with transverse dimensions that are less than the wavelengths of the perturbing waves - the pumping waves (PW) - in a vacuum

  20. Mitotic chromosome condensation in vertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Vagnarelli, Paola, E-mail: P.Vagnarelli@ed.ac.uk

    2012-07-15

    Work from several laboratories over the past 10-15 years has revealed that, within the interphase nucleus, chromosomes are organized into spatially distinct territories [T. Cremer, C. Cremer, Chromosome territories, nuclear architecture and gene regulation in mammalian cells, Nat. Rev. Genet. 2 (2001) 292-301 and T. Cremer, M. Cremer, S. Dietzel, S. Muller, I. Solovei, S. Fakan, Chromosome territories-a functional nuclear landscape, Curr. Opin. Cell Biol. 18 (2006) 307-316]. The overall compaction level and intranuclear location varies as a function of gene density for both entire chromosomes [J.A. Croft, J.M. Bridger, S. Boyle, P. Perry, P. Teague,W.A. Bickmore, Differences in the localization and morphology of chromosomes in the human nucleus, J. Cell Biol. 145 (1999) 1119-1131] and specific chromosomal regions [N.L. Mahy, P.E. Perry, S. Gilchrist, R.A. Baldock, W.A. Bickmore, Spatial organization of active and inactive genes and noncoding DNA within chromosome territories, J. Cell Biol. 157 (2002) 579-589] (Fig. 1A, A'). In prophase, when cyclin B activity reaches a high threshold, chromosome condensation occurs followed by Nuclear Envelope Breakdown (NEB) [1]. At this point vertebrate chromosomes appear as compact structures harboring an attachment point for the spindle microtubules physically recognizable as a primary constriction where the two sister chromatids are held together. The transition from an unshaped interphase chromosome to the highly structured mitotic chromosome (compare Figs. 1A and B) has fascinated researchers for several decades now; however a definite picture of how this process is achieved and regulated is not yet in our hands and it will require more investigation to comprehend the complete process. From a biochemical point of view a vertebrate mitotic chromosomes is composed of DNA, histone proteins (60%) and non-histone proteins (40%) [6]. I will discuss below what is known to date on the contribution of these two different classes

  1. Mitotic chromosome condensation in vertebrates

    International Nuclear Information System (INIS)

    Work from several laboratories over the past 10–15 years has revealed that, within the interphase nucleus, chromosomes are organized into spatially distinct territories [T. Cremer, C. Cremer, Chromosome territories, nuclear architecture and gene regulation in mammalian cells, Nat. Rev. Genet. 2 (2001) 292–301 and T. Cremer, M. Cremer, S. Dietzel, S. Muller, I. Solovei, S. Fakan, Chromosome territories—a functional nuclear landscape, Curr. Opin. Cell Biol. 18 (2006) 307–316]. The overall compaction level and intranuclear location varies as a function of gene density for both entire chromosomes [J.A. Croft, J.M. Bridger, S. Boyle, P. Perry, P. Teague,W.A. Bickmore, Differences in the localization and morphology of chromosomes in the human nucleus, J. Cell Biol. 145 (1999) 1119–1131] and specific chromosomal regions [N.L. Mahy, P.E. Perry, S. Gilchrist, R.A. Baldock, W.A. Bickmore, Spatial organization of active and inactive genes and noncoding DNA within chromosome territories, J. Cell Biol. 157 (2002) 579–589] (Fig. 1A, A'). In prophase, when cyclin B activity reaches a high threshold, chromosome condensation occurs followed by Nuclear Envelope Breakdown (NEB) [1]. At this point vertebrate chromosomes appear as compact structures harboring an attachment point for the spindle microtubules physically recognizable as a primary constriction where the two sister chromatids are held together. The transition from an unshaped interphase chromosome to the highly structured mitotic chromosome (compare Figs. 1A and B) has fascinated researchers for several decades now; however a definite picture of how this process is achieved and regulated is not yet in our hands and it will require more investigation to comprehend the complete process. From a biochemical point of view a vertebrate mitotic chromosomes is composed of DNA, histone proteins (60%) and non-histone proteins (40%) [6]. I will discuss below what is known to date on the contribution of these two different

  2. Gametocidal chromosomes enhancing chromosome aberration in common wheat induced by 5-azacytidine.

    Science.gov (United States)

    Su, W-Y; Cong, W-W; Shu, Y-J; Wang, D; Xu, G-H; Guo, C-H

    2013-01-01

    The gametocidal (Gc) chromosome from Aegilops spp induces chromosome mutation, which is introduced into common wheat as a tool of chromosome manipulation for genetic improvement. The Gc chromosome functions similar to a restriction-modification system in bacteria, in which DNA methylation is an important regulator. We treated root tips of wheat carrying Gc chromosomes with the hypomethylation agent 5-azacytidine; chromosome breakage and micronuclei were observed in these root tips. The frequency of aberrations differed in wheat containing different Gc chromosomes, suggesting different functions inducing chromosome breakage. Gc chromosome 3C caused the greatest degree of chromosome aberration, while Gc chromosome 3C(SAT) and 2C caused only slight chromosome aberration. Gc chromosome 3C induced different degrees of chromosome aberration in wheat varieties Triticum aestivum var. Chinese Spring and Norin 26, demonstrating an inhibition function in common wheat. PMID:23884766

  3. Chromosome conservation in squamate reptiles revealed by comparative chromosome painting

    Czech Academy of Sciences Publication Activity Database

    Giovannotti, M.; Pokorná, Martina; Kratochvíl, L.; Caputo, V.; Olmo, E.; Ferguson-Smith, M. A.; Rens, W.

    Manchester : ICCS, 2011. 78-78. [Intarnational Chromosome Conference /18./. 29.08.2011-02.09.2011, Manchester] Institutional research plan: CEZ:AV0Z50450515 Keywords : squamate reptiles Subject RIV: EG - Zoology

  4. Numerous transitions of sex chromosomes in Diptera.

    Directory of Open Access Journals (Sweden)

    Beatriz Vicoso

    2015-04-01

    Full Text Available Many species groups, including mammals and many insects, determine sex using heteromorphic sex chromosomes. Diptera flies, which include the model Drosophila melanogaster, generally have XY sex chromosomes and a conserved karyotype consisting of six chromosomal arms (five large rods and a small dot, but superficially similar karyotypes may conceal the true extent of sex chromosome variation. Here, we use whole-genome analysis in 37 fly species belonging to 22 different families of Diptera and uncover tremendous hidden diversity in sex chromosome karyotypes among flies. We identify over a dozen different sex chromosome configurations, and the small dot chromosome is repeatedly used as the sex chromosome, which presumably reflects the ancestral karyotype of higher Diptera. However, we identify species with undifferentiated sex chromosomes, others in which a different chromosome replaced the dot as a sex chromosome or in which up to three chromosomal elements became incorporated into the sex chromosomes, and others yet with female heterogamety (ZW sex chromosomes. Transcriptome analysis shows that dosage compensation has evolved multiple times in flies, consistently through up-regulation of the single X in males. However, X chromosomes generally show a deficiency of genes with male-biased expression, possibly reflecting sex-specific selective pressures. These species thus provide a rich resource to study sex chromosome biology in a comparative manner and show that similar selective forces have shaped the unique evolution of sex chromosomes in diverse fly taxa.

  5. Production of artificial radioelements

    International Nuclear Information System (INIS)

    The techniques used in the production of artificial radioelements are described, with special emphasis on the following points: - nuclear reactions and use of reactors; - chemical separation methods and methods for enriching the activity of preparations; - protection of personnel and handling methods. (author)

  6. Artificial Left Ventricle

    CERN Document Server

    Ranjbar, Saeed; Meybodi, Mahmood Emami

    2014-01-01

    This Artificial left ventricle is based on a simple conic assumption shape for left ventricle where its motion is made by attached compressed elastic tubes to its walls which are regarded to electrical points at each nodal .This compressed tubes are playing the role of myofibers in the myocardium of the left ventricle. These elastic tubes have helical shapes and are transacting on these helical bands dynamically. At this invention we give an algorithm of this artificial left ventricle construction that of course the effect of the blood flow in LV is observed with making beneficiary used of sensors to obtain this effecting, something like to lifegates problem. The main problem is to evaluate powers that are interacted between elastic body (left ventricle) and fluid (blood). The main goal of this invention is to show that artificial heart is not just a pump, but mechanical modeling of LV wall and its interaction with blood in it (blood movement modeling) can introduce an artificial heart closed to natural heart...

  7. Observations of artificial satellites

    Directory of Open Access Journals (Sweden)

    A. MAMMANO

    1964-06-01

    Full Text Available The following publication gives the results of photographic
    observations of artificial satellites made at Asiago during the second
    and third year of this programme. The fixed camera technique and that
    with moving film (the latter still in its experimental stage have been used.

  8. Artificial intelligence within AFSC

    Science.gov (United States)

    Gersh, Mark A.

    1990-01-01

    Information on artificial intelligence research in the Air Force Systems Command is given in viewgraph form. Specific research that is being conducted at the Rome Air Development Center, the Space Technology Center, the Human Resources Laboratory, the Armstrong Aerospace Medical Research Laboratory, the Armamant Laboratory, and the Wright Research and Development Center is noted.

  9. Terahertz Artificial Dielectric Lens

    Science.gov (United States)

    Mendis, Rajind; Nagai, Masaya; Wang, Yiqiu; Karl, Nicholas; Mittleman, Daniel M.

    2016-03-01

    We have designed, fabricated, and experimentally characterized a lens for the THz regime based on artificial dielectrics. These are man-made media that mimic properties of naturally occurring dielectric media, or even manifest properties that cannot generally occur in nature. For example, the well-known dielectric property, the refractive index, which usually has a value greater than unity, can have a value less than unity in an artificial dielectric. For our lens, the artificial-dielectric medium is made up of a parallel stack of 100 μm thick metal plates that form an array of parallel-plate waveguides. The convergent lens has a plano-concave geometry, in contrast to conventional dielectric lenses. Our results demonstrate that this lens is capable of focusing a 2 cm diameter beam to a spot size of 4 mm, at the design frequency of 0.17 THz. The results further demonstrate that the overall power transmission of the lens can be better than certain conventional dielectric lenses commonly used in the THz regime. Intriguingly, we also observe that under certain conditions, the lens boundary demarcated by the discontinuous plate edges actually resembles a smooth continuous surface. These results highlight the importance of this artificial-dielectric technology for the development of future THz-wave devices.

  10. Artificial Gravity Research Plan

    Science.gov (United States)

    Gilbert, Charlene

    2014-01-01

    This document describes the forward working plan to identify what countermeasure resources are needed for a vehicle with an artificial gravity module (intermittent centrifugation) and what Countermeasure Resources are needed for a rotating transit vehicle (continuous centrifugation) to minimize the effects of microgravity to Mars Exploration crewmembers.

  11. Spatially Resolved Artificial Chemistry

    DEFF Research Database (Denmark)

    Fellermann, Harold

    2009-01-01

    made a class of models accessible to the realms of artificial chemistry that represent reacting molecules in a coarse-grained fashion in continuous space. This chapter introduces the mathematical models of Brownian dynamics (BD) and dissipative particle dynamics (DPD) for molecular motion and reaction...

  12. Natural or Artificial Intelligence?

    Czech Academy of Sciences Publication Activity Database

    Havlík, Vladimír

    Plzeň: University of West Bohemia, 2013 - (Romportl, J.; Ircing, P.; Zackova, E.; Polak, M.; Schuster, R.), s. 15-27 ISBN 978-80-261-0275-5. [International Conference Beyond AI 2013. Plzeň (CZ), 12.11.2013-14.11.2013] Institutional support: RVO:67985955 Keywords : artificial intelligence * natural intelligence * artifact * natural process * intrinsic intentionality Subject RIV: AA - Philosophy ; Religion

  13. Artificial Intelligence and CALL.

    Science.gov (United States)

    Underwood, John H.

    The potential application of artificial intelligence (AI) to computer-assisted language learning (CALL) is explored. Two areas of AI that hold particular interest to those who deal with language meaning--knowledge representation and expert systems, and natural-language processing--are described and examples of each are presented. AI contribution…

  14. Micromachined Artificial Haircell

    Science.gov (United States)

    Liu, Chang (Inventor); Engel, Jonathan (Inventor); Chen, Nannan (Inventor); Chen, Jack (Inventor)

    2010-01-01

    A micromachined artificial sensor comprises a support coupled to and movable with respect to a substrate. A polymer, high-aspect ratio cilia-like structure is disposed on and extends out-of-plane from the support. A strain detector is disposed with respect to the support to detect movement of the support.

  15. Human Chromosome 21: Mapping of the chromosomes and cloning of cDNAs

    Energy Technology Data Exchange (ETDEWEB)

    Antonarakis, S.E.

    1991-09-01

    The objective of the research funded by DOE grant DE-FG02-89ER60857 from 6/15/89 to 8/31/91 was to contribute to the physical mapping of human chromosome 21 (HC21) by cloning large fragments of DNA into Yeast Artificial Chromosomes (YACs) and identify YACs that map on HC21. A total of 54 sequence tagged sites (STS) have been developed and mapped in our laboratory to HC21 and can be used as initial reference points for YAC identification and construction of overlapping clones. A small YAC library was constructed which is HC21 specific. DNA from somatic cell hybrid WAV17 or from flow-sorted HC21 was partially digested with EcoRI, ligated into vectors PJS97, PJS98, and YACs have been obtained with average size insert of more than 300 kb. This library has been deposited in D. Patterson's lab for the Joint YAC screening effort. Additional YAC libraries from ICI Pharmaceuticals or from Los Alamos National Laboratories have been screened with several STS and positive YACs have been identified. Work in progress includes screening of YAC libraries in order to construct overlapping clones, characterization of the cloning ends of YACs, characterization of additional STS and cloning of HC21 specific cDNAs. 15 refs., 2 figs., 5 tabs.

  16. Familial transmission of a deletion of chromosome 21 derived from a translocation between chromosome 21 and an inverted chromosome 22.

    Science.gov (United States)

    Aviv, H; Lieber, C; Yenamandra, A; Desposito, F

    1997-06-27

    Chromosome analysis of a newborn boy with Down syndrome resulted in the identification of a family with an unusual derivative chromosome 22. The child has 46 chromosomes, including two chromosomes 21, one normal chromosome 22, and a derivative chromosome 22. Giemsa banding and fluorescent in situ hybridization (FISH) studies show that the derivative chromosome is chromosome 22 with evidence of both paracentric and pericentric inversions, joined to the long arm of chromosome 21 from 21q21.2 to qter. The rearrangement results in partial trisomy 21 extending from 21q21.2 to 21q terminus in the patient. The child's mother, brother, maternal aunt, and maternal grandmother are all carriers of the derivative chromosome. All have 45 chromosomes, with one normal chromosome 21, one normal chromosome 22, and the derivative chromosome 22. The rearrangement results in the absence of the short arm, the centromere, and the proximal long arm of chromosome 21 (del 21pter-21q21.2) in carriers. Carriers of the derivative chromosome in this family have normal physical appearance, mild learning disabilities and poor social adjustment. PMID:9182781

  17. Meiosis and chromosome painting of sex chromosome systems in Ceboidea.

    Science.gov (United States)

    Mudry, M D; Rahn, I M; Solari, A J

    2001-06-01

    The identity of the chromosomes involved in the multiple sex system of Alouatta caraya (Aca) and the possible distribution of this system among other Ceboidea were investigated by chromosome painting of mitotic cells from five species and by analysis of meiosis at pachytene in two species. The identity of the autosome #7 (X2) involved in the multiple system of Aca and its breakage points were demonstrated by both meiosis and chromosome painting. These features are identical to those described by Consigliere et al. [1996] in Alouatta seniculus sara (Assa) and Alouatta seniculus arctoidea (Asar). This multiple system was absent in the other four Ceboidea species studied here. However, data from the literature strongly suggest the presence of this multiple in other members of this genus. The presence of this multiple system among several species and subspecies that show high levels of chromosome rearrangements may suggest a special selective value of this multiple. The meiotic features of the sex systems of Aca and Cebus apella paraguayanus (Cap) are strikingly different at pachytene, as the latter system is similar to the sex pair of man and other primates. The relatively large genetic distances between species presently showing this multiple system suggest that its origin is not recent. Other members of the same genus should be investigated at meiosis and by chromosome painting in order to know the extent and distribution of this complex sex-chromosome system. PMID:11376445

  18. Introduction to Artificial Neural Networks

    DEFF Research Database (Denmark)

    Larsen, Jan

    1999-01-01

    The note addresses introduction to signal analysis and classification based on artificial feed-forward neural networks.......The note addresses introduction to signal analysis and classification based on artificial feed-forward neural networks....

  19. Inflatable artificial sphincter - series (image)

    Science.gov (United States)

    An artificial urinary sphincter is used to treat stress incontinence in men that is caused by urethral dysfunction such ... An artificial sphincter consists of three parts: a cuff that fits around the bladder neck a pressure regulating balloon ...

  20. Chromosome fragility in Freemartin cattle

    Directory of Open Access Journals (Sweden)

    V. Barbieri

    2010-04-01

    Full Text Available The aim of the present study was to verify chromosome fragility in freemartin cattle using chromosome aberration (CA and sister chromatid exchange (SCE tests. A total of eighteen co-twins were investigated. Fourteen animals were identified as cytogenetically chimeric (2n=60, XX/XY while 4 were classified as normal. Freemartin cattle showed a higher percentage of aneuploid cells (18.64% and highly significant statistical differences (P < 0.001 in mean values of gaps (4.53 ± 2.05, chromatid breaks (0.26 ± 0.51, and significant statistical differences (P < 0.005 in mean values of chromosome breaks (0.12 ± 0.43 when compared to 10 control animals from single births (aneuploid cells, 11.20%; gaps, 2.01 ± 1.42; chromatid breaks, 0.05 ± 0.22; chromosome breaks, 0.02 ± 0.14.

  1. Artificial Intelligence and Information Retrieval.

    Science.gov (United States)

    Teodorescu, Ioana

    1987-01-01

    Compares artificial intelligence and information retrieval paradigms for natural language understanding, reviews progress to date, and outlines the applicability of artificial intelligence to question answering systems. A list of principal artificial intelligence software for database front end systems is appended. (CLB)

  2. Methods for chromosome-specific staining

    Science.gov (United States)

    Gray, Joe W.; Pinkel, Daniel

    1995-01-01

    Methods and compositions for chromosome-specific staining are provided. Compositions comprise heterogenous mixtures of labeled nucleic acid fragments having substantially complementary base sequences to unique sequence regions of the chromosomal DNA for which their associated staining reagent is specific. Methods include methods for making the chromosome-specific staining compositions of the invention, and methods for applying the staining compositions to chromosomes.

  3. Chromosome Architecture and Genome Organization

    OpenAIRE

    Giorgio Bernardi

    2015-01-01

    How the same DNA sequences can function in the three-dimensional architecture of interphase nucleus, fold in the very compact structure of metaphase chromosomes and go precisely back to the original interphase architecture in the following cell cycle remains an unresolved question to this day. The strategy used to address this issue was to analyze the correlations between chromosome architecture and the compositional patterns of DNA sequences spanning a size range from a few hundreds to a few...

  4. Chromosome evolution in Neotropical butterflies

    OpenAIRE

    Saura, Anssi; Von Schoultz, Barbara; Saura, Anja O.; Brown, Keith S., Jr.

    2013-01-01

    We list the chromosome numbers for 65 species of Neotropical Hesperiidae and 104 species or subspecies of Pieridae. In Hesperiidae the tribe Pyrrhopygini have a modal n = 28, Eudaminae and Pyrgini a modal n = 31, while Hesperiinae have n = around 29. Among Pieridae, Coliadinae have a strong modal n = 31 and among Pierinae Anthocharidini are almost fixed for n = 15 while Pierini vary with n = 26 as the most common chromosome number. Dismorphiinae show wide variation. We discuss these results i...

  5. Numerically abnormal chromosome constitutions in humans

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-12-31

    Chapter 24, discusses numerically abnormal chromosome constitutions in humans. This involves abnormalities of human chromosome number, including polyploidy (when the number of sets of chromosomes increases) and aneuploidy (when the number of individual normal chromosomes changes). Chapter sections discuss the following chromosomal abnormalities: human triploids, imprinting and uniparental disomy, human tetraploids, hydatidiform moles, anomalies caused by chromosomal imbalance, 13 trisomy (D{sub 1} trisomy, Patau syndrome), 21 trisomy (Down syndrome), 18 trisomy syndrome (Edwards syndrome), other autosomal aneuploidy syndromes, and spontaneous abortions. The chapter concludes with remarks on the nonrandom participation of chromosomes in trisomy. 69 refs., 3 figs., 4 tabs.

  6. Chromosome evolution in Neotropical butterflies.

    Science.gov (United States)

    Saura, Anssi; Von Schoultz, Barbara; Saura, Anja O; Brown, Keith S

    2013-06-01

    We list the chromosome numbers for 65 species of Neotropical Hesperiidae and 104 species or subspecies of Pieridae. In Hesperiidae the tribe Pyrrhopygini have a modal n = 28, Eudaminae and Pyrgini a modal n = 31, while Hesperiinae have n = around 29. Among Pieridae, Coliadinae have a strong modal n = 31 and among Pierinae Anthocharidini are almost fixed for n = 15 while Pierini vary with n = 26 as the most common chromosome number. Dismorphiinae show wide variation. We discuss these results in the context of chromosome numbers of over 1400 Neotropical butterfly species and subspecies derived from about 3000 populations published here and in earlier papers of a series. The overall results show that many Neotropical groups are characterized by karyotype instability with several derived modal numbers or none at all, while almost all taxa of Lepidoptera studied from the other parts of the world have one of n = 29-31 as modal numbers. Possibly chromosome number changes become fixed in the course of speciation driven by biotic interactions. Population subdivision and structuring facilitate karyotype change. Factors that stabilize chromosome numbers include hybridization among species sharing the same number, migration, sexual selection and possibly the distribution of chromosomes within the nucleus. PMID:23865963

  7. Chromosome Architecture and Genome Organization

    Science.gov (United States)

    Bernardi, Giorgio

    2015-01-01

    How the same DNA sequences can function in the three-dimensional architecture of interphase nucleus, fold in the very compact structure of metaphase chromosomes and go precisely back to the original interphase architecture in the following cell cycle remains an unresolved question to this day. The strategy used to address this issue was to analyze the correlations between chromosome architecture and the compositional patterns of DNA sequences spanning a size range from a few hundreds to a few thousands Kilobases. This is a critical range that encompasses isochores, interphase chromatin domains and boundaries, and chromosomal bands. The solution rests on the following key points: 1) the transition from the looped domains and sub-domains of interphase chromatin to the 30-nm fiber loops of early prophase chromosomes goes through the unfolding into an extended chromatin structure (probably a 10-nm “beads-on-a-string” structure); 2) the architectural proteins of interphase chromatin, such as CTCF and cohesin sub-units, are retained in mitosis and are part of the discontinuous protein scaffold of mitotic chromosomes; 3) the conservation of the link between architectural proteins and their binding sites on DNA through the cell cycle explains the “mitotic memory” of interphase architecture and the reversibility of the interphase to mitosis process. The results presented here also lead to a general conclusion which concerns the existence of correlations between the isochore organization of the genome and the architecture of chromosomes from interphase to metaphase. PMID:26619076

  8. Artificial Enzymes, "Chemzymes"

    DEFF Research Database (Denmark)

    Bjerre, Jeannette; Rousseau, Cyril Andre Raphaël; Pedersen, Lavinia Georgeta M;

    2008-01-01

    Enzymes have fascinated scientists since their discovery and, over some decades, one aim in organic chemistry has been the creation of molecules that mimic the active sites of enzymes and promote catalysis. Nevertheless, even today, there are relatively few examples of enzyme models that...... successfully perform Michaelis-Menten catalysis under enzymatic conditions (i.e., aqueous medium, neutral pH, ambient temperature) and for those that do, very high rate accelerations are seldomly seen. This review will provide a brief summary of the recent developments in artificial enzymes, so called...... "Chemzymes", based on cyclodextrins and other molecules. Only the chemzymes that have shown enzyme-like activity that has been quantified by different methods will be mentioned. This review will summarize the work done in the field of artificial glycosidases, oxidases, epoxidases, and esterases, as well as...

  9. Evolution of Sex Chromosomes in Insects

    OpenAIRE

    Kaiser, Vera B; Bachtrog, Doris

    2010-01-01

    Sex chromosomes have many unusual features relative to autosomes. Y (or W) chromosomes lack genetic recombination, are male- (female-) limited, and show an abundance of genetically inert heterochromatic DNA but contain few functional genes. X (or Z) chromosomes also show sex-biased transmission (i.e., X chromosomes show female-biased and Z-chromosomes show male-biased inheritance) and are hemizygous in the heterogametic sex. Their unusual ploidy level and pattern of inheritance imply that sex...

  10. The Mouse Clock Locus: Sequence and Comparative Analysis of 204 Kb from Mouse Chromosome 5

    OpenAIRE

    Wilsbacher, Lisa D.; Sangoram, Ashvin M.; Antoch, Marina P.; Takahashi, Joseph S.

    2000-01-01

    The Clock gene encodes a basic helix-loop-helix (bHLH)–PAS transcription factor that regulates circadian rhythms in mice. We previously cloned Clock in mouse and human using a battery of behavioral and molecular techniques, including shotgun sequencing of two bacterial artificial chromosome (BAC) clones. Here we report the finished sequence of a 204-kb region from mouse chromosome 5. This region contains the complete loci for the Clock and Tpardl (pFT27) genes, as well as the 3′ partial locus...

  11. Artificial organisms that sleep.

    OpenAIRE

    Mirolli, Marco; Parisi, Domenico

    2003-01-01

    Abstract Populations of artificial organisms live in an environment in which light is cyclically present (day) or absent (night). Since being active during night is non-adaptive (activity consumes energy which is not compensated by the food found at night) the organisms evolve a sleep/wake behavioral pattern of being active during daytime and sleeping during nighttime. When the population moves to a different environment that contains "caves", they have to get out of a cave although the dark ...

  12. Impacts of Artificial Intelligence

    OpenAIRE

    Trappl, R.

    1986-01-01

    This book, which is intended to serve as the first stage in an iterative process of detecting, predicting, and assessing the impacts of Artificial Intelligence opens with a short "one-hour course" in AI, which is intended to provide a nontechnical informative introduction to the material which follows. Next comes an overview chapter which is based on an extensive literature search, the position papers, and discussions. The next section of the book contains position papers whose richness...

  13. Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Kapil Nahar

    2012-12-01

    Full Text Available An artificial neural network is an information-processing paradigm that is inspired by the way biological nervous systems, such as the brain, process information. The key element of this paradigm is the novel structure of the information processing system. It is composed of a large number of highly interconnected processing elements (neurons working in unison to solve specific problems. Ann’s, like people, learn by example.

  14. Artificial Intelligence in Transition

    OpenAIRE

    Hart, Peter E.

    1984-01-01

    In the past fifteen years artificial intelligence has changed from being the preoccupation of a handful of scientists to a thriving enterprise that has captured the imagination of world leaders and ordinary citizens alike. While corporate and government officials organize new projects whose potential impact is widespread, to date few people have been more affected by the transition than those already in the field. I review here some aspects of this transition, and pose some issues that it rai...

  15. Artificial neural network modelling

    CERN Document Server

    Samarasinghe, Sandhya

    2016-01-01

    This book covers theoretical aspects as well as recent innovative applications of Artificial Neural networks (ANNs) in natural, environmental, biological, social, industrial and automated systems. It presents recent results of ANNs in modelling small, large and complex systems under three categories, namely, 1) Networks, Structure Optimisation, Robustness and Stochasticity 2) Advances in Modelling Biological and Environmental Systems and 3) Advances in Modelling Social and Economic Systems. The book aims at serving undergraduates, postgraduates and researchers in ANN computational modelling. .

  16. Intelligence, Artificial and Otherwise

    OpenAIRE

    Chace, William M.

    1984-01-01

    I rise now to speak with the assumption that all of you know very well what I am going to say. I am the humanist here, the professor of English. We humanists, when asked to speak on questions of science and technology, are notorious for offering an embarrassed and ignorant respect toward those matters, a respect, however, which can all too quickly degenerate into insolent condescension. Face to face with the reality of computer technology, say, or with "artificial intelligence," we humanists ...

