WorldWideScience

Sample records for human genetic code

  1. Rewriting the Genetic Code.

    Science.gov (United States)

    Mukai, Takahito; Lajoie, Marc J; Englert, Markus; Söll, Dieter

    2017-09-08

    The genetic code-the language used by cells to translate their genomes into proteins that perform many cellular functions-is highly conserved throughout natural life. Rewriting the genetic code could lead to new biological functions such as expanding protein chemistries with noncanonical amino acids (ncAAs) and genetically isolating synthetic organisms from natural organisms and viruses. It has long been possible to transiently produce proteins bearing ncAAs, but stabilizing an expanded genetic code for sustained function in vivo requires an integrated approach: creating recoded genomes and introducing new translation machinery that function together without compromising viability or clashing with endogenous pathways. In this review, we discuss design considerations and technologies for expanding the genetic code. The knowledge obtained by rewriting the genetic code will deepen our understanding of how genomes are designed and how the canonical genetic code evolved.

  2. Scientific rationality, uncertainty and the governance of human genetics: an interview study with researchers at deCODE genetics.

    Science.gov (United States)

    Hjörleifsson, Stefán; Schei, Edvin

    2006-07-01

    Technology development in human genetics is fraught with uncertainty, controversy and unresolved moral issues, and industry scientists are sometimes accused of neglecting the implications of their work. The present study was carried out to elicit industry scientists' reflections on the relationship between commercial, scientific and ethical dimensions of present day genetics and the resources needed for robust governance of new technologies. Interviewing scientists of the company deCODE genetics in Iceland, we found that in spite of optimism, the informants revealed ambiguity and uncertainty concerning the use of human genetic technologies for the prevention of common diseases. They concurred that uncritical marketing of scientific success might cause exaggerated public expectations of health benefits from genetics, with the risk of backfiring and causing resistance to genetics in the population. On the other hand, the scientists did not address dilemmas arising from the commercial nature of their own employer. Although the scientists tended to describe public fear as irrational, they identified issues where scepticism might be well founded and explored examples where they, despite expert knowledge, held ambiguous or tentative personal views on the use of predictive genetic technologies. The rationality of science was not seen as sufficient to ensure beneficial governance of new technologies. The reflexivity and suspension of judgement demonstrated in the interviews exemplify productive features of moral deliberation in complex situations. Scientists should take part in dialogues concerning the governance of genetic technologies, acknowledge any vested interests, and use their expertise to highlight, not conceal the technical and moral complexity involved.

  3. Analysis of protein-coding genetic variation in 60,706 humans.

    Science.gov (United States)

    Lek, Monkol; Karczewski, Konrad J; Minikel, Eric V; Samocha, Kaitlin E; Banks, Eric; Fennell, Timothy; O'Donnell-Luria, Anne H; Ware, James S; Hill, Andrew J; Cummings, Beryl B; Tukiainen, Taru; Birnbaum, Daniel P; Kosmicki, Jack A; Duncan, Laramie E; Estrada, Karol; Zhao, Fengmei; Zou, James; Pierce-Hoffman, Emma; Berghout, Joanne; Cooper, David N; Deflaux, Nicole; DePristo, Mark; Do, Ron; Flannick, Jason; Fromer, Menachem; Gauthier, Laura; Goldstein, Jackie; Gupta, Namrata; Howrigan, Daniel; Kiezun, Adam; Kurki, Mitja I; Moonshine, Ami Levy; Natarajan, Pradeep; Orozco, Lorena; Peloso, Gina M; Poplin, Ryan; Rivas, Manuel A; Ruano-Rubio, Valentin; Rose, Samuel A; Ruderfer, Douglas M; Shakir, Khalid; Stenson, Peter D; Stevens, Christine; Thomas, Brett P; Tiao, Grace; Tusie-Luna, Maria T; Weisburd, Ben; Won, Hong-Hee; Yu, Dongmei; Altshuler, David M; Ardissino, Diego; Boehnke, Michael; Danesh, John; Donnelly, Stacey; Elosua, Roberto; Florez, Jose C; Gabriel, Stacey B; Getz, Gad; Glatt, Stephen J; Hultman, Christina M; Kathiresan, Sekar; Laakso, Markku; McCarroll, Steven; McCarthy, Mark I; McGovern, Dermot; McPherson, Ruth; Neale, Benjamin M; Palotie, Aarno; Purcell, Shaun M; Saleheen, Danish; Scharf, Jeremiah M; Sklar, Pamela; Sullivan, Patrick F; Tuomilehto, Jaakko; Tsuang, Ming T; Watkins, Hugh C; Wilson, James G; Daly, Mark J; MacArthur, Daniel G

    2016-08-18

    Large-scale reference data sets of human genetic variation are critical for the medical and functional interpretation of DNA sequence changes. Here we describe the aggregation and analysis of high-quality exome (protein-coding region) DNA sequence data for 60,706 individuals of diverse ancestries generated as part of the Exome Aggregation Consortium (ExAC). This catalogue of human genetic diversity contains an average of one variant every eight bases of the exome, and provides direct evidence for the presence of widespread mutational recurrence. We have used this catalogue to calculate objective metrics of pathogenicity for sequence variants, and to identify genes subject to strong selection against various classes of mutation; identifying 3,230 genes with near-complete depletion of predicted protein-truncating variants, with 72% of these genes having no currently established human disease phenotype. Finally, we demonstrate that these data can be used for the efficient filtering of candidate disease-causing variants, and for the discovery of human 'knockout' variants in protein-coding genes.

  4. What Froze the Genetic Code?

    National Research Council Canada - National Science Library

    Lluís Ribas de Pouplana; Adrian Gabriel Torres; albert Rafels-Ybern

    2017-01-01

    The frozen accident theory of the Genetic Code was a proposal by Francis Crick that attempted to explain the universal nature of the Genetic Code and the fact that it only contains information for twenty amino acids...

  5. Human Disease-Associated Genetic Variation Impacts Large Intergenic Non-Coding RNA Expression

    NARCIS (Netherlands)

    Kumar, Vinod; Westra, Harm-Jan; Karjalainen, Juha; Zhernakova, Daria V.; Esko, Tonu; Hrdlickova, Barbara; Almeida, Rodrigo; Zhernakova, Alexandra; Reinmaa, Eva; Hofker, Marten H.; Fehrmann, Rudolf S. N.; Fu, Jingyuan; Withoff, Sebo; Metspalu, Andres; Franke, Lude; Wijmenga, Cisca; Vosa, Urmo

    2013-01-01

    Recently it has become clear that only a small percentage (7%) of disease-associated single nucleotide polymorphisms (SNPs) are located in protein-coding regions, while the remaining 93% are located in gene regulatory regions or in intergenic regions. Thus, the understanding of how genetic variation

  6. What Froze the Genetic Code?

    Science.gov (United States)

    Ribas de Pouplana, Lluís; Torres, Adrian Gabriel; Rafels-Ybern, Àlbert

    2017-04-05

    The frozen accident theory of the Genetic Code was a proposal by Francis Crick that attempted to explain the universal nature of the Genetic Code and the fact that it only contains information for twenty amino acids. Fifty years later, it is clear that variations to the universal Genetic Code exist in nature and that translation is not limited to twenty amino acids. However, given the astonishing diversity of life on earth, and the extended evolutionary time that has taken place since the emergence of the extant Genetic Code, the idea that the translation apparatus is for the most part immobile remains true. Here, we will offer a potential explanation to the reason why the code has remained mostly stable for over three billion years, and discuss some of the mechanisms that allow species to overcome the intrinsic functional limitations of the protein synthesis machinery.

  7. Hacking the genetic code of mammalian cells.

    Science.gov (United States)

    Schwarzer, Dirk

    2009-07-06

    A genetic shuttle: The highlighted article, which was recently published by Schultz, Geierstanger and co-workers, describes a straightforward scheme for enlarging the genetic code of mammalian cells. An orthogonal tRNA/aminoacyl-tRNA synthetase pair specific for a new amino acid can be evolved in E. coli and subsequently transferred into mammalian cells. The feasibility of this approach was demonstrated by adding a photocaged lysine derivative to the genetic repertoire of a human cell line.

  8. RNA splicing. The human splicing code reveals new insights into the genetic determinants of disease.

    Science.gov (United States)

    Xiong, Hui Y; Alipanahi, Babak; Lee, Leo J; Bretschneider, Hannes; Merico, Daniele; Yuen, Ryan K C; Hua, Yimin; Gueroussov, Serge; Najafabadi, Hamed S; Hughes, Timothy R; Morris, Quaid; Barash, Yoseph; Krainer, Adrian R; Jojic, Nebojsa; Scherer, Stephen W; Blencowe, Benjamin J; Frey, Brendan J

    2015-01-01

    To facilitate precision medicine and whole-genome annotation, we developed a machine-learning technique that scores how strongly genetic variants affect RNA splicing, whose alteration contributes to many diseases. Analysis of more than 650,000 intronic and exonic variants revealed widespread patterns of mutation-driven aberrant splicing. Intronic disease mutations that are more than 30 nucleotides from any splice site alter splicing nine times as often as common variants, and missense exonic disease mutations that have the least impact on protein function are five times as likely as others to alter splicing. We detected tens of thousands of disease-causing mutations, including those involved in cancers and spinal muscular atrophy. Examination of intronic and exonic variants found using whole-genome sequencing of individuals with autism revealed misspliced genes with neurodevelopmental phenotypes. Our approach provides evidence for causal variants and should enable new discoveries in precision medicine.

  9. Overcoming Challenges in Engineering the Genetic Code.

    Science.gov (United States)

    Lajoie, M J; Söll, D; Church, G M

    2016-02-27

    Withstanding 3.5 billion years of genetic drift, the canonical genetic code remains such a fundamental foundation for the complexity of life that it is highly conserved across all three phylogenetic domains. Genome engineering technologies are now making it possible to rationally change the genetic code, offering resistance to viruses, genetic isolation from horizontal gene transfer, and prevention of environmental escape by genetically modified organisms. We discuss the biochemical, genetic, and technological challenges that must be overcome in order to engineer the genetic code.

  10. Future of the Genetic Code

    Directory of Open Access Journals (Sweden)

    Hong Xue

    2017-02-01

    Full Text Available The methods for establishing synthetic lifeforms with rewritten genetic codes comprising non-canonical amino acids (NCAA in addition to canonical amino acids (CAA include proteome-wide replacement of CAA, insertion through suppression of nonsense codon, and insertion via the pyrrolysine and selenocysteine pathways. Proteome-wide reassignments of nonsense codons and sense codons are also under development. These methods enable the application of NCAAs to enrich both fundamental and applied aspects of protein chemistry and biology. Sense codon reassignment to NCAA could incur problems arising from the usage of anticodons as identity elements on tRNA, and possible misreading of NNY codons by UNN anticodons. Evidence suggests that the problem of anticodon as identity elements can be diminished or resolved through removal from the tRNA of all identity elements besides the anticodons, and the problem of misreading of NNY codons by UNN anticodon can be resolved by the retirement of both the UNN anticodon and its complementary NNA codon from the proteome in the event that a restrictive post-transcriptional modification of the UNN anticodon by host enzymes to prevent the misreading cannot be obtained.

  11. The path to the genetic code.

    Science.gov (United States)

    Szymanski, Maciej; Barciszewski, Jan

    2017-11-01

    In December of 1966 the last nucleotide triplet in the genetic code has been assigned (Brenner et al., 1967 [1]) thus completing years of studies aimed at deciphering the nature of the relationship between the sequences of genes and proteins. The end product, the table of the genetic code, was a crowning achievement of the quest to unravel the basic mechanisms underlying functioning of all living organisms on the molecular level. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. The Problem of Evolving a Genetic Code

    Science.gov (United States)

    Woese, Carl R.

    1970-01-01

    Proposes models for the evolution of the genetic code and translation mechanisms. Suggests that the translation process is so complex and precise that it must have evolved in many stages, and that the evolution of the code was influenced by the constraints imposed by the evolving translation mechanism. (EB)

  13. Expanding the genetic code of Mus musculus

    Science.gov (United States)

    Han, Songmi; Yang, Aerin; Lee, Soonjang; Lee, Han-Woong; Park, Chan Bae; Park, Hee-Sung

    2017-01-01

    Here we report the expansion of the genetic code of Mus musculus with various unnatural amino acids including Nɛ-acetyl-lysine. Stable integration of transgenes encoding an engineered Nɛ-acetyl-lysyl-tRNA synthetase (AcKRS)/tRNAPyl pair into the mouse genome enables site-specific incorporation of unnatural amino acids into a target protein in response to the amber codon. We demonstrate temporal and spatial control of protein acetylation in various organs of the transgenic mouse using a recombinant green fluorescent protein (GFPuv) as a model protein. This strategy will provide a powerful tool for systematic in vivo study of cellular proteins in the most commonly used mammalian model organism for human physiology and disease. PMID:28220771

  14. HOW TO REPRESENT THE GENETIC CODE?

    Directory of Open Access Journals (Sweden)

    N.S. Santos-Magalhães

    2004-05-01

    Full Text Available The advent of molecular genetic comprises a true revolution of far-reaching consequences for human-kind, which evolved into a specialized branch of the modern-day Biochemistry. The analysis of specicgenomic information are gaining wide-ranging interest because of their signicance to the early diag-nosis of disease, and the discovery of modern drugs. In order to take advantage of a wide assortmentof signal processing (SP algorithms, the primary step of modern genomic SP involves convertingsymbolic-DNA sequences into complex-valued signals. How to represent the genetic code? Despitebeing extensively known, the DNA mapping into proteins is one of the relevant discoveries of genetics.The genetic code (GC is revisited in this work, addressing other descriptions for it, which can beworthy for genomic SP. Three original representations are discussed. The inner-to-outer map buildson the unbalanced role of nucleotides of a codon. A two-dimensional-Gray genetic representationis oered as a structured map that can help interpreting DNA spectrograms or scalograms. Theseare among the powerful visual tools for genome analysis, which depends on the choice of the geneticmapping. Finally, the world-chart for the GC is investigated. Evoking the cyclic structure of thegenetic mapping, it can be folded joining the left-right borders, and the top-bottom frontiers. As aresult, the GC can be drawn on the surface of a sphere resembling a world-map. Eight parallels oflatitude are required (four in each hemisphere as well as four meridians of longitude associated tofour corresponding anti-meridians. The tropic circles have 11.25o, 33.75o, 56.25o, and 78.5o (Northand South. Starting from an arbitrary Greenwich meridian, the meridians of longitude can be plottedat 22.5o, 67.5o, 112.5o, and 157.5o (East and West. Each triplet is assigned to a single point on thesurface that we named Nirenberg-Kohamas Earth. Despite being valuable, usual representations forthe GC can be

  15. Expanding the eukaryotic genetic code

    Energy Technology Data Exchange (ETDEWEB)

    Chin, Jason W.; Cropp, T. Ashton; Anderson, J. Christopher; Schultz, Peter G.

    2017-02-28

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, orthogonal pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  16. Expanding the eukaryotic genetic code

    Science.gov (United States)

    Chin, Jason W.; Cropp, T. Ashton; Anderson, J. Christopher; Schultz, Peter G.

    2013-01-22

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, orthogonal pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  17. The puzzling origin of the genetic code.

    Science.gov (United States)

    Cedergren, R; Miramontes, P

    1996-06-01

    Recent results add to the mystery of the origin of the genetic code. In spite of early doubts, RNA can discriminate between hydrophobic amino acids under certain contexts. Moreover, codon reassignment, which has taken place in several organisms and mitochondria, is not a random process. Finally, phylogenies of some aminoacyl-tRNA synthetases suggest that the entire code was not completely assigned at the time of the divergence of bacteria from nucleated cells.

  18. Can the genetic code be mathematically described?

    Science.gov (United States)

    Gonzalez, Diego L

    2004-04-01

    From a mathematical point of view, the genetic code is a surjective mapping between the set of the 64 possible three-base codons and the set of 21 elements composed of the 20 amino acids plus the Stop signal. Redundancy and degeneracy therefore follow. In analogy with the genetic code, non-power integer-number representations are also surjective mappings between sets of different cardinality and, as such, also redundant. However, none of the non-power arithmetics studied so far nor other alternative redundant representations are able to match the actual degeneracy of the genetic code. In this paper we develop a slightly more general framework that leads to the following surprising results: i) the degeneracy of the genetic code is mathematically described, ii) a new symmetry is uncovered within this degeneracy, iii) by assigning a binary string to each of the codons, their classification into definite parity classes according to the corresponding sequence of bases is made possible. This last result is particularly appealing in connection with the fact that parity coding is the basis of the simplest strategies devised for error correction in man-made digital data transmission systems.

  19. Collective evolution and the genetic code.

    Science.gov (United States)

    Vetsigian, Kalin; Woese, Carl; Goldenfeld, Nigel

    2006-07-11

    A dynamical theory for the evolution of the genetic code is presented, which accounts for its universality and optimality. The central concept is that a variety of collective, but non-Darwinian, mechanisms likely to be present in early communal life generically lead to refinement and selection of innovation-sharing protocols, such as the genetic code. Our proposal is illustrated by using a simplified computer model and placed within the context of a sequence of transitions that early life may have made, before the emergence of vertical descent.

  20. Quaternionic representation of the genetic code.

    Science.gov (United States)

    Carlevaro, C Manuel; Irastorza, Ramiro M; Vericat, Fernando

    2016-03-01

    A heuristic diagram of the evolution of the standard genetic code is presented. It incorporates, in a way that resembles the energy levels of an atom, the physical notion of broken symmetry and it is consistent with original ideas by Crick on the origin and evolution of the code as well as with the chronological order of appearance of the amino acids along the evolution as inferred from work that mixtures known experimental results with theoretical speculations. Suggested by the diagram we propose a Hamilton quaternions based mathematical representation of the code as it stands now-a-days. The central object in the description is a codon function that assigns to each amino acid an integer quaternion in such a way that the observed code degeneration is preserved. We emphasize the advantages of a quaternionic representation of amino acids taking as an example the folding of proteins. With this aim we propose an algorithm to go from the quaternions sequence to the protein three dimensional structure which can be compared with the corresponding experimental one stored at the Protein Data Bank. In our criterion the mathematical representation of the genetic code in terms of quaternions merits to be taken into account because it describes not only most of the known properties of the genetic code but also opens new perspectives that are mainly derived from the close relationship between quaternions and rotations. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  1. Synthetic biology: Tailor-made genetic codes

    Science.gov (United States)

    Jewett, Michael C.; Noireaux, Vincent

    2016-04-01

    Expanding the range of amino acids polymerizable by ribosomes could enable new functionalities to be added to polypeptides. Now, the genetic code has been reprogrammed using a reconstituted in vitro translation system to enable synthesis of unnatural peptides with unmatched flexibility.

  2. Mathematical Fundamentals for the Noise Immunity of the Genetic Code.

    Science.gov (United States)

    Fimmel, Elena; Strüngmann, Lutz

    2017-09-13

    Symmetry is one of the essential and most visible patterns that can be seen in nature. Starting from the left-right symmetry of the human body, all types of symmetry can be found in crystals, plants, animals and nature as a whole. Similarly, principals of symmetry are also some of the fundamental and most useful tools in modern mathematical natural science that play a major role in theory and applications. As a consequence, it is not surprising that the desire to understand the origin of life, based on the genetic code, forces us to involve symmetry as a mathematical concept. The genetic code can be seen as a key to biological self-organisation. All living organisms have the same molecular bases - an alphabet consisting of four letters (nitrogenous bases): adenine, cytosine, guanine, and thymine. Linearly ordered sequences of these bases contain the genetic information for synthesis of proteins in all forms of life. Thus, one of the most fascinating riddles of nature is to explain why the genetic code is as it is. Genetic coding possesses noise immunity which is the fundamental feature that allows to pass on the genetic information from parents to their descendants. Hence, since the time of the discovery of the genetic code, scientists have tried to explain the noise immunity of the genetic information. In this chapter we will discuss recent results in mathematical modelling of the genetic code with respect to noise immunity, in particular error-detection and error-correction. We will focus on two central properties: Degeneracy and frameshift correction. Different amino acids are encoded by different quantities of codons and a connection between this degeneracy and the noise immunity of genetic information is a long standing hypothesis. Biological implications of the degeneracy have been intensively studied and whether the natural code is a frozen accident or a highly optimised product of evolution is still controversially discussed. Symmetries in the structure of

  3. The neutral emergence of error minimized genetic codes superior to the standard genetic code.

    Science.gov (United States)

    Massey, Steven E

    2016-11-07

    The standard genetic code (SGC) assigns amino acids to codons in such a way that the impact of point mutations is reduced, this is termed 'error minimization' (EM). The occurrence of EM has been attributed to the direct action of selection, however it is difficult to explain how the searching of alternative codes for an error minimized code can occur via codon reassignments, given that these are likely to be disruptive to the proteome. An alternative scenario is that EM has arisen via the process of genetic code expansion, facilitated by the duplication of genes encoding charging enzymes and adaptor molecules. This is likely to have led to similar amino acids being assigned to similar codons. Strikingly, we show that if during code expansion the most similar amino acid to the parent amino acid, out of the set of unassigned amino acids, is assigned to codons related to those of the parent amino acid, then genetic codes with EM superior to the SGC easily arise. This scheme mimics code expansion via the gene duplication of charging enzymes and adaptors. The result is obtained for a variety of different schemes of genetic code expansion and provides a mechanistically realistic manner in which EM has arisen in the SGC. These observations might be taken as evidence for self-organization in the earliest stages of life. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Xenomicrobiology: a roadmap for genetic code engineering.

    Science.gov (United States)

    Acevedo-Rocha, Carlos G; Budisa, Nediljko

    2016-09-01

    Biology is an analytical and informational science that is becoming increasingly dependent on chemical synthesis. One example is the high-throughput and low-cost synthesis of DNA, which is a foundation for the research field of synthetic biology (SB). The aim of SB is to provide biotechnological solutions to health, energy and environmental issues as well as unsustainable manufacturing processes in the frame of naturally existing chemical building blocks. Xenobiology (XB) goes a step further by implementing non-natural building blocks in living cells. In this context, genetic code engineering respectively enables the re-design of genes/genomes and proteins/proteomes with non-canonical nucleic (XNAs) and amino (ncAAs) acids. Besides studying information flow and evolutionary innovation in living systems, XB allows the development of new-to-nature therapeutic proteins/peptides, new biocatalysts for potential applications in synthetic organic chemistry and biocontainment strategies for enhanced biosafety. In this perspective, we provide a brief history and evolution of the genetic code in the context of XB. We then discuss the latest efforts and challenges ahead for engineering the genetic code with focus on substitutions and additions of ncAAs as well as standard amino acid reductions. Finally, we present a roadmap for the directed evolution of artificial microbes for emancipating rare sense codons that could be used to introduce novel building blocks. The development of such xenomicroorganisms endowed with a 'genetic firewall' will also allow to study and understand the relation between code evolution and horizontal gene transfer. © 2016 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  5. Cracking the Genetic Code | NIH MedlinePlus the Magazine

    Science.gov (United States)

    ... this page please turn Javascript on. Cracking the Genetic Code, From NIH Director Dr. Francis S. Collins Past Issues / ... moment in science in 2000: Cracking of the genetic code raised the prospect of pinpointing the root causes ...

  6. Two perspectives on the origin of the standard genetic code.

    Science.gov (United States)

    Sengupta, Supratim; Aggarwal, Neha; Bandhu, Ashutosh Vishwa

    2014-12-01

    The origin of a genetic code made it possible to create ordered sequences of amino acids. In this article we provide two perspectives on code origin by carrying out simulations of code-sequence coevolution in finite populations with the aim of examining how the standard genetic code may have evolved from more primitive code(s) encoding a small number of amino acids. We determine the efficacy of the physico-chemical hypothesis of code origin in the absence and presence of horizontal gene transfer (HGT) by allowing a diverse collection of code-sequence sets to compete with each other. We find that in the absence of horizontal gene transfer, natural selection between competing codes distinguished by differences in the degree of physico-chemical optimization is unable to explain the structure of the standard genetic code. However, for certain probabilities of the horizontal transfer events, a universal code emerges having a structure that is consistent with the standard genetic code.

  7. Metalloprotein design using genetic code expansion.

    Science.gov (United States)

    Hu, Cheng; Chan, Sunney I; Sawyer, Elizabeth B; Yu, Yang; Wang, Jiangyun

    2014-09-21

    More than one third of all proteins are metalloproteins. They catalyze important reactions such as photosynthesis, nitrogen fixation and CO2 reduction. Metalloproteins such as the olfactory receptors also serve as highly elaborate sensors. Here we review recent developments in functional metalloprotein design using the genetic code expansion approach. We show that, through the site-specific incorporation of metal-chelating unnatural amino acids (UAAs), proton and electron transfer mediators, and UAAs bearing bioorthogonal reaction groups, small soluble proteins can recapitulate and expand the important functions of complex metalloproteins. Further developments along this route may result in cell factories and live-cell sensors with unprecedented efficiency and selectivity.

  8. Human hemoglobin genetics

    Energy Technology Data Exchange (ETDEWEB)

    Honig, G.R.; Adams, J.G.

    1986-01-01

    This book contains the following 10 chapters: Introduction; The Human Hemoglobins; The Human Globin Genes; Hemoglobin Synthesis and Globin Gene Expression; The Globin Gene Mutations - A. Mechanisms and Classification; The Globin Gene Mutations - B. Their Phenotypes and Clinical Expression; The Genetics of the Human Globin Gene Loci: Formal Genetics and Gene Linkage; The Geographic Distribution of Globin Gene Variation; Labortory Identification, Screening, Education, and Counseling for Abnormal Hemoglobins and Thalassemias; and Approaches to the Treatment of the Hemoglobin Disorders.

  9. Optimality properties of a proposed precursor to the genetic code.

    Science.gov (United States)

    Butler, Thomas; Goldenfeld, Nigel

    2009-09-01

    We calculate the optimality score of a doublet precursor to the canonical genetic code with respect to mitigating the effects of point mutations and compare our results to corresponding ones for the canonical genetic code. We find that the proposed precursor is much less optimal than that of the canonical code. Our results render unlikely the notion that the doublet precursor was an intermediate state in the evolution of the canonical genetic code. These findings support the notion that code optimality reflects evolutionary dynamics, and that if such a doublet code originally had a biochemical significance, it arose before the emergence of translation.

  10. Efforts and Challenges in Engineering the Genetic Code.

    Science.gov (United States)

    Lin, Xiao; Yu, Allen Chi Shing; Chan, Ting Fung

    2017-03-14

    This year marks the 48th anniversary of Francis Crick's seminal work on the origin of the genetic code, in which he first proposed the "frozen accident" hypothesis to describe evolutionary selection against changes to the genetic code that cause devastating global proteome modification. However, numerous efforts have demonstrated the viability of both natural and artificial genetic code variations. Recent advances in genetic engineering allow the creation of synthetic organisms that incorporate noncanonical, or even unnatural, amino acids into the proteome. Currently, successful genetic code engineering is mainly achieved by creating orthogonal aminoacyl-tRNA/synthetase pairs to repurpose stop and rare codons or to induce quadruplet codons. In this review, we summarize the current progress in genetic code engineering and discuss the challenges, current understanding, and future perspectives regarding genetic code modification.

  11. Efforts and Challenges in Engineering the Genetic Code

    Directory of Open Access Journals (Sweden)

    Xiao Lin

    2017-03-01

    Full Text Available This year marks the 48th anniversary of Francis Crick’s seminal work on the origin of the genetic code, in which he first proposed the “frozen accident” hypothesis to describe evolutionary selection against changes to the genetic code that cause devastating global proteome modification. However, numerous efforts have demonstrated the viability of both natural and artificial genetic code variations. Recent advances in genetic engineering allow the creation of synthetic organisms that incorporate noncanonical, or even unnatural, amino acids into the proteome. Currently, successful genetic code engineering is mainly achieved by creating orthogonal aminoacyl-tRNA/synthetase pairs to repurpose stop and rare codons or to induce quadruplet codons. In this review, we summarize the current progress in genetic code engineering and discuss the challenges, current understanding, and future perspectives regarding genetic code modification.

  12. Analysis of the optimality of the standard genetic code.

    Science.gov (United States)

    Kumar, Balaji; Saini, Supreet

    2016-07-19

    Many theories have been proposed attempting to explain the origin of the genetic code. While strong reasons remain to believe that the genetic code evolved as a frozen accident, at least for the first few amino acids, other theories remain viable. In this work, we test the optimality of the standard genetic code against approximately 17 million genetic codes, and locate 29 which outperform the standard genetic code at the following three criteria: (a) robustness to point mutation; (b) robustness to frameshift mutation; and (c) ability to encode additional information in the coding region. We use a genetic algorithm to generate and score codes from different parts of the associated landscape, which are, as a result, presumably more representative of the entire landscape. Our results show that while the genetic code is sub-optimal for robustness to frameshift mutation and the ability to encode additional information in the coding region, it is very strongly selected for robustness to point mutation. This coupled with the observation that the different performance indicator scores for a particular genetic code are negatively correlated makes the standard genetic code nearly optimal for the three criteria tested in this work.

  13. A Binary Representation of the Genetic Code

    CERN Document Server

    Nemzer, Louis R

    2016-01-01

    This article introduces a novel binary representation of the canonical genetic code, in which each of the four mRNA nucleotide bases is assigned a unique 2-bit identifier. These designations have a physiological meaning derived from the molecular structures of, and relationships between, the bases. In this scheme, the 64 possible triplet codons are each indexed by a 6-bit label. The order of the bits reflects the hierarchical organization manifested by the DNA replication/repair and tRNA translation systems. Transition and transversion mutations are naturally expressed as basic binary operations, and the severity of the different types is analyzed. Using a principal component analysis, it is shown that physicochemical properties of amino acids related to protein folding also correlate with particular bit positions of their respective labels. Thus, the likelihood for a particular point mutation to be conservative, and therefore less likely to cause a change in protein functionality, can be estimated.

  14. Different types of secondary information in the genetic code.

    Science.gov (United States)

    Maraia, Richard J; Iben, James R

    2014-07-01

    Whole-genome and functional analyses suggest a wealth of secondary or auxiliary genetic information (AGI) within the redundancy component of the genetic code. Although there are multiple aspects of biased codon use, we focus on two types of auxiliary information: codon-specific translational pauses that can be used by particular proteins toward their unique folding and biased codon patterns shared by groups of functionally related mRNAs with coordinate regulation. AGI is important to genetics in general and to human disease; here, we consider influences of its three major components, biased codon use itself, variations in the tRNAome, and anticodon modifications that distinguish synonymous decoding. AGI is plastic and can be used by different species to different extents, with tissue-specificity and in stress responses. Because AGI is species-specific, it is important to consider codon-sensitive experiments when using heterologous systems; for this we focus on the tRNA anticodon loop modification enzyme, CDKAL1, and its link to type 2 diabetes. Newly uncovered tRNAome variability among humans suggests roles in penetrance and as a genetic modifier and disease modifier. Development of experimental and bioinformatics methods are needed to uncover additional means of auxiliary genetic information.

  15. Flexibility of the genetic code with respect to DNA structure

    DEFF Research Database (Denmark)

    Baisnée, P. F.; Baldi, Pierre; Brunak, Søren

    2001-01-01

    Motivation. The primary function of DNA is to carry genetic information through the genetic code. DNA, however, contains a variety of other signals related, for instance, to reading frame, codon bias, pairwise codon bias, splice sites and transcription regulation, nucleosome positioning and DNA...... structure. Here we study the relationship between the genetic code and DNA structure and address two questions. First, to which degree does the degeneracy of the genetic code and the acceptable amino acid substitution patterns allow for the superimposition of DNA structural signals to protein coding...... sequences? Second, is the origin or evolution of the genetic code likely to have been constrained by DNA structure? Results. We develop an index for code flexibility with respect to DNA structure. Using five different di- or tri-nucleotide models of sequence-dependent DNA structure, we show...

  16. Some mathematical refinements concerning error minimization in the genetic code.

    Science.gov (United States)

    Buhrman, Harry; van der Gulik, Peter T S; Kelk, Steven M; Koolen, Wouter M; Stougie, Leen

    2011-01-01

    The genetic code is known to have a high level of error robustness and has been shown to be very error robust compared to randomly selected codes, but to be significantly less error robust than a certain code found by a heuristic algorithm. We formulate this optimization problem as a Quadratic Assignment Problem and use this to formally verify that the code found by the heuristic algorithm is the global optimum. We also argue that it is strongly misleading to compare the genetic code only with codes sampled from the fixed block model, because the real code space is orders of magnitude larger. We thus enlarge the space from which random codes can be sampled from approximately 2.433 × 10(18) codes to approximately 5.908 × 10(45) codes. We do this by leaving the fixed block model, and using the wobble rules to formulate the characteristics acceptable for a genetic code. By relaxing more constraints, three larger spaces are also constructed. Using a modified error function, the genetic code is found to be more error robust compared to a background of randomly generated codes with increasing space size. We point out that these results do not necessarily imply that the code was optimized during evolution for error minimization, but that other mechanisms could be the reason for this error robustness.

  17. A multiobjective approach to the genetic code adaptability problem.

    Science.gov (United States)

    de Oliveira, Lariza Laura; de Oliveira, Paulo S L; Tinós, Renato

    2015-02-19

    The organization of the canonical code has intrigued researches since it was first described. If we consider all codes mapping the 64 codes into 20 amino acids and one stop codon, there are more than 1.51×10(84) possible genetic codes. The main question related to the organization of the genetic code is why exactly the canonical code was selected among this huge number of possible genetic codes. Many researchers argue that the organization of the canonical code is a product of natural selection and that the code's robustness against mutations would support this hypothesis. In order to investigate the natural selection hypothesis, some researches employ optimization algorithms to identify regions of the genetic code space where best codes, according to a given evaluation function, can be found (engineering approach). The optimization process uses only one objective to evaluate the codes, generally based on the robustness for an amino acid property. Only one objective is also employed in the statistical approach for the comparison of the canonical code with random codes. We propose a multiobjective approach where two or more objectives are considered simultaneously to evaluate the genetic codes. In order to test our hypothesis that the multiobjective approach is useful for the analysis of the genetic code adaptability, we implemented a multiobjective optimization algorithm where two objectives are simultaneously optimized. Using as objectives the robustness against mutation with the amino acids properties polar requirement (objective 1) and robustness with respect to hydropathy index or molecular volume (objective 2), we found solutions closer to the canonical genetic code in terms of robustness, when compared with the results using only one objective reported by other authors. Using more objectives, more optimal solutions are obtained and, as a consequence, more information can be used to investigate the adaptability of the genetic code. The multiobjective approach

  18. Recent evidence for evolution of the genetic code

    Science.gov (United States)

    Osawa, S.; Jukes, T. H.; Watanabe, K.; Muto, A.

    1992-01-01

    The genetic code, formerly thought to be frozen, is now known to be in a state of evolution. This was first shown in 1979 by Barrell et al. (G. Barrell, A. T. Bankier, and J. Drouin, Nature [London] 282:189-194, 1979), who found that the universal codons AUA (isoleucine) and UGA (stop) coded for methionine and tryptophan, respectively, in human mitochondria. Subsequent studies have shown that UGA codes for tryptophan in Mycoplasma spp. and in all nonplant mitochondria that have been examined. Universal stop codons UAA and UAG code for glutamine in ciliated protozoa (except Euplotes octacarinatus) and in a green alga, Acetabularia. E. octacarinatus uses UAA for stop and UGA for cysteine. Candida species, which are yeasts, use CUG (leucine) for serine. Other departures from the universal code, all in nonplant mitochondria, are CUN (leucine) for threonine (in yeasts), AAA (lysine) for asparagine (in platyhelminths and echinoderms), UAA (stop) for tyrosine (in planaria), and AGR (arginine) for serine (in several animal orders) and for stop (in vertebrates). We propose that the changes are typically preceded by loss of a codon from all coding sequences in an organism or organelle, often as a result of directional mutation pressure, accompanied by loss of the tRNA that translates the codon. The codon reappears later by conversion of another codon and emergence of a tRNA that translates the reappeared codon with a different assignment. Changes in release factors also contribute to these revised assignments. We also discuss the use of UGA (stop) as a selenocysteine codon and the early history of the code.

  19. Recent evidence for evolution of the genetic code

    Science.gov (United States)

    Osawa, S.; Jukes, T. H.; Watanabe, K.; Muto, A.

    1992-01-01

    The genetic code, formerly thought to be frozen, is now known to be in a state of evolution. This was first shown in 1979 by Barrell et al. (G. Barrell, A. T. Bankier, and J. Drouin, Nature [London] 282:189-194, 1979), who found that the universal codons AUA (isoleucine) and UGA (stop) coded for methionine and tryptophan, respectively, in human mitochondria. Subsequent studies have shown that UGA codes for tryptophan in Mycoplasma spp. and in all nonplant mitochondria that have been examined. Universal stop codons UAA and UAG code for glutamine in ciliated protozoa (except Euplotes octacarinatus) and in a green alga, Acetabularia. E. octacarinatus uses UAA for stop and UGA for cysteine. Candida species, which are yeasts, use CUG (leucine) for serine. Other departures from the universal code, all in nonplant mitochondria, are CUN (leucine) for threonine (in yeasts), AAA (lysine) for asparagine (in platyhelminths and echinoderms), UAA (stop) for tyrosine (in planaria), and AGR (arginine) for serine (in several animal orders) and for stop (in vertebrates). We propose that the changes are typically preceded by loss of a codon from all coding sequences in an organism or organelle, often as a result of directional mutation pressure, accompanied by loss of the tRNA that translates the codon. The codon reappears later by conversion of another codon and emergence of a tRNA that translates the reappeared codon with a different assignment. Changes in release factors also contribute to these revised assignments. We also discuss the use of UGA (stop) as a selenocysteine codon and the early history of the code.

  20. A binary representation of the genetic code.

    Science.gov (United States)

    Nemzer, Louis R

    2017-05-01

    This article introduces a novel binary representation of the canonical genetic code based on both the structural similarities of the nucleotides, as well as the physicochemical properties of the encoded amino acids. Each of the four mRNA bases is assigned a unique 2-bit identifier, so that the 64 triplet codons are each indexed by a 6-bit label. The ordering of the bits reflects the hierarchical organization manifested by the DNA replication/repair and tRNA translation systems. In this system, transition and transversion mutations are naturally expressed as binary operations, and the severities of the different point mutations can be analyzed. Using a principal component analysis, it is shown that the physicochemical properties of amino acids related to protein folding also correlate with certain bit positions of their respective labels. Thus, the likelihood for a point mutation to be conservative, and less likely to cause a change in protein functionality, can be estimated. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Schrödinger's code-script: not a genetic cipher but a code of development.

    Science.gov (United States)

    Walsby, A E; Hodge, M J S

    2017-06-01

    In his book What is Life? Erwin Schrödinger coined the term 'code-script', thought by some to be the first published suggestion of a hereditary code and perhaps a forerunner of the genetic code. The etymology of 'code' suggests three meanings relevant to 'code-script which we distinguish as 'cipher-code', 'word-code' and 'rule-code'. Cipher-codes and word-codes entail translation of one set of characters into another. The genetic code comprises not one but two cipher-codes: the first is the DNA 'base-pairing cipher'; the second is the 'nucleotide-amino-acid cipher', which involves the translation of DNA base sequences into amino-acid sequences. We suggest that Schrödinger's code-script is a form of 'rule-code', a set of rules that, like the 'highway code' or 'penal code', requires no translation of a message. Schrödinger first relates his code-script to chromosomal genes made of protein. Ignorant of its properties, however, he later abandons 'protein' and adopts in its place a hypothetical, isomeric 'aperiodic solid' whose atoms he imagines rearranged in countless different conformations, which together are responsible for the patterns of ontogenetic development. In an attempt to explain the large number of combinations required, Schrödinger referred to the Morse code (a cipher) but in doing so unwittingly misled readers into believing that he intended a cipher-code resembling the genetic code. We argue that the modern equivalent of Schrödinger's code-script is a rule-code of organismal development based largely on the synthesis, folding, properties and interactions of numerous proteins, each performing a specific task. Copyright © 2016. Published by Elsevier Ltd.

  2. A symbiotic liaison between the genetic and epigenetic code

    Directory of Open Access Journals (Sweden)

    Holger eHeyn

    2014-05-01

    Full Text Available With rapid advances in sequencing technologies, we are undergoing a paradigm shift from hypothesis- to data-driven research. Genome-wide profiling efforts gave informative insights into biological processes; however, considering the wealth of variation, the major challenge remains their meaningful interpretation. In particular sequence variation in non-coding contexts is often challenging to interpret. Here, data integration approaches for the identification of functional genetic variability represent a likely solution. Exemplary, functional linkage analysis integrating genotype and expression data determined regulatory quantitative trait loci (QTL and proposed causal relationships. In addition to gene expression, epigenetic regulation and specifically DNA methylation was established as highly valuable surrogate mark for functional variance of the genetic code. Epigenetic modification served as powerful mediator trait to elucidate mechanisms forming phenotypes in health and disease. Particularly, integrative studies of genetic and DNA methylation data yet guided interpretation strategies of risk genotypes, but also proved their value for physiological traits, such as natural human variation and aging. This Perspective seeks to illustrate the power of data integration in the genomic era exemplified by DNA methylation quantitative trait loci (meQTLs. However, the model is further extendable to virtually all traceable molecular traits.

  3. The degeneracy of the genetic code and Hadamard matrices

    CERN Document Server

    Petoukhov, Sergey V

    2008-01-01

    The matrix form of the presentation of the genetic code is described as the cognitive form to analyze structures of the genetic code. A similar matrix form is utilized in the theory of signal processing. The Kronecker family of the genetic matrices is investigated, which is based on the genetic matrix [C A; U G], where C, A, U, G are the letters of the genetic alphabet. This matrix in the third Kronecker power is the (8*8)-matrix, which contains 64 triplets. Peculiarities of the degeneracy of the vertebrate mitochondria genetic code are reflected in the symmetrical black-and-white mosaic of this genetic (8*8)-matrix. This mosaic matrix is connected algorithmically with Hadamard matrices unexpectedly, which are famous in the theory of signal processing, quantum mechanics and quantum computers.

  4. Non-Standard Genetic Codes Define New Concepts for Protein Engineering

    OpenAIRE

    Bezerra, Ana R; Guimarães, Ana R.; Santos, Manuel A. S.

    2015-01-01

    The essential feature of the genetic code is the strict one-to-one correspondence between codons and amino acids. The canonical code consists of three stop codons and 61 sense codons that encode 20% of the amino acid repertoire observed in nature. It was originally designated as immutable and universal due to its conservation in most organisms, but sequencing of genes from the human mitochondrial genomes revealed deviations in codon assignments. Since then, alternative codes have been reporte...

  5. Origin and evolutionary process of the genetic code.

    Science.gov (United States)

    Ikehara, Kenji; Niihara, Yuka

    2007-01-01

    The genetic code plots the relationship between a triplet base sequence on RNA and an amino acid that corresponds to a protein associated with a required function in organisms. Accurate knowledge about the genetic code, including its origin and evolutionary process, would be helpful for determining the causes of genetic disorders and discovering new medical treatments, as well as for understanding the origin of life. This review begins with discussion of several well-known theories on the origin of the genetic code. Then, a GNC-SNS primitive genetic code hypothesis, which we originally proposed, is explained in relation to the weak points of other theories. S and N denote G or C and any of the four bases, respectively. We also introduce our hypothesis of the GADV-protein world hypothesis on the origin of life, where GADV stands for the four amino acids, Gly[G], Ala[A], Asp[D] and Val[V]. Next, we discuss the reason why genetic disorders, which should be triggered by base replacements, are repressed at a low level under the universal genetic code. Finally, we explain the current difficulties we faced in treating genetic disorders, suggesting a prospect for a new type of treatments of these disorders.

  6. On the Uniqueness of the Standard Genetic Code.

    Science.gov (United States)

    Zamudio, Gabriel S; José, Marco V

    2017-02-13

    In this work, we determine the biological and mathematical properties that are sufficient and necessary to uniquely determine both the primeval RNY (purine-any base-pyrimidine) code and the standard genetic code (SGC). These properties are: the evolution of the SGC from the RNY code; the degeneracy of both codes, and the non-degeneracy of the assignments of aminoacyl-tRNA synthetases (aaRSs) to amino acids; the wobbling property; the consideration that glycine was the first amino acid; the topological and symmetrical properties of both codes.

  7. Multiplexed coding in the human basal ganglia

    Science.gov (United States)

    Andres, D. S.; Cerquetti, D.; Merello, M.

    2016-04-01

    A classic controversy in neuroscience is whether information carried by spike trains is encoded by a time averaged measure (e.g. a rate code), or by complex time patterns (i.e. a time code). Here we apply a tool to quantitatively analyze the neural code. We make use of an algorithm based on the calculation of the temporal structure function, which permits to distinguish what scales of a signal are dominated by a complex temporal organization or a randomly generated process. In terms of the neural code, this kind of analysis makes it possible to detect temporal scales at which a time patterns coding scheme or alternatively a rate code are present. Additionally, finding the temporal scale at which the correlation between interspike intervals fades, the length of the basic information unit of the code can be established, and hence the word length of the code can be found. We apply this algorithm to neuronal recordings obtained from the Globus Pallidus pars interna from a human patient with Parkinson’s disease, and show that a time pattern coding and a rate coding scheme co-exist at different temporal scales, offering a new example of multiplexed neuronal coding.

  8. Advances in human genetics

    Energy Technology Data Exchange (ETDEWEB)

    Harris, H.; Hirschhorn, K. (eds.)

    1993-01-01

    This book has five chapters covering peroxisomal diseases, X-linked immunodeficiencies, genetic mutations affecting human lipoproteins and their receptors and enzymes, genetic aspects of cancer, and Gaucher disease. The chapter on peroxisomes covers their discovery, structure, functions, disorders, etc. The chapter on X-linked immunodeficiencies discusses such diseases as agammaglobulinemia, severe combined immunodeficiency, Wiskott-Aldrich syndrome, animal models, linkage analysis, etc. Apolipoprotein formation, synthesis, gene regulation, proteins, etc. are the main focus of chapter 3. The chapter on cancer covers such topics as oncogene mapping and the molecular characterization of some recessive oncogenes. Gaucher disease is covered from its diagnosis, classification, and prevention, to its organ system involvement and molecular biology.

  9. A realistic model under which the genetic code is optimal.

    Science.gov (United States)

    Buhrman, Harry; van der Gulik, Peter T S; Klau, Gunnar W; Schaffner, Christian; Speijer, Dave; Stougie, Leen

    2013-10-01

    The genetic code has a high level of error robustness. Using values of hydrophobicity scales as a proxy for amino acid character, and the mean square measure as a function quantifying error robustness, a value can be obtained for a genetic code which reflects the error robustness of that code. By comparing this value with a distribution of values belonging to codes generated by random permutations of amino acid assignments, the level of error robustness of a genetic code can be quantified. We present a calculation in which the standard genetic code is shown to be optimal. We obtain this result by (1) using recently updated values of polar requirement as input; (2) fixing seven assignments (Ile, Trp, His, Phe, Tyr, Arg, and Leu) based on aptamer considerations; and (3) using known biosynthetic relations of the 20 amino acids. This last point is reflected in an approach of subdivision (restricting the random reallocation of assignments to amino acid subgroups, the set of 20 being divided in four such subgroups). The three approaches to explain robustness of the code (specific selection for robustness, amino acid-RNA interactions leading to assignments, or a slow growth process of assignment patterns) are reexamined in light of our findings. We offer a comprehensive hypothesis, stressing the importance of biosynthetic relations, with the code evolving from an early stage with just glycine and alanine, via intermediate stages, towards 64 codons carrying todays meaning.

  10. The information capacity of the genetic code: Is the natural code optimal?

    Science.gov (United States)

    Kuruoglu, Ercan E; Arndt, Peter F

    2017-04-21

    We envision the molecular evolution process as an information transfer process and provide a quantitative measure for information preservation in terms of the channel capacity according to the channel coding theorem of Shannon. We calculate Information capacities of DNA on the nucleotide (for non-coding DNA) and the amino acid (for coding DNA) level using various substitution models. We extend our results on coding DNA to a discussion about the optimality of the natural codon-amino acid code. We provide the results of an adaptive search algorithm in the code domain and demonstrate the existence of a large number of genetic codes with higher information capacity. Our results support the hypothesis of an ancient extension from a 2-nucleotide codon to the current 3-nucleotide codon code to encode the various amino acids. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Pathways of Genetic Code Evolution in Ancient and Modern Organisms.

    Science.gov (United States)

    Sengupta, Supratim; Higgs, Paul G

    2015-06-01

    There have been two distinct phases of evolution of the genetic code: an ancient phase--prior to the divergence of the three domains of life, during which the standard genetic code was established--and a modern phase, in which many alternative codes have arisen in specific groups of genomes that differ only slightly from the standard code. Here we discuss the factors that are most important in these two phases, and we argue that these are substantially different. In the modern phase, changes are driven by chance events such as tRNA gene deletions and codon disappearance events. Selection acts as a barrier to prevent changes in the code. In contrast, in the ancient phase, selection for increased diversity of amino acids in the code can be a driving force for addition of new amino acids. The pathway of code evolution is constrained by avoiding disruption of genes that are already encoded by earlier versions of the code. The current arrangement of the standard code suggests that it evolved from a four-column code in which Gly, Ala, Asp, and Val were the earliest encoded amino acids.

  12. Alternative genetic code for amino acids and transfer RNA revisited.

    Science.gov (United States)

    Hamashima, Kiyofumi; Kanai, Akio

    2013-06-01

    The genetic code is highly conserved among all organisms and its evolution is thought to be strictly limited. However, an increasing number of studies have reported non-standard codes in prokaryotic and eukaryotic genomes. Most of these deviations from the standard code are attributable to tRNA changes relating to, for example, codon/anticodon base pairing and tRNA/aminoacyl-tRNA synthetase recognition. In this review, we focus on tRNA, a key molecule in the translation of the genetic code, and summarize the most recently published information on the evolutionary divergence of the tRNAs. Surprisingly, although higher eukaryotes, such as the nematode (worm), utilize the standard genetic code, newly identified nematode-specific tRNAs (nev-tRNAs) translate nucleotides in a manner that transgresses the code. Furthermore, a variety of additional functions of tRNAs, beyond their translation of the genetic code, have emerged rapidly. We also review these intriguing new aspects of tRNA, which have potential impacts on translational control, RNA silencing, antibiotic resistance, RNA biosynthesis, and transcriptional regulation.

  13. Improving the efficiency of the genetic code by varying the codon length--the perfect genetic code.

    Science.gov (United States)

    Doig, A J

    1997-10-07

    The function of DNA is to specify protein sequences. The four-base "alphabet" used in nucleic acids is translated to the 20 base alphabet of proteins (plus a stop signal) via the genetic code. The code is neither overlapping nor punctuated, but has mRNA sequences read in successive triplet codons until reaching a stop codon. The true genetic code uses three bases for every amino acid. The efficiency of the genetic code can be significantly increased if the requirement for a fixed codon length is dropped so that the more common amino acids have shorter codon lengths and rare amino acids have longer codon lengths. More efficient codes can be derived using the Shannon-Fano and Huffman coding algorithms. The compression achieved using a Huffman code cannot be improved upon. I have used these algorithms to derive efficient codes for representing protein sequences using both two and four bases. The length of DNA required to specify the complete set of protein sequences could be significantly shorter if transcription used a variable codon length. The restriction to a fixed codon length of three bases means that it takes 42% more DNA than the minimum necessary, and the genetic code is 70% efficient. One can think of many reasons why this maximally efficient code has not evolved: there is very little redundancy so almost any mutation causes an amino acid change. Many mutations will be potentially lethal frame-shift mutations, if the mutation leads to a change in codon length. It would be more difficult for the machinery of transcription to cope with a variable codon length. Nevertheless, in the strict and narrow sense of coding for protein sequences using the minimum length of DNA possible, the Huffman code derived here is perfect.

  14. [Criminal code and assisted human reproduction].

    Science.gov (United States)

    Cortés Bechiarelli, Emilio

    2009-01-01

    The Spanish Criminal Code punishes in the article 161 the crime of assisted reproduction of the woman without her assent as a form of crime relative to the genetic manipulation. The crime protects a specific area of the freedom of decision of the woman, which is the one that she has dealing with the right to the procreation at the moment of being fertilized. The sentence would include the damages to the health provoked by the birth or the abortion. The crime is a common one--everyone can commit it--and it is not required a result of pregnancy, but it is consumed by the mere intervention on the body of the woman, and its interpretation is contained on the Law 14/2006, of may 26, on technologies of human assisted reproduction. The aim of the work is to propose to consider valid the assent given by the sixteen-year-old women (and older) in coherence with the Project of Law about sexual and reproductive health and voluntary interruption of the pregnancy that is studied at this moment, in Spain, in order to harmonize the legal systems.

  15. OPTIMIZATION BASED ON LMPROVED REAL—CODED GENETIC ALGORITHM

    Institute of Scientific and Technical Information of China (English)

    ShiYu; YuShenglin

    2002-01-01

    An improved real-coded genetic algorithm is pro-posed for global optimization of functionsl.The new algo-rithm is based om the judgement of the searching perfor-mance of basic real-coded genetic algorithm.The opera-tions of basic real-coded genetic algorithm are briefly dis-cussed and selected.A kind of chaos sequence is described in detail and added in the new algorithm ad a disturbance factor.The strategy of field partition is also used to im-prove the strcture of the new algorithm.Numerical ex-periment shows that the mew genetic algorithm can find the global optimum of complex funtions with satistaiting precision.

  16. Unnatural reactive amino acid genetic code additions

    Science.gov (United States)

    Deiters, Alexander; Cropp, Ashton T; Chin, Jason W; Anderson, Christopher J; Schultz, Peter G

    2013-05-21

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  17. Unnatural reactive amino acid genetic code additions

    Science.gov (United States)

    Deiters, Alexander; Cropp, T. Ashton; Chin, Jason W.; Anderson, J. Christopher; Schultz, Peter G.

    2014-08-26

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, orthogonal pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  18. Deciphering the genetic regulatory code using an inverse error control coding framework.

    Energy Technology Data Exchange (ETDEWEB)

    Rintoul, Mark Daniel; May, Elebeoba Eni; Brown, William Michael; Johnston, Anna Marie; Watson, Jean-Paul

    2005-03-01

    We have found that developing a computational framework for reconstructing error control codes for engineered data and ultimately for deciphering genetic regulatory coding sequences is a challenging and uncharted area that will require advances in computational technology for exact solutions. Although exact solutions are desired, computational approaches that yield plausible solutions would be considered sufficient as a proof of concept to the feasibility of reverse engineering error control codes and the possibility of developing a quantitative model for understanding and engineering genetic regulation. Such evidence would help move the idea of reconstructing error control codes for engineered and biological systems from the high risk high payoff realm into the highly probable high payoff domain. Additionally this work will impact biological sensor development and the ability to model and ultimately develop defense mechanisms against bioagents that can be engineered to cause catastrophic damage. Understanding how biological organisms are able to communicate their genetic message efficiently in the presence of noise can improve our current communication protocols, a continuing research interest. Towards this end, project goals include: (1) Develop parameter estimation methods for n for block codes and for n, k, and m for convolutional codes. Use methods to determine error control (EC) code parameters for gene regulatory sequence. (2) Develop an evolutionary computing computational framework for near-optimal solutions to the algebraic code reconstruction problem. Method will be tested on engineered and biological sequences.

  19. Does the human brain have unique genetically determined networks coding logical and ethical principles and aesthetics? From Plato to novel mirror networks.

    Science.gov (United States)

    Agnati, Luigi Francesco; Agnati, Achille; Mora, Francisco; Fuxe, Kjell

    2007-08-01

    Starting from the assumption that philosophers carry out "experiments" not on concrete objects, but on concepts and relationships between concepts, it could be postulated that the philosopher's way to proceed is not basically different from that followed by scientists. From this similarity of approaches it can be considered that some philosophical problems and theories have a high impact on how to address scientific investigations. One of these issues is certainly the philosophical debate over innate ideas, which is central to the conflict between rationalist and empiricist epistemologies. We started our reflections on the possible presence of innate ideas in the human brain from the observation that there exists strong experimental support for the view that not only complex behaviours (e.g., sexual courtship, parental care) but also aesthetic and ethic judgements can be, at least in part, genetically determined. On these grounds it is suggested that neurobiological findings can give important contributions to the philosophical debate on innatism by putting forward possible explanatory models and heuristic hypotheses.

  20. Origin and evolution of the genetic code: the universal enigma.

    Science.gov (United States)

    Koonin, Eugene V; Novozhilov, Artem S

    2009-02-01

    The genetic code is nearly universal, and the arrangement of the codons in the standard codon table is highly nonrandom. The three main concepts on the origin and evolution of the code are the stereochemical theory, according to which codon assignments are dictated by physicochemical affinity between amino acids and the cognate codons (anticodons); the coevolution theory, which posits that the code structure coevolved with amino acid biosynthesis pathways; and the error minimization theory under which selection to minimize the adverse effect of point mutations and translation errors was the principal factor of the code's evolution. These theories are not mutually exclusive and are also compatible with the frozen accident hypothesis, that is, the notion that the standard code might have no special properties but was fixed simply because all extant life forms share a common ancestor, with subsequent changes to the code, mostly, precluded by the deleterious effect of codon reassignment. Mathematical analysis of the structure and possible evolutionary trajectories of the code shows that it is highly robust to translational misreading but there are numerous more robust codes, so the standard code potentially could evolve from a random code via a short sequence of codon series reassignments. Thus, much of the evolution that led to the standard code could be a combination of frozen accident with selection for error minimization although contributions from coevolution of the code with metabolic pathways and weak affinities between amino acids and nucleotide triplets cannot be ruled out. However, such scenarios for the code evolution are based on formal schemes whose relevance to the actual primordial evolution is uncertain. A real understanding of the code origin and evolution is likely to be attainable only in conjunction with a credible scenario for the evolution of the coding principle itself and the translation system.

  1. Reducing the genetic code induces massive rearrangement of the proteome.

    Science.gov (United States)

    O'Donoghue, Patrick; Prat, Laure; Kucklick, Martin; Schäfer, Johannes G; Riedel, Katharina; Rinehart, Jesse; Söll, Dieter; Heinemann, Ilka U

    2014-12-02

    Expanding the genetic code is an important aim of synthetic biology, but some organisms developed naturally expanded genetic codes long ago over the course of evolution. Less than 1% of all sequenced genomes encode an operon that reassigns the stop codon UAG to pyrrolysine (Pyl), a genetic code variant that results from the biosynthesis of Pyl-tRNA(Pyl). To understand the selective advantage of genetically encoding more than 20 amino acids, we constructed a markerless tRNA(Pyl) deletion strain of Methanosarcina acetivorans (ΔpylT) that cannot decode UAG as Pyl or grow on trimethylamine. Phenotypic defects in the ΔpylT strain were evident in minimal medium containing methanol. Proteomic analyses of wild type (WT) M. acetivorans and ΔpylT cells identified 841 proteins from >7,000 significant peptides detected by MS/MS. Protein production from UAG-containing mRNAs was verified for 19 proteins. Translation of UAG codons was verified by MS/MS for eight proteins, including identification of a Pyl residue in PylB, which catalyzes the first step of Pyl biosynthesis. Deletion of tRNA(Pyl) globally altered the proteome, leading to >300 differentially abundant proteins. Reduction of the genetic code from 21 to 20 amino acids led to significant down-regulation in translation initiation factors, amino acid metabolism, and methanogenesis from methanol, which was offset by a compensatory (100-fold) up-regulation in dimethyl sulfide metabolic enzymes. The data show how a natural proteome adapts to genetic code reduction and indicate that the selective value of an expanded genetic code is related to carbon source range and metabolic efficiency.

  2. Origin and Evolution of the Universal Genetic Code.

    Science.gov (United States)

    Koonin, Eugene V; Novozhilov, Artem S

    2017-08-30

    The standard genetic code (SGC) is virtually universal among extant life forms. Although many deviations from the universal code exist, particularly in organelles and prokaryotes with small genomes, they are limited in scope and obviously secondary. The universality of the code likely results from the combination of a frozen accident, i.e., the deleterious effect of codon reassignment in the SGC, and the inhibitory effect of changes in the code on horizontal gene transfer. The structure of the SGC is nonrandom and ensures high robustness of the code to mutational and translational errors. However, this error minimization is most likely a by-product of the primordial code expansion driven by the diversification of the repertoire of protein amino acids, rather than a direct result of selection. Phylogenetic analysis of translation system components, in particular aminoacyl-tRNA synthetases, shows that, at a stage of evolution when the translation system had already attained high fidelity, the correspondence between amino acids and cognate codons was determined by recognition of amino acids by RNA molecules, i.e., proto-tRNAs. We propose an experimentally testable scenario for the evolution of the code that combines recognition of amino acids by unique sites on proto-tRNAs (distinct from the anticodons), expansion of the code via proto-tRNA duplication, and frozen accident. Expected final online publication date for the Annual Review of Genetics Volume 51 is November 23, 2017. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

  3. Horizontal symmetry in the algebraic approach of genetic code

    CERN Document Server

    Godina-Nava, J J

    2013-01-01

    Using concepts of physics of elementary particles concerning the breaking of symmetry and grannd unified theory we propose to study with the algebraic approximation the degeneracy finded in the genetic code with the incorporation of a horizontal symmetry used in gauge theories to fit the contents of the multiplets of the genetic code. It is used the algebraic approch of Hornos et. al. \\cite{main,PRL71,PRE,MPLB}. We propose an example for the incorporation of horizontal symmetry to study mixtures of elements of the multiplets.

  4. Horizontal symmetry in the algebraic approach of genetic code

    OpenAIRE

    Godina-Nava, J. J.

    2013-01-01

    Using concepts of physics of elementary particles concerning the breaking of symmetry and grannd unified theory we propose to study with the algebraic approximation the degeneracy finded in the genetic code with the incorporation of a horizontal symmetry used in gauge theories to fit the contents of the multiplets of the genetic code. It is used the algebraic approch of Hornos et. al. \\cite{main,PRL71,PRE,MPLB}. We propose an example for the incorporation of horizontal symmetry to study mixtu...

  5. The Genetic Code as a Periodic Table Algebraic Aspects

    CERN Document Server

    Bashford, J D

    2000-01-01

    The systematics of indices of physico-chemical properties of codons and amino acids across the genetic code are examined. Using a simple numerical labelling scheme for nucleic acid bases, data can be fitted as low-order polynomials of the 6 coordinates in the 64-dimensional codon weight space. The work confirms and extends recent studies by Siemion of protein conformational parameters. The connections between the present work, and recent studies of the genetic code structure using dynamical symmetry algebras, are pointed out.

  6. Genetics and recent human evolution.

    Science.gov (United States)

    Templeton, Alan R

    2007-07-01

    Starting with "mitochondrial Eve" in 1987, genetics has played an increasingly important role in studies of the last two million years of human evolution. It initially appeared that genetic data resolved the basic models of recent human evolution in favor of the "out-of-Africa replacement" hypothesis in which anatomically modern humans evolved in Africa about 150,000 years ago, started to spread throughout the world about 100,000 years ago, and subsequently drove to complete genetic extinction (replacement) all other human populations in Eurasia. Unfortunately, many of the genetic studies on recent human evolution have suffered from scientific flaws, including misrepresenting the models of recent human evolution, focusing upon hypothesis compatibility rather than hypothesis testing, committing the ecological fallacy, and failing to consider a broader array of alternative hypotheses. Once these flaws are corrected, there is actually little genetic support for the out-of-Africa replacement hypothesis. Indeed, when genetic data are used in a hypothesis-testing framework, the out-of-Africa replacement hypothesis is strongly rejected. The model of recent human evolution that emerges from a statistical hypothesis-testing framework does not correspond to any of the traditional models of human evolution, but it is compatible with fossil and archaeological data. These studies also reveal that any one gene or DNA region captures only a small part of human evolutionary history, so multilocus studies are essential. As more and more loci became available, genetics will undoubtedly offer additional insights and resolutions of human evolution.

  7. Next-generation human genetics

    OpenAIRE

    Shendure, Jay

    2011-01-01

    The field of human genetics is being reshaped by exome and genome sequencing. Several lessons are evident from observing the rapid development of this area over the past 2 years, and these may be instructive with respect to what we should expect from 'next-generation human genetics' in the next few years.

  8. Genetic Mapping in Human Disease

    OpenAIRE

    Altshuler, David; Daly, Mark J; Lander, Eric S.

    2008-01-01

    Genetic mapping provides a powerful approach to identify genes and biological processes underlying any trait influenced by inheritance, including human diseases. We discuss the intellectual foundations of genetic mapping of Mendelian and complex traits in humans, examine lessons emerging from linkage analysis of Mendelian diseases and genome-wide association studies of common diseases, and discuss questions and challenges that lie ahead.

  9. Report: Human cancer genetics

    Institute of Scientific and Technical Information of China (English)

    LI Marilyn; ALBERTSON Donna

    2006-01-01

    The short report will be focused on the genetic basis and possible mechanisms of tumorigenesis, common types of cancer, the importance of genetic diagnosis of cancer, and the methodology of cancer genetic diagnosis. They will also review presymptomatic testing of hereditary cancers, and the application of expression profiling to identify patients likely to benefit from particular therapeutic approaches.

  10. Human cancer genetics*

    OpenAIRE

    2006-01-01

    The short report will be focused on the genetic basis and possible mechanisms of tumorigenesis, common types of cancer, the importance of genetic diagnosis of cancer, and the methodology of cancer genetic diagnosis. They will also review presymptomatic testing of hereditary cancers, and the application of expression profiling to identify patients likely to benefit from particular therapeutic approaches.

  11. On the Organizational Dynamics of the Genetic Code

    KAUST Repository

    Zhang, Zhang

    2011-06-07

    The organization of the canonical genetic code needs to be thoroughly illuminated. Here we reorder the four nucleotides—adenine, thymine, guanine and cytosine—according to their emergence in evolution, and apply the organizational rules to devising an algebraic representation for the canonical genetic code. Under a framework of the devised code, we quantify codon and amino acid usages from a large collection of 917 prokaryotic genome sequences, and associate the usages with its intrinsic structure and classification schemes as well as amino acid physicochemical properties. Our results show that the algebraic representation of the code is structurally equivalent to a content-centric organization of the code and that codon and amino acid usages under different classification schemes were correlated closely with GC content, implying a set of rules governing composition dynamics across a wide variety of prokaryotic genome sequences. These results also indicate that codons and amino acids are not randomly allocated in the code, where the six-fold degenerate codons and their amino acids have important balancing roles for error minimization. Therefore, the content-centric code is of great usefulness in deciphering its hitherto unknown regularities as well as the dynamics of nucleotide, codon, and amino acid compositions.

  12. On the organizational dynamics of the genetic code.

    Science.gov (United States)

    Zhang, Zhang; Yu, Jun

    2011-04-01

    The organization of the canonical genetic code needs to be thoroughly illuminated. Here we reorder the four nucleotides-adenine, thymine, guanine and cytosine-according to their emergence in evolution, and apply the organizational rules to devising an algebraic representation for the canonical genetic code. Under a framework of the devised code, we quantify codon and amino acid usages from a large collection of 917 prokaryotic genome sequences, and associate the usages with its intrinsic structure and classification schemes as well as amino acid physicochemical properties. Our results show that the algebraic representation of the code is structurally equivalent to a content-centric organization of the code and that codon and amino acid usages under different classification schemes were correlated closely with GC content, implying a set of rules governing composition dynamics across a wide variety of prokaryotic genome sequences. These results also indicate that codons and amino acids are not randomly allocated in the code, where the six-fold degenerate codons and their amino acids have important balancing roles for error minimization. Therefore, the content-centric code is of great usefulness in deciphering its hitherto unknown regularities as well as the dynamics of nucleotide, codon, and amino acid compositions.

  13. A Mutation Model from First Principles of the Genetic Code.

    Science.gov (United States)

    Thorvaldsen, Steinar

    2016-01-01

    The paper presents a neutral Codons Probability Mutations (CPM) model of molecular evolution and genetic decay of an organism. The CPM model uses a Markov process with a 20-dimensional state space of probability distributions over amino acids. The transition matrix of the Markov process includes the mutation rate and those single point mutations compatible with the genetic code. This is an alternative to the standard Point Accepted Mutation (PAM) and BLOcks of amino acid SUbstitution Matrix (BLOSUM). Genetic decay is quantified as a similarity between the amino acid distribution of proteins from a (group of) species on one hand, and the equilibrium distribution of the Markov chain on the other. Amino acid data for the eukaryote, bacterium, and archaea families are used to illustrate how both the CPM and PAM models predict their genetic decay towards the equilibrium value of 1. A family of bacteria is studied in more detail. It is found that warm environment organisms on average have a higher degree of genetic decay compared to those species that live in cold environments. The paper addresses a new codon-based approach to quantify genetic decay due to single point mutations compatible with the genetic code. The present work may be seen as a first approach to use codon-based Markov models to study how genetic entropy increases with time in an effectively neutral biological regime. Various extensions of the model are also discussed.

  14. On the physical basis for ambiguity in genetic coding interactions.

    Science.gov (United States)

    Grosjean, H J; de Henau, S; Crothers, D M

    1978-02-01

    We report the relative stabilities, in the form of complex lifetimes, of complexes between the tRNAs complementary, or nearly so, in their anticodons. The results show striking parallels with the genetic coding rules, including the wobble interaction and the role of modified nucleotides S2U and V (a 5-oxyacetic acid derivative of U). One important difference between the genetic code and the pairing rules in the tRNA-tRNA interaction is the stability in the latter of the short wobble pairs, which the wobble hypothesis excludes. We stress the potential of U for translational errors, and suggest a simple stereochemical basis for ribosome-mediated discrimination against short wobble pairs. Surprisingly, the stability of anticodon-anticodon complexes does not vary systematically on base sequence. Because of the close similarity to the genetic coding rules, it is tempting to speculate that the interaction between two RNA loops may have been part of the physical basis for the evolutionary origin of the genetic code, and that this mechanism may still be utilized by folding the mRNA on the ribosome into a loop similar to the anticodon loop.

  15. [Direct genetic manipulation and criminal code in Venezuela: absolute criminal law void?].

