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Sample records for genetics screening differential

  1. Breast cancer genetic risk profile is differentially associated with interval and screen-detected breast cancers.

    Science.gov (United States)

    Li, J; Holm, J; Bergh, J; Eriksson, M; Darabi, H; Lindström, L S; Törnberg, S; Hall, P; Czene, K

    2015-03-01

    Polygenic risk profiles computed from multiple common susceptibility alleles for breast cancer have been shown to identify women at different levels of breast cancer risk. We evaluated whether this genetic risk stratification can also be applied to discriminate between screen-detected and interval cancers, which are usually associated with clinicopathological and survival differences. A 77 single-nucleotide polymorphism polygenic risk score (PRS) was constructed for breast cancer overall and by estrogen receptor (ER) status. PRS was inspected as a continuous (per standard deviation increment) variable in a case-only design. Modification of the PRS by mammographic density was evaluated by fitting an additional interaction term. PRS weighted by breast cancer overall estimates was found to be differentially associated with 1865 screen-detected and 782 interval cancers in the LIBRO-1 study {age-adjusted odds ratio (OR)perSD [95% confidence interval (CI)] 0.91 [0.83-0.99], P = 0.023}. The association was found to be more significant for PRS weighted by ER-positive breast cancer estimates [ORperSD = 0.90 (0.82-0.98), P = 0.011]. This result was corroborated by two independent studies [combined ORperSD = 0.87 (0.76-1.00), P = 0.058] with no evidence of heterogeneity. When enriched for 'true' interval cancers among nondense breasts, the difference in the association with PRS in screen-detected and interval cancers became more pronounced [ORperSD = 0.74 (0.62-0.89), P = 0.001], with a significant interaction effect between PRS and mammographic density (Pinteraction = 0.017). To our knowledge, this is the first report looking into the genetic differences between screen-detected and interval cancers. It is an affirmation that the two types of breast cancer may have unique underlying biology. © The Author 2014. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  2. Prenatal screening and genetics

    DEFF Research Database (Denmark)

    Alderson, P; Aro, A R; Dragonas, T

    2001-01-01

    Although the term 'genetic screening' has been used for decades, this paper discusses how, in its most precise meaning, genetic screening has not yet been widely introduced. 'Prenatal screening' is often confused with 'genetic screening'. As we show, these terms have different meanings, and we...... examine definitions of the relevant concepts in order to illustrate this point. The concepts are i) prenatal, ii) genetic screening, iii) screening, scanning and testing, iv) maternal and foetal tests, v) test techniques and vi) genetic conditions. So far, prenatal screening has little connection...... with precisely defined genetics. There are benefits but also disadvantages in overstating current links between them in the term genetic screening. Policy making and professional and public understandings about screening could be clarified if the distinct meanings of prenatal screening and genetic screening were...

  3. Prenatal screening and genetics

    NARCIS (Netherlands)

    Alderson, P.; Aro, A.R.; Dragonas, T.; Ettorre, E.; Hemminki, E.; Jalinoja, P.; Santalahti, P.; Tijmstra, T.

    Although the term 'genetic screening' has been used for decades, this paper discusses how, in its most precise meaning, genetic screening has not yet been widely introduced. 'Prenatal screening' is often confused with 'genetic screening'. As we show, these terms have different meanings, and we

  4. Prenatal screening and genetics

    NARCIS (Netherlands)

    Alderson, P.; Aro, A.R.; Dragonas, T.; Ettorre, E.; Hemminki, E.; Jalinoja, P.; Santalahti, P.; Tijmstra, T.

    2001-01-01

    Although the term 'genetic screening' has been used for decades, this paper discusses how, in its most precise meaning, genetic screening has not yet been widely introduced. 'Prenatal screening' is often confused with 'genetic screening'. As we show, these terms have different meanings, and we exami

  5. Prenatal screening and genetics

    DEFF Research Database (Denmark)

    Alderson, P; Aro, A R; Dragonas, T

    2001-01-01

    Although the term 'genetic screening' has been used for decades, this paper discusses how, in its most precise meaning, genetic screening has not yet been widely introduced. 'Prenatal screening' is often confused with 'genetic screening'. As we show, these terms have different meanings, and we ex...

  6. Prenatal Genetic Screening Tests

    Science.gov (United States)

    ... cells from the fetus or placenta obtained through amniocentesis or chorionic villus sampling (CVS) . FAQ164 “Prenatal Genetic ... should be followed by a diagnostic test with amniocentesis or CVS. The cell-free DNA screening test ...

  7. Optimal screening for genetic diseases.

    Science.gov (United States)

    Nævdal, Eric

    2014-12-01

    Screening for genetic diseases is performed in many regions and/or ethnic groups where there is a high prevalence of possibly malign genes. The propagation of such genes can be considered a dynamic externality. Given that many of these diseases are untreatable and give rise to truly tragic outcomes, they are a source of societal concern, and the screening process should perhaps be regulated. This paper incorporates a standard model of genetic propagation into an economic model of dynamic management to derive cost benefit rules for optimal screening. The highly non-linear nature of genetic dynamics gives rise to perhaps surprising results that include discontinuous controls and threshold effects. One insight is that any screening program that is in place for any amount of time should screen all individuals in a target population. The incorporation of genetic models may prove to be useful to several emerging fields in economics such as genoeconomics, neuroeconomics and paleoeconomics.

  8. Judaism, genetic screening and genetic therapy.

    Science.gov (United States)

    Rosner, F

    1998-01-01

    Genetic screening, gene therapy and other applications of genetic engineering are permissible in Judaism when used for the treatment, cure, or prevention of disease. Such genetic manipulation is not considered to be a violation of God's natural law, but a legitimate implementation of the biblical mandate to heal. If Tay-Sachs disease, diabetes, hemophilia, cystic fibrosis, Huntington's disease or other genetic diseases can be cured or prevented by "gene surgery," then it is certainly permitted in Jewish law. Genetic premarital screening is encouraged in Judaism for the purpose of discouraging at-risk marriages for a fatal illness such as Tay-Sachs disease. Neonatal screening for treatable conditions such as phenylketonuria is certainly desirable and perhaps required in Jewish law. Preimplantation screening and the implantation of only "healthy" zygotes into the mother's womb to prevent the birth of an affected child are probably sanctioned in Jewish law. Whether or not these assisted reproduction techniques may be used to choose the sex of one's offspring, to prevent the birth of a child with a sex-linked disease such as hemophilia, has not yet been ruled on by modern rabbinic decisions. Prenatal screening with the specific intent of aborting an affected fetus is not allowed according to most rabbinic authorities, although a minority view permits it "for great need." Not to have children if both parents are carriers of genetic diseases such as Tay-Sachs is not a Jewish option. Preimplantation screening is preferable. All screening test results must remain confidential. Judaism does not permit the alteration or manipulation of physical traits and characteristics such as height, eye and hair color, facial features and the like, when such change provides no useful benefit to mankind. On the other hand, it is permissible to clone organisms and microorganisms to facilitate the production of insulin, growth hormone, and other agents intended to benefit mankind and to

  9. Newborn genetic screening: blessing or curse?

    Science.gov (United States)

    Kenner, C; Amlung, S

    1999-10-01

    Newly discovered genes and advances in genetic screening programs prompt many questions reflecting the kinds of ethical dilemmas that go hand in hand with life-changing discoveries. Neonatal genetic screening has been a standard of care for some time, but as our knowledge in the field of genetics expands, should we continue with the same approach? What newborn genetic screening tests should be mandatory, and what are the long-range consequences associated with testing? This article reviews genetic modes of inheritance, outlines and explains the most common newborn screening tests, and enumerates the ethical issues associated with these screening procedures. The role of the neonatal nurse in the newborn genetic screening process is discussed.

  10. Genome-wide gene expression profiling and a forward genetic screen show that differential expression of the sodium ion transporter Ena21 contributes to the differential tolerance of Candida albicans and Candida dubliniensis to osmotic stress.

    LENUS (Irish Health Repository)

    Enjalbert, Brice

    2009-04-01

    Candida albicans is more pathogenic than Candida dubliniensis. However, this disparity in virulence is surprising given the high level of sequence conservation and the wide range of phenotypic traits shared by these two species. Increased sensitivity to environmental stresses has been suggested to be a possible contributory factor to the lower virulence of C. dubliniensis. In this study, we investigated, in the first comparison of C. albicans and C. dubliniensis by transcriptional profiling, global gene expression in each species when grown under conditions in which the two species exhibit differential stress tolerance. The profiles revealed similar core responses to stresses in both species, but differences in the amplitude of the general transcriptional responses to thermal, salt and oxidative stress. Differences in the regulation of specific stress genes were observed between the two species. In particular, ENA21, encoding a sodium ion transporter, was strongly induced in C. albicans but not in C. dubliniensis. In addition, ENA21 was identified in a forward genetic screen for C. albicans genomic sequences that increase salt tolerance in C. dubliniensis. Introduction of a single copy of CaENA21 was subsequently shown to be sufficient to confer salt tolerance upon C. dubliniensis.

  11. Culture and genetic screening in Africa.

    Science.gov (United States)

    Jegede, Ayodele S

    2009-12-01

    Africa is a continent in transition amidst a revival of cultural practices. Over previous years the continent was robbed of the benefits of medical advances by unfounded cultural practices surrounding its cultural heritage. In a fast moving field like genetic screening, discussions of social and policy aspects frequently need to take place at an early stage to avoid the dilemma encountered by Western medicine. This paper, examines the potential challenges to genetic screening in Africa. It discusses how cultural practices may affect genetic screening. It views genomics science as a culture which is trying to diffuse into another one. It argues that understanding the existing culture will help the diffusion process. The paper emphasizes the importance of genetic screening for Africa, by assessing the current level of burden of diseases in the continent and shows its role in reducing disease prevalence. The paper identifies and discusses the cultural challenges that are likely to confront genetic screening on the continent, such as the worldview, rituals and taboos, polygyny, culture of son preference and so on. It also discusses cultural practices that may promote the science such as inheritance practices, spouse selection practices and naming patterns. Factors driving the cultural challenges are identified and discussed, such as socialization process, patriarchy, gender, belief system and so on. Finally, the paper discusses the way forward and highlights the ethical considerations of doing genetic screening on the continent. However, the paper also recognizes that African culture is not monolithic and therefore makes a case for exceptions.

  12. Genetic screening and democracy: lessons from debating genetic screening criteria in the Netherlands.

    Science.gov (United States)

    van El, Carla Geertruida; Pieters, Toine; Cornel, Martina

    2012-04-01

    Recent decades have witnessed increasing possibilities for genetic testing and screening. In clinical genetics, the doctor's office defined a secluded space for discussion of sensitive reproductive options in cases of elevated risk for genetic disorders in individuals or their offspring. When prenatal screening for all pregnant women became conceivable, the potential increase in scale made social and ethical concerns relevant for the whole of society. Whereas genetic testing in clinical genetic practice was widely accepted, prenatal screening at a population level met with unease. Concerns were raised regarding social pressure to screen: the sum of individual choice might result in a 'collective eugenics'. The government's involvement also raised suspicion: actively offering screening evoked associations with eugenic population policies from the first half of the 20th century. By reconstructing elements of policy and public debate on prenatal screening in the Netherlands from the past 30 years, this article discusses how the government has gradually changed its role in balancing the interest of the individual and the collective on genetic reproductive issues. Against a background of increasing knowledge about and demand for prenatal screening among the population, governmental policy changed from focusing on protection by banning screening toward facilitating screening in a careful and ethically sound way by providing adequate information, decision aids and quality assessment instruments. In the meanwhile, invigorating democracy in public debate may entail discussing concepts of 'the good life' in relation to living with or without impairments and dealing with genetic information about oneself or one's offspring.

  13. Screening Test Items for Differential Item Functioning

    Science.gov (United States)

    Longford, Nicholas T.

    2014-01-01

    A method for medical screening is adapted to differential item functioning (DIF). Its essential elements are explicit declarations of the level of DIF that is acceptable and of the loss function that quantifies the consequences of the two kinds of inappropriate classification of an item. Instead of a single level and a single function, sets of…

  14. Genetic screening services provided in Turkey.

    Science.gov (United States)

    Erdem, Yurdagül; Tekşen, Fulya

    2013-12-01

    In Turkey, the rate of consanguineous marriage is quite high (22-24 %) and as a result, the incidence of autosomal recessive diseases and congenital anomalies is also very high and gives rise to a serious public health problem. In the last three decades, great effort has been made to avoid increases in the prevalence of these hereditary diseases. For this purpose, population-based premarital, prenatal, neonatal and adult genetic screening programs are performed in various centers such as Community Health Centers, Early Diagnosis of Cancer and Education Centers (KETEM), Prenatal and Neonatal Departments of Universities and State Hospitals and Thalessemia Screening Centers. Such centers are staffed by health professionals including physicians, family physicians, nurses, midwives, biologists and medical geneticists. Genetic counseling is also provided to patients attending these centers after screening tests are performed. Since there are no specialized training programs for genetic counselors, genetic counseling is generally provided by doctors or medical geneticists. The aim of this paper is to give an overview of the genetic screening services provided in Turkey, the prevalence of genetic diseases and the design of intensive educational programs for health professionals.

  15. Pragmatic approaches to genetic screening.

    NARCIS (Netherlands)

    Mallia, P.; Have, H.A.M.J. ten

    2005-01-01

    Pragmatic approaches to genetic testing are discussed and appraised. Whilst there are various schools of pragmatism, the Deweyan approach seems to be the most appreciated in bioethics as it allows a historical approach indebted to Hegel. This in turn allows the pragmatist to specify and balance prin

  16. In vitro fertilization with preimplantation genetic screening

    NARCIS (Netherlands)

    Mastenbroek, Sebastiaan; Twisk, Moniek; van Echten-Arends, Jannie; Sikkema-Raddatz, Birgit; Korevaar, Johanna C.; Verhoeve, Harold R.; Vogel, Niels E. A.; Arts, Eus G. J. M.; de Vries, Jan W. A.; Bossuyt, Patrick M.; Buys, Charles H. C. M.; Heineman, Maas Jan; Repping, Sjoerd; van der Veen, Fulco

    2007-01-01

    BACKGROUND: Pregnancy rates in women of advanced maternal age undergoing in vitro fertilization (IVF) are disappointingly low. It has been suggested that the use of preimplantation genetic screening of cleavage-stage embryos for aneuploidies may improve the effectiveness of IVF in these women.

  17. Genetic screens in Caenorhabditis elegans models for neurodegenerative diseases

    NARCIS (Netherlands)

    Alvarenga Fernandes Sin, Olga; Michels, Helen; Nollen, Ellen A. A.

    2014-01-01

    Caenorhabditis elegans comprises unique features that make it an attractive model organism in diverse fields of biology. Genetic screens are powerful to identify genes and C. elegans can be customized to forward or reverse genetic screens and to establish gene function. These genetic screens can be

  18. Genetic screens in Caenorhabditis elegans models for neurodegenerative diseases

    NARCIS (Netherlands)

    Alvarenga Fernandes Sin, Olga; Michels, Helen; Nollen, Ellen A. A.

    2014-01-01

    Caenorhabditis elegans comprises unique features that make it an attractive model organism in diverse fields of biology. Genetic screens are powerful to identify genes and C. elegans can be customized to forward or reverse genetic screens and to establish gene function. These genetic screens can be

  19. Sources of Error in Mammalian Genetic Screens

    Directory of Open Access Journals (Sweden)

    Laura Magill Sack

    2016-09-01

    Full Text Available Genetic screens are invaluable tools for dissection of biological phenomena. Optimization of such screens to enhance discovery of candidate genes and minimize false positives is thus a critical aim. Here, we report several sources of error common to pooled genetic screening techniques used in mammalian cell culture systems, and demonstrate methods to eliminate these errors. We find that reverse transcriptase-mediated recombination during retroviral replication can lead to uncoupling of molecular tags, such as DNA barcodes (BCs, from their associated library elements, leading to chimeric proviral genomes in which BCs are paired to incorrect ORFs, shRNAs, etc. This effect depends on the length of homologous sequence between unique elements, and can be minimized with careful vector design. Furthermore, we report that residual plasmid DNA from viral packaging procedures can contaminate transduced cells. These plasmids serve as additional copies of the PCR template during library amplification, resulting in substantial inaccuracies in measurement of initial reference populations for screen normalization. The overabundance of template in some samples causes an imbalance between PCR cycles of contaminated and uncontaminated samples, which results in a systematic artifactual depletion of GC-rich library elements. Elimination of contaminating plasmid DNA using the bacterial endonuclease Benzonase can restore faithful measurements of template abundance and minimize GC bias.

  20. DNA microsatellite analysis for tomato genetic differentiation

    Directory of Open Access Journals (Sweden)

    Miskoska-Milevska Elizabeta

    2015-01-01

    Full Text Available Commonly used method for determination of the genetic diversity among the populations is the test for genetic differentiation. DNA microsatellite markers are usually used to investigate the genetic structure of natural populations. The aim of this study was to evaluate the applicability of eight DNA microsatellite loci (LECH13, LE21085, LEMDDNa, LEEF1Aa, LELEUZIP, LE20592, TMS9 and LE2A11 in genetic differentiation of six morphologically different tomato varieties (var. grandifolium from subsp. cultum; var. cerasiforme - red and yellow, var. pruniforme and var. pyriforme from subsp. subspontaneum; and var. racemigerum from subsp. spontaneum. The fragment analyses was performed using Applied Biosystems DNA analyzer (ABI 3130 and GeneMapper® Software program. The data were analysed using the specific program Power Marker Software. The average number of detected alleles was 3,625. Also, the average PIC value for all 8 DNA microsatellites loci was 0,3571. The genetic differentiation test in the researched tomato subspecies showed minor differentiation for locus LELEUZIP (- 0,0009, modest differentiation for locus LECH13 (0,0896, locus LEMDDNa (0,0896 and locus LE21085 (0,0551 and major differentiation for locus LE2A11 (0,7633, locus LEEF1Aa (0,6167, locus TMS9 (0.4967 and locus LE20592 (0,4263. On the other hand, in the estimated tomato varieties, locus LE21085 (0,0297, locus LECH13 (0,0256 and locus LELEUZIP (0,0005 showed minor differentiation, locus LEMDDNa (0,1333 showed modest differentiation, while locus TMS9 (0,5929, locus LEEF1Aa (0,5006, locus LE2A11 (0,4013 and locus LE20592 (0,2606 showed major differentiation. The eight DNA microsatellite loci can be applicable solution for tomato genetic differentiation. The overall results suggest that these microsatellite loci could be used in further population genetic studies of tomatoes.

  1. GAMPMS: Genetic algorithm managed peptide mutant screening.

    Science.gov (United States)

    Long, Thomas; McDougal, Owen M; Andersen, Tim

    2015-06-30

    The prominence of endogenous peptide ligands targeted to receptors makes peptides with the desired binding activity good molecular scaffolds for drug development. Minor modifications to a peptide's primary sequence can significantly alter its binding properties with a receptor, and screening collections of peptide mutants is a useful technique for probing the receptor-ligand binding domain. Unfortunately, the combinatorial growth of such collections can limit the number of mutations which can be explored using structure-based molecular docking techniques. Genetic algorithm managed peptide mutant screening (GAMPMS) uses a genetic algorithm to conduct a heuristic search of the peptide's mutation space for peptides with optimal binding activity, significantly reducing the computational requirements of the virtual screening. The GAMPMS procedure was implemented and used to explore the binding domain of the nicotinic acetylcholine receptor (nAChR) α3β2-isoform with a library of 64,000 α-conotoxin (α-CTx) MII peptide mutants. To assess GAMPMS's performance, it was compared with a virtual screening procedure that used AutoDock to predict the binding affinity of each of the α-CTx MII peptide mutants with the α3β2-nAChR. The GAMPMS implementation performed AutoDock simulations for as few as 1140 of the 64,000 α-CTx MII peptide mutants and could consistently identify a set of 10 peptides with an aggregated binding energy that was at least 98% of the aggregated binding energy of the 10 top peptides from the exhaustive AutoDock screening.

  2. Genetic differentiation of watermelon landraces in Mozambique ...

    African Journals Online (AJOL)

    Ezedom Theresa

    2013-09-04

    Sep 4, 2013 ... 2 Department of Plant and Environmental Sciences, Faculty of Science, University ... country, were analysed to assess their genetic differentiation. ...... Plant. Cell Physiol. 41: 864-873. Levi A, Thomas CE, Trebitsh T, Salman A, ...

  3. Ecological and Genetic Barriers Differentiate Natural Populations of Saccharomyces cerevisiae.

    Science.gov (United States)

    Clowers, Katie J; Heilberger, Justin; Piotrowski, Jeff S; Will, Jessica L; Gasch, Audrey P

    2015-09-01

    How populations that inhabit the same geographical area become genetically differentiated is not clear. To investigate this, we characterized phenotypic and genetic differences between two populations of Saccharomyces cerevisiae that in some cases inhabit the same environment but show relatively little gene flow. We profiled stress sensitivity in a group of vineyard isolates and a group of oak-soil strains and found several niche-related phenotypes that distinguish the populations. We performed bulk-segregant mapping on two of the distinguishing traits: The vineyard-specific ability to grow in grape juice and oak-specific tolerance to the cell wall damaging drug Congo red. To implicate causal genes, we also performed a chemical genomic screen in the lab-strain deletion collection and identified many important genes that fell under quantitative trait loci peaks. One gene important for growth in grape juice and identified by both the mapping and the screen was SSU1, a sulfite-nitrite pump implicated in wine fermentations. The beneficial allele is generated by a known translocation that we reasoned may also serve as a genetic barrier. We found that the translocation is prevalent in vineyard strains, but absent in oak strains, and presents a postzygotic barrier to spore viability. Furthermore, the translocation was associated with a fitness cost to the rapid growth rate seen in oak-soil strains. Our results reveal the translocation as a dual-function locus that enforces ecological differentiation while producing a genetic barrier to gene flow in these sympatric populations.

  4. Fast evolutionary genetic differentiation during experimental colonizations

    Indian Academy of Sciences (India)

    Josiane Santos; Marta Pascual; Pedro Simões; Inês Fragata; Michael R. Rose; Margarida Matos

    2013-08-01

    Founder effects during colonization of a novel environment are expected to change the genetic composition of populations, leading to differentiation between the colonizer population and its source population. Another expected outcome is differentiation among populations derived from repeated independent colonizations starting from the same source. We have previously detected significant founder effects affecting rate of laboratory adaptation among Drosophila subobscura laboratory populations derived from the wild. We also showed that during the first generations in the laboratory, considerable genetic differentiation occurs between foundations. The present study deepens that analysis, taking into account the natural sampling hierarchy of six foundations, derived from different locations, different years and from two samples in one of the years. We show that striking stochastic effects occur in the first two generations of laboratory culture, effects that produce immediate differentiation between foundations, independent of the source of origin and despite similarity among all founders. This divergence is probably due to powerful genetic sampling effects during the first few generations of culture in the novel laboratory environment, as a result of a significant drop in $N_{\\text{e}}$. Changes in demography as well as high variance in reproductive success in the novel environment may contribute to the low values of $N_{\\text{e}}$. This study shows that estimates of genetic differentiation between natural populations may be accurate when based on the initial samples collected in the wild, though considerable genetic differentiation may occur in the very first generations of evolution in a new, confined environment. Rapid and significant evolutionary changes can thus occur during the early generations of a founding event, both in the wild and under domestication, effects of interest for both scientific and conservation purposes.

  5. Genetic Screening for Familial Gastric Cancer

    Directory of Open Access Journals (Sweden)

    Oliveira Carla

    2004-05-01

    Full Text Available Abstract Approximately 10% of gastric cancer cases show familial clustering but only 1-3% of gastric carcinomas arise as a result of inherited gastric cancer predisposition syndromes. Direct proof that Hereditary Gastric Cancer a genetic disease with a germline gene defect has come from the demonstration of co-segregation of germline E-cadherin (CDH1 mutations with early onset diffuse gastric cancer in families with an autosomal dominant pattern of inheritance (HDGC. E-cadherin is a transmembrane calcium-dependent cell-adhesion molecule involved in cell-junction formation and the maintenance of epithelial integrity. In this review, we describe frequency and type of CDH1 mutations in sporadic and familial gastric cancer. Further we demonstrate the functional significance of some CDH1 germline missense mutations found in HDGC. We also discuss the CDH1 polymorphisms that have been associated to gastric cancer. We report other types of malignancies associated to HDGC, besides diffuse gastric cancer. Moreover, we review the data available on putative alternative candidate genes screened in familial gastric cancer. Finally, we briefly discuss the role of low-penetrance genes and Helicobacter pylori in gastric cancer. This knowledge is a fundamental step towards accurate genetic counselling, in which a highly specialised pre-symptomatic therapeutic intervention should be offered.

  6. Moving up the slippery slope: mandated genetic screening on Cyprus.

    Science.gov (United States)

    Cowan, Ruth Schwartz

    2009-02-15

    Many social scientists and bioethicists have argued that genetic screening is a new form of eugenics. Examination of the development of the quasi-mandated screening program for beta-thalassemia in the Republic of Cyprus (1970-1984) demonstrates that there is nothing eugenic about modern genetic screening practices. The Cypriot screening program involves mandated premarital carrier screening, voluntary prenatal diagnosis (originally through fetoscopy, now through CVS), and voluntary termination of afflicted pregnancies-all at public expense. In the Republic of Cyprus, the mandating agency for genetic screening is the established church, so this examination also demonstrates that religious authorities with profound objections to abortion can balance that moral precept against others, such as the imperative to reduce suffering that sometimes conflict with it. (c) 2009 Wiley-Liss, Inc.

  7. The art and design of genetic screens: maize.

    Science.gov (United States)

    Candela, Héctor; Hake, Sarah

    2008-03-01

    Maize (Zea mays) is an excellent model for basic research. Genetic screens have informed our understanding of developmental processes, meiosis, epigenetics and biochemical pathways--not only in maize but also in other cereal crops. We discuss the forward and reverse genetic screens that are possible in this organism, and emphasize the available tools. Screens exploit the well-studied behaviour of transposon systems, and the distinctive chromosomes allow an integration of cytogenetics into mutagenesis screens and analyses. The imminent completion of the maize genome sequence provides the essential resource to move seamlessly from gene to phenotype and back.

  8. Meckel Syndrome: Genetics, Perinatal Findings, and Differential Diagnosis

    Directory of Open Access Journals (Sweden)

    Chih-Ping Chen

    2007-03-01

    Full Text Available Meckel syndrome (MKS is a lethal, autosomal recessive disorder characterized by occipital encephalocele, bilateral renal cystic dysplasia, hepatic ductal proliferation, fibrosis and cysts, and polydactyly. Genetic heterogeneity of MKS has been established by three reported MKS loci, i.e., MKS1 on 17q23, MKS2 on 11q13, and MKS3 on 8q21.13-q22.1. MKS1 encodes a component of flagellar apparatus basal body proteome, which is associated with ciliary function. MKS3 encodes a seven-transmembrane receptor protein, meckelin. The identification of the MKS3 gene as well as the MKS1 gene enables molecular genetic testing for at-risk families, and allows accurate genetic counseling, carrier testing, and prenatal diagnosis. Pregnancies with MKS fetuses may be associated with an elevated maternal serum α-fetoprotein level and an abnormal screening result in the second-trimester maternal serum screening test. The classic MKS triad of occipital encephalocele, postaxial polydactyly, and bilateral enlarged multicystic kidneys can be diagnosed before the 14th gestational weeks by ultrasonography. However, later in pregnancy, severe oligohydramnios may make the diagnosis of polydactyly and encephalocele difficult. Differential diagnosis for MKS includes autosomal recessive polycystic kidney disease, trisomy 13, Smith-Lemli-Opitz syndrome, hydrolethalus syndrome, Senior-Loken syndrome, Joubert syndrome, Bardet-Biedl syndrome, and oral-facial-digital syndrome type 1. This article provides an overview of genetics, perinatal findings, and differential diagnosis of MKS. The ciliopathy underlies the pathogenesis of MKS. Prenatal diagnosis of bilateral enlarged multicystic kidneys should alert MKS and prompt a thorough investigation of central nervous system malformations and polydactyly.

  9. Antenatal screening and the gendering of genetic responsibility

    Directory of Open Access Journals (Sweden)

    Reed Kate

    2007-09-01

    Full Text Available Abstract Background The objective of this study is to explore men's and women's perceptions of antenatal blood screening. The study will assess the impact of these perceptions on decision-making regarding diagnostic testing and selective abortion, and on parental feelings of genetic responsibility. By exploring gender and antenatal screening in this way, the research aims to contribute to our understanding of lay perceptions of genetic screening and increase our knowledge of the decision-making process in screening. Research design This qualitative study will be based on semi-structured interviews with twenty pregnant women and twenty male partners in the post-industrial city of Sheffield, UK. All interviews will be taped, transcribed and analysed thematically using NVIVO, a qualitative software package. Discussion The findings of this study have relevance to existing debates on the social and ethical implications of reproductive genetics. A better understanding of male and female perceptions of the screening process could improve guidance and practice in antenatal screening and genetic counselling. It will also inform and contribute to the development of theory on gender and genetic screening.

  10. Private and public eugenics: genetic and screening in India

    NARCIS (Netherlands)

    Gupta, J.A.

    2007-01-01

    Epidemiologists and geneticists claim that genetics has an increasing role to play in public health policies and programs in the future. Within this perspective, genetic testing and screening are instrumental in avoiding the birth of children with serious, costly or untreatable disorders. This paper

  11. Genetic dissection of mammalian ERAD through comparative haploid and CRISPR forward genetic screens

    DEFF Research Database (Denmark)

    Timms, Richard T.; Menzies, Sam A.; Tchasovnikarova, Iva A.

    2016-01-01

    The application of forward genetic screens to cultured human cells represents a powerful method to study gene function. The repurposing of the bacterial CRISPR/Cas9 system provides an effective method to disrupt gene function in mammalian cells, and has been applied to genome-wide screens. Here, we...... compare the efficacy of genome-wide CRISPR/Cas9-mediated forward genetic screens versus gene-trap mutagenesis screens in haploid human cells, which represent the existing ‘gold standard’ method. This head-to-head comparison aimed to identify genes required for the endoplasmic reticulum....../3-associated disulphide reductase. Genome-wide CRISPR/Cas9-mediated screens together with haploid genetic screens provide a powerful addition to the forward genetic toolbox....

  12. The art and design of genetic screens: mouse.

    Science.gov (United States)

    Kile, Benjamin T; Hilton, Douglas J

    2005-07-01

    Humans are mammals, not bacteria or plants, yeast or nematodes, insects or fish. Mice are also mammals, but unlike gorilla and goat, fox and ferret, giraffe and jackal, they are suited perfectly to the laboratory environment and genetic experimentation. In this review, we will summarize the tools, tricks and techniques for executing forward genetic screens in the mouse and argue that this approach is now accessible to most biologists, rather than being the sole domain of large national facilities and specialized genetics laboratories.

  13. Technical Update: Preimplantation Genetic Diagnosis and Screening.

    Science.gov (United States)

    Dahdouh, Elias M; Balayla, Jacques; Audibert, François; Wilson, R Douglas; Audibert, François; Brock, Jo-Ann; Campagnolo, Carla; Carroll, June; Chong, Karen; Gagnon, Alain; Johnson, Jo-Ann; MacDonald, William; Okun, Nanette; Pastuck, Melanie; Vallée-Pouliot, Karine

    2015-05-01

    Objectif : Mettre à jour et passer en revue les techniques et les indications du diagnostic génétique préimplantatoire et du dépistage génétique préimplantatoire. Options : Discussion au sujet des aspects techniques et génétiques des techniques génésiques préimplantatoires, particulièrement en ce qui concerne celles qui font appel aux nouvelles technologies cytogénétiques et à la biopsie au stade de l’embryon. Issues : Les issues cliniques obtenues par les techniques génésiques à la suite du recours au diagnostic génétique préimplantatoire et au dépistage génétique préimplantatoire sont incluses. La présente mise à jour ne traite pas en détail des issues indésirables qui ont été signalées en association avec les technologies de procréation assistée. Résultats : La littérature publiée a été récupérée par l’intermédiaire de recherches menées dans Medline et The Cochrane Library en avril 2014 au moyen d’un vocabulaire contrôlé (« aneuploidy », « blastocyst/physiology », « genetic diseases », « preimplantation diagnosis/methods », « fertilization in vitro ») et de mots clés (p. ex. « preimplantation genetic diagnosis », « preimplantation genetic screening », « comprehensive chromosome screening », « aCGH », « SNP microarray », « qPCR » et « embryo selection ») appropriés. Les résultats ont été restreints aux analyses systématiques, aux études observationnelles et aux essais comparatifs randomisés / essais cliniques comparatifs publiés en anglais entre 1990 et avril 2014. Aucune restriction n’a été imposée en matière de langue. Les recherches ont été mises à jour de façon régulière et intégrées à la directive clinique jusqu’en janvier 2015. Des publications additionnelles ont été identifiées à partir des bibliographies des articles récupérés. La littérature grise (non publiée) a été identifiée par l’intermédiaire de

  14. Big screens with small RNAs : loss of function genetic screens to identify novel cancer genes

    NARCIS (Netherlands)

    Mullenders, J.

    2009-01-01

    This thesis described the construction and screening of one of the first large scale RNAi libraries for use in human cells. Functional genetic screens with this library have led to the identification of novel cancer genes. These cancer genes function in several pathways including the p53 tumor suppr

  15. Hepatic differentiation of human pluripotent stem cells in miniaturized format suitable for high-throughput screen

    Directory of Open Access Journals (Sweden)

    Arnaud Carpentier

    2016-05-01

    Full Text Available The establishment of protocols to differentiate human pluripotent stem cells (hPSCs including embryonic (ESC and induced pluripotent (iPSC stem cells into functional hepatocyte-like cells (HLCs creates new opportunities to study liver metabolism, genetic diseases and infection of hepatotropic viruses (hepatitis B and C viruses in the context of specific genetic background. While supporting efficient differentiation to HLCs, the published protocols are limited in terms of differentiation into fully mature hepatocytes and in a smaller-well format. This limitation handicaps the application of these cells to high-throughput assays. Here we describe a protocol allowing efficient and consistent hepatic differentiation of hPSCs in 384-well plates into functional hepatocyte-like cells, which remain differentiated for more than 3 weeks. This protocol affords the unique opportunity to miniaturize the hPSC-based differentiation technology and facilitates screening for molecules in modulating liver differentiation, metabolism, genetic network, and response to infection or other external stimuli.

  16. Measuring differentiation among populations at different levels of genetic integration

    Directory of Open Access Journals (Sweden)

    Gregorius Hans-Rolf

    2008-09-01

    Full Text Available Abstract Background Most genetic studies of population differentiation are based on gene-pool frequencies. Population differences for gene associations that show up as deviations from Hardy-Weinberg proportions (homologous association or gametic disequilibria (non-homologous association are disregarded. Thus little is known about patterns of population differentiation at higher levels of genetic integration nor the causal forces. Results To fill this gap, a conceptual approach to the description and analysis of patterns of genetic differentiation at arbitrary levels of genetic integration (single or multiple loci, varying degrees of ploidy is introduced. Measurement of differentiation is based on the measure Δ of genetic distance between populations, which is in turn based on an elementary genic difference between individuals at any given level of genetic integration. It is proven that Δ does not decrease when the level of genetic integration is increased, with equality if the gene associations at the higher level follow the same function in both populations (e.g. equal inbreeding coefficients, no association between loci. The pattern of differentiation is described using the matrix of pairwise genetic distances Δ and the differentiation snail based on the symmetric population differentiation ΔSD. A measure of covariation compares patterns between levels. To show the significance of the observed differentiation among possible gene associations, a special permutation analysis is proposed. Applying this approach to published genetic data on oak, the differentiation is found to increase considerably from lower to higher levels of integration, revealing variation in the forms of gene association among populations. Conclusion This new approach to the analysis of genetic differentiation among populations demonstrates that the consideration of gene associations within populations adds a new quality to studies on population differentiation that is

  17. Genetic dissection of mammalian ERAD through comparative haploid and CRISPR forward genetic screens

    DEFF Research Database (Denmark)

    Timms, Richard T.; Menzies, Sam A.; Tchasovnikarova, Iva A.;

    2016-01-01

    The application of forward genetic screens to cultured human cells represents a powerful method to study gene function. The repurposing of the bacterial CRISPR/Cas9 system provides an effective method to disrupt gene function in mammalian cells, and has been applied to genome-wide screens. Here, ...

  18. Coupled mutagenesis screens and genetic mapping in zebrafish.

    Science.gov (United States)

    Rawls, John F; Frieda, Matthew R; McAdow, Anthony R; Gross, Jason P; Clayton, Chad M; Heyen, Candy K; Johnson, Stephen L

    2003-01-01

    Forward genetic analysis is one of the principal advantages of the zebrafish model system. However, managing zebrafish mutant lines derived from mutagenesis screens and mapping the corresponding mutations and integrating them into the larger collection of mutations remain arduous tasks. To simplify and focus these endeavors, we developed an approach that facilitates the rapid mapping of new zebrafish mutations as they are generated through mutagenesis screens. We selected a minimal panel of 149 simple sequence length polymorphism markers for a first-pass genome scan in crosses involving C32 and SJD inbred lines. We also conducted a small chemical mutagenesis screen that identified several new mutations affecting zebrafish embryonic melanocyte development. Using our first-pass marker panel in bulked-segregant analysis, we were able to identify the genetic map positions of these mutations as they were isolated in our screen. Rapid mapping of the mutations facilitated stock management, helped direct allelism tests, and should accelerate identification of the affected genes. These results demonstrate the efficacy of coupling mutagenesis screens with genetic mapping. PMID:12663538

  19. An animal model of differential genetic risk for methamphetamine intake

    Directory of Open Access Journals (Sweden)

    Tamara ePhillips

    2015-09-01

    Full Text Available The question of whether genetic factors contribute to risk for methamphetamine (MA use and dependence has not been intensively investigated. Compared to human populations, genetic animal models offer the advantages of control over genetic family history and drug exposure. Using selective breeding, we created lines of mice that differ in genetic risk for voluntary MA intake and identified the chromosomal addresses of contributory genes. A quantitative trait locus was identified on chromosome 10 that accounts for more than 50% of the genetic variance in MA intake in the selected mouse lines. In addition, behavioral and physiological screening identified differences corresponding with risk for MA intake that have generated hypotheses that are testable in humans. Heightened sensitivity to aversive and certain physiological effects of MA, such as MA-induced reduction in body temperature, are hallmarks of mice bred for low MA intake. Furthermore, unlike MA-avoiding mice, MA-preferring mice are sensitive to rewarding and reinforcing MA effects, and to MA-induced increases in brain extracellular dopamine levels. Gene expression analyses implicate the importance of a network enriched in transcription factor genes, some of which regulate the mu opioid receptor gene, Oprm1, in risk for MA use. Neuroimmune factors appear to play a role in differential response to MA between the mice bred for high and low intake. In addition, chromosome 10 candidate gene studies provide strong support for a trace amine associated receptor 1 gene, Taar1, polymorphism in risk for MA intake. MA is a trace amine-associated receptor 1 (TAAR1 agonist, and a non-functional Taar1 allele segregates with high MA consumption. Thus, reduced TAAR1 function has the potential to increase risk for MA use. Overall, existing findings support the MA drinking lines as a powerful model for identifying genetic factors involved in determining risk for harmful MA use. Future directions include the

  20. Coeliac disease and autoimmune disease-genetic overlap and screening.

    Science.gov (United States)

    Lundin, Knut E A; Wijmenga, Cisca

    2015-09-01

    Coeliac disease is a treatable, gluten-induced disease that often occurs concurrently with other autoimmune diseases. In genetic studies since 2007, a partial genetic overlap between these diseases has been revealed and further insights into the pathophysiology of coeliac disease and autoimmunity have been gained. However, genetic screening is not sensitive and specific enough to accurately predict disease development. The current method to diagnose individuals with coeliac disease is serological testing for the presence of autoantibodies whilst the patient is on a regular, gluten-containing diet, followed by gastroduodenoscopy with duodenal biopsy. Serological test results can also predict the probability of coeliac disease development, even if asymptomatic. In patients with autoimmune diseases known to occur alongside coeliac disease (particularly type 1 diabetes mellitus or thyroid disorders), disease screening-and subsequent treatment if coeliac disease is detected-could have beneficial effects on progression or potential complications of both diseases, owing to the effectiveness of gluten-free dietary interventions in coeliac disease. However, whether diagnosis of coeliac disease and subsequent dietary treatment can prevent autoimmune diseases is debated. In this Review, the genetic and immunological features of coeliac disease, overlap with other autoimmune diseases and implications for current screening strategies will be discussed.

  1. Genome-wide screen for differential DNA methylation associated with neural cell differentiation in mouse.

    Directory of Open Access Journals (Sweden)

    Rene Cortese

    Full Text Available Cellular differentiation involves widespread epigenetic reprogramming, including modulation of DNA methylation patterns. Using Differential Methylation Hybridization (DMH in combination with a custom DMH array containing 51,243 features covering more than 16,000 murine genes, we carried out a genome-wide screen for cell- and tissue-specific differentially methylated regions (tDMRs in undifferentiated embryonic stem cells (ESCs, in in-vitro induced neural stem cells (NSCs and 8 differentiated embryonic and adult tissues. Unsupervised clustering of the generated data showed distinct cell- and tissue-specific DNA methylation profiles, revealing 202 significant tDMRs (p1.96 enrichment for genes involved in neural differentiation, including, for example, Jag1 and Tcf4. Our results provide robust evidence for the relevance of DNA methylation in early neural development and identify novel marker candidates for neural cell differentiation.

  2. A comprehensive platform for highly multiplexed mammalian functional genetic screens

    Directory of Open Access Journals (Sweden)

    Cheung-Ong Kahlin

    2011-05-01

    Full Text Available Abstract Background Genome-wide screening in human and mouse cells using RNA interference and open reading frame over-expression libraries is rapidly becoming a viable experimental approach for many research labs. There are a variety of gene expression modulation libraries commercially available, however, detailed and validated protocols as well as the reagents necessary for deconvolving genome-scale gene screens using these libraries are lacking. As a solution, we designed a comprehensive platform for highly multiplexed functional genetic screens in human, mouse and yeast cells using popular, commercially available gene modulation libraries. The Gene Modulation Array Platform (GMAP is a single microarray-based detection solution for deconvolution of loss and gain-of-function pooled screens. Results Experiments with specially constructed lentiviral-based plasmid pools containing ~78,000 shRNAs demonstrated that the GMAP is capable of deconvolving genome-wide shRNA "dropout" screens. Further experiments with a larger, ~90,000 shRNA pool demonstrate that equivalent results are obtained from plasmid pools and from genomic DNA derived from lentivirus infected cells. Parallel testing of large shRNA pools using GMAP and next-generation sequencing methods revealed that the two methods provide valid and complementary approaches to deconvolution of genome-wide shRNA screens. Additional experiments demonstrated that GMAP is equivalent to similar microarray-based products when used for deconvolution of open reading frame over-expression screens. Conclusion Herein, we demonstrate four major applications for the GMAP resource, including deconvolution of pooled RNAi screens in cells with at least 90,000 distinct shRNAs. We also provide detailed methodologies for pooled shRNA screen readout using GMAP and compare next-generation sequencing to GMAP (i.e. microarray based deconvolution methods.

  3. Combination of hearing screening and genetic screening for deafness-susceptibility genes in newborns.

    Science.gov (United States)

    Yao, Gen-Dong; Li, Shou-Xia; Chen, Ding-Li; Feng, Hai-Qin; Zhao, Su-Bin; Liu, Yong-Jie; Guo, Li-Li; Yang, Zhi-Ming; Zhang, Xiao-Fang; Sun, Cai-Xia; Wang, Ze-Hui; Zhang, Wei-Yong

    2014-01-01

    The aim of this study was to determine the clinical significance of the results of screening of newborn hearing and the incidence of deafness-susceptibility genes. One thousand newborn babies in the Handan Center Hospital (Handan, China) underwent screening of hearing and deafness-susceptibility genes. The first screening test was carried out using otoacoustic emissions (OAEs). Babies with hearing loss who failed to pass the initial screening were scheduled for rescreening at 42 days after birth. Cord blood was used for the screening of deafness-susceptibility genes, namely the GJB2, SLC26A4 and mitochondrial 12S rRNA (MTRNR1) genes. Among the 1,000 neonates that underwent the first hearing screening, 25 exhibited left-sided hearing loss, 21 exhibited right-sided hearing loss and 15 cases had binaural hearing loss. After rescreening 42 days later, only one of the initial 61 cases exhibited hearing loss under OAE testing. The neonatal deafness gene tests showed two cases with 1555A>G mutation and two cases with 1494C>T mutation of the MTRNR1 gene. In the SLC26A4 gene screening, four cases exhibited the heterozygous IVS7-2A>G mutation and one case exhibited heterozygous 1226G>A mutation. In the GJB2 gene screening, two cases exhibited the homozygous 427C>T mutation and 10 exhibited the heterozygous 235delC mutation. The genetic screening revealed 21 newborns with mutations in the three deafness-susceptibility genes. The overall carrier rate was 2.1% (21/1,000). The association of hearing and gene screening may be the promising screening strategy for the diagnosis of hearing loss.

  4. Genetic screening for infertility: When should it be done?

    Directory of Open Access Journals (Sweden)

    Elda Kara

    2010-07-01

    Primary amenorrhea should be investigated by karyotype analysis and selected mutation screening according to the patient's clinical features. Karyotype analyses and FMR1 gene screening is recommended in cases of POF. At present the infertility of patients with POF cannot be restored if the diagnosis is made after complete follicular depletion, but in some cases, early diagnosis by genetic investigation may instead lead to the advice of early conception or oocyte harvesting and preservation. In addition, the accumulation and annotation of array comparative genomic hybridization data might, in the near future, lead to the identification of pathogenetic copy number variations and genes involved in POF. Karyotype analysis of both partners is recommended in all couples with recurrent pregnancy loss. No routine genetic test can be recommended so far in patients with PCOS.

  5. Forward genetic screen for auxin-deficient mutants by cytokinin.

    Science.gov (United States)

    Wu, Lei; Luo, Pan; Di, Dong-Wei; Wang, Li; Wang, Ming; Lu, Cheng-Kai; Wei, Shao-Dong; Zhang, Li; Zhang, Tian-Zi; Amakorová, Petra; Strnad, Miroslav; Novák, Ondřej; Guo, Guang-Qin

    2015-07-06

    Identification of mutants with impairments in auxin biosynthesis and dynamics by forward genetic screening is hindered by the complexity, redundancy and necessity of the pathways involved. Furthermore, although a few auxin-deficient mutants have been recently identified by screening for altered responses to shade, ethylene, N-1-naphthylphthalamic acid (NPA) or cytokinin (CK), there is still a lack of robust markers for systematically isolating such mutants. We hypothesized that a potentially suitable phenotypic marker is root curling induced by CK, as observed in the auxin biosynthesis mutant CK-induced root curling 1 / tryptophan aminotransferase of Arabidopsis 1 (ckrc1/taa1). Phenotypic observations, genetic analyses and biochemical complementation tests of Arabidopsis seedlings displaying the trait in large-scale genetic screens showed that it can facilitate isolation of mutants with perturbations in auxin biosynthesis, transport and signaling. However, unlike transport/signaling mutants, the curled (or wavy) root phenotypes of auxin-deficient mutants were significantly induced by CKs and could be rescued by exogenous auxins. Mutants allelic to several known auxin biosynthesis mutants were re-isolated, but several new classes of auxin-deficient mutants were also isolated. The findings show that CK-induced root curling provides an effective marker for discovering genes involved in auxin biosynthesis or homeostasis.

  6. Habitat fragmentation causes rapid genetic differentiation and ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-08-04

    Aug 4, 2009 ... differentiation and homogenization in natural plant populations – A ... The effects of habitat fragmentations on the forage grass Leymus thinness (Trin.) Tzvel, which ... selection etc, combined together with ecological factors.

  7. Global burden of genetic disease and the role of genetic screening.

    Science.gov (United States)

    Verma, I C; Puri, R D

    2015-10-01

    It is estimated that 5.3% of newborns will suffer from a genetic disorder, when followed up until the age of 25 years. In developing, as compared to western countries, hemoglobinopathies and glucose-6-phosphate dehydrogenase deficiency have a higher incidence due to severe falciparum malaria in the distant past, and autosomal recessive disorders have a higher frequency due to greater proportion of consanguineous marriages. Chromosomal disorders have a combined frequency of 1 in 153 births, therefore screening for chromosomal disorders is essential, using biochemical markers, ultrasonography, and recently by non-invasive prenatal diagnosis based on cell-free fetal DNA in maternal plasma. Preconceptional counseling should be encouraged. For genetic disorders screening should be carried out, ideally after marriage, but before pregnancy. The disorders to be screened depend upon ethnicity. Metabolic disorders have a high incidence in developing countries due to greater rate of consanguineous marriages. Newborn screening is recommended to reduce the burden of these disorders, as many metabolic disorders can be treated. Hearing and critical congenital heart disease should both be screened in the newborn period.

  8. Pooled-matrix protein interaction screens using Barcode Fusion Genetics.

    Science.gov (United States)

    Yachie, Nozomu; Petsalaki, Evangelia; Mellor, Joseph C; Weile, Jochen; Jacob, Yves; Verby, Marta; Ozturk, Sedide B; Li, Siyang; Cote, Atina G; Mosca, Roberto; Knapp, Jennifer J; Ko, Minjeong; Yu, Analyn; Gebbia, Marinella; Sahni, Nidhi; Yi, Song; Tyagi, Tanya; Sheykhkarimli, Dayag; Roth, Jonathan F; Wong, Cassandra; Musa, Louai; Snider, Jamie; Liu, Yi-Chun; Yu, Haiyuan; Braun, Pascal; Stagljar, Igor; Hao, Tong; Calderwood, Michael A; Pelletier, Laurence; Aloy, Patrick; Hill, David E; Vidal, Marc; Roth, Frederick P

    2016-04-22

    High-throughput binary protein interaction mapping is continuing to extend our understanding of cellular function and disease mechanisms. However, we remain one or two orders of magnitude away from a complete interaction map for humans and other major model organisms. Completion will require screening at substantially larger scales with many complementary assays, requiring further efficiency gains in proteome-scale interaction mapping. Here, we report Barcode Fusion Genetics-Yeast Two-Hybrid (BFG-Y2H), by which a full matrix of protein pairs can be screened in a single multiplexed strain pool. BFG-Y2H uses Cre recombination to fuse DNA barcodes from distinct plasmids, generating chimeric protein-pair barcodes that can be quantified via next-generation sequencing. We applied BFG-Y2H to four different matrices ranging in scale from ~25 K to 2.5 M protein pairs. The results show that BFG-Y2H increases the efficiency of protein matrix screening, with quality that is on par with state-of-the-art Y2H methods.

  9. Generation of Mouse Haploid Somatic Cells by Small Molecules for Genome-wide Genetic Screening

    Directory of Open Access Journals (Sweden)

    Zheng-Quan He

    2017-08-01

    Full Text Available The recent success of derivation of mammalian haploid embryonic stem cells (haESCs has provided a powerful tool for large-scale functional analysis of the mammalian genome. However, haESCs rapidly become diploidized after differentiation, posing challenges for genetic analysis. Here, we show that the spontaneous diploidization of haESCs happens in metaphase due to mitotic slippage. Diploidization can be suppressed by small-molecule-mediated inhibition of CDK1 and ROCK. Through ROCK inhibition, we can generate haploid somatic cells of all three germ layers from haESCs, including terminally differentiated neurons. Using piggyBac transposon-based insertional mutagenesis, we generated a haploid neural cell library harboring genome-wide mutations for genetic screening. As a proof of concept, we screened for Mn2+-mediated toxicity and identified the Park2 gene. Our findings expand the applications of mouse haploid cell technology to somatic cell types and may also shed light on the mechanisms of ploidy maintenance.

  10. Genetic structure and differentiation of the Italian catria horse.

    Science.gov (United States)

    Bigi, Daniele; Perrotta, Giovanna

    2012-01-01

    Catria is 1 of the 22 native Italian horse breeds that now survive from a larger number. Thirty individuals, representative of the Catria horse, were analyzed for 11 microsatellites and compared with data of 10 breeds reared in Italy. Three different approaches, genetic distances, correspondence analysis, and clustering methods, were considered to study genetic relationships among Catria and the other horse populations. Genetic differentiation among breeds was highly significant (P origin with Maremmano and Italian Heavy Draught. Genetic relationships among Catria and the other breeds are consistent with the breed's documented history. The data and information found here can be utilized in the organization of conservation programmes planned to reduce inbreeding and to minimize loss of genetic variability.

  11. Genetic alterations in poorly differentiated and undifferentiated thyroid carcinomas.

    Science.gov (United States)

    Soares, Paula; Lima, Jorge; Preto, Ana; Castro, Patricia; Vinagre, João; Celestino, Ricardo; Couto, Joana P; Prazeres, Hugo; Eloy, Catarina; Máximo, Valdemar; Sobrinho-Simões, M

    2011-12-01

    Thyroid gland presents a wide spectrum of tumours derived from follicular cells that range from well differentiated, papillary and follicular carcinoma (PTC and FTC, respectively), usually carrying a good prognosis, to the clinically aggressive, poorly differentiated (PDTC) and undifferentiated thyroid carcinoma (UTC).It is usually accepted that PDTC and UTC occur either de novo or progress from a pre-existing well differentiated carcinoma through a multistep process of genetic and epigenetic changes that lead to clonal expansion and neoplastic development. Mutations and epigenetic alterations in PDTC and UTC are far from being totally clarified. Assuming that PDTC and UTC may derive from well differentiated thyroid carcinomas (WDTC), it is expected that some PDTC and UTC would harbour genetic alterations that are typical of PTC and FTC. This is the case for some molecular markers (BRAF and NRAS) that are present in WDTC, PDTC and UTC. Other genes, namely P53, are almost exclusively detected in less differentiated and undifferentiated thyroid tumours, supporting a diagnosis of PDTC or, much more often, UTC. Thyroid-specific rearrangements RET/PTC and PAX8/PPARγ, on the other hand, are rarely found in PDTC and UTC, suggesting that these genetic alterations do not predispose cells to dedifferentiation. In the present review we have summarized the molecular changes associated with the two most aggressive types of thyroid cancer.

  12. Genetic Alterations in Poorly Differentiated and Undifferentiated Thyroid Carcinomas

    Science.gov (United States)

    Soares, Paula; Lima, Jorge; Preto, Ana; Castro, Patricia; Vinagre, João; Celestino, Ricardo; Couto, Joana P; Prazeres, Hugo; Eloy, Catarina; Máximo, Valdemar; Sobrinho-Simões, M

    2011-01-01

    Thyroid gland presents a wide spectrum of tumours derived from follicular cells that range from well differentiated, papillary and follicular carcinoma (PTC and FTC, respectively), usually carrying a good prognosis, to the clinically aggressive, poorly differentiated (PDTC) and undifferentiated thyroid carcinoma (UTC). It is usually accepted that PDTC and UTC occur either de novo or progress from a pre-existing well differentiated carcinoma through a multistep process of genetic and epigenetic changes that lead to clonal expansion and neoplastic development. Mutations and epigenetic alterations in PDTC and UTC are far from being totally clarified. Assuming that PDTC and UTC may derive from well differentiated thyroid carcinomas (WDTC), it is expected that some PDTC and UTC would harbour genetic alterations that are typical of PTC and FTC. This is the case for some molecular markers (BRAF and NRAS) that are present in WDTC, PDTC and UTC. Other genes, namely P53, are almost exclusively detected in less differentiated and undifferentiated thyroid tumours, supporting a diagnosis of PDTC or, much more often, UTC. Thyroid-specific rearrangements RET/PTC and PAX8/PPARγ, on the other hand, are rarely found in PDTC and UTC, suggesting that these genetic alterations do not predispose cells to dedifferentiation. In the present review we have summarized the molecular changes associated with the two most aggressive types of thyroid cancer. PMID:22654560

  13. Worldwide genetic differentiation in the common fouling barnacle, Amphibalanus amphitrite

    KAUST Repository

    Chen, Hsi-Nien

    2014-10-21

    © 2014, © 2014 Taylor & Francis. Amphibalanus amphitrite is a common fouling barnacle distributed globally in tropical and subtropical waters. In the present study, the genetic (mitochondrial cytochrome oxidase subunit I) and morphological differentiation in A. amphitrite from 25 localities around the world were investigated. The results revealed three clades within A. amphitrite with a genetic divergence of ~ 4% among clades, whereas there were no diagnostic morphological differences among clades. Clade 1 is widely distributed in both temperate and tropical waters, whereas Clade 3 is currently restricted to the tropical region. The deep divergence among clades suggests historical isolation within A. amphitrite; thus, the present geographical overlaps are possibly a result of the combined effects of rising sea level and human-mediated dispersals. This study highlights the genetic differentiation that exists in a common, widely distributed fouling organism with great dispersal potential; future antifouling research should take into account the choice of lineages.

  14. Applying theological developments to bioethical issues such as genetic screening.

    Science.gov (United States)

    Mallia, Pierre; ten Have, Henk

    2005-01-01

    Catholic movements within the centre of Roman Catholic doctrine recently have discussed Trinitarian theology as applied to sciences, arts, economics, health and other social areas. We explore the possibilities Trinitarian theology offers to bioethical debate, concentrating particularly on genetic screening and testing. It is important therefore to analyse the philosophical implications of this approach onto the bioethical world, where much disagreement occurs on fundamental issues. It is Catholic basic teaching to recognize and see God's hand in plurality, not merely as a cliche and then doing what we feel is right, but to recognize how to live in a pluralistic world. We recognize, in agreement with these theologians, that in order for a Trinitarian mode of understanding to be used by those doing bioethical debate, there is a need to depart from fundamentalism.

  15. Genome-wide genetic screening with chemically mutagenized haploid embryonic stem cells

    OpenAIRE

    Forment, Josep V.; Herzog, Mareike; Coates, Julia; Konopka, Tomasz; Gapp, Bianca V.; Nijman, Sebastian M.; Adams, David J; Keane, Thomas M.; Jackson, Stephen P.

    2016-01-01

    This is the author accepted manuscript. In model organisms, classical genetic screening via random mutagenesis provides key insights into the molecular bases of genetic interactions, helping to define synthetic lethality, synthetic viability and drug-resistance mechanisms. The limited genetic tractability of diploid mammalian cells, however, precludes this approach. Here, we demonstrate the feasibility of classical genetic screening in mammalian systems by using haploid cells, chemical mut...

  16. Screening for Differentially Expressed Proteins Relevant to the Differential Diagnosis of Sarcoidosis and Tuberculosis.