  17. Artificial sweetener; Jinko kanmiryo

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-08-01

    The patents related to the artificial sweetener that it is introduced to the public in 3 years from 1996 until 1998 are 115 cases. The sugar quality which makes an oligosaccharide and sugar alcohol the subject is greatly over 28 cases of the non-sugar quality in the one by the kind as a general tendency of these patents at 73 cases in such cases as the Aspartame. The method of manufacture patent, which included new material around other peptides, the oligosaccharide and sugar alcohol isn`t inferior to 56 cases of the formation thing patent at 43 cases, and pays attention to the thing, which is many by the method of manufacture, formation. There is most improvement of the quality of sweetness with 31 cases in badness of the aftertaste which is characteristic of the artificial sweetener and so on, and much stability including the improvement in the flavor of food by the artificial sweetener, a long time and dissolution, fluid nature and productivity and improvement of the economy such as a cost are seen with effect on a purpose. (NEDO)

  18. Retrospective dosimetry using chromosome painting

    International Nuclear Information System (INIS)

    Chromosome aberration frequency measured in peripheral lymphocytes of persons exposed to ionizing radiation has been used since 1960s for dose assessment. Suspected overexposure is usually evaluated by the frequency of dicentrics and centric rings using an appropriate in vitro calibration curve. However, these chromosome aberrations are unstable with time after exposure and dose reconstruction may encounter uncertainties when the time between the exposure and the analysis is considerable or even unknown. It appears that translocations persist with time after exposure and may be used as an indication of acute past overexposures. Moreover, they appear to accumulate the cytogenetical information, which correlates with the dose received under fractionated, chronic or even occupational exposure conditions. Translocations may be detected using G-banding, which allows to score the total amount of radiation induced translocations but it is a time consuming method, or by Chromosome Painting, a method base on the Fluorescence in situ Hybridization (FISH) technique, painting only some chromosome pairs with specific whole chromosome probes and then extrapolating the observed translocation frequencies to the full genome. The latter method allows a faster aberration scoring than G-banding and appears to be the most promissory tool for biodosimetry, particularly when it is necessary to assess low doses and consequently to score a large number of metaphases, e.g. radiation workers exposed within dose limits. As with the unstable chromosome aberration, it is necessary an in vitro calibration curve based on the frequency of stable chromosome aberrations to assess doses. Our laboratory performed calibration curves for Co60 γ-rays based on the frequencies of unstable (dicentrics and centric rings detected by conventional Giemsa staining) and stable chromosome aberrations (translocations and inversions, detected by G-banding). In order to minimize the interlaboratory variability, we

  19. The Reduction of Chromosome Number in Meiosis Is Determined by Properties Built into the Chromosomes

    OpenAIRE

    Paliulis, Leocadia V.; Nicklas, R. Bruce

    2000-01-01

    In meiosis I, two chromatids move to each spindle pole. Then, in meiosis II, the two are distributed, one to each future gamete. This requires that meiosis I chromosomes attach to the spindle differently than meiosis II chromosomes and that they regulate chromosome cohesion differently. We investigated whether the information that dictates the division type of the chromosome comes from the whole cell, the spindle, or the chromosome itself. Also, we determined when chromosomes can switch from ...

  20. Chromosome segregation in plant meiosis

    Directory of Open Access Journals (Sweden)

    Linda eZamariola

    2014-06-01

    Full Text Available Faithful chromosome segregation in meiosis is essential for ploidy stability over sexual life cycles. In plants, defective chromosome segregation caused by gene mutations or other factors leads to the formation of unbalanced or unreduced gametes creating aneuploid or polyploid progeny, respectively. Accurate segregation requires the coordinated execution of conserved processes occurring throughout the two meiotic cell divisions. Synapsis and recombination ensure the establishment of chiasmata that hold homologous chromosomes together allowing their correct segregation in the first meiotic division, which is also tightly regulated by cell-cycle dependent release of cohesin and monopolar attachment of sister kinetochores to microtubules. In meiosis II, bi-orientation of sister kinetochores and proper spindle orientation correctly segregate chromosomes in four haploid cells. Checkpoint mechanisms acting at kinetochores control the accuracy of kinetochore-microtubule attachment, thus ensuring the completion of segregation. Here we review the current knowledge on the processes taking place during chromosome segregation in plant meiosis, focusing on the characterization of the molecular factors involved.

  1. Radiation-induced chromosomal instability

    Energy Technology Data Exchange (ETDEWEB)

    Ritter, S. [GSI, Biophysics, Darmstadt (Germany)

    1999-03-01

    Recent studies on radiation-induced chromosomal instability in the progeny of exposed mammalian cells were briefly described as well as other related studies. For the analysis of chromosomal damage in clones, cells were seeded directly after exposure in cell well-dish to form single cell clones and post-irradiation chromosome aberrations were scored. Both exposure to isoeffective doses of X-ray or 270 MeV/u C-ions (13 keV/{mu}m) increased the number of clones with abnormal karyotype and the increase was similar for X-ray and for C-ions. Meanwhile, in the progeny of cells for mass cultures, there was no indication of a delayed expression of chromosomal damage up to 40 population doublings after the exposure. A high number of aberrant cells were only observed directly after exposure to 10.7 MeV/u O-ions, i.e. in the first cycle cells and decreased with subsequent cell divisions. The reason for these differences in the radiation-induced chromosomal instability between clonal isolates and mass culture has not been clarified. Recent studies indicated that genomic instability occurs at a high frequency in the progeny of cells irradiated with both sparsely and densely ionizing radiation. Such genomic instability is thought likely to increase the risk of carcinogenesis, but more data are required for a well understanding of the health risks resulting from radiation-induced delayed instability. (M.N.)

  2. Dean flow fractionation of chromosomes

    Science.gov (United States)

    Hockin, Matt; Sant, Himanshu J.; Capecchi, Mario; Gale, Bruce K.

    2016-03-01

    Efforts to transfer intact mammalian chromosomes between cells have been attempted for more than 50 years with the consistent result being transfer of sub unit length pieces regardless of method. Inertial microfluidics is a new field that has shown much promise in addressing the fractionation of particles in the 2-20 μm size range (with unknown limits) and separations are based upon particles being carried by curving confined flows (within a spiral shaped, often rectangular flow chamber) and migrating to stable "equilibrium" positions of varying distance from a chamber wall depending on the balance of dean and lift forces. We fabricated spiral channels for inertial microfluidic separations using a standard soft lithography process. The concentration of chromosomes, small contaminant DNA and large cell debris in each outlets were evaluated using microscope (60X) and a flow cytometer. Using Dean Flow Fractionation, we were able to focus 4.5 times more chromosomes in outlet 2 compared to outlet 4 where most of the large debris is found. We recover 16% of the chromosomes in outlet #1- 50% in 2, 23% in 3 and 11% in 4. It should be noted that these estimates of recovery do not capture one piece of information- it actually may be that the chromosomes at each outlet are physically different and work needs to be done to verify this potential.

  3. Chromosomal rearrangement interferes with meiotic X chromosome inactivation

    Czech Academy of Sciences Publication Activity Database

    Homolka, David; Ivánek, Robert; Čapková, Jana; Jansa, Petr; Forejt, Jiří

    2007-01-01

    Roč. 17, č. 10 (2007), s. 1431-1437. ISSN 1088-9051 R&D Projects: GA MŠk(CZ) 1M0520; GA ČR GA301/06/1334; GA ČR GA301/07/1383 Grant ostatní: Howard Hughes Medical Institute(US) HHMI 55000306 Institutional research plan: CEZ:AV0Z50520514 Keywords : chromosomal translocations * meiotic X chromosome inactivation * spermatogenesis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 11.224, year: 2007

  4. Chromosome region-specific libraries for human genome analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kao, Fa-Ten.

    1992-08-01

    During the grant period progress has been made in the successful demonstration of regional mapping of microclones derived from microdissection libraries; successful demonstration of the feasibility of converting microclones with short inserts into yeast artificial chromosome clones with very large inserts for high resolution physical mapping of the dissected region; Successful demonstration of the usefulness of region-specific microclones to isolate region-specific cDNA clones as candidate genes to facilitate search for the crucial genes underlying genetic diseases assigned to the dissected region; and the successful construction of four region-specific microdissection libraries for human chromosome 2, including 2q35-q37, 2q33-q35, 2p23-p25 and 2p2l-p23. The 2q35-q37 library has been characterized in detail. The characterization of the other three libraries is in progress. These region-specific microdissection libraries and the unique sequence microclones derived from the libraries will be valuable resources for investigators engaged in high resolution physical mapping and isolation of disease-related genes residing in these chromosomal regions.

  5. Artificial intelligence in hematology.

    Science.gov (United States)

    Zini, Gina

    2005-10-01

    Artificial intelligence (AI) is a computer based science which aims to simulate human brain faculties using a computational system. A brief history of this new science goes from the creation of the first artificial neuron in 1943 to the first artificial neural network application to genetic algorithms. The potential for a similar technology in medicine has immediately been identified by scientists and researchers. The possibility to store and process all medical knowledge has made this technology very attractive to assist or even surpass clinicians in reaching a diagnosis. Applications of AI in medicine include devices applied to clinical diagnosis in neurology and cardiopulmonary diseases, as well as the use of expert or knowledge-based systems in routine clinical use for diagnosis, therapeutic management and for prognostic evaluation. Biological applications include genome sequencing or DNA gene expression microarrays, modeling gene networks, analysis and clustering of gene expression data, pattern recognition in DNA and proteins, protein structure prediction. In the field of hematology the first devices based on AI have been applied to the routine laboratory data management. New tools concern the differential diagnosis in specific diseases such as anemias, thalassemias and leukemias, based on neural networks trained with data from peripheral blood analysis. A revolution in cancer diagnosis, including the diagnosis of hematological malignancies, has been the introduction of the first microarray based and bioinformatic approach for molecular diagnosis: a systematic approach based on the monitoring of simultaneous expression of thousands of genes using DNA microarray, independently of previous biological knowledge, analysed using AI devices. Using gene profiling, the traditional diagnostic pathways move from clinical to molecular based diagnostic systems. PMID:16203606

  6. Escape Artists of the X Chromosome.

    Science.gov (United States)

    Balaton, Bradley P; Brown, Carolyn J

    2016-06-01

    Inactivation of one X chromosome in mammalian females achieves dosage compensation between XX females and XY males; however, over 15% of human X-linked genes continue to be expressed from the inactive X chromosome. New genomic methodologies have improved our identification and characterization of these escape genes, revealing the importance of DNA sequence, chromatin structure, and chromosome ultrastructure in regulating expression from an otherwise inactive chromosome. Study of these exceptions to the rule of silencing highlights the interconnectedness of chromatin and chromosome structure in X-chromosome inactivation (XCI). Recent advances also demonstrate the importance of these genes in sexually dimorphic disease risk, particularly cancer. PMID:27103486

  7. Polymer artificial muscles

    Directory of Open Access Journals (Sweden)

    Tissaphern Mirfakhrai

    2007-04-01

    Full Text Available The various types of natural muscle are incredible material systems that enable the production of large deformations by repetitive molecular motions. Polymer artificial muscle technologies are being developed that produce similar strains and higher stresses using electrostatic forces, electrostriction, ion insertion, and molecular conformational changes. Materials used include elastomers, conducting polymers, ionically conducting polymers, and carbon nanotubes. The mechanisms, performance, and remaining challenges associated with these technologies are described. Initial applications are being developed, but further work by the materials community should help make these technologies applicable in a wide range of devices where muscle-like motion is desirable.

  8. Uncertainty in artificial intelligence

    CERN Document Server

    Kanal, LN

    1986-01-01

    How to deal with uncertainty is a subject of much controversy in Artificial Intelligence. This volume brings together a wide range of perspectives on uncertainty, many of the contributors being the principal proponents in the controversy.Some of the notable issues which emerge from these papers revolve around an interval-based calculus of uncertainty, the Dempster-Shafer Theory, and probability as the best numeric model for uncertainty. There remain strong dissenting opinions not only about probability but even about the utility of any numeric method in this context.

  9. Bayesian artificial intelligence

    CERN Document Server

    Korb, Kevin B

    2010-01-01

    Updated and expanded, Bayesian Artificial Intelligence, Second Edition provides a practical and accessible introduction to the main concepts, foundation, and applications of Bayesian networks. It focuses on both the causal discovery of networks and Bayesian inference procedures. Adopting a causal interpretation of Bayesian networks, the authors discuss the use of Bayesian networks for causal modeling. They also draw on their own applied research to illustrate various applications of the technology.New to the Second EditionNew chapter on Bayesian network classifiersNew section on object-oriente

  10. Mechanism of artificial heart

    CERN Document Server

    Yamane, Takashi

    2016-01-01

    This book first describes medical devices in relation to regenerative medicine before turning to a more specific topic: artificial heart technologies. Not only the pump mechanisms but also the bearing, motor mechanisms, and materials are described, including expert information. Design methods are described to enhance hemocompatibility: main concerns are reduction of blood cell damage and protein break, as well as prevention of blood clotting. Regulatory science from R&D to clinical trials is also discussed to verify the safety and efficacy of the devices.

  11. Adults with Chromosome 18 Abnormalities.

    Science.gov (United States)

    Soileau, Bridgette; Hasi, Minire; Sebold, Courtney; Hill, Annice; O'Donnell, Louise; Hale, Daniel E; Cody, Jannine D

    2015-08-01

    The identification of an underlying chromosome abnormality frequently marks the endpoint of a diagnostic odyssey. However, families are frequently left with more questions than answers as they consider their child's future. In the case of rare chromosome conditions, a lack of longitudinal data often makes it difficult to provide anticipatory guidance to these families. The objective of this study is to describe the lifespan, educational attainment, living situation, and behavioral phenotype of adults with chromosome 18 abnormalities. The Chromosome 18 Clinical Research Center has enrolled 483 individuals with one of the following conditions: 18q-, 18p-, Tetrasomy 18p, and Ring 18. As a part of the ongoing longitudinal study, we collect data on living arrangements, educational level attained, and employment status as well as data on executive functioning and behavioral skills on an annual basis. Within our cohort, 28 of the 483 participants have died, the majority of whom have deletions encompassing the TCF4 gene or who have unbalanced rearrangement involving other chromosomes. Data regarding the cause of and age at death are presented. We also report on the living situation, educational attainment, and behavioral phenotype of the 151 participants over the age of 18. In general, educational level is higher for people with all these conditions than implied by the early literature, including some that received post-high school education. In addition, some individuals are able to live independently, though at this point they represent a minority of patients. Data on executive function and behavioral phenotype are also presented. Taken together, these data provide insight into the long-term outcome for individuals with a chromosome 18 condition. This information is critical in counseling families on the range of potential outcomes for their child. PMID:25403900

  12. Hierarchical multifractal representation of symbolic sequences and application to human chromosomes

    Science.gov (United States)

    Provata, A.; Katsaloulis, P.

    2010-02-01

    The two-dimensional density correlation matrix is constructed for symbolic sequences using contiguous segments of arbitrary size. The multifractal spectrum obtained from this matrix motif is shown to characterize the correlations in the symbolic sequences. This method is applied to entire human chromosomes, shuffled human chromosomes, reconstructed human genomic sequences and to artificial random sequences. It is shown that all human chromosomes have common characteristics in their multifractal spectrum and deviate substantially from random and uncorrelated sequences of the same size. Small deviations are observed between the longer and the shorter chromosomes, especially for the higher (in absolute values) statistical moments. The correlations are crucial for the form of the multifractal spectrum; surrogate shuffled chromosomes present randomlike spectrum, distinctly different from the actual chromosomes. Analytical approaches based on hierarchical superposition of tensor products show that retaining pair correlations in the sequences leads to a closer representation of the genomic multifractal spectra, especially in the region of negative exponents, due to the underrepresentation of various functional units (such as the cytosine-guanine CG combination and its complementary GC complex). Retaining higher-order correlations in the construction of the tensor products is a way to approach closer the structure of the multifractal spectra of the actual genomic sequences. This hierarchical approach is generic and is applicable to other correlated symbolic sequences.

  13. Adaptive radiation in the Hawaiian silversword alliance (Compositae-Madiinae). II. Cytogenetics of artificial and natural hybrids

    International Nuclear Information System (INIS)

    The Hawaiian silversword alliance of Argyroxiphium, Dubautia, and Wilkesia, in spite of exhibiting spectacular morphological, ecological, physiological, and chromosomal diversity, is remarkably cohesive, genetically. This is attested to by the ease of production of artificial hybrids and by the high frequency of spontaneous hybridization among such life forms as mat-forming subshrub, monocarpic rosette shrub, polycarpic shrub, cushion plant, tree, and vine. Even the least fertile of these hybrids is capable of producing backcross progeny. Moreover, first generation interspecific and intergeneric hybrids have been successfully used to produce trispecific hybrids in a number of instances. In general, the widest hybrid combinations have been as readily produced as crosses within a species. At present eight genomes or chromosome races distinguished by reciprocal translocations are recognized on the basis of meiotic analysis of artificial and spontaneous hybrids. Seven of these races are found among those species with 14 pairs of chromosomes. The eighth genome very likely characterizes all nine species of this alliance that have 13 pairs of chromosomes. The cytogenetic data indicate that redundancy of translocations involving the same chromosomes has been a recurrent theme in the chromosomal differentiation of these taxa. There appears to be little, if any, correlation between chromosomal evolution and adaptive radiation as assessed by gross habital differentiation in this group. However, within Dubautia, a novel ecophysiological trait associated with colonization of xeric habitats is restricted to species with n = 13. In contrast to the bulk of the Hawaiian flora, which is characterized by self-compatibility and chromosomal stability, it is suggested that the occurrence of self-incompatibility in the Hawaiian Madiinae may have favored selection of supergenes via chromosomal repatterning, and this may account for the diversity of chromosome structure seen in this group

  14. Making chromosome abnormalities treatable conditions.

    Science.gov (United States)

    Cody, Jannine DeMars; Hale, Daniel Esten

    2015-09-01

    Individuals affected by the classic chromosome deletion syndromes which were first identified at the beginning of the genetic age, are now positioned to benefit from genomic advances. This issue highlights five of these conditions (4p-, 5p-, 11q-, 18p-, and 18q-). It focuses on the increased in understanding of the molecular underpinnings and envisions how these can be transformed into effective treatments. While it is scientifically exciting to see the phenotypic manifestations of hemizygosity being increasingly understood at the molecular and cellular level, it is even more amazing to consider that we are now on the road to making chromosome abnormalities treatable conditions. PMID:26351122

  15. Using Chromosomes to Teach Evolution: Chromosomal Rearrangements in Speciation Events.

    Science.gov (United States)

    Offner, Susan

    1994-01-01

    Uses diagrams to aid in discussing how the English map of the human chromosomes, published by Offner in 1993, can be used to illustrate some important questions in evolution, as well as give students a glimpse into some of the mechanisms underlying evolutionary change. (ZWH)

  16. Characterization of chromosome structures of Falconinae (Falconidae, Falconiformes, Aves) by chromosome painting and delineation of chromosome rearrangements during their differentiation

    OpenAIRE

    Nishida, Chizuko; Ishijima, Junko; KOSAKA, Ayumi; Tanabe, Hideyuki; Habermann, Felix A.; Griffin, Darren K.; MATSHUDA, Yoichi; 秀之, 田辺

    2008-01-01

    Karyotypes of most bird species are characterized by around 2n = 80 chromosomes, comprising 7–10 pairs of large- and medium-sized macrochromosomes including sex chromosomes and numerous morphologically indistinguishable microchromosomes. The Falconinae of the Falconiformes has a different karyotype from the typical avian karyotype in low chromosome numbers, little size difference between macrochromosomes and a smaller number of microchromosomes. To characterize chromosome structures of Falcon...

  17. Characterization of chromosome structures of Falconinae (Falconidae, Falconiformes, Aves) by chromosome painting and delineation of chromosome rearrangements during their differentiation

    OpenAIRE

    Nishida, Chizuko; Ishijima, Junko; KOSAKA, Ayumi; Tanabe, Hideyuki; Habermann, Felix A.; Griffin, Darren K.; Matsuda, Yoichi

    2008-01-01

    Karyotypes of most bird species are characterized by around 2n = 80 chromosomes, comprising 7Y10 pairs of large- and medium-sized macrochromosomes including sex chromosomes and numerous morphologically indistinguishable microchromosomes. The Falconinae of the Falconiformes has a different karyotype from the typical avian karyotype in low chromosome numbers, little size difference between macrochromosomes and a smaller number of microchromosomes. To characterize chromosome structures of Falcon...

  18. Whole-genome profiling and shotgun sequencing delivers an anchored, gene-decorated, physical map assembly of bread wheat chromosome 6A

    OpenAIRE

    Poursarebani, N.; Nussbaumer, T.; Šimková, H. (Hana); Šafář, J.; Witsenboer, H.; van Oeveren, J.; Doležel, J. (Jaroslav); Mayer, K. F. X.; N. Stein; Schnurbusch, T.

    2014-01-01

    Bread wheat (Triticum aestivum L.) is the most important staple food crop for 35% of the world's population. International efforts are underway to facilitate an increase in wheat production, of which the International Wheat Genome Sequencing Consortium (IWGSC) plays an important role. As part of this effort, we have developed a sequence-based physical map of wheat chromosome 6A using whole-genome profiling (WGP (TM)). The bacterial artificial chromosome (BAC) contig assembly tools FINGERPRINT...

  19. Mathematical glimpse on the Y chromosome degeneration

    Science.gov (United States)

    Lobo, M. P.

    2006-04-01

    The Y chromosomes are genetically degenerate and do not recombine with their matching partners X. Non-recombination of XY pairs has been pointed out as the key factor for the degeneration of the Y chromosome. The aim here is to show that there is a mathematical asymmetry in sex chromosomes which leads to the degeneration of Y chromosomes even in the absence of XX and XY recombination. A model for sex-chromosome evolution in a stationary regime is proposed. The consequences of their asymmetry are analyzed and lead us to a couple of conclusions. First, Y chromosome degeneration shows up sqrt{2} more often than X chromosome degeneration. Second, if nature prohibits female mortalities from beeing exactly 50%, then Y chromosome degeneration is inevitable.

  20. CHROMOSOMAL MULTIPLICITY IN BURKHOLDERIA CEPACIA

    Science.gov (United States)

    We have used CHEF gel electrophoresis to screen preparations of large DNA from different Burkholderia cepacia isolates for the presence of DNA species corresponding to the linearized forms of the three chromosomes of 3.4,2.5, and 0.9 Mb identified in B. cepacia strain 17616. DNA ...

  1. Vibrio chromosome-specific families

    DEFF Research Database (Denmark)

    Lukjancenko, Oksana; Ussery, David

    2014-01-01

    We have compared chromosome-specific genes in a set of 18 finished Vibrio genomes, and, in addition, also calculated the pan- and core-genomes from a data set of more than 250 draft Vibrio genome sequences. These genomes come from 9 known species and 2 unknown species. Within the finished...

  2. Chromosome Territory Modeller and Viewer.

    Science.gov (United States)

    Tkacz, Magdalena A; Chromiński, Kornel; Idziak-Helmcke, Dominika; Robaszkiewicz, Ewa; Hasterok, Robert

    2016-01-01

    This paper presents ChroTeMo, a tool for chromosome territory modelling, accompanied by ChroTeVi-a chromosome territory visualisation software that uses the data obtained by ChroTeMo. These tools have been developed in order to complement the molecular cytogenetic research of interphase nucleus structure in a model grass Brachypodium distachyon. Although the modelling tool has been initially created for one particular species, it has universal application. The proposed version of ChroTeMo allows for generating a model of chromosome territory distribution in any given plant or animal species after setting the initial, species-specific parameters. ChroTeMo has been developed as a fully probabilistic modeller. Due to this feature, the comparison between the experimental data on the structure of a nucleus and the results obtained from ChroTeMo can indicate whether the distribution of chromosomes inside a nucleus is also fully probabilistic or is subjected to certain non-random patterns. The presented tools have been written in Python, so they are multiplatform, portable and easy to read. Moreover, if necessary they can be further developed by users writing their portions of code. The source code, documentation, and wiki, as well as the issue tracker and the list of related articles that use ChroTeMo and ChroTeVi, are accessible in a public repository at Github under GPL 3.0 license. PMID:27505434

  3. Chromosome Territory Modeller and Viewer

    Science.gov (United States)

    Idziak-Helmcke, Dominika; Robaszkiewicz, Ewa; Hasterok, Robert

    2016-01-01

    This paper presents ChroTeMo, a tool for chromosome territory modelling, accompanied by ChroTeVi–a chromosome territory visualisation software that uses the data obtained by ChroTeMo. These tools have been developed in order to complement the molecular cytogenetic research of interphase nucleus structure in a model grass Brachypodium distachyon. Although the modelling tool has been initially created for one particular species, it has universal application. The proposed version of ChroTeMo allows for generating a model of chromosome territory distribution in any given plant or animal species after setting the initial, species-specific parameters. ChroTeMo has been developed as a fully probabilistic modeller. Due to this feature, the comparison between the experimental data on the structure of a nucleus and the results obtained from ChroTeMo can indicate whether the distribution of chromosomes inside a nucleus is also fully probabilistic or is subjected to certain non-random patterns. The presented tools have been written in Python, so they are multiplatform, portable and easy to read. Moreover, if necessary they can be further developed by users writing their portions of code. The source code, documentation, and wiki, as well as the issue tracker and the list of related articles that use ChroTeMo and ChroTeVi, are accessible in a public repository at Github under GPL 3.0 license. PMID:27505434

  4. Artificial organs: recent progress in artificial hearing and vision.

    Science.gov (United States)

    Ifukube, Tohru

    2009-01-01

    Artificial sensory organs are a prosthetic means of sending visual or auditory information to the brain by electrical stimulation of the optic or auditory nerves to assist visually impaired or hearing-impaired people. However, clinical application of artificial sensory organs, except for cochlear implants, is still a trial-and-error process. This is because how and where the information transmitted to the brain is processed is still unknown, and also because changes in brain function (plasticity) remain unknown, even though brain plasticity plays an important role in meaningful interpretation of new sensory stimuli. This article discusses some basic unresolved issues and potential solutions in the development of artificial sensory organs such as cochlear implants, brainstem implants, artificial vision, and artificial retinas. PMID:19330498

  5. Multicolor spectral karyotyping of human chromosomes.

    Science.gov (United States)

    Schröck, E; du Manoir, S; Veldman, T; Schoell, B; Wienberg, J; Ferguson-Smith, M A; Ning, Y; Ledbetter, D H; Bar-Am, I; Soenksen, D; Garini, Y; Ried, T

    1996-07-26

    The simultaneous and unequivocal discernment of all human chromosomes in different colors would be of significant clinical and biologic importance. Whole-genome scanning by spectral karyotyping allowed instantaneous visualization of defined emission spectra for each human chromosome after fluorescence in situ hybridization. By means of computer separation (classification) of spectra, spectrally overlapping chromosome-specific DNA probes could be resolved, and all human chromosomes were simultaneously identified. PMID:8662537

  6. CHROMOSOMAL ABNORMALITIES IN PATIENTS WITH SPERM DISORDERS

    OpenAIRE

    L. Y. Pylyp; L. A. Spinenko; V. D. Zukin; N. M. Bilko

    2013-01-01

    Chromosomal abnormalities are among the most common genetic causes of spermatogenic disruptions. Carriers of chromosomal abnormalities are at increased risk of infertility, miscarriage or birth of a child with unbalanced karyotype due to the production of unbalanced gametes. The natural selection against chromosomally abnormal sperm usually prevents fertilization with sperm barring in cases of serious chromosomal abnormalities. However, assisted reproductive technologies in general and intrac...

  7. Evolution of sex chromosomes ZW of Schistosoma mansoni inferred from chromosome paint and BAC mapping analyses.

    Science.gov (United States)

    Hirai, Hirohisa; Hirai, Yuriko; LoVerde, Philip T

    2012-12-01

    Chromosomes of schistosome parasites among digenetic flukes have a unique evolution because they exhibit the sex chromosomes ZW, which are not found in the other groups of flukes that are hermaphrodites. We conducted molecular cytogenetic analyses for investigating the sex chromosome evolution using chromosome paint analysis and BAC clones mapping. To carry this out, we developed a technique for making paint probes of genomic DNA from a single scraped chromosome segment using a chromosome microdissection system, and a FISH mapping technique for BAC clones. Paint probes clearly identified each of the 8 pairs of chromosomes by a different fluorochrome color. Combination analysis of chromosome paint analysis with Z/W probes and chromosome mapping with 93 BAC clones revealed that the W chromosome of Schistosoma mansoni has evolved by at least four inversion events and heterochromatinization. Nine of 93 BAC clones hybridized with both the Z and W chromosomes, but the locations were different between Z and W chromosomes. The homologous regions were estimated to have moved from the original Z chromosome to the differentiated W chromosome by three inversions events that occurred before W heterohcromatinization. An inversion that was observed in the heterochromatic region of the W chromosome likely occurred after W heterochromatinization. These inversions and heterochromatinization are hypothesized to be the key factors that promoted the evolution of the W chromosome of S. mansoni. PMID:22831897

  8. Chromosome Aberrations by Heavy Ions

    Science.gov (United States)

    Ballarini, Francesca; Ottolenghi, Andrea

    It is well known that mammalian cells exposed to ionizing radiation can show different types of chromosome aberrations (CAs) including dicentrics, translocations, rings, deletions and complex exchanges. Chromosome aberrations are a particularly relevant endpoint in radiobiology, because they play a fundamental role in the pathways leading either to cell death, or to cell conversion to malignancy. In particular, reciprocal translocations involving pairs of specific genes are strongly correlated (and probably also causally-related) with specific tumour types; a typical example is the BCR-ABL translocation for Chronic Myeloid Leukaemia. Furthermore, aberrations can be used for applications in biodosimetry and more generally as biomarkers of exposure and risk, that is the case for cancer patients monitored during Carbon-ion therapy and astronauts exposed to space radiation. Indeed hadron therapy and astronauts' exposure to space radiation represent two of the few scenarios where human beings can be exposed to heavy ions. After a brief introduction on the main general features of chromosome aberrations, in this work we will address key aspects of the current knowledge on chromosome aberration induction, both from an experimental and from a theoretical point of view. More specifically, in vitro data will be summarized and discussed, outlining important issues such as the role of interphase death/mitotic delay and that of complex-exchange scoring. Some available in vivo data on cancer patients and astronauts will be also reported, together with possible interpretation problems. Finally, two of the few available models of chromosome aberration induction by ionizing radiation (including heavy ions) will be described and compared, focusing on the different assumptions adopted by the authors and on how these models can deal with heavy ions.