    Science.gov (United States)

    Cermeño Zambrano, Fernando G De J

    2002-01-01

    The judicial regulation of genetic biotechnology applied to the human genome is of big relevance currently in Venezuela due to the drafting of an innovative bioethical law in the country's parliament. This article will highlight the constitutional normative of Venezuela's 1999 Constitution regarding this subject, as it establishes the framework from which this matter will be legally regulated. The approach this article makes towards the genetic biotechnology applied to the human genome is made taking into account the Venezuelan penal law and by highlighting the violent genetic manipulations that have criminal relevance. The genetic biotechnology applied to the human genome has another important relevance as a consequence of the reformulation of the Venezuelan Penal Code discussed by the country's National Assembly. Therefore, a concise study of the country's penal code will be made in this article to better understand what judicial-penal properties have been protected by the Venezuelan penal legislation. This last step will enable us to identify the penal tools Venezuela counts on to face direct genetic manipulations. We will equally indicate the existing punitive loophole and that should be covered by the penal legislator. In conclusion, this essay concerns criminal policy, referred to the direct genetic manipulations on the human genome that haven't been typified in Venezuelan law, thus discovering a genetic biotechnology paradise.

  16. The "Wow! signal" of the terrestrial genetic code

    Science.gov (United States)

    shCherbak, Vladimir I.; Makukov, Maxim A.

    2013-05-01

    It has been repeatedly proposed to expand the scope for SETI, and one of the suggested alternatives to radio is the biological media. Genomic DNA is already used on Earth to store non-biological information. Though smaller in capacity, but stronger in noise immunity is the genetic code. The code is a flexible mapping between codons and amino acids, and this flexibility allows modifying the code artificially. But once fixed, the code might stay unchanged over cosmological timescales; in fact, it is the most durable construct known. Therefore it represents an exceptionally reliable storage for an intelligent signature, if that conforms to biological and thermodynamic requirements. As the actual scenario for the origin of terrestrial life is far from being settled, the proposal that it might have been seeded intentionally cannot be ruled out. A statistically strong intelligent-like "signal" in the genetic code is then a testable consequence of such scenario. Here we show that the terrestrial code displays a thorough precision-type orderliness matching the criteria to be considered an informational signal. Simple arrangements of the code reveal an ensemble of arithmetical and ideographical patterns of the same symbolic language. Accurate and systematic, these underlying patterns appear as a product of precision logic and nontrivial computing rather than of stochastic processes (the null hypothesis that they are due to chance coupled with presumable evolutionary pathways is rejected with P-value artificiality, among which are the symbol of zero, the privileged decimal syntax and semantical symmetries. Besides, extraction of the signal involves logically straightforward but abstract operations, making the patterns essentially irreducible to any natural origin. Plausible ways of embedding the signal into the code and possible interpretation of its content are discussed. Overall, while the code is nearly optimized biologically, its limited capacity is used extremely

  17. p-Adic Degeneracy of the Genetic Code

    CERN Document Server

    Dragovich, Branko

    2007-01-01

    Degeneracy of the genetic code is a biological way to minimize effects of the undesirable mutation changes. Degeneration has a natural description on the 5-adic space of 64 codons $\\mathcal{C}_5 (64) = \\{n_0 + n_1 5 + n_2 5^2 : n_i = 1, 2, 3, 4 \\} ,$ where $n_i$ are digits related to nucleotides as follows: C = 1, A = 2, T = U = 3, G = 4. The smallest 5-adic distance between codons joins them into 16 quadruplets, which under 2-adic distance decay into 32 doublets. p-Adically close codons are assigned to one of 20 amino acids, which are building blocks of proteins, or code termination of protein synthesis. We shown that genetic code multiplets are made of the p-adic nearest codons.

  18. On the possible origin and evolution of the genetic code

    Science.gov (United States)

    Jukes, T. H.

    1974-01-01

    The genetic code is examined for indications of possible preceding codes that existed during early evolution. Eight of the 20 amino acids are coded by 'quartets' of codons with fourfold degeneracy, and 16 such quartets can exist, so that an earlier code could have provided for 15 or 16 amino acids, rather than 20. If twofold degeneracy is postulated for the first position of the codon, there could have been ten amino acids in the code. It is speculated that these may have been phenylalanine, valine, proline, alanine, histidine, glutamine, glutanic acid, aspartic acid, cysteine and glycine. There is a notable deficiency of arginine in proteins, despite the fact that it has six codons. Simultaneously, there is more lysine in proteins than would be expected from its two codons, if the four bases in mRNA are equiprobable and are arranged randomly. It is speculated that arginine is an 'intruder' into the genetic code, and that it may have displayed another amino acid such as ornithine, or may even have displayed lysine from some of its previous codon assignments. As a result, natural selection has favored lysine against the fact that it has only two codons.

  19. On the possible origin and evolution of the genetic code

    Science.gov (United States)

    Jukes, T. H.

    1974-01-01

    The genetic code is examined for indications of possible preceding codes that existed during early evolution. Eight of the 20 amino acids are coded by 'quartets' of codons with fourfold degeneracy, and 16 such quartets can exist, so that an earlier code could have provided for 15 or 16 amino acids, rather than 20. If twofold degeneracy is postulated for the first position of the codon, there could have been ten amino acids in the code. It is speculated that these may have been phenylalanine, valine, proline, alanine, histidine, glutamine, glutanic acid, aspartic acid, cysteine and glycine. There is a notable deficiency of arginine in proteins, despite the fact that it has six codons. Simultaneously, there is more lysine in proteins than would be expected from its two codons, if the four bases in mRNA are equiprobable and are arranged randomly. It is speculated that arginine is an 'intruder' into the genetic code, and that it may have displayed another amino acid such as ornithine, or may even have displayed lysine from some of its previous codon assignments. As a result, natural selection has favored lysine against the fact that it has only two codons.

  20. Expanding the genetic code of Salmonella with non-canonical amino acids

    Science.gov (United States)

    Gan, Qinglei; Lehman, Brent P.; Bobik, Thomas A.; Fan, Chenguang

    2016-01-01

    The diversity of non-canonical amino acids (ncAAs) endows proteins with new features for a variety of biological studies and biotechnological applications. The genetic code expansion strategy, which co-translationally incorporates ncAAs into specific sites of target proteins, has been applied in many organisms. However, there have been only few studies on pathogens using genetic code expansion. Here, we introduce this technique into the human pathogen Salmonella by incorporating p-azido-phenylalanine, benzoyl-phenylalanine, acetyl-lysine, and phosphoserine into selected Salmonella proteins including a microcompartment shell protein (PduA), a type III secretion effector protein (SteA), and a metabolic enzyme (malate dehydrogenase), and demonstrate practical applications of genetic code expansion in protein labeling, photocrosslinking, and post-translational modification studies in Salmonella. This work will provide powerful tools for a wide range of studies on Salmonella. PMID:28008993

  1. Evolution of the genetic code from the GC- to the AGUC-alphabet

    OpenAIRE

    Semenov, Denis A.

    2007-01-01

    A hypothesis of the evolution of the genetic code is proposed, the leading mechanism of which is the nucleotide spontaneous damage leading to AT-enrichment of the genome. The hypothesis accounts for stability of the genetic code towards point mutations, the presence of code dialects, and the symmetry of the genetic code table.

  2. A unified model of the standard genetic code.

    Science.gov (United States)

    José, Marco V; Zamudio, Gabriel S; Morgado, Eberto R

    2017-03-01

    The Rodin-Ohno (RO) and the Delarue models divide the table of the genetic code into two classes of aminoacyl-tRNA synthetases (aaRSs I and II) with recognition from the minor or major groove sides of the tRNA acceptor stem, respectively. These models are asymmetric but they are biologically meaningful. On the other hand, the standard genetic code (SGC) can be derived from the primeval RNY code (R stands for purines, Y for pyrimidines and N any of them). In this work, the RO-model is derived by means of group actions, namely, symmetries represented by automorphisms, assuming that the SGC originated from a primeval RNY code. It turns out that the RO-model is symmetric in a six-dimensional (6D) hypercube. Conversely, using the same automorphisms, we show that the RO-model can lead to the SGC. In addition, the asymmetric Delarue model becomes symmetric by means of quotient group operations. We formulate isometric functions that convert the class aaRS I into the class aaRS II and vice versa. We show that the four polar requirement categories display a symmetrical arrangement in our 6D hypercube. Altogether these results cannot be attained, neither in two nor in three dimensions. We discuss the present unified 6D algebraic model, which is compatible with both the SGC (based upon the primeval RNY code) and the RO-model.

  3. Regulation of the genetic code in megakaryocytes and platelets.

    Science.gov (United States)

    Rondina, M T; Weyrich, A S

    2015-06-01

    Platelets are generated from nucleated precursors referred to as megakaryocytes. The formation of platelets is one of the most elegant and unique developmental processes in eukaryotes. Because they enter the circulation without nuclei, platelets are often considered simple, non-complex cells that have limited functions beyond halting blood flow. However, emerging evidence over the past decade demonstrates that platelets are more sophisticated than previously considered. Platelets carry a rich repertoire of messenger RNAs (mRNAs), microRNAs (miRNAs), and proteins that contribute to primary (adhesion, aggregation, secretion) and alternative (immune regulation, RNA transfer, translation) functions. It is also becoming increasingly clear that the 'genetic code' of platelets changes with race, genetic disorders, or disease. Changes in the 'genetic code' can occur at multiple points including megakaryocyte development, platelet formation, or in circulating platelets. This review focuses on regulation of the 'genetic code' in megakaryocytes and platelets and its potential contribution to health and disease. © 2015 International Society on Thrombosis and Haemostasis.

  4. Exceptional error minimization in putative primordial genetic codes

    Directory of Open Access Journals (Sweden)

    Koonin Eugene V

    2009-11-01

    Full Text Available Abstract Background The standard genetic code is redundant and has a highly non-random structure. Codons for the same amino acids typically differ only by the nucleotide in the third position, whereas similar amino acids are encoded, mostly, by codon series that differ by a single base substitution in the third or the first position. As a result, the code is highly albeit not optimally robust to errors of translation, a property that has been interpreted either as a product of selection directed at the minimization of errors or as a non-adaptive by-product of evolution of the code driven by other forces. Results We investigated the error-minimization properties of putative primordial codes that consisted of 16 supercodons, with the third base being completely redundant, using a previously derived cost function and the error minimization percentage as the measure of a code's robustness to mistranslation. It is shown that, when the 16-supercodon table is populated with 10 putative primordial amino acids, inferred from the results of abiotic synthesis experiments and other evidence independent of the code's evolution, and with minimal assumptions used to assign the remaining supercodons, the resulting 2-letter codes are nearly optimal in terms of the error minimization level. Conclusion The results of the computational experiments with putative primordial genetic codes that contained only two meaningful letters in all codons and encoded 10 to 16 amino acids indicate that such codes are likely to have been nearly optimal with respect to the minimization of translation errors. This near-optimality could be the outcome of extensive early selection during the co-evolution of the code with the primordial, error-prone translation system, or a result of a unique, accidental event. Under this hypothesis, the subsequent expansion of the code resulted in a decrease of the error minimization level that became sustainable owing to the evolution of a high

  5. The genetic code as a periodic table: algebraic aspects.

    Science.gov (United States)

    Bashford, J D; Jarvis, P D

    2000-01-01

    The systematics of indices of physico-chemical properties of codons and amino acids across the genetic code are examined. Using a simple numerical labelling scheme for nucleic acid bases, A=(-1,0), C=(0,-1), G=(0,1), U=(1,0), data can be fitted as low order polynomials of the six coordinates in the 64-dimensional codon weight space. The work confirms and extends the recent studies by Siemion et al. (1995. BioSystems 36, 231-238) of the conformational parameters. Fundamental patterns in the data such as codon periodicities, and related harmonics and reflection symmetries, are here associated with the structure of the set of basis monomials chosen for fitting. Results are plotted using the Siemion one-step mutation ring scheme, and variants thereof. The connections between the present work, and recent studies of the genetic code structure using dynamical symmetry algebras, are pointed out.

  6. Load Flow Analysis Using Real Coded Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Himakar Udatha

    2014-02-01

    Full Text Available This paper presents a Real Coded Genetic Algorithm (RCGA for finding the load flow solution of electrical power systems. The proposed method is based on the minimization of the real and reactive power mismatches at various buses. The traditional methods such as Gauss-Seidel method and Newton-Raphson (NR method have certain drawbacks under abnormal operating condition. In order to overcome these problems, the load flow solution based on Real Coded Genetic Algorithm (RCGA is presented in this paper. Two cross over techniques, Arithmetic crossover and heuristic crossover are used to solve the power flow problem. The proposed method is applied for 3-bus, 5-bus and 6-bus systems and the results are presented.

  7. A Scenario on the Stepwise Evolution of the Genetic Code

    Institute of Scientific and Technical Information of China (English)

    Jing-Fa; Xiao; Jun; Yu

    2007-01-01

    It is believed that in the RNA world the operational (ribozymes) and the infor- mational (riboscripts) RNA molecules were created with only three (adenosine, uridine, and guanosine) and two (adenosine and uridine) nucleosides, respectively, so that the genetic code started uncomplicated. Ribozymes subsequently evolved to be able to cut and paste themselves and riboscripts were acceptive to rigor- ous editing (adenosine to inosine); the intensive diversification of RNA molecules shaped novel cellular machineries that are capable of polymerizing amino acids-a new type of cellular building materials for life. Initially, the genetic code, encoding seven amino acids, was created only to distinguish purine and pyrimidine; it was later expanded in a stepwise way to encode 12, 15, and 20 amino acids through the relief of guanine from its roles as operational signals and through the recruitment of cytosine. Therefore, the maturation of the genetic code also coincided with (1) the departure of aminoacyl-tRNA synthetases (AARSs) from the primordial translation machinery, (2) the replacement of informational RNA by DNA, and (3) the co-evolution of AARSs and their cognate tRNAs. This model predicts gradual replacements of RNA-made molecular mechanisms, cellular processes by proteins, and informational exploitation by DNA.

  8. An analysis of the metabolic theory of the origin of the genetic code

    Science.gov (United States)

    Amirnovin, R.; Bada, J. L. (Principal Investigator)

    1997-01-01

    A computer program was used to test Wong's coevolution theory of the genetic code. The codon correlations between the codons of biosynthetically related amino acids in the universal genetic code and in randomly generated genetic codes were compared. It was determined that many codon correlations are also present within random genetic codes and that among the random codes there are always several which have many more correlations than that found in the universal code. Although the number of correlations depends on the choice of biosynthetically related amino acids, the probability of choosing a random genetic code with the same or greater number of codon correlations as the universal genetic code was found to vary from 0.1% to 34% (with respect to a fairly complete listing of related amino acids). Thus, Wong's theory that the genetic code arose by coevolution with the biosynthetic pathways of amino acids, based on codon correlations between biosynthetically related amino acids, is statistical in nature.

  9. A cybernetic approach to the origin of the genetic coding mechanism. II. Formation of the code series.

    Science.gov (United States)

    Batchinsky, A G; Ratner, V A

    1976-08-01

    The sequential fulfillment of the principle of succession necessarily guides the main steps of the genetic code evolution to be reflected in its structure. The general scheme of the code series formation is proposed basing on the idea of "group coding" (Woese, 1970). The genetic code supposedly evolved by means of successive divergence of pra-ARS's loci, accompanied by increasing specification of recognition capacity of amino acids and triplets. The sense of codons had not been changed on any step of stochastic code evolution. The formulated rules for code series formation produce a code version, similar to the contemporary one. Based on these rules the scheme of pra-ARS's divergence is proposed resulting in the grouping of amino acids by their polarity and size. Later steps in the evolution of the genetic code were probably based on more detailed features of the amino acids (for example, on their functional similarities like their interchangeabilities in isofunctional proteins).

  10. A systematic survey of loss-of-function variants in human protein-coding genes

    NARCIS (Netherlands)

    MacArthur, D.G.; Balasubramanian, S.; Frankish, A.; Huang, N.; Morris, J.; Walter, K.; Jostins, L.; Habegger, L.; Pickrell, J.K.; Montgomery, S.B.; Albers, C.A.; Zhang, Z.D.; Conrad, D.F.; Lunter, G.; Zheng, H.; Ayub, Q.; DePristo, M.A.; Banks, E.; Hu, M.; Handsaker, R.E.; Rosenfeld, J.A.; Fromer, M.; Jin, M.; Mu, X.J.; Khurana, E.; Ye, K.; Kay, M.; Saunders, G.I.; Suner, M.M.; Hunt, T.; Barnes, I.H.; Amid, C.; Carvalho-Silva, D.R.; Bignell, A.H.; Snow, C.; Yngvadottir, B.; Bumpstead, S.; Cooper, D.N.; Xue, Y.; Romero, I.G.; Genomes Project, C.; Wang, J.; Li, Y.; Gibbs, R.A.; McCarroll, S.A.; Dermitzakis, E.T.; Pritchard, J.K.; Barrett, J.C.; Harrow, J.; Hurles, M.E.; Gerstein, M.B.; Tyler-Smith, C.

    2012-01-01

    Genome-sequencing studies indicate that all humans carry many genetic variants predicted to cause loss of function (LoF) of protein-coding genes, suggesting unexpected redundancy in the human genome. Here we apply stringent filters to 2951 putative LoF variants obtained from 185 human genomes to det

  11. The Genetic Codes: Mathematical Formulae and an Inverse Symmetry-Information Relationship

    Directory of Open Access Journals (Sweden)

    Tidjani Négadi

    2016-12-01

    Full Text Available First, mathematical formulae faithfully describing the distributions of amino acids and codons and reproducing the degeneracies in the various known genetic codes, including the standard genetic code, are constructed, by hand. Second, we summarize another mathematical approach relying on the use of q-deformations to describe these same genetic codes, and add a new application not considered before. Third, by considering these same genetic codes, we find, qualitatively, that an inverse symmetry-information relationship exists.

  12. A Mathematical Model Accounting for the Organisation in Multiplets of the Genetic Code

    OpenAIRE

    Sciarrino, A.

    2001-01-01

    Requiring stability of genetic code against translation errors, modelised by suitable mathematical operators in the crystal basis model of the genetic code, the main features of the organisation in multiplets of the mitochondrial and of the standard genetic code are explained.

  13. An Autotrophic Origin for the Coded Amino Acids is Concordant with the Coevolution Theory of the Genetic Code.

    Science.gov (United States)

    Di Giulio, Massimo

    2016-10-01

    The coevolution theory of the origin of the genetic code maintains that the biosynthetic relationships between amino acids co-evolved with the genetic code organization. In other words, the metabolism of amino acids co-evolved with the organization of the genetic code because the biosynthetic pathways of amino acids occurred on tRNA-like molecules. Thus, a heterotrophic origin of amino acids-also only of those involved in the early phase of the structuring of the genetic code-would seem to contradict the main postulate of the coevolution theory. As a matter of fact, this origin not being linked to the metabolism of amino acids in any way-being taken from a physical setting-would seem to remove the possibility that this metabolism had instead heavily contributed to the structuring of the genetic code. Therefore, I have analyzed the structure of the genetic code and mechanisms that brought to its structuring for understanding if the coevolution theory is compatible with autotrophic or heterotrophic conditions. One of the arguments was that an autotrophic origin of amino acids would have the advantage to be able to directly link their metabolism to the structure of the genetic code if-as hypothesized by the coevolution theory-the biosyntheses of amino acids occurred on tRNA-like molecules. Simultaneously, a heterotrophic origin would not have been able to link the metabolism of amino acids to the structure of the genetic code for the absence of a precise determinism of allocation of amino acids, that is to say of a clear mechanism-linked to tRNA-like molecules, for example-that would have determined the specific pattern observed in the genetic code of the biosynthetic relationships between amino acids. The conclusion is that an autotrophic origin of coded amino acids would seem to be the condition under which the genetic code originated.

  14. Genetic algorithms with permutation coding for multiple sequence alignment.

    Science.gov (United States)

    Ben Othman, Mohamed Tahar; Abdel-Azim, Gamil

    2013-08-01

    Multiple sequence alignment (MSA) is one of the topics of bio informatics that has seriously been researched. It is known as NP-complete problem. It is also considered as one of the most important and daunting tasks in computational biology. Concerning this a wide number of heuristic algorithms have been proposed to find optimal alignment. Among these heuristic algorithms are genetic algorithms (GA). The GA has mainly two major weaknesses: it is time consuming and can cause local minima. One of the significant aspects in the GA process in MSA is to maximize the similarities between sequences by adding and shuffling the gaps of Solution Coding (SC). Several ways for SC have been introduced. One of them is the Permutation Coding (PC). We propose a hybrid algorithm based on genetic algorithms (GAs) with a PC and 2-opt algorithm. The PC helps to code the MSA solution which maximizes the gain of resources, reliability and diversity of GA. The use of the PC opens the area by applying all functions over permutations for MSA. Thus, we suggest an algorithm to calculate the scoring function for multiple alignments based on PC, which is used as fitness function. The time complexity of the GA is reduced by using this algorithm. Our GA is implemented with different selections strategies and different crossovers. The probability of crossover and mutation is set as one strategy. Relevant patents have been probed in the topic.

  15. Shannon information entropy in the canonical genetic code.

    Science.gov (United States)

    Nemzer, Louis R

    2017-02-21

    The Shannon entropy measures the expected information value of messages. As with thermodynamic entropy, the Shannon entropy is only defined within a system that identifies at the outset the collections of possible messages, analogous to microstates, that will be considered indistinguishable macrostates. This fundamental insight is applied here for the first time to amino acid alphabets, which group the twenty common amino acids into families based on chemical and physical similarities. To evaluate these schemas objectively, a novel quantitative method is introduced based the inherent redundancy in the canonical genetic code. Each alphabet is taken as a separate system that partitions the 64 possible RNA codons, the microstates, into families, the macrostates. By calculating the normalized mutual information, which measures the reduction in Shannon entropy, conveyed by single nucleotide messages, groupings that best leverage this aspect of fault tolerance in the code are identified. The relative importance of properties related to protein folding - like hydropathy and size - and function, including side-chain acidity, can also be estimated. This approach allows the quantification of the average information value of nucleotide positions, which can shed light on the coevolution of the canonical genetic code with the tRNA-protein translation mechanism. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Evolution of the genetic code through progressive symmetry breaking.

    Science.gov (United States)

    Lenstra, Reijer

    2014-04-21

    Evolution of the genetic code in an early RNA world is dependent on the steadily improving specificity of the coevolving protein synthesis machinery for codons, anticodons, tRNAs and amino acids. In the beginning, there is RNA but the machinery does not distinguish yet between the codons, which therefore all encode the same information. Synonymous codons are equivalent under a symmetry group that exchanges (permutes) the codons without affecting the code. The initial group changes any codon into any other by permuting the order of the bases in the triplet as well as by replacing the four RNA bases with each other at every codon position. This group preserves the differences between codons, known as Hamming distances, with a 1-distance corresponding to a single point mutation. Stepwise breaking of the group into subgroups divides the 64 codons into progressively smaller subsets - blocks of equivalent codons under the smaller symmetry groups, with each block able to encode a different message. This formalism prescribes how the evolving machinery increasingly differentiates between codons. The model indicates that primitive ribosomes first identified a unique mRNA reading frame to break the group permuting the order of the bases and subsequently enforced increasingly stringent codon-anticodon basepairing rules to break the subgroups permuting the four bases at each codon position. The modern basepairing rules evolve in five steps and at each step the number of codon blocks doubles. The fourth step generates 16 codon blocks corresponding with the 16 family boxes of the standard code and the last step splits these boxes into 32 blocks of commonly two, but rarely one or three, synonymous codons. The evolving codes transmit at most one message per codon block and as the number of messages increases so does the specificity of the code and of protein synthesis. The selective advantage conferred by better functioning proteins drives the symmetry breaking process. Over time

  17. Interleaver Design Method for Turbo Codes Based on Genetic Algorithm

    Institute of Scientific and Technical Information of China (English)

    Tan Ying; Sun Hong; Zhou Huai-bei

    2004-01-01

    This paper describes a new interleaver construction technique for turbo code. The technique searches as much as possible pseudo-random interleaving patterns under a certain condition using genetic algorithms(GAs). The new interleavers have the superiority of the S-random interleavers and this interleaver construction technique can reduce the time taken to generate pseudo-random interleaving patterns under a certain condition. Tbe results obtained indicate that the new interleavers yield an equal to or better performance than the Srandom interleavers. Compared to the S-random interleaver,this design requires a lower level of computational complexity.

  18. Quantum control using genetic algorithms in quantum communication: superdense coding

    Science.gov (United States)

    Domínguez-Serna, Francisco; Rojas, Fernando

    2015-06-01

    We present a physical example model of how Quantum Control with genetic algorithms is applied to implement the quantum superdense code protocol. We studied a model consisting of two quantum dots with an electron with spin, including spin-orbit interaction. The electron and the spin get hybridized with the site acquiring two degrees of freedom, spin and charge. The system has tunneling and site energies as time dependent control parameters that are optimized by means of genetic algorithms to prepare a hybrid Bell-like state used as a transmission channel. This state is transformed to obtain any state of the four Bell basis as required by superdense protocol to transmit two bits of classical information. The control process protocol is equivalent to implement one of the quantum gates in the charge subsystem. Fidelities larger than 99.5% are achieved for the hybrid entangled state preparation and the superdense operations.

  19. A Content-Centric Organization of the Genetic Code

    Institute of Scientific and Technical Information of China (English)

    Jun Yu

    2007-01-01

    The codon table for the canonical genetic code can be rearranged in such a way that the code is divided into four quarters and two halves according to the variability of their GC and purine contents, respectively. For prokaryotic genomes, when the genomic GC content increases, their amino acid contents tend to be restricted to the GC-rich quarter and the purine-content insensitive half, where all codons are fourfold degenerate and relatively mutation-tolerant. Conversely, when the genomic GC content decreases, most of the codons retract to the AU-rich quarter and the purine-content sensitive half; most of the codons not only remain encoding physicochemically diversified amino acids but also vary when transversion (between purine and pyrimidine) happens. Amino acids with sixfolddegenerate codons are distributed into all four quarters and across the two halves; their fourfold-degenerate codons are all partitioned into the purine-insensitive half in favorite of robustness against mutations. The features manifested in the rearranged codon table explain most of the intrinsic relationship between protein coding sequences (the informational content) and amino acid compositions (the functional content). The renovated codon table is useful in predicting abundant amino acids and positioning the amino acids with related or distinct physicochemical properties.

  20. Decoding the non-coding genome: elucidating genetic risk outside the coding genome.

    Science.gov (United States)

    Barr, C L; Misener, V L

    2016-01-01

    Current evidence emerging from genome-wide association studies indicates that the genetic underpinnings of complex traits are likely attributable to genetic variation that changes gene expression, rather than (or in combination with) variation that changes protein-coding sequences. This is particularly compelling with respect to psychiatric disorders, as genetic changes in regulatory regions may result in differential transcriptional responses to developmental cues and environmental/psychosocial stressors. Until recently, however, the link between transcriptional regulation and psychiatric genetic risk has been understudied. Multiple obstacles have contributed to the paucity of research in this area, including challenges in identifying the positions of remote (distal from the promoter) regulatory elements (e.g. enhancers) and their target genes and the underrepresentation of neural cell types and brain tissues in epigenome projects - the availability of high-quality brain tissues for epigenetic and transcriptome profiling, particularly for the adolescent and developing brain, has been limited. Further challenges have arisen in the prediction and testing of the functional impact of DNA variation with respect to multiple aspects of transcriptional control, including regulatory-element interaction (e.g. between enhancers and promoters), transcription factor binding and DNA methylation. Further, the brain has uncommon DNA-methylation marks with unique genomic distributions not found in other tissues - current evidence suggests the involvement of non-CG methylation and 5-hydroxymethylation in neurodevelopmental processes but much remains unknown. We review here knowledge gaps as well as both technological and resource obstacles that will need to be overcome in order to elucidate the involvement of brain-relevant gene-regulatory variants in genetic risk for psychiatric disorders. © 2015 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

  1. Chirality in a quaternionic representation of the genetic code.

    Science.gov (United States)

    Manuel Carlevaro, C; Irastorza, Ramiro M; Vericat, Fernando

    2016-12-01

    A quaternionic representation of the genetic code, previously reported by the authors (BioSystems 141 (10-19), 2016), is updated in order to incorporate chirality of nucleotide bases and amino acids. The original representation associates with each nucleotide base a prime integer quaternion of norm 7 and involves a function that assigns to each codon, represented by three of these quaternions, another integer quaternion (amino acid type quaternion). The assignation is such that the essentials of the standard genetic code (particularly its degeneration) are preserved. To show the advantages of such a quaternionic representation we have designed an algorithm to go from the primary to the tertiary structure of the protein. The algorithm uses, besides of the type quaternions, a second kind of quaternions with real components that we additionally associate with the amino acids according to their order along the proteins (order quaternions). In this context, we incorporate chirality in our representation by observing that the set of eight integer quaternions of norm 7 can be partitioned into a pair of subsets of cardinality four each with their elements mutually conjugate and by putting them into correspondence one to one with the two sets of enantiomers (D and L) of the four nucleotide bases adenine, cytosine, guanine and uracil, respectively. We then propose two diagrams in order to describe the hypothetical evolution of the genetic codes corresponding to both of the chiral systems of affinities: D-nucleotide bases/L-amino acids and L-nucleotide bases/D-amino acids at reading frames 5'→3' and 3'→5', respectively. Guided by these diagrams we define functions that in each case assign to the triplets of D- (L-) bases a L- (D-) amino acid type integer quaternion. Specifically, the integer quaternion associated with a given D-amino acid is the conjugate of that one corresponding to the enantiomer L. The chiral type quaternions obtained for the amino acids are used

  2. RNA editing and modifications of RNAs might have favoured the evolution of the triplet genetic code from an ennuplet code.

    Science.gov (United States)

    Di Giulio, Massimo; Moracci, Marco; Cobucci-Ponzano, Beatrice

    2014-10-21

    Here we suggest that the origin of the genetic code, that is to say, the birth of first mRNAs has been triggered by means of a widespread modification of all RNAs (proto-mRNAs and proto-tRNAs), as today observed in the RNA editing and in post-transcriptional modifications of RNAs, which are considered as fossils of this evolutionary stage of the genetic code origin. We consider also that other mechanisms, such as the trans-translation and ribosome frameshifting, could have favoured the transition from an ennuplet code to a triplet code. Therefore, according to our hypothesis all these mechanisms would be reflexive of this period of the evolutionary history of the genetic code. Copyright © 2014. Published by Elsevier Ltd.

  3. Three stages in the evolution of the genetic code

    Science.gov (United States)

    Baumann, U.; Oro, J.

    1993-01-01

    A diversification of the genetic code based on the number of codons available for the proteinous amino acids is established. Three groups of amino acids during evolution of the code are distinguished. On the basis of their chemical complexity those amino acids emerging later in a translation process are derived. Codon number and chemical complexity indicate that His, Phe, Tyr, Cys and either Lys or Asn were introduced in the second stage, whereas the number of codons alone gives evidence that Trp and Met were introduced in the third stage. The amino acids of stage 1 use purine-rich codons, while all the amino acids introduced in the second stage, in contrast, use pyrimidines in the third position of their codons. A low abundance of pyrimidines during early translation is derived. This assumption is supported by experiments on non-enzymatic replication and interactions of hairpin loops with a complementary strand. A back extrapolation concludes a high purine content of the first nucleic acids, which gradually decreased during their evolution. Amino acids independently available from prebiotic synthesis were thus correlated to purine-rich codons. Implications on the prebiotic replication are discussed also in the light of recent codon usage data.

  4. Genetic variation and human longevity.

    Science.gov (United States)

    Soerensen, Mette

    2012-05-01

    The overall aim of the PhD project was to elucidate the association of human longevity with genetic variation in major candidate genes and pathways of longevity. Based on a thorough literature and database search we chose to apply a pathway approach; to explore variation in genes composing the DNA damage signaling, DNA repair, GH/IGF-1/insulin signaling and pro-/antioxidant pathways. In addition, 16 genes which did not belong to the core of either pathway, however recurrently regarded as candidate genes of longevity (e.g. APOE), were included. In this way a total of 168 genes were selected for investigation. We decided to explore the genetic variation in the form of single nucleotide polymorphisms (SNPs), a highly investigated type of genetic variation. SNPs having potential functional impact (e.g. affecting binding of transcription factors) were identified, so were specific SNPs in the candidate genes previously published to be associated with human longevity. To cover the majority of the common genetic variation in the 168 gene regions (encoding regions plus 5,000 bp upstream and 1,000 downstream) we applied the tagging SNP approach via the HapMap Consortium. Consequently 1,536 SNPs were selected. The majority of the previous publications on genetic variation and human longevity had employed a case-control study design, e.g. comparing centenarians to middle-aged controls. This type of study design is somehow prone to bias introduced by for instance cohort effects, i.e. differences in characteristics of cases and controls, a kind of bias which is avoided when a prospective cohort is under study. Therefore, we chose to investigate 1,200 individuals of the Danish 1905 birth cohort, which have been followed since 1998 when the members were 92-93 years old. The genetic contribution to human longevity has been estimated to be most profound during the late part of life, thus these oldest-old individuals are excellent for investigating such effect. The follow-up survival

  5. Genetic code flexibility in microorganisms: novel mechanisms and impact on physiology.

    Science.gov (United States)

    Ling, Jiqiang; O'Donoghue, Patrick; Söll, Dieter

    2015-11-01

    The genetic code, initially thought to be universal and immutable, is now known to contain many variations, including biased codon usage, codon reassignment, ambiguous decoding and recoding. As a result of recent advances in the areas of genome sequencing, biochemistry, bioinformatics and structural biology, our understanding of genetic code flexibility has advanced substantially in the past decade. In this Review, we highlight the prevalence, evolution and mechanistic basis of genetic code variations in microorganisms, and we discuss how this flexibility of the genetic code affects microbial physiology.

  6. Position and locality constrained soft coding for human action recognition

    Science.gov (United States)

    Wang, Bin; Liu, Yu; Xiao, Wenhua; Xu, Wei; Zhang, Maojun

    2013-10-01

    Although the traditional bag-of-words model has shown promising results for human action recognition, in the feature coding phase, the ambiguous features from different body parts are still difficult to distinguish. Furthermore, it also suffers from serious representation error. We propose an innovative coding strategy called position and locality constrained soft coding (PLSC) to overcome these limitations. PLSC uses the feature position in a human oriented region of interest (ROI) to distinguish the ambiguous features. We first construct a subdictionary for each feature by selecting the bases from their spatial neighbor in human ROI. Then, a modified soft coding with locality constraint is adopted to alleviate the quantization error and preserve the manifold structure of features. This novel coding algorithm increases both the representation accuracy and discriminative power with low computational cost. The human action recognition experimental results on KTH, Weizmann, and UCF sports datasets show that PLSC can achieve a better performance than previous competing feature coding methods.

  7. A human-specific de novo protein-coding gene associated with human brain functions.

    Directory of Open Access Journals (Sweden)

    Chuan-Yun Li

    2010-03-01

    Full Text Available To understand whether any human-specific new genes may be associated with human brain functions, we computationally screened the genetic vulnerable factors identified through Genome-Wide Association Studies and linkage analyses of nicotine addiction and found one human-specific de novo protein-coding gene, FLJ33706 (alternative gene symbol C20orf203. Cross-species analysis revealed interesting evolutionary paths of how this gene had originated from noncoding DNA sequences: insertion of repeat elements especially Alu contributed to the formation of the first coding exon and six standard splice junctions on the branch leading to humans and chimpanzees, and two subsequent substitutions in the human lineage escaped two stop codons and created an open reading frame of 194 amino acids. We experimentally verified FLJ33706's mRNA and protein expression in the brain. Real-Time PCR in multiple tissues demonstrated that FLJ33706 was most abundantly expressed in brain. Human polymorphism data suggested that FLJ33706 encodes a protein under purifying selection. A specifically designed antibody detected its protein expression across human cortex, cerebellum and midbrain. Immunohistochemistry study in normal human brain cortex revealed the localization of FLJ33706 protein in neurons. Elevated expressions of FLJ33706 were detected in Alzheimer's brain samples, suggesting the role of this novel gene in human-specific pathogenesis of Alzheimer's disease. FLJ33706 provided the strongest evidence so far that human-specific de novo genes can have protein-coding potential and differential protein expression, and be involved in human brain functions.

  8. A human-specific de novo protein-coding gene associated with human brain functions.

    Directory of Open Access Journals (Sweden)

    Chuan-Yun Li

    2010-03-01

    Full Text Available To understand whether any human-specific new genes may be associated with human brain functions, we computationally screened the genetic vulnerable factors identified through Genome-Wide Association Studies and linkage analyses of nicotine addiction and found one human-specific de novo protein-coding gene, FLJ33706 (alternative gene symbol C20orf203. Cross-species analysis revealed interesting evolutionary paths of how this gene had originated from noncoding DNA sequences: insertion of repeat elements especially Alu contributed to the formation of the first coding exon and six standard splice junctions on the branch leading to humans and chimpanzees, and two subsequent substitutions in the human lineage escaped two stop codons and created an open reading frame of 194 amino acids. We experimentally verified FLJ33706's mRNA and protein expression in the brain. Real-Time PCR in multiple tissues demonstrated that FLJ33706 was most abundantly expressed in brain. Human polymorphism data suggested that FLJ33706 encodes a protein under purifying selection. A specifically designed antibody detected its protein expression across human cortex, cerebellum and midbrain. Immunohistochemistry study in normal human brain cortex revealed the localization of FLJ33706 protein in neurons. Elevated expressions of FLJ33706 were detected in Alzheimer's brain samples, suggesting the role of this novel gene in human-specific pathogenesis of Alzheimer's disease. FLJ33706 provided the strongest evidence so far that human-specific de novo genes can have protein-coding potential and differential protein expression, and be involved in human brain functions.

  9. [Genetic Bases of Human Comorbidity].

    Science.gov (United States)

    Puzyrev, V P

    2015-04-01

    In this review, the development of ideas focused on the phenomenon of disease combination (comorbidity) in humans is discussed. The genetic bases of the three forms of the phenomenon, comorbidity (syntropias), inverse comorbidity (dystropias), and comorbidity of Mendelian and multifactorial diseases, are analyzed. The results of personal genome-wide association studies of the genetic risk profile that may predispose an individual to cardiovascular disease continuum (CDC), including coronary heart disease, type 2 diabetes, hypertension, and hypercholesterolemia (CDC syntropy), as well as the results of bioinformatic analysis of common genes and the networks of molecular interactions for two (bronchial asthma and pulmonary tuberculosis) diseases rarely found in one patient (dystropy), are presented. The importance of the diseasome and network medicine concepts in the study of comorbidity is emphasized. Promising areas in genomic studies of comorbidities for disease classification and the development of personalized medicine are designated.

  10. Genetic aspects of human obesity.

    Science.gov (United States)

    Larder, Rachel; Lim, Chung Thong; Coll, Anthony P

    2014-01-01

    Obesity and its related metabolic consequences represent a major public health problem. Huge changes within the environment have undoubtedly contributed to the increased prevalence of obesity but genetic factors are also critical in determining an individual's predisposition to gain weight. The last two decades have seen a huge increase in the understanding of the mechanisms controlling appetitive behavior, body composition, and energy expenditure. Many regions throughout the central nervous system play critical roles in these processes but the hypothalamus, in particular, receives and orchestrates a variety of signals to bring about coordinated changes in energy balance. Reviewing data from human genetic and model organism studies, we consider how disruptions of hypothalamic pathways evolved to maintain energy homeostasis and go on to cause obesity. We highlight ongoing technological developments which continue to lead to novel insights and discuss how this increased knowledge may lead to effective therapeutic interventions in the future.

  11. Evolution of the genetic code by incorporation of amino acids that improved or changed protein function.

    Science.gov (United States)

    Francis, Brian R

    2013-10-01

    Fifty years have passed since the genetic code was deciphered, but how the genetic code came into being has not been satisfactorily addressed. It is now widely accepted that the earliest genetic code did not encode all 20 amino acids found in the universal genetic code as some amino acids have complex biosynthetic pathways and likely were not available from the environment. Therefore, the genetic code evolved as pathways for synthesis of new amino acids became available. One hypothesis proposes that early in the evolution of the genetic code four amino acids-valine, alanine, aspartic acid, and glycine-were coded by GNC codons (N = any base) with the remaining codons being nonsense codons. The other sixteen amino acids were subsequently added to the genetic code by changing nonsense codons into sense codons for these amino acids. Improvement in protein function is presumed to be the driving force behind the evolution of the code, but how improved function was achieved by adding amino acids has not been examined. Based on an analysis of amino acid function in proteins, an evolutionary mechanism for expansion of the genetic code is described in which individual coded amino acids were replaced by new amino acids that used nonsense codons differing by one base change from the sense codons previously used. The improved or altered protein function afforded by the changes in amino acid function provided the selective advantage underlying the expansion of the genetic code. Analysis of amino acid properties and functions explains why amino acids are found in their respective positions in the genetic code.

  12. Auditory coding of human movement kinematics.

    Science.gov (United States)

    Vinken, Pia M; Kröger, Daniela; Fehse, Ursula; Schmitz, Gerd; Brock, Heike; Effenberg, Alfred O

    2013-01-01

    Although visual perception is dominant on motor perception, control and learning, auditory information can enhance and modulate perceptual as well as motor processes in a multifaceted manner. During last decades new methods of auditory augmentation had been developed with movement sonification as one of the most recent approaches expanding auditory movement information also to usually mute phases of movement. Despite general evidence on the effectiveness of movement sonification in different fields of applied research there is nearly no empirical proof on how sonification of gross motor human movement should be configured to achieve information rich sound sequences. Such lack of empirical proof is given for (a) the selection of suitable movement features as well as for (b) effective kinetic-acoustical mapping patterns and for (c) the number of regarded dimensions of sonification. In this study we explore the informational content of artificial acoustical kinematics in terms of a kinematic movement sonification using an intermodal discrimination paradigm. In a repeated measure design we analysed discrimination rates of six everyday upper limb actions to evaluate the effectiveness of seven different kinds of kinematic-acoustical mappings as well as short-term learning effects. The kinematics of the upper limb actions were calculated based on inertial motion sensor data and transformed into seven different sonifications. Sound sequences were randomly presented to participants and discrimination rates as well as confidence of choice were analysed. Data indicate an instantaneous comprehensibility of the artificial movement acoustics as well as short-term learning effects. No differences between different dimensional encodings became evident thus indicating a high efficiency for intermodal pattern discrimination for the acoustically coded velocity distribution of the actions. Taken together movement information related to continuous kinematic parameters can be

  13. Arbitrariness is not enough: towards a functional approach to the genetic code.

    Science.gov (United States)

    Lacková, Ľudmila; Matlach, Vladimír; Faltýnek, Dan

    2017-05-09

    Arbitrariness in the genetic code is one of the main reasons for a linguistic approach to molecular biology: the genetic code is usually understood as an arbitrary relation between amino acids and nucleobases. However, from a semiotic point of view, arbitrariness should not be the only condition for definition of a code, consequently it is not completely correct to talk about "code" in this case. Yet we suppose that there exist a code in the process of protein synthesis, but on a higher level than the nucleic bases chains. Semiotically, a code should be always associated with a function and we propose to define the genetic code not only relationally (in basis of relation between nucleobases and amino acids) but also in terms of function (function of a protein as meaning of the code). Even if the functional definition of meaning in the genetic code has been discussed in the field of biosemiotics, its further implications have not been considered. In fact, if the function of a protein represents the meaning of the genetic code (the sign's object), then it is crucial to reconsider the notion of its expression (the sign) as well. In our contribution, we will show that the actual model of the genetic code is not the only possible and we will propose a more appropriate model from a semiotic point of view.

  14. FREQUENCY-CODED OPTIMIZATION OF HOPPED-FREQUENCY PULSE SIGNAL BASED ON GENETIC ALGORITHM

    Institute of Scientific and Technical Information of China (English)

    Liu Zheng; Mu Xuehua

    2005-01-01

    The Frequency-Coded Pulse (FCP) signal has good performance of range and Doppler resolution. This paper first gives the mathematical expression of the ambiguity function for FCP signals, and then presents a coding rule for optimizing FCP signal. The genetic algorithm is presented to solve this kind of problem for optimizing codes. Finally, an example for optimizing calculation is illustrated and the optimized frequency coding results are given with the code length N=64 and N=128 respectively.

  15. [Quality assurance in human genetic testing].

    Science.gov (United States)

    Stuhrmann-Spangenberg, Manfred

    2015-02-01

    Advances in technical developments of genetic diagnostics for more than 50 years, as well as the fact that human genetic testing is usually performed only once in a lifetime, with additional impact for blood relatives, are determining the extraordinary importance of quality assurance in human genetic testing. Abidance of laws, directives, and guidelines plays a major role. This article aims to present the major laws, directives, and guidelines with respect to quality assurance of human genetic testing, paying careful attention to internal and external quality assurance. The information on quality assurance of human genetic testing was obtained through a web-based search of the web pages that are referred to in this article. Further information was retrieved from publications in the German Society of Human Genetics and through a PubMed-search using term quality + assurance + genetic + diagnostics. The most important laws, directives, and guidelines for quality assurance of human genetic testing are the gene diagnostics law (GenDG), the directive of the Federal Medical Council for quality control of clinical laboratory analysis (RiliBÄK), and the S2K guideline for human genetic diagnostics and counselling. In addition, voluntary accreditation under DIN EN ISO 15189:2013 offers a most recommended contribution towards quality assurance of human genetic testing. Legal restraints on quality assurance of human genetic testing as mentioned in § 5 GenDG are fulfilled once RiliBÄK requirements are followed.

  16. Genetic diversity of human RNase 8

    Directory of Open Access Journals (Sweden)

    Chan Calvin C

    2012-01-01

    Full Text Available Abstract Background Ribonuclease 8 is a member of the RNase A family of secretory ribonucleases; orthologs of this gene have been found only in primate genomes. RNase 8 is a divergent paralog of RNase 7, which is lysine-enriched, highly conserved, has prominent antimicrobial activity, and is expressed in both normal and diseased skin; in contrast, the physiologic function of RNase 8 remains uncertain. Here, we examine the genetic diversity of human RNase 8, a subject of significant interest given the existence of functional pseudogenes (coding sequences that are otherwise intact but with mutations in elements crucial for ribonucleolytic activity in non-human primate genomes. Results RNase 8 expression was detected in adult human lung, spleen and testis tissue by quantitative reverse-transcription PCR. Only two single-nucleotide polymorphisms and four unique alleles were identified within the RNase 8 coding sequence; nucleotide sequence diversity (π = 0.00122 ± 0.00009 per site was unremarkable for a human nuclear gene. We isolated transcripts encoding RNase 8 via rapid amplification of cDNA ends (RACE and RT-PCR which included a distal potential translational start site followed by sequence encoding an additional 30 amino acids that are conserved in the genomes of several higher primates. The distal translational start site is functional and promotes RNase 8 synthesis in transfected COS-7 cells. Conclusions These results suggest that RNase 8 may diverge considerably from typical RNase A family ribonucleases and may likewise exhibit unique function. This finding prompts a reconsideration of what we have previously termed functional pseudogenes, as RNase 8 may be responding to constraints that promote significant functional divergence from the canonical structure and enzymatic activity characteristic of the RNase A family.

  17. Simulated evolution applied to study the genetic code optimality using a model of codon reassignments

    Directory of Open Access Journals (Sweden)

    Monteagudo Ángel

    2011-02-01

    Full Text Available Abstract Background As the canonical code is not universal, different theories about its origin and organization have appeared. The optimization or level of adaptation of the canonical genetic code was measured taking into account the harmful consequences resulting from point mutations leading to the replacement of one amino acid for another. There are two basic theories to measure the level of optimization: the statistical approach, which compares the canonical genetic code with many randomly generated alternative ones, and the engineering approach, which compares the canonical code with the best possible alternative. Results Here we used a genetic algorithm to search for better adapted hypothetical codes and as a method to guess the difficulty in finding such alternative codes, allowing to clearly situate the canonical code in the fitness landscape. This novel proposal of the use of evolutionary computing provides a new perspective in the open debate between the use of the statistical approach, which postulates that the genetic code conserves amino acid properties far better than expected from a random code, and the engineering approach, which tends to indicate that the canonical genetic code is still far from optimal. We used two models of hypothetical codes: one that reflects the known examples of codon reassignment and the model most used in the two approaches which reflects the current genetic code translation table. Although the standard code is far from a possible optimum considering both models, when the more realistic model of the codon reassignments was used, the evolutionary algorithm had more difficulty to overcome the efficiency of the canonical genetic code. Conclusions Simulated evolution clearly reveals that the canonical genetic code is far from optimal regarding its optimization. Nevertheless, the efficiency of the canonical code increases when mistranslations are taken into account with the two models, as indicated by the

  18. Extreme genetic code optimality from a molecular dynamics calculation of amino acid polar requirement

    Science.gov (United States)

    Butler, Thomas; Goldenfeld, Nigel; Mathew, Damien; Luthey-Schulten, Zaida

    2009-06-01

    A molecular dynamics calculation of the amino acid polar requirement is used to score the canonical genetic code. Monte Carlo simulation shows that this computational polar requirement has been optimized by the canonical genetic code, an order of magnitude more than any previously known measure, effectively ruling out a vertical evolution dynamics. The sensitivity of the optimization to the precise metric used in code scoring is consistent with code evolution having proceeded through the communal dynamics of statistical proteins using horizontal gene transfer, as recently proposed. The extreme optimization of the genetic code therefore strongly supports the idea that the genetic code evolved from a communal state of life prior to the last universal common ancestor.

  19. Extreme genetic code optimality from a molecular dynamics calculation of amino acid polar requirement.

    Science.gov (United States)

    Butler, Thomas; Goldenfeld, Nigel; Mathew, Damien; Luthey-Schulten, Zaida

    2009-06-01

    A molecular dynamics calculation of the amino acid polar requirement is used to score the canonical genetic code. Monte Carlo simulation shows that this computational polar requirement has been optimized by the canonical genetic code, an order of magnitude more than any previously known measure, effectively ruling out a vertical evolution dynamics. The sensitivity of the optimization to the precise metric used in code scoring is consistent with code evolution having proceeded through the communal dynamics of statistical proteins using horizontal gene transfer, as recently proposed. The extreme optimization of the genetic code therefore strongly supports the idea that the genetic code evolved from a communal state of life prior to the last universal common ancestor.

  20. A colorful origin for the genetic code: information theory, statistical mechanics and the emergence of molecular codes.

    Science.gov (United States)

    Tlusty, Tsvi

    2010-09-01

    The genetic code maps the sixty-four nucleotide triplets (codons) to twenty amino-acids. While the biochemical details of this code were unraveled long ago, its origin is still obscure. We review information-theoretic approaches to the problem of the code's origin and discuss the results of a recent work that treats the code in terms of an evolving, error-prone information channel. Our model - which utilizes the rate-distortion theory of noisy communication channels - suggests that the genetic code originated as a result of the interplay of the three conflicting evolutionary forces: the needs for diverse amino-acids, for error-tolerance and for minimal cost of resources. The description of the code as an information channel allows us to mathematically identify the fitness of the code and locate its emergence at a second-order phase transition when the mapping of codons to amino-acids becomes nonrandom. The noise in the channel brings about an error-graph, in which edges connect codons that are likely to be confused. The emergence of the code is governed by the topology of the error-graph, which determines the lowest modes of the graph-Laplacian and is related to the map coloring problem. (c) 2010 Elsevier B.V. All rights reserved.

  1. Genetic basis of human brain evolution

    OpenAIRE

    Vallender, Eric J.; Mekel-Bobrov, Nitzan; Lahn, Bruce T

    2008-01-01

    Human evolution is characterized by a rapid increase in brain size and complexity. Decades of research have made important strides in identifying anatomical and physiological substrates underlying the unique features of the human brain. By contrast, it has become possible only very recently to examine the genetic basis of human brain evolution. Through comparative genomics, tantalizing insights regarding human brain evolution have emerged. The genetic changes that potentially underlie human b...

  2. Probable relationship between partitions of the set of codons and the origin of the genetic code.

    Science.gov (United States)

    Salinas, Dino G; Gallardo, Mauricio O; Osorio, Manuel I

    2014-03-01

    Here we study the distribution of randomly generated partitions of the set of amino acid-coding codons. Some results are an application from a previous work, about the Stirling numbers of the second kind and triplet codes, both to the cases of triplet codes having four stop codons, as in mammalian mitochondrial genetic code, and hypothetical doublet codes. Extending previous results, in this work it is found that the most probable number of blocks of synonymous codons, in a genetic code, is similar to the number of amino acids when there are four stop codons, as well as it could be for a primigenious doublet code. Also it is studied the integer partitions associated to patterns of synonymous codons and it is shown, for the canonical code, that the standard deviation inside an integer partition is one of the most probable. We think that, in some early epoch, the genetic code might have had a maximum of the disorder or entropy, independent of the assignment between codons and amino acids, reaching a state similar to "code freeze" proposed by Francis Crick. In later stages, maybe deterministic rules have reassigned codons to amino acids, forming the natural codes, such as the canonical code, but keeping the numerical features describing the set partitions and the integer partitions, like a "fossil numbers"; both kinds of partitions about the set of amino acid-coding codons. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  3. Genetic toxicities of human teratogens.

    Science.gov (United States)

    Bishop, J B; Witt, K L; Sloane, R A

    1997-12-12

    Birth defects cause a myriad of societal problems and place tremendous anguish on the affected individual and his or her family. Current estimates categorize about 3% of all newborn infants as having some form of birth defect or congenital anomaly. As more precise means of detecting subtle anomalies become available this estimate, no doubt, will increase. Even though birth defects have been observed in newborns throughout history, our knowledge about the causes and mechanisms through which these defects are manifested is limited. For example, it has been estimated that around 20% of all birth defects are due to gene mutations, 5-10% to chromosomal abnormalities, and another 5-10% to exposure to a known teratogenic agent or maternal factor [D.A. Beckman, R.L. Brent, Mechanisms of teratogenesis. Ann. Rev. Pharmacol. Toxicol. 24 (1984) 483-500; K. Nelson, L.B. Holmes Malformations due to presumed spontaneous mutations in newborn infants, N. Engl. J. Med. 320 (1989) 19-23.]. Together, these percentages account for only 30-40%, leaving the etiology of more than half of all human birth defects unexplained. It has been speculated that environmental factors account for no more than one-tenth of all congenital anomalies [D.A. Beckman, R.L. Brent, Mechanisms of teratogenesis, Ann. Rev. Pharmacol. Toxicol. 24 (1984) 483-500]. Furthermore, since there is no evidence in humans that the exposure of an individual to any mutagen measurably increases the risk of congenital anomalies in his or her offspring' [J.F. Crow, C. Denniston, Mutation in human populations, Adv. Human Genet. 14 (1985) 59-121; J.M. Friedman, J.E. Polifka, Teratogenic Effects of Drugs: A Resource for Clinicians (TERIS). The John Hopkins University Press, Baltimore, 1994], the mutagenic activity of environmental agents and drugs as a factor in teratogenesis has been given very little attention. Epigenetic activity has also been given only limited consideration as a mechanism for teratogenesis. As new molecular

  4. A large health system's approach to utilization of the genetic counselor CPT® 96040 code.

    Science.gov (United States)

    Gustafson, Shanna L; Pfeiffer, Gail; Eng, Charis

    2011-12-01

    : In 2007, CPT® code 96040 was approved for genetic counseling services provided by nonphysician providers. Because of professional recognition and licensure limitations, experiences in direct billing by genetic counselors for these services are limited. A minority of genetics clinics report using this code because of limitations, including perceived denial of the code and confusion regarding compliant use of this code. We present results of our approach to 96040 billing for genetic counseling services under a supervising physicians National Provider ID number in a strategy for integration of genetics services within nongenetics specialty departments of a large academic medical center. : The 96040 billing encounters were tracked for a 14-month period and analyzed for reimbursement by private payers. Association of denial by diagnosis code or specialty of genetics service was statistically analyzed. Descriptive data regarding appointment availability are also summarized. : Of 350 encounters January 2008 to February 2009, 289 (82%) were billed to private payers. Of these, 62.6% received some level of reimbursement. No association was seen for denial when analyzed by the diagnosis code or by genetics focus. Through this model, genetics appointment availability minimally doubled. : Using 96040 allowed for expanding access to genetics services, increased appointment availability, and was successful in obtaining reimbursement for more than half of encounters billed.

  5. Coevolution Theory of the Genetic Code at Age Forty: Pathway to Translation and Synthetic Life.

    Science.gov (United States)

    Wong, J Tze-Fei; Ng, Siu-Kin; Mat, Wai-Kin; Hu, Taobo; Xue, Hong

    2016-03-16

    The origins of the components of genetic coding are examined in the present study. Genetic information arose from replicator induction by metabolite in accordance with the metabolic expansion law. Messenger RNA and transfer RNA stemmed from a template for binding the aminoacyl-RNA synthetase ribozymes employed to synthesize peptide prosthetic groups on RNAs in the Peptidated RNA World. Coevolution of the genetic code with amino acid biosynthesis generated tRNA paralogs that identify a last universal common ancestor (LUCA) of extant life close to Methanopyrus, which in turn points to archaeal tRNA introns as the most primitive introns and the anticodon usage of Methanopyrus as an ancient mode of wobble. The prediction of the coevolution theory of the genetic code that the code should be a mutable code has led to the isolation of optional and mandatory synthetic life forms with altered protein alphabets.

  6. Coevolution Theory of the Genetic Code at Age Forty: Pathway to Translation and Synthetic Life

    Directory of Open Access Journals (Sweden)

    J. Tze-Fei Wong

    2016-03-01

    Full Text Available The origins of the components of genetic coding are examined in the present study. Genetic information arose from replicator induction by metabolite in accordance with the metabolic expansion law. Messenger RNA and transfer RNA stemmed from a template for binding the aminoacyl-RNA synthetase ribozymes employed to synthesize peptide prosthetic groups on RNAs in the Peptidated RNA World. Coevolution of the genetic code with amino acid biosynthesis generated tRNA paralogs that identify a last universal common ancestor (LUCA of extant life close to Methanopyrus, which in turn points to archaeal tRNA introns as the most primitive introns and the anticodon usage of Methanopyrus as an ancient mode of wobble. The prediction of the coevolution theory of the genetic code that the code should be a mutable code has led to the isolation of optional and mandatory synthetic life forms with altered protein alphabets.

  7. Coevolution Theory of the Genetic Code at Age Forty: Pathway to Translation and Synthetic Life

    Science.gov (United States)

    Wong, J. Tze-Fei; Ng, Siu-Kin; Mat, Wai-Kin; Hu, Taobo; Xue, Hong

    2016-01-01

    The origins of the components of genetic coding are examined in the present study. Genetic information arose from replicator induction by metabolite in accordance with the metabolic expansion law. Messenger RNA and transfer RNA stemmed from a template for binding the aminoacyl-RNA synthetase ribozymes employed to synthesize peptide prosthetic groups on RNAs in the Peptidated RNA World. Coevolution of the genetic code with amino acid biosynthesis generated tRNA paralogs that identify a last universal common ancestor (LUCA) of extant life close to Methanopyrus, which in turn points to archaeal tRNA introns as the most primitive introns and the anticodon usage of Methanopyrus as an ancient mode of wobble. The prediction of the coevolution theory of the genetic code that the code should be a mutable code has led to the isolation of optional and mandatory synthetic life forms with altered protein alphabets. PMID:26999216

  8. Promoter Analysis Reveals Globally Differential Regulation of Human Long Non-Coding RNA and Protein-Coding Genes

    KAUST Repository

    Alam, Tanvir

    2014-10-02

    Transcriptional regulation of protein-coding genes is increasingly well-understood on a global scale, yet no comparable information exists for long non-coding RNA (lncRNA) genes, which were recently recognized to be as numerous as protein-coding genes in mammalian genomes. We performed a genome-wide comparative analysis of the promoters of human lncRNA and protein-coding genes, finding global differences in specific genetic and epigenetic features relevant to transcriptional regulation. These two groups of genes are hence subject to separate transcriptional regulatory programs, including distinct transcription factor (TF) proteins that significantly favor lncRNA, rather than coding-gene, promoters. We report a specific signature of promoter-proximal transcriptional regulation of lncRNA genes, including several distinct transcription factor binding sites (TFBS). Experimental DNase I hypersensitive site profiles are consistent with active configurations of these lncRNA TFBS sets in diverse human cell types. TFBS ChIP-seq datasets confirm the binding events that we predicted using computational approaches for a subset of factors. For several TFs known to be directly regulated by lncRNAs, we find that their putative TFBSs are enriched at lncRNA promoters, suggesting that the TFs and the lncRNAs may participate in a bidirectional feedback loop regulatory network. Accordingly, cells may be able to modulate lncRNA expression levels independently of mRNA levels via distinct regulatory pathways. Our results also raise the possibility that, given the historical reliance on protein-coding gene catalogs to define the chromatin states of active promoters, a revision of these chromatin signature profiles to incorporate expressed lncRNA genes is warranted in the future.

  9. 130 FEMINISM AND HUMAN GENETIC ENGINEERING: A ...

    African Journals Online (AJOL)

    Ike Odimegwu

    Abstract. Human genetic in the area of Bio-ethics is a new, rapidly advancing. Science. ... Human genetic engineering, a recent one in medical science and practice, is one ..... The Church on Cloning and Stem Cell Research. The teaching of ...

  10. The "periodic table" of the genetic code: A new way to look at the code and the decoding process.

    Science.gov (United States)

    Komar, Anton A

    2016-01-01

    Henri Grosjean and Eric Westhof recently presented an information-rich, alternative view of the genetic code, which takes into account current knowledge of the decoding process, including the complex nature of interactions between mRNA, tRNA and rRNA that take place during protein synthesis on the ribosome, and it also better reflects the evolution of the code. The new asymmetrical circular genetic code has a number of advantages over the traditional codon table and the previous circular diagrams (with a symmetrical/clockwise arrangement of the U, C, A, G bases). Most importantly, all sequence co-variances can be visualized and explained based on the internal logic of the thermodynamics of codon-anticodon interactions.

  11. A p-Adic Model of DNA Sequence and Genetic Code

    CERN Document Server

    Dragovich, Branko

    2007-01-01

    Using basic properties of p-adic numbers, we consider a simple new approach to describe main aspects of DNA sequence and genetic code. Central role in our investigation plays an ultrametric p-adic information space which basic elements are nucleotides, codons and genes. We show that a 5-adic model is appropriate for DNA sequence. This 5-adic model, combined with 2-adic distance, is also suitable for genetic code and for a more advanced employment in genomics. We find that genetic code degeneracy is related to the p-adic distance between codons.

  12. A possible step in the origin of the genetic code.

    Science.gov (United States)

    Orgel, L. E.

    1972-01-01

    It is suggested that the earliest coding polynucleotides contained a high proportion of alternating sequences of purines and pyrimidines, and that these sequences coded for polypeptides in which hydrophobic and hydrophylic amino acids alternated. Structural properties of such alternating polypeptides are discussed.

  13. A Statistical Analysis of the Robustness of Alternate Genetic Coding Tables

    Directory of Open Access Journals (Sweden)

    Isil Aksan Kurnaz

    2008-05-01

    Full Text Available The rules that specify how the information contained in DNA is translated into amino acid “language” during protein synthesis are called “the genetic code”, commonly called the “Standard” or “Universal” Genetic Code Table. As a matter of fact, this coding table is not at all “universal”: in addition to different genetic code tables used by different organisms, even within the same organism the nuclear and mitochondrial genes may be subject to two different coding tables. Results In an attempt to understand the advantages and disadvantages these coding tables may bring to an organism, we have decided to analyze various coding tables on genes subject to mutations, and have estimated how these genes “survive” over generations. We have used this as indicative of the “evolutionary” success of that particular coding table. We find that the “standard” genetic code is not actually the most robust of all coding tables, and interestingly, Flatworm Mitochondrial Code (FMC appears to be the highest ranking coding table given our assumptions. Conclusions It is commonly hypothesized that the more robust a genetic code, the better suited it is for maintenance of the genome. Our study shows that, given the assumptions in our model, Standard Genetic Code is quite poor when compared to other alternate code tables in terms of robustness. This brings about the question of why Standard Code has been so widely accepted by a wider variety of organisms instead of FMC, which needs to be addressed for a thorough understanding of genetic code evolution.

  14. Codon size reduction as the origin of the triplet genetic code.

    Directory of Open Access Journals (Sweden)

    Pavel V Baranov

    Full Text Available The genetic code appears to be optimized in its robustness to missense errors and frameshift errors. In addition, the genetic code is near-optimal in terms of its ability to carry information in addition to the sequences of encoded proteins. As evolution has no foresight, optimality of the modern genetic code suggests that it evolved from less optimal code variants. The length of codons in the genetic code is also optimal, as three is the minimal nucleotide combination that can encode the twenty standard amino acids. The apparent impossibility of transitions between codon sizes in a discontinuous manner during evolution has resulted in an unbending view that the genetic code was always triplet. Yet, recent experimental evidence on quadruplet decoding, as well as the discovery of organisms with ambiguous and dual decoding, suggest that the possibility of the evolution of triplet decoding from living systems with non-triplet decoding merits reconsideration and further exploration. To explore this possibility we designed a mathematical model of the evolution of primitive digital coding systems which can decode nucleotide sequences into protein sequences. These coding systems can evolve their nucleotide sequences via genetic events of Darwinian evolution, such as point-mutations. The replication rates of such coding systems depend on the accuracy of the generated protein sequences. Computer simulations based on our model show that decoding systems with codons of length greater than three spontaneously evolve into predominantly triplet decoding systems. Our findings suggest a plausible scenario for the evolution of the triplet genetic code in a continuous manner. This scenario suggests an explanation of how protein synthesis could be accomplished by means of long RNA-RNA interactions prior to the emergence of the complex decoding machinery, such as the ribosome, that is required for stabilization and discrimination of otherwise weak triplet codon

  15. Simple association of the genetic code with hexagrams of the Book of Changes (I Ching

    Directory of Open Access Journals (Sweden)

    Sergey P. Fedotov

    2016-11-01

    Full Text Available Article "Simple association of the genetic code and hexagrams of the Book of Changes (I Ching" is based on the provisions of previous paper "The genetic code as a structure of the Five elements in Chinese philosophy" where the hypothesis regarding the principles of formation of digrams and trigrams in Chinese philosophy are proposed. It allowed to suggest an idea of digrams and trigrams as a tool for description of DNA codons in the process of their interaction, each with others as an independent oscillator (objects, generating its own natural frequency. On the basis of this hypothesis it is considered the logic of structure of trigrams from the Book of Changes (I Ching, the properties of Start and Stop codons, and the properties of their position in the general order of the King Wen. It is suggested that hexagrams order of King Wen describes dynamics of pulse process in the human body as a process of interaction of amino acids which are programmed by codons on the base of frequency (wavelength peculiarities. In addition, a comparative study of the properties between peptide products (manufactured on the base of research of Institute of Gerontology and Bioregulation – St. Petersburg and the scheme of daily activity of codons are represented.

  16. Genetic basis of human brain evolution.

    Science.gov (United States)

    Vallender, Eric J; Mekel-Bobrov, Nitzan; Lahn, Bruce T

    2008-12-01

    Human evolution is characterized by a rapid increase in brain size and complexity. Decades of research have made important strides in identifying anatomical and physiological substrates underlying the unique features of the human brain. By contrast, it has become possible only very recently to examine the genetic basis of human brain evolution. Through comparative genomics, tantalizing insights regarding human brain evolution have emerged. The genetic changes that potentially underlie human brain evolution span a wide range from single-nucleotide substitutions to large-scale structural alterations of the genome. Similarly, the functional consequences of these genetic changes vary greatly, including protein-sequence alterations, cis-regulatory changes and even the emergence of new genes and the extinction of existing ones. Here, we provide a general review of recent findings into the genetic basis of human brain evolution, highlight the most notable trends that have emerged and caution against over-interpretation of current data.

  17. Matrix genetics, part 2: the degeneracy of the genetic code and the octave algebra with two quasi-real units (the genetic octave Yin-Yang-algebra)

    CERN Document Server

    Petoukhov, Sergey V

    2008-01-01

    Algebraic properties of the genetic code are analyzed. The investigations of the genetic code on the basis of matrix approaches ("matrix genetics") are described. The degeneracy of the vertebrate mitochondria genetic code is reflected in the black-and-white mosaic of the (8*8)-matrix of 64 triplets, 20 amino acids and stop-signals. This mosaic genetic matrix is connected with the matrix form of presentation of the special 8-dimensional Yin-Yang-algebra and of its particular 4-dimensional case. The special algorithm, which is based on features of genetic molecules, exists to transform the mosaic genomatrix into the matrices of these algebras. Two new numeric systems are defined by these 8-dimensional and 4-dimensional algebras: genetic Yin-Yang-octaves and genetic tetrions. Their comparison with quaternions by Hamilton is presented. Elements of new "genovector calculation" and ideas of "genetic mechanics" are discussed. These algebras are considered as models of the genetic code and as its possible pre-code ba...

  18. Genetic enhancement, human nature, and rights.

    Science.gov (United States)

    McConnell, Terrance

    2010-08-01

    Authors such as Francis Fukuyama, the President's Council on Bioethics, and George Annas have argued that biotechnological interventions that aim to promote genetic enhancement pose a threat to human nature. This paper clarifies what conclusions these critics seek to establish, and then shows that there is no plausible account of human nature that will meet the conditions necessary to support this position. Appeals to human nature cannot establish a prohibition against the pursuit of genetic enhancement.

  19. Human genetic determinants of dengue virus susceptibility.

    Science.gov (United States)

    Coffey, Lark L; Mertens, Eva; Brehin, Anne-Claire; Fernandez-Garcia, Maria Dolores; Amara, Ali; Després, Philippe; Sakuntabhai, Anavaj

    2009-02-01

    Dengue virus (DENV) is an emerging mosquito-borne pathogen that produces significant morbidity worldwide resulting in an estimated 50-100 million infections annually. DENV causes a spectrum of illness ranging from inapparent infection to life-threatening hemorrhagic fever and shock. The varied DENV disease outcome is determined by complex interactions between immunopathologic, viral, and human genetic factors. This review summarizes these interactions with a focus on human genetic determinants of DENV susceptibility, including human leukocyte antigens, blood type, and single nucleotide polymorphisms in immune response genes that have been associated with DENV disease. We also discuss other factors related to DENV outcome including viral genetic determinants, age, ethnicity, and nutritional status as they relate to DENV susceptibility. We emphasize the need for functional genetics studies to complement association-based data and we call for controlled study designs and standard clinical DENV disease definitions that will strengthen conclusions based on human genetic DENV studies.