    Directory of Open Access Journals (Sweden)

    Shan-Shan Du

    Full Text Available In this study, we sought to identify differentially expressed proteins in the serum of patients with sarcoidosis or tuberculosis and to evaluate these proteins as markers for the differential diagnosis of sarcoidosis and sputum-negative tuberculosis.Using protein microarrays, we identified 3 proteins exhibiting differential expression between patients with sarcoidosis and tuberculosis. Elevated expression of these proteins was verified using the enzyme-linked immunosorbent assay (ELISA and was further confirmed by immunohistochemistry. Receiver operating characteristic (ROC curve, logistic regression analysis, parallel, and serial tests were used to evaluate the diagnostic efficacy of the proteins.Intercellular Adhesion Molecule 1(ICAM-1 and leptin were screened for differentially expressed proteins relevant to sarcoidosis and tuberculosis. Using ROC curves, we found that ICAM-1 (cutoff value: 57740 pg/mL had an area under the curve (AUC, sensitivity, and specificity of 0.718, 62.3%, and 79.5% respectively, while leptin (cutoff value: 1193.186 pg/mL had an AUC, sensitivity, and specificity of 0.763, 88.3%, and 65.8%, respectively. Logistic regression analysis revealed that the AUC, sensitivity, and specificity of combined leptin and ICAM-1 were 0.787, 89.6%, and 65.8%, respectively, while those of combined leptin, ICAM-1, and body mass index (BMI were 0.837, 90.9%, and 64.4%, respectively, which had the greatest diagnostic value. Parallel and serial tests indicated that the BMI-leptin parallel with the ICAM-1 serial was the best diagnostic method, achieving a sensitivity and specificity of 86.5% and 73.1%, respectively. Thus, our results identified elevated expression of ICAM-1 and leptin in serum and granulomas of sarcoidosis patients.ICAM-1 and leptin were found to be potential markers for the diagnosis of sarcoidosis and differential diagnosis of sarcoidosis and sputum-negative tuberculosis.

  17. Genetic analysis of population differentiation and adaptation in Leuciscus waleckii.

    Science.gov (United States)

    Chang, Yumei; Tang, Ran; Sun, Xiaowen; Liang, Liqun; Chen, Jinping; Huang, Jinfeng; Dou, Xinjie; Tao, Ran

    2013-12-01

    Demographic events and natural selection both influence animal phenotypic and genetic variation; exploring the effects of demography and selection on population divergence is of great significance in evolutionary biology. To uncover the causes behind the patterns of genetic differentiation and adaptation among six populations of Leuciscus waleckii from Dali Basin (two populations, alkaline vs. freshwater) and Amur Basin (four populations, freshwater rivers vs. alkaline lake), a set of 21 unlinked polymorphic microsatellite markers and two mitochondrial DNA sequences (Cytb and D-loop) were applied to examine whether populations from different environments or habitats have distinct genetic differentiation and whether alkalinity is the major factor that caused population divergence. Bayesian analysis and principal component analysis as well as haplotype network analysis showed that these populations are primarily divided into two groups, which are congruent with geographic separation but not inconsistent with the habitat environment (alkalinity). Using three different approaches, outlier detection indicated that one locus, HLJYL017, may be under directional selection and involved in local adaptation processes. Overall, this study suggested that demographic events and selection of local environmental conditions including of alkalinity are jointly responsible for population divergence. These findings constitute an important step towards the understanding of the genetic basis of differentiation and adaptation, as well as towards the conservation of L. waleckii.

  18. Genetic differentiation among sympatric cuckoo host races: males matter.

    Science.gov (United States)

    Fossøy, Frode; Antonov, Anton; Moksnes, Arne; Røskaft, Eivin; Vikan, Johan R; Møller, Anders P; Shykoff, Jacqui A; Stokke, Bård G

    2011-06-07

    Generalist parasites regularly evolve host-specific races that each specialize on one particular host species. Many host-specific races originate from geographically structured populations where local adaptations to different host species drive the differentiation of distinct races. However, in sympatric populations where several host races coexist, gene flow could potentially disrupt such host-specific adaptations. Here, we analyse genetic differentiation among three sympatrically breeding host races of the brood-parasitic common cuckoo, Cuculus canorus. In this species, host-specific adaptations are assumed to be controlled by females only, possibly via the female-specific W-chromosome, thereby avoiding that gene flow via males disrupts local adaptations. Although males were more likely to have offspring in two different host species (43% versus 7%), they did not have significantly more descendants being raised outside their putative foster species than females (9% versus 2%). We found significant genetic differentiation for both biparentally inherited microsatellite DNA markers and maternally inherited mitochondrial DNA markers. To our knowledge, this is the first study that finds significant genetic differentiation in biparentally inherited markers among cuckoo host-specific races. Our results imply that males also may contribute to the evolution and maintenance of the different races, and hence that the genes responsible for egg phenotype may be found on autosomal chromosomes rather than the female-specific W-chromosome as previously assumed.

  19. Quantifying population genetic differentiation from next-generation sequencing data

    DEFF Research Database (Denmark)

    Fumagalli, Matteo; Garrett Vieira, Filipe Jorge; Korneliussen, Thorfinn Sand

    2013-01-01

    Over the last few years, new high-throughput DNA sequencing technologies have dramatically increased speed and reduced sequencing costs. However, the use of these sequencing technologies is often challenged by errors and biases associated with the bioinformatical methods used for analyzing the data...... method for quantifying population genetic differentiation from next-generation sequencing data. In addition, we present a strategy to investigate population structure via Principal Components Analysis. Through extensive simulations, we compare the new method herein proposed to approaches based...... individuals, suggesting that employing this new method is useful for investigating the genetic relationships of populations sampled at low coverage....

  20. Genetic Counseling and Screening of Consanguineous Couples and Their Offspring: Recommendations of the National Society of Genetic Counselors.

    Science.gov (United States)

    Bennett, Robin L; Motulsky, Arno G; Bittles, Alan; Hudgins, Louanne; Uhrich, Stefanie; Doyle, Debra Lochner; Silvey, Kerry; Scott, C Ronald; Cheng, Edith; McGillivray, Barbara; Steiner, Robert D; Olson, Debra

    2002-04-01

    The objective of this document is to provide recommendations for genetic counseling and screening for consanguineous couples (related as second cousins or closer) and their offspring with the goals of1. providing preconception reproductive options2. improving pregnancy outcome and identifying reproductive choices3. reducing morbidity and mortality in the 1st years of life, and4. respecting psychosocial and multicultural issues.The recommendations are the opinions of a multicenter working group (the Consanguinity Working Group (CWG)) with expertise in genetic counseling, medical genetics, biochemical genetics, genetic epidemiology, pediatrics, perinatology, and public health genetics, which was convened by the National Society of Genetic Counselors (NSGC). The consensus of the CWG and NSGC reviewers is that beyond a thorough medical family history with follow-up of significant findings, no additional preconception screening is recommended for consanguineous couples. Consanguineous couples should be offered similar genetic screening as suggested for any couple of their ethnic group. During pregnancy, consanguineous couples should be offered maternal-fetal serum marker screening and high-resolution fetal ultrasonography. Newborns should be screened for impaired hearing and detection of treatable inborn errors of metabolism. These recommendations should not be construed as dictating an exclusive course of management, nor does use of such recommendations guarantee a particular outcome. The professional judgment of a health care provider, familiar with the facts and circumstances of a specific case, will always supersede these recommendations.

  1. Quantifying population genetic differentiation from next-generation sequencing data

    DEFF Research Database (Denmark)

    Fumagalli, Matteo; Vieira, Filipe G.; Korneliussen, Thorfinn Sand;

    2013-01-01

    Over the last few years, new high-throughput DNA sequencing technologies have dramatically increased speed and reduced sequencing costs. However, the use of these sequencing technologies is often challenged by errors and biases associated with the bioinformatical methods used for analyzing the da...... individuals, suggesting that employing this new method is useful for investigating the genetic relationships of populations sampled at low coverage....... method for quantifying population genetic differentiation from next-generation sequencing data. In addition, we present a strategy to investigate population structure via Principal Components Analysis. Through extensive simulations, we compare the new method herein proposed to approaches based...... on genotype calling and demonstrate a marked improvement in estimation accuracy for a wide range of conditions. We apply the method to a large-scale genomic data set of domesticated and wild silkworms sequenced at low coverage. We find that we can infer the fine-scale genetic structure of the sampled...

  2. Does local adaptation to resources explain genetic differentiation among Daphnia populations?

    Science.gov (United States)

    Allen, Michael R; Thum, Ryan A; Cáceres, Carla E

    2010-08-01

    Substantial genetic differentiation is frequently observed among populations of cyclically parthenogenetic zooplankton despite their high dispersal capabilities and potential for gene flow. Local adaptation has been invoked to explain population genetic differentiation despite high dispersal, but several neutral models that account for basic life history features also predict high genetic differentiation. Here, we study genetic differentiation among four populations of Daphnia pulex in east central Illinois. As with other studies of Daphnia, we demonstrate substantial population genetic differentiation despite close geographic proximity (explain genetic differentiation among these Daphnia populations and that other factors related to extinction/colonization dynamics, a long approach to equilibrium F(ST) or substantial genetic drift due to a low number of individuals hatching from the egg bank each season may explain genetic differentiation.

  3. 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

  4. Genetic differential susceptibility to the effects of parenting.

    Science.gov (United States)

    Belsky, Jay; van IJzendoorn, Marinus H

    2017-06-01

    Intervention efforts aimed at remediating or preventing problems in children typically prove only moderately effective due to substantial heterogeneity in their efficacy. It thus becomes important to account for such variation in intervention efficacy. Here we summarize illustrative evidence that, due to their genetic make-up, some children benefit more from interventions targeting parenting than do others. Whereas some work documents the role of single, 'candidate' genes, other work reveals the utility of compositing multiple genes and genetic pathways. Collectively, this research extends prior observational work indicating that children most negatively affected by adverse experiences also benefit the most from supportive ones, while underscoring the need for research illuminating underlying neurobiological mechanisms that instantiate differential susceptibility to environmental influences. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Genetic biomarkers for brain hemisphere differentiation in Parkinson's Disease

    Science.gov (United States)

    Hourani, Mou'ath; Mendes, Alexandre; Berretta, Regina; Moscato, Pablo

    2007-11-01

    This work presents a study on the genetic profile of the left and right hemispheres of the brain of a mouse model of Parkinson's disease (PD). The goal is to characterize, in a genetic basis, PD as a disease that affects these two brain regions in different ways. Using the same whole-genome microarray expression data introduced by Brown et al. (2002) [1], we could find significant differences in the expression of some key genes, well-known to be involved in the mechanisms of dopamine production control and PD. The problem of selecting such genes was modeled as the MIN (α,β)—FEATURE SET problem [2]; a similar approach to that employed previously to find biomarkers for different types of cancer using gene expression microarray data [3]. The Feature Selection method produced a series of genetic signatures for PD, with distinct expression profiles in the Parkinson's model and control mice experiments. In addition, a close examination of the genes composing those signatures shows that many of them belong to genetic pathways or have ontology annotations considered to be involved in the onset and development of PD. Such elements could provide new clues on which mechanisms are implicated in hemisphere differentiation in PD.

  6. Stakeholder perspectives on the implementation of genetic carrier screening in a changing landscape.

    Science.gov (United States)

    Holtkamp, Kim C A; Vos, Evelien M; Rigter, Tessel; Lakeman, Phillis; Henneman, Lidewij; Cornel, Martina C

    2017-02-16

    In most countries, genetic carrier screening is neither offered, nor embedded in mainstream healthcare. Technological developments have triggered a two-fold transition in carrier screening: the expansion from screening one single disorder to many disorders simultaneously, and offering screening universally, regardless of ancestry. This study aims to identify general and population-specific barriers and needs reflected by stakeholders regarding the implementation of carrier screening in a changing landscape. Seventeen semi-structured interviews were conducted with Dutch key stakeholders working in the practical and scientific field of carrier screening. The constellation approach was used to categorise barriers and needs into three levels: culture, structure and practice. Barriers on a cultural level include: undecidedness about the desirability of carrier screening, and a lack of priority of screening in mainstream healthcare. On a structural level barriers included: need for organisational structures in healthcare for embedding carrier screening, need for guidelines, financial structures, practical tools for overcoming challenges during counselling, and a need for training and education of both professionals and the public. A lack of demand for screening by the public, and a need for a division of responsibilities were barriers on a practical level. The absence of a collective sense of urgency for genetic carrier screening, a lack of organisational structures, and uncertainty or even disagreement about the responsibilities seem to be important barriers in the implementation of carrier screening. Stakeholders therefore suggest that change agents should be formally acknowledged to strategically plan broadening of current initiatives and attune different stakeholders.

  7. A chemical genetics approach for specific differentiation of stem cells to somatic cells: a new promising therapeutical approach.

    Science.gov (United States)

    Sachinidis, Agapios; Sotiriadou, Isaia; Seelig, Bianca; Berkessel, Albrecht; Hescheler, Jürgen

    2008-01-01

    Cell replacement therapy of severe degenerative diseases such as diabetes, myocardial infarction and Parkinson's disease through transplantation of somatic cells generated from embryonic stem (ES) cells is currently receiving considerable attention for the therapeutic applications. ES cells harvested from the inner cell mass (ICM) of the early embryo, can proliferate indefinitely in vitro while retaining the ability to differentiate into all somatic cells thereby providing an unlimited renewable source of somatic cells. In this context, identifying soluble factors, in particular chemically synthesized small molecules, and signal cascades involved in specific differentiation processes toward a defined tissue specific cell type are crucial for optimizing the generation of somatic cells in vitro for therapeutic approaches. However, experimental models are required allowing rapid and "easy-to-handle" parallel screening of chemical libraries to achieve this goal. Recently, the forward chemical genetic screening strategy has been postulated to screen small molecules in cellular systems for a specific desired phenotypic effect. The current review is focused on the progress of ES cell research in the context of the chemical genetics to identify small molecules promoting specific differentiation of ES cells to desired cell phenotype. Chemical genetics in the context of the cell ES-based cell replacement therapy remains a challenge for the near future for several scientific fields including chemistry, molecular biology, medicinal physics and robotic technologies.

  8. Genetic synthetic lethality screen at the single gene level in cultured human cells

    OpenAIRE

    Simons, Arnold H.; Dafni, Naomi; Dotan, Iris; Oron, Yoram; Canaani, Dan

    2001-01-01

    Recently, we demonstrated the feasibility of a chemical synthetic lethality screen in cultured human cells. We now demonstrate the principles for a genetic synthetic lethality screen. The technology employs both an immortalized human cell line deficient in the gene of interest, which is complemented by an episomal survival plasmid expressing the wild-type cDNA for the gene of interest, and the use of a novel GFP-based double-label fluorescence system. Dominant negative genetic suppressor elem...

  9. Systematic genetic screening in a prospective group of Danish patients with pheochromocytoma

    DEFF Research Database (Denmark)

    Hansen, Morten Steen Svarer; Jacobsen, Niels; Frederiksen, Anja Lisbeth

    2017-01-01

    Recent guidelines recommend consideration of genetic screening in all newly diagnosed patients with pheochromocytoma. Patients diagnosed with pheochromocytoma in the Region of Southern Denmark during 2006-2013 without previously recognized monogenetic etiology were offered genetic screening...... for mutations in the VHL, RET, SDHB, SDHC, and SDHD genes. A total of 41 patients were included, and genetic data were available in 35. In four of the 35 patients, a pathogenic variant was identified prior to the diagnosis of pheochromocytoma (von Hippel-Lindau disease, n=2; neurofibromatosis type 1, n=2......). The patients carrying a genetic mutation were all younger than 45 years at time of diagnosis of pheochromocytoma, two patients presented with bilateral tumors, and one patient had a positive family history of pheochromocytoma. Genetic screening of the remaining 31 patients did not identify any mutations...

  10. Chemical genetics and drug screening in Drosophila cancer models

    Institute of Scientific and Technical Information of China (English)

    Mara Gladstone; Tin Tin Su

    2011-01-01

    Drug candidates often fail in preclinical and clinical testing because of reasons of efficacy and/or safety.It would be time- and cost-efficient to have screening models that reduce the rate of such false positive candidates that appear promising at first but fail later.In this regard,it would be particularly useful to have a rapid and inexpensive whole animal model that can pre-select hits from high-throughput screens but before testing in costly rodent assays.Drosophila melanogaster has emerged as a potential whole animal model for drug screening.Of particular interest have been drugs that must act in the context of multi-cellularity such as those for neurological disorders and cancer.A recent review provides a comprehensive summary of drug screening in Drosophila,but with an emphasis on neurodegenerative disorders.Here,we review Drosophila screens in the literature aimed at cancer therapeutics.

  11. Pherotypes are driving genetic differentiation within Streptococcus pneumoniae

    Directory of Open Access Journals (Sweden)

    Ramirez Mario

    2009-09-01

    Full Text Available Abstract Background The boundaries of bacterial species and the mechanisms underlying bacterial speciation are matters of intense debate. Theoretical studies have shown that recombination acts as a strong cohesive force preventing divergence in bacterial populations. Streptococcus pneumoniae populations have the telltale signs of high recombination with competence implicated as the major driving force behind gene exchange. Competence in S. pneumoniae is triggered by a quorum-sensing mechanism controlled by the competence-stimulating peptide pheromone. Results We studied the distribution of the two major pherotypes in the pneumococcal population and their association with serotype, antimicrobial resistance and genetic lineage. Using multilocus sequence data we evaluated pherotype influence on the dynamics of horizontal gene transfer. We show that pherotype is a clonal property of pneumococci. Standard population genetic analysis and multilocus infinite allele model simulations support the hypothesis that two genetically differentiated populations are defined by the major pherotypes. Conclusion Severe limitations to gene flow can therefore occur in bacterial species in the absence of geographical barriers and within highly recombinogenic populations. This departure from panmixia can have important consequences for our understanding of the response of pneumococci to human imposed selective pressures such as vaccination and antibiotic use.

  12. Genetic Differentiation of Japanese Sardinella (Sardinella zunasi)Populations in the Northwest Pacific Revealed by ISSR Analysis

    Institute of Scientific and Technical Information of China (English)

    YING Yiping; GAO Tianxiang; MIAO Zhenqing

    2011-01-01

    Knowledge of population genetic structure plays an important role in fisheries management.In this research,Inter-Simple-Sequence-Repeat (ISSR) markers were employed to evaluate the genetic structure of Japanese sardinella (Sardinella zunasi) populations in the Northwest Pacific.Eighty seven individuals from 5 locations were screened using 4 highly polymorphic primers.A total of 173 polymorphic loci were detected out of 191 loci amplified.Small but significant genetic differentiation was detected between the Chinese and Japanese populations by both AMOVA and pairwise Fsr analyses,which was further supported by cluster analysis.We consider that climate change during glaciations should be responsible for the genetic differentiation.Isolation by geographic distance among populations was observed,indicating that the distance might also lead to the genetic differentiation.However,no genetic structure was found within the populations off both the Chinese and Japanese coasts,indicating a high-level along-coast gene flow,which might result from ocean current transport and common ground for over-wintering.

  13. Low genetic diversity and high genetic differentiation in the critically endangered Omphalogramma souliei (Primulaceae):implications for its conservation

    Institute of Scientific and Technical Information of China (English)

    Yuan HUANG; Chang-Qin ZHANG; De-Zhu LI

    2009-01-01

    Omphalogramma souliei Franch. Is an endangered perennial herb only distributed in alpine areas of SW China. ISSR markers were applied to determine the genetic variation and genetic structure of 60 individuals of three populations of O. Souliei in NW Yunnan, China. The genetic diversity at the species level is low with P= 42.5% (percentage of polymorphic bands) and Hsp=0.1762 (total genetic diversity). However, a high level of genetic differentiation among populations was detected based on different measures (Nei's genetic diversity analysis: Gst=0.6038; AMOVA analysis: Fst=0.6797). Low level of genetic diversity within populations and significant genetic differentiation among populations might be due to the mixed mating system in which xenog-amy predominated and autogamy played an assistant role in O. Souliei. The genetic drift due to small population size and limited current gene flow also resulted in significant genetic differentiation. The assessment of genetic variation and differentiation of the endangered species provides important information for conservation on a genetic basis. Conservation strategies for this rare endemic species are proposed.

  14. Coeliac disease and autoimmune disease-genetic overlap and screening

    NARCIS (Netherlands)

    Lundin, Knut E. A.; Wijmenga, Cisca

    Coeliac disease is a treatable, gluten-induced disease that often occurs concurrently with other autoimmune diseases. In genetic studies since 2007, a partial genetic overlap between these diseases has been revealed and further insights into the pathophysiology of coeliac disease and autoimmunity

  15. A recessive genetic screen for components of the RNA interference pathway in mouse embryonic stem cells.

    Science.gov (United States)

    Trombly, Melanie I; Wang, Xiaozhong

    2010-01-01

    Several key components of the RNA interference (RNAi) pathway were identified in genetic screens performed in nonmammalian model organisms. To identify components of the mammalian RNAi pathway, we developed a recessive genetic screen in mouse embryonic stem (ES) cells. Recessive genetic screens are feasible in ES cells that are Bloom-syndrome protein (Blm-) deficient. Therefore, we constructed a reporter cell line in Blm-deficient ES cells to isolate RNAi mutants through a simple drug-selection scheme. This chapter describes how we used retroviral gene traps to mutagenize the reporter cell line and select for RNAi mutants. Putative RNAi mutants were confirmed using a separate functional assay. The location of the gene trap was then identified using molecular techniques such as Splinkerette PCR. Our screening strategy successfully isolated several mutant clones of Argonaute2, a vital component of the RNAi pathway.

  16. Microsatellite variability reveals high genetic diversity and low genetic differentiation in a critical giant panda population

    Institute of Scientific and Technical Information of China (English)

    Jiandong YANG; Zhihe ZHANG; Fujun SHEN; Xuyu YANG; Liang ZHANG; Limin CHEN; Wenping ZHANG; Qing ZHU; Rong HOU

    2011-01-01

    Understanding present patterns of genetic diversity is critical in order to design effective conservation and management strategies for endangered species.Tangjiahe Nature Reserve (NR) is one of the most important national reserves for giant pandas Ailuropoda melanoleuca in China.Previous studies have shown that giant pandas in Tangjiahe NR may be threatened by population decline and fragmentation.Here we used 10 microsatellite DNA markers to assess the genetic variability in the Tangjiahe population.The results indicate a low level of genetic differentiation between the Hongshihe and Motianling subpopulations in the reserve.Assignment tests using the Bayesian clustering method in STRUCTURE identified one genetic cluster from 42 individuals of the two subpopulations.All individuals from the same subpopulation were assigned to one cluster.This indicates high gene flow between subpopulations.F statistic analyses revealed a low Fls-value of 0.024 in the total population and implies a randomly mating population in Tangjiahe NR.Additionally,our data show a high level of genetic diversity for the Tangjiahe population.Mean allele number (A),Allelic richness (AR) and mean expected heterozygosity (HE) for the Tangiiahe population was 5.9,5.173 and 0.703,respectively.This wild giant panda population can be restored through concerted effort [Current Zoology 57 (6):717-724,2011].

  17. Microsatellite variability reveals high genetic diversity and low genetic differentiation in a critical giant panda population

    Directory of Open Access Journals (Sweden)

    Jiandong YANG, Zhihe ZHANG, Fujun SHEN, Xuyu YANG, Liang ZHANG, Limin CHEN, Wenping ZHANG, Qing ZHU, Rong HOU

    2011-12-01

    Full Text Available Understanding present patterns of genetic diversity is critical in order to design effective conservation and management strategies for endangered species. Tangjiahe Nature Reserve (NR is one of the most important national reserves for giant pandas Ailuropoda melanoleuca in China. Previous studies have shown that giant pandas in Tangjiahe NR may be threatened by population decline and fragmentation. Here we used 10 microsatellite DNA markers to assess the genetic variability in the Tangjiahe population. The results indicate a low level of genetic differentiation between the Hongshihe and Motianling subpopulations in the reserve. Assignment tests using the Bayesian clustering method in STRUCTURE identified one genetic cluster from 42 individuals of the two subpopulations. All individuals from the same subpopulation were assigned to one cluster. This indicates high gene flow between subpopulations. F statistic analyses revealed a low FIS-value of 0.024 in the total population and implies a randomly mating population in Tangjiahe NR. Additionally, our data show a high level of genetic diversity for the Tangjiahe population. Mean allele number (A, Allelic richness (AR and mean expected heterozygosity (HE for the Tangjiahe population was 5.9, 5.173 and 0.703, respectively. This wild giant panda population can be restored through concerted effort [Current Zoology 57 (6: 717–724, 2011].

  18. Medical and lay attitudes towards genetic screening and testing in Finland

    DEFF Research Database (Denmark)

    Toiviainen, Hanna; Jallinoja, Piia; Aro, Arja R

    2003-01-01

    The purpose of this study was to compare physicians', midwives' and lay people's attitudes towards genetic screening and testing to find out whether medical education and experience influence attitudes of genetic screening and testing. The study was based on comparison of answers to joint questions...... referred to as midwives in the following; n=800, response rate 79%), and lay people (n=2000, response rate 62%). Midwives were more worried about the consequences of genetic testing and stressed the autonomy of the customer more strongly than lay people did. Furthermore, professionals considered that lay...

  19. Finding Approximate Analytic Solutions to Differential Equations by Seed Selection Genetic Programming

    Institute of Scientific and Technical Information of China (English)

    侯进军

    2007-01-01

    @@ 1 Seed Selection Genetic Programming In Genetic Programming, each tree in population shows an algebraic or surmounting expression, and each algebraic or surmounting expression shows an approximate analytic solution to differential equations.

  20. Differential screening identifies transcripts with depot-dependent expression in white adipose tissues

    Directory of Open Access Journals (Sweden)

    Zhou Shengli

    2008-08-01

    Full Text Available Abstract Background The co-morbidities of obesity are tied to location of excess fat in the intra-abdominal as compared to subcutaneous white adipose tissue (WAT depot. Genes distinctly expressed in WAT depots may impart depot-dependent physiological functions. To identify such genes, we prepared subtractive cDNA libraries from murine subcutaneous (SC or intra-abdominal epididymal (EP white adipocytes. Results Differential screening and qPCR validation identified 7 transcripts with 2.5-fold or greater enrichment in EP vs. SC adipocytes. Boc, a component of the hedgehog signaling pathway demonstrated highest enrichment (~12-fold in EP adipocytes. We also identified a dramatic enrichment in SC adipocytes vs. EP adipocytes and in SC WAT vs. EP WAT for transcript(s for the major urinary proteins (Mups, small secreted proteins with pheromone functions that are members of the lipocalin family. Expression of Boc and Mup transcript was further assessed in murine tissues, adipogenesis models, and obesity. qPCR analysis reveals that EP WAT is a major site of expression of Boc transcript. Furthermore, Boc transcript expression decreased in obese EP WAT with a concomitant upregulation of Boc transcript in the obese SC WAT depot. Assessment of the Boc binding partner Cdon in adipose tissue and cell fractions thereof, revealed transcript expression similar to Boc; suggestive of a role for the Boc-Cdon axis in WAT depot function. Mup transcripts were predominantly expressed in liver and in the SC and RP WAT depots and increased several thousand-fold during differentiation of primary murine preadipocytes to adipocytes. Mup transcripts were also markedly reduced in SC WAT and liver of ob/ob genetically obese mice compared to wild type. Conclusion Further assessment of WAT depot-enriched transcripts may uncover distinctions in WAT depot gene expression that illuminate the physiological impact of regional adiposity.

  1. Applying theological developments to bioethical issues such as genetic screening.

    NARCIS (Netherlands)

    Mallia, P.; Have, H.A.M.J. ten

    2005-01-01

    Catholic movements within the centre of Roman Catholic doctrine recently have discussed Trinitarian theology as applied to sciences, arts, economics, health and other social areas. We explore the possibilities Trinitarian theology offers to bioethical debate, concentrating particularly on genetic sc

  2. Screening for oral precancer with noninvasive genetic cytology

    NARCIS (Netherlands)

    Bremmer, J.F.; Graveland, A.P.; Brink, A.; Braakhuis, B.J.M.; Kuik, D.J.; Leemans, C.R.; Bloemena, E.; van der Waal, I.; Brakenhoff, R.H.

    2009-01-01

    Oral squamous cell carcinomas develop in precancerous fields consisting of genetically altered mucosal epithelial cells. These precancerous fields may appear as clinically visible lesions, in particular, oral leukoplakia, but the large majority remains clinically undetectable. The aim of this study

  3. Pathways and barriers to genetic testing and screening: Molecular genetics meets the high-risk family. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Duster, T.

    1998-11-01

    The proliferation of genetic screening and testing is requiring increasing numbers of Americans to integrate genetic knowledge and interventions into their family life and personal experience. This study examines the social processes that occur as families at risk for two of the most common autosomal recessive diseases, sickle cell disease (SC) and cystic fibrosis (CF), encounter genetic testing. Each of these diseases is found primarily in a different ethnic/racial group (CF in Americans of North European descent and SC in Americans of West African descent). This has permitted them to have a certain additional lens on the role of culture in integrating genetic testing into family life and reproductive planning. A third type of genetic disorder, the thalassemias was added to the sample in order to extent the comparative frame and to include other ethnic and racial groups.

  4. Genetic structure in the coral, Montastraea cavernosa: assessing genetic differentiation among and within Mesophotic reefs.

    Directory of Open Access Journals (Sweden)

    Daniel A Brazeau

    Full Text Available Mesophotic coral reefs (30-150 m have recently received increased attention as a potential source of larvae (e.g., the refugia hypothesis to repopulate a select subset of the shallow water (<30 m coral fauna. To test the refugia hypothesis we used highly polymorphic Amplified Fragment Length Polymorphism (AFLP markers as a means to assess small-scale genetic heterogeneity between geographic locations and across depth clines in the Caribbean coral, Montastraea cavernosa. Zooxanthellae-free DNA extracts of coral samples (N = 105 were analyzed from four depths, shallow (3-10 m, medium (15-25 m, deep (30-50 m and very deep (60-90 m from Little Cayman Island (LCI, Lee Stocking Island (LSI, Bahamas and San Salvador (SS, Bahamas which range in distance from 170 to 1,600 km apart. Using AMOVA analysis there were significant differences in ΦST values in pair wise comparisons between LCI and LSI. Among depths at LCI, there was significant genetic differentiation between shallow and medium versus deep and very deep depths in contrast there were no significant differences in ΦST values among depths at LSI. The assignment program AFLPOP, however, correctly assigned 95.7% of the LCI and LSI samples to the depths from which they were collected, differentiating among populations as little as 10 to 20 m in depth from one another. Discriminant function analysis of the data showed significant differentiation among samples when categorized by collection site as well as collection depth. FST outlier analyses identified 2 loci under positive selection and 3 under balancing selection at LCI. At LSI 2 loci were identified, both showing balancing selection. This data shows that adult populations of M. cavernosa separated by depths of tens of meters exhibits significant genetic structure, indicative of low population connectivity among and within sites and are not supplying successful recruits to adjacent coral reefs less than 30 m in depth.

  5. Genetic identity and differential gene expression between Trichomonas vaginalis and Trichomonas tenax.

    Science.gov (United States)

    Kucknoor, Ashwini S; Mundodi, Vasanthakrishna; Alderete, Jf

    2009-03-18

    Trichomonas vaginalis is a human urogenital pathogen responsible for trichomonosis, the number-one, non-viral sexually transmitted disease (STD) worldwide, while T. tenax is a commensal of the human oral cavity, found particularly in patients with poor oral hygiene and advanced periodontal disease. The extent of genetic identity between T. vaginalis and its oral commensal counterpart is unknown. Genes that were differentially expressed in T. vaginalis were identified by screening three independent subtraction cDNA libraries enriched for T. vaginalis genes. The same thirty randomly selected cDNA clones encoding for proteins with specific functions associated with colonization were identified from each of the subtraction cDNA libraries. In addition, a T. vaginalis cDNA expression library was screened with patient sera that was first pre-adsorbed with an extract of T. tenax antigens, and seven specific cDNA clones were identified from this cDNA library. Interestingly, some of the clones identified by the subtraction cDNA screening were also obtained from the cDNA expression library with the pre-adsorbed sera. Moreover and noteworthy, clones identified by both the procedures were found to be up-regulated in expression in T. vaginalis upon contact with vaginal epithelial cells, suggesting a role for these gene products in host colonization. Semi-quantitative RT-PCR analysis of select clones showed that the genes were not unique to T. vaginalis and that these genes were also present in T. tenax, albeit at very low levels of expression. These results suggest that T. vaginalis and T. tenax have remarkable genetic identity and that T. vaginalis has higher levels of gene expression when compared to that of T. tenax. The data may suggest that T. tenax could be a variant of T. vaginalis.

  6. Genetic identity and differential gene expression between Trichomonas vaginalis and Trichomonas tenax

    Directory of Open Access Journals (Sweden)

    Mundodi Vasanthakrishna

    2009-03-01

    Full Text Available Abstract Background Trichomonas vaginalis is a human urogenital pathogen responsible for trichomonosis, the number-one, non-viral sexually transmitted disease (STD worldwide, while T. tenax is a commensal of the human oral cavity, found particularly in patients with poor oral hygiene and advanced periodontal disease. The extent of genetic identity between T. vaginalis and its oral commensal counterpart is unknown. Results Genes that were differentially expressed in T. vaginalis were identified by screening three independent subtraction cDNA libraries enriched for T. vaginalis genes. The same thirty randomly selected cDNA clones encoding for proteins with specific functions associated with colonization were identified from each of the subtraction cDNA libraries. In addition, a T. vaginalis cDNA expression library was screened with patient sera that was first pre-adsorbed with an extract of T. tenax antigens, and seven specific cDNA clones were identified from this cDNA library. Interestingly, some of the clones identified by the subtraction cDNA screening were also obtained from the cDNA expression library with the pre-adsorbed sera. Moreover and noteworthy, clones identified by both the procedures were found to be up-regulated in expression in T. vaginalis upon contact with vaginal epithelial cells, suggesting a role for these gene products in host colonization. Semi-quantitative RT-PCR analysis of select clones showed that the genes were not unique to T. vaginalis and that these genes were also present in T. tenax, albeit at very low levels of expression. Conclusion These results suggest that T. vaginalis and T. tenax have remarkable genetic identity and that T. vaginalis has higher levels of gene expression when compared to that of T. tenax. The data may suggest that T. tenax could be a variant of T. vaginalis.

  7. Chemical screen identifies FDA-approved drugs and target pathways that induce precocious pancreatic endocrine differentiation.

    Science.gov (United States)

    Rovira, Meritxell; Huang, Wei; Yusuff, Shamila; Shim, Joong Sup; Ferrante, Anthony A; Liu, Jun O; Parsons, Michael J

    2011-11-29

    Pancreatic β-cells are an essential source of insulin and their destruction because of autoimmunity causes type I diabetes. We conducted a chemical screen to identify compounds that would induce the differentiation of insulin-producing β-cells in vivo. To do this screen, we brought together the use of transgenic zebrafish as a model of β-cell differentiation, a unique multiwell plate that allows easy visualization of lateral views of swimming larval fish and a library of clinical drugs. We identified six hits that can induce precocious differentiation of secondary islets in larval zebrafish. Three of these six hits were known drugs with a considerable background of published data on mechanism of action. Using pharmacological approaches, we have identified and characterized two unique pathways in β-cell differentiation in the zebrafish, including down-regulation of GTP production and retinoic acid biosynthesis.

  8. Screening for Outliers in Multiple Trait Genetic Evaluarion

    DEFF Research Database (Denmark)

    Madsen, Per; Pösa, Jukka; Pedersen, Jørn

    2012-01-01

    genetic evaluation in dairy cattle. Application of such is simple to implement and increased the accuracy of predicted breeding values for animals that has one or more records edited. Potential biases in evaluations for contemporary animals were also reduced. Optimum editing rules can be determined using......Use of multivariate models in genetic evaluation requires a multivariate method for detecting erroneous outliers that cannot be detected using univariate methods. A simple rule for detecting outliers based on an approximated Mahanalobis distance was applied to Jersey data from the routine Nordic...

  9. No beneficial effect of preimplantation genetic screening in women of advanced maternal age with a high risk for embryonic aneuploidy

    NARCIS (Netherlands)

    Twisk, Moniek; Mastenbroek, Sebastiaan; Hoek, Annemieke; Heineman, Maas-Jan; van der Veen, Fulco; Bossuyt, Patrick M.; Repping, Sjoerd; Korevaar, Johanna C.

    2008-01-01

    Human preimplantation embryos generated through in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) treatments show a variable rate of numerical chromosome abnormalities or aneuploidies. Preimplantation genetic screening (PGS) has been designed to screen for aneuploidies in high

  10. No beneficial effect of preimplantation genetic screening in women of advanced maternal age with a high risk for embryonic aneuploidy

    NARCIS (Netherlands)

    Twisk, Moniek; Mastenbroek, Sebastiaan; Hoek, Annemieke; Heineman, Maas-Jan; van der Veen, Fulco; Bossuyt, Patrick M.; Repping, Sjoerd; Korevaar, Johanna C.

    2008-01-01

    Human preimplantation embryos generated through in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) treatments show a variable rate of numerical chromosome abnormalities or aneuploidies. Preimplantation genetic screening (PGS) has been designed to screen for aneuploidies in high

  11. Screening of differentially expressed genes in pathological scar tissues using expression microarray.

    Science.gov (United States)

    Huang, L P; Mao, Z; Zhang, L; Liu, X X; Huang, C; Jia, Z S

    2015-09-09

    Pathological scar tissues and normal skin tissues were differentiated by screening for differentially expressed genes in pathologic scar tissues via gene expression microarray. The differentially expressed gene data was analyzed by gene ontology and pathway analyses. There were 5001 up- or down-regulated genes in 2-fold differentially expressed genes, 956 up- or down-regulated genes in 5-fold differentially expressed genes, and 114 up- or down-regulated genes in 20-fold differentially expressed genes. Therefore, significant differences were observed in the gene expression in pathological scar tissues and normal foreskin tissues. The development of pathological scar tissues has been correlated to changes in multiple genes and pathways, which are believed to form a dynamic network connection.

  12. A genetic screen for components of the mammalian RNA interference pathway in Bloom-deficient mouse embryonic stem cells

    OpenAIRE

    2009-01-01

    Genetic screens performed in model organisms have helped identify key components of the RNA interference (RNAi) pathway. Recessive genetic screens have recently become feasible through the use of mouse embryonic stem (ES) cells that are Bloom's syndrome protein (Blm) deficient. Here, we developed and performed a recessive genetic screen to identify components of the mammalian RNAi pathway in Blm-deficient ES cells. Genome-wide mutagenesis using a retroviral gene trap strategy resulted in the ...

  13. Screening of spontaneous castor bean accesses for genetic ...

    African Journals Online (AJOL)

    Tuoyo Aghomotsegin

    2016-10-05

    Oct 5, 2016 ... 1Department of Agricultural Engineering, Federal University of Campina Grande ... sizing the consequences of human actions in the ... significant increase in the literature of the use of ... genetic improvement programs of this culture in Brazil, ... subsequent selection according to color pattern, weight, health,.

  14. Moderating effects of autism on parent views of genetic screening for aggression.

    Science.gov (United States)

    May, Michael E; Brandt, Rachel C; Bohannan, Joseph K

    2012-10-01

    Advances in gene-environment interaction research have revealed genes that are associated with aggression. However, little is known about parent perceptions of genetic screening for behavioral symptoms like aggression as opposed to diagnosing disabilities. These perceptions may influence future research endeavors involving genetic linkage studies to behavior, including proactive approaches for parents to avoid events leading to aggression. The purpose of this study was to solicit the perspectives of parents who have children with autism about screening for genes associated with aggression, compared to responses from those who have children without disabilities and those planning to have children. Parents of children with autism were more likely to support screening and the use of the results to seek treatment if necessary. Results are discussed in the context of surveillance screening and systematic early intervention for behavioral symptoms related to autism. The results may provide insight for clincians, researchers, policymakers, and advocacy groups related to diagnosing and treating aggression in people with autism.

  15. The conditional nature of genetic interactions: the consequences of wild-type backgrounds on mutational interactions in a genome-wide modifier screen.

    Directory of Open Access Journals (Sweden)

    Sudarshan Chari

    Full Text Available The phenotypic outcome of a mutation cannot be simply mapped onto the underlying DNA variant. Instead, the phenotype is a function of the allele, the genetic background in which it occurs and the environment where the mutational effects are expressed. While the influence of genetic background on the expressivity of individual mutations is recognized, its consequences on the interactions between genes, or the genetic network they form, is largely unknown. The description of genetic networks is essential for much of biology; yet if, and how, the topologies of such networks are influenced by background is unknown. Furthermore, a comprehensive examination of the background dependent nature of genetic interactions may lead to identification of novel modifiers of biological processes. Previous work in Drosophila melanogaster demonstrated that wild-type genetic background influences the effects of an allele of scalloped (sd, with respect to both its principal consequence on wing development and its interactions with a mutation in optomotor blind. In this study we address whether the background dependence of mutational interactions is a general property of genetic systems by performing a genome wide dominant modifier screen of the sd(E3 allele in two wild-type genetic backgrounds using molecularly defined deletions. We demonstrate that ~74% of all modifiers of the sd(E3 phenotype are background-dependent due in part to differential sensitivity to genetic perturbation. These background dependent interactions include some with qualitative differences in the phenotypic outcome, as well as instances of sign epistasis. This suggests that genetic interactions are often contingent on genetic background, with flexibility in genetic networks due to segregating variation in populations. Such background dependent effects can substantially alter conclusions about how genes influence biological processes, the potential for genetic screens in alternative wild

  16. Bias in estimating accuracy of a binary screening test with differential disease verification.

    Science.gov (United States)

    Alonzo, Todd A; Brinton, John T; Ringham, Brandy M; Glueck, Deborah H

    2011-07-10

    Sensitivity, specificity, positive and negative predictive value are typically used to quantify the accuracy of a binary screening test. In some studies, it may not be ethical or feasible to obtain definitive disease ascertainment for all subjects using a gold standard test. When a gold standard test cannot be used, an imperfect reference test that is less than 100 per cent sensitive and specific may be used instead. In breast cancer screening, for example, follow-up for cancer diagnosis is used as an imperfect reference test for women where it is not possible to obtain gold standard results. This incomplete ascertainment of true disease, or differential disease verification, can result in biased estimates of accuracy. In this paper, we derive the apparent accuracy values for studies subject to differential verification. We determine how the bias is affected by the accuracy of the imperfect reference test, the percent who receive the imperfect reference standard test not receiving the gold standard, the prevalence of the disease, and the correlation between the results for the screening test and the imperfect reference test. It is shown that designs with differential disease verification can yield biased estimates of accuracy. Estimates of sensitivity in cancer screening trials may be substantially biased. However, careful design decisions, including selection of the imperfect reference test, can help to minimize bias. A hypothetical breast cancer screening study is used to illustrate the problem.

  17. The future role of genetic screening to detect newborns at risk of childhood-onset hearing loss

    Science.gov (United States)

    2013-01-01

    Objective: To explore the future potential of genetic screening to detect newborns at risk of childhood-onset hearing loss. Design: An expert led discussion of current and future developments in genetic technology and the knowledge base of genetic hearing loss to determine the viability of genetic screening and the implications for screening policy. Results and Discussion: Despite increasing pressure to adopt genetic technologies, a major barrier for genetic screening in hearing loss is the uncertain clinical significance of the identified mutations and their interactions. Only when a reliable estimate of the future risk of hearing loss can be made at a reasonable cost, will genetic screening become viable. Given the speed of technological advancement this may be within the next 10 years. Decision-makers should start to consider how genetic screening could augment current screening programmes as well as the associated data processing and storage requirements. Conclusion: In the interim, we suggest that decision makers consider the benefits of (1) genetically testing all newborns and children with hearing loss, to determine aetiology and to increase knowledge of the genetic causes of hearing loss, and (2) consider screening pregnant women for the m.1555A> G mutation to reduce the risk of aminoglycoside antibiotic-associated hearing loss. PMID:23131088

  18. Separating the effects of habitat area, fragmentation and matrix resistance on genetic differentiation in complex landscapes

    Science.gov (United States)

    Samuel A. Cushman; Andrew J. Shirk; Erin L. Landguth

    2012-01-01

    Little is known about how variation in landscape mosaics affects genetic differentiation. The goal of this paper is to quantify the relative importance of habitat area and configuration, as well as the contrast in resistance between habitat and non-habitat, on genetic differentiation. We hypothesized that habitat configuration would be more influential than habitat...

  19. PRENATAL DIAGNOSIS AND SCREENING OF GENETIC ABNORMALITIES IN EARLY PREGNANCY

    Directory of Open Access Journals (Sweden)

    Jyothi Kiran Kohli

    2016-11-01

    Full Text Available BACKGROUND Genetic diseases are one of the major causes of hospital admissions due to disability and mortality particularly among children (1:5 children of hospital admission either partially/completely as distribution of genetic diseases is not related to socioeconomic background, which implies that developing world has a large number of genetic diseases largely left uncared for, i.e. overall incidence of foetal/neonatal loss due to genetic/genetic environmental causes are as follows: 1:50 newborns have major congenital abnormality, 1:100 have a unifactorial disorder, 1:200 have a major chromosomal abnormality before birth. Diagnosis of chromosomal anomalies in foetus is one of the most important challenges in modern perinatology as invasive or noninvasive methods. The aim of the study is to review on cytogenetic evaluation of CVS obtained (transcervically during first trimester of pregnancy by direct karyotyping of tissue. MATERIALS AND METHODS This study was conducted in 2001 in Department of Anatomy along with Obstetrics and Gynaecology Department, LNJP Hospital. 37 healthy cases with 6-12 weeks of gestational age coming for medical termination of pregnancy were included in the study. After written informed consent for procedure, ultrasound-guided transcervical chorionic villus sampling was done (Brambati’s method. Tissue procured was then processed for direct karyotyping and studied. Metaphase spreads were photographed and karyotypes prepared and studied. RESULTS Out of 37 pregnant females, 30 samples were successfully prepared and processed by Direct method out of which 23 were normal female (46, XX and 7 were normal male (46, XY. No normal anomaly was detected. Best biopsies were obtained with 8-12 weeks gestation. G Banding could not be performed as chromosome obtained were found to be resistant to banding. CONCLUSIONS To summarise chromosome preparations obtained from CVS by Direct method has advantage of providing sufficient number

  20. Relevant genetic differentiation among Brazilian populations of Anastrepha fraterculus (Diptera, Tephritidae)

    Science.gov (United States)

    Manni, Mosè; Lima, Kátia Manuela; Guglielmino, Carmela Rosalba; Lanzavecchia, Silvia Beatriz; Juri, Marianela; Vera, Teresa; Cladera, Jorge; Scolari, Francesca; Gomulski, Ludvik; Bonizzoni, Mariangela; Gasperi, Giuliano; Silva, Janisete Gomes; Malacrida, Anna Rodolfa

    2015-01-01

    Abstract We used a population genetic approach to detect the presence of genetic diversity among six populations of Anastrepha fraterculus across Brazil. To this aim, we used Simple Sequence Repeat (SSR) markers, which may capture the presence of differentiative processes across the genome in distinct populations. Spatial analyses of molecular variance were used to identify groups of populations that are both genetically and geographically homogeneous while also being maximally differentiated from each other. The spatial analysis of genetic diversity indicates that the levels of diversity among the six populations vary significantly on an eco-geographical basis. Particularly, altitude seems to represent a differentiating adaptation, as the main genetic differentiation is detected between the two populations present at higher altitudes and the other four populations at sea level. The data, together with the outcomes from different cluster analyses, identify a genetic diversity pattern that overlaps with the distribution of the known morphotypes in the Brazilian area. PMID:26798258

  1. Impact of blastocyst biopsy and comprehensive chromosome screening technology on preimplantation genetic screening: a systematic review of randomized controlled trials.

    Science.gov (United States)

    Dahdouh, Elias M; Balayla, Jacques; García-Velasco, Juan Antonio

    2015-03-01

    Embryonic aneuploidy is highly prevalent in IVF cycles and contributes to decreased implantation rates, IVF cycle failure and early pregnancy loss. Preimplantation genetic screening (PGS) selects the most competent (euploid) embryos for transfer, and has been proposed to improve IVF outcomes. Use of PGS with fluorescence-in-situ hybridization technology after day 3 embryo biopsy (PGS-v1) significantly lowers live birth rates and is not recommended for use. Comprehensive chromosome screening technology, which assesses the whole chromosome complement, can be achieved using different genetic platforms. Whether PGS using comprehensive chromosome screening after blastocyst biopsy (PGS-v2) improves IVF outcomes remains to be determined. A systematic review of randomized controlled trials was conducted on PGS-v2. Three trials met full inclusion criteria, comparing PGS-v2 and routine IVF care. PGS-v2 is associated with higher clinical implantation rates, and higher ongoing pregnancy rates when the same number of embryos is transferred in both PGS and control groups. Additionally, PGS-v2 improves embryo selection in eSET practice, maintaining the same ongoing pregnancy rates between PGS and control groups, while sharply decreasing multiple pregnancy rates. These results stem from good-prognosis patients undergoing IVF. Whether these findings can be extrapolated to poor-prognosis patients with decreased ovarian reserve remains to be determined. Copyright © 2014 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  2. Multicriteria Gene Screening for Analysis of Differential Expression with DNA Microarrays

    Directory of Open Access Journals (Sweden)

    Alfred O. Hero

    2004-01-01

    Full Text Available This paper introduces a statistical methodology for the identification of differentially expressed genes in DNA microarray experiments based on multiple criteria. These criteria are false discovery rate (FDR, variance-normalized differential expression levels (paired t statistics, and minimum acceptable difference (MAD. The methodology also provides a set of simultaneous FDR confidence intervals on the true expression differences. The analysis can be implemented as a two-stage algorithm in which there is an initial screen that controls only FDR, which is then followed by a second screen which controls both FDR and MAD. It can also be implemented by computing and thresholding the set of FDR P values for each gene that satisfies the MAD criterion. We illustrate the procedure to identify differentially expressed genes from a wild type versus knockout comparison of microarray data.

  3. Screening differentially expressed genes in mouse hepatocarcinoma ascites cell line with high potential of lymphatic metastasis

    Institute of Scientific and Technical Information of China (English)

    Xiao-Nan Cui; Jian-Wu Tang; Li Hou; Bo Song; Li Li; Ji-Wei Liu

    2005-01-01

    AIM: To screen genes differentially expressed in mouse hepatocarcinoma ascites cell line with high potential of lymphatic metastasis.METHODS: A subtracted cDNA library of mouse hepatocarcinoma cell line with high potential of lymphatic metastatic Hca-F and its synogenetic cell line Hca-P with a low metastatic potential was constructed by suppression subtracted hybridization(SSH) method. The screened clones of the subtracted library were sequenced and GeneBank homology search was performed.RESULTS: Fourteen differentially expressed cDNA fragments of Hca-F were obtained with two novel genes.CONCLUSION: SSH is a useful technique to detect differentially expressioned genes and an effective method to clone novel genes.

  4. A Forward Genetic Screening for Prostate Cancer Progression Genes

    Science.gov (United States)

    2012-10-01

    melanoma. Nature 436, 117‐122 (2005). 26. J.C. Cronin et al. Frequent mutations in the MITF pathway in melanoma.  Pigment   Cell Melanoma Res. 22, 435‐444... bacterial genetics. J Mol Biol 116: 125–159. 3. Ding S, Wu X, Li G, Han M, Zhuang Y, et al. (2005) Efficient transposition of the piggyBac (PB) transposon

  5. Serial founder effects and genetic differentiation during worldwide range expansion of monarch butterflies

    Science.gov (United States)

    Pierce, Amanda A.; Zalucki, Myron P.; Bangura, Marie; Udawatta, Milan; Kronforst, Marcus R.; Altizer, Sonia; Haeger, Juan Fernández; de Roode, Jacobus C.

    2014-01-01

    Range expansions can result in founder effects, increasing genetic differentiation between expanding populations and reducing genetic diversity along the expansion front. However, few studies have addressed these effects in long-distance migratory species, for which high dispersal ability might counter the effects of genetic drift. Monarchs (Danaus plexippus) are best known for undertaking a long-distance annual migration in North America, but have also dispersed around the world to form populations that do not migrate or travel only short distances. Here, we used microsatellite markers to assess genetic differentiation among 18 monarch populations and to determine worldwide colonization routes. Our results indicate that North American monarch populations connected by land show limited differentiation, probably because of the monarch's ability to migrate long distances. Conversely, we found high genetic differentiation between populations separated by large bodies of water. Moreover, we show evidence for serial founder effects across the Pacific, suggesting stepwise dispersal from a North American origin. These findings demonstrate that genetic drift played a major role in shaping allele frequencies and created genetic differentiation among newly formed populations. Thus, range expansion can give rise to genetic differentiation and declines in genetic diversity, even in highly mobile species. PMID:25377462

  6. Optimizing human embryonic stem cells differentiation efficiency by screening size-tunable homogenous embryoid bodies.

    Science.gov (United States)

    Moon, Sung-Hwan; Ju, Jongil; Park, Soon-Jung; Bae, Daekyeong; Chung, Hyung-Min; Lee, Sang-Hoon

    2014-07-01

    Human embryonic stem cells (hESCs) are generally induced to differentiate by forming spherical structures termed embryoid bodies (EBs) in the presence of soluble growth factors. hEBs are generated by suspending small clumps of hESC colonies; however, the resulting hEBs are heterogeneous because this method lacks the ability to control the number of cells in individual EBs. This heterogeneity affects factors that influence differentiation such as cell-cell contact and the diffusion of soluble factors, and consequently, the differentiation capacity of each EB varies. Here, we fabricated size-tunable concave microwells to control the physical environment, thereby regulating the size of EBs formed from single hESCs. Defined numbers of single hESCs were forced to aggregate and generate uniformly sized EBs with high fidelity, and the size of the EBs was controlled using concave microwells of different diameters. Differentiation patterns in H9- and CHA15-hESCs were affected by EB size in both the absence and presence of growth factors. By screening EB size in the presence of various BMP4 concentrations, a two-fold increase in endothelial cell differentiation was achieved. Because each hESC line has unique characteristics, the findings of this study demonstrate that concave microwells could be used to screen different EB sizes and growth factor concentrations to optimize differentiation for each hESC line.

  7. Effect of screening for cystic-fibrosis on the influence of genetic-counseling

    NARCIS (Netherlands)

    Dankert-Roelse, J E; te Meerman, G J; Knol, K; ten Kate, L P

    1987-01-01

    We studied the influence of genetic counseling for cystic fibrosis on family planning, using neonatal screening, family size at time of diagnosis, and maternal age as possible determinants for reproductive behaviour. The expected number of children born to mothers of equal age and parity in the same

  8. Neurological Condition of Infants Born After In Vitro Fertilization With Preimplantation Genetic Screening

    NARCIS (Netherlands)

    Middelburg, Karin J.; Heineman, Maas J.; Haadsma, Maaike L.; Bos, Arend F.; Kok, Joke H.; Hadders-Algra, Mijna

    2010-01-01

    Aim of this study was to evaluate the effect of preimplantation genetic screening (PGS) on neurodevelopmental outcome in children. We conducted a prospective follow-up Study of children born to women randomly assigned to in vitro fertilization with or without PGS. Primary outcome was adverse neurolo

  9. Screening of genetic parameters for soluble protein expression in Escherichia coli

    DEFF Research Database (Denmark)

    Vernet, Erik; Kotzsch, Alexander; Voldborg, Bjørn

    2011-01-01

    . Here we present a screening strategy for expression of biomedically relevant proteins in Escherichia coli using a panel of six different genetic variations. These include engineered strains for rare codon supplementation, increased disulfide bond formation in the cytoplasm and novel vectors...

  10. Incidental findings, genetic screening and the challenge of personalisation

    Directory of Open Access Journals (Sweden)

    Carlo Petrini

    2014-12-01

    Full Text Available Genetic tests frequently produce more information than is initially expected. Several documents have addressed this issue and offer suggestions regarding how this information should be managed and, in particular, concerning the expedience of revealing (or not revealing it to the persons concerned. While the approaches to the management of these incidental findings (IFs vary, it is usually recommended that the information be disclosed if there is confirmed clinical utility and the possibility of treatment or prevention. However, this leaves unsolved some fundamental issues such as the different ways of interpreting "clinical utility", countless sources of uncertainty and varying ways of defining the notion of "incidental". Guidelines and other reference documents can offer indications to those responsible for managing IFs but should not be allowed to relieve researchers and healthcare professionals of their responsibilities.

  11. CRISPR-Cas9 for medical genetic screens: applications and future perspectives.

    Science.gov (United States)

    Xue, Hui-Ying; Ji, Li-Juan; Gao, Ai-Mei; Liu, Ping; He, Jing-Dong; Lu, Xiao-Jie

    2016-02-01

    CRISPR-Cas9 (clustered regularly interspaced short palindromic repeats-CRISPR associated nuclease 9) systems have emerged as versatile and convenient (epi)genome editing tools and have become an important player in medical genetic research. CRISPR-Cas9 and its variants such as catalytically inactivated Cas9 (dead Cas9, dCas9) and scaffold-incorporating single guide sgRNA (scRNA) have been applied in various genomic screen studies. CRISPR screens enable high-throughput interrogation of gene functions in health and diseases. Compared with conventional RNAi screens, CRISPR screens incur less off-target effects and are more versatile in that they can be used in multiple formats such as knockout, knockdown and activation screens, and can target coding and non-coding regions throughout the genome. This powerful screen platform holds the potential of revolutionising functional genomic studies in the near future. Herein, we introduce the mechanisms of (epi)genome editing mediated by CRISPR-Cas9 and its variants, introduce the procedures and applications of CRISPR screen in functional genomics, compare it with conventional screen tools and at last discuss current challenges and opportunities and propose future directions.

  12. Genetic Screening of Couples with Recurrent Spontaneous Abortion

    Directory of Open Access Journals (Sweden)

    M. Nail Alp

    2006-01-01

    Full Text Available The aim of this study was to determine the chromosomal abberations and their incidence in non-consanguineous couples with a history of two or more than two spontaneous abortion. In the study, we carried out cytogenetic analysis on 434 couples. Patients detected with chromosome abnormality were evaluated according to their pedigree analysis, and also patients’ relatives were screened for the same abnormality. Peripheral blood were taken from patients, then performed with lymphocyte culture and stained by binded using Giemsa-banding method. For each individual, 20-30-cells chromosomes were counted and around 5-10 well-binded metaphase chromosomes were karyotyped for numerical and structural chromosomal aberrations. Of 434 couples investigated, 30 (6.91% were found to have chromosomal abnormality, in one of couples partners. In 13 of couples (2.99%, one of partners was found to be balanced translocation carrier. Of these, 7 (1.61%were found to be reciprocal carrier, while 6 (1.38% Robertsonian-type balanced translocation carrier. Gonadal mosaicism was found in 3 couples (0.69%, pericentric 9 inversion in 8 couples (1.85 %, while 6 couples showed different chromosomal structure from each other. These chromosomal aberrations may cause of abortion due to high incidence in general population.