  9. Chromosome Doubling of Microspore-Derived Plants from Cabbage (Brassica oleracea var. capitata L.) and Broccoli (Brassica oleracea var. italica L.)

    Science.gov (United States)

    Yuan, Suxia; Su, Yanbin; Liu, Yumei; Li, Zhansheng; Fang, Zhiyuan; Yang, Limei; Zhuang, Mu; Zhang, Yangyong; Lv, Honghao; Sun, Peitian

    2015-01-01

    Chromosome doubling of microspore-derived plants is an important factor in the practical application of microspore culture technology because breeding programs require a large number of genetically stable, homozygous doubled haploid plants with a high level of fertility. In the present paper, 29 populations of microspore-derived plantlets from cabbage (Brassica oleracea var. capitata) and broccoli (Brassica oleracea var. italica) were used to study the ploidy level and spontaneous chromosome doubling of these populations, the artificial chromosome doubling induced by colchicine, and the influence of tissue culture duration on the chromosomal ploidy of the microspore-derived regenerants. Spontaneous chromosome doubling occurred randomly and was genotype dependent. In the plant populations derived from microspores, there were haploids, diploids, and even a low frequency of polyploids and mixed-ploidy plantlets. The total spontaneous doubling in the 14 cabbage populations ranged from 0 to 76.9%, compared with 52.2 to 100% in the 15 broccoli populations. To improve the rate of chromosome doubling, an efficient and reliable artificial chromosome doubling protocol (i.e., the immersion of haploid plantlet roots in a colchicine solution) was developed for cabbage and broccoli microspore-derived haploids. The optimal chromosome doubling of the haploids was obtained with a solution of 0.2% colchicine for 9–12 h or 0.4% colchicine for 3–9 h for cabbage and 0.05% colchicine for 6–12 h for broccoli. This protocol produced chromosome doubling in over 50% of the haploid genotypes for most of the populations derived from cabbage and broccoli. Notably, after 1 or more years in tissue culture, the chromosomes of the haploids were doubled, and most of the haploids turned into doubled haploid or mixed-ploidy plants. This is the first report indicating that tissue culture duration can change the chromosomal ploidy of microspore-derived regenerants. PMID:26734028

  10. A case of trisomy of chromosome 15

    OpenAIRE

    Coldwell, S; Fitzgerald, B.; Semmens, J.M.; Ede, R; Bateman, C

    1981-01-01

    We describe a case of trisomy of chromosome 15 in an infant who presented at birth with numerous abnormalities. As far as we are aware this chromosomal abnormality has not been described before. On the basis of this one case there appear to be no features which are specific to this chromosomal abnormality.

  11. Artificial sweeteners - a review.

    Science.gov (United States)

    Chattopadhyay, Sanchari; Raychaudhuri, Utpal; Chakraborty, Runu

    2014-04-01

    Now a days sugar free food are very much popular because of their less calorie content. So food industry uses various artificial sweeteners which are low in calorie content instead of high calorie sugar. U.S. Food and Drug Administration has approved aspartame, acesulfame-k, neotame, cyclamate and alitame for use as per acceptable daily intake (ADI) value. But till date, breakdown products of these sweeteners have controversial health and metabolic effects. On the other hand, rare sugars are monosaccharides and have no known health effects because it does not metabolize in our body, but shows same sweet taste and bulk property as sugar. Rare sugars have no such ADI value and are mainly produced by using bioreactor and so inspite of high demand, rare sugars cannot be produced in the desired quantities. PMID:24741154

  12. Artificial Immune Systems (2010)

    CERN Document Server

    Greensmith, Julie; Aickelin, Uwe

    2010-01-01

    The human immune system has numerous properties that make it ripe for exploitation in the computational domain, such as robustness and fault tolerance, and many different algorithms, collectively termed Artificial Immune Systems (AIS), have been inspired by it. Two generations of AIS are currently in use, with the first generation relying on simplified immune models and the second generation utilising interdisciplinary collaboration to develop a deeper understanding of the immune system and hence produce more complex models. Both generations of algorithms have been successfully applied to a variety of problems, including anomaly detection, pattern recognition, optimisation and robotics. In this chapter an overview of AIS is presented, its evolution is discussed, and it is shown that the diversification of the field is linked to the diversity of the immune system itself, leading to a number of algorithms as opposed to one archetypal system. Two case studies are also presented to help provide insight into the m...

  13. A Primer on Artificial Intelligence.

    Science.gov (United States)

    Leal, Ralph A.

    A survey of literature on recent advances in the field of artificial intelligence provides a comprehensive introduction to this field for the non-technical reader. Important areas covered are: (1) definitions, (2) the brain and thinking, (3) heuristic search, and (4) programing languages used in the research of artificial intelligence. Some…

  14. Generalized Adaptive Artificial Neural Networks

    Science.gov (United States)

    Tawel, Raoul

    1993-01-01

    Mathematical model of supervised learning by artificial neural network provides for simultaneous adjustments of both temperatures of neurons and synaptic weights, and includes feedback as well as feedforward synaptic connections. Extension of mathematical model described in "Adaptive Neurons For Artificial Neural Networks" (NPO-17803). Dynamics of neural network represented in new model by less-restrictive continuous formalism.

  15. Sucrose compared with artificial sweeteners

    DEFF Research Database (Denmark)

    Sørensen, Lone Brinkmann; Vasilaras, Tatjana H; Astrup, Arne;

    2014-01-01

    There is a lack of appetite studies in free-living subjects supplying the habitual diet with either sucrose or artificially sweetened beverages and foods. Furthermore, the focus of artificial sweeteners has only been on the energy intake (EI) side of the energy-balance equation. The data are from a...

  16. Soft computing in artificial intelligence

    CERN Document Server

    Matson, Eric

    2014-01-01

    This book explores the concept of artificial intelligence based on knowledge-based algorithms. Given the current hardware and software technologies and artificial intelligence theories, we can think of how efficient to provide a solution, how best to implement a model and how successful to achieve it. This edition provides readers with the most recent progress and novel solutions in artificial intelligence. This book aims at presenting the research results and solutions of applications in relevance with artificial intelligence technologies. We propose to researchers and practitioners some methods to advance the intelligent systems and apply artificial intelligence to specific or general purpose. This book consists of 13 contributions that feature fuzzy (r, s)-minimal pre- and β-open sets, handling big coocurrence matrices, Xie-Beni-type fuzzy cluster validation, fuzzy c-regression models, combination of genetic algorithm and ant colony optimization, building expert system, fuzzy logic and neural network, ind...

  17. Beyond AI: Artificial Dreams Conference

    CERN Document Server

    Zackova, Eva; Kelemen, Jozef; Beyond Artificial Intelligence : The Disappearing Human-Machine Divide

    2015-01-01

    This book is an edited collection of chapters based on the papers presented at the conference “Beyond AI: Artificial Dreams” held in Pilsen in November 2012. The aim of the conference was to question deep-rooted ideas of artificial intelligence and cast critical reflection on methods standing at its foundations.  Artificial Dreams epitomize our controversial quest for non-biological intelligence, and therefore the contributors of this book tried to fully exploit such a controversy in their respective chapters, which resulted in an interdisciplinary dialogue between experts from engineering, natural sciences and humanities.   While pursuing the Artificial Dreams, it has become clear that it is still more and more difficult to draw a clear divide between human and machine. And therefore this book tries to portrait such an image of what lies beyond artificial intelligence: we can see the disappearing human-machine divide, a very important phenomenon of nowadays technological society, the phenomenon which i...

  18. Chromosomal instability in Streptomyces avermitilis: major deletion in the central region and stable circularized chromosome

    Directory of Open Access Journals (Sweden)

    Wen Ying

    2010-07-01

    Full Text Available Abstract Background The chromosome of Streptomyces has been shown to be unstable, frequently undergoing gross chromosomal rearrangements. However, the mechanisms underlying this phenomenon remain unclear, with previous studies focused on two chromosomal ends as targets for rearrangements. Here we investigated chromosomal instability of Streptomyces avermitilis, an important producer of avermectins, and characterized four gross chromosomal rearrangement events, including a major deletion in the central region. The present findings provide a valuable contribution to the mechanistic study of genetic instability in Streptomyces. Results Thirty randomly-selected "bald" mutants derived from the wild-type strain all contained gross chromosomal rearrangements of various types. One of the bald mutants, SA1-8, had the same linear chromosomal structure as the high avermectin-producing mutant 76-9. Chromosomes of both strains displayed at least three independent chromosomal rearrangements, including chromosomal arm replacement to form new 88-kb terminal inverted repeats (TIRs, and two major deletions. One of the deletions eliminated the 36-kb central region of the chromosome, but surprisingly did not affect viability of the cells. The other deletion (74-kb was internal to the right chromosomal arm. The chromosome of another bald mutant, SA1-6, was circularized with deletions at both ends. No obvious homology was found in all fusion sequences. Generational stability analysis showed that the chromosomal structure of SA1-8 and SA1-6 was stable. Conclusions Various chromosomal rearrangements, including chromosomal arm replacement, interstitial deletions and chromosomal circularization, occurred in S. avermitilis by non-homologous recombination. The finding of an inner deletion involving in the central region of S. avermitilis chromosome suggests that the entire Streptomyces chromosome may be the target for rearrangements, which are not limited, as previously

  19. The origin of human chromosome 2 analyzed by comparative chromosome mapping with a DNA microlibrary

    OpenAIRE

    Wienberg, Johannes; Jauch, Anna; Lüdecke, H J; Senger, G; Horsthemke, B; Claussen, U; Cremer, Thomas; Arnold, N.; Lengauer, Christoph

    1994-01-01

    Fluorescencein situ hybridization (FISH) of microlibraries established from distinct chromosome subregions can test the evolutionary conservation of chromosome bands as well as chromosomal rearrangements that occurred during primate evolution and will help to clarify phylogenetic relationships. We used a DNA library established by microdissection and microcloning from the entire long arm of human chromosome 2 for fluorescencein situ hybridization and comparative mapping of the chromosomes of ...

  20. Temporal genomic evolution of bird sex chromosomes

    DEFF Research Database (Denmark)

    Wang, Zongji; Zhang, Jilin; Yang, Wei;

    2014-01-01

    driving forces of Z chromosome evolution, we analyze here 45 newly available bird genomes and four species' transcriptomes, over their course of recombination loss between the sex chromosomes. RESULTS: We show Z chromosomes in general have a significantly higher substitution rate in introns and synonymous...... evolved very recently. CONCLUSIONS: In conclusion, we uncover that the sequence and expression patterns of Z chromosome genes covary with their ages of becoming Z-linked. In contrast to the mammalian X chromosomes, such patterns are mainly driven by mutational bias and genetic drift in birds, due...... to the opposite sex-biased inheritance of Z vs. X....

  1. Holoprosencephaly due to numeric chromosome abnormalities.

    Science.gov (United States)

    Solomon, Benjamin D; Rosenbaum, Kenneth N; Meck, Jeanne M; Muenke, Maximilian

    2010-02-15

    Holoprosencephaly (HPE) is the most common malformation of the human forebrain. When a clinician identifies a patient with HPE, a routine chromosome analysis is often the first genetic test sent for laboratory analysis in order to assess for a structural or numerical chromosome anomaly. An abnormality of chromosome number is overall the most frequently identified etiology in a patient with HPE. These abnormalities include trisomy 13, trisomy 18, and triploidy, though several others have been reported. Such chromosome number abnormalities are almost universally fatal early in gestation or in infancy. Clinical features of specific chromosome number abnormalities may be recognized by phenotypic manifestations in addition to the HPE. PMID:20104610

  2. Novel insights into mitotic chromosome condensation

    Science.gov (United States)

    Piskadlo, Ewa; Oliveira, Raquel A.

    2016-01-01

    The fidelity of mitosis is essential for life, and successful completion of this process relies on drastic changes in chromosome organization at the onset of nuclear division. The mechanisms that govern chromosome compaction at every cell division cycle are still far from full comprehension, yet recent studies provide novel insights into this problem, challenging classical views on mitotic chromosome assembly. Here, we briefly introduce various models for chromosome assembly and known factors involved in the condensation process (e.g. condensin complexes and topoisomerase II). We will then focus on a few selected studies that have recently brought novel insights into the mysterious way chromosomes are condensed during nuclear division.

  3. Transient Microgeographic Clines during B Chromosome Invasion.

    Science.gov (United States)

    Camacho, Juan Pedro M; Shaw, Michael W; Cabrero, Josefa; Bakkali, Mohammed; Ruíz-Estévez, Mercedes; Ruíz-Ruano, Francisco J; Martín-Blázquez, Rubén; López-León, María Dolores

    2015-11-01

    The near-neutral model of B chromosome evolution predicts that the invasion of a new population should last some tens of generations, but the details on how it proceeds in real populations are mostly unknown. Trying to fill this gap, we analyze here a natural population of the grasshopper Eyprepocnemis plorans at three time points during the last 35 years. Our results show that B chromosome frequency increased significantly during this period and that a cline observed in 1992 had disappeared in 2012 once B chromosome frequency reached an upper limit at all sites sampled. This indicates that, during B chromosome invasion, transient clines for B chromosome frequency are formed at the invasion front on a microgeographic scale. Computer simulation experiments showed that the pattern of change observed for genotypic frequencies is consistent with the existence of B chromosome drive through females and selection against individuals with a high number of B chromosomes. PMID:26655780

  4. Mitosis. Microtubule detyrosination guides chromosomes during mitosis.

    Science.gov (United States)

    Barisic, Marin; Silva e Sousa, Ricardo; Tripathy, Suvranta K; Magiera, Maria M; Zaytsev, Anatoly V; Pereira, Ana L; Janke, Carsten; Grishchuk, Ekaterina L; Maiato, Helder

    2015-05-15

    Before chromosomes segregate into daughter cells, they align at the mitotic spindle equator, a process known as chromosome congression. Centromere-associated protein E (CENP-E)/Kinesin-7 is a microtubule plus-end-directed kinetochore motor required for congression of pole-proximal chromosomes. Because the plus-ends of many astral microtubules in the spindle point to the cell cortex, it remains unknown how CENP-E guides pole-proximal chromosomes specifically toward the equator. We found that congression of pole-proximal chromosomes depended on specific posttranslational detyrosination of spindle microtubules that point to the equator. In vitro reconstitution experiments demonstrated that CENP-E-dependent transport was strongly enhanced on detyrosinated microtubules. Blocking tubulin tyrosination in cells caused ubiquitous detyrosination of spindle microtubules, and CENP-E transported chromosomes away from spindle poles in random directions. Thus, CENP-E-driven chromosome congression is guided by microtubule detyrosination. PMID:25908662

  5. CHROMOSOMAL ABNORMALITIES IN PATIENTS WITH RECURRENT MISCARRIAGE

    Directory of Open Access Journals (Sweden)

    Daniela Mierla

    2012-06-01

    Full Text Available Chromosomal abnormalities are involved in the etiology of recurrent spontaneous pregnancy loss and sub-fertility. The purpose of this study was to determine the frequency and contribution of chromosomal abnormalities in recurrent miscarriages. The results obtained and literature review are helpful in understanding the importance of cytogenetics analysis of female infertility. To investigate the distribution of chromosomal abnormalities in the Romanian population with recurrent miscarriage, karyotype analysis by G-banding was performed from peripheral blood in 967 women infertility. Results: Chromosomal abnormalities were found to 79 women (8,17%. The percentage of chromosomal abnormalities in the studied population correlates with the data in the literature. Chromosomal abnormalities could play the important role in etiology of infertility and are more frequently detected in this group of patients compared to general population. In the infertile couples balanced chromosomal abnormalities are the main cause of spontaneous abortions.

  6. [The evolution of human Y chromosome].

    Science.gov (United States)

    Yang, Xianrong; Wang, Meiqin; Li, Shaohua

    2014-09-01

    The human Y chromosome is always intriguing for researchers, because of its role in gender determination and its unusual evolutionary history. The Y chromosome evolves from an autosome, and its evolution has been characterized by massive gene decay. The lack of recombination and protein-coding genes and high content of repetitive sequences have hindered the progress in our understanding of the Y chromosome biology. Recently, with the advances in comparative genomics and sequencing technology, the research on Y chromosome has become a hotspot, with an intensified debate about Y-chromosome final destination resulting from degeneration. This review focuses on the structure, inheritance characteristics, gene content, and the origin and evolution of Y chromosome. We also discuss the long-term destiny of Y chromosome. PMID:25252301

  7. Dynamics of chromosome segregation in Escherichia coli

    DEFF Research Database (Denmark)

    Nielsen, Henrik Jørck

    2007-01-01

    Since the 1960’es the conformation and segregation of the chromosome in Escherichia coli has been a subject of interest for many scientists. However, after 40 years of research, we still know incredibly little about how the chromosome is organized inside the cell, how it manages to duplicate this...... and reliable method enabled us to start the analysis on the distribution of various chromosomal loci inside slowly growing cells. With the actual counting and measuring no longer being any problem we could easily analyze 14 loci distributed on the E.coli chromosome. More than 15.000 cells were...... on the P1 par system. Using the new system, which is based on the pMT1 par system from Yersenia pestis, we labeled loci on opposite sides of the E.coli chromosome simultaneously and were able to show that the E.coli chromosome is organized with one chromosomal arm in each cell half. This astounding...

  8. Microdissection and chromosome painting of the alien chromosome in an addition line of wheat-Thinopyrum intermedium

    Science.gov (United States)

    The chromosome painting is an efficient tool for chromosome research. However, plant chromosome painting is relatively underdeveloped. In this study, chromosome painting was developed and used to identify alien chromosomes in TAi-27, a wheat-Thinopyrum intermedium addition line, and chromosomes of...

  9. The artificial leaf.

    Science.gov (United States)

    Nocera, Daniel G

    2012-05-15

    To convert the energy of sunlight into chemical energy, the leaf splits water via the photosynthetic process to produce molecular oxygen and hydrogen, which is in a form of separated protons and electrons. The primary steps of natural photosynthesis involve the absorption of sunlight and its conversion into spatially separated electron-hole pairs. The holes of this wireless current are captured by the oxygen evolving complex (OEC) of photosystem II (PSII) to oxidize water to oxygen. The electrons and protons produced as a byproduct of the OEC reaction are captured by ferrodoxin of photosystem I. With the aid of ferrodoxin-NADP(+) reductase, they are used to produce hydrogen in the form of NADPH. For a synthetic material to realize the solar energy conversion function of the leaf, the light-absorbing material must capture a solar photon to generate a wireless current that is harnessed by catalysts, which drive the four electron/hole fuel-forming water-splitting reaction under benign conditions and under 1 sun (100 mW/cm(2)) illumination. This Account describes the construction of an artificial leaf comprising earth-abundant elements by interfacing a triple junction, amorphous silicon photovoltaic with hydrogen- and oxygen-evolving catalysts made from a ternary alloy (NiMoZn) and a cobalt-phosphate cluster (Co-OEC), respectively. The latter captures the structural and functional attributes of the PSII-OEC. Similar to the PSII-OEC, the Co-OEC self-assembles upon oxidation of an earth-abundant metal ion from 2+ to 3+, may operate in natural water at room temperature, and is self-healing. The Co-OEC also activates H(2)O by a proton-coupled electron transfer mechanism in which the Co-OEC is increased by four hole equivalents akin to the S-state pumping of the Kok cycle of PSII. X-ray absorption spectroscopy studies have established that the Co-OEC is a structural relative of Mn(3)CaO(4)-Mn cubane of the PSII-OEC, where Co replaces Mn and the cubane is extended in a

  10. International workshop of chromosome 19

    Energy Technology Data Exchange (ETDEWEB)

    Pericak-Vance, M.A. (Duke Univ. Medical Center, Durham, NC (United States). Div. of Neurology); Carrano, A.J. (Lawrence Livermore National Lab., CA (United States))

    1991-09-16

    This document summarizes the workshop on physical and genetic mapping of chromosome 19. The first session discussed the major disease loci found on the chromosome. The second session concentrated on reference families, markers and linkage maps. The third session concentrated on radiation hybrid mapping, somatic cell hybrid panels, macro restriction maps and YACs, followed by cDNA and long range physical maps. The fourth session concentrated on compiling consensus genetic and physical maps as well as discussing regions of conflict. The final session dealt with the LLNL cosmid contig database and comparative mapping of homologous regions of the human and mouse genomes, and ended with a discussion of resource sharing. 18 refs., 2 figs. (MHB)

  11. Development of an integrated computerized scheme for metaphase chromosome image analysis: a robustness experiment

    Science.gov (United States)

    Wang, Xingwei; Zheng, Bin; Li, Shibo; Mulvihill, John J.; Wood, Marc C.; Yuan, Chaowei; Chen, Wei; Liu, Hong

    2008-02-01

    Our integrated computer-aided detection (CAD) scheme includes three basic modules. The first module detects whether a microscopic digital image depicts a metaphase chromosome cell. If a cell is detected, the scheme will justify whether it is analyzable with a decision tree. Once an analyzable cell is detected, the second module is applied to segment individual chromosomes and to compute two important features. Specifically, the scheme utilizes a modified thinning algorithm to identify the medial axis of a chromosome. By tracking perpendicular lines along the medial axis, the scheme computes four feature profiles, identifies centromeres, and assigns polarities of chromosomes based on a set of pre-optimized rules. The third module is followed to classify chromosomes into 24 types. In this module, each chromosome is initially represented by a vector of 31 features. A two-layer classifier with 8 artificial neural networks (ANN) is optimized by a genetic algorithm. A testing chromosome is first classified into one of the seven groups by the ANN in the first layer. Another ANN is then automatically selected from the seven ANNs in the second layer (one for each group) to further classify this chromosome into one of 24 types. To test the performance and robustness of this CAD scheme, we randomly selected and assembled an independent testing dataset. The dataset contains 100 microscopic digital images including 50 analyzable and 50 un-analyzable metphase cells identified by the experts. The centromere location, the corresponding polarity, and karyotype for each individual chromosome were recorded in the "truth" file. The performance of the CAD scheme applied to this image dataset is analyzed and compared with the results in the true file. The assessment accuracies are 93% for the first module, 90.8% for centromere identification and 93.2% for polarity assignment in the second module, over 96% for six chromosome groups and 81.8% for one group in the third module

  12. natural or artificial diets

    Directory of Open Access Journals (Sweden)

    A. O. Meyer-Willerer

    2005-01-01

    Full Text Available Se probaron alimentos artificiales y naturales con larva de camarón (Litopenaeus vannamei cultivados en diferentes recipientes. Estos fueron ocho frascos cónicos con 15L, ocho acuarios con 50L y como grupo control, seis tanques de fibra de vidrio con 1500L; todos con agua marina fresca y filtrada. La densidad inicial en todos los recipientes fue de 70 nauplios/L. Aquellos en frascos y acuarios recibieron ya sea dieta natural o artificial. El grupo control fue cultivado con dieta natural en los tanques grandes que utilizan los laboratorios para la producción masiva de postlarvas. El principal producto de excreción de larva de camarón es el ión amonio, que es tóxico cuando está presente en concentraciones elevadas. Se determinó diariamente con el método colorimétrico del indofenol. Los resultados muestran diferencias en la concentración del ión amonio y en la sobrevivencia de larvas entre las diferentes dietas y también entre los diferentes recipientes. En aquellos con volúmenes pequeños comparados con los grandes, se presentó mayor concentración de amonio (500 a 750µg/L, en aquellos con dietas naturales, debido a que este ión sirve de fertilizante a las algas adicionadas, necesitando efectuar recambios diarios de agua posteriores al noveno día de cultivo para mantener este ión a una concentración subletal. Se obtuvo una baja cosecha de postlarvas (menor a 15% con el alimento artificial larvario, debido a la presencia de protozoarios, alimentándose con el producto comercial precipitado en el fondo de los frascos o acuarios. Los acuarios con larvas alimentadas con dieta natural también mostraron concentraciones subletales de amonio al noveno día; sin embargo, la sobrevivencia fue cuatro veces mayor que con dietas artificiales. Los tanques control con dietas naturales presentaron tasas de sobrevivencia (70 ± 5% similares a la reportada por otros laboratorios.

  13. Baseline chromosome aberrations in children

    Czech Academy of Sciences Publication Activity Database

    Merlo, D.F.; Ceppi, M.; Stagi, E.; Bocchini, V.; Šrám, Radim; Rössner st., Pavel

    2007-01-01

    Roč. 172, - (2007), s. 60-67. ISSN 0378-4274 Grant ostatní: EU(EU) 2002-02198; EU(EU) 2005-016320 Institutional research plan: CEZ:AV0Z50390512 Source of funding: R - rámcový projekt EK ; R - rámcový projekt EK Keywords : chromosome aberrations * children * molecular epidemiology Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 2.826, year: 2007

  14. Clonality - X Chromosome Inactivation Assay

    OpenAIRE

    sprotocols

    2014-01-01

    Author: Molecular Profiling Initiative, NCI This method was successful in our lab using prostate tissue and for our specific objectives. Investigators must be aware that they will need to tailor the following protocol for their own research objectives and tissue under study. Investigators can utilize X chromosome inactivation (methylation) to determine the clonality status of a tumor or premalignant lesion in females. The technique is based on a methylation-sensitive restriction enzym...

  15. Hobo transposons causing chromosomal breakpoints.

    OpenAIRE

    Ladevèze, V; Aulard, S.; Chaminade, N; Périquet, G; Lemeunier, F

    1998-01-01

    Several laboratory surveys have shown that transposable elements (TEs) can cause chromosomal breaks and lead to inversions, as in dysgenic crosses involving P-elements. However, it is not presently clear what causes inversions in natural populations of Drosophila. The only direct molecular studies must be taken as evidence against the involvement of mobile elements. Here, in Drosophila lines transformed with the hobo transposable element, and followed for 100 generations, we show the appearan...

  16. Chromosomal instability determines taxane response

    OpenAIRE

    Swanton, Charles; Nicke, Barbara; Schuett, Marion; Eklund, Aron C.; Ng, Charlotte; Li, Qiyuan; Hardcastle, Thomas; Lee, Alvin; Roy, Rajat; East, Philip; Kschischo, Maik; Endesfelder, David; Wylie, Paul; Kim, Se Nyun; Chen, Jie-Guang

    2009-01-01

    Microtubule-stabilizing (MTS) agents, such as taxanes, are important chemotherapeutics with a poorly understood mechanism of action. We identified a set of genes repressed in multiple cell lines in response to MTS agents and observed that these genes are overexpressed in tumors exhibiting chromosomal instability (CIN). Silencing 22/50 of these genes, many of which are involved in DNA repair, caused cancer cell death, suggesting that these genes are involved in the survival of aneuploid cells....

  17. The structural diversity of artificial genetic polymers.

    Science.gov (United States)

    Anosova, Irina; Kowal, Ewa A; Dunn, Matthew R; Chaput, John C; Van Horn, Wade D; Egli, Martin

    2016-02-18

    Synthetic genetics is a subdiscipline of synthetic biology that aims to develop artificial genetic polymers (also referred to as xeno-nucleic acids or XNAs) that can replicate in vitro and eventually in model cellular organisms. This field of science combines organic chemistry with polymerase engineering to create alternative forms of DNA that can store genetic information and evolve in response to external stimuli. Practitioners of synthetic genetics postulate that XNA could be used to safeguard synthetic biology organisms by storing genetic information in orthogonal chromosomes. XNA polymers are also under active investigation as a source of nuclease resistant affinity reagents (aptamers) and catalysts (xenozymes) with practical applications in disease diagnosis and treatment. In this review, we provide a structural perspective on known antiparallel duplex structures in which at least one strand of the Watson-Crick duplex is composed entirely of XNA. Currently, only a handful of XNA structures have been archived in the Protein Data Bank as compared to the more than 100 000 structures that are now available. Given the growing interest in xenobiology projects, we chose to compare the structural features of XNA polymers and discuss their potential to access new regions of nucleic acid fold space. PMID:26673703

  18. Chromosome aberration assays in Allium

    Energy Technology Data Exchange (ETDEWEB)

    Grant, W.F.