  20. Critical roles for a genetic code alteration in the evolution of the genus Candida.

    Science.gov (United States)

    Silva, Raquel M; Paredes, João A; Moura, Gabriela R; Manadas, Bruno; Lima-Costa, Tatiana; Rocha, Rita; Miranda, Isabel; Gomes, Ana C; Koerkamp, Marian J G; Perrot, Michel; Holstege, Frank C P; Boucherie, Hélian; Santos, Manuel A S

    2007-10-31

    During the last 30 years, several alterations to the standard genetic code have been discovered in various bacterial and eukaryotic species. Sense and nonsense codons have been reassigned or reprogrammed to expand the genetic code to selenocysteine and pyrrolysine. These discoveries highlight unexpected flexibility in the genetic code, but do not elucidate how the organisms survived the proteome chaos generated by codon identity redefinition. In order to shed new light on this question, we have reconstructed a Candida genetic code alteration in Saccharomyces cerevisiae and used a combination of DNA microarrays, proteomics and genetics approaches to evaluate its impact on gene expression, adaptation and sexual reproduction. This genetic manipulation blocked mating, locked yeast in a diploid state, remodelled gene expression and created stress cross-protection that generated adaptive advantages under environmental challenging conditions. This study highlights unanticipated roles for codon identity redefinition during the evolution of the genus Candida, and strongly suggests that genetic code alterations create genetic barriers that speed up speciation.

  1. Statistical mechanics of the genetic code: a glimpse of early life?

    Science.gov (United States)

    Goldenfeld, Nigel

    2012-02-01

    Relics of early life, preceding even the last universal common ancestor of all life on Earth, are present in the structure of the modern day canonical genetic code --- the map between DNA sequence and amino acids that form proteins. The code is not random, as often assumed, but instead is now known to have certain error minimisation properties. How could such a code evolve, when it would seem that mutations to the code itself would cause the wrong proteins to be translated, thus killing the organism? I show how a unique and optimal genetic code can emerge over evolutionary time from digital life simulations, but only if horizontal gene transfer was a much stronger characteristic of early life than it is now. These results suggest a natural scenario in which evolution exhibits three distinct dynamical regimes, differentiated respectively by the way in which information flow, genetic novelty and complexity emerge. Possible observational signatures of these predictions are discussed.

  2. The genetic code and its optimization for kinetic energy conservation in polypeptide chains.

    Science.gov (United States)

    Guilloux, Antonin; Jestin, Jean-Luc

    2012-08-01

    Why is the genetic code the way it is? Concepts from fields as diverse as molecular evolution, classical chemistry, biochemistry and metabolism have been used to define selection pressures most likely to be involved in the shaping of the genetic code. Here minimization of kinetic energy disturbances during protein evolution by mutation allows an optimization of the genetic code to be highlighted. The quadratic forms corresponding to the kinetic energy term are considered over the field of rational numbers. Arguments are given to support the introduction of notions from basic number theory within this context. The observations found to be consistent with this minimization are statistically significant. The genetic code may well have been optimized according to energetic criteria so as to improve folding and dynamic properties of polypeptide chains. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  3. Behavior genetic modeling of human fertility

    DEFF Research Database (Denmark)

    Rodgers, J L; Kohler, H P; Kyvik, K O

    2001-01-01

    Try) and number of children (NumCh). Behavior genetic models were fitted using structural equation modeling and DF analysis. A consistent medium-level additive genetic influence was found for NumCh, equal across genders; a stronger genetic influence was identified for FirstTry, greater for females than for males......Behavior genetic designs and analysis can be used to address issues of central importance to demography. We use this methodology to document genetic influence on human fertility. Our data come from Danish twin pairs born from 1953 to 1959, measured on age at first attempt to get pregnant (First...

  4. A new neutron energy spectrum unfolding code using a two steps genetic algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Shahabinejad, H., E-mail: shahabinejad1367@yahoo.com; Hosseini, S.A.; Sohrabpour, M.

    2016-03-01

    A new neutron spectrum unfolding code TGASU (Two-steps Genetic Algorithm Spectrum Unfolding) has been developed to unfold the neutron spectrum from a pulse height distribution which was calculated using the MCNPX-ESUT computational Monte Carlo code. To perform the unfolding process, the response matrices were generated using the MCNPX-ESUT computational code. Both one step (common GA) and two steps GAs have been implemented to unfold the neutron spectra. According to the obtained results, the new two steps GA code results has shown closer match in all energy regions and particularly in the high energy regions. The results of the TGASU code have been compared with those of the standard spectra, LSQR method and GAMCD code. The results of the TGASU code have been demonstrated to be more accurate than that of the existing computational codes for both under-determined and over-determined problems.

  5. A new neutron energy spectrum unfolding code using a two steps genetic algorithm

    Science.gov (United States)

    Shahabinejad, H.; Hosseini, S. A.; Sohrabpour, M.

    2016-03-01

    A new neutron spectrum unfolding code TGASU (Two-steps Genetic Algorithm Spectrum Unfolding) has been developed to unfold the neutron spectrum from a pulse height distribution which was calculated using the MCNPX-ESUT computational Monte Carlo code. To perform the unfolding process, the response matrices were generated using the MCNPX-ESUT computational code. Both one step (common GA) and two steps GAs have been implemented to unfold the neutron spectra. According to the obtained results, the new two steps GA code results has shown closer match in all energy regions and particularly in the high energy regions. The results of the TGASU code have been compared with those of the standard spectra, LSQR method and GAMCD code. The results of the TGASU code have been demonstrated to be more accurate than that of the existing computational codes for both under-determined and over-determined problems.

  6. A New Method Of Gene Coding For A Genetic Algorithm Designed For Parametric Optimization

    Directory of Open Access Journals (Sweden)

    Radu BELEA

    2003-12-01

    Full Text Available In a parametric optimization problem the genes code the real parameters of the fitness function. There are two coding techniques known under the names of: binary coded genes and real coded genes. The comparison between these two is a controversial subject since the first papers about parametric optimization have appeared. An objective analysis regarding the advantages and disadvantages of the two coding techniques is difficult to be done while different format information is compared. The present paper suggests a gene coding technique that uses the same format for both binary coded genes and for the real coded genes. After unifying the real parameters representation, the next criterion is going to be applied: the differences between the two techniques are statistically measured by the effect of the genetic operators over some random generated fellows.

  7. Natural genetic variation impacts expression levels of coding, non-coding, and antisense transcripts in fission yeast

    DEFF Research Database (Denmark)

    Clément-Ziza, Mathieu; Marsellach, Francesc X.; Codlin, Sandra

    2014-01-01

    Our current understanding of how natural genetic variation affects gene expression beyond well-annotated coding genes is still limited. The use of deep sequencing technologies for the study of expression quantitative trait loci (eQTLs) has the potential to close this gap. Here, we generated...... to be affected by eQTLs as protein-coding RNAs. We identified a genetic variation of swc5 that modifies the levels of 871 RNAs, with effects on both sense and antisense transcription, and show that this effect most likely goes through a compromised deposition of the histone variant H2A.Z. The strains, methods...... the first recombinant strain library for fission yeast and conducted an RNA-seq-based QTL study of the coding, non-coding, and antisense transcriptomes. We show that the frequency of distal effects (trans-eQTLs) greatly exceeds the number of local effects (cis-eQTLs) and that non-coding RNAs are as likely...

  8. JPEG2000 COMPRESSION CODING USING HUMAN VISUAL SYSTEM MODEL

    Institute of Scientific and Technical Information of China (English)

    Xiao Jiang; Wu Chengke

    2005-01-01

    In order to apply the Human Visual System (HVS) model to JPEG2000 standard,several implementation alternatives are discussed and a new scheme of visual optimization isintroduced with modifying the slope of rate-distortion. The novelty is that the method of visual weighting is not lifting the coefficients in wavelet domain, but is complemented by code stream organization. It remains all the features of Embedded Block Coding with Optimized Truncation (EBCOT) such as resolution progressive, good robust for error bit spread and compatibility of lossless compression. Well performed than other methods, it keeps the shortest standard codestream and decompression time and owns the ability of VIsual Progressive (VIP) coding.

  9. Origins of gene, genetic code, protein and life: comprehensive view of life systems from a GNC-SNS primitive genetic code hypothesis

    Indian Academy of Sciences (India)

    K Ikehara

    2002-03-01

    We have investigated the origin of genes, the genetic code, proteins and life using six indices (hydropathy, -helix, -sheet and -turn formabilities, acidic amino acid content and basic amino acid content) necessary for appropriate three-dimensional structure formation of globular proteins. From the analysis of microbial genes, we have concluded that newly-born genes are products of nonstop frames (NSF) on antisense strands of microbial GC-rich genes [GC-NSF(a)] and from SNS repeating sequences [(SNS)n] similar to the GC-NSF(a) (S and N mean G or C and either of four bases, respectively). We have also proposed that the universal genetic code used by most organisms on the earth presently could be derived from a GNC-SNS primitive genetic code. We have further presented the [GADV]-protein world hypothesis of the origin of life as well as a hypothesis of protein production, suggesting that proteins were originally produced by random peptide formation of amino acids restricted in specific amino acid compositions termed as GNC-, SNS- and GC-NSF(a)-0th order structures of proteins. The [GADV]-protein world hypothesis is primarily derived from the GNC-primitive genetic code hypothesis. It is also expected that basic properties of extant genes and proteins could be revealed by considerations based on the scenario with four stages.

  10. Genetic Searching Algorithm for Optimal Runlength—Limited Codes with Error Control

    Institute of Scientific and Technical Information of China (English)

    RenQingsheng; YeZhongxing

    1997-01-01

    A genetic searching algorithm is presented to construct arbitrarily concatenatable block code with runlength(d,k)constraints.The code also has the ability to correct error during decoding.A similar eliminating operator and an anti-symbiotic operator are suggested to improve the efficiency of the algorithm.

  11. Recurrent Coding Sequence Variation Explains Only A Small Fraction of the Genetic Architecture of Colorectal Cancer

    NARCIS (Netherlands)

    Timofeeva, Maria N.; Ben Kinnersley, [Unknown; Farrington, Susan M.; Whiffin, Nicola; Palles, Claire; Svinti, Victoria; Lloyd, Amy; Gorman, Maggie; Ooi, Li-Yin; Hosking, Fay; Barclay, Ella; Zgaga, Lina; Dobbins, Sara; Martin, Lynn; Theodoratou, Evropi; Broderick, Peter; Tenesa, Albert; Smillie, Claire; Grimes, Graeme; Hayward, Caroline; Campbell, Archie; Porteous, David; Deary, Ian J.; Harris, Sarah E.; Northwood, Emma L.; Barrett, Jennifer H.; Smith, Gillian; Wolf, Roland; Forman, David; Morreau, Hans; Ruano, Dina; Tops, Carli; Wijnen, Juul; Schrumpf, Melanie; Boot, Arnoud; Vasen, Hans F. A.; Hes, Frederik J.; van Wezel, Tom; Franke, Andre; Lieb, Wolgang; Schafmayer, Clemens; Hampe, Jochen; Buch, Stephan; Propping, Peter; Hemminki, Kari; Foersti, Asta; Westers, Helga; Hofstra, Robert; Pinheiro, Manuela; Pinto, Carla; Teixeira, Manuel; Ruiz-Ponte, Clara; Fernandez-Rozadilla, Ceres; Carracedo, Angel; Castells, Antoni; Castellvi-Bel, Sergi; Campbell, Harry; Bishop, D. Timothy; Tomlinson, Ian P. M.; Dunlop, Malcolm G.; Houlston, Richard S.

    2015-01-01

    Whilst common genetic variation in many non-coding genomic regulatory regions are known to impart risk of colorectal cancer (CRC), much of the heritability of CRC remains unexplained. To examine the role of recurrent coding sequence variation in CRC aetiology, we genotyped 12,638 CRCs cases and 29,0

  12. Problem-Based Test: An "In Vitro" Experiment to Analyze the Genetic Code

    Science.gov (United States)

    Szeberenyi, Jozsef

    2010-01-01

    Terms to be familiar with before you start to solve the test: genetic code, translation, synthetic polynucleotide, leucine, serine, filter precipitation, radioactivity measurement, template, mRNA, tRNA, rRNA, aminoacyl-tRNA synthesis, ribosomes, degeneration of the code, wobble, initiation, and elongation of protein synthesis, initiation codon.…

  13. Recurrent Coding Sequence Variation Explains Only A Small Fraction of the Genetic Architecture of Colorectal Cancer

    NARCIS (Netherlands)

    Timofeeva, Maria N.; Ben Kinnersley, [Unknown; Farrington, Susan M.; Whiffin, Nicola; Palles, Claire; Svinti, Victoria; Lloyd, Amy; Gorman, Maggie; Ooi, Li-Yin; Hosking, Fay; Barclay, Ella; Zgaga, Lina; Dobbins, Sara; Martin, Lynn; Theodoratou, Evropi; Broderick, Peter; Tenesa, Albert; Smillie, Claire; Grimes, Graeme; Hayward, Caroline; Campbell, Archie; Porteous, David; Deary, Ian J.; Harris, Sarah E.; Northwood, Emma L.; Barrett, Jennifer H.; Smith, Gillian; Wolf, Roland; Forman, David; Morreau, Hans; Ruano, Dina; Tops, Carli; Wijnen, Juul; Schrumpf, Melanie; Boot, Arnoud; Vasen, Hans F. A.; Hes, Frederik J.; van Wezel, Tom; Franke, Andre; Lieb, Wolgang; Schafmayer, Clemens; Hampe, Jochen; Buch, Stephan; Propping, Peter; Hemminki, Kari; Foersti, Asta; Westers, Helga; Hofstra, Robert; Pinheiro, Manuela; Pinto, Carla; Teixeira, Manuel; Ruiz-Ponte, Clara; Fernandez-Rozadilla, Ceres; Carracedo, Angel; Castells, Antoni; Castellvi-Bel, Sergi; Campbell, Harry; Bishop, D. Timothy; Tomlinson, Ian P. M.; Dunlop, Malcolm G.; Houlston, Richard S.

    2015-01-01

    Whilst common genetic variation in many non-coding genomic regulatory regions are known to impart risk of colorectal cancer (CRC), much of the heritability of CRC remains unexplained. To examine the role of recurrent coding sequence variation in CRC aetiology, we genotyped 12,638 CRCs cases and 29,0

  14. Recurrent Coding Sequence Variation Explains only A Small Fraction of the Genetic Architecture of Colorectal Cancer

    NARCIS (Netherlands)

    M.N. Timofeeva (Maria N.); B. Kinnersley (Ben); S.M. Farrington (Susan M.); N. Whiffin (Nicola); C. Palles (Claire); V. Svinti (Victoria); A. Lloyd (Amy); M. Gorman (Maggie); L.-Y. Ooi (Li-Yin); F. Hosking (Fay); E. Barclay (Ella); L. Zgaga (Lina); S.E. Dobbins (Sara E.); L. Martin (Lynn); E. Theodoratou (Evropi); P. Broderick (Peter); A. Tenesa (Albert); C. Smillie (Claire); G. Grimes (Graeme); C. Hayward (Caroline); A. Campbell (Archie); D. Porteous (David); I.J. Deary (Ian J.); S.E. Harris (Sarah); J.B. Northwood (John Blackman); J.H. Barrett (Jennifer H.); G. Smith (Gillian); R. Wolf (Roland); D. Forman (David); H. Morreau (Hans); D. Ruano (Dina); C. Tops (Carli); J.T. Wijnen (Juul); M. Schrumpf (Melanie); A. Boot (Arnoud); H. Vasen (Hans); F.J. Hes (Frederik); T. van Wezel (Tom); A. Franke (Andre); W. Lieb (Wolgang); C. Schafmayer (Clemens); J. Hampe (Jochen); T. Buch (Thorsten); P. Propping (Peter); K. Hemminki (Kari); A. Försti (Asta); H. Westers (Helga); R.M.W. Hofstra (Robert); M. Pinheiro (Manuela); C. Pinto (Carla); P.J. Teixeira; C. Ruiz-Ponte (Clara); C. Fernández-Rozadilla (Ceres); A. Carracedo (Angel); A. Castells; S. Castellví-Bel; H. Campbell (Harry); D.T. Bishop (David Timothy); I. Tomlinson (Ian); M.G. Dunlop (Malcolm); R. Houlston (Richard)

    2015-01-01

    textabstractWhilst common genetic variation in many non-coding genomic regulatory regions are known to impart risk of colorectal cancer (CRC), much of the heritability of CRC remains unexplained. To examine the role of recurrent coding sequence variation in CRC aetiology, we genotyped 12,638 CRCs ca

  15. Recurrent Coding Sequence Variation Explains only A Small Fraction of the Genetic Architecture of Colorectal Cancer

    NARCIS (Netherlands)

    M.N. Timofeeva (Maria N.); B. Kinnersley (Ben); S.M. Farrington (Susan M.); N. Whiffin (Nicola); C. Palles (Claire); V. Svinti (Victoria); A. Lloyd (Amy); M. Gorman (Maggie); L.-Y. Ooi (Li-Yin); F. Hosking (Fay); E. Barclay (Ella); L. Zgaga (Lina); S.E. Dobbins (Sara E.); L. Martin (Lynn); E. Theodoratou (Evropi); P. Broderick (Peter); A. Tenesa (Albert); C. Smillie (Claire); G. Grimes (Graeme); C. Hayward (Caroline); A. Campbell (Archie); D. Porteous (David); I.J. Deary (Ian J.); S.E. Harris (Sarah); J.B. Northwood (John Blackman); J.H. Barrett (Jennifer H.); G. Smith (Gillian); R. Wolf (Roland); D. Forman (David); H. Morreau (Hans); D. Ruano (Dina); C. Tops (Carli); J.T. Wijnen (Juul); M. Schrumpf (Melanie); A. Boot (Arnoud); H. Vasen (Hans); F.J. Hes (Frederik); T. van Wezel (Tom); A. Franke (Andre); W. Lieb (Wolgang); C. Schafmayer (Clemens); J. Hampe (Jochen); T. Buch (Thorsten); P. Propping (Peter); K. Hemminki (Kari); A. Försti (Asta); H. Westers (Helga); R.M.W. Hofstra (Robert); M. Pinheiro (Manuela); C. Pinto (Carla); P.J. Teixeira; C. Ruiz-Ponte (Clara); C. Fernández-Rozadilla (Ceres); A. Carracedo (Angel); A. Castells; S. Castellví-Bel; H. Campbell (Harry); D.T. Bishop (David Timothy); I. Tomlinson (Ian); M.G. Dunlop (Malcolm); R. Houlston (Richard)

    2015-01-01

    textabstractWhilst common genetic variation in many non-coding genomic regulatory regions are known to impart risk of colorectal cancer (CRC), much of the heritability of CRC remains unexplained. To examine the role of recurrent coding sequence variation in CRC aetiology, we genotyped 12,638 CRCs ca

  16. Junk DNA and the long non-coding RNA twist in cancer genetics

    NARCIS (Netherlands)

    H. Ling (Hui); K. Vincent; M. Pichler; R. Fodde (Riccardo); I. Berindan-Neagoe (Ioana); F.J. Slack (Frank); G.A. Calin (George)

    2015-01-01

    textabstractThe central dogma of molecular biology states that the flow of genetic information moves from DNA to RNA to protein. However, in the last decade this dogma has been challenged by new findings on non-coding RNAs (ncRNAs) such as microRNAs (miRNAs). More recently, long non-coding RNAs (lnc

  17. Recurrent Coding Sequence Variation Explains only A Small Fraction of the Genetic Architecture of Colorectal Cancer

    NARCIS (Netherlands)

    M.N. Timofeeva (Maria N.); B. Kinnersley (Ben); S.M. Farrington (Susan M.); N. Whiffin (Nicola); C. Palles (Claire); V. Svinti (Victoria); A. Lloyd (Amy); M. Gorman (Maggie); L.-Y. Ooi (Li-Yin); F. Hosking (Fay); E. Barclay (Ella); L. Zgaga (Lina); S.E. Dobbins (Sara E.); L. Martin (Lynn); E. Theodoratou (Evropi); P. Broderick (Peter); A. Tenesa (Albert); C. Smillie (Claire); G. Grimes (Graeme); C. Hayward (Caroline); A. Campbell (Archie); D. Porteous (David); I.J. Deary (Ian J.); S.E. Harris (Sarah); J.B. Northwood (John Blackman); J.H. Barrett (Jennifer H.); G. Smith (Gillian); R. Wolf (Roland); D. Forman (David); H. Morreau (Hans); D. Ruano (Dina); C. Tops (Carli); J.T. Wijnen (Juul); M. Schrumpf (Melanie); A. Boot (Arnoud); H. Vasen (Hans); F.J. Hes (Frederik); T. van Wezel (Tom); A. Franke (Andre); W. Lieb (Wolgang); C. Schafmayer (Clemens); J. Hampe (Jochen); T. Buch (Thorsten); P. Propping (Peter); K. Hemminki (Kari); A. Försti (Asta); H. Westers (Helga); R.M.W. Hofstra (Robert); M. Pinheiro (Manuela); C. Pinto (Carla); P.J. Teixeira; C. Ruiz-Ponte (Clara); C. Fernández-Rozadilla (Ceres); A. Carracedo (Angel); A. Castells; S. Castellví-Bel; H. Campbell (Harry); D.T. Bishop (David Timothy); I. Tomlinson (Ian); M.G. Dunlop (Malcolm); R. Houlston (Richard)

    2015-01-01

    textabstractWhilst common genetic variation in many non-coding genomic regulatory regions are known to impart risk of colorectal cancer (CRC), much of the heritability of CRC remains unexplained. To examine the role of recurrent coding sequence variation in CRC aetiology, we genotyped 12,638 CRCs

  18. Genetic hotels for the standard genetic code: evolutionary analysis based upon novel three-dimensional algebraic models.

    Science.gov (United States)

    José, Marco V; Morgado, Eberto R; Govezensky, Tzipe

    2011-07-01

    Herein, we rigorously develop novel 3-dimensional algebraic models called Genetic Hotels of the Standard Genetic Code (SGC). We start by considering the primeval RNA genetic code which consists of the 16 codons of type RNY (purine-any base-pyrimidine). Using simple algebraic operations, we show how the RNA code could have evolved toward the current SGC via two different intermediate evolutionary stages called Extended RNA code type I and II. By rotations or translations of the subset RNY, we arrive at the SGC via the former (type I) or via the latter (type II), respectively. Biologically, the Extended RNA code type I, consists of all codons of the type RNY plus codons obtained by considering the RNA code but in the second (NYR type) and third (YRN type) reading frames. The Extended RNA code type II, comprises all codons of the type RNY plus codons that arise from transversions of the RNA code in the first (YNY type) and third (RNR) nucleotide bases. Since the dimensions of remarkable subsets of the Genetic Hotels are not necessarily integer numbers, we also introduce the concept of algebraic fractal dimension. A general decoding function which maps each codon to its corresponding amino acid or the stop signals is also derived. The Phenotypic Hotel of amino acids is also illustrated. The proposed evolutionary paths are discussed in terms of the existing theories of the evolution of the SGC. The adoption of 3-dimensional models of the Genetic and Phenotypic Hotels will facilitate the understanding of the biological properties of the SGC.

  19. Genetic evidence for conserved non-coding element function across species--the ears have it

    Directory of Open Access Journals (Sweden)

    Eric E Turner

    2014-01-01

    Full Text Available Comparison of genomic sequences from diverse vertebrate species has revealed numerous highly conserved regions that do not appear to encode proteins or functional RNAs. Often these conserved non-coding elements, or CNEs, direct gene expression to specific tissues in transgenic models, demonstrating they have regulatory function. CNEs are frequently found near ‘developmental’ genes, particularly transcription factors, implying that these elements have essential regulatory roles in development. However, actual examples demonstrating CNE regulatory functions across species have been few, and recent loss-of-function studies of several CNEs in mice have shown relatively minor effects. In this Perspectives article, we discuss new findings in fancy rats and Highland cattle demonstrating that function of a CNE near the Hmx1 gene is crucial for normal external ear development and resembles loss-of function Hmx1 coding mutations in mice and humans. These findings provide important support for similar developmental roles of CNEs in divergent species, and reinforce the concept that CNEs should be examined systematically in the ongoing search for genetic causes of human developmental disorders in the era of genome-scale sequencing.

  20. Complex phylogenetic distribution of a non-canonical genetic code in green algae

    Directory of Open Access Journals (Sweden)

    Keeling Patrick J

    2010-10-01

    Full Text Available Abstract Background A non-canonical nuclear genetic code, in which TAG and TAA have been reassigned from stop codons to glutamine, has evolved independently in several eukaryotic lineages, including the ulvophycean green algal orders Dasycladales and Cladophorales. To study the phylogenetic distribution of the standard and non-canonical genetic codes, we generated sequence data of a representative set of ulvophycean green algae and used a robust green algal phylogeny to evaluate different evolutionary scenarios that may account for the origin of the non-canonical code. Results This study demonstrates that the Dasycladales and Cladophorales share this alternative genetic code with the related order Trentepohliales and the genus Blastophysa, but not with the Bryopsidales, which is sister to the Dasycladales. This complex phylogenetic distribution whereby all but one representative of a single natural lineage possesses an identical deviant genetic code is unique. Conclusions We compare different evolutionary scenarios for the complex phylogenetic distribution of this non-canonical genetic code. A single transition to the non-canonical code followed by a reversal to the canonical code in the Bryopsidales is highly improbable due to the profound genetic changes that coincide with codon reassignment. Multiple independent gains of the non-canonical code, as hypothesized for ciliates, are also unlikely because the same deviant code has evolved in all lineages. Instead we favor a stepwise acquisition model, congruent with the ambiguous intermediate model, whereby the non-canonical code observed in these green algal orders has a single origin. We suggest that the final steps from an ambiguous intermediate situation to a non-canonical code have been completed in the Trentepohliales, Dasycladales, Cladophorales and Blastophysa but not in the Bryopsidales. We hypothesize that in the latter lineage an initial stage characterized by translational ambiguity was

  1. The genetics of human obesity.

    Science.gov (United States)

    Xia, Qianghua; Grant, Struan F A

    2013-04-01

    It has long been known that there is a genetic component to obesity, and that characterizing this underlying factor would likely offer the possibility of better intervention in the future. Monogenic obesity has proved to be relatively straightforward, with a combination of linkage analysis and mouse models facilitating the identification of multiple genes. In contrast, genome-wide association studies have successfully revealed a variety of genetic loci associated with the more common form of obesity, allowing for very strong consensus on the underlying genetic architecture of the phenotype for the first time. Although a number of significant findings have been made, it appears that very little of the apparent heritability of body mass index has actually been explained to date. New approaches for data analyses and advances in technology will be required to uncover the elusive missing heritability, and to aid in the identification of the key causative genetic underpinnings of obesity. © 2013 New York Academy of Sciences.

  2. Chromatin remodeling: the interface between extrinsic cues and the genetic code?

    Science.gov (United States)

    Ezzat, Shereen

    2008-10-01

    The successful completion of the human genome project ushered a new era of hope and skepticism. However, the promise of finding the fundamental basis of human traits and diseases appears less than fulfilled. The original premise was that the DNA sequence of every gene would allow precise characterization of critical differences responsible for altered cellular functions. The characterization of intragenic mutations in cancers paved the way for early screening and the design of targeted therapies. However, it has also become evident that unmasking genetic codes alone cannot explain the diversity of disease phenotypes within a population. Further, classic genetics has not been able to explain the differences that have been observed among identical twins or even cloned animals. This new reality has re-ignited interest in the field of epigenetics. While traditionally defined as heritable changes that can alter gene expression without affecting the corresponding DNA sequence, this definition has come into question. The extent to which epigenetic change can also be acquired in response to chemical stimuli represents an exciting dimension in the "nature vs nurture" debate. In this review I will describe a series of studies in my laboratory that illustrate the significance of epigenetics and its potential clinical implications.

  3. Revertant mosaicism in human genetic disorders

    NARCIS (Netherlands)

    Jonkman, MF

    1999-01-01

    Somatic reversion of inherited mutations is known for many years in plant breeding, however it was recognized only recently in humans. The concept of revertant mosaicism is important in medical genetics. (C) 1999 Wiley-Liss, Inc.

  4. Breaking the Genetic Code in a Letter by Max Delbruck.

    Science.gov (United States)

    Fox, Marty

    1996-01-01

    Describes a classroom exercise that uses a letter from Max Delbruck to George Beadle to stimulate interest in the mechanics of a nonoverlapping comma-free code. Enables students to participate in the rich history of molecular biology and illustrates to them that scientists and science can be fun. (JRH)

  5. The genetics of human obesity.

    Science.gov (United States)

    Waalen, Jill

    2014-10-01

    The heritability of obesity has long been appreciated and the genetics of obesity has been the focus of intensive study for decades. Early studies elucidating genetic factors involved in rare monogenic and syndromic forms of extreme obesity focused attention on dysfunction of hypothalamic leptin-related pathways in the control of food intake as a major contributor. Subsequent genome-wide association studies of common genetic variants identified novel loci that are involved in more common forms of obesity across populations of diverse ethnicities and ages. The subsequent search for factors contributing to the heritability of obesity not explained by these 2 approaches ("missing heritability") has revealed additional rare variants, copy number variants, and epigenetic changes that contribute. Although clinical applications of these findings have been limited to date, the increasing understanding of the interplay of these genetic factors with environmental conditions, such as the increased availability of high calorie foods and decreased energy expenditure of sedentary lifestyles, promises to accelerate the translation of genetic findings into more successful preventive and therapeutic interventions.

  6. Efficient Dual Domain Decoding of Linear Block Codes Using Genetic Algorithms

    Directory of Open Access Journals (Sweden)

    Ahmed Azouaoui

    2012-01-01

    Full Text Available A computationally efficient algorithm for decoding block codes is developed using a genetic algorithm (GA. The proposed algorithm uses the dual code in contrast to the existing genetic decoders in the literature that use the code itself. Hence, this new approach reduces the complexity of decoding the codes of high rates. We simulated our algorithm in various transmission channels. The performance of this algorithm is investigated and compared with competitor decoding algorithms including Maini and Shakeel ones. The results show that the proposed algorithm gives large gains over the Chase-2 decoding algorithm and reach the performance of the OSD-3 for some quadratic residue (QR codes. Further, we define a new crossover operator that exploits the domain specific information and compare it with uniform and two point crossover. The complexity of this algorithm is also discussed and compared to other algorithms.

  7. De Novo Origin of Human Protein-Coding Genes

    Science.gov (United States)

    Wu, Dong-Dong; Irwin, David M.; Zhang, Ya-Ping

    2011-01-01

    The de novo origin of a new protein-coding gene from non-coding DNA is considered to be a very rare occurrence in genomes. Here we identify 60 new protein-coding genes that originated de novo on the human lineage since divergence from the chimpanzee. The functionality of these genes is supported by both transcriptional and proteomic evidence. RNA–seq data indicate that these genes have their highest expression levels in the cerebral cortex and testes, which might suggest that these genes contribute to phenotypic traits that are unique to humans, such as improved cognitive ability. Our results are inconsistent with the traditional view that the de novo origin of new genes is very rare, thus there should be greater appreciation of the importance of the de novo origination of genes. PMID:22102831

  8. Genetic code correlations - Amino acids and their anticodon nucleotides

    Science.gov (United States)

    Weber, A. L.; Lacey, J. C., Jr.

    1978-01-01

    The data here show direct correlations between both the hydrophobicity and the hydrophilicity of the homocodonic amino acids and their anticodon nucleotides. While the differences between properties of uracil and cytosine derivatives are small, further data show that uracil has an affinity for charged species. Although these data suggest that molecular relationships between amino acids and anticodons were responsible for the origin of the code, it is not clear what the mechanism of the origin might have been.

  9. An Efficient Soft Decoder of Block Codes Based on Compact Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Ahmed Azouaoui

    2012-09-01

    Full Text Available Soft-decision decoding is an NP-hard problem with great interest to developers of communication systems. We present an efficient soft-decision decoder of linear block codes based on compact genetic algorithm (cGA and compare its performances with various other decoding algorithms including Shakeel algorithm. The proposed algorithm uses the dual code in contrast to Shakeel algorithm which uses the code itself. Hence, this new approach reduces the decoding complexity of high rates codes. The complexity and an optimized version of this new algorithm are also presented and discussed.

  10. The genetics of neuroticism and human values.

    Science.gov (United States)

    Zacharopoulos, George; Lancaster, Thomas M; Maio, Gregory R; Linden, David E J

    2016-04-01

    Human values and personality have been shown to share genetic variance in twin studies. However, there is a lack of evidence about the genetic components of this association. This study examined the interplay between genes, values and personality in the case of neuroticism, because polygenic scores were available for this personality trait. First, we replicated prior evidence of a positive association between the polygenic neuroticism score (PNS) and neuroticism. Second, we found that the PNS was significantly associated with the whole human value space in a sinusoidal waveform that was consistent with Schwartz's circular model of human values. These results suggest that it is useful to consider human values in the analyses of genetic contributions to personality traits. They also pave the way for an investigation of the biological mechanisms contributing to human value orientations.

  11. Genetically Modified Pig Models for Human Diseases

    Institute of Scientific and Technical Information of China (English)

    Nana Fan; Liangxue Lai

    2013-01-01

    Genetically modified animal models are important for understanding the pathogenesis of human disease and developing therapeutic strategies.Although genetically modified mice have been widely used to model human diseases,some of these mouse models do not replicate important disease symptoms or pathology.Pigs are more similar to humans than mice in anatomy,physiology,and genome.Thus,pigs are considered to be better animal models to mimic some human diseases.This review describes genetically modified pigs that have been used to model various diseases including neurological,cardiovascular,and diabetic disorders.We also discuss the development in gene modification technology that can facilitate the generation of transgenic pig models for human diseases.

  12. Origins of biological information and the genetic code

    Science.gov (United States)

    Fox, S. W.

    1974-01-01

    Information, defined as the capacity of a molecule or system for selective interactions with other molecules or systems, is followed through its evolution from prebiological information to protoribosomes. Emphasis is on proteins and protein-like polymers, and later on ATP. The research will contribute more to the understanding of the essence of the genetic mechanism.

  13. Human genetic factors in tuberculosis: an update.

    Science.gov (United States)

    van Tong, Hoang; Velavan, Thirumalaisamy P; Thye, Thorsten; Meyer, Christian G

    2017-09-01

    Tuberculosis (TB) is a major threat to human health, especially in many developing countries. Human genetic variability has been recognised to be of great relevance in host responses to Mycobacterium tuberculosis infection and in regulating both the establishment and the progression of the disease. An increasing number of candidate gene and genome-wide association studies (GWAS) have focused on human genetic factors contributing to susceptibility or resistance to TB. To update previous reviews on human genetic factors in TB we searched the MEDLINE database and PubMed for articles from 1 January 2014 through 31 March 2017 and reviewed the role of human genetic variability in TB. Search terms applied in various combinations were 'tuberculosis', 'human genetics', 'candidate gene studies', 'genome-wide association studies' and 'Mycobacterium tuberculosis'. Articles in English retrieved and relevant references cited in these articles were reviewed. Abstracts and reports from meetings were also included. This review provides a recent summary of associations of polymorphisms of human genes with susceptibility/resistance to TB. © 2017 John Wiley & Sons Ltd.

  14. Developing a Working Code of Ethics for Human Resource Personnel.

    Science.gov (United States)

    Rampal, Kuldip R.

    1991-01-01

    To develop codes of ethics for their profession, college human resources personnel must first understand their primary job-related responsibilities. These include being alert to evolving organizational needs; coordinating needed training of employees; appreciating the nuances of psychology, communication, and motivation; and observing employee…

  15. The Graph, Geometry and Symmetries of the Genetic Code with Hamming Metric

    Directory of Open Access Journals (Sweden)

    Reijer Lenstra

    2015-07-01

    Full Text Available The similarity patterns of the genetic code result from similar codons encoding similar messages. We develop a new mathematical model to analyze these patterns. The physicochemical characteristics of amino acids objectively quantify their differences and similarities; the Hamming metric does the same for the 64 codons of the codon set. (Hamming distances equal the number of different codon positions: AAA and AAC are at 1-distance; codons are maximally at 3-distance. The CodonPolytope, a 9-dimensional geometric object, is spanned by 64 vertices that represent the codons and the Euclidian distances between these vertices correspond one-to-one with intercodon Hamming distances. The CodonGraph represents the vertices and edges of the polytope; each edge equals a Hamming 1-distance. The mirror reflection symmetry group of the polytope is isomorphic to the largest permutation symmetry group of the codon set that preserves Hamming distances. These groups contain 82,944 symmetries. Many polytope symmetries coincide with the degeneracy and similarity patterns of the genetic code. These code symmetries are strongly related with the face structure of the polytope with smaller faces displaying stronger code symmetries. Splitting the polytope stepwise into smaller faces models an early evolution of the code that generates this hierarchy of code symmetries. The canonical code represents a class of 41,472 codes with equivalent symmetries; a single class among an astronomical number of symmetry classes comprising all possible codes.

  16. An evaluation of mitochondrial tRNA gene evolution and its relation to the genetic code.

    Science.gov (United States)

    Cedergren, R J

    1982-04-01

    Extensive sequence data on mitochondrial (mt) tRNAs give for the first time an opportunity to evaluate tRNA gene evolution in this organelle. Deductions from these gene structures relate to the evolution of tRNA genes in other cellular systems and to the origin of the genetic code. Mt tRNAs, in contrast to the prokaryotic nature of chloroplastic tRNA structure, can not at the present time be definitely related to either prokaryotic or eukaryotic tRNAs, probably because of a higher mutation rate in mitochondria. Fungal mt tRNAs having the same anticodon and function are generally similar enough to be considered homologous. Comparisons af all mt tRNA sequences contained in the same mitochondrion indicate that some tRNAs originated by duplication of a prototypic gene which, after divergence, led to tRNAs having different amino acid specificities. The deviant mt genetic code, although admittedly permitting a simpler decoding mechanism, is not useful in determining whether the origin of mitochondria had preceded or was derived from prokaryotes or eukaryotes, since the genetic code is variable even among mitochondria. Variants of the mt genetic code lead to speculation on the nature of the primordial code and its relation to the present "universal" code.

  17. Local conditions for global stability in the space of codons of the genetic code.

    Science.gov (United States)

    Salinas, Dino G; Gallardo, Mauricio O; Osorio, Manuel I

    2016-12-01

    The polar requirement is an attribute of amino acids that is a major determinant of the structure and function of the proteins, and it plays a role in the flexibility and robustness of the genetic code. The viability of an organism depends on flexibility, which allows the exploration of new functions. However, robustness is necessary to protect the organism from deleterious changes derived from misreading errors and single-point mutations. Compared with random codes, the standard genetic code is one of the most robust against such errors. Here, using analytical and numerical calculations and the set of amino acid-encoding codons, we have proposed some local conditions that are necessary for the optimal robustness of the genetic code, and we explored the association between the local conditions and the robustness. The localness of the proposed conditions and the underlying evolutionary mechanism, which begins with a random code and progresses toward more efficient codes (e.g., the standard code), might be biologically plausible. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  18. An overview of human genetic privacy.

    Science.gov (United States)

    Shi, Xinghua; Wu, Xintao

    2017-01-01

    The study of human genomics is becoming a Big Data science, owing to recent biotechnological advances leading to availability of millions of personal genome sequences, which can be combined with biometric measurements from mobile apps and fitness trackers, and of human behavior data monitored from mobile devices and social media. With increasing research opportunities for integrative genomic studies through data sharing, genetic privacy emerges as a legitimate yet challenging concern that needs to be carefully addressed, not only for individuals but also for their families. In this paper, we present potential genetic privacy risks and relevant ethics and regulations for sharing and protecting human genomics data. We also describe the techniques for protecting human genetic privacy from three broad perspectives: controlled access, differential privacy, and cryptographic solutions. © 2016 New York Academy of Sciences.

  19. Mendelism in human genetics: 100 years on.

    Science.gov (United States)

    Majumdar, Sisir K

    2003-01-01

    Genetics (Greek word--'genes' = born) is a science without an objective past. But the genre of genetics was always roaming in the corridors of human psyche since antiquity. The account of heritable deformities in human often appears in myths and legends. Ancient Hindu Caste system was based on the assumption that both desirable and undesirable traits are passed from generation to generation. In Babylonia 60 birth defects were listed on Clay tablets written around 5,000 year ago. The Jewish Talmud contains accurate description of the inheritance of haemophilia--a human genetic disorder. The Upanisads vedant--800--200 BC provides instructions for the choice of a wife emphasizing that no heritable illness should be present and that the family should show evidence of good character for several preceding generations. These examples indicate that heritable human traits played a significant role in social customs are presented in this article.

  20. Synthetic alienation of microbial organisms by using genetic code engineering: Why and how?

    Science.gov (United States)

    Kubyshkin, Vladimir; Budisa, Nediljko

    2017-08-01

    The main goal of synthetic biology (SB) is the creation of biodiversity applicable for biotechnological needs, while xenobiology (XB) aims to expand the framework of natural chemistries with the non-natural building blocks in living cells to accomplish artificial biodiversity. Protein and proteome engineering, which overcome limitation of the canonical amino acid repertoire of 20 (+2) prescribed by the genetic code by using non-canonic amino acids (ncAAs), is one of the main focuses of XB research. Ideally, estranging the genetic code from its current form via systematic introduction of ncAAs should enable the development of bio-containment mechanisms in synthetic cells potentially endowing them with a "genetic firewall" i.e. orthogonality which prevents genetic information transfer to natural systems. Despite rapid progress over the past two decades, it is not yet possible to completely alienate an organism that would use and maintain different genetic code associations permanently. In order to engineer robust bio-contained life forms, the chemical logic behind the amino acid repertoire establishment should be considered. Starting from recent proposal of Hartman and Smith about the genetic code establishment in the RNA world, here the authors mapped possible biotechnological invasion points for engineering of bio-contained synthetic cells equipped with non-canonical functionalities. Copyright © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Developing a code of ethics for human cloning.

    Science.gov (United States)

    Collmann, J; Graber, G

    2000-01-01

    Under what conditions might the cloning of human beings constitute an ethical practice? A tendency exists to analyze human cloning merely as a technical procedure. As with all revolutionary technological developments, however, human cloning potentially exists in a broad social context that will both shape and be shaped by the biological techniques. Although human cloning must be subjected to technical analysis that addresses fundamental ethical questions such as its safety and efficacy, questions exist that focus our attention on broader issues. Asserting that cloning inevitably leads to undesirable consequences commits the fallacy of technological determinism and untenably separates technological and ethical evaluation. Drawing from the Report of the National Bioethics Advisory Committee and Aldous Huxley's Brave New World, we offer a draft "Code of Ethics for Human Cloning" in order to stimulate discussion about the ethics of the broader ramifications of human cloning as well as its particular technological properties.

  2. Genetics of obesity in humans.

    Science.gov (United States)

    Farooqi, Sadaf; O'Rahilly, Stephen

    2006-12-01

    Considerable attention has focused on deciphering the hypothalamic pathways that mediate the behavioral and metabolic effects of leptin. We and others have identified several single gene defects that disrupt the molecules in the leptin-melanocortin pathway causing severe obesity in humans. In this review, we consider these human monogenic obesity syndromes and discuss how far the characterization of these patients has informed our understanding of the physiological role of leptin and the melanocortins in the regulation of human body weight and neuroendocrine function.

  3. Human genetics of diabetic vascular complications

    Indian Academy of Sciences (India)

    Zi-Hui Tang; Zhou Fang; Linuo Zhou

    2013-12-01

    Diabetic vascular complications (DVC) affecting several important organ systems of human body such as the cardiovascular system constitute a major public health problem. There is evidence demonstrating that genetic factors contribute to the risk of DVC genetic variants, structural variants, and epigenetic changes play important roles in the development of DVC. Genetic linkage studies have uncovered a number of genetic loci that may shape the risk of DVC. Genetic association studies have identified many common genetic variants for susceptibility to DVC. Structural variants such as copy number variation and interactions of gene × environment have also been detected by association analysis. Apart from the nuclear genome, mitochondrial DNA plays a critical role in regulation of development of DVC. Epigenetic studies have indicated epigenetic changes in chromatin affecting gene transcription in response to environmental stimuli, which provided a large body of evidence of regulating development of diabetes mellitus. Recently, a new window has opened on identifying rare and common genetic loci through next generation sequencing technologies. This review focusses on the current knowledge of the genetic and epigenetic basis of DVC. Ultimately, identification of genes or genetic loci, structural variants and epigenetic changes contributing to risk of or protection from DVC will help uncover the complex mechanism(s) underlying DVC, with crucial implications for the development of personalized medicine for diabetes mellitus and its complications.

  4. Yury Borisovich Rumer and his 'biological papers' on the genetic code.

    Science.gov (United States)

    Fimmel, Elena; Strüngmann, Lutz

    2016-03-13

    Yury Borisovich Rumer was one of the most important theoretical physicists of the former Soviet Union in the early 1930s. However, he also wrote a few 'biological papers' on the standard genetic code after he read Crick's and Nirenberg's pioneering papers on the topic. Rumer's articles on the 'Systematization of Codons in the Genetic Code' (Rumer 1966 Doklady Akademii nauk SSSR 167, 1393-1394); Rumer 1968 Doklady Akademii nauk SSSR 183, 225-226; Rumer 1969 Doklady Akademii nauk SSSR 187, 937-938, where he suggested the idea of partitioning codons depending on their redundancy-the first mention of symmetry in the genetic code-were published in Russian only. Due to their importance and their frequent citation, we here present translations of these articles into English in order to make them accessible to a broader community. © 2016 The Author(s).

  5. Mean-Adaptive Real-Coding Genetic Algorithm and its Applications to Electromagnetic Optimization (Part One

    Directory of Open Access Journals (Sweden)

    Z. Raida

    2007-09-01

    Full Text Available In the paper, a novel instance of the real-coding steady-state genetic algorithm, called the Mean-adaptive real-coding genetic algorithm, is put forward. In this instance, three novel implementations of evolution operators are incorporated. Those are a recombination and two mutation operators. All of the evolution operators are designed with the aim of possessing a big explorative power. Moreover, one of the mutation operators exhibits self-adaptive behavior and the other exhibits adaptive behavior, thereby allowing the algorithm to self-control its own mutability as the search advances. This algorithm also takes advantage of population-elitist selection, acting as a replacement policy, being adopted from evolution strategies. The purpose of this paper (i.e., the first part is to provide theoretical foundations of a robust and advanced instance of the real-coding genetic algorithm having the big potential of being successfully applied to electromagnetic optimization.

  6. Genetic Conflict in Human Pregnancy

    OpenAIRE

    1993-01-01

    Pregnancy has commonly been viewed as a cooperative interaction between a mother and her fetus. The effects of natural selection on genes expressed in fetuses, however, may be opposed by the effects of natural selection on genes expressed in mothers. In this sense, a genetic conflict can be said to exist between maternal and fetal genes. Fetal genes will be selected to increase the transfer of nutrients to their fetus, and maternal genes will be selected to limit transfers in excess of Soma m...

  7. Organizing conceptual knowledge in humans with a gridlike code.

    Science.gov (United States)

    Constantinescu, Alexandra O; O'Reilly, Jill X; Behrens, Timothy E J

    2016-06-17

    It has been hypothesized that the brain organizes concepts into a mental map, allowing conceptual relationships to be navigated in a manner similar to that of space. Grid cells use a hexagonally symmetric code to organize spatial representations and are the likely source of a precise hexagonal symmetry in the functional magnetic resonance imaging signal. Humans navigating conceptual two-dimensional knowledge showed the same hexagonal signal in a set of brain regions markedly similar to those activated during spatial navigation. This gridlike signal is consistent across sessions acquired within an hour and more than a week apart. Our findings suggest that global relational codes may be used to organize nonspatial conceptual representations and that these codes may have a hexagonal gridlike pattern when conceptual knowledge is laid out in two continuous dimensions.

  8. Possibilities for the evolution of the genetic code from a preceding form

    Science.gov (United States)

    Jukes, T. H.

    1973-01-01

    Analysis of the interaction between mRNA codons and tRNA anticodons suggests a model for the evolution of the genetic code. Modification of the nucleic acid following the anticodon is at present essential in both eukaryotes and prokaryotes to ensure fidelity of translation of codons starting with A, and the amino acids which could be coded for before the evolution of the modifying enzymes can be deduced.

  9. Summary of evidence for an anticodonic basis for the origin of the genetic code

    Science.gov (United States)

    Lacey, J. C., Jr.; Mullins, D. W., Jr.

    1981-01-01

    This article summarizes data supporting the hypothesis that the genetic code origin was based on relationships (probably affinities) between amino acids and their anticodon nucleotides. Selective activation seems to follow from selective affinity and consequently, incorporation of amino acids into peptides can also be selective. It is suggested that these selectivities in affinity and activation, coupled with the base pairing specificities, allowed the origin of the code and the process of translation.

  10. Widespread occurrence of 5-methylcytosine in human coding and non-coding RNA.

    Science.gov (United States)

    Squires, Jeffrey E; Patel, Hardip R; Nousch, Marco; Sibbritt, Tennille; Humphreys, David T; Parker, Brian J; Suter, Catherine M; Preiss, Thomas

    2012-06-01

    The modified base 5-methylcytosine (m(5)C) is well studied in DNA, but investigations of its prevalence in cellular RNA have been largely confined to tRNA and rRNA. In animals, the two m(5)C methyltransferases NSUN2 and TRDMT1 are known to modify specific tRNAs and have roles in the control of cell growth and differentiation. To map modified cytosine sites across a human transcriptome, we coupled bisulfite conversion of cellular RNA with next-generation sequencing. We confirmed 21 of the 28 previously known m(5)C sites in human tRNAs and identified 234 novel tRNA candidate sites, mostly in anticipated structural positions. Surprisingly, we discovered 10,275 sites in mRNAs and other non-coding RNAs. We observed that distribution of modified cytosines between RNA types was not random; within mRNAs they were enriched in the untranslated regions and near Argonaute binding regions. We also identified five new sites modified by NSUN2, broadening its known substrate range to another tRNA, the RPPH1 subunit of RNase P and two mRNAs. Our data demonstrates the widespread presence of modified cytosines throughout coding and non-coding sequences in a transcriptome, suggesting a broader role of this modification in the post-transcriptional control of cellular RNA function.

  11. Virus-host co-evolution under a modified nuclear genetic code

    Directory of Open Access Journals (Sweden)

    Derek J. Taylor

    2013-03-01

    Full Text Available Among eukaryotes with modified nuclear genetic codes, viruses are unknown. However, here we provide evidence of an RNA virus that infects a fungal host (Scheffersomyces segobiensis with a derived nuclear genetic code where CUG codes for serine. The genomic architecture and phylogeny are consistent with infection by a double-stranded RNA virus of the genus Totivirus. We provide evidence of past or present infection with totiviruses in five species of yeasts with modified genetic codes. All but one of the CUG codons in the viral genome have been eliminated, suggesting that avoidance of the modified codon was important to viral adaptation. Our mass spectroscopy analysis indicates that a congener of the host species has co-opted and expresses a capsid gene from totiviruses as a cellular protein. Viral avoidance of the host’s modified codon and host co-option of a protein from totiviruses suggest that RNA viruses co-evolved with yeasts that underwent a major evolutionary transition from the standard genetic code.

  12. Genetic code evolution reveals the neutral emergence of mutational robustness, and information as an evolutionary constraint.

    Science.gov (United States)

    Massey, Steven E

    2015-04-24

    The standard genetic code (SGC) is central to molecular biology and its origin and evolution is a fundamental problem in evolutionary biology, the elucidation of which promises to reveal much about the origins of life. In addition, we propose that study of its origin can also reveal some fundamental and generalizable insights into mechanisms of molecular evolution, utilizing concepts from complexity theory. The first is that beneficial traits may arise by non-adaptive processes, via a process of "neutral emergence". The structure of the SGC is optimized for the property of error minimization, which reduces the deleterious impact of point mutations. Via simulation, it can be shown that genetic codes with error minimization superior to the SGC can emerge in a neutral fashion simply by a process of genetic code expansion via tRNA and aminoacyl-tRNA synthetase duplication, whereby similar amino acids are added to codons related to that of the parent amino acid. This process of neutral emergence has implications beyond that of the genetic code, as it suggests that not all beneficial traits have arisen by the direct action of natural selection; we term these "pseudaptations", and discuss a range of potential examples. Secondly, consideration of genetic code deviations (codon reassignments) reveals that these are mostly associated with a reduction in proteome size. This code malleability implies the existence of a proteomic constraint on the genetic code, proportional to the size of the proteome (P), and that its reduction in size leads to an "unfreezing" of the codon - amino acid mapping that defines the genetic code, consistent with Crick's Frozen Accident theory. The concept of a proteomic constraint may be extended to propose a general informational constraint on genetic fidelity, which may be used to explain variously, differences in mutation rates in genomes with differing proteome sizes, differences in DNA repair capacity and genome GC content between organisms, a

  13. Genetic Code Evolution Reveals the Neutral Emergence of Mutational Robustness, and Information as an Evolutionary Constraint

    Directory of Open Access Journals (Sweden)

    Steven E. Massey

    2015-04-01

    Full Text Available The standard genetic code (SGC is central to molecular biology and its origin and evolution is a fundamental problem in evolutionary biology, the elucidation of which promises to reveal much about the origins of life. In addition, we propose that study of its origin can also reveal some fundamental and generalizable insights into mechanisms of molecular evolution, utilizing concepts from complexity theory. The first is that beneficial traits may arise by non-adaptive processes, via a process of “neutral emergence”. The structure of the SGC is optimized for the property of error minimization, which reduces the deleterious impact of point mutations. Via simulation, it can be shown that genetic codes with error minimization superior to the SGC can emerge in a neutral fashion simply by a process of genetic code expansion via tRNA and aminoacyl-tRNA synthetase duplication, whereby similar amino acids are added to codons related to that of the parent amino acid. This process of neutral emergence has implications beyond that of the genetic code, as it suggests that not all beneficial traits have arisen by the direct action of natural selection; we term these “pseudaptations”, and discuss a range of potential examples. Secondly, consideration of genetic code deviations (codon reassignments reveals that these are mostly associated with a reduction in proteome size. This code malleability implies the existence of a proteomic constraint on the genetic code, proportional to the size of the proteome (P, and that its reduction in size leads to an “unfreezing” of the codon – amino acid mapping that defines the genetic code, consistent with Crick’s Frozen Accident theory. The concept of a proteomic constraint may be extended to propose a general informational constraint on genetic fidelity, which may be used to explain variously, differences in mutation rates in genomes with differing proteome sizes, differences in DNA repair capacity and genome

  14. RNA-DNA sequence differences spell genetic code ambiguities

    DEFF Research Database (Denmark)

    Bentin, Thomas; Nielsen, Michael L

    2013-01-01

    A recent paper in Science by Li et al. 2011(1) reports widespread sequence differences in the human transcriptome between RNAs and their encoding genes termed RNA-DNA differences (RDDs). The findings could add a new layer of complexity to gene expression but the study has been criticized. ...

  15. Investigations with methanobacteria and with evolution of the genetic code

    Science.gov (United States)

    Jukes, T. H.

    1986-01-01

    Mycoplasma capricolum was found by Osawa et al. to use UGA as the code of tryptophan and to contain 75% A + T in its DNA. This change could have been from evolutionary pressure to replace C + G by A + T. Numerous studies have been reported of evolution of proteins as measured by amino acid replacements that are observed when homologus proteins, such as hemoglobins from various vertebrates, are compared. These replacements result from nucleotide substitutions in amino acid codons in the corresponding genes. Simultaneously, silent nucleotide substitutions take place that can be studied when sequences of the genes are compared. These silent evolutionary changes take place mostly in third positions of codons. Two types of nucleotide substitutions are recognized: pyrimidine-pyrimidine and purine-purine interchanges (transitions) and pyriidine-purine interchanges (transversions). Silent transitions are favored when a corresponding transversion would produce an amino acid replacement. Conversely, silent transversions are favored by probability when transitions and transversions will both be silent. Extensive examples of these situations have been found in protein genes, and it is evident that transversions in silent positions predominate in family boxes in most of the examples studied. In associated research a streptomycete from cow manure was found to produce an extracellular enzyme capable of lysing the pseudomurein-contining methanogen Methanobacterium formicicum.

  16. Genetics of human male infertility.

    Science.gov (United States)

    Poongothai, J; Gopenath, T S; Manonayaki, S

    2009-04-01

    Infertility is defined as a failure to conceive in a couple trying to reproduce for a period of two years without conception. Approximately 15 percent of couples are infertile, and among these couples, male factor infertility accounts for approximately 50 percent of causes. Male infertility is a multifactorial syndrome encompassing a wide variety of disorders. In more than half of infertile men, the cause of their infertility is unknown (idiopathic) and could be congenital or acquired. Infertility in men can be diagnosed initially by semen analysis. Seminograms of infertile men may reveal many abnormal conditions, which include azoospermia, oligozoospermia, teratozoospermia, asthenozoospermia, necrospermia and pyospermia. The current estimate is that about 30 percent of men seeking help at the infertility clinic are found to have oligozoospermia or azoospermia of unknown aetiology. Therefore, there is a need to find the cause of infertility. The causes are known in less than half of these cases, out of which genetic or inherited disease and specific abnormalities in the Y chromosome are major factors. About 10-20 percent of males presenting without sperm in the ejaculate carry a deletion of the Y chromosome. This deleted region includes the Azoospermia Factor (AZF) locus, located in the Yq11, which is divided into four recurrently deleted non-overlapping subregions designated as AZFa, AZFb, AZFc and AZFd. Each of these regions may be associated with a particular testicular histology, and several candidate genes have been found within these regions. The Deleted in Azoospermia (DAZ) gene family is reported to be the most frequently deleted AZF candidate gene and is located in the AZFc region. Recently, a partial, novel Y chromosome 1.6-Mb deletion, designated "gr/gr" deletion, has been described specifically in infertile men with varying degrees of spermatogenic failure. The DAZ gene has an autosomal homologue, DAZL (DAZ-Like), on the short arm of the chromosome 3 (3

  17. Resequencing of 200 human exomes identifies an excess of low-frequency non-synonymous coding variants

    DEFF Research Database (Denmark)

    Li, Yingrui; Vinckenbosch, Nicolas; Tian, Geng

    2010-01-01

    Targeted capture combined with massively parallel exome sequencing is a promising approach to identify genetic variants implicated in human traits. We report exome sequencing of 200 individuals from Denmark with targeted capture of 18,654 coding genes and sequence coverage of each individual exome...

  18. Human cancer long non-coding RNA transcriptomes.

    Directory of Open Access Journals (Sweden)

    Ewan A Gibb

    Full Text Available Once thought to be a part of the 'dark matter' of the genome, long non-coding RNAs (lncRNAs are emerging as an integral functional component of the mammalian transcriptome. LncRNAs are a novel class of mRNA-like transcripts which, despite no known protein-coding potential, demonstrate a wide range of structural and functional roles in cellular biology. However, the magnitude of the contribution of lncRNA expression to normal human tissues and cancers has not been investigated in a comprehensive manner. In this study, we compiled 272 human serial analysis of gene expression (SAGE libraries to delineate lncRNA transcription patterns across a broad spectrum of normal human tissues and cancers. Using a novel lncRNA discovery pipeline we parsed over 24 million SAGE tags and report lncRNA expression profiles across a panel of 26 different normal human tissues and 19 human cancers. Our findings show extensive, tissue-specific lncRNA expression in normal tissues and highly aberrant lncRNA expression in human cancers. Here, we present a first generation atlas for lncRNA profiling in cancer.

  19. Long Non-Coding RNAs and Complex Human Diseases

    Directory of Open Access Journals (Sweden)

    Changning Liu

    2013-09-01

    Full Text Available Long non-coding RNAs (lncRNAs are a heterogeneous class of RNAs that are generally defined as non-protein-coding transcripts longer than 200 nucleotides. Recently, an increasing number of studies have shown that lncRNAs can be involved in various critical biological processes, such as chromatin remodeling, gene transcription, and protein transport and trafficking. Moreover, lncRNAs are dysregulated in a number of complex human diseases, including coronary artery diseases, autoimmune diseases, neurological disorders, and various cancers, which indicates their important roles in these diseases. Here, we reviewed the current understanding of lncRNAs, including their definition and subclassification, regulatory functions, and potential roles in different types of complex human diseases.

  20. GENETIC ALGORITHM FOR DECODING LINEAR CODES OVER AWGN AND FADING CHANNELS

    Directory of Open Access Journals (Sweden)

    H. BERBIA

    2011-08-01

    Full Text Available This paper introduces a decoder for binary linear codes based on Genetic Algorithm (GA over the Gaussian and Rayleigh flat fading channel. The performances and compututional complexity of our decoder applied to BCH and convolutional codes are good compared to Chase-2 and Viterbi algorithm respectively. It show that our algorithm is less complex for linear block codes of large block length; furthermore it's performances can be improved by tuning the decoder's parameters, in particular the number of individuals by population and the number of generations

  1. Finite population analysis of the effect of horizontal gene transfer on the origin of an universal and optimal genetic code

    Science.gov (United States)

    Aggarwal, Neha; Vishwa Bandhu, Ashutosh; Sengupta, Supratim

    2016-06-01

    The origin of a universal and optimal genetic code remains a compelling mystery in molecular biology and marks an essential step in the origin of DNA and protein based life. We examine a collective evolution model of genetic code origin that allows for unconstrained horizontal transfer of genetic elements within a finite population of sequences each of which is associated with a genetic code selected from a pool of primordial codes. We find that when horizontal transfer of genetic elements is incorporated in this more realistic model of code-sequence coevolution in a finite population, it can increase the likelihood of emergence of a more optimal code eventually leading to its universality through fixation in the population. The establishment of such an optimal code depends on the probability of HGT events. Only when the probability of HGT events is above a critical threshold, we find that the ten amino acid code having a structure that is most consistent with the standard genetic code (SGC) often gets fixed in the population with the highest probability. We examine how the threshold is determined by factors like the population size, length of the sequences and selection coefficient. Our simulation results reveal the conditions under which sharing of coding innovations through horizontal transfer of genetic elements may have facilitated the emergence of a universal code having a structure similar to that of the SGC.

  2. Finite population analysis of the effect of horizontal gene transfer on the origin of an universal and optimal genetic code.

    Science.gov (United States)

    Aggarwal, Neha; Bandhu, Ashutosh Vishwa; Sengupta, Supratim

    2016-05-27

    The origin of a universal and optimal genetic code remains a compelling mystery in molecular biology and marks an essential step in the origin of DNA and protein based life. We examine a collective evolution model of genetic code origin that allows for unconstrained horizontal transfer of genetic elements within a finite population of sequences each of which is associated with a genetic code selected from a pool of primordial codes. We find that when horizontal transfer of genetic elements is incorporated in this more realistic model of code-sequence coevolution in a finite population, it can increase the likelihood of emergence of a more optimal code eventually leading to its universality through fixation in the population. The establishment of such an optimal code depends on the probability of HGT events. Only when the probability of HGT events is above a critical threshold, we find that the ten amino acid code having a structure that is most consistent with the standard genetic code (SGC) often gets fixed in the population with the highest probability. We examine how the threshold is determined by factors like the population size, length of the sequences and selection coefficient. Our simulation results reveal the conditions under which sharing of coding innovations through horizontal transfer of genetic elements may have facilitated the emergence of a universal code having a structure similar to that of the SGC.

  3. Identification of proteins binding coding and non-coding human RNAs using protein microarrays

    Directory of Open Access Journals (Sweden)

    Siprashvili Zurab

    2012-11-01

    Full Text Available Abstract Background The regulation and function of mammalian RNAs has been increasingly appreciated to operate via RNA-protein interactions. With the recent discovery of thousands of novel human RNA molecules by high-throughput RNA sequencing, efficient methods to uncover RNA-protein interactions are urgently required. Existing methods to study proteins associated with a given RNA are laborious and require substantial amounts of cell-derived starting material. To overcome these limitations, we have developed a rapid and large-scale approach to characterize binding of in vitro transcribed labeled RNA to ~9,400 human recombinant proteins spotted on protein microarrays. Results We have optimized methodology to probe human protein microarrays with full-length RNA molecules and have identified 137 RNA-protein interactions specific for 10 coding and non-coding RNAs. Those proteins showed strong enrichment for common human RNA binding domains such as RRM, RBD, as well as K homology and CCCH type zinc finger motifs. Previously unknown RNA-protein interactions were discovered using this technique, and these interactions were biochemically verified between TP53 mRNA and Staufen1 protein as well as between HRAS mRNA and CNBP protein. Functional characterization of the interaction between Staufen 1 protein and TP53 mRNA revealed a novel role for Staufen 1 in preserving TP53 RNA stability. Conclusions Our approach demonstrates a scalable methodology, allowing rapid and efficient identification of novel human RNA-protein interactions using RNA hybridization to human protein microarrays. Biochemical validation of newly identified interactions between TP53-Stau1 and HRAS-CNBP using reciprocal pull-down experiments, both in vitro and in vivo, demonstrates the utility of this approach to study uncharacterized RNA-protein interactions.

  4. Frozen Accident Pushing 50: Stereochemistry, Expansion, and Chance in the Evolution of the Genetic Code.

    Science.gov (United States)

    Koonin, Eugene V

    2017-05-23

    Nearly 50 years ago, Francis Crick propounded the frozen accident scenario for the evolution of the genetic code along with the hypothesis that the early translation system consisted primarily of RNA. Under the frozen accident perspective, the code is universal among modern life forms because any change in codon assignment would be highly deleterious. The frozen accident can be considered the default theory of code evolution because it does not imply any specific interactions between amino acids and the cognate codons or anticodons, or any particular properties of the code. The subsequent 49 years of code studies have elucidated notable features of the standard code, such as high robustness to errors, but failed to develop a compelling explanation for codon assignments. In particular, stereochemical affinity between amino acids and the cognate codons or anticodons does not seem to account for the origin and evolution of the code. Here, I expand Crick's hypothesis on RNA-only translation system by presenting evidence that this early translation already attained high fidelity that allowed protein evolution. I outline an experimentally testable scenario for the evolution of the code that combines a distinct version of the stereochemical hypothesis, in which amino acids are recognized via unique sites in the tertiary structure of proto-tRNAs, rather than by anticodons, expansion of the code via proto-tRNA duplication, and the frozen accident.

  5. Open Genetic Code: on open source in the life sciences.

    Science.gov (United States)

    Deibel, Eric

    2014-01-01

    The introduction of open source in the life sciences is increasingly being suggested as an alternative to patenting. This is an alternative, however, that takes its shape at the intersection of the life sciences and informatics. Numerous examples can be identified wherein open source in the life sciences refers to access, sharing and collaboration as informatic practices. This includes open source as an experimental model and as a more sophisticated approach of genetic engineering. The first section discusses the greater flexibly in regard of patenting and the relationship to the introduction of open source in the life sciences. The main argument is that the ownership of knowledge in the life sciences should be reconsidered in the context of the centrality of DNA in informatic formats. This is illustrated by discussing a range of examples of open source models. The second part focuses on open source in synthetic biology as exemplary for the re-materialization of information into food, energy, medicine and so forth. The paper ends by raising the question whether another kind of alternative might be possible: one that looks at open source as a model for an alternative to the commodification of life that is understood as an attempt to comprehensively remove the restrictions from the usage of DNA in any of its formats.

  6. Two proofreading steps amplify the accuracy of genetic code translation.

    Science.gov (United States)

    Ieong, Ka-Weng; Uzun, Ülkü; Selmer, Maria; Ehrenberg, Måns

    2016-11-29

    Aminoacyl-tRNAs (aa-tRNAs) are selected by the messenger RNA programmed ribosome in ternary complex with elongation factor Tu (EF-Tu) and GTP and then, again, in a proofreading step after GTP hydrolysis on EF-Tu. We use tRNA mutants with different affinities for EF-Tu to demonstrate that proofreading of aa-tRNAs occurs in two consecutive steps. First, aa-tRNAs in ternary complex with EF-Tu·GDP are selected in a step where the accuracy increases linearly with increasing aa-tRNA affinity to EF-Tu. Then, following dissociation of EF-Tu·GDP from the ribosome, the accuracy is further increased in a second and apparently EF-Tu-independent step. Our findings identify the molecular basis of proofreading in bacteria, highlight the pivotal role of EF-Tu for fast and accurate protein synthesis, and illustrate the importance of multistep substrate selection in intracellular processing of genetic information.

  7. File Compression and Expansion of the Genetic Code by the use of the Yin/Yang Directions to find its Sphered Cube.

    Science.gov (United States)

    Castro-Chavez, Fernando

    2014-07-01

    The objective of this article is to demonstrate that the genetic code can be studied and represented in a 3-D Sphered Cube for bioinformatics and for education by using the graphical help of the ancient "Book of Changes" or I Ching for the comparison, pair by pair, of the three basic characteristics of nucleotides: H-bonds, molecular structure, and their tautomerism. The source of natural biodiversity is the high plasticity of the genetic code, analyzable with a reverse engineering of its 2-D and 3-D representations (here illustrated), but also through the classical 64-hexagrams of the ancient I Ching, as if they were the 64-codons or words of the genetic code. In this article, the four elements of the Yin/Yang were found by correlating the 3×2=6 sets of Cartesian comparisons of the mentioned properties of nucleic acids, to the directionality of their resulting blocks of codons grouped according to their resulting amino acids and/or functions, integrating a 384-codon Sphered Cube whose function is illustrated by comparing six brain peptides and a promoter of osteoblasts from Humans versus Neanderthal, as well as to Negadi's work on the importance of the number 384 within the genetic code. Starting with the codon/anticodon correlation of Nirenberg, published in full here for the first time, and by studying the genetic code and its 3-D display, the buffers of reiteration within codons codifying for the same amino acid, displayed the two long (binary number one) and older Yin/Yang arrows that travel in opposite directions, mimicking the parental DNA strands, while annealing to the two younger and broken (binary number zero) Yin/Yang arrows, mimicking the new DNA strands; the graphic analysis of the of the genetic code and its plasticity was helpful to compare compatible sequences (human compatible to human versus neanderthal compatible to neanderthal), while further exploring the wondrous biodiversity of nature for educational purposes.

  8. Human Genetic Disorders of Axon Guidance

    OpenAIRE

    Engle, Elizabeth C

    2010-01-01

    This article reviews symptoms and signs of aberrant axon connectivity in humans, and summarizes major human genetic disorders that result, or have been proposed to result, from defective axon guidance. These include corpus callosum agenesis, L1 syndrome, Joubert syndrome and related disorders, horizontal gaze palsy with progressive scoliosis, Kallmann syndrome, albinism, congenital fibrosis of the extraocular muscles type 1, Duane retraction syndrome, and pontine tegmental cap dysplasia. Gene...