  13. Genetic screening of the inherited Ichtyosis causative mutation in Chianina cattle

    Directory of Open Access Journals (Sweden)

    Luciano Molteni

    2010-01-01

    Full Text Available Inherited Ichthyosis, Chianina, Causative mutation, Genetic screening.Inherited Ichthyosis is a genetic disorder reported in both humans and animals, including bovines. Two inherited forms were reported in cattle and both are transmitted in an autosomal recessive manner: Ichthyosis Fetalis (IF and Ichthyosis Congenita (IC. A causative mutation of IF in Chianina cattle was recently indentified in the ABC12 gene. This work reports the first genetic screening using this recently available genetic test on Chianina cattle. Tests were performed on both the population of farm breeding selected young bulls (131 samples randomly chosen and high breeding value sires (16 samples. Results confirm a low total prevalence of carriers in the selected sire population (2/131; 1.5% and the presence of the disease allele among the high value selected sires (1/16; 6.3%. This result strengthens the importance to continue the genetic screening program, particularly in performance tested bulls approved for use in AI or natural service.

  14. Nonstationary patterns of isolation-by-distance: inferring measures of local genetic differentiation with Bayesian kriging.

    Science.gov (United States)

    Duforet-Frebourg, Nicolas; Blum, Michael G B

    2014-04-01

    Patterns of isolation-by-distance (IBD) arise when population differentiation increases with increasing geographic distances. Patterns of IBD are usually caused by local spatial dispersal, which explains why differences of allele frequencies between populations accumulate with distance. However, spatial variations of demographic parameters such as migration rate or population density can generate nonstationary patterns of IBD where the rate at which genetic differentiation accumulates varies across space. To characterize nonstationary patterns of IBD, we infer local genetic differentiation based on Bayesian kriging. Local genetic differentiation for a sampled population is defined as the average genetic differentiation between the sampled population and fictive neighboring populations. To avoid defining populations in advance, the method can also be applied at the scale of individuals making it relevant for landscape genetics. Inference of local genetic differentiation relies on a matrix of pairwise similarity or dissimilarity between populations or individuals such as matrices of FST between pairs of populations. Simulation studies show that maps of local genetic differentiation can reveal barriers to gene flow but also other patterns such as continuous variations of gene flow across habitat. The potential of the method is illustrated with two datasets: single nucleotide polymorphisms from human Swedish populations and dominant markers for alpine plant species.

  15. Patterns of post-glacial genetic differentiation in marginal populations of a marine microalga.

    Science.gov (United States)

    Tahvanainen, Pia; Alpermann, Tilman J; Figueroa, Rosa Isabel; John, Uwe; Hakanen, Päivi; Nagai, Satoshi; Blomster, Jaanika; Kremp, Anke

    2012-01-01

    This study investigates the genetic structure of an eukaryotic microorganism, the toxic dinoflagellate Alexandrium ostenfeldii, from the Baltic Sea, a geologically young and ecologically marginal brackish water estuary which is predicted to support evolution of distinct, genetically impoverished lineages of marine macroorganisms. Analyses of the internal transcribed spacer (ITS) sequences and Amplified Fragment Length Polymorphism (AFLP) of 84 A. ostenfeldii isolates from five different Baltic locations and multiple external sites revealed that Baltic A. ostenfeldii is phylogenetically differentiated from other lineages of the species and micro-geographically fragmented within the Baltic Sea. Significant genetic differentiation (F(ST)) between northern and southern locations was correlated to geographical distance. However, instead of discrete genetic units or continuous genetic differentiation, the analysis of population structure suggests a complex and partially hierarchic pattern of genetic differentiation. The observed pattern suggests that initial colonization was followed by local differentiation and varying degrees of dispersal, most likely depending on local habitat conditions and prevailing current systems separating the Baltic Sea populations. Local subpopulations generally exhibited low levels of overall gene diversity. Association analysis suggests predominately asexual reproduction most likely accompanied by frequency shifts of clonal lineages during planktonic growth. Our results indicate that the general pattern of genetic differentiation and reduced genetic diversity of Baltic populations found in large organisms also applies to microscopic eukaryotic organisms.

  16. Patterns of post-glacial genetic differentiation in marginal populations of a marine microalga.

    Directory of Open Access Journals (Sweden)

    Pia Tahvanainen

    Full Text Available This study investigates the genetic structure of an eukaryotic microorganism, the toxic dinoflagellate Alexandrium ostenfeldii, from the Baltic Sea, a geologically young and ecologically marginal brackish water estuary which is predicted to support evolution of distinct, genetically impoverished lineages of marine macroorganisms. Analyses of the internal transcribed spacer (ITS sequences and Amplified Fragment Length Polymorphism (AFLP of 84 A. ostenfeldii isolates from five different Baltic locations and multiple external sites revealed that Baltic A. ostenfeldii is phylogenetically differentiated from other lineages of the species and micro-geographically fragmented within the Baltic Sea. Significant genetic differentiation (F(ST between northern and southern locations was correlated to geographical distance. However, instead of discrete genetic units or continuous genetic differentiation, the analysis of population structure suggests a complex and partially hierarchic pattern of genetic differentiation. The observed pattern suggests that initial colonization was followed by local differentiation and varying degrees of dispersal, most likely depending on local habitat conditions and prevailing current systems separating the Baltic Sea populations. Local subpopulations generally exhibited low levels of overall gene diversity. Association analysis suggests predominately asexual reproduction most likely accompanied by frequency shifts of clonal lineages during planktonic growth. Our results indicate that the general pattern of genetic differentiation and reduced genetic diversity of Baltic populations found in large organisms also applies to microscopic eukaryotic organisms.

  17. Quantifying effects of environmental and geographical factors on patterns of genetic differentiation.

    Science.gov (United States)

    Lee, Cheng-Ruei; Mitchell-Olds, Thomas

    2011-11-01

    Elucidating the factors influencing genetic differentiation is an important task in biology, and the relative contribution from natural selection and genetic drift has long been debated. In this study, we used a regression-based approach to simultaneously estimate the quantitative contributions of environmental adaptation and isolation by distance on genetic variation in Boechera stricta, a wild relative of Arabidopsis. Patterns of discrete and continuous genetic differentiation coexist within this species. For the discrete differentiation between two major genetic groups, environment has larger contribution than geography, and we also identified a significant environment-by-geography interaction effect. Elsewhere in the species range, we found a latitudinal cline of genetic variation reflecting only isolation by distance. To further confirm the effect of environmental selection on genetic divergence, we identified the specific environmental variables predicting local genotypes in allopatric and sympatric regions. Water availability was identified as the possible cause of differential local adaptation in both geographical regions, confirming the role of environmental adaptation in driving and maintaining genetic differentiation between the two major genetic groups. In addition, the environment-by-geography interaction is further confirmed by the finding that water availability is represented by different environmental factors in the allopatric and sympatric regions. In conclusion, this study shows that geographical and environmental factors together created stronger and more discrete genetic differentiation than isolation by distance alone, which only produced a gradual, clinal pattern of genetic variation. These findings emphasize the importance of environmental selection in shaping patterns of species-wide genetic variation in the natural environment.

  18. A differential drug screen for compounds that select against antibiotic resistance.

    Directory of Open Access Journals (Sweden)

    Remy Chait

    Full Text Available Antibiotics increase the frequency of resistant bacteria by providing them a competitive advantage over sensitive strains. Here, we develop a versatile assay for differential chemical inhibition of competing microbial strains, and use it to identify compounds that preferentially inhibit tetracycline-resistant relative to sensitive bacteria, thus "inverting" selection for resistance. Our assay distinguishes compounds selecting directly against specific resistance mechanisms and compounds whose selection against resistance is based on their physiological interaction with tetracycline and is more general with respect to resistance mechanism. A pilot screen indicates that both types of selection-inverting compounds are secreted by soil microbes, suggesting that nature has evolved a repertoire of chemicals that counteracts antibiotic resistance. Finally, we show that our assay can more generally permit simple, direct screening for drugs based on their differential activity against different strains or targets.

  19. Lifting the Differentiation Embargo.

    Science.gov (United States)

    Latif, Anne-Louise; Holyoake, Tessa L

    2016-09-22

    Effective differentiation therapy for acute myeloid leukemia (AML) has been restricted to a small subset of patients with one defined genetic abnormality. Using an unbiased small molecule screen, Sykes et al. now identify a mechanism of de-repression of differentiation in several models of AML driven by distinct genetic drivers.

  20. A High Throughput Phenotypic Screening reveals compounds that counteract premature osteogenic differentiation of HGPS iPS-derived mesenchymal stem cells

    Science.gov (United States)

    Lo Cicero, Alessandra; Jaskowiak, Anne-Laure; Egesipe, Anne-Laure; Tournois, Johana; Brinon, Benjamin; Pitrez, Patricia R.; Ferreira, Lino; de Sandre-Giovannoli, Annachiara; Levy, Nicolas; Nissan, Xavier

    2016-01-01

    Hutchinson-Gilford progeria syndrome (HGPS) is a rare fatal genetic disorder that causes systemic accelerated aging in children. Thanks to the pluripotency and self-renewal properties of induced pluripotent stem cells (iPSC), HGPS iPSC-based modeling opens up the possibility of access to different relevant cell types for pharmacological approaches. In this study, 2800 small molecules were explored using high-throughput screening, looking for compounds that could potentially reduce the alkaline phosphatase activity of HGPS mesenchymal stem cells (MSCs) committed into osteogenic differentiation. Results revealed seven compounds that normalized the osteogenic differentiation process and, among these, all-trans retinoic acid and 13-cis-retinoic acid, that also decreased progerin expression. This study highlights the potential of high-throughput drug screening using HGPS iPS-derived cells, in order to find therapeutic compounds for HGPS and, potentially, for other aging-related disorders. PMID:27739443

  1. Screening and analysis of differentially expressed genes of dermal papillae cells with aggregative behavior

    Institute of Scientific and Technical Information of China (English)

    宋志强; 郝飞; 杨卫兵; 王继文; 邹锋

    2004-01-01

    Objective: To screen and clone differentially expressed genes of dermal papillae cells (DPC) with aggregative behavior, and to explore the molecular mechanism of their aggregation. Methods: Total RNAs were extracted from DPC with and without aggregative behavior and double strand cDNAs were synthesized by using SMART cDNA synthesis, respectively. The cDNA fragments of differentially expressed genes in DPCs with aggregative behavior were isolated by suppression subtractive hybridization. Positive clones were screened by PCR method and verified by cDNA dot blot, Northern blot and then analyzed through homologous retrieving. Results: A subtractive cDNA library of DPC with aggregative behavior has been successfully constructed. The result of screening and cloning of the library showed that, DPC with aggregative behavior could expresse genes related to homologous aggregation, proliferation and cycle control, including known genes (capping protein, paladin, vascular endothelial growth factor), hematopoietic stem/progenitor cells (HSPC) related clone (HSPC011 and HSPC016) and a new gene. Conclusion: The construction of subtracted library of DPC lays solid foundation for screening and cloning new and specific genes related to aggregative behavior of DPC. Several genes might be cooperatively involved in the homologous aggregation, proliferation and cycle control of DPC. Among these genes, capping protein and palladin might be closely related to the aggregative behavior of dermal papilla cells, and VEGF and HSPC related clone would be responsible for the status of higher proliferation of dermal papilla cells.

  2. A post-developmental genetic screen for zebrafish models of inherited liver disease.

    Directory of Open Access Journals (Sweden)

    Seok-Hyung Kim

    Full Text Available Nonalcoholic fatty liver disease (NAFLD is one of the most common causes of chronic liver disease such as simple steatosis, nonalcoholic steatohepatitis (NASH, cirrhosis and fibrosis. However, the molecular pathogenesis and genetic variations causing NAFLD are poorly understood. The high prevalence and incidence of NAFLD suggests that genetic variations on a large number of genes might be involved in NAFLD. To identify genetic variants causing inherited liver disease, we used zebrafish as a model system for a large-scale mutant screen, and adopted a whole genome sequencing approach for rapid identification of mutated genes found in our screen. Here, we report on a forward genetic screen of ENU mutagenized zebrafish. From 250 F2 lines of ENU mutagenized zebrafish during post-developmental stages (5 to 8 days post fertilization, we identified 19 unique mutant zebrafish lines displaying visual evidence of hepatomegaly and/or steatosis with no developmental defects. Histological analysis of mutants revealed several specific phenotypes, including common steatosis, micro/macrovesicular steatosis, hepatomegaly, ballooning, and acute hepatocellular necrosis. This work has identified multiple post-developmental mutants and establishes zebrafish as a novel animal model for post-developmental inherited liver disease.

  3. A post-developmental genetic screen for zebrafish models of inherited liver disease.

    Science.gov (United States)

    Kim, Seok-Hyung; Wu, Shu-Yu; Baek, Jeong-In; Choi, Soo Young; Su, Yanhui; Flynn, Charles R; Gamse, Joshua T; Ess, Kevin C; Hardiman, Gary; Lipschutz, Joshua H; Abumrad, Naji N; Rockey, Don C

    2015-01-01

    Nonalcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease such as simple steatosis, nonalcoholic steatohepatitis (NASH), cirrhosis and fibrosis. However, the molecular pathogenesis and genetic variations causing NAFLD are poorly understood. The high prevalence and incidence of NAFLD suggests that genetic variations on a large number of genes might be involved in NAFLD. To identify genetic variants causing inherited liver disease, we used zebrafish as a model system for a large-scale mutant screen, and adopted a whole genome sequencing approach for rapid identification of mutated genes found in our screen. Here, we report on a forward genetic screen of ENU mutagenized zebrafish. From 250 F2 lines of ENU mutagenized zebrafish during post-developmental stages (5 to 8 days post fertilization), we identified 19 unique mutant zebrafish lines displaying visual evidence of hepatomegaly and/or steatosis with no developmental defects. Histological analysis of mutants revealed several specific phenotypes, including common steatosis, micro/macrovesicular steatosis, hepatomegaly, ballooning, and acute hepatocellular necrosis. This work has identified multiple post-developmental mutants and establishes zebrafish as a novel animal model for post-developmental inherited liver disease.

  4. Frequency of chromosomal aneuploidy in high quality embryos from young couples using preimplantation genetic screening

    Directory of Open Access Journals (Sweden)

    Farzaneh Fesahat

    2017-09-01

    Full Text Available Background: Selection of the best embryo for transfer is very important in assisted reproductive technology (ART. Using morphological assessment for this selection demonstrated that the correlation between embryo morphology and implantation potential is relatively weak. On the other hand, aneuploidy is a key genetic factor that can influence human reproductive success in ART. Objective: The aim of this lab trial study was to evaluate the incidence of aneuploidies in five chromosomes in the morphologically high-quality embryos from young patients undergoing ART for sex selection. Materials and Methods: A total of 97 high quality embryos from 23 women at the age of 37or younger years that had previously undergone preimplantation genetic screening for sex selection were included in this study. After washing, the slides of blastomeres from embryos of patients were reanalyzed by fluorescence in-situ hybridization for chromosomes 13, 18 and 21. Results: There was a significant rate of aneuploidy determination in the embryos using preimplantation genetic screening for both sex and three evaluated autosomal chromosomes compared to preimplantation genetic screening for only sex chromosomes (62.9% vs. 24.7%, p=0.000. The most frequent detected chromosomal aneuploidy was trisomy or monosomy of chromosome 13. Conclusion: There is considerable numbers of chromosomal abnormalities in embryos generated in vitro which cause in vitro fertilization failure and it seems that morphological characterization of embryos is not a suitable method for choosing the embryos without these abnormalities

  5. Genetic diversity and differentiation in roses: A gardenrose perspective

    NARCIS (Netherlands)

    Vukosavljev, M.; Zhang, J.; Esselink, G.; Westende, van 't W.P.C.; Cox, P.; Visser, R.G.F.; Arens, P.; Smulders, M.J.M.

    2013-01-01

    tFor the first time genetic diversity among modern garden rose cultivars has been evaluated using a setof 24 microsatellite markers covering most chromosomes. A total of 518 different alleles were obtainedin the set of 138 rose cultivars and this led to the conclusion that in terms of genetic

  6. Genetic Variation in Dopamine Pathways Differentially Associated with Smoking Progression in Adolescence

    Science.gov (United States)

    Laucht, Manfred; Becker, Katja; Frank, Josef; Schmidt, Martin H.; Esser, Gunter; Treutlein, Jens; Skowronek, Markus H.; Schumann, Gunter

    2008-01-01

    A study examines whether genetic variation in dopamine pathways differentially associate with smoking progression in adolescence. Results indicate the influence of specific dopamine genes in different stages of smoking progression in adolescents.

  7. Genetic Variation in Dopamine Pathways Differentially Associated with Smoking Progression in Adolescence

    Science.gov (United States)

    Laucht, Manfred; Becker, Katja; Frank, Josef; Schmidt, Martin H.; Esser, Gunter; Treutlein, Jens; Skowronek, Markus H.; Schumann, Gunter

    2008-01-01

    A study examines whether genetic variation in dopamine pathways differentially associate with smoking progression in adolescence. Results indicate the influence of specific dopamine genes in different stages of smoking progression in adolescents.

  8. Low but contrasting neutral genetic differentiation shaped by winter temperature in European great tits.

    NARCIS (Netherlands)

    Lemoine, M.; Lucek, K.; Perrier, C.; Saladin, V.; Adriaensen, F.; Barba, E.; Belda, E.J.; Charmantier, A.; Cichoń, M.; Eeva, T.; Grégoire, A.; Hinde, C.A.; Johnsen, A.; Komdeur, J.; Mänd, R.; Matthysen, E.; Norte, A.C.; Pitala, N.; Sheldon, B.C.; Slagsvold, T.; Tinbergen, J.M.; Török, J.; Ubels, R.; van Oers, K.; Visser, M.E.; Doligez, Blandine; Richner, Heinz

    2016-01-01

    Gene flow is usually thought to reduce genetic divergence and impede local adaptation by homogenising gene pools between populations. However, evidence for local adaptation and phenotypic differentiation in highly mobile species, experiencing high levels of gene flow, is emerging. Assessing

  9. Low but contrasting neutral genetic differentiation shaped by winter temperature in European great tits

    NARCIS (Netherlands)

    Lemoine, Melissa; Lucek, Kay; Perrier, Charles; Saladin, Verena; Adriaensen, Frank; Barba, Emilio; Belda, Eduardo J.; Charmantier, Anne; Cichon, Mariusz; Eeva, Tapio; Gregoire, Arnaud; Hinde, Camilla A.; Johnsen, Arild; Komdeur, Jan; Mand, Raivo; Matthysen, Erik; Norte, Ana Claudia; Pitala, Natalia; Sheldon, Ben C.; Slagsvold, Tore; Tinbergen, Joost M.; Torok, Janos; Ubels, Richard; Van Oers, Kees; Visser, Marcel E.; Doligez, Blandine; Richner, Heinz

    Gene flow is usually thought to reduce genetic divergence and impede local adaptation by homogenising gene pools between populations. However, evidence for local adaptation and phenotypic differentiation in highly mobile species, experiencing high levels of gene flow, is emerging. Assessing

  10. Non-genetic heterogeneity, criticality and cell differentiation

    Science.gov (United States)

    Pal, Mainak; Ghosh, Sayantari; Bose, Indrani

    2015-02-01

    The different cell types in a living organism acquire their identity through the process of cell differentiation in which multipotent progenitor cells differentiate into distinct cell types. Experimental evidence and analysis of large-scale microarray data establish the key role played by a two-gene motif in cell differentiation in a number of cell systems. The two genes express transcription factors which repress each other's expression and autoactivate their own production. A number of theoretical models have recently been proposed based on the two-gene motif to provide a physical understanding of how cell differentiation occurs. In this paper, we study a simple model of cell differentiation which assumes no cooperativity in the regulation of gene expression by the transcription factors. The latter repress each other's activity directly through DNA binding and indirectly through the formation of heterodimers. We specifically investigate how deterministic processes combined with stochasticity contribute in bringing about cell differentiation. The deterministic dynamics of our model give rise to a supercritical pitchfork bifurcation from an undifferentiated stable steady state to two differentiated stable steady states. The stochastic dynamics of our model are studied using the approaches based on the Langevin equations and the linear noise approximation. The simulation results provide a new physical understanding of recent experimental observations. We further propose experimental measurements of quantities like the variance and the lag-1 autocorrelation function in protein fluctuations as the early signatures of an approaching bifurcation point in the cell differentiation process.

  11. A genome-wide screen indicates correlation between differentiation and expression of metabolism related genes.

    Science.gov (United States)

    Roy, Priti; Kumar, Brijesh; Shende, Akhilesh; Singh, Anupama; Meena, Anil; Ghosal, Ritika; Ranganathan, Madhav; Bandyopadhyay, Amitabha

    2013-01-01

    Differentiated tissues may be considered as materials with distinct properties. The differentiation program of a given tissue ensures that it acquires material properties commensurate with its function. It may be hypothesized that some of these properties are acquired through production of tissue-specific metabolites synthesized by metabolic enzymes. To establish correlation between metabolism and organogenesis we have carried out a genome-wide expression study of metabolism related genes by RNA in-situ hybridization. 23% of the metabolism related genes studied are expressed in a tissue-restricted but not tissue-exclusive manner. We have conducted the screen on whole mount chicken (Gallus gallus) embryos from four distinct developmental stages to correlate dynamic changes in expression patterns of metabolic enzymes with spatio-temporally unique developmental events. Our data strongly suggests that unique combinations of metabolism related genes, and not specific metabolic pathways, are upregulated during differentiation. Further, expression of metabolism related genes in well established signaling centers that regulate different aspects of morphogenesis indicates developmental roles of some of the metabolism related genes. The database of tissue-restricted expression patterns of metabolism related genes, generated in this study, should serve as a resource for systematic identification of these genes with tissue-specific functions during development. Finally, comprehensive understanding of differentiation is not possible unless the downstream genes of a differentiation cascade are identified. We propose, metabolic enzymes constitute a significant portion of these downstream target genes. Thus our study should help elucidate different aspects of tissue differentiation.

  12. A genome-wide screen indicates correlation between differentiation and expression of metabolism related genes.

    Directory of Open Access Journals (Sweden)

    Priti Roy

    Full Text Available Differentiated tissues may be considered as materials with distinct properties. The differentiation program of a given tissue ensures that it acquires material properties commensurate with its function. It may be hypothesized that some of these properties are acquired through production of tissue-specific metabolites synthesized by metabolic enzymes. To establish correlation between metabolism and organogenesis we have carried out a genome-wide expression study of metabolism related genes by RNA in-situ hybridization. 23% of the metabolism related genes studied are expressed in a tissue-restricted but not tissue-exclusive manner. We have conducted the screen on whole mount chicken (Gallus gallus embryos from four distinct developmental stages to correlate dynamic changes in expression patterns of metabolic enzymes with spatio-temporally unique developmental events. Our data strongly suggests that unique combinations of metabolism related genes, and not specific metabolic pathways, are upregulated during differentiation. Further, expression of metabolism related genes in well established signaling centers that regulate different aspects of morphogenesis indicates developmental roles of some of the metabolism related genes. The database of tissue-restricted expression patterns of metabolism related genes, generated in this study, should serve as a resource for systematic identification of these genes with tissue-specific functions during development. Finally, comprehensive understanding of differentiation is not possible unless the downstream genes of a differentiation cascade are identified. We propose, metabolic enzymes constitute a significant portion of these downstream target genes. Thus our study should help elucidate different aspects of tissue differentiation.

  13. Population differentiation in Pacific salmon: local adaptation, genetic drift, or the environment?

    Science.gov (United States)

    Adkison, M.D.

    1995-01-01

    Morphological, behavioral, and life-history differences between Pacific salmon (Oncorhynchus spp.) populations are commonly thought to reflect local adaptation, and it is likewise common to assume that salmon populations separated by small distances are locally adapted. Two alternatives to local adaptation exist: random genetic differentiation owing to genetic drift and founder events, and genetic homogeneity among populations, in which differences reflect differential trait expression in differing environments. Population genetics theory and simulations suggest that both alternatives are possible. With selectively neutral alleles, genetic drift can result in random differentiation despite many strays per generation. Even weak selection can prevent genetic drift in stable populations; however, founder effects can result in random differentiation despite selective pressures. Overlapping generations reduce the potential for random differentiation. Genetic homogeneity can occur despite differences in selective regimes when straying rates are high. In sum, localized differences in selection should not always result in local adaptation. Local adaptation is favored when population sizes are large and stable, selection is consistent over large areas, selective diffeentials are large, and straying rates are neither too high nor too low. Consideration of alternatives to local adaptation would improve both biological research and salmon conservation efforts.

  14. Elevation, Not Deforestation, Promotes Genetic Differentiation in a Pioneer Tropical Tree

    Science.gov (United States)

    Castilla, Antonio R.; Pope, Nathaniel; Jaffé, Rodolfo; Jha, Shalene

    2016-01-01

    The regeneration of disturbed forest is an essential part of tropical forest ecology, both with respect to natural disturbance regimes and large-scale human-mediated logging, grazing, and agriculture. Pioneer tree species are critical for facilitating the transition from deforested land to secondary forest because they stabilize terrain and enhance connectivity between forest fragments by increasing matrix permeability and initiating disperser community assembly. Despite the ecological importance of early successional species, little is known about their ability to maintain gene flow across deforested landscapes. Utilizing highly polymorphic microsatellite markers, we examined patterns of genetic diversity and differentiation for the pioneer understory tree Miconia affinis across the Isthmus of Panama. Furthermore, we investigated the impact of geographic distance, forest cover, and elevation on genetic differentiation among populations using circuit theory and regression modeling within a landscape genetics framework. We report marked differences in historical and contemporary migration rates and moderately high levels of genetic differentiation in M. affinis populations across the Isthmus of Panama. Genetic differentiation increased significantly with elevation and geographic distance among populations; however, we did not find that forest cover enhanced or reduced genetic differentiation in the study region. Overall, our results reveal strong dispersal for M. affinis across human-altered landscapes, highlighting the potential use of this species for reforestation in tropical regions. Additionally, this study demonstrates the importance of considering topography when designing programs aimed at conserving genetic diversity within degraded tropical landscapes. PMID:27280872

  15. Geographic genetic differentiation of a malaria parasite, Plasmodium mexicanum, and its lizard host, Sceloporus occidentalis.

    Science.gov (United States)

    Fricke, Jennifer M; Vardo-Zalik, Anne M; Schall, Jos J

    2010-04-01

    Gene flow, and resulting degree of genetic differentiation among populations, will shape geographic genetic patterns and possibly local adaptation of parasites and their hosts. Some studies of Plasmodium falciparum in humans show substantial differentiation of the parasite in locations separated by only a few kilometers, a paradoxical finding for a parasite in a large, mobile host. We examined genetic differentiation of the malaria parasite Plasmodium mexicanum, and its lizard host, Sceloporus occidentalis, at 8 sites in northern California, with the use of variable microsatellite markers for both species. These lizards are small and highly territorial, so we expected local genetic differentiation of both parasite and lizard. Populations of P. mexicanum were found to be differentiated by analysis of 5 markers (F(st) values >0.05-0.10) over distances as short as 230-400 m, and greatly differentiated (F(st) values >0.25) for sites separated by approximately 10 km. In contrast, the lizard host had no, or very low, levels of differentiation for 3 markers, even for sites >40 km distant. Thus, gene flow for the lizard was great, but despite the mobility of the vertebrate host, the parasite was locally genetically distinct. This discrepancy could result if infected lizards move little, but their noninfected relatives were more mobile. Previous studies on the virulence of P. mexicanum for fence lizards support this hypothesis. However, changing prevalence of the parasite, without changes in density of the lizard, could also result in this pattern.

  16. Familial disorders of sexual differentiation: a clinical and molecular genetic evaluation

    NARCIS (Netherlands)

    A.L.M. Boehmer (Annemie)

    2000-01-01

    textabstractSexual determination and differentiation are series of events starting with the establishment of genetic sex at fertilization, proceeding with the translation of genetic sex into gonadal sex, and culminating in the translation of gonadal sex into body sex. This three-step model is still

  17. Impact of Geography and Climate on the Genetic Differentiation of the Subtropical Pine Pinus yunnanensis.

    Directory of Open Access Journals (Sweden)

    Baosheng Wang

    Full Text Available Southwest China is a biodiversity hotspot characterized by complex topography, heterogeneous regional climates and rich flora. The processes and driving factors underlying this hotspot remain to be explicitly tested across taxa to gain a general understanding of the evolution of biodiversity and speciation in the region. In this study, we examined the role played by historically neutral processes, geography and environment in producing the current genetic diversity of the subtropical pine Pinus yunnanensis. We used genetic and ecological methods to investigate the patterns of genetic differentiation and ecological niche divergence across the distribution range of this species. We found both continuous genetic differentiation over the majority of its range, and discrete isolated local clusters. The discrete differentiation between two genetic groups in the west and east peripheries is consistent with niche divergence and geographical isolation of these groups. In the central area of the species' range, population structure was shaped mainly by neutral processes and geography rather than by ecological selection. These results show that geographical and environmental factors together created stronger and more discrete genetic differentiation than isolation by distance alone, and illustrate the importance of ecological factors in forming or maintaining genetic divergence across a complex landscape. Our findings differ from other phylogenetic studies that identified the historical drainage system in the region as the primary factor shaping population structure, and highlight the heterogeneous contributions that geography and environment have made to genetic diversity among taxa in southwest China.

  18. Contemporary and historic factors influence differently genetic differentiation and diversity in a tropical palm.

    Science.gov (United States)

    da Silva Carvalho, C; Ribeiro, M C; Côrtes, M C; Galetti, M; Collevatti, R G

    2015-09-01

    Population genetics theory predicts loss in genetic variability because of drift and inbreeding in isolated plant populations; however, it has been argued that long-distance pollination and seed dispersal may be able to maintain gene flow, even in highly fragmented landscapes. We tested how historical effective population size, historical migration and contemporary landscape structure, such as forest cover, patch isolation and matrix resistance, affect genetic variability and differentiation of seedlings in a tropical palm (Euterpe edulis) in a human-modified rainforest. We sampled 16 sites within five landscapes in the Brazilian Atlantic forest and assessed genetic variability and differentiation using eight microsatellite loci. Using a model selection approach, none of the covariates explained the variation observed in inbreeding coefficients among populations. The variation in genetic diversity among sites was best explained by historical effective population size. Allelic richness was best explained by historical effective population size and matrix resistance, whereas genetic differentiation was explained by matrix resistance. Coalescence analysis revealed high historical migration between sites within landscapes and constant historical population sizes, showing that the genetic differentiation is most likely due to recent changes caused by habitat loss and fragmentation. Overall, recent landscape changes have a greater influence on among-population genetic variation than historical gene flow process. As immediate restoration actions in landscapes with low forest amount, the development of more permeable matrices to allow the movement of pollinators and seed dispersers may be an effective strategy to maintain microevolutionary processes.

  19. Population genetic differentiation of height and body mass index across Europe

    DEFF Research Database (Denmark)

    Robinson, Matthew R.; Hemani, Gibran; Medina-Gomez, Carolina;

    2015-01-01

    Across-nation differences in the mean values for complex traits are common(1-8), but the reasons for these differences are unknown. Here we find that many independent loci contribute to population genetic differences in height and body mass index (BMI) in 9,416 individuals across 14 European coun...... for both phenotypes. Observed differences in height among populations reflected the predicted genetic means (r = 0.51; P Europe masked genetic differentiation for BMI (P

  20. Preimplantation Genetic Screening: An Effective Testing for Infertile and Repeated Miscarriage Patients?

    Directory of Open Access Journals (Sweden)

    Ning Wang

    2010-01-01

    Full Text Available Aneuploidy in pregnancy is known to increase with advanced maternal age (AMA and associate with repeated implantation failure (RIF, and repeated miscarriage (RM. Preimplantation genetic screening (PGS has been introduced into clinical practice, screening, and eliminating aneuploidy embryos, which can improve the chance of conceptions for infertility cases with poor prognosis. These patients are a good target group to assess the possible benefit of aneuploidy screening. Although practiced widely throughout the world, there still exist some doubts about the efficacy of this technique. Recent randomized trials were not as desirable as we expected, suggesting that PGS needs to be reconsidered. The aim of this review is to discuss the efficacy of PGS.

  1. Statement of The American Society of Human Genetics on cystic fibrosis carrier screening

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-01

    The identification in 1989 of the cystic fibrosis (CF) gene and its most common mutation immediately raised the possibility of CF carrier detection by DNA analysis. The American Society of Human Genetics (ASHG) issued a statement recommending that CF carrier testing should be made available to individuals with a family history of CF. It was also stated that screening of individuals or couples in the general population should not be offered until the rate of CF carrier detection improves. An additional prerequisite emphasized the need for the establishment of effective educational and counseling programs consistent with previous widely accepted principles. An NIH workshop reached similar conclusions. ASHG recommendations are that screening be limited to individuals with a family history of CF, testing should be accompanied by education and counseling, screening should be voluntary and confidential with appropriate laboratory quality controls, and efforts should be expanded to educate health care providers and the public.

  2. [Biochemical screening and genetic diagnosis of thalassemia in children from Kunming].

    Science.gov (United States)

    Wen, Bai-Ping; Fan, Mao; Dai, Hong-Jian; Zhuang, Yu; Liu, Hong-Ling; Yang, Jun-Yi; Yang, Xiao-Hong; Deng, Wen-Guo

    2011-02-01

    To investigate the types and frequency of gene mutations in children with thalassemia in Kunming, Yunan Province. A biochemical screening for thalassemia was performed by testing RBC fragility, MCV and hemoglobin electrophoresis on 1338 children from Kunming, Yunnan Province. Genetic diagnosis was performed on the children with α-thalassemia by gap-PCR and on the children with β-thalassemia by PCR-RDB. The positive rate of the biochemical screening for thalassemia was 11.36% (152 cases). The positive rate of genetic diagnosis was 8.59% (115 cases). Of the 115 cases, α-thalassemia was found in 43 cases, β-thalassemia in 68 cases and α-combined-β thalassemia in 4 cases.--SEA/αα accounted for 47%, -α4.2/αα accounted for 21%, and HbH disease accounted for 14%. Six genotypes were found in 68 cases of β-thalassemia and the mutation frequency of βE was the highest (32%), followed by CD41-42 (24%), CD17 (23%), IVS-II654 (10%), CD71-72 (10%), and -28 (1%). The frequency of gene mutations for thalassemia is high in children from Kunming, Yunnan Province. Premarital and prenatal screenings and genetic diagnosis for thalassemia should be carried out in this area.

  3. Genetic Influence on the Peripheral Blood CD4+ T-cell Differentiation Status in CMV Infection

    DEFF Research Database (Denmark)

    Goldeck, David; Larsen, Lisbeth Aagaard; Christiansen, Lene

    2016-01-01

    A latent infection with cytomegalovirus (CMV), a ubiquitous beta herpesvirus, is associated with an accumulation of late-differentiated memory T-cells, often accompanied by a reciprocal reduced frequency of early-differentiated cells (commonly also referred to as "naïve"). However, this impact...... heritability analysis confirmed a substantial contribution of genetics to the differentiation status of T-cells in CMV infection. The humoral (IgG) response to different CMV antigens also seems to be genetically influenced, suggesting that a similar degree of immune control of the virus in MZ twins might...

  4. Screening and Identification Differentially Displayed Genes in Fore Stomach Carcinoma of Mice

    Institute of Scientific and Technical Information of China (English)

    Hong-xu Zhang; Dan-dan Liu; Lin Li; Ru-bing Duan; Li Wang; Jing Cao; Li-juan Zhi

    2009-01-01

    Objective: To screen and identify key genes differentially displayed in mouse fore stomach carcinoma, in order to elucidate the molecular mechanism underlying carcinogenesis.Methods: The animal models complied with each period of NIH mouse fore stomach carcinoma induced by N-Nitrososarcosineethylester (NSEE) were used in this study. The mice were euthanized on days 14, 28, 56, 77 and 84, respectively, after NSEE-piped treatment, and classified according to their pathologies. The differentially expressed genes were isolated from both normal and morbid tissues by mRNA differential display technique and screened by using Reverse Northern blot. Bioinformatics were employed to analyze the results observed. After identification, ten fragments were cloned and matched with GENEBANK database through homologous analysis.Results: One gene was found identical to splicing factor 3b subunit 1 (Sf3b1), while seven fragments hold the homology of known cDNA clones. In contrast, other two fragments had extremely low identity to any genes registered in GENBANK databases.Conclusion: It is the first time to demonstrate in this study that splicing factor3b, subunit1 (Sf3b1) is related to mouse fore stomach carcinoma. Furthermore, ESC-3 and ESC-4 are suggested to contribute to the development of mouse fore stomach carcinoma, thus may be candidates of new targets of oncogenes.

  5. Large genetic screens for gynogenesis and androgenesis haploid inducers in Arabidopsis thaliana failed to identify mutants

    Directory of Open Access Journals (Sweden)

    Virginie ePortemer

    2015-03-01

    Full Text Available Gynogenesis is a process in which the embryo genome originates exclusively from female origin, following embryogenesis stimulation by a male gamete. In contrast, androgenesis is the development of embryos that contain only the male nuclear genetic background. Both phenomena are of great interest in plant breeding as haploidisation is an efficient tool to reduce the length of breeding schemes to create varieties. Although few inducer lines have been described, the genetic control of these phenomena is poorly understood. We developed genetic screens to identify mutations that would induce gynogenesis or androgenesis in Arabidopsis thaliana. The ability of mutant pollen to induce either gynogenesis or androgenesis was tested by crossing mutagenized plants as males. Seedlings from these crosses were screened with recessive phenotypic markers, one genetically controlled by the female genome and another by the male genome. Positive and negative controls confirmed the unambiguous detection of both gynogenesis and androgenesis events. This strategy was applied to 1,666 EMS-mutagenised lines and 47 distant Arabidopsis strains. While an internal control suggested that the mutagenesis reached saturation, no gynogenesis or androgenesis inducer was found. However, spontaneous gynogenesis was observed at a frequency of 1/10,800. Altogether, these results suggest that no simple EMS-induced mutation in the male genome is able to induce gynogenesis or androgenesis in Arabidopsis.

  6. Genetic differentiation between conspecific populations of Merodon avidus A (Diptera, Syrphidae

    Directory of Open Access Journals (Sweden)

    Milankov Vesna R.

    2004-01-01

    Full Text Available Allozyme variability of populations of Merodon avidus A (M i l a n - k o v et al., 2001 from Dubašnica Mountain (Serbia, Morinj Bay (Montenegro and Pindos Mountain (Greece was analysed. The influence of gene flow on genetic differentiation among populations from the three biogeographical regions was also investigated. Genetic differentiaiton quantified by the Fst value, which is an inverse function of gene flow between populations, seemed to be correlated to both geographic and genetic distance (D, N e i, 1978, Namely in the population pairs Morinj - Dubašnica (253 km air distance, Morinj - Pindos (390km air distance genetic differentiation and genetic distance increased with the geographic distance (Fst = 0.133, D = 0.022 and Fst = 0.309, D = 0.052, respectively. The exception was the population pair Dubašnica - Pindos (500 km air distance, where a lower degree of genetic differentiation was observed (Fst = 0.266; D = 0.047 than was expected based solely on the geographic distance. Results of this study suggest that that genetic differentiation among conspecific populations depends not only on the number of migrants (i. e. gene flow, but also on different selection pressure in different habits.

  7. Island selection on mammalian life-histories: genetic differentiation in offspring size

    Directory of Open Access Journals (Sweden)

    Saunanen Raimo

    2008-10-01

    Full Text Available Abstract Background Since Darwin's pioneering work, evolutionary changes in isolated island populations of vertebrates have continued to provide the strongest evidence for the theory of natural selection. Besides macro-evolutionary changes, micro-evolutionary changes and the relative importance of natural selection vs. genetic drift are under intense investigation. Our study focuses on the genetic differentiation in morphological and life-history traits in insular populations of a small mammal the bank vole Myodes glareolus. Results Our results do not support the earlier findings for larger adult size or lower reproductive effort in insular populations of small mammals. However, the individuals living on islands produced larger offspring than individuals living on the mainland. Genetic differentiation in offspring size was further confirmed by the analyses of quantitative genetics in lab. In insular populations, genetic differentiation in offspring size simultaneously decreases the additive genetic variation (VA for that trait. Furthermore, our analyses of differentiation in neutral marker loci (Fst indicate that VA is less than expected on the basis of genetic drift alone, and thus, a lower VA in insular populations could be caused by natural selection. Conclusion We believe that different selection pressures (e.g. higher intraspecific competition in an insular environment might favour larger offspring size in small mammals. Island selection for larger offspring could be the preliminary mechanism in a process which could eventually lead to a smaller litter size and lower reproductive effort frequently found in insular vertebrates.

  8. The effect of dynamical screening on helium (e, 2e) fully differential cross-sections

    Institute of Scientific and Technical Information of China (English)

    Sun Shi-Yan; Jia Xiang-Fu; Miao Xiang-Yang; Zhang Jun-Feng; Xie Yi; Li Xiong-Wei; Shi Wen-Qiang

    2009-01-01

    This paper presents the fully differential cross sections (FDCS) for 102eV electron impact single ionization of helium for both the coplanar and perpendicular plane asymmetric geometries within the framework of dynamically screened three-Coulomb-wave theory. Comparisons are made with the experimental data and those of the three-Coulomb wave function model and second-order distorted-wave Born method. The angular distribution and relative heights of the present FDCS is found to be in very good agreement with the experimental data in the perpendicular plane geometry.It is shown that dynamical screening effects are significant in this geometry. Three-body coupling is expected to be weak in the coplanar geometry, although the precise absolute value of the cross section is still sensitive to the interaction details.

  9. Genetic differentiation and gene flow among six sheep breeds of Mongolian group in China

    Institute of Scientific and Technical Information of China (English)

    Yan GENG; Zhangping YANG; Hong CHANG; Yongjiang MAO; Wei SUN; Xiaoya GUO; Dongyan QU

    2008-01-01

    The level of genetic differentiation,gene flow and the relationship between geographical distance and genetic differentiation among six sheep populations of Mongolian group in China (Tong sheep,small-tailed Han sheep,Hu sheep,Tan sheep,Ujumuqin sheep and Bayinbuluk sheep) were analyzed using seven microsatellites.The trees were constructed from diversity coefficient (DC) distances among the six sheep populations.The overall heterozygote deficit across all the populations (Fit) was between 0.167 (OarAE101) and 0.044 (MAF33).The overall significant deficit of heterozygote,because of inbreeding within breeds,(Fis) was between 0.089 (OarFCB304) and 0.005 (MAF33).The coefficient of genetic differentiation (Fst) was between 0.100 (OarAE101) and 0.022 (Oar-FCB48).It indicated that 3.9% of the total genetic variation could be explained by breed differences and the remaining 96.1% by differences among individuals for each population.This illustrated that most variations existed within breeds and genetic differentiation level were very low among sheep breeds of the Mongolian Group in China.The average number of effective migrants exchanged per generation (Nem) ranged from 2.7369 (Tan sheep and Bayinbuluk sheep) to 44.3928 (Tong sheep and Hu sheep),and the mean value was 11.25213.Significantly positive relationships between the level of genetic differentiation and geographical distance and genetic distances were detected.It is concluded that genetic differentiation of sheep breeds of Mongolian group in China is mainly the result of natural selection (different living conditions).

  10. Genetic differentiation between African and European Midwife Toads (Alytes, Discoglossidae)

    NARCIS (Netherlands)

    Arntzen, J.W.; Szymura, J.M.

    1984-01-01

    Toads of the genus Alytes from the Rif mountains in Morocco are electrophoretically very similar to Iberian Alytes obstetricans (DieN = 0.07). Genetic distance estimates across the Straits of Gibraltar do not exceed the values found among European samples. The data point to relatively recent coloniz

  11. Genetic diversity and differentiation of Pseudophoenix (Arecaceae) in Hispaniola

    Science.gov (United States)

    Technical Abstract Pseudophoenix ekmanii Burret, P. lediniana Read, and P. vinifera (Mart.) Becc. (Arecaceae) are endemic to Hispaniola. The more wide-ranging P. sargentii H.Wendl. ex Sarg. occurs on this island as well. The population genetic diversity and structure of Pseudophoenix was investigate...

  12. Movement behavior explains genetic differentiation in American black bears

    Science.gov (United States)

    Samuel A Cushman; Jesse S. Lewis

    2010-01-01

    Individual-based landscape genetic analyses provide empirically based models of gene flow. It would be valuable to verify the predictions of these models using independent data of a different type. Analyses using different data sources that produce consistent results provide strong support for the generality of the findings. Mating and dispersal movements are the...

  13. Screening of herbal extracts influencing hematopoiesis and their chemical genetic effects in embryonic zebrafish

    Institute of Scientific and Technical Information of China (English)

    Rajaretinam Rajesh Kannan; Samuel Gnana Prakash Vincent

    2012-01-01

    Objective: To screen the herbal extracts influencing the hematopoietic stem cells (HSC) in zebrafish embryos and their chemical genetic effects. Methods: The herbals used in this study had been widely applicable in Siddha medicines in South India. Herbal extracts were treated in zebrafish embryos at 4 d post fertilization and the extracts inducing the HSC were enumerated in hemocytometer. The biocompatibility and the organogenesis of the screened extracts were assessed in the zebrafish embryos for their chemical genetic effects. The LC50 values were calculated with their parallel control. The blood cells were enumerated. Results: The level of RBC was found increased in the Bergera koenigii (B. koenigii) at 15 μg/mL (P<0.05), Mimosa pudica (M. pudica) at 20 μg/mL (P<0.05) and Solanum trilobatum (S. trilobatum) at 25 μg/mL (P<0.05) and decreased RBC level was found in Phyllanthus niruri (P. niruri) at 30 μg/mL (P<0.05). The WBC count was found increased in S. trilobatum at 20 μg/mL (P<0.05) and Annona muricata (Annona muricata) at 15 μg/mL (P<0.05) and the Vitis quadrangularis (V. quadrangularis) at 20 μg/mL (P<0.05) decreased the WBC level. There were no notable effects in heart beats and the chemical genetic effects were observed at higher concentration of the extract resulting in Pericardial bulging, trunk tail flexure with heart edema, fin fold deformities etc. Conclusions: This in vivo based screening of Hematopoiesis is an inexpensive assay to screen herbal compounds and found that S. trilobatum extract influenced embryonic HSC in zebrafish, which could be a therapeutic for blood related disorders.

  14. A genetic screen in Drosophila reveals novel cytoprotective functions of the autophagy-lysosome pathway.

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    Andrew M Arsham

    Full Text Available The highly conserved autophagy-lysosome pathway is the primary mechanism for breakdown and recycling of macromolecular and organellar cargo in the eukaryotic cell. Autophagy has recently been implicated in protection against cancer, neurodegeneration, and infection, and interest is increasing in additional roles of autophagy in human health, disease, and aging. To search for novel cytoprotective features of this pathway, we carried out a genetic mosaic screen for mutations causing increased lysosomal and/or autophagic activity in the Drosophila melanogaster larval fat body. By combining Drosophila genetics with live-cell imaging of the fluorescent dye LysoTracker Red and fixed-cell imaging of autophagy-specific fluorescent protein markers, the screen was designed to identify essential metazoan genes whose disruption causes increased flux through the autophagy-lysosome pathway. The screen identified a large number of genes associated with the protein synthesis and ER-secretory pathways (e.g. aminoacyl tRNA synthetases, Oligosaccharyl transferase, Sec61alpha, and with mitochondrial function and dynamics (e.g. Rieske iron-sulfur protein, Dynamin-related protein 1. We also observed that increased lysosomal and autophagic activity were consistently associated with decreased cell size. Our work demonstrates that disruption of the synthesis, transport, folding, or glycosylation of ER-targeted proteins at any of multiple steps leads to autophagy induction. In addition to illuminating cytoprotective features of autophagy in response to cellular damage, this screen establishes a genetic methodology for investigating cell biological phenotypes in live cells, in the context of viable wild type organisms.

  15. Contrasting patterns of genetic differentiation among Blackcaps (Sylvia atricapilla with divergent migratory orientations in Europe.

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    Raeann Mettler

    Full Text Available Migratory divides are thought to facilitate behavioral, ecological, and genetic divergence among populations with different migratory routes. However, it is currently contentious how much genetic divergence is needed to maintain distinct migratory behavior across migratory divides. Here we investigate patterns of neutral genetic differentiation among Blackcap (Sylvia atricapilla populations with different migratory strategies across Europe. We compare the level of genetic divergence of populations migrating to southwestern (SW or southeastern (SE wintering areas with birds wintering in the British Isles following a recently established northwesterly (NW migration route. The migratory divide between SW and SE wintering areas can be interpreted as a result of a re-colonization process after the last glaciation. Thus we predicted greater levels of genetic differentiation among the SW/SE populations. However, a lack of genetic differentiation was found between SW and SE populations, suggesting that interbreeding likely occurs among Blackcaps with different migratory orientations across a large area; therefore the SW/SE migratory divide can be seen as diffuse, broad band and is, at best, a weak isolating barrier. Conversely, weak, albeit significant genetic differentiation was evident between NW and SW migrants breeding sympatrically in southern Germany, suggesting a stronger isolating mechanism may be acting in this population. Populations located within/near the SW/SE contact zone were the least genetically divergent from NW migrants, confirming NW migrants likely originated from within the contact zone. Significant isolation-by-distance was found among eastern Blackcap populations (i.e. SE migrants, but not among western populations (i.e. NW and SW migrants, revealing different patterns of genetic divergence among Blackcap populations in Europe. We discuss possible explanations for the genetic structure of European Blackcaps and how gene flow

  16. Contrasting Patterns of Genetic Differentiation among Blackcaps (Sylvia atricapilla) with Divergent Migratory Orientations in Europe

    Science.gov (United States)

    Mettler, Raeann; Schaefer, H. Martin; Chernetsov, Nikita; Fiedler, Wolfgang; Hobson, Keith A.; Ilieva, Mihaela; Imhof, Elisabeth; Johnsen, Arild; Renner, Swen C.; Rolshausen, Gregor; Serrano, David; Wesołowski, Tomasz; Segelbacher, Gernot

    2013-01-01

    Migratory divides are thought to facilitate behavioral, ecological, and genetic divergence among populations with different migratory routes. However, it is currently contentious how much genetic divergence is needed to maintain distinct migratory behavior across migratory divides. Here we investigate patterns of neutral genetic differentiation among Blackcap (Sylvia atricapilla) populations with different migratory strategies across Europe. We compare the level of genetic divergence of populations migrating to southwestern (SW) or southeastern (SE) wintering areas with birds wintering in the British Isles following a recently established northwesterly (NW) migration route. The migratory divide between SW and SE wintering areas can be interpreted as a result of a re-colonization process after the last glaciation. Thus we predicted greater levels of genetic differentiation among the SW/SE populations. However, a lack of genetic differentiation was found between SW and SE populations, suggesting that interbreeding likely occurs among Blackcaps with different migratory orientations across a large area; therefore the SW/SE migratory divide can be seen as diffuse, broad band and is, at best, a weak isolating barrier. Conversely, weak, albeit significant genetic differentiation was evident between NW and SW migrants breeding sympatrically in southern Germany, suggesting a stronger isolating mechanism may be acting in this population. Populations located within/near the SW/SE contact zone were the least genetically divergent from NW migrants, confirming NW migrants likely originated from within the contact zone. Significant isolation-by-distance was found among eastern Blackcap populations (i.e. SE migrants), but not among western populations (i.e. NW and SW migrants), revealing different patterns of genetic divergence among Blackcap populations in Europe. We discuss possible explanations for the genetic structure of European Blackcaps and how gene flow influences the

  17. Teratogen screening using transcriptome profiling of differentiating human embryonic stem cells.

    Science.gov (United States)

    Mayshar, Yoav; Yanuka, Ofra; Benvenisty, Nissim

    2011-06-01

    Teratogens are substances that may cause defects in normal embryonic development while not necessarily being toxic in adults. Identification of possible teratogenic compounds has been historically beset by the species-specific nature of the teratogen response. To examine teratogenic effects on early human development we performed non-biased expression profiling of differentiating human embryonic and induced pluripotent stem cells treated with several drugs--ethanol, lithium, retinoic acid (RA), caffeine and thalidomide, which is known to be highly species specific. Our results point to the potency of specific teratogens and their affected tissues and pathways. Specifically, we could show that ethanol caused dramatic increase in endodermal differentiation, RA caused misregulation of neural development and thalidomide affected both these processes. We thus propose this method as a valuable addition to currently available animal screening approaches.

  18. Identification of common genetic modifiers of neurodegenerative diseases from an integrative analysis of diverse genetic screens in model organisms

    Directory of Open Access Journals (Sweden)

    Chen Xi

    2012-02-01

    Full Text Available Abstract Background An array of experimental models have been developed in the small model organisms C. elegans, S. cerevisiae and D. melanogaster for the study of various neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, and expanded polyglutamine diseases as exemplified by Huntington's disease (HD and related ataxias. Genetic approaches to determine the nature of regulators of the disease phenotypes have ranged from small scale to essentially whole genome screens. The published data covers distinct models in all three organisms and one important question is the extent to which shared genetic factors can be uncovered that affect several or all disease models. Surprisingly it has appeared that there may be relatively little overlap and that many of the regulators may be organism or disease-specific. There is, however, a need for a fully integrated analysis of the available genetic data based on careful comparison of orthologues across the species to determine the real extent of overlap. Results We carried out an integrated analysis using C. elegans as the baseline model organism since this is the most widely studied in this context. Combination of data from 28 published studies using small to large scale screens in all three small model organisms gave a total of 950 identifications of genetic regulators. Of these 624 were separate genes with orthologues in C. elegans. In addition, 34 of these genes, which all had human orthologues, were found to overlap across studies. Of the common genetic regulators some such as chaperones, ubiquitin-related enzymes (including the E3 ligase CHIP which directly links the two pathways and histone deacetylases were involved in expected pathways whereas others such as the peroxisomal acyl CoA-oxidase suggest novel targets for neurodegenerative disease therapy Conclusions We identified a significant number of overlapping regulators of neurodegenerative disease models. Since the diseases

  19. Screening ToxCast™ Phase I Chemicals in a Mouse Embryonic Stem Cell Adherent Cell Differentiation and Cytotoxicity (ACDC) Assay

    Science.gov (United States)

    An Adherent Cell Differentiation and Cytotoxicity (ACDC) in vitro assay with mouse embryonic stem cells was used to screen the ToxCast Phase I chemical library for effects on cellular differentiation and cell number. The U.S. Environmental Protection Agency (EPA) established the ...

  20. A genetic screen to isolate Toxoplasma gondii host-cell egress mutants.

    Science.gov (United States)

    Coleman, Bradley I; Gubbels, Marc-Jan

    2012-02-08

    The widespread, obligate intracellular, protozoan parasite Toxoplasma gondii causes opportunistic disease in immuno-compromised patients and causes birth defects upon congenital infection. The lytic replication cycle is characterized by three stages: 1. active invasion of a nucleated host cell; 2. replication inside the host cell; 3. active egress from the host cell. The mechanism of egress is increasingly being appreciated as a unique, highly regulated process, which is still poorly understood at the molecular level. The signaling pathways underlying egress have been characterized through the use of pharmacological agents acting on different aspects of the pathways. As such, several independent triggers of egress have been identified which all converge on the release of intracellular Ca(2+), a signal that is also critical for host cell invasion. This insight informed a candidate gene approach which led to the identification of plant like calcium dependent protein kinase (CDPK) involved in egress. In addition, several recent breakthroughs in understanding egress have been made using (chemical) genetic approaches. To combine the wealth of pharmacological information with the increasing genetic accessibility of Toxoplasma we recently established a screen permitting the enrichment for parasite mutants with a defect in host cell egress. Although chemical mutagenesis using N-ethyl-N-nitrosourea (ENU) or ethyl methanesulfonate (EMS) has been used for decades in the study of Toxoplasma biology, only recently has genetic mapping of mutations underlying the phenotypes become routine. Furthermore, by generating temperature-sensitive mutants, essential processes can be dissected and the underlying genes directly identified. These mutants behave as wild-type under the permissive temperature (35 °C), but fail to proliferate at the restrictive temperature (40 °C) as a result of the mutation in question. Here we illustrate a new phenotypic screening method to isolate mutants

  1. Conflict between genetic and phenotypic differentiation: the evolutionary history of a 'lost and rediscovered' shorebird.

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    Frank E Rheindt

    Full Text Available Understanding and resolving conflicts between phenotypic and genetic differentiation is central to evolutionary research. While phenotypically monomorphic species may exhibit deep genetic divergences, some morphologically distinct taxa lack notable genetic differentiation. Here we conduct a molecular investigation of an enigmatic shorebird with a convoluted taxonomic history, the White-faced Plover (Charadrius alexandrinus dealbatus, widely regarded as a subspecies of the Kentish Plover (C. alexandrinus. Described as distinct in 1863, its name was consistently misapplied in subsequent decades until taxonomic clarification ensued in 2008. Using a recently proposed test of species delimitation, we reconfirm the phenotypic distinctness of dealbatus. We then compare three mitochondrial and seven nuclear DNA markers among 278 samples of dealbatus and alexandrinus from across their breeding range and four other closely related plovers. We fail to find any population genetic differentiation between dealbatus and alexandrinus, whereas the other species are deeply diverged at the study loci. Kentish Plovers join a small but growing list of species for which low levels of genetic differentiation are accompanied by the presence of strong phenotypic divergence, suggesting that diagnostic phenotypic characters may be encoded by few genes that are difficult to detect. Alternatively, gene expression differences may be crucial in producing different phenotypes whereas neutral differentiation may be lagging behind.