    1982-01-01

    The common onion (Allium cepa) is an excellent plant for the assay of chromosome aberrations after chemical treatment. Other species of Allium (A. cepa var. proliferum, A. carinatum, A. fistulosum and A. sativum) have also been used but to a much lesser extent. Protocols have been given for using root tips from either bulbs or seeds of Allium cepa to study the cytological end-points, such as chromosome breaks and exchanges, which follow the testing of chemicals in somatic cells. It is considered that both mitotic and meiotic end-points should be used to a greater extent in assaying the cytogenetic effects of a chemical. From a literature survey, 148 chemicals are tabulated that have been assayed in 164 Allium tests for their clastogenic effect. Of the 164 assays which have been carried out, 75 are reported as giving a positive reaction, 49 positive and with a dose response, 1 positive and temperature-related, 9 borderline positive, and 30 negative; 76% of the chemicals gave a definite positive response. It is proposed that the Allium test be included among those tests routinely used for assessing chromosomal damage induced by chemicals.

  19. Chromosome rearrangements and transposable elements.

    Science.gov (United States)

    Lonnig, Wolf-Ekkehard; Saedler, Heinz

    2002-01-01

    There has been limited corroboration to date for McClintock's vision of gene regulation by transposable elements (TEs), although her proposition on the origin of species by TE-induced complex chromosome reorganizations in combination with gene mutations, i.e., the involvement of both factors in relatively sudden formations of species in many plant and animal genera, has been more promising. Moreover, resolution is in sight for several seemingly contradictory phenomena such as the endless reshuffling of chromosome structures and gene sequences versus synteny and the constancy of living fossils (or stasis in general). Recent wide-ranging investigations have confirmed and enlarged the number of earlier cases of TE target site selection (hot spots for TE integration), implying preestablished rather than accidental chromosome rearrangements for nonhomologous recombination of host DNA. The possibility of a partly predetermined generation of biodiversity and new species is discussed. The views of several leading transposon experts on the rather abrupt origin of new species have not been synthesized into the macroevolutionary theory of the punctuated equilibrium school of paleontology inferred from thoroughly consistent features of the fossil record. PMID:12429698

  20. Chromosome evolution in Solanum traced by cross-species BAC-FISH.

    Science.gov (United States)

    Szinay, Dóra; Wijnker, Erik; van den Berg, Ronald; Visser, Richard G F; de Jong, Hans; Bai, Yuling

    2012-08-01

    Chromosomal rearrangements are relatively rare evolutionary events and can be used as markers to study karyotype evolution. This research aims to use such rearrangements to study chromosome evolution in Solanum. Chromosomal rearrangements between Solanum crops and several related wild species were investigated using tomato and potato bacterial artificial chromosomes (BACs) in a multicolour fluorescent in situ hybridization (FISH). The BACs selected are evenly distributed over seven chromosomal arms containing inversions described in previous studies. The presence/absence of these inversions among the studied Solanum species were determined and the order of the BAC-FISH signals was used to construct phylogenetic trees.Compared with earlier studies, data from this study provide support for the current grouping of species into different sections within Solanum; however, there are a few notable exceptions, such as the tree positions of S. etuberosum (closer to the tomato group than to the potato group) and S. lycopersicoides (sister to S. pennellii). These apparent contradictions might be explained by interspecific hybridization events and/or incomplete lineage sorting. This cross-species BAC painting technique provides unique information on genome organization, evolution and phylogenetic relationships in a wide variety of species. Such information is very helpful for introgressive breeding. PMID:22686400

  1. Chromosome doubling in Paspalum notatum var. saure (cultivar Pensacola

    Directory of Open Access Journals (Sweden)

    Luis Weiler

    2015-04-01

    Full Text Available Paspalum notatum is one of the most important native grassland species of southern Brazil, and the main forage source for livestock. The native ecotypes are tetraploid and have apomictic reproduction, which prevents the registration and protection of plant varieties. However, the cultivated variety Paspalum notatum var. saurae (cultivar Pensacola is diploid and sexual. The objective of this study was to artificially produce polyploid cv. Pensacola plants, to be used as female parents in crosses with male tetraploid and apomictic parents. Seedlings and seeds were immersed in colchicine solutions for different periods. A tetraploid chromosome number was confirmed in three plants. The reproduction mode of the resulting polyploid plants will be assessed; if confirmed to be sexual, they can be used in crosses with native apomictic plants to breed new intraspecific hybrids.

  2. Artificial frustrated spin systems

    Science.gov (United States)

    Perrin, Y.; Chioar, I. A.; Nguyen, V. D.; Lacour, D.; Hehn, M.; Montaigne, F.; Canals, B.; Rougemaille, N.

    2015-09-01

    Complex architectures of nanostructures are routinely elaborated using bottom-up or nanofabrication processes. This technological capability allows scientists to engineer materials with properties that do not exist in nature, but also to manufacture model systems to explore fundamental issues in condensed matter physics. Two-dimensional frustrated arrays of magnetic nanostructures are one class of systems for which theoretical predictions can be tested experimentally. These systems have been the subject of intense research in the last few years and allowed the investigation of a rich physics and fascinating phenomena, such as the exploration of the extensively degenerate ground-state manifolds of spin ice systems, the evidence of new magnetic phases in purely two-dimensional lattices, and the observation of pseudoexcitations involving classical analogues of magnetic monopoles. We show here, experimentally and theoretically, that simple magnetic geometries can lead to unconventional, non-collinear spin textures. For example, kagome arrays of inplane magnetized nano-islands do not show magnetic order. Instead, these systems are characterized by spin textures with intriguing properties, such as chirality, coexistence of magnetic order and disorder, and charge crystallization. Magnetic frustration effects in lithographically patterned kagome arrays of nanomagnets with out-of-plane magnetization also lead to an unusal, and still unknown, magnetic ground state manifold. Besides the influence of the lattice geometry, the micromagnetic nature of the elements constituting the arrays introduce the concept of chiral magnetic monopoles, bringing additional complexity into the physics of artificial frustrated spin systems.

  3. Artificial Immune Systems Tutorial

    CERN Document Server

    Aickelin, Uwe

    2008-01-01

    The biological immune system is a robust, complex, adaptive system that defends the body from foreign pathogens. It is able to categorize all cells (or molecules) within the body as self-cells or non-self cells. It does this with the help of a distributed task force that has the intelligence to take action from a local and also a global perspective using its network of chemical messengers for communication. There are two major branches of the immune system. The innate immune system is an unchanging mechanism that detects and destroys certain invading organisms, whilst the adaptive immune system responds to previously unknown foreign cells and builds a response to them that can remain in the body over a long period of time. This remarkable information processing biological system has caught the attention of computer science in recent years. A novel computational intelligence technique, inspired by immunology, has emerged, called Artificial Immune Systems. Several concepts from the immune have been extracted an...

  4. Artificial Immune Systems

    CERN Document Server

    Aickelin, Uwe

    2009-01-01

    The biological immune system is a robust, complex, adaptive system that defends the body from foreign pathogens. It is able to categorize all cells (or molecules) within the body as self-cells or non-self cells. It does this with the help of a distributed task force that has the intelligence to take action from a local and also a global perspective using its network of chemical messengers for communication. There are two major branches of the immune system. The innate immune system is an unchanging mechanism that detects and destroys certain invading organisms, whilst the adaptive immune system responds to previously unknown foreign cells and builds a response to them that can remain in the body over a long period of time. This remarkable information processing biological system has caught the attention of computer science in recent years. A novel computational intelligence technique, inspired by immunology, has emerged, called Artificial Immune Systems. Several concepts from the immune have been extracted an...

  5. Comparative analysis of sex chromosomes in Leporinus species (Teleostei, Characiformes) using chromosome painting

    Science.gov (United States)

    2013-01-01

    Background The Leporinus genus, belonging to the Anostomidae family, is an interesting model for studies of sex chromosome evolution in fish, particularly because of the presence of heteromorphic sex chromosomes only in some species of the genus. In this study we used W chromosome-derived probes in a series of cross species chromosome painting experiments to try to understand events of sex chromosome evolution in this family. Results W chromosome painting probes from Leporinus elongatus, L. macrocephalus and L. obtusidens were hybridized to each others chromosomes. The results showed signals along their W chromosomes and the use of L. elongatus W probe against L. macrocephalus and L. obtusidens also showed signals over the Z chromosome. No signals were observed when the later aforementioned probe was used in hybridization procedures against other four Anostomidae species without sex chromosomes. Conclusions Our results demonstrate a common origin of sex chromosomes in L. elongatus, L. macrocephalus and L. obtusidens but suggest that the L. elongatus chromosome system is at a different evolutionary stage. The absence of signals in the species without differentiated sex chromosomes does not exclude the possibility of cryptic sex chromosomes, but they must contain other Leporinus W sequences than those described here. PMID:23822802

  6. Whole chromosome painting of B chromosomes of the red-eye tetra Moenkhausia sanctaefilomenae (Teleostei, Characidae)

    Science.gov (United States)

    Scudeler, Patricia Elda Sobrinho; Diniz, Débora; Wasko, Adriane Pinto; Oliveira, Claudio; Foresti, Fausto

    2015-01-01

    Abstract B chromosomes are dispensable genomic elements found in different groups of animals and plants. In the present study, a whole chromosome probe was generated from a specific heterochromatic B chromosome occurring in cells of the characidae fish Moenkhausia sanctaefilomenae (Steindachner, 1907). The chromosome painting probes were used in fluorescence in situ hybridization (FISH) experiments for the assessment of metaphase chromosomes obtained from individuals from three populations of Moenkhausia sanctaefilomenae. The results revealed that DNA sequences were shared between a specific B chromosome and many chromosomes of the A complement in all populations analyzed, suggesting a possible intra-specific origin of these B chromosomes. However, no hybridization signals were observed in other B chromosomes found in the same individuals, implying a possible independent origin of B chromosome variants in this species. FISH experiments using 18S rDNA probes revealed the presence of non-active ribosomal genes in some B chromosomes and in some chromosomes of the A complement, suggesting that at least two types of B chromosomes had an independent origin. The role of heterochromatic segments and ribosomal sequences in the origin of B chromosomes were discussed. PMID:26753081

  7. Chromosomal divergence and evolutionary inferences in Rhodniini based on the chromosomal location of ribosomal genes

    Directory of Open Access Journals (Sweden)

    Sebastian Pita

    2013-05-01

    Full Text Available In this study, we used fluorescence in situ hybridisation to determine the chromosomal location of 45S rDNA clusters in 10 species of the tribe Rhodniini (Hemiptera: Reduviidae: Triatominae. The results showed striking inter and intraspecific variability, with the location of the rDNA clusters restricted to sex chromosomes with two patterns: either on one (X chromosome or both sex chromosomes (X and Y chromosomes. This variation occurs within a genus that has an unchanging diploid chromosome number (2n = 22, including 20 autosomes and 2 sex chromosomes and a similar chromosome size and genomic DNA content, reflecting a genome dynamic not revealed by these chromosome traits. The rDNA variation in closely related species and the intraspecific polymorphism in Rhodnius ecuadoriensis suggested that the chromosomal position of rDNA clusters might be a useful marker to identify recently diverged species or populations. We discuss the ancestral position of ribosomal genes in the tribe Rhodniini and the possible mechanisms involved in the variation of the rDNA clusters, including the loss of rDNA loci on the Y chromosome, transposition and ectopic pairing. The last two processes involve chromosomal exchanges between both sex chromosomes, in contrast to the widely accepted idea that the achiasmatic sex chromosomes of Heteroptera do not interchange sequences.

  8. Genome-wide analysis of host-chromosome binding sites for Epstein-Barr Virus Nuclear Antigen 1 (EBNA1

    Directory of Open Access Journals (Sweden)

    Wang Pu

    2010-10-01

    Full Text Available Abstract The Epstein-Barr Virus (EBV Nuclear Antigen 1 (EBNA1 protein is required for the establishment of EBV latent infection in proliferating B-lymphocytes. EBNA1 is a multifunctional DNA-binding protein that stimulates DNA replication at the viral origin of plasmid replication (OriP, regulates transcription of viral and cellular genes, and tethers the viral episome to the cellular chromosome. EBNA1 also provides a survival function to B-lymphocytes, potentially through its ability to alter cellular gene expression. To better understand these various functions of EBNA1, we performed a genome-wide analysis of the viral and cellular DNA sites associated with EBNA1 protein in a latently infected Burkitt lymphoma B-cell line. Chromatin-immunoprecipitation (ChIP combined with massively parallel deep-sequencing (ChIP-Seq was used to identify cellular sites bound by EBNA1. Sites identified by ChIP-Seq were validated by conventional real-time PCR, and ChIP-Seq provided quantitative, high-resolution detection of the known EBNA1 binding sites on the EBV genome at OriP and Qp. We identified at least one cluster of unusually high-affinity EBNA1 binding sites on chromosome 11, between the divergent FAM55 D and FAM55B genes. A consensus for all cellular EBNA1 binding sites is distinct from those derived from the known viral binding sites, suggesting that some of these sites are indirectly bound by EBNA1. EBNA1 also bound close to the transcriptional start sites of a large number of cellular genes, including HDAC3, CDC7, and MAP3K1, which we show are positively regulated by EBNA1. EBNA1 binding sites were enriched in some repetitive elements, especially LINE 1 retrotransposons, and had weak correlations with histone modifications and ORC binding. We conclude that EBNA1 can interact with a large number of cellular genes and chromosomal loci in latently infected cells, but that these sites are likely to represent a complex ensemble of direct and indirect EBNA

  9. Development of an enhanced chromosomal expression system based on porin synthesis operon for halophile Halomonas sp.

    Science.gov (United States)

    Yin, Jin; Fu, Xiao-Zhi; Wu, Qiong; Chen, Jin-Chun; Chen, Guo-Qiang

    2014-11-01

    Since halophile Halomonas spp. can grow contamination free in seawater under unsterile and continuous conditions, it holds great promise for industrial biotechnology to produce low-cost chemicals in an economic way. Yet, metabolic engineering methods are urgently needed for Halomonas spp. It is commonly known that chromosomal expression is more stable yet weaker than plasmid one is. To overcome this challenge, a novel chromosomal expression method was developed for halophile Halomonas TD01 and its derivatives based on a strongly expressed porin gene as a site for external gene integration. The gene of interest was inserted downstream the porin gene, forming an artificial operon porin-inserted gene. This chromosome expression system was proven functional by some examples: First, chromosomal expression of heterologous polyhydroxybutyrate (PHB) synthase gene phaC Re from Ralstonia eutropha completely restored the PHB accumulation level in endogenous phaC knockout mutant of Halomonas TD01. The integrated phaC Re was expressed at the highest level when inserted at the locus of porin compared with insertions in other chromosome locations. Second, an inducible expression system was constructed in phaC-deleted Halomonas TD01 by integrating the lac repressor gene (lacI) into the porin site in the host chromosome. The native porin promoter was inserted with the key 21 bp DNA of lac operator (lacO) sequence to become an inducible promoter encoded in a plasmid. This inducible system allowed on-off switch of gene expression in Halomonas TD strains. Thus, the stable and strong chromosomal expression method in Halomonas TD spp. was established. PMID:25070598

  10. Chromosome analysis of arsenic affected cattle

    Directory of Open Access Journals (Sweden)

    S. Shekhar

    2014-10-01

    Full Text Available Aim: The aim was to study the chromosome analysis of arsenic affected cattle. Materials and Methods: 27 female cattle (21 arsenic affected and 6 normal were selected for cytogenetical study. The blood samples were collected, incubated, and cultured using appropriate media and specific methods. The samples were analyzed for chromosome number and morphology, relative length of the chromosome, arm ratio, and centromere index of X chromosome and chromosomal abnormalities in arsenic affected cattle to that of normal ones. Results: The diploid number of metaphase chromosomes in arsenic affected cattle as well as in normal cattle were all 2n=60, 58 being autosomes and 2 being sex chromosomes. From the centromeric position, karyotyping studies revealed that all the 29 pair of autosomes was found to be acrocentric or telocentric, and the sex chromosomes (XX were submetacentric in both normal and arsenic affected cattle. The relative length of all the autosome pairs and sex chrosomosome pair was found to be higher in normal than that of arsenic affected cattle. The mean arm ratio of X-chromosome was higher in normal than that of arsenic affected cattle, but it is reverse in case of centromere index value of X-chromosome. There was no significant difference of arm ratio and centromere index of X-chromosomes between arsenic affected and normal cattle. No chromosomal abnormalities were found in arsenic affected cattle. Conclusion: The chromosome analysis of arsenic affected cattle in West Bengal reported for the first time in this present study which may serve as a guideline for future studies in other species. These reference values will also help in comparison of cytological studies of arsenic affected cattle to that of various toxicants.

  11. The peripheral chromosome scaffold, a novel structural component of mitotic chromosomes.

    Science.gov (United States)

    Sheval, Eugene V; Polyakov, Vladimir Y

    2008-06-01

    Using an original high-salt extraction protocol, we observed a novel chromosome substructure, referred to as the peripheral chromosome scaffold. This chromosome domain contained the perichromosomal layer proteins pKi-67, B23/nucleophosmin and fibrillarin, but no DNA fragments (i.e., the loop domain bases were not associated with the peripheral scaffold). Modern models of chromosome organization do not predict the existence of a peripheral chromosome scaffold domain, and thus our observations have conceptual implications for understanding chromosome architecture. PMID:18337132

  12. Artificial Life Meets Computational Creativity?

    OpenAIRE

    McMullin, Barry

    2009-01-01

    I (briefly) review the history of work in Artificial Life on the problem of the open-ended evolutionary growth of complexity in computational worlds. This is then put into the context of evolutionary epistemology and human creativity.

  13. Darwin, artificial selection, and poverty.

    Science.gov (United States)

    Sanchez, Luis

    2010-03-01

    This paper argues that the processes of evolutionary selection are becoming increasingly artificial, a trend that goes against the belief in a purely natural selection process claimed by Darwin's natural selection theory. Artificial selection is mentioned by Darwin, but it was ignored by Social Darwinists, and it is all but absent in neo-Darwinian thinking. This omission results in an underestimation of probable impacts of artificial selection upon assumed evolutionary processes, and has implications for the ideological uses of Darwin's language, particularly in relation to poverty and other social inequalities. The influence of artificial selection on genotypic and phenotypic adaptations arguably represents a substantial shift in the presumed path of evolution, a shift laden with both biological and political implications. PMID:20812798

  14. Artificial Reefs and Ocean Dumping.

    Science.gov (United States)

    Glueck, Richard D.

    1983-01-01

    Activities and instructional strategies for two multigrade lessons are provided. Activity objectives include describing an artificial reef (such as a sunken ocean liner) as an ecosystem, knowing animal types in the ecosystem, and describing a food web. (JN)

  15. Artificial Intelligence in Civil Engineering

    Directory of Open Access Journals (Sweden)

    Pengzhen Lu

    2012-01-01

    Full Text Available Artificial intelligence is a branch of computer science, involved in the research, design, and application of intelligent computer. Traditional methods for modeling and optimizing complex structure systems require huge amounts of computing resources, and artificial-intelligence-based solutions can often provide valuable alternatives for efficiently solving problems in the civil engineering. This paper summarizes recently developed methods and theories in the developing direction for applications of artificial intelligence in civil engineering, including evolutionary computation, neural networks, fuzzy systems, expert system, reasoning, classification, and learning, as well as others like chaos theory, cuckoo search, firefly algorithm, knowledge-based engineering, and simulated annealing. The main research trends are also pointed out in the end. The paper provides an overview of the advances of artificial intelligence applied in civil engineering.

  16. Artificial weathering of granite

    Directory of Open Access Journals (Sweden)

    Silva Hermo, B.

    2008-06-01

    Full Text Available This article summarizes a series of artificial weathering tests run on granite designed to: simulate the action of weathering agents on buildings and identify the underlying mechanisms, determine the salt resistance of different types of rock; evaluate consolidation and water-repellent treatment durability; and confirm hypotheses about the origin of salts such as gypsum that are often found in granite buildings. Salt crystallization tests were also conducted, using sodium chloride, sodium sulphate, calcium sulphate and seawater solutions. One of these tests was conducted in a chamber specifically designed to simulate salt spray weathering and another in an SO2 chamber to ascertain whether granite is subject to sulphation. The test results are analyzed and discussed, along with the shortcomings of each type of trial as a method for simulating the decay observed in monuments. The effect of factors such as wet-dry conditions, type of saline solution and the position of the planes of weakness on the type of decay is also addressed.En este trabajo se hace una síntesis de varios ensayos de alteración artificial realizados con rocas graníticas. Estos ensayos tenían distintos objetivos: reproducir las formas de alteración encontradas en los edificios para llegar a conocer los mecanismos que las generan, determinar la resistencia de las diferentes rocas a la acción de las sales, evaluar la durabilidad de tratamientos de consolidación e hidrofugación y constatar hipótesis acerca del origen de algunas sales, como el yeso, que aparecen frecuentemente en edificios graníticos. En los ensayos de cristalización de sales se utilizaron disoluciones de cloruro de sodio, sulfato de sodio, sulfato de calcio y agua de mar. Uno de estos ensayos se llevó a cabo en una cámara especialmente diseñada para reproducir la alteración por aerosol marino y otro se realizó en una cámara de SO2, con el objeto de comprobar si en rocas graníticas se puede producir

  17. The handbook of artificial intelligence

    CERN Document Server

    Barr, Avron

    1982-01-01

    The Handbook of Artificial Intelligence, Volume II focuses on the improvements in artificial intelligence (AI) and its increasing applications, including programming languages, intelligent CAI systems, and the employment of AI in medicine, science, and education. The book first elaborates on programming languages for AI research and applications-oriented AI research. Discussions cover scientific applications, teiresias, applications in chemistry, dependencies and assumptions, AI programming-language features, and LISP. The manuscript then examines applications-oriented AI research in medicine

  18. Rewritable Artificial Magnetic Charge Ice

    OpenAIRE

    Wang, Yong-Lei; Xiao, Zhi-Li; Snezhko, Alexey; Xu, Jing; Ocola, Leonidas E.; Divan, Ralu; Pearson, John E.; Crabtree, George W.; Kwok, Wai-Kwong

    2016-01-01

    Artificial ices enable the study of geometrical frustration by design and through direct observation. However, it has proven difficult to achieve tailored long-range ordering of their diverse configurations, limiting both fundamental and applied research directions. We designed an artificial spin structure that produces a magnetic charge ice with tunable long-range ordering of eight different configurations. We also developed a technique to precisely manipulate the local magnetic charge state...

  19. Medical applications of artificial intelligence

    CERN Document Server

    Agah, Arvin

    2013-01-01

    Enhanced, more reliable, and better understood than in the past, artificial intelligence (AI) systems can make providing healthcare more accurate, affordable, accessible, consistent, and efficient. However, AI technologies have not been as well integrated into medicine as predicted. In order to succeed, medical and computational scientists must develop hybrid systems that can effectively and efficiently integrate the experience of medical care professionals with capabilities of AI systems. After providing a general overview of artificial intelligence concepts, tools, and techniques, Medical Ap

  20. What are artificial neural networks?

    DEFF Research Database (Denmark)

    Krogh, Anders

    2008-01-01

    Artificial neural networks have been applied to problems ranging from speech recognition to prediction of protein secondary structure, classification of cancers and gene prediction. How do they work and what might they be good for? Udgivelsesdato: 2008-Feb......Artificial neural networks have been applied to problems ranging from speech recognition to prediction of protein secondary structure, classification of cancers and gene prediction. How do they work and what might they be good for? Udgivelsesdato: 2008-Feb...

  1. DNA Probe Pooling for Rapid Delineation of Chromosomal Breakpoints

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Chun-Mei; Kwan, Johnson; Baumgartner, Adolf; Weier, Jingly F.; Wang, Mei; Escudero, Tomas; Munne' , Santiago; Zitzelsberger, Horst F.; Weier, Heinz-Ulrich

    2009-01-30

    Structural chromosome aberrations are hallmarks of many human genetic diseases. The precise mapping of translocation breakpoints in tumors is important for identification of genes with altered levels of expression, prediction of tumor progression, therapy response, or length of disease-free survival as well as the preparation of probes for detection of tumor cells in peripheral blood. Similarly, in vitro fertilization (IVF) and preimplantation genetic diagnosis (PGD) for carriers of balanced, reciprocal translocations benefit from accurate breakpoint maps in the preparation of patient-specific DNA probes followed by a selection of normal or balanced oocytes or embryos. We expedited the process of breakpoint mapping and preparation of case-specific probes by utilizing physically mapped bacterial artificial chromosome (BAC) clones. Historically, breakpoint mapping is based on the definition of the smallest interval between proximal and distal probes. Thus, many of the DNA probes prepared for multi-clone and multi-color mapping experiments do not generate additional information. Our pooling protocol described here with examples from thyroid cancer research and PGD accelerates the delineation of translocation breakpoints without sacrificing resolution. The turnaround time from clone selection to mapping results using tumor or IVF patient samples can be as short as three to four days.

  2. Deciphering evolutionary strata on plant sex chromosomes and fungal mating-type chromosomes through compositional segmentation.

    Science.gov (United States)

    Pandey, Ravi S; Azad, Rajeev K

    2016-03-01

    Sex chromosomes have evolved from a pair of homologous autosomes which differentiated into sex determination systems, such as XY or ZW system, as a consequence of successive recombination suppression between the gametologous chromosomes. Identifying the regions of recombination suppression, namely, the "evolutionary strata", is central to understanding the history and dynamics of sex chromosome evolution. Evolution of sex chromosomes as a consequence of serial recombination suppressions is well-studied for mammals and birds, but not for plants, although 48 dioecious plants have already been reported. Only two plants Silene latifolia and papaya have been studied until now for the presence of evolutionary strata on their X chromosomes, made possible by the sequencing of sex-linked genes on both the X and Y chromosomes, which is a requirement of all current methods that determine stratum structure based on the comparison of gametologous sex chromosomes. To circumvent this limitation and detect strata even if only the sequence of sex chromosome in the homogametic sex (i.e. X or Z chromosome) is available, we have developed an integrated segmentation and clustering method. In application to gene sequences on the papaya X chromosome and protein-coding sequences on the S. latifolia X chromosome, our method could decipher all known evolutionary strata, as reported by previous studies. Our method, after validating on known strata on the papaya and S. latifolia X chromosome, was applied to the chromosome 19 of Populus trichocarpa, an incipient sex chromosome, deciphering two, yet unknown, evolutionary strata. In addition, we applied this approach to the recently sequenced sex chromosome V of the brown alga Ectocarpus sp. that has a haploid sex determination system (UV system) recovering the sex determining and pseudoautosomal regions, and then to the mating-type chromosomes of an anther-smut fungus Microbotryum lychnidis-dioicae predicting five strata in the non

  3. Chromosome engineering: power tools for plant genetics.

    Science.gov (United States)

    Chan, Simon W L

    2010-12-01

    The term "chromosome engineering" describes technologies in which chromosomes are manipulated to change their mode of genetic inheritance. This review examines recent innovations in chromosome engineering that promise to greatly increase the efficiency of plant breeding. Haploid Arabidopsis thaliana have been produced by altering the kinetochore protein CENH3, yielding instant homozygous lines. Haploid production will facilitate reverse breeding, a method that downregulates recombination to ensure progeny contain intact parental chromosomes. Another chromosome engineering success is the conversion of meiosis into mitosis, which produces diploid gametes that are clones of the parent plant. This is a key step in apomixis (asexual reproduction through seeds) and could help to preserve hybrid vigor in the future. New homologous recombination methods in plants will potentiate many chromosome engineering applications. PMID:20933291

  4. Radiation induced chromosome instability in human fibroblasts

    International Nuclear Information System (INIS)

    Evidence has been arising that some biological effects can manifest many cell divisions after irradiation. We have demonstrated that de novo chromosome instability can be detected 10- 15 mean population doubling after heavy ion irradiations. This chromosome instability is characterized by end to end fusions between specific chromosomes. The specificity of the instability may differ from one donor to another but for the same donor, the same instability should be observed after irradiation, during the senescence process and after SV40 transfection (before crisis). In irradiated primary culture fibroblasts, the expression of the delayed chromosomal instability lasts for several cell divisions without inducing cell death. Several rounds of fusions- breakage-fusions can be performed and unbalanced clones emerge (gain or loss of chromosomes with the shorter telomeres would become unstable first.. The difference in the chromosomal instability among donors could be due to a polymorphism in telomere lengths. This could induce large variation in long term response to irradiation among individuals. (author)

  5. DNA sequences and composition from 12 BAC clones-derived MUSB SSR markers mapped to cotton (Gossypium Hirsutum L. x G. Barbadense L.)chromosomes 11 and 21

    Science.gov (United States)

    To discover resistance (R) and/or pathogen-induced (PR) genes involved in disease response, 12 bacterial artificial chromosome (BAC) clones from cv. Acala Maxxa (G. hirsutum) were sequenced at the Clemson University, Genomics Institute, Clemson, SC. These BACs derived MUSB single sequence repeat (SS...

  6. Meiosis I: When Chromosomes Undergo Extreme Makeover

    OpenAIRE

    Miller, Matthew P.; Amon, Angelika; Ünal, Elçin

    2013-01-01

    The ultimate success of cell division relies on the accurate partitioning of the genetic material. Errors in this process occur in nearly all tumors and are the leading cause of miscarriages and congenital birth defects in humans. Two cell divisions, mitosis and meiosis, use common as well as unique mechanisms to ensure faithful chromosome segregation. In mitosis, alternating rounds of DNA replication and chromosome segregation preserves the chromosome complement of the progenitor cell. In co...