  9. Human genetics: international projects and personalized medicine.

    Science.gov (United States)

    Apellaniz-Ruiz, Maria; Gallego, Cristina; Ruiz-Pinto, Sara; Carracedo, Angel; Rodríguez-Antona, Cristina

    2016-03-01

    In this article, we present the progress driven by the recent technological advances and new revolutionary massive sequencing technologies in the field of human genetics. We discuss this knowledge in relation with drug response prediction, from the germline genetic variation compiled in the 1000 Genomes Project or in the Genotype-Tissue Expression project, to the phenome-genome archives, the international cancer projects, such as The Cancer Genome Atlas or the International Cancer Genome Consortium, and the epigenetic variation and its influence in gene expression, including the regulation of drug metabolism. This review is based on the lectures presented by the speakers of the Symposium "Human Genetics: International Projects & New Technologies" from the VII Conference of the Spanish Pharmacogenetics and Pharmacogenomics Society, held on the 20th and 21st of April 2015.

  10. An improved Genetic Algorithm of Bi-level Coding for Flexible Job Shop Scheduling Problems

    Directory of Open Access Journals (Sweden)

    Ye Li

    2014-07-01

    Full Text Available The current study presents an improved genetic algorithm(GA for the flexible job shop scheduling problem (FJSP. The coding is divided into working sequence level and machine level and two effective crossover operators and mutation operators are designed for the generation and reduce the disruptive effects of genetic operators. The algorithm is tested on instances of 10 working sequences and 10 machines. Computational results show that the proposed GA was successfully and efficiently applied to the FJSP. The results were compared with other approaches, such as traditional GA and GA with neural network. Compared to traditional genetic algorithm, the proposed approach yields significant improvement in solution quality.

  11. On models of the genetic code generated by binary dichotomic algorithms.

    Science.gov (United States)

    Gumbel, Markus; Fimmel, Elena; Danielli, Alberto; Strüngmann, Lutz

    2015-02-01

    In this paper we introduce the concept of a BDA-generated model of the genetic code which is based on binary dichotomic algorithms (BDAs). A BDA-generated model is based on binary dichotomic algorithms (BDAs). Such a BDA partitions the set of 64 codons into two disjoint classes of size 32 each and provides a generalization of known partitions like the Rumer dichotomy. We investigate what partitions can be generated when a set of different BDAs is applied sequentially to the set of codons. The search revealed that these models are able to generate code tables with very different numbers of classes ranging from 2 to 64. We have analyzed whether there are models that map the codons to their amino acids. A perfect matching is not possible. However, we present models that describe the standard genetic code with only few errors. There are also models that map all 64 codons uniquely to 64 classes showing that BDAs can be used to identify codons precisely. This could serve as a basis for further mathematical analysis using coding theory, for example. The hypothesis that BDAs might reflect a molecular mechanism taking place in the decoding center of the ribosome is discussed. The scan demonstrated that binary dichotomic partitions are able to model different aspects of the genetic code very well. The search was performed with our tool Beady-A. This software is freely available at http://mi.informatik.hs-mannheim.de/beady-a. It requires a JVM version 6 or higher.

  12. A global reference for human genetic variation

    DEFF Research Database (Denmark)

    Auton, Adam; Abecasis, Goncalo R.; M. Altshuler, David;

    2015-01-01

    The 1000 Genomes Project set out to provide a comprehensive description of common human genetic variation by applying whole-genome sequencing to a diverse set of individuals from multiple populations. Here we report completion of the project, having reconstructed the genomes of 2,504 individuals ...

  13. Stress, Neural Systems, and Genetic Code: An Interview with Neuroscientist Judy Cameron. Perspectives

    Science.gov (United States)

    National Scientific Council on the Developing Child, 2006

    2006-01-01

    Research indicates some early life stresses can have a profound impact, resulting in changes in brain function and behavior, and even differences in the ways some genes express their particular genetic code signature. At various times during early development, different neural systems appear to have an increased sensitivity to stress and can…

  14. Unassigned Codons, Nonsense Suppression, and Anticodon Modifications in the Evolution of the Genetic Code

    NARCIS (Netherlands)

    P.T.S. van der Gulik (Peter); W.D. Hoff (Wouter)

    2011-01-01

    htmlabstractThe origin of the genetic code is a central open problem regarding the early evolution of life. Here, we consider two undeveloped but important aspects of possible scenarios for the evolutionary pathway of the translation machinery: the role of unassigned codons in early stages

  15. Stress, Neural Systems, and Genetic Code: An Interview with Neuroscientist Judy Cameron. Perspectives

    Science.gov (United States)

    National Scientific Council on the Developing Child, 2006

    2006-01-01

    Research indicates some early life stresses can have a profound impact, resulting in changes in brain function and behavior, and even differences in the ways some genes express their particular genetic code signature. At various times during early development, different neural systems appear to have an increased sensitivity to stress and can…

  16. Real-Coded Quantum-Inspired Genetic Algorithm-Based BP Neural Network Algorithm

    Directory of Open Access Journals (Sweden)

    Jianyong Liu

    2015-01-01

    Full Text Available The method that the real-coded quantum-inspired genetic algorithm (RQGA used to optimize the weights and threshold of BP neural network is proposed to overcome the defect that the gradient descent method makes the algorithm easily fall into local optimal value in the learning process. Quantum genetic algorithm (QGA is with good directional global optimization ability, but the conventional QGA is based on binary coding; the speed of calculation is reduced by the coding and decoding processes. So, RQGA is introduced to explore the search space, and the improved varied learning rate is adopted to train the BP neural network. Simulation test shows that the proposed algorithm is effective to rapidly converge to the solution conformed to constraint conditions.

  17. The non-power model of the genetic code: a paradigm for interpreting genomic information.

    Science.gov (United States)

    Gonzalez, Diego Luis; Giannerini, Simone; Rosa, Rodolfo

    2016-03-13

    In this article, we present a mathematical framework based on redundant (non-power) representations of integer numbers as a paradigm for the interpretation of genomic information. The core of the approach relies on modelling the degeneracy of the genetic code. The model allows one to explain many features and symmetries of the genetic code and to uncover hidden symmetries. Also, it provides us with new tools for the analysis of genomic sequences. We review briefly three main areas: (i) the Euplotid nuclear code, (ii) the vertebrate mitochondrial code, and (iii) the main coding/decoding strategies used in the three domains of life. In every case, we show how the non-power model is a natural unified framework for describing degeneracy and deriving sound biological hypotheses on protein coding. The approach is rooted on number theory and group theory; nevertheless, we have kept the technical level to a minimum by focusing on key concepts and on the biological implications. © 2016 The Author(s).

  18. Overview of genetic analysis of human opioid receptors.

    Science.gov (United States)

    Spampinato, Santi M

    2015-01-01

    The human μ-opioid receptor gene (OPRM1), due to its genetic and structural variation, has been a target of interest in several pharmacogenetic studies. The μ-opioid receptor (MOR), encoded by OPRM1, contributes to regulate the analgesic response to pain and also controls the rewarding effects of many drugs of abuse, including opioids, nicotine, and alcohol. Genetic polymorphisms of opioid receptors are candidates for the variability of clinical opioid effects. The non-synonymous polymorphism A118G of the OPRM1 has been repeatedly associated with the efficacy of opioid treatments for pain and various types of dependence. Genetic analysis of human opioid receptors has evidenced the presence of numerous polymorphisms either in exonic or in intronic sequences as well as the presence of synonymous coding variants that may have important effects on transcription, mRNA stability, and splicing, thus affecting gene function despite not directly disrupting any specific residue. Genotyping of opioid receptors is still in its infancy and a relevant progress in this field can be achieved by using advanced gene sequencing techniques described in this review that allow the researchers to obtain vast quantities of data on human genomes and transcriptomes in a brief period of time and with affordable costs.

  19. Genetic Manipulation of Human Embryonic Stem Cells.

    Science.gov (United States)

    Eiges, Rachel

    2016-01-01

    One of the great advantages of embryonic stem (ES) cells over other cell types is their accessibility to genetic manipulation. They can easily undergo genetic modifications while remaining pluripotent, and can be selectively propagated, allowing the clonal expansion of genetically altered cells in culture. Since the first isolation of ES cells in mice, many effective techniques have been developed for gene delivery and manipulation of ES cells. These include transfection, electroporation, and infection protocols, as well as different approaches for inserting, deleting, or changing the expression of genes. These methods proved to be extremely useful in mouse ES cells, for monitoring and directing differentiation, discovering unknown genes, and studying their function, and are now being extensively implemented in human ES cells (HESCs). This chapter describes the different approaches and methodologies that have been applied for the genetic manipulation of HESCs and their applications. Detailed protocols for generating clones of genetically modified HESCs by transfection, electroporation, and infection will be described, with special emphasis on the important technical details that are required for this purpose. All protocols are equally effective in human-induced pluripotent stem (iPS) cells.

  20. Human Genetic Disorders of Axon Guidance

    Science.gov (United States)

    Engle, Elizabeth C.

    2010-01-01

    This article reviews symptoms and signs of aberrant axon connectivity in humans, and summarizes major human genetic disorders that result, or have been proposed to result, from defective axon guidance. These include corpus callosum agenesis, L1 syndrome, Joubert syndrome and related disorders, horizontal gaze palsy with progressive scoliosis, Kallmann syndrome, albinism, congenital fibrosis of the extraocular muscles type 1, Duane retraction syndrome, and pontine tegmental cap dysplasia. Genes mutated in these disorders can encode axon growth cone ligands and receptors, downstream signaling molecules, and axon transport motors, as well as proteins without currently recognized roles in axon guidance. Advances in neuroimaging and genetic techniques have the potential to rapidly expand this field, and it is feasible that axon guidance disorders will soon be recognized as a new and significant category of human neurodevelopmental disorders. PMID:20300212

  1. Molecular genetics of human lactase deficiencies.

    Science.gov (United States)

    Järvelä, Irma; Torniainen, Suvi; Kolho, Kaija-Leena

    2009-01-01

    Lactase non-persistence (adult-type hypolactasia) is present in more than half of the human population and is caused by the down-regulation of lactase enzyme activity during childhood. Congenital lactase deficiency (CLD) is a rare severe gastrointestinal disorder of new-borns enriched in the Finnish population. Both lactase deficiencies are autosomal recessive traits and characterized by diminished expression of lactase activity in the intestine. Genetic variants underlying both forms have been identified. Here we review the current understanding of the molecular defects of human lactase deficiencies and their phenotype-genotype correlation, the implications on clinical practice, and the understanding of their function and role in human evolution.

  2. Genetic variation in the non-coding genome : Involvement of micro-RNAs and long non-coding RNAs in disease

    NARCIS (Netherlands)

    Hrdlickova, Barbara; de Almeida, Rodrigo Coutinho; Borek, Zuzanna; Withoff, Sebo

    2014-01-01

    It has been found that the majority of disease-associated genetic variants identified by genome-wide association studies are located outside of protein-coding regions, where they seem to affect regions that control transcription (promoters, enhancers) and non-coding RNAs that also can influence gene

  3. Genetic Heterogeneity in Algerian Human Populations.

    Science.gov (United States)

    Bekada, Asmahan; Arauna, Lara R; Deba, Tahria; Calafell, Francesc; Benhamamouch, Soraya; Comas, David

    2015-01-01

    The demographic history of human populations in North Africa has been characterized by complex processes of admixture and isolation that have modeled its current gene pool. Diverse genetic ancestral components with different origins (autochthonous, European, Middle Eastern, and sub-Saharan) and genetic heterogeneity in the region have been described. In this complex genetic landscape, Algeria, the largest country in Africa, has been poorly covered, with most of the studies using a single Algerian sample. In order to evaluate the genetic heterogeneity of Algeria, Y-chromosome, mtDNA and autosomal genome-wide makers have been analyzed in several Berber- and Arab-speaking groups. Our results show that the genetic heterogeneity found in Algeria is not correlated with geography or linguistics, challenging the idea of Berber groups being genetically isolated and Arab groups open to gene flow. In addition, we have found that external sources of gene flow into North Africa have been carried more often by females than males, while the North African autochthonous component is more frequent in paternally transmitted genome regions. Our results highlight the different demographic history revealed by different markers and urge to be cautious when deriving general conclusions from partial genomic information or from single samples as representatives of the total population of a region.

  4. Human Genetics of Diabetic Retinopathy: Current Perspectives

    Directory of Open Access Journals (Sweden)

    Daniel P. K. Ng

    2010-01-01

    Full Text Available Diabetic retinopathy (DR is a most severe microvascular complication which, if left unchecked, can be sight-threatening. With the global prevalence of diabetes being relentlessly projected to rise to 438 million subjects by 2030, DR will undoubtedly pose a major public health concern. Efforts to unravel the human genetics of DR have been undertaken using the candidate gene and linkage approaches, while GWAS efforts are still lacking. Aside from evidence for a few genes including aldose reductase and vascular endothelial growth factor, the genetics of DR remain poorly elucidated. Nevertheless, the promise of impactful scientific discoveries may be realized if concerted and collaborative efforts are mounted to identify the genes for DR. Harnessing new genetic technologies and resources such as the upcoming 1000 Genomes Project will help advance this field of research, and potentially lead to a rich harvest of insights into the biological mechanisms underlying this debilitating complication.

  5. A global reference for human genetic variation

    DEFF Research Database (Denmark)

    Auton, Adam; Abecasis, Goncalo R.; M. Altshuler, David

    2015-01-01

    The 1000 Genomes Project set out to provide a comprehensive description of common human genetic variation by applying whole-genome sequencing to a diverse set of individuals from multiple populations. Here we report completion of the project, having reconstructed the genomes of 2,504 individuals...... from 26 populations using a combination of low-coverage whole-genome sequencing, deep exome sequencing, and dense microarray genotyping. We characterized a broad spectrum of genetic variation, in total over 88 million variants (84.7 million single nucleotide polymorphisms (SNPs), 3.6 million short...... insertions/deletions (indels), and 60,000 structural variants), all phased onto high-quality haplotypes. This resource includes >99% of SNP variants with a frequency of >1% for a variety of ancestries. We describe the distribution of genetic variation across the global sample, and discuss the implications...

  6. PrimeIndel: four-prime-number genetic code for indel decryption and sequence read alignment.

    Science.gov (United States)

    Lam, Ching-Wan

    2014-09-25

    To decrypt a doubly heterozygous sequence (DHS) in order to define the indel mutation for mutation reporting, an algorithm recursively searching the overlapped nucleotide using an offset of nucleotide positions can decrypt the indel without using a reference sequence. However, as genetic code is letter-based, special computer programs are required to run the decryption algorithm. The previous text-based algorithm was converted to a number-based algorithm by expressing DNA sequence from a 4-letter genetic code to a 4-prime-number genetic code, i.e., converting A, C, G, T to 2, 3, 5, and 7. This algorithm based on prime-number genetic code is called PrimeIndel and is executable by spreadsheet. Using prime number coded DNA sequence, the overlapped nucleotide between any 2 positions of the DHS is represented by the greatest common divisor (GCD) of the multiplication product of 2 prime numbers. This algorithm can also be used for aligning multiple overlapping sequence reads by in-silico DHS formation. The indel size of the in-silico formed DHS indicates the positions in the paired sequences for correct alignment. DHSs were successfully decrypted by the prime number-based algorithm and sequence reads were aligned correctly. DNA sequence expressed in prime numbers can be used for the decryption of DHS and the alignment of sequence reads using a well-known mathematical function GCD of a spreadsheet program. PrimeIndel is a useful tool for mutation reporting in clinical laboratories. The software is downloadable from http://www.patho.hku.hk/staff/list/cwlam.htm. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Evidence from glycine transfer RNA of a frozen accident at the dawn of the genetic code

    Directory of Open Access Journals (Sweden)

    Tate Warren P

    2008-12-01

    Full Text Available Abstract Background Transfer RNA (tRNA is the means by which the cell translates DNA sequence into protein according to the rules of the genetic code. A credible proposition is that tRNA was formed from the duplication of an RNA hairpin half the length of the contemporary tRNA molecule, with the point at which the hairpins were joined marked by the canonical intron insertion position found today within tRNA genes. If these hairpins possessed a 3'-CCA terminus with different combinations of stem nucleotides (the ancestral operational RNA code, specific aminoacylation and perhaps participation in some form of noncoded protein synthesis might have occurred. However, the identity of the first tRNA and the initial steps in the origin of the genetic code remain elusive. Results Here we show evidence that glycine tRNA was the first tRNA, as revealed by a vestigial imprint in the anticodon loop sequences of contemporary descendents. This provides a plausible mechanism for the missing first step in the origin of the genetic code. In 448 of 466 glycine tRNA gene sequences from bacteria, archaea and eukaryote cytoplasm analyzed, CCA occurs immediately upstream of the canonical intron insertion position, suggesting the first anticodon (NCC for glycine has been captured from the 3'-terminal CCA of one of the interacting hairpins as a result of an ancestral ligation. Conclusion That this imprint (including the second and third nucleotides of the glycine tRNA anticodon has been retained through billions of years of evolution suggests Crick's 'frozen accident' hypothesis has validity for at least this very first step at the dawn of the genetic code. Reviewers This article was reviewed by Dr Eugene V. Koonin, Dr Rob Knight and Dr David H Ardell.

  8. On origin of genetic code and tRNA before translation

    Directory of Open Access Journals (Sweden)

    Szathmáry Eörs

    2011-02-01

    Full Text Available Abstract Background Synthesis of proteins is based on the genetic code - a nearly universal assignment of codons to amino acids (aas. A major challenge to the understanding of the origins of this assignment is the archetypal "key-lock vs. frozen accident" dilemma. Here we re-examine this dilemma in light of 1 the fundamental veto on "foresight evolution", 2 modular structures of tRNAs and aminoacyl-tRNA synthetases, and 3 the updated library of aa-binding sites in RNA aptamers successfully selected in vitro for eight amino acids. Results The aa-binding sites of arginine, isoleucine and tyrosine contain both their cognate triplets, anticodons and codons. We have noticed that these cases might be associated with palindrome-dinucleotides. For example, one-base shift to the left brings arginine codons CGN, with CG at 1-2 positions, to the respective anticodons NCG, with CG at 2-3 positions. Formally, the concomitant presence of codons and anticodons is also expected in the reverse situation, with codons containing palindrome-dinucleotides at their 2-3 positions, and anticodons exhibiting them at 1-2 positions. A closer analysis reveals that, surprisingly, RNA binding sites for Arg, Ile and Tyr "prefer" (exactly as in the actual genetic code the anticodon(2-3/codon(1-2 tetramers to their anticodon(1-2/codon(2-3 counterparts, despite the seemingly perfect symmetry of the latter. However, since in vitro selection of aa-specific RNA aptamers apparently had nothing to do with translation, this striking preference provides a new strong support to the notion of the genetic code emerging before translation, in response to catalytic (and possibly other needs of ancient RNA life. Consistently with the pre-translation origin of the code, we propose here a new model of tRNA origin by the gradual, Fibonacci process-like, elongation of a tRNA molecule from a primordial coding triplet and 5'DCCA3' quadruplet (D is a base-determinator to the eventual 76 base

  9. The central role of tRNA in genetic code expansion.

    Science.gov (United States)

    Reynolds, Noah M; Vargas-Rodriguez, Oscar; Söll, Dieter; Crnković, Ana

    2017-03-18

    The development of orthogonal translation systems (OTSs) for genetic code expansion (GCE) has allowed for the incorporation of a diverse array of non-canonical amino acids (ncAA) into proteins. Transfer RNA, the central molecule in the translation of the genetic message into proteins, plays a significant role in the efficiency of ncAA incorporation. Here we review the biochemical basis of OTSs for genetic code expansion. We focus on the role of tRNA and discuss strategies used to engineer tRNA for the improvement of ncAA incorporation into proteins. The engineering of orthogonal tRNAs for GCE has significantly improved the incorporation of ncAAs. However, there are numerous unintended consequences of orthogonal tRNA engineering that cannot be predicted ab initio. Genetic code expansion has allowed for the incorporation of a great diversity of ncAAs and novel chemistries into proteins, making significant contributions to our understanding of biological molecules and interactions. This article is part of a Special Issue entitled "Biochemistry of Synthetic Biology - Recent Developments" Guest Editor: Dr. Ilka Heinemann and Dr. Patrick O'Donoghue. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Human Genetic Engineering: A Survey of Student Value Stances

    Science.gov (United States)

    Wilson, Sara McCormack; And Others

    1975-01-01

    Assesses the values of high school and college students relative to human genetic engineering and recommends that biology educators explore instructional strategies merging human genetic information with value clarification techniques. (LS)

  11. Human genetics in troubled times and places.

    Science.gov (United States)

    Harper, Peter S

    2018-01-01

    The development of human genetics world-wide during the twentieth century, especially across Europe, has occurred against a background of repeated catastrophes, including two world wars and the ideological problems and repression posed by Nazism and Communism. The published scientific literature gives few hints of these problems and there is a danger that they will be forgotten. The First World War was largely indiscriminate in its carnage, but World War 2 and the preceding years of fascism were associated with widespread migration, especially of Jewish workers expelled from Germany, and of their children, a number of whom would become major contributors to the post-war generation of human and medical geneticists in Britain and America. In Germany itself, eminent geneticists were also involved in the abuses carried out in the name of 'eugenics' and 'race biology'. However, geneticists in America, Britain and the rest of Europe were largely responsible for the ideological foundations of these abuses. In the Soviet Union, geneticists and genetics itself became the object of persecution from the 1930s till as late as the mid 1960s, with an almost complete destruction of the field during this time; this extended also to Eastern Europe and China as part of the influence of Russian communism. Most recently, at the end of the twentieth century, China saw a renewal of government sponsored eugenics programmes, now mostly discarded. During the post-world war 2 decades, human genetics research benefited greatly from recognition of the genetic dangers posed by exposure to radiation, following the atomic bomb explosions in Japan, atmospheric testing and successive accidental nuclear disasters in Russia. Documenting and remembering these traumatic events, now largely forgotten among younger workers, is essential if we are to fully understand the history of human genetics and avoid the repetition of similar disasters in the future. The power of modern human genetic and genomic

  12. Automation of RELAP5 input calibration and code validation using genetic algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Phung, Viet-Anh, E-mail: vaphung@kth.se [Division of Nuclear Power Safety, Royal Institute of Technology, Roslagstullsbacken 21, 10691 Stockholm (Sweden); Kööp, Kaspar, E-mail: kaspar@safety.sci.kth.se [Division of Nuclear Power Safety, Royal Institute of Technology, Roslagstullsbacken 21, 10691 Stockholm (Sweden); Grishchenko, Dmitry, E-mail: dmitry@safety.sci.kth.se [Division of Nuclear Power Safety, Royal Institute of Technology, Roslagstullsbacken 21, 10691 Stockholm (Sweden); Vorobyev, Yury, E-mail: yura3510@gmail.com [National Research Center “Kurchatov Institute”, Kurchatov square 1, Moscow 123182 (Russian Federation); Kudinov, Pavel, E-mail: pavel@safety.sci.kth.se [Division of Nuclear Power Safety, Royal Institute of Technology, Roslagstullsbacken 21, 10691 Stockholm (Sweden)

    2016-04-15

    Highlights: • Automated input calibration and code validation using genetic algorithm is presented. • Predictions generally overlap experiments for individual system response quantities (SRQs). • It was not possible to predict simultaneously experimental maximum flow rate and oscillation period. • Simultaneous consideration of multiple SRQs is important for code validation. - Abstract: Validation of system thermal-hydraulic codes is an important step in application of the codes to reactor safety analysis. The goal of the validation process is to determine how well a code can represent physical reality. This is achieved by comparing predicted and experimental system response quantities (SRQs) taking into account experimental and modelling uncertainties. Parameters which are required for the code input but not measured directly in the experiment can become an important source of uncertainty in the code validation process. Quantification of such parameters is often called input calibration. Calibration and uncertainty quantification may become challenging tasks when the number of calibrated input parameters and SRQs is large and dependencies between them are complex. If only engineering judgment is employed in the process, the outcome can be prone to so called “user effects”. The goal of this work is to develop an automated approach to input calibration and RELAP5 code validation against data on two-phase natural circulation flow instability. Multiple SRQs are used in both calibration and validation. In the input calibration, we used genetic algorithm (GA), a heuristic global optimization method, in order to minimize the discrepancy between experimental and simulation data by identifying optimal combinations of uncertain input parameters in the calibration process. We demonstrate the importance of the proper selection of SRQs and respective normalization and weighting factors in the fitness function. In the code validation, we used maximum flow rate as the

  13. Advances in gene technology: Human genetic disorders

    Energy Technology Data Exchange (ETDEWEB)

    Scott, W.A.; Ahmad, F.; Black, S.; Schultz, J.; Whelan, W.J.

    1984-01-01

    This book discusses the papers presented at the conference on the subject of ''advances in Gene technology: Human genetic disorders''. Molecular biology of various carcinomas and inheritance of metabolic diseases is discussed and technology advancement in diagnosis of hereditary diseases is described. Some of the titles discussed are-Immunoglobulin genes translocation and diagnosis; hemophilia; oncogenes; oncogenic transformations; experimental data on mice, hamsters, birds carcinomas and sarcomas.

  14. Comprehensive reconstruction andvisualization of non-coding regulatorynetworks in human

    Directory of Open Access Journals (Sweden)

    Vincenzo eBonnici

    2014-12-01

    Full Text Available Research attention has been powered to understand the functional roles of non-coding RNAs (ncRNAs. Many studies have demonstrated their deregulation in cancer and other human disorders. ncRNAs are also present in extracellular human body fluids such as serum and plasma, giving them a great potential as non-invasive biomarkers. However, non-coding RNAs have been relatively recently discovered and a comprehensive database including all of them is still missing. Reconstructing and visualizing the network of ncRNAs interactions are important steps to understand their regulatory mechanism in complex systems. This work presents ncRNA-DB, a NoSQL database that integrates ncRNAs data interactions from a large number of well established online repositories. The interactions involve RNA, DNA, proteins and diseases. ncRNA-DB is available at http://ncrnadb.scienze.univr.it/ncrnadb/. It is equipped with three interfaces: web based, command line and a Cytoscape app called ncINetView. By accessing only one resource, users can search for ncRNAs and their interactions, build a network annotated with all known ncRNAs and associated diseases, and use all visual and mining features available in Cytoscape.

  15. A probabilistic coding based quantum genetic algorithm for multiple sequence alignment.

    Science.gov (United States)

    Huo, Hongwei; Xie, Qiaoluan; Shen, Xubang; Stojkovic, Vojislav

    2008-01-01

    This paper presents an original Quantum Genetic algorithm for Multiple sequence ALIGNment (QGMALIGN) that combines a genetic algorithm and a quantum algorithm. A quantum probabilistic coding is designed for representing the multiple sequence alignment. A quantum rotation gate as a mutation operator is used to guide the quantum state evolution. Six genetic operators are designed on the coding basis to improve the solution during the evolutionary process. The features of implicit parallelism and state superposition in quantum mechanics and the global search capability of the genetic algorithm are exploited to get efficient computation. A set of well known test cases from BAliBASE2.0 is used as reference to evaluate the efficiency of the QGMALIGN optimization. The QGMALIGN results have been compared with the most popular methods (CLUSTALX, SAGA, DIALIGN, SB_PIMA, and QGMALIGN) results. The QGMALIGN results show that QGMALIGN performs well on the presenting biological data. The addition of genetic operators to the quantum algorithm lowers the cost of overall running time.

  16. Pervasive hitchhiking at coding and regulatory sites in humans.

    Directory of Open Access Journals (Sweden)

    James J Cai

    2009-01-01

    Full Text Available Much effort and interest have focused on assessing the importance of natural selection, particularly positive natural selection, in shaping the human genome. Although scans for positive selection have identified candidate loci that may be associated with positive selection in humans, such scans do not indicate whether adaptation is frequent in general in humans. Studies based on the reasoning of the MacDonald-Kreitman test, which, in principle, can be used to evaluate the extent of positive selection, suggested that adaptation is detectable in the human genome but that it is less common than in Drosophila or Escherichia coli. Both positive and purifying natural selection at functional sites should affect levels and patterns of polymorphism at linked nonfunctional sites. Here, we search for these effects by analyzing patterns of neutral polymorphism in humans in relation to the rates of recombination, functional density, and functional divergence with chimpanzees. We find that the levels of neutral polymorphism are lower in the regions of lower recombination and in the regions of higher functional density or divergence. These correlations persist after controlling for the variation in GC content, density of simple repeats, selective constraint, mutation rate, and depth of sequencing coverage. We argue that these results are most plausibly explained by the effects of natural selection at functional sites -- either recurrent selective sweeps or background selection -- on the levels of linked neutral polymorphism. Natural selection at both coding and regulatory sites appears to affect linked neutral polymorphism, reducing neutral polymorphism by 6% genome-wide and by 11% in the gene-rich half of the human genome. These findings suggest that the effects of natural selection at linked sites cannot be ignored in the study of neutral human polymorphism.

  17. A thermodynamic basis for prebiotic amino acid synthesis and the nature of the first genetic code

    CERN Document Server

    Higgs, Paul G

    2009-01-01

    Of the twenty amino acids used in proteins, ten were formed in Miller's atmospheric discharge experiments. The two other major proposed sources of prebiotic amino acid synthesis include formation in hydrothermal vents and delivery to Earth via meteorites. We combine observational and experimental data of amino acid frequencies formed by these diverse mechanisms and show that, regardless of the source, these ten early amino acids can be ranked in order of decreasing abundance in prebiotic contexts. This order can be predicted by thermodynamics. The relative abundances of the early amino acids were most likely reflected in the composition of the first proteins at the time the genetic code originated. The remaining amino acids were incorporated into proteins after pathways for their biochemical synthesis evolved. This is consistent with theories of the evolution of the genetic code by stepwise addition of new amino acids. These are hints that key aspects of early biochemistry may be universal.

  18. CONGESTION MANAGEMENT IN DEREGULATED POWER SYSTEMS USING REAL CODED GENETIC ALGORITHM

    Directory of Open Access Journals (Sweden)

    Sujatha Balaraman

    2010-11-01

    Full Text Available In this paper, an efficient method has been proposed for transmission line over load alleviation in deregulated power system using real coded genetic algorithm (RCGA. For secure operation of power system, the network loading has to be maintained within specified limits. Transmission line congestion initiates the cascading outages which forces the system to collapse. Accurate prediction and alleviation of line overloads is the suitable corrective action to avoid network collapse. In this paper an attempt is made to explore the use of real coded genetic algorithm to find the optimal generation rescheduling for relieving congestion. The effectiveness of the proposed algorithm has been analyzed on IEEE 30 bus test system. The results obtained by the proposed method are found to be quite encouraging when compared with Simulated Annealing (SA and hence it will be useful in electrical restructuring.

  19. Online genetic databases informing human genome epidemiology

    Directory of Open Access Journals (Sweden)

    Higgins Julian PT

    2007-07-01

    Full Text Available Abstract Background With the advent of high throughput genotyping technology and the information available via projects such as the human genome sequencing and the HapMap project, more and more data relevant to the study of genetics and disease risk will be produced. Systematic reviews and meta-analyses of human genome epidemiology studies rely on the ability to identify relevant studies and to obtain suitable data from these studies. A first port of call for most such reviews is a search of MEDLINE. We examined whether this could be usefully supplemented by identifying databases on the World Wide Web that contain genetic epidemiological information. Methods We conducted a systematic search for online databases containing genetic epidemiological information on gene prevalence or gene-disease association. In those containing information on genetic association studies, we examined what additional information could be obtained to supplement a MEDLINE literature search. Results We identified 111 databases containing prevalence data, 67 databases specific to a single gene and only 13 that contained information on gene-disease associations. Most of the latter 13 databases were linked to MEDLINE, although five contained information that may not be available from other sources. Conclusion There is no single resource of structured data from genetic association studies covering multiple diseases, and in relation to the number of studies being conducted there is very little information specific to gene-disease association studies currently available on the World Wide Web. Until comprehensive data repositories are created and utilized regularly, new data will remain largely inaccessible to many systematic review authors and meta-analysts.

  20. A unique genetic code change in the mitochondrial genome of the parasitic nematode Radopholus similis

    Directory of Open Access Journals (Sweden)

    Van Leeuwen Thomas

    2009-09-01

    Full Text Available Abstract Background Mitochondria (mt contain their own autonomously replicating DNA, constituted as a small circular genome encoding essential subunits of the respiratory chain. Mt DNA is characterized by a genetic code which differs from the standard one. Interestingly, the mt genome of nematodes share some peculiar features, such as small transfer RNAs, truncated ribosomal RNAs and - in the class of Chromadorean nematodes - unidirectional transcription. Findings We present the complete mt genomic sequence (16,791 bp of the plant-parasitic nematode Radopholus similis (class Chromadorea. Although it has a gene content similar to most other nematodes, many idiosyncrasies characterize the extremely AT-rich mt genome of R. similis (85.4% AT. The secondary structure of the large (16S rRNA is further reduced, the gene order is unique, the large non-coding region contains two large repeats, and most interestingly, the UAA codon is reassigned from translation termination to tyrosine. In addition, 7 out of 12 protein-coding genes lack a canonical stop codon and analysis of transcriptional data showed the absence of polyadenylation. Northern blot analysis confirmed that only one strand is transcribed and processed. Furthermore, using nucleotide content bias methods, regions for the origin of replication are suggested. Conclusion The extraordinary mt genome of R. similis with its unique genetic code appears to contain exceptional features correlated to DNA decoding. Therefore the genome may provide an incentive to further elucidate these barely understood processes in nematodes. This comprehension may eventually lead to parasitic nematode-specific control targets as healthy mitochondria are imperative for organism survival. In addition, the presented genome is an interesting exceptional event in genetic code evolution.

  1. Analysis of genetic code ambiguity arising from nematode-specific misacylated tRNAs.

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    Kiyofumi Hamashima

    Full Text Available The faithful translation of the genetic code requires the highly accurate aminoacylation of transfer RNAs (tRNAs. However, it has been shown that nematode-specific V-arm-containing tRNAs (nev-tRNAs are misacylated with leucine in vitro in a manner that transgresses the genetic code. nev-tRNA(Gly (CCC and nev-tRNA(Ile (UAU, which are the major nev-tRNA isotypes, could theoretically decode the glycine (GGG codon and isoleucine (AUA codon as leucine, causing GGG and AUA codon ambiguity in nematode cells. To test this hypothesis, we investigated the functionality of nev-tRNAs and their impact on the proteome of Caenorhabditis elegans. Analysis of the nucleotide sequences in the 3' end regions of the nev-tRNAs showed that they had matured correctly, with the addition of CCA, which is a crucial posttranscriptional modification required for tRNA aminoacylation. The nuclear export of nev-tRNAs was confirmed with an analysis of their subcellular localization. These results show that nev-tRNAs are processed to their mature forms like common tRNAs and are available for translation. However, a whole-cell proteome analysis found no detectable level of nev-tRNA-induced mistranslation in C. elegans cells, suggesting that the genetic code is not ambiguous, at least under normal growth conditions. Our findings indicate that the translational fidelity of the nematode genetic code is strictly maintained, contrary to our expectations, although deviant tRNAs with misacylation properties are highly conserved in the nematode genome.

  2. ANT: Software for Generating and Evaluating Degenerate Codons for Natural and Expanded Genetic Codes.

    Science.gov (United States)

    Engqvist, Martin K M; Nielsen, Jens

    2015-08-21

    The Ambiguous Nucleotide Tool (ANT) is a desktop application that generates and evaluates degenerate codons. Degenerate codons are used to represent DNA positions that have multiple possible nucleotide alternatives. This is useful for protein engineering and directed evolution, where primers specified with degenerate codons are used as a basis for generating libraries of protein sequences. ANT is intuitive and can be used in a graphical user interface or by interacting with the code through a defined application programming interface. ANT comes with full support for nonstandard, user-defined, or expanded genetic codes (translation tables), which is important because synthetic biology is being applied to an ever widening range of natural and engineered organisms. The Python source code for ANT is freely distributed so that it may be used without restriction, modified, and incorporated in other software or custom data pipelines.

  3. Codon sextets with leading role of serine create "ideal" symmetry classification scheme of the genetic code.

    Science.gov (United States)

    Rosandić, Marija; Paar, Vladimir

    2014-06-10

    The standard classification scheme of the genetic code is organized for alphabetic ordering of nucleotides. Here we introduce the new, "ideal" classification scheme in compact form, for the first time generated by codon sextets encoding Ser, Arg and Leu amino acids. The new scheme creates the known purine/pyrimidine, codon-anticodon, and amino/keto type symmetries and a novel A+U rich/C+G rich symmetry. This scheme is built from "leading" and "nonleading" groups of 32 codons each. In the ensuing 4 × 16 scheme, based on trinucleotide quadruplets, Ser has a central role as initial generator. Six codons encoding Ser and six encoding Arg extend continuously along a linear array in the "leading" group, and together with four of six Leu codons uniquely define construction of the "leading" group. The remaining two Leu codons enable construction of the "nonleading" group. The "ideal" genetic code suggests the evolution of genetic code with serine as an initiator. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Inclusion of the fitness sharing technique in an evolutionary algorithm to analyze the fitness landscape of the genetic code adaptability.

    Science.gov (United States)

    Santos, José; Monteagudo, Ángel

    2017-03-27

    The canonical code, although prevailing in complex genomes, is not universal. It was shown the canonical genetic code superior robustness compared to random codes, but it is not clearly determined how it evolved towards its current form. The error minimization theory considers the minimization of point mutation adverse effect as the main selection factor in the evolution of the code. We have used simulated evolution in a computer to search for optimized codes, which helps to obtain information about the optimization level of the canonical code in its evolution. A genetic algorithm searches for efficient codes in a fitness landscape that corresponds with the adaptability of possible hypothetical genetic codes. The lower the effects of errors or mutations in the codon bases of a hypothetical code, the more efficient or optimal is that code. The inclusion of the fitness sharing technique in the evolutionary algorithm allows the extent to which the canonical genetic code is in an area corresponding to a deep local minimum to be easily determined, even in the high dimensional spaces considered. The analyses show that the canonical code is not in a deep local minimum and that the fitness landscape is not a multimodal fitness landscape with deep and separated peaks. Moreover, the canonical code is clearly far away from the areas of higher fitness in the landscape. Given the non-presence of deep local minima in the landscape, although the code could evolve and different forces could shape its structure, the fitness landscape nature considered in the error minimization theory does not explain why the canonical code ended its evolution in a location which is not an area of a localized deep minimum of the huge fitness landscape.

  5. Does genetic diversity predict health in humans?

    Directory of Open Access Journals (Sweden)

    Hanne C Lie

    Full Text Available Genetic diversity, especially at genes important for immune functioning within the Major Histocompatibility Complex (MHC, has been associated with fitness-related traits, including disease resistance, in many species. Recently, genetic diversity has been associated with mate preferences in humans. Here we asked whether these preferences are adaptive in terms of obtaining healthier mates. We investigated whether genetic diversity (heterozygosity and standardized mean d(2 at MHC and nonMHC microsatellite loci, predicted health in 153 individuals. Individuals with greater allelic diversity (d(2 at nonMHC loci and at one MHC locus, linked to HLA-DRB1, reported fewer symptoms over a four-month period than individuals with lower d(2. In contrast, there were no associations between MHC or nonMHC heterozygosity and health. NonMHC-d(2 has previously been found to predict male preferences for female faces. Thus, the current findings suggest that nonMHC diversity may play a role in both natural and sexual selection acting on human populations.

  6. Genetic & epigenetic approach to human obesity

    Directory of Open Access Journals (Sweden)

    K Rajender Rao

    2014-01-01

    Full Text Available Obesity is an important clinical and public health challenge, epitomized by excess adipose tissue accumulation resulting from an imbalance in energy intake and energy expenditure. It is a forerunner for a variety of other diseases such as type-2-diabetes (T2D, cardiovascular diseases, some types of cancer, stroke, hyperlipidaemia and can be fatal leading to premature death. Obesity is highly heritable and arises from the interplay of multiple genes and environmental factors. Recent advancements in Genome-wide association studies (GWAS have shown important steps towards identifying genetic risks and identification of genetic markers for lifestyle diseases, especially for a metabolic disorder like obesity. According to the 12 th u0 pdate of Human Obesity Gene Map there are 253 quantity trait loci (QTL for obesity related phenotypes from 61 genome wide scan studies. Contribution of genetic propensity of individual ethnic and racial variations in obesity is an active area of research. Further, understanding its complexity as to how these variations could influence ones susceptibility to become or remain obese will lead us to a greater understanding of how obesity occurs and hopefully, how to prevent and treat this condition. In this review, various strategies adapted for such an analysis based on the recent advances in genome wide and functional variations in human obesity are discussed.

  7. Genetic & epigenetic approach to human obesity.

    Science.gov (United States)

    Rao, K Rajender; Lal, Nirupama; Giridharan, N V

    2014-11-01

    Obesity is an important clinical and public health challenge, epitomized by excess adipose tissue accumulation resulting from an imbalance in energy intake and energy expenditure. It is a forerunner for a variety of other diseases such as type-2-diabetes (T2D), cardiovascular diseases, some types of cancer, stroke, hyperlipidaemia and can be fatal leading to premature death. Obesity is highly heritable and arises from the interplay of multiple genes and environmental factors. Recent advancements in Genome-wide association studies (GWAS) have shown important steps towards identifying genetic risks and identification of genetic markers for lifestyle diseases, especially for a metabolic disorder like obesity. According to the 12th Update of Human Obesity Gene Map there are 253 quantity trait loci (QTL) for obesity related phenotypes from 61 genome wide scan studies. Contribution of genetic propensity of individual ethnic and racial variations in obesity is an active area of research. Further, understanding its complexity as to how these variations could influence ones susceptibility to become or remain obese will lead us to a greater understanding of how obesity occurs and hopefully, how to prevent and treat this condition. In this review, various strategies adapted for such an analysis based on the recent advances in genome wide and functional variations in human obesity are discussed.

  8. Genetic & epigenetic approach to human obesity

    Science.gov (United States)

    Rao, K. Rajender; Lal, Nirupama; Giridharan, N.V.

    2014-01-01

    Obesity is an important clinical and public health challenge, epitomized by excess adipose tissue accumulation resulting from an imbalance in energy intake and energy expenditure. It is a forerunner for a variety of other diseases such as type-2-diabetes (T2D), cardiovascular diseases, some types of cancer, stroke, hyperlipidaemia and can be fatal leading to premature death. Obesity is highly heritable and arises from the interplay of multiple genes and environmental factors. Recent advancements in Genome-wide association studies (GWAS) have shown important steps towards identifying genetic risks and identification of genetic markers for lifestyle diseases, especially for a metabolic disorder like obesity. According to the 12th Update of Human Obesity Gene Map there are 253 quantity trait loci (QTL) for obesity related phenotypes from 61 genome wide scan studies. Contribution of genetic propensity of individual ethnic and racial variations in obesity is an active area of research. Further, understanding its complexity as to how these variations could influence ones susceptibility to become or remain obese will lead us to a greater understanding of how obesity occurs and hopefully, how to prevent and treat this condition. In this review, various strategies adapted for such an analysis based on the recent advances in genome wide and functional variations in human obesity are discussed. PMID:25579139

  9. A quantum-inspired genetic algorithm based on probabilistic coding for multiple sequence alignment.

    Science.gov (United States)

    Huo, Hong-Wei; Stojkovic, Vojislav; Xie, Qiao-Luan

    2010-02-01

    Quantum parallelism arises from the ability of a quantum memory register to exist in a superposition of base states. Since the number of possible base states is 2(n), where n is the number of qubits in the quantum memory register, one operation on a quantum computer performs what an exponential number of operations on a classical computer performs. The power of quantum algorithms comes from taking advantages of quantum parallelism. Quantum algorithms are exponentially faster than classical algorithms. Genetic optimization algorithms are stochastic search algorithms which are used to search large, nonlinear spaces where expert knowledge is lacking or difficult to encode. QGMALIGN--a probabilistic coding based quantum-inspired genetic algorithm for multiple sequence alignment is presented. A quantum rotation gate as a mutation operator is used to guide the quantum state evolution. Six genetic operators are designed on the coding basis to improve the solution during the evolutionary process. The experimental results show that QGMALIGN can compete with the popular methods, such as CLUSTALX and SAGA, and performs well on the presenting biological data. Moreover, the addition of genetic operators to the quantum-inspired algorithm lowers the cost of overall running time.

  10. Application of hybrid coded genetic algorithm in fuzzy neural network controller

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Presents the fuzzy neural network optimized by hybrid coded genetic algorithm of decimal encoding and bi nary encoding, the searching ability and stability of genetic algorithms enhanced by using binary encoding during the crossover operation and decimal encoding during the mutation operation, and the way of accepting new individuals by probability adopted, by which a new individual is accepted and its parent is discarded when its fitness is higher than that of its parent, and a new individual is accepted by probability when its fitness is lower than that of its parent. And concludes with calculations made with an example that these improvements enhance the speed of genetic algorithms to optimize the fuzzy neural network controller.

  11. Informed consent in human experimentation before the Nuremberg code.

    Science.gov (United States)

    Vollmann, J; Winau, R

    1996-12-07

    The issue of ethics with respect to medical experimentation in Germany during the 1930s and 1940s was crucial at the Nuremberg trials and related trials of doctors and public health officials. Those involved in horrible crimes attempted to excuse themselves by arguing that there were no explicit rules governing medical research on human beings in Germany during the period and that research practices in Germany were not different from those in allied countries. In this context the Nuremberg code of 1947 is generally regarded as the first document to set out ethical regulations in human experimentation based on informed consent. New research, however, indicates that ethical issues of informed consent in guidelines for human experimentation were recognised as early as the nineteenth century. These guidelines shed light on the still contentious issue of when the concepts of autonomy, informed consent, and therapeutic and non-therapeutic research first emerged. This issue assumes renewed importance in the context of current attempts to assess liability and responsibility for the abuse of people in various experiments conducted since the second world war in the United States, Canada, Russia, and other nations.

  12. Genetically engineered mouse models and human osteosarcoma

    Directory of Open Access Journals (Sweden)

    Ng Alvin JM

    2012-10-01

    Full Text Available Abstract Osteosarcoma is the most common form of bone cancer. Pivotal insight into the genes involved in human osteosarcoma has been provided by the study of rare familial cancer predisposition syndromes. Three kindreds stand out as predisposing to the development of osteosarcoma: Li-Fraumeni syndrome, familial retinoblastoma and RecQ helicase disorders, which include Rothmund-Thomson Syndrome in particular. These disorders have highlighted the important roles of P53 and RB respectively, in the development of osteosarcoma. The association of OS with RECQL4 mutations is apparent but the relevance of this to OS is uncertain as mutations in RECQL4 are not found in sporadic OS. Application of the knowledge or mutations of P53 and RB in familial and sporadic OS has enabled the development of tractable, highly penetrant murine models of OS. These models share many of the cardinal features associated with human osteosarcoma including, importantly, a high incidence of spontaneous metastasis. The recent development of these models has been a significant advance for efforts to improve our understanding of the genetics of human OS and, more critically, to provide a high-throughput genetically modifiable platform for preclinical evaluation of new therapeutics.

  13. Deciphering the four-letter code : The genetic basis of complex traits and common disease

    NARCIS (Netherlands)

    Pulit, S.L.

    2016-01-01

    Deoxyribonucleic acid (DNA) is made up of four bases: adenine (A), cytosine (C), guanine (G), and thymine (T). Assembled in a strategic fashion, these bases code for the unique genomes of all walks of life, from viruses, to rodents, to primates. The human genome, mapped completely for the first time

  14. Deciphering the four-letter code : The genetic basis of complex traits and common disease

    NARCIS (Netherlands)

    Pulit, S.L.

    2016-01-01

    Deoxyribonucleic acid (DNA) is made up of four bases: adenine (A), cytosine (C), guanine (G), and thymine (T). Assembled in a strategic fashion, these bases code for the unique genomes of all walks of life, from viruses, to rodents, to primates. The human genome, mapped completely for the first time

  15. DeepSAGE reveals genetic variants associated with alternative polyadenylation and expression of coding and non-coding transcripts.

    Directory of Open Access Journals (Sweden)

    Daria V Zhernakova

    2013-06-01

    Full Text Available Many disease-associated variants affect gene expression levels (expression quantitative trait loci, eQTLs and expression profiling using next generation sequencing (NGS technology is a powerful way to detect these eQTLs. We analyzed 94 total blood samples from healthy volunteers with DeepSAGE to gain specific insight into how genetic variants affect the expression of genes and lengths of 3'-untranslated regions (3'-UTRs. We detected previously unknown cis-eQTL effects for GWAS hits in disease- and physiology-associated traits. Apart from cis-eQTLs that are typically easily identifiable using microarrays or RNA-sequencing, DeepSAGE also revealed many cis-eQTLs for antisense and other non-coding transcripts, often in genomic regions containing retrotransposon-derived elements. We also identified and confirmed SNPs that affect the usage of alternative polyadenylation sites, thereby potentially influencing the stability of messenger RNAs (mRNA. We then combined the power of RNA-sequencing with DeepSAGE by performing a meta-analysis of three datasets, leading to the identification of many more cis-eQTLs. Our results indicate that DeepSAGE data is useful for eQTL mapping of known and unknown transcripts, and for identifying SNPs that affect alternative polyadenylation. Because of the inherent differences between DeepSAGE and RNA-sequencing, our complementary, integrative approach leads to greater insight into the molecular consequences of many disease-associated variants.

  16. DNA indels in coding regions reveal selective constraints on protein evolution in the human lineage

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    Messer Philipp W

    2007-10-01

    Full Text Available Abstract Background Insertions and deletions of DNA segments (indels are together with substitutions the major mutational processes that generate genetic variation. Here we focus on recent DNA insertions and deletions in protein coding regions of the human genome to investigate selective constraints on indels in protein evolution. Results Frequencies of inserted and deleted amino acids differ from background amino acid frequencies in the human proteome. Small amino acids are overrepresented, while hydrophobic, aliphatic and aromatic amino acids are strongly suppressed. Indels are found to be preferentially located in protein regions that do not form important structural domains. Amino acid insertion and deletion rates in genes associated with elementary biochemical reactions (e. g. catalytic activity, ligase activity, electron transport, or catabolic process are lower compared to those in other genes and are therefore subject to stronger purifying selection. Conclusion Our analysis indicates that indels in human protein coding regions are subject to distinct levels of selective pressure with regard to their structural impact on the amino acid sequence, as well as to general properties of the genes they are located in. These findings confirm that many commonly accepted characteristics of selective constraints for substitutions are also valid for amino acid insertions and deletions.

  17. Social and Psychological Aspects of Applied Human Genetics: A Bibliography.

    Science.gov (United States)

    Sorenson, James R., Comp.

    This bibliography is a selective compilation of books and articles which focus on the psychological and social issues of applied human genetics. It is centered in particular around problems, issues, and discussions of genetic counseling, the primary mechanism by which human genetics has been applied to date. It includes those entries which, on the…

  18. Genetic Testing and Its Implications: Human Genetics Researchers Grapple with Ethical Issues.

    Science.gov (United States)

    Rabino, Isaac

    2003-01-01

    Contributes systematic data on the attitudes of scientific experts who engage in human genetics research about the pros, cons, and ethical implications of genetic testing. Finds that they are highly supportive of voluntary testing and the right to know one's genetic heritage. Calls for greater genetic literacy. (Contains 87 references.) (Author/NB)

  19. Somatic retrotransposition alters the genetic landscape of the human brain.

    Science.gov (United States)

    Baillie, J Kenneth; Barnett, Mark W; Upton, Kyle R; Gerhardt, Daniel J; Richmond, Todd A; De Sapio, Fioravante; Brennan, Paul M; Rizzu, Patrizia; Smith, Sarah; Fell, Mark; Talbot, Richard T; Gustincich, Stefano; Freeman, Thomas C; Mattick, John S; Hume, David A; Heutink, Peter; Carninci, Piero; Jeddeloh, Jeffrey A; Faulkner, Geoffrey J

    2011-10-30

    Retrotransposons are mobile genetic elements that use a germline 'copy-and-paste' mechanism to spread throughout metazoan genomes. At least 50 per cent of the human genome is derived from retrotransposons, with three active families (L1, Alu and SVA) associated with insertional mutagenesis and disease. Epigenetic and post-transcriptional suppression block retrotransposition in somatic cells, excluding early embryo development and some malignancies. Recent reports of L1 expression and copy number variation in the human brain suggest that L1 mobilization may also occur during later development. However, the corresponding integration sites have not been mapped. Here we apply a high-throughput method to identify numerous L1, Alu and SVA germline mutations, as well as 7,743 putative somatic L1 insertions, in the hippocampus and caudate nucleus of three individuals. Surprisingly, we also found 13,692 somatic Alu insertions and 1,350 SVA insertions. Our results demonstrate that retrotransposons mobilize to protein-coding genes differentially expressed and active in the brain. Thus, somatic genome mosaicism driven by retrotransposition may reshape the genetic circuitry that underpins normal and abnormal neurobiological processes.

  20. An algorithm for the study of DNA sequence evolution based on the genetic code.

    Science.gov (United States)

    Sirakoulis, G Ch; Karafyllidis, I; Sandaltzopoulos, R; Tsalides, Ph; Thanailakis, A

    2004-11-01

    Recent studies of the quantum-mechanical processes in the DNA molecule have seriously challenged the principle that mutations occur randomly. The proton tunneling mechanism causes tautomeric transitions in base pairs resulting in mutations during DNA replication. The meticulous study of the quantum-mechanical phenomena in DNA may reveal that the process of mutagenesis is not completely random. We are still far away from a complete quantum-mechanical model of DNA sequence mutagenesis because of the complexity of the processes and the complex three-dimensional structure of the molecule. In this paper we have developed a quantum-mechanical description of DNA evolution and, following its outline, we have constructed a classical model for DNA evolution assuming that some aspects of the quantum-mechanical processes have influenced the determination of the genetic code. Conversely, our model assumes that the genetic code provides information about the quantum-mechanical mechanisms of mutagenesis, as the current code is the product of an evolutionary process that tries to minimize the spurious consequences of mutagenesis. Based on this model we develop an algorithm that can be used to study the accumulation of mutations in a DNA sequence. The algorithm has a user-friendly interface and the user can change key parameters in order to study relevant hypotheses.

  1. Hydroxylation of a conserved tRNA modification establishes non-universal genetic code in echinoderm mitochondria.

    Science.gov (United States)

    Nagao, Asuteka; Ohara, Mitsuhiro; Miyauchi, Kenjyo; Yokobori, Shin-Ichi; Yamagishi, Akihiko; Watanabe, Kimitsuna; Suzuki, Tsutomu

    2017-09-01

    The genetic code is not frozen but still evolving, which can result in the acquisition of 'dialectal' codons that deviate from the universal genetic code. RNA modifications in the anticodon region of tRNAs play a critical role in establishing such non-universal genetic codes. In echinoderm mitochondria, the AAA codon specifies asparagine instead of lysine. By analyzing mitochondrial (mt-) tRNA(Lys) isolated from the sea urchin (Mesocentrotus nudus), we discovered a novel modified nucleoside, hydroxy-N(6)-threonylcarbamoyladenosine (ht(6)A), 3' adjacent to the anticodon (position 37). Biochemical analysis revealed that ht(6)A37 has the ability to prevent mt-tRNA(Lys) from misreading AAA as lysine, thereby indicating that hydroxylation of N(6)-threonylcarbamoyladenosine (t(6)A) contributes to the establishment of the non-universal genetic code in echinoderm mitochondria.

  2. Neural coding of movement direction in the healthy human brain.

    Directory of Open Access Journals (Sweden)

    Christopher D Cowper-Smith

    Full Text Available Neurophysiological studies in monkeys show that activity of neurons in primary cortex (M1, pre-motor cortex (PMC, and cerebellum varies systematically with the direction of reaching movements. These neurons exhibit preferred direction tuning, where the level of neural activity is highest when movements are made in the preferred direction (PD, and gets progressively lower as movements are made at increasing degrees of offset from the PD. Using a functional magnetic resonance imaging adaptation (fMRI-A paradigm, we show that PD coding does exist in regions of the human motor system that are homologous to those observed in non-human primates. Consistent with predictions of the PD model, we show adaptation (i.e., a lower level of the blood oxygen level dependent (BOLD time-course signal in M1, PMC, SMA, and cerebellum when consecutive wrist movements were made in the same direction (0° offset relative to movements offset by 90° or 180°. The BOLD signal in dorsolateral prefrontal cortex adapted equally in all movement offset conditions, mitigating against the possibility that the present results are the consequence of differential task complexity or attention to action in each movement offset condition.

  3. Coding potential of the products of alternative splicing in human.

    KAUST Repository

    Leoni, Guido

    2011-01-20

    BACKGROUND: Analysis of the human genome has revealed that as much as an order of magnitude more of the genomic sequence is transcribed than accounted for by the predicted and characterized genes. A number of these transcripts are alternatively spliced forms of known protein coding genes; however, it is becoming clear that many of them do not necessarily correspond to a functional protein. RESULTS: In this study we analyze alternative splicing isoforms of human gene products that are unambiguously identified by mass spectrometry and compare their properties with those of isoforms of the same genes for which no peptide was found in publicly available mass spectrometry datasets. We analyze them in detail for the presence of uninterrupted functional domains, active sites as well as the plausibility of their predicted structure. We report how well each of these strategies and their combination can correctly identify translated isoforms and derive a lower limit for their specificity, that is, their ability to correctly identify non-translated products. CONCLUSIONS: The most effective strategy for correctly identifying translated products relies on the conservation of active sites, but it can only be applied to a small fraction of isoforms, while a reasonably high coverage, sensitivity and specificity can be achieved by analyzing the presence of non-truncated functional domains. Combining the latter with an assessment of the plausibility of the modeled structure of the isoform increases both coverage and specificity with a moderate cost in terms of sensitivity.

  4. Visual Coding of Human Bodies: Perceptual Aftereffects Reveal Norm-Based, Opponent Coding of Body Identity

    Science.gov (United States)

    Rhodes, Gillian; Jeffery, Linda; Boeing, Alexandra; Calder, Andrew J.

    2013-01-01

    Despite the discovery of body-selective neural areas in occipitotemporal cortex, little is known about how bodies are visually coded. We used perceptual adaptation to determine how body identity is coded. Brief exposure to a body (e.g., anti-Rose) biased perception toward an identity with opposite properties (Rose). Moreover, the size of this…

  5. Genetic Code Expansion as a Tool to Study Regulatory Processes of Transcription

    Science.gov (United States)

    Schmidt, Moritz; Summerer, Daniel

    2014-02-01

    The expansion of the genetic code with noncanonical amino acids (ncAA) enables the chemical and biophysical properties of proteins to be tailored, inside cells, with a previously unattainable level of precision. A wide range of ncAA with functions not found in canonical amino acids have been genetically encoded in recent years and have delivered insights into biological processes that would be difficult to access with traditional approaches of molecular biology. A major field for the development and application of novel ncAA-functions has been transcription and its regulation. This is particularly attractive, since advanced DNA sequencing- and proteomics-techniques continue to deliver vast information on these processes on a global level, but complementing methodologies to study them on a detailed, molecular level and in living cells have been comparably scarce. In a growing number of studies, genetic code expansion has now been applied to precisely control the chemical properties of transcription factors, RNA polymerases and histones, and this has enabled new insights into their interactions, conformational changes, cellular localizations and the functional roles of posttranslational modifications.

  6. Matrix genetics, part 3: the evolution of the genetic code from the viewpoint of the genetic octave Yin-Yang-algebra

    CERN Document Server

    Petoukhov, Sergey V

    2008-01-01

    The set of known dialects of the genetic code (GC) is analyzed from the viewpoint of the genetic octave Yin-Yang-algebra. This algebra was described in the previous author's publications. The algebra was discovered on the basis of structural features of the GC in the matrix form of its presentation ("matrix genetics"). The octave Yin-Yang-algebra is considered as the pre-code or as the model of the GC. From the viewpoint of this algebraic model, for example, the sets of 20 amino acids and of 64 triplets consist of sub-sets of "male", "female" and "androgynous" molecules, etc. This algebra permits to reveal hidden peculiarities of the structure and evolution of the GC and to propose the conception of "sexual" relationships among genetic molecules. The first results of the analysis of the GC systems from such algebraic viewpoint say about the close connection between evolution of the GC and this algebra. They include 8 evolutionary rules of the dialects of the GC. The evolution of the GC is appeared as the stru...

  7. Novel Ciliate Genetic Code Variants Including the Reassignment of All Three Stop Codons to Sense Codons in Condylostoma magnum.

    Science.gov (United States)

    Heaphy, Stephen M; Mariotti, Marco; Gladyshev, Vadim N; Atkins, John F; Baranov, Pavel V

    2016-11-01

    mRNA translation in many ciliates utilizes variant genetic codes where stop codons are reassigned to specify amino acids. To characterize the repertoire of ciliate genetic codes, we analyzed ciliate transcriptomes from marine environments. Using codon substitution frequencies in ciliate protein-coding genes and their orthologs, we inferred the genetic codes of 24 ciliate species. Nine did not match genetic code tables currently assigned by NCBI. Surprisingly, we identified a novel genetic code where all three standard stop codons (TAA, TAG, and TGA) specify amino acids in Condylostoma magnum We provide evidence suggesting that the functions of these codons in C. magnum depend on their location within mRNA. They are decoded as amino acids at internal positions, but specify translation termination when in close proximity to an mRNA 3' end. The frequency of stop codons in protein coding sequences of closely related Climacostomum virens suggests that it may represent a transitory state. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  8. The Biosynthetic Order of Amino Acid Addition to the Genetic Code

    CERN Document Server

    Davis, B K

    2002-01-01

    The previously formulated model for the evolution of the genetic code was shown to clarify why base triplets of some precursor amino acids differ by a single base from product amino acid codons, while others show less homology. First, the model indicated that the direction of code evolution changed on expansion from the N-fixers code (stage 2). Growth of the code from 16 codons in the NAN column (N, any standard nucleotide) proceeded by assignment of codons in the GNN, ANN, CNN and UNN rows. Expansion phase (stage 4 to 7) precursor/product pairs that spanned this shift included aspartate/threonine, aspartate/methionine and glutamate/proline. Both 5' and mid-base differ in the codons of each of these pairs. Second, post-expansion additions (stage 9 to 14) required codon reassignment, eliminating initial correlations. Codons for the post-expansion pair, aspartate (glutamate)/arginine, also differ at both 5' and mid-base sites. Third, the distribution of core structure groups among acceptors indicated that varia...

  9. Rate-prediction structure complexity analysis for multi-view video coding using hybrid genetic algorithms

    Science.gov (United States)

    Liu, Yebin; Dai, Qionghai; You, Zhixiang; Xu, Wenli

    2007-01-01

    Efficient exploitation of the temporal and inter-view correlation is critical to multi-view video coding (MVC), and the key to it relies on the design of prediction chain structure according to the various pattern of correlations. In this paper, we propose a novel prediction structure model to design optimal MVC coding schemes along with tradeoff analysis in depth between compression efficiency and prediction structure complexity for certain standard functionalities. Focusing on the representation of the entire set of possible chain structures rather than certain typical ones, the proposed model can given efficient MVC schemes that adaptively vary with the requirements of structure complexity and video source characteristics (the number of views, the degrees of temporal and interview correlations). To handle large scale problem in model optimization, we deploy a hybrid genetic algorithm which yields satisfactory results shown in the simulations.

  10. Genetic algorithms applied to reconstructing coded imaging of neutrons and analysis of residual watermark.

    Science.gov (United States)

    Zhang, Tiankui; Hu, Huasi; Jia, Qinggang; Zhang, Fengna; Chen, Da; Li, Zhenghong; Wu, Yuelei; Liu, Zhihua; Hu, Guang; Guo, Wei

    2012-11-01

    Monte-Carlo simulation of neutron coded imaging based on encoding aperture for Z-pinch of large field-of-view with 5 mm radius has been investigated, and then the coded image has been obtained. Reconstruction method of source image based on genetic algorithms (GA) has been established. "Residual watermark," which emerges unavoidably in reconstructed image, while the peak normalization is employed in GA fitness calculation because of its statistical fluctuation amplification, has been discovered and studied. Residual watermark is primarily related to the shape and other parameters of the encoding aperture cross section. The properties and essential causes of the residual watermark were analyzed, while the identification on equivalent radius of aperture was provided. By using the equivalent radius, the reconstruction can also be accomplished without knowing the point spread function (PSF) of actual aperture. The reconstruction result is close to that by using PSF of the actual aperture.

  11. Genetic algorithms applied to reconstructing coded imaging of neutrons and analysis of residual watermark

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Tiankui; Hu Huasi; Jia Qinggang; Zhang Fengna; Liu Zhihua; Hu Guang; Guo Wei [School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); Chen Da [School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); College of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Li Zhenghong [Institute of Nuclear Physics and Chemistry, CAEP, Mianyang, 621900 Sichuan (China); Wu Yuelei [School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); Nuclear and Radiation Safety Centre, State Environmental Protection Administration (SEPA), Beijing 100082 (China)

    2012-11-15

    Monte-Carlo simulation of neutron coded imaging based on encoding aperture for Z-pinch of large field-of-view with 5 mm radius has been investigated, and then the coded image has been obtained. Reconstruction method of source image based on genetic algorithms (GA) has been established. 'Residual watermark,' which emerges unavoidably in reconstructed image, while the peak normalization is employed in GA fitness calculation because of its statistical fluctuation amplification, has been discovered and studied. Residual watermark is primarily related to the shape and other parameters of the encoding aperture cross section. The properties and essential causes of the residual watermark were analyzed, while the identification on equivalent radius of aperture was provided. By using the equivalent radius, the reconstruction can also be accomplished without knowing the point spread function (PSF) of actual aperture. The reconstruction result is close to that by using PSF of the actual aperture.

  12. Neural coding of cooperative vs. affective human interactions: 150 ms to code the action's purpose.

    Directory of Open Access Journals (Sweden)

    Alice Mado Proverbio

    Full Text Available The timing and neural processing of the understanding of social interactions was investigated by presenting scenes in which 2 people performed cooperative or affective actions. While the role of the human mirror neuron system (MNS in understanding actions and intentions is widely accepted, little is known about the time course within which these aspects of visual information are automatically extracted. Event-Related Potentials were recorded in 35 university students perceiving 260 pictures of cooperative (e.g., 2 people dragging a box or affective (e.g., 2 people smiling and holding hands interactions. The action's goal was automatically discriminated at about 150-170 ms, as reflected by occipito/temporal N170 response. The swLORETA inverse solution revealed the strongest sources in the right posterior cingulate cortex (CC for affective actions and in the right pSTS for cooperative actions. It was found a right hemispheric asymmetry that involved the fusiform gyrus (BA37, the posterior CC, and the medial frontal gyrus (BA10/11 for the processing of affective interactions, particularly in the 155-175 ms time window. In a later time window (200-250 ms the processing of cooperative interactions activated the left post-central gyrus (BA3, the left parahippocampal gyrus, the left superior frontal gyrus (BA10, as well as the right premotor cortex (BA6. Women showed a greater response discriminative of the action's goal compared to men at P300 and anterior negativity level (220-500 ms. These findings might be related to a greater responsiveness of the female vs. male MNS. In addition, the discriminative effect was bilateral in women and was smaller and left-sided in men. Evidence was provided that perceptually similar social interactions are discriminated on the basis of the agents' intentions quite early in neural processing, differentially activating regions devoted to face/body/action coding, the limbic system and the MNS.

  13. Synthesis of Site-Specific Radiolabeled Antibodies for Radioimmunotherapy via Genetic Code Expansion.

    Science.gov (United States)

    Wu, Yiming; Zhu, Hua; Zhang, Bo; Liu, Fei; Chen, Jingxian; Wang, Yufei; Wang, Yan; Zhang, Ziwei; Wu, Ling; Si, Longlong; Xu, Huan; Yao, Tianzhuo; Xiao, Sulong; Xia, Qing; Zhang, Lihe; Yang, Zhi; Zhou, Demin

    2016-10-19

    Radioimmunotherapy (RIT) delivers radioisotopes to antigen-expressing cells via monoantibodies for the imaging of lesions or medical therapy. The chelates are typically conjugated to the antibody through cysteine or lysine residues, resulting in heterogeneous chelate-to-antibody ratios and various conjugation sites. To overcome this heterogeneity, we have developed an approach for site-specific radiolabeling of antibodies by combination of genetic code expansion and click chemistry. As a proof-of-concept study, model systems including anti-CD20 antibody rituximab, positron-emitting isotope (64)Cu, and a newly synthesized bifunctional linker (4-dibenzocyclooctynol-1,4,7,10-tetraazacyclotetradecane-1,4,7,10-tetraacetic acid, DIBO-DOTA) were used. The approach consists of three steps: (1) site-specific incorporation of an azido group-bearing amino acid (NEAK) via the genetic code expansion technique at the defined sites of the antibody as a "chemical handle"; (2) site-specific and quantitative conjugation of bifunctional linkers with the antibodies under a mild condition; and (3) radiolabeling of the chelate-modified antibodies with the appropriate isotope. We used heavy-chain A122NEAK rituximab as proof-of-concept and obtained a homogeneous radioconjugate with precisely two chelates per antibody, incorporated only at the chosen sites. The conjugation did not alter the binding and pharmacokinetics of the rituximab, as indicated by in vitro assays and in vivo PET imaging. We believe our research is a good supplement to the genetic code expansion technique for the development of novel radioimmunoconjugates.

  14. Real-coded genetic algorithm for optimal vibration control of flexible structure

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Presents the study on the optimum location of actuators/sensors for active vibration control in aerospace flexible structures with the performance function first built by maximization of dissipation energy due to control action and a real-coded genetic algorithm then proposed to produce a global-optimum solution, and proves the feasibility and advantages of this algorithm with the example of a standard test function and a two-collocated actuators/sensors cantilever, and comparing the results with those given in the literatures.

  15. Improvements of real coded genetic algorithms based on differential operators preventing premature convergence

    CERN Document Server

    Hrstka, O; 10.1016/S0965-9978(03)00113-3

    2009-01-01

    This paper presents several types of evolutionary algorithms (EAs) used for global optimization on real domains. The interest has been focused on multimodal problems, where the difficulties of a premature convergence usually occurs. First the standard genetic algorithm (SGA) using binary encoding of real values and its unsatisfactory behavior with multimodal problems is briefly reviewed together with some improvements of fighting premature convergence. Two types of real encoded methods based on differential operators are examined in detail: the differential evolution (DE), a very modern and effective method firstly published by R. Storn and K. Price, and the simplified real-coded differential genetic algorithm SADE proposed by the authors. In addition, an improvement of the SADE method, called CERAF technology, enabling the population of solutions to escape from local extremes, is examined. All methods are tested on an identical set of objective functions and a systematic comparison based on a reliable method...