  2. Quantitative proteomic analysis for high-throughput screening of differential glycoproteins in hepatocellular carcinoma serum

    Institute of Scientific and Technical Information of China (English)

    Hua-Jun Gao; Ya-Jing Chen; Duo Zuo; Ming-Ming Xiao; Ying Li; Hua Guo; Ning Zhang; Rui-Bing Chen

    2015-01-01

    Objective:Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths. Novel serum biomarkers are required to increase the sensitivity and specificity of serum screening for early HCC diagnosis. This study employed a quantitative proteomic strategy to analyze the differential expression of serum glycoproteins between HCC and normal control serum samples. Methods:Lectin affnity chromatography (LAC) was used to enrich glycoproteins from the serum samples. Quantitative mass spectrometric analysis combined with stable isotope dimethyl labeling and 2D liquid chromatography (LC) separations were performed to examine the differential levels of the detected proteins between HCC and control serum samples. Western blot was used to analyze the differential expression levels of the three serum proteins. Results:A total of 2,280 protein groups were identiifed in the serum samples from HCC patients by using the 2D LC-MS/MS method. Up to 36 proteins were up-regulated in the HCC serum, whereas 19 proteins were down-regulated. Three differential glycoproteins, namely, fibrinogen gamma chain (FGG), FOS-like antigen 2 (FOSL2), and α-1, 6-mannosylglycoprotein 6-β-N-acetylglucosaminyltransferase B (MGAT5B) were validated by Western blot. All these three proteins were up-regulated in the HCC serum samples. Conclusion:A quantitative glycoproteomic method was established and proven useful to determine potential novel biomarkers for HCC.

  3. Quantitative proteomic analysis for high-throughput screening of differential glycoproteins in hepatocellular carcinoma serum

    Science.gov (United States)

    Gao, Hua-Jun; Chen, Ya-Jing; Zuo, Duo; Xiao, Ming-Ming; Li, Ying; Guo, Hua; Zhang, Ning; Chen, Rui-Bing

    2015-01-01

    Objective Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths. Novel serum biomarkers are required to increase the sensitivity and specificity of serum screening for early HCC diagnosis. This study employed a quantitative proteomic strategy to analyze the differential expression of serum glycoproteins between HCC and normal control serum samples. Methods Lectin affinity chromatography (LAC) was used to enrich glycoproteins from the serum samples. Quantitative mass spectrometric analysis combined with stable isotope dimethyl labeling and 2D liquid chromatography (LC) separations were performed to examine the differential levels of the detected proteins between HCC and control serum samples. Western blot was used to analyze the differential expression levels of the three serum proteins. Results A total of 2,280 protein groups were identified in the serum samples from HCC patients by using the 2D LC-MS/MS method. Up to 36 proteins were up-regulated in the HCC serum, whereas 19 proteins were down-regulated. Three differential glycoproteins, namely, fibrinogen gamma chain (FGG), FOS-like antigen 2 (FOSL2), and α-1,6-mannosylglycoprotein 6-β-N-acetylglucosaminyltransferase B (MGAT5B) were validated by Western blot. All these three proteins were up-regulated in the HCC serum samples. Conclusion A quantitative glycoproteomic method was established and proven useful to determine potential novel biomarkers for HCC. PMID:26487969

  4. Genetics differentiation between Arctic and Antarctic monothalamous foraminiferans

    DEFF Research Database (Denmark)

    Pawlowski, Jan; Majewski, Wojciech; Longet, David

    2008-01-01

    Monothalamous (single-chambered) foraminifers are a major component of the benthic meiofauna in high latitude regions. Several morphologically similar species are common in the Arctic and Antarctic. However, it is uncertain whether these morphospecies are genetically identical, or whether...... from Norwegian fjords. Our study has revealed a high number of cryptic species within each of the examined genera, and demonstrates the unexplored potential of monothalamous foraminifers for use as a tool to evaluate the origin and biogeography of polar meiofauna....

  5. Sex-differential genetic effect of phosphodiesterase 4D (PDE4D on carotid atherosclerosis

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    Guo Yuh-Cherng

    2010-06-01

    Full Text Available Abstract Background The phosphodiesterase 4D (PDE4D gene was reported as a susceptibility gene to stroke. The genetic effect might be attributed to its role in modulating the atherogenic process in the carotid arteries. Using carotid intima-media thickness (IMT and plaque index as phenotypes, the present study sought to determine the influence of this gene on subclinical atherosclerosis. Methods Carotid ultrasonography was performed on 1013 stroke-free subjects who participated in the health screening programs (age 52.6 ± 12.2; 47.6% men. Genotype distribution was compared among the high-risk (plaque index ≥ 4, low-risk (index = 1-3, and reference (index = 0 groups. We analyzed continuous IMT data and further dichotomized IMT data using mean plus one standard deviation as the cutoff level. Because the plaque prevalence and IMT values displayed a notable difference between men and women, we carried out sex-specific analyses in addition to analyzing the overall data. Rs702553 at the PDE4D gene was selected because it conferred a risk for young stroke in our previous report. Previous young stroke data (190 cases and 211 controls with an additional 532 control subjects without ultrasonic data were shown as a cross-validation for the genetic effect. Results In the overall analyses, the rare homozygote of rs702553 led to an OR of 3.1 (p = 0.034 for a plaque index ≥ 4. When subjects were stratified by sex, the genetic effect was only evident in men but not in women. Comparing male subjects with plaque index ≥ 4 and those with plaque index = 0, the TT genotype was over-represented (27.6% vs. 13.4%, p = 0.008. For dichotomized IMT data in men, the TT genotype had an OR of 2.1 (p = 0.032 for a thicker IMT at the common carotid artery compared with the (AA + AT genotypes. In women, neither IMT nor plaque index was associated with rs702553. Similarly, SNP rs702553 was only significant in young stroke men (OR = 1.8, p = 0.025 but not in women (p = 0

  6. Analysis of genetic diversity and differentiation of seven stocks of Litopenaeus vannamei using microsatellite markers

    Science.gov (United States)

    Zhang, Kai; Wang, Weiji; Li, Weiya; Zhang, Quanqi; Kong, Jie

    2014-08-01

    Seven microsatellite markers were used to evaluate the genetic diversity and differentiation of seven stocks of Litopenaeus vannamei, which were introduced from Central and South America to China. All seven microsatellite loci were polymorphic, with polymorphism information content ( PIC) values ranging from 0.593 to 0.952. Totally 92 alleles were identified, and the number of alleles ( Na) and effective alleles ( Ne) varied between 4 and 21 and 2.7 and 14.6, respectively. Observed heterozygosity ( H o) values were lower than the expected heterozygosity ( H e) values (0.526-0.754), which indicated that the seven stocks possessed a rich genetic diversity. Thirty-seven tests were detected for reasonable significant deviation from Hardy-Weinberg equilibrium. F is values were positive at five loci, suggesting that there was a relatively high degree of inbreeding within stocks. Pairwise F st values ranged from 0.0225 to 0.151, and most of the stock pairs were moderately differentiated. Genetic distance and cluster analysis using UPGMA revealed a close genetic relationship of L. vannamei between Pop2 and Pop3. AMOVA indicated that the genetic variation among stocks (11.3%) was much lower than that within stocks (88.7%). Although the seven stocks had a certain degree of genetic differentiation and a rich genetic diversity, there is an increasing risk of decreased performance due to inbreeding in subsequent generations.

  7. An analysis of differential item functioning by gender in the Learning Disability Screening Questionnaire (LDSQ).

    Science.gov (United States)

    Murray, Aja Louise; Booth, Tom; McKenzie, Karen

    2015-04-01

    The Learning Disability Screening Questionnaire (LDSQ; McKenzie & Paxton, 2006) was developed as a brief screen for intellectual disability. Although several previous studies have evaluated the LDSQ with respect to its utility as a clinical and research tool, no studies have considered the fairness of the test across males and females. In the current study we, therefore, used a multi-group item response theory approach to assess differential item functioning across gender in a sample of 211 males and 132 females assessed in clinical and forensic settings. Although the test did not show evidence of differential item functioning by gender, it was necessary to exclude one item due to estimation problems and to combine two very highly related items (concerning reading and writing ability) into a single literacy item Thus, in addition to being generally supportive of the utility of the LDSQ, our results also highlight possible areas of weakness in the tool and suggest possible amendments that could be made to test content to improve the test in future revisions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Genetic differentiation between marine iguanas from different breeding sites on the island of Santa Fe (Galapagos Archipelago).

    Science.gov (United States)

    Lanterbecq, Deborah; Glaberman, Scott; Vitousek, Maren Noelani; Steinfartz, Sebastian; Benavides, Edgar; Wikelski, Martin; Caccone, Adalgisa

    2010-01-01

    We studied patterns of genetic diversity within and among 5 populations (318 individuals) of Galápagos marine iguanas (Amblyrhynchus cristatus) from the island Santa Fé. Populations were separated by distances of 0.2 to 9.9 km. We sequenced 1182 base pairs of the mitochondrial control region and screened 13 microsatellite loci for variability. We also added data from 5 populations (397 individuals) sampled on 4 neighboring islands (Santa Cruz, Floreana, Espanola, and San Cristobal). The 5 Santa Fé populations, revealed as genetically distinct from populations on other islands, present relatively low levels of genetic diversity, which are similar for both microsatellite (average observed heterozygosity from 0.7686 to 0.7773) and mitochondrial DNA (mtDNA) markers (haplotypic and nucleotide diversity from 0.587 to 0.728 and from 0.00079 to 0.00293, respectively), and comparable with those observed in similar-sized sampling sites on other islands. There was frequency-based evidence of genetic structure between northern and southern sites on Santa Fé (F(st) of 0.0027-0.0115 for microsatellite and 0.0447-0.2391 for mtDNA), but the 4 southern sites showed little differentiation. Most of the intra-island genetic variation was allocated within rather than between sites. There was no evidence of sex-biased dispersal or population substructuring due to lek-mating behavior, suggesting that these 2 observed behaviors are not strong enough to leave an evolutionary signal on genetic patterns in this species.

  9. Genetic differential susceptibility on trial: meta-analytic support from randomized controlled experiments.

    Science.gov (United States)

    van Ijzendoorn, Marinus H; Bakermans-Kranenburg, Marian J

    2015-02-01

    The most stringent test of differential susceptibility theory is provided by randomized control trials examining the moderating role of genetic markers of differential susceptibility in experimental manipulations of the environment (Gene × Experimental Environment interactions), being at least 10 times more powerful than correlational Gene × Environment interaction studies. We identified 22 experiments involving 3,257 participants with various developmental outcomes (e.g., externalizing problems, internalizing behaviors, and cognitive development). Effect sizes contrasting experimental versus control group were computed both for subjects with the polymorphism considered indicative of heightened susceptibility (e.g., the dopamine receptor D4 gene seven-repeat allele and the serotonin transporter polymorphic region short allele) and others expected to be low in susceptibility (e.g., the dopamine receptor D4 gene four-repeat allele and the serotonin transporter polymorphic region short allele). Clear-cut experimental support for genetic differential susceptibility emerged: the combined effect size of the interventions for the susceptible genotypes amounted to r = .33 (95% confidence interval = 0.23, 0.42; p differential susceptibility than microtrials, and differential susceptibility was more clearly observed in trials with externalizing and cognitive outcomes than with internalizing problems. This meta-analysis shows proof of principle for genetic differential susceptibility and indicates that it is time to explore its mechanisms and limits. The concept of differential susceptibility alters the idea of constitutional "risk" factors (reactive temperament and risk genotypes), and points to intervention efficacy hidden in Gene × Environment interactions.

  10. Genetic differentiation among sexually compatible relatives of Brassica napus L.

    Directory of Open Access Journals (Sweden)

    Pipan Barbara

    2013-01-01

    Full Text Available Analysis of gene flow between Brassica napus L. and its sexually compatible relatives that could be found in the wild in Slovenia was performed by microsatellite analysis using fifteen selected primer pairs. Genotypes included in the study were obtained from the field survey of sexually compatible relatives of B. napus in natural habitats around Slovenia and from reference collections. Two different wild species of all the presented sexually compatible relatives of B. napus were found in Slovenia, B. rapa and Sinapis arvensis. The reference genotypes included varieties and wild forms from internal collections as marketable seeds or from gene banks. Reference genotypes were represented by the following species and subspecies: B. napus ssp. napobrassica, B. napus ssp. napus, B. nigra, B. oleracea, B. rapa ssp. oleifera, Diplotaxis muralis; D. tenuifolia, Raphanus raphanistrum, R. sativus, R. sativus var. oleiformis, Rapistrum rugosum, S. alba and S. arvensis. Estimation of gene flow described by average number of migrants was 0.72 followed by 0.20 migrants. Due to the observed gene migrations, genetic drift and selection, Hardy-Weinberg equilibrium was not met. The mean number of alleles over all loci was 16.9, the average polymorphic information content was 0.43. We found four highly divergent and polymorphic loci (Na12-C08, Na10-A08, Ni3-G04b and BRMS-050 at statistically significant level (p<0.05 of gene flow detected. Over all gene diversity intra-individual among populations (0.55 was lower than inter-individual among population (0.77. The results of genetic linkages based standard genetic distance and unweighted pair group method with arithmetic mean clustering method, generally divided the genotypes in three divergent groups. Similar results were obtained by principal coordinate analysis where three main groups were constructed according to three factors. A real number of genetic clusters demonstrated a clear separation between populations

  11. Genetic differentiation of watermelon landrace types in Mali revealed by microsatellite (SSR) markers

    DEFF Research Database (Denmark)

    Nantoume, Aminata Dolo; Andersen, Sven Bode; Jensen, Brita Dahl

    2013-01-01

    This study describes the genetic differentiation of a collection of 134 watermelon landrace accessions from Mali, representing red fleshed dessert and white fleshed seed and cooking type watermelons from five regions, plus three commercial dessert type cultivars with red flesh. The material...... the accessions into use groups (dessert, cooking, seed processing) explained 25 % of the variation. When categorising the accessions further into 10 landrace types, differentiated on the basis of use groups, local accession name, flesh colour and seed phenotype, these landrace types explained 26...... % of the variation. Analysis with the software Structure revealed that the accessions with confidence could be separated into two major genetic groups, related to flesh colour (red and white) of the watermelon fruits. The same analysis further indicated that the material may be differentiated into eight genetic sub...

  12. Hybridizing Differential Evolution with a Genetic Algorithm for Color Image Segmentation

    Directory of Open Access Journals (Sweden)

    R. V. V. Krishna

    2016-10-01

    Full Text Available This paper proposes a hybrid of differential evolution and genetic algorithms to solve the color image segmentation problem. Clustering based color image segmentation algorithms segment an image by clustering the features of color and texture, thereby obtaining accurate prototype cluster centers. In the proposed algorithm, the color features are obtained using the homogeneity model. A new texture feature named Power Law Descriptor (PLD which is a modification of Weber Local Descriptor (WLD is proposed and further used as a texture feature for clustering. Genetic algorithms are competent in handling binary variables, while differential evolution on the other hand is more efficient in handling real parameters. The obtained texture feature is binary in nature and the color feature is a real value, which suits very well the hybrid cluster center optimization problem in image segmentation. Thus in the proposed algorithm, the optimum texture feature centers are evolved using genetic algorithms, whereas the optimum color feature centers are evolved using differential evolution.

  13. Testing for direct genetic effects using a screening step in family-based association studies

    Directory of Open Access Journals (Sweden)

    Sharon M Lutz

    2013-11-01

    Full Text Available In genome wide association studies (GWAS, families based studies tend to have less power to detect genetic associations than population based studies, such as case-control studies. This can be an issue when testing if genes in a family based GWAS have a direct effect on the phenotype of interest or if the genes act indirectly through a secondary phenotype. When multiple SNPs are tested for a direct effect in the family based study, a screening step can be used to minimize the burden of multiple comparisons in the causal analysis. We propose a 2-stage screening step that can be incorporated into the family based association test (FBAT approach similar to the conditional mean model approach in the VanSteen-algorithm [1]. Simulations demonstrate that the type 1 error is preserved and this method is advantageous when multiple markers are tested. This method is illustrated by an application to the Framingham Heart Study.

  14. Neonatal Screening: Some Ethical Issues of Expanding Spectrum for Genetically Determined Diseases

    Directory of Open Access Journals (Sweden)

    S. S. Deryabina

    2015-01-01

    Full Text Available The article considers philosophical questions of neonatal screening technology. The main focus is on ethical and methodological issues that inevitably arise when expanding the number of scanned nosologies and applying genetic research methods. Questions concerning the existing discrepancy between technical capacity and the practical level of healthcare delivery and the probabilistic nature of results obtained by molecular testing are analyzed in terms of methodology. Access to information about the DNA-testing of newborns and the linkage between neonatal screening and prenatal diagnostics are among the most topical ethical problems raised within this article. One of the purposes of this article is to draw the attention of the public — especially it concerns current and prospective parents and volunteer organizations — to these contemporary problems.

  15. Large-Scale Forward Genetic Screening Analysis of Development of Hematopoiesis in Zebrafish

    Institute of Scientific and Technical Information of China (English)

    Kun Wang; Ning Ma; Yiyue Zhang; Wenqing Zhang; Zhibin Huang; Lingfeng Zhao; Wei Liu; Xiaohui Chen; Ping Meng; Qing Lin; Yali Chi; Mengchang Xu

    2012-01-01

    Zebrafish is a powerful model for the investigation of hematopoiesis.In order to isolate novel mutants with hematopoietic defects,large-scale mutagenesis screening of zebrafish was performed.By scoring specific hematopoietic markers,52 mutants were identified and then classified into four types based on specific phenotypic traits.Each mutant represented a putative mutation of a gene regulating the relevant aspect of hematopoiesis,including early macrophage development,early granulopoiesis,embryonic myelopoiesis,and definitive erythropoiesis/lymphopoiesis.Our method should be applicable for other types of genetic screening in zebrafish.In addition,further study of the mutants we identified may help to unveil the molecular basis of hematopoiesis.

  16. Genetic screens and functional genomics using CRISPR/Cas9 technology.

    Science.gov (United States)

    Hartenian, Ella; Doench, John G

    2015-04-01

    Functional genomics attempts to understand the genome by perturbing the flow of information from DNA to RNA to protein, in order to learn how gene dysfunction leads to disease. CRISPR/Cas9 technology is the newest tool in the geneticist's toolbox, allowing researchers to edit DNA with unprecedented ease, speed and accuracy, and representing a novel means to perform genome-wide genetic screens to discover gene function. In this review, we first summarize the discovery and characterization of CRISPR/Cas9, and then compare it to other genome engineering technologies. We discuss its initial use in screening applications, with a focus on optimizing on-target activity and minimizing off-target effects. Finally, we comment on future challenges and opportunities afforded by this technology.

  17. Genetic Screening for Bacterial Mutants in Liquid Growth Media By Fluorescence-Activated Cell Sorting

    Science.gov (United States)

    Abuaita, Basel H.; Withey, Jeffrey H.

    2010-01-01

    Many bacterial pathogens have defined in vitro virulence inducing conditions in liquid media which lead to production of virulence factors important during an infection. Identifying mutants that no longer respond to virulence inducing conditions will increase our understanding of bacterial pathogenesis. However, traditional genetic screens require growth on solid media. Bacteria in a single colony are in every phase of the growth curve, which complicates the analysis and make screens for growth phase-specific mutants problematic. Here, we utilize fluorescence-activated cell sorting in conjunction with random transposon mutagenesis to isolate bacteria grown in liquid media that are defective in virulence activation. This method permits analysis of an entire bacterial population in real time and selection of individual bacterial mutants with the desired gene expression profile at any time point after induction. We have used this method to identify Vibrio cholerae mutants defective in virulence induction. PMID:21094189

  18. Habitat Fragmentation Differentially Affects Genetic Variation, Phenotypic Plasticity and Survival in Populations of a Gypsum Endemic.

    Science.gov (United States)

    Matesanz, Silvia; Rubio Teso, María Luisa; García-Fernández, Alfredo; Escudero, Adrián

    2017-01-01

    Habitat fragmentation, i.e., fragment size and isolation, can differentially alter patterns of neutral and quantitative genetic variation, fitness and phenotypic plasticity of plant populations, but their effects have rarely been tested simultaneously. We assessed the combined effects of size and connectivity on these aspects of genetic and phenotypic variation in populations of Centaurea hyssopifolia, a narrow endemic gypsophile that previously showed performance differences associated with fragmentation. We grew 111 maternal families sampled from 10 populations that differed in their fragment size and connectivity in a common garden, and characterized quantitative genetic variation, phenotypic plasticity to drought for key functional traits, and plant survival, as a measure of population fitness. We also assessed neutral genetic variation within and among populations using eight microsatellite markers. Although C. hyssopifolia is a narrow endemic gypsophile, we found substantial neutral genetic variation and quantitative variation for key functional traits. The partition of genetic variance indicated that a higher proportion of variation was found within populations, which is also consistent with low population differentiation in molecular markers, functional traits and their plasticity. This, combined with the generally small effect of habitat fragmentation suggests that gene flow among populations is not restricted, despite large differences in fragment size and isolation. Importantly, population's similarities in genetic variation and plasticity did not reflect the lower survival observed in isolated populations. Overall, our results indicate that, although the species consists of genetically variable populations able to express functional plasticity, such aspects of adaptive potential may not always reflect populations' survival. Given the differential effects of habitat connectivity on functional traits, genetic variation and fitness, our study highlights

  19. Habitat Fragmentation Differentially Affects Genetic Variation, Phenotypic Plasticity and Survival in Populations of a Gypsum Endemic

    Directory of Open Access Journals (Sweden)

    Silvia Matesanz

    2017-05-01

    Full Text Available Habitat fragmentation, i.e., fragment size and isolation, can differentially alter patterns of neutral and quantitative genetic variation, fitness and phenotypic plasticity of plant populations, but their effects have rarely been tested simultaneously. We assessed the combined effects of size and connectivity on these aspects of genetic and phenotypic variation in populations of Centaurea hyssopifolia, a narrow endemic gypsophile that previously showed performance differences associated with fragmentation. We grew 111 maternal families sampled from 10 populations that differed in their fragment size and connectivity in a common garden, and characterized quantitative genetic variation, phenotypic plasticity to drought for key functional traits, and plant survival, as a measure of population fitness. We also assessed neutral genetic variation within and among populations using eight microsatellite markers. Although C. hyssopifolia is a narrow endemic gypsophile, we found substantial neutral genetic variation and quantitative variation for key functional traits. The partition of genetic variance indicated that a higher proportion of variation was found within populations, which is also consistent with low population differentiation in molecular markers, functional traits and their plasticity. This, combined with the generally small effect of habitat fragmentation suggests that gene flow among populations is not restricted, despite large differences in fragment size and isolation. Importantly, population’s similarities in genetic variation and plasticity did not reflect the lower survival observed in isolated populations. Overall, our results indicate that, although the species consists of genetically variable populations able to express functional plasticity, such aspects of adaptive potential may not always reflect populations’ survival. Given the differential effects of habitat connectivity on functional traits, genetic variation and fitness

  20. Mitochondrial DNA markers reveal high genetic diversity and strong genetic differentiation in populations of Dendrolimus kikuchii Matsumura (Lepidoptera: Lasiocampidae).

    Science.gov (United States)

    Men, Qiulei; Xue, Guoxi; Mu, Dan; Hu, Qingling; Huang, Minyi

    2017-01-01

    Dendrolimus kikuchii Matsumura, 1927 is a serious forest pest causing great damage to coniferous trees in China. Despite its economic importance, the population genetics of this pest are poorly known. We used three mitochondrial genes (COI, COII and Cytb) to investigate the genetic diversity and genetic differentiation of 15 populations collected from the main distribution regions of D. kikuchii in China. Populations show high haplotype and nucleotide diversity. Haplotype network and phylogenetic analysis divides the populations into three major clades, the central and southeastern China (CC+SEC) clade, the eastern China (EC) clade, and the southwestern China (SWC) clade. Populations collected from adjacent localities share the same clade, which is consistent with the strong relationship of isolation by distance (r = 0.74824, P = 0.00001). AMOVA analysis indicated that the major portion of this molecular genetic variation is found among the three groups of CC+SEC, EC and SWC (61.26%). Of 105 pairwise FST comparisons, 93 show high genetic differentiation. Populations of Puer (PE), Yangshuo (YS) and Leishan (LS) are separated from other populations by a larger genetic distance. Distributions of pairwise differences obtained with single and combined gene data from the overall populations are multimodal, suggesting these populations had no prior population expansion in southern China. The nonsignificant neutral test on the basis of Tajima' D and Fu's Fs, and the lack of a star-shaped haplotype network together with the multiple haplotypes support this hypothesis. Pleistocene climatic fluctuations, combined with the host specificity to Pinus species, made these regions of south China into a refuge for D. kikuchii. The high level of population genetic structuring is related to their weak flight capacity, their variations of life history and the geographic distance among populations.

  1. A score based on screening tests to differentiate mild cognitive impairment from subjective memory complaints

    Directory of Open Access Journals (Sweden)

    Fábio Henrique de Gobbi Porto

    2013-09-01

    Full Text Available It is not easy to differentiate patients with mild cognitive impairment (MCI from subjective memory complainers (SMC. Assessments with screening cognitive tools are essential, particularly in primary care where most patients are seen. The objective of this study was to evaluate the diagnostic accuracy of screening cognitive tests and to propose a score derived from screening tests. Elderly subjects with memory complaints were evaluated using the Mini Mental State Examination (MMSE and the Brief Cognitive Battery (BCB. We added two delayed recalls in the MMSE (a delayed recall and a late-delayed recall, LDR, and also a phonemic fluency test of letter P fluency (LPF. A score was created based on these tests. The diagnoses were made on the basis of clinical consensus and neuropsychological testing. Receiver operating characteristic curve analyses were used to determine area under the curve (AUC, the sensitivity and specificity for each test separately and for the final proposed score. MMSE, LDR, LPF and delayed recall of BCB scores reach statistically significant differences between groups (P=0.000, 0.03, 0.001 and 0.01, respectively. Sensitivity, specificity and AUC were MMSE: 64%, 79% and 0.75 (cut off <29; LDR: 56%, 62% and 0.62 (cut off <3; LPF: 71%, 71% and 0.71 (cut off <14; delayed recall of BCB: 56%, 82% and 0.68 (cut off <9. The proposed score reached a sensitivity of 88% and 76% and specificity of 62% and 75% for cut off over 1 and over 2, respectively. AUC were 0.81. In conclusion, a score created from screening tests is capable of discriminating MCI from SMC with moderate to good accurancy.

  2. Population and subspecific genetic differentiation in the foxtail pine (Pinus balfouriana).

    Science.gov (United States)

    Oline, D K; Mitton, J B; Grant, M C

    2000-10-01

    We performed an allozyme survey of genetic differentiation in Pinus balfouriana, a subalpine conifer endemic to California that is comprised of two allopatric subspecies, one in the Klamath Mountains and the other in the southern Sierra Nevada. Although the two subspecies are morphologically distinct and gene flow between them is virtually nonexistent, we observed much higher levels of differentiation among populations within a subspecies than between the two subspecies. Differentiation is particularly strong in the Klamath populations (multilocus FST = 0.242), which are small, isolated, and ecologically marginal. We attribute this strong differentiation to the mountain island effect, in which populations restricted to high elevations become isolated from each other on different mountains separated by unsuitable intervening habitat, with consequent reduced gene flow allowing populations to evolve independently. Populations of P. balfouriana in the Klamath region only exist scattered on the few highest ridges and peaks that rise above 2,000 m, which defines the lower limit of the species elevational distribution. This pattern of distribution has allowed genetic drift and allelic sorting through historical events to produce strong population-level differentiation, which was likely in place before the two subspecies were geographically separated. Because P. balfouriana occurs on both serpentine soils and nonserpentine soils in the Klamath Mountains, we tested for genetic differentiation between populations growing on serpentine versus nonserpentine soils and our results were equivocal. Our data, combined with several other studies of conifers, show that the mountain island effect can produce significant genetic differentiation in conifers whose life-history traits of widely dispersed pollen, long generation times, and high outcrossing rates would lead us to predict a more homogenous population genetic structure.

  3. Differential Genetic and Environmental Influences on Reactive and Proactive Aggression in Children

    OpenAIRE

    2008-01-01

    While significant heritability for childhood aggression has been claimed, it is not known whether there are differential genetic and environmental contributions to proactive and reactive forms of aggression in children. This study quantifies genetic and environmental contributions to these two forms of aggression in an ethnically diverse urban sample of 9–10 year old twins (N=1219), and compares results across different informants (child self-report, mother, and teacher ratings) using the Rea...

  4. A Genetic Screen Identifies Hypothalamic Fgf15 as a Regulator of Glucagon Secretion

    Directory of Open Access Journals (Sweden)

    Alexandre Picard

    2016-11-01

    Full Text Available The counterregulatory response to hypoglycemia, which restores normal blood glucose levels to ensure sufficient provision of glucose to the brain, is critical for survival. To discover underlying brain regulatory systems, we performed a genetic screen in recombinant inbred mice for quantitative trait loci (QTL controlling glucagon secretion in response to neuroglucopenia. We identified a QTL on the distal part of chromosome 7 and combined this genetic information with transcriptomic analysis of hypothalami. This revealed Fgf15 as the strongest candidate to control the glucagon response. Fgf15 was expressed by neurons of the dorsomedial hypothalamus and the perifornical area. Intracerebroventricular injection of FGF19, the human ortholog of Fgf15, reduced activation by neuroglucopenia of dorsal vagal complex neurons, of the parasympathetic nerve, and lowered glucagon secretion. In contrast, silencing Fgf15 in the dorsomedial hypothalamus increased neuroglucopenia-induced glucagon secretion. These data identify hypothalamic Fgf15 as a regulator of glucagon secretion.

  5. Quick genetic screening using targeted next-generation sequencing in patients with tuberous sclerosis.

    Science.gov (United States)

    Liu, Qing; Huang, Yan; Zhang, Mingrong; Wang, Lian Qing; Guo, Xia Nan; Si, Nuo; Qi, Zhan; Zhou, Xiang Qin; Cui, Li-ying

    2015-04-01

    Tuberous sclerosis complex is an autosomal dominant disorder characterized by hamartomas in multiple organ systems. Mutations in the 2 large genes TSC1 and TSC2 have been demonstrated to be associated with tuberous sclerosis complex by various mutation screening methods. Targeted next-generation sequencing for genetic analysis is performed in the current study and is proved to be less cost, labor, and time consuming compared with Sanger sequencing. Two de novo and 1 recurrent TSC2 mutation in patients with tuberous sclerosis complex were revealed. Clinical details of patients were described and the underlying mechanism of the 2 novel TSC2 mutations, c.245G>A(p.W82X) and c.5405_5408dupACTT(p.P1803Lfs*25), were discussed. These results added to variability of TSC mutation spectrum and suggest that targeted next-generation sequencing could be the primary choice over Sanger sequencing in future tuberous sclerosis complex genetic counseling.

  6. High degree of genetic differentiation in marine three-spined sticklebacks (Gasterosteus aculeatus).

    Science.gov (United States)

    Defaveri, Jacquelin; Shikano, Takahito; Shimada, Yukinori; Merilä, Juha

    2013-09-01

    Populations of widespread marine organisms are typically characterized by a low degree of genetic differentiation in neutral genetic markers, but much less is known about differentiation in genes whose functional roles are associated with specific selection regimes. To uncover possible adaptive population divergence and heterogeneous genomic differentiation in marine three-spined sticklebacks (Gasterosteus aculeatus), we used a candidate gene-based genome-scan approach to analyse variability in 138 microsatellite loci located within/close to (genetic differentiation in markers classified as neutral or under balancing selection-as determined with several outlier detection methods-was low (F(ST) = 0.033 or 0.011, respectively), whereas average FST for directionally selected markers was significantly higher (F(ST) = 0.097). Clustering analyses provided support for genomic and geographic heterogeneity in selection: six genetic clusters were identified based on allele frequency differences in the directionally selected loci, whereas four were identified with the neutral loci. Allelic variation in several loci exhibited significant associations with environmental variables, supporting the conjecture that temperature and salinity, but not optic conditions, are important drivers of adaptive divergence among populations. In general, these results suggest that in spite of the high degree of physical connectivity and gene flow as inferred from neutral marker genes, marine stickleback populations are strongly genetically structured in loci associated with functionally relevant genes.

  7. New Advances of Preimplantation and Prenatal Genetic Screening and Noninvasive Testing as a Potential Predictor of Health Status of Babies

    Directory of Open Access Journals (Sweden)

    Tanya Milachich

    2014-01-01

    Full Text Available The current morphologically based selection of human embryos for transfer cannot detect chromosome aneuploidies. So far, only biopsy techniques have been able to screen for chromosomal aneuploidies in the in vitro fertilization (IVF embryos. Preimplantation genetic diagnosis (PGD or screening (PGS involves the biopsy of oocyte polar bodies or embryonic cells and has become a routine clinical procedure in many IVF clinics worldwide, including recent development of comprehensive chromosome screening of all 23 pairs of chromosomes by microarrays for aneuploidy screening. The routine preimplantation and prenatal genetic diagnosis (PND require testing in an aggressive manner. These procedures may be invasive to the growing embryo and fetus and potentially could compromise the clinical outcome. Therefore the aim of this review is to summarize not only the new knowledge on preimplantation and prenatal genetic diagnosis in humans, but also on the development of potential noninvasive embryo and fetal testing that might play an important role in the future.

  8. Flies across the water: genetic differentiation and reproductive isolation in allopatric desert Drosophila.

    Science.gov (United States)

    Markow, Therese A; Castrezana, Sergio; Pfeiler, Edward

    2002-03-01

    Between sister species of Drosophila, both pre- and postzygotic reproductive isolation commonly appear by the time a Nei's genetic distance of 0.5 is observed. The degree of genetic differentiation present when allopatric populations of the same Drosophila species exhibit incipient reproductive isolation has not been systematically investigated. Here we compare the relationship between genetic differentiation and pre- and postzygotic isolation among allopatric populations of three cactophilic desert Drosophila: D. mettleri, D. nigrospiracula, and D. mojavensis. The range of all three is interrupted by the Gulf of California, while two species, D. mettleri and D. mojavensis, have additional allopatric populations residing on distant Santa Catalina Island, off the coast of southern California. Significant population structure exists within all three species, but only for allopatric populations of D. mojavensis is significant isolation at the prezygotic level observed. The genetic distances for the relevant populations of D. mojavensis were in the range of 0.12, similar to that for D. mettleri whose greatest D = 0.11 was unassociated with any form of isolation. These observations suggest further investigations of Drosophila populations with genetic distances in this range be undertaken to identify any potential patterns in the relationship between degree of genetic differentiation and the appearance of pre- and/or postzygotic isolation.

  9. Regional genetic differentiation in the blue mussel from the Baltic Sea area

    Science.gov (United States)

    Larsson, J.; Lind, E. E.; Corell, H.; Grahn, M.; Smolarz, K.; Lönn, M.

    2017-08-01

    Connectivity plays an important role in shaping the genetic structure and in evolution of local adaptation. In the marine environment barriers to gene flow are in most cases caused by gradients in environmental factors, ocean circulation and/or larval behavior. Despite the long pelagic larval stages, with high potential for dispersal many marine organisms have been shown to have a fine scale genetic structuring. In this study, by using a combination of high-resolution genetic markers, species hybridization data and biophysical modeling we can present a comprehensive picture of the evolutionary landscape for a keystone species in the Baltic Sea, the blue mussel. We identified distinct genetic differentiation between the West Coast, Baltic Proper and Bothnian Sea regions, with lower gene diversity in the Bothnian Sea. Oceanographic connectivity together with salinity and to some extent species identity provides explanations for the genetic differentiation between the West Coast and the Baltic Sea (Baltic Proper and Bothnian Sea). The genetic differentiation between the Baltic Proper and Bothnian Sea cannot be directly explained by oceanographic connectivity, species identity or salinity, while the lower connectivity to the Bothnian Sea may explain the lower gene diversity.

  10. Genetic and Ecotypic Differentiation in a Californian Plant Polyploid Complex (Grindelia, Asteraceae)

    OpenAIRE

    Abigail J Moore; Moore, William L.; Baldwin, Bruce G.

    2014-01-01

    Studies of ecotypic differentiation in the California Floristic Province have contributed greatly to plant evolutionary biology since the pioneering work of Clausen, Keck, and Hiesey. The extent of gene flow and genetic differentiation across interfertile ecotypes that span major habitats in the California Floristic Province is understudied, however, and is important for understanding the prospects for local adaptation to evolve or persist in the face of potential gene flow across populations...

  11. Inlfuence of Host Shift on Genetic Differentiation of the Oriental Fruit Fly, Bactrocera dorsalis

    Institute of Scientific and Technical Information of China (English)

    WAN Xuan-wu; LIU Ying-hong; LUO Lin-ming; FENG Chuan-hong; WANG Sheng; MA Li

    2014-01-01

    Invasion of the oriental fruit lfy, Bactrocera dorsalis, into new niches containing different food sources (a process referred to as host shift), may cause population genetic differentiation and sympatric speciation. To attempt to infer that experimentally, test populations were established by transferring a subset of the original populations, which had been grown on banana for many generations, onto navel orange, and then subculturing the navel orange population and banana population for at least 20 generations. Four pairs of SSR primers with high polymorphism on laboratory strains were used to detect population genetic differentiation. All six tested populations (the 5th, 10th and 15th generations of B. dorsalis fed on banana and navel orange, respectively) were found to have low genetic diversity. Furthermore, the genetic diversity of the navel orange populations was found to decline after being crossed for several generations. Populations initially were deviated from Hardy-Weinberg equilibrium, however, equilibrium was achieved with increasing numbers of generations in both of the host populations. Limited gene lfows were found among the six populations. The Nei’s standard genetic distances between the two host populations of the same generation were initially low, but increased with generation number. Genetic distances between banana and navel orange populations of the same generation were lower than genetic distances between different generations grown on the same host plant. Analysis of molecular distance (AMOVA) results based on generation groups and host groups demonstrated that genetic variation among generations was greater than that between the two host populations. The results indicated that population genetic differentiation occurred after the host shift, albeit at low level. Biogeography and taxonomy of the B. dorsalis complex revealed that speciation of B. dorsalis might be tightly associated with host shift or host specialization of B. dorsalis

  12. Differential genetic regulation of canine hip dysplasia and osteoarthritis.

    Directory of Open Access Journals (Sweden)

    Zhengkui Zhou

    Full Text Available BACKGROUND: Canine hip dysplasia (HD is a common polygenic trait characterized by hip malformation that results in osteoarthritis (OA. The condition in dogs is very similar to developmental dysplasia of the human hip which also leads to OA. METHODOLOGY/PRINCIPAL FINDINGS: A total of 721 dogs, including both an association and linkage population, were genotyped. The association population included 8 pure breeds (Labrador retriever, Greyhounds, German Shepherd, Newfoundland, Golden retriever, Rottweiler, Border Collie and Bernese Mountain Dog. The linkage population included Labrador retrievers, Greyhounds, and their crosses. Of these, 366 dogs were genotyped at ∼22,000 single nucleotide polymorphism (SNP loci and a targeted screen across 8 chromosomes with ∼3,300 SNPs was performed on 551 dogs (196 dogs were common to both sets. A mixed linear model approach was used to perform an association study on this combined association and linkage population. The study identified 4 susceptibility SNPs associated with HD and 2 SNPs associated with hip OA. CONCLUSION/SIGNIFICANCE: The identified SNPs included those near known genes (PTPRD, PARD3B, and COL15A1 reported to be associated with, or expressed in, OA in humans. This suggested that the canine model could provide a unique opportunity to identify genes underlying natural HD and hip OA, which are common and debilitating conditions in both dogs and humans.

  13. Review:Aluminium tolerance in barley (Hordeum vulgare L.): physiological mechanisms, genetics and screening methods

    Institute of Scientific and Technical Information of China (English)

    WANG Jun-ping; RAMAN Harsh; ZHANG Guo-ping; MENDHAM Neville; ZHOU Mei-xue

    2006-01-01

    Aluminium (Al) toxicity is one of the major limiting factors for barley production on acid soils. It inhibits root cell division and elongation, thus reducing water and nutrient uptake, consequently resulting in poor plant growth and yield. Plants tolerate Al either through external resistance mechanisms, by which Al is excluded from plant tissues or internal tolerance mechanisms, conferring the ability of plants to tolerate Al ion in the plant symplasm where Al that has permeated the plasmalemma is sequestered or converted into an innocuous form. Barley is considered to be most sensitive to Al toxicity among cereal species. Al tolerance in barley has been assessed by several methods, such as nutrient solution culture, soil bioassay and field screening. Genetic and molecular mapping research has shown that Al tolerance in barley is controlled by a single locus which is located on chromosome 4H. Molecular markers linked with Al tolerance loci have been identified and validated in a range of diverse populations. This paper reviews the (1) screening methods for evaluating Al tolerance, (2) genetics and (3) mechanisms underlying Al tolerance in barley.

  14. Multiplicity of experimental approaches to therapy for genetic muscle diseases and necessity for population screening.

    Science.gov (United States)

    Laing, Nigel G

    2008-01-01

    Currently a multiplicity of experimental approaches to therapy for genetic muscle diseases is being investigated. These include replacement of the missing gene, manipulation of the gene message, repair of the mutation, upregulation of an alternative gene and pharmacological interventions targeting a number of systems. A number of these approaches are in current clinical trials. There is considerable anticipation that perhaps more than one of the approaches will finally prove of clinical benefit, but there are many voices of caution. No matter which approaches might ultimately prove effective, there is a consensus that for most benefit to the patients it will be necessary to start treatment as early as possible. A consensus is also developing that the only way to do this is to implement population-based newborn screening to identify affected children shortly after birth. Population-based newborn screening is currently practised in very few places in the world and it brings with it implications for prevention rather than cure of genetic muscle diseases.

  15. A forward genetic screen reveals essential and non-essential RNAi factors in Paramecium tetraurelia.

    Science.gov (United States)

    Marker, Simone; Carradec, Quentin; Tanty, Véronique; Arnaiz, Olivier; Meyer, Eric

    2014-06-01

    In most eukaryotes, small RNA-mediated gene silencing pathways form complex interacting networks. In the ciliate Paramecium tetraurelia, at least two RNA interference (RNAi) mechanisms coexist, involving distinct but overlapping sets of protein factors and producing different types of short interfering RNAs (siRNAs). One is specifically triggered by high-copy transgenes, and the other by feeding cells with double-stranded RNA (dsRNA)-producing bacteria. In this study, we designed a forward genetic screen for mutants deficient in dsRNA-induced silencing, and a powerful method to identify the relevant mutations by whole-genome sequencing. We present a set of 47 mutant alleles for five genes, revealing two previously unknown RNAi factors: a novel Paramecium-specific protein (Pds1) and a Cid1-like nucleotidyl transferase. Analyses of allelic diversity distinguish non-essential and essential genes and suggest that the screen is saturated for non-essential, single-copy genes. We show that non-essential genes are specifically involved in dsRNA-induced RNAi while essential ones are also involved in transgene-induced RNAi. One of the latter, the RNA-dependent RNA polymerase RDR2, is further shown to be required for all known types of siRNAs, as well as for sexual reproduction. These results open the way for the dissection of the genetic complexity, interconnection, mechanisms and natural functions of RNAi pathways in P. tetraurelia.

  16. High genetic differentiation with no evidence of hybridisation between four limpet species (Patella spp. revealed by allozyme loci

    Directory of Open Access Journals (Sweden)

    Alexandra Sá-Pinto

    2007-12-01

    Full Text Available The occurrence of hybridisation between limpet species of the genus Patella has always been a contentious issue. Although a previous allozyme study reported high differentiation and no hybridisation between Patella vulgata Linnaeus, 1758, Patella depressa Pennant, 1777 and Patella ulyssiponensis Gmelin, 1791 along English shores, the recent finding of an mtDNA haplotype of P. depressa in a P. vulgata individual raised new doubts on this issue. To further study the possibility of hybridisation between limpet species and their level of genetic differentiation, ten allozyme loci were screened using starch gel electrophoresis for P. ulyssiponensis, P. depressa, P. vulgata and Patella rustica Linnaeus, 1758, from the Atlantic coast of the Iberian Peninsula. Our results show high differentiation between species, which could be clearly separated into different clusters with a Bayesian clustering algorithm. No significant signs of hybridisation were detected between any of the four species. Thus, the hypothesis of hybridisation between P. vulgata and P. depressa across their sympatric distribution is not supported. Two sympatric clusters were recovered within P. vulgata that could be related to Hardy-Weinberg disequilibrium found in locus MPI. Finally, due to the high level of intraspecific variability, the studied loci are interesting tools for the analysis of population structure and stock identification.

  17. Flow Cytometry Enables Multiplexed Measurements of Genetically Encoded Intramolecular FRET Sensors Suitable for Screening.

    Science.gov (United States)

    Doucette, Jaimee; Zhao, Ziyan; Geyer, Rory J; Barra, Melanie M; Balunas, Marcy J; Zweifach, Adam

    2016-07-01

    Genetically encoded sensors based on intramolecular FRET between CFP and YFP are used extensively in cell biology research. Flow cytometry has been shown to offer a means to measure CFP-YFP FRET; we suspected it would provide a unique way to conduct multiplexed measurements from cells expressing different FRET sensors, which is difficult to do with microscopy, and that this could be used for screening. We confirmed that flow cytometry accurately measures FRET signals using cells transiently transfected with an ERK activity reporter, comparing responses measured with imaging and cytometry. We created polyclonal long-term transfectant lines, each expressing a different intramolecular FRET sensor, and devised a way to bar-code four distinct populations of cells. We demonstrated the feasibility of multiplexed measurements and determined that robust multiplexed measurements can be conducted in plate format. To validate the suitability of the method for screening, we measured responses from a plate of bacterial extracts that in unrelated experiments we had determined contained the protein kinase C (PKC)-activating compound teleocidin A-1. The multiplexed assay correctly identifying the teleocidin A-1-containing well. We propose that multiplexed cytometric FRET measurements will be useful for analyzing cellular function and for screening compound collections.

  18. Genetic analysis and SOD1 mutation screening in Iranian amyotrophic lateral sclerosis patients.

    Science.gov (United States)

    Alavi, Afagh; Nafissi, Shahriar; Rohani, Mohammad; Zamani, Babak; Sedighi, Behnaz; Shamshiri, Hosein; Fan, Jian-Bing; Ronaghi, Mostafa; Elahi, Elahe

    2013-05-01

    Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease, and the most common in European populations. Results of genetic analysis and mutation screening of SOD1 in a cohort of 60 Iranian ALS patients are here reported. Initially, linkage analysis in 4 families identified a disease-linked locus that included the known ALS gene, SOD1. Screening of SOD1 identified homozygous p.Asp90Ala causing mutations in all the linked families. Haplotype analysis suggests that the p.Asp90Ala alleles in the Iranian patients might share a common founder with the renowned Scandinavian recessive p.Asp90Ala allele. Subsequent screening in all the patients resulted in identification of 3 other mutations in SOD1, including p.Leu84Phe in the homozygous state. Phenotypic features of the mutation-bearing patients are presented. SOD1 mutations were found in 11.7% of the cohort, 38.5% of the familial ALS probands, and 4.25% of the sporadic ALS cases. SOD1 mutations contribute significantly to ALS among Iranians.

  19. New multiplex PCR methods for rapid screening of genetically modified organisms in foods

    Directory of Open Access Journals (Sweden)

    Nelly eDatukishvili

    2015-07-01

    Full Text Available We present novel multiplex PCR methods for rapid and reliable screening of genetically modified organisms (GMOs. New designed PCR primers targeting four frequently used GMO specific sequences permitted identification of new DNA markers, in particular 141 bp fragment of cauliflower mosaic virus (CaMV 35S promoter, 224 bp fragment of Agrobacterium tumefaciens nopaline synthase (NOS terminator, 256 bp fragment of 5-enolppyruvylshikimate-phosphate synthase (epsps gene and 258 bp fragment of Cry1Ab delta-endotoxin (cry1Ab gene for GMO screening. The certified reference materials containing Roundup Ready soybean (RRS and maize MON 810 were applied for the development and optimization of uniplex and multiplex PCR systems. Evaluation of amplification products by agarose gel electrophoresis using negative and positive controls confirmed high specificity and sensitivity at 0.1% GMO for both RRS and MON 810. The fourplex PCR was developed and optimized that allows simultaneous detection of three common transgenic elements, such as: CaMV 35S promoter, NOS terminator, epsps gene together with soybean-specific lectin gene. The triplex PCR developed enables simultaneous identification of transgenic elements, such as: 35S promoter and cry1Ab gene together with maize zein gene. The analysis of different processed foods demonstrated that multiplex PCR methods developed in this study are useful for accurate and fast screening of GM food products.

  20. New multiplex PCR methods for rapid screening of genetically modified organisms in foods.

    Science.gov (United States)

    Datukishvili, Nelly; Kutateladze, Tamara; Gabriadze, Inga; Bitskinashvili, Kakha; Vishnepolsky, Boris

    2015-01-01

    We present novel multiplex PCR methods for rapid and reliable screening of genetically modified organisms (GMOs). New designed PCR primers targeting four frequently used GMO specific sequences permitted identification of new DNA markers, in particular 141 bp fragment of cauliflower mosaic virus (CaMV) 35S promoter, 224 bp fragment of Agrobacterium tumefaciens nopaline synthase (NOS) terminator, 256 bp fragment of 5-enolppyruvylshikimate-phosphate synthase (epsps) gene and 258 bp fragment of Cry1Ab delta-endotoxin (cry1Ab) gene for GMO screening. The certified reference materials containing Roundup Ready soybean (RRS) and maize MON 810 were applied for the development and optimization of uniplex and multiplex PCR systems. Evaluation of amplification products by agarose gel electrophoresis using negative and positive controls confirmed high specificity and sensitivity at 0.1% GMO for both RRS and MON 810. The fourplex PCR was developed and optimized that allows simultaneous detection of three common transgenic elements, such as: CaMV 35S promoter, NOS terminator, epsps gene together with soybean-specific lectin gene. The triplex PCR developed enables simultaneous identification of transgenic elements, such as: 35S promoter and cry1Ab gene together with maize zein gene. The analysis of different processed foods demonstrated that multiplex PCR methods developed in this study are useful for accurate and fast screening of GM food products.

  1. A genetic screen for components of the mammalian RNA interference pathway in Bloom-deficient mouse embryonic stem cells.

    Science.gov (United States)

    Trombly, Melanie I; Su, Hong; Wang, Xiaozhong

    2009-03-01

    Genetic screens performed in model organisms have helped identify key components of the RNA interference (RNAi) pathway. Recessive genetic screens have recently become feasible through the use of mouse embryonic stem (ES) cells that are Bloom's syndrome protein (Blm) deficient. Here, we developed and performed a recessive genetic screen to identify components of the mammalian RNAi pathway in Blm-deficient ES cells. Genome-wide mutagenesis using a retroviral gene trap strategy resulted in the isolation of putative homozygous RNAi mutant cells. Candidate clones were confirmed by an independent RNAi-based reporter assay and the causative gene trap integration site was identified using molecular techniques. Our screen identified multiple mutant cell lines of Argonaute 2 (Ago2), a known essential component of the RNAi pathway. This result demonstrates that true RNAi components can be isolated by this screening strategy. Furthermore, Ago2 homozygous mutant ES cells provide a null genetic background to perform mutational analyses of the Ago2 protein. Using genetic rescue, we resolve an important controversy regarding the role of two phenylalanine residues in Ago2 activity.

  2. High genetic differentiation and cross-shelf patterns of genetic diversity among Great Barrier Reef populations of Symbiodinium

    Science.gov (United States)

    Howells, E. J.; van Oppen, M. J. H.; Willis, B. L.

    2009-03-01

    The resilience of Symbiodinium harboured by corals is dependent on the genetic diversity and extent of connectivity among reef populations. This study presents genetic analyses of Great Barrier Reef (GBR) populations of clade C Symbiodinium hosted by the alcyonacean coral, Sinularia flexibilis. Allelic variation at four newly developed microsatellite loci demonstrated that Symbiodinium populations are genetically differentiated at all spatial scales from 16 to 1,360 km (pairwise ΦST = 0.01-0.47, mean = 0.22); the only exception being two neighbouring populations in the Cairns region separated by 17 km. This indicates that gene flow is restricted for Symbiodinium C hosted by S. flexibilis on the GBR. Patterns of population structure reflect longshore circulation patterns and limited cross-shelf mixing, suggesting that passive transport by currents is the primary mechanism of dispersal in Symbiodinium types that are acquired horizontally. There was no correlation between the genetic structure of Symbiodinium populations and their host S. flexibilis, most likely because different factors affect the dispersal and recruitment of each partner in the symbiosis. The genetic diversity of these Symbiodinium reef populations is on average 1.5 times lower on inshore reefs than on offshore reefs. Lower inshore diversity may reflect the impact of recent bleaching events on Sinularia assemblages, which have been more widespread and severe on inshore reefs, but may also have been shaped by historical sea level fluctuations or recent migration patterns.

  3. Morphological and genetic differentiation of Bufo toads: two cryptic species in Western Europe (Anura, Bufonidae)

    NARCIS (Netherlands)

    Arntzen, J.W.; McAtear, J.; Recuero, E.; Ziermann, J.M.; Ohler, A.; Alphen, van J.; Martínez-Solano, I.

    2013-01-01

    The Common toad Bufo bufo sensu lato is a widespread, morphologically conserved taxon. Recent studies have uncovered deep genetic differentiation between population groups, highlighting the need to revise the current taxonomy of the group and recognize additional species. Here we investigate

  4. Morphological and Genetic Differentiation within the Southernmost Vector of Chagas Disease: Triatoma patagonica (Hemiptera - Reduviidae).

    Science.gov (United States)

    Nattero, Julieta; Pita, Sebastián; Calleros, Lucía; Crocco, Liliana; Panzera, Yanina; Rodríguez, Claudia S; Panzera, Francisco

    2016-01-01

    The epidemiological importance of Chagas disease vectors largely depends on their spreading ability and adaptation to domestic habitats. Triatoma patagonica is a secondary vector of Chagas disease endemic of Argentina, and it has been found colonizing domiciles and most commonly peridomiciliary structures in several Argentine provinces and morphological variation along its distribution range have been described. To asses if population differentiation represents geographic variants or true biological species, multiple genetic and phenotypic approaches and laboratory cross-breeding were performed in T. patagonica peridomestic populations. Analyses of chromatic variation of forewings, their size and the content of C-heterochromatin on chromosomes revealed that populations are structured following a North-South latitudinal variation. Cytochrome c oxidase I mitochondrial gene (COI) nucleotide analysis showed a mean genetic distance of 5.2% between the most distant populations. The cross-breeding experiments suggest a partial reproductive isolation between some populations with 40% of couples not laying eggs and low hatching efficiency. Our findings reveal phenotypic and genetic variations that suggest an incipient differentiation processes among T. patagonica populations with a pronounced phenotypic and genetic divergence between the most distant populations. The population differentiation here reported is probably related to differential environmental conditions and it could reflect the occurrence of an incipient speciation process in T. patagonica.

  5. Genetic variation and differentiation in parent-descendant cattle and bison populations

    Science.gov (United States)

    Genetic variation and differentiation at 32 microsatellite DNA loci is quantified for parent-descendant cattle populations and parent-descendant bison (Bison bison) populations. Heterozygosity (Ho) and numbers of alleles/locus (AR) are less in the Line 1 Hereford inbred cattle population than in t...

  6. Morphological and Genetic Differentiation within the Southernmost Vector of Chagas Disease: Triatoma patagonica (Hemiptera – Reduviidae)

    Science.gov (United States)

    Pita, Sebastián; Calleros, Lucía; Crocco, Liliana; Panzera, Yanina; Rodríguez, Claudia S.; Panzera, Francisco

    2016-01-01

    The epidemiological importance of Chagas disease vectors largely depends on their spreading ability and adaptation to domestic habitats. Triatoma patagonica is a secondary vector of Chagas disease endemic of Argentina, and it has been found colonizing domiciles and most commonly peridomiciliary structures in several Argentine provinces and morphological variation along its distribution range have been described. To asses if population differentiation represents geographic variants or true biological species, multiple genetic and phenotypic approaches and laboratory cross-breeding were performed in T. patagonica peridomestic populations. Analyses of chromatic variation of forewings, their size and the content of C-heterochromatin on chromosomes revealed that populations are structured following a North-South latitudinal variation. Cytochrome c oxidase I mitochondrial gene (COI) nucleotide analysis showed a mean genetic distance of 5.2% between the most distant populations. The cross-breeding experiments suggest a partial reproductive isolation between some populations with 40% of couples not laying eggs and low hatching efficiency. Our findings reveal phenotypic and genetic variations that suggest an incipient differentiation processes among T. patagonica populations with a pronounced phenotypic and genetic divergence between the most distant populations. The population differentiation here reported is probably related to differential environmental conditions and it could reflect the occurrence of an incipient speciation process in T. patagonica. PMID:28005972

  7. Enhanced computational methods for quantifying the effect of geographic and environmental isolation on genetic differentiation

    NARCIS (Netherlands)

    Botta, Filippo; Eriksen, Casper; Fontaine, Michael Christophe; Guillot, Gilles

    2015-01-01

    In a recent paper, Bradburd et al. (2013) proposed a model to quantify the relative effect ofgeographic and environmental distance on genetic differentiation. Here, we enhance this method in several ways. 1. We modify the covariance model so as to fit better with mainstream geostatistical models and

  8. Genetic Differentiation of Different Geographical Populations of Bemisia tabaci (Gennadius) Complex

    Institute of Scientific and Technical Information of China (English)

    CHU Dong; LIU Guo-xia; FAN Zhong-xue; TAO Yun-li; ZHANG You-jun

    2007-01-01

    Bemisia tabaci (Gennadius) is a species complex, which includes different geographical populations with genetic differentiation. The recent progress on the genetic differentiation of various geographical populations of B. tabaci complex was introduced. The genetic differentiation was further analyzed on the basis of the sequences of mtDNA COI and rDNA ITSl recorded in the world's GenBank. Five groups are defined on the basis of mtDNA COI and rDNA ITS1, including the Asia group, America group, Africa group, Australia group, and Biotype B/Mediterranean/Middle East/ Northern Africa/Biotype Ms group. There are several ungrouped geographical classifications, such as the Uganda population, Ivory Coast population, and Taiwan population. Geographical isolation may be the most important factor that contributed to the genetic differentiation of various geographical populations of B. tabaci. Many populations with biological advantages invaded new regions and caused severe economic losses within human activity. It is necessary to strengthen the research of B. tabaci biotype to prevent the spread of invaded populations and the invasion of potentially dangerous populations.

  9. Genetic algorithms and Markov Chain Monte Carlo: Differential Evolution Markov Chain makes Bayesian computing easy

    NARCIS (Netherlands)

    Braak, ter C.J.F.