  7. Novel Gene Acquisition on Carnivore Y Chromosomes

    OpenAIRE

    Murphy, William J.; A J Pearks Wilkerson; Terje Raudsepp; Richa Agarwala; Schäffer, Alejandro A.; Roscoe Stanyon; Chowdhary, Bhanu P

    2006-01-01

    Despite its importance in harboring genes critical for spermatogenesis and male-specific functions, the Y chromosome has been largely excluded as a priority in recent mammalian genome sequencing projects. Only the human and chimpanzee Y chromosomes have been well characterized at the sequence level. This is primarily due to the presumed low overall gene content and highly repetitive nature of the Y chromosome and the ensuing difficulties using a shotgun sequence approach for assembly. Here we...

  8. Identification of bacterial cells by chromosomal painting.

    OpenAIRE

    Lanoil, B. D.; Giovannoni, S J

    1997-01-01

    Chromosomal painting is a technique for the microscopic localization of genetic material. It has been applied at the subcellular level to identify regions of eukaryotic chromosomes. Here we describe the development of bacterial chromosomal painting (BCP), a related technology for the identification of bacterial cells. Purified genomic DNAs from six bacterial strains were labeled by nick translation with the fluorochrome Fluor-X, Cy3, or Cy5. The average size of the labeled fragments was ca. 5...

  9. Holoprosencephaly due to Numeric Chromosome Abnormalities

    OpenAIRE

    Solomon, Benjamin D.; Rosenbaum, Kenneth N.; Meck, Jeanne M.; Muenke, Maximilian

    2010-01-01

    Holoprosencephaly (HPE) is the most common malformation of the human forebrain. When a clinician identifies a patient with HPE, a routine chromosome analysis is often the first genetic test sent for laboratory analysis in order to assess for a structural or numerical chromosome anomaly. An abnormality of chromosome number is overall the most frequently identified etiology in a patient with HPE. These abnormalities include trisomy 13, trisomy 18, and triploidy, though several others have been ...

  10. CHROMOSOMAL ABNORMALITIES IN PATIENTS WITH RECURRENT MISCARRIAGE

    OpenAIRE

    Daniela Mierla; Viorica Radoi; Veronica Stoian

    2012-01-01

    Chromosomal abnormalities are involved in the etiology of recurrent spontaneous pregnancy loss and sub-fertility. The purpose of this study was to determine the frequency and contribution of chromosomal abnormalities in recurrent miscarriages. The results obtained and literature review are helpful in understanding the importance of cytogenetics analysis of female infertility. To investigate the distribution of chromosomal abnormalities in the Romanian population with recurrent miscarriage, ka...

  11. How does DNA break during chromosomal translocations?

    OpenAIRE

    Nambiar, Mridula; Raghavan, Sathees C.

    2011-01-01

    Chromosomal translocations are one of the most common types of genetic rearrangements and are molecular signatures for many types of cancers. They are considered as primary causes for cancers, especially lymphoma and leukemia. Although many translocations have been reported in the last four decades, the mechanism by which chromosomes break during a translocation remains largely unknown. In this review, we summarize recent advances made in understanding the molecular mechanism of chromosomal t...

  12. Advances in plant chromosome genomics

    Czech Academy of Sciences Publication Activity Database

    Doležel, Jaroslav; Vrána, Jan; Cápal, Petr; Kubaláková, Marie; Burešová, Veronika; Šimková, Hana

    2014-01-01

    Roč. 32, č. 1 (2014), s. 122-136. ISSN 0734-9750 R&D Projects: GA ČR GAP501/10/1740; GA ČR GAP501/10/1778; GA ČR GBP501/12/G090; GA MŠk(CZ) LO1204 Grant ostatní: GA MŠk(CZ) ED0007/01/01 Institutional support: RVO:61389030 Keywords : BAC library * Chromosome sorting * Cytogenetics Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 9.015, year: 2014

  13. Multiple chromosomes of Azotobacter vinelandii.

    OpenAIRE

    1989-01-01

    The number of copies of the genes leuB, nifH, nifD, and nifK per cell of Azotobacter vinelandii has been determined to be about 80. A beta-lactamase gene was integrated into the A. vinelandii chromosome by single-point crossover. Subsequently, we have been able to detect nearly 80 copies of this beta-lactamase gene per cell of A. vinelandii when cultured for a large number of generations in the presence of ampicillin. The multiple copies of the beta-lactamase gene do not seem to be present on...

  14. Chromosome banding in Amphibia. XXIV. The B chromosomes of Gastrotheca espeletia (Anura, Hylidae).

    Science.gov (United States)

    Schmid, M; Ziegler, C G; Steinlein, C; Nanda, I; Haaf, T

    2002-01-01

    The mitotic chromosomes of an Ecuadorian population of the marsupial frog Gastrotheca espeletia were analyzed by means of banding techniques and fluorescence in situ hybridization. This species is characterized by unusual supernumerary (B) chromosomes. The maximum number of B chromosomes is 9 and they occur in three different morphological types. Banding analyses show that the B chromosomes are completely heterochromatic, consist of AT base pair-rich repeated DNA sequences, replicate their DNA in very late S-phase of the cell cycle, and are probably derived from a centromeric or paracentromeric region of a standard (A) chromosome. Exceptionally, the B chromosomes carry 18S + 28S ribosomal RNA genes and the conserved vertebrate telomeric DNA sequence appears to be underrepresented. Flow cytometric measurements of the nuclear DNA content differentiate between individuals with different numbers of B chromosomes. Significantly more B chromosomes are present in female than in male animals. PMID:12438715

  15. Giemsa C-banding of Barley Chromosomes. IV. Chromosomal Constitution of Autotetraploid Barley

    DEFF Research Database (Denmark)

    Linde-Laursen, Ib

    1984-01-01

    homologues of each of the chromosomes. The aneuploid C2--seedlings were fairly equally distributed on hypo-and hyperploids, and on the seven chromosome groups. This suggests that a particular chromosome is lost or gained at random in gametes and embryos. The 11 C3--seedlings comprised seven true euploids......The progeny of an autotetraploid barley plant (C1) consisted of 45 tetraploids and 33 aneuploids. Giemsa C-banding was used to identify each of the chromosomes in 20 euploid and 31 aneuploid C2--seedlings, and in 11 C3--offspring of aneuploid C2--plants. The euploid C2--seedlings all had four......, one seedling with 2n=28 having an extra chromosome 6 and missing one chromosome 3, and three seedlings with 2n=29. The chromosomal composition of aneuploid C3--seedlings did not reflect that of their aneuploid C2--parents with respect to missing or extra chromosomes. Two hypohexaploid C2--seedlings...

  16. Microtubule detyrosination guides chromosomes during mitosis

    OpenAIRE

    Barisic, Marin; Silva e Sousa, Ricardo; Tripathy, Suvranta K.; Magiera, Maria M.; Zaytsev, Anatoly V.; Pereira, Ana L.; Janke, Carsten; Grishchuk, Ekaterina L.; Maiato, Helder

    2015-01-01

    Before chromosomes segregate into daughter cells they align at the mitotic spindle equator, a process known as chromosome congression. CENP-E/Kinesin-7 is a microtubule plus-end-directed kinetochore motor required for congression of pole-proximal chromosomes. Because the plus-ends of many astral microtubules in the spindle point to the cell cortex, it remains unknown how CENP-E guides pole-proximal chromosomes specifically towards the equator. Here we found that congression of pole-proximal c...

  17. Exceptional Complex Chromosomal Rearrangements in Three Generations

    Directory of Open Access Journals (Sweden)

    Hannie Kartapradja

    2015-01-01

    Full Text Available We report an exceptional complex chromosomal rearrangement (CCR found in three individuals in a family that involves 4 chromosomes with 5 breakpoints. The CCR was ascertained in a phenotypically abnormal newborn with additional chromosomal material on the short arm of chromosome 4. Maternal karyotyping indicated that the mother carried an apparently balanced CCR involving chromosomes 4, 6, 11, and 18. Maternal transmission of the derivative chromosome 4 resulted in partial trisomy for chromosomes 6q and 18q and a partial monosomy of chromosome 4p in the proband. Further family studies found that the maternal grandmother carried the same apparently balanced CCR as the proband’s mother, which was confirmed using the whole chromosome painting (WCP FISH. High resolution whole genome microarray analysis of DNA from the proband’s mother found no evidence for copy number imbalance in the vicinity of the CCR translocation breakpoints, or elsewhere in the genome, providing evidence that the mother’s and grandmother’s CCRs were balanced at a molecular level. This structural rearrangement can be categorized as an exceptional CCR due to its complexity and is a rare example of an exceptional CCR being transmitted in balanced and/or unbalanced form across three generations.

  18. Chromosome heteromorphisms in the Japanese, 3

    International Nuclear Information System (INIS)

    The type and frequency of chromosome variants detected by the C-staining method were ascertained in 1,857 individuals residing in Hiroshima. The most frequent heteromorphic variant was the total inversion of the C-band in chromosome 9 found in 27 individuals (1.45%). The total inversion of the C-band in chromosome 1 was not seen in this sample, but the partial inversion of the C-band in chromosome 1 was found in 18 persons (0.97%). Partial inversion was also detected in the C-band in chromosome 9 in 22 individuals (1.18%). In chromosome 16, neither total nor partial inversion of the C-band was observed in the present study. The frequencies of chromosomes 1, 9, and 16 with a very large C-band were 0.70%, 0.22%, and 0.54%, respectively. Aside from these (1, 9, and 16) a very large C-band was found occasionally in chromosomes 4, 5, 6, 11, 12, 14, and 15, and an unusual insertion of the Y chromosome was observed. A total of 128 C-band variants (6.89%) was found in the 1,857 Hiroshima residents. (author)

  19. Cognitive and medical features of chromosomal aneuploidy.

    Science.gov (United States)

    Hutaff-Lee, Christa; Cordeiro, Lisa; Tartaglia, Nicole

    2013-01-01

    This chapter describes the physical characteristics, medical complications, and cognitive and psychological profiles that are associated with chromosomal aneuploidy conditions, a group of conditions in which individuals are born with one or more additional chromosome. Overall, chromosomal aneuploidy conditions occur in approximately 1 in 250 children. Information regarding autosomal disorders including trisomy 21 (Down syndrome), trisomy 13 (Patau syndrome), and trisomy 18 (Edward syndrome) are presented. Sex chromosome aneuploidy conditions such as Klinefelter syndrome (47,XXY), XYY, trisomy X, and Turner syndrome (45,X), in addition to less frequently occurring tetrasomy and pentasomy conditions are also covered. Treatment recommendations and suggestions for future research directions are discussed. PMID:23622175

  20. Chromosomal aberrations in ore miners of Slovakia

    International Nuclear Information System (INIS)

    A pilot study was performed in which the incidence of chromosomal aberrations in lymphocytes of miners in ore mines located in Central Slovakia was monitored and related to lifetime underground radon exposure and to lifetime smoking. The conclusions drawn from the results of the study were as follows: the counts of chromosomal aberrations in lymphocytes of miners were significantly higher than in an age matched control group of white-collar staff; the higher counts of chromosomal aberrations could be ascribed to underground exposure of miners and to smoking; a dependence of chromosomal aberration counts on the exposure to radon could not be assessed. (A.K.)

  1. Chromosomal replicons of higher plants

    Energy Technology Data Exchange (ETDEWEB)

    Van' t Hof, J.

    1987-03-16

    This brief discussion of replicons of higher plants offers a glimpse into the properties of chromosomal DNA replication. It gives evidence that the S phase of unrelated plant species is comprised of temporally ordered replicon families that increase in number with genome size. This orderly process, which assures a normal inheritance of genetic material to recipient daughter cells, is maintained at the level of replicon clusters by two mutually exclusive mechanisms, one involving the rate at which single replicons replicate their allotment of DNA, and another by means of the tempo-pause. The same two mechanisms are used by cells to alter the pattern of chromosomal DNA replication just prior to and during normal development. Both mechanisms are genetically determined and produce genetic effects when disturbed of disrupted by additional non-conforming DNAs. Further insight into how these two mechanisms operate requires more molecular information about the nature of replicons and the factors that govern when a replicon family replicates. Plant material is a rich and ideal source for this information just awaiting exploitation. 63 refs.

  2. Increased chromosome radiosensitivity during pregnancy

    International Nuclear Information System (INIS)

    It was necessary to consider the risks of exposure of pregnant women, not only in relation to the child, but also in relation to their own hypersensitivity. We have demonstrated that pregnancy increases radiosensitivity of chromosome in the mouse at the end of gestation. This is of importance since it may have implications on radioprotection of pregnant women and give experimental guidelines to the problems of hypersensitivity to drugs and cancer aggravation during pregnancy. Blood obtained from women at various times of pregnancy was exposed to ionizing radiations. By comparison to non-pregnant women, an increase in chromosome breakage was observed in metaphases from lymphocytes, after short-term culture in the presence of the serum of the same donor. Immediately after delivery, this increase in radiosensitivity disappeared. In a prospective study, serial analyses showed a very strong correlation between the amount of pregnancy hormones, progesterone in particular, and the increase in radiosensitivity. Pregnant women may have an increased sensitivity to ionizing radiation during the second half of their pregnancy. This study provides the first evidence in human that radiosensitivity may vary in relation to physiological conditions

  3. Retrospective dosimetry by chromosomal analysis

    International Nuclear Information System (INIS)

    The joint EU/CIS project ECP-6, was set up to examine whether cytogenetic dosimetry is possible for persons irradiated years previously at Chernobyl. The paper describes the possibility of achieving this by the examination of blood lymphocytes for unstable and stable chromosome aberrations; dicentrics and translocations. Emphasis was placed on the relatively new fluorescence in situ hybridization (FISH) method for rapid screening for stable translocations. In a collaborative experiment in vitro dose response calibration curves for dicentrics and FISH were produced with gamma radiation over the range 0-1.0 Gy. A pilot study of about 60 liquidators with registered doses ranging from 0-300 mSv was undertaken to determine whether the chromosomal methods may verify the recorded doses. It was concluded that the dicentric is no longer valid as a measured endpoint. Translocations may be used to verify early dosimetry carried out on highly irradiated persons. For the vast majority of lesser exposed subjects FISH is impractical as an individual dosimeter; it may have some value for comparing groups of subjects

  4. Chromosomal instability determines taxane response.

    Science.gov (United States)

    Swanton, Charles; Nicke, Barbara; Schuett, Marion; Eklund, Aron C; Ng, Charlotte; Li, Qiyuan; Hardcastle, Thomas; Lee, Alvin; Roy, Rajat; East, Philip; Kschischo, Maik; Endesfelder, David; Wylie, Paul; Kim, Se Nyun; Chen, Jie-Guang; Howell, Michael; Ried, Thomas; Habermann, Jens K; Auer, Gert; Brenton, James D; Szallasi, Zoltan; Downward, Julian

    2009-05-26

    Microtubule-stabilizing (MTS) agents, such as taxanes, are important chemotherapeutics with a poorly understood mechanism of action. We identified a set of genes repressed in multiple cell lines in response to MTS agents and observed that these genes are overexpressed in tumors exhibiting chromosomal instability (CIN). Silencing 22/50 of these genes, many of which are involved in DNA repair, caused cancer cell death, suggesting that these genes are involved in the survival of aneuploid cells. Overexpression of these "CIN-survival" genes is associated with poor outcome in estrogen receptor-positive breast cancer and occurs frequently in basal-like and Her2-positive cases. In diploid cells, but not in chromosomally unstable cells, paclitaxel causes repression of CIN-survival genes, followed by cell death. In the OV01 ovarian cancer clinical trial, a high level of CIN was associated with taxane resistance but carboplatin sensitivity, indicating that CIN may determine MTS response in vivo. Thus, pretherapeutic assessment of CIN may optimize treatment stratification and clinical trial design using these agents. PMID:19458043

  5. Chromosomal replicons of higher plants

    International Nuclear Information System (INIS)

    This brief discussion of replicons of higher plants offers a glimpse into the properties of chromosomal DNA replication. It gives evidence that the S phase of unrelated plant species is comprised of temporally ordered replicon families that increase in number with genome size. This orderly process, which assures a normal inheritance of genetic material to recipient daughter cells, is maintained at the level of replicon clusters by two mutually exclusive mechanisms, one involving the rate at which single replicons replicate their allotment of DNA, and another by means of the tempo-pause. The same two mechanisms are used by cells to alter the pattern of chromosomal DNA replication just prior to and during normal development. Both mechanisms are genetically determined and produce genetic effects when disturbed of disrupted by additional non-conforming DNAs. Further insight into how these two mechanisms operate requires more molecular information about the nature of replicons and the factors that govern when a replicon family replicates. Plant material is a rich and ideal source for this information just awaiting exploitation. 63 refs

  6. The X chromosome of monotremes shares a highly conserved region with the eutherian and marsupial X chromosomes despite the absence of X chromosome inactivation

    Energy Technology Data Exchange (ETDEWEB)

    Watson, J.M.; Spencer, J.A.; Graves, J.A.M. (La Trobe Univ., Bundoora, Victoria (Australia)); Riggs, A.D. (Beckman Inst., Duarte, CA (USA))

    1990-09-01

    Eight genes, located on the long arm of the human X chromosome and present on the marsupial X chromosome, were mapped by in situ hybridization to the chromosomes of the platypus Ornithorhynchus anatinus, one of the three species of monotreme mammals. All were located on the X chromosome. The authors conclude that the long arm of the human X chromosome represents a highly conserved region that formed part of the X chromosome in a mammalian ancestor at least 150 million years ago. Since three of these genes are located on the long arm of the platypus X chromosome, which is G-band homologous to the Y chromosome and apparently exempt from X chromosome inactivation, the conservation of this region has evidently not depended on isolation by X-Y chromosome differentiation and X chromosome inactivation.

  7. Biological Effects Of Artificial Illumination

    Science.gov (United States)

    Corth, Richard

    1980-10-01

    We are increasingly being warned of the possible effects of so called "polluted" light, that is light that differs in spectral content from that of sunlight. We should be concerned, we are told, because all animals and plants have evolved under this natural daylight and therefore any difference between that illuminant and the artificial illuminants that are on the market today, is suspect. The usual presentation of the differences between the sunlight and the artificial illuminants are as shown in Figure 1. Here we are shown the spectral power distribution of sunlight and Cool White fluorescent light. The spectral power distributions of each have been normalized to some convenient wavelength so that each can be seen and easily compared on the same figure. But this presentation is misleading for one does not experience artificial illuminants at the same intensity as one experiences sunlight. Sunlight intensities are ordinarily found to be in the 8000 to 10,000 footcandle range whereas artificial illuminants are rarely experienced at intensity levels greater than 100 footcandles. Therefore a representative difference between the two types of illumination conditions is more accurately represented as in Figure 2. Thus if evolutionary adaptations require that humans and other animals be exposed to sunlight to ensure wellbeing, it is clear that one must be exposed to sunlight intensities. It is not feasible to expect that artificially illuminated environments will be lit to the same intensity as sunlight

  8. Chromosomal painting and ZW sex chromosomes differentiation in Characidium (Characiformes, Crenuchidae

    Directory of Open Access Journals (Sweden)

    Artoni Roberto F

    2011-07-01

    Full Text Available Abstract Background The Characidium (a Neotropical fish group have a conserved diploid number (2n = 50, but show remarkable differences among species and populations in relation to sex chromosome systems and location of nucleolus organizer regions (NOR. In this study, we isolated a W-specific probe for the Characidium and characterized six Characidium species/populations using cytogenetic procedures. We analyzed the origin and differentiation of sex and NOR-bearing chromosomes by chromosome painting in populations of Characidium to reveal their evolution, phylogeny, and biogeography. Results A W-specific probe for efficient chromosome painting was isolated by microdissection and degenerate oligonucleotide primed-polymerase chain reaction (DOP-PCR amplification of W chromosomes from C. gomesi. The W probe generated weak signals dispersed on the proto sex chromosomes in C. zebra, dispersed signals in both W and Z chromosomes in C. lauroi and, in C. gomesi populations revealed a proximal site on the long arms of the Z chromosome and the entire W chromosome. All populations showed small terminal W probe sites in some autosomes. The 18S rDNA revealed distinctive patterns for each analyzed species/population with regard to proto sex chromosome, sex chromosome pair, and autosome location. Conclusions The results from dual-color fluorescence in situ hybridization (dual-color FISH using W and 18S rDNA probes allowed us to infer the putative evolutionary pathways for the differentiation of sex chromosomes and NORs, from structural rearrangements in a sex proto-chromosome, followed by gene erosion and heterochromatin amplification, morphological differentiation of the sex chromosomal pair, and NOR transposition, giving rise to the distinctive patterns observed among species/populations of Characidium. Biogeographic isolation and differentiation of sex chromosomes seem to have played a major role in the speciation process in this group of fish.

  9. Chromosomal painting and ZW sex chromosomes differentiation in Characidium (Characiformes, Crenuchidae)

    Science.gov (United States)

    2011-01-01

    Background The Characidium (a Neotropical fish group) have a conserved diploid number (2n = 50), but show remarkable differences among species and populations in relation to sex chromosome systems and location of nucleolus organizer regions (NOR). In this study, we isolated a W-specific probe for the Characidium and characterized six Characidium species/populations using cytogenetic procedures. We analyzed the origin and differentiation of sex and NOR-bearing chromosomes by chromosome painting in populations of Characidium to reveal their evolution, phylogeny, and biogeography. Results A W-specific probe for efficient chromosome painting was isolated by microdissection and degenerate oligonucleotide primed-polymerase chain reaction (DOP-PCR) amplification of W chromosomes from C. gomesi. The W probe generated weak signals dispersed on the proto sex chromosomes in C. zebra, dispersed signals in both W and Z chromosomes in C. lauroi and, in C. gomesi populations revealed a proximal site on the long arms of the Z chromosome and the entire W chromosome. All populations showed small terminal W probe sites in some autosomes. The 18S rDNA revealed distinctive patterns for each analyzed species/population with regard to proto sex chromosome, sex chromosome pair, and autosome location. Conclusions The results from dual-color fluorescence in situ hybridization (dual-color FISH) using W and 18S rDNA probes allowed us to infer the putative evolutionary pathways for the differentiation of sex chromosomes and NORs, from structural rearrangements in a sex proto-chromosome, followed by gene erosion and heterochromatin amplification, morphological differentiation of the sex chromosomal pair, and NOR transposition, giving rise to the distinctive patterns observed among species/populations of Characidium. Biogeographic isolation and differentiation of sex chromosomes seem to have played a major role in the speciation process in this group of fish. PMID:21787398

  10. Artificial sweeteners: safe or unsafe?

    Science.gov (United States)

    Qurrat-ul-Ain; Khan, Sohaib Ahmed

    2015-02-01

    Artificial sweeteners or intense sweeteners are sugar substitutes that are used as an alternative to table sugar. They are many times sweeter than natural sugar and as they contain no calories, they may be used to control weight and obesity. Extensive scientific research has demonstrated the safety of the six low-calorie sweeteners currently approved for use in foods in the U.S. and Europe (stevia, acesulfame-K, aspartame, neotame, saccharin and sucralose), if taken in acceptable quantities daily. There is some ongoing debate over whether artificial sweetener usage poses a health threat .This review article aims to cover thehealth benefits, and risks, of consuming artificial sweeteners, and discusses natural sweeteners which can be used as alternatives. PMID:25842566

  11. Computational aerodynamics and artificial intelligence

    Science.gov (United States)

    Mehta, U. B.; Kutler, P.

    1984-01-01

    The general principles of artificial intelligence are reviewed and speculations are made concerning how knowledge based systems can accelerate the process of acquiring new knowledge in aerodynamics, how computational fluid dynamics may use expert systems, and how expert systems may speed the design and development process. In addition, the anatomy of an idealized expert system called AERODYNAMICIST is discussed. Resource requirements for using artificial intelligence in computational fluid dynamics and aerodynamics are examined. Three main conclusions are presented. First, there are two related aspects of computational aerodynamics: reasoning and calculating. Second, a substantial portion of reasoning can be achieved with artificial intelligence. It offers the opportunity of using computers as reasoning machines to set the stage for efficient calculating. Third, expert systems are likely to be new assets of institutions involved in aeronautics for various tasks of computational aerodynamics.

  12. Artificial heart for humanoid robot

    Science.gov (United States)

    Potnuru, Akshay; Wu, Lianjun; Tadesse, Yonas

    2014-03-01

    A soft robotic device inspired by the pumping action of a biological heart is presented in this study. Developing artificial heart to a humanoid robot enables us to make a better biomedical device for ultimate use in humans. As technology continues to become more advanced, the methods in which we implement high performance and biomimetic artificial organs is getting nearer each day. In this paper, we present the design and development of a soft artificial heart that can be used in a humanoid robot and simulate the functions of a human heart using shape memory alloy technology. The robotic heart is designed to pump a blood-like fluid to parts of the robot such as the face to simulate someone blushing or when someone is angry by the use of elastomeric substrates and certain features for the transport of fluids.

  13. Non-disjunction of chromosome 13

    DEFF Research Database (Denmark)

    Bugge, Merete; Collins, Andrew; Hertz, Jens Michael;

    2007-01-01

    recombination in both maternal MI and MII errors and the former is associated with a significant number of tetrads (33%) that are nullichiasmate, which do not appear to be a feature of normal chromosome 13 meiosis. This study supports the evidence for subtle chromosome-specific influences on the mechanisms that...

  14. Chromosome number9 specific repetitive DNA sequence

    International Nuclear Information System (INIS)

    Human repetitive DNA libraries have been constructed and various recombinant DNA clones isolated that are likely candidates for chromosome specific sequences. The first clone tested (pHuR 98; plasmid human repeat 98) was biotinylated and hybridized to human chromosomes in situ. The hybridized recombinant probe was detected with fluoresceinated avidin, and chromosomes were counter-stained with either propidium iodide or distamycin-DAPI. Specific hybridization to chromosome band 9q1 was obtained. The localization was confirmed by hybridizing radiolabeled pHuR 98 DNA to human chromosomes sorted by flow cytometry. Various methods, including orthogonal field pulsed gel electrophoresis analysis indicate that 75 kilobase blocks of this sequence are interspersed with other repetitive DNA sequences in this chromosome band. This study is the first to report a human repetitive DNA sequence uniquely localized to a specific chromosome. This clone provides an easily detected and highly specific chromosomal marker for molecular cytogenetic analyses in numerous basic research and clinical studies

  15. Chromosomal characterization of Pseudonannolene strinatii (Spirostreptida, Pseudonannolenidae

    Directory of Open Access Journals (Sweden)

    Kleber Agari Campos

    2004-03-01

    Full Text Available The chromosomes of the cave millipede Pseudonannolene strinatii Mauriès, 1974 were investigated. The diploid chromosome number was found to be 2n=16, XX/XY; the C-banding technique revealed a large amount of heterochromatin while the silver staining technique (Ag-NOR evidenced the presence of heteromorphism of the NORs in some cells.

  16. Chromosomal Aneuploidies and Early Embryonic Developmental Arrest

    Directory of Open Access Journals (Sweden)

    Maria Maurer

    2015-07-01

    Full Text Available Background: Selecting the best embryo for transfer, with the highest chance of achieving a vital pregnancy, is a major goal in current in vitro fertilization (IVF technology. The high rate of embryonic developmental arrest during IVF treatment is one of the limitations in achieving this goal. Chromosomal abnormalities are possibly linked with chromosomal arrest and selection against abnormal fertilization products. The objective of this study was to evaluate the frequency and type of chromosomal abnormalities in preimplantation embryos with developmental arrest. Materials and Methods: This cohort study included blastomeres of embryos with early developmental arrest that were biopsied and analyzed by fluorescence in-situ hybridization (FISH with probes for chromosomes 13, 16, 18, 21 and 22. Forty-five couples undergoing IVF treatment were included, and 119 arrested embryos were biopsied. All probes were obtained from the Kinderwunsch Zentrum, Linz, Austria, between August 2009 and August 2011. Results: Of these embryos, 31.6% were normal for all chromosomes tested, and 68.4% were abnormal. Eleven embryos were uniformly aneuploid, 20 were polyploid, 3 were haploid, 11 displayed mosaicism and 22 embryos exhibited chaotic chromosomal complement. Conclusion: Nearly 70% of arrested embryos exhibit chromosomal errors, making chromosomal abnormalities a major cause of embryonic arrest and may be a further explanation for the high developmental failure rates during culture of the embryos in the IVF setting.

  17. Mechanisms of Chromosome Number Evolution in Yeast

    Science.gov (United States)

    Gordon, Jonathan L.; Byrne, Kevin P.; Wolfe, Kenneth H.