  16. Engineering the Genetic Code in Cells and Animals: Biological Considerations and Impacts.

    Science.gov (United States)

    Wang, Lei

    2017-10-06

    Expansion of the genetic code allows unnatural amino acids (Uaas) to be site-specifically incorporated into proteins in live biological systems, thus enabling novel properties selectively introduced into target proteins in vivo for basic biological studies and for engineering of novel biological functions. Orthogonal components including tRNA and aminoacyl-tRNA synthetase (aaRS) are expressed in live cells to decode a unique codon (often the amber stop codon UAG) as the desired Uaa. Initially developed in E. coli, this methodology has now been expanded in multiple eukaryotic cells and animals. In this Account, we focus on addressing various biological challenges for rewriting the genetic code, describing impacts of code expansion on cell physiology and discussing implications for fundamental studies of code evolution. Specifically, a general method using the type-3 polymerase III promoter was developed to efficiently express prokaryotic tRNAs as orthogonal tRNAs and a transfer strategy was devised to generate Uaa-specific aaRS for use in eukaryotic cells and animals. The aaRSs have been found to be highly amenable for engineering substrate specificity toward Uaas that are structurally far deviating from the native amino acid, dramatically increasing the stereochemical diversity of Uaas accessible. Preparation of the Uaa in ester or dipeptide format markedly increases the bioavailability of Uaas to cells and animals. Nonsense-mediated mRNA decay (NMD), an mRNA surveillance mechanism of eukaryotic cells, degrades mRNA containing a premature stop codon. Inhibition of NMD increases Uaa incorporation efficiency in yeast and Caenorhabditis elegans. In bacteria, release factor one (RF1) competes with the orthogonal tRNA for the amber stop codon to terminate protein translation, leading to low Uaa incorporation efficiency. Contradictory to the paradigm that RF1 is essential, it is discovered that RF1 is actually nonessential in E. coli. Knockout of RF1 dramatically

  17. Genetic Modification of Preimplantation Embryos: Toward Adequate Human Research Policies

    OpenAIRE

    Dresser, Rebecca

    2004-01-01

    Citing advances in transgenic animal research and setbacks in human trials of somatic cell genetic interventions, some scientists and others want to begin planning for research involving the genetic modification of human embryos. Because this form of genetic modification could affect later-born children and their offspring, the protection of human subjects should be a priority in decisions about whether to proceed with such research. Yet because of gaps in existing federal policies, embryo mo...

  18. Worldwide genetic and cultural change in human evolution.

    Science.gov (United States)

    Creanza, Nicole; Feldman, Marcus W

    2016-12-01

    Both genetic variation and certain culturally transmitted phenotypes show geographic signatures of human demographic history. As a result of the human cultural predisposition to migrate to new areas, humans have adapted to a large number of different environments. Migration to new environments alters genetic selection pressures, and comparative genetic studies have pinpointed numerous likely targets of this selection. However, humans also exhibit many cultural adaptations to new environments, such as practices related to clothing, shelter, and food. Human culture interacts with genes and the environment in complex ways, and studying genes and culture together can deepen our understanding of human evolution.

  19. The human genetic history of South Asia.

    Science.gov (United States)

    Majumder, Partha P

    2010-02-23

    South Asia--comprising India, Pakistan, countries in the sub-Himalayan region and Myanmar--was one of the first geographical regions to have been peopled by modern humans. This region has served as a major route of dispersal to other geographical regions, including southeast Asia. The Indian society comprises tribal, ranked caste, and other populations that are largely endogamous. As a result of evolutionary antiquity and endogamy, populations of India show high genetic differentiation and extensive structuring. Linguistic differences of populations provide the best explanation of genetic differences observed in this region of the world. Within India, consistent with social history, extant populations inhabiting northern regions show closer affinities with Indo-European speaking populations of central Asia that those inhabiting southern regions. Extant southern Indian populations may have been derived from early colonizers arriving from Africa along the southern exit route. The higher-ranked caste populations, who were the torch-bearers of Hindu rituals, show closer affinities with central Asian, Indo-European speaking, populations.

  20. Genetic modification of preimplantation embryos: toward adequate human research policies.

    Science.gov (United States)

    Dresser, Rebecca

    2004-01-01

    Citing advances in transgenic animal research and setbacks in human trials of somatic cell genetic interventions, some scientists and others want to begin planning for research involving the genetic modification of human embryos. Because this form of genetic modification could affect later-born children and their offspring, the protection of human subjects should be a priority in decisions about whether to proceed with such research. Yet because of gaps in existing federal policies, embryo modification proposals might not receive adequate scientific and ethical scrutiny. This article describes current policy shortcomings and recommends policy actions designed to ensure that the investigational genetic modification of embryos meets accepted standards for research on human subjects.

  1. Analysis of Dengue Virus Genetic Diversity during Human and Mosquito Infection Reveals Genetic Constraints.

    Science.gov (United States)

    Sessions, October M; Wilm, Andreas; Kamaraj, Uma Sangumathi; Choy, Milly M; Chow, Angelia; Chong, Yuwen; Ong, Xin Mei; Nagarajan, Niranjan; Cook, Alex R; Ooi, Eng Eong

    2015-01-01

    Dengue viruses (DENV) cause debilitating and potentially life-threatening acute disease throughout the tropical world. While drug development efforts are underway, there are concerns that resistant strains will emerge rapidly. Indeed, antiviral drugs that target even conserved regions in other RNA viruses lose efficacy over time as the virus mutates. Here, we sought to determine if there are regions in the DENV genome that are not only evolutionarily conserved but genetically constrained in their ability to mutate and could hence serve as better antiviral targets. High-throughput sequencing of DENV-1 genome directly from twelve, paired dengue patients' sera and then passaging these sera into the two primary mosquito vectors showed consistent and distinct sequence changes during infection. In particular, two residues in the NS5 protein coding sequence appear to be specifically acquired during infection in Ae. aegypti but not Ae. albopictus. Importantly, we identified a region within the NS3 protein coding sequence that is refractory to mutation during human and mosquito infection. Collectively, these findings provide fresh insights into antiviral targets and could serve as an approach to defining evolutionarily constrained regions for therapeutic targeting in other RNA viruses.

  2. Structural phylogenomics retrodicts the origin of the genetic code and uncovers the evolutionary impact of protein flexibility.

    Science.gov (United States)

    Caetano-Anollés, Gustavo; Wang, Minglei; Caetano-Anollés, Derek

    2013-01-01

    The genetic code shapes the genetic repository. Its origin has puzzled molecular scientists for over half a century and remains a long-standing mystery. Here we show that the origin of the genetic code is tightly coupled to the history of aminoacyl-tRNA synthetase enzymes and their interactions with tRNA. A timeline of evolutionary appearance of protein domain families derived from a structural census in hundreds of genomes reveals the early emergence of the 'operational' RNA code and the late implementation of the standard genetic code. The emergence of codon specificities and amino acid charging involved tight coevolution of aminoacyl-tRNA synthetases and tRNA structures as well as episodes of structural recruitment. Remarkably, amino acid and dipeptide compositions of single-domain proteins appearing before the standard code suggest archaic synthetases with structures homologous to catalytic domains of tyrosyl-tRNA and seryl-tRNA synthetases were capable of peptide bond formation and aminoacylation. Results reveal that genetics arose through coevolutionary interactions between polypeptides and nucleic acid cofactors as an exacting mechanism that favored flexibility and folding of the emergent proteins. These enhancements of phenotypic robustness were likely internalized into the emerging genetic system with the early rise of modern protein structure.

  3. Real Coded Genetic Algorithm Based Improvement of Efficiency in Interleaved Boost Converter

    Directory of Open Access Journals (Sweden)

    K Valarmathi

    2015-02-01

    Full Text Available   The reliability, efficiency, and controllability of Photo Voltaic power systems can be increased by embedding the components of a Boost Converter. Currently, the converter technology overcomes the main problems of manufacturing cost, efficiency and mass production. Issue to limit the life span of a Photo Voltaic inverter is the huge electrolytic capacitor across the Direct Current bus for energy decoupling. This paper presents a two-phase interleaved boost converter which ensures 180 angle phase shift between the two interleaved converters. The Proportional Integral controller is used to reshape that the controller attempts to minimize the error by adjusting the control inputs and also real coded genetic algorithm is proposed for tuning of controlling parameters of Proportional Integral controller. The real coded genetic algorithm is applied in the Interleaved Boost Converter with Advanced Pulse Width Modulation Techniques for improving the results of efficiency and reduction of ripple current. Simulation results illustrate the improvement of efficiency and the diminution of ripple current.

  4. Recurrent Coding Sequence Variation Explains Only A Small Fraction of the Genetic Architecture of Colorectal Cancer

    Science.gov (United States)

    Timofeeva, Maria N.; Kinnersley, Ben; Farrington, Susan M.; Whiffin, Nicola; Palles, Claire; Svinti, Victoria; Lloyd, Amy; Gorman, Maggie; Ooi, Li-Yin; Hosking, Fay; Barclay, Ella; Zgaga, Lina; Dobbins, Sara; Martin, Lynn; Theodoratou, Evropi; Broderick, Peter; Tenesa, Albert; Smillie, Claire; Grimes, Graeme; Hayward, Caroline; Campbell, Archie; Porteous, David; Deary, Ian J.; Harris, Sarah E.; Northwood, Emma L.; Barrett, Jennifer H.; Smith, Gillian; Wolf, Roland; Forman, David; Morreau, Hans; Ruano, Dina; Tops, Carli; Wijnen, Juul; Schrumpf, Melanie; Boot, Arnoud; Vasen, Hans F A; Hes, Frederik J.; van Wezel, Tom; Franke, Andre; Lieb, Wolgang; Schafmayer, Clemens; Hampe, Jochen; Buch, Stephan; Propping, Peter; Hemminki, Kari; Försti, Asta; Westers, Helga; Hofstra, Robert; Pinheiro, Manuela; Pinto, Carla; Teixeira, Manuel; Ruiz-Ponte, Clara; Fernández-Rozadilla, Ceres; Carracedo, Angel; Castells, Antoni; Castellví-Bel, Sergi; Campbell, Harry; Bishop, D. Timothy; Tomlinson, Ian P M; Dunlop, Malcolm G.; Houlston, Richard S.

    2015-01-01

    Whilst common genetic variation in many non-coding genomic regulatory regions are known to impart risk of colorectal cancer (CRC), much of the heritability of CRC remains unexplained. To examine the role of recurrent coding sequence variation in CRC aetiology, we genotyped 12,638 CRCs cases and 29,045 controls from six European populations. Single-variant analysis identified a coding variant (rs3184504) in SH2B3 (12q24) associated with CRC risk (OR = 1.08, P = 3.9 × 10−7), and novel damaging coding variants in 3 genes previously tagged by GWAS efforts; rs16888728 (8q24) in UTP23 (OR = 1.15, P = 1.4 × 10−7); rs6580742 and rs12303082 (12q13) in FAM186A (OR = 1.11, P = 1.2 × 10−7 and OR = 1.09, P = 7.4 × 10−8); rs1129406 (12q13) in ATF1 (OR = 1.11, P = 8.3 × 10−9), all reaching exome-wide significance levels. Gene based tests identified associations between CRC and PCDHGA genes (P < 2.90 × 10−6). We found an excess of rare, damaging variants in base-excision (P = 2.4 × 10−4) and DNA mismatch repair genes (P = 6.1 × 10−4) consistent with a recessive mode of inheritance. This study comprehensively explores the contribution of coding sequence variation to CRC risk, identifying associations with coding variation in 4 genes and PCDHG gene cluster and several candidate recessive alleles. However, these findings suggest that recurrent, low-frequency coding variants account for a minority of the unexplained heritability of CRC. PMID:26553438

  5. APPLICATION OF INTEGER CODING ACCELERATING GENETIC ALGORITHM IN RECTANGULAR CUTTING STOCK PROBLEM

    Institute of Scientific and Technical Information of China (English)

    FANG Hui; YIN Guofu; LI Haiqing; PENG Biyou

    2006-01-01

    An improved genetic algorithm and its application to resolve cutting stock problem are presented. It is common to apply simple genetic algorithm (SGA) to cutting stock problem, but the huge amount of computing of SGA is a serious problem in practical application. Accelerating genetic algorithm (AGA) based on integer coding and AGA's detailed steps are developed to reduce the amount of computation, and a new kind of rectangular parts blank layout algorithm is designed for rectangular cutting stock problem. SGA is adopted to produce individuals within given evolution process, and the variation interval of these individuals is taken as initial domain of the next optimization process, thus shrinks searching range intensively and accelerates the evaluation process of SGA.To enhance the diversity of population and to avoid the algorithm stagnates at local optimization result, fixed number of individuals are produced randomly and replace the same number of parents in every evaluation process. According to the computational experiment, it is observed that this improved GA converges much sooner than SGA, and is able to get the balance of good result and high efficiency in the process of optimization for rectangular cutting stock problem.

  6. Metabolic thrift and the genetic basis of human obesity

    OpenAIRE

    O’Rourke, Robert W.

    2014-01-01

    Evolution has molded metabolic thrift within humans, a genetic heritage that, when thrust into our modern “obesogenic” environment, creates the current obesity crisis. Modern genetic analysis has identified genetic and epigenetic contributors to obesity, an understanding of which will guide the development of environmental, pharmacologic, and genetic therapeutic interventions. “The voyage was so long, food and water ran out. One hundred of the paddlers died; forty men remained. The voyager...

  7. Can Using Human Examples Facilitate Learning Mendelian Genetics Concepts?

    Science.gov (United States)

    Moore, John M.; And Others

    1992-01-01

    Reports an experimental study of 80 ninth grade biology students randomly assigned to treatment and control groups to determine whether the use of human examples in instructional strategies on Mendelian genetics increases acquisition and retention of genetics concepts. Results indicate that use of human examples in contrast to traditional examples…

  8. Behavior genetic modeling of human fertility

    DEFF Research Database (Denmark)

    Rodgers, J L; Kohler, H P; Kyvik, K O;

    2001-01-01

    Try) and number of children (NumCh). Behavior genetic models were fitted using structural equation modeling and DF analysis. A consistent medium-level additive genetic influence was found for NumCh, equal across genders; a stronger genetic influence was identified for FirstTry, greater for females than for males...

  9. Postnatal Human Genetic Enhancement – A Consideration of Children’s Right to Be Genetically Enhanced

    OpenAIRE

    Tamir, Sivan

    2016-01-01

    This paper considers children’s rights with respect to genetic enhancement (GE). It is focused on the futuristic prospect of postnatal GE, namely, genetic modifications, in vivo, of actual existing individuals. More specifically, the paper examines whether, in a future reality where pre- and postnatal human GE is safely and prevalently practiced, a child would have a right to be genetically enhanced by her parents or guardians, as well as the right not to be genetically enhanced. It is in fac...

  10. Leveraging human genetics to guide drug target discovery.

    Science.gov (United States)

    Stitziel, Nathan O; Kathiresan, Sekar

    2017-07-01

    Identifying appropriate molecular targets is a critical step in drug development. Despite many advantages, the traditional tools of observational epidemiology and cellular or animal models of disease can be misleading in identifying causal pathways likely to lead to successful therapeutics. Here, we review some favorable aspects of human genetics studies that have the potential to accelerate drug target discovery. These include using genetic studies to identify pathways relevant to human disease, leveraging human genetics to discern causal relationships between biomarkers and disease, and studying genetic variation in humans to predict the potential efficacy and safety of inhibitory compounds aimed at molecular targets. We present some examples taken from studies of plasma lipids and coronary artery disease to highlight how human genetics can accelerate therapeutics development. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. An atlas of human long non-coding RNAs with accurate 5′ ends

    KAUST Repository

    Hon, Chung-Chau

    2017-02-28

    Long non-coding RNAs (lncRNAs) are largely heterogeneous and functionally uncharacterized. Here, using FANTOM5 cap analysis of gene expression (CAGE) data, we integrate multiple transcript collections to generate a comprehensive atlas of 27,919 human lncRNA genes with high-confidence 5′ ends and expression profiles across 1,829 samples from the major human primary cell types and tissues. Genomic and epigenomic classification of these lncRNAs reveals that most intergenic lncRNAs originate from enhancers rather than from promoters. Incorporating genetic and expression data, we show that lncRNAs overlapping trait-associated single nucleotide polymorphisms are specifically expressed in cell types relevant to the traits, implicating these lncRNAs in multiple diseases. We further demonstrate that lncRNAs overlapping expression quantitative trait loci (eQTL)-associated single nucleotide polymorphisms of messenger RNAs are co-expressed with the corresponding messenger RNAs, suggesting their potential roles in transcriptional regulation. Combining these findings with conservation data, we identify 19,175 potentially functional lncRNAs in the human genome.

  12. Genetic coding and united-hypercomplex systems in the models of algebraic biology.

    Science.gov (United States)

    Petoukhov, Sergey V

    2017-08-01

    Structured alphabets of DNA and RNA in their matrix form of representations are connected with Walsh functions and a new type of systems of multidimensional numbers. This type generalizes systems of complex numbers and hypercomplex numbers, which serve as the basis of mathematical natural sciences and many technologies. The new systems of multi-dimensional numbers have interesting mathematical properties and are called in a general case as "systems of united-hypercomplex numbers" (or briefly "U-hypercomplex numbers"). They can be widely used in models of multi-parametrical systems in the field of algebraic biology, artificial life, devices of biological inspired artificial intelligence, etc. In particular, an application of U-hypercomplex numbers reveals hidden properties of genetic alphabets under cyclic permutations in their doublets and triplets. A special attention is devoted to the author's hypothesis about a multi-linguistic in DNA-sequences in a relation with an ensemble of U-numerical sub-alphabets. Genetic multi-linguistic is considered as an important factor to provide noise-immunity properties of the multi-channel genetic coding. Our results attest to the conformity of the algebraic properties of the U-numerical systems with phenomenological properties of the DNA-alphabets and with the complementary device of the double DNA-helix. It seems that in the modeling field of algebraic biology the genetic-informational organization of living bodies can be considered as a set of united-hypercomplex numbers in some association with the famous slogan of Pythagoras "the numbers rule the world". Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Genetic differences between avian and human isolates of Candida dubliniensis.

    LENUS (Irish Health Repository)

    McManus, Brenda A

    2009-09-01

    When Candida dubliniensis isolates obtained from seabird excrement and from humans in Ireland were compared by using multilocus sequence typing, 13 of 14 avian isolates were genetically distinct from human isolates. The remaining avian isolate was indistinguishable from a human isolate, suggesting that transmission may occur between humans and birds.

  14. The Optimization of Dispersion Properties of Photonic Crystal Fibers Using a Real-Coded Genetic Algorithm

    Institute of Scientific and Technical Information of China (English)

    YIN Guo-Bing; LI Shu-Guang; LIU Shuo; WANG Xiao-Yan

    2011-01-01

    @@ A real-coded genetic algorithm (GA) combined with a fully vectorial effective index method (FVEIM) is employed to design structures of photonic crystal fibers (PCFs) with user defined dispersion properties theoretically.The structures of PCFs whose solid cores axe doped GeO with zero-dispersions at 0.7-3.9μm are optimized and the flat dispersion ranges through the R+L+C band and the negative dispersion is -1576.26 ps.km·nm at 1.55μm.Analyses show that the zero-dispersion wavelength (ZDW) could be one of many ZDWs for the same fiber structure; PCFs couM alter the dispersion to be flattened through the R+L+C band with a single air-hole diameter; and negative dispersion requires high air filling rate at 1.55μm.The method is proved to be elegant for solving this inverse problem.

  15. Photoactivatable Mussel-Based Underwater Adhesive Proteins by an Expanded Genetic Code.

    Science.gov (United States)

    Hauf, Matthias; Richter, Florian; Schneider, Tobias; Faidt, Thomas; Martins, Berta M; Baumann, Tobias; Durkin, Patrick; Dobbek, Holger; Jacobs, Karin; Möglich, Andreas; Budisa, Nediljko

    2017-09-19

    Marine mussels exhibit potent underwater adhesion abilities under hostile conditions by employing 3,4-dihydroxyphenylalanine (DOPA)-rich mussel adhesive proteins (MAPs). However, their recombinant production is a major biotechnological challenge. Herein, a novel strategy based on genetic code expansion has been developed by engineering efficient aminoacyl-transfer RNA synthetases (aaRSs) for the photocaged noncanonical amino acid ortho-nitrobenzyl DOPA (ONB-DOPA). The engineered ONB-DOPARS enables in vivo production of MAP type 5 site-specifically equipped with multiple instances of ONB-DOPA to yield photocaged, spatiotemporally controlled underwater adhesives. Upon exposure to UV light, these proteins feature elevated wet adhesion properties. This concept offers new perspectives for the production of recombinant bioadhesives. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Nonlinear System Identification with a Real–Coded Genetic Algorithm (RCGA

    Directory of Open Access Journals (Sweden)

    Cherif Imen

    2015-12-01

    Full Text Available This paper is devoted to the blind identification problem of a special class of nonlinear systems, namely, Volterra models, using a real-coded genetic algorithm (RCGA. The model input is assumed to be a stationary Gaussian sequence or an independent identically distributed (i.i.d. process. The order of the Volterra series is assumed to be known. The fitness function is defined as the difference between the calculated cumulant values and analytical equations in which the kernels and the input variances are considered. Simulation results and a comparative study for the proposed method and some existing techniques are given. They clearly show that the RCGA identification method performs better in terms of precision, time of convergence and simplicity of programming.

  17. Optimization of energy saving device combined with a propeller using real-coded genetic algorithm

    Directory of Open Access Journals (Sweden)

    Ryu Tomohiro

    2014-06-01

    Full Text Available This paper presents a numerical optimization method to improve the performance of the propeller with Turbo-Ring using real-coded genetic algorithm. In the presented method, Unimodal Normal Distribution Crossover (UNDX and Minimal Generation Gap (MGG model are used as crossover operator and generation-alternation model, respectively. Propeller characteristics are evaluated by a simple surface panel method “SQCM” in the optimization process. Blade sections of the original Turbo-Ring and propeller are replaced by the NACA66 a = 0.8 section. However, original chord, skew, rake and maximum blade thickness distributions in the radial direction are unchanged. Pitch and maximum camber distributions in the radial direction are selected as the design variables. Optimization is conducted to maximize the efficiency of the propeller with Turbo-Ring. The experimental result shows that the efficiency of the optimized propeller with Turbo-Ring is higher than that of the original propeller with Turbo-Ring.

  18. Aminoacyl-tRNA synthetases, the genetic code, and the evolutionary process.

    Science.gov (United States)

    Woese, C R; Olsen, G J; Ibba, M; Söll, D

    2000-03-01

    The aminoacyl-tRNA synthetases (AARSs) and their relationship to the genetic code are examined from the evolutionary perspective. Despite a loose correlation between codon assignments and AARS evolutionary relationships, the code is far too highly structured to have been ordered merely through the evolutionary wanderings of these enzymes. Nevertheless, the AARSs are very informative about the evolutionary process. Examination of the phylogenetic trees for each of the AARSs reveals the following. (i) Their evolutionary relationships mostly conform to established organismal phylogeny: a strong distinction exists between bacterial- and archaeal-type AARSs. (ii) Although the evolutionary profiles of the individual AARSs might be expected to be similar in general respects, they are not. It is argued that these differences in profiles reflect the stages in the evolutionary process when the taxonomic distributions of the individual AARSs became fixed, not the nature of the individual enzymes. (iii) Horizontal transfer of AARS genes between Bacteria and Archaea is asymmetric: transfer of archaeal AARSs to the Bacteria is more prevalent than the reverse, which is seen only for the "gemini group. " (iv) The most far-ranging transfers of AARS genes have tended to occur in the distant evolutionary past, before or during formation of the primary organismal domains. These findings are also used to refine the theory that at the evolutionary stage represented by the root of the universal phylogenetic tree, cells were far more primitive than their modern counterparts and thus exchanged genetic material in far less restricted ways, in effect evolving in a communal sense.

  19. Inferences of Recent and Ancient Human Population History Using Genetic and Non-Genetic Data

    Science.gov (United States)

    Kitchen, Andrew

    2008-01-01

    I have adopted complementary approaches to inferring human demographic history utilizing human and non-human genetic data as well as cultural data. These complementary approaches form an interdisciplinary perspective that allows one to make inferences of human history at varying timescales, from the events that occurred tens of thousands of years…

  20. Genetic contributions to human brain morphology and intelligence

    DEFF Research Database (Denmark)

    Hulshoff Pol, HE; Schnack, HG; Posthuma, D

    2006-01-01

    Variation in gray matter (GM) and white matter (WM) volume of the adult human brain is primarily genetically determined. Moreover, total brain volume is positively correlated with general intelligence, and both share a common genetic origin. However, although genetic effects on morphology...... of specific GM areas in the brain have been studied, the heritability of focal WM is unknown. Similarly, it is unresolved whether there is a common genetic origin of focal GM and WM structures with intelligence. We explored the genetic influence on focal GM and WM densities in magnetic resonance brain images.......55). Intelligence shared a common genetic origin with superior occipitofrontal, callosal, and left optical radiation WM and frontal, occipital, and parahippocampal GM (phenotypic correlations up to 0.35). These findings point to a neural network that shares a common genetic origin with human intelligence...

  1. Three stages during the evolution of the genetic code. [Abstract only

    Science.gov (United States)

    Baumann, U.; Oro, J.

    1994-01-01

    A diversification of the genetic code based on the number of codons available for the proteinous amino acids is established. Three groups of amino acids during evolution of the code are distinguished. On the basis of their chemical complexity and a small codon number those amino acids emerging later in a translation process are derived. Both criteria indicate that His, Phe, Tyr, Cys and either Lys or Asn were introduced in the second stage, whereas the number of codons alone gives evidence that Trp and Met were introduced in the third stage. The amino acids of stage one use purines rich codons, thus purines have been retained in their third codon position. All the amino acids introduced in the second stage, in contrast, use pyrimidines in this codon position. A low abundance of pyrimidines during early translation is derived. This assumption is supported by experiments on non enzymatic replication and interactions of DNA hairpin loops with a complementary strand. A back extrapolation concludes a high purine content of the first nucleic acids which gradually decreased during their evolution. Amino acids independently available form prebiotic synthesis were thus correlated to purine rich codons. Conclusions on prebiotic replication are discussed also in the light of recent codon usage data.

  2. A population genetics-phylogenetics approach to inferring natural selection in coding sequences.

    Directory of Open Access Journals (Sweden)

    Daniel J Wilson

    2011-12-01

    Full Text Available Through an analysis of polymorphism within and divergence between species, we can hope to learn about the distribution of selective effects of mutations in the genome, changes in the fitness landscape that occur over time, and the location of sites involved in key adaptations that distinguish modern-day species. We introduce a novel method for the analysis of variation in selection pressures within and between species, spatially along the genome and temporally between lineages. We model codon evolution explicitly using a joint population genetics-phylogenetics approach that we developed for the construction of multiallelic models with mutation, selection, and drift. Our approach has the advantage of performing direct inference on coding sequences, inferring ancestral states probabilistically, utilizing allele frequency information, and generalizing to multiple species. We use a Bayesian sliding window model for intragenic variation in selection coefficients that efficiently combines information across sites and captures spatial clustering within the genome. To demonstrate the utility of the method, we infer selective pressures acting in Drosophila melanogaster and D. simulans from polymorphism and divergence data for 100 X-linked coding regions.

  3. Bandwidth optimization of a Planar Inverted-F Antenna using binary and real coded genetic algorithms

    Institute of Scientific and Technical Information of China (English)

    AMEERUDDEN Mohammad Riyad; RUGHOOPUTH Harry C S

    2009-01-01

    With the exponential development of mobile communications and the miniaturization of radio frequency transceivers, the need for small and low profile antennas at mobile frequencies is constantly growing. Therefore, new antennas should be developed to provide larger bandwidth and at the same time small dimensions. Although the gain in bandwidth performances of an antenna are directly related to its dimensions in relation to the wavelength, the aim is to keep the overall size of the antenna constant and from there, find the geometry and structure that give the best performance. The design and bandwidth optimization of a Planar Inverted-F Antenna (PIFA) were introduced in order to achieve a larger bandwidth in the 2 GHz band, using two optimization techniques based upon genetic algorithms (GA), namely the Binary Coded GA (BCGA) and Real-Coded GA (RCGA). During the optimization process, the different PIFA models were evaluated using the finite-difference time domain (FDTD) method-a technique belonging to the general class of differential time domain numerical modeling methods.

  4. Intramolecular interactions in aminoacyl nucleotides: Implications regarding the origin of genetic coding and protein synthesis

    Science.gov (United States)

    Lacey, J. C., Jr.; Mullins, D. W., Jr.; Watkins, C. L.; Hall, L. M.

    1986-01-01

    Cellular organisms store information as sequences of nucleotides in double stranded DNA. This information is useless unless it can be converted into the active molecular species, protein. This is done in contemporary creatures first by transcription of one strand to give a complementary strand of mRNA. The sequence of nucleotides is then translated into a specific sequence of amino acids in a protein. Translation is made possible by a genetic coding system in which a sequence of three nucleotides codes for a specific amino acid. The origin and evolution of any chemical system can be understood through elucidation of the properties of the chemical entities which make up the system. There is an underlying logic to the coding system revealed by a correlation of the hydrophobicities of amino acids and their anticodonic nucleotides (i.e., the complement of the codon). Its importance lies in the fact that every amino acid going into protein synthesis must first be activated. This is universally accomplished with ATP. Past studies have concentrated on the chemistry of the adenylates, but more recently we have found, through the use of NMR, that we can observe intramolecular interactions even at low concentrations, between amino acid side chains and nucleotide base rings in these adenylates. The use of this type of compound thus affords a novel way of elucidating the manner in which amino acids and nucleotides interact with each other. In aqueous solution, when a hydrophobic amino acid is attached to the most hydrophobic nucleotide, AMP, a hydrophobic interaction takes place between the amino acid side chain and the adenine ring. The studies to be reported concern these hydrophobic interactions.

  5. A four-column theory for the origin of the genetic code: tracing the evolutionary pathways that gave rise to an optimized code

    Directory of Open Access Journals (Sweden)

    Higgs Paul G

    2009-04-01

    Full Text Available Abstract Background The arrangement of the amino acids in the genetic code is such that neighbouring codons are assigned to amino acids with similar physical properties. Hence, the effects of translational error are minimized with respect to randomly reshuffled codes. Further inspection reveals that it is amino acids in the same column of the code (i.e. same second base that are similar, whereas those in the same row show no particular similarity. We propose a 'four-column' theory for the origin of the code that explains how the action of selection during the build-up of the code leads to a final code that has the observed properties. Results The theory makes the following propositions. (i The earliest amino acids in the code were those that are easiest to synthesize non-biologically, namely Gly, Ala, Asp, Glu and Val. (ii These amino acids are assigned to codons with G at first position. Therefore the first code may have used only these codons. (iii The code rapidly developed into a four-column code where all codons in the same column coded for the same amino acid: NUN = Val, NCN = Ala, NAN = Asp and/or Glu, and NGN = Gly. (iv Later amino acids were added sequentially to the code by a process of subdivision of codon blocks in which a subset of the codons assigned to an early amino acid were reassigned to a later amino acid. (v Later amino acids were added into positions formerly occupied by amino acids with similar properties because this can occur with minimal disruption to the proteins already encoded by the earlier code. As a result, the properties of the amino acids in the final code retain a four-column pattern that is a relic of the earliest stages of code evolution. Conclusion The driving force during this process is not the minimization of translational error, but positive selection for the increased diversity and functionality of the proteins that can be made with a larger amino acid alphabet. Nevertheless, the code that results is one

  6. Some pungent arguments against the physico-chemical theories of the origin of the genetic code and corroborating the coevolution theory.

    Science.gov (United States)

    Di Giulio, Massimo

    2017-02-07

    Whereas it is extremely easy to prove that "if the biosynthetic relationships between amino acids were fundamental in the structuring of the genetic code, then their physico-chemical properties might also be revealed in the genetic code table"; it is, on the contrary, impossible to prove that "if the physico-chemical properties of amino acids were fundamental in the structuring of the genetic code, then the presence of the biosynthetic relationships between amino acids should not be revealed in the genetic code". And, given that in the genetic code table are mirrored both the biosynthetic relationships between amino acids and their physico-chemical properties, all this would be a test that would falsify the physico-chemical theories of the origin of the genetic code. That is to say, if the physico-chemical properties of amino acids had a fundamental role in organizing the genetic code, then we would not have duly revealed the presence - in the genetic code - of the biosynthetic relationships between amino acids, and on the contrary this has been observed. Therefore, this falsifies the physico-chemical theories of genetic code origin. Whereas, the coevolution theory of the origin of the genetic code would be corroborated by this analysis, because it would be able to give a description of evolution of the genetic code more coherent with the indisputable empirical observations that link both the biosynthetic relationships of amino acids and their physico-chemical properties to the evolutionary organization of the genetic code. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Translocation Properties of Primitive Molecular Machines and Their Relevance to the Structure of the Genetic Code

    CERN Document Server

    Aldana, M; Larralde, H; Martínez-Mekler, G; Aldana, Maximino; Cocho, Germinal; Larralde, Hernan; Martinez-Mekler, Gustavo

    2002-01-01

    We address the question, related with the origin of the genetic code, of why are there three bases per codon in the translation to protein process. As a followup to our previous work, we approach this problem by considering the translocation properties of primitive molecular machines, which capture basic features of ribosomal/messenger RNA interactions, while operating under prebiotic conditions. Our model consists of a short one-dimensional chain of charged particles(rRNA antecedent) interacting with a polymer (mRNA antecedent) via electrostatic forces. The chain is subject to external forcing that causes it to move along the polymer which is fixed in a quasi one dimensional geometry. Our numerical and analytic studies of statistical properties of random chain/polymer potentials suggest that, under very general conditions, a dynamics is attained in which the chain moves along the polymer in steps of three monomers. By adjusting the model in order to consider present day genetic sequences, we show that the ab...

  8. An orthogonalized platform for genetic code expansion in both bacteria and eukaryotes.

    Science.gov (United States)

    Italia, James S; Addy, Partha Sarathi; Wrobel, Chester J J; Crawford, Lisa A; Lajoie, Marc J; Zheng, Yunan; Chatterjee, Abhishek

    2017-02-13

    In this study, we demonstrate the feasibility of expanding the genetic code of Escherichia coli using its own tryptophanyl-tRNA synthetase and tRNA (TrpRS-tRNA(Trp)) pair. This was made possible by first functionally replacing this endogenous pair with an E. coli-optimized counterpart from Saccharomyces cerevisiae, and then reintroducing the liberated E. coli TrpRS-tRNA(Trp) pair into the resulting strain as a nonsense suppressor, which was then followed by its directed evolution to genetically encode several new unnatural amino acids (UAAs). These engineered TrpRS-tRNA(Trp) variants were also able to drive efficient UAA mutagenesis in mammalian cells. Since bacteria-derived aminoacyl-tRNA synthetase (aaRS)-tRNA pairs are typically orthogonal in eukaryotes, our work provides a general strategy to develop additional aaRS-tRNA pairs that can be used for UAA mutagenesis of proteins expressed in both E. coli and eukaryotes.

  9. A Real-coded Genetic Algorithm Applied to Optimum Design of a Low Solidity Vaned Diffuser for Diffuser Pump

    Institute of Scientific and Technical Information of China (English)

    Jun LI; Hiroshi TSUKAMOTO

    2001-01-01

    A numerical procedure for hydrodynamic redesign of the conventional vaned diffuser into the low solidity vaned diffuser by means of a real-ceded genetic algorithm with Boltzmann, Tournament and Roulette Wheel selection is presented. In the first part, an investigation on the relative efficiency of the different real-coded genetic algorithm is carried out on a typical mathematical test function. The real-coded genetic algorithm with Boltzmann selection shows the best optimization performance compared to the Tournament and Roulette Wheel selection. In the second part, an approach to redesign the vaned diffuser profile is introduced. Goal of the optimum design is to search the highest static pressure recovery coefficient and low solidity vaned diffuser. The result of the low solidity vaned diffuser optimum design confirms that the efficiency and optimization performance of the real-coded Boltzmann selection genetic algorithm outperforms the other selection methods. A comparison between the designed low solidity vaned diffuser and original vaned diffuser shows that the diffuser pump with the redesigned low solidity vaned diffuser has the higher static pressure recovery and improved total hydrodynamic performance. In addition,the smaller outlet diameter of designed vaned diffuser tends to a more compact size of diffuser pump compared to the original diffuser pump. The obtained results also demonstrate the real-coded Boltzmann selection genetic algorithm is a promising optimization algorithm for centrifugal pumps design.

  10. Seeking perfection: a Kantian look at human genetic engineering.

    Science.gov (United States)

    Gunderson, Martin

    2007-01-01

    It is tempting to argue that Kantian moral philosophy justifies prohibiting both human germ-line genetic engineering and non-therapeutic genetic engineering because they fail to respect human dignity. There are, however, good reasons for resisting this temptation. In fact, Kant's moral philosophy provides reasons that support genetic engineering-even germ-line and non-therapeutic. This is true of Kant's imperfect duties to seek one's own perfection and the happiness of others. It is also true of the categorical imperative. Kant's moral philosophy does, however, provide limits to justifiable genetic engineering.

  11. Organizing conceptual knowledge in humans with a gridlike code

    NARCIS (Netherlands)

    Constantinescu, A.O.; O'Reilly, J.X.; Behrens, T.E.J.

    2016-01-01

    Grid cells are thought to provide the neuronal code that underlies spatial knowledge in the brain. Grid cells have mostly been studied in the context of path integration. However, recent theoretical studies have suggested that they may have a broader role in the organization of general knowledge. Co

  12. Predictive coding for motion stimuli in human early visual cortex

    NARCIS (Netherlands)

    Schellekens, Wouter; van Wezel, Richard J A; Petridou, Natalia; Ramsey, Nick F.; Raemaekers, Mathijs

    2016-01-01

    The current study investigates if early visual cortical areas, V1, V2 and V3, use predictive coding to process motion information. Previous studies have reported biased visual motion responses at locations where novel visual information was presented (i.e., the motion trailing edge), which is plausi

  13. Predictive coding for motion stimuli in human early visual cortex

    NARCIS (Netherlands)

    Schellekens, Wouter; Wezel, van Richard J.A.; Petridou, Natalia; Ramsey, Nick F.; Raemeakers, Mathijs; Zaborszky, L.; Zilles, K.

    2014-01-01

    The current study investigates if early visual cortical areas, V1, V2 and V3, use predictive coding to process motion information. Previous studies have reported biased visual motion responses at locations where novel visual information was presented (i.e., the motion trailing edge), which is plausi

  14. Organizing conceptual knowledge in humans with a gridlike code

    NARCIS (Netherlands)

    Constantinescu, A.O.; O'Reilly, J.X.; Behrens, T.E.J.

    2016-01-01

    Grid cells are thought to provide the neuronal code that underlies spatial knowledge in the brain. Grid cells have mostly been studied in the context of path integration. However, recent theoretical studies have suggested that they may have a broader role in the organization of general knowledge.

  15. The Nuremberg Code subverts human health and safety by requiring animal modeling

    OpenAIRE

    Greek Ray; Pippus Annalea; Hansen Lawrence A

    2012-01-01

    Abstract Background The requirement that animals be used in research and testing in order to protect humans was formalized in the Nuremberg Code and subsequent national and international laws, codes, and declarations. Discussion We review the history of these requirements and contrast what was known via science about animal models then with what is known now. We further analyze the predictive...

  16. Reflections on the Field of Human Genetics: A Call for Increased Disease Genetics Theory.

    Science.gov (United States)

    Schrodi, Steven J

    2016-01-01

    Development of human genetics theoretical models and the integration of those models with experiment and statistical evaluation are critical for scientific progress. This perspective argues that increased effort in disease genetics theory, complementing experimental, and statistical efforts, will escalate the unraveling of molecular etiologies of complex diseases. In particular, the development of new, realistic disease genetics models will help elucidate complex disease pathogenesis, and the predicted patterns in genetic data made by these models will enable the concurrent, more comprehensive statistical testing of multiple aspects of disease genetics predictions, thereby better identifying disease loci. By theoretical human genetics, I intend to encompass all investigations devoted to modeling the heritable architecture underlying disease traits and studies of the resulting principles and dynamics of such models. Hence, the scope of theoretical disease genetics work includes construction and analysis of models describing how disease-predisposing alleles (1) arise, (2) are transmitted across families and populations, and (3) interact with other risk and protective alleles across both the genome and environmental factors to produce disease states. Theoretical work improves insight into viable genetic models of diseases consistent with empirical results from linkage, transmission, and association studies as well as population genetics. Furthermore, understanding the patterns of genetic data expected under realistic disease models will enable more powerful approaches to discover disease-predisposing alleles and additional heritable factors important in common diseases. In spite of the pivotal role of disease genetics theory, such investigation is not particularly vibrant.

  17. Insights into the genetic foundations of human communication.

    Science.gov (United States)

    Graham, Sarah A; Deriziotis, Pelagia; Fisher, Simon E

    2015-03-01

    The human capacity to acquire sophisticated language is unmatched in the animal kingdom. Despite the discontinuity in communicative abilities between humans and other primates, language is built on ancient genetic foundations, which are being illuminated by comparative genomics. The genetic architecture of the language faculty is also being uncovered by research into neurodevelopmental disorders that disrupt the normally effortless process of language acquisition. In this article, we discuss the strategies that researchers are using to reveal genetic factors contributing to communicative abilities, and review progress in identifying the relevant genes and genetic variants. The first gene directly implicated in a speech and language disorder was FOXP2. Using this gene as a case study, we illustrate how evidence from genetics, molecular cell biology, animal models and human neuroimaging has converged to build a picture of the role of FOXP2 in neurodevelopment, providing a framework for future endeavors to bridge the gaps between genes, brains and behavior.

  18. Fetal magnetic resonance imaging and human genetics

    Energy Technology Data Exchange (ETDEWEB)

    Hengstschlaeger, Markus [Medical Genetics, Obstetrics and Gynecology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna (Austria)]. E-mail: markus.hengstschlaeger@meduniwien.ac.at

    2006-02-15

    The use of fetal magnetic resonance imaging (MRI), in addition to prenatal genetic testing and sonography, has the potential to improve prenatal diagnosis of genetic disorders. MRI plays an important role in the evaluation of fetal abnormalities and malformations. Fetal MRI often enables a differential diagnosis, a determination of the extent of the disorder, the prognosis, and an improvement in therapeutic management. For counseling of parents, as well as to basically understand how genetic aberrations affect fetal development, it is of great importance to correlate different genotypes with fetal MRI data.

  19. Animal models for human genetic diseases

    African Journals Online (AJOL)

    Sharif Sons

    organisms are extensively used in applied research in agriculture, industry, and also in medicine, where they are ... in genetic disorder that is critical for embryonic .... by practical limitations and ethical concerns. ..... American journal of medical.

  20. Molecular genetics of human pigmentation diversity

    National Research Council Canada - National Science Library

    Sturm, Richard A

    2009-01-01

    The genetic basis underlying normal variation in the pigmentary traits of skin, hair and eye colour has been the subject of intense research directed at understanding the diversity seen both between...

  1. The role of genetic variants in human longevity.

    Science.gov (United States)

    Chung, Wen-Hung; Dao, Ro-Lan; Chen, Liang-Kung; Hung, Shuen-Iu

    2010-11-01

    Human longevity is a complex phenotype with a strong genetic predisposition. Increasing evidence has revealed the genetic antecedents of human longevity. This article aims to review the data of various case/control association studies that examine the difference in genetic polymorphisms between long-lived people and younger subjects across different human populations. There are more than 100 candidate genes potentially involved in human longevity; this article particularly focuses on genes of the insulin/IGF-1 pathway, FOXO3A, FOXO1A, lipoprotein metabolism (e.g., APOE and PON1), and cell-cycle regulators (e.g., TP53 and P21). Since the confirmed genetic components for human longevity are few to date, further precise assessment of the genetic contributions is required. Gaining a better understanding of the contribution of genetics to human longevity may assist in the design of improved treatment methods for age-related diseases, delay the aging process, and, ultimately, prolong the human lifespan.

  2. Discovery of coding genetic variants influencing diabetes-related serum biomarkers and their impact on risk of type 2 diabetes

    DEFF Research Database (Denmark)

    Ahluwalia, Tarun Veer Singh; Allin, Kristine Højgaard; Sandholt, Camilla Helene;

    2015-01-01

    CONTEXT: Type 2 diabetes (T2D) prevalence is spiraling globally, and knowledge of its pathophysiological signatures is crucial for a better understanding and treatment of the disease. OBJECTIVE: We aimed to discover underlying coding genetic variants influencing fasting serum levels of nine...

  3. Global human genetics of HIV-1 infection and China

    Institute of Scientific and Technical Information of China (English)

    Tuo Fu ZHU; Tie Jian FENG; Xin XIAO; Hui WANG; Bo Ping ZHOU

    2005-01-01

    Genetic polymorphisms in human genes can influence the risk for HIV-1 infection and disease progression, although the reported effects of these alleles have been inconsistent. This review highlights the recent discoveries on global and Chinese genetic polymorphisms and their association with HIV-1 transmission and disease progression.

  4. The etiology and molecular genetics of human pigmentation disorders.

    Science.gov (United States)

    Baxter, Laura L; Pavan, William J

    2013-01-01

    Pigmentation, defined as the placement of pigment in skin, hair, and eyes for coloration, is distinctive because the location, amount, and type of pigmentation provides a visual manifestation of genetic heterogeneity in pathways regulating the pigment-producing cells, melanocytes. The scope of this genetic heterogeneity in humans ranges from normal to pathological pigmentation phenotypes. Clinically, normal human pigmentation encompasses a variety of skin and hair color as well as punctate pigmentation such as melanocytic nevi (moles) or ephelides (freckles), while abnormal human pigmentation exhibits markedly reduced or increased pigment levels, known as hypopigmentation and hyperpigmentation, respectively. Elucidation of the molecular genetics underlying pigmentation has revealed genes important for melanocyte development and function. Furthermore, many pigmentation disorders show additional defects in cells other than melanocytes, and identification of the genetic insults in these disorders has revealed pleiotropic genes, where a single gene is required for various functions in different cell types. Thus, unravelling the genetics of easily visualized pigmentation disorders has identified molecular similarities between melanocytes and less visible cell types/tissues, arising from a common developmental origin and/or shared genetic regulatory pathways. Herein we discuss notable human pigmentation disorders and their associated genetic alterations, focusing on the fact that the developmental genetics of pigmentation abnormalities are instructive for understanding normal pathways governing development and function of melanocytes. Copyright © 2012 Wiley Periodicals, Inc.

  5. An integrated map of genetic variation from 1.092 human genomes

    DEFF Research Database (Denmark)

    Abecasis, Goncalo R.; Auton, Adam; Brooks, Lisa D.

    2012-01-01

    By characterizing the geographic and functional spectrum of human genetic variation, the 1000 Genomes Project aims to build a resource to help to understand the genetic contribution to disease. Here we describe the genomes of 1,092 individuals from 14 populations, constructed using a combination...... deletions. We show that individuals from different populations carry different profiles of rare and common variants, and that low-frequency variants show substantial geographic differentiation, which is further increased by the action of purifying selection. We show that evolutionary conservation and coding...... consequence are key determinants of the strength of purifying selection, that rare-variant load varies substantially across biological pathways, and that each individual contains hundreds of rare non-coding variants at conserved sites, such as motif-disrupting changes in transcription-factor-binding sites...

  6. Use of fluorescent proteins and color-coded imaging to visualize cancer cells with different genetic properties.

    Science.gov (United States)

    Hoffman, Robert M

    2016-03-01

    Fluorescent proteins are very bright and available in spectrally-distinct colors, enable the imaging of color-coded cancer cells growing in vivo and therefore the distinction of cancer cells with different genetic properties. Non-invasive and intravital imaging of cancer cells with fluorescent proteins allows the visualization of distinct genetic variants of cancer cells down to the cellular level in vivo. Cancer cells with increased or decreased ability to metastasize can be distinguished in vivo. Gene exchange in vivo which enables low metastatic cancer cells to convert to high metastatic can be color-coded imaged in vivo. Cancer stem-like and non-stem cells can be distinguished in vivo by color-coded imaging. These properties also demonstrate the vast superiority of imaging cancer cells in vivo with fluorescent proteins over photon counting of luciferase-labeled cancer cells.

  7. Application of Projection Pursuit Evaluation Model Based on Real-Coded Accelerating Genetic Algorithm in Evaluating Wetland Soil Quality Variations in the Sanjiang Plain,China

    Institute of Scientific and Technical Information of China (English)

    FU QIANG; XIE YONGGANG; WEI ZIMIN

    2003-01-01

    A new technique of dimension reduction named projection pursuit is applied to model and evaluatewetland soil quality variations in the Sanjiang Plain, Helongjiang Province, China. By adopting the im-proved real-coded accelerating genetic algorithm (RAGA), the projection direction is optimized and multi-dimensional indexes are converted into low-dimensional space. Classification of wetland soils and evaluationof wetland soil quality variations are realized by pursuing optimum projection direction and projection func-tion value. Therefore, by adopting this new method, any possible human interference can be avoided andsound results can be achieved in researching quality changes and classification of wetland soils.

  8. Differential DNA methylation profiles of coding and non-coding genes define hippocampal sclerosis in human temporal lobe epilepsy.

    Science.gov (United States)

    Miller-Delaney, Suzanne F C; Bryan, Kenneth; Das, Sudipto; McKiernan, Ross C; Bray, Isabella M; Reynolds, James P; Gwinn, Ryder; Stallings, Raymond L; Henshall, David C

    2015-03-01

    Temporal lobe epilepsy is associated with large-scale, wide-ranging changes in gene expression in the hippocampus. Epigenetic changes to DNA are attractive mechanisms to explain the sustained hyperexcitability of chronic epilepsy. Here, through methylation analysis of all annotated C-phosphate-G islands and promoter regions in the human genome, we report a pilot study of the methylation profiles of temporal lobe epilepsy with or without hippocampal sclerosis. Furthermore, by comparative analysis of expression and promoter methylation, we identify methylation sensitive non-coding RNA in human temporal lobe epilepsy. A total of 146 protein-coding genes exhibited altered DNA methylation in temporal lobe epilepsy hippocampus (n = 9) when compared to control (n = 5), with 81.5% of the promoters of these genes displaying hypermethylation. Unique methylation profiles were evident in temporal lobe epilepsy with or without hippocampal sclerosis, in addition to a common methylation profile regardless of pathology grade. Gene ontology terms associated with development, neuron remodelling and neuron maturation were over-represented in the methylation profile of Watson Grade 1 samples (mild hippocampal sclerosis). In addition to genes associated with neuronal, neurotransmitter/synaptic transmission and cell death functions, differential hypermethylation of genes associated with transcriptional regulation was evident in temporal lobe epilepsy, but overall few genes previously associated with epilepsy were among the differentially methylated. Finally, a panel of 13, methylation-sensitive microRNA were identified in temporal lobe epilepsy including MIR27A, miR-193a-5p (MIR193A) and miR-876-3p (MIR876), and the differential methylation of long non-coding RNA documented for the first time. The present study therefore reports select, genome-wide DNA methylation changes in human temporal lobe epilepsy that may contribute to the molecular architecture of the epileptic brain.

  9. Differential DNA methylation profiles of coding and non-coding genes define hippocampal sclerosis in human temporal lobe epilepsy

    Science.gov (United States)

    Miller-Delaney, Suzanne F.C.; Bryan, Kenneth; Das, Sudipto; McKiernan, Ross C.; Bray, Isabella M.; Reynolds, James P.; Gwinn, Ryder; Stallings, Raymond L.

    2015-01-01

    Temporal lobe epilepsy is associated with large-scale, wide-ranging changes in gene expression in the hippocampus. Epigenetic changes to DNA are attractive mechanisms to explain the sustained hyperexcitability of chronic epilepsy. Here, through methylation analysis of all annotated C-phosphate-G islands and promoter regions in the human genome, we report a pilot study of the methylation profiles of temporal lobe epilepsy with or without hippocampal sclerosis. Furthermore, by comparative analysis of expression and promoter methylation, we identify methylation sensitive non-coding RNA in human temporal lobe epilepsy. A total of 146 protein-coding genes exhibited altered DNA methylation in temporal lobe epilepsy hippocampus (n = 9) when compared to control (n = 5), with 81.5% of the promoters of these genes displaying hypermethylation. Unique methylation profiles were evident in temporal lobe epilepsy with or without hippocampal sclerosis, in addition to a common methylation profile regardless of pathology grade. Gene ontology terms associated with development, neuron remodelling and neuron maturation were over-represented in the methylation profile of Watson Grade 1 samples (mild hippocampal sclerosis). In addition to genes associated with neuronal, neurotransmitter/synaptic transmission and cell death functions, differential hypermethylation of genes associated with transcriptional regulation was evident in temporal lobe epilepsy, but overall few genes previously associated with epilepsy were among the differentially methylated. Finally, a panel of 13, methylation-sensitive microRNA were identified in temporal lobe epilepsy including MIR27A, miR-193a-5p (MIR193A) and miR-876-3p (MIR876), and the differential methylation of long non-coding RNA documented for the first time. The present study therefore reports select, genome-wide DNA methylation changes in human temporal lobe epilepsy that may contribute to the molecular architecture of the epileptic brain. PMID

  10. The role of crossover operator in evolutionary-based approach to the problem of genetic code optimization.

    Science.gov (United States)

    Błażej, Paweł; Wnȩtrzak, Małgorzata; Mackiewicz, Paweł

    2016-12-01

    One of theories explaining the present structure of canonical genetic code assumes that it was optimized to minimize harmful effects of amino acid replacements resulting from nucleotide substitutions and translational errors. A way to testify this concept is to find the optimal code under given criteria and compare it with the canonical genetic code. Unfortunately, the huge number of possible alternatives makes it impossible to find the optimal code using exhaustive methods in sensible time. Therefore, heuristic methods should be applied to search the space of possible solutions. Evolutionary algorithms (EA) seem to be ones of such promising approaches. This class of methods is founded both on mutation and crossover operators, which are responsible for creating and maintaining the diversity of candidate solutions. These operators possess dissimilar characteristics and consequently play different roles in the process of finding the best solutions under given criteria. Therefore, the effective searching for the potential solutions can be improved by applying both of them, especially when these operators are devised specifically for a given problem. To study this subject, we analyze the effectiveness of algorithms for various combinations of mutation and crossover probabilities under three models of the genetic code assuming different restrictions on its structure. To achieve that, we adapt the position based crossover operator for the most restricted model and develop a new type of crossover operator for the more general models. The applied fitness function describes costs of amino acid replacement regarding their polarity. Our results indicate that the usage of crossover operators can significantly improve the quality of the solutions. Moreover, the simulations with the crossover operator optimize the fitness function in the smaller number of generations than simulations without this operator. The optimal genetic codes without restrictions on their structure

  11. Genetic Expeditions with Haploid Human Cells

    NARCIS (Netherlands)

    Jae, L.T.

    2015-01-01

    Random mutagenesis followed by phenotypic selection (forward genetics) is among the most powerful tools to elucidate the molecular basis of intricate biological processes and has been used in a suite of model organisms throughout the last century. However, its application to cultured mammalian cells

  12. Molecular Genetic Study of Human Esophageal Carcinoma

    Science.gov (United States)

    1991-07-16

    carcinogenic processes ( Doerfler , 1983). Direct evidence has shown that the DNA alkylation product, o’-methyl deoxyguanosine was higher in the DNA...of north China and the genetic approach to its control. Genes and Disease, (Science Press, Beijing, China) 1985. Doerfler , W. DNA methylation and

  13. Human Handedness: More Evidence for Genetic Involvement.

    Science.gov (United States)

    Longstreth, Langdon E.

    1980-01-01

    A series of environmental-genetical analyses of the left-handedness of 1,950 college students indicates that left-handedness is familial: it is more frequent in families in which at least one parent is left-handed. (Author/CM)

  14. A global reference for human genetic variation

    DEFF Research Database (Denmark)

    Auton, Adam; Abecasis, Goncalo R.; M. Altshuler, David;

    2015-01-01

    insertions/deletions (indels), and 60,000 structural variants), all phased onto high-quality haplotypes. This resource includes >99% of SNP variants with a frequency of >1% for a variety of ancestries. We describe the distribution of genetic variation across the global sample, and discuss the implications...

  15. Genetic Expeditions with Haploid Human Cells

    NARCIS (Netherlands)

    Jae, L.T.

    2015-01-01

    Random mutagenesis followed by phenotypic selection (forward genetics) is among the most powerful tools to elucidate the molecular basis of intricate biological processes and has been used in a suite of model organisms throughout the last century. However, its application to cultured mammalian cells

  16. Human embryonic stem cells carrying mutations for severe genetic disorders.

    Science.gov (United States)

    Frumkin, Tsvia; Malcov, Mira; Telias, Michael; Gold, Veronica; Schwartz, Tamar; Azem, Foad; Amit, Ami; Yaron, Yuval; Ben-Yosef, Dalit

    2010-04-01

    Human embryonic stem cells (HESCs) carrying specific mutations potentially provide a valuable tool for studying genetic disorders in humans. One preferable approach for obtaining these cell lines is by deriving them from affected preimplantation genetically diagnosed embryos. These unique cells are especially important for modeling human genetic disorders for which there are no adequate research models. They can be further used to gain new insights into developmentally regulated events that occur during human embryo development and that are responsible for the manifestation of genetically inherited disorders. They also have great value for the exploration of new therapeutic protocols, including gene-therapy-based treatments and disease-oriented drug screening and discovery. Here, we report the establishment of 15 different mutant human embryonic stem cell lines derived from genetically affected embryos, all donated by couples undergoing preimplantation genetic diagnosis in our in vitro fertilization unit. For further information regarding access to HESC lines from our repository, for research purposes, please email dalitb@tasmc.health.gov.il.

  17. The aminoacyl-tRNA synthetases had only a marginal role in the origin of the organization of the genetic code: Evidence in favor of the coevolution theory.

    Science.gov (United States)

    Di Giulio, Massimo

    2017-11-07

    The coevolution theory of the origin of the genetic code suggests that the organization of the genetic code coevolved with the biosynthetic relationships between amino acids. The mechanism that allowed this coevolution was based on tRNA-like molecules on which-this theory-would postulate the biosynthetic transformations between amino acids to have occurred. This mechanism makes a prediction on how the role conducted by the aminoacyl-tRNA synthetases (ARSs), in the origin of the genetic code, should have been. Indeed, if the biosynthetic transformations between amino acids occurred on tRNA-like molecules, then there was no need to link amino acids to these molecules because amino acids were already charged on tRNA-like molecules, as the coevolution theory suggests. In spite of the fact that ARSs make the genetic code responsible for the first interaction between a component of nucleic acids and that of proteins, for the coevolution theory the role of ARSs should have been entirely marginal in the genetic code origin. Therefore, I have conducted a further analysis of the distribution of the two classes of ARSs and of their subclasses-in the genetic code table-in order to perform a falsification test of the coevolution theory. Indeed, in the case in which the distribution of ARSs within the genetic code would have been highly significant, then the coevolution theory would be falsified since the mechanism on which it is based would not predict a fundamental role of ARSs in the origin of the genetic code. I found that the statistical significance of the distribution of the two classes of ARSs in the table of the genetic code is low or marginal, whereas that of the subclasses of ARSs statistically significant. However, this is in perfect agreement with the postulates of the coevolution theory. Indeed, the only case of statistical significance-regarding the classes of ARSs-is appreciable for the CAG code, whereas for its complement-the UNN/NUN code-only a marginal

  18. Genetic variants of the human dipeptide transporter PEPT1

    DEFF Research Database (Denmark)

    Anderle, Pascale; Nielsen, Carsten Uhd; Pinsonneault, Julia

    2006-01-01

    We tested whether genetic polymorphisms affect activity of the dipeptide transporter PEPT1, which mediates bioavailability of peptidomimetic drugs. All 23 exons and adjoining intronic sections of PEPT1 (SLC15A1) were sequenced in 247 individuals of various ethnic origins (Coriell collection). Of 38...... single nucleotide polymorphisms (SNPs), 21 occurred in intronic and non-coding regions and 17 in exonic coding region, of which nine were nonsynonymous. Eight nonsynonymous variants were cloned into expression vectors and functionally characterized after transient transfection into Cos7 and Chinese...... formation of a splice variant (PEPT1-RF). PEPT1-RF mRNA levels ranged from 2 to 44% of total PEPT1-related mRNA, with potential consequences for drug absorption. Together with previous results, this study reveals a relatively low level of genetic variability in polymorphisms affecting both protein function...

  19. Experimental studies related to the origin of the genetic code and the process of protein synthesis - A review

    Science.gov (United States)

    Lacey, J. C., Jr.; Mullins, D. W., Jr.

    1983-01-01

    A survey is presented of the literature on the experimental evidence for the genetic code assignments and the chemical reactions involved in the process of protein synthesis. In view of the enormous number of theoretical models that have been advanced to explain the origin of the genetic code, attention is confined to experimental studies. Since genetic coding has significance only within the context of protein synthesis, it is believed that the problem of the origin of the code must be dealt with in terms of the origin of the process of protein synthesis. It is contended that the answers must lie in the nature of the molecules, amino acids and nucleotides, the affinities they might have for one another, and the effect that those affinities must have on the chemical reactions that are related to primitive protein synthesis. The survey establishes that for the bulk of amino acids, there is a direct and significant correlation between the hydrophobicity rank of the amino acids and the hydrophobicity rank of their anticodonic dinucleotides.

  20. Experimental studies related to the origin of the genetic code and the process of protein synthesis - A review

    Science.gov (United States)

    Lacey, J. C., Jr.; Mullins, D. W., Jr.

    1983-01-01

    A survey is presented of the literature on the experimental evidence for the genetic code assignments and the chemical reactions involved in the process of protein synthesis. In view of the enormous number of theoretical models that have been advanced to explain the origin of the genetic code, attention is confined to experimental studies. Since genetic coding has significance only within the context of protein synthesis, it is believed that the problem of the origin of the code must be dealt with in terms of the origin of the process of protein synthesis. It is contended that the answers must lie in the nature of the molecules, amino acids and nucleotides, the affinities they might have for one another, and the effect that those affinities must have on the chemical reactions that are related to primitive protein synthesis. The survey establishes that for the bulk of amino acids, there is a direct and significant correlation between the hydrophobicity rank of the amino acids and the hydrophobicity rank of their anticodonic dinucleotides.

  1. Single nucleotide polymorphisms with cis-regulatory effects on long non-coding transcripts in human primary monocytes.

    Directory of Open Access Journals (Sweden)

    Jonas Carlsson Almlöf

    Full Text Available We applied genome-wide allele-specific expression analysis of monocytes from 188 samples. Monocytes were purified from white blood cells of healthy blood donors to detect cis-acting genetic variation that regulates the expression of long non-coding RNAs. We analysed 8929 regions harboring genes for potential long non-coding RNA that were retrieved from data from the ENCODE project. Of these regions, 60% were annotated as intergenic, which implies that they do not overlap with protein-coding genes. Focusing on the intergenic regions, and using stringent analysis of the allele-specific expression data, we detected robust cis-regulatory SNPs in 258 out of 489 informative intergenic regions included in the analysis. The cis-regulatory SNPs that were significantly associated with allele-specific expression of long non-coding RNAs were enriched to enhancer regions marked for active or bivalent, poised chromatin by histone modifications. Out of the lncRNA regions regulated by cis-acting regulatory SNPs, 20% (n = 52 were co-regulated with the closest protein coding gene. We compared the identified cis-regulatory SNPs with those in the catalog of SNPs identified by genome-wide association studies of human diseases and traits. This comparison identified 32 SNPs in loci from genome-wide association studies that displayed a strong association signal with allele-specific expression of non-coding RNAs in monocytes, with p-values ranging from 6.7×10(-7 to 9.5×10(-89. The identified cis-regulatory SNPs are associated with diseases of the immune system, like multiple sclerosis and rheumatoid arthritis.

  2. Genetic engineering of human pluripotent cells using TALE nucleases.

    Science.gov (United States)

    Hockemeyer, Dirk; Wang, Haoyi; Kiani, Samira; Lai, Christine S; Gao, Qing; Cassady, John P; Cost, Gregory J; Zhang, Lei; Santiago, Yolanda; Miller, Jeffrey C; Zeitler, Bryan; Cherone, Jennifer M; Meng, Xiangdong; Hinkley, Sarah J; Rebar, Edward J; Gregory, Philip D; Urnov, Fyodor D; Jaenisch, Rudolf

    2011-07-07

    Targeted genetic engineering of human pluripotent cells is a prerequisite for exploiting their full potential. Such genetic manipulations can be achieved using site-specific nucleases. Here we engineered transcription activator-like effector nucleases (TALENs) for five distinct genomic loci. At all loci tested we obtained human embryonic stem cell (ESC) and induced pluripotent stem cell (iPSC) clones carrying transgenic cassettes solely at the TALEN-specified location. Our data suggest that TALENs employing the specific architectures described here mediate site-specific genome modification in human pluripotent cells with similar efficiency and precision as do zinc-finger nucleases (ZFNs).

  3. Quantum Genetics in terms of Quantum Reversible Automata and Quantum Computation of Genetic Codes and Reverse Transcription

    CERN Document Server

    Baianu,I C

    2004-01-01

    The concepts of quantum automata and quantum computation are studied in the context of quantum genetics and genetic networks with nonlinear dynamics. In previous publications (Baianu,1971a, b) the formal concept of quantum automaton and quantum computation, respectively, were introduced and their possible implications for genetic processes and metabolic activities in living cells and organisms were considered. This was followed by a report on quantum and abstract, symbolic computation based on the theory of categories, functors and natural transformations (Baianu,1971b; 1977; 1987; 2004; Baianu et al, 2004). The notions of topological semigroup, quantum automaton, or quantum computer, were then suggested with a view to their potential applications to the analogous simulation of biological systems, and especially genetic activities and nonlinear dynamics in genetic networks. Further, detailed studies of nonlinear dynamics in genetic networks were carried out in categories of n-valued, Lukasiewicz Logic Algebra...

  4. A Model of Genetic Variation in Human Social Networks

    CERN Document Server

    Fowler, James H; Christakis, Nicholas A

    2008-01-01

    Social networks influence the evolution of cooperation and they exhibit strikingly systematic patterns across a wide range of human contexts. Both of these facts suggest that variation in the topological attributes of human social networks might have a genetic basis. While genetic variation accounts for a significant portion of the variation in many complex social behaviors, the heritability of egocentric social network attributes is unknown. Here we show that three of these attributes (in-degree, transitivity, and centrality) are heritable. We then develop a "mirror network" method to test extant network models and show that none accounts for observed genetic variation in human social networks. We propose an alternative "attract and introduce" model that generates significant heritability as well as other important network features, and we show that this model with two simple forms of heterogeneity is well suited to the modeling of real social networks in humans. These results suggest that natural selection ...

  5. A binary mixed integer coded genetic algorithm for multi-objective optimization of nuclear research reactor fuel reloading

    Energy Technology Data Exchange (ETDEWEB)

    Binh, Do Quang [University of Technical Education Ho Chi Minh City (Viet Nam); Huy, Ngo Quang [University of Industry Ho Chi Minh City (Viet Nam); Hai, Nguyen Hoang [Centre for Research and Development of Radiation Technology, Ho Chi Minh City (Viet Nam)

    2014-12-15

    This paper presents a new approach based on a binary mixed integer coded genetic algorithm in conjunction with the weighted sum method for multi-objective optimization of fuel loading patterns for nuclear research reactors. The proposed genetic algorithm works with two types of chromosomes: binary and integer chromosomes, and consists of two types of genetic operators: one working on binary chromosomes and the other working on integer chromosomes. The algorithm automatically searches for the most suitable weighting factors of the weighting function and the optimal fuel loading patterns in the search process. Illustrative calculations are implemented for a research reactor type TRIGA MARK II loaded with the Russian VVR-M2 fuels. Results show that the proposed genetic algorithm can successfully search for both the best weighting factors and a set of approximate optimal loading patterns that maximize the effective multiplication factor and minimize the power peaking factor while satisfying operational and safety constraints for the research reactor.

  6. Human longevity: Genetics or Lifestyle? It takes two to tango.

    Science.gov (United States)

    Passarino, Giuseppe; De Rango, Francesco; Montesanto, Alberto

    2016-01-01

    Healthy aging and longevity in humans are modulated by a lucky combination of genetic and non-genetic factors. Family studies demonstrated that about 25 % of the variation in human longevity is due to genetic factors. The search for genetic and molecular basis of aging has led to the identification of genes correlated with the maintenance of the cell and of its basic metabolism as the main genetic factors affecting the individual variation of the aging phenotype. In addition, studies on calorie restriction and on the variability of genes associated with nutrient-sensing signaling, have shown that ipocaloric diet and/or a genetically efficient metabolism of nutrients, can modulate lifespan by promoting an efficient maintenance of the cell and of the organism. Recently, epigenetic studies have shown that epigenetic modifications, modulated by both genetic background and lifestyle, are very sensitive to the aging process and can either be a biomarker of the quality of aging or influence the rate and the quality of aging. On the whole, current studies are showing that interventions modulating the interaction between genetic background and environment is essential to determine the individual chance to attain longevity.

  7. The Human Rights Code, 1988, 8 July 1988.

    Science.gov (United States)

    1988-01-01

    This Act prohibits discrimination on the basis of sex and marital status, among other things, with respect to accommodation practices, employment practices, and publications. In its employment practices provisions, it mandates equal pay for equal work and outlaws harassment and unwelcome sexual solicitation. Under the Act, the Newfoundland Human Rights Commission, already established, is given the power to investigate complaints, effect settlements, and refer matters to a board of inquiry for further action. full text

  8. Informed consent in human experimentation before the Nuremberg code.

    OpenAIRE

    Vollmann, J; Winau, R.

    1996-01-01

    The issue of ethics with respect to medical experimentation in Germany during the 1930s and 1940s was crucial at the Nuremberg trials and related trials of doctors and public health officials. Those involved in horrible crimes attempted to excuse themselves by arguing that there were no explicit rules governing medical research on human beings in Germany during the period and that research practices in Germany were not different from those in allied countries. In this context the Nuremberg co...