    2004-01-01

    Differential Evolution (DE) is a simple genetic algorithm for numerical optimization in real parameter spaces. In a statistical context one would not just want the optimum but also its uncertainty. The uncertainty distribution can be obtained by a Bayesian analysis (after specifying prior and likeli

  10. Low but contrasting neutral genetic differentiation shaped by winter temperature in European great tits.

    NARCIS (Netherlands)

    Lemoine, M.; Lucek, K.; Perrier, C.; Saladin, V.; Adriaensen, F.; Barba, E.; Belda, E.J.; Charmantier, A.; Cichoń, M.; Eeva, T.; Grégoire, A.; Hinde, C.A.; Johnsen, A.; Komdeur, J.; Mänd, R.; Matthysen, E.; Norte, A.C.; Pitala, N.; Sheldon, B.C.; Slagsvold, T.; Tinbergen, J.M.; Török, J.; Ubels, R.; van Oers, K.; Visser, M.E.; Doligez, Blandine; Richner, Heinz

    2016-01-01

    Gene flow is usually thought to reduce genetic divergence and impede local adaptation by homogenising gene pools between populations. However, evidence for local adaptation and phenotypic differentiation in highly mobile species, experiencing high levels of gene flow, is emerging. Assessing populati

  11. Low but contrasting neutral genetic differentiation shaped by winter temperature in European great tits

    NARCIS (Netherlands)

    Lemoine, Mélissa; Lucek, Kay; Perrier, Charles; Saladin, Verena; Adriaensen, Frank; Barba, Emilio; Belda, Eduardo J.; Charmantier, Anne; Cichoń, Mariusz; Eeva, Tapio; Grégoire, Arnaud; Hinde, Camilla A.; Johnsen, Arild; Komdeur, Jan; Mänd, Raivo; Matthysen, Erik; Norte, Ana Cláudia; Pitala, Natalia; Sheldon, Ben C.; Slagsvold, Tore; Tinbergen, Joost M.; Török, János; Ubels, Richard; Oers, van Kees; Visser, Marcel E.; Doligez, Blandine; Richner, Heinz

    2016-01-01

    Gene flow is usually thought to reduce genetic divergence and impede local adaptation by homogenising gene pools between populations. However, evidence for local adaptation and phenotypic differentiation in highly mobile species, experiencing high levels of gene flow, is emerging. Assessing popul

  12. Low but contrasting neutral genetic differentiation shaped by winter temperature in European great tits

    NARCIS (Netherlands)

    Lemoine, Melissa; Lucek, Kay; Perrier, Charles; Saladin, Verena; Adriaensen, Frank; Barba, Emilio; Belda, Eduardo J.; Charmantier, Anne; Cichon, Mariusz; Eeva, Tapio; Gregoire, Arnaud; Hinde, Camilla A.; Johnsen, Arild; Komdeur, Jan; Mand, Raivo; Matthysen, Erik; Norte, Ana Claudia; Pitala, Natalia; Sheldon, Ben C.; Slagsvold, Tore; Tinbergen, Joost M.; Torok, Janos; Ubels, Richard; Van Oers, Kees; Visser, Marcel E.; Doligez, Blandine; Richner, Heinz

    2016-01-01

    Gene flow is usually thought to reduce genetic divergence and impede local adaptation by homogenising gene pools between populations. However, evidence for local adaptation and phenotypic differentiation in highly mobile species, experiencing high levels of gene flow, is emerging. Assessing populati

  13. Genetic differentiation in life history between Daphnia galeata population: an adaptation to local predations regimes?

    NARCIS (Netherlands)

    Declerck, S.A.J.; Weber, A.

    2003-01-01

    Species of the water flea Daphnia exhibit constitutive as well as phenotypically inducible anti-predator defence strategies, involving life history, morphological and behavioural traits. We explored the hypothesis of genetic differentiation in anti-predator defence strategies using Daphnia clones

  14. Effects of climatic gradients on genetic differentiation of Caragana on the Ordos Plateau, China

    Science.gov (United States)

    Jiuyan Yang; Samuel A. Cushman; Jie Yang; Mingbo Yang; Tiejun Bao

    2013-01-01

    The genus Caragana (Fabr.) in the Ordos Plateau of Inner Mongolia, China, provides a strong opportunity to investigate patterns of genetic differentiation along steep climatic gradients, and to identify the environmental factors most likely to be responsible for driving the radiation. This study used a factorial, multi-model approach to evaluate alternative hypotheses...

  15. Low but contrasting neutral genetic differentiation shaped by winter temperature in European great tits

    NARCIS (Netherlands)

    Lemoine, Mélissa; Lucek, Kay; Perrier, Charles; Saladin, Verena; Adriaensen, Frank; Barba, Emilio; Belda, Eduardo J.; Charmantier, Anne; Cichoń, Mariusz; Eeva, Tapio; Grégoire, Arnaud; Hinde, Camilla A.; Johnsen, Arild; Komdeur, Jan; Mänd, Raivo; Matthysen, Erik; Norte, Ana Cláudia; Pitala, Natalia; Sheldon, Ben C.; Slagsvold, Tore; Tinbergen, Joost M.; Török, János; Ubels, Richard; Oers, van Kees; Visser, Marcel E.; Doligez, Blandine; Richner, Heinz

    2016-01-01

    Gene flow is usually thought to reduce genetic divergence and impede local adaptation by homogenising gene pools between populations. However, evidence for local adaptation and phenotypic differentiation in highly mobile species, experiencing high levels of gene flow, is emerging. Assessing

  16. Low but contrasting neutral genetic differentiation shaped by winter temperature in European great tits

    NARCIS (Netherlands)

    Lemoine, Mélissa; Lucek, Kay; Perrier, Charles; Saladin, Verena; Adriaensen, Frank; Barba, Emilio; Belda, Eduardo J.; Charmantier, Anne; Cichoń, Mariusz; Eeva, Tapio; Grégoire, Arnaud; Hinde, Camilla A.; Johnsen, Arild; Komdeur, Jan; Mänd, Raivo; Matthysen, Erik; Norte, Ana Cláudia; Pitala, Natalia; Sheldon, Ben C.; Slagsvold, Tore; Tinbergen, Joost M.; Török, János; Ubels, Richard; Oers, van Kees; Visser, Marcel E.; Doligez, Blandine; Richner, Heinz

    2016-01-01

    Gene flow is usually thought to reduce genetic divergence and impede local adaptation by homogenising gene pools between populations. However, evidence for local adaptation and phenotypic differentiation in highly mobile species, experiencing high levels of gene flow, is emerging. Assessing popul

  17. Low but contrasting neutral genetic differentiation shaped by winter temperature in European great tits

    NARCIS (Netherlands)

    Lemoine, Melissa; Lucek, Kay; Perrier, Charles; Saladin, Verena; Adriaensen, Frank; Barba, Emilio; Belda, Eduardo J.; Charmantier, Anne; Cichon, Mariusz; Eeva, Tapio; Gregoire, Arnaud; Hinde, Camilla A.; Johnsen, Arild; Komdeur, Jan; Mand, Raivo; Matthysen, Erik; Norte, Ana Claudia; Pitala, Natalia; Sheldon, Ben C.; Slagsvold, Tore; Tinbergen, Joost M.; Torok, Janos; Ubels, Richard; Van Oers, Kees; Visser, Marcel E.; Doligez, Blandine; Richner, Heinz

    2016-01-01

    Gene flow is usually thought to reduce genetic divergence and impede local adaptation by homogenising gene pools between populations. However, evidence for local adaptation and phenotypic differentiation in highly mobile species, experiencing high levels of gene flow, is emerging. Assessing populati

  18. Low but contrasting neutral genetic differentiation shaped by winter temperature in European great tits.

    NARCIS (Netherlands)

    Lemoine, M.; Lucek, K.; Perrier, C.; Saladin, V.; Adriaensen, F.; Barba, E.; Belda, E.J.; Charmantier, A.; Cichoń, M.; Eeva, T.; Grégoire, A.; Hinde, C.A.; Johnsen, A.; Komdeur, J.; Mänd, R.; Matthysen, E.; Norte, A.C.; Pitala, N.; Sheldon, B.C.; Slagsvold, T.; Tinbergen, J.M.; Török, J.; Ubels, R.; van Oers, K.; Visser, M.E.; Doligez, Blandine; Richner, Heinz

    2016-01-01

    Gene flow is usually thought to reduce genetic divergence and impede local adaptation by homogenising gene pools between populations. However, evidence for local adaptation and phenotypic differentiation in highly mobile species, experiencing high levels of gene flow, is emerging. Assessing populati

  19. Asynchrony of seasons: genetic differentiation associated with geographic variation in climatic seasonality and reproductive phenology.

    Science.gov (United States)

    Quintero, Ignacio; González-Caro, Sebastián; Zalamea, Paul-Camilo; Cadena, Carlos Daniel

    2014-09-01

    Many organisms exhibit distinct breeding seasons tracking food availability. If conspecific populations inhabit areas that experience different temporal cycles in food availability spurred by variation in precipitation regimes, then they should display asynchronous breeding seasons. Thus, such populations might exhibit a temporal barrier to gene flow, which may potentially promote genetic differentiation. We test a central prediction of this hypothesis, namely, that individuals living in areas with more asynchronous precipitation regimes should be more genetically differentiated than individuals living in areas with more similar precipitation regimes. Using mitochondrial DNA sequences, climatic data, and geographical/ecological distances between individuals of 57 New World bird species mostly from the tropics, we examined the effect of asynchronous precipitation (a proxy for asynchronous resource availability) on genetic differentiation. We found evidence for a positive and significant cross-species effect of precipitation asynchrony on genetic distance after accounting for geographical/ecological distances, suggesting that current climatic conditions may play a role in population differentiation. Spatial asynchrony in climate may thus drive evolutionary divergence in the absence of overt geographic barriers to gene flow; this mechanism contrasts with those invoked by most models of biotic diversification emphasizing physical or ecological changes to the landscape as drivers of divergence.

  20. Effects of specialization on genetic differentiation in sister species of bark beetles.

    Science.gov (United States)

    Kelley, S T; Farrell, B D; Mitton, J B

    2000-02-01

    We investigated the relative importance of resource use and geography on genetic differentiation in the sister-species pair of generalist and specialist bark beetles: Dendroctonus ponderosae and D. jeffreyi (Coleoptera: Scolytidae). In two regions, where the distributions of these species overlap, we collected specimens of the generalist from multiple host species and specimens of the specialist from its single host species. Using allozyme techniques, we uncovered genetic differentiation between generalist populations on different host species in the same region (one locus in each region). However, a much stronger pattern of differentiation was found between specialist populations in the two distantly separated regions (three loci). With mtDNA, we found no significant differentiation between regions in the specialist, or among host species in the generalist, although there was some differentiation between regions in the generalist (AMOVA, P < 0.05). Overall, the generalist populations maintained approximately 10 times the genetic variation in mtDNA as the specialist populations, which suggests that the specialist either has generally smaller population sizes than the generalist, or has experienced a historical population bottleneck.

  1. Genetic differentiation between sympatric and allopatric wintering populations of Snow Geese

    Science.gov (United States)

    Humphries, E.M.; Peters, J.L.; Jonsson, J.E.; Stone, R.; Afton, A.D.; Omland, K.E.

    2009-01-01

    Blackwater National Wildlife Refuge on the Delmarva Peninsula, Maryland, USA has been the wintering area of a small population of Lesser Snow Geese (Chen caerulescens caerulescens; LSGO) since the 1930s. Snow Geese primarily pair in wintering areas and gene flow could be restricted between this and other LSGO wintering populations. Winter pair formation also could facilitate interbreeding with sympatric but morphologically differentiated Greater Snow Geese (C. c. atlantica; GSGO).We sequenced 658 bp of the mitochondrial DNA control region for 68 Snow Geese from East Coast and Louisiana wintering populations to examine the level of genetic differentiation among populations and subspecies. We found no evidence for genetic differentiation between LSGO populations but, consistent with morphological differences, LSGO and GSGO were significantly differentiated. We also found a lack of genetic differentiation between different LSGO morphotypes from Louisiana. We examined available banding data and found the breeding range of Delmarva LSGO overlaps extensively with LSGO that winter in Louisiana, and documented movements between wintering populations. Our results suggest the Delmarva population of LSGO is not a unique population unit apart from Mid-Continent Snow Geese. ?? 2009 by the Wilson Ornithological Society.

  2. Population differentiation in Pacific salmon: local adaptation, genetic drift, or the environment?

    Energy Technology Data Exchange (ETDEWEB)

    Adkison, M.D. [Washington Univ., Seattle, WA (United States). Coll. of Fisheries

    1995-12-01

    The effects of local adaptation among Pacific salmon populations were discussed. Morphological and behavioural differences between Pacific salmon are believed to be a result of local adaptation. Two alternatives were recognized: (1) random genetic differentiation owing to genetic drift and founder events, and (2) genetic homogeneity among populations. In general, local adaptation is favoured when population sizes are large and stable, when selection is consistent over large areas, when selective differentials are large, and straying rates are neither too high nor too low. Since there are definite limits to local adaptation, particularly on fine spatial scales, consideration of alternatives to local adaptation could improve both basic science and conservation efforts. 127 refs., 2 tabs., 3 figs.

  3. Genetic Variability Overrides the Impact of Parental Cell Type and Determines iPSC Differentiation Potential

    Directory of Open Access Journals (Sweden)

    Aija Kyttälä

    2016-02-01

    Full Text Available Reports on the retention of somatic cell memory in induced pluripotent stem cells (iPSCs have complicated the selection of the optimal cell type for the generation of iPSC biobanks. To address this issue we compared transcriptomic, epigenetic, and differentiation propensities of genetically matched human iPSCs derived from fibroblasts and blood, two tissues of the most practical relevance for biobanking. Our results show that iPSC lines derived from the same donor are highly similar to each other. However, genetic variation imparts a donor-specific expression and methylation profile in reprogrammed cells that leads to variable functional capacities of iPSC lines. Our results suggest that integration-free, bona fide iPSC lines from fibroblasts and blood can be combined in repositories to form biobanks. Due to the impact of genetic variation on iPSC differentiation, biobanks should contain cells from large numbers of donors.

  4. Genetic differentiation and population structure of five ethnic groups of Punjab (North-West India).

    Science.gov (United States)

    Singh, Gagandeep; Talwar, Indu; Sharma, Rubina; Matharoo, Kawaljit; Bhanwer, A J S

    2016-12-01

    The state of Punjab in the North-West part of India has acted as the main passage for all the major human invasions into the Indian subcontinent. It has resulted in the mixing of foreign gene pool into the local populations, which led to an extensive range of genetic diversity and has influenced the genetic structure of populations in Punjab, North-West India. The present study was conducted to examine the genetic structure, relationships, and extent of genetic differentiation in five Indo-European speaking ethnic groups of Punjab. A total of 1021 unrelated samples belonging to Banias, Brahmins, Jat Sikhs, Khatris, and Scheduled castes were analyzed for four human-specific Ins/Del polymorphic loci (ACE, APO, PLAT, and D1) and three restriction fragment length polymorphisms ESR (PvuII), LPL (PvuII), and T2 (MspI) using Polymerase chain reaction (PCR). All the loci were found to be polymorphic among the studied populations. The frequency of the Alu insertion at APO locus was observed to exhibit the highest value (82.6-96.3 %), whereas D1 exhibited the lowest (26.5-45.6 %) among all the ethnic groups. The average heterozygosity among the studied populations ranged from 0.3816 in Banias to 0.4163 in Khatris. The FST values ranged from 0.0418 to 0.0033 for the PLAT and LPL loci, respectively, with an average value being 0.0166. Phylogenetic analysis revealed that Banias and Khatris are genetically closest to each other. The Jat Sikhs are genetically close to Brahmins and are distant from the Banias. The Jat Sikhs, Banias, Brahmins, and Khatris are genetically very distant from the Scheduled castes. Overall, Uniform allele frequency distribution patterns, high average heterozygosity values, and a small degree of genetic differentiation in this study suggest a genetic proximity among the selected populations. A low level of genetic differentiation was observed in the studied population groups indicating that genetic drift might have been small or negligible in shaping

  5. 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...

  6. Functional Genetic Screen to Identify Interneurons Governing Behaviorally Distinct Aspects of Drosophila Larval Motor Programs

    Directory of Open Access Journals (Sweden)

    Matt Q. Clark

    2016-07-01

    Full Text Available Drosophila larval crawling is an attractive system to study rhythmic motor output at the level of animal behavior. Larval crawling consists of waves of muscle contractions generating forward or reverse locomotion. In addition, larvae undergo additional behaviors, including head casts, turning, and feeding. It is likely that some neurons (e.g., motor neurons are used in all these behaviors, but the identity (or even existence of neurons dedicated to specific aspects of behavior is unclear. To identify neurons that regulate specific aspects of larval locomotion, we performed a genetic screen to identify neurons that, when activated, could elicit distinct motor programs. We used 165 Janelia CRM-Gal4 lines—chosen for sparse neuronal expression—to ectopically express the warmth-inducible neuronal activator TrpA1, and screened for locomotor defects. The primary screen measured forward locomotion velocity, and we identified 63 lines that had locomotion velocities significantly slower than controls following TrpA1 activation (28°. A secondary screen was performed on these lines, revealing multiple discrete behavioral phenotypes, including slow forward locomotion, excessive reverse locomotion, excessive turning, excessive feeding, immobile, rigid paralysis, and delayed paralysis. While many of the Gal4 lines had motor, sensory, or muscle expression that may account for some or all of the phenotype, some lines showed specific expression in a sparse pattern of interneurons. Our results show that distinct motor programs utilize distinct subsets of interneurons, and provide an entry point for characterizing interneurons governing different elements of the larval motor program.

  7. Preliminary Study on Thalassemia Screening and Genetic Counseling in Selective Hmong People in Saraburi Province, Thailand

    Directory of Open Access Journals (Sweden)

    Pa Vang

    2008-01-01

    Full Text Available it can lead to the destruction of red blood cells. Studies have shown that there is a high prevalence of thalassemia in Southeast Asia. The Institute of Health Research, Chulalongkorn University developed a successful “Module” to screen for thalassemia in the Thai population, however, it has not been implemented in the minority population in Thailand. In this study, we investigated the feasibility of the newly developed educational and thalassemia screening program with the Hmong population. The primary aim of this study was to test this program. The secondary aim was to determine the prevalence of thalassemia in the Hmong and provide education. A third aim was to determine the reliability of two different screening methods in the Hmong population. A pre-test and post-test design was used; participants (N=12 were individuals residing in Thailand with the ability to read English and between the ages 18-50. The participants met twice with the researchers to complete the program. The first contact consisted of assessing participants’ knowledge about thalassemia, providing thalassemia information and education about genetic counseling, and drawing blood samples. The second contact consisted of assessing knowledge, providing a written report of individual blood sample results and counseling. The initial interview revealed that the majority of the participants (82% did not know anything about thalassemia prior to participation. The program was easy to understand by most participants (90%. Of the eleven Hmong participants, two tested positive for being a possible carrier for thalassemia. In order to reduce the prevalence of thalassemia, it is necessary to engage in risk reduction health services. The modified screening method proved to be as effective as the standard method. Therefore, the program can expand and be used in other regional populations with low cost.

  8. Genetic screening and evaluation for chromosomal abnormalities of infertile males in Jilin Province, China.

    Science.gov (United States)

    Zhang, M; Fan, H-T; Zhang, Q-S; Wang, X-Y; Yang, X; Tian, W-J; Li, R-W

    2015-12-08

    Chromosomal abnormality is the most common genetic cause of male infertility, particularly in cases of azoospermia, oligozoospermia, and recurrent spontaneous abortion. Chromosomal rearrangement may interrupt an important gene or exert position effects. The functionality of genes at specific breakpoints, perhaps with a specific role in spermatogenesis, may be altered by such rearrangements. Structural chromosome abnormalities are furthermore known to increase the risk of pregnancy loss. In this study, we aimed to assess chromosomal defects in infertile men from Jilin Province, China, by genetic screening and to evaluate the relationship between structural chromosome abnormalities and male infertility. The prevalence of chromosomal abnormalities among the study participants (receiving genetic counseling in Jilin Province, China) was 10.55%. The most common chromosome abnormality was Klinefelter syndrome, and the study findings suggested that azoospermia and oligospermia may result from structural chromosomal abnormalities. Chromosome 1 was shown to be most commonly involved in male infertility and balanced chromosomal translocation was identified as one of the causes of recurrent spontaneous abortion. Chromosomes 4, 7, and 10 were the most commonly involved chromosomes in male partners of women experiencing repeated abortion.

  9. Solar Radiation-Associated Adaptive SNP Genetic Differentiation in Wild Emmer Wheat, Triticum dicoccoides

    Science.gov (United States)

    Ren, Jing; Chen, Liang; Jin, Xiaoli; Zhang, Miaomiao; You, Frank M.; Wang, Jirui; Frenkel, Vladimir; Yin, Xuegui; Nevo, Eviatar; Sun, Dongfa; Luo, Ming-Cheng; Peng, Junhua

    2017-01-01

    Whole-genome scans with large number of genetic markers provide the opportunity to investigate local adaptation in natural populations and identify candidate genes under positive selection. In the present study, adaptation genetic differentiation associated with solar radiation was investigated using 695 polymorphic SNP markers in wild emmer wheat originated in a micro-site at Yehudiyya, Israel. The test involved two solar radiation niches: (1) sun, in-between trees; and (2) shade, under tree canopy, separated apart by a distance of 2–4 m. Analysis of molecular variance showed a small (0.53%) but significant portion of overall variation between the sun and shade micro-niches, indicating a non-ignorable genetic differentiation between sun and shade habitats. Fifty SNP markers showed a medium (0.05 ≤ FST ≤ 0.15) or high genetic differentiation (FST > 0.15). A total of 21 outlier loci under positive selection were identified by using four different FST-outlier testing algorithms. The markers and genome locations under positive selection are consistent with the known patterns of selection. These results suggested that genetic differentiation between sun and shade habitats is substantial, radiation-associated, and therefore ecologically determined. Hence, the results of this study reflected effects of natural selection through solar radiation on EST-related SNP genetic diversity, resulting presumably in different adaptive complexes at a micro-scale divergence. The present work highlights the evolutionary theory and application significance of solar radiation-driven natural selection in wheat improvement. PMID:28352272

  10. Physical therapist screening and differential diagnosis for traumatic-onset elbow pain: A case report.

    Science.gov (United States)

    VanWye, William R; Hoover, Donald L; Willgruber, Sean

    2016-10-01

    Elbow pain can originate from many sources yet have similar signs and symptoms, thereby presenting differential diagnostic challenges. The elbow is commonly injured, thus requiring all clinicians to possess excellent diagnostic skills. A 24-year-old woman slipped and fell on her outstretched left hand, experiencing immediate elbow pain. The same day radiographs were deemed negative by her orthopedist, who referred her to physical therapy with the diagnoses of elbow sprain and contusion. Immediately after examining the patient, the physical therapist consulted with the referring orthopedist. The decision to consult was based on: the mechanism of injury, pain severity out of proportion to the referred diagnoses, significantly limited ROM, abnormal joint end feels, exquisite pain with tactile and tuning fork bony palpation, and positive elbow extension test. The treating physical therapist shared the above-noted findings with the orthopedist, who overruled and recommended continuing the original prescription of non-steroidal anti-inflammatory medication and physical therapist treatment for four weeks. The physical therapist's updated plan of care at four weeks noted the patient's continued reports of pain, functional limitations, and disability. A magnetic resonance image (MRI) was then ordered, revealing a radial head fracture. A thorough history and examination by the physical therapist led to clustering of signs and symptoms, allowing for the development of a differential diagnosis list which included occult radial head fracture. All clinicians should be prepared to screen for complex conditions. Timely diagnosis and improved outcomes for clinically complex patients are increasingly necessary in contemporary healthcare reimbursement models.

  11. Combinatorial Screening of Mesenchymal Stem Cell Adhesion and Differentiation Using Polymer Pen Lithography

    Science.gov (United States)

    Cabezas, Maria D.; Eichelsdoerfer, Daniel J.; Brown, Keith A.; Mrksich, Milan; Mirkin, Chad A.

    2014-01-01

    The extracellular matrix (ECM) is a complex, spatially inhomogeneous environment that is host to myriad cell–receptor interactions that promote changes in cell behavior. These biological systems can be probed and simulated with engineered surfaces,but doing so demands careful control over the arrangement of ligands. Here, we describe how such surfaces can be fabricated by utilizing polymer pen lithography (PPL), which is a cantilever-free scanning probe lithographic method that utilizes polymeric pen arrays to generate patterns over large areas. With the advent of PPL, fundamental questions in cell biology can be answered by recapitulating cell–ECM interactions to explore how these interactions lead to changes in cell behavior. Here, we describe an approach for the combinatorial screening of cell adhesion behavior to gain understanding of how ECM protein feature size dictates osteogenic differentiation of mesenchymal stem cells. The technique outlined here is generalizable to other biological systems and can be paired with quantitative analytical methods to probe important processes such as cell polarization, proliferation, signaling, and differentiation. PMID:24439289

  12. Genetic Differentiation between Quercus frainetto Ten. and Q. pubescens Willd. in Romania

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    Alexandru Lucian CURTU

    2011-05-01

    Full Text Available Little is known about genetic differences among Quercus frainetto and Q. pubescens, two species of section Dascia Kotschy (subgenus Lepidobalanus, white oaks that reach in Romania the margins of their natural distribution range. A set of genomic SSRs (simple sequence repeats and EST (expressed sequence tags-SSRs was used to estimate the genetic differentiation among four natural populations of the two species. Q. pubescens had higher values of genetic diversity than Q. frainetto, although the differences were not significant. Two out of seven marker-loci, QrZAG112 and QpZAG110, displayed very high FST values. Averaged across loci, the genetic differentiation was high and significant (FST = 0.067. Genetic distances were much higher among species than among populations within species. A Bayesian analysis indicated that two is the most appropriate number of genetic clusters. Using a blind procedure (i.e. based on multilocus genotypes only the vast majority of sampled individuals (90% could be assigned to the cluster corresponding to their phenotypes. When information about sampling localities was introduced in the assignment test, all individual trees were correctly classified. The higher degree of admixture in Q. frainetto as compared to Q. pubescens may be explained by different rates of introgressive hybridization.

  13. Genetic differentiation and delimitation between ecologically diverged Populus euphratica and P. pruinosa.

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    Juan Wang

    Full Text Available BACKGROUND: The fixed genetic differences between ecologically divergent species were found to change greatly depending on the markers examined. With such species it is difficult to differentiate between shared ancestral polymorphisms and past introgressions between the diverging species. In order to disentangle these possibilities and provide a further case for DNA barcoding of plants, we examine genetic differentiation between two ecologically divergent poplar species, Populus euphratica Oliver and P. pruinosa Schrenk using three different types of genetic marker. METHODOLOGY/PRINCIPAL FINDINGS: We genotyped 290 individuals from 29 allopatric and sympatric populations, using chloroplast (cp DNA, nuclear (nr ITS sequences and eight simple sequence repeat (SSR loci. Three major cpDNA haplotypes were widely shared between the two species and between-species cpDNA differentiation (F(CT was very low, even lower than among single species populations. The average SSR F(CT values were higher. Bayesian clustering analysis of all loci allowed a clear delineation of the two species. Gene flow, determined by examining all SSR loci, was obvious but only slightly asymmetrical. However, the two species were almost fixed for two different nrITS genotypes that had the highest F(CT, although a few introgressed individuals were detected both in allopatric and sympatric populations. CONCLUSIONS: The two species shared numerous ancestral polymorphisms at cpDNA and a few SSR loci. Both ITS and a combination of nuclear SSR data could be used to differentiate between the two species. Introgressions and gene flow were obvious between the two species either during or after their divergence. Our findings underscore the complex genetic differentiations between ecologically diverged species and highlight the importance of nuclear DNA (especially ITS differentiation for delimiting closely related plant species.

  14. Elucidating the role of genetic drift and natural selection in cork oak differentiation regarding drought tolerance.

    Science.gov (United States)

    Ramírez-Valiente, J A; Lorenzo, Z; Soto, A; Valladares, F; Gil, L; Aranda, I

    2009-09-01

    Drought is the main selection agent in Mediterranean ecosystems and it has been suggested as an important evolutionary force responsible for population diversification in these types of environments. However, population divergence in quantitative traits can be driven by either natural selection, genetic drift or both. To investigate the roles of these forces on among-population divergence in ecophysiological traits related to drought tolerance (carbon isotope discrimination, specific leaf area, leaf size and leaf nitrogen content), we compared molecular and quantitative genetic differentiation in a common garden experiment including thirteen cork oak (Quercus suber L.) populations across a gradient of rainfall and temperature. Population differentiation for height, specific leaf area, leaf size and nitrogen leaf content measured during a dry year far exceeded the molecular differentiation measured by six nuclear microsatellites. Populations from dry-cool sites showed the lowest nitrogen leaf content and the smallest and thickest leaves contrasting with those from humid-warm sites. These results suggest (i) these traits are subjected to divergence selection and (ii) the genetic differences among populations are partly due to climate adaptation. By contrast, the low among-population divergence found in basal diameter, annual growth and carbon isotopic discrimination (a surrogate for water use efficiency) suggests low or no divergence selection for these traits. Among-population differentiation for neutral markers was not a good predictor for differentiation regarding the quantitative traits studied here, except for leaf size. The correlation observed between the genetic differentiation for leaf size and that for molecular markers was exclusively due to the association between leaf size and the microsatellite QpZAG46, which suggests a possible linkage between QpZAG46 and genes encoding for leaf size.

  15. Natal philopatry does not lead to population genetic differentiation in Buller's albatross (Thalassarche bulleri bulleri).

    Science.gov (United States)

    van Bekkum, Margo; Sagar, Paul M; Stahl, Jean-Claude; Chambers, Geoffrey K

    2006-01-01

    Genetic variability in the only two existing populations of Buller's albatross (Thalassarche bulleri bulleri) was assessed using six polymorphic microsatellite loci. Large biological samples were obtained from both the Snares (n = 99) and the Solander Islands (n = 27). Several measures of genetic differentiation including F(ST) and R(ST) and a principal coordinates analysis (PCO) suggest a complete absence of genetic structure between three breeding colonies on the Snares Islands, and between them and one breeding colony on the Solander Islands. Mark/recapture studies of recently banded albatross chicks on the Snares found high natal philopatry in T. b. bulleri, but the microsatellite DNA data suggest that sufficient gene flow still occurs between all four breeding colonies to maintain a genetically homogeneous population overall.

  16. Genetic Differentiation of Pinus koraiensis under Different Altitude Conditions in Changbai Mountain

    Institute of Scientific and Technical Information of China (English)

    FENGFujuan

    2004-01-01

    The genetic differentiation of Korean pine (Pinus koraiensis) in different altitudes in Changbai Mountain was analyzed by ISSR technique, and it was found that the level of genetic diversity of Korean pine reduces along with altitude increasing in Changbai Mountain. The variation of Korean pine is mainly from intra-population and there is a positive relativity between genetic distance and vertical geographic distance of Korean pine in different altitudes. The genetic coherence shows that altitude has less insulation to Korean pine. Therefore, it is deduced that the terrain formation of vertical distribution of Korean pine is a result of diffusion from lower altitude to higher altitude in the course of enlarging its adaptability.

  17. Focal congenital hyperinsulinism managed by medical treatment: a diagnostic algorithm based on molecular genetic screening.

    Science.gov (United States)

    Maiorana, Arianna; Barbetti, Fabrizio; Boiani, Arianna; Rufini, Vittoria; Pizzoferro, Milena; Francalanci, Paola; Faletra, Flavio; Nichols, Colin G; Grimaldi, Chiara; de Ville de Goyet, Jean; Rahier, Jacques; Henquin, Jean-Claude; Dionisi-Vici, Carlo

    2014-11-01

    Congenital hyperinsulinism (CHI) requires rapid diagnosis and treatment to avoid irreversible neurological sequelae due to hypoglycaemia. Aetiological diagnosis is instrumental in directing the appropriate therapy. Current diagnostic algorithms provide a complete set of diagnostic tools including (i) biochemical assays, (ii) genetic facility and (iii) state-of-the-art imaging. They consider the response to a therapeutic diazoxide trial an early, crucial step before proceeding (or not) to specific genetic testing and eventually imaging, aimed at distinguishing diffuse vs focal CHI. However, interpretation of the diazoxide test is not trivial and can vary between research groups, which may lead to inappropriate decisions. Objective of this report is proposing a new algorithm in which early genetic screening, rather than diazoxide trial, dictates subsequent clinical decisions. Two CHI patients weaned from parenteral glucose infusion and glucagon after starting diazoxide. No hypoglycaemia was registered during a 72-h continuous glucose monitoring (CGMS), or hypoglycaemic episodes were present for no longer than 3% of 72-h. Normoglycaemia was obtained by low-medium dose diazoxide combined with frequent carbohydrate feeds for several years. We identified monoallelic, paternally inherited mutations in KATP channel genes, and (18) F-DOPA PET-CT revealed a focal lesion that was surgically resected, resulting in complete remission of hypoglycaemia. Although rare, some patients with focal lesions may be responsive to diazoxide. As a consequence, we propose an algorithm that is not based on a 'formal' diazoxide response but on genetic testing, in which patients carrying paternally inherited ABCC8 or KCNJ11 mutations should always be subjected to (18) F-DOPA PET-CT. © 2014 John Wiley & Sons Ltd.

  18. Contrasted patterns of genetic differentiation across eight bird species in the Lesser Antilles.

    Science.gov (United States)

    Khimoun, Aurélie; Arnoux, Emilie; Martel, Guillaume; Pot, Alexandre; Eraud, Cyril; Condé, Béatriz; Loubon, Maxime; Théron, Franck; Covas, Rita; Faivre, Bruno; Garnier, Stéphane

    2016-02-01

    Archipelagoes are considered as "natural laboratories" for studying processes that shape the distribution of diversity. The Lesser Antilles provide a favorable geographical context for divergence to occur. However, although morphological subspecies have been described across this archipelago in numerous avian species, the potential for the Lesser Antilles in driving intra-specific genetic divergence in highly mobile organisms such as birds remains understudied. Here, we assessed level of intra-specific genetic diversity and differentiation between three islands of the Lesser Antilles (Guadeloupe, Dominica and Martinique) using a multi-species approach on eight bird species. For each species, we built a set of microsatellite markers from cross-species amplifications. Significant patterns of inter-island and/or within-island genetic differentiation were detected in all species. However, levels of intra-specific genetic differentiation among the eight bird species were not always consistent with the boundaries of subspecies previously described in the sampled islands. These results suggest different histories of colonization/expansion and/or different species-specific ecological traits affecting gene flow, advocating for multi-species studies of historical and contemporary factors shaping the distribution of diversity on islands.

  19. High genetic diversity with moderate differentiation in Juniperus excelsa from Lebanon and the eastern Mediterranean region

    Science.gov (United States)

    Douaihy, Bouchra; Vendramin, Giovanni G.; Boratyński, Adam; Machon, Nathalie; Bou Dagher-Kharrat, Magda

    2011-01-01

    Background and aims Juniperus excelsa is an important woody species in the high mountain ecosystems of the eastern Mediterranean Basin where it constitutes the only coniferous species found at the tree line. The genetic diversity within and among J. excelsa populations of the eastern Mediterranean Basin is studied in the light of their historical fragmentation. Methodology Nuclear microsatellites originally developed for Juniperus communis and J. przewalskii were tested on 320 individuals from 12 different populations originating from Lebanon, Turkey, Cyprus, Greece and the Ukraine. Principal results Among the 31 nuclear microsatellite primers tested, only three produced specific amplification products, with orthology confirmed by sequence analysis. They were then used for genetic diversity studies. The mean number of alleles and the expected heterozygosity means were Na=8.78 and He=0.76, respectively. The fixation index showed a significant deviation from Hardy–Weinberg equilibrium and an excess of homozygotes (FIS=0.27–0.56). A moderate level of genetic differentiation was observed among the populations (FST=0.075, P2000 m) in Lebanon. These populations were differentiated from the other populations that are grouped into three sub-clusters. Conclusions High levels of genetic diversity were observed at species and population levels. The high level of differentiation in the high-mountain Lebanese populations reflects a long period of isolation or possibly a different origin. The admixture observed in other populations from Lebanon suggests a more recent separation from the Turkish–southeastern European populations. PMID:22476474

  20. High genetic diversity with moderate differentiation in Juniperus excelsa from Lebanon and the eastern Mediterranean region.

    Science.gov (United States)

    Douaihy, Bouchra; Vendramin, Giovanni G; Boratyński, Adam; Machon, Nathalie; Bou Dagher-Kharrat, Magda

    2011-01-01

    Juniperus excelsa is an important woody species in the high mountain ecosystems of the eastern Mediterranean Basin where it constitutes the only coniferous species found at the tree line. The genetic diversity within and among J. excelsa populations of the eastern Mediterranean Basin is studied in the light of their historical fragmentation. Nuclear microsatellites originally developed for Juniperus communis and J. przewalskii were tested on 320 individuals from 12 different populations originating from Lebanon, Turkey, Cyprus, Greece and the Ukraine. Among the 31 nuclear microsatellite primers tested, only three produced specific amplification products, with orthology confirmed by sequence analysis. They were then used for genetic diversity studies. The mean number of alleles and the expected heterozygosity means were N(a)=8.78 and H(e)=0.76, respectively. The fixation index showed a significant deviation from Hardy-Weinberg equilibrium and an excess of homozygotes (F(IS)=0.27-0.56). A moderate level of genetic differentiation was observed among the populations (F(ST)=0.075, P2000 m) in Lebanon. These populations were differentiated from the other populations that are grouped into three sub-clusters. High levels of genetic diversity were observed at species and population levels. The high level of differentiation in the high-mountain Lebanese populations reflects a long period of isolation or possibly a different origin. The admixture observed in other populations from Lebanon suggests a more recent separation from the Turkish-southeastern European populations.

  1. A Genome-Wide Test of the Differential Susceptibility Hypothesis Reveals a Genetic Predictor of Differential Response to Psychological Treatments for Child Anxiety Disorders

    NARCIS (Netherlands)

    Keers, Robert; Coleman, Jonathan R. I.; Lester, Kathryn J.; Roberts, Susanna; Breen, Gerome; Thastum, Mikael; Bogels, Susan; Schneider, Silvia; Heiervang, Einar; Meiser-Stedman, Richard; Nauta, Maaike; Creswell, Cathy; Thirlwall, Kerstin; Rapee, Ronald M.; Hudson, Jennifer L.; Lewis, Cathryn; Plomin, Robert; Eley, Thalia C.

    2016-01-01

    Background: The differential susceptibly hypothesis suggests that certain genetic variants moderate the effects of both negative and positive environments on mental health and may therefore be important predictors of response to psychological treatments. Nevertheless, the identification of such

  2. A Genome-Wide Test of the Differential Susceptibility Hypothesis Reveals a Genetic Predictor of Differential Response to Psychological Treatments for Child Anxiety Disorders

    NARCIS (Netherlands)

    Keers, Robert; Coleman, Jonathan R. I.; Lester, Kathryn J.; Roberts, Susanna; Breen, Gerome; Thastum, Mikael; Bogels, Susan; Schneider, Silvia; Heiervang, Einar; Meiser-Stedman, Richard; Nauta, Maaike; Creswell, Cathy; Thirlwall, Kerstin; Rapee, Ronald M.; Hudson, Jennifer L.; Lewis, Cathryn; Plomin, Robert; Eley, Thalia C.

    2016-01-01

    Background: The differential susceptibly hypothesis suggests that certain genetic variants moderate the effects of both negative and positive environments on mental health and may therefore be important predictors of response to psychological treatments. Nevertheless, the identification of such vari

  3. Novel Polymorphic Microsatellite Markers Reveal Genetic Differentiation between Two Sympatric Types of Galaxea fascicularis.

    Directory of Open Access Journals (Sweden)

    Yuichi Nakajima

    Full Text Available The reef-building, scleractinian coral, Galaxea fascicularis, is classified into soft and hard types, based on nematocyst morphology. This character is correlated with the length of the mitochondrial non-coding region (mt-Long: soft colony type, and nematocysts with wide capsules and long shafts; mt-Short: hard colony type, and nematocysts with thin capsules and short shafts. We isolated and characterized novel polymorphic microsatellite markers for G. fascicularis using next-generation sequencing. Based upon the mitochondrial non-coding region, 53 of the 97 colonies collected were mt-Long (mt-L and 44 were mt-Short (mt-S. Among the 53 mt-L colonies, 27 loci were identified as amplifiable, polymorphic microsatellite loci, devoid of somatic mutations and free of scoring errors. Eleven of those 27 loci were also amplifiable and polymorphic in the 44 mt-S colonies; these 11 are cross-type microsatellite loci. The other 16 loci were considered useful only for mt-L colonies. These 27 loci identified 10 multilocus lineages (MLLs among the 53 mt-L colonies (NMLL/N = 0.189, and the 11 cross-type loci identified 7 MLLs in 44 mt-S colonies (NMLL/N = 0.159. Significant genetic differentiation between the two types was detected based on the genetic differentiation index (FST = 0.080, P = 0.001. Bayesian clustering also indicated that these two types are genetically isolated. While nuclear microsatellite genotypes also showed genetic differentiation between mitochondrial types, the mechanism of divergence is not yet clear. These markers will be useful to estimate genetic diversity, differentiation, and connectivity among populations, and to understand evolutionary processes, including divergence of types in G. fascicularis.

  4. Familial Mediterranean fever without cardinal symptoms and role of genetic screening.

    Science.gov (United States)

    Ulas, T; Buyukhatipoglu, H; Bes, C; Dal, M S; Hacıbekiroglu, I; Apucu, H G; Borlu, F

    2012-07-19

    Familial Mediterranean fever is an autosomal recessive disorder characterized by paroxysmal episodes of fever and serosal inflammation. The classical presentation is fever and severe recurrent abdominal pain due to serositis that lasts for one to three days and the resolves spontaneously. Between the episodes patients are asymptomatic. Ninety-five percent of patients with familial mediterranean fever have painful episodes localized to the abdomen, which is usually the dominant manifestation of the disease. Herein, we present a case of 34-year-old man with incomplete abdominal pain episode of familial mediterranean fever limited to the epigastrum and had no cardinals symptoms of this disease. The diagnosis was made by genetic screening. Successful treatment response was achieved by colchicine.

  5. Familial Mediterranean fever without cardinal symptoms and role of genetic screening

    Directory of Open Access Journals (Sweden)

    I. Hacıbekiroglu

    2012-07-01

    Full Text Available Familial mediterranean fever is an autosomal recessive disorder characterized by paroxysmal episodes of fever and serosal inflammation. The classical presentation is fever and severe recurrent abdominal pain due to serositis that lasts for one to three days and the resolves spontaneously. Between the episodes patients are asymptomatic. Ninety-five percent of patients with familial mediterranean fever have painful episodes localized to the abdomen, which is usually the dominant manifestation of the disease. Herein, we present a case of 34-year-old man with incomplete abdominal pain episode of familial mediterranean fever limited to the epigastrum and had no cardinals symptoms of this disease. The diagnosis was made by genetic screening. Succesful treatment response was achieved by colchicine.

  6. Designer babies on tap? Medical students' attitudes to pre-implantation genetic screening.

    Science.gov (United States)

    Meisenberg, Gerhard

    2009-03-01

    This paper describes two studies about the determinants of attitudes to pre-implantation genetic screening in a multicultural sample of medical students from the United States. Sample sizes were 292 in study 1 and 1464 in study 2. Attitudes were of an undifferentiated nature, but respondents did make a major distinction between use for disease prevention and use for enhancement. No strong distinctions were made between embryo selection and germ line gene manipulations, and between somatic gene therapy and germ line gene manipulations. Religiosity was negatively associated with acceptance of "designer baby" technology for Christians and Muslims but not Hindus. However, the strongest and most consistent influence was an apparently moralistic stance against active and aggressive interference with natural processes in general. Trust in individuals and institutions was unrelated to acceptance of the technology, indicating that fear of abuse by irresponsible individuals and corporations is not an important determinant of opposition.

  7. Accelerated Genetic Algorithm Solutions Of Some Parametric Families Of Stochastic Differential Equations

    Directory of Open Access Journals (Sweden)

    Eman Ali Hussain

    2015-01-01

    Full Text Available Absract In this project A new method for solving Stochastic Differential Equations SDEs deriving by Wiener process numerically will be construct and implement using Accelerated Genetic Algorithm AGA. An SDE is a differential equation in which one or more of the terms and hence the solutions itself is a stochastic process. Solving stochastic differential equations requires going away from the recognizable deterministic setting of ordinary and partial differential equations into a world where the evolution of a quantity has an inherent random component and where the expected behavior of this quantity can be described in terms of probability distributions. We applied our method on the Ito formula which is equivalent to the SDE to find approximation solution of the SDEs. Numerical experiments illustrate the behavior of the proposed method.

  8. Genetic diversity and differentiation of Juniperus thurifera in Spain and Morocco as determined by SSR.

    Science.gov (United States)

    Teixeira, Helena; Rodríguez-Echeverría, Susana; Nabais, Cristina

    2014-01-01

    Juniperus thurifera L. is an important tree endemic to the western Mediterranean basin that it is able to grow in semi-arid climates. It nowadays exhibits a disjunct distribution pattern, occurring in North Africa, Spain, France and the Italian Alps. The Strait of Gibraltar has acted as an efficient barrier against gene flow between African and European populations, which are considered different subspecies by some authors. We aimed at describing the intraspecific genetic diversity of J. thurifera in populations from the Iberian Peninsula and Morocco and the phylogeographical relationships among these populations. The ploidy level of J. thurifera was examined and eleven nuclear microsatellites (nSSRs) developed for J. thurifera were assessed for genotyping this species. Six nSSRs were polymorphic and subsequently used to assess the genetic diversity and structure of the studied populations. Genotyping of the tetraploid J. thurifera using nuclear microsatellites supports the separation of Moroccan and Spanish populations into two genetically differentiated groups that correspond to the proposed subspecies africana and thurifera. High values of within population genetic diversity were found, that accounted for 90% of the total genetic variance, while population structure was weak. The estimators of genetic diversity were higher in populations of Spain than in populations of Morocco pointing for a possible loss of genetic diversity during the spread of this species to Africa from Europe.

  9. Novel assay of competitively differentiated polymerase chain reaction for screening point mutation of hepatitis B virus

    Institute of Scientific and Technical Information of China (English)

    Xiao-Mou Peng; Xue-Juan Chen; Jian-Guo Li; Lin Gu; Yang-Su Huang; Zhi-Liang Gao

    2003-01-01

    AIM: Point mutation, one of the commonest gene mutations,is the most important molecular pathogenesis of cancer and chronic infection. The commonest methods for detection of point mutation are based on polymerase chain reaction (PCR). These techniques, however, cannot be used in large scale screening since they are neither accurate nor simple.For this reason, this study established a novel method of competitively differentiated PCR (CD-PCR) for screening point mutation in clinical practice.METHODS: Two competitively differentiated primers for mutant-type and wild-type templates respectively with an identically complemented region in 3′ end except for last 2base pairs and a different non-complemented region in 5′end were designed. Thus, competitive amplification might be carried out at a lower annealing temperature at first, and then differentiated amplification at a higher annealing temperature when primers could not combine with initial templates. The amplification was performed in one-tube.The products of CD-PCR were detected using microplate hybridization assay. CD-PCR was evaluated by detecting G1896A variant of hepatitis B virus (HBV) in form of recombinant plasmids and in sera from patients with hepatitis B, and compared with allele-specific PCR (AS-PCR) and competitive AS-PCR.RESULTS: CD-PCR was successfully established. It could clearly distinguish wild-type and mutant-type plasmid DNA of G1896A variant when the amount of plasmid DNA was between 102-108copies/reaction, while for AS-PCR and competitive AS-PCR, the DNA amount was between 102-104copies/reaction. CD-PCR could detect one copy of G1896A variant among 10-100 copies of wild-type plasmid DNA. The specificity of CD-PCR was higher than those of AS-PCR and competitive AS-PCR in the detection of HBV G1896A variant in sera from patients with hepatitis B. CD-PCR was independent of the amount of HBV DNA in serum. HBV G1896A variant was more often found in HBeAg (-) patients with a lower level of

  10. Genetic differentiation between Segugio dell’Appennino and Segugio Maremmano dog breeds assessed by microsatellite markers

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    Vincenzo La Manna

    2015-07-01

    Full Text Available The domestic dog (Canis Familiaris was the first species to be tamed and bred to occupy a variety of functions. The Segugio dell’Appennino and Segugio Maremmano are two Italian breeds used extensively as hunting dogs. Microsatellites and other genetic markers are useful tools in evaluating the within and between breed genetic variation. The aim of this study was to investigate genetic differentiation among the two breeds through the analysis of 21 microsatellite markers. The two populations share the same geographical regions but have been over time selected on different parameters to achieve specific functions. All the analysed microsatellite markers were polymorphic and the average number of alleles per locus was 8.19. The mean FIT index (0.051; P<0.05 highlights that at some point in time, the normal gene flow among the animals was disrupted, giving rise to a heterozygote deficiency in both breeds, and this is confirmed by the mean FST fixation index (0.010; P<0.05 clearly indicating an absence of a significant genetic differentiation between the two breeds. The mean FIS value was significantly different from zero (0.042 (P<0.05 reconfirming the presence of a lack of heterozygosity in the studied samples. The values of observed and expected heterozygosity were similar in the two breeds. AMOVA, PCA and STRUCTURE analysis, all emphasise the lack of significant differences among the two breeds in terms of genetic differentiation. The presence of a population substructure is probably due to a genetic introgression from different Segugio breeds, that can be confirmed with further studies.

  11. Genetic architecture of transcript-level variation in differentiating xylem of a eucalyptus hybrid.

    Science.gov (United States)

    Kirst, Matias; Basten, Christopher J; Myburg, Alexander A; Zeng, Zhao-Bang; Sederoff, Ronald R

    2005-04-01

    Species diversity may have evolved by differential regulation of a similar set of genes. To analyze and compare the genetic architecture of transcript regulation in different genetic backgrounds of Eucalyptus, microarrays were used to examine variation in mRNA abundance in the differentiating xylem of a E. grandis pseudobackcross population [E. grandis x F(1) hybrid (E. grandis x E. globulus)]. Least-squares mean estimates of transcript levels were generated for 2608 genes in 91 interspecific backcross progeny. The quantitative measurements of variation in transcript abundance for specific genes were mapped as expression QTL (eQTL) in two single-tree genetic linkage maps (F(1) hybrid paternal and E. grandis maternal). EQTL were identified for 1067 genes in the two maps, of which 811 were located in the F(1) hybrid paternal map, and 451 in the E. grandis maternal map. EQTL for 195 genes mapped to both parental maps, the majority of which localized to nonhomologous linkage groups, suggesting trans-regulation by different loci in the two genetic backgrounds. For 821 genes, a single eQTL that explained up to 70% of the transcript-level variation was identified. Hotspots with colocalized eQTL were identified in both maps and typically contained genes associated with specific metabolic and regulatory pathways, suggesting coordinated genetic regulation.

  12. Temporal and spatial genetic differentiation in the crab Liocarcinus depurator across the Atlantic-Mediterranean transition

    Science.gov (United States)

    Pascual, Marta; Palero, Ferran; García-Merchán, Víctor Hugo; Macpherson, Enrique; Robainas-Barcia, Aymée; Mestres, Francesc; Roda, Tania; Abelló, Pere

    2016-01-01

    Spatial genetic studies often require sampling broadly separated areas, difficult to access simultaneously. Although comparing localities surveyed at different time periods might result in spurious genetic differentiation, there is a general believe on the stability of genetic structure through time, particularly if sampled localities are isolated or very distant. By analysing spatial and temporal genetic differentiation of the portunid crab Liocarcinus depurator we assessed the contribution of historical and contemporary processes on population connectivity patterns across three main oceanographic discontinuities along the Atlantic-Mediterranean transition: Gibraltar Strait, Almeria-Oran Front and Ibiza Channel. A partial fragment of the cytochrome oxidase I gene was sequenced in 366 individuals collected from localities at both sides of each discontinuity during three time periods. Although localities showed genetic fluctuations through time, a significant gradient was detected along the coast for all sampling periods. Significant inter-annual differences identified within the Alicante area, north of the Almeria-Oran Front, were associated with shifts in the relative contribution of Atlantic and Mediterranean water masses. The persistence of a clinal pattern in the Atlantic-Mediterranean transition area together with local fluctuations suggests a complex balance of dispersal and selection. PMID:27431989

  13. High regional genetic differentiation of an endangered relict plant Craigia yunnanensis and implications for its conservation

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    Jing Yang

    2016-10-01

    Full Text Available Of the genus Craigia, widespread in the Tertiary, only two relict species survived to modern times. One species is now possibly extinct and the other one, Craigia yunnanensis, is severely endangered. Extensive surveys have located six C. yunnanensis populations in Yunnan province, southwest China. Using fluorescent amplified fragment length polymorphism (AFLP, the genetic diversity and population structure of these populations were examined. It was found that genetic diversity of C. yunnanensis was moderate at the species level, but low at regional and population levels. Analysis of population structure showed significant genetic differentiation between Wenshan and Dehong regions, apparently representing two geographically isolated for long time refuges. There are also clear indications of isolation between populations, which, together with anthropogenically caused decline of population size, will lead to general loss of the species genetic variation with subsequent loss of adaptive potential. To conserve the genetic integrity of C. yunnanensis, we recommend that ex-situ conservation should include representative samples from every population of the two differentiated regions (e.g. Wenshan and Dehong. The crosses between individuals originated from different regions should be avoided because of a high risk of outbreeding depression. As all the extant populations of C. yunnanensis are in unprotected areas with strong anthropogenic impact, there is no alternative to reintroduction of C. yunnanensis into suitable protected locations.

  14. Genetic differentiation of Arthrobacter population from heavy metal-contaminated environment

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hanbo; REN Weimin; SHAO Qiyong; DUAN Changqun

    2007-01-01

    Six samples containing extremely high concentration of Pb,Zn,and Cd were obtained from the layers of 5-10 cm and 25-30 cm three tailing piles,with ages of about 10,20 and more than 80 years,respectively.Then,48 bacterial strains were obtained from these samples,and subsequently their phylogenetic positions were determined by analysis on the partial sequence of 16S rRNA gene (fragment length ranging from 474 to 708 bp).These isolates were members of the Arthrobacter genus,phylogenetically close to A.keyseri and A.ureafaciens,with sequence ranging from 99.1%to 100%.Furthermore,genetic variation between subpopulations from different samples was revealed by analysis on their randomly amplified polymorphic DNA profile.Nei genetic distance showed that the greatest differentiation occurred between subpopulation A and C.Notably,either genetic distance between subpopulations from the layers of 5-10 cm and 25-30 cm of each tailing pile or between same layers of different tailing pile increased with the history of tailings.Moreover,correlation analysis showed that soluble Pb has a significantly negative relationship with Nei'gene diversity of subpopulation.It was assumed that soluble Pb may be responsible for the reduced genetic diversity of the Arthrobacter population.Our data provided evidence that genetic differentiation of microbial populations was consistent with the changes of environmental factors,particularly heavy metals.

  15. A genetic screen reveals a periplasmic copper chaperone required for nitrite reductase activity in pathogenic Neisseria.

    Science.gov (United States)

    Jen, Freda E-C; Djoko, Karrera Y; Bent, Stephen J; Day, Christopher J; McEwan, Alastair G; Jennings, Michael P

    2015-09-01

    Under conditions of low oxygen availability, Neisseria meningitidis and Neisseria gonorrhoeae are able to respire via a partial denitrification pathway in which nitrite is converted to nitrous oxide. In this process, nitrite reductase (AniA), a copper (Cu)-containing protein converts nitrite to NO, and this product is converted to nitrous oxide by nitric oxide reductase (NorB). NorB also confers protection against toxic NO, and so we devised a conditional lethal screen, using a norB mutant, to identify mutants that were resistant to nitrite-dependent killing. After random-deletion mutagenesis of N. meningitidis, this genetic screen identified a gene encoding a Cu chaperone that is essential for AniA function, AccA. Purified AccA binds one Cu (I) ion and also possesses a second binding site for Cu (II). This novel periplasmic Cu chaperone (AccA) appears to be essential for provision of Cu ions to AniA of pathogenic Neisseria to generate an active nitrite reductase. Apart from the Neisseria genus, AccA is distributed across a wide range of environmental Proteobacteria species. © FASEB.

  16. Genetic modifier screens reveal new components that interact with the Drosophila dystroglycan-dystrophin complex.

    Directory of Open Access Journals (Sweden)

    Mariya M Kucherenko

    Full Text Available The Dystroglycan-Dystrophin (Dg-Dys complex has a capacity to transmit information from the extracellular matrix to the cytoskeleton inside the cell. It is proposed that this interaction is under tight regulation; however the signaling/regulatory components of Dg-Dys complex remain elusive. Understanding the regulation of the complex is critical since defects in this complex cause muscular dystrophy in humans. To reveal new regulators of the Dg-Dys complex, we used a model organism Drosophila melanogaster and performed genetic interaction screens to identify modifiers of Dg and Dys mutants in Drosophila wing veins. These mutant screens revealed that the Dg-Dys complex interacts with genes involved in muscle function and components of Notch, TGF-beta and EGFR signaling pathways. In addition, components of pathways that are required for cellular and/or axonal migration through cytoskeletal regulation, such as Semaphorin-Plexin, Frazzled-Netrin and Slit-Robo pathways show interactions with Dys and/or Dg. These data suggest that the Dg-Dys complex and the other pathways regulating extracellular information transfer to the cytoskeletal dynamics are more intercalated than previously thought.

  17. The minisequencing method: a simple strategy for genetic screening of MEN 2 families

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    Domingues Rita

    2002-05-01

    Full Text Available Abstract Background Multiple endocrine neoplasia type 2 is an autosomal dominant disorder. MEN 2A is characterized by medullary thyroid carcinoma, pheochromocytoma and hyperparathyroidism; MEN 2B by medullary thyroid carcinoma, pheochromocytoma and characteristic stigmata. Activating germline mutations of the RET proto oncogene are responsible for this hereditary syndrome. Codon 634 mutations are the most common mutations occurring in MEN 2A families whereas a specific mutation at codon 918 is observed in the great majority of MEN 2B families. Analysis of these codons will provide a final diagnosis in the great majority of affected families making unnecessary further studies. To specifically study the codons 634 and 918 we used a minisequencing method as an alternative method to complete sequencing. Results Using this mutation detection method we were able to reproduce in all cases, representative of 7 families, the information previously obtained by direct sequencing of PCR products. Depending on the number of primers used in the minisequencing reaction, we were able to interrogate either only one nucleotide of the target codon or the three nucleotides simultaneously. Conclusions This technique appears as a simple, rapid and efficient method for genetic screening of MEN 2 families. It can be utilized to seek for unknown mutations at specific codons or to screen for previously identified mutations and is therefore of interest to study index cases or individuals at risk. Results suggest that complete sequencing is unnecessary.