    2011-01-01

    The whole-genome duplication (WGD) that occurred during yeast evolution changed the basal number of chromosomes from 8 to 16. However, the number of chromosomes in post-WGD species now ranges between 10 and 16, and the number in non-WGD species (Zygosaccharomyces, Kluyveromyces, Lachancea, and Ashbya) ranges between 6 and 8. To study the mechanism by which chromosome number changes, we traced the ancestry of centromeres and telomeres in each species. We observe only two mechanisms by which the number of chromosomes has decreased, as indicated by the loss of a centromere. The most frequent mechanism, seen 8 times, is telomere-to-telomere fusion between two chromosomes with the concomitant death of one centromere. The other mechanism, seen once, involves the breakage of a chromosome at its centromere, followed by the fusion of the two arms to the telomeres of two other chromosomes. The only mechanism by which chromosome number has increased in these species is WGD. Translocations and inversions have cycled telomere locations, internalizing some previously telomeric genes and creating novel telomeric locations. Comparison of centromere structures shows that the length of the CDEII region is variable between species but uniform within species. We trace the complete rearrangement history of the Lachancea kluyveri genome since its common ancestor with Saccharomyces and propose that its exceptionally low level of rearrangement is a consequence of the loss of the non-homologous end joining (NHEJ) DNA repair pathway in this species. PMID:21811419

  18. Genomic Dark Matter Illuminated: Anopheles Y Chromosomes.

    Science.gov (United States)

    Redmond, Seth N; Neafsey, Daniel E

    2016-08-01

    Hall et al. have strategically used long-read sequencing technology to characterize the structure and highly repetitive content of the Y chromosome in Anopheles malaria mosquitoes. Their work confirms that this important but elusive heterochromatic sex chromosome is evolving extremely rapidly and harbors a remarkably small number of genes. PMID:27263828

  19. Physical map of the Bacillus cereus chromosome.

    OpenAIRE

    Kolstø, A B; Grønstad, A; Oppegaard, H

    1990-01-01

    A physical map of the Bacillus cereus chromosome has been constructed by aligning 11 NotI fragments, ranging in size from 200 to 1,300 kilobases. The size of the chromosome is about 5.7 megabases. This is the first Bacillus genome of which a complete physical map has been described.

  20. Compositions for chromosome-specific staining

    Science.gov (United States)

    Gray, Joe W.; Pinkel, Daniel

    1998-01-01

    Methods and compositions for staining based upon nucleic acid sequence that employ nucleic acid probes are provided. Said methods produce staining patterns that can be tailored for specific cytogenetic analyses. Said probes are appropriate for in situ hybridization and stain both interphase and metaphase chromosomal material with reliable signals. The nucleic acid probes are typically of a complexity greater than 50 kb, the complexity depending upon the cytogenetic application. Methods are provided to disable the hybridization capacity of shared, high copy repetitive sequences and/or remove such sequences to provide for useful contrast. Still further methods are provided to produce chromosome-specific staining reagents which are made specific to the targeted chromosomal material, which can be one or more whole chromosomes, one or more regions on one or more chromosomes, subsets of chromosomes and/or the entire genome. Probes and test kits are provided for use in tumor cytogenetics, in the detection of disease related loci, in analysis of structural abnormalities, such as translocations, and for biological dosimetry. Further, methods and prenatal test kits are provided to stain targeted chromosomal material of fetal cells, including fetal cells obtained from maternal blood. Still further, the invention provides for automated means to detect and analyse chromosomal abnormalities.

  1. Construction of physical maps for the sex-specific regions of papaya sex chromosomes

    Directory of Open Access Journals (Sweden)

    Na Jong-Kuk

    2012-05-01

    Full Text Available Abstract Background Papaya is a major fruit crop in tropical and subtropical regions worldwide. It is trioecious with three sex forms: male, female, and hermaphrodite. Sex determination is controlled by a pair of nascent sex chromosomes with two slightly different Y chromosomes, Y for male and Yh for hermaphrodite. The sex chromosome genotypes are XY (male, XYh (hermaphrodite, and XX (female. The papaya hermaphrodite-specific Yh chromosome region (HSY is pericentromeric and heterochromatic. Physical mapping of HSY and its X counterpart is essential for sequencing these regions and uncovering the early events of sex chromosome evolution and to identify the sex determination genes for crop improvement. Results A reiterate chromosome walking strategy was applied to construct the two physical maps with three bacterial artificial chromosome (BAC libraries. The HSY physical map consists of 68 overlapped BACs on the minimum tiling path, and covers all four HSY-specific Knobs. One gap remained in the region of Knob 1, the only knob structure shared between HSY and X, due to the lack of HSY-specific sequences. This gap was filled on the physical map of the HSY corresponding region in the X chromosome. The X physical map consists of 44 BACs on the minimum tiling path with one gap remaining in the middle, due to the nature of highly repetitive sequences. This gap was filled on the HSY physical map. The borders of the non-recombining HSY were defined genetically by fine mapping using 1460 F2 individuals. The genetically defined HSY spanned approximately 8.5 Mb, whereas its X counterpart extended about 5.4 Mb including a 900 Kb region containing the Knob 1 shared by the HSY and X. The 8.5 Mb HSY corresponds to 4.5 Mb of its X counterpart, showing 4 Mb (89% DNA sequence expansion. Conclusion The 89% increase of DNA sequence in HSY indicates rapid expansion of the Yh chromosome after genetic recombination was suppressed 2–3 million years ago. The

  2. Artificial intelligence techniques in Prolog

    CERN Document Server

    Shoham, Yoav

    1993-01-01

    Artificial Intelligence Techniques in Prolog introduces the reader to the use of well-established algorithmic techniques in the field of artificial intelligence (AI), with Prolog as the implementation language. The techniques considered cover general areas such as search, rule-based systems, and truth maintenance, as well as constraint satisfaction and uncertainty management. Specific application domains such as temporal reasoning, machine learning, and natural language are also discussed.Comprised of 10 chapters, this book begins with an overview of Prolog, paying particular attention to Prol

  3. Principles of artificial neural networks

    CERN Document Server

    Graupe, Daniel

    2013-01-01

    Artificial neural networks are most suitable for solving problems that are complex, ill-defined, highly nonlinear, of many and different variables, and/or stochastic. Such problems are abundant in medicine, in finance, in security and beyond. This volume covers the basic theory and architecture of the major artificial neural networks. Uniquely, it presents 18 complete case studies of applications of neural networks in various fields, ranging from cell-shape classification to micro-trading in finance and to constellation recognition - all with their respective source codes. These case studies

  4. Rewritable artificial magnetic charge ice

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yong-Lei; Xiao, Zhili; Snezhko, Alexey; Xu, Jing; Ocola, Leonidas E.; Divan, Ralu; Pearson, John E.; Crabtree, George W.; Kwok, Wai-Kwong

    2016-05-20

    Artificial ices enable the study of geometrical frustration by design and through direct observation. However, it has proven difficult to achieve tailored long-range ordering of their diverse configurations, limiting both fundamental and applied research directions. We designed an artificial spin structure that produces a magnetic charge ice with tunable long-range ordering of eight different configurations. We also developed a technique to precisely manipulate the local magnetic charge states and demonstrate write-read-erase multifunctionality at room temperature. This globally reconfigurable and locally writable magnetic charge ice could provide a setting for designing magnetic monopole defects, tailoring magnonics, and controlling the properties of other two-dimensional materials.

  5. Rewritable artificial magnetic charge ice

    Science.gov (United States)

    Wang, Yong-Lei; Xiao, Zhi-Li; Snezhko, Alexey; Xu, Jing; Ocola, Leonidas E.; Divan, Ralu; Pearson, John E.; Crabtree, George W.; Kwok, Wai-Kwong

    2016-05-01

    Artificial ices enable the study of geometrical frustration by design and through direct observation. However, it has proven difficult to achieve tailored long-range ordering of their diverse configurations, limiting both fundamental and applied research directions. We designed an artificial spin structure that produces a magnetic charge ice with tunable long-range ordering of eight different configurations. We also developed a technique to precisely manipulate the local magnetic charge states and demonstrate write-read-erase multifunctionality at room temperature. This globally reconfigurable and locally writable magnetic charge ice could provide a setting for designing magnetic monopole defects, tailoring magnonics, and controlling the properties of other two-dimensional materials.

  6. Artificial Life in Quantum Technologies

    Science.gov (United States)

    Alvarez-Rodriguez, Unai; Sanz, Mikel; Lamata, Lucas; Solano, Enrique

    2016-02-01

    We develop a quantum information protocol that models the biological behaviours of individuals living in a natural selection scenario. The artificially engineered evolution of the quantum living units shows the fundamental features of life in a common environment, such as self-replication, mutation, interaction of individuals, and death. We propose how to mimic these bio-inspired features in a quantum-mechanical formalism, which allows for an experimental implementation achievable with current quantum platforms. This study paves the way for the realization of artificial life and embodied evolution with quantum technologies.

  7. Mapping of human chromosomal regions related to neoplasia: evidence from chromosomes 1 and 17

    Energy Technology Data Exchange (ETDEWEB)

    Rowley, J.D.

    1977-12-01

    In clonal aberrations leading to an excess or partial excess of chromosome I, trisomy for bands 1q25-1q32 was noted in the myeloid cells from all of 34 patients who had various disorders such as acute leukemia, polycythemia vera, and myelofibrosis. This was not the result of a particularly fragile site in that region of the chromosome because the break points in reciprocal translocations that involve it occurred almost exclusively in the short arm. Two consistent rearrangements that have been observed in chromosome 17 produced either duplication of the entire long arm or a translocation of the distal portion of the long arm to chromosome 15. The nonrandom chromosomal changes found in hematologic disorders can now be correlated with the gene loci on these chromosomes or chromosomal segments. Seventy-five genes related to various metabolic enzymes have been mapped; it may be significant that chromosomes carrying gene loci related to nucleic acid metabolism are more frequently involved in hematologic disorders (and other malignancies as well) than are gene loci related to intermediary or carbohydrate metabolism. Furthermore, the known virus-human chromosome associations are closely correlated with the chromosomes affected in hematologic disorders. If one of the effects of carcinogens (including viruses) is to activate genes that regulate host cell DNA synthesis, and if translocations or duplications of specific chromosomal segments produce the same effect, then either of these mechanisms might provide the affected cell with a proliferative advantage.

  8. Review of the Y chromosome and hypertension

    Directory of Open Access Journals (Sweden)

    D. Ely

    2000-06-01

    Full Text Available The Y chromosome from spontaneously hypertensive rats (SHR has a locus that raises blood pressure 20-25 mmHg. Associated with the SHR Y chromosome effect is a 4-week earlier pubertal rise of testosterone and dependence upon the androgen receptor for the full blood pressure effect. Several indices of enhanced sympathetic nervous system (SNS activity are also associated with the SHR Y chromosome. Blockade of SNS outflow reduced the blood pressure effect. Salt sensitivity was increased by the Y chromosome as was salt appetite which was SNS dependent. A strong correlation (r = 0.57, P<0.001 was demonstrable between plasma testosterone and angiotensin II. Coronary collagen increased with blood pressure and the presence of the SHR Y chromosome. A promising candidate gene for the Y effect is the Sry locus (testis determining factor, a transcription factor which may also have other functions.

  9. Genetic conflict and sex chromosome evolution

    Science.gov (United States)

    Meiklejohn, Colin D; Tao, Yun

    2009-01-01

    Chromosomal sex determination systems create the opportunity for the evolution of selfish genetic elements that increase the transmission of one sex chromosome at the expense of its homolog. Because such selfish elements on sex chromosomes can reduce fertility and distort the sex ratio of progeny, unlinked suppressors are expected to evolve, bringing different regions of the genome into conflict over the meiotic transmission of the sex chromosomes. Here we argue that recurrent genetic conflict over sex chromosome transmission is an important evolutionary force that has shaped a wide range of seemingly disparate phenomena including the epigenetic regulation of genes expressed in the germline, the distribution of genes in the genome, and the evolution of hybrid sterility between species. PMID:19931208

  10. Advances in understanding paternally transmitted Chromosomal Abnormalities

    Energy Technology Data Exchange (ETDEWEB)

    Marchetti, F; Sloter, E; Wyrobek, A J

    2001-03-01

    Multicolor FISH has been adapted for detecting the major types of chromosomal abnormalities in human sperm including aneuploidies for clinically-relevant chromosomes, chromosomal aberrations including breaks and rearrangements, and other numerical abnormalities. The various sperm FISH assays have been used to evaluate healthy men, men of advanced age, and men who have received mutagenic cancer therapy. The mouse has also been used as a model to investigate the mechanism of paternally transmitted genetic damage. Sperm FISH for the mouse has been used to detect chromosomally abnormal mouse sperm, while the PAINT/DAPI analysis of mouse zygotes has been used to evaluate the types of chromosomal defects that can be paternally transmitted to the embryo and their effects on embryonic development.

  11. New Y chromosomes and early stages of sex chromosome differentiation: sex determination in Megaselia

    Indian Academy of Sciences (India)

    Walther Traut

    2010-09-01

    The phorid fly Megaselia scalaris is a laboratory model for the turnover and early differentiation of sex chromosomes. Isolates from the field have an XY sex-determining mechanism with chromosome pair 2 acting as X and Y chromosomes. The sex chromosomes are homomorphic but display early signs of sex chromosome differentiation: a low level of molecular differences between X and Y. The male-determining function $(M)$, maps to the distal part of the Y chromosome’s short arm. In laboratory cultures, new Y chromosomes with no signs of a molecular differentiation arise at a low rate, probably by transposition of to these chromosomes. Downstream of the primary signal, the homologue of the Drosophila doublesex (dsx) is part of the sex-determining pathway while Sex-lethal (Sxl), though structurally conserved, is not.

  12. Y-chromosome evolution: emerging insights into processes of Y-chromosome degeneration.

    Science.gov (United States)

    Bachtrog, Doris

    2013-02-01

    The human Y chromosome is intriguing not only because it harbours the master-switch gene that determines gender but also because of its unusual evolutionary history. The Y chromosome evolved from an autosome, and its evolution has been characterized by massive gene decay. Recent whole-genome and transcriptome analyses of Y chromosomes in humans and other primates, in Drosophila species and in plants have shed light on the current gene content of the Y chromosome, its origins and its long-term fate. Furthermore, comparative analysis of young and old Y chromosomes has given further insights into the evolutionary and molecular forces triggering Y-chromosome degeneration and into the evolutionary destiny of the Y chromosome. PMID:23329112

  13. Novel gene acquisition on carnivore Y chromosomes.

    Directory of Open Access Journals (Sweden)

    2006-03-01

    Full Text Available Despite its importance in harboring genes critical for spermatogenesis and male-specific functions, the Y chromosome has been largely excluded as a priority in recent mammalian genome sequencing projects. Only the human and chimpanzee Y chromosomes have been well characterized at the sequence level. This is primarily due to the presumed low overall gene content and highly repetitive nature of the Y chromosome and the ensuing difficulties using a shotgun sequence approach for assembly. Here we used direct cDNA selection to isolate and evaluate the extent of novel Y chromosome gene acquisition in the genome of the domestic cat, a species from a different mammalian superorder than human, chimpanzee, and mouse (currently being sequenced. We discovered four novel Y chromosome genes that do not have functional copies in the finished human male-specific region of the Y or on other mammalian Y chromosomes explored thus far. Two genes are derived from putative autosomal progenitors, and the other two have X chromosome homologs from different evolutionary strata. All four genes were shown to be multicopy and expressed predominantly or exclusively in testes, suggesting that their duplication and specialization for testis function were selected for because they enhance spermatogenesis. Two of these genes have testis-expressed, Y-borne copies in the dog genome as well. The absence of the four newly described genes on other characterized mammalian Y chromosomes demonstrates the gene novelty on this chromosome between mammalian orders, suggesting it harbors many lineage-specific genes that may go undetected by traditional comparative genomic approaches. Specific plans to identify the male-specific genes encoded in the Y chromosome of mammals should be a priority.

  14. Chromosome differentiation patterns during cichlid fish evolution

    Directory of Open Access Journals (Sweden)

    Nirchio Mauro

    2010-06-01

    Full Text Available Abstract Background Cichlid fishes have been the subject of increasing scientific interest because of their rapid adaptive radiation which has led to an extensive ecological diversity and their enormous importance to tropical and subtropical aquaculture. To increase our understanding of chromosome evolution among cichlid species, karyotypes of one Asian, 22 African, and 30 South American cichlid species were investigated, and chromosomal data of the family was reviewed. Results Although there is extensive variation in the karyotypes of cichlid fishes (from 2n = 32 to 2n = 60 chromosomes, the modal chromosome number for South American species was 2n = 48 and the modal number for the African ones was 2n = 44. The only Asian species analyzed, Etroplus maculatus, was observed to have 46 chromosomes. The presence of one or two macro B chromosomes was detected in two African species. The cytogenetic mapping of 18S ribosomal RNA (18S rRNA gene revealed a variable number of clusters among species varying from two to six. Conclusions The karyotype diversification of cichlids seems to have occurred through several chromosomal rearrangements involving fissions, fusions and inversions. It was possible to identify karyotype markers for the subfamilies Pseudocrenilabrinae (African and Cichlinae (American. The karyotype analyses did not clarify the phylogenetic relationship among the Cichlinae tribes. On the other hand, the two major groups of Pseudocrenilabrinae (tilapiine and haplochromine were clearly discriminated based on the characteristics of their karyotypes. The cytogenetic mapping of 18S ribosomal RNA (18S rRNA gene did not follow the chromosome diversification in the family. The dynamic evolution of the repeated units of rRNA genes generates patterns of chromosomal distribution that do not help follows the phylogenetic relationships among taxa. The presence of B chromosomes in cichlids is of particular interest because they may not be represented in

  15. Chromosomal control of pig populations in France: 2002–2006 survey

    Directory of Open Access Journals (Sweden)

    Pinton Alain

    2007-09-01

    Full Text Available Abstract The chromosomal control of pig populations has been widely developed in France over the last ten years. By December 31st, 2006, 13 765 individuals had been karyotyped in our laboratory, 62% of these since 2002. Ninety percent were young purebred boars controlled before service in artificial insemination centres, and 3% were hypoprolific boars. So far, 102 constitutional structural chromosomal rearrangements (67 since 2002 have been described. Fifty-six were reciprocal translocations and 8 peri- or paracentric inversions. For the first time since the beginning of the programme and after more than 11 000 pigs had been karyotyped, one Robertsonian translocation was identified in 2005 and two others in 2006. The estimated prevalence of balanced structural chromosomal rearrangements in a sample of more than 7700 young boars controlled before service was 0.47%. Twenty-one of the 67 rearrangements described since 2002 were identified in hypoprolific boars. All were reciprocal translocations. Twelve mosaics (XX/XY in 11 individuals, XY/XXY in one individual were also diagnosed. Two corresponded to hypoprolific boars, and three to intersexed animals. The results presented in this communication would justify an intensification of the chromosomal control of French and, on a broader scale, European and North-American pig populations.

  16. Morphological images analysis and chromosomic aberrations classification based on fuzzy logic

    International Nuclear Information System (INIS)

    This work has implemented a methodology for automation of images analysis of chromosomes of human cells irradiated at IEA-R1 nuclear reactor (located at IPEN, Sao Paulo, Brazil), and therefore subject to morphological aberrations. This methodology intends to be a tool for helping cytogeneticists on identification, characterization and classification of chromosomal metaphasic analysis. The methodology development has included the creation of a software application based on artificial intelligence techniques using Fuzzy Logic combined with image processing techniques. The developed application was named CHRIMAN and is composed of modules that contain the methodological steps which are important requirements in order to achieve an automated analysis. The first step is the standardization of the bi-dimensional digital image acquisition procedure through coupling a simple digital camera to the ocular of the conventional metaphasic analysis microscope. Second step is related to the image treatment achieved through digital filters application; storing and organization of information obtained both from image content itself, and from selected extracted features, for further use on pattern recognition algorithms. The third step consists on characterizing, counting and classification of stored digital images and extracted features information. The accuracy in the recognition of chromosome images is 93.9%. This classification is based on classical standards obtained at Buckton [1973], and enables support to geneticist on chromosomic analysis procedure, decreasing analysis time, and creating conditions to include this method on a broader evaluation system on human cell damage due to ionizing radiation exposure. (author)

  17. Transposon-mediated chromosomal integration of transgenes in the parasitic nematode Strongyloides ratti and establishment of stable transgenic lines.

    Directory of Open Access Journals (Sweden)

    Hongguang Shao

    Full Text Available Genetic transformation is a potential tool for analyzing gene function and thereby identifying new drug and vaccine targets in parasitic nematodes, which adversely affect more than one billion people. We have previously developed a robust system for transgenesis in Strongyloides spp. using gonadal microinjection for gene transfer. In this system, transgenes are expressed in promoter-regulated fashion in the F1 but are silenced in subsequent generations, presumably because of their location in repetitive episomal arrays. To counteract this silencing, we explored transposon-mediated chromosomal integration of transgenes in S. ratti. To this end, we constructed a donor vector encoding green fluorescent protein (GFP under the control of the Ss-act-2 promoter with flanking inverted tandem repeats specific for the piggyBac transposon. In three experiments, free-living Strongyloides ratti females were transformed with this donor vector and a helper plasmid encoding the piggyBac transposase. A mean of 7.9% of F1 larvae were GFP-positive. We inoculated rats with GFP-positive F1 infective larvae, and 0.5% of 6014 F2 individuals resulting from this host passage were GFP-positive. We cultured GFP-positive F2 individuals to produce GFP-positive F3 L3i for additional rounds of host and culture passage. Mean GFP expression frequencies in subsequent generations were 15.6% in the F3, 99.0% in the F4, 82.4% in the F5 and 98.7% in the F6. The resulting transgenic lines now have virtually uniform GFP expression among all progeny after at least 10 generations of passage. Chromosomal integration of the reporter transgenes was confirmed by Southern blotting and splinkerette PCR, which revealed the transgene flanked by S. ratti genomic sequences corresponding to five discrete integration sites. BLAST searches of flanking sequences against the S. ratti genome revealed integrations in five contigs. This result provides the basis for two powerful functional genomic tools

  18. Chromosomal rearrangements in cattle and pigs revealed by chromosome microdissection and chromosome painting

    OpenAIRE

    Yerle Martine; Ducos Alain; Pinton Alain

    2003-01-01

    Abstract A pericentric inversion of chromosome 4 in a boar, as well as a case of (2q-;5p+) translocation mosaicism in a bull were analysed by chromosome painting using probes generated by conventional microdissection. For the porcine inversion, probes specific for p arms and q arms were produced and hybridised simultaneously on metaphases of a heterozygote carrier. In the case of the bovine translocation, two whole chromosome probes (chromosome 5, and derived chromosome 5) were elaborated and...

  19. Artificial life, the new paradigm

    International Nuclear Information System (INIS)

    A chronological synthesis of the most important facts is presented in the theoretical development and computational simulation that they have taken to the formation of a new paradigm that is known as artificial life; their characteristics and their main investigation lines are analyzed. Finally, a description of its work is made in the National University of Colombia

  20. Parallel artificial liquid membrane extraction

    DEFF Research Database (Denmark)

    Gjelstad, Astrid; Rasmussen, Knut Einar; Parmer, Marthe Petrine;

    2013-01-01

    This paper reports development of a new approach towards analytical liquid-liquid-liquid membrane extraction termed parallel artificial liquid membrane extraction. A donor plate and acceptor plate create a sandwich, in which each sample (human plasma) and acceptor solution is separated by an...

  1. Artificial Intelligence Assists Ultrasonic Inspection

    Science.gov (United States)

    Schaefer, Lloyd A.; Willenberg, James D.

    1992-01-01

    Subtle indications of flaws extracted from ultrasonic waveforms. Ultrasonic-inspection system uses artificial intelligence to help in identification of hidden flaws in electron-beam-welded castings. System involves application of flaw-classification logic to analysis of ultrasonic waveforms.

  2. Artificial neural networks in medicine

    Energy Technology Data Exchange (ETDEWEB)

    Keller, P.E.

    1994-07-01

    This Technology Brief provides an overview of artificial neural networks (ANN). A definition and explanation of an ANN is given and situations in which an ANN is used are described. ANN applications to medicine specifically are then explored and the areas in which it is currently being used are discussed. Included are medical diagnostic aides, biochemical analysis, medical image analysis and drug development.

  3. WASTEWATER TREATMENT BY ARTIFICIAL WETLANDS

    Science.gov (United States)

    Studies of artificial wetlands at Santee, California demonstrated the capacity of wetlands systems for integrated secondary and advanced treatment of municipal wastewaters. When receiving a blend of primary and secondary wastewaters at a blend ratio of 1:2 (6 cm per day: 12 cm pe...

  4. Making Artificial Seawater More Natural

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ Marine fish will die if placed in fresh water and they cannot live in simple salt water. Instead, they need water that contains a mixture of different ingredients, as found in natural seawater. Conventional methods of making artificial seawater have shortcomings, because the water so achieved is only composed of mineral elements and lacks organic components similar to those in natural seawater.

  5. Artificial Video for Video Analysis

    Science.gov (United States)

    Gallis, Michael R.

    2010-01-01

    This paper discusses the use of video analysis software and computer-generated animations for student activities. The use of artificial video affords the opportunity for students to study phenomena for which a real video may not be easy or even possible to procure, using analysis software with which the students are already familiar. We will…

  6. Sex chromosome evolution: platypus gene mapping suggests that part of the human X chromosome was originally autosomal.

    OpenAIRE

    Watson, J M; Spencer, J. A.; Riggs, A D; Graves, J.A.

    1991-01-01

    To investigate the evolution of the mammalian sex chromosomes, we have compared the gene content of the X chromosomes in the mammalian groups most distantly related to man (marsupials and monotremes). Previous work established that genes on the long arm of the human X chromosome are conserved on the X chromosomes in all mammals, revealing that this region was part of an ancient mammalian X chromosome. However, we now report that several genes located on the short arm of the human X chromosome...

  7. Generation of meiomaps of genome-wide recombination and chromosome segregation in human oocytes.

    Science.gov (United States)

    Ottolini, Christian S; Capalbo, Antonio; Newnham, Louise; Cimadomo, Danilo; Natesan, Senthilkumar A; Hoffmann, Eva R; Ubaldi, Filippo M; Rienzi, Laura; Handyside, Alan H

    2016-07-01

    We have developed a protocol for the generation of genome-wide maps (meiomaps) of recombination and chromosome segregation for the three products of human female meiosis: the first and second polar bodies (PB1 and PB2) and the corresponding oocyte. PB1 is biopsied and the oocyte is artificially activated by exposure to calcium ionophore, after which PB2 is biopsied and collected with the corresponding oocyte. The whole genomes of the polar bodies and oocytes are amplified by multiple displacement amplification and, together with maternal genomic DNA, genotyped for ∼300,000 single-nucleotide polymorphisms (SNPs) genome-wide by microarray. Informative maternal heterozygous SNPs are phased using a haploid PB2 or oocyte as a reference. A simple algorithm is then used to identify the maternal haplotypes for each chromosome, in all of the products of meiosis for each oocyte. This allows mapping of crossovers and analysis of chromosome segregation patterns. The protocol takes a minimum of 3-5 d and requires a clinical embryologist with micromanipulation experience and a molecular biologist with basic bioinformatic skills. It has several advantages over previous methods; importantly, the use of artificial oocyte activation avoids the creation of embryos for research purposes. In addition, compared with next-generation sequencing, targeted SNP genotyping is cost-effective and it simplifies the bioinformatic analysis, as only one haploid reference sample is required to establish phase for maternal haplotyping. Finally, meiomapping is more informative than copy-number analysis alone for analysis of chromosome segregation patterns. Using this protocol, we have provided new insights that may lead to improvements in assisted reproduction for the treatment of infertility. PMID:27310263

  8. The bacterial artificial chromosome (BAC) library of the narrow-leafed lupin (Lupinus angustifolius L.)

    Czech Academy of Sciences Publication Activity Database

    Kasprzak, A.; Šafář, Jan; Janda, Jaroslav; Doležel, Jaroslav; Wolko, B.; Naganowska, B.

    2006-01-01

    Roč. 11, - (2006), s. 396-407. ISSN 1425-8153 R&D Projects: GA MŠk(CZ) LC06004 Institutional research plan: CEZ:AV0Z50380511 Keywords : BAC * genomic DNA library * Lupinus angustifolius L. Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.238, year: 2006

  9. Analysis of herpesvirus host specificity determinants using herpesvirus genomes as bacterial artificial chromosomes.

    Science.gov (United States)

    Arii, Jun; Kato, Kentaro; Kawaguchi, Yasushi; Tohya, Yukinobu; Akashi, Hiroomi

    2009-08-01

    Almost all mammalian alphaherpesviruses can grow in cells derived from several types of animals in vitro. However, FHV-1 can only infect feline cell lines. For this reason, FHV-1 should be a good model to investigate species barriers to herpesviruses in vivo. To apply bacterial mutagenesis of FHV-1, we cloned the FHV-1 genome as a BAC. Using lambda and flp recombinations, we introduced a monomeric red fluorescence protein into the C-terminus of glycoprotein D. Although GFP in the constructed recombinant FHV-1, a transfectant of the bacmid of FHV-1 that possessed the GFP, acted in non-feline cell lines, the virus could not enter non-feline cell lines, demonstrating that the host specificity of FHV-1 was restricted in an early step of infection. The host range of canine herpesvirus is limited to dogs in vitro and in vivo; it cannot enter non-canine cell lines as a result of infection but the GFP is active by transfection, revealing the same result that the restriction step is at an early stage of infection. These results suggest the possibility of breaking species barriers of FHV-1 and CHV by modifying the gene(s) that act at the early stage of infection. PMID:19659927

  10. Expression and function profiling of orphan nuclear receptors using bacterial artificial chromosome (BAC) transgenesis.