  9. The Evolution of Human Intelligence and the Coefficient of Additive Genetic Variance in Human Brain Size

    Science.gov (United States)

    Miller, Geoffrey F.; Penke, Lars

    2007-01-01

    Most theories of human mental evolution assume that selection favored higher intelligence and larger brains, which should have reduced genetic variance in both. However, adult human intelligence remains highly heritable, and is genetically correlated with brain size. This conflict might be resolved by estimating the coefficient of additive genetic…

  10. The Evolution of Human Intelligence and the Coefficient of Additive Genetic Variance in Human Brain Size

    Science.gov (United States)

    Miller, Geoffrey F.; Penke, Lars

    2007-01-01

    Most theories of human mental evolution assume that selection favored higher intelligence and larger brains, which should have reduced genetic variance in both. However, adult human intelligence remains highly heritable, and is genetically correlated with brain size. This conflict might be resolved by estimating the coefficient of additive genetic…

  11. Proton Dose Assessment to the Human Eye Using Monte Carlo N-Particle Transport Code (MCNPX)

    Science.gov (United States)

    2006-08-01

    objective of this project was to develop a simple MCNPX model of the human eye to approximate dose delivered from proton therapy. The calculated dose...computer code MCNPX that approximates dose delivered during proton therapy. The calculations considered proton interactions and secondary interactions...Volume Calculation The MCNPX code has limited ability to compute the volumes of defined cells. The dosimetric volumes in the outer wall of the eye are

  12. Human genetics of infectious diseases: a unified theory

    Science.gov (United States)

    Casanova, Jean-Laurent; Abel, Laurent

    2007-01-01

    Since the early 1950s, the dominant paradigm in the human genetics of infectious diseases postulates that rare monogenic immunodeficiencies confer vulnerability to multiple infectious diseases (one gene, multiple infections), whereas common infections are associated with the polygenic inheritance of multiple susceptibility genes (one infection, multiple genes). Recent studies, since 1996 in particular, have challenged this view. A newly recognised group of primary immunodeficiencies predisposing the individual to a principal or single type of infection is emerging. In parallel, several common infections have been shown to reflect the inheritance of one major susceptibility gene, at least in some populations. This novel causal relationship (one gene, one infection) blurs the distinction between patient-based Mendelian genetics and population-based complex genetics, and provides a unified conceptual frame for exploring the molecular genetic basis of infectious diseases in humans. PMID:17255931

  13. Anticodon Modifications in the tRNA Set of LUCA and the Fundamental Regularity in the Standard Genetic Code

    Science.gov (United States)

    van der Gulik, Peter T. S.; Hoff, Wouter D.

    2016-01-01

    Based on (i) an analysis of the regularities in the standard genetic code and (ii) comparative genomics of the anticodon modification machinery in the three branches of life, we derive the tRNA set and its anticodon modifications as it was present in LUCA. Previously we proposed that an early ancestor of LUCA contained a set of 23 tRNAs with unmodified anticodons that was capable of translating all 20 amino acids while reading 55 of the 61 sense codons of the standard genetic code (SGC). Here we use biochemical and genomic evidence to derive that LUCA contained a set of 44 or 45 tRNAs containing 2 or 3 modifications while reading 59 or 60 of the 61 sense codons. Subsequent tRNA modifications occurred independently in the Bacteria and Eucarya, while the Archaea have remained quite close to the tRNA set as it was present in LUCA. PMID:27454314

  14. A Trio of Human Molecular Genetics PCR Assays

    Science.gov (United States)

    Reinking, Jeffrey L.; Waldo, Jennifer T.; Dinsmore, Jannett

    2013-01-01

    This laboratory exercise demonstrates three different analytical forms of the polymerase chain reaction (PCR) that allow students to genotype themselves at four different loci. Here, we present protocols to allow students to a) genotype a non-coding polymorphic Variable Number of Tandem Repeat (VNTR) locus on human chromosome 5 using conventional…

  15. A Trio of Human Molecular Genetics PCR Assays

    Science.gov (United States)

    Reinking, Jeffrey L.; Waldo, Jennifer T.; Dinsmore, Jannett

    2013-01-01

    This laboratory exercise demonstrates three different analytical forms of the polymerase chain reaction (PCR) that allow students to genotype themselves at four different loci. Here, we present protocols to allow students to a) genotype a non-coding polymorphic Variable Number of Tandem Repeat (VNTR) locus on human chromosome 5 using conventional…

  16. Primer on Molecular Genetics; DOE Human Genome Program

    Science.gov (United States)

    1992-04-01

    This report is taken from the April 1992 draft of the DOE Human Genome 1991--1992 Program Report, which is expected to be published in May 1992. The primer is intended to be an introduction to basic principles of molecular genetics pertaining to the genome project. The material contained herein is not final and may be incomplete. Techniques of genetic mapping and DNA sequencing are described.

  17. Common genetic variants influence human subcortical brain structures

    OpenAIRE

    Hibar, Derrek P.; Stein, Jason L.; Renteria, Miguel E.; Arias-Vasquez, Alejandro,; Desrivieres, Sylvane; Jahanshad, Neda; Toro, Roberto; Wittfeld, Katharina; Abramovic, Lucija; Andersson, Micael; Aribisala, Benjamin S.; Armstrong, Nicola J.; Bernard, Manon; Bohlken, Marc M.; Boks, Marco P

    2015-01-01

    The highly complex structure of the human brain is strongly shaped by genetic influences(1). Subcortical brain regions form circuits with cortical areas to coordinate movement(2), learning, memory(3) and motivation(4), and altered circuits can lead to abnormal behaviour and disease(5). To investigate how common genetic variants affect the structure of these brain regions, here we conduct genome-wide association studies of the volumes of seven subcortical regions and the intracranial volume de...

  18. Primer on molecular genetics. DOE Human Genome Program

    Energy Technology Data Exchange (ETDEWEB)

    1992-04-01

    This report is taken from the April 1992 draft of the DOE Human Genome 1991--1992 Program Report, which is expected to be published in May 1992. The primer is intended to be an introduction to basic principles of molecular genetics pertaining to the genome project. The material contained herein is not final and may be incomplete. Techniques of genetic mapping and DNA sequencing are described.

  19. Simulation platform of economical operation and dispatch for power plant based on float-coded genetic algorithm

    Institute of Scientific and Technical Information of China (English)

    朱奕; 伞冶; 马克茂

    2004-01-01

    This paper discusses a float-coded genetic algorithm and its application to the optimization of the power plant operation concerning the simulation problem of economical operation for power plant systems. The method proposed realizes the load optimization between generating units of power plants and their loads, solves the problem of influence of a unit plant pause spoilage and load variance on the optimal plant combination and load, and finally establishes a simulation platform for the power plant economical operation.

  20. Genetics of human episodic memory: dealing with complexity.

    Science.gov (United States)

    Papassotiropoulos, Andreas; de Quervain, Dominique J-F

    2011-09-01

    Episodic memory is a polygenic behavioral trait with substantial heritability estimates. Despite its complexity, recent empirical evidence supports the notion that behavioral genetic studies of episodic memory might successfully identify trait-associated molecules and pathways. The development of high-throughput genotyping methods, of elaborated statistical analyses and of phenotypic assessment methods at the neural systems level will facilitate the reliable identification of novel memory-related genes. Importantly, a necessary crosstalk between behavioral genetic studies and investigation of causality by molecular genetic studies will ultimately pave the way towards the identification of biologically important, and hopefully druggable, genes and molecular pathways related to human episodic memory.

  1. A current genetic and epigenetic view on human aging mechanisms.

    Science.gov (United States)

    Ostojić, Sala; Pereza, Nina; Kapović, Miljenko

    2009-06-01

    The process of aging is one of the most complex and intriguing biological phenomenons. Aging is a genetically regulated process in which the organism's maximum lifespan potential is pre-determined, while the rate of aging is influenced by environmental factors and lifestyle. Considering the complexity of mechanisms involved in the regulation of aging process, up to this date there isn't a major, unifying theory which could explain them. As genetic/epigenetic and environmental factors both inevitably influence the aging process, here we present a review on the genetic and epigenetic regulation of the most important molecular and cellular mechanisms involved in the process of aging. Based on the studies on oxidative stress, metabolism, genome stability, epigenetic modifications and cellular senescence in animal models and humans, we give an overview of key genetic and molecular pathways related to aging. As most of genetic manipulations which influence the aging process also affect reproduction, we discuss aging in humans as a post-reproductive genetically determined process. After the age of reproductive success, aging continously progresses which clinically coincides with the onset of most chronic diseases, cancers and dementions. As evolution shapes the genomes for reproductive success and not for post-reproductive survival, aging could be defined as a protective mechanism which ensures the preservation and progress of species through the modification, trasmission and improvement of genetic material.

  2. Genetic Effects on Fine-Grained Human Cortical Regionalization.

    Science.gov (United States)

    Cui, Yue; Liu, Bing; Zhou, Yuan; Fan, Lingzhong; Li, Jin; Zhang, Yun; Wu, Huawang; Hou, Bing; Wang, Chao; Zheng, Fanfan; Qiu, Chengxiang; Rao, Li-Lin; Ning, Yuping; Li, Shu; Jiang, Tianzi

    2016-09-01

    Various brain structural and functional features such as cytoarchitecture, topographic mapping, gyral/sulcal anatomy, and anatomical and functional connectivity have been used in human brain parcellation. However, the fine-grained intrinsic genetic architecture of the cortex remains unknown. In the present study, we parcellated specific regions of the cortex into subregions based on genetic correlations (i.e., shared genetic influences) between the surface area of each pair of cortical locations within the seed region. The genetic correlations were estimated by comparing the correlations of the surface area between monozygotic and dizygotic twins using bivariate twin models. Our genetic subdivisions of diverse brain regions were reproducible across 2 independent datasets and corresponded closely to fine-grained functional specializations. Furthermore, subregional genetic correlation profiles were generally consistent with functional connectivity patterns. Our findings indicate that the magnitude of the genetic covariance in brain anatomy could be used to delineate the boundaries of functional subregions of the brain and may be of value in the next generation human brain atlas.

  3. HACking the centromere chromatin code: insights from human artificial chromosomes.

    Science.gov (United States)

    Bergmann, Jan H; Martins, Nuno M C; Larionov, Vladimir; Masumoto, Hiroshi; Earnshaw, William C

    2012-07-01

    The centromere is a specialized chromosomal region that serves as the assembly site of the kinetochore. At the centromere, CENP-A nucleosomes form part of a chromatin landscape termed centrochromatin. This chromatin environment conveys epigenetic marks regulating kinetochore formation. Recent work sheds light on the intricate relationship between centrochromatin state, the CENP-A assembly pathway and the maintenance of centromere function. Here, we review the emerging picture of how chromatin affects mammalian kinetochore formation. We place particular emphasis on data obtained from Human Artificial Chromosome (HAC) biology and the targeted engineering of centrochromatin using synthetic HACs. We discuss implications of these findings, which indicate that a delicate balance of histone modifications and chromatin state dictates both de novo centromere formation and the maintenance of centromere identity in dividing cell populations.

  4. Attempting To Break the Code in Student Comprehension of Genetic Concepts.

    Science.gov (United States)

    Marbach-Ad, Gili

    2001-01-01

    Probes students' understanding of the relationships between genetic concepts. Identifies alternative conceptions and compartmentalization between related concepts. Argues that genetic instruction in 9th and 12th grade and in college in Israel needs improvement. (Author/MM)

  5. Development of Human-Tracking Robot by Using QR Code Recognition

    Science.gov (United States)

    Eimon, Koki; Anezaki, Takashi; Tansuriyavong, Suriyon; Yagi, Yasushi

    In this paper, we propose a human-tracking robot that can be used in some commercial establishments, such as airports and factories. Human-tracking process involves four main steps. The first step involves robust personal identification by using QR code recognition. It is the most important step in human tracking. The second step is location detection by shape-based pattern matching in order to determine the position of the QR code when the human being tracked moves far from the robot. The third step involves auxiliary re-detection by using IR cameras and retroreflectors in case that local detection is difficult in the second step. The fourth step is robot control to maintain the correct distance for human tracking. In a measurement experiment for rate of QR code recognition, it was shown that the rate of QR code recognition was 99.9% and that location detection is robust. In a robot-control experiment, it was shown that the tracking is accurate. During tracking, the robot maintains an appropriate distance from the human.

  6. Regulatory consequences of neuronal ELAV-like protein binding to coding and non-coding RNAs in human brain

    Science.gov (United States)

    Scheckel, Claudia; Drapeau, Elodie; Frias, Maria A; Park, Christopher Y; Fak, John; Zucker-Scharff, Ilana; Kou, Yan; Haroutunian, Vahram; Ma'ayan, Avi

    2016-01-01

    Neuronal ELAV-like (nELAVL) RNA binding proteins have been linked to numerous neurological disorders. We performed crosslinking-immunoprecipitation and RNAseq on human brain, and identified nELAVL binding sites on 8681 transcripts. Using knockout mice and RNAi in human neuroblastoma cells, we showed that nELAVL intronic and 3' UTR binding regulates human RNA splicing and abundance. We validated hundreds of nELAVL targets among which were important neuronal and disease-associated transcripts, including Alzheimer's disease (AD) transcripts. We therefore investigated RNA regulation in AD brain, and observed differential splicing of 150 transcripts, which in some cases correlated with differential nELAVL binding. Unexpectedly, the most significant change of nELAVL binding was evident on non-coding Y RNAs. nELAVL/Y RNA complexes were specifically remodeled in AD and after acute UV stress in neuroblastoma cells. We propose that the increased nELAVL/Y RNA association during stress may lead to nELAVL sequestration, redistribution of nELAVL target binding, and altered neuronal RNA splicing. DOI: http://dx.doi.org/10.7554/eLife.10421.001 PMID:26894958

  7. FitSKIRT: genetic algorithms to automatically fit dusty galaxies with a Monte Carlo radiative transfer code

    CERN Document Server

    De Geyter, Gert; Fritz, Jacopo; Camps, Peter

    2012-01-01

    We present FitSKIRT, a method to efficiently fit radiative transfer models to UV/optical images of dusty galaxies. These images have the advantage that they have better spatial resolution compared to FIR/submm data. FitSKIRT uses the GAlib genetic algorithm library to optimize the output of the SKIRT Monte Carlo radiative transfer code. Genetic algorithms prove to be a valuable tool in handling the multi- dimensional search space as well as the noise induced by the random nature of the Monte Carlo radiative transfer code. FitSKIRT is tested on artificial images of a simulated edge-on spiral galaxy, where we gradually increase the number of fitted parameters. We find that we can recover all model parameters, even if all 11 model parameters are left unconstrained. Finally, we apply the FitSKIRT code to a V-band image of the edge-on spiral galaxy NGC4013. This galaxy has been modeled previously by other authors using different combinations of radiative transfer codes and optimization methods. Given the different...

  8. Evolutionary hallmarks of the human proteome: chasing the age and coregulation of protein-coding genes.

    Science.gov (United States)

    Lopes, Katia de Paiva; Campos-Laborie, Francisco José; Vialle, Ricardo Assunção; Ortega, José Miguel; De Las Rivas, Javier

    2016-10-25

    The development of large-scale technologies for quantitative transcriptomics has enabled comprehensive analysis of the gene expression profiles in complete genomes. RNA-Seq allows the measurement of gene expression levels in a manner far more precise and global than previous methods. Studies using this technology are altering our view about the extent and complexity of the eukaryotic transcriptomes. In this respect, multiple efforts have been done to determine and analyse the gene expression patterns of human cell types in different conditions, either in normal or pathological states. However, until recently, little has been reported about the evolutionary marks present in human protein-coding genes, particularly from the combined perspective of gene expression and protein evolution. We present a combined analysis of human protein-coding gene expression profiling and time-scale ancestry mapping, that places the genes in taxonomy clades and reveals eight evolutionary major steps ("hallmarks"), that include clusters of functionally coherent proteins. The human expressed genes are analysed using a RNA-Seq dataset of 116 samples from 32 tissues. The evolutionary analysis of the human proteins is performed combining the information from: (i) a database of orthologous proteins (OMA), (ii) the taxonomy mapping of genes to lineage clades (from NCBI Taxonomy) and (iii) the evolution time-scale mapping provided by TimeTree (Timescale of Life). The human protein-coding genes are also placed in a relational context based in the construction of a robust gene coexpression network, that reveals tighter links between age-related protein-coding genes and finds functionally coherent gene modules. Understanding the relational landscape of the human protein-coding genes is essential for interpreting the functional elements and modules of our active genome. Moreover, decoding the evolutionary history of the human genes can provide very valuable information to reveal or uncover their

  9. Evolutionary hallmarks of the human proteome: chasing the age and coregulation of protein-coding genes

    Directory of Open Access Journals (Sweden)

    Katia de Paiva Lopes

    2016-10-01

    Full Text Available Abstract Background The development of large-scale technologies for quantitative transcriptomics has enabled comprehensive analysis of the gene expression profiles in complete genomes. RNA-Seq allows the measurement of gene expression levels in a manner far more precise and global than previous methods. Studies using this technology are altering our view about the extent and complexity of the eukaryotic transcriptomes. In this respect, multiple efforts have been done to determine and analyse the gene expression patterns of human cell types in different conditions, either in normal or pathological states. However, until recently, little has been reported about the evolutionary marks present in human protein-coding genes, particularly from the combined perspective of gene expression and protein evolution. Results We present a combined analysis of human protein-coding gene expression profiling and time-scale ancestry mapping, that places the genes in taxonomy clades and reveals eight evolutionary major steps (“hallmarks”, that include clusters of functionally coherent proteins. The human expressed genes are analysed using a RNA-Seq dataset of 116 samples from 32 tissues. The evolutionary analysis of the human proteins is performed combining the information from: (i a database of orthologous proteins (OMA, (ii the taxonomy mapping of genes to lineage clades (from NCBI Taxonomy and (iii the evolution time-scale mapping provided by TimeTree (Timescale of Life. The human protein-coding genes are also placed in a relational context based in the construction of a robust gene coexpression network, that reveals tighter links between age-related protein-coding genes and finds functionally coherent gene modules. Conclusions Understanding the relational landscape of the human protein-coding genes is essential for interpreting the functional elements and modules of our active genome. Moreover, decoding the evolutionary history of the human genes can

  10. Genetic and Epigenetic Discoveries in Human Retinoblastoma.

    Science.gov (United States)

    McEvoy, Justina D; Dyer, Michael A

    2015-01-01

    Retinoblastoma is a rare pediatric cancer of the retina. Nearly all retinoblastomas are initiated through the biallelic inactivation of the retinoblastoma tumor susceptibility gene (RB1). Whole-genome sequencing has made it possible to identify secondary genetic lesions following RB1 inactivation. One of the major discoveries from retinoblastoma sequencing studies is that some retinoblastoma tumors have stable genomes. Subsequent epigenetic studies showed that changes in the epigenome contribute to the rapid progression of retinoblastoma following RB1 gene inactivation. In addition, gene amplification and elevated expression of p53 antagonists, MDM2 and MDM4, may also play an important role in retinoblastoma tumorigenesis. The knowledge gained from these recent molecular, cellular, genomic, and epigenomic analyses are now being integrated to identify new therapeutic approaches that can help save lives and vision in children with retinoblastoma, with fewer long-term side effects.

  11. Genetic and biomarker studies of human longevity

    NARCIS (Netherlands)

    Deelen, Joris

    2014-01-01

    The aim of this thesis was to identify novel lifespan regulating loci that influence human longevity and population mortality. To this end, we performed two genome-wide association studies, one of long-lived individuals from the family-based Leiden Longevity Study (LLS) and an extended one of long-l

  12. Human aggression across the lifespan: genetic propensities and environmental moderators.

    Science.gov (United States)

    Tuvblad, Catherine; Baker, Laura A

    2011-01-01

    This chapter reviews the recent evidence of genetic and environmental influences on human aggression. Findings from a large selection of the twin and adoption studies that have investigated the genetic and environmental architecture of aggressive behavior are summarized. These studies together show that about half (50%) of the variance in aggressive behavior is explained by genetic influences in both males and females, with the remaining 50% of the variance being explained by environmental factors not shared by family members. Form of aggression (reactive, proactive, direct/physical, indirect/relational), method of assessment (laboratory observation, self-report, ratings by parents and teachers), and age of the subjects-all seem to be significant moderators of the magnitude of genetic and environmental influences on aggressive behavior. Neither study design (twin vs. sibling adoption design) nor sex (male vs. female) seems to impact the magnitude of the genetic and environmental influences on aggression. There is also some evidence of gene-environment interaction (G × E) from both twin/adoption studies and molecular genetic studies. Various measures of family adversity and social disadvantage have been found to moderate genetic influences on aggressive behavior. Findings from these G × E studies suggest that not all individuals will be affected to the same degree by experiences and exposures, and that genetic predispositions may have different effects depending on the environment.

  13. Coding of multisensory temporal patterns in human superior temporal sulcus

    Directory of Open Access Journals (Sweden)

    Toemme eNoesselt

    2012-08-01

    Full Text Available Philosophers, psychologists, and neuroscientists have long been interested in how the temporal aspects of perception are represented in the brain. In the present study, we investigated the neural basis of the temporal perception of synchrony/asynchrony for audiovisual speech stimuli using functional magnetic imaging (fMRI. Subjects judged the temporal relation of (asynchronous audiovisual speech streams, and indicated any changes in their perception of the stimuli over time. Differential hemodynamic responses for synchronous versus asynchronous stimuli were observed in the multisensory superior temporal sulcus complex (mSTS-c and prefrontal cortex. Within mSTS-c we found adjacent regions expressing an enhanced BOLD-response to the different physical (asynchrony conditions. These regions were further modulated by the subjects’ perceptual state. By calculating the distances between the modulated regions within mSTS-c in single-subjects we demonstrate that the ‘auditory’ and ‘visual leading areas’ lie closer to ‘synchrony areas’ than to each other. Moreover, analysis of interregional connectivity indicates a stronger functional connection between multisensory prefrontal cortex and mSTS-c during the perception of asynchrony. Taken together, these results therefore suggest the presence of distinct sub-regions within the human STS-c for the maintenance of temporal relations for audiovisual speech stimuli plus differential functional connectivity with prefrontal regions. The respective local activity in mSTS-c is dependent both upon the physical properties of the stimuli presented and upon the subjects’ perception of (asynchrony.

  14. Human fertility, molecular genetics, and natural selection in modern societies.

    Directory of Open Access Journals (Sweden)

    Felix C Tropf

    Full Text Available Research on genetic influences on human fertility outcomes such as number of children ever born (NEB or the age at first childbirth (AFB has been solely based on twin and family-designs that suffer from problematic assumptions and practical limitations. The current study exploits recent advances in the field of molecular genetics by applying the genomic-relationship-matrix based restricted maximum likelihood (GREML methods to quantify for the first time the extent to which common genetic variants influence the NEB and the AFB of women. Using data from the UK and the Netherlands (N = 6,758, results show significant additive genetic effects on both traits explaining 10% (SE = 5 of the variance in the NEB and 15% (SE = 4 in the AFB. We further find a significant negative genetic correlation between AFB and NEB in the pooled sample of -0.62 (SE = 0.27, p-value = 0.02. This finding implies that individuals with genetic predispositions for an earlier AFB had a reproductive advantage and that natural selection operated not only in historical, but also in contemporary populations. The observed postponement in the AFB across the past century in Europe contrasts with these findings, suggesting an evolutionary override by environmental effects and underscoring that evolutionary predictions in modern human societies are not straight forward. It emphasizes the necessity for an integrative research design from the fields of genetics and social sciences in order to understand and predict fertility outcomes. Finally, our results suggest that we may be able to find genetic variants associated with human fertility when conducting GWAS-meta analyses with sufficient sample size.

  15. Human fertility, molecular genetics, and natural selection in modern societies.

    Science.gov (United States)

    Tropf, Felix C; Stulp, Gert; Barban, Nicola; Visscher, Peter M; Yang, Jian; Snieder, Harold; Mills, Melinda C

    2015-01-01

    Research on genetic influences on human fertility outcomes such as number of children ever born (NEB) or the age at first childbirth (AFB) has been solely based on twin and family-designs that suffer from problematic assumptions and practical limitations. The current study exploits recent advances in the field of molecular genetics by applying the genomic-relationship-matrix based restricted maximum likelihood (GREML) methods to quantify for the first time the extent to which common genetic variants influence the NEB and the AFB of women. Using data from the UK and the Netherlands (N = 6,758), results show significant additive genetic effects on both traits explaining 10% (SE = 5) of the variance in the NEB and 15% (SE = 4) in the AFB. We further find a significant negative genetic correlation between AFB and NEB in the pooled sample of -0.62 (SE = 0.27, p-value = 0.02). This finding implies that individuals with genetic predispositions for an earlier AFB had a reproductive advantage and that natural selection operated not only in historical, but also in contemporary populations. The observed postponement in the AFB across the past century in Europe contrasts with these findings, suggesting an evolutionary override by environmental effects and underscoring that evolutionary predictions in modern human societies are not straight forward. It emphasizes the necessity for an integrative research design from the fields of genetics and social sciences in order to understand and predict fertility outcomes. Finally, our results suggest that we may be able to find genetic variants associated with human fertility when conducting GWAS-meta analyses with sufficient sample size.

  16. Comparable frequencies of coding mutations and loss of imprinting in human pluripotent cells derived by nuclear transfer and defined factors.

    Science.gov (United States)

    Johannesson, Bjarki; Sagi, Ido; Gore, Athurva; Paull, Daniel; Yamada, Mitsutoshi; Golan-Lev, Tamar; Li, Zhe; LeDuc, Charles; Shen, Yufeng; Stern, Samantha; Xu, Nanfang; Ma, Hong; Kang, Eunju; Mitalipov, Shoukhrat; Sauer, Mark V; Zhang, Kun; Benvenisty, Nissim; Egli, Dieter

    2014-11-06

    The recent finding that reprogrammed human pluripotent stem cells can be derived by nuclear transfer into human oocytes as well as by induced expression of defined factors has revitalized the debate on whether one approach might be advantageous over the other. Here we compare the genetic and epigenetic integrity of human nuclear-transfer embryonic stem cell (NT-ESC) lines and isogenic induced pluripotent stem cell (iPSC) lines, derived from the same somatic cell cultures of fetal, neonatal, and adult origin. The two cell types showed similar genome-wide gene expression and DNA methylation profiles. Importantly, NT-ESCs and iPSCs had comparable numbers of de novo coding mutations, but significantly more than parthenogenetic ESCs. As iPSCs, NT-ESCs displayed clone- and gene-specific aberrations in DNA methylation and allele-specific expression of imprinted genes. The occurrence of these genetic and epigenetic defects in both NT-ESCs and iPSCs suggests that they are inherent to reprogramming, regardless of derivation approach.

  17. Large animal models of rare genetic disorders: sheep as phenotypically relevant models of human genetic disease.

    Science.gov (United States)

    Pinnapureddy, Ashish R; Stayner, Cherie; McEwan, John; Baddeley, Olivia; Forman, John; Eccles, Michael R

    2015-09-02

    Animals that accurately model human disease are invaluable in medical research, allowing a critical understanding of disease mechanisms, and the opportunity to evaluate the effect of therapeutic compounds in pre-clinical studies. Many types of animal models are used world-wide, with the most common being small laboratory animals, such as mice. However, rodents often do not faithfully replicate human disease, despite their predominant use in research. This discordancy is due in part to physiological differences, such as body size and longevity. In contrast, large animal models, including sheep, provide an alternative to mice for biomedical research due to their greater physiological parallels with humans. Completion of the full genome sequences of many species, and the advent of Next Generation Sequencing (NGS) technologies, means it is now feasible to screen large populations of domesticated animals for genetic variants that resemble human genetic diseases, and generate models that more accurately model rare human pathologies. In this review, we discuss the notion of using sheep as large animal models, and their advantages in modelling human genetic disease. We exemplify several existing naturally occurring ovine variants in genes that are orthologous to human disease genes, such as the Cln6 sheep model for Batten disease. These, and other sheep models, have contributed significantly to our understanding of the relevant human disease process, in addition to providing opportunities to trial new therapies in animals with similar body and organ size to humans. Therefore sheep are a significant species with respect to the modelling of rare genetic human disease, which we summarize in this review.

  18. [Human genetic data from a data protection law perspective].

    Science.gov (United States)

    Schulte In den Bäumen, Tobias

    2007-02-01

    The collection and use of genetic data have caused much concern in the German population. Data protection is widely seen as the tool to address these fears. The term genetic data is not self-explanatory, as it depends on the different types of genetic diseases. The protection of genetic data as defined with regard to the different sets of diseases needs to fit into the preexisting data protection legislation. Still, the particularities of genetic data such as the multipersonal impact need to be considered. A balance between the information needs of society and the right to privacy requires a medically driven criteria. The medical term of indication which corresponds with the data protection term of purpose should serve as a tool in order to balance the rights of the patients and their relatives or between clients and third persons involved. Some countries have set up new legislative acts to address the challenges of human genetics. The current state of German data protection law leaves citizen rather unprotected as long as the data are used for medical purposes in a wider sense. A special law on the collection of genetic data has been discussed for several years, but it should be questioned whether the scope of a sector-specific law would serve citizens better. It seems to be preferable to adjust the existing Data Protection Act rather than drafting a specific law which covers the field of human genetics. This adaptation should reflect upon the different technical ways in which genetic data are collected and used.

  19. Genetics meets metabolomics: a genome-wide association study of metabolite profiles in human serum.

    Science.gov (United States)

    Gieger, Christian; Geistlinger, Ludwig; Altmaier, Elisabeth; Hrabé de Angelis, Martin; Kronenberg, Florian; Meitinger, Thomas; Mewes, Hans-Werner; Wichmann, H-Erich; Weinberger, Klaus M; Adamski, Jerzy; Illig, Thomas; Suhre, Karsten

    2008-11-01

    The rapidly evolving field of metabolomics aims at a comprehensive measurement of ideally all endogenous metabolites in a cell or body fluid. It thereby provides a functional readout of the physiological state of the human body. Genetic variants that associate with changes in the homeostasis of key lipids, carbohydrates, or amino acids are not only expected to display much larger effect sizes due to their direct involvement in metabolite conversion modification, but should also provide access to the biochemical context of such variations, in particular when enzyme coding genes are concerned. To test this hypothesis, we conducted what is, to the best of our knowledge, the first GWA study with metabolomics based on the quantitative measurement of 363 metabolites in serum of 284 male participants of the KORA study. We found associations of frequent single nucleotide polymorphisms (SNPs) with considerable differences in the metabolic homeostasis of the human body, explaining up to 12% of the observed variance. Using ratios of certain metabolite concentrations as a proxy for enzymatic activity, up to 28% of the variance can be explained (p-values 10(-16) to 10(-21)). We identified four genetic variants in genes coding for enzymes (FADS1, LIPC, SCAD, MCAD) where the corresponding metabolic phenotype (metabotype) clearly matches the biochemical pathways in which these enzymes are active. Our results suggest that common genetic polymorphisms induce major differentiations in the metabolic make-up of the human population. This may lead to a novel approach to personalized health care based on a combination of genotyping and metabolic characterization. These genetically determined metabotypes may subscribe the risk for a certain medical phenotype, the response to a given drug treatment, or the reaction to a nutritional intervention or environmental challenge.

  20. Genetics meets metabolomics: a genome-wide association study of metabolite profiles in human serum.

    Directory of Open Access Journals (Sweden)

    Christian Gieger

    2008-11-01

    Full Text Available The rapidly evolving field of metabolomics aims at a comprehensive measurement of ideally all endogenous metabolites in a cell or body fluid. It thereby provides a functional readout of the physiological state of the human body. Genetic variants that associate with changes in the homeostasis of key lipids, carbohydrates, or amino acids are not only expected to display much larger effect sizes due to their direct involvement in metabolite conversion modification, but should also provide access to the biochemical context of such variations, in particular when enzyme coding genes are concerned. To test this hypothesis, we conducted what is, to the best of our knowledge, the first GWA study with metabolomics based on the quantitative measurement of 363 metabolites in serum of 284 male participants of the KORA study. We found associations of frequent single nucleotide polymorphisms (SNPs with considerable differences in the metabolic homeostasis of the human body, explaining up to 12% of the observed variance. Using ratios of certain metabolite concentrations as a proxy for enzymatic activity, up to 28% of the variance can be explained (p-values 10(-16 to 10(-21. We identified four genetic variants in genes coding for enzymes (FADS1, LIPC, SCAD, MCAD where the corresponding metabolic phenotype (metabotype clearly matches the biochemical pathways in which these enzymes are active. Our results suggest that common genetic polymorphisms induce major differentiations in the metabolic make-up of the human population. This may lead to a novel approach to personalized health care based on a combination of genotyping and metabolic characterization. These genetically determined metabotypes may subscribe the risk for a certain medical phenotype, the response to a given drug treatment, or the reaction to a nutritional intervention or environmental challenge.

  1. PCR-free quantitative detection of genetically modified organism from raw materials. An electrochemiluminescence-based bio bar code method.

    Science.gov (United States)

    Zhu, Debin; Tang, Yabing; Xing, Da; Chen, Wei R

    2008-05-15

    A bio bar code assay based on oligonucleotide-modified gold nanoparticles (Au-NPs) provides a PCR-free method for quantitative detection of nucleic acid targets. However, the current bio bar code assay requires lengthy experimental procedures including the preparation and release of bar code DNA probes from the target-nanoparticle complex and immobilization and hybridization of the probes for quantification. Herein, we report a novel PCR-free electrochemiluminescence (ECL)-based bio bar code assay for the quantitative detection of genetically modified organism (GMO) from raw materials. It consists of tris-(2,2'-bipyridyl) ruthenium (TBR)-labeled bar code DNA, nucleic acid hybridization using Au-NPs and biotin-labeled probes, and selective capture of the hybridization complex by streptavidin-coated paramagnetic beads. The detection of target DNA is realized by direct measurement of ECL emission of TBR. It can quantitatively detect target nucleic acids with high speed and sensitivity. This method can be used to quantitatively detect GMO fragments from real GMO products.

  2. GENETIC STUDY OF HUMAN CELLS IN VITRO

    Science.gov (United States)

    Chang, R. Shihman

    1960-01-01

    The isolation of carbohydrate variants from cultures of HeLa and conjunctival cells was described. Factors inherent in the cell culture system, such as parent populations and dialyzed serums, have been shown to influence the outcome of variant isolations. Established stable variants incorporated significantly more pentoses or lactate into various cell fractions than the parent cultures. Besides their abilities to propagate continuously in the selecting environments, the variants multiplied slower, were more susceptible to sub-zero preservation and the cytotoxic effect of D-2-deoxyglucose, showed lower cloning efficiencies and were less susceptible to the deleterious effect of glucose oxidase. The ribose variants also differed from the parent cultures in morphological appearance such as formation of multinucleated cells and ring-shaped colonies. They converted more ribose into other component sugars of mucopolysaccharides than the parent cultures. Preliminary analyses of the mucopolysaccharides extracted from the ribose variants and parent cultures showed large difference in their carbohydrate (Molisch-positive materials) and DNA ratios. Evidence suggests that a sequence of interrelated events from genetic selection to primitive morphogenesis has been established. PMID:13692337

  3. Unraveling the genetics of human obesity.

    Directory of Open Access Journals (Sweden)

    David M Mutch

    2006-12-01

    Full Text Available The use of modern molecular biology tools in deciphering the perturbed biochemistry and physiology underlying the obese state has proven invaluable. Identifying the hypothalamic leptin/melanocortin pathway as critical in many cases of monogenic obesity has permitted targeted, hypothesis-driven experiments to be performed, and has implicated new candidates as causative for previously uncharacterized clinical cases of obesity. Meanwhile, the effects of mutations in the melanocortin-4 receptor gene, for which the obese phenotype varies in the degree of severity among individuals, are now thought to be influenced by one's environmental surroundings. Molecular approaches have revealed that syndromes (Prader-Willi and Bardet-Biedl previously assumed to be controlled by a single gene are, conversely, regulated by multiple elements. Finally, the application of comprehensive profiling technologies coupled with creative statistical analyses has revealed that interactions between genetic and environmental factors are responsible for the common obesity currently challenging many Westernized societies. As such, an improved understanding of the different "types" of obesity not only permits the development of potential therapies, but also proposes novel and often unexpected directions in deciphering the dysfunctional state of obesity.

  4. Fine-scaled human genetic structure revealed by SNP microarrays.

    Science.gov (United States)

    Xing, Jinchuan; Watkins, W Scott; Witherspoon, David J; Zhang, Yuhua; Guthery, Stephen L; Thara, Rangaswamy; Mowry, Bryan J; Bulayeva, Kazima; Weiss, Robert B; Jorde, Lynn B

    2009-05-01

    We report an analysis of more than 240,000 loci genotyped using the Affymetrix SNP microarray in 554 individuals from 27 worldwide populations in Africa, Asia, and Europe. To provide a more extensive and complete sampling of human genetic variation, we have included caste and tribal samples from two states in South India, Daghestanis from eastern Europe, and the Iban from Malaysia. Consistent with observations made by Charles Darwin, our results highlight shared variation among human populations and demonstrate that much genetic variation is geographically continuous. At the same time, principal components analyses reveal discernible genetic differentiation among almost all identified populations in our sample, and in most cases, individuals can be clearly assigned to defined populations on the basis of SNP genotypes. All individuals are accurately classified into continental groups using a model-based clustering algorithm, but between closely related populations, genetic and self-classifications conflict for some individuals. The 250K data permitted high-level resolution of genetic variation among Indian caste and tribal populations and between highland and lowland Daghestani populations. In particular, upper-caste individuals from Tamil Nadu and Andhra Pradesh form one defined group, lower-caste individuals from these two states form another, and the tribal Irula samples form a third. Our results emphasize the correlation of genetic and geographic distances and highlight other elements, including social factors that have contributed to population structure.

  5. Molecular genetics of human obesity: A comprehensive review.

    Science.gov (United States)

    Singh, Rajan Kumar; Kumar, Permendra; Mahalingam, Kulandaivelu

    2017-02-01

    Obesity and its related health complications is a major problem worldwide. Hypothalamus and their signalling molecules play a critical role in the intervening and coordination with energy balance and homeostasis. Genetic factors play a crucial role in determining an individual's predisposition to the weight gain and being obese. In the past few years, several genetic variants were identified as monogenic forms of human obesity having success over common polygenic forms. In the context of molecular genetics, genome-wide association studies (GWAS) approach and their findings signified a number of genetic variants predisposing to obesity. However, the last couple of years, it has also been noticed that alterations in the environmental and epigenetic factors are one of the key causes of obesity. Hence, this review might be helpful in the current scenario of molecular genetics of human obesity, obesity-related health complications (ORHC), and energy homeostasis. Future work based on the clinical discoveries may play a role in the molecular dissection of genetic approaches to find more obesity-susceptible gene loci. Copyright © 2016 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.

  6. Medical and human genetics 1977: trends and directions.

    Science.gov (United States)

    Motulsky, A G

    1978-03-01

    Our field is in a rapid state of evolution. The broader concerns of human genetics not of immediate medical interest such as behavioral genetics are often investigated by persons not trained or identified as human geneticists. Both medical genetics and human genetics in general have prospered when various biologic techniques have been applied to genetic concepts. A search for novel biologic methods may provide new insights and may bridge the gulf between Mendelian and biometric approaches in studies of behavior and of common diseases. Medical geneticists need to broaden their fields of interest to encompass other fields than those of pediatric interest alone. We need to attract more basic scientists. Our field is evolving from a largely research oriented science to a service-oriented specialty. This logical development is a sign of increasing maturity and makes available to the public the results of our research. The resulting stresses and strains need careful watching to prevent their slowing the momentum of our science which can contribute continued insights into the many problems of behavior, health, and disease.

  7. Mutations enabling displacement of tryptophan by 4-fluorotryptophan as a canonical amino acid of the genetic code.

    Science.gov (United States)

    Yu, Allen Chi-Shing; Yim, Aldrin Kay-Yuen; Mat, Wai-Kin; Tong, Amy Hin-Yan; Lok, Si; Xue, Hong; Tsui, Stephen Kwok-Wing; Wong, J Tze-Fei; Chan, Ting-Fung

    2014-03-01

    The 20 canonical amino acids of the genetic code have been invariant over 3 billion years of biological evolution. Although various aminoacyl-tRNA synthetases can charge their cognate tRNAs with amino acid analogs, there has been no known displacement of any canonical amino acid from the code. Experimental departure from this universal protein alphabet comprising the canonical amino acids was first achieved in the mutants of the Bacillus subtilis QB928 strain, which after serial selection and mutagenesis led to the HR23 strain that could use 4-fluorotryptophan (4FTrp) but not canonical tryptophan (Trp) for propagation. To gain insight into this displacement of Trp from the genetic code by 4FTrp, genome sequencing was performed on LC33 (a precursor strain of HR23), HR23, and TR7 (a revertant of HR23 that regained the capacity to propagate on Trp). Compared with QB928, the negative regulator mtrB of Trp transport was found to be knocked out in LC33, HR23, and TR7, and sigma factor sigB was mutated in HR23 and TR7. Moreover, rpoBC encoding RNA polymerase subunits were mutated in three independent isolates of TR7 relative to HR23. Increased expression of sigB was also observed in HR23 and in TR7 growing under 4FTrp. These findings indicated that stabilization of the genetic code can be provided by just a small number of analog-sensitive proteins, forming an oligogenic barrier that safeguards the canonical amino acids throughout biological evolution.

  8. Genetic alterations by human papillomaviruses in oncogenesis.

    Science.gov (United States)

    Lazo, P A; Gallego, M I; Ballester, S; Feduchi, E

    1992-03-30

    The integration sites in the cellular genome of human papillomavirus are located in chromosomal regions always associated with oncogenes or other known tumor phenotypes. Two regions, 8q24 and 12q13, are common to several cases of cervical carcinoma and can have integrated more than one type of papillomavirus DNA. These two chromosomal regions contain several genes implicated in oncogenesis. These observations strongly imply that viral integration sites of DNA tumor viruses can be used as the access point to chromosomal regions where genes implicated in the tumor phenotype are located, a situation similar to that of non-transforming retroviruses.

  9. The Nuremberg Code subverts human health and safety by requiring animal modeling

    Science.gov (United States)

    2012-01-01

    Background The requirement that animals be used in research and testing in order to protect humans was formalized in the Nuremberg Code and subsequent national and international laws, codes, and declarations. Discussion We review the history of these requirements and contrast what was known via science about animal models then with what is known now. We further analyze the predictive value of animal models when used as test subjects for human response to drugs and disease. We explore the use of animals for models in toxicity testing as an example of the problem with using animal models. Summary We conclude that the requirements for animal testing found in the Nuremberg Code were based on scientifically outdated principles, compromised by people with a vested interest in animal experimentation, serve no useful function, increase the cost of drug development, and prevent otherwise safe and efficacious drugs and therapies from being implemented. PMID:22769234

  10. The Nuremberg Code subverts human health and safety by requiring animal modeling

    Directory of Open Access Journals (Sweden)

    Greek Ray

    2012-07-01

    Full Text Available Abstract Background The requirement that animals be used in research and testing in order to protect humans was formalized in the Nuremberg Code and subsequent national and international laws, codes, and declarations. Discussion We review the history of these requirements and contrast what was known via science about animal models then with what is known now. We further analyze the predictive value of animal models when used as test subjects for human response to drugs and disease. We explore the use of animals for models in toxicity testing as an example of the problem with using animal models. Summary We conclude that the requirements for animal testing found in the Nuremberg Code were based on scientifically outdated principles, compromised by people with a vested interest in animal experimentation, serve no useful function, increase the cost of drug development, and prevent otherwise safe and efficacious drugs and therapies from being implemented.

  11. Non-coding RNAs in pluripotency and neural differentiation of human pluripotent stem cells

    Science.gov (United States)

    Lukovic, Dunja; Moreno-Manzano, Victoria; Klabusay, Martin; Stojkovic, Miodrag; Bhattacharya, Shomi S.; Erceg, Slaven

    2014-01-01

    Several studies have demonstrated the important role of non-coding RNAs as regulators of posttranscriptional processes, including stem cells self-renewal and neural differentiation. Human embryonic stem cells (hESCs) and induced pluripotent stem cells (ihPSCs) show enormous potential in regenerative medicine due to their capacity to differentiate to virtually any type of cells of human body. Deciphering the role of non-coding RNAs in pluripotency, self-renewal and neural differentiation will reveal new molecular mechanisms involved in induction and maintenances of pluripotent state as well as triggering these cells toward clinically relevant cells for transplantation. In this brief review we will summarize recently published studies which reveal the role of non-coding RNAs in pluripotency and neural differentiation of hESCs and ihPSC. PMID:24860598

  12. Articulated Human Motion Tracking Using Sequential Immune Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Yi Li

    2013-01-01

    Full Text Available We formulate human motion tracking as a high-dimensional constrained optimization problem. A novel generative method is proposed for human motion tracking in the framework of evolutionary computation. The main contribution is that we introduce immune genetic algorithm (IGA for pose optimization in latent space of human motion. Firstly, we perform human motion analysis in the learnt latent space of human motion. As the latent space is low dimensional and contents the prior knowledge of human motion, it makes pose analysis more efficient and accurate. Then, in the search strategy, we apply IGA for pose optimization. Compared with genetic algorithm and other evolutionary methods, its main advantage is the ability to use the prior knowledge of human motion. We design an IGA-based method to estimate human pose from static images for initialization of motion tracking. And we propose a sequential IGA (S-IGA algorithm for motion tracking by incorporating the temporal continuity information into the traditional IGA. Experimental results on different videos of different motion types show that our IGA-based pose estimation method can be used for initialization of motion tracking. The S-IGA-based motion tracking method can achieve accurate and stable tracking of 3D human motion.

  13. Genetic variation and the de novo assembly of human genomes.

    Science.gov (United States)

    Chaisson, Mark J P; Wilson, Richard K; Eichler, Evan E

    2015-11-01

    The discovery of genetic variation and the assembly of genome sequences are both inextricably linked to advances in DNA-sequencing technology. Short-read massively parallel sequencing has revolutionized our ability to discover genetic variation but is insufficient to generate high-quality genome assemblies or resolve most structural variation. Full resolution of variation is only guaranteed by complete de novo assembly of a genome. Here, we review approaches to genome assembly, the nature of gaps or missing sequences, and biases in the assembly process. We describe the challenges of generating a complete de novo genome assembly using current technologies and the impact that being able to perfectly sequence the genome would have on understanding human disease and evolution. Finally, we summarize recent technological advances that improve both contiguity and accuracy and emphasize the importance of complete de novo assembly as opposed to read mapping as the primary means to understanding the full range of human genetic variation.

  14. Therapeutic Targets of Triglyceride Metabolism as Informed by Human Genetics.

    Science.gov (United States)

    Bauer, Robert C; Khetarpal, Sumeet A; Hand, Nicholas J; Rader, Daniel J

    2016-04-01

    Human genetics has contributed to the development of multiple drugs to treat hyperlipidemia and coronary artery disease (CAD), most recently including antibodies targeting PCSK9 to reduce LDL cholesterol. Despite these successes, a large burden of CAD remains. Genetic and epidemiological studies have suggested that circulating triglyceride (TG)-rich lipoproteins (TRLs) are a causal risk factor for CAD, presenting an opportunity for novel therapeutic strategies. We discuss recent unbiased human genetics testing, including genome-wide association studies (GWAS) and whole-genome or -exome sequencing, that have identified the lipoprotein lipase (LPL) and hepatic lipogenesis pathways as important mechanisms in the regulation of circulating TRLs. Further strengthening the causal relationship between TRLs and CAD, findings such as these may provide novel targets for much-needed potential therapeutic interventions. Copyright © 2016. Published by Elsevier Ltd.

  15. Pervasive genetic integration directs the evolution of human skull shape.

    Science.gov (United States)

    Martínez-Abadías, Neus; Esparza, Mireia; Sjøvold, Torstein; González-José, Rolando; Santos, Mauro; Hernández, Miquel; Klingenberg, Christian Peter

    2012-04-01

    It has long been unclear whether the different derived cranial traits of modern humans evolved independently in response to separate selection pressures or whether they resulted from the inherent morphological integration throughout the skull. In a novel approach to this issue, we combine evolutionary quantitative genetics and geometric morphometrics to analyze genetic and phenotypic integration in human skull shape. We measured human skulls in the ossuary of Hallstatt (Austria), which offer a unique opportunity because they are associated with genealogical data. Our results indicate pronounced covariation of traits throughout the skull. Separate simulations of selection for localized shape changes corresponding to some of the principal derived characters of modern human skulls produced outcomes that were similar to each other and involved a joint response in all of these traits. The data for both genetic and phenotypic shape variation were not consistent with the hypothesis that the face, cranial base, and cranial vault are completely independent modules but relatively strongly integrated structures. These results indicate pervasive integration in the human skull and suggest a reinterpretation of the selective scenario for human evolution where the origin of any one of the derived characters may have facilitated the evolution of the others.

  16. Human loci involved in drug biotransformation: worldwide genetic variation, population structure, and pharmacogenetic implications.

    Science.gov (United States)

    Maisano Delser, Pierpaolo; Fuselli, Silvia

    2013-05-01

    Understanding the role of inheritance in individual variation in drug response is the focus of pharmacogenetics (PGx). A key part of this understanding is quantifying the role of genetic ancestry in this phenotypic outcome. To provide insight into the relationship between ethnicity and drug response, this study first infers the global distribution of PGx variation and defines its structure. Second, the study evaluates if geographic population structure stems from all PGx loci in general, or if structure is caused by specific genes. Lastly, we identify the genetic variants contributing the greatest proportion of such structure. Our study describes the global genetic structure of PGx loci across the 52 populations of the Human Genome Diversity Cell-Line Panel, the most inclusive set of human populations freely available for studies on human genetic variation. By analysing genetic variation at 1,001 single nucleotide polymorphisms (SNPs) involved in biotransformation of exogenous substances, we describe the between-populations PGx variation, as well geographical groupings of diversity. In addition, with discriminant analysis of principal component (DAPC), we infer how many and which groups of populations are supported by PGx variation, and identify which SNPs actually contribute to the PGx structure between such groups. Our results show that intergenic, synonymous and non-synonymous SNPs show similar levels of genetic variation across the globe. Conversely, loci coding for Cytochrome P450s (mainly metabolizing exogenous substances) show significantly higher levels of genetic diversity between populations than the other gene categories. Overall, genetic variation at PGx loci correlates with geographic distances between populations, and the apportionment of genetic variation is similar to that observed for the rest of the genome. In other words, the pattern of PGx variation has been mainly shaped by the demographic history of our species, as in the case of most of our

  17. Exploring human brain lateralization with molecular genetics and genomics.

    Science.gov (United States)

    Francks, Clyde

    2015-11-01

    Lateralizations of brain structure and motor behavior have been observed in humans as early as the first trimester of gestation, and are likely to arise from asymmetrical genetic-developmental programs, as in other animals. Studies of gene expression levels in postmortem tissue samples, comparing the left and right sides of the human cerebral cortex, have generally not revealed striking transcriptional differences between the hemispheres. This is likely due to lateralization of gene expression being subtle and quantitative. However, a recent re-analysis and meta-analysis of gene expression data from the adult superior temporal and auditory cortex found lateralization of transcription of genes involved in synaptic transmission and neuronal electrophysiology. Meanwhile, human subcortical mid- and hindbrain structures have not been well studied in relation to lateralization of gene activity, despite being potentially important developmental origins of asymmetry. Genetic polymorphisms with small effects on adult brain and behavioral asymmetries are beginning to be identified through studies of large datasets, but the core genetic mechanisms of lateralized human brain development remain unknown. Identifying subtly lateralized genetic networks in the brain will lead to a new understanding of how neuronal circuits on the left and right are differently fine-tuned to preferentially support particular cognitive and behavioral functions. © 2015 New York Academy of Sciences.

  18. Common genetic variants influence human subcortical brain structures

    NARCIS (Netherlands)

    Hibar, Derrek P.; Stein, Jason L.; Renteria, Miguel E.; Arias-Vasquez, Alejandro; Desrivieres, Sylvane; Jahanshad, Neda; Toro, Roberto; Wittfeld, Katharina; Abramovic, Lucija; Andersson, Micael; Aribisala, Benjamin S.; Armstrong, Nicola J.; Bernard, Manon; Bohlken, Marc M.; Boks, Marco P.; Bralten, Janita; Brown, Andrew A.; Chakravarty, M. Mallar; Chen, Qiang; Ching, Christopher R. K.; Cuellar-Partida, Gabriel; den Braber, Anouk; Giddaluru, Sudheer; Goldman, Aaron L.; Grimm, Oliver; Guadalupe, Tulio; Hass, Johanna; Woldehawariat, Girma; Holmes, Avram J.; Hoogman, Martine; Janowitz, Deborah; Jia, Tianye; Kim, Sungeun; Klein, Marieke; Kraemer, Bernd; Lee, Phil H.; Loohuis, Loes M. Olde; Luciano, Michelle; Macare, Christine; Mather, Karen A.; Mattheisen, Manuel; Milaneschi, Yuri; Nho, Kwangsik; Papmeyer, Martina; Ramasamy, Adaikalavan; Risacher, Shannon L.; Roiz-Santianez, Roberto; Rose, Emma J.; Salami, Alireza; Saemann, Philipp G.; Schmaal, Lianne; Schork, Andrew J.; Shin, Jean; Strike, Lachlan T.; Teumer, Alexander; van Donkelaar, Marjolein M. J.; van Eijk, Kristel R.; Walters, Raymond K.; Westlye, Lars T.; Whelan, Christopher D.; Winkler, Anderson M.; Zwiers, Marcel P.; Alhusaini, Saud; Athanasiu, Lavinia; Ehrlich, Stefan; Hakobjan, Marina M. H.; Hartberg, Cecilie B.; Haukvik, Unn K.; Heister, Angelien J. G. A. M.; Hoehn, David; Kasperaviciute, Dalia; Liewald, David C. M.; Lopez, Lorna M.; Makkinje, Remco R. R.; Matarin, Mar; Naber, Marlies A. M.; McKay, D. Reese; Needham, Margaret; Nugent, Allison C.; Puetz, Benno; Royle, Natalie A.; Shen, Li; Sprooten, Emma; Trabzuni, Daniah; van der Marel, Saskia S. L.; van Hulzen, Kimm J. E.; Walton, Esther; Wolf, Christiane; Almasy, Laura; Ames, David; Arepalli, Sampath; Assareh, Amelia A.; Bastin, Mark E.; Brodaty, Henry; Bulayeva, Kazima B.; Carless, Melanie A.; Cichon, Sven; Corvin, Aiden; Curran, Joanne E.; Czisch, Michael; de Zubicaray, Greig I.; Dillman, Allissa; Duggirala, Ravi; Dyer, Thomas D.; Erk, Susanne; Fedko, Iryna O.; Ferrucci, Luigi; Foroud, Tatiana M.; Fox, Peter T.; Fukunaga, Masaki; Gibbs, J. Raphael; Goering, Harald H. H.; Green, Robert C.; Guelfi, Sebastian; Hansell, Narelle K.; Hartman, Catharina A.; Hegenscheid, Katrin; Heinz, Andreas; Hernandez, Dena G.; Heslenfeld, Dirk J.; Hoekstra, Pieter J.; Holsboer, Florian; Homuth, Georg; Hottenga, Jouke-Jan; Ikeda, Masashi; Jack, Clifford R.; Jenkinson, Mark; Johnson, Robert; Kanai, Ryota; Keil, Maria; Kent, Jack W.; Kochunov, Peter; Kwok, John B.; Lawrie, Stephen M.; Liu, Xinmin; Longo, Dan L.; McMahon, Katie L.; Meisenzah, Eva; Melle, Ingrid; Mahnke, Sebastian; Montgomery, Grant W.; Mostert, Jeanette C.; Muehleisen, Thomas W.; Nalls, Michael A.; Nichols, Thomas E.; Nilsson, Lars G.; Noethen, Markus M.; Ohi, Kazutaka; Olvera, Rene L.; Perez-Iglesias, Rocio; Pike, G. Bruce; Potkin, Steven G.; Reinvang, Ivar; Reppermund, Simone; Rietschel, Marcella; Romanczuk-Seiferth, Nina; Rosen, Glenn D.; Rujescu, Dan; Schnell, Knut; Schofield, Peter R.; Smith, Colin; Steen, Vidar M.; Sussmann, Jessika E.; Thalamuthu, Anbupalam; Toga, Arthur W.; Traynor, Bryan J.; Troncoso, Juan; Turner, Jessica A.; Valdes Hernandez, Maria C.; van't Ent, Dennis; van der Brug, Marcel; van der Wee, Nic J. A.; van Tol, Marie-Jose; Veltman, Dick J.; Wassink, Thomas H.; Westman, Eric; Zielke, Ronald H.; Zonderman, Alan B.; Ashbrook, David G.; Hager, Reinmar; Lu, Lu; McMahon, Francis J.; Morris, Derek W.; Williams, Robert W.; Brunner, Han G.; Buckner, Randy L.; Buitelaar, Jan K.; Cahn, Wiepke; Calhoun, Vince D.; Cavalleri, Gianpiero L.; Crespo-Facorro, Benedicto; Dale, Anders M.; Davies, Gareth E.; Delanty, Norman; Depondt, Chantal; Djurovic, Srdjan; Drevets, Wayne C.; Espeseth, Thomas; Gollub, Randy L.; Ho, Beng-Choon; Hoffman, Wolfgang; Hosten, Norbert; Kahn, Rene S.; Le Hellard, Stephanie; Meyer-Lindenberg, Andreas; Mueller-Myhsok, Bertram; Nauck, Matthias; Nyberg, Lars; Pandolfo, Massimo; Penninx, Brenda W. J. H.; Roffman, Joshua L.; Sisodiya, Sanjay M.; Smoller, Jordan W.; van Bokhoven, Hans; van Haren, Neeltje E. M.; Voelzke, Henry; Walter, Henrik; Weiner, Michael W.; Wen, Wei; White, Tonya; Agartz, Ingrid; Andreassen, Ole A.; Blangero, John; Boomsma, Dorret I.; Brouwer, Rachel M.; Cannon, Dara M.; Cookson, Mark R.; de Geus, Eco J. C.; Deary, Ian J.; Donohoe, Gary; Fernandez, Guillen; Fisher, Simon E.; Francks, Clyde; Glahn, David C.; Grabe, Hans J.; Gruber, Oliver; Hardy, John; Hashimoto, Ryota; Pol, Hilleke E. Hulshoff; Joensson, Erik G.; Kloszewska, Iwona; Lovestone, Simon; Mattay, Venkata S.; Mecocci, Patrizia; McDonald, Colm; McIntosh, Andrew M.; Ophoff, Roel A.; Paus, Tomas; Pausova, Zdenka; Ryten, Mina; Sachdev, Perminder S.; Saykin, Andrew J.; Simmons, Andy; Singleton, Andrew; Soininen, Hilkka; Wardlaw, Joanna M.; Weale, Michael E.; Weinberger, Daniel R.; Adams, Hieab H. H.; Launer, Lenore J.; Seiler, Stephan; Schmidt, Reinhold; Chauhan, Ganesh; Satizabal, Claudia L.; Becker, James T.; Yanek, Lisa; van der Lee, Sven J.; Ebling, Maritza; Fischl, Bruce; Longstreth, W. T.; Greve, Douglas; Schmidt, Helena; Nyquist, Paul; Vinke, Louis N.; van Duijn, Cornelia M.; Xue, Luting; Mazoyer, Bernard; Bis, Joshua C.; Gudnason, Vilmundur; Seshadri, Sudha; Ikram, M. Arfan; Martin, Nicholas G.; Wright, Margaret J.; Schumann, Gunter; Franke, Barbara; Thompson, Paul M.; Medland, Sarah E.

    2015-01-01

    The highly complex structure of the human brain is strongly shaped by genetic influences(1). Subcortical brain regions form circuits with cortical areas to coordinate movement(2), learning, memory(3) and motivation(4), and altered circuits can lead to abnormal behaviour and disease(5). To investigat

  19. Common genetic variants influence human subcortical brain structures

    NARCIS (Netherlands)

    D.P. Hibar (Derrek); J.L. Stein; M.E. Rentería (Miguel); A. Arias-Vásquez (Alejandro); S. Desrivières (Sylvane); N. Jahanshad (Neda); R. Toro (Roberto); K. Wittfeld (Katharina); L. Abramovic (Lucija); M. Andersson (Micael); B. Aribisala (Benjamin); N.J. Armstrong (Nicola J.); M. Bernard (Manon); M.M. Bohlken (Marc M.); M.P.M. Boks (Marco); L.B.C. Bralten (Linda); A.A. Brown (Andrew); M.M. Chakravarty (M. Mallar); Q. Chen (Qiang); C.R.K. Ching (Christopher); G. Cuellar-Partida (Gabriel); A. den Braber (Anouk); S. Giddaluru (Sudheer); A.L. Goldman (Aaron L.); O. Grimm (Oliver); T. Guadalupe (Tulio); J. Hass (Johanna); G. Woldehawariat (Girma); A.J. Holmes (Avram); M. Hoogman (Martine); D. Janowitz (Deborah); T. Jia (Tianye); S. Kim (Shinseog); M. Klein (Marieke); B. Kraemer (Bernd); P.H. Lee (Phil H.); L.M. Olde Loohuis (Loes M.); M. Luciano (Michelle); C. MacAre (Christine); R. Mather; M. Mattheisen (Manuel); Y. Milaneschi (Yuri); K. Nho (Kwangsik); M. Papmeyer (Martina); A. Ramasamy (Adaikalavan); S.L. Risacher (Shannon); R. Roiz-Santiañez (Roberto); E.J. Rose (Emma); A. Salami (Alireza); P.G. Sämann (Philipp); L. Schmaal (Lianne); N.J. Schork (Nicholas); J. Shin (Jean); V.M. Strike (Vanessa); A. Teumer (Alexander); M.M.J. Van Donkelaar (Marjolein M. J.); K.R. van Eijk (Kristel); R.K. Walters (Raymond); L.T. Westlye (Lars); C.D. Whelan (Christopher); A.M. Winkler (Anderson); M.P. Zwiers (Marcel); S. Alhusaini (Saud); L. Athanasiu (Lavinia); S.M. Ehrlich (Stefan); M. Hakobjan (Marina); C.B. Hartberg (Cecilie B.); U.K. Haukvik (Unn); A.J.G.A.M. Heister (Angelien J. G. A. M.); D. Hoehn (David); D. Kasperaviciute (Dalia); D.C. Liewald (David C.); L.M. Lopez (Lorna); R.R.R. Makkinje (Remco R. R.); M. Matarin (Mar); M.A.M. Naber (Marlies A. M.); D. Reese McKay; M. Needham (Margaret); A.C. Nugent (Allison); B. Pütz (Benno); N.A. Royle (Natalie); L. Shen (Li); R. Sprooten (Roy); D. Trabzuni (Danyah); S.S.L. Van Der Marel (Saskia S. L.); K.J.E. Van Hulzen (Kimm J. E.); E. Walton (Esther); A. Björnsson (Asgeir); L. Almasy (Laura); D. Ames (David); S. Arepalli (Sampath); A.A. Assareh; M.E. Bastin (Mark); H. Brodaty (Henry); K. Bulayeva (Kazima); M.A. Carless (Melanie); S. Cichon (Sven); A. Corvin (Aiden); J.E. Curran (Joanne); M. Czisch (Michael); G.I. de Zubicaray (Greig); A. Dillman (Allissa); A. Duggirala (Aparna); M.D. Dyer (Matthew); S. Erk; I. Fedko (Iryna); L. Ferrucci (Luigi); T. Foroud (Tatiana); P.T. Fox (Peter); M. Fukunaga (Masaki); J. Raphael Gibbs; H.H.H. Göring (Harald H.); R.C. Green (Robert C.); S. Guelfi (Sebastian); N.K. Hansell (Narelle); C.A. Hartman (Catharina); K. Hegenscheid (Katrin); J. Heinz (Judith); D.G. Hernandez (Dena); D.J. Heslenfeld (Dirk); P.J. Hoekstra (Pieter); F. Holsboer; G. Homuth (Georg); J.J. Hottenga (Jouke Jan); M. Ikeda (Masashi); C.R. Jack Jr. (Clifford); S. Jenkinson (Sarah); R. Johnson (Robert); R. Kanai (Ryota); M. Keil (Maria); J.W. Kent (Jack W.); P. Kochunov (Peter); J.B. Kwok (John B.); S. Lawrie (Stephen); X. Liu (Xinmin); D.L. Longo (Dan L.); K.L. Mcmahon (Katie); E. Meisenzahl (Eva); I. Melle (Ingrid); S. Mohnke (Sebastian); G.W. Montgomery (Grant); J.C. Mostert (Jeanette C.); T.W. Mühleisen (Thomas); M.A. Nalls (Michael); T.E. Nichols (Thomas); L.G. Nilsson; M.M. Nöthen (Markus); K. Ohi (Kazutaka); R.L. Olvera (Rene); R. Perez-Iglesias (Rocio); G. Bruce Pike; S.G. Potkin (Steven); I. Reinvang (Ivar); S. Reppermund; M. Rietschel (M.); N. Seiferth (Nina); G.D. Rosen (Glenn D.); D. Rujescu (Dan); K. Schnell (Kerry); C.J. Schofield (Christopher); C. Smith (Colin); V.M. Steen (Vidar); J. Sussmann (Jessika); A. Thalamuthu (Anbupalam); A.W. Toga (Arthur W.); B. Traynor (Bryan); J.C. Troncoso (Juan); J. Turner (Jessica); M.C. Valdés Hernández (Maria); D. van 't Ent (Dennis); M.P. van der Brug (Marcel); N.J. van der Wee (Nic); M.J.D. van Tol (Marie-José); D.J. Veltman (Dick); A.M.J. Wassink (Annemarie); E. Westman (Eric); R.H. Zielke (Ronald H.); A.B. Zonderman (Alan B.); D.G. Ashbrook (David G.); R. Hager (Reinmar); L. Lu (Lu); F.J. Mcmahon (Francis J); D.W. Morris (Derek W); R.W. Williams (Robert W.); H.G. Brunner; M. Buckner; J.K. Buitelaar (Jan K.); W. Cahn (Wiepke); V.D. Calhoun Vince D. (V.); G. Cavalleri (Gianpiero); B. Crespo-Facorro (Benedicto); A.M. Dale (Anders); G.E. Davies (Gareth); N. Delanty; C. Depondt (Chantal); S. Djurovic (Srdjan); D.A. Drevets (Douglas); T. Espeseth (Thomas); R.L. Gollub (Randy); B.C. Ho (Beng ); W. Hoffmann (Wolfgang)

    2015-01-01

    textabstractThe highly complex structure of the human brain is strongly shaped by genetic influences. Subcortical brain regions form circuits with cortical areas to coordinate movement, learning, memory and motivation, and altered circuits can lead to abnormal behaviour and disease. To investigate

  20. Common genetic variants influence human subcortical brain structures

    NARCIS (Netherlands)

    Hibar, D.P.; Stein, J.L.; Renteria, M.E.; Arias Vasquez, A.; Desrivieres, S.; Jahanshad, N.; Toro, R.; Wittfeld, K.; Abramovic, L.; Andersson, M.; Aribisala, B.S.; Armstrong, N.J.; Bernard, M.; Bohlken, M.M.; Boks, M.P.; Bralten, J.; Brown, A.A.; Chakravarty, M.M.; Chen, Q.; Ching, C.R.; Cuellar-Partida, G.; Braber, A.; Giddaluru, S.; Goldman, A.L.; Grimm, O.; Guadalupe, T.; Hass, J.; Woldehawariat, G.; Holmes, A.J.; Hoogman, M.; Janowitz, D.; Jia, T.; Kim, S.; Klein, M.; Kraemer, B.; Lee, P.H.; Olde Loohuis, L.M.; Luciano, M.; Macare, C.; Mather, K.A.; Mattheisen, M.; Milaneschi, Y.; Nho, K.; Papmeyer, M.; Ramasamy, A.; Risacher, S.L.; Roiz-Santianez, R.; Rose, E.J.; Salami, A.; Samann, P.G.; Schmaal, L.; Schork, A.J.; Shin, J.; Strike, L.T.; Teumer, A.; Donkelaar, M.M.J. van; Eijk, K.R. van; Walters, R.K.; Westlye, L.T.; Whelan, C.D.; Winkler, A.M.; Zwiers, M.P.; Alhusaini, S.; Athanasiu, L.; Ehrlich, S.; Hakobjan, M.M.; Hartberg, C.B.; Haukvik, U.K.; Heister, A.J.; Hoehn, D.; Kasperaviciute, D.; Liewald, D.C.; Lopez, L.M.; Makkinje, R.R.; Matarin, M.; Naber, M.; McKay, D.R.; Needham, M.; Nugent, A.C.; Putz, B.; Royle, N.A.; Shen, L.; Sprooten, E.; Trabzuni, D.; Marel, S.S. van der; Hulzen, K.J.E. van; Walton, E.; Wolf, C.; Almasy, L.; Ames, D.; Arepalli, S.; Assareh, A.A.; Bastin, M.E.; Brodaty, H.; Bulayeva, K.B.; Carless, M.A.; Cichon, S.; Corvin, A.; Curran, J.E.; Czisch, M.; Fisher, S.E.