  18. Genetic screening for chromosomal abnormalities and Y chromosome microdeletions in Chinese infertile men.

    Science.gov (United States)

    Fu, Li; Xiong, Da-Ke; Ding, Xian-Ping; Li, Chuang; Zhang, Li-Yuan; Ding, Min; Nie, Shuang-Shuang; Quan, Qiang

    2012-06-01

    To investigate the frequency and type of both chromosomal abnormalities and Y chromosome microdeletions and analyze their association with defective spermatogenesis in Chinese infertile men. This is a single center study. Karyotyping using G-banding and screening for Y chromosome microdeletion by multiplex polymerase chain reaction(PCR)were performed in 200 controls and 1,333 infertile men, including 945 patients with non-obstructive azoospermia and 388 patients with severe oligozoospermia. Out of 1,333 infertile patients, 154(11.55%) presented chromosomal abnormalities. Of these, 139 of 945 (14.71%) were from the azoospermic and 15 of 388 (3.87%) from the severe oligozoospermic patient groups. The incidence of sex chromosomal abnormalities in men with azoospermia was 11.53% compared with 1.03% in men with severe oligozoospermia (P chromosome microdeletions. The incidence of azoospermia factor(AZF) microdeletion was 11.75% and 8.51% in patients with azoospermia and severe oligozoospermia respectively. Deletion of AZFc was the most common and deletions in AZFa or AZFab or AZFabc were found in azoospermic men. In addition, 34 patients had chromosomal abnormalities among the 144 patients with Y chromosome microdeletions. No chromosomal abnormality and microdeletion in AZF region were detected in controls. There was a high incidence (19.80%) of chromosomal abnormalities and Y chromosomal microdeletions in Chinese infertile males with azoospermia or severe oligozoospermia. These findings strongly suggest that genetic screening should be advised to infertile men before starting assisted reproductive treatments.

  19. GAPscreener: An automatic tool for screening human genetic association literature in PubMed using the support vector machine technique

    Directory of Open Access Journals (Sweden)

    Khoury Muin J

    2008-04-01

    Full Text Available Abstract Background Synthesis of data from published human genetic association studies is a critical step in the translation of human genome discoveries into health applications. Although genetic association studies account for a substantial proportion of the abstracts in PubMed, identifying them with standard queries is not always accurate or efficient. Further automating the literature-screening process can reduce the burden of a labor-intensive and time-consuming traditional literature search. The Support Vector Machine (SVM, a well-established machine learning technique, has been successful in classifying text, including biomedical literature. The GAPscreener, a free SVM-based software tool, can be used to assist in screening PubMed abstracts for human genetic association studies. Results The data source for this research was the HuGE Navigator, formerly known as the HuGE Pub Lit database. Weighted SVM feature selection based on a keyword list obtained by the two-way z score method demonstrated the best screening performance, achieving 97.5% recall, 98.3% specificity and 31.9% precision in performance testing. Compared with the traditional screening process based on a complex PubMed query, the SVM tool reduced by about 90% the number of abstracts requiring individual review by the database curator. The tool also ascertained 47 articles that were missed by the traditional literature screening process during the 4-week test period. We examined the literature on genetic associations with preterm birth as an example. Compared with the traditional, manual process, the GAPscreener both reduced effort and improved accuracy. Conclusion GAPscreener is the first free SVM-based application available for screening the human genetic association literature in PubMed with high recall and specificity. The user-friendly graphical user interface makes this a practical, stand-alone application. The software can be downloaded at no charge.

  20. Spatial pattern and genetic diversity estimates are linked in stochastic models of population differentiation

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    Diniz-Filho José Alexandre Felizola

    2000-01-01

    Full Text Available In the present study, we used both simulations and real data set analyses to show that, under stochastic processes of population differentiation, the concepts of spatial heterogeneity and spatial pattern overlap. In these processes, the proportion of variation among and within a population (measured by G ST and 1 - G ST, respectively is correlated with the slope and intercept of a Mantel's test relating genetic and geographic distances. Beyond the conceptual interest, the inspection of the relationship between population heterogeneity and spatial pattern can be used to test departures from stochasticity in the study of population differentiation.

  1. Development of genetic diversity, differentiation and structure over 500 years in four ponderosa pine populations.

    Science.gov (United States)

    Lesser, M R; Parchman, T L; Jackson, S T

    2013-05-01

    Population history plays an important role in shaping contemporary levels of genetic variation and geographic structure. This is especially true in small, isolated range-margin populations, where effects of inbreeding, genetic drift and gene flow may be more pronounced than in large continuous populations. Effects of landscape fragmentation and isolation distance may have implications for persistence of range-margin populations if they are demographic sinks. We studied four small, disjunct populations of ponderosa pine over a 500-year period. We coupled demographic data obtained through dendroecological methods with microsatellite data to discern how and when contemporary levels of allelic diversity, among and within-population levels of differentiation, and geographic structure, arose. Alleles accumulated rapidly following initial colonization, demonstrating proportionally high levels of gene flow into the populations. At population sizes of approximately 100 individuals, allele accumulation saturated. Levels of genetic differentiation among populations (F(ST) and Jost's D(est)) and diversity within populations (F(IS)) remained stable through time. There was no evidence of geographic genetic structure at any time in the populations' history. Proportionally, high gene flow in the early stages of population growth resulted in rapid accumulation of alleles and quickly created relatively homogenous genetic patterns among populations. Our study demonstrates that contemporary levels of genetic diversity were formed quickly and early in population development. How contemporary genetic diversity accumulates over time is a key facet of understanding population growth and development. This is especially relevant given the extent and speed at which species ranges are predicted to shift in the coming century.

  2. A Genetic Screen for Mutants with Supersized Lipid Droplets in Caenorhabditis elegans

    Science.gov (United States)

    Li, Shiwei; Xu, Shibin; Ma, Yanli; Wu, Shuang; Feng, Yu; Cui, Qingpo; Chen, Lifeng; Zhou, Shuang; Kong, Yuanyuan; Zhang, Xiaoyu; Yu, Jialei; Wu, Mengdi; Zhang, Shaobing O.

    2016-01-01

    To identify genes that regulate the dynamics of lipid droplet (LD) size, we have used the genetically tractable model organism Caenorhabditis elegans, whose wild-type LD population displays a steady state of size with an upper limit of 3 μm in diameter. From a saturated forward genetic screen of 6.7 × 105 mutagenized haploid genomes, we isolated 118 mutants with supersized intestinal LDs often reaching 10 μm. These mutants define nine novel complementation groups, in addition to four known genes (maoc-1, dhs-28, daf-22, and prx-10). The nine groups are named drop (lipid droplet abnormal) and categorized into four classes. Class I mutants drop-5 and drop-9, similar to prx-10, are up-regulated in ACS-22-DGAT-2-dependent LD growth, resistant to LD hydrolysis, and defective in peroxisome import. Class II mutants drop-2, drop-3, drop-6, and drop-7 are up-regulated in LD growth, are resistant to LD hydrolysis, but are not defective in peroxisome import. Class III mutants drop-1 and drop-8 are neither up-regulated in LD growth nor resistant to LD hydrolysis, but seemingly up-regulated in LD fusion. Class IV mutant drop-4 is cloned as sams-1 and, different to the other three classes, is ACS-22-independent and hydrolysis-resistant. These four classes of supersized LD mutants should be valuable for mechanistic studies of LD cellular processes including growth, hydrolysis, and fusion. PMID:27261001

  3. A Genetic Screen for Mutants with Supersized Lipid Droplets in Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Shiwei Li

    2016-08-01

    Full Text Available To identify genes that regulate the dynamics of lipid droplet (LD size, we have used the genetically tractable model organism Caenorhabditis elegans, whose wild-type LD population displays a steady state of size with an upper limit of 3 μm in diameter. From a saturated forward genetic screen of 6.7 × 105 mutagenized haploid genomes, we isolated 118 mutants with supersized intestinal LDs often reaching 10 μm. These mutants define nine novel complementation groups, in addition to four known genes (maoc-1, dhs-28, daf-22, and prx-10. The nine groups are named drop (lipid droplet abnormal and categorized into four classes. Class I mutants drop-5 and drop-9, similar to prx-10, are up-regulated in ACS-22-DGAT-2-dependent LD growth, resistant to LD hydrolysis, and defective in peroxisome import. Class II mutants drop-2, drop-3, drop-6, and drop-7 are up-regulated in LD growth, are resistant to LD hydrolysis, but are not defective in peroxisome import. Class III mutants drop-1 and drop-8 are neither up-regulated in LD growth nor resistant to LD hydrolysis, but seemingly up-regulated in LD fusion. Class IV mutant drop-4 is cloned as sams-1 and, different to the other three classes, is ACS-22-independent and hydrolysis-resistant. These four classes of supersized LD mutants should be valuable for mechanistic studies of LD cellular processes including growth, hydrolysis, and fusion.

  4. Validation of a semiconductor next-generation sequencing assay for the clinical genetic screening of CFTR.

    Science.gov (United States)

    Trujillano, Daniel; Weiss, Maximilian E R; Köster, Julia; Papachristos, Efstathios B; Werber, Martin; Kandaswamy, Krishna Kumar; Marais, Anett; Eichler, Sabrina; Creed, Jenny; Baysal, Erol; Jaber, Iqbal Yousuf; Mehaney, Dina Ahmed; Farra, Chantal; Rolfs, Arndt

    2015-09-01

    Genetic testing for cystic fibrosis and CFTR-related disorders mostly relies on laborious molecular tools that use Sanger sequencing to scan for mutations in the CFTR gene. We have explored a more efficient genetic screening strategy based on next-generation sequencing (NGS) of the CFTR gene. We validated this approach in a cohort of 177 patients with previously known CFTR mutations and polymorphisms. Genomic DNA was amplified using the Ion AmpliSeq™ CFTR panel. The DNA libraries were pooled, barcoded, and sequenced using an Ion Torrent PGM sequencer. The combination of different robust bioinformatics tools allowed us to detect previously known pathogenic mutations and polymorphisms in the 177 samples, without detecting spurious pathogenic calls. In summary, the assay achieves a sensitivity of 94.45% (95% CI: 92% to 96.9%), with a specificity of detecting nonvariant sites from the CFTR reference sequence of 100% (95% CI: 100% to 100%), a positive predictive value of 100% (95% CI: 100% to 100%), and a negative predictive value of 99.99% (95% CI: 99.99% to 100%). In addition, we describe the observed allelic frequencies of 94 unique definitely and likely pathogenic, uncertain, and neutral CFTR variants, some of them not previously annotated in the public databases. Strikingly, a seven exon spanning deletion as well as several more technically challenging variants such as pathogenic poly-thymidine-guanine and poly-thymidine (poly-TG-T) tracts were also detected. Targeted NGS is ready to substitute classical molecular methods to perform genetic testing on the CFTR gene.

  5. [Genetic structure, subdivision, and population differentiation in Stankewiczii pine Pinus stankewiczii (Sukacz.) Fomin from Mountain Crimea].

    Science.gov (United States)

    Korshikov, I I; Gorlova, E M

    2006-06-01

    In order to analyze the genetic structure, subdivision and differentiation within and between two small isolated populations of the Crimea relict endemic, Pinus stankewiczii (Sukacz.) Fomin, electrophoretic analysis of the isozyme variation at nine enzymatic systems was carried out using 183 oldest trees. It was demonstrated that in populations of P. stankewiczii, 80% of the genes were in polymorphic state. Each tree was heterozygous at 19.1% loci, and at 21.6% loci in artificial 50-year-old plantation. The genetic structure of two populations was less differentiated (DN = 0.006), compared to their individual localities (DN = 0.008-0.009). Within-population subdivision of the diffusely dispersed populations was higher (FST-GST = 1.8-2.0%) than that of the populations themselves (0.8%).

  6. Genetic and epigenetic effect of estrogen on mesenchymal stem cell maintenance and differentiation

    OpenAIRE

    2013-01-01

    Ankara : The Department of Molecular Biology and Genetics and the Graduate School of Engineering and Science of Bilkent Univ., 2013. Thesis (Ph. D.) -- Bilkent University, 2013. Includes bibliographical references leaves 126-143. Mesenchymal stem cells (MSCs) have the potential to differentiate into multiple cell types and immune privileged characteristics. These features make MSCs a hope in tissue engineering and cell based treatment applications. Tremendous amount of stud...

  7. Landscape characteristics influence morphological and genetic differentiation in a widespread raptor (Buteo jamaicensis).

    Science.gov (United States)

    Hull, Joshua M; Hull, Angus C; Sacks, Benjamin N; Smith, Jeff P; Ernest, Holly B

    2008-02-01

    Landscape-scale population genetic structure in vagile vertebrates was commonly considered to be a contradiction in terms whereas recent studies have demonstrated behaviour and habitat associated structure in several such species. We investigate whether landscape features influence morphological and genetic differentiation in a widespread, mobile raptor. To accurately describe genetic differentiation associated with regional landscape factors, we first investigated subspecies relationships at a continental scale. We used 17 microsatellite loci and five morphological measurements to investigate differentiation between eastern and western subspecies of red-tailed hawks (Buteo jamaicensis) and to identify patterns between differentiation and habitat within western North America. Bayesian and frequency-based analyses of microsatellite data revealed clear distinctions between B. j. borealis (eastern) and B. j. calurus (western) samples. Furthermore, hawks sampled in Texas were stouter than those collected from the Rocky Mountains and farther west. Among western samples, birds from the Great Basin, Rocky Mountains, and Washington were significantly different in morphology than those from Oregon and California. We identified a pattern of isolation by distance among western breeding sites around the Sierra Nevada. Given the long-range dispersal capabilities of raptors, this pattern suggests that population-specific habitat preferences, corresponding with habitat breaks between eastern and western slopes of the Sierra Nevada, and/or regionally variable population densities limit migration between the Mediterranean habitat of central California and the xeric habitats of southern California and interior west. We suggest habitat preferences and regionally disparate population densities may play a role in shaping genetic structure in vagile avian taxa.

  8. Population genetics of the understory fishtail palm Chamaedorea ernesti-augusti in Belize: high genetic connectivity with local differentiation

    Directory of Open Access Journals (Sweden)

    Thomas Meredith M

    2009-10-01

    Full Text Available Abstract Background Developing a greater understanding of population genetic structure in lowland tropical plant species is highly relevant to our knowledge of increasingly fragmented forests and to the conservation of threatened species. Specific studies are particularly needed for taxa whose population dynamics are further impacted by human harvesting practices. One such case is the fishtail or xaté palm (Chamaedorea ernesti-augusti of Central America, whose wild-collected leaves are becoming progressively more important to the global ornamental industry. We use microsatellite markers to describe the population genetics of this species in Belize and test the effects of climate change and deforestation on its recent and historical effective population size. Results We found high levels of inbreeding coupled with moderate or high allelic diversity within populations. Overall high gene flow was observed, with a north and south gradient and ongoing differentiation at smaller spatial scales. Immigration rates among populations were more difficult to discern, with minimal evidence for isolation by distance. We infer a tenfold reduction in effective population size ca. 10,000 years ago, but fail to detect changes attributable to Mayan or contemporary deforestation. Conclusion Populations of C. ernesti-augusti are genetically heterogeneous demes at a local spatial scale, but are widely connected at a regional level in Belize. We suggest that the inferred patterns in population genetic structure are the result of the colonization of this species into Belize following expansion of humid forests in combination with demographic and mating patterns. Within populations, we hypothesize that low aggregated population density over large areas, short distance pollen dispersal via thrips, low adult survival, and low fruiting combined with early flowering may contribute towards local inbreeding via genetic drift. Relatively high levels of regional connectivity

  9. Microsatellite genetic diversity and differentiation of native and introduced grass carp populations in three continents

    Science.gov (United States)

    Chapman, Duane C.; Chen, Qin; Wang, Chenghui; Zhao, Jinlian; Lu, Guoqing; Zsigmond, Jeney; Li, Si-Fa

    2012-01-01

    Grass carp (Ctenopharyngodon idella), a freshwater species native to China, has been introduced to about 100 countries/regions and poses both biological and environmental challenges to the receiving ecosystems. In this study, we analyzed genetic variation in grass carp from three introduced river systems (Mississippi River Basin in US, Danube River in Hungary, and Tone River in Japan) as well as its native ranges (Yangtze, Pearl, and Amur Rivers) in China using 21 novel microsatellite loci. The allelic richness, observed heterozygosity, and within-population gene diversity were found to be lower in the introduced populations than in the native populations, presumably due to the small founder population size of the former. Significant genetic differentiation was found between all pairwise populations from different rivers. Both principal component analysis and Bayesian clustering analysis revealed obvious genetic distinction between the native and introduced populations. Interestingly, genetic bottlenecks were detected in the Hungarian and Japanese grass carp populations, but not in the North American population, suggesting that the Mississippi River Basin grass carp has experienced rapid population expansion with potential genetic diversification during the half-century since its introduction. Consequently, the combined forces of the founder effect, introduction history, and rapid population expansion help explaining the observed patterns of genetic diversity within and among both native and introduced populations of the grass carp.

  10. Patients' ratings of genetic conditions validate a taxonomy to simplify decisions about preconception carrier screening via genome sequencing.

    Science.gov (United States)

    Leo, Michael C; McMullen, Carmit; Wilfond, Benjamin S; Lynch, Frances L; Reiss, Jacob A; Gilmore, Marian J; Himes, Patricia; Kauffman, Tia L; Davis, James V; Jarvik, Gail P; Berg, Jonathan S; Harding, Cary; Kennedy, Kathleen A; Simpson, Dana Kostiner; Quigley, Denise I; Richards, C Sue; Rope, Alan F; Goddard, Katrina A B

    2016-03-01

    Advances in genome sequencing and gene discovery have created opportunities to efficiently assess more genetic conditions than ever before. Given the large number of conditions that can be screened, the implementation of expanded carrier screening using genome sequencing will require practical methods of simplifying decisions about the conditions for which patients want to be screened. One method to simplify decision making is to generate a taxonomy based on expert judgment. However, expert perceptions of condition attributes used to classify these conditions may differ from those used by patients. To understand whether expert and patient perceptions differ, we asked women who had received preconception genetic carrier screening in the last 3 years to fill out a survey to rate the attributes (predictability, controllability, visibility, and severity) of several autosomal recessive or X-linked genetic conditions. These conditions were classified into one of five taxonomy categories developed by subject experts (significantly shortened lifespan, serious medical problems, mild medical problems, unpredictable medical outcomes, and adult-onset conditions). A total of 193 women provided 739 usable ratings across 20 conditions. The mean ratings and correlations demonstrated that participants made distinctions across both attributes and categories. Aggregated mean attribute ratings across categories demonstrated logical consistency between the key features of each attribute and category, although participants perceived little difference between the mild and serious categories. This study provides empirical evidence for the validity of our proposed taxonomy, which will simplify patient decisions for results they would like to receive from preconception carrier screening via genome sequencing.

  11. Psychosocial Aspects of Hereditary Cancer (PAHC) questionnaire: development and testing of a screening questionnaire for use in clinical cancer genetics

    NARCIS (Netherlands)

    Eijzenga, W.; Bleiker, E.M.A.; Hahn, D.E.E.; Kluijt, I.; Sidharta, G.N.; Gundy, C.; Aaronson, N.K.

    2014-01-01

    Background: Up to three-quarters of individuals who undergo cancer genetic counseling and testing report psychosocial problems specifically related to that setting. The objectives of this study were to develop and evaluate the screening properties of a questionnaire designed to assess specific psych

  12. Use of the Photoactic Ability of a Bacterium to Teach the Genetic Principles of Random Mutagenesis & Mutant Screening

    Science.gov (United States)

    Din, Neena; Bird, Terry H.; Berleman, James E.

    2007-01-01

    In this article, the authors present a laboratory activity that relies on the use of a very versatile bacterial system to introduce the concept of how mutagenesis can be used for molecular and genetic analysis of living organisms. They have used the techniques of random mutagenesis and selection/screening to obtain strains of the organism "R.…

  13. Statistical measures of genetic differentiation of populations:Rationales, history and current states

    Institute of Scientific and Technical Information of China (English)

    Liang MA; Ya-Jie JI; De-Xing ZHANG

    2015-01-01

    Population differentiation is a fundamental process of evolution, and many evolutionary studies, such as population genetics, phylogeography and conservation biology, all require the inference of population differentiation. Recently, there has been a lot of debate over the validity ofFST (and its analogueGST) as a measure for population genetic differentiation, notably since the proposal of the new indexD in 2008. Although several papers reviewed or explored specific features of these statistical measures, a succinct account of this bewildering issue with an overall update appears to be desirable. This is the purpose of the present review. The available statistics generally fall into two categories, represented byFST andD, respectively. None of them is perfect in measuring population genetic differentiation. Nevertheless, they each have advantages and are valuable for current re-search. In practice, both indices should be calculated and a comparison of them can generate useful insights into the evolutionary processes that influence population differentiation.FST (GST) has some unique irreplaceable characteristics assuring its standing as the default measure for the foreseeable near future. Also, it will continue to serve as the standard for any alternative measures to contrast with. Instead of being anxious about making choice between these indices, one should pay due attention to the equili-brium status and the level of diversity (especiallyHS) of the populations, since they largely sway the power of a given statistic to address a specific question. We provide a multi-faceted comparative summary of the various statistics, which can serve as a basic reference for readers to guide their applications [Current Zoology 61 (5): 886–897, 2015].

  14. Lack of population genetic differentiation of a marine ovoviviparous fish Sebastes schlegelii in Northwestern Pacific.

    Science.gov (United States)

    Zhang, Hui; Yanagimoto, Takashi; Zhang, Xiumei; Song, Na; Gao, Tianxiang

    2016-05-01

    Sebastes schlegelii is one of the fishes that aggregate around drifting seaweed during early development. To examine the population genetic structure of S. schlegelii, a 452-bp fragment of the mtDNA control region was sequenced and used to interpret life history characteristics and larval dispersal strategy. Two-hundred and twenty-one individuals from 13 sites across the entire range of S. schlegelii in China, Japan and Korea were analyzed. A neighbor-joining tree and network showed that there were no significant genealogical structures corresponding to sampling locations. AMOVA, pair-wise FST and exact test revealed no significant genetic differentiation among locations. The migration rate among locations was high based on the result of LAMARC. We conclude that larval dispersal with drifting seaweed and the current environmental factors may play an important role in shaping the contemporary phylogeographic pattern and genetic homogeneity of S. schlegelii.

  15. Local environment but not genetic differentiation influences biparental care in ten plover populations.

    Directory of Open Access Journals (Sweden)

    Orsolya Vincze

    Full Text Available Social behaviours are highly variable between species, populations and individuals. However, it is contentious whether behavioural variations are primarily moulded by the environment, caused by genetic differences, or a combination of both. Here we establish that biparental care, a complex social behaviour that involves rearing of young by both parents, differs between closely related populations, and then test two potential sources of variation in parental behaviour between populations: ambient environment and genetic differentiation. We use 2904 hours behavioural data from 10 geographically distinct Kentish (Charadrius alexandrinus and snowy plover (C. nivosus populations in America, Europe, the Middle East and North Africa to test these two sources of behavioural variation. We show that local ambient temperature has a significant influence on parental care: with extreme heat (above 40 °C total incubation (i.e. % of time the male or female incubated the nest increased, and female share (% female share of incubation decreased. By contrast, neither genetic differences between populations, nor geographic distances predicted total incubation or female's share of incubation. These results suggest that the local environment has a stronger influence on a social behaviour than genetic differentiation, at least between populations of closely related species.

  16. Molecular genetic differentiation in earthworms inhabiting a heterogeneous Pb-polluted landscape

    Energy Technology Data Exchange (ETDEWEB)

    Andre, J., E-mail: Andrej@cardiff.ac.u [Cardiff School of Biosciences, Cardiff University, BIOSI 1, Museum Avenue, Cardiff CF10 3TL (United Kingdom); Department of Soil Science, School of Human and Environmental Sciences, University of Reading, Whiteknights, Reading RG6 6DW (United Kingdom); King, R.A. [Cardiff School of Biosciences, Cardiff University, BIOSI 1, Museum Avenue, Cardiff CF10 3TL (United Kingdom); Stuerzenbaum, S.R. [King' s College London, School of Biomedical and Health Sciences, Pharmaceutical Sciences Division, London SE1 9NH (United Kingdom); Kille, P. [Cardiff School of Biosciences, Cardiff University, BIOSI 1, Museum Avenue, Cardiff CF10 3TL (United Kingdom); Hodson, M.E. [Department of Soil Science, School of Human and Environmental Sciences, University of Reading, Whiteknights, Reading RG6 6DW (United Kingdom); Morgan, A.J. [Cardiff School of Biosciences, Cardiff University, BIOSI 1, Museum Avenue, Cardiff CF10 3TL (United Kingdom)

    2010-03-15

    A Pb-mine site situated on acidic soil, but comprising of Ca-enriched islands around derelict buildings was used to study the spatial pattern of genetic diversity in Lumbricus rubellus. Two distinct genetic lineages ('A' and 'B'), differentiated at both the mitochondrial (mtDNA COII) and nuclear level (AFLPs) were revealed with a mean inter-lineage mtDNA sequence divergence of approximately 13%, indicative of a cryptic species complex. AFLP analysis indicates that lineage A individuals within one central 'ecological island' site are uniquely clustered, with little genetic overlap with lineage A individuals at the two peripheral sites. FTIR microspectroscopy of Pb-sequestering chloragocytes revealed different phosphate profiles in residents of adjacent acidic and calcareous islands. Bioinformatics found over-representation of Ca pathway genes in EST{sub Pb} libraries. Subsequent sequencing of a Ca-transport gene, SERCA, revealed mutations in the protein's cytosolic domain. We recommend the mandatory genotyping of all individuals prior to field-based ecotoxicological assays, particularly those using discriminating genomic technologies. - Landscapes punctuated by Pb-polluted islands have engendered local genetic differentiation in resident earthworms.

  17. Genetic diversity and differentiation of mud crab Scylla serrata populations from southeastern China

    Institute of Scientific and Technical Information of China (English)

    LI Zhongbao; LI Shaojing; WANG Guizhong

    2004-01-01

    The genetic diversity and differentiation of 6 mud crab Scylla serrata populations from southeastern China are investigated using allozyme electrophoresis. The mean number of alleles per locus population is 1.3 ± 0.1; the percentage of polymorphic loci per population is 27.3; the observed heterozygosity ranges from ( 0.195 ± 0.083)to ( 0.241 ± 0.090) and the expected heterozygosity ranges from ( 0.105 ± 0.043 ) to ( 0.131 ± 0.047 ). The coefficient of gene differentiation among populations is low (Fst =0.032), indicating that only 3.2 % of the total genetic diversity comes from inter-population, while the remaining 96.8 % comes from intra-population differences.The genetic distance among populations is 0.000~0.008 (the average is 0.002). Gene flow among the populations is large (Nm= 7.56).Genetic structure is very similar among 6 Scylla serrata populations.

  18. Regional genetic differentiation among populations of Cladocora caespitosa in the Western Mediterranean

    Science.gov (United States)

    Casado-Amezúa, Pilar; Kersting, Diego K.; Templado, José; Machordom, Annie

    2014-12-01

    Cladocora caespitosa is the only reef-forming zooxanthellate scleractinian in the Mediterranean Sea. This endemic coral has suffered severe mortality events at different Mediterranean sites owing to anomalous summer heat waves related to global climate change. In this study, we assessed genetic structure and gene flow among four populations of this species in the Western Mediterranean Sea: Cape Palos (SE Spain), Cala Galdana (Balearic Islands), Columbretes Islands, and L'Ametlla (NE Spain). The results obtained from Bayesian approaches, F ST statistics, and Bayesian analysis of migration rates suggest certain levels of genetic differentiation driven by high levels of self-recruitment, a fact that is supported by egg-retention mechanisms. Conversely, genetic connectivity among distant populations, even if generally low, seems to be related to sporadic dispersal events through regional surface currents linked to the spawning period that occurs at the end of summer-beginning of autumn. These features, together with a certain isolation of the Columbretes Islands, could explain the regional genetic differentiation found among populations. These results help to better understand population structure and connectivity of the species and will serve as an approach for further studies on different aspects of the biology and ecology of C. caespitosa.

  19. Genetic diversity of and differentiation among five populations of blunt snout bream (Megalobrama amblycephala revealed by SRAP markers: implications for conservation and management.

    Directory of Open Access Journals (Sweden)

    Wei Ji

    Full Text Available The blunt snout bream (Megalobrama amblycephala is an important freshwater aquaculture fish throughout China. Because of widespread introductions of this species to many regions, the genetic diversity of wild and natural populations is now threatened. In the present study, SRAP (sequence-related amplified polymorphism markers were used to assess genetic diversity of blunt snout bream. Three natural populations (Liangzi Lake, Poyang Lake and Yuni Lake, one cultured population (Nanxian and one genetic strain ('Pujiang No. 1' of blunt snout bream were screened with 88 SRAP primer combinations, of which 13 primer pairs produced stable and reproducible amplification patterns. In total, 172 bands were produced, of which 132 bands were polymorphic. Nei's gene diversity (h and Shannon's information index (I values provided evidence of differences in genetic diversity among the five populations (Poyang Lake>Liangzi Lake>Nanxian>'Pujiang No. 1'>Yuni Lake. Based on cluster analysis conducted on genetic distance values, the five blunt snout bream populations were divided into three groups, Poyang Lake and Liangzi Lake (natural populations, Nanxian and 'Pujiang No. 1' (cultured population and genetically selected strain, and Yuni Lake (natural population. Significant genetic differentiation was found among the five populations using analysis of molecular variance (AMOVA, with more genetic divergence existing among populations (55.49%, than within populations (44.51%. This molecular marker technique is a simple and efficient method to quantify genetic diversity within and among fish populations, and is employed here to help manage and conserve germplasm variability of blunt snout bream and to support the ongoing selective breeding programme for this fish.

  20. Genetic differentiation and karyotype variation in Hedysarum chaiyrakanicum, an endemic species of Tuva Republic, Russia.

    Science.gov (United States)

    Zvyagina, Natalia S; Dorogina, Olga V; Krasnikov, Alexander A

    2016-05-01

    Overgrazing and mining affect vegetation, particularly in mountains. At times, it goes to such an extent that the plant species become vulnerable and slowly extinct from its habitat. Such endemic species need to be protected. One such endemic species Hedysarum chaiyrakanicum Kurbatsky, a vulnerable steppe vegetation of Tuva Republic, Russia was evaluated for its genetic diversity and taxonomic definition using molecular technique and chromosome number adjustment. The genetic differentiation among H. chaiyrakanicum, H. setigerum Turcz. and H. gmelinii Ledeb. genotypes was determined using five inter-simple sequence repeat (ISSR) markers and then examined with Nei's genetic distance coefficient (D) and Shannon's information index (H). A total of 134 reproducible bands were detected with polymorphism percentage of 98%. The genetic diversity of H. chaiyrakanicum was found to be 0.343 while the Shannon index H(sp) was determined as 8 06. The chromosome number 2n = 16 is newly observed within the H. chaiyrakanicum. The genetic relationship based on ISSR data supported the taxonomic distinction of H. chaiyrakanicum from H. setigerum and H. gmelinii. We recommend both in situ and ex situ conservation strategies, specially germplasm sampling, to save this endemic species.

  1. Genetic differentiation among populations of the Roseate Spoonbill (Platalea ajaja; Aves: Pelecaniformes) in three Brazilian Wetlands.

    Science.gov (United States)

    Miño, Carolina Isabel; Del Lama, Silvia Nassif

    2014-08-01

    Effective population size, levels of genetic diversity, gene flow, and genetic structuring were assessed in 205 colonial Roseate spoonbills from 11 breeding colonies from north, central west, and south Brazil. Colonies and regions exhibited similar moderate levels of diversity at five microsatellite loci (mean expected heterozygosity range 0.50-0.62; allelic richness range 3.17-3.21). The central west region had the highest Ne (59). F ST values revealed low but significant genetic structuring among colonies within the north and within the south regions. Significant global genetic structuring was found between the northern and central western populations as well as between the northern and southern populations. An individual-based Bayesian clustering method inferred three population clusters. Assignment tests correctly allocated up to 64% of individuals to their source regions. Collectively, results revealed complex demographic dynamics, with ongoing gene flow on a local scale, but genetic differentiation on a broader scale. Populations in the three regions may all be conserved, but special concern should be given to central western ones, which can significantly contribute to the species' gene pool in Brazil.

  2. Genetic Diversity and Population Differentiation of the Causal Agent of Citrus Black Spot in Brazil

    Directory of Open Access Journals (Sweden)

    Ester Wickert

    2012-01-01

    Full Text Available One of the most important diseases that affect sweet orange orchards in Brazil is the Citrus Black Spot that is caused by the fungus Guignardia citricarpa. This disease causes irreparable losses due to the premature falling of fruit, as well as its severe effects on the epidermis of ripe fruit that renders them unacceptable at the fresh fruit markets. Despite the fact that the fungus and the disease are well studied, little is known about the genetic diversity and the structure of the fungi populations in Brazilian orchards. The objective of this work was study the genetic diversity and population differentiation of G. citricarpa associated with four sweet orange varieties in two geographic locations using DNA sequence of ITS1-5.8S-ITS2 region from fungi isolates. We observed that different populations are closely related and present little genetic structure according to varieties and geographic places with the highest genetic diversity distributed among isolates of the same populations. The same haplotypes were sampled in different populations from the same and different orange varieties and from similar and different origins. If new and pathogenic fungi would become resistant to fungicides, the observed genetic structure could rapidly spread this new form from one population to others.

  3. Genetic differentiation of the Kittlitz's Murrelet Brachyramphus brevirostris in the Aleutian Islands and Gulf of Alaska

    Science.gov (United States)

    Birt, T.P.; Mackinnon, D.; Piatt, J.F.; Friesen, V.L.

    2011-01-01

    Information about the distribution of genetic variation within and among local populations of the Kittlitz's Murrelet Brachyramphus brevirostris is needed for effective conservation of this rare and declining species. We compared variation in a 429 base pair fragment of the mitochondrial control region and 11 microsatellite loci among 53 Kittlitz's Murrelets from three sites in the western Aleutian Islands (Attu Island) and Gulf of Alaska (Glacier Bay and Kachemak Bay). We found that birds in these two regions differ genetically in three assessments: (1) global and pairwise indices of genetic differentiation were significantly greater than zero, (2) mitochondrial haplotypes differed by a minimum of nine substitutions, and (3) molecular assignments indicated little gene flow between regions. The data suggest that birds in these regions have been genetically isolated for an extended period. We conclude that Kittlitz's Murrelets from Attu Island and from the Gulf of Alaska represent separate evolutionarily significant units, and should be treated as such for conservation. Genetic data for Kittlitz's Murrelets from the remainder of the breeding range are urgently needed.

  4. Differential genetic and environmental influences on developmental trajectories of antisocial behavior from adolescence to young adulthood.

    Science.gov (United States)

    Zheng, Yao; Cleveland, H Harrington

    2015-12-01

    Little research has investigated differential genetic and environmental influences on different developmental trajectories of antisocial behavior. This study examined genetic and environmental influences on liabilities of being in life-course-persistent (LCP) and adolescent-limited (AL) type delinquent groups from adolescence to young adulthood while considering nonviolent and violent delinquency subtypes and gender differences. A genetically informative sample (n = 356, 15-16 years) from the first three waves of In-Home Interview of the National Longitudinal Study of Adolescent to Adult Health was used, with 94 monozygotic and 84 dizygotic pairs of same-sex twins (50% male). Biometric liability threshold models were fit and found that the male-specific LCP type class, chronic, showed more genetic influences, while the AL type classes, decliner and desister, showed more environmental influences. Genetic liability and shared environment both influence the persistence of antisocial behavior. The development of female antisocial behavior appears to be influenced more by shared environment.

  5. Differential effect of caffeine intake in subjects with genetic susceptibility to Parkinson's Disease.

    Science.gov (United States)

    Kumar, Prakash M; Paing, Swe Swe Thet; Li, HuiHua; Pavanni, R; Yuen, Y; Zhao, Y; Tan, Eng King

    2015-11-02

    We examined if caffeine intake has a differential effect in subjects with high and low genetic susceptibility to Parkinson's disease (PD), a common neurodegenerative disorder. A case control study involving 812 subjects consisting of PD and healthy controls were conducted. Caffeine intake assessed by a validated questionnaire and genotyping of PD gene risk variant (LRRK2 R1628P) was carried out. Compared to caffeine takers with the wild-type genotype (low genetic susceptibility), non-caffeine takers with R1628P variant (high genetic susceptibility) had a 15 times increased risk of developing PD (OR = 15.4, 95% CI = (1.94, 122), P = 0.01), whereas caffeine takers with R1628P (intermediate susceptibility) had a 3 times risk (OR = 3.07, 95% CI = (2.02, 4.66), P Caffeine intake would significantly reduce the risk of PD much more in those with high genetic susceptibility compared to those with low genetic susceptibility.

  6. Regulators of Trypanosoma brucei cell cycle progression and differentiation identified using a kinome-wide RNAi screen.

    Directory of Open Access Journals (Sweden)

    Nathaniel G Jones

    2014-01-01

    Full Text Available The African trypanosome, Trypanosoma brucei, maintains an integral link between cell cycle regulation and differentiation during its intricate life cycle. Whilst extensive changes in phosphorylation have been documented between the mammalian bloodstream form and the insect procyclic form, relatively little is known about the parasite's protein kinases (PKs involved in the control of cellular proliferation and differentiation. To address this, a T. brucei kinome-wide RNAi cell line library was generated, allowing independent inducible knockdown of each of the parasite's 190 predicted protein kinases. Screening of this library using a cell viability assay identified ≥42 PKs that are required for normal bloodstream form proliferation in culture. A secondary screen identified 24 PKs whose RNAi-mediated depletion resulted in a variety of cell cycle defects including in G1/S, kinetoplast replication/segregation, mitosis and cytokinesis, 15 of which are novel cell cycle regulators. A further screen identified for the first time two PKs, named repressor of differentiation kinase (RDK1 and RDK2, depletion of which promoted bloodstream to procyclic form differentiation. RDK1 is a membrane-associated STE11-like PK, whilst RDK2 is a NEK PK that is essential for parasite proliferation. RDK1 acts in conjunction with the PTP1/PIP39 phosphatase cascade to block uncontrolled bloodstream to procyclic form differentiation, whilst RDK2 is a PK whose depletion efficiently induces differentiation in the absence of known triggers. Thus, the RNAi kinome library provides a valuable asset for functional analysis of cell signalling pathways in African trypanosomes as well as drug target identification and validation.

  7. Genetic differentiation of Puccinia triticina populations in the Middle East and genetic similarity with populations in Central Asia.

    Science.gov (United States)

    Kolmer, J A; Ordoñez, M E; Manisterski, J; Anikster, Y

    2011-07-01

    Leaf rust of wheat, caused by Puccinia triticina, is a common and widespread disease in the Middle East. The objective of this study was to determine whether genetically differentiated groups of P. triticina are present in the Middle East region and to compare the population from the Middle East with the previously characterized population from Central Asia to determine whether genetically similar groups of isolates are found in the two regions. In total, 118 isolates of P. triticina collected from common wheat and durum wheat in Egypt, Israel, Turkey, Ethiopia, and Kenya were tested for virulence on 20 lines of wheat with single genes for leaf rust resistance and for molecular genotypes with 23 simple-sequence repeat (SSR) markers. After removal of isolates with identical virulence and SSR genotype in each country, 103 isolates were retained for further analysis. Clustering of SSR genotypes based on two-dimensional principal coordinates and virulence to wheat differential lines grouped the isolates into four Middle East (ME) groups. The two largest ME groups had virulence phenotypes typical of isolates collected from common wheat and two smaller ME groups had virulence typical of isolates collected from durum wheat. All pairs of ME groups were significantly differentiated for SSR genotype based on R(ST) and F(ST) statistics, and for virulence phenotype based on Φ(PT). All ME groups had observed values of heterozygosity greater than expected and significant fixation indices that indicated the clonal reproduction of urediniospores in the overall population. Linkage disequilibria for SSR genotypes was high across the entire population. The overall values of R(ST) and F(ST) were lower when isolates were grouped by country of origin that indicated the likely migration of isolates within the region. Although the two ME groups with virulence typical of isolates from common wheat were not differentiated for SSR genotype from groups of isolates from Central Asia based on

  8. A Genetic Screen To Assess Dopamine Receptor (DopR1 Dependent Sleep Regulation in Drosophila

    Directory of Open Access Journals (Sweden)

    Yiqin Jiang

    2016-12-01

    Full Text Available Sleep is an essential behavioral state of rest that is regulated by homeostatic drives to ensure a balance of sleep and activity, as well as independent arousal mechanisms in the central brain. Dopamine has been identified as a critical regulator of both sleep behavior and arousal. Here, we present results of a genetic screen that selectively restored the Dopamine Receptor (DopR/DopR1/dumb to specific neuroanatomical regions of the adult Drosophila brain to assess requirements for DopR in sleep behavior. We have identified subsets of the mushroom body that utilizes DopR in daytime sleep regulation. These data are supported by multiple examples of spatially restricted genetic rescue data in discrete circuits of the mushroom body, as well as immunohistochemistry that corroborates the localization of DopR protein within mushroom body circuits. Independent loss of function data using an inducible RNAi construct in the same specific circuits also supports a requirement for DopR in daytime sleep. Additional circuit activation of discrete DopR+ mushroom body neurons also suggests roles for these subpopulations in sleep behavior. These conclusions support a new separable function for DopR in daytime sleep regulation within the mushroom body. This daytime regulation is independent of the known role of DopR in nighttime sleep, which is regulated within the Fan-Shaped Body (FSB. This study provides new neuroanatomical loci for exploration of dopaminergic sleep functions in Drosophila, and expands our understanding of sleep regulation during the day vs. night.

  9. Evaluation of a novel electronic genetic screening and clinical decision support tool in prenatal clinical settings.

    Science.gov (United States)

    Edelman, Emily A; Lin, Bruce K; Doksum, Teresa; Drohan, Brian; Edelson, Vaughn; Dolan, Siobhan M; Hughes, Kevin; O'Leary, James; Vasquez, Lisa; Copeland, Sara; Galvin, Shelley L; DeGroat, Nicole; Pardanani, Setul; Gregory Feero, W; Adams, Claire; Jones, Renee; Scott, Joan

    2014-07-01

    "The Pregnancy and Health Profile" (PHP) is a free prenatal genetic screening and clinical decision support (CDS) software tool for prenatal providers. PHP collects family health history (FHH) during intake and provides point-of-care risk assessment for providers and education for patients. This pilot study evaluated patient and provider responses to PHP and effects of using PHP in practice. PHP was implemented in four clinics. Surveys assessed provider confidence and knowledge and patient and provider satisfaction with PHP. Data on the implementation process were obtained through semi-structured interviews with administrators. Quantitative survey data were analyzed using Chi square test, Fisher's exact test, paired t tests, and multivariate logistic regression. Open-ended survey questions and interviews were analyzed using qualitative thematic analysis. Of the 83% (513/618) of patients that provided feedback, 97% felt PHP was easy to use and 98% easy to understand. Thirty percent (21/71) of participating physicians completed both pre- and post-implementation feedback surveys [13 obstetricians (OBs) and 8 family medicine physicians (FPs)]. Confidence in managing genetic risks significantly improved for OBs on 2/6 measures (p values ≤0.001) but not for FPs. Physician knowledge did not significantly change. Providers reported value in added patient engagement and reported mixed feedback about the CDS report. We identified key steps, resources, and staff support required to implement PHP in a clinical setting. To our knowledge, this study is the first to report on the integration of patient-completed, electronically captured and CDS-enabled FHH software into primary prenatal practice. PHP is acceptable to patients and providers. Key to successful implementation in the future will be customization options and interoperability with electronic health records.

  10. Genetic differentiation between 'Araucana' creole and 'Hampshire Down' sheeps in Chile

    Directory of Open Access Journals (Sweden)

    Silvana Bravo

    2015-03-01

    Full Text Available Genetic diversity studies in domestic animals allow evaluating genetic variation within and among breeds mainly for conservation purposes. In Chile exist isolated recovery programs, conservation and characterization of animal genetic resources, a consequence of which the vast majority of them have not been characterized, poorly used, and some of them have become extinct. The aim of this research was to determine genetic diversity and relationship between 'Araucana' creole and 'Hampshire Down' sheeps based on microsatellite markers; sheep breeds with similar phenotypic characteristics, raised in the south of Chile. A total of 64 'Araucana' sheep ('Araucana' from Freire, AF: 27, 'Araucana' from Padre Las Casas, AP: 10, 'Araucana' from Chol Chol, AC: 15, 'Araucana' from Villarrica, AV: 12 and 43 'Hampshire Down' sheep ('Hampshire' from Marchigue, HM: 18, 'Hampshire' from Valdivia, HV: 11, 'Hampshire' from San José, HS: 14 were analyzed using 17 microsatellite markers for determine the genetic diversity and relationship between breeds. A total of 284 alleles were observed with average polymorphic information content equal to 0.76, showing that the microsatellites panel used was highly informative. Estimated heterozygosity ranged from 0.73 in 'Hampshire Down' to 0.85 in 'Araucana'. The low inbreeding or endogamy coefficient (F IS, 0.022 and total inbreeding estimate (F IT, 0.070 indicated low level of inbreeding within and among breeds. The phylogenetic tree showed a separation between HS and HV, and the other sheep populations. The results indicated high genetic variability, low inbreeding, and low genetic differentiation, except for HV and HS, and were in according with geographical location and breeding practices.

  11. Studies of Resurgent Bed Bugs: Population Genetic Structure, Impact of Aggregation on Development and Molecular Screening for Bartonella

    Science.gov (United States)

    Saenz, Virna Lisa

    The recent resurgence of bed bugs (Cimex lectularius L.) has created an unprecedented demand for research on its biology. The main objectives of this dissertation research were to investigate several aspects of bed bug biology: infestation and dispersal dynamics at a large and small geographical scale using molecular markers, to determine the impact of aggregation on bed bug development and to screen bed bug populations for a re-emergent pathogen. First, we studied the infestation and dispersal dynamics of bed bugs at large geographical scale (e.g., across cities, states). Although bed bug infestations are on the rise, there is a poor understanding of their dispersal patterns and sources of infestation. We conducted a genetic study of 21 bed bug infestations from the eastern United States. We genotyped samples comprised of 8 - 10 individuals per infestation at nine polymorphic microsatellite loci. Despite high genetic diversity across all infestations, with 5 -- 17 alleles per locus (mean = 10.3), we found low genetic diversity (1 -- 4 alleles per locus) within all but one of the infestations. These results suggest that nearly all the studied infestations were started by a small propagule possibly consisting of a singly mated female and/or her progeny. All infestations were strongly genetically differentiated from each other (mean pairwise FST between populations = 0.68) and we did not find strong evidence of a geographic pattern of structuring. The high level of genetic diversity across infestations from the eastern United States together with the lack of geographically organized structure is consistent with multiple introductions into the United States from foreign sources. This work is described in Chapter 2 and was published in the Journal of Medical Entomology in 2012. Second, we investigated dispersal and infestation dynamics of bed bugs at a fine geographical scale within three multistory apartment buildings: one from Raleigh, NC and two from Jersey City, NJ

  12. Genetic studies of Polish migraine patients: screening for causative mutations in four migraine-associated genes.

    Science.gov (United States)

    Domitrz, Izabela; Kosiorek, Michalina; Żekanowski, Cezary; Kamińska, Anna

    2016-01-08

    Migraine is the most common neurological disorder, affecting approximately 12 % of the adult population worldwide, caused by both environmental and genetic factors. Three causative genes have been identified in familial hemiplegic migraine (FHM) families: CACNA1A, ATP1A2, and SCNA1A. Recently, several mutations in KCNK18 have also been found as causative factors in migraine development. The aim of our study was to identify the genetic background of migraine in the Polish population. Sixty patients with migraine without aura (MO) or with different types of migraine with aura (MA), including sporadic hemiplegic, familial hemiplegic, and probable familial hemiplegic, were screened for mutations in the four genes previously linked with different types of migraine (ATP1A2, CACNA1A, SCN1A, and KCNK18). Two missense mutations were found. One novel mutation in SCN1A, encoding α subunit of sodium channel, causing amino acid change M1500V localized to a region encoding inactivation loop between transmembrane domains III and IV of the channel, was detected in a female FHM patient. The M1500V mutation was absent in a group of 62 controls, as well as in the ExAC database. The second, already known missense mutation S231P in KCNK18 was found in a female MA patient. Additionally, a novel intronic polymorphism possibly affecting alternative splicing of SCN1A, at chr2:16685249, g.77659T>C, and c.4581+32A>G, located between exons 24 and 25, in a region encoding the inactivation loop of the sodium channel was found in a female MO patient. No mutations in ATP1A2 or CACNA1A were found in the study group. The presence of SCN1A mutations and absence of mutations in ATP1A2 or CACNA1A suggest that the Polish patients represent FHM type 3. On the other hand, the presence of KCNK18 mutation indicated another FHM subtype. It could be speculated that contrary to other European populations, the genetic basis of migraine in the Polish population involves mutations in genes not included in the

  13. Similarity in recombination rate estimates highly correlates with genetic differentiation in humans.

    Directory of Open Access Journals (Sweden)

    Hafid Laayouni

    Full Text Available Recombination varies greatly among species, as illustrated by the poor conservation of the recombination landscape between humans and chimpanzees. Thus, shorter evolutionary time frames are needed to understand the evolution of recombination. Here, we analyze its recent evolution in humans. We calculated the recombination rates between adjacent pairs of 636,933 common single-nucleotide polymorphism loci in 28 worldwide human populations and analyzed them in relation to genetic distances between populations. We found a strong and highly significant correlation between similarity in the recombination rates corrected for effective population size and genetic differentiation between populations. This correlation is observed at the genome-wide level, but also for each chromosome and when genetic distances and recombination similarities are calculated independently from different parts of the genome. Moreover, and more relevant, this relationship is robustly maintained when considering presence/absence of recombination hotspots. Simulations show that this correlation cannot be explained by biases in the inference of recombination rates caused by haplotype sharing among similar populations. This result indicates a rapid pace of evolution of recombination, within the time span of differentiation of modern humans.

  14. Screening and genetic manipulation of green organisms for establishment of biological life support systems in space.

    Science.gov (United States)

    Saei, Amir Ata; Omidi, Amir Ali; Barzegari, Abolfazl

    2013-01-01

    Curiosity has driven humankind to explore and conquer space. However, today, space research is not a means to relieve this curiosity anymore, but instead has turned into a need. To support the crew in distant expeditions, supplies should either be delivered from the Earth, or prepared for short durations through physiochemical methods aboard the space station. Thus, research continues to devise reliable regenerative systems. Biological life support systems may be the only answer to human autonomy in outposts beyond Earth. For construction of an artificial extraterrestrial ecosystem, it is necessary to search for highly adaptable super-organisms capable of growth in harsh space environments. Indeed, a number of organisms have been proposed for cultivation in space. Meanwhile, some manipulations can be done to increase their photosynthetic potential and stress tolerance. Genetic manipulation and screening of plants, microalgae and cyanobacteria is currently a fascinating topic in space bioengineering. In this commentary, we will provide a viewpoint on the realities, limitations and promises in designing biological life support system based on engineered and/or selected green organism. Special focus will be devoted to the engineering of key photosynthetic enzymes in pioneer green organisms and their potential use in establishment of transgenic photobioreactors in space.

  15. Successful birth of South India's first twins after preimplantation genetic screening of embryos

    Directory of Open Access Journals (Sweden)

    Priya Selvaraj

    2016-01-01

    Full Text Available We report the first documented successful birth of twins following preimplantation genetic screening (PGS of cleavage stage embryos by array comparative genomic hybridization (CGH technology, in South India. The case was a 28-year-old woman with the previous history of preclinical pregnancy and a miscarriage in two attempted in vitro fertilization cycles. Day 3 cleavage stage embryos were generated by conventional long protocol with the use of a gonadotropin-releasing hormone analog and a combination of recombinant folliculotropins and human menopausal gonadotropins. Intracytoplasmic sperm injection of oocytes thus obtained was performed, and 10 selected embryos underwent PGS using the array CGH technique. Two normal blastocysts were transferred to the patient, and she conceived twins. She delivered at 35 weeks of gestation by elective cesarean on November 19, 2014. She delivered a healthy male and female baby weighing 2.19 kg and 2.26 kg, respectively. Postnatal evaluation of babies was also normal, and the hospital course was uneventful. PGS has a definitive indication in assisted reproductive technology programs and can be utilized to improve pregnancy rates significantly.

  16. A Forward Genetic Screen for Molecules Involved in Pheromone-Induced Dauer Formation in Caenorhabditis elegans

    Science.gov (United States)

    Neal, Scott J.; Park, JiSoo; DiTirro, Danielle; Yoon, Jason; Shibuya, Mayumi; Choi, Woochan; Schroeder, Frank C.; Butcher, Rebecca A.; Kim, Kyuhyung; Sengupta, Piali

    2016-01-01

    Animals must constantly assess their surroundings and integrate sensory cues to make appropriate behavioral and developmental decisions. Pheromones produced by conspecific individuals provide critical information regarding environmental conditions. Ascaroside pheromone concentration and composition are instructive in the decision of Caenorhabditis elegans to either develop into a reproductive adult or enter into the stress-resistant alternate dauer developmental stage. Pheromones are sensed by a small set of sensory neurons, and integrated with additional environmental cues, to regulate neuroendocrine signaling and dauer formation. To identify molecules required for pheromone-induced dauer formation, we performed an unbiased forward genetic screen and identified phd (pheromone response-defective dauer) mutants. Here, we describe new roles in dauer formation for previously identified neuronal molecules such as the WD40 domain protein QUI-1 and MACO-1 Macoilin, report new roles for nociceptive neurons in modulating pheromone-induced dauer formation, and identify tau tubulin kinases as new genes involved in dauer formation. Thus, phd mutants define loci required for the detection, transmission, or integration of pheromone signals in the regulation of dauer formation. PMID:26976437

  17. A Sleeping Beauty forward genetic screen identifies new genes and pathways driving osteosarcoma development and metastasis

    Science.gov (United States)

    Moriarity, Branden S; Otto, George M; Rahrmann, Eric P; Rathe, Susan K; Wolf, Natalie K; Weg, Madison T; Manlove, Luke A; LaRue, Rebecca S; Temiz, Nuri A; Molyneux, Sam D; Choi, Kwangmin; Holly, Kevin J; Sarver, Aaron L; Scott, Milcah C; Forster, Colleen L; Modiano, Jaime F; Khanna, Chand; Hewitt, Stephen M; Khokha, Rama; Yang, Yi; Gorlick, Richard; Dyer, Michael A; Largaespada, David A

    2016-01-01

    Osteosarcomas are sarcomas of the bone, derived from osteoblasts or their precursors, with a high propensity to metastasize. Osteosarcoma is associated with massive genomic instability, making it problematic to identify driver genes using human tumors or prototypical mouse models, many of which involve loss of Trp53 function. To identify the genes driving osteosarcoma development and metastasis, we performed a Sleeping Beauty (SB) transposon-based forward genetic screen in mice with and without somatic loss of Trp53. Common insertion site (CIS) analysis of 119 primary tumors and 134 metastatic nodules identified 232 sites associated with osteosarcoma development and 43 sites associated with metastasis, respectively. Analysis of CIS-associated genes identified numerous known and new osteosarcoma-associated genes enriched in the ErbB, PI3K-AKT-mTOR and MAPK signaling pathways. Lastly, we identified several oncogenes involved in axon guidance, including Sema4d and Sema6d, which we functionally validated as oncogenes in human osteosarcoma. PMID:25961939

  18. Genome-wide screening for genetic loci associated with noise-induced hearing loss.

    Science.gov (United States)

    White, Cory H; Ohmen, Jeffrey D; Sheth, Sonal; Zebboudj, Amina F; McHugh, Richard K; Hoffman, Larry F; Lusis, Aldons J; Davis, Richard C; Friedman, Rick A

    2009-04-01

    Noise-induced hearing loss (NIHL) is one of the more common sources of environmentally induced hearing loss in adults. In a mouse model, Castaneous (CAST/Ei) is an inbred strain that is resistant to NIHL, while the C57BL/6J strain is susceptible. We have used the genome-tagged mice (GTM) library of congenic strains, carrying defined segments of the CAST/Ei genome introgressed onto the C57BL/6J background, to search for loci modifying the noise-induced damage seen in the C57BL/6J strain. NIHL was induced by exposing 6-8-week old mice to 108 dB SPL intensity noise. We tested the hearing of each mouse strain up to 23 days after noise exposure using auditory brainstem response (ABR). This study identifies a number of genetic loci that modify the initial response to damaging noise, as well as long-term recovery. The data suggest that multiple alleles within the CAST/Ei genome modify the pathogenesis of NIHL and that screening congenic libraries for loci that underlie traits of interest can be easily carried out in a high-throughput fashion.

  19. Screening genetically modified organisms using multiplex-PCR coupled with oligonucleotide microarray.

    Science.gov (United States)

    Xu, Jia; Miao, Haizhen; Wu, Houfei; Huang, Wensheng; Tang, Rong; Qiu, Minyan; Wen, Jianguo; Zhu, Shuifang; Li, Yao

    2006-07-15

    In this research, we developed a multiplex polymerase chain reaction (multiplex-PCR) coupled with a DNA microarray system simultaneously aiming at many targets in a consecutive reaction to detect a genetically modified organism (GMO). There are a total of 20 probes for detecting a GMO in a DNA microarray which can be classified into three categories according to their purpose: the first for screening GMO from un-transgenic plants based on the common elements such as promoter, reporter and terminator genes; the second for specific gene confirmation based on the target gene sequences such as herbicide-resistance or insect-resistance genes; the third for species-specific genes which the sequences are unique for different plant species. To ensure the reliability of this method, different kinds of positive and negative controls were used in DNA microarray. Commercial GM soybean, maize, rapeseed and cotton were identified by means of this method and further confirmed by PCR analysis and sequencing. The results indicate that this method discriminates between the GMOs very quickly and in a cost-saving and more time efficient way. It can detect more than 95% of currently commercial GMO plants and the limits of detection are 0.5% for soybean and 1% for maize. This method is proved to be a new method for routine analysis of GMOs.

  20. Data on screening and identification of genetically modified papaya in food supplements.

    Science.gov (United States)

    Prins, Theo W; Scholtens, Ingrid M J; Bak, Arno W; van Dijk, Jeroen P; Voorhuijzen, Marleen M; Laurensse, Emile J; Kok, Esther J

    2016-12-01

    This article contains data related to the research article entitled "A case study to determine the geographical origin of unknown GM papaya in routine food sample analysis, followed by identification of papaya events 16-0-1 and 18-2-4" (Prins et al., 2016) [1]. Quantitative real-time PCR (qPCR) with targets that are putatively present in genetically modified (GM) papaya was used as a first screening to narrow down the vast array of candidates. The combination of elements P-nos and nptII was further confirmed by amplification and subsequent sequencing of the P-nos/nptII construct. Next, presence of the candidate GM papayas 16-0-1 and 18-2-4 were investigated by amplification and sequencing of event-spanning regions on the left and right border. This data article reports the Cq values for GM elements, the nucleotide sequence of the P-nos/nptII construct and the presence of GM papaya events 18-2-4 and/or 16-0-1 in five samples that were randomly sampled to be analysed in the framework of the official Dutch GMO monitoring program for food.