    OpenAIRE

    Nemoz-Gaillard, Eric; Tsai, Ming-Jer; Tsai, Sophia Y.

    2003-01-01

    The long term goal of the Nuclear Receptor Signaling Atlas (NURSA) resides in unraveling the physiological and pathological functions of nuclear receptors (NRs) at the molecular, biochemical and cellular levels. This multi-oriented task requires complementary approaches in order to determine the specific function(s) and precise expression and receptor activity patterns for each individual conventional or orphan receptor. To attain this objective, we have chose to turn to technologies recently...

  11. Construction of a bacterial artificial chromosome library of S-type CMS maize mitochondria

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In order to isolate mitochondrial genes easily, we have developed a new method to construct S-type CMS maize mitochondrial gene library by means of embedding mitochondria and enzymatic digesting mitochondria in situ, preparing mtDNA by electrophoresis, digesting LMP agarose with β-agarase, using BAC vector and electroporation. About 2 500 white clones of Mo17 CMS-J mitochondrial gene library were obtained with the average size of 18.24 kb, ranging from 5 to 40 kb, 63.6% inserts came from mitochondrial genome and represented 48 ′ mitochondrial genome equivalents. All the probes had detected the positive clones in the gene library. It is helpful to elucidating the maize mitochondrial genome structure and mechanism of S-type CMS, and may give some valuable reference to the construction of other plant mitochondrial genome library.

  12. Viral Bacterial Artificial Chromosomes: Generation, Mutagenesis, and Removal of Mini-F Sequences

    Directory of Open Access Journals (Sweden)

    B. Karsten Tischer

    2012-01-01

    Full Text Available Maintenance and manipulation of large DNA and RNA virus genomes had presented an obstacle for virological research. BAC vectors provided a solution to both problems as they can harbor large DNA sequences and can efficiently be modified using well-established mutagenesis techniques in Escherichia coli. Numerous DNA virus genomes of herpesvirus and pox virus were cloned into mini-F vectors. In addition, several reverse genetic systems for RNA viruses such as members of Coronaviridae and Flaviviridae could be established based on BAC constructs. Transfection into susceptible eukaryotic cells of virus DNA cloned as a BAC allows reconstitution of recombinant viruses. In this paper, we provide an overview on the strategies that can be used for the generation of virus BAC vectors and also on systems that are currently available for various virus species. Furthermore, we address common mutagenesis techniques that allow modification of BACs from single-nucleotide substitutions to deletion of viral genes or insertion of foreign sequences. Finally, we review the reconstitution of viruses from BAC vectors and the removal of the bacterial sequences from the virus genome during this process.

  13. Specific cloning of human DNA as yeast artificial chromosomes by transformation-associated recombination.

    OpenAIRE

    Larionov, V.; Kouprina, N; Graves, J.; Chen, X N; Korenberg, J R; Resnick, M A

    1996-01-01

    DNA molecules undergoing transformation into yeast are highly recombinogenic, even when diverged. We reasoned that transformation-associated recombination (TAR) could be employed to clone large DNAs containing repeat sequences, thereby eliminating the need for in vitro enzymatic reactions such as restriction and ligation and reducing the amount of DNA handling. Gently isolated human DNA was transformed directly into yeast spheroplasts along with two genetically marked (M1 and M2) linearized v...

  14. Precise cloning and tandem integration of large polyketide biosynthetic gene cluster using Streptomyces artificial chromosome system

    OpenAIRE

    Nah, Hee-Ju; Woo, Min-Woo; Choi, Si-Sun; Kim, Eung-Soo

    2015-01-01

    Background Direct cloning combined with heterologous expression of a secondary metabolite biosynthetic gene cluster has become a useful strategy for production improvement and pathway modification of potentially valuable natural products present at minute quantities in original isolates of actinomycetes. However, precise cloning and efficient overexpression of an entire biosynthetic gene cluster remains challenging due to the ineffectiveness of current genetic systems in manipulating large-si...

  15. Cloning and Mutagenesis of the Murine Gammaherpesvirus 68 Genome as an Infectious Bacterial Artificial Chromosome

    OpenAIRE

    Adler, Heiko; Messerle, Martin; Wagner, Markus; Koszinowski, Ulrich H.

    2000-01-01

    Gammaherpesviruses cause important infections of humans, in particular in immunocompromised patients. Recently, murine gammaherpesvirus 68 (MHV-68) infection of mice has been developed as a small animal model of gammaherpesvirus pathogenesis. Efficient generation of mutants of MHV-68 would significantly contribute to the understanding of viral gene functions in virus-host interaction, thereby further enhancing the potential of this model. To this end, we cloned the MHV-68 genome as a bacteria...

  16. Artificial Chromosomes to Explore and to Exploit Biosynthetic Capabilities of Actinomycetes

    OpenAIRE

    Rosa Alduina; Giuseppe Gallo

    2012-01-01

    Actinomycetes are an important source of biologically active compounds, like antibiotics, antitumor agents, and immunosuppressors. Genome sequencing is revealing that this class of microorganisms has larger genomes relative to other bacteria and uses a considerable fraction of its coding capacity (5–10%) for the production of mostly cryptic secondary metabolites. To access actinomycetes biosynthetic capabilities or to improve the pharmacokinetic properties and production yields of these chemi...

  17. Feasibility of physical map construction from fingerprinted bacterial artificial chromosome libraries of polyploid plant species

    Czech Academy of Sciences Publication Activity Database

    Luo, M. C.; Ma, Y. Q.; You, F. M.; Anderson, O. D.; Kopecký, David; Šimková, Hana; Šafář, Jan; Doležel, Jaroslav; Gill, B.; McGuire, P. E.; Dvorak, J.

    2010-01-01

    Roč. 11, č. 122 (2010), s. 1-8. ISSN 1471-2164 Institutional research plan: CEZ:AV0Z50380511 Keywords : BREAD WHEAT * TETRAPLOID WHEAT * GENETIC-MAP Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.206, year: 2010

  18. Assembly and characterization of heterochromatin and euchromatin on human artificial chromosomes

    OpenAIRE

    Grimes, Brenda R.; Babcock, Jennifer; Rudd, M. Katharine; Chadwick, Brian; Willard, Huntington F.

    2004-01-01

    Background Human centromere regions are characterized by the presence of alpha-satellite DNA, replication late in S phase and a heterochromatic appearance. Recent models propose that the centromere is organized into conserved chromatin domains in which chromatin containing CenH3 (centromere-specific H3 variant) at the functional centromere (kinetochore) forms within regions of heterochromatin. To address these models, we assayed formation of heterochromatin and euchromatin on de novo human ar...

  19. Complete Genomes of Classical Swine Fever Virus Cloned into Bacterial Artificial Chromosomes

    DEFF Research Database (Denmark)

    Rasmussen, Thomas Bruun; Reimann, I.; Uttenthal, Åse;

    Complete genome amplification of viral RNA provides a new tool for the generation of modified pestiviruses. We have used our full-genome amplification strategy for generation of amplicons representing complete genomes of classical swine fever virus. The amplicons were cloned directly into a stable...

  20. BACTERIAL ARTIFICIAL CHROMOSOME(BAC)LIBRARIES CONSTRUCTED FROM THE GENETIC STANDARD OF UPLAND COTTON

    Science.gov (United States)

    Two BAC libraries and one plant transformation-competent BIBAC library were developed from the Gossypium hirsutum acc. TM-1 for the development of an integrative cotton physical and genetic map and other genomic applications. TM-1 is the most desirable choice for the physical map of Upland cotton be...

  1. Cloning of Bovine herpesvirus type 1 and type 5 as infectious bacterial artifical chromosomes

    OpenAIRE

    Ackermann Mathias; Fraefel Cornel; Gabev Evgeni; Tobler Kurt

    2009-01-01

    Abstract Background Bovine herpesviruses type 1 (BoHV1) and type 5 (BoHV5) are two closely related pathogens of cattle. The identity of the two viruses on the amino acid level averages 82%. Despite their high antigenetic similarities the two pathogens induce distinctive clinical signs. BoHV1 causes respiratory and genital tract infections while BoHV5 leads to severe encephalitis in calves. Findings The viral genomes of BoHV1 and BoHV5 were cloned as infectious bacterial artificial chromosomes...

  2. Nonrandom chromosomal changes in human malignant cells

    Energy Technology Data Exchange (ETDEWEB)

    Rowley, J D

    1977-01-01

    The role of chromosomal changes in human malignant cells has been the subject of much debate. The observation of nonrandom chromosomal changes has become well recognized in chronic myelogenous leukemia, and more recently in acute myelogenous leukemia. In the present report, data are presented on the sites of duplication of chromosome No. 1 in hematologic disorders. Trisomy for region lq25 to lq32 was observed in every one of 34 patients whose cells showed duplication of some part of chromosome No. 1. Adjacent regions lq21 to lq25, and lq32 to lqter, also were trisomic in the majority of patients. Two patients had deletions, one of lq32 to qter, and the other, of lp32 to pter. The sites of chromosomal breaks leading to trisomy differ from those involved in balanced reciprocal translocations. Some of these sites are sometimes, but not always, vulnerable in constitutional chromosomal abnormalities. The nature of the proliferative advantage conferred on myeloid cells by these chromosomal changes is unknown.

  3. Chromosome number evolution in skippers (Lepidoptera, Hesperiidae).

    Science.gov (United States)

    Lukhtanov, Vladimir A

    2014-01-01

    Lepidoptera (butterflies and moths), as many other groups of animals and plants, simultaneously represent preservation of ancestral karyotype in the majority of families with a high degree of chromosome number instability in numerous independently evolved phylogenetic lineages. However, the pattern and trends of karyotype evolution in some Lepidoptera families are poorly studied. Here I provide a survey of chromosome numbers in skippers (family Hesperiidae) based on intensive search and analysis of published data. I demonstrate that the majority of skippers preserve the haploid chromosome number n=31 that seems to be an ancestral number for the Hesperiidae and the order Lepidoptera at whole. However, in the tribe Baorini the derived number n=16 is the most typical state which can be used as a (syn)apomorphic character in further phylogenetic investigations. Several groups of skippers display extreme chromosome number variations on within-species (e.g. the representatives of the genus Carcharodus Hübner, [1819]) and between-species (e.g. the genus Agathymus Freeman, 1959) levels. Thus, these groups can be used as model systems for future analysis of the phenomenon of chromosome instability. Interspecific chromosomal differences are also shown to be useful for discovering and describing new cryptic species of Hesperiidae representing in such a way a powerful tool in biodiversity research. Generally, the skipper butterflies promise to be an exciting group that will significantly contribute to the growing knowledge of patterns and processes of chromosome evolution. PMID:25610542

  4. Chromosome number evolution in skippers (Lepidoptera, Hesperiidae

    Directory of Open Access Journals (Sweden)

    Vladimir Lukhtanov

    2014-11-01

    Full Text Available Lepidoptera (butterflies and moths, as many other groups of animals and plants, simultaneously represent preservation of ancestral karyotype in the majority of families with a high degree of chromosome number instability in numerous independently evolved phylogenetic lineages. However, the pattern and trends of karyotype evolution in some Lepidoptera families are poorly studied. Here I provide a survey of chromosome numbers in skippers (family Hesperiidae based on intensive search and analysis of published data. I demonstrate that the majority of skippers preserve the haploid chromosome number n=31 that seems to be an ancestral number for the Hesperiidae and the order Lepidoptera at whole. However, in the tribe Baorini the derived number n=16 is the most typical state which can be used as a (synapomorphic character in further phylogenetic investigations. Several groups of skippers display extreme chromosome number variations on within-species (e.g. the representatives of the genus Carcharodus Hübner, [1819] and between-species (e.g. the genus Agathymus Freeman, 1959 levels. Thus, these groups can be used as model systems for future analysis of the phenomenon of chromosome instability. Interspecific chromosomal differences are also shown to be useful for discovering and describing new cryptic species of Hesperiidae representing in such a way a powerful tool in biodiversity research. Generally, the skipper butterflies promise to be an exciting group that will significantly contribute to the growing knowledge of patterns and processes of chromosome evolution.

  5. Group 3 chromosome bin maps of wheat and their relationship to rice chromosome 1.

    Science.gov (United States)

    Munkvold, J D; Greene, R A; Bermudez-Kandianis, C E; La Rota, C M; Edwards, H; Sorrells, S F; Dake, T; Benscher, D; Kantety, R; Linkiewicz, A M; Dubcovsky, J; Akhunov, E D; Dvorák, J; Miftahudin; Gustafson, J P; Pathan, M S; Nguyen, H T; Matthews, D E; Chao, S; Lazo, G R; Hummel, D D; Anderson, O D; Anderson, J A; Gonzalez-Hernandez, J L; Peng, J H; Lapitan, N; Qi, L L; Echalier, B; Gill, B S; Hossain, K G; Kalavacharla, V; Kianian, S F; Sandhu, D; Erayman, M; Gill, K S; McGuire, P E; Qualset, C O; Sorrells, M E

    2004-10-01

    The focus of this study was to analyze the content, distribution, and comparative genome relationships of 996 chromosome bin-mapped expressed sequence tags (ESTs) accounting for 2266 restriction fragments (loci) on the homoeologous group 3 chromosomes of hexaploid wheat (Triticum aestivum L.). Of these loci, 634, 884, and 748 were mapped on chromosomes 3A, 3B, and 3D, respectively. The individual chromosome bin maps revealed bins with a high density of mapped ESTs in the distal region and bins of low density in the proximal region of the chromosome arms, with the exception of 3DS and 3DL. These distributions were more localized on the higher-resolution group 3 consensus map with intermediate regions of high-mapped-EST density on both chromosome arms. Gene ontology (GO) classification of mapped ESTs was not significantly different for homoeologous group 3 chromosomes compared to the other groups. A combined analysis of the individual bin maps using 537 of the mapped ESTs revealed rearrangements between the group 3 chromosomes. Approximately 232 (44%) of the consensus mapped ESTs matched sequences on rice chromosome 1 and revealed large- and small-scale differences in gene order. Of the group 3 mapped EST unigenes approximately 21 and 32% matched the Arabidopsis coding regions and proteins, respectively, but no chromosome-level gene order conservation was detected. PMID:15514041

  6. Artificial Intelligence Databases: A Survey and Comparison.

    Science.gov (United States)

    Stern, David

    1990-01-01

    Identifies and describes online databases containing references to materials on artificial intelligence, robotics, and expert systems, and compares them in terms of scope and usage. Recommendations for conducting online searches on artificial intelligence and related fields are offered. (CLB)

  7. Coming Soon: A Wearable Artificial Kidney?

    Science.gov (United States)

    ... medlineplus/news/fullstory_159246.html Coming Soon: A Wearable Artificial Kidney? Small trial suggests device might be ... themselves of clunky machines, moving about with a "wearable artificial kidney" instead. That's the promise of a ...

  8. Artificial Cervical Disc Replacement Improves Mobility

    Science.gov (United States)

    Artificial Cervical Disc Replacement Improves Mobility February 18, 2009 From PinnacleHealth, Harrisburg, PA Welcome to this “OR ... this new technology with the use of an artificial disc has some significant benefits over the previous ...

  9. Introduction to Concepts in Artificial Neural Networks

    Science.gov (United States)

    Niebur, Dagmar

    1995-01-01

    This introduction to artificial neural networks summarizes some basic concepts of computational neuroscience and the resulting models of artificial neurons. The terminology of biological and artificial neurons, biological and machine learning and neural processing is introduced. The concepts of supervised and unsupervised learning are explained with examples from the power system area. Finally, a taxonomy of different types of neurons and different classes of artificial neural networks is presented.

  10. Chromosome heteromorphism quantified by high-resolution bivariate flow karyotyping.

    Science.gov (United States)

    Trask, B; van den Engh, G; Mayall, B; Gray, J W

    1989-11-01

    Maternal and paternal homologues of many chromosome types can be differentiated on the basis of their peak position in Hoechst 33258 versus chromomycin A3 bivariate flow karyotypes. We demonstrate here the magnitude of DNA content differences among normal chromosomes of the same type. Significant peak-position differences between homologues were observed for an average of four chromosome types in each of the karyotypes of 98 different individuals. The frequency of individuals with differences in homologue peak positions varied among chromosome types: e.g., chromosome 15, 61%; chromosome 3, 4%. Flow karyotypes of 33 unrelated individuals were compared to determine the range of peak position among normal chromosomes. Chromosomes Y, 21, 22, 15, 16, 13, 14, and 19 were most heteromorphic, and chromosomes 2-8 and X were least heteromorphic. The largest chromosome 21 was 45% larger than the smallest 21 chromosome observed. The base composition of the variable regions differed among chromosome types. DNA contents of chromosome variants determined from flow karyotypes were closely correlated to measurements of DNA content made of gallocyanin chrome alum-stained metaphase chromosomes on slides. Fluorescence in situ hybridization with chromosome-specific repetitive sequences indicated that variability in their copy number is partly responsible for peak-position variability in some chromosomes. Heteromorphic chromosomes are identified for which parental flow karyotype information will be essential if de novo rearrangements resulting in small DNA content changes are to be detected with flow karyotyping. PMID:2479266

  11. Adaptation through chromosomal inversions in Anopheles

    Directory of Open Access Journals (Sweden)

    Diego eAyala

    2014-05-01

    Full Text Available Chromosomal inversions have been repeatedly involved in local adaptation in a large number of animals and plants. The ecological and behavioral plasticity of Anopheles species - human malaria vectors - is mirrored by high amounts of polymorphic inversions. The adaptive significance of chromosomal inversions has been consistently attested by strong and significant correlations between their frequencies and a number of phenotypic traits. Here, we provide an extensive literature review of the different adaptive traits associated with chromosomal inversions in the genus Anopheles. Traits having important consequences for the success of present and future vector control measures, such as insecticide resistance and behavioral changes, are discussed.

  12. Reproductive Incompatibility Involving Senegalese Aedes aegypti (L) Is Associated with Chromosome Rearrangements

    Science.gov (United States)

    Dickson, Laura B.; Sharakhova, Maria V.; Timoshevskiy, Vladimir A.; Fleming, Karen L.; Caspary, Alex; Sylla, Massamba; Black, William C.

    2016-01-01

    Aedes aegypti, the primary vector of dengue, yellow fever and Zika flaviviruses, consists of at least two subspecies. Aedes aegypti (Aaa) is light in color, has pale scales on the first abdominal tergite, oviposits in artificial containers, and preferentially feeds on humans. Aedes aegypti formosus (Aaf), has a dark cuticle, is restricted to sub-Saharan Africa, has no pale scales on the first abdominal tergite and frequently oviposits in natural containers. Scale patterns correlate with cuticle color in East Africa but not in Senegal, West Africa where black cuticle mosquitoes display a continuum of scaling patterns and breed domestically indoors. An earlier laboratory study did not indicate any pre- or postzygotic barriers to gene flow between Aaa and Aaf in East Africa. However, similar attempts to construct F1 intercross families between Aaa laboratory strains and Senegal Ae. aegypti (SenAae) failed due to poor F1 oviposition and low F2 egg-to-adult survival. Insemination and assortative mating experiments failed to identify prezygotic mating barriers. Backcrosses were performed to test for postzygotic isolation patterns consistent with Haldane’s rule modified for species, like Aedes, that have an autosomal sex determining locus (SDL). Egg-pupal survival was predicted to be low in females mated to hybrid F1 males but average when a male mates with a hybrid F1 female. Survival was in fact significantly reduced when females mated to hybrid males but egg-pupal survival was significantly increased when males were mated to hybrid F1 females. These observations are therefore inconclusive with regards to Haldane’s rule. Basic cytogenetic analyses and Fluorescent In Situ Hybridization (FISH) experiments were performed to compare SenAae strains with the IB12 strain of Aaa that was used for genome sequencing and physical mapping. Some SenAae strains had longer chromosomes than IB12 and significantly different centromeric indices on chromosomes 1 and 3. DAPI staining

  13. Reproductive Incompatibility Involving Senegalese Aedes aegypti (L) Is Associated with Chromosome Rearrangements.

    Science.gov (United States)

    Dickson, Laura B; Sharakhova, Maria V; Timoshevskiy, Vladimir A; Fleming, Karen L; Caspary, Alex; Sylla, Massamba; Black, William C

    2016-04-01

    Aedes aegypti, the primary vector of dengue, yellow fever and Zika flaviviruses, consists of at least two subspecies. Aedes aegypti (Aaa) is light in color, has pale scales on the first abdominal tergite, oviposits in artificial containers, and preferentially feeds on humans. Aedes aegypti formosus (Aaf), has a dark cuticle, is restricted to sub-Saharan Africa, has no pale scales on the first abdominal tergite and frequently oviposits in natural containers. Scale patterns correlate with cuticle color in East Africa but not in Senegal, West Africa where black cuticle mosquitoes display a continuum of scaling patterns and breed domestically indoors. An earlier laboratory study did not indicate any pre- or postzygotic barriers to gene flow between Aaa and Aaf in East Africa. However, similar attempts to construct F1 intercross families between Aaa laboratory strains and Senegal Ae. aegypti (SenAae) failed due to poor F1 oviposition and low F2 egg-to-adult survival. Insemination and assortative mating experiments failed to identify prezygotic mating barriers. Backcrosses were performed to test for postzygotic isolation patterns consistent with Haldane's rule modified for species, like Aedes, that have an autosomal sex determining locus (SDL). Egg-pupal survival was predicted to be low in females mated to hybrid F1 males but average when a male mates with a hybrid F1 female. Survival was in fact significantly reduced when females mated to hybrid males but egg-pupal survival was significantly increased when males were mated to hybrid F1 females. These observations are therefore inconclusive with regards to Haldane's rule. Basic cytogenetic analyses and Fluorescent In Situ Hybridization (FISH) experiments were performed to compare SenAae strains with the IB12 strain of Aaa that was used for genome sequencing and physical mapping. Some SenAae strains had longer chromosomes than IB12 and significantly different centromeric indices on chromosomes 1 and 3. DAPI staining was

  14. Chromosomal abnormalities in patients with sperm disorders

    Directory of Open Access Journals (Sweden)

    L. Y. Pylyp

    2013-02-01

    Full Text Available Chromosomal abnormalities are among the most common genetic causes of spermatogenic disruptions. Carriers of chromosomal abnormalities are at increased risk of infertility, miscarriage or birth of a child with unbalanced karyotype due to the production of unbalanced gametes. The natural selection against chromosomally abnormal sperm usually prevents fertilization with sperm barring in cases of serious chromosomal abnormalities. However, assisted reproductive technologies in general and intracytoplasmic sperm injection in particular, enable the transmission of chromosomal abnormalities to the progeny. Therefore, cytogenetic studies are important in patients with male factor infertility before assisted reproduction treatment. The purpose of the current study was to investigate the types and frequencies of chromosomal abnormalities in 724 patients with infertility and to estimate the risk of chromosomal abnormalities detection in subgroups of patients depending on the severity of spermatogenic disruption, aiming at identifying groups of patients in need of cytogenetic studies. Karyotype analysis was performed in 724 blood samples of men attending infertility clinic. Chromosomal preparation was performed by standard techniques. At least 20 GTG-banded metaphase plates with the resolution from 450 to 750 bands per haploid set were analysed in each case. When chromosomal mosaicism was suspected, this number was increased to 50. Abnormal karyotypes were observed in 48 (6.6% patients, including 67% of autosomal abnormalities and 33% of gonosomal abnormalities. Autosomal abnormalities were represented by structural rearrangements. Reciprocal translocations were the most common type of structural chromosomal abnormalities in the studied group, detected with the frequency of 2.6% (n = 19, followed by Robertsonian translocation, observed with the frequency of 1.2% (n = 9. The frequency of inversions was 0.6% (n = 4. Gonosomal abnormalities included 14 cases

  15. Impact of Artificial Intelligence on Economic Theory

    OpenAIRE

    Tshilidzi Marwala

    2015-01-01

    Artificial intelligence has impacted many aspects of human life. This paper studies the impact of artificial intelligence on economic theory. In particular we study the impact of artificial intelligence on the theory of bounded rationality, efficient market hypothesis and prospect theory.

  16. Artificial Intelligence in Canada: A Review

    OpenAIRE

    Mccalla, Gordon; Cercone, Nick

    1984-01-01

    Canadians have made many contributions to artificial intelligence over the years. This article presents a summary of current research in artificial intelligence in Canada and acquaints readers with the Canadian organization for artificial intelligence -- the Canadian Society for the Computational Studies of Intelligence / Societe Canadienne pour l' Etude de l'Intelligence par Ordinateur (CSCSI/ SCEIO).

  17. Artificial Ant Species on Solving Optimization Problems

    OpenAIRE

    Pintea, Camelia-M.

    2013-01-01

    During the last years several ant-based techniques were involved to solve hard and complex optimization problems. The current paper is a short study about the influence of artificial ant species in solving optimization problems. There are studied the artificial Pharaoh Ants, Lasius Niger and also artificial ants with no special specificity used commonly in Ant Colony Optimization.

  18. 49 CFR 176.148 - Artificial lighting.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Artificial lighting. 176.148 Section 176.148... Requirements for Class 1 (Explosive) Materials Precautions During Loading and Unloading § 176.148 Artificial lighting. Electric lights, except arc lights, are the only form of artificial lighting permitted...

  19. 21 CFR 886.3200 - Artificial eye.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Artificial eye. 886.3200 Section 886.3200 Food and... OPHTHALMIC DEVICES Prosthetic Devices § 886.3200 Artificial eye. (a) Identification. An artificial eye is a device resembling the anterior portion of the eye, usually made of glass or plastic, intended to...

  20. A karyological analysis of the artificial hybridization between Clarias gariepinus (Burchell, 1822) and Heterobranchus longifilis Valenciennes, 1840 (Pisces; Clariidae)

    OpenAIRE

    Teugels, G.G.; Ozouf-Costazt, C.; Legendre, Marc; Parrent, M.

    1992-01-01

    A karyological analysis of an artificial hybridization (reciprocical crosses) between two African clariid catfish, #Clarias gariepinus$ (Burchell, 1822) and #Heterobranchus longifilis$ Valencienne, 1840, was performed. #C. gariepinus$ has a standard karyotype of 2n = 56, while #H. longifilis$ has 2n = 52. The hybrids revealed an intermediate karyotype (2n = 54), and it appears as if they have totalized the haploid chromosome number of both parental species, excluding gynogenesis or androgenes...

  1. Chromosome landmarks and autosome-sex chromosome translocations in Rumex hastatulus, a plant with XX/XY1Y2 sex chromosome system.

    Science.gov (United States)

    Grabowska-Joachimiak, Aleksandra; Kula, Adam; Książczyk, Tomasz; Chojnicka, Joanna; Sliwinska, Elwira; Joachimiak, Andrzej J

    2015-06-01

    Rumex hastatulus is the North American endemic dioecious plant with heteromorphic sex chromosomes. It is differentiated into two chromosomal races: Texas (T) race characterised by a simple XX/XY sex chromosome system and North Carolina (NC) race with a polymorphic XX/XY1Y2 sex chromosome system. The gross karyotype morphology in NC race resembles the derived type, but chromosomal changes that occurred during its evolution are poorly understood. Our C-banding/DAPI and fluorescence in situ hybridization (FISH) experiments demonstrated that Y chromosomes of both races are enriched in DAPI-positive sequences and that the emergence of polymorphic sex chromosome system was accompanied by the break of ancestral Y chromosome and switch in the localization of 5S rDNA, from autosomes to sex chromosomes (X and Y2). Two contrasting domains were detected within North Carolina Y chromosomes: the older, highly heterochromatinised, inherited from the original Y chromosome and the younger, euchromatic, representing translocated autosomal material. The flow-cytometric DNA estimation showed ∼3.5 % genome downsizing in the North Carolina race. Our results are in contradiction to earlier reports on the lack of heterochromatin within Y chromosomes of this species and enable unambiguous identification of autosomes involved in the autosome-heterosome translocation, providing useful chromosome landmarks for further studies on the karyotype and sex chromosome differentiation in this species. PMID:25394583

  2. Visualization of yeast chromosomal DNA

    Science.gov (United States)

    Lubega, Seth

    1990-01-01

    The DNA molecule is the most significant life molecule since it codes the blue print for other structural and functional molecules of all living organisms. Agarose gel electrophoresis is now being widely used to separate DNA of virus, bacteria, and lower eukaryotes. The task was undertaken of reviewing the existing methods of DNA fractionation and microscopic visualization of individual chromosonal DNA molecules by gel electrophoresis as a basis for a proposed study to investigate the feasibility of separating DNA molecules in free fluids as an alternative to gel electrophoresis. Various techniques were studied. On the molecular level, agarose gel electrophoresis is being widely used to separate chromosomal DNA according to molecular weight. Carl and Olson separate and characterized the entire karyotype of a lab strain of Saccharomyces cerevisiae. Smith et al. and Schwartz and Koval independently reported the visualization of individual DNA molecules migrating through agarose gel matrix during electrophoresis. The techniques used by these researchers are being reviewed in the lab as a basis for the proposed studies.