    2015-01-01

    The highly complex structure of the human brain is strongly shaped by genetic influences. Subcortical brain regions form circuits with cortical areas to coordinate movement, learning, memory and motivation, and altered circuits can lead to abnormal behaviour and disease. To investigate how common

  1. Common genetic variants influence human subcortical brain structures

    NARCIS (Netherlands)

    Hibar, Derrek P.; Stein, Jason L.; Renteria, Miguel E.; Arias-Vasquez, Alejandro; Desrivieres, Sylvane; Jahanshad, Neda; Toro, Roberto; Wittfeld, Katharina; Abramovic, Lucija; Andersson, Micael; Aribisala, Benjamin S.; Armstrong, Nicola J.; Bernard, Manon; Bohlken, Marc M.; Boks, Marco P.; Bralten, Janita; Brown, Andrew A.; Chakravarty, M. Mallar; Chen, Qiang; Ching, Christopher R. K.; Cuellar-Partida, Gabriel; den Braber, Anouk; Giddaluru, Sudheer; Goldman, Aaron L.; Grimm, Oliver; Guadalupe, Tulio; Hass, Johanna; Woldehawariat, Girma; Holmes, Avram J.; Hoogman, Martine; Janowitz, Deborah; Jia, Tianye; Kim, Sungeun; Klein, Marieke; Kraemer, Bernd; Lee, Phil H.; Loohuis, Loes M. Olde; Luciano, Michelle; Macare, Christine; Mather, Karen A.; Mattheisen, Manuel; Milaneschi, Yuri; Nho, Kwangsik; Papmeyer, Martina; Ramasamy, Adaikalavan; Risacher, Shannon L.; Roiz-Santianez, Roberto; Rose, Emma J.; Salami, Alireza; Saemann, Philipp G.; Schmaal, Lianne; Schork, Andrew J.; Shin, Jean; Strike, Lachlan T.; Teumer, Alexander; van Donkelaar, Marjolein M. J.; van Eijk, Kristel R.; Walters, Raymond K.; Westlye, Lars T.; Whelan, Christopher D.; Winkler, Anderson M.; Zwiers, Marcel P.; Alhusaini, Saud; Athanasiu, Lavinia; Ehrlich, Stefan; Hakobjan, Marina M. H.; Hartberg, Cecilie B.; Haukvik, Unn K.; Heister, Angelien J. G. A. M.; Hoehn, David; Kasperaviciute, Dalia; Liewald, David C. M.; Lopez, Lorna M.; Makkinje, Remco R. R.; Matarin, Mar; Naber, Marlies A. M.; McKay, D. Reese; Needham, Margaret; Nugent, Allison C.; Puetz, Benno; Royle, Natalie A.; Shen, Li; Sprooten, Emma; Trabzuni, Daniah; van der Marel, Saskia S. L.; van Hulzen, Kimm J. E.; Walton, Esther; Wolf, Christiane; Almasy, Laura; Ames, David; Arepalli, Sampath; Assareh, Amelia A.; Bastin, Mark E.; Brodaty, Henry; Bulayeva, Kazima B.; Carless, Melanie A.; Cichon, Sven; Corvin, Aiden; Curran, Joanne E.; Czisch, Michael; de Zubicaray, Greig I.; Dillman, Allissa; Duggirala, Ravi; Dyer, Thomas D.; Erk, Susanne; Fedko, Iryna O.; Ferrucci, Luigi; Foroud, Tatiana M.; Fox, Peter T.; Fukunaga, Masaki; Gibbs, J. Raphael; Goering, Harald H. H.; Green, Robert C.; Guelfi, Sebastian; Hansell, Narelle K.; Hartman, Catharina A.; Hegenscheid, Katrin; Heinz, Andreas; Hernandez, Dena G.; Heslenfeld, Dirk J.; Hoekstra, Pieter J.; Holsboer, Florian; Homuth, Georg; Hottenga, Jouke-Jan; Ikeda, Masashi; Jack, Clifford R.; Jenkinson, Mark; Johnson, Robert; Kanai, Ryota; Keil, Maria; Kent, Jack W.; Kochunov, Peter; Kwok, John B.; Lawrie, Stephen M.; Liu, Xinmin; Longo, Dan L.; McMahon, Katie L.; Meisenzah, Eva; Melle, Ingrid; Mahnke, Sebastian; Montgomery, Grant W.; Mostert, Jeanette C.; Muehleisen, Thomas W.; Nalls, Michael A.; Nichols, Thomas E.; Nilsson, Lars G.; Noethen, Markus M.; Ohi, Kazutaka; Olvera, Rene L.; Perez-Iglesias, Rocio; Pike, G. Bruce; Potkin, Steven G.; Reinvang, Ivar; Reppermund, Simone; Rietschel, Marcella; Romanczuk-Seiferth, Nina; Rosen, Glenn D.; Rujescu, Dan; Schnell, Knut; Schofield, Peter R.; Smith, Colin; Steen, Vidar M.; Sussmann, Jessika E.; Thalamuthu, Anbupalam; Toga, Arthur W.; Traynor, Bryan J.; Troncoso, Juan; Turner, Jessica A.; Valdes Hernandez, Maria C.; van't Ent, Dennis; van der Brug, Marcel; van der Wee, Nic J. A.; van Tol, Marie-Jose; Veltman, Dick J.; Wassink, Thomas H.; Westman, Eric; Zielke, Ronald H.; Zonderman, Alan B.; Ashbrook, David G.; Hager, Reinmar; Lu, Lu; McMahon, Francis J.; Morris, Derek W.; Williams, Robert W.; Brunner, Han G.; Buckner, Randy L.; Buitelaar, Jan K.; Cahn, Wiepke; Calhoun, Vince D.; Cavalleri, Gianpiero L.; Crespo-Facorro, Benedicto; Dale, Anders M.; Davies, Gareth E.; Delanty, Norman; Depondt, Chantal; Djurovic, Srdjan; Drevets, Wayne C.; Espeseth, Thomas; Gollub, Randy L.; Ho, Beng-Choon; Hoffman, Wolfgang; Hosten, Norbert; Kahn, Rene S.; Le Hellard, Stephanie; Meyer-Lindenberg, Andreas; Mueller-Myhsok, Bertram; Nauck, Matthias; Nyberg, Lars; Pandolfo, Massimo; Penninx, Brenda W. J. H.; Roffman, Joshua L.; Sisodiya, Sanjay M.; Smoller, Jordan W.; van Bokhoven, Hans; van Haren, Neeltje E. M.; Voelzke, Henry; Walter, Henrik; Weiner, Michael W.; Wen, Wei; White, Tonya; Agartz, Ingrid; Andreassen, Ole A.; Blangero, John; Boomsma, Dorret I.; Brouwer, Rachel M.; Cannon, Dara M.; Cookson, Mark R.; de Geus, Eco J. C.; Deary, Ian J.; Donohoe, Gary; Fernandez, Guillen; Fisher, Simon E.; Francks, Clyde; Glahn, David C.; Grabe, Hans J.; Gruber, Oliver; Hardy, John; Hashimoto, Ryota; Pol, Hilleke E. Hulshoff; Joensson, Erik G.; Kloszewska, Iwona; Lovestone, Simon; Mattay, Venkata S.; Mecocci, Patrizia; McDonald, Colm; McIntosh, Andrew M.; Ophoff, Roel A.; Paus, Tomas; Pausova, Zdenka; Ryten, Mina; Sachdev, Perminder S.; Saykin, Andrew J.; Simmons, Andy; Singleton, Andrew; Soininen, Hilkka; Wardlaw, Joanna M.; Weale, Michael E.; Weinberger, Daniel R.; Adams, Hieab H. H.; Launer, Lenore J.; Seiler, Stephan; Schmidt, Reinhold; Chauhan, Ganesh; Satizabal, Claudia L.; Becker, James T.; Yanek, Lisa; van der Lee, Sven J.; Ebling, Maritza; Fischl, Bruce; Longstreth, W. T.; Greve, Douglas; Schmidt, Helena; Nyquist, Paul; Vinke, Louis N.; van Duijn, Cornelia M.; Xue, Luting; Mazoyer, Bernard; Bis, Joshua C.; Gudnason, Vilmundur; Seshadri, Sudha; Ikram, M. Arfan; Martin, Nicholas G.; Wright, Margaret J.; Schumann, Gunter; Franke, Barbara; Thompson, Paul M.; Medland, Sarah E.

    2015-01-01

    The highly complex structure of the human brain is strongly shaped by genetic influences(1). Subcortical brain regions form circuits with cortical areas to coordinate movement(2), learning, memory(3) and motivation(4), and altered circuits can lead to abnormal behaviour and disease(5). To

  2. Improved genetic manipulation of human embryonic stem cells.

    NARCIS (Netherlands)

    Braam, S.R.; Denning, C.; van den Brink, S.; Kats, P.; Hochstenbach, R.; Passier, R.; Mummery, C.L.

    2008-01-01

    Low efficiency of transfection limits the ability to genetically manipulate human embryonic stem cells (hESCs), and differences in cell derivation and culture methods require optimization of transfection protocols. We transiently transferred multiple independent hESC lines with different growth requ

  3. Human Fertility, Molecular Genetics, and Natural Selection in Modern Societies

    NARCIS (Netherlands)

    Tropf, Felix C.; Stulp, Gert; Barban, Nicola; Visscher, Peter M.; Yang, Jian; Snieder, Harold; Mills, Melinda C.

    2015-01-01

    Research on genetic influences on human fertility outcomes such as number of children ever born (NEB) or the age at first childbirth (AFB) has been solely based on twin and family-designs that suffer from problematic assumptions and practical limitations. The current study exploits recent advances

  4. Public Attitudes toward Human Genetic Manipulation: A Revitalization of Eugenics?

    Science.gov (United States)

    Veglia, Geremia; And Others

    The purpose of this investigation was to measure the attitudes of college students across the United States concerning the possible use of genetic manipulation, especially in terms of enhancing human physical and intellectual characteristics. The instrument used was divided into three general areas of inquiry: the first, designed to measure the…

  5. Common genetic variants influence human subcortical brain structures

    NARCIS (Netherlands)

    D.P. Hibar (Derrek); J.L. Stein; M.E. Rentería (Miguel); A. Arias-Vásquez (Alejandro); S. Desrivières (Sylvane); N. Jahanshad (Neda); R. Toro (Roberto); K. Wittfeld (Katharina); L. Abramovic; M. Andersson (Micael); B. Aribisala (Benjamin); N.J. Armstrong (Nicola J.); M. Bernard (Manon); M.M. Bohlken (Marc M.); M.P.M. Boks (Marco); L.B.C. Bralten (Linda); A.A. Brown (Andrew); M.M. Chakravarty (M. Mallar); Q. Chen (Qiang); C.R.K. Ching (Christopher); G. Cuellar-Partida (Gabriel); A. den Braber (Anouk); S. Giddaluru (Sudheer); A.L. Goldman (Aaron L.); O. Grimm (Oliver); T. Guadalupe (Tulio); J. Hass (Johanna); G. Woldehawariat (Girma); A.J. Holmes (Avram); M. Hoogman (Martine); D. Janowitz (Deborah); T. Jia (Tianye); S. Kim (Shinseog); M. Klein (Marieke); B. Kraemer (Bernd); P.H. Lee (Phil H.); L.M. Olde Loohuis (Loes M.); M. Luciano (Michelle); C. MacAre (Christine); R. Mather; M. Mattheisen (Manuel); Y. Milaneschi (Yuri); K. Nho (Kwangsik); M. Papmeyer (Martina); A. Ramasamy (Adaikalavan); S.L. Risacher (Shannon); R. Roiz-Santiañez (Roberto); E.J. Rose (Emma); A. Salami (Alireza); P.G. Sämann (Philipp); L. Schmaal (Lianne); N.J. Schork (Nicholas); J. Shin (Jean); V.M. Strike (Vanessa); A. Teumer (Alexander); M.M.J. Van Donkelaar (Marjolein M. J.); K.R. van Eijk (Kristel); R.K. Walters (Raymond); L.T. Westlye (Lars); C.D. Whelan (Christopher); A.M. Winkler (Anderson); M.P. Zwiers (Marcel); S. Alhusaini (Saud); L. Athanasiu (Lavinia); S.M. Ehrlich (Stefan); M. Hakobjan (Marina); C.B. Hartberg (Cecilie B.); U.K. Haukvik (Unn); A.J.G.A.M. Heister (Angelien J. G. A. M.); D. Hoehn (David); D. Kasperaviciute (Dalia); D.C. Liewald (David C.); L.M. Lopez (Lorna); R.R.R. Makkinje (Remco R. R.); M. Matarin (Mar); M.A.M. Naber (Marlies A. M.); D. Reese McKay; M. Needham (Margaret); A.C. Nugent (Allison); B. Pütz (Benno); N.A. Royle (Natalie); L. Shen (Li); R. Sprooten (Roy); D. Trabzuni (Danyah); S.S.L. Van Der Marel (Saskia S. L.); K.J.E. Van Hulzen (Kimm J. E.); E. Walton (Esther); A. Björnsson (Asgeir); L. Almasy (Laura); D. Ames (David); S. Arepalli (Sampath); A.A. Assareh; M.E. Bastin (Mark); H. Brodaty (Henry); K. Bulayeva (Kazima); M.A. Carless (Melanie); S. Cichon (Sven); A. Corvin (Aiden); J.E. Curran (Joanne); M. Czisch (Michael); G.I. de Zubicaray (Greig); A. Dillman (Allissa); A. Duggirala (Aparna); M.D. Dyer (Matthew); S. Erk; I. Fedko (Iryna); L. Ferrucci (Luigi); T. Foroud (Tatiana); P.T. Fox (Peter); M. Fukunaga (Masaki); J. Raphael Gibbs; H.H.H. Göring (Harald H.); R.C. Green (Robert C.); S. Guelfi (Sebastian); N.K. Hansell (Narelle); C.A. Hartman (Catharina); K. Hegenscheid (Katrin); J. Heinz (Judith); D.G. Hernandez (Dena); D.J. Heslenfeld (Dirk); P.J. Hoekstra (Pieter); F. Holsboer; G. Homuth (Georg); J.J. Hottenga (Jouke Jan); M. Ikeda (Masashi); C.R. Jack Jr. (Clifford); S. Jenkinson (Sarah); R. Johnson (Robert); R. Kanai (Ryota); M. Keil (Maria); J.W. Kent (Jack W.); P. Kochunov (Peter); J.B. Kwok (John B.); S. Lawrie (Stephen); X. Liu (Xinmin); D.L. Longo (Dan L.); K.L. Mcmahon (Katie); E. Meisenzahl (Eva); I. Melle (Ingrid); S. Mohnke (Sebastian); G.W. Montgomery (Grant); J.C. Mostert (Jeanette C.); T.W. Mühleisen (Thomas); M.A. Nalls (Michael); T.E. Nichols (Thomas); L.G. Nilsson; M.M. Nöthen (Markus); K. Ohi (Kazutaka); R.L. Olvera (Rene); R. Perez-Iglesias (Rocio); G. Bruce Pike; S.G. Potkin (Steven); I. Reinvang (Ivar); S. Reppermund; M. Rietschel (M.); N. Seiferth (Nina); G.D. Rosen (Glenn D.); D. Rujescu (Dan); K. Schnell (Kerry); C.J. Schofield (Christopher); C. Smith (Colin); V.M. Steen (Vidar); J. Sussmann (Jessika); A. Thalamuthu (Anbupalam); A.W. Toga (Arthur W.); B. Traynor (Bryan); J.C. Troncoso (Juan); J. Turner (Jessica); M.C. Valdés Hernández (Maria); D. van 't Ent (Dennis); M.P. van der Brug (Marcel); N.J. van der Wee (Nic); M.J.D. van Tol (Marie-José); D.J. Veltman (Dick); A.M.J. Wassink (Annemarie); E. Westman (Eric); R.H. Zielke (Ronald H.); A.B. Zonderman (Alan B.); D.G. Ashbrook (David G.); R. Hager (Reinmar); L. Lu (Lu); F.J. Mcmahon (Francis J); D.W. Morris (Derek W); R.W. Williams (Robert W.); H.G. Brunner; M. Buckner; J.K. Buitelaar (Jan K.); W. Cahn (Wiepke); V.D. Calhoun Vince D. (V.); G. Cavalleri (Gianpiero); B. Crespo-Facorro (Benedicto); A.M. Dale (Anders); G.E. Davies (Gareth); N. Delanty; C. Depondt (Chantal); S. Djurovic (Srdjan); D.A. Drevets (Douglas); T. Espeseth (Thomas); R.L. Gollub (Randy); B.C. Ho (Beng ); W. Hoffmann (Wolfgang); N. Hosten (Norbert); R. Kahn; S. Le Hellard (Stephanie); A. Meyer-Lindenberg; B. Müller-Myhsok (B.); M. Nauck (Matthias); L. Nyberg (Lars); M. Pandolfo (Massimo); B.W.J.H. Penninx (Brenda); J.L. Roffman (Joshua); S.M. Sisodiya (Sanjay); J.W. Smoller; H. van Bokhoven (Hans); N.E.M. van Haren (Neeltje E.); H. Völzke (Henry); H.J. Walter (Henrik); M.W. Weiner (Michael); W. Wen (Wei); T.J.H. White (Tonya); I. Agartz (Ingrid); O.A. Andreassen (Ole A.); J. Blangero (John); D.I. Boomsma (Dorret); R.M. Brouwer (Rachel); D.M. Cannon (Dara); M.R. Cookson (Mark); E.J.C. de Geus (Eco); I.J. Deary (Ian J.); D.J. Donohoe (Dennis); G. Fernandez (Guillén); S.E. Fisher (Simon); C. Francks (Clyde); D.C. Glahn (David); H.J. Grabe (Hans Jörgen); O. Gruber (Oliver); J. Hardy (John); R. Hashimoto (Ryota); H.E. Hulshoff Pol (Hilleke); E.G. Jönsson (Erik); I. Kloszewska (Iwona); S. Lovestone (Simon); V.S. Mattay (Venkata S.); P. Mecocci (Patrizia); C. McDonald (Colm); A.M. McIntosh (Andrew); R.A. Ophoff (Roel); T. Paus (Tomas); Z. Pausova (Zdenka); M. Ryten (Mina); P.S. Sachdev (Perminder); A.J. Saykin (Andrew); A. Simmons (Andrew); A. Singleton (Andrew); H. Soininen (H.); J.M. Wardlaw (J.); M.E. Weale (Michael); D.R. Weinberger (Daniel); H.H.H. Adams (Hieab); L.J. Launer (Lenore); S. Seiler (Stephan); R. Schmidt (Reinhold); G. Chauhan (Ganesh); C.L. Satizabal (Claudia L.); J.T. Becker (James); L.R. Yanek (Lisa); S. van der Lee (Sven); M. Ebling (Maritza); B. Fischl (Bruce); W.T. Longstreth Jr; D. Greve (Douglas); R. Schmidt (Reinhold); P. Nyquist (Paul); L.N. Vinke (Louis N.); C.M. van Duijn (Cock); L. Xue (Luting); B. Mazoyer (Bernard); J.C. Bis (Joshua); V. Gudnason (Vilmundur); S. Seshadri (Sudha); M.A. Ikram (Arfan); N.G. Martin (Nicholas); M.J. Wright (Margaret); G. Schumann (Gunter); B. Franke (Barbara); P.M. Thompson (Paul); S.E. Medland (Sarah Elizabeth)

    2015-01-01

    textabstractThe highly complex structure of the human brain is strongly shaped by genetic influences. Subcortical brain regions form circuits with cortical areas to coordinate movement, learning, memory and motivation, and altered circuits can lead to abnormal behaviour and disease. To investigate h

  6. Human life: genetic or social construction?

    Science.gov (United States)

    Yudin, Boris

    2005-01-01

    I am going to discuss some present-day tendencies in the development of the very old debate on nature vs nurture. There is a widespread position describing the history of this debate as a pendulum-like process. Some three decades ago there was a time of overwhelming prevalence of the position stressing social factors in determining human character and behavior; now the pendulum has come to the opposite side and those who stress the role of biology, of genes are in favor. Yet in my view rather acute opposition of both positions still exists. Its existence depends not so much on new scientific discoveries as on some social and cultural factors which are more conservative than the development of science. More than that, we can even talk about competition of these two positions.

  7. Obcells as proto-organisms: membrane heredity, lithophosphorylation, and the origins of the genetic code, the first cells, and photosynthesis.

    Science.gov (United States)

    Cavalier-Smith, T

    2001-01-01

    I attempt to sketch a unified picture of the origin of living organisms in their genetic, bioenergetic, and structural aspects. Only selection at a higher level than for individual selfish genes could power the cooperative macromolecular coevolution required for evolving the genetic code. The protein synthesis machinery is too complex to have evolved before membranes. Therefore a symbiosis of membranes, replicators, and catalysts probably mediated the origin of the code and the transition from a nucleic acid world of independent molecular replicators to a nucleic acid/protein/lipid world of reproducing organisms. Membranes initially functioned as supramolecular structures to which different replicators attached and were selected as a higher-level reproductive unit: the proto-organism. I discuss the roles of stereochemistry, gene divergence, codon capture, and selection in the code's origin. I argue that proteins were primarily structural not enzymatic and that the first biological membranes consisted of amphipathic peptidyl-tRNAs and prebiotic mixed lipids. The peptidyl-tRNAs functioned as genetically-specified lipid analogues with hydrophobic tails (ancestral signal peptides) and hydrophilic polynucleotide heads. Protoribosomes arose from two cooperating RNAs: peptidyl transferase (large subunit) and mRNA-binder (small subunit). Early proteins had a second key role: coupling energy flow to the phosphorylation of gene and peptide precursors, probably by lithophosphorylation by membrane-anchored kinases scavenging geothermal polyphosphate stocks. These key evolutionary steps probably occurred on the outer surface of an 'inside out-cell' or obcell, which evolved an unambiguous hydrophobic code with four prebiotic amino acids and proline, and initiation by isoleucine anticodon CAU; early proteins and nucleozymes were all membrane-attached. To improve replication, translation, and lithophosphorylation, hydrophilic substrate-binding and catalytic domains were later

  8. MassCode liquid arrays as a tool for multiplexed high-throughput genetic profiling.

    Directory of Open Access Journals (Sweden)

    Gregory S Richmond

    Full Text Available Multiplexed detection assays that analyze a modest number of nucleic acid targets over large sample sets are emerging as the preferred testing approach in such applications as routine pathogen typing, outbreak monitoring, and diagnostics. However, very few DNA testing platforms have proven to offer a solution for mid-plexed analysis that is high-throughput, sensitive, and with a low cost per test. In this work, an enhanced genotyping method based on MassCode technology was devised and integrated as part of a high-throughput mid-plexing analytical system that facilitates robust qualitative differential detection of DNA targets. Samples are first analyzed using MassCode PCR (MC-PCR performed with an array of primer sets encoded with unique mass tags. Lambda exonuclease and an array of MassCode probes are then contacted with MC-PCR products for further interrogation and target sequences are specifically identified. Primer and probe hybridizations occur in homogeneous solution, a clear advantage over micro- or nanoparticle suspension arrays. The two cognate tags coupled to resultant MassCode hybrids are detected in an automated process using a benchtop single quadrupole mass spectrometer. The prospective value of using MassCode probe arrays for multiplexed bioanalysis was demonstrated after developing a 14plex proof of concept assay designed to subtype a select panel of Salmonella enterica serogroups and serovars. This MassCode system is very flexible and test panels can be customized to include more, less, or different markers.

  9. 利用遗传算法构造QC-LDPC码%Construction of QC-LDPC Codes with Genetic Algorithm

    Institute of Scientific and Technical Information of China (English)

    郑丹玲; 穆攀; 田凯; 袁建国

    2015-01-01

    A new method is proposed to construct a large girth quasi-cyclic low density parity check( QC-LDPC) code with Genetic Algorithm( GA) by consideration of LDPC codes under the influence of girth. This method depends on computer search,uses GA repeatedly,improves girth step by step. A large girth is obtained,at the same time LDPC codes with a quasi-cyclic structure is constructed. Analysis shows its complexity has a linear relationship with code length. Simulation results illustrate that when the bit error rate(BER) is 10-6 QC-LDPC codes constructed with the new method has net coding gain(NCG) of 0. 15 dB,0. 5 dB,0. 2 dB over LDPC code based on Euclidean Geometry,Gallager random codes and Mackay random codes,respectively,and it is easy to restore and be implemented in hardware because of quasi-cy-clic structure.%考虑到围长(girth)对低密度奇偶校验(LDPC)码的影响,提出了一种利用遗传算法构造大girth的准循环LDPC( QC-LDPC)码的新方法。该方法借助于计算机搜索,多次运用遗传算法,分步提高girth,在得到大girth 的同时,构造出具有准循环结构的LDPC码。分析发现,该构造方法的复杂度与码长成线性关系。仿真结果表明:在误码率( BER)为10-6时,新方法构造的QC-LDPC码比基于欧式几何构造方法、Gallager和Mackay构造法分别获得约0.15 dB、0.5 dB和0.2 dB的净编码增益( NCG),且因具有准循环结构更易于存储和硬件实现。

  10. The humankind genome: from genetic diversity to the origin of human diseases.

    Science.gov (United States)

    Belizário, Jose E

    2013-12-01

    Genome-wide association studies have failed to establish common variant risk for the majority of common human diseases. The underlying reasons for this failure are explained by recent studies of resequencing and comparison of over 1200 human genomes and 10 000 exomes, together with the delineation of DNA methylation patterns (epigenome) and full characterization of coding and noncoding RNAs (transcriptome) being transcribed. These studies have provided the most comprehensive catalogues of functional elements and genetic variants that are now available for global integrative analysis and experimental validation in prospective cohort studies. With these datasets, researchers will have unparalleled opportunities for the alignment, mining, and testing of hypotheses for the roles of specific genetic variants, including copy number variations, single nucleotide polymorphisms, and indels as the cause of specific phenotypes and diseases. Through the use of next-generation sequencing technologies for genotyping and standardized ontological annotation to systematically analyze the effects of genomic variation on humans and model organism phenotypes, we will be able to find candidate genes and new clues for disease's etiology and treatment. This article describes essential concepts in genetics and genomic technologies as well as the emerging computational framework to comprehensively search websites and platforms available for the analysis and interpretation of genomic data.

  11. Distribution of trinucleotide microsatellites in different categories of mammalian genomic sequence: Implications for human genetic diseases

    Energy Technology Data Exchange (ETDEWEB)

    Stallings, R.L. (Univ. of Pittsburgh, PA (United States))

    1994-05-01

    The distribution of all trinucleotide microsatellite sequences in the GenBank database was surveyed to provide insight into human genetic disease syndromes that result from expansion of microsatellites. The microsatellite motif (CAG)[sub n] is one of the most abundant microsatellite motifs in human GenBank DNA sequences and is the most abundant microsatellite found in exons. This fact may explain why (CAG)[sub n] repeats are thus far the predominant microsatellites expanded in human genetic diseases. Surprisingly, (CAG)[sub n] microsatellites are excluded from intronic regions in a strand-specific fashion, possibly because of similarity to the 3[prime] consensus splice site, CAGG. A comparison of the positions of microsatellites in human vs rodent homologous sequences indicates that some arrays are not extensively conserved for long periods of time, even when they form parts of protein coding sequences. The general lack of conservation of trinucleotide repeat loci in diverse mammals indicates that animal models for some human microsatellite expansion syndromes may be difficult to find. 20 refs., 5 tabs.

  12. Defining the genetic architecture of human developmental language impairment.

    Science.gov (United States)

    Li, Ning; Bartlett, Christopher W

    2012-04-09

    Language is a uniquely human trait, which poses limitations on animal models for discovering biological substrates and pathways. Despite this challenge, rapidly developing biotechnology in the field of genomics has made human genetics studies a viable alternative route for defining the molecular neuroscience of human language. This is accomplished by studying families that transmit both normal and disordered language across generations. The language disorder reviewed here is specific language impairment (SLI), a developmental deficiency in language acquisition despite adequate opportunity, normal intelligence, and without any apparent neurological etiology. Here, we describe disease gene discovery paradigms as applied to SLI families and review the progress this field has made. After review the evidence that genetic factors influence SLI, we discuss methods and findings from scans of the human chromosomes, including the main replicated regions on chromosomes 13, 16 and 19 and two identified genes, ATP2C2 and CMIP that appear to account for the language variation on chromosome 16. Additional work has been done on candidate genes, i.e., genes chosen a priori and not through a genome scanning studies, including several studies of CNTNAP2 and some recent work implicating BDNF as a gene x gene interaction partner of genetic variation on chromosome 13 that influences language. These recent developments may allow for better use of post-mortem human brain samples functional studies and animal models for circumscribed language subcomponents. In the future, the identification of genetic variation associated with language phenotypes will provide the molecular pathways to understanding human language. Copyright © 2012 Elsevier Inc. All rights reserved.

  13. Genetical genomic determinants of alcohol consumption in rats and humans

    Directory of Open Access Journals (Sweden)

    Mangion Jonathan

    2009-10-01

    Full Text Available Abstract Background We have used a genetical genomic approach, in conjunction with phenotypic analysis of alcohol consumption, to identify candidate genes that predispose to varying levels of alcohol intake by HXB/BXH recombinant inbred rat strains. In addition, in two populations of humans, we assessed genetic polymorphisms associated with alcohol consumption using a custom genotyping array for 1,350 single nucleotide polymorphisms (SNPs. Our goal was to ascertain whether our approach, which relies on statistical and informatics techniques, and non-human animal models of alcohol drinking behavior, could inform interpretation of genetic association studies with human populations. Results In the HXB/BXH recombinant inbred (RI rats, correlation analysis of brain gene expression levels with alcohol consumption in a two-bottle choice paradigm, and filtering based on behavioral and gene expression quantitative trait locus (QTL analyses, generated a list of candidate genes. A literature-based, functional analysis of the interactions of the products of these candidate genes defined pathways linked to presynaptic GABA release, activation of dopamine neurons, and postsynaptic GABA receptor trafficking, in brain regions including the hypothalamus, ventral tegmentum and amygdala. The analysis also implicated energy metabolism and caloric intake control as potential influences on alcohol consumption by the recombinant inbred rats. In the human populations, polymorphisms in genes associated with GABA synthesis and GABA receptors, as well as genes related to dopaminergic transmission, were associated with alcohol consumption. Conclusion Our results emphasize the importance of the signaling pathways identified using the non-human animal models, rather than single gene products, in identifying factors responsible for complex traits such as alcohol consumption. The results suggest cross-species similarities in pathways that influence predisposition to consume

  14. The neural code for face orientation in the human fusiform face area.

    Science.gov (United States)

    Ramírez, Fernando M; Cichy, Radoslaw M; Allefeld, Carsten; Haynes, John-Dylan

    2014-09-01

    Humans recognize faces and objects with high speed and accuracy regardless of their orientation. Recent studies have proposed that orientation invariance in face recognition involves an intermediate representation where neural responses are similar for mirror-symmetric views. Here, we used fMRI, multivariate pattern analysis, and computational modeling to investigate the neural encoding of faces and vehicles at different rotational angles. Corroborating previous studies, we demonstrate a representation of face orientation in the fusiform face-selective area (FFA). We go beyond these studies by showing that this representation is category-selective and tolerant to retinal translation. Critically, by controlling for low-level confounds, we found the representation of orientation in FFA to be compatible with a linear angle code. Aspects of mirror-symmetric coding cannot be ruled out when FFA mean activity levels are considered as a dimension of coding. Finally, we used a parametric family of computational models, involving a biased sampling of view-tuned neuronal clusters, to compare different face angle encoding models. The best fitting model exhibited a predominance of neuronal clusters tuned to frontal views of faces. In sum, our findings suggest a category-selective and monotonic code of face orientation in the human FFA, in line with primate electrophysiology studies that observed mirror-symmetric tuning of neural responses at higher stages of the visual system, beyond the putative homolog of human FFA.

  15. Stable RNA hairpins in 88 coding regions of human mRNA

    Institute of Scientific and Technical Information of China (English)

    PAN Min; WANG Chuanming; LIU Ciquan

    2004-01-01

    RNA hairpins containing UNCG, GNRA, CUUG (N=A, U, C or G, R=G or A) loops are unusually thermodynamic stable and conserved structures. The structural features of these hairpin loops are very special, and they play very important roles in vivo. They are prevalent in rRNA, catalytic RNA and non-coding mRNA. However, the 5′ C(UUCG)G 3′ hairpin is not found in the folding structure of 88 human mRNA coding regions. It is also different from rRNA in that there is no preference for certain sequences among tetraloops in these 88 mRNA folding structures.

  16. miR-148 targets human DNMT3b protein coding region

    OpenAIRE

    Duursma, Anja M.; Kedde, Martijn; Schrier, Mariette; le Sage, Carlos; Agami, Reuven

    2008-01-01

    MicroRNAs (miRNAs) are small noncoding RNA molecules of 20–24 nucleotides that regulate gene expression. In animals, miRNAs form imperfect interactions with sequences in the 3′ Untranslated region (3′UTR) of mRNAs, causing translational inhibition and mRNA decay. In contrast, plant miRNAs mostly associate with protein coding regions. Here we show that human miR-148 represses DNA methyltransferase 3b (Dnmt3b) gene expression through a region in its coding sequence. This region is evolutionary ...

  17. [Assisted reproduction and artificial insemination and genetic manipulation in the Criminal Code of the Federal District, Mexico].

    Science.gov (United States)

    Brena Sesma, Ingrid

    2004-01-01

    The article that one presents has for purpose outline and comment on the recent modifications to the Penal Code for the Federal District of México which establish, for the first time, crimes related to the artificial procreation and to the genetic manipulation. Also one refers to the interaction of the new legal texts with the sanitary legislation of the country. Since it will be stated in some cases they present confrontations between the penal and the sanitary reglamentation and some points related to the legality or unlawfulness of a conduct that stayed without the enough development. These lacks will complicate the application of the new rules of the Penal Code of the Federal District.

  18. Genetic analysis of coding SNPs in blood-brain barrier transporter MDR1 in European Parkinson's disease patients.

    Science.gov (United States)

    Funke, Claudia; Soehn, Anne S; Tomiuk, Juergen; Riess, Olaf; Berg, Daniela

    2009-04-01

    Parkinson's disease (PD) is characterized by the loss of dopaminergic neurons and the presence of intracytoplasmic inclusions (Lewy bodies). Iron, which is elevated in the substantia nigra of PD patients, seems to be of pivotal importance, because of its capacity to enhance the amplification of reactive oxygen species. As iron enters and exits the brain via transport proteins in the blood-brain barrier (BBB), these proteins may represent candidates for a genetic susceptibility to PD. P-glycoprotein (P-gp) is one important efflux pump in the BBB. There is evidence that the function of P-gp is impaired in PD patients. In the current study we examined ten coding single nucleotide polymorphisms in the multidrug resistance gene 1 (MDR1) encoding P-gp to assess whether certain genotypes are associated with PD. However, genotyping of 300 PD patients and 302 healthy controls did not reveal a significant association between coding MDR1 gene polymorphisms and PD.

  19. Mapping genetic influences on the corticospinal motor system in humans

    DEFF Research Database (Denmark)

    Cheeran, B J; Ritter, C; Rothwell, J C

    2009-01-01

    It is becoming increasingly clear that genetic variations account for a certain amount of variance in the acquisition and maintenance of different skills. Until now, several levels of genetic influences were examined, ranging from global heritability estimates down to the analysis...... of the contribution of single nucleotide polymorphisms (SNP) and variable number tandem repeats. In humans, the corticospinal motor system is essential to the acquisition of fine manual motor skills which require a finely tuned coordination of activity in distal forelimb muscles. Here we review recent brain mapping...

  20. Genetic variants in long non-coding RNA MIAT contribute to risk of paranoid schizophrenia in a Chinese Han population.

    Science.gov (United States)

    Rao, Shu-Quan; Hu, Hui-Ling; Ye, Ning; Shen, Yan; Xu, Qi

    2015-08-01

    The heritability of schizophrenia has been reported to be as high as ~80%, but the contribution of genetic variants identified to this heritability remains to be estimated. Long non-coding RNAs (LncRNAs) are involved in multiple processes critical to normal cellular function and dysfunction of lncRNA MIAT may contribute to the pathophysiology of schizophrenia. However, the genetic evidence of lncRNAs involved in schizophrenia has not been documented. Here, we conducted a two-stage association analysis on 8 tag SNPs that cover the whole MIAT locus in two independent Han Chinese schizophrenia case-control cohorts (discovery sample from Shanxi Province: 1093 patients with paranoid schizophrenia and 1180 control subjects; replication cohort from Jilin Province: 1255 cases and 1209 healthy controls). In discovery stage, significant genetic association with paranoid schizophrenia was observed for rs1894720 (χ(2)=74.20, P=7.1E-18), of which minor allele (T) had an OR of 1.70 (95% CI=1.50-1.91). This association was confirmed in the replication cohort (χ(2)=22.66, P=1.9E-06, OR=1.32, 95%CI 1.18-1.49). Besides, a weak genotypic association was detected for rs4274 (χ(2)=4.96, df=2, P=0.03); the AA carriers showed increased disease risk (OR=1.30, 95%CI=1.03-1.64). No significant association was found between any haplotype and paranoid schizophrenia. The present studies showed that lncRNA MIAT was a novel susceptibility gene for paranoid schizophrenia in the Chinese Han population. Considering that most lncRNAs locate in non-coding regions, our result may explain why most susceptibility loci for schizophrenia identified by genome wide association studies were out of coding regions.

  1. Genetics of multifactorial disorders: proceedings of the 6th Pan Arab Human Genetics Conference

    OpenAIRE

    Nair, Pratibha; Bizzari, Sami; Rajah, Nirmal; Assaf, Nada; Al-Ali, Mahmoud Taleb; Hamzeh, Abdul Rezzak

    2016-01-01

    The 6th Pan Arab Human Genetics Conference (PAHGC), “Genetics of Multifactorial Disorders” was organized by the Center for Arab Genomic Studies (http://www.cags.org.ae) in Dubai, United Arab Emirates from 21 to 23 January, 2016. The PAHGCs are held biennially to provide a common platform to bring together regional and international geneticists to share their knowledge and to discuss common issues. Over 800 delegates attended the first 2 days of the conference and these came from various medic...

  2. Breaking the code: Statistical methods and methodological issues in psychiatric genetics

    NARCIS (Netherlands)

    Stringer, S.

    2015-01-01

    The genome-wide association (GWA) era has confirmed the heritability of many psychiatric disorders, most notably schizophrenia. Thousands of genetic variants with individually small effect sizes cumulatively constitute a large contribution to the heritability of psychiatric disorders. This thesis

  3. An enhancement of selection and crossover operations in real-coded genetic algorithm for large-dimensionality optimization

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Noh Sung; Lee, Jongsoo [Yonsei University, Seoul (Korea, Republic of)

    2016-01-15

    The present study aims to implement a new selection method and a novel crossover operation in a real-coded genetic algorithm. The proposed selection method facilitates the establishment of a successively evolved population by combining several subpopulations: an elitist subpopulation, an off-spring subpopulation and a mutated subpopulation. A probabilistic crossover is performed based on the measure of probabilistic distance between the individuals. The concept of ‘allowance’ is suggested to describe the level of variance in the crossover operation. A number of nonlinear/non-convex functions and engineering optimization problems are explored to verify the capacities of the proposed strategies. The results are compared with those obtained from other genetic and nature-inspired algorithms.

  4. An automatic modeling system of the reaction mechanisms for chemical vapor deposition processes using real-coded genetic algorithms.

    Science.gov (United States)

    Takahashi, Takahiro; Nakai, Hiroyuki; Kinpara, Hiroki; Ema, Yoshinori

    2011-09-01

    The identification of appropriate reaction models is very helpful for developing chemical vapor deposition (CVD) processes. In this study, we have developed an automatic system to model reaction mechanisms in the CVD processes by analyzing the experimental results, which are cross-sectional shapes of the deposited films on substrates with micrometer- or nanometer-sized trenches. We designed the inference engine to model the reaction mechanism in the system by the use of real-coded genetic algorithms (RCGAs). We studied the dependence of the system performance on two methods using simple genetic algorithms (SGAs) and the RCGAs; the one involves the conventional GA operators and the other involves the blend crossover operator (BLX-alpha). Although we demonstrated that the systems using both the methods could successfully model the reaction mechanisms, the RCGAs showed the better performance with respect to the accuracy and the calculation cost for identifying the models.

  5. Organizing Conceptual Knowledge in Humans with a Grid-like Code

    Science.gov (United States)

    Behrens, Timothy E. J.

    2017-01-01

    It has been hypothesized that the brain organizes concepts into a mental map, allowing conceptual relationships to be navigated in a similar fashion to space. Grid cells use a hexagonally-symmetric code to organize spatial representations and are the likely source of a precise hexagonal symmetry in the functional magnetic resonance imaging signal. Humans navigating conceptual two-dimensional knowledge showed the same hexagonal signal in a strikingly similar set of brain regions to those activated during spatial navigation. This grid-like signal is consistent across sessions acquired within an hour and more than a week apart. Our findings suggest that global relational codes may be used to organize non-spatial conceptual representations and that these codes may have hexagonal grid-like pattern when conceptual knowledge is laid out in two continuous dimensions. PMID:27313047

  6. Computational approaches towards understanding human long non-coding RNA biology.

    Science.gov (United States)

    Jalali, Saakshi; Kapoor, Shruti; Sivadas, Ambily; Bhartiya, Deeksha; Scaria, Vinod

    2015-07-15

    Long non-coding RNAs (lncRNAs) form the largest class of non-protein coding genes in the human genome. While a small subset of well-characterized lncRNAs has demonstrated their significant role in diverse biological functions like chromatin modifications, post-transcriptional regulation, imprinting etc., the functional significance of a vast majority of them still remains an enigma. Increasing evidence of the implications of lncRNAs in various diseases including cancer and major developmental processes has further enhanced the need to gain mechanistic insights into the lncRNA functions. Here, we present a comprehensive review of the various computational approaches and tools available for the identification and annotation of long non-coding RNAs. We also discuss a conceptual roadmap to systematically explore the functional properties of the lncRNAs using computational approaches.

  7. Precise and in situ genetic humanization of 6 Mb of mouse immunoglobulin genes.

    Science.gov (United States)

    Macdonald, Lynn E; Karow, Margaret; Stevens, Sean; Auerbach, Wojtek; Poueymirou, William T; Yasenchak, Jason; Frendewey, David; Valenzuela, David M; Giallourakis, Cosmas C; Alt, Frederick W; Yancopoulos, George D; Murphy, Andrew J

    2014-04-01

    Genetic humanization, which involves replacing mouse genes with their human counterparts, can create powerful animal models for the study of human genes and diseases. One important example of genetic humanization involves mice humanized for their Ig genes, allowing for human antibody responses within a mouse background (HumAb mice) and also providing a valuable platform for the generation of fully human antibodies as therapeutics. However, existing HumAb mice do not have fully functional immune systems, perhaps because of the manner in which they were genetically humanized. Heretofore, most genetic humanizations have involved disruption of the endogenous mouse gene with simultaneous introduction of a human transgene at a new and random location (so-called KO-plus-transgenic humanization). More recent efforts have attempted to replace mouse genes with their human counterparts at the same genetic location (in situ humanization), but such efforts involved laborious procedures and were limited in size and precision. We describe a general and efficient method for very large, in situ, and precise genetic humanization using large compound bacterial artificial chromosome-based targeting vectors introduced into mouse ES cells. We applied this method to genetically humanize 3-Mb segments of both the mouse heavy and κ light chain Ig loci, by far the largest genetic humanizations ever described. This paper provides a detailed description of our genetic humanization approach, and the companion paper reports that the humoral immune systems of mice bearing these genetically humanized loci function as efficiently as those of WT mice.

  8. Can a few non-coding mutations make a human brain?

    Science.gov (United States)

    Franchini, Lucía F; Pollard, Katherine S

    2015-10-01

    The recent finding that the human version of a neurodevelopmental enhancer of the Wnt receptor Frizzled 8 (FZD8) gene alters neural progenitor cell cycle timing and brain size is a step forward to understanding human brain evolution. The human brain is distinctive in terms of its cognitive abilities as well as its susceptibility to neurological disease. Identifying which of the millions of genomic changes that occurred during human evolution led to these and other uniquely human traits is extremely challenging. Recent studies have demonstrated that many of the fastest evolving regions of the human genome function as gene regulatory enhancers during embryonic development and that the human-specific mutations in them might alter expression patterns. However, elucidating molecular and cellular effects of sequence or expression pattern changes is a major obstacle to discovering the genetic bases of the evolution of our species. There is much work to do before human-specific genetic and genomic changes are linked to complex human traits. © 2015 The Authors. BioEssays Published by WILEY Periodicals, Inc.

  9. Naming 'junk': Human non-protein coding RNA (ncRNA gene nomenclature

    Directory of Open Access Journals (Sweden)

    Wright Mathew W

    2011-01-01

    Full Text Available Abstract Previously, the majority of the human genome was thought to be 'junk' DNA with no functional purpose. Over the past decade, the field of RNA research has rapidly expanded, with a concomitant increase in the number of non-protein coding RNA (ncRNA genes identified in this 'junk'. Many of the encoded ncRNAs have already been shown to be essential for a variety of vital functions, and this wealth of annotated human ncRNAs requires standardised naming in order to aid effective communication. The HUGO Gene Nomenclature Committee (HGNC is the only organisation authorised to assign standardised nomenclature to human genes. Of the 30,000 approved gene symbols currently listed in the HGNC database (http://www.genenames.org/search, the majority represent protein-coding genes; however, they also include pseudogenes, phenotypic loci and some genomic features. In recent years the list has also increased to include almost 3,000 named human ncRNA genes. HGNC is actively engaging with the RNA research community in order to provide unique symbols and names for each sequence that encodes an ncRNA. Most of the classical small ncRNA genes have now been provided with a unique nomenclature, and work on naming the long (> 200 nucleotides non-coding RNAs (lncRNAs is ongoing.

  10. Development of human reliability analysis methodology and its computer code during low power/shutdown operation

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Chang Hyun; You, Young Woo; Huh, Chang Wook; Kim, Ju Yeul; Kim Do Hyung; Kim, Yoon Ik; Yang, Hui Chang [Seoul National University, Seoul (Korea, Republic of); Jae, Moo Sung [Hansung University, Seoul (Korea, Republic of)

    1997-07-01

    The objective of this study is to develop the appropriate procedure that can evaluate the human error in LP/S(lower power/shutdown) and the computer code that calculate the human error probabilities(HEPs) using this framework. The assessment of applicability of the typical HRA methodologies to LP/S is conducted and a new HRA procedure, SEPLOT (Systematic Evaluation Procedure for LP/S Operation Tasks) which presents the characteristics of LP/S is developed by selection and categorization of human actions by reviewing present studies. This procedure is applied to evaluate the LOOP(Loss of Off-site Power) sequence and the HEPs obtained by using SEPLOT are used to quantitative evaluation of the core uncovery frequency. In this evaluation one of the dynamic reliability computer codes, DYLAM-3 which has the advantages against the ET/FT is used. The SEPLOT developed in this study can give the basis and arrangement as to the human error evaluation technique. And this procedure can make it possible to assess the dynamic aspects of accidents leading to core uncovery applying the HEPs obtained by using the SEPLOT as input data to DYLAM-3 code, Eventually, it is expected that the results of this study will contribute to improve safety in LP/S and reduce uncertainties in risk. 57 refs. 17 tabs., 33 figs. (author)

  11. Ethics in human experimentation: the two military physicians who helped develop the Nuremberg Code.

    Science.gov (United States)

    Temme, Leonard A

    2003-12-01

    The Nuremberg Code is generally considered the beginning of modern ethics in human experimentation. The Code is a list of 10 principles that Judge Walter Beals included in the judgment he delivered at the close of the Nuremberg Medical Trial on 19 August 1947. Recently, scholars have studied the origin of the Code, who wrote it, and why. This is important to military medicine and the Aerospace Medical Association in particular because many of the defendants claimed their crimes were experiments in aviation and environmental physiology conducted under wartime conditions. The chief prosecutor of the Nuremberg Medical Trial, General Telford Taylor, relied on the guidance of an advisor provided by the American Medical Association, Andrew C. Ivy, one of the foremost physiologists of his time. The neurologist, Leo Alexander, then a colonel in the U.S. Army Reserves, was another medical advisor. Both men were crucial to the development of Taylor's courtroom strategy. The material Alexander and Ivy provided was incorporated verbatim in the section of the judgment that became the Code. Although both men contributed to the Code, Ivy provided what seems to be the first formulation of many of these principles during a meeting of Allied medical investigators at the Pasteur Institute in July 1946. Naval researchers should note that Ivy had been the Director of the Research Division of the Naval Medical Research Institute when it was commissioned on October 27, 1942.

  12. Common genetic variants influence human subcortical brain structures.

    Science.gov (United States)

    Hibar, Derrek P; Stein, Jason L; Renteria, Miguel E; Arias-Vasquez, Alejandro; Desrivières, Sylvane; Jahanshad, Neda; Toro, Roberto; Wittfeld, Katharina; Abramovic, Lucija; Andersson, Micael; Aribisala, Benjamin S; Armstrong, Nicola J; Bernard, Manon; Bohlken, Marc M; Boks, Marco P; Bralten, Janita; Brown, Andrew A; Chakravarty, M Mallar; Chen, Qiang; Ching, Christopher R K; Cuellar-Partida, Gabriel; den Braber, Anouk; Giddaluru, Sudheer; Goldman, Aaron L; Grimm, Oliver; Guadalupe, Tulio; Hass, Johanna; Woldehawariat, Girma; Holmes, Avram J; Hoogman, Martine; Janowitz, Deborah; Jia, Tianye; Kim, Sungeun; Klein, Marieke; Kraemer, Bernd; Lee, Phil H; Olde Loohuis, Loes M; Luciano, Michelle; Macare, Christine; Mather, Karen A; Mattheisen, Manuel; Milaneschi, Yuri; Nho, Kwangsik; Papmeyer, Martina; Ramasamy, Adaikalavan; Risacher, Shannon L; Roiz-Santiañez, Roberto; Rose, Emma J; Salami, Alireza; Sämann, Philipp G; Schmaal, Lianne; Schork, Andrew J; Shin, Jean; Strike, Lachlan T; Teumer, Alexander; van Donkelaar, Marjolein M J; van Eijk, Kristel R; Walters, Raymond K; Westlye, Lars T; Whelan, Christopher D; Winkler, Anderson M; Zwiers, Marcel P; Alhusaini, Saud; Athanasiu, Lavinia; Ehrlich, Stefan; Hakobjan, Marina M H; Hartberg, Cecilie B; Haukvik, Unn K; Heister, Angelien J G A M; Hoehn, David; Kasperaviciute, Dalia; Liewald, David C M; Lopez, Lorna M; Makkinje, Remco R R; Matarin, Mar; Naber, Marlies A M; McKay, D Reese; Needham, Margaret; Nugent, Allison C; Pütz, Benno; Royle, Natalie A; Shen, Li; Sprooten, Emma; Trabzuni, Daniah; van der Marel, Saskia S L; van Hulzen, Kimm J E; Walton, Esther; Wolf, Christiane; Almasy, Laura; Ames, David; Arepalli, Sampath; Assareh, Amelia A; Bastin, Mark E; Brodaty, Henry; Bulayeva, Kazima B; Carless, Melanie A; Cichon, Sven; Corvin, Aiden; Curran, Joanne E; Czisch, Michael; de Zubicaray, Greig I; Dillman, Allissa; Duggirala, Ravi; Dyer, Thomas D; Erk, Susanne; Fedko, Iryna O; Ferrucci, Luigi; Foroud, Tatiana M; Fox, Peter T; Fukunaga, Masaki; Gibbs, J Raphael; Göring, Harald H H; Green, Robert C; Guelfi, Sebastian; Hansell, Narelle K; Hartman, Catharina A; Hegenscheid, Katrin; Heinz, Andreas; Hernandez, Dena G; Heslenfeld, Dirk J; Hoekstra, Pieter J; Holsboer, Florian; Homuth, Georg; Hottenga, Jouke-Jan; Ikeda, Masashi; Jack, Clifford R; Jenkinson, Mark; Johnson, Robert; Kanai, Ryota; Keil, Maria; Kent, Jack W; Kochunov, Peter; Kwok, John B; Lawrie, Stephen M; Liu, Xinmin; Longo, Dan L; McMahon, Katie L; Meisenzahl, Eva; Melle, Ingrid; Mohnke, Sebastian; Montgomery, Grant W; Mostert, Jeanette C; Mühleisen, Thomas W; Nalls, Michael A; Nichols, Thomas E; Nilsson, Lars G; Nöthen, Markus M; Ohi, Kazutaka; Olvera, Rene L; Perez-Iglesias, Rocio; Pike, G Bruce; Potkin, Steven G; Reinvang, Ivar; Reppermund, Simone; Rietschel, Marcella; Romanczuk-Seiferth, Nina; Rosen, Glenn D; Rujescu, Dan; Schnell, Knut; Schofield, Peter R; Smith, Colin; Steen, Vidar M; Sussmann, Jessika E; Thalamuthu, Anbupalam; Toga, Arthur W; Traynor, Bryan J; Troncoso, Juan; Turner, Jessica A; Valdés Hernández, Maria C; van 't Ent, Dennis; van der Brug, Marcel; van der Wee, Nic J A; van Tol, Marie-Jose; Veltman, Dick J; Wassink, Thomas H; Westman, Eric; Zielke, Ronald H; Zonderman, Alan B; Ashbrook, David G; Hager, Reinmar; Lu, Lu; McMahon, Francis J; Morris, Derek W; Williams, Robert W; Brunner, Han G; Buckner, Randy L; Buitelaar, Jan K; Cahn, Wiepke; Calhoun, Vince D; Cavalleri, Gianpiero L; Crespo-Facorro, Benedicto; Dale, Anders M; Davies, Gareth E; Delanty, Norman; Depondt, Chantal; Djurovic, Srdjan; Drevets, Wayne C; Espeseth, Thomas; Gollub, Randy L; Ho, Beng-Choon; Hoffmann, Wolfgang; Hosten, Norbert; Kahn, René S; Le Hellard, Stephanie; Meyer-Lindenberg, Andreas; Müller-Myhsok, Bertram; Nauck, Matthias; Nyberg, Lars; Pandolfo, Massimo; Penninx, Brenda W J H; Roffman, Joshua L; Sisodiya, Sanjay M; Smoller, Jordan W; van Bokhoven, Hans; van Haren, Neeltje E M; Völzke, Henry; Walter, Henrik; Weiner, Michael W; Wen, Wei; White, Tonya; Agartz, Ingrid; Andreassen, Ole A; Blangero, John; Boomsma, Dorret I; Brouwer, Rachel M; Cannon, Dara M; Cookson, Mark R; de Geus, Eco J C; Deary, Ian J; Donohoe, Gary; Fernández, Guillén; Fisher, Simon E; Francks, Clyde; Glahn, David C; Grabe, Hans J; Gruber, Oliver; Hardy, John; Hashimoto, Ryota; Hulshoff Pol, Hilleke E; Jönsson, Erik G; Kloszewska, Iwona; Lovestone, Simon; Mattay, Venkata S; Mecocci, Patrizia; McDonald, Colm; McIntosh, Andrew M; Ophoff, Roel A; Paus, Tomas; Pausova, Zdenka; Ryten, Mina; Sachdev, Perminder S; Saykin, Andrew J; Simmons, Andy

    2015-04-01

    The highly complex structure of the human brain is strongly shaped by genetic influences. Subcortical brain regions form circuits with cortical areas to coordinate movement, learning, memory and motivation, and altered circuits can lead to abnormal behaviour and disease. To investigate how common genetic variants affect the structure of these brain regions, here we conduct genome-wide association studies of the volumes of seven subcortical regions and the intracranial volume derived from magnetic resonance images of 30,717 individuals from 50 cohorts. We identify five novel genetic variants influencing the volumes of the putamen and caudate nucleus. We also find stronger evidence for three loci with previously established influences on hippocampal volume and intracranial volume. These variants show specific volumetric effects on brain structures rather than global effects across structures. The strongest effects were found for the putamen, where a novel intergenic locus with replicable influence on volume (rs945270; P = 1.08 × 10(-33); 0.52% variance explained) showed evidence of altering the expression of the KTN1 gene in both brain and blood tissue. Variants influencing putamen volume clustered near developmental genes that regulate apoptosis, axon guidance and vesicle transport. Identification of these genetic variants provides insight into the causes of variability in human brain development, and may help to determine mechanisms of neuropsychiatric dysfunction.

  13. The influence of recombination on human genetic diversity.

    Directory of Open Access Journals (Sweden)

    Chris C A Spencer

    2006-09-01

    Full Text Available In humans, the rate of recombination, as measured on the megabase scale, is positively associated with the level of genetic variation, as measured at the genic scale. Despite considerable debate, it is not clear whether these factors are causally linked or, if they are, whether this is driven by the repeated action of adaptive evolution or molecular processes such as double-strand break formation and mismatch repair. We introduce three innovations to the analysis of recombination and diversity: fine-scale genetic maps estimated from genotype experiments that identify recombination hotspots at the kilobase scale, analysis of an entire human chromosome, and the use of wavelet techniques to identify correlations acting at different scales. We show that recombination influences genetic diversity only at the level of recombination hotspots. Hotspots are also associated with local increases in GC content and the relative frequency of GC-increasing mutations but have no effect on substitution rates. Broad-scale association between recombination and diversity is explained through covariance of both factors with base composition. To our knowledge, these results are the first evidence of a direct and local influence of recombination hotspots on genetic variation and the fate of individual mutations. However, that hotspots have no influence on substitution rates suggests that they are too ephemeral on an evolutionary time scale to have a strong influence on broader scale patterns of base composition and long-term molecular evolution.

  14. Identification of evolutionarily conserved non-AUG-initiated N-terminal extensions in human coding sequences.

    LENUS (Irish Health Repository)

    Ivanov, Ivaylo P

    2011-05-01

    In eukaryotes, it is generally assumed that translation initiation occurs at the AUG codon closest to the messenger RNA 5\\' cap. However, in certain cases, initiation can occur at codons differing from AUG by a single nucleotide, especially the codons CUG, UUG, GUG, ACG, AUA and AUU. While non-AUG initiation has been experimentally verified for a handful of human genes, the full extent to which this phenomenon is utilized--both for increased coding capacity and potentially also for novel regulatory mechanisms--remains unclear. To address this issue, and hence to improve the quality of existing coding sequence annotations, we developed a methodology based on phylogenetic analysis of predicted 5\\' untranslated regions from orthologous genes. We use evolutionary signatures of protein-coding sequences as an indicator of translation initiation upstream of annotated coding sequences. Our search identified novel conserved potential non-AUG-initiated N-terminal extensions in 42 human genes including VANGL2, FGFR1, KCNN4, TRPV6, HDGF, CITED2, EIF4G3 and NTF3, and also affirmed the conservation of known non-AUG-initiated extensions in 17 other genes. In several instances, we have been able to obtain independent experimental evidence of the expression of non-AUG-initiated products from the previously published literature and ribosome profiling data.

  15. The ethics of human genetic intervention: a postmodern perspective.

    Science.gov (United States)

    Dyer, A R

    1997-03-01

    Gene therapy for a particular disease like Parkinson's involves ethical principles worked out for other diseases. The major ethical issues for gene therapy (and the corresponding ethical principles) are safety (nonmalfeasance), efficacy (beneficence), informed consent (autonomy), and allocation of resources (justice). Yet genetic engineering (germ-line interventions or interventions to enhance human potentialities) raises emotions and fears that might cause resistance to gene therapies. Looking at these technologies in a postmodern perspective helps one to appreciate the issues at stake in social and cultural change with a new technology such as gene therapy. While "modern" technology and ethics have focused on the autonomy of the individual, we are beginning to see a lessening of such emphasis on individualism and autonomy and more emphasis on the health of the population. Such a social change could cause technologies about which society may currently be cautious (such as human genetic interventions) to become more acceptable or even expected.

  16. Somatic retrotransposition alters the genetic landscape of the human brain

    OpenAIRE

    Baillie, J. Kenneth; Barnett, Mark W.; Upton, Kyle R; Gerhardt, Daniel J.; Richmond, Todd A.; De Sapio, Fioravante; Brennan, Paul; Rizzu, Patrizia; Smith, Sarah; Fell, Mark; Talbot, Richard T; Gustincich, Stefano; Freeman, Thomas C.; Mattick, John S.; Hume, David A

    2011-01-01

    Retrotransposons are mobile genetic elements that employ a germ line “copy-and-paste” mechanism to spread throughout metazoan genomes 1 . At least 50% of the human genome is derived from retrotransposons, with three active families (L1, Alu and SVA) associated with insertional mutagenesis and disease 2-3 . Epigenetic and post-transcriptional suppression block retrotransposition in somatic cells 4-5 , excluding early embryo development and some malignancies 6-7 . Recent reports of L1 expressio...

  17. [Teaching experience in integrated course of human development and genetics].

    Science.gov (United States)

    Qiu, Guang-Rong; Li, Xiao-Ming; Chen, Fang-Jie; Li, Chun-Yi; Liu, Hong; Li, Fu-Cai; Jin, Chun-Lian; Sun, Gui-Yuan; Liu, Cai-Xia; Zhao, Yan-Yan; Sun, Kai-Lai

    2010-04-01

    Establishment of integrated course system in human development and genetics is an important part of course reformation, and the improvement of this system is achieved by integrating the content of course, stabilizing teaching force, building teaching materials and applying problem-based learning. Integrity-PBL teaching model is founded and proved to be feasible and effective by teaching practice. Therefore, it maybe play an important role in improving teaching effect and cultivating ability of students to analyse and solve problems.

  18. Molecular basis of telomere dysfunction in human genetic diseases.

    Science.gov (United States)

    Sarek, Grzegorz; Marzec, Paulina; Margalef, Pol; Boulton, Simon J

    2015-11-01

    Mutations in genes encoding proteins required for telomere structure, replication, repair and length maintenance are associated with several debilitating human genetic disorders. These complex telomere biology disorders (TBDs) give rise to critically short telomeres that affect the homeostasis of multiple organs. Furthermore, genome instability is often a hallmark of telomere syndromes, which are associated with increased cancer risk. Here, we summarize the molecular causes and cellular consequences of disease-causing mutations associated with telomere dysfunction.

  19. The personification of animals: coding of human and nonhuman body parts based on posture and function.

    Science.gov (United States)

    Welsh, Timothy N; McDougall, Laura; Paulson, Stephanie

    2014-09-01

    The purpose of the present research was to determine how humans represent the bodies and limbs of nonhuman mammals based on anatomical and functional properties. To this end, participants completed a series of body-part compatibility tasks in which they responded with a thumb or foot response to the color of a stimulus (red or blue, respectively) presented on different limbs of several animals. Across the studies, this compatibility task was conducted with images of human and nonhuman animals (bears, cows, and monkeys) in bipedal or quadrupedal postures. The results revealed that the coding of the limbs of nonhuman animals is strongly influenced by the posture of the body, but not the functional capacity of the limb. Specifically, body-part compatibility effects were present for both human and nonhuman animals when the figures were in a bipedal posture, but were not present when the animals were in a quadrupedal stance (Experiments 1a-c). Experiments 2a and 2b revealed that the posture-based body-part compatibility effects were not simply a vertical spatial compatibility effect or due to a mismatch between the posture of the body in the image and the participant. These data indicate that nonhuman animals in a bipedal posture are coded with respect to the "human" body representation, whereas nonhuman animals in a quadrupedal posture are not mapped to the human body representation. Overall, these studies provide new insight into the processes through which humans understand, mimic, and learn from the actions of nonhuman animals.

  20. Long non-coding RNA expression during aging in the human subependymal zone

    Directory of Open Access Journals (Sweden)

    Guy eBarry

    2015-03-01

    Full Text Available The human subependymal zone (SEZ is debatably a source of newly born neurons throughout life and neurogenesis is a multi-step process requiring distinct transcripts during cell proliferation and early neuronal maturation, along with orchestrated changes in gene expression during cell state/fate transitions. Furthermore, it is becoming increasingly clear that the majority of our genome that results in production of non-protein coding RNAs plays vital roles in the evolution, development, adaptation and region-specific function of the human brain. We predicted that some transcripts expressed in the SEZ may be unique to this specialized brain region, and that a comprehensive transcriptomic analysis of this region would aid in defining expression changes during neuronal birth and growth in adult humans. Here, we used deep RNA sequencing of human SEZ tissue during adulthood and aging to characterize the transcriptional landscape with a particular emphasis on long non-coding RNAs (lncRNAs. The data shows predicted age-related changes in mRNAs encoding proliferation, progenitor and inflammatory proteins as well as a unique subset of lncRNAs that are highly expressed in the human SEZ, many of which have unknown functions. Our results suggest the existence of robust proliferative and neuronal differentiation potential in the adult human SEZ and lay the foundation for understanding the involvement of lncRNAs in postnatal neurogenesis and potentially associated neurodevelopmental diseases that emerge after birth.

  1. Role of Non-coding Regulatory RNA in the Virulence of Human Pathogenic Vibrios

    Science.gov (United States)

    Pérez-Reytor, Diliana; Plaza, Nicolás; Espejo, Romilio T.; Navarrete, Paola; Bastías, Roberto; Garcia, Katherine

    2017-01-01

    In recent decades, the identification of small non-coding RNAs in bacteria has revealed an important regulatory mechanism of gene expression involved in the response to environmental signals and to the control of virulence. In the family Vibrionaceae, which includes several human and animal pathogens, small non-coding RNAs (sRNAs) are closely related to important processes including metabolism, quorum sensing, virulence, and fitness. Studies conducted in silico and experiments using microarrays and high-throughput RNA sequencing have led to the discovery of an unexpected number of sRNAs in Vibrios. The present review discusses the most relevant reports regarding the mechanisms of action of sRNAs and their implications in the virulence of the main human pathogens in the family Vibrionaceae: Vibrio parahaemolyticus, V. vulnificus and V. cholerae. PMID:28123382

  2. Topological Pressure and Coding Sequence Density Estimation in the Human Genome

    CERN Document Server

    Koslicki, David

    2011-01-01

    Inspired by concepts from ergodic theory, we give new insight into coding sequence (CDS) density estimation for the human genome. Our approach is based on the introduction and study of topological pressure: a numerical quantity assigned to any finite sequence based on an appropriate notion of `weighted information content'. For human DNA sequences, each codon is assigned a suitable weight, and using a window size of approximately 60,000bp, we obtain a very strong positive correlation between CDS density and topological pressure. The weights are selected by an optimization procedure, and can be interpreted as quantitative data on the relative importance of different codons for the density estimation of coding sequences. This gives new insight into codon usage bias which is an important subject where long standing questions remain open. Inspired again by ergodic theory, we use the weightings on the codons to define a probability measure on finite sequences. We demonstrate that this measure is effective in disti...

  3. On the evolution of the standard genetic code: vestiges of critical scale invariance from the RNA world in current prokaryote genomes.

    Directory of Open Access Journals (Sweden)

    Marco V José

    Full Text Available Herein two genetic codes from which the primeval RNA code could have originated the standard genetic code (SGC are derived. One of them, called extended RNA code type I, consists of all codons of the type RNY (purine-any base-pyrimidine plus codons obtained by considering the RNA code but in the second (NYR type and third (YRN type reading frames. The extended RNA code type II, comprises all codons of the type RNY plus codons that arise from transversions of the RNA code in the first (YNY type and third (RNR nucleotide bases. In order to test if putative nucleotide sequences in the RNA World and in both extended RNA codes, share the same scaling and statistical properties to those encountered in current prokaryotes, we used the genomes of four Eubacteria and three Archaeas. For each prokaryote, we obtained their respective genomes obeying the RNA code or the extended RNA codes types I and II. In each case, we estimated the scaling properties of triplet sequences via a renormalization group approach, and we calculated the frequency distributions of distances for each codon. Remarkably, the scaling properties of the distance series of some codons from the RNA code and most codons from both extended RNA codes turned out to be identical or very close to the scaling properties of codons of the SGC. To test for the robustness of these results, we show, via computer simulation experiments, that random mutations of current genomes, at the rates of 10(-10 per site per year during three billions of years, were not enough for destroying the observed patterns. Therefore, we conclude that most current prokaryotes may still contain relics of the primeval RNA World and that both extended RNA codes may well represent two plausible evolutionary paths between the RNA code and the current SGC.

  4. Human genetic variation and the gut microbiome in disease.

    Science.gov (United States)

    Hall, Andrew Brantley; Tolonen, Andrew C; Xavier, Ramnik J

    2017-08-21

    Taxonomic and functional changes to the composition of the gut microbiome have been implicated in multiple human diseases. Recent microbiome genome-wide association studies reveal that variants in many human genes involved in immunity and gut architecture are associated with an altered composition of the gut microbiome. Although many factors can affect the microbial organisms residing in the gut, a number of recent findings support the hypothesis that certain host genetic variants predispose an individual towards microbiome dysbiosis. This condition, in which the normal microbiome population structure is disturbed, is a key feature in disorders of metabolism and immunity.

  5. Recent genetic discoveries implicating ion channels in human cardiovascular diseases.

    Science.gov (United States)

    George, Alfred L

    2014-04-01

    The term 'channelopathy' refers to human genetic disorders caused by mutations in genes encoding ion channels or their interacting proteins. Recent advances in this field have been enabled by next-generation DNA sequencing strategies such as whole exome sequencing with several intriguing and unexpected discoveries. This review highlights important discoveries implicating ion channels or ion channel modulators in cardiovascular disorders including cardiac arrhythmia susceptibility, cardiac conduction phenotypes, pulmonary and systemic hypertension. These recent discoveries further emphasize the importance of ion channels in the pathophysiology of human disease and as important druggable targets.

  6. Genetic Programming Neural Networks: A Powerful Bioinformatics Tool for Human Genetics.

    Science.gov (United States)

    Ritchie, Marylyn D; Motsinger, Alison A; Bush, William S; Coffey, Christopher S; Moore, Jason H

    2007-01-01

    The identification of genes that influence the risk of common, complex disease primarily through interactions with other genes and environmental factors remains a statistical and computational challenge in genetic epidemiology. This challenge is partly due to the limitations of parametric statistical methods for detecting genetic effects that are dependent solely or partially on interactions. We have previously introduced a genetic programming neural network (GPNN) as a method for optimizing the architecture of a neural network to improve the identification of genetic and gene-environment combinations associated with disease risk. Previous empirical studies suggest GPNN has excellent power for identifying gene-gene and gene-environment interactions. The goal of this study was to compare the power of GPNN to stepwise logistic regression (SLR) and classification and regression trees (CART) for identifying gene-gene and gene-environment interactions. SLR and CART are standard methods of analysis for genetic association studies. Using simulated data, we show that GPNN has higher power to identify gene-gene and gene-environment interactions than SLR and CART. These results indicate that GPNN may be a useful pattern recognition approach for detecting gene-gene and gene-environment interactions in studies of human disease.

  7. Genetic Markers of Human Evolution Are Enriched in Schizophrenia

    DEFF Research Database (Denmark)

    Srinivasan, Saurabh; Bettella, Francesco; Mattingsdal, Morten;

    2015-01-01

    and ancillary information on genetic variants. We used information from the evolutionary proxy measure called the Neanderthal selective sweep (NSS) score. RESULTS: Gene loci associated with schizophrenia are significantly (p = 7.30 × 10(-9)) more prevalent in genomic regions that are likely to have undergone...... recent positive selection in humans (i.e., with a low NSS score). Variants in brain-related genes with a low NSS score confer significantly higher susceptibility than variants in other brain-related genes. The enrichment is strongest for schizophrenia, but we cannot rule out enrichment for other......BACKGROUND: Why schizophrenia has accompanied humans throughout our history despite its negative effect on fitness remains an evolutionary enigma. It is proposed that schizophrenia is a by-product of the complex evolution of the human brain and a compromise for humans' language, creative thinking...

  8. Ancestral Reconstruction of a Pre-LUCA Aminoacyl-tRNA Synthetase Ancestor Supports the Late Addition of Trp to the Genetic Code.