  1. Dehydroepiandrosterone (DHEA) reduces embryo aneuploidy: direct evidence from preimplantation genetic screening (PGS).

    Science.gov (United States)

    Gleicher, Norbert; Weghofer, Andrea; Barad, David H

    2010-11-10

    Dehydroepiandrosterone (DHEA) has been reported to improve pregnancy chances in women with diminished ovarian reserve (DOR), and to reduce miscarriage rates by 50-80%. Such an effect is mathematically inconceivable without beneficial effects on embryo ploidy. This study, therefore, assesses effects of DHEA on embryo aneuploidy. In a 1:2, matched case control study 22 consecutive women with DOR, supplemented with DHEA, underwent preimplantation genetic screening (PGS) of embryos during in vitro fertilization (IVF) cycles. Each was matched by patient age and time period of IVF with two control IVF cycles without DHEA supplementation (n = 44). PGS was performed for chromosomes X, Y, 13, 16, 18, 21 and 22, and involved determination of numbers and percentages of aneuploid embryos. DHEA supplementation to a significant degree reduced number (P = 0.029) and percentages (P DHEA effects on DOR patients, at least partially, are the likely consequence of lower embryo aneuploidy. DHEA supplementation also deserves investigation in older fertile women, attempting to conceive, where a similar effect, potentially, could positively affect public health.

  2. Preimplantation genetic screening (PGS) still in search of a clinical application: a systematic review

    Science.gov (United States)

    2014-01-01

    Only a few years ago the American Society of Assisted Reproductive Medicine (ASRM), the European Society for Human Reproduction and Embryology (ESHRE) and the British Fertility Society declared preimplantation genetic screening (PGS#1) ineffective in improving in vitro fertilization (IVF) pregnancy rates and in reducing miscarriage rates. A presumably upgraded form of the procedure (PGS#2) has recently been reintroduced, and is here assessed in a systematic review. PGS#2 in comparison to PGS#1 is characterized by: (i) trophectoderm biopsy on day 5/6 embryos in place of day-3 embryo biopsy; and (ii) fluorescence in-situ hybridization (FISH) of limited chromosome numbers is replaced by techniques, allowing aneuploidy assessments of all 24 chromosome pairs. Reviewing the literature, we were unable to identify properly conducted prospective clinical trials in which IVF outcomes were assessed based on “intent to treat”. Whether PGS#2 improves IVF outcomes can, therefore, not be determined. Reassessments of data, alleged to support the efficacy of PGS#2, indeed, suggest the opposite. Like with PGS#1, the introduction of PGS#2 into unrestricted IVF practice again appears premature, and threatens to repeat the PGS#1 experience, when thousands of women experienced reductions in IVF pregnancy chances, while expecting improvements. PGS#2 is an unproven and still experimental procedure, which, until evidence suggests otherwise, should only be offered under study conditions, and with appropriate informed consents. PMID:24628895

  3. A Forward Genetic Screen for Molecules Involved in Pheromone-Induced Dauer Formation in Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Scott J. Neal

    2016-05-01

    Full Text Available Animals must constantly assess their surroundings and integrate sensory cues to make appropriate behavioral and developmental decisions. Pheromones produced by conspecific individuals provide critical information regarding environmental conditions. Ascaroside pheromone concentration and composition are instructive in the decision of Caenorhabditis elegans to either develop into a reproductive adult or enter into the stress-resistant alternate dauer developmental stage. Pheromones are sensed by a small set of sensory neurons, and integrated with additional environmental cues, to regulate neuroendocrine signaling and dauer formation. To identify molecules required for pheromone-induced dauer formation, we performed an unbiased forward genetic screen and identified phd (pheromone response-defective dauer mutants. Here, we describe new roles in dauer formation for previously identified neuronal molecules such as the WD40 domain protein QUI-1 and MACO-1 Macoilin, report new roles for nociceptive neurons in modulating pheromone-induced dauer formation, and identify tau tubulin kinases as new genes involved in dauer formation. Thus, phd mutants define loci required for the detection, transmission, or integration of pheromone signals in the regulation of dauer formation.

  4. A Forward Genetic Screen for Molecules Involved in Pheromone-Induced Dauer Formation in Caenorhabditis elegans.

    Science.gov (United States)

    Neal, Scott J; Park, JiSoo; DiTirro, Danielle; Yoon, Jason; Shibuya, Mayumi; Choi, Woochan; Schroeder, Frank C; Butcher, Rebecca A; Kim, Kyuhyung; Sengupta, Piali

    2016-05-03

    Animals must constantly assess their surroundings and integrate sensory cues to make appropriate behavioral and developmental decisions. Pheromones produced by conspecific individuals provide critical information regarding environmental conditions. Ascaroside pheromone concentration and composition are instructive in the decision of Caenorhabditis elegans to either develop into a reproductive adult or enter into the stress-resistant alternate dauer developmental stage. Pheromones are sensed by a small set of sensory neurons, and integrated with additional environmental cues, to regulate neuroendocrine signaling and dauer formation. To identify molecules required for pheromone-induced dauer formation, we performed an unbiased forward genetic screen and identified phd (pheromone response-defective dauer) mutants. Here, we describe new roles in dauer formation for previously identified neuronal molecules such as the WD40 domain protein QUI-1 and MACO-1 Macoilin, report new roles for nociceptive neurons in modulating pheromone-induced dauer formation, and identify tau tubulin kinases as new genes involved in dauer formation. Thus, phd mutants define loci required for the detection, transmission, or integration of pheromone signals in the regulation of dauer formation.

  5. High Genetic Differentiation among European White Oak Species (Quercus spp. at a Dehydrin Gene

    Directory of Open Access Journals (Sweden)

    Iacob CRĂCIUNESC

    2015-12-01

    Full Text Available Dehydryn genes are involved in plant response to environmental stress and may be useful to examine functional diversity in relation to adaptive variation. Recently, a dehydrin gene (DHN3 was isolated in Quercus petraea and showed little differentiation between populations of the same species in an altitudinal transect. In the present study, inter- and intraspecific differentiation patterns in closely related and interfertile oaks were investigated for the first time at the DHN3 locus. A four-oak-species stand (Quercus frainetto Ten., Q. petraea (Matt. Liebl., Q. pubescens Willd., Q. robur L. and two populations for each of five white oak species (Q. frainetto Ten., Q. petraea (Matt. Liebl., Q. pubescens Willd., Q. robur L. and Q. pedunculiflora K. Koch were analyzed. Three alleles shared by all five oak species were observed. However, only two alleles were present in each population, but with different frequencies according to the species. At population level, all interspecific pairs of populations showed significant differentiation, except for pure Q. robur and Q. pedunculiflora populations. In contrast, no significant differentiation (p > 0.05 was found among conspecific populations. The DHN3 locus proved to be very useful to differentiate Q. frainetto and Q. pubescens from Q. pedunculiflora (FST = 0.914 and 0.660, respectively and Q. robur (FST = 0.858 and 0.633, respectively. As expected, the lowest level of differentiation was detected between the most closely related species, Q. robur and Q. pedunculiflora (FST = 0.020. Our results suggest that DHN3 can be an important genetic marker for differentiating among European white oak species.

  6. Molecular and Genetic Analysis of Hormone-Regulated Differential Cell Elongation in Arabidopsis

    Energy Technology Data Exchange (ETDEWEB)

    Ecker, Joseph R.

    2005-09-15

    We have utilized the response of Arabidopsis seedlings to the plant hormone ethylene to identify new genes involved in the regulation of ethylene biosynthesis, perception, signal transduction and differential cell growth. In building a genetic framework for the action of these genes, we have developed a molecular model that has facilitated our understanding of the molecular requirements of ethylene for cell elongation processes. The ethylene response pathway in Arabidopsis appears to be primarily linear and is defined by the genes: ETR1, ETR2, ERS1, ERS2, EIN4, CTR1, EIN2, EIN3, EIN5, EIN6, and EIN. Downstream branches identified by the HLS1, EIR1, and AUX1 genes involve interactions with other hormonal (auxin) signals in the process of differential cell elongation in the hypocotyl hook. Cloning and characterization of HLS1 (and three HLL genes) and ETO1 (and ETOL genes) in my laboratory has been supported under this award. HLS1 is required for differential elongation of cells in the hypocotyl and may act in the establishment of hormone gradients. Also during the previous period, we have identified and characterized a gene that genetically acts upstream of the ethylene receptors. ETO1 encodes negative regulators of ethylene biosynthesis.

  7. Molecular and Genetic Analysis of Hormone-Regulated Differential Cell Elongation in Arabidopsis

    Energy Technology Data Exchange (ETDEWEB)

    Ecker, Joseph R.

    2002-12-03

    The authors have utilized the response of Arabidopsis seedlings to the plant hormone ethylene to identify new genes involved in the regulation of ethylene biosynthesis, perception, signal transduction and differential cell growth. In building a genetic framework for the action of these genes, they developed a molecular model that has facilitated the understanding of the molecular requirements of ethylene for cell elongation processes. The ethylene response pathway in Arabidopsis appears to be primarily linear and is defined by the genes: ETR1, ETR2, ERS1, ERS2, EIN4, CTR1, EIN2, EIN3, EIN5 EIN6, and EIN. Downstream branches identified by the HLS1, EIR1, and AUX1 genes involve interactions with other hormonal (auxin) signals in the process of differential cell elongation in the hypocotyl hook. Cloning and characterization of HLS1 and three HLS1-LIKE genes in the laboratory has been supported under this award. HLS1 is required for differential elongation of cells in the hypocotyl and may act in the establishment of hormone gradients. Also during the award period, they have identified and begun preliminary characterization of two genes that genetically act upstream of the ethylene receptors. ETO1 and RAN1 encode negative regulators of ethylene biosynthesis and signaling respectively. Progress on the analysis of these genes along with HOOKLESS1 is described.

  8. Genetic analysis and mapping of gene fzp(t) controlling spikelet differentiation in rice

    Institute of Scientific and Technical Information of China (English)

    段远霖; 李维明; 吴为人; 潘润森; 周元昌; 祁建民; 林荔辉; 陈志伟; 毛大梅; 刘华清; 张丹凤; 薛勇彪

    2003-01-01

    A mutant of spikelet differentiation in rice called frizzle panicle (fzp) was discovered in the progeny of a cross between Oryza sativa ssp. indica cv. V20B and cv. Hua1B. The mutant exhibits normal plant morphology but has apparently fewer tillers. The most striking change in fzp is that its spikelet differentiation is completely blocked, with unlimited subsequent rachis branches generated from the positions where spikelets normally develop in wild-type plants. Genetic analysis suggests that fzp is controlled by a single recessive gene, which is temporarily named fzp (t). Based on its mutant phenotype, fzp (t) represents a key gene controlling spikelet differentiation. Some F2 mutant plants derived from various genetic background appeared as the "middle type", suggesting that the action of fzp (t) is influenced by the presence of redundant, modifier or interactive genes. By using simple sequence repeat (SSR) markers and bulked segregant analysis (BSA) method, fzp (t) gene was mapped in the terminal region of the long arm of chromosome 7, with RM172 and RM248 on one side, 3.2 cM and 6.4 cM from fzp (t), and RM18 and RM234 on the other side, 23.1 cM and 26.3 cM from fzp(t), respectively. These results will facilitate the positional cloning and function studies of the gene.

  9. Environmental and Historical Determinants of Patterns of Genetic Differentiation in Wild Soybean (Glycine soja Sieb. et Zucc).

    Science.gov (United States)

    He, Shui-Lian; Wang, Yun-Sheng; Li, De-Zhu; Yi, Ting-Shuang

    2016-03-08

    Wild soybean, the direct progenitor of cultivated soybean, inhabits a wide distribution range across the mainland of East Asia and the Japanese archipelago. A multidisciplinary approach combining analyses of population genetics based on 20 nuclear microsatellites and one plastid locus were applied to reveal the genetic variation of wild soybean, and the contributions of geographical, environmental factors and historic climatic change on its patterns of genetic differentiation. High genetic diversity and significant genetic differentiation were revealed in wild soybean. Wild soybean was inferred to be limited to southern and central China during the Last Glacial Maximum (LGM) and experienced large-scale post-LGM range expansion into northern East Asia. A substantial northward range shift has been predicted to occur by the 2080s. A stronger effect of isolation by environment (IBE) versus isolation by geographical distance (IBD) was found for genetic differentiation in wild soybean, which suggested that environmental factors were responsible for the adaptive eco-geographical differentiation. This study indicated that IBE and historical climatic change together shaped patterns of genetic variation and differentiation of wild soybean. Different conservation measures should be implemented on different populations according to their adaptive potential to future changes in climate and human-induced environmental changes.

  10. Effect of anthropogenic landscape features on population genetic differentiation of Przewalski's gazelle: main role of human settlement.

    Directory of Open Access Journals (Sweden)

    Ji Yang

    Full Text Available Anthropogenic landscapes influence evolutionary processes such as population genetic differentiation, however, not every type of landscape features exert the same effect on a species, hence it is necessary to estimate their relative effect for species management and conservation. Przewalski's gazelle (Procapra przewalskii, which inhabits a human-altered area on Qinghai-Tibet Plateau, is one of the most endangered antelope species in the world. Here, we report a landscape genetic study on Przewalski's gazelle. We used skin and fecal samples of 169 wild gazelles collected from nine populations and thirteen microsatellite markers to assess the genetic effect of anthropogenic landscape features on this species. For comparison, the genetic effect of geographical distance and topography were also evaluated. We found significant genetic differentiation, six genetic groups and restricted dispersal pattern in Przewalski's gazelle. Topography, human settlement and road appear to be responsible for observed genetic differentiation as they were significantly correlated with both genetic distance measures [F(ST/(1-F(ST and F'(ST/(1-F'(ST] in Mantel tests. IBD (isolation by distance was also inferred as a significant factor in Mantel tests when genetic distance was measured as F(ST/(1-F(ST. However, using partial Mantel tests, AIC(c calculations, causal modeling and AMOVA analysis, we found that human settlement was the main factor shaping current genetic differentiation among those tested. Altogether, our results reveal the relative influence of geographical distance, topography and three anthropogenic landscape-type on population genetic differentiation of Przewalski's gazelle and provide useful information for conservation measures on this endangered species.

  11. Genetic differentiation between the ant Myrmica rubra and its microgynous social parasite

    DEFF Research Database (Denmark)

    Vepsäläinen, K.; Ebsen, J. R.; Savolainen, R.;

    2009-01-01

    that the parasitic morph of M. rubra may be an incipient species, but it remains unclear to what extent the observed genetic differentiation between host and inquiline is due to possible assortative mating and selection against hybrids or to recurrent bottlenecking and genetic drift. We conclude that an explicitly...

  12. Clinical and genetic aspects of bicuspid aortic valve: a proposed model for family screening based on a review of literature

    Directory of Open Access Journals (Sweden)

    Hubert Baars

    2015-04-01

    Full Text Available Bicuspid aortic valve (BAV is the most common congenital cardiac defect causing serious morbidity including valvular dysfunction and thoracic aortic aneurysms (TAA in around 30% of BAV patients. Cardiological screening of first-degree relatives is advised in recent guidelines given the observed familial clustering of BAV. However, guidelines regarding screening of family members and DNA testing are not unequivocal. The aim of this review is to provide an overview of the literature on echocardiographic screening in first-degree relatives of BAV patients and to propose a model for family screening. In addition, we provide a flowchart for DNA testing. We performed a PubMed search and included studies providing data on echocardiographic screening in asymptomatic relatives of BAV patients. Nine studies were included. In 5.8-47.4% of the families BAV was shown to be familial. Of the screened first-degree relatives 1.8-11% was found to be affected with BAV. Results regarding a potential risk of TAA in first-degree relatives with a tricuspid aortic valve (TAV were conflicting. The reported familial clustering of BAV underlines the importance of cardiological screening in relatives. After reviewing the available family history, patient characteristics and the results of cardiological screening in relatives, follow-up in relatives with a TAV and/or DNA testing may be advised in a subset of families. In this study we propose a model for the clinical and genetic work-up in BAV families, based on the most extensive literature review on family screening performed until now.

  13. Is there evidence that we should screen the general population for Lynch syndrome with genetic testing? A systematic review

    Science.gov (United States)

    Prince, Anya E R; Cadigan, R Jean; Henderson, Gail E; Evans, James P; Adams, Michael; Coker-Schwimmer, Emmanuel; Penn, Dolly C; Van Riper, Marcia; Corbie-Smith, Giselle; Jonas, Daniel E

    2017-01-01

    Background The emerging dual imperatives of personalized medicine and technologic advances make population screening for preventable conditions resulting from genetic alterations a realistic possibility. Lynch syndrome is a potential screening target due to its prevalence, penetrance, and the availability of well-established, preventive interventions. However, while population screening may lower incidence of preventable conditions, implementation without evidence may lead to unintentional harms. We examined the literature to determine whether evidence exists that screening for Lynch-associated mismatch repair (MMR) gene mutations leads to improved overall survival, cancer-specific survival, or quality of life. Documenting evidence and gaps is critical to implementing genomic approaches in public health and guiding future research. Materials and methods Our 2014–2015 systematic review identified studies comparing screening with no screening in the general population, and controlled studies assessing analytic validity of targeted next-generation sequencing, and benefits or harms of interventions or screening. We conducted meta-analyses for the association between early or more frequent colonoscopies and health outcomes. Results Twelve studies met our eligibility criteria. No adequate evidence directly addressed the main question or the harms of screening in the general population. Meta-analyses found relative reductions of 68% for colorectal cancer incidence (relative risk: 0.32, 95% confidence interval: 0.23–0.43, three cohort studies, 590 participants) and 78% for all-cause mortality (relative risk: 0.22, 95% confidence interval: 0.09–0.56, three cohort studies, 590 participants) for early or more frequent colonoscopies among family members of people with cancer who also had an associated MMR gene mutation. Conclusion Inadequate evidence exists examining harms and benefits of population-based screening for Lynch syndrome. Lack of evidence highlights the need

  14. Diversification in the genetic architecture of gene expression and transcriptional networks in organ differentiation of Populus.

    Science.gov (United States)

    Drost, Derek R; Benedict, Catherine I; Berg, Arthur; Novaes, Evandro; Novaes, Carolina R D B; Yu, Qibin; Dervinis, Christopher; Maia, Jessica M; Yap, John; Miles, Brianna; Kirst, Matias

    2010-05-04

    A fundamental goal of systems biology is to identify genetic elements that contribute to complex phenotypes and to understand how they interact in networks predictive of system response to genetic variation. Few studies in plants have developed such networks, and none have examined their conservation among functionally specialized organs. Here we used genetical genomics in an interspecific hybrid population of the model hardwood plant Populus to uncover transcriptional networks in xylem, leaves, and roots. Pleiotropic eQTL hotspots were detected and used to construct coexpression networks a posteriori, for which regulators were predicted based on cis-acting expression regulation. Networks were shown to be enriched for groups of genes that function in biologically coherent processes and for cis-acting promoter motifs with known roles in regulating common groups of genes. When contrasted among xylem, leaves, and roots, transcriptional networks were frequently conserved in composition, but almost invariably regulated by different loci. Similarly, the genetic architecture of gene expression regulation is highly diversified among plant organs, with less than one-third of genes with eQTL detected in two organs being regulated by the same locus. However, colocalization in eQTL position increases to 50% when they are detected in all three organs, suggesting conservation in the genetic regulation is a function of ubiquitous expression. Genes conserved in their genetic regulation among all organs are primarily cis regulated (approximately 92%), whereas genes with eQTL in only one organ are largely trans regulated. Trans-acting regulation may therefore be the primary driver of differentiation in function between plant organs.

  15. Adaptive divergence despite strong genetic drift: genomic analysis of the evolutionary mechanisms causing genetic differentiation in the island fox (Urocyon littoralis).

    Science.gov (United States)

    Funk, W Chris; Lovich, Robert E; Hohenlohe, Paul A; Hofman, Courtney A; Morrison, Scott A; Sillett, T Scott; Ghalambor, Cameron K; Maldonado, Jesus E; Rick, Torben C; Day, Mitch D; Polato, Nicholas R; Fitzpatrick, Sarah W; Coonan, Timothy J; Crooks, Kevin R; Dillon, Adam; Garcelon, David K; King, Julie L; Boser, Christina L; Gould, Nicholas; Andelt, William F

    2016-05-01

    The evolutionary mechanisms generating the tremendous biodiversity of islands have long fascinated evolutionary biologists. Genetic drift and divergent selection are predicted to be strong on islands and both could drive population divergence and speciation. Alternatively, strong genetic drift may preclude adaptation. We conducted a genomic analysis to test the roles of genetic drift and divergent selection in causing genetic differentiation among populations of the island fox (Urocyon littoralis). This species consists of six subspecies, each of which occupies a different California Channel Island. Analysis of 5293 SNP loci generated using Restriction-site Associated DNA (RAD) sequencing found support for genetic drift as the dominant evolutionary mechanism driving population divergence among island fox populations. In particular, populations had exceptionally low genetic variation, small Ne (range = 2.1-89.7; median = 19.4), and significant genetic signatures of bottlenecks. Moreover, islands with the lowest genetic variation (and, by inference, the strongest historical genetic drift) were most genetically differentiated from mainland grey foxes, and vice versa, indicating genetic drift drives genome-wide divergence. Nonetheless, outlier tests identified 3.6-6.6% of loci as high FST outliers, suggesting that despite strong genetic drift, divergent selection contributes to population divergence. Patterns of similarity among populations based on high FST outliers mirrored patterns based on morphology, providing additional evidence that outliers reflect adaptive divergence. Extremely low genetic variation and small Ne in some island fox populations, particularly on San Nicolas Island, suggest that they may be vulnerable to fixation of deleterious alleles, decreased fitness and reduced adaptive potential.

  16. Genetic differentiation among Maconellicoccus hirsutus (Hemiptera: Pseudococcidae) populations living on different host plants.

    Science.gov (United States)

    Rosas-García, Ninfa M; Sarmiento-Benavides, Sandra L; Villegas-Mendoza, Jesús M; Hernández-Delgado, Sanjuana; Mayek-Pérez, Netzahualcoyotl

    2010-06-01

    The pink hibiscus mealybug Maconellicoccus hirsutus (Green) is a dangerous pest that damages a wide variety of agricultural, horticultural, and forestry crops. Amplified fragment length polymorphism (AFLP) fingerprints were used to characterize the genetic variation of 11 M. hirsutus populations infesting three plant species in Nayarit, Mexico. Analysis was carried out using four primers combinations, producing 590 polymorphic bands. Cluster analysis, as well as bootstrap dendrogram and nonmetric multidimensional scaling analysis, grouped M. hirsutus populations according to their host plant. The estimated F(ST) values indicated a high differentiation in M. hirsutus populations among the three host plant species. These results were also supported by a Bayesian analysis, which indicated a population clustering robustness according to their host plant. Genetic variation among populations is not caused by geographic distances, as shown by a Mantel test.

  17. Genetic characterization, species differentiation and detection of Fasciola spp. by molecular approaches

    Directory of Open Access Journals (Sweden)

    Li Hai-Long

    2011-06-01

    Full Text Available Abstract Liver flukes belonging to the genus Fasciola are among the causes of foodborne diseases of parasitic etiology. These parasites cause significant public health problems and substantial economic losses to the livestock industry. Therefore, it is important to definitively characterize the Fasciola species. Current phenotypic techniques fail to reflect the full extent of the diversity of Fasciola spp. In this respect, the use of molecular techniques to identify and differentiate Fasciola spp. offer considerable advantages. The advent of a variety of molecular genetic techniques also provides a powerful method to elucidate many aspects of Fasciola biology, epidemiology, and genetics. However, the discriminatory power of these molecular methods varies, as does the speed and ease of performance and cost. There is a need for the development of new methods to identify the mechanisms underpinning the origin and maintenance of genetic variation within and among Fasciola populations. The increasing application of the current and new methods will yield a much improved understanding of Fasciola epidemiology and evolution as well as more effective means of parasite control. Herein, we provide an overview of the molecular techniques that are being used for the genetic characterization, detection and genotyping of Fasciola spp..

  18. Differential detection of genetic Loci underlying stem and root lignin content in Populus.

    Directory of Open Access Journals (Sweden)

    Tongming Yin

    Full Text Available In this study, we established a comprehensive genetic map with a large number of progeny from a three-generation hybrid Populus intercross, and phenotyped the lignin content, S/G ratio and 28 cell wall subcomponents both in stems and roots for the mapping individuals. Phenotypic analysis revealed that lignin content and syringyl-to-guaiacyl (S/G ratio using pyrolysis molecular beam mass spectroscopy (pyMBMS varied among mapping individuals. Phenotypic analysis revealed that stem lignin content is significantly higher than that in root and the quantified traits can be classified into four distinct groups, with strong correlations observed among components within organs. Altogether, 179 coordinating QTLs were detected, and they were co-localized into 49 genetic loci, 27 of which appear to be pleiotropic. Many of the detected genetic loci were detected differentially in stem and root. This is the first report of separate genetic loci controlling cell wall phenotypes above and below ground. These results suggest that it may be possible to modify lignin content and composition via breed and/or engineer as a means of simultaneously improving Populus for cellulosic ethanol production and carbon sequestration.

  19. Forward genetics screens using macrophages to identify Toxoplasma gondii genes important for resistance to IFN-γ-dependent cell autonomous immunity.

    Science.gov (United States)

    Walwyn, Odaelys; Skariah, Sini; Lynch, Brian; Kim, Nathaniel; Ueda, Yukari; Vohora, Neal; Choe, Josh; Mordue, Dana G

    2015-03-12

    Toxoplasma gondii, the causative agent of toxoplasmosis, is an obligate intracellular protozoan pathogen. The parasite invades and replicates within virtually any warm blooded vertebrate cell type. During parasite invasion of a host cell, the parasite creates a parasitophorous vacuole (PV) that originates from the host cell membrane independent of phagocytosis within which the parasite replicates. While IFN-dependent-innate and cell mediated immunity is important for eventual control of infection, innate immune cells, including neutrophils, monocytes and dendritic cells, can also serve as vehicles for systemic dissemination of the parasite early in infection. An approach is described that utilizes the host innate immune response, in this case macrophages, in a forward genetic screen to identify parasite mutants with a fitness defect in infected macrophages following activation but normal invasion and replication in naïve macrophages. Thus, the screen isolates parasite mutants that have a specific defect in their ability to resist the effects of macrophage activation. The paper describes two broad phenotypes of mutant parasites following activation of infected macrophages: parasite stasis versus parasite degradation, often in amorphous vacuoles. The parasite mutants are then analyzed to identify the responsible parasite genes specifically important for resistance to induced mediators of cell autonomous immunity. The paper presents a general approach for the forward genetics screen that, in theory, can be modified to target parasite genes important for resistance to specific antimicrobial mediators. It also describes an approach to evaluate the specific macrophage antimicrobial mediators to which the parasite mutant is susceptible. Activation of infected macrophages can also promote parasite differentiation from the tachyzoite to bradyzoite stage that maintains chronic infection. Therefore, methodology is presented to evaluate the importance of the identified

  20. Predicting Risk in Space: Genetic Markers for Differential Vulnerability to Sleep Restriction

    Science.gov (United States)

    Goel, Namni; Dinges, David F.

    2013-01-01

    Several laboratories have found large, highly reliable individual differences in the magnitude of cognitive performance, fatigue and sleepiness, and sleep homeostatic vulnerability to acute total sleep deprivation and to chronic sleep restriction in healthy adults. Such individual differences in neurobehavioral performance are also observed in space flight as a result of sleep loss. The reasons for these stable phenotypic differential vulnerabilities are unknown: such differences are not yet accounted for by demographic factors, IQ or sleep need, and moreover, psychometric scales do not predict those individuals cognitively vulnerable to sleep loss. The stable, trait-like (phenotypic) inter-individual differences observed in response to sleep loss—with intraclass correlation coefficients accounting for 58%-92% of the variance in neurobehavioral measures— point to an underlying genetic component. To this end, we utilized multi-day highly controlled laboratory studies to investigate the role of various common candidate gene variants—each independently—in relation to cumulative neurobehavioral and sleep homeostatic responses to sleep restriction. These data suggest that common genetic variations (polymorphisms) involved in sleep-wake, circadian, and cognitive regulation may serve as markers for prediction of inter-individual differences in sleep homeostatic and neurobehavioral vulnerability to sleep restriction in healthy adults. Identification of genetic predictors of differential vulnerability to sleep restriction—as determined from candidate gene studies—will help identify astronauts most in need of fatigue countermeasures in space flight and inform medical standards for obtaining adequate sleep in space. This review summarizes individual differences in neurobehavioral vulnerability to sleep deprivation and ongoing genetic efforts to identify markers of such differences. PMID:23524958

  1. Philopatry drives genetic differentiation in an island archipelago: comparative population genetics of Galapagos Nazca boobies (Sula granti) and great frigatebirds (Fregata minor).

    Science.gov (United States)

    Levin, Iris I; Parker, Patricia G

    2012-11-01

    Seabirds are considered highly mobile, able to fly great distances with few apparent barriers to dispersal. However, it is often the case that seabird populations exhibit strong population genetic structure despite their potential vagility. Here we show that Galapagos Nazca booby (Sula granti) populations are substantially differentiated, even within the small geographic scale of this archipelago. On the other hand, Galapagos great frigatebird (Fregata minor) populations do not show any genetic structure. We characterized the genetic differentiation by sampling five colonies of both species in the Galapagos archipelago and analyzing eight microsatellite loci and three mitochondrial genes. Using an F-statistic approach on the multilocus data, we found significant differentiation between nearly all island pairs of Nazca booby populations and a Bayesian clustering analysis provided support for three distinct genetic clusters. Mitochondrial DNA showed less differentiation of Nazca booby colonies; only Nazca boobies from the island of Darwin were significantly differentiated from individuals throughout the rest of the archipelago. Great frigatebird populations showed little to no evidence for genetic differentiation at the same scale. Only two island pairs (Darwin - Wolf, N. Seymour - Wolf) were significantly differentiated using the multilocus data, and only two island pairs had statistically significant φ(ST) values (N. Seymour - Darwin, N. Seymour - Wolf) according to the mitochondrial data. There was no significant pattern of isolation by distance for either species calculated using both markers. Seven of the ten Nazca booby migration rates calculated between island pairs were in the south or southeast to north or northwest direction. The population differentiation found among Galapagos Nazca booby colonies, but not great frigatebird colonies, is most likely due to differences in natal and breeding philopatry.

  2. Enhanced computational methods for quantifying the effect of geographic and environmental isolation on genetic differentiation

    DEFF Research Database (Denmark)

    Botta, Filippo; Eriksen, Casper; Fontaine, Michaël C.;

    2015-01-01

    method allowing us to deal with genomic data sets (several hundred thousands loci). 3. We also illustrate the potential of the method by re-analysing three data sets, namely harbour porpoises in Europe, coyotes in California and herrings in the Baltic Sea. 4. The computer program developed here is freely......1. In a recent paper, Bradburd et al. (Evolution, 67, 2013, 3258) proposed a model to quantify the relative effect of geographic and environmental distance on genetic differentiation. Here, we enhance this method in several ways. 2. We modify the covariance model so as to fit better with mainstream...

  3. Genetic differentiation between cave and surface-dwelling populations of Garra barreimiae (Cyprinidae in Oman

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    Seemann Robert

    2011-06-01

    Full Text Available Abstract Background Phenotypic similarities among cave-dwelling animals displaying troglomorphic characters (e.g. reduced eyes and lack of pigmentation have induced a long-term discussion about the forces driving convergent evolution. Here we introduce Garra barreimiae Fowler & Steinitz, 1956, as an interesting system to study the evolution of troglomorphic characters. The only hitherto known troglomorphic population of this species lives in Al Hoota Cave (Sultanate of Oman close to a surface population. As a first approach, we assessed the genetic differentiation between the two morphotypes of G. barreimiae to determine whether gene flow still occurs. Results We analysed the mitochondrial control region (CR. In G. barreimiae the CR starts immediately downstream of the tRNA-Thr gene, while the tRNA-Pro gene is missing at this genomic location. Interestingly, a putative tRNA-Pro sequence is found within the CR. The phylogenetic analyses of the CR sequences yielded a tree divided into three clades: Clade 1 has a high genetic distance to the other clades and contains the individuals of three populations which are separated by a watershed from all the others. Clade 2 comprises the individuals from Wadi Bani Khalid, the geographically most remote population. Clade 3 comprises all other populations investigated including that of Al Hoota Cave. The latter forms a haplogroup which also includes individuals from the adjacent surface population. Conclusions Our data indicates that the troglomorphic cave population is of quite recent origin supporting the hypothesis that selection drives the fast evolution of troglomorphic traits. In this context pleiotropic effects might play an important role as it has been shown for Astyanax. There seems to be some gene flow from the cave population into the adjacent surface populations. One blind individual, found at a surface locality geographically distinct from Al Hoota Cave, is genetically differentiated from the

  4. Epigenetic Library Screen Identifies Abexinostat as Novel Regulator of Adipocytic and Osteoblastic Differentiation of Human Skeletal (Mesenchymal) Stem Cells

    DEFF Research Database (Denmark)

    Ali; Hamam; Alfayez;

    2016-01-01

    The epigenetic mechanisms promoting lineage-specific commitment of human skeletal (mesenchymal or stromal) stem cells (hMSCs) into adipocytes or osteoblasts are still not fully understood. Herein, we performed an epigenetic library functional screen and identified several novel compounds, including...... abexinostat, which promoted adipocytic and osteoblastic differentiation of hMSCs. Using gene expression microarrays, chromatin immunoprecipitation for H3K9Ac combined with high-throughput DNA sequencing (ChIP-seq), and bioinformatics, we identified several key genes involved in regulating stem cell...... or stromal) stem cells (hMSCs). These data provide new insight into the understanding of the relationship between the epigenetic effect of histone deacetylase inhibitors, transcription factors, and differentiation pathways controlling adipocyte and osteoblast differentiation of hMSCs. Manipulating...

  5. Genetic and ecotypic differentiation in a Californian plant polyploid complex (Grindelia, Asteraceae.

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    Abigail J Moore

    Full Text Available Studies of ecotypic differentiation in the California Floristic Province have contributed greatly to plant evolutionary biology since the pioneering work of Clausen, Keck, and Hiesey. The extent of gene flow and genetic differentiation across interfertile ecotypes that span major habitats in the California Floristic Province is understudied, however, and is important for understanding the prospects for local adaptation to evolve or persist in the face of potential gene flow across populations in different ecological settings. We used microsatellite data to examine local differentiation in one of these lineages, the Pacific Coast polyploid complex of the plant genus Grindelia (Asteraceae. We examined 439 individuals in 10 different populations. The plants grouped broadly into a coastal and an inland set of populations. The coastal group contained plants from salt marshes and coastal bluffs, as well as a population growing in a serpentine grassland close to the coast, while the inland group contained grassland plants. No evidence for hybridization was found at the single location where adjacent populations of the two groups were sampled. In addition to differentiation along ecotypic lines, there was also a strong signal of local differentiation, with the plants grouping strongly by population. The strength of local differentiation is consistent with the extensive morphological variation observed across populations and the history of taxonomic confusion in the group. The Pacific Clade of Grindelia and other young Californian plant groups warrant additional analysis of evolutionary divergence along the steep coast-to-inland climatic gradient, which has been associated with local adaptation and ecotype formation since the classic studies of Clausen, Keck, and Hiesey.

  6. Genetic and ecotypic differentiation in a Californian plant polyploid complex (Grindelia, Asteraceae).

    Science.gov (United States)

    Moore, Abigail J; Moore, William L; Baldwin, Bruce G

    2014-01-01

    Studies of ecotypic differentiation in the California Floristic Province have contributed greatly to plant evolutionary biology since the pioneering work of Clausen, Keck, and Hiesey. The extent of gene flow and genetic differentiation across interfertile ecotypes that span major habitats in the California Floristic Province is understudied, however, and is important for understanding the prospects for local adaptation to evolve or persist in the face of potential gene flow across populations in different ecological settings. We used microsatellite data to examine local differentiation in one of these lineages, the Pacific Coast polyploid complex of the plant genus Grindelia (Asteraceae). We examined 439 individuals in 10 different populations. The plants grouped broadly into a coastal and an inland set of populations. The coastal group contained plants from salt marshes and coastal bluffs, as well as a population growing in a serpentine grassland close to the coast, while the inland group contained grassland plants. No evidence for hybridization was found at the single location where adjacent populations of the two groups were sampled. In addition to differentiation along ecotypic lines, there was also a strong signal of local differentiation, with the plants grouping strongly by population. The strength of local differentiation is consistent with the extensive morphological variation observed across populations and the history of taxonomic confusion in the group. The Pacific Clade of Grindelia and other young Californian plant groups warrant additional analysis of evolutionary divergence along the steep coast-to-inland climatic gradient, which has been associated with local adaptation and ecotype formation since the classic studies of Clausen, Keck, and Hiesey.

  7. A genetic screen for replication initiation defective (rid mutants in Schizosaccharomyces pombe

    Directory of Open Access Journals (Sweden)

    Locovei Alexandra M

    2010-08-01

    Full Text Available Abstract In fission yeast the intra-S phase and DNA damage checkpoints are activated in response to inhibition of DNA replication or DNA damage, respectively. The intra-S phase checkpoint responds to stalled replication forks leading to the activation of the Cds1 kinase that both delays cell cycle progression and stabilizes DNA replication forks. The DNA damage checkpoint, that operates during the G2 phase of the cell cycle delays mitotic progression through activation of the checkpoint kinase, Chk1. Delay of the cell cycle is believed to be essential to allow time for either replication restart (in S phase or DNA damage repair (in G2. Previously, our laboratory showed that fission yeast cells deleted for the N-terminal half of DNA polymerase ε (Cdc20 are delayed in S phase, but surprisingly require Chk1 rather than Cds1 to maintain cell viability. Several additional DNA replication mutants were then tested for their dependency on Chk1 or Cds1 when grown under semi-permissive temperatures. We discovered that mutants defective in DNA replication initiation are sensitive only to loss of Chk1, whilst mutations that inhibit DNA replication elongation are sensitive to loss of both Cds1 and Chk1. To confirm that the Chk1-sensitive, Cds1-insensitive phenotype (rid phenotype is specific to mutants defective in DNA replication initiation, we completed a genetic screen for cell cycle mutants that require Chk1, but not Cds1 to maintain cell viability when grown at semi-permissive temperatures. Our screen identified two mutants, rid1-1 and rid2-1, that are defective in Orc1 and Mcm4, respectively. Both mutants show defects in DNA replication initiation consistent with our hypothesis that the rid phenotype is replication initiation specific. In the case of Mcm4, the mutation has been mapped to a highly conserved region of the protein that appears to be required for DNA replication initiation, but not elongation. Therefore, we conclude that the cellular

  8. High genetic differentiation between the M and S molecular forms of Anopheles gambiae in Africa.

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    Caroline Esnault

    Full Text Available BACKGROUND: Anopheles gambiae, a major vector of malaria, is widely distributed throughout sub-Saharan Africa. In an attempt to eliminate infective mosquitoes, researchers are trying to develop transgenic strains that are refractory to the Plasmodium parasite. Before any release of transgenic mosquitoes can be envisaged, we need an accurate picture of the differentiation between the two molecular forms of An. gambiae, termed M and S, which are of uncertain taxonomic status. METHODOLOGY/PRINCIPAL FINDINGS: Insertion patterns of three transposable elements (TEs were determined in populations from Benin, Burkina Faso, Cameroon, Ghana, Ivory Coast, Madagascar, Mali, Mozambique, Niger, and Tanzania, using Transposon Display, a TE-anchored strategy based on Amplified Fragment Length Polymorphism. The results reveal a clear differentiation between the M and S forms, whatever their geographical origin, suggesting an incipient speciation process. CONCLUSIONS/SIGNIFICANCE: Any attempt to control the transmission of malaria by An. gambiae using either conventional or novel technologies must take the M/S genetic differentiation into account. In addition, we localized three TE insertion sites that were present either in every individual or at a high frequency in the M molecular form. These sites were found to be located outside the chromosomal regions that are suspected of involvement in the speciation event between the two forms. This suggests that these chromosomal regions are either larger than previously thought, or there are additional differentiated genomic regions interspersed with undifferentiated regions.

  9. High Genetic Differentiation between the M and S Molecular Forms of Anopheles gambiae in Africa

    Science.gov (United States)

    Esnault, Caroline; Boulesteix, Matthieu; Duchemin, Jean Bernard; Koffi, Alphonsine A.; Chandre, Fabrice; Dabiré, Roch; Robert, Vincent; Simard, Frédéric; Tripet, Frédéric; Donnelly, Martin J.; Fontenille, Didier; Biémont, Christian

    2008-01-01

    Background Anopheles gambiae, a major vector of malaria, is widely distributed throughout sub-Saharan Africa. In an attempt to eliminate infective mosquitoes, researchers are trying to develop transgenic strains that are refractory to the Plasmodium parasite. Before any release of transgenic mosquitoes can be envisaged, we need an accurate picture of the differentiation between the two molecular forms of An. gambiae, termed M and S, which are of uncertain taxonomic status. Methodology/Principal Findings Insertion patterns of three transposable elements (TEs) were determined in populations from Benin, Burkina Faso, Cameroon, Ghana, Ivory Coast, Madagascar, Mali, Mozambique, Niger, and Tanzania, using Transposon Display, a TE-anchored strategy based on Amplified Fragment Length Polymorphism. The results reveal a clear differentiation between the M and S forms, whatever their geographical origin, suggesting an incipient speciation process. Conclusions/Significance Any attempt to control the transmission of malaria by An. gambiae using either conventional or novel technologies must take the M/S genetic differentiation into account. In addition, we localized three TE insertion sites that were present either in every individual or at a high frequency in the M molecular form. These sites were found to be located outside the chromosomal regions that are suspected of involvement in the speciation event between the two forms. This suggests that these chromosomal regions are either larger than previously thought, or there are additional differentiated genomic regions interspersed with undifferentiated regions. PMID:18414665

  10. Real-time polymerase chain reaction detection of cauliflower mosaic virus to complement the 35S screening assay for genetically modified organisms.

    Science.gov (United States)

    Cankar, Katarina; Ravnikar, Maja; Zel, Jana; Gruden, Kristina; Toplak, Natasa

    2005-01-01

    Labeling of genetically modified organisms (GMOs) is now in place in many countries, including the European Union, in order to guarantee the consumer's choice between GM and non-GM products. Screening of samples is performed by polymerase chain reaction (PCR) amplification of regulatory sequences frequently introduced into genetically modified plants. Primers for the 35S promoter from Cauliflower mosaic virus (CaMV) are those most frequently used. In virus-infected plants or in samples contaminated with plant material carrying the virus, false-positive results can consequently occur. A system for real-time PCR using a TaqMan minor groove binder probe was designed that allows recognition of virus coat protein in the sample, thus allowing differentiation between transgenic and virus-infected samples. We measured the efficiency of PCR amplification, limits of detection and quantification, range of linearity, and repeatability of the assay in order to assess the applicability of the assay for routine analysis. The specificity of the detection system was tested on various virus isolates and plant species. All 8 CaMV isolates were successfully amplified using the designed system. No cross-reactivity was detected with DNA from 3 isolates of the closely related Carnation etched ring virus. Primers do not amplify plant DNA from available genetically modified maize and soybean lines or from different species of Brassicaceae or Solanaceae that are natural hosts for CaMV. We evaluated the assay for different food matrixes by spiking CaMV DNA into DNA from food samples and have successfully amplified CaMV from all samples. The assay was tested on rapeseed samples from routine GMO testing that were positive in the 35S screening assay, and the presence of the virus was confirmed.

  11. piggyBac transposon somatic mutagenesis with an activated reporter and tracker (PB-SMART for genetic screens in mice.

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    Sean F Landrette

    Full Text Available Somatic forward genetic screens have the power to interrogate thousands of genes in a single animal. Retroviral and transposon mutagenesis systems in mice have been designed and deployed in somatic tissues for surveying hematopoietic and solid tumor formation. In the context of cancer, the ability to visually mark mutant cells would present tremendous advantages for identifying tumor formation, monitoring tumor growth over time, and tracking tumor infiltrations and metastases into wild-type tissues. Furthermore, locating mutant clones is a prerequisite for screening and analyzing most other somatic phenotypes. For this purpose, we developed a system using the piggyBac (PB transposon for somatic mutagenesis with an activated reporter and tracker, called PB-SMART. The PB-SMART mouse genetic screening system can simultaneously induce somatic mutations and mark mutated cells using bioluminescence or fluorescence. The marking of mutant cells enable analyses that are not possible with current somatic mutagenesis systems, such as tracking cell proliferation and tumor growth, detecting tumor cell infiltrations, and reporting tissue mutagenesis levels by a simple ex vivo visual readout. We demonstrate that PB-SMART is highly mutagenic, capable of tumor induction with low copy transposons, which facilitates the mapping and identification of causative insertions. We further integrated a conditional transposase with the PB-SMART system, permitting tissue-specific mutagenesis with a single cross to any available Cre line. Targeting the germline, the system could also be used to conduct F1 screens. With these features, PB-SMART provides an integrated platform for individual investigators to harness the power of somatic mutagenesis and phenotypic screens to decipher the genetic basis of mammalian biology and disease.

  12. A Sleeping Beauty DNA transposon-based genetic sensor for functional screening of vitamin D3 analogues

    DEFF Research Database (Denmark)

    Staunstrup, Nicklas Heine; Sharma, Nynne; Bak, Rasmus Otkjær;

    2011-01-01

    Analogues of vitamin D3 are extensively used in the treatment of various illnesses, such as osteoporosis, inflammatory skin diseases, and cancer. Functional testing of new vitamin D3 analogues and formulations for improved systemic and topical administration is supported by sensitive screening me...... analogues. The tri-cistronic genetic sensor encodes a drug-sensoring protein, a reporter protein expressed from an activated sensor-responsive promoter, and a resistance marker....

  13. [Genetic screening of patients with familial hypercholesterolemia and insurability for life insurance policies and disability cover policies].

    Science.gov (United States)

    Homsma, S J; Lansberg, P J; Kastelein, J J

    2004-03-01

    In the Netherlands, people with familial hypercholesterolaemia (FH) have been actively screened since 1994 by means of DNA analysis. Recently, the Stichting Opsporing Erfelijke Hypercholesterolemie (Foundation for the Detection of Familial Hypercholesterolaemia) initiated a large scale-screening programme aimed at finding all 40,000 people. The Dutch ministry of Health, Welfare and Sport is providing the financial support. Genetic screening has social implications and raises questions on insurability. The Dutch Medical Examination Act prohibits insurers from posing questions about untreatable, serious inheritable conditions for insured sums under a certain value: for life-insurance policies policies insurers can request information for the purpose of an accurate risk classification. Insurance contracts can be accepted at normal rates if the target value of LDL-cholesterol < 4 mmol/l and additional risk factors such as smoking and an abnormal BMI are absent; the risk is determined by the phenotype and clinical factors and not by the genotype.

  14. [Large-scale population-based genetic screening and prenatal diagnosis for thalassemias in Zhuhai City of Guangdong Province].

    Science.gov (United States)

    Zhou, Yu-qiu; Shang, Xuan; Yin, Bao-min; Xiong, Fu; Xiao, Qi-zhi; Zhou, Wan-jun; Zhang, Yong-liang; Xu, Xiang-min

    2012-02-01

    To report the results of preventive control program of severe thalassemias in Zhuhai City of Guangdong Province from 1998 to 2010. As the guide centre of marriage and childbearing and the greatest maternity hospital in Zhuhai City of Guangdong Province, Zhuhai Municipal Maternity and Child Healthcare Hospital constructed the genetic screening network for thalassemias testing and referred for follow-up and for genetic counseling. The couples for premarital medical examination or regular healthcare examination in pregnancy were enrolled to this preventive control program. A conventional strategy of screening for heterozygote was used to identify the α- and β-thalassemia traits in women and their spouses according to the standard procedures of hematological phenotype analysis which was recommended by Thalassemia International Federation (TIF). Then those suspected couples at risk were diagnosed for α- and β-thalassemia by PCR-based DNA assays. The couples at risk for severe thalassemias were counseled and offered prenatal diagnosis and termination of pregnancy in case of an affected fetus in the rights of consent and of option voluntarily. From January 1998 to December 2010, 85 522 brides and grooms-to-be for premarital screening and 41 503 pregnant women in addition to 14 141 partners for prenatal screening were recorded, the covering rates of premarital screening and prenatal screening in the city were 92.698% (from 1998 to 2003) and 27.667% (from 2004 to 2010), respectively. Totally 10 726 cases were found to be the carriers of thalassemias, with 7393 for α-thalassemia (5.237%, 7 393/141 166) and 3333 for β-thalassemia (2.361%, 3 333/141 166). A total of 257 couples at-risk for severe thalassemias were detected including 190 for α-thalassemia and 67 for β-thalassemia. Among them, 251 (97.7%, 251/257) couples were performed prenatal diagnosis. During the preventive control program, a total of 72 fetuses with severe thalassemias including hemoglobin H disease

  15. Parallel genetic divergence among coastal-marine ecotype pairs of European anchovy explained by differential introgression after secondary contact.

    Science.gov (United States)

    Le Moan, A; Gagnaire, P-A; Bonhomme, F

    2016-07-01

    Ecophenotypic differentiation among replicate ecotype pairs within a species complex is often attributed to independent outcomes of parallel divergence driven by adaptation to similar environmental contrasts. However, the extent to which parallel phenotypic and genetic divergence patterns have emerged independently is increasingly questioned by population genomic studies. Here, we document the extent of genetic differentiation within and among two geographic replicates of the coastal and marine ecotypes of the European anchovy (Engraulis encrasicolus) gathered from Atlantic and Mediterranean locations. Using a genome-wide data set of RAD-derived SNPs, we show that habitat type (marine vs. coastal) is the most important component of genetic differentiation among populations of anchovy. By analysing the joint allele frequency spectrum of each coastal-marine ecotype pair, we show that genomic divergence patterns between ecotypes can be explained by a postglacial secondary contact following a long period of allopatric isolation (c. 300 kyrs). We found strong support for a model including heterogeneous migration among loci, suggesting that secondary gene flow has eroded past differentiation at different rates across the genome. Markers experiencing reduced introgression exhibited strongly correlated differentiation levels among Atlantic and Mediterranean regions. These results support that partial reproductive isolation and parallel genetic differentiation among replicate pairs of anchovy ecotypes are largely due to a common divergence history prior to secondary contact. They moreover provide comprehensive insights into the origin of a surprisingly strong fine-scale genetic structuring in a high gene flow marine fish, which should improve stock management and conservation actions.

  16. A conditional piggyBac transposition system for genetic screening in mice identifies oncogenic networks in pancreatic cancer.

    Science.gov (United States)

    Rad, Roland; Rad, Lena; Wang, Wei; Strong, Alexander; Ponstingl, Hannes; Bronner, Iraad F; Mayho, Matthew; Steiger, Katja; Weber, Julia; Hieber, Maren; Veltkamp, Christian; Eser, Stefan; Geumann, Ulf; Öllinger, Rupert; Zukowska, Magdalena; Barenboim, Maxim; Maresch, Roman; Cadiñanos, Juan; Friedrich, Mathias; Varela, Ignacio; Constantino-Casas, Fernando; Sarver, Aaron; Ten Hoeve, Jelle; Prosser, Haydn; Seidler, Barbara; Bauer, Judith; Heikenwälder, Mathias; Metzakopian, Emmanouil; Krug, Anne; Ehmer, Ursula; Schneider, Günter; Knösel, Thomas; Rümmele, Petra; Aust, Daniela; Grützmann, Robert; Pilarsky, Christian; Ning, Zemin; Wessels, Lodewyk; Schmid, Roland M; Quail, Michael A; Vassiliou, George; Esposito, Irene; Liu, Pentao; Saur, Dieter; Bradley, Allan

    2015-01-01

    Here we describe a conditional piggyBac transposition system in mice and report the discovery of large sets of new cancer genes through a pancreatic insertional mutagenesis screen. We identify Foxp1 as an oncogenic transcription factor that drives pancreatic cancer invasion and spread in a mouse model and correlates with lymph node metastasis in human patients with pancreatic cancer. The propensity of piggyBac for open chromatin also enabled genome-wide screening for cancer-relevant noncoding DNA, which pinpointed a Cdkn2a cis-regulatory region. Histologically, we observed different tumor subentities and discovered associated genetic events, including Fign insertions in hepatoid pancreatic cancer. Our studies demonstrate the power of genetic screening to discover cancer drivers that are difficult to identify by other approaches to cancer genome analysis, such as downstream targets of commonly mutated human cancer genes. These piggyBac resources are universally applicable in any tissue context and provide unique experimental access to the genetic complexity of cancer.

  17. Electrochemical sensor for multiplex screening of genetically modified DNA: identification of biotech crops by logic-based biomolecular analysis.

    Science.gov (United States)

    Liao, Wei-Ching; Chuang, Min-Chieh; Ho, Ja-An Annie

    2013-12-15

    Genetically modified (GM) technique, one of the modern biomolecular engineering technologies, has been deemed as profitable strategy to fight against global starvation. Yet rapid and reliable analytical method is deficient to evaluate the quality and potential risk of such resulting GM products. We herein present a biomolecular analytical system constructed with distinct biochemical activities to expedite the computational detection of genetically modified organisms (GMOs). The computational mechanism provides an alternative to the complex procedures commonly involved in the screening of GMOs. Given that the bioanalytical system is capable of processing promoter, coding and species genes, affirmative interpretations succeed to identify specified GM event in terms of both electrochemical and optical fashions. The biomolecular computational assay exhibits detection capability of genetically modified DNA below sub-nanomolar level and is found interference-free by abundant coexistence of non-GM DNA. This bioanalytical system, furthermore, sophisticates in array fashion operating multiplex screening against variable GM events. Such a biomolecular computational assay and biosensor holds great promise for rapid, cost-effective, and high-fidelity screening of GMO. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Automated, quantitative cognitive/behavioral screening of mice: for genetics, pharmacology, animal cognition and undergraduate instruction.

    Science.gov (United States)

    Gallistel, C R; Balci, Fuat; Freestone, David; Kheifets, Aaron; King, Adam

    2014-02-26

    We describe a high-throughput, high-volume, fully automated, live-in 24/7 behavioral testing system for assessing the effects of genetic and pharmacological manipulations on basic mechanisms of cognition and learning in mice. A standard polypropylene mouse housing tub is connected through an acrylic tube to a standard commercial mouse test box. The test box has 3 hoppers, 2 of which are connected to pellet feeders. All are internally illuminable with an LED and monitored for head entries by infrared (IR) beams. Mice live in the environment, which eliminates handling during screening. They obtain their food during two or more daily feeding periods by performing in operant (instrumental) and Pavlovian (classical) protocols, for which we have written protocol-control software and quasi-real-time data analysis and graphing software. The data analysis and graphing routines are written in a MATLAB-based language created to simplify greatly the analysis of large time-stamped behavioral and physiological event records and to preserve a full data trail from raw data through all intermediate analyses to the published graphs and statistics within a single data structure. The data-analysis code harvests the data several times a day and subjects it to statistical and graphical analyses, which are automatically stored in the "cloud" and on in-lab computers. Thus, the progress of individual mice is visualized and quantified daily. The data-analysis code talks to the protocol-control code, permitting the automated advance from protocol to protocol of individual subjects. The behavioral protocols implemented are matching, autoshaping, timed hopper-switching, risk assessment in timed hopper-switching, impulsivity measurement, and the circadian anticipation of food availability. Open-source protocol-control and data-analysis code makes the addition of new protocols simple. Eight test environments fit in a 48 in x 24 in x 78 in cabinet; two such cabinets (16 environments) may be

  19. Establishment of a system based on universal multiplex-PCR for screening genetically modified crops.

    Science.gov (United States)

    Lu, I-Jen; Lin, Chih-Hui; Pan, Tzu-Ming

    2010-03-01

    The rapid development of many genetically modified (GM) crops in the past two decades makes it necessary to introduce an alternative strategy for routine screening and identification. In this study, we established a universal multiplex PCR detection system which will effectively reduce the number of reactions needed for sample identification. The PCR targets of this system include the six most frequently used transgenic elements: cauliflower mosaic virus (CaMV) 35S promoter, Agrobacterium tumefaciens nopaline synthase (nos) promoter, Agrobacterium tumefaciens nopaline synthase (nos) terminator, the neomycin phosphotransferase II (nptII) gene, the 5-enolpyruvylshikimate-3-phosphate synthase (CP4 epsps) gene of Agrobacterium tumefaciens strain CP4, and the phosphinothricin N-acetyltransferase (pat) gene. According to the AGBIOS database, the coverage of this detection system is 93% of commercial GM crops. This detection system could detect all certified reference materials (CRMs) at the 1.0% level. The correct combination of all the CRM amplicon patterns proved the specificity of this multiplex PCR system. Furthermore, the amplicon patterns of this multiplex PCR detection system could be used as an index of classification which will narrow the range of possible GM products. The simulation result of this multiplex PCR detection system on all commercialized 139 GM products in the AGBIOS database showed that the maximum number of PCR reactions needed to identify an unknown sample can be reduced to 13. In this study, we established a high-throughput multiplex PCR detection system with feasible sensitivity, specificity, and cost. By incorporating this detection system, the routine GM crop-detection process will meet the challenges resulting from a rapid increase in the number of GM crops in the future.

  20. Identification of genes important for cutaneous function revealed by a large scale reverse genetic screen in the mouse.

    Science.gov (United States)

    DiTommaso, Tia; Jones, Lynelle K; Cottle, Denny L; Gerdin, Anna-Karin; Vancollie, Valerie E; Watt, Fiona M; Ramirez-Solis, Ramiro; Bradley, Allan; Steel, Karen P; Sundberg, John P; White, Jacqueline K; Smyth, Ian M

    2014-10-01

    The skin is a highly regenerative organ which plays critical roles in protecting the body and sensing its environment. Consequently, morbidity and mortality associated with skin defects represent a significant health issue. To identify genes important in skin development and homeostasis, we have applied a high throughput, multi-parameter phenotype screen to the conditional targeted mutant mice generated by the Wellcome Trust Sanger Institute's Mouse Genetics Project (Sanger-MGP). A total of 562 different mouse lines were subjected to a variety of tests assessing cutaneous expression, macroscopic clinical disease, histological change, hair follicle cycling, and aberrant marker expression. Cutaneous lesions were associated with mutations in 23 different genes. Many of these were not previously associated with skin disease in the organ (Mysm1, Vangl1, Trpc4ap, Nom1, Sparc, Farp2, and Prkab1), while others were ascribed new cutaneous functions on the basis of the screening approach (Krt76, Lrig1, Myo5a, Nsun2, and Nf1). The integration of these skin specific screening protocols into the Sanger-MGP primary phenotyping pipelines marks the largest reported reverse genetic screen undertaken in any organ and defines approaches to maximise the productivity of future projects of this nature, while flagging genes for further characterisation.

  1. Identification of genes important for cutaneous function revealed by a large scale reverse genetic screen in the mouse.

    Directory of Open Access Journals (Sweden)

    Tia DiTommaso

    2014-10-01

    Full Text Available The skin is a highly regenerative organ which plays critical roles in protecting the body and sensing its environment. Consequently, morbidity and mortality associated with skin defects represent a significant health issue. To identify genes important in skin development and homeostasis, we have applied a high throughput, multi-parameter phenotype screen to the conditional targeted mutant mice generated by the Wellcome Trust Sanger Institute's Mouse Genetics Project (Sanger-MGP. A total of 562 different mouse lines were subjected to a variety of tests assessing cutaneous expression, macroscopic clinical disease, histological change, hair follicle cycling, and aberrant marker expression. Cutaneous lesions were associated with mutations in 23 different genes. Many of these were not previously associated with skin disease in the organ (Mysm1, Vangl1, Trpc4ap, Nom1, Sparc, Farp2, and Prkab1, while others were ascribed new cutaneous functions on the basis of the screening approach (Krt76, Lrig1, Myo5a, Nsun2, and Nf1. The integration of these skin specific screening protocols into the Sanger-MGP primary phenotyping pipelines marks the largest reported reverse genetic screen undertaken in any organ and defines approaches to maximise the productivity of future projects of this nature, while flagging genes for further characterisation.

  2. Comparative Haploid Genetic Screens Reveal Divergent Pathways in the Biogenesis and Trafficking of Glycophosphatidylinositol-Anchored Proteins

    Directory of Open Access Journals (Sweden)

    Eric M. Davis

    2015-06-01

    Full Text Available Glycophosphatidylinositol-anchored proteins (GPI-APs play essential roles in physiology, but their biogenesis and trafficking have not been systematically characterized. Here, we took advantage of the recently available haploid genetics approach to dissect GPI-AP pathways in human cells using prion protein (PrP and CD59 as model molecules. Our screens recovered a large number of common and unexpectedly specialized factors in the GPI-AP pathways. PIGN, PGAP2, and PIGF, which encode GPI anchor-modifying enzymes, were selectively isolated in the CD59 screen, suggesting that GPI anchor composition significantly influences the biogenesis of GPI-APs in a substrate-dependent manner. SEC62 and SEC63, which encode components of the ER-targeting machinery, were selectively recovered in the PrP screen, indicating that they do not constitute a universal route for the biogenesis of mammalian GPI-APs. Together, these comparative haploid genetic screens demonstrate that, despite their similarity in overall architecture and subcellular localization, GPI-APs follow markedly distinct biosynthetic and trafficking pathways.

  3. Genetic differentiation in pointing dog breeds inferred from microsatellites and mitochondrial DNA sequence.

    Science.gov (United States)

    Parra, D; Méndez, S; Cañón, J; Dunner, S

    2008-02-01

    Recent studies presenting genetic analysis of dog breeds do not focus specifically on genetic relationships among pointing dog breeds, although hunting was among the first traits of interest when dogs were domesticated. This report compares histories with genetic relationships among five modern breeds of pointing dogs (English Setter, English Pointer, Epagneul Breton, Deutsch Drahthaar and German Shorthaired Pointer) collected in Spain using mitochondrial, autosomal and Y-chromosome information. We identified 236 alleles in autosomal microsatellites, four Y-chromosome haplotypes and 18 mitochondrial haplotypes. Average F(ST) values were 11.2, 14.4 and 13.1 for autosomal, Y-chromosome microsatellite markers and mtDNA sequence respectively, reflecting relatively high genetic differentiation among breeds. The high gene diversity observed in the pointing breeds (61.7-68.2) suggests contributions from genetically different individuals, but that these individuals originated from the same ancestors. The modern English Setter, thought to have arisen from the Old Spanish Pointer, was the first breed to cluster independently when using autosomal markers and seems to share a common maternal origin with the English Pointer and German Shorthaired Pointer, either via common domestic breed females in the British Isles or through the Old Spanish Pointer females taken to the British Isles in the 14th and 16th centuries. Analysis of mitochondrial DNA sequence indicates the isolation of the Epagneul Breton, which has been formally documented, and shows Deutsch Drahthaar as the result of crossing the German Shorthaired Pointer with other breeds. Our molecular data are consistent with historical documents.

  4. Infrastructure and Educational Needs of Newborn Screening Short-Term Follow-Up Programs within the Southeast Regional Newborn Screening & Genetics Collaborative: A Pilot Survey

    Directory of Open Access Journals (Sweden)

    Cecelia A. Bellcross

    2015-10-01

    Full Text Available Newborn screening (NBS follow-up protocols vary significantly by state, and there is a need to better understand the infrastructure and communication flow of NBS programs. In addition, assessment of the educational needs of families and providers with regard to the implications of NBS results is required to inform the development of appropriate informational resources and training opportunities. To begin to address these issues, we administered a web-based survey to state NBS coordinators within the Southeast Regional Newborn Screening & Genetics Collaborative (SERC. Fourteen coordinators responded to the survey, including at least one from each of the 10 SERC states/territories. Over one-third of respondents had never received formal training regarding the metabolic conditions identified on NBS. Most communicated results via telephone or fax, though two centers indicated use of a web-based platform. Only two programs were involved in directly reporting results to the family. Four programs reported a long-term follow-up protocol. Deficits were noted for primary care provider (PCP knowledge of metabolic disorders identified on NBS, and how to inform parents of abnormal results. Close to half indicated that the adequacy of the number of genetic counselors, dietitians, and medical/biochemical geneticists was minimal to insufficient. Respondents uniformly recognized the importance of providing additional educational and informational resources in multiple categories to NBS staff, PCPs, and families.

  5. Mitochondrial genetic differentiation and morphological difference of Miniopterus fuliginosus and Miniopterus magnater in China and Vietnam.

    Science.gov (United States)

    Li, Shi; Sun, Keping; Lu, Guanjun; Lin, Aiqing; Jiang, Tinglei; Jin, Longru; Hoyt, Joseph R; Feng, Jiang

    2015-03-01

    Because of its complicated systematics, the bent-winged bat is one of the most frequently studied bat species groups. In China, two morphologically similar bent-winged bat species, Miniopterus fuliginosus and Miniopterus magnater were identified, but their distribution range and genetic differentiation are largely unexplored. In this study, we applied DNA bar codes and two other mitochondrial DNA genes including morphological parameters to determine the phylogeny, genetic differentiation, spatial distribution, and morphological difference of the M. fuliginosus and M. magnater sampled from China and one site in Vietnam. Mitochondrial DNA gene genealogies revealed two monophyletic lineages throughout the Tropic of Cancer. According to DNA bar code divergences, one is M. fuliginosus corresponding to the Chinese mainland and the other is M. magnater corresponding to tropical regions including Hainan and Guangdong provinces of China and Vietnam. Their most recent common ancestor was dated to the early stage of the Quaternary glacial period (ca. 2.26 million years ago [Ma] on the basis of D-loop data, and ca. 1.69-2.37 Ma according to ND2). A population expansion event was inferred for populations of M. fuliginosus at 0.14 Ma. The two species probably arose in separate Pleistocene refugia under different climate zones. They significantly differed in forearm length, maxillary third molar width, and greatest length of the skull.

  6. Genetic evidence for complexity in ethnic differentiation and history in East Africa.

    Science.gov (United States)

    Poloni, Estella S; Naciri, Yamama; Bucho, Rute; Niba, Régine; Kervaire, Barbara; Excoffier, Laurent; Langaney, André; Sanchez-Mazas, Alicia

    2009-11-01

    The Afro-Asiatic and Nilo-Saharan language families come into contact in Western Ethiopia. Ethnic diversity is particularly high in the South, where the Nilo-Saharan Nyangatom and the Afro-Asiatic Daasanach dwell. Despite their linguistic differentiation, both populations rely on a similar agripastoralist mode of subsistence. Analysis of mitochondrial DNA extracted from Nyangatom and Daasanach archival sera revealed high levels of diversity, with most sequences belonging to the L haplogroups, the basal branches of the mitochondrial phylogeny. However, in sharp contrast with other Ethiopian populations, only 5% of the Nyangatom and Daasanach sequences belong to haplogroups M and N. The Nyangatom and Daasanach were found to be significantly differentiated, while each of them displays close affinities with some Tanzanian populations. The strong genetic structure found over East Africa was neither associated with geography nor with language, a result confirmed by the analysis of 6711 HVS-I sequences of 136 populations mainly from Africa. Processes of migration, language shift and group absorption are documented by linguists and ethnographers for the Nyangatom and Daasanach, thus pointing to the probably transient and plastic nature of these ethnic groups. These processes, associated with periods of isolation, could explain the high diversity and strong genetic structure found in East Africa.

  7. Bias in estimating accuracy of a binary screening test with differential disease verification

    OpenAIRE

    Alonzo, Todd A.; Brinton, John T; Ringham, Brandy M; Glueck, Deborah H.

    2011-01-01

    Sensitivity, specificity, positive and negative predictive value are typically used to quantify the accuracy of a binary screening test. In some studies it may not be ethical or feasible to obtain definitive disease ascertainment for all subjects using a gold standard test. When a gold standard test cannot be used an imperfect reference test that is less than 100% sensitive and specific may be used instead. In breast cancer screening, for example, follow-up for cancer diagnosis is used as an ...

  8. Selection and drift influence genetic differentiation of insular Canada lynx (Lynx canadensis) on Newfoundland and Cape Breton Island.

    Science.gov (United States)

    Prentice, Melanie B; Bowman, Jeff; Khidas, Kamal; Koen, Erin L; Row, Jeffrey R; Murray, Dennis L; Wilson, Paul J

    2017-05-01

    Island populations have long been important for understanding the dynamics and mechanisms of evolution in natural systems. While genetic drift is often strong on islands due to founder events and population bottlenecks, the strength of selection can also be strong enough to counteract the effects of drift. Here, we used several analyses to identify the roles of genetic drift and selection on genetic differentiation and diversity of Canada lynx (Lynx canadensis) across eastern Canada, including the islands of Cape Breton and Newfoundland. Specifically, we assessed whether we could identify a genetic component to the observed morphological differentiation that has been reported across insular and mainland lynx. We used a dinucleotide repeat within the promoter region of a functional gene that has been linked to mammalian body size, insulin-like growth factor-1 (IGF-1). We found high genetic differentiation at neutral molecular markers but convergence of allele frequencies at the IGF-1 locus. Thus, we showed that while genetic drift has influenced the observed genetic structure of lynx at neutral molecular markers, natural selection has also played a role in the observed patterns of genetic diversity at the IGF-1 locus of insular lynx.

  9. Woody climbers show greater population genetic differentiation than trees: Insights into the link between ecological traits and diversification.

    Science.gov (United States)

    Gianoli, Ernesto; Torres-Díaz, Cristian; Ruiz, Eduardo; Salgado-Luarte, Cristian; Molina-Montenegro, Marco A; Saldaña, Alfredo; Ríos, Rodrigo S

    2016-12-01

    The climbing habit is a key innovation in plants: climbing taxa have higher species richness than nonclimbing sister groups. We evaluated the hypothesis that climbing plant species show greater among-population genetic differentiation than nonclimber species. We compared the among-population genetic distance in woody climbers (eight species, 30 populations) and trees (seven species, 29 populations) coexisting in nine communities in a temperate rainforest. We also compared within-population genetic diversity in co-occurring woody climbers and trees in two communities. Mean genetic distance between populations of climbers was twice that of trees. Isolation by distance (increase in genetic distance with geographic distance) was greater for climbers. Climbers and trees showed similar within-population genetic diversity. Our longevity estimate suggested that climbers had shorter generation times, while other biological features often associated with diversification (dispersal and pollination syndromes, mating system, size, and metabolic rate) did not show significant differences between groups. We hypothesize that the greater population differentiation in climbers could result from greater evolutionary responses to local selection acting on initially higher within-population genetic diversity, which could be driven by neutral processes associated with shorter generation times. Increased population genetic differentiation could be incorporated as another line of evidence when testing for key innovations. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  10. Integrated screening concept in women with genetic predisposition for breast cancer; Integriertes Frueherkennungskonzept bei Frauen mit genetischer Praedisposition fuer Brustkrebs

    Energy Technology Data Exchange (ETDEWEB)

    Bick, U. [Muenster Univ. (Germany). Inst. fuer Klinische Radiologie

    1997-08-01

    Breast cancer is in 5% of cases due to a genetic disposition. BRCA1 and BRCA2 are by far the most common breast cancer susceptibility genes. For a woman with a genetic predisposition, the individual risk of developing breast cancer sometime in her life is between 70 and 90%. Compared to the spontaneous forms of breast cancer, woman with a genetic predisposition often develop breast cancer at a much younger age. This is why conventional screening programs on the basis of mammography alone cannot be applied without modification to this high-risk group. In this article, an integrated screening concept for women with genetic prodisposition for breast cancer using breast self-examination, clinical examination, ultrasound, mammography and magnetic resonance imaging is introduced. (orig.) [Deutsch] Mammakarzinome sind in etwa 5% auf eine genetische Disposition zurueckzufuehren. Am haeufigsten finden sich Mutationen im Bereich der Gene BRCA1 und BRCA2. Frauen mit einer genetischen Disposition erkranken in etwa 70-90% im Laufe ihres Lebens an einem Mammakarzinom. Das Erkrankungsalter bei diesen Frauen liegt in der Regel deutlich niedriger als bei den spontanen Formen des Mammakarzinoms, so dass vorhandene Frueherkennungskonzepte auf der Basis eines Mammographiescrennings nicht ohne weiteres auf dieses Hochrisikokollektiv uebertragbar sind. Im folgenden wird ein integriertes Konzept zur Frueherkennung bei Frauen mit genetischer Praedisposition fuer ein Mammakarzinom auf der Basis von Brustselbstuntersuchung, klinischer Untersuchung, Sonographie, Mammographie und Magnetresonanztomographie vorgestellt. (orig.)

  11. Genetic differentiation of strongyloides stercoralis from two different climate zones revealed by 18S ribosomal DNA sequence comparison.

    Science.gov (United States)

    Pakdee, Wallop; Thaenkham, Urusa; Dekumyoy, Paron; Sa-Nguankiat, Surapol; Maipanich, Wanna; Pubampen, Somchit

    2012-11-01

    Over 70 countries in tropical and subtropical zones are endemic areas for Strongyloides stercoralis, with a higher prevalence of the parasite often occurring in tropical regions compared to subtropical ones. In order to explore genetic variations of S. stercoralis form different climate zones, 18S ribosomal DNA of parasite specimens obtained from Thailand were sequenced and compared with those from Japan. The maximum likelihood indicates that S. stercoralis populations from these two different climate zones have genetically diverged. The genetic relationship between S. stercoralis populations is not related to the host species, but rather to moisture and temperature. These factors may directly drive genetic differentiation among isolated populations of S. stercoralis.

  12. Space mutagenesis of genetically engineered bacteria expressing recombinant human interferon α1b and screening of higher yielding strains.

    Science.gov (United States)

    Wang, Junfeng; Liu, Changting; Liu, Jinyi; Fang, Xiangqun; Xu, Chen; Guo, Yinghua; Chang, De; Su, Longxiang

    2014-03-01

    The aim of this study was to investigate the space mutagenesis of genetically engineered bacteria expressing recombinant human interferon α1b. The genetically engineered bacteria expressing the recombinant interferon α1b were sent into outer space on the Chinese Shenzhou VIII spacecraft. After the 17 day space flight, mutant strains that highly expressed the target gene were identified. After a series of screening of spaceflight-treated bacteria and the quantitative comparison of the mutant strains and original strain, we found five strains that showed a significantly higher production of target proteins, compared with the original strain. Our results support the notion that the outer space environment has unique effects on the mutation breeding of microorganisms, including genetically engineered strains. Mutant strains that highly express the target protein could be obtained through spaceflight-induced mutagenesis.

  13. Genetic diversity and differentiation of three populations of Penaeus monodon Fabricus

    Institute of Scientific and Technical Information of China (English)

    WANG Guizhong; TAN Shuhua; LI shaojing; YE Haihui

    2008-01-01

    Genetic diversity of two wild Penaeus monodon populations sampled from the coastal waters of Qinglan ( Hainan Province of China, HN) and Malaysia (KD),and the F1 generation of a Thailand broodstock population (CP) were examined by vertical polyacryl- amide gel electrophoresis.Of 21 loci encoded by ten enzymes,11 were polymorphic.The mean proportions of polymorphic loci of HN,KD and CP were 36.36%,45.45% and 50.00%,with the average heterezygosities of 0.135,0.181 and 0.191,and the effective numbers of alleles per loci were 1.300,1.330 and 1.329,respectively.The divergent indexes of HN,KD and CP were 0.023,0.124,and 0.117,respectively.The genetic distance between the two wild populations was 0.005,and the gene differ- entiation coefficient was also very low (0.014).The results indicated that the F1 generation population had a higher genetic di- versity than the two wild populations,and that the HN population had the lowest one.There was no significant differentiation be- tween HN and KD populations and all populations existed with a slight heterozygote excess.

  14. [Genetic Differentiation of the Three Species of Genus Astragalus L. of Section Cenantrum Bunge (Fabaceae)].

    Science.gov (United States)

    Dymshakova, O S; Krivenko, D A; Belyaev, A Yu; Verkhozina, A V

    2015-08-01

    Genetic differentiation based on allozyme data was detected between species of the genus Astragalus L., section Cenantrum Bunge (Fabaceae): A.frigidus (L.) A. Gray s.l., A. mongholicus Bunge s. l, and A. sericeocanus Gontsch, which is endemic to the Northeast coast of Lake Baikal. The results of allozyme analysis confirm the natural division of the section into subsections based on morphological features. Differences between A. frigidus (subsection Elliptica Gontsch.) and A. mongholicus and A. sericeocanus (subsection Semilunaria Gontsch.) were observed. These differences were caused by the presence of species-specific alleles and the allele frequencies of the primary alleles, DN = 1.24. The genetic distance obtained for A. mongholicus and A. sericeocanus (0.10) corresponds to the status of closely related species of one subsection. Between populations of A. frigidus and between populations of A. mongholicus from the central part of areal, DN = 0.02 and 0.03 respectively. This genetic distance corresponds to the interpopulation level and was determined by the allele frequencies. The peripheral population of A. mongholicus is separated (DN = 0.36), which is probably due to the long isolation and the "founder effect."

  15. Genetic polymorphism and evolutionary differentiation of Eastern Chinese Han: a comprehensive and comparative analysis on KIRs

    Science.gov (United States)

    Yin, Caiyong; Hu, Li; Huang, Huijie; Yu, Yanfang; Li, Zheng; Ji, Qiang; Kong, Xiaochao; Wang, Zhongqun; Yan, Jinchuan; Yan, Jiangwei; Zhu, Bofeng; Chen, Feng

    2017-01-01

    Killer cell immunoglobulin-like receptor genes, namely KIRs, cluster together within the 160 kb genomic DNA region. In this study, we used PCR-SSP approach and successfully identified the genotype of 17 KIR genes in 123 independent healthy donors residing in the Jiangsu province, China. All individuals were positive at the 7 genes. The observed carrier gene frequencies (OFs) of remaining 10 KIRs ranged from 14.63% (KIR2DS3) to 95.93% (KIR3DL1). We found 27 distinct genotypes excluding KIR1D. The most frequent occurred in 63 individuals (51.22%). The linkage disequilibrium analysis signified 29 positive and 6 negative relations in 45 pairwise comparisons. To study population differentiation, we drew a Heatmap based on the data of KIRs from 59 populations and conducted Hierarchical Clustering by Euclidean distances. We next validated our results by estimating pairwise DA distances and illustrating a Neighbor-Joining tree, as well as a MDS plot covering 3 additional Chinese Han groups. The phylogenetic reconstruction and cluster analysis strongly indicated a genetically close relationship between Eastern and Jilin Hans. In conclusion, the present study provided a meritorious resource of KIR genotyping for population genetics, and could be helpful to uncover the genetic mechanism of KIRs in immune disease in the future. PMID:28205529

  16. Genetic polymorphism and evolutionary differentiation of Eastern Chinese Han: a comprehensive and comparative analysis on KIRs.

    Science.gov (United States)

    Yin, Caiyong; Hu, Li; Huang, Huijie; Yu, Yanfang; Li, Zheng; Ji, Qiang; Kong, Xiaochao; Wang, Zhongqun; Yan, Jinchuan; Yan, Jiangwei; Zhu, Bofeng; Chen, Feng

    2017-02-16

    Killer cell immunoglobulin-like receptor genes, namely KIRs, cluster together within the 160 kb genomic DNA region. In this study, we used PCR-SSP approach and successfully identified the genotype of 17 KIR genes in 123 independent healthy donors residing in the Jiangsu province, China. All individuals were positive at the 7 genes. The observed carrier gene frequencies (OFs) of remaining 10 KIRs ranged from 14.63% (KIR2DS3) to 95.93% (KIR3DL1). We found 27 distinct genotypes excluding KIR1D. The most frequent occurred in 63 individuals (51.22%). The linkage disequilibrium analysis signified 29 positive and 6 negative relations in 45 pairwise comparisons. To study population differentiation, we drew a Heatmap based on the data of KIRs from 59 populations and conducted Hierarchical Clustering by Euclidean distances. We next validated our results by estimating pairwise DA distances and illustrating a Neighbor-Joining tree, as well as a MDS plot covering 3 additional Chinese Han groups. The phylogenetic reconstruction and cluster analysis strongly indicated a genetically close relationship between Eastern and Jilin Hans. In conclusion, the present study provided a meritorious resource of KIR genotyping for population genetics, and could be helpful to uncover the genetic mechanism of KIRs in immune disease in the future.

  17. Genetic Diversity and Population Differentiation of Guignardia mangiferae from “Tahiti” Acid Lime

    Directory of Open Access Journals (Sweden)

    Ester Wickert

    2012-01-01

    Full Text Available Among the citrus plants, “Tahiti” acid lime is known as a host of G. mangiferae fungi. This species is considered endophytic for citrus plants and is easily isolated from asymptomatic fruits and leaves. G. mangiferae is genetically related and sometimes confused with G. citricarpa which causes Citrus Black Spot (CBS. “Tahiti” acid lime is one of the few species that means to be resistant to this disease because it does not present symptoms. Despite the fact that it is commonly found in citric plants, little is known about the populations of G. mangiferae associated with these plants. Hence, the objective of this work was to gain insights about the genetic diversity of the G. mangiferae populations that colonize “Tahiti” acid limes by sequencing cistron ITS1-5.8S-ITS2. It was verified that “Tahiti” acid lime plants are hosts of G. mangiferae and also of G. citricarpa, without presenting symptoms of CBS. Populations of G. mangiferae present low-to-moderate genetic diversity and show little-to-moderate levels of population differentiation. As gene flow was detected among the studied populations and they share haplotypes, it is possible that all populations, from citrus plants and also from the other known hosts of this fungus, belong to one great panmictic population.

  18. Six-year outcome of the national premarital screening and genetic counseling program for sickle cell disease and β-thalassemia in Saudi Arabia

    National Research Council Canada - National Science Library

    Memish, Ziad Ahmed; Saeedi, Mohammad Y

    2011-01-01

    Saudi Arabia has a high prevalence of hereditary hemoglobin disorders. Data has been collected by the Saudi Premarital Screening and Genetic Counseling Program on the prevalence of sickle cell disease and β...

  19. Pattern of genetic differentiation of an incipient speciation process: The case of the high Andean killifish Orestias

    Science.gov (United States)

    Guerrero-Jiménez, Claudia Jimena; Peña, Fabiola; Morales, Pamela; Méndez, Marco; Sallaberry, Michel; Vila, Irma; Poulin, Elie

    2017-01-01

    During the Pleistocene and Holocene, the southwest Andean Altiplano (17°-22°S) was affected by repeated fluctuations in water levels, high volcanic activity and major tectonic movements. In the early Holocene the humid Tauca phase shifted to the arid conditions that have lasted until the present, producing endorheic rivers, lakes, lagoons and wetlands. The endemic fish Orestias (Cyprinodontidae) represents a good model to observe the genetic differentiation that characterizes an incipient speciation process in allopatry since the morphospecies described inhabit a restricted geographic area, with present habitat fragmentation. The genetic diversity and population structure of four endemic morphospecies of Orestias (Cyprinodontidae) found in the Lauca National Park (LNP) analyzed with mitochondrial markers (Control Region) and eight microsatellites, revealed the existence of genetic groups that matches the fragmentation of these systems. High values of genetic and phylogeographic differentiation indices were observed between Chungará Lake and Piacota lagoon. The group composed of the Lauca River, Copapujo and Chuviri wetlands sampling sites showed a clear signal of expansion, with a star-like haplotype network. Levels of genetic differentiation were lower than in Chungará and Piacota, suggesting that these localities would have differentiated after the bottlenecks linked to the collapse of Parinacota volcano. The Parinacota sample showed a population signal that differed from the other localities revealing greater genetic diversity and a disperse network, presenting haplotypes shared with other LNP localities. A mixing pattern of the different genetic groups was evident using the microsatellite markers. The chronology of the vicariance events in LNP may indicate that the partition process of the Orestias populations was gradual. Considering this, and in view of the genetic results, we may conclude that the morphospecies from LNP are populations in ongoing

  20. Pattern of genetic differentiation of an incipient speciation process: The case of the high Andean killifish Orestias.

    Science.gov (United States)

    Guerrero-Jiménez, Claudia Jimena; Peña, Fabiola; Morales, Pamela; Méndez, Marco; Sallaberry, Michel; Vila, Irma; Poulin, Elie

    2017-01-01

    During the Pleistocene and Holocene, the southwest Andean Altiplano (17°-22°S) was affected by repeated fluctuations in water levels, high volcanic activity and major tectonic movements. In the early Holocene the humid Tauca phase shifted to the arid conditions that have lasted until the present, producing endorheic rivers, lakes, lagoons and wetlands. The endemic fish Orestias (Cyprinodontidae) represents a good model to observe the genetic differentiation that characterizes an incipient speciation process in allopatry since the morphospecies described inhabit a restricted geographic area, with present habitat fragmentation. The genetic diversity and population structure of four endemic morphospecies of Orestias (Cyprinodontidae) found in the Lauca National Park (LNP) analyzed with mitochondrial markers (Control Region) and eight microsatellites, revealed the existence of genetic groups that matches the fragmentation of these systems. High values of genetic and phylogeographic differentiation indices were observed between Chungará Lake and Piacota lagoon. The group composed of the Lauca River, Copapujo and Chuviri wetlands sampling sites showed a clear signal of expansion, with a star-like haplotype network. Levels of genetic differentiation were lower than in Chungará and Piacota, suggesting that these localities would have differentiated after the bottlenecks linked to the collapse of Parinacota volcano. The Parinacota sample showed a population signal that differed from the other localities revealing greater genetic diversity and a disperse network, presenting haplotypes shared with other LNP localities. A mixing pattern of the different genetic groups was evident using the microsatellite markers. The chronology of the vicariance events in LNP may indicate that the partition process of the Orestias populations was gradual. Considering this, and in view of the genetic results, we may conclude that the morphospecies from LNP are populations in ongoing

  1. The power to detect recent fragmentation events using genetic differentiation methods.

    Directory of Open Access Journals (Sweden)

    Michael W Lloyd

    Full Text Available Habitat loss and fragmentation are imminent threats to biological diversity worldwide and thus are fundamental issues in conservation biology. Increased isolation alone has been implicated as a driver of negative impacts in populations associated with fragmented landscapes. Genetic monitoring and the use of measures of genetic divergence have been proposed as means to detect changes in landscape connectivity. Our goal was to evaluate the sensitivity of Wright's F st, Hedrick' G'st , Sherwin's MI, and Jost's D to recent fragmentation events across a range of population sizes and sampling regimes. We constructed an individual-based model, which used a factorial design to compare effects of varying population size, presence or absence of overlapping generations, and presence or absence of population sub-structuring. Increases in population size, overlapping generations, and population sub-structuring each reduced F st, G'st , MI, and D. The signal of fragmentation was detected within two generations for all metrics. However, the magnitude of the change in each was small in all cases, and when N e was >100 individuals it was extremely small. Multi-generational sampling and population estimates are required to differentiate the signal of background divergence from changes in Fst , G'st , MI, and D associated with fragmentation. Finally, the window during which rapid change in Fst , G'st , MI, and D between generations occurs can be small, and if missed would lead to inconclusive results. For these reasons, use of F st, G'st , MI, or D for detecting and monitoring changes in connectivity is likely to prove difficult in real-world scenarios. We advocate use of genetic monitoring only in conjunction with estimates of actual movement among patches such that one could compare current movement with the genetic signature of past movement to determine there has been a change.

  2. Evolutionary concepts in ecotoxicology: tracing the genetic background of differential cadmium sensitivities in invertebrate lineages.

    Science.gov (United States)

    Dallinger, Reinhard; Höckner, Martina

    2013-07-01

    In many toxicological and ecotoxicological studies and experimental setups, the investigator is mainly interested in traditional parameters such as toxicity data and effects of toxicants on molecular, cellular or physiological functions of individuals, species or statistical populations. It is clear, however, that such approaches focus on the phenotype level of animal species, whilst the genetic and evolutionary background of reactions to environmental toxicants may remain untold. In ecotoxicological risk assessment, moreover, species sensitivities towards pollutants are often regarded as random variables in a statistical approach. Beyond statistics, however, toxicant sensitivity of every species assumes a biological significance, especially if we consider that sensitivity traits have developed in lineages of species with common evolutionary roots. In this article, the genetic and evolutionary background of differential Cd sensitivities among invertebrate populations and species and their potential of adaptation to environmental Cd exposure will be highlighted. Important evolutionary and population genetic concepts such as genome structure and their importance for evolutionary adaptation, population structure of affected individuals, as well as micro and macroevolutionary mechanisms of Cd resistance in invertebrate lineages will be stressed by discussing examples of work from our own laboratory along with a review of relevant literature data and a brief discussion of open questions along with some perspectives for further research. Both, differences and similarities in Cd sensitivity traits of related invertebrate species can only be understood if we consider the underlying evolutionary processes and genetic (or epigenetic) mechanisms. Keeping in mind this perception can help us to better understand and interpret more precisely why the sensitivity of some species or species groups towards a certain toxicant (or metal) may be ranked in the lower or higher range of

  3. Pre-marital screening for sickle cell haemoglobin and genetic counseling: awareness and acceptability among undergraduate students of a Nigerian University

    OpenAIRE

    Ugwu N.I.

    2016-01-01

    Background: Sickle cell disease (SCD) is a genetic disease which is more prevalent in developing countries. Pre-marital screening for sickle cell disorder is helpful in the prevention and control of the condition. Aim: The aim of this study was to assess the level of awareness and acceptability of premarital genetic counseling and screening for sickle cell haemoglobin among undergraduate students of Ebonyi State University Abakaliki, South eastern, Nigeria. Methods: A cross-sectio...

  4. Impact of human genome initiative-derived technology on genetic testing, screening and counseling: Cultural, ethical and legal issues

    Energy Technology Data Exchange (ETDEWEB)

    Trottier, R.W.; Hodgin, F.C.; Imara, M.; Phoenix, D.; Lybrook, S. (Morehouse Coll., Atlanta, GA (United States). School of Medicine); Crandall, L.A.; Moseley, R.E.; Armotrading, D. (Florida Univ., Gainesville, FL (United States). Coll. of Medicine)

    1993-01-01

    Genetic medical services provided by the Georgia Division of Public Health in two northern and two central districts are compared to services provided in a district in which a tertiary care facility is located. Genetics outreach public health nurses play key roles in Georgia's system of Children's Health Services Genetics Program, including significant roles as counselors and information sources on special needs social services and support organizations. Unique features of individual health districts, (e.g., the changing face of some rural communities in ethnocultural diversity and socioeconomic character), present new challenges to current and future genetics services delivery. Preparedness as to educational needs of both health professionals and the lay population is of foremost concern in light of the ever expanding knowledge and technology in medical genetics. Perspectives on genetics and an overview of services offered by a local private sector counselor are included for comparison to state supported services. The nature of the interactions which transpire between private and public genetic services resources in Georgia will be described. A special focus of this research includes issues associated with sickle cell disease newborn screening service delivery process in Georgia, with particular attention paid to patient follow-up and transition to primary care. Of particular interest to this focus is the problem of loss to follow-up in the current system. Critical factors in education and counseling of sickle cell patients and the expectations of expanding roles of primary care physicians are discussed. The Florida approach to the delivery of genetic services contrasts to the Georgia model by placing more emphasis on a consultant-specialist team approach.

  5. SYBR® Green qPCR Screening Methods for Detection of Anti-herbicide Genes in Genetically Modiifed Processed Products

    Institute of Scientific and Technical Information of China (English)

    Zhen Zhen; Lv Wei; Tang Zhi-fen; Liu Ying; Ao Jin-xia; Yuan Xiao-han; Zhang Ming-hui; Qiu You-wen; Gao Xue-jun

    2016-01-01

    The use of genetically modified organisms (GMOs) as food products becomes more and more widespread. The European Union has implemented a set of very strict procedures for the approval to grow, import and/or utilize GMOs as food or food ingredients. Thus, analytical methods for detection of GMOs are necessary in order to verify compliance with labelling requirements. There are few effective screening methods for processed GM (genetically modified) products. Three anti-herbicide genes (CP4-EPSPS,BAR andPAT) are common exogenous genes used in commercialized transgenic soybean, maize and rice. In the present study, a new SYBR® Green qPCR screening method was developed to simultaneously detect the three exogenous anti-herbicide genes and one endogenous gene in a run. We tested seven samples of representative processed products (soya lecithin, soya protein powder, chocolate beverage, infant rice cereal, maize protein powder, maize starch, and maize jam) using the developed method, and amplicons of endogenous gene and transgenic fragments were obtained from all the processed products, and the sensitivity was 0.1%. These results indicated that SYBR® Green qPCR screening method was appropriate for qualitative detection of transgenic soybean, maize and rice in processed products.

  6. Microsatellite DNA reveals population genetic differentiation among sprat (Sprattus sprattus) sampled throughout the Northeast Atlantic, including Norwegian fjords

    DEFF Research Database (Denmark)

    Glover, Kevin A.; Skaala, Øystein; Limborg, Morten;

    2011-01-01

    Glover, K. A., Skaala, Ø., Limborg, M., Kvamme, C., and Torstensen, E. Microsatellite DNA reveals population genetic differentiation among sprat (Sprattus sprattus) sampled throughout the Northeast Atlantic, including Norwegian fjords. – ICES Journal of Marine Science, 68: 2145–2151. Sprat...... (Sprattus sprattus), small pelagic shoaling fish, were sampled from the Celtic, North, and Baltic seas, and 10 Norwegian fjords. Significant overall genetic differentiation was observed among samples when analysed with eight microsatellite DNA loci (Global FST = 0.0065, p ... differences were observed between the Baltic and all other samples (largest pairwise FST = 0.043, p sample from the Celtic Sea (CEL) and the North Sea (NSEA; FST = 0.001, p = 0.16), but variable levels of genetic differentiation were...

  7. Individual Programming for Children with Learning Disabilities as Determined by Screening, Identification, and Differential Diagnosis.

    Science.gov (United States)

    Guyton, Gladys

    A program for screening, identifying, and diagnosing learning disabilities is described. The multidisciplinary approach is emphasized. The school psychologist or counselor, the coordinator of the language therapy program, the administrative staff, and the classroom teacher meet to share findings and impressions, and the information is synthesized…

  8. Two forward genetic screens for vein density mutants in sorghum converge on a cytochrome P450 gene in the brassinosteroid pathway.

    Science.gov (United States)

    Rizal, Govinda; Thakur, Vivek; Dionora, Jacqueline; Karki, Shanta; Wanchana, Samart; Acebron, Kelvin; Larazo, Nikki; Garcia, Richard; Mabilangan, Abigail; Montecillo, Florencia; Danila, Florence; Mogul, Reychelle; Pablico, Paquito; Leung, Hei; Langdale, Jane A; Sheehy, John; Kelly, Steven; Quick, William Paul

    2015-10-01

    The specification of vascular patterning in plants has interested plant biologists for many years. In the last decade a new context has emerged for this interest. Specifically, recent proposals to engineer C(4) traits into C(3) plants such as rice require an understanding of how the distinctive venation pattern in the leaves of C(4) plants is determined. High vein density with Kranz anatomy, whereby photosynthetic cells are arranged in encircling layers around vascular bundles, is one of the major traits that differentiate C(4) species from C(3) species. To identify genetic factors that specify C(4) leaf anatomy, we generated ethyl methanesulfonate- and γ-ray-mutagenized populations of the C(4) species sorghum (Sorghum bicolor), and screened for lines with reduced vein density. Two mutations were identified that conferred low vein density. Both mutations segregated in backcrossed F(2) populations as homozygous recessive alleles. Bulk segregant analysis using next-generation sequencing revealed that, in both cases, the mutant phenotype was associated with mutations in the CYP90D2 gene, which encodes an enzyme in the brassinosteroid biosynthesis pathway. Lack of complementation in allelism tests confirmed this result. These data indicate that the brassinosteroid pathway promotes high vein density in the sorghum leaf, and suggest that differences between C(4) and C(3) leaf anatomy may arise in part through differential activity of this pathway in the two leaf types.

  9. Genetic diversity and differentiation of sea trout (Salmo trutta) populations in Lithuanian rivers assessed by microsatellite DNA variation.

    Science.gov (United States)

    Samuiloviene, Aurelija; Kontautas, Antanas; Gross, Riho

    2009-11-01

    The genetic diversity and differentiation of sea trout were studied in three river basins in Lithuania: Akmena-Dane, Bartuva, and Nemunas. A total of 282 individuals were genotyped at eight microsatellite loci. A similar level of genetic diversity was found in all of the populations studied: mean allelic richness ranged from 3.64 to 5.03, and average expected heterozygosity ranged from 0.588 to 0.721. Significant genetic divergence was observed among the different river basins as well as between populations within the drainages. All pairwise F (ST) values were highly significant, ranging from 0.027 to 0.197. The analysis of molecular variance showed rather weak hierarchical population structuring within the Nemunas basin, which may be explained by extensive gene flow among different river basins or, alternatively, reflect the influence of artificial breeding. Information on genetic diversity and differentiation of the Lithuanian sea trout populations will be useful for future management decisions.

  10. Genetic differentiation induced by spaceflight treatment of Cistanche deserticola and identification of inter-simple sequence repeat markers associated with its medicinal constituent contents

    Science.gov (United States)

    Wu, Y.; Yang, D. Y.; Tu, P. F.; Tian, Y. Z.; Guo, Y. H.; Wang, X. M.; Li, X. B.

    2011-02-01

    The dried, fleshy stems of Cistanche deserticola (Orobanchaceae) are popular tonics in Traditional Chinese Medicine (TCM) to treat the inability of kidney in expelling extra fluid in the body, causing fluid retention, and reform reproductive system. However, the wild plants of C. deserticola have become endangered due to habitat downsizing and over-harvesting for its medicinal usages. The present research was carried out for the following purposes: (1) promoting the space-breeding research; (2) providing molecular evidence for agricultural selective breeding; and (3) protecting this endangered herbal medicine and conserving its genetic resources.In this study, plants were cultivated from seeds specifically treated in spaceflight for seven days, and sampled to screen positive mutants and identify ISSR markers associated with their medicinal constituents. As a result, nine out of the 94 ISSR primers were showed high polymorphism, and a total of 118 bands were generated, of which 80 were polymorphic, ranging from 250 to 2600 bp. The spaceflight mutants were found to have lower coefficient of gene differentiation (Gst = 0.0269), and higher gene flow (Nm = 18.0740) than those of the controls (Gst = 0.2067 and Nm = 1.9185). The results demonstrated that most of the genetic variation were harnessed within populations (>97%). The Analysis of Molecular Variance (AMOVA) revealed high genetic variation within populations (88.03%) and low genetic differentiation among regions (-18.83%) and populations (30.79%), respectively. The results also indicated a profound difference between spaceflight condition and that on the earth. The unique vacuum environment of spaceflight was suggested to induce DNA mutation and various variations of C. deserticola. In addition, six particular ISSR markers were identified, cloned and sequenced; one of them, CA41939-934, was found positively correlated with acteoside with correlation coefficient values of 0.264 (P molecular evidence for

  11. Investigating the viability of genetic screening/testing for RA susceptibility using combinations of five confirmed risk loci

    Science.gov (United States)

    McClure, Annie; Lunt, Mark; Eyre, Steve; Ke, Xiayi; Thomson, Wendy; Hinks, Anne; Bowes, John; Gibbons, Laura; Plant, Darren; Wilson, Anthony G.; Marinou, Ioanna; Morgan, Ann W.; Emery, Paul; Steer, Sophia; Hocking, Lynne J.; Reid, David M.; Wordsworth, Paul; Harrison, Pille; Worthington, Jane

    2009-01-01

    Objective. Five loci—the shared epitope (SE) of HLA-DRB1, the PTPN22 gene, a locus on 6q23, the STAT4 gene and a locus mapping to the TRAF1/C5 genetic region—have now been unequivocally confirmed as conferring susceptibility to RA. The largest single effect is conferred by SE. We hypothesized that combinations of susceptibility alleles may increase risk over and above that of any individual locus alone. Methods. We analysed data from 4238 RA cases and 1811 controls, for which genotypes were available at all five loci. Results. Statistical analysis identified eight high-risk combinations conferring an odds ratio >6 compared with carriage of no susceptibility variants and, interestingly, 10% population controls carried a combination conferring high risk. All high-risk combinations included SE, and all but one contained PTPN22. Statistical modelling showed that a model containing only these two loci could achieve comparable sensitivity and specificity to a model including all five. Furthermore, replacing SE (which requires full subtyping at the HLA-DRB1 gene) with DRB1*1/4/10 carriage resulted in little further loss of information (correlation coefficient between models = 0.93). Conclusions. This represents the first exploration of the viability of population screening for RA and identifies several high-risk genetic combinations. However, given the population incidence of RA, genetic screening based on these loci alone is neither sufficiently sensitive nor specific at the current time. PMID:19741008

  12. Maine Coon renal screening: ultrasonographical characterisation and preliminary genetic analysis for common genes in cats with renal cysts.

    Science.gov (United States)

    Gendron, Karine; Owczarek-Lipska, Marta; Lang, Johann; Leeb, Tosso

    2013-12-01

    The objective of this study was to assess the prevalence of renal cysts and other renal abnormalities in purebred Maine Coon cats, and to characterise these through genetic typing. Voluntary pre-breeding screening programmes for polycystic kidney disease (PKD) are offered for this breed throughout Switzerland, Germany and other northern European countries. We performed a retrospective evaluation of Maine Coon screening for renal disease at one institution over an 8-year period. Renal ultrasonography was performed in 187 healthy Maine Coon cats. Renal changes were observed in 27 of these cats. Renal cysts were found in seven cats, and were mostly single and unilateral (6/7, 85.7%), small (mean 3.6 mm) and located at the corticomedullary junction (4/6, 66.7%). Sonographical changes indicating chronic kidney disease (CKD) were observed in 10/187 (5.3%) cats and changes of unknown significance were documented in 11/187 (5.9%) cats. All six cats genetically tested for PKD1 were negative for the mutation, and gene sequencing of these cats did not demonstrate any common genetic sequences. Cystic renal disease occurs with a low prevalence in Maine Coons and is unrelated to the PKD observed in Persians and related breeds. Ultrasonographical findings compatible with CKD are not uncommon in juvenile Maine Coons.

  13. Quantitative genome-wide genetic interaction screens reveal global epistatic relationships of protein complexes in Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Mohan Babu

    2014-02-01

    Full Text Available Large-scale proteomic analyses in Escherichia coli have documented the composition and physical relationships of multiprotein complexes, but not their functional organization into biological pathways and processes. Conversely, genetic interaction (GI screens can provide insights into the biological role(s of individual gene and higher order associations. Combining the information from both approaches should elucidate how complexes and pathways intersect functionally at a systems level. However, such integrative analysis has been hindered due to the lack of relevant GI data. Here we present a systematic, unbiased, and quantitative synthetic genetic array screen in E. coli describing the genetic dependencies and functional cross-talk among over 600,000 digenic mutant combinations. Combining this epistasis information with putative functional modules derived from previous proteomic data and genomic context-based methods revealed unexpected associations, including new components required for the biogenesis of iron-sulphur and ribosome integrity, and the interplay between molecular chaperones and proteases. We find that functionally-linked genes co-conserved among γ-proteobacteria are far more likely to have correlated GI profiles than genes with divergent patterns of evolution. Overall, examining bacterial GIs in the context of protein complexes provides avenues for a deeper mechanistic understanding of core microbial systems.

  14. Assessing T lymphocyte function and differentiation by genetically encoded reporter systems.

    Science.gov (United States)

    Hoekstra, Mirjam E; Dijkgraaf, Feline E; Schumacher, Ton N; Rohr, Jan C

    2015-07-01

    Upon infection, antigen-specific T lymphocytes become activated, proliferate, differentiate, and acquire various effector functions. Much of our understanding of the molecular mechanisms underlying these processes derives from studies leveraging gene deletion, RNAi, and overexpression approaches. However, these perturbations do not inform on the regulation of gene activity under physiological conditions. Genetic reporter systems that couple biological events to detectable output signals are capable of providing this information. Here, we review the reporter approaches being currently used to investigate various aspects of T cell behavior, and discuss advantages and disadvantages inherent to different designs. We outline emerging applications based on recent advances in other fields, and highlight the potential of synthetic biology and genome engineering to address open questions in the field.

  15. Multi-object optimization design for differential and grading toothed roll crusher using a genetic algorithm

    Institute of Scientific and Technical Information of China (English)

    ZHAO La-la; WANG Zhong-bin; ZANG Feng

    2008-01-01

    Our differential and grading toothed roll crusher blends the advantages of a toothed roll crusher and a jaw crusher and possesses characteristics of great crushing, high breaking efficiency, multi-sieving and has, for the moment, made up for the shortcomings of the toothed roll crusher. The moving jaw of the crusher is a crank-rocker mechanism. For optimizing the dynamic performance and improving the cracking capability of the crusher, a mathematical model was established to optimize the transmission angle γ and to minimize the travel characteristic value m of the moving jaw. Genetic algorithm is used to optimize the crusher crank-rocker mechanism for multi-object design and an optimum result is obtained. According to the implementation, it is shown that the performance of the crusher and the cracking capability of the moving jaw have been improved.

  16. Cultural Concerns when Counseling Orthodox Jewish Couples for Genetic Screening and PGD.

    Science.gov (United States)

    Grazi, Richard V; Wolowelsky, Joel B

    2015-12-01

    There is a spectrum of attitudes within the Orthodox Jewish community towards genetic testing and PGD. Increased understanding of the belief systems of the Orthodox Jewish population will enhance the genetic counselors' ability to better serve this unique group of patients. By improving cultural competence, genetic counselors can help patients choose the testing options that they deem appropriate, while simultaneously respecting the patient's belief system.

  17. Global genetic differentiation in a cosmopolitan pest of stored beans: effects of geography, host-plant usage and anthropogenic factors.

    Directory of Open Access Journals (Sweden)

    Midori Tuda

    Full Text Available Genetic differentiation can be promoted allopatrically by geographic isolation of populations due to limited dispersal ability and diversification over time or sympatrically through, for example, host-race formation. In crop pests, the trading of crops across the world can lead to intermixing of genetically distinct pest populations. However, our understanding of the importance of allopatric and sympatric genetic differentiation in the face of anthropogenic genetic intermixing is limited. Here, we examined global sequence variation in two mitochondrial and one nuclear genes in the seed beetle Callosobruchus maculatus that uses different legumes as hosts. We analyzed 180 samples from 42 populations of this stored bean pest from tropical and subtropical continents and archipelagos: Africa, the Middle East, South and Southeast Asia, Oceania and South America. For the mitochondrial genes, there was weak but significant genetic differentiation across continents/archipelagos. Further, we found pronounced differentiation among subregions within continents/archipelagos both globally and within Africa but not within Asia. We suggest that multiple introductions into Asia and subsequent intermixing within Asia have generated this pattern. The isolation by distance hypothesis was supported globally (with or without continents controlled but not when host species was restricted to cowpeas Vigna unguiculata, the ancestral host of C. maculatus. We also document significant among-host differentiation both globally and within Asia, but not within Africa. We failed to reject a scenario of a constant population size in the recent past combined with selective neutrality for the mitochondrial genes. We conclude that mitochondrial DNA differentiation is primarily due to geographic isolation within Africa and to multiple invasions by different alleles, followed by host shifts, within Asia. The weak inter-continental differentiation is most likely due to frequent inter

  18. Global genetic differentiation in a cosmopolitan pest of stored beans: effects of geography, host-plant usage and anthropogenic factors.

    Science.gov (United States)

    Tuda, Midori; Kagoshima, Kumiko; Toquenaga, Yukihiko; Arnqvist, Göran

    2014-01-01

    Genetic differentiation can be promoted allopatrically by geographic isolation of populations due to limited dispersal ability and diversification over time or sympatrically through, for example, host-race formation. In crop pests, the trading of crops across the world can lead to intermixing of genetically distinct pest populations. However, our understanding of the importance of allopatric and sympatric genetic differentiation in the face of anthropogenic genetic intermixing is limited. Here, we examined global sequence variation in two mitochondrial and one nuclear genes in the seed beetle Callosobruchus maculatus that uses different legumes as hosts. We analyzed 180 samples from 42 populations of this stored bean pest from tropical and subtropical continents and archipelagos: Africa, the Middle East, South and Southeast Asia, Oceania and South America. For the mitochondrial genes, there was weak but significant genetic differentiation across continents/archipelagos. Further, we found pronounced differentiation among subregions within continents/archipelagos both globally and within Africa but not within Asia. We suggest that multiple introductions into Asia and subsequent intermixing within Asia have generated this pattern. The isolation by distance hypothesis was supported globally (with or without continents controlled) but not when host species was restricted to cowpeas Vigna unguiculata, the ancestral host of C. maculatus. We also document significant among-host differentiation both globally and within Asia, but not within Africa. We failed to reject a scenario of a constant population size in the recent past combined with selective neutrality for the mitochondrial genes. We conclude that mitochondrial DNA differentiation is primarily due to geographic isolation within Africa and to multiple invasions by different alleles, followed by host shifts, within Asia. The weak inter-continental differentiation is most likely due to frequent inter-continental gene

  19. Genetic screening for Krabbe disease: learning from the past and looking to the future.

    Science.gov (United States)

    Macarov, Michal; Zlotogora, Joel; Meiner, Vardiella; Khatib, Zinab; Sury, Vivi; Mengistu, Getu; Bargal, Ruth; Shmueli, Esther; Meidan, Bela; Zeigler, Marsha

    2011-03-01

    In Israel, Krabbe disease is frequent in two Moslem Arab villages in the Jerusalem area. In this paper we present our experience of almost four decades with diagnosis of Krabbe disease, carrier screening and prenatal diagnosis. The screening program is well accepted by the community, and there is a clear trend towards premarital testing. The screening program and prenatal diagnosis have led to a decrease in the incidence of Krabbe disease from 1.6 per 1,000 live births to 0.82 per 1,000. Copyright © 2011 Wiley-Liss, Inc.

  20. Vorinostat induces apoptosis and differentiation in myeloid malignancies: genetic and molecular mechanisms.

    Directory of Open Access Journals (Sweden)

    Gabriela Silva

    Full Text Available BACKGROUND: Aberrant epigenetic patterns are central in the pathogenesis of haematopoietic diseases such as myelodysplastic syndromes (MDS and acute myeloid leukaemia (AML. Vorinostat is a HDACi which has produced responses in these disorders. The purpose of this study was to address the functional effects of vorinostat in leukemic cell lines and primary AML and MDS myeloid cells and to dissect the genetic and molecular mechanisms by which it exerts its action. METHODOLOGY/PRINCIPAL FINDINGS: Functional assays showed vorinostat promoted cell cycle arrest, inhibited growth, and induced apoptosis and differentiation of K562, HL60 and THP-1 and of CD33(+ cells from AML and MDS patients. To explore the genetic mechanism for these effects, we quantified gene expression modulation by vorinostat in these cells. Vorinostat increased expression of genes down-regulated in MDS and/or AML (cFOS, COX2, IER3, p15, RAI3 and suppressed expression of genes over-expressed in these malignancies (AXL, c-MYC, Cyclin D1 and modulated cell cycle and apoptosis genes in a manner which would favor cell cycle arrest, differentiation, and apoptosis of neoplastic cells, consistent with the functional assays. Reporter assays showed transcriptional effect of vorinostat on some of these genes was mediated by proximal promoter elements in GC-rich regions. Vorinostat-modulated expression of some genes was potentiated by mithramycin A, a compound that interferes with SP1 binding to GC-rich DNA sequences, and siRNA-mediated SP1 reduction. ChIP assays revealed vorinostat inhibited DNA binding of SP1 to the proximal promoter regions of these genes. These results suggest vorinostat transcriptional action in some genes is regulated by proximal promoter GC-rich DNA sequences and by SP1. CONCLUSION: This study sheds light on the effects of vorinostat in AML and MDS and supports the implementation of clinical trials to explore the use of vorinostat in the treatment of these diseases.

  1. Newborn screening for lysosomal diseases: current status and potential interface with population medical genetics in Latin America.

    Science.gov (United States)

    Giugliani, Roberto

    2012-09-01

    The aim of newborn screening (NBS) programs is to detect a condition in a presymptomatic baby and provide management measures which could significantly improve the natural history of the disease. NBS programs for metabolic diseases were first introduced in North America and Europe and in the 1960s for phenylketonuria, expanded a few years later to include congenital hypothyroidism, and have been growing steadily in terms of number of conditions tested for and number of countries and births covered. Lysosomal storage diseases (LSDs) are a group of around 50 genetic conditions in which a defect in a lysosomal function occurs. LSDs are progressive conditions, being usually asymptomatic at birth, but with clinical features becoming apparent in childhood, with severe manifestations in most instances, high morbidity and shortened life span. Although individually rare, the prevalence of LSDs is significant when the group is considered as a whole (around 1:4,000-1:9,000 live births). Several management techniques, including bone marrow transplantation, enzyme replacement therapy, substrate inhibition therapy, pharmacological chaperones and many other approaches are transforming the LSDs into treatable conditions. However, lack of awareness and lack of access to tests cause a significant delay between onset of symptoms and diagnosis. Several lines of evidence showing that the earlier introduction of therapy may provide a better outcome, are bringing support to the idea of including LSDs in NBS programs. Due to advances in technology, high-throughput multiplex methods are now available for mass screening of several LSDs. Pilot projects were already developed in many countries for some LSDs, with interesting results. Although some NBS in Latin America has been carried out since the 1970s, it has so far been incorporated as a public health program in only a few countries in the region. It will probably take many years before NBS is implemented in most Latin American countries

  2. What drivers phenotypic divergence in Leymus chinensis (Poaceae) on large-scale gradient, climate or genetic differentiation?

    Science.gov (United States)

    Yuan, Shan; Ma, Linna; Guo, Chengyuan; Wang, Renzhong

    2016-05-01

    Elucidating the driving factors among-population divergence is an important task in evolutionary biology, however the relative contribution from natural selection and neutral genetic differentiation has been less debated. A manipulation experiment was conducted to examine whether the phenotypic divergence of Leymus chinensis depended on climate variations or genetic differentiations at 18 wild sites along a longitudinal gradient from 114 to 124°E in northeast China and at common garden condition of transplantation. Demographical, morphological and physiological phenotypes of 18 L. chinensis populations exhibited significant divergence along the gradient, but these divergent variations narrowed significantly at the transplantation. Moreover, most of the phenotypes were significantly correlated with mean annual precipitation and temperature in wild sites, suggesting that climatic variables played vital roles in phenotypic divergence of the species. Relative greater heterozygosity (HE), genotype evenness (E) and Shannon-Wiener diversity (I) in western group of populations suggested that genetic differentiation also drove phenotypic divergence of the species. However, neutral genetic differentiation (FST = 0.041) was greatly lower than quantitative differentiation (QST = 0.199), indicating that divergent selection/climate variable was the main factor in determining the phenotypic divergence of the species along the large-scale gradient.

  3. A Novel Frizzled-Based Screening Tool Identifies Genetic Modifiers of Planar Cell Polarity in Drosophila Wings

    Directory of Open Access Journals (Sweden)

    Jose Maria Carvajal-Gonzalez

    2016-12-01

    Full Text Available Most mutant alleles in the Fz-PCP pathway genes were discovered in classic Drosophila screens looking for recessive loss-of-function (LOF mutations. Nonetheless, although Fz-PCP signaling is sensitive to increased doses of PCP gene products, not many screens have been performed in the wing under genetically engineered Fz overexpression conditions, mostly because the Fz phenotypes were strong and/or not easy to score and quantify. Here, we present a screen based on an unexpected mild Frizzled gain-of-function (GOF phenotype. The leakiness of a chimeric Frizzled protein designed to be accumulated in the endoplasmic reticulum (ER generated a reproducible Frizzled GOF phenotype in Drosophila wings. Using this genotype, we first screened a genome-wide collection of large deficiencies and found 16 strongly interacting genomic regions. Next, we narrowed down seven of those regions to finally test 116 candidate genes. We were, thus, able to identify eight new loci with a potential function in the PCP context. We further analyzed and confirmed krasavietz and its interactor short-stop as new genes acting during planar cell polarity establishment with a function related to actin and microtubule dynamics.

  4. Practical experiences with an extended screening strategy for genetically modified organisms (GMOs) in real-life samples.

    Science.gov (United States)

    Scholtens, Ingrid; Laurensse, Emile; Molenaar, Bonnie; Zaaijer, Stephanie; Gaballo, Heidi; Boleij, Peter; Bak, Arno; Kok, Esther

    2013-09-25

    Nowadays most animal feed products imported into Europe have a GMO (genetically modified organism) label. This means that they contain European Union (EU)-authorized GMOs. For enforcement of these labeling