  3. Dynamic changes in paternal X-chromosome activity during imprinted X-chromosome inactivation in mice

    OpenAIRE

    Patrat, Catherine; Okamoto, Ikuhiro; Diabangouaya, Patricia; Vialon, Vivian; Le Baccon, Patricia; Chow, Jennifer; Heard, Edith

    2009-01-01

    In mammals, X-chromosome dosage compensation is achieved by inactivating one of the two X chromosomes in females. In mice, X inactivation is initially imprinted, with inactivation of the paternal X (Xp) chromosome occurring during preimplantation development. One theory is that the Xp is preinactivated in female embryos, because of its previous silence during meiosis in the male germ line. The extent to which the Xp is active after fertilization and the exact time of onset of X-linked gene si...

  4. Tracking Chromosome Evolution in Southern African Gerbils Using Flow-Sorted Chromosome Paints

    OpenAIRE

    Knight, L.I.; Ng, B. L.; Cheng, W; Fu, B.; Yang, F.; Rambau, R V

    2013-01-01

    Desmodillus and Gerbilliscus (formerly Tatera) comprise a monophyletic group of gerbils (subfamily Gerbillinae) which last shared an ancestor approximately 8 million years ago; diploid chromosome number variation among the species ranges from 2n = 36 to 2n = 50. In an attempt to shed more light on chromosome evolution and speciation in these rodents, we compared the karyotypes of 7 species, representing 3 genera, based on homology data revealed by chromosome painting with probes derived from ...

  5. Haploidization via Chromosome Elimination: Means and Mechanisms.

    Science.gov (United States)

    Ishii, Takayoshi; Karimi-Ashtiyani, Raheleh; Houben, Andreas

    2016-04-29

    The ability to generate haploids and subsequently induce chromosome doubling significantly accelerates the crop breeding process. Haploids have been induced through the generation of plants from haploid tissues (in situ gynogenesis and androgenesis) and through the selective loss of a parental chromosome set via inter- or intraspecific hybridization. Here, we focus on the mechanisms responsible for this selective chromosome elimination. CENH3, a variant of the centromere-specific histone H3, has been exploited to create an efficient method of haploid induction, and we discuss this approach in some detail. Parallels have been drawn with chromosome-specific elimination, which occurs as a normal part of differentiation and sex determination in many plant and animal systems. PMID:26772657

  6. Cancer chromosomal instability: therapeutic and diagnostic challenges

    OpenAIRE

    McGranahan, Nicholas; Burrell, Rebecca A.; Endesfelder, David; Novelli, Marco R; Swanton, Charles

    2012-01-01

    This review provides a much-needed translational perspective into the issue of aneuploidy and chromosomal instability, discussing the prognostic value of CIN assessment in human tumours, methods to analyze it and how it could be therapeutically targeted.

  7. Lattice animal model of chromosome organization

    Science.gov (United States)

    Iyer, Balaji V. S.; Arya, Gaurav

    2012-07-01

    Polymer models tied together by constraints of looping and confinement have been used to explain many of the observed organizational characteristics of interphase chromosomes. Here we introduce a simple lattice animal representation of interphase chromosomes that combines the features of looping and confinement constraints into a single framework. We show through Monte Carlo simulations that this model qualitatively captures both the leveling off in the spatial distance between genomic markers observed in fluorescent in situ hybridization experiments and the inverse decay in the looping probability as a function of genomic separation observed in chromosome conformation capture experiments. The model also suggests that the collapsed state of chromosomes and their segregation into territories with distinct looping activities might be a natural consequence of confinement.

  8. Chromosome studies in the genus Jatropha L.

    Directory of Open Access Journals (Sweden)

    R.Sasikala and M.Paramathma

    2010-07-01

    Full Text Available The inflorescences of ten species of the genus Jatropha were fixed in Cornoy’s fluid (6:3:1. Acetocarmine stain (2% wasused for staining the pollen mother cells. Seven species exhibited 11 bivalents and 2n =22 and x=11. But the two otherspecies, J.villosa var. villosa and J.villosa var. ramnadensis showed only 10 bivalents and 2n number of 20 chromosomesand x=10. The study concluded the occurrence of two kinds of haploid chromosome numbers of n =10 and n =11. ExceptJatropha tanjorensis, cytological investigation in all species exhibited normal and complete pairing and bivalent formationin metaphase I and equal separation of chromosome in anaphase and indicated that the course of meiosis was normal.Jatropha tanjorensis did not exhibit normal course of meiosis and no proper count of chromosomes could be made. Presentchromosomal studies in Jatropha revealed the existence of two basic chromosomes numbers x = 5 and x = 6.

  9. System for the analysis of plant chromosomes

    International Nuclear Information System (INIS)

    The paper describes a computer system for the automation workers of recognition analysis and interpretation of plant chromosomes. This system permit to carry out the analysis in a more comfortable and faster way, using the image processing techniques

  10. Computer automation and artificial intelligence

    International Nuclear Information System (INIS)

    Rapid advances in computing, resulting from micro chip revolution has increased its application manifold particularly for computer automation. Yet the level of automation available, has limited its application to more complex and dynamic systems which require an intelligent computer control. In this paper a review of Artificial intelligence techniques used to augment automation is presented. The current sequential processing approach usually adopted in artificial intelligence has succeeded in emulating the symbolic processing part of intelligence, but the processing power required to get more elusive aspects of intelligence leads towards parallel processing. An overview of parallel processing with emphasis on transputer is also provided. A Fuzzy knowledge based controller for amination drug delivery in muscle relaxant anesthesia on transputer is described. 4 figs. (author)

  11. Economic reasoning and artificial intelligence.

    Science.gov (United States)

    Parkes, David C; Wellman, Michael P

    2015-07-17

    The field of artificial intelligence (AI) strives to build rational agents capable of perceiving the world around them and taking actions to advance specified goals. Put another way, AI researchers aim to construct a synthetic homo economicus, the mythical perfectly rational agent of neoclassical economics. We review progress toward creating this new species of machine, machina economicus, and discuss some challenges in designing AIs that can reason effectively in economic contexts. Supposing that AI succeeds in this quest, or at least comes close enough that it is useful to think about AIs in rationalistic terms, we ask how to design the rules of interaction in multi-agent systems that come to represent an economy of AIs. Theories of normative design from economics may prove more relevant for artificial agents than human agents, with AIs that better respect idealized assumptions of rationality than people, interacting through novel rules and incentive systems quite distinct from those tailored for people. PMID:26185245

  12. Label Free Chromosome Translocation Detection with Silicon nanowires

    DEFF Research Database (Denmark)

    Kwasny, Dorota; Andersen, Karsten Brandt; Frøhling, Kasper Bayer;

    HROMOSOME translocation, which is a rearrangement of arms between two chromosomes, is a major group of chromosome abnormalities leading to cancer. As a result, two derivative chromosomes with sequences coming from both chromosomes are formed. The current translocation detection method is a Fluore...

  13. Methods and compositions for chromosome-specific staining

    Science.gov (United States)

    Gray, Joe W.; Pinkel, Daniel

    2003-07-22

    Methods and compositions for chromosome-specific staining are provided. Compositions comprise heterogenous mixtures of labeled nucleic acid fragments having substantially complementary base sequences to unique sequence regions of the chromosomal DNA for which their associated staining reagent is specific. Methods include methods for making the chromosome-specific staining compositions of the invention, and methods for applying the staining compositions to chromosomes.

  14. The hierarchically organized splitting of chromosomal bands for all human chromosomes

    Directory of Open Access Journals (Sweden)

    Liehr Thomas

    2009-01-01

    Full Text Available Abstract Background Chromosome banding is widely used in cytogenetics. However, the biological nature of hierarchically organized splitting of chromosomal bands of human chromosomes is an enigma and has not been, as yet, studied. Results Here we present for the first time the hierarchically organized splitting of chromosomal bands in their sub-bands for all human chromosomes. To do this, array-proved multicolor banding (aMCB probe-sets for all human chromosomes were applied to normal metaphase spreads of three different G-band levels. We confirmed for all chromosomes to be a general principle that only Giemsa-dark bands split into dark and light sub-bands, as we demonstrated previously by chromosome stretching. Thus, the biological band splitting is in > 50% of the sub-bands different than implemented by the ISCN nomenclature suggesting also a splitting of G-light bands. Locus-specific probes exemplary confirmed the results of MCB. Conclusion Overall, the present study enables a better understanding of chromosome architecture. The observed difference of biological and ISCN band-splitting may be an explanation why mapping data from human genome project do not always fit the cytogenetic mapping.

  15. Y chromosome evolution: emerging insights into processes of Y chromosome degeneration

    Science.gov (United States)

    Bachtrog, Doris

    2014-01-01

    The human Y chromosome is intriguing not only because it harbours the master-switch gene determining gender but also because of its unusual evolutionary trajectory. Previously an autosome, Y chromosome evolution has been characterized by massive gene decay. Recent whole-genome and transcriptome analyses of Y chromosomes in humans and other primates, in Drosophila species as well as in plants have shed light on the current gene content of the Y, its origins and its long-term fate. Comparative analysis of young and old Y chromosomes have given further insights into the evolutionary and molecular forces triggering Y degeneration and its evolutionary destiny. PMID:23329112

  16. Localization of topoisomerase II in mitotic chromosomes

    OpenAIRE

    1985-01-01

    In the preceding article we described a polyclonal antibody that recognizes cSc-1, a major polypeptide component of the chicken mitotic chromosome scaffold. This polypeptide was shown to be chicken topoisomerase II. In the experiments described in the present article we use indirect immunofluorescence and immunoelectron microscopy to examine the distribution of topoisomerase II within intact chromosomes. We also describe a simple experimental protocol that differentiates antigens that are int...

  17. Female meiotic sex chromosome inactivation in chicken.

    Directory of Open Access Journals (Sweden)

    Sam Schoenmakers

    2009-05-01

    Full Text Available During meiotic prophase in male mammals, the heterologous X and Y chromosomes remain largely unsynapsed, and meiotic sex chromosome inactivation (MSCI leads to formation of the transcriptionally silenced XY body. In birds, the heterogametic sex is female, carrying Z and W chromosomes (ZW, whereas males have the homogametic ZZ constitution. During chicken oogenesis, the heterologous ZW pair reaches a state of complete heterologous synapsis, and this might enable maintenance of transcription of Z- and W chromosomal genes during meiotic prophase. Herein, we show that the ZW pair is transiently silenced, from early pachytene to early diplotene using immunocytochemistry and gene expression analyses. We propose that ZW inactivation is most likely achieved via spreading of heterochromatin from the W on the Z chromosome. Also, persistent meiotic DNA double-strand breaks (DSBs may contribute to silencing of Z. Surprisingly, gammaH2AX, a marker of DSBs, and also the earliest histone modification that is associated with XY body formation in mammalian and marsupial spermatocytes, does not cover the ZW during the synapsed stage. However, when the ZW pair starts to desynapse, a second wave of gammaH2AX accumulates on the unsynapsed regions of Z, which also show a reappearance of the DSB repair protein RAD51. This indicates that repair of meiotic DSBs on the heterologous part of Z is postponed until late pachytene/diplotene, possibly to avoid recombination with regions on the heterologously synapsed W chromosome. Two days after entering diplotene, the Z looses gammaH2AX and shows reactivation. This is the first report of meiotic sex chromosome inactivation in a species with female heterogamety, providing evidence that this mechanism is not specific to spermatogenesis. It also indicates the presence of an evolutionary force that drives meiotic sex chromosome inactivation independent of the final achievement of synapsis.

  18. Abnormal sex chromosome constitution and longitudinal growth

    DEFF Research Database (Denmark)

    Aksglaede, Lise; Skakkebaek, Niels E; Juul, Anders

    2008-01-01

    Growth is a highly complex process regulated by the interaction between sex steroids and the GH IGF-axis. However, other factors such as sex chromosome-related genes play independent roles.......Growth is a highly complex process regulated by the interaction between sex steroids and the GH IGF-axis. However, other factors such as sex chromosome-related genes play independent roles....

  19. Y chromosome microdeletions in Turkish infertile men

    OpenAIRE

    Zamani Ayse; Kutlu Ruhusen; Durakbasi-Dursun H; Gorkemli Huseyin; Acar Aynur

    2006-01-01

    AIMS: To detect the frequency and types of both chromosomal abnormalities and Y chromosome microdeletions in infertile men attending to our university intracytoplasmic sperm injection ICSI/IVF centre and fertile control subjects in our patient population. SETTINGS AND DESIGN: A total of 50 infertile men who were referred to IVF center of Meram medical faculty were selected for the molecular azospermia factor (AZF) screening program. MATERIALS AND METHODS: Karyotype analysis and polymeras...

  20. Demasculinization of the Anopheles gambiae X chromosome

    Directory of Open Access Journals (Sweden)

    Magnusson Kalle

    2012-05-01

    Full Text Available Abstract Background In a number of organisms sex-biased genes are non-randomly distributed between autosomes and the shared sex chromosome X (or Z. Studies on Anopheles gambiae have produced conflicting results regarding the underrepresentation of male-biased genes on the X chromosome and it is unclear to what extent sexual antagonism, dosage compensation or X-inactivation in the male germline, the evolutionary forces that have been suggested to affect the chromosomal distribution of sex-biased genes, are operational in Anopheles. Results We performed a meta-analysis of sex-biased gene expression in Anopheles gambiae which provides evidence for a general underrepresentation of male-biased genes on the X-chromosome that increased in significance with the observed degree of sex-bias. A phylogenomic comparison between Drosophila melanogaster, Aedes aegypti and Culex quinquefasciatus also indicates that the Anopheles X chromosome strongly disfavours the evolutionary conservation of male-biased expression and that novel male-biased genes are more likely to arise on autosomes. Finally, we demonstrate experimentally that transgenes situated on the Anopheles gambiae X chromosome are transcriptionally silenced in the male germline. Conclusion The data presented here support the hypothesis that the observed demasculinization of the Anopheles X chromosome is driven by X-chromosome inactivation in the male germline and by sexual antagonism. The demasculinization appears to be the consequence of a loss of male-biased expression, rather than a failure in the establishment or the extinction of male-biased genes.

  1. Delayed chromosomal instability induced by DNA damage.

    OpenAIRE

    Marder, B A; Morgan, W. F.

    1993-01-01

    DNA damage induced by ionizing radiation can result in gene mutation, gene amplification, chromosome rearrangements, cellular transformation, and cell death. Although many of these changes may be induced directly by the radiation, there is accumulating evidence for delayed genomic instability following X-ray exposure. We have investigated this phenomenon by studying delayed chromosomal instability in a hamster-human hybrid cell line by means of fluorescence in situ hybridization. We examined ...

  2. Plasmid and chromosome segregation in prokaryotes

    DEFF Research Database (Denmark)

    Møller-Jensen, Jakob; Bugge Jensen, Rasmus; Gerdes, Kenn

    2000-01-01

    Recent major advances in the understanding of prokaryotic DNA segregation have been achieved by using fluorescence microscopy to visualize the localization of cellular components. Plasmids and bacterial chromosomes are partitioned in a highly dynamic fashion, suggesting the presence of a mitotic......-like apparatus in prokaryotes. The identification of chromosomal homologues of the well-characterized plasmid partitioning genes indicates that there could be a general mechanism of bacterial DNA partitioning. Udgivelsesdato: July 1...

  3. Principles of chromosomal organization: lessons from yeast

    OpenAIRE

    Zimmer, Christophe; Fabre, Emmanuelle

    2011-01-01

    The spatial organization of genes and chromosomes plays an important role in the regulation of several DNA processes. However, the principles and forces underlying this nonrandom organization are mostly unknown. Despite its small dimension, and thanks to new imaging and biochemical techniques, studies of the budding yeast nucleus have led to significant insights into chromosome arrangement and dynamics. The dynamic organization of the yeast genome during interphase argues for both the physica...

  4. Assembly of Lampbrush Chromosomes from Sperm Chromatin

    OpenAIRE

    Gall, Joseph G.; Murphy, Christine

    1998-01-01

    We have examined the behavior of demembranated sperm heads when injected into the germinal vesicle (GV) of amphibian oocytes. Xenopus sperm heads injected into Xenopus GVs swelled immediately and within hours began to stain with an antibody against RNA polymerase II (Pol II). Over time each sperm head became a loose mass of chromosome-like threads, which by 24–48 h resolved into individually recognizable lampbrush chromosomes (LBCs). Although LBCs derived from sperm are unreplicated single ch...

  5. Sequence conservation on the Y chromosome

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, L.H.; Yang-Feng, L. [Yale Univ. School of Medicine, New Haven, CT (United States); Lau, C. [Univ. of California, San Francisco, CA (United States)

    1994-09-01

    The Y chromosome is present in all mammals and is considered to be essential to sex determination. Despite intense genomic research, only a few genes have been identified and mapped to this chromosome in humans. Several of them, such as SRY and ZFY, have been demonstrated to be conserved and Y-located in other mammals. In order to address the issue of sequence conservation on the Y chromosome, we performed fluorescence in situ hybridization (FISH) with DNA from a human Y cosmid library as a probe to study the Y chromosomes from other mammalian species. Total DNA from 3,000-4,500 cosmid pools were labeled with biotinylated-dUTP and hybridized to metaphase chromosomes. For human and primate preparations, human cot1 DNA was included in the hybridization mixture to suppress the hybridization from repeat sequences. FISH signals were detected on the Y chromosomes of human, gorilla, orangutan and baboon (Old World monkey) and were absent on those of squirrel monkey (New World monkey), Indian munjac, wood lemming, Chinese hamster, rat and mouse. Since sequence analysis suggested that specific genes, e.g. SRY and ZFY, are conserved between these two groups, the lack of detectable hybridization in the latter group implies either that conservation of the human Y sequences is limited to the Y chromosomes of the great apes and Old World monkeys, or that the size of the syntenic segment is too small to be detected under the resolution of FISH, or that homologeous sequences have undergone considerable divergence. Further studies with reduced hybridization stringency are currently being conducted. Our results provide some clues as to Y-sequence conservation across species and demonstrate the limitations of FISH across species with total DNA sequences from a particular chromosome.

  6. Chromosomal profile of indigenous pig (Sus scrofa

    Directory of Open Access Journals (Sweden)

    P. Guru Vishnu

    2015-02-01

    Full Text Available Aim: The objective of this study was to investigate the chromosomal profile of indigenous pigs by computing morphometric measurements. Materials and Methods: A cytogenetic study was carried out in 60 indigenous pigs to analyze the chromosomal profile by employing the short term peripheral blood lymphocyte culture technique. Results: The modal chromosome number (2n in indigenous pigs was found to be 38 and a fundamental number of 64 as in the exotic. First chromosome was the longest pair, and thirteenth pair was the second largest while Y-chromosome was the smallest in the karyotype of the pig. The mean relative length, arm ratio, centromeric indices and morphological indices of chromosomes varied from 1.99±0.01 to 11.23±0.09, 1.04±0.05 to 2.95±0.02, 0.51±0.14 to 0.75±0.09 and 2.08±0.07 to 8.08±0.15%, respectively in indigenous pigs. Sex had no significant effect (p>0.05 on all the morphometric measurements studied. Conclusion: The present study revealed that among autosomes first five pairs were sub metacentric, next two pairs were sub telocentric (6-7, subsequent five pairs were metacentric (8-12 and remaining six pairs were telocentric (13-18, while both allosomes were metacentric. The chromosomal number, morphology and various morphometric measurements of the chromosomes of the indigenous pigs were almost similar to those established breeds reported in the literature.

  7. Die Haplotypisierung des Y-Chromosoms

    OpenAIRE

    Roewer, Lutz

    2001-01-01

    Haploid vererbte Polymorphismen des Y-Chromosoms sind wichtige diagnostische Werkzeuge der forensischen Genetik und verwandter Disziplinen, insbesondere der Anthropologie. Geschlechtsspezifität und uniparentaler Erbgang der Merkmale ermöglichen eine Reihe von Untersuchungen, die mit autosomalen Markern erfolglos bleiben müssen. Kurze tandem-repetitive STR-Sequenzen, die polymorphen Marker der Wahl im forensischen Labor, sind auch auf dem Y-Chromosom nachzuweisen. Aufgrund der rekombinationsfr...

  8. Simple generation of site-directed point mutations in the Escherichia coli chromosome using Red®/ET® Recombination

    Directory of Open Access Journals (Sweden)

    Jung Kirsten

    2008-04-01

    Full Text Available Abstract Background Introducing point mutations into bacterial chromosomes is important for further progress in studies relying on functional genomics, systems- and synthetic biology, and for metabolic engineering. For many investigations, chromosomal systems are required rather than artificial plasmid based systems. Results Here we describe the introduction of a single point mutation into the Escherichia coli chromosome by site-directed mutagenesis without leaving any selection marker. We used Red®/ET® Recombination in combination with rpsL counter-selection to introduce a single point mutation into the E. coli MG1655 genome, one of the widely used bacterial model strains in systems biology. The method we present is rapid and highly efficient. Since single-stranded synthetic oligonucleotides can be used for recombination, any chromosomal modification can be designed. Conclusion Chromosomal modifications performed by rpsL counter-selection may also be used for other bacteria that contain an rpsL homologue, since Red®/ET® Recombination has been applied to several enteric bacteria before.

  9. cDNA cloning, tissue distribution, and chromosomal localization of myelodysplasia/Myeloid Leukemia Factor 2 (MLF2)

    Energy Technology Data Exchange (ETDEWEB)

    Kuefer, M.U.; Valentine, V.; Behm, F.G. [St. Jude Children`s Research Hospital, Memphis, TN (United States)] [and others

    1996-07-15

    A fusion gene between nucleophosmin (NPM) and myelodysplasia/myeloid leukemia factor 1 (MLF1) and myelodysplasia/myeloid leukemia factor 1 (MLF1) is formed by a recurrent t(3;5)(q25.1;q34) in myelodysplastic syndrome and acute myeloid leukemia. Here we report the identification of a novel gene, MLF2, which contains an open reading frame of 744 bp encoding a 248-amino-acid protein highly related to the previously identified MLF1 protein (63% similarity, 40% identity). In contrast to the tissue-restricted expression pattern of MLF1, and MLF2 messenger RNA is expressed ubiquitously. The MLF2 gene locus was mapped by fluorescence in situ hybridization to human chromosome 12p13, a chromosomal region frequently involved in translocations and deletions in acute leukemias of lymphoid or myeloid lineage. In a physical map of chromosome 12, MLF2 was found to reside on the yeast artificial chromosome clone 765b9. Southern blotting analysis of malignant cell DNAs prepared from a series of acute lymphoblastic leukemia cases with translocations involving chromosome arm 12p, as well as a group of acute myeloid leukemias with various cytogenetic abnormalities, failed to reveal MLF2 gene rearrangements. 19 refs., 2 figs.

  10. A Definition of Artificial Intelligence

    OpenAIRE

    Dobrev, Dimiter

    2012-01-01

    In this paper we offer a formal definition of Artificial Intelligence and this directly gives us an algorithm for construction of this object. Really, this algorithm is useless due to the combinatory explosion. The main innovation in our definition is that it does not include the knowledge as a part of the intelligence. So according to our definition a newly born baby also is an Intellect. Here we differs with Turing's definition which suggests that an Intellect is a person with knowledge gai...

  11. Psychological Studies and Artificial Intelligence

    OpenAIRE

    Ringle, Martin

    1983-01-01

    This paper argues for the position that experimental human studies are relevant to most facets of AI research and that closer ties between AI and experimental psychology will enhance the development of booth the principles of artificial intelligence and their implementation in computers. Raising psychological assumptions from the level of ad hoc intuitions to the level of systematic empirical observation, in the long run, will improve the quality of AI research and help to integrate it with r...

  12. Formation of artificial ionospheric ducts

    OpenAIRE

    Milikh, G. M.; Papadopoulos, K.; Shroff, H; Chang, C. L.; Wallace, T; E. V. Mishin; Parrot, Michel; Berthelier, Jean-Jacques

    2008-01-01

    International audience It is well known that strong electron heating by a powerful HF-facility can lead to the formation of electron and ion density perturbations that stretch along the magnetic field line. Those density perturbations can serve as ducts for ELF waves, both of natural and artificial origin. This paper presents the first experimental evidence of plasma modifications associated with ion outflows due to HF heating. The experiments were conducted using the HAARP heater during t...

  13. Worldwide variations in artificial skyglow

    OpenAIRE

    Kyba, Christopher C. M.; Kai Pong Tong; Jonathan Bennie; Ignacio Birriel; Jennifer J. Birriel; Andrew Cool; Arne Danielsen; Davies, Thomas W; den Outer, Peter N.; William Edwards; Rainer Ehlert; Fabio Falchi; Jürgen Fischer; Andrea Giacomelli; Francesco Giubbilini

    2015-01-01

    Despite constituting a widespread and significant environmental change, understanding of artificial nighttime skyglow is extremely limited. Until now, published monitoring studies have been local or regional in scope, and typically of short duration. In this first major international compilation of monitoring data we answer several key questions about skyglow properties. Skyglow is observed to vary over four orders of magnitude, a range hundreds of times larger than was the case before artifi...

  14. Automated Scheduling Via Artificial Intelligence

    Science.gov (United States)

    Biefeld, Eric W.; Cooper, Lynne P.

    1991-01-01

    Artificial-intelligence software that automates scheduling developed in Operations Mission Planner (OMP) research project. Software used in both generation of new schedules and modification of existing schedules in view of changes in tasks and/or available resources. Approach based on iterative refinement. Although project focused upon scheduling of operations of scientific instruments and other equipment aboard spacecraft, also applicable to such terrestrial problems as scheduling production in factory.

  15. Artificial color perception using microwaves

    CERN Document Server

    Choudhury, Debesh

    2013-01-01

    We report the feasibility of artificial color perception under microwave illumination using a standard microwave source and an antenna. We have sensed transmitted microwave power through color objects and have distinguished the colors by analyzing the sensed transmitted power. Experiments are carried out using a Gunn diode as the microwave source, some colored liquids as the objects and a microwave diode as the detector. Results are presented which open up an unusual but new way of perceiving colors using microwaves.

  16. Artificial Sweeteners versus Natural Sweeteners

    OpenAIRE

    Neacsu, N.A.; Madar, A.

    2014-01-01

    Carbohydrates are an important dietary nutrient which is mostly used to supply energy to the body, as well as a carbon source for synthesis of other needed chemicals. In addition, mono- and disaccharides are craved because of their sweetness. We present different types of sweeteners, which are the basic contents of foods which we consume every day and are demonstrated the positive and negative effects of natural and artificial sweeteners.

  17. Artificial knowledge an evolutionary approach

    OpenAIRE

    McMullin, Finbar Vincent

    1992-01-01

    I present a new analysis of the problem, situation in Artificial Intelligence (AI), grounded in a Popperian epistemology. I first review arguments purporting to establish that no purely “computational” system can realise genuine mentality. I conclude that the question is still open; but that the more pressing question is whether such a system can even exhibit intelligent behaviour. Attention is thus directed at the computational embodiment of knowledge, and its growth. I suggest that much...

  18. Artificial color perception using microwaves

    OpenAIRE

    Choudhury, Debesh; Caulfield, H. John

    2013-01-01

    We report the feasibility of artificial color perception under microwave illumination using a standard microwave source and an antenna. We have sensed transmitted microwave power through color objects and have distinguished the colors by analyzing the sensed transmitted power. Experiments are carried out using a Gunn diode as the microwave source, some colored liquids as the objects and a microwave diode as the detector. Results are presented which open up an unusual but new way of perceiving...

  19. Educational Advances in Artificial Intelligence

    OpenAIRE

    Brown, Laura E.; Michigan Technological University; Kauchak, David; University of California, San Diego

    2013-01-01

    The emergence of massive open online courses has initiated a broad national-wide discussion on higher education practices, models, and pedagogy.  Artificial intelligence and machine learning courses were at the forefront of this trend and are also being used to serve personalized, managed content in the back-end systems. Massive open online courses are just one example of the sorts of pedagogical innovations being developed to better teach AI. This column will discuss and share innovative ed...

  20. The X chromosome of monotremes shares a highly conserved region with the eutherian and marsupial X chromosomes despite the absence of X chromosome inactivation.

    OpenAIRE

    Watson, J M; Spencer, J. A.; Riggs, A D; Graves, J.A.

    1990-01-01

    Eight genes, located on the long arm of the human X chromosome and present on the marsupial X chromosome, were mapped by in situ hybridization to the chromosomes of the platypus Ornithorhynchus anatinus, one of the three species of monotreme mammals. All were located on the X chromosome. We conclude that the long arm of the human X chromosome represents a highly conserved region that formed part of the X chromosome in a mammalian ancestor at least 150 million years ago. Since three of these g...