    Science.gov (United States)

    Fournier, G P; Alm, E J

    2015-04-01

    The genetic code was likely complete in its current form by the time of the last universal common ancestor (LUCA). Several scenarios have been proposed for explaining the code's pre-LUCA emergence and expansion, and the relative order of the appearance of amino acids used in translation. One co-evolutionary model of genetic code expansion proposes that at least some amino acids were added to the code by the ancient divergence of aminoacyl-tRNA synthetase (aaRS) families. Of all the amino acids used within the genetic code, Trp is most frequently claimed as a relatively recent addition. We observe that, since TrpRS and TyrRS are paralogous protein families retaining significant sequence similarity, the inferred sequence composition of their ancestor can be used to evaluate this co-evolutionary model of genetic code expansion. We show that ancestral sequence reconstructions of the pre-LUCA paralog ancestor of TyrRS and TrpRS have several sites containing Tyr, yet a complete absence of sites containing Trp. This is consistent with the paralog ancestor being specific for the utilization of Tyr, with Trp being a subsequent addition to the genetic code facilitated by a process of aaRS divergence and neofunctionalization. Only after this divergence could Trp be specifically encoded and incorporated into proteins, including the TyrRS and TrpRS descendant lineages themselves. This early absence of Trp is observed under both homogeneous and non-homogeneous models of ancestral sequence reconstruction. Simulations support that this observed absence of Trp is unlikely to be due to chance or model bias. These results support that the final stages of genetic code evolution occurred well within the "protein world," and that the presence-absence of Trp within conserved sites of ancient protein domains is a likely measure of their relative antiquity, permitting the relative timing of extremely early events within protein evolution before LUCA.

  9. Structure-infectivity analysis of the human rhinovirus genomic RNA 3' non-coding region.

    OpenAIRE

    1996-01-01

    The specific recognition of genomic positive strand RNAS as templates for the synthesis of intermediate negative strands by the picornavirus replication machinery is presumably mediated by cis-acting sequences within the genomic RNA 3' non-coding region (NCR). A structure-infectivity analysis was conducted on the 44 nt human rhinovirus 14 (HRV14) 3' NCR to identify the primary sequence and/or secondary structure determinants required for viral replication. Using biochemical RNA secondary stru...

  10. The Australian joint inquiry into the Protection of Human Genetic Information.

    Science.gov (United States)

    Weisbrot, David

    2003-04-01

    The Australian Law Reform Commission (ALRC) and the Australian Health Ethics Committee are currently engaged in an inquiry into the Protection of Human Genetic Information. In particular, the Attorney-General and the Minister for Health and Ageing have asked us to focus, in relation to human genetic information and tissue samples, on how best to ensure world's best practice in relation to: privacy protection; protection against unlawful discrimination; and the maintenance of high ethical standards in medical research and clinical practice. While initial concerns and controversies have related mainly to aspects of medical research (e.g. consent; re-use of samples) and access to private insurance coverage, relevant issues arise in a wide variety of contexts, including: employment; medical practice; tissue banks and genetic databases; health administration; superannuation; access to government services (e.g. schools, nursing homes); law enforcement; and use by government authorities (e.g. for immigration purposes) or other bodies (e.g. by sports associations). Under the Australian federal system, it is also the case that laws and practices may vary across states and territories. For example, neonatal genetic testing is standard, but storage and retention policies for the resulting 'Guthrie cards' differ markedly. Similarly, some states have developed highly linked health information systems (e.g. incorporating hospitals, doctors' offices and public records), while others discourage such linkages owing to concerns about privacy. The challenge for Australia is to develop policies, standards and practices that promote the intelligent use of genetic information, while providing a level of security with which the community feels comfortable. The inquiry is presently reviewing the adequacy of existing laws and regulatory mechanisms, but recognizes that it will be even more important to develop a broad mix of strategies, such as community and professional education, and the

  11. The evolutionary history of Saccharomyces species inferred from completed mitochondrial genomes and revision in the 'yeast mitochondrial genetic code'.

    Science.gov (United States)

    Sulo, Pavol; Szabóová, Dana; Bielik, Peter; Poláková, Silvia; Šoltys, Katarína; Jatzová, Katarína; Szemes, Tomáš

    2017-06-15

    The yeast Saccharomyces are widely used to test ecological and evolutionary hypotheses. A large number of nuclear genomic DNA sequences are available, but mitochondrial genomic data are insufficient. We completed mitochondrial DNA (mtDNA) sequencing from Illumina MiSeq reads for all Saccharomyces species. All are circularly mapped molecules decreasing in size with phylogenetic distance from Saccharomyces cerevisiae but with similar gene content including regulatory and selfish elements like origins of replication, introns, free-standing open reading frames or GC clusters. Their most profound feature is species-specific alteration in gene order. The genetic code slightly differs from well-established yeast mitochondrial code as GUG is used rarely as the translation start and CGA and CGC code for arginine. The multilocus phylogeny, inferred from mtDNA, does not correlate with the trees derived from nuclear genes. mtDNA data demonstrate that Saccharomyces cariocanus should be assigned as a separate species and Saccharomyces bayanus CBS 380T should not be considered as a distinct species due to mtDNA nearly identical to Saccharomyces uvarum mtDNA. Apparently, comparison of mtDNAs should not be neglected in genomic studies as it is an important tool to understand the origin and evolutionary history of some yeast species. © The Author 2017. Published by Oxford University Press on behalf of Kazusa DNA Research Institute.

  12. Remediating Viking Origins: Genetic Code as Archival Memory of the Remote Past.

    Science.gov (United States)

    Scully, Marc; King, Turi; Brown, Steven D

    2013-10-01

    This article introduces some early data from the Leverhulme Trust-funded research programme, 'The Impact of the Diasporas on the Making of Britain: evidence, memories, inventions'. One of the interdisciplinary foci of the programme, which incorporates insights from genetics, history, archaeology, linguistics and social psychology, is to investigate how genetic evidence of ancestry is incorporated into identity narratives. In particular, we investigate how 'applied genetic history' shapes individual and familial narratives, which are then situated within macro-narratives of the nation and collective memories of immigration and indigenism. It is argued that the construction of genetic evidence as a 'gold standard' about 'where you really come from' involves a remediation of cultural and archival memory, in the construction of a 'usable past'. This article is based on initial questionnaire data from a preliminary study of those attending DNA collection sessions in northern England. It presents some early indicators of the perceived importance of being of Viking descent among participants, notes some emerging patterns and considers the implications for contemporary debates on migration, belonging and local and national identity.

  13. Biological genesis: the first step from dead matter to life. A contribution to the nature of DNA, RNA, and the genetic code

    Directory of Open Access Journals (Sweden)

    Schmidt FH

    2013-04-01

    Full Text Available Friedrich H Schmidt Retired, Schramberg, Germany Abstract: Information is understood semantically in the special case of the genetic code as the contents of news-bearing and genetically acting molecules. The connection of single molecules to groups and molecule chains can be referred to as syntactic. Well-defined information is not only exchanged between molecules in biology like nucleic and amino acids cooperating in the genetic code: the topic of this article is that an exchange of information could also occur between inorganic and organic substances, eg, mineral crystals interacting with organic molecules. This may have played a role in the origins of life on earth. As the origin of the genetic code and the mechanism of its translation is still an unresolved problem, so is the interaction of inorganic substances and organic substances still an open question. Stereochemical similarities existing between code and amino acids cannot explain the relationship completely and are not present between inorganic and organic molecules at all. Symmetry is a structural entity in organic chemistry and organisms, and Δ-values calculated by a mathematical algorithm and introduced in this article give an estimate of symmetry and transferred information. Symmetric Δ-values exist in minerals as well as in genetic molecules, and could thus bring dead material to life before DNA, RNA, and enzymes were developed. The fact that symmetry is important as a quality of organic matter with the function of the genetic code is pointed out in the works of other authors, who are cited in this paper. Keywords: genetic information, genetic code, symmetry in inorganic and organic molecules, calculation of Δ-values

  14. Can a few non‐coding mutations make a human brain?

    Science.gov (United States)

    Franchini, Lucía F.

    2015-01-01

    The recent finding that the human version of a neurodevelopmental enhancer of the Wnt receptor Frizzled 8 (FZD8) gene alters neural progenitor cell cycle timing and brain size is a step forward to understanding human brain evolution. The human brain is distinctive in terms of its cognitive abilities as well as its susceptibility to neurological disease. Identifying which of the millions of genomic changes that occurred during human evolution led to these and other uniquely human traits is extremely challenging. Recent studies have demonstrated that many of the fastest evolving regions of the human genome function as gene regulatory enhancers during embryonic development and that the human‐specific mutations in them might alter expression patterns. However, elucidating molecular and cellular effects of sequence or expression pattern changes is a major obstacle to discovering the genetic bases of the evolution of our species. There is much work to do before human‐specific genetic and genomic changes are linked to complex human traits. Also watch the Video Abstract. PMID:26350501

  15. THE RESPECT FOR HUMAN DIGNITY THROUGHOUT LIFE AS REFLECTED IN THE NEW CIVIL CODE

    Directory of Open Access Journals (Sweden)

    Alexandru MIHUŢ

    2011-04-01

    Full Text Available During the development of social politics, philosophyand medicine in relation to human dignity, they have been involved in theprocesses of evolution and involution which unfortunately can still be feltnowadays, both on a global and a national level. The Universal Declaration ofHuman Rights (adopted by the General Assembly of the U.N. on December 10,1948, the UNESCO’s Constituting Act (in its Head Note, The UniversalDeclaration on Bioethics and Human Rights (adopted by the UNESCO onOctober 19, 2005 also stress out the respect for human dignity. The Law No. 95/ 2006 and the Code of Medical Professional Ethics focuses on the rights of thepatient, its quintessence being the right to choose one’s physician, and therespect for the patient’s dignity appears as a corollary of these rights. The keyissue of the new Civil Code focuses on “the life, health, physical and mentalintegrity of any person” which are equally guaranteed and protected. Section 61(1 “The interest and welfare of the human being must take precedence over theunique interest of society or science” – Section 61 (2.

  16. Production of Recombinant Vector Containing the Coding Sequence of Human Hepcidin

    Directory of Open Access Journals (Sweden)

    Keyhanvar, N.

    2013-01-01

    Full Text Available Background and objective: Hepcidin is a cystein-rich antimicrobial peptide,which is secreted by the liver. It fights against wide spectrum of bacteria, virusesand fungi and it is a major regulator of iron homeostasis. Today, scientists havemade many efforts on the production of hepcidin. Baculovirus expression systemis one of the best eukaryotic expression systems for production of recombinanthepcidin and production of the recombinant vector is one of the most importantsteps in this expression system.Material & Methods: First, the total RNA was separated from HepG2 cell lineas a source of hepcidin expression. Then, after synthesis of total cDNA, humanhepcidin sequence was amplified, using specific primers by PCR method. Next,hepcidin sequence was cloned into pTZ57R/T vector. After digestion ofrecombinant vector using ECoRI and BamHI restriction enzymes, recombinantpFastBac HT B vector containing human hepcidin cDNA was produced.Results: Coding sequence of human hepcidin is correctly cloned into pTZ57R/Tvector and sub cloning into pFastBac HT B vector is performed successfully. Thepresence of a clear band near 274 bp resulted from PCR amplification andrestriction enzyme are the confirmation of the cloning of human hepcidin.Conclusion: According to our knowledge, the present study is the first work thatfocuses on recombinant vector containing coding sequence of human prohepcidin.This recombinant vector can be used for human hepcidin production.Keywords: Vector; Hepcidin; Iron

  17. Obesity: from animal models to human genetics to practical applications.

    Science.gov (United States)

    Warden, Craig H; Fisler, Janis S

    2010-01-01

    Although many animal models are used in genetic studies, the mouse is most common. Analysis of single-gene mutations, linkage analysis in crossbred strains, and gene targeting are the primary techniques used to associate obesity phenotypes with specific genes or alleles. The orthologous human gene can then be tested, either in linkage studies in families or in genome-wide association studies (GWAS), for effect on the phenotype. Frequent lack of concordance between mouse and human obesity genes may be due to the difference in phenotypes measured in humans (body mass index) versus mouse (fat mass or % body fat), lack of intermediate phenotypes, and the fact that identified genes account for only a small percentage of the heritability of common obesity, suggesting that many genes remain unknown. New technology allows analysis of individual genomes at a reasonable cost, making large-scale obesity genome projects in humans feasible. Such projects could identify common allelic variants that contribute to obesity and to variable individual response to obesity therapy. Currently, family history may be more predictive than genetics for risk of obesity, but individual testing could ultimately guide therapy and, in the aggregate, guide public health policy. The primary limitation to development of genotype-based diets is that successful randomized diet trials of widely ranging macronutrient content, adequately powered for finding rare Mendelian mutations, have not been performed. Copyright © 2010 Elsevier Inc. All rights reserved.

  18. Genetic and phenotypic consequences of introgression between humans and Neanderthals.

    Science.gov (United States)

    Wills, Christopher

    2011-01-01

    Strong evidence for introgression of Neanderthal genes into parts of the modern human gene pool has recently emerged. The evidence indicates that some populations of modern humans have received infusions of genes from two different groups of Neanderthals. One of these Neanderthal groups lived in the Middle East and Central Europe and the other group (the Denisovans) is known to have lived in Central Asia and was probably more widespread. This review examines two questions. First, how were these introgressions detected and what does the genetic evidence tell us about their nature and extent? We will see that an unknown but possibly large fraction of the entire Neanderthal gene complement may have survived in modern humans. Even though each modern European and Asian carries only a few percent of genes that can be traced back to Neanderthals, different individuals carry different subgroups of these introgressed genes. Second, what is the likelihood that this Neanderthal genetic legacy has had phenotypic effects on modern humans? We examine evidence for and against the possibility that some of the surviving fragments of Neanderthal genomes have been preserved by natural selection, and we explore the ways in which more evidence bearing on this question will become available in the future.

  19. Scaling up: human genetics as a Cold War network.

    Science.gov (United States)

    Lindee, Susan

    2014-09-01

    In this commentary I explore how the papers here illuminate the processes of collection that have been so central to the history of human genetics since 1945. The development of human population genetics in the Cold War period produced databases and biobanks that have endured into the present, and that continue to be used and debated. In the decades after the bomb, scientists collected and transferred human biological materials and information from populations of interest, and as they moved these biological resources or biosocial resources acquired new meanings and uses. The papers here collate these practices and map their desires and ironies. They explore how a large international network of geneticists, biological anthropologists, virologists and other physicians and scientists interacted with local informants, research subjects and public officials. They also track the networks and standards that mobilized the transfer of information, genealogies, tissue and blood samples. As Joanna Radin suggests here, the massive collections of human biological materials and data were often understood to be resources for an "as-yet-unknown" future. The stories told here contain elements of surveillance, extraction, salvage and eschatology. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Systematic analysis, comparison, and integration of disease based human genetic association data and mouse genetic phenotypic information

    Directory of Open Access Journals (Sweden)

    Wang S Alex

    2010-01-01

    Full Text Available Abstract Background The genetic contributions to human common disorders and mouse genetic models of disease are complex and often overlapping. In common human diseases, unlike classical Mendelian disorders, genetic factors generally have small effect sizes, are multifactorial, and are highly pleiotropic. Likewise, mouse genetic models of disease often have pleiotropic and overlapping phenotypes. Moreover, phenotypic descriptions in the literature in both human and mouse are often poorly characterized and difficult to compare directly. Methods In this report, human genetic association results from the literature are summarized with regard to replication, disease phenotype, and gene specific results; and organized in the context of a systematic disease ontology. Similarly summarized mouse genetic disease models are organized within the Mammalian Phenotype ontology. Human and mouse disease and phenotype based gene sets are identified. These disease gene sets are then compared individually and in large groups through dendrogram analysis and hierarchical clustering analysis. Results Human disease and mouse phenotype gene sets are shown to group into disease and phenotypically relevant groups at both a coarse and fine level based on gene sharing. Conclusion This analysis provides a systematic and global perspective on the genetics of common human disease as compared to itself and in the context of mouse genetic models of disease.

  1. Human genetic differentiation across the Strait of Gibraltar

    Directory of Open Access Journals (Sweden)

    Sanchez-Mazas Alicia

    2010-08-01

    Full Text Available Abstract Background The Strait of Gibraltar is a crucial area in the settlement history of modern humans because it represents a possible connection between Africa and Europe. So far, genetic data were inconclusive about the fact that this strait constitutes a barrier to gene flow, as previous results were highly variable depending on the genetic locus studied. The present study evaluates the impact of the Gibraltar region in reducing gene flow between populations from North-Western Africa and South-Western Europe, by comparing formally various genetic loci. First, we compute several statistics of population differentiation. Then, we use an original simulation approach in order to infer the most probable evolutionary scenario for the settlement of the area, taking into account the effects of both demography and natural selection at some loci. Results We show that the genetic patterns observed today in the region of the Strait of Gibraltar may reflect an ancient population genetic structure which has not been completely erased by more recent events such as Neolithic migrations. Moreover, the differences observed among the loci (i.e. a strong genetic boundary revealed by the Y-chromosome polymorphism and, at the other extreme, no genetic differentiation revealed by HLA-DRB1 variation across the strait suggest specific evolutionary histories like sex-mediated migration and natural selection. By considering a model of balancing selection for HLA-DRB1, we here estimate a coefficient of selection of 2.2% for this locus (although weaker in Europe than in Africa, which is in line with what was estimated from synonymous versus non-synonymous substitution rates. Selection at this marker thus appears strong enough to leave a signature not only at the DNA level, but also at the population level where drift and migration processes were certainly relevant. Conclusions Our multi-loci approach using both descriptive analyses and Bayesian inferences lead to

  2. Genetic characterization of three novel chicken parvovirus strains based on analysis of their coding sequences.

    Science.gov (United States)

    Koo, Bon-Sang; Lee, Hae-Rim; Jeon, Eun-Ok; Han, Moo-Sung; Min, Kyeong-Cheol; Lee, Seung-Baek; Bae, Yeon-Ji; Cho, Sun-Hyung; Mo, Jong-Suk; Kwon, Hyuk Moo; Sung, Haan Woo; Kim, Jong-Nyeo; Mo, In-Pil

    2015-01-01

    Chicken parvovirus (ChPV) is one of the causative agents of viral enteritis. Recently, the genome of the ABU-P1 strain of ChPV was fully sequenced and determined to have a distinct genomic composition compared with that of vertebrate parvoviruses. However, no comparative sequence analysis of coding regions of ChPVs was possible because of the lack of other sequence information. In this study, we obtained the nucleotide sequences of all genomic coding regions of three ChPVs by polymerase chain reaction using 13 primer sets, and deduced the amino acid sequences from the nucleotide sequences. The non-structural protein 1 (NS1) gene of the three ChPVs showed 95.0 to 95.5% nucleotide sequence identity and 96.5 to 98.1% amino acid sequence identity to those of NS1 from the ABU-P1 strain, respectively, and even higher nucleotide and amino acid similarities to one another. The viral proteins (VP) gene was more divergent between the three ChPV Korean strains and ABU-P1, with 88.1 to 88.3% nucleotide identity and 93.0% amino acid identity. Analysis of the putative tertiary structure of the ChPV VP2 protein showed that variable regions with less than 80% nucleotide similarity between the three Korean strains and ABU-P1 occurred in large loops of the VP2 protein believed to be involved in antigenicity, pathogenicity, and tissue tropism in other parvoviruses. Based on our analysis of full-length coding sequences, we discovered greater variation in ChPV strains than reported previously, especially in partial regions of the VP2 protein.

  3. Influence of human genetic variation on nutritional requirements.

    Science.gov (United States)

    Stover, Patrick J

    2006-02-01

    Genetic variation is known to affect food tolerances among human subpopulations and may also influence dietary requirements, giving rise to the new field of nutritional genomics and raising the possibility of individualizing nutritional intake for optimal health and disease prevention on the basis of an individual's genome. However, because gene-diet interactions are complex and poorly understood, the use of genomic knowledge to adjust population-based dietary recommendations is not without risk. Whereas current recommendations target most of the population to prevent nutritional deficiencies, inclusion of genomic criteria may indicate subpopulations that may incur differential benefit or risk from generalized recommendations and fortification policies. Current efforts to identify gene alleles that affect nutrient utilization have been enhanced by the identification of genetic variations that have expanded as a consequence of selection under extreme conditions. Identification of genetic variation that arose as a consequence of diet as a selective pressure helps to identify gene alleles that affect nutrient utilization. Understanding the molecular mechanisms underlying gene-nutrient interactions and their modification by genetic variation is expected to result in dietary recommendations and nutritional interventions that optimize individual health.

  4. Common genetic variants influence human subcortical brain structures

    Science.gov (United States)

    Hibar, Derrek P.; Stein, Jason L.; Renteria, Miguel E.; Arias-Vasquez, Alejandro; Desrivières, Sylvane; Jahanshad, Neda; Toro, Roberto; Wittfeld, Katharina; Abramovic, Lucija; Andersson, Micael; Aribisala, Benjamin S.; Armstrong, Nicola J.; Bernard, Manon; Bohlken, Marc M.; Boks, Marco P.; Bralten, Janita; Brown, Andrew A.; Chakravarty, M. Mallar; Chen, Qiang; Ching, Christopher R. K.; Cuellar-Partida, Gabriel; den Braber, Anouk; Giddaluru, Sudheer; Goldman, Aaron L.; Grimm, Oliver; Guadalupe, Tulio; Hass, Johanna; Woldehawariat, Girma; Holmes, Avram J.; Hoogman, Martine; Janowitz, Deborah; Jia, Tianye; Kim, Sungeun; Klein, Marieke; Kraemer, Bernd; Lee, Phil H.; Olde Loohuis, Loes M.; Luciano, Michelle; Macare, Christine; Mather, Karen A.; Mattheisen, Manuel; Milaneschi, Yuri; Nho, Kwangsik; Papmeyer, Martina; Ramasamy, Adaikalavan; Risacher, Shannon L.; Roiz-Santiañez, Roberto; Rose, Emma J.; Salami, Alireza; Sämann, Philipp G.; Schmaal, Lianne; Schork, Andrew J.; Shin, Jean; Strike, Lachlan T.; Teumer, Alexander; van Donkelaar, Marjolein M. J.; van Eijk, Kristel R.; Walters, Raymond K.; Westlye, Lars T.; Whelan, Christopher D.; Winkler, Anderson M.; Zwiers, Marcel P.; Alhusaini, Saud; Athanasiu, Lavinia; Ehrlich, Stefan; Hakobjan, Marina M. H.; Hartberg, Cecilie B.; Haukvik, Unn K.; Heister, Angelien J. G. A. M.; Hoehn, David; Kasperaviciute, Dalia; Liewald, David C. M.; Lopez, Lorna M.; Makkinje, Remco R. R.; Matarin, Mar; Naber, Marlies A. M.; McKay, D. Reese; Needham, Margaret; Nugent, Allison C.; Pütz, Benno; Royle, Natalie A.; Shen, Li; Sprooten, Emma; Trabzuni, Daniah; van der Marel, Saskia S. L.; van Hulzen, Kimm J. E.; Walton, Esther; Wolf, Christiane; Almasy, Laura; Ames, David; Arepalli, Sampath; Assareh, Amelia A.; Bastin, Mark E.; Brodaty, Henry; Bulayeva, Kazima B.; Carless, Melanie A.; Cichon, Sven; Corvin, Aiden; Curran, Joanne E.; Czisch, Michael; de Zubicaray, Greig I.; Dillman, Allissa; Duggirala, Ravi; Dyer, Thomas D.; Erk, Susanne; Fedko, Iryna O.; Ferrucci, Luigi; Foroud, Tatiana M.; Fox, Peter T.; Fukunaga, Masaki; Gibbs, J. Raphael; Göring, Harald H. H.; Green, Robert C.; Guelfi, Sebastian; Hansell, Narelle K.; Hartman, Catharina A.; Hegenscheid, Katrin; Heinz, Andreas; Hernandez, Dena G.; Heslenfeld, Dirk J.; Hoekstra, Pieter J.; Holsboer, Florian; Homuth, Georg; Hottenga, Jouke-Jan; Ikeda, Masashi; Jack, Clifford R.; Jenkinson, Mark; Johnson, Robert; Kanai, Ryota; Keil, Maria; Kent, Jack W.; Kochunov, Peter; Kwok, John B.; Lawrie, Stephen M.; Liu, Xinmin; Longo, Dan L.; McMahon, Katie L.; Meisenzahl, Eva; Melle, Ingrid; Mohnke, Sebastian; Montgomery, Grant W.; Mostert, Jeanette C.; Mühleisen, Thomas W.; Nalls, Michael A.; Nichols, Thomas E.; Nilsson, Lars G.; Nöthen, Markus M.; Ohi, Kazutaka; Olvera, Rene L.; Perez-Iglesias, Rocio; Pike, G. Bruce; Potkin, Steven G.; Reinvang, Ivar; Reppermund, Simone; Rietschel, Marcella; Romanczuk-Seiferth, Nina; Rosen, Glenn D.; Rujescu, Dan; Schnell, Knut; Schofield, Peter R.; Smith, Colin; Steen, Vidar M.; Sussmann, Jessika E.; Thalamuthu, Anbupalam; Toga, Arthur W.; Traynor, Bryan J.; Troncoso, Juan; Turner, Jessica A.; Valdés Hernández, Maria C.; van ’t Ent, Dennis; van der Brug, Marcel; van der Wee, Nic J. A.; van Tol, Marie-Jose; Veltman, Dick J.; Wassink, Thomas H.; Westman, Eric; Zielke, Ronald H.; Zonderman, Alan B.; Ashbrook, David G.; Hager, Reinmar; Lu, Lu; McMahon, Francis J.; Morris, Derek W.; Williams, Robert W.; Brunner, Han G.; Buckner, Randy L.; Buitelaar, Jan K.; Cahn, Wiepke; Calhoun, Vince D.; Cavalleri, Gianpiero L.; Crespo-Facorro, Benedicto; Dale, Anders M.; Davies, Gareth E.; Delanty, Norman; Depondt, Chantal; Djurovic, Srdjan; Drevets, Wayne C.; Espeseth, Thomas; Gollub, Randy L.; Ho, Beng-Choon; Hoffmann, Wolfgang; Hosten, Norbert; Kahn, René S.; Le Hellard, Stephanie; Meyer-Lindenberg, Andreas; Müller-Myhsok, Bertram; Nauck, Matthias; Nyberg, Lars; Pandolfo, Massimo; Penninx, Brenda W. J. H.; Roffman, Joshua L.; Sisodiya, Sanjay M.; Smoller, Jordan W.; van Bokhoven, Hans; van Haren, Neeltje E. M.; Völzke, Henry; Walter, Henrik; Weiner, Michael W.; Wen, Wei; White, Tonya; Agartz, Ingrid; Andreassen, Ole A.; Blangero, John; Boomsma, Dorret I.; Brouwer, Rachel M.; Cannon, Dara M.; Cookson, Mark R.; de Geus, Eco J. C.; Deary, Ian J.; Donohoe, Gary; Fernández, Guillén; Fisher, Simon E.; Francks, Clyde; Glahn, David C.; Grabe, Hans J.; Gruber, Oliver; Hardy, John; Hashimoto, Ryota; Hulshoff Pol, Hilleke E.; Jönsson, Erik G.; Kloszewska, Iwona; Lovestone, Simon; Mattay, Venkata S.; Mecocci, Patrizia; McDonald, Colm; McIntosh, Andrew M.; Ophoff, Roel A.; Paus, Tomas; Pausova, Zdenka; Ryten, Mina; Sachdev, Perminder S.; Saykin, Andrew J.; Simmons, Andy; Singleton, Andrew; Soininen, Hilkka; Wardlaw, Joanna M.; Weale, Michael E.; Weinberger, Daniel R.; Adams, Hieab H. H.; Launer, Lenore J.; Seiler, Stephan; Schmidt, Reinhold; Chauhan, Ganesh; Satizabal, Claudia L.; Becker, James T.; Yanek, Lisa; van der Lee, Sven J.; Ebling, Maritza; Fischl, Bruce; Longstreth, W. T.; Greve, Douglas; Schmidt, Helena; Nyquist, Paul; Vinke, Louis N.; van Duijn, Cornelia M.; Xue, Luting; Mazoyer, Bernard; Bis, Joshua C.; Gudnason, Vilmundur; Seshadri, Sudha; Ikram, M. Arfan; Martin, Nicholas G.; Wright, Margaret J.; Schumann, Gunter; Franke, Barbara; Thompson, Paul M.; Medland, Sarah E.

    2015-01-01

    The highly complex structure of the human brain is strongly shaped by genetic influences1. Subcortical brain regions form circuits with cortical areas to coordinate movement2, learning, memory3 and motivation4, and altered circuits can lead to abnormal behaviour and disease2. To investigate how common genetic variants affect the structure of these brain regions, here we conduct genome-wide association studies of the volumes of seven subcortical regions and the intracranial volume derived from magnetic resonance images of 30,717 individuals from 50 cohorts. We identify five novel genetic variants influencing the volumes of the putamen and caudate nucleus. We also find stronger evidence for three loci with previously established influences on hippocampal volume5 and intracranial volume6. These variants show specific volumetric effects on brain structures rather than global effects across structures. The strongest effects were found for the putamen, where a novel intergenic locus with replicable influence on volume (rs945270; P = 1.08 × 10−33; 0.52% variance explained) showed evidence of altering the expression of the KTN1 gene in both brain and blood tissue. Variants influencing putamen volume clustered near developmental genes that regulate apoptosis, axon guidance and vesicle transport. Identification of these genetic variants provides insight into the causes of variability inhuman brain development, and may help to determine mechanisms of neuropsychiatric dysfunction. PMID:25607358

  5. [Influence of genetic factors on human sexual orientation. Review].

    Science.gov (United States)

    Rodríguez-Larralde, Alvaro; Paradisi, Irene

    2009-09-01

    Human sexual orientation is a complex trait, influenced by several genes, experiential and sociocultural factors. These elements interact and produce a typical pattern of sexual orientation towards the opposite sex. Some exceptions exist, like bisexuality and homosexuality, which seem to be more frequent in males than females. Traditional methods for the genetic study of behavior multifactorial characteristics consist in detecting the presence of familial aggregation. In order to identify the importance of genetic and environmental factors in this aggregation, the concordance of the trait for monozygotic and dizygotic twins and for adopted sibs, reared together and apart, is compared. These types of studies have shown that familial aggregation is stronger for male than for female homosexuality. Based on the threshold method for multifactorial traits, and varying the frequency of homosexuality in the population between 4 and 10%, heritability estimates between 0.27 and 0.76 have been obtained. In 1993, linkage between homosexuality and chromosomal region Xq28 based on molecular approaches was reported. Nevertheless, this was not confirmed in later studies. Recently, a wide search of the genome has given significant or close to significant linkage values with regions 7q36, 8p12 and 10q26, which need to be studied more closely. Deviation in the proportion of X chromosome inactivation in mothers of homosexuals seems to favor the presence of genes related with sexual orientation in this chromosome. There is still much to be known about the genetics of human homosexuality.

  6. Human copy number variation and complex genetic disease.

    Science.gov (United States)

    Girirajan, Santhosh; Campbell, Catarina D; Eichler, Evan E

    2011-01-01

    Copy number variants (CNVs) play an important role in human disease and population diversity. Advancements in technology have allowed for the analysis of CNVs in thousands of individuals with disease in addition to thousands of controls. These studies have identified rare CNVs associated with neuropsychiatric diseases such as autism, schizophrenia, and intellectual disability. In addition, copy number polymorphisms (CNPs) are present at higher frequencies in the population, show high diversity in copy number, sequence, and structure, and have been associated with multiple phenotypes, primarily related to immune or environmental response. However, the landscape of copy number variation still remains largely unexplored, especially for smaller CNVs and those embedded within complex regions of the human genome. An integrated approach including characterization of single nucleotide variants and CNVs in a large number of individuals with disease and normal genomes holds the promise of thoroughly elucidating the genetic basis of human disease and diversity.

  7. Detection of genetic diversity and selection at the coding region of the melanocortin receptor 1 (MC1R) gene in Tibetan pigs and Landrace pigs.

    Science.gov (United States)

    Liu, Rui; Jin, Long; Long, Keren; Chai, Jie; Ma, Jideng; Tang, Qianzi; Tian, Shilin; Hu, Yaodong; Lin, Ling; Wang, Xun; Jiang, Anan; Li, Xuewei; Li, Mingzhou

    2016-01-10

    Domestication and subsequent selective pressures have produced a large variety of pig coat colors in different regions and breeds. The melanocortin 1 receptor (MC1R) gene plays a crucial role in determining coat color of mammals. Here, we investigated genetic diversity and selection at the coding region of the porcine melanocortin receptor 1 (MC1R) in Tibetan pigs and Landrace pigs. By contrast, genetic variability was much lower in Landrace pigs than in Tibetan pigs. Meanwhile, haplotype analysis showed that Tibetan pigs possessed shared haplotypes, suggesting a possibility of recent introgression event by way of crossbreeding with neighboring domestic pigs or shared ancestral polymorphism. Additionally, we detected positive selection at the MC1R in both Tibetan pigs and Landrace pigs through the dN/dS analysis. These findings suggested that novel phenotypic change (dark coat color) caused by novel mutations may help Tibetan pigs against intensive solar ultraviolet (UV) radiation and camouflage in wild environment, whereas white coat color in Landrace were intentionally selected by human after domestication. Furthermore, both the phylogenetic analysis and the network analysis provided clues that MC1R in Asian and European wild boars may have initially experienced different selective pressures, and MC1R alleles diversified in modern domesticated pigs.

  8. Computational identification of human long intergenic non-coding RNAs using a GA-SVM algorithm.

    Science.gov (United States)

    Wang, Yanqiu; Li, Yang; Wang, Qi; Lv, Yingli; Wang, Shiyuan; Chen, Xi; Yu, Xuexin; Jiang, Wei; Li, Xia

    2014-01-01

    Long intergenic non-coding RNAs (lincRNAs) are a new type of non-coding RNAs and are closely related with the occurrence and development of diseases. In previous studies, most lincRNAs have been identified through next-generation sequencing. Because lincRNAs exhibit tissue-specific expression, the reproducibility of lincRNA discovery in different studies is very poor. In this study, not including lincRNA expression, we used the sequence, structural and protein-coding potential features as potential features to construct a classifier that can be used to distinguish lincRNAs from non-lincRNAs. The GA-SVM algorithm was performed to extract the optimized feature subset. Compared with several feature subsets, the five-fold cross validation results showed that this optimized feature subset exhibited the best performance for the identification of human lincRNAs. Moreover, the LincRNA Classifier based on Selected Features (linc-SF) was constructed by support vector machine (SVM) based on the optimized feature subset. The performance of this classifier was further evaluated by predicting lincRNAs from two independent lincRNA sets. Because the recognition rates for the two lincRNA sets were 100% and 99.8%, the linc-SF was found to be effective for the prediction of human lincRNAs.

  9. Phase-amplitude coupling supports phase coding in human ECoG

    Science.gov (United States)

    Watrous, Andrew J; Deuker, Lorena; Fell, Juergen; Axmacher, Nikolai

    2015-01-01

    Prior studies have shown that high-frequency activity (HFA) is modulated by the phase of low-frequency activity. This phenomenon of phase-amplitude coupling (PAC) is often interpreted as reflecting phase coding of neural representations, although evidence for this link is still lacking in humans. Here, we show that PAC indeed supports phase-dependent stimulus representations for categories. Six patients with medication-resistant epilepsy viewed images of faces, tools, houses, and scenes during simultaneous acquisition of intracranial recordings. Analyzing 167 electrodes, we observed PAC at 43% of electrodes. Further inspection of PAC revealed that category specific HFA modulations occurred at different phases and frequencies of the underlying low-frequency rhythm, permitting decoding of categorical information using the phase at which HFA events occurred. These results provide evidence for categorical phase-coded neural representations and are the first to show that PAC coincides with phase-dependent coding in the human brain. DOI: http://dx.doi.org/10.7554/eLife.07886.001 PMID:26308582

  10. Specificity-Determining DNA Triplet Code for Positioning of Human Preinitiation Complex.

    Science.gov (United States)

    Goldshtein, Matan; Lukatsky, David B

    2017-05-23

    The notion that transcription factors bind DNA only through specific, consensus binding sites has been recently questioned. No specific consensus motif for the positioning of the human preinitiation complex (PIC) has been identified. Here, we reveal that nonconsensus, statistical, DNA triplet code provides specificity for the positioning of the human PIC. In particular, we reveal a highly nonrandom, statistical pattern of repetitive nucleotide triplets that correlates with the genomewide binding preferences of PIC measured by Chip-exo. We analyze the triplet enrichment and depletion near the transcription start site and identify triplets that have the strongest effect on PIC-DNA nonconsensus binding. Using statistical mechanics, a random-binder model without fitting parameters, with genomic DNA sequence being the only input, we further validate that the nonconsensus nucleotide triplet code constitutes a key signature providing PIC binding specificity in the human genome. Our results constitute a proof-of-concept for, to our knowledge, a new design principle for protein-DNA recognition in the human genome, which can lead to a better mechanistic understanding of transcriptional regulation. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  11. Dynamics of genetic variation at gliadin-coding loci in bread wheat cultivars developed in small grains research center (Kragujevac during last 35 years

    Directory of Open Access Journals (Sweden)

    Novosljska-Dragovič Aleksandra

    2005-01-01

    Full Text Available Multiple alleles of gliadin-coding loci are well-known genetic markers of common wheat genotypes. Based on analysis of gliadin patterns in common wheat cultivars developed at the Small Grains Research Center in Kragujevac dynamics of genetic variability at gliadin-coding loci has been surveyed for the period of 35 years. It was shown that long-term breeding of the wheat cultivars involved gradual replacement of ancient alleles for those widely spread in some regions in the world, which belong to well-known cultivars-donor of some important traits. Developing cultivars whose pedigree involved much new foreign genetic material has increased genetic diversity as well as has changed frequency of alleles of gliadin-coding loci. So we can conclude that the genetic profile of modern Serbian cultivars has changed considerably. Genetic formula of gliadin was made for each the cultivar studied. The most frequent alleles of gliadin-coding loci among modern cultivars should be of great interest of breeders because these alleles are probably linked with genes that confer advantage to their carriers at present.

  12. Oxytocin receptor genetic variation promotes human trust behavior

    Directory of Open Access Journals (Sweden)

    Frank eKrueger

    2012-02-01

    Full Text Available Given that human trust behavior is heritable and intranasal administration of oxytocin enhances trust, the oxytocin receptor (OXTR gene is an excellent candidate to investigate genetic contributions to individual variations in trust behavior. Although a single-nucleotide polymorphism involving an adenine (A/ guanine (G transition (rs53576 has been associated with socio-emotional phenotypes, its link to trust behavior is unclear. We combined genotyping of healthy male students with the administration of a trust game experiment. Our results show that a naturally occurring genetic variation (rs53576 in the OXTR gene is reliably associated with trust behavior rather than a general increase in trustworthy or risk behaviors. Individuals homozygous for the G allele (GG showed higher trust behavior than individuals with A allele carriers (AA/AG. Although the molecular functionality of this polymorphism is still unknown, future research should clarify how the OXTR gene interacts with other genes and the environment in promoting socio-emotional behaviors.

  13. Genetic engineering of human embryonic stem cells with lentiviral vectors.

    Science.gov (United States)

    Xiong, Chen; Tang, Dong-Qi; Xie, Chang-Qing; Zhang, Li; Xu, Ke-Feng; Thompson, Winston E; Chou, Wayne; Gibbons, Gary H; Chang, Lung-Ji; Yang, Li-Jun; Chen, Yuqing E

    2005-08-01

    Human embryonic stem (hES) cells present a valuable source of cells with a vast therapeutic potential. However, the low efficiency of directed differentiation of hES cells remains a major obstacle in their uses for regenerative medicine. While differentiation may be controlled by the genetic manipulation, effective and efficient gene transfer into hES cells has been an elusive goal. Here, we show stable and efficient genetic manipulations of hES cells using lentiviral vectors. This method resulted in the establishment of stable gene expression without loss of pluripotency in hES cells. In addition, lentiviral vectors were effective in conveying the expression of an U6 promoter-driven small interfering RNA (siRNA), which was effective in silencing its specific target. Taken together, our results suggest that lentiviral gene delivery holds great promise for hES cell research and application.

  14. Genetics of the dentofacial variation in human malocclusion.

    Science.gov (United States)

    Moreno Uribe, L M; Miller, S F

    2015-04-01

    Malocclusions affect individuals worldwide, resulting in compromised function and esthetics. Understanding the etiological factors contributing to the variation in dentofacial morphology associated with malocclusions is the key to develop novel treatment approaches. Advances in dentofacial phenotyping, which is the comprehensive characterization of hard and soft tissue variation in the craniofacial complex, together with the acquisition of large-scale genomic data have started to unravel genetic mechanisms underlying facial variation. Knowledge on the genetics of human malocclusion is limited even though results attained thus far are encouraging, with promising opportunities for future research. This review summarizes the most common dentofacial variations associated with malocclusions and reviews the current knowledge of the roles of genes in the development of malocclusions. Lastly, this review will describe ways to advance malocclusion research, following examples from the expanding fields of phenomics and genomic medicine, which aim to better patient outcomes.

  15. Human Genetic Disorders and Knockout Mice Deficient in Glycosaminoglycan

    Directory of Open Access Journals (Sweden)

    Shuji Mizumoto

    2014-01-01

    Full Text Available Glycosaminoglycans (GAGs are constructed through the stepwise addition of respective monosaccharides by various glycosyltransferases and maturated by epimerases and sulfotransferases. The structural diversity of GAG polysaccharides, including their sulfation patterns and sequential arrangements, is essential for a wide range of biological activities such as cell signaling, cell proliferation, tissue morphogenesis, and interactions with various growth factors. Studies using knockout mice of enzymes responsible for the biosynthesis of the GAG side chains of proteoglycans have revealed their physiological functions. Furthermore, mutations in the human genes encoding glycosyltransferases, sulfotransferases, and related enzymes responsible for the biosynthesis of GAGs cause a number of genetic disorders including chondrodysplasia, spondyloepiphyseal dysplasia, and Ehlers-Danlos syndromes. This review focused on the increasing number of glycobiological studies on knockout mice and genetic diseases caused by disturbances in the biosynthetic enzymes for GAGs.

  16. Recollections of J.B.S. Haldane, with special reference to Human Genetics in India

    Science.gov (United States)

    Dronamraju, Krishna R.

    2012-01-01

    This paper is a brief account of the scientific work of J.B.S. Haldane (1892–1964), with special reference to early research in Human Genetics. Brief descriptions of Haldane's background, his important contributions to the foundations of human genetics, his move to India from Great Britain and the research carried out in Human Genetics in India under his direction are outlined. Population genetic research on Y-linkage in man, inbreeding, color blindness and other aspects are described. PMID:22754215

  17. Transcriptome interrogation of human myometrium identifies differentially expressed sense-antisense pairs of protein-coding and long non-coding RNA genes in spontaneous labor at term.

    Science.gov (United States)

    Romero, Roberto; Tarca, Adi L; Chaemsaithong, Piya; Miranda, Jezid; Chaiworapongsa, Tinnakorn; Jia, Hui; Hassan, Sonia S; Kalita, Cynthia A; Cai, Juan; Yeo, Lami; Lipovich, Leonard

    2014-09-01

    To identify differentially expressed long non-coding RNA (lncRNA) genes in human myometrium in women with spontaneous labor at term. Myometrium was obtained from women undergoing cesarean deliveries who were not in labor (n = 19) and women in spontaneous labor at term (n = 20). RNA was extracted and profiled using an Illumina® microarray platform. We have used computational approaches to bound the extent of long non-coding RNA representation on this platform, and to identify co-differentially expressed and correlated pairs of long non-coding RNA genes and protein-coding genes sharing the same genomic loci. We identified co-differential expression and correlation at two genomic loci that contain coding-lncRNA gene pairs: SOCS2-AK054607 and LMCD1-NR_024065 in women in spontaneous labor at term. This co-differential expression and correlation was validated by qRT-PCR, an experimental method completely independent of the microarray analysis. Intriguingly, one of the two lncRNA genes differentially expressed in term labor had a key genomic structure element, a splice site, that lacked evolutionary conservation beyond primates. We provide, for the first time, evidence for coordinated differential expression and correlation of cis-encoded antisense lncRNAs and protein-coding genes with known as well as novel roles in pregnancy in the myometrium of women in spontaneous labor at term.

  18. Rational genomics I: antisense open reading frames and codon bias in short-chain oxido reductase enzymes and the evolution of the genetic code.

    Science.gov (United States)

    Duax, William L; Huether, Robert; Pletnev, Vladimir Z; Langs, David; Addlagatta, Anthony; Connare, Sonjay; Habegger, Lukas; Gill, Jay

    2005-12-01

    The short-chain oxidoreductase (SCOR) family of enzymes includes over 6000 members, extending from bacteria and archaea to humans. Nucleic acid sequence analysis reveals that significant numbers of these genes are remarkably free of stopcodons in reading frames other than the coding frame, including those on the antisense strand. The genes from this subset also use almost entirely the GC-rich half of the 64 codons. Analysis of a million hypothetical genes having random nucleotide composition shows that the percentage of SCOR genes having multiple open reading frames exceeds random by a factor of as much as 1 x 10(6). Nevertheless, screening the content of the SWISS-PROT TrEMBL database reveals that 15% of all genes contain multiple open reading frames. The SCOR genes having multiple open reading frames and a GC-rich coding bias exhibit a similar GC bias in the nucleotide triple composition of their DNA. This bias is not correlated with the GC content of the species in which the SCOR genes are found. One possible explanation for the conservation of multiple open reading frames and extreme bias in nucleic acid composition in the family of Rossman folds is that the primordial member of this family was encoded early using only very stable GC-rich DNA and that evolution proceeded with extremely limited introduction of any codons having two or more adenine or thymine nucleotides. These and other data suggest that the SCOR family of enzymes may even have diverged from a common ancestor before most of the AT-rich half of the genetic code was fully defined.

  19. Mapping the genetic architecture of gene expression in human liver.

    Directory of Open Access Journals (Sweden)

    Eric E Schadt

    2008-05-01

    Full Text Available Genetic variants that are associated with common human diseases do not lead directly to disease, but instead act on intermediate, molecular phenotypes that in turn induce changes in higher-order disease traits. Therefore, identifying the molecular phenotypes that vary in response to changes in DNA and that also associate with changes in disease traits has the potential to provide the functional information required to not only identify and validate the susceptibility genes that are directly affected by changes in DNA, but also to understand the molecular networks in which such genes operate and how changes in these networks lead to changes in disease traits. Toward that end, we profiled more than 39,000 transcripts and we genotyped 782,476 unique single nucleotide polymorphisms (SNPs in more than 400 human liver samples to characterize the genetic architecture of gene expression in the human liver, a metabolically active tissue that is important in a number of common human diseases, including obesity, diabetes, and atherosclerosis. This genome-wide association study of gene expression resulted in the detection of more than 6,000 associations between SNP genotypes and liver gene expression traits, where many of the corresponding genes identified have already been implicated in a number of human diseases. The utility of these data for elucidating the causes of common human diseases is demonstrated by integrating them with genotypic and expression data from other human and mouse populations. This provides much-needed functional support for the candidate susceptibility genes being identified at a growing number of genetic loci that have been identified as key drivers of disease from genome-wide association studies of disease. By using an integrative genomics approach, we highlight how the gene RPS26 and not ERBB3 is supported by our data as the most likely susceptibility gene for a novel type 1 diabetes locus recently identified in a large

  20. Predicting human genetic interactions from cancer genome evolution.

    Directory of Open Access Journals (Sweden)

    Xiaowen Lu

    Full Text Available Synthetic Lethal (SL genetic interactions play a key role in various types of biological research, ranging from understanding genotype-phenotype relationships to identifying drug-targets against cancer. Despite recent advances in empirical measuring SL interactions in human cells, the human genetic interaction map is far from complete. Here, we present a novel approach to predict this map by exploiting patterns in cancer genome evolution. First, we show that empirically determined SL interactions are reflected in various gene presence, absence, and duplication patterns in hundreds of cancer genomes. The most evident pattern that we discovered is that when one member of an SL interaction gene pair is lost, the other gene tends not to be lost, i.e. the absence of co-loss. This observation is in line with expectation, because the loss of an SL interacting pair will be lethal to the cancer cell. SL interactions are also reflected in gene expression profiles, such as an under representation of cases where the genes in an SL pair are both under expressed, and an over representation of cases where one gene of an SL pair is under expressed, while the other one is over expressed. We integrated the various previously unknown cancer genome patterns and the gene expression patterns into a computational model to identify SL pairs. This simple, genome-wide model achieves a high prediction power (AUC = 0.75 for known genetic interactions. It allows us to present for the first time a comprehensive genome-wide list of SL interactions with a high estimated prediction precision, covering up to 591,000 gene pairs. This unique list can potentially be used in various application areas ranging from biotechnology to medical genetics.

  1. Robotics for recombinant DNA and human genetics research

    Energy Technology Data Exchange (ETDEWEB)

    Beugelsdijk, T.J.

    1990-01-01

    In October of 1989, molecular biologists throughout the world formally embarked on ultimately determining the set of genetic instructions for a human being. Called by some the Manhattan Project'' a molecular biology, pursuit of this goal is projected to require approximately 3000 man years of effort over a 15-year period. The Humane Genome Initiative is a worldwide research effort that has the goal of analyzing the structure of human deoxyribonucleic acid (DNA) and determining the location of all human genes. The Department of Energy (DOE) has designated three of its national laboratories as centers for the Human Genome Project. These are Los Alamos National Laboratory (LANL), Lawrence Livermore National Laboratory (LLNL), and Lawrence Berkeley Laboratory (LBL). These laboratories are currently working on different, but complementary technology development areas in support of the Human Genome Project. The robotics group at LANL is currently working at developing the technologies that address the problems associated with physical mapping. This article describes some of these problems and discusses some of the robotics approaches and engineering tolls applicable to their solution. 7 refs., 8 figs., 1 tab.

  2. Comparison of non-coding RNAs in human and canine cancer

    Directory of Open Access Journals (Sweden)

    Siegfried eWagner

    2013-04-01

    Full Text Available The discovery of the post-transcriptional gene silencing by small non-protein-coding RNAs is considered as a major breakthrough in biology. In the last decade we just started to realize the biologic function and complexity of gene regulation by small non-coding RNAs. Post-transcriptional gene silencing (PTGS is a conserved phenomenon which was observed in various species such as fungi, worms, plants and mammals. Micro RNAs (miRNA and small interfering RNAs (siRNAs are two gene silencing mediators constituting an evolutionary conserved class of non-coding RNAs regulating many biological processes in eukaryotes. As this small RNAs appear to regulate gene expression at translational and transcriptional level it is not surprising that during the last decade many human diseases among them Alzheimer's disease, cardiovascular diseases and various cancer types were associated with deregulated miRNA expression. Consequently small RNAs are considered to hold big promises as therapeutic agents. However despite of the enormous therapeutic potential many questions remain unanswered. A major critical point, when evaluating novel therapeutic approaches, is the transfer of in vitro settings to an in vivo model. Classical animal models rely on the laboratory kept animals under artificial conditions and often missing an intact immune system. Model organisms with spontaneously occurring tumors as e.g. dogs provide the possibility to evaluate therapeutic agents under the surveillance of an in intact immune system and thereby providing an authentic tumor reacting scenario. Considering the genomic similarity between canines and humans and the advantages of the dog as cancer model system for human neoplasias the analyses of the complex role of small RNAs in canine tumor development could be of major value for both species. Herein we discuss comparatively the role of miRNAs in human and canine cancer development and highlight the potential and advantages of the model

  3. Microarray analysis of Long non-coding RNA expression profiles in human gastric cells and tissues with Helicobacter pylori Infection.

    Science.gov (United States)

    Zhu, Hong; Wang, Qiang; Yao, Yizheng; Fang, Jian; Sun, Fengying; Ni, Ying; Shen, Yixin; Wang, Hua; Shao, Shihe

    2015-12-21

    Although Helicobacter pylori (H.pylori) is the dominant gastrointestinal pathogen, the genetic and molecular mechanisms underlying H.pylori-related diseases have not been fully elucidated. Long non-coding RNAs (lncRNAs) have been identified in eukaryotic cells, many of which play important roles in regulating biological processes and pathogenesis. However, the expression changes of lncRNAs in human infected by H.pylori have been rarely reported. This study aimed to identify the dysregulated lncRNAs in human gastric epithelial cells and tissues infected with H.pylori. The aberrant expression profiles of lncRNAs and mRNAs in GES-1 cells with or without H.pylori infection were explored by microarray analysis. LncRNA-mRNA co-expression network was constructed based on Pearson correlation analysis. Gene Ontology (GO) and KEGG Pathway analyses of aberrantly expressed mRNAs were performed to identify the related biological functions and pathologic pathways. The expression changes of target lncRNAs were validated by qRT-PCR to confirm the microarray data in both cells and clinical specimens. Three hundred three lncRNAs and 565 mRNAs were identified as aberrantly expressed transcripts (≥2 or ≤0.5-fold change, P microarray. These dysregulated lncRNAs might contribute to the pathological processes during H.pylori infection.

  4. Symmetry Breaking and Adaptation The Genetic Code of Retroviral Env Proteins

    CERN Document Server

    Vera, S

    1996-01-01

    Although several synonymous codons can encode the same aminoacid, this symmetry is generally broken in natural genetic systems. In this article, we show that the symmetry breaking can result from selective pressures due to the violation of the synonym symmetry by mutation and recombination. We conjecture that this enhances the probability to produce mutants that are well-adapted to the current environment. Evidence is found in the codon frequencies of the HIV resistant to the current immunological attack, are found with a greater frequency than their less mutable synonyms.

  5. A genetic basis for mechanosensory traits in humans.

    Science.gov (United States)

    Frenzel, Henning; Bohlender, Jörg; Pinsker, Katrin; Wohlleben, Bärbel; Tank, Jens; Lechner, Stefan G; Schiska, Daniela; Jaijo, Teresa; Rüschendorf, Franz; Saar, Kathrin; Jordan, Jens; Millán, José M; Gross, Manfred; Lewin, Gary R

    2012-01-01

    In all vertebrates hearing and touch represent two distinct sensory systems that both rely on the transformation of mechanical force into electrical signals. There is an extensive literature describing single gene mutations in humans that cause hearing impairment, but there are essentially none for touch. Here we first asked if touch sensitivity is a heritable trait and second whether there are common genes that influence different mechanosensory senses like hearing and touch in humans. Using a classical twin study design we demonstrate that touch sensitivity and touch acuity are highly heritable traits. Quantitative phenotypic measures of different mechanosensory systems revealed significant correlations between touch and hearing acuity in a healthy human population. Thus mutations in genes causing deafness genes could conceivably negatively influence touch sensitivity. In agreement with this hypothesis we found that a proportion of a cohort of congenitally deaf young adults display significantly impaired measures of touch sensitivity compared to controls. In contrast, blind individuals showed enhanced, not diminished touch acuity. Finally, by examining a cohort of patients with Usher syndrome, a genetically well-characterized deaf-blindness syndrome, we could show that recessive pathogenic mutations in the USH2A gene influence touch acuity. Control Usher syndrome cohorts lacking demonstrable pathogenic USH2A mutations showed no impairment in touch acuity. Our study thus provides comprehensive evidence that there are common genetic elements that contribute to touch and hearing and has identified one of these genes as USH2A.

  6. A genetic basis for mechanosensory traits in humans.

    Directory of Open Access Journals (Sweden)

    Henning Frenzel

    Full Text Available In all vertebrates hearing and touch represent two distinct sensory systems that both rely on the transformation of mechanical force into electrical signals. There is an extensive literature describing single gene mutations in humans that cause hearing impairment, but there are essentially none for touch. Here we first asked if touch sensitivity is a heritable trait and second whether there are common genes that influence different mechanosensory senses like hearing and touch in humans. Using a classical twin study design we demonstrate that touch sensitivity and touch acuity are highly heritable traits. Quantitative phenotypic measures of different mechanosensory systems revealed significant correlations between touch and hearing acuity in a healthy human population. Thus mutations in genes causing deafness genes could conceivably negatively influence touch sensitivity. In agreement with this hypothesis we found that a proportion of a cohort of congenitally deaf young adults display significantly impaired measures of touch sensitivity compared to controls. In contrast, blind individuals showed enhanced, not diminished touch acuity. Finally, by examining a cohort of patients with Usher syndrome, a genetically well-characterized deaf-blindness syndrome, we could show that recessive pathogenic mutations in the USH2A gene influence touch acuity. Control Usher syndrome cohorts lacking demonstrable pathogenic USH2A mutations showed no impairment in touch acuity. Our study thus provides comprehensive evidence that there are common genetic elements that contribute to touch and hearing and has identified one of these genes as USH2A.

  7. miR-148 targets human DNMT3b protein coding region.

    Science.gov (United States)

    Duursma, Anja M; Kedde, Martijn; Schrier, Mariette; le Sage, Carlos; Agami, Reuven

    2008-05-01

    MicroRNAs (miRNAs) are small noncoding RNA molecules of 20-24 nucleotides that regulate gene expression. In animals, miRNAs form imperfect interactions with sequences in the 3' Untranslated region (3'UTR) of mRNAs, causing translational inhibition and mRNA decay. In contrast, plant miRNAs mostly associate with protein coding regions. Here we show that human miR-148 represses DNA methyltransferase 3b (Dnmt3b) gene expression through a region in its coding sequence. This region is evolutionary conserved and present in the Dnmt3b splice variants Dnmt3b1, Dnmt3b2, and Dnmt3b4, but not in the abundantly expressed Dnmt3b3. Whereas overexpression of miR-148 results in decreased DNMT3b1 expression, short-hairpin RNA-mediated miR-148 repression leads to an increase in DNMT3b1 expression. Interestingly, mutating the putative miR-148 target site in Dnmt3b1 abolishes regulation by miR-148. Moreover, endogenous Dnmt3b3 mRNA, which lacks the putative miR-148 target site, is resistant to miR-148-mediated regulation. Thus, our results demonstrate that the coding sequence of Dnmt3b mediates regulation by the miR-148 family. More generally, we provide evidence that coding regions of human genes can be targeted by miRNAs, and that such a mechanism might play a role in determining the relative abundance of different splice variants.

  8. Genetics in endocrinology: genetic variation in deiodinases: a systematic review of potential clinical effects in humans.

    Science.gov (United States)

    Verloop, Herman; Dekkers, Olaf M; Peeters, Robin P; Schoones, Jan W; Smit, Johannes W A

    2014-09-01

    Iodothyronine deiodinases represent a family of selenoproteins involved in peripheral and local homeostasis of thyroid hormone action. Deiodinases are expressed in multiple organs and thyroid hormone affects numerous biological systems, thus genetic variation in deiodinases may affect multiple clinical endpoints. Interest in clinical effects of genetic variation in deiodinases has clearly increased. We aimed to provide an overview for the role of deiodinase polymorphisms in human physiology and morbidity. In this systematic review, studies evaluating the relationship between deiodinase polymorphisms and clinical parameters in humans were eligible. No restrictions on publication date were imposed. The following databases were searched up to August 2013: Pubmed, EMBASE (OVID-version), Web of Science, COCHRANE Library, CINAHL (EbscoHOST-version), Academic Search Premier (EbscoHOST-version), and ScienceDirect. Deiodinase physiology at molecular and tissue level is described, and finally the role of these polymorphisms in pathophysiological conditions is reviewed. Deiodinase type 1 (D1) polymorphisms particularly show moderate-to-strong relationships with thyroid hormone parameters, IGF1 production, and risk for depression. D2 variants correlate with thyroid hormone levels, insulin resistance, bipolar mood disorder, psychological well-being, mental retardation, hypertension, and risk for osteoarthritis. D3 polymorphisms showed no relationship with inter-individual variation in serum thyroid hormone parameters. One D3 polymorphism was associated with risk for osteoarthritis. Genetic deiodinase profiles only explain a small proportion of inter-individual variations in serum thyroid hormone levels. Evidence suggests a role of genetic deiodinase variants in certain pathophysiological conditions. The value for determination of deiodinase polymorphism in clinical practice needs further investigation. © 2014 European Society of Endocrinology.

  9. The coding region of the human c-mos pseudogene contains Alu repeat insertions.

    Science.gov (United States)

    Zabarovsky, E R; Chumakov, I M; Prassolov, V S; Kisselev, L L

    1984-10-01

    We have determined the nucleotide sequence of an 841-bp fragment derived from a segment of the human genome previously cloned by Chumakov et al. [Gene 17 (1982) 19-26] and Zabarovsky et al. [Gene 23 (1983) 379-384] and containing regions homologous to the viral mos gene probe. This sequence displays homology with part of the coding region of the human and murine c-mos genes, contains several termination codons, and is interrupted by two Alu-family elements flanked by short direct repeats. Probably, the progenitor of the human c-mos gene was duplicated approximately at the time of mammalian divergence, was converted to a pseudogene, and acquired insertions of two Alu elements.

  10. Optimal design of FIR high pass filter based on L1 error approximation using real coded genetic algorithm

    Directory of Open Access Journals (Sweden)

    Apoorva Aggarwal

    2015-12-01

    Full Text Available In this paper, an optimal design of linear phase digital finite impulse response (FIR highpass (HP filter using the L1-norm based real-coded genetic algorithm (RCGA is investigated. A novel fitness function based on L1 norm is adopted to enhance the design accuracy. Optimized filter coefficients are obtained by defining the filter objective function in L1 sense using RCGA. Simulation analysis unveils that the performance of the RCGA adopting this fitness function is better in terms of signal attenuation ability of the filter, flatter passband and the convergence rate. Observations are made on the percentage improvement of this algorithm over the gradient-based L1 optimization approach on various factors by a large amount. It is concluded that RCGA leads to the best solution under specified parameters for the FIR filter design on account of slight unnoticeable higher transition width.

  11. Numeral series hidden in the distribution of atomic mass of amino acids to codon domains in the genetic code.

    Science.gov (United States)

    Wohlin, Åsa

    2015-03-21

    The distribution of codons in the nearly universal genetic code is a long discussed issue. At the atomic level, the numeral series 2x(2) (x=5-0) lies behind electron shells and orbitals. Numeral series appear in formulas for spectral lines of hydrogen. The question here was if some similar scheme could be found in the genetic code. A table of 24 codons was constructed (synonyms counted as one) for 20 amino acids, four of which have two different codons. An atomic mass analysis was performed, built on common isotopes. It was found that a numeral series 5 to 0 with exponent 2/3 times 10(2) revealed detailed congruency with codon-grouped amino acid side-chains, simultaneously with the division on atom kinds, further with main 3rd base groups, backbone chains and with codon-grouped amino acids in relation to their origin from glycolysis or the citrate cycle. Hence, it is proposed that this series in a dynamic way may have guided the selection of amino acids into codon domains. Series with simpler exponents also showed noteworthy correlations with the atomic mass distribution on main codon domains; especially the 2x(2)-series times a factor 16 appeared as a conceivable underlying level, both for the atomic mass and charge distribution. Furthermore, it was found that atomic mass transformations between numeral systems, possibly interpretable as dimension degree steps, connected the atomic mass of codon bases with codon-grouped amino acids and with the exponent 2/3-series in several astonishing ways. Thus, it is suggested that they may be part of a deeper reference system.

  12. Functional assessment of human coding mutations affecting skin pigmentation using zebrafish.

    Directory of Open Access Journals (Sweden)

    Zurab R Tsetskhladze

    Full Text Available A major challenge in personalized medicine is the lack of a standard way to define the functional significance of the numerous nonsynonymous, single nucleotide coding variants that are present in each human individual. To begin to address this problem, we have used pigmentation as a model polygenic trait, three common human polymorphisms thought to influence pigmentation, and the zebrafish as a model system. The approach is based on the rescue of embryonic zebrafish mutant phenotypes by "humanized" zebrafish orthologous mRNA. Two hypomorphic polymorphisms, L374F in SLC45A2, and A111T in SLC24A5, have been linked to lighter skin color in Europeans. The phenotypic effect of a second coding polymorphism in SLC45A2, E272K, is unclear. None of these polymorphisms had been tested in the context of a model organism. We have confirmed that zebrafish albino fish are mutant in slc45a2; wild-type slc45a2 mRNA rescued the albino mutant phenotype. Introduction of the L374F polymorphism into albino or the A111T polymorphism into slc24a5 (golden abolished mRNA rescue of the respective mutant phenotypes, consistent with their known contributions to European skin color. In contrast, the E272K polymorphism had no effect on phenotypic rescue. The experimental conclusion that E272K is unlikely to affect pigmentation is consistent with a lack of correlation between this polymorphism and quantitatively measured skin color in 59 East Asian humans. A survey of mutations causing human oculocutaneous albinism yielded 257 missense mutations, 82% of which are theoretically testable in zebrafish. The developed approach may be extended to other model systems and may potentially contribute to our understanding the functional relationships between DNA sequence variation, human biology, and disease.

  13. Liberal or Conservative? Genetic Rhetoric, Disability, and Human Species Modification

    Directory of Open Access Journals (Sweden)

    Christopher F. Goodey

    2016-11-01

    Full Text Available A certain political rhetoric is implicit and sometimes explicit in the advocacy of human genetic modification (indicating here both the enhancement and the prevention of disability. The main claim is that it belongs to a liberal tradition. From a perspective supplied by the history and philosophy of science rather than by ethics, the content of that claim is examined to see if such a self-description is justified. The techniques are analyzed by which apparently liberal arguments get to be presented as “reasonable” in a juridical sense that draws on theories of law and rhetoric.

  14. The impact of preimplantation genetic diagnosis on human embryos

    Directory of Open Access Journals (Sweden)

    García-Ferreyra J.

    2016-12-01

    Full Text Available Chromosome abnormalities are extremely common in human oocytes and embryos and are associated with a variety of negative outcomes for both natural cycles and those using assisted reproduction techniques. Aneuploidies embryos may fail to implant in the uterus, miscarry, or lead to children with serious medical problems (e.g., Down syndrome. Preimplantation genetic diagnosis (PGD is a technique that allows the detection of aneuploidy in embryos and seeks to improve the clinical outcomes od assisted reproduction treatments, by ensuring that the embryos chosen for the transfer are chromosomally normal.

  15. Genetics and Human Agency: Comment on Dar-Nimrod and Heine (2011)

    Science.gov (United States)

    Turkheimer, Eric

    2011-01-01

    Dar-Nimrod and Heine (2011) decried genetic essentialism without denying the importance of genetics in the genesis of human behavior, and although I agree on both counts, a deeper issue remains unaddressed: how should we adjust our cognitions about our own behavior in light of genetic influence, or is it perhaps not necessary to take genetics into…

  16. Genetics and Human Agency: Comment on Dar-Nimrod and Heine (2011)

    Science.gov (United States)

    Turkheimer, Eric

    2011-01-01

    Dar-Nimrod and Heine (2011) decried genetic essentialism without denying the importance of genetics in the genesis of human behavior, and although I agree on both counts, a deeper issue remains unaddressed: how should we adjust our cognitions about our own behavior in light of genetic influence, or is it perhaps not necessary to take genetics into…

  17. Alu repeats as markers for human population genetics

    Energy Technology Data Exchange (ETDEWEB)

    Batzer, M.A.; Alegria-Hartman, M. [Lawrence Livermore National Lab., CA (United States); Bazan, H. [Louisiana State Univ., New Orleans, LA (United States). Medical Center] [and others

    1993-09-01

    The Human-Specific (HS) subfamily of Alu sequences is comprised of a group of 500 nearly identical members which are almost exclusively restricted to the human genome. Individual subfamily members share an average of 97.9% nucleotide identity with each other and an average of 98.9% nucleotide identity with the HS subfamily consensus sequence. HS Alu family members are thought to be derived from a single source ``master`` gene, and have an average age of 2.8 million years. We have developed a Polymerase Chain Reaction (PCR) based assay using primers complementary to the 5 in. and 3 in. unique flanking DNA sequences from each HS Alu that allows the locus to be assayed for the presence or absence of an Alu repeat. Individual HS Alu sequences were found to be either monomorphic or dimorphic for the presence or absence of each repeat. The monomorphic HS Alu family members inserted in the human genome after the human/great ape divergence (which is thought to have occurred 4--6 million years ago), but before the radiation of modem man. The dimorphic HS Alu sequences inserted in the human genome after the radiation of modem man (within the last 200,000-one million years) and represent a unique source of information for human population genetics and forensic DNA analyses. These sites can be developed into Dimorphic Alu Sequence Tagged Sites (DASTS) for the Human Genome Project as well. HS Alu family member insertion dimorphism differs from other types of polymorphism (e.g. Variable Number of Tandem Repeat [VNTR] or Restriction Fragment Length Polymorphism [RFLP]) because individuals share HS Alu family member insertions based upon identity by descent from a common ancestor as a result of a single event which occurred one time within the human population. The VNTR and RFLP polymorphisms may arise multiple times within a population and are identical by state only.

  18. Genetic code translation displays a linear trade-off between efficiency and accuracy of tRNA selection

    Science.gov (United States)

    Johansson, Magnus; Zhang, Jingji; Ehrenberg, Måns

    2012-01-01

    Rapid and accurate translation of the genetic code into protein is fundamental to life. Yet due to lack of a suitable assay, little is known about the accuracy-determining parameters and their correlation with translational speed. Here, we develop such an assay, based on Mg2+ concentration changes, to determine maximal accuracy limits for a complete set of single-mismatch codon–anticodon interactions. We found a simple, linear trade-off between efficiency of cognate codon reading and accuracy of tRNA selection. The maximal accuracy was highest for the second codon position and lowest for the third. The results rationalize the existence of proofreading in code reading and have implications for the understanding of tRNA modifications, as well as of translation error-modulating ribosomal mutations and antibiotics. Finally, the results bridge the gap between in vivo and in vitro translation and allow us to calibrate our test tube conditions to represent the environment inside the living cell. PMID:22190491

  19. Functional testing strategy for coding genetic variants of unclear significance in MLH1 in Lynch syndrome diagnosis.

    Science.gov (United States)

    Hinrichsen, Inga; Schäfer, Dieter; Langer, Deborah; Köger, Nicole; Wittmann, Margarethe; Aretz, Stefan; Steinke, Verena; Holzapfel, Stefanie; Trojan, Jörg; König, Rainer; Zeuzem, Stefan; Brieger, Angela; Plotz, Guido

    2015-02-01

    Lynch syndrome is caused by inactivating mutations in the MLH1 gene, but genetic variants of unclear significance frequently preclude diagnosis. Functional testing can reveal variant-conferred defects in gene or protein function. Based on functional defect frequencies and clinical applicability of test systems, we developed a functional testing strategy aimed at efficiently detecting pathogenic defects in coding MLH1 variants. In this strategy, tests of repair activity and expression are prioritized over analyses of subcellular protein localization and messenger RNA (mRNA) formation. This strategy was used for four unclear coding MLH1 variants (p.Asp41His, p.Leu507Phe, p.Gln689Arg, p.Glu605del + p.Val716Met). Expression was analyzed using a transfection system, mismatch repair (MMR) activity by complementation in vitro, mRNA formation by reverse transcriptase-PCR in carrier lymphocyte mRNA, and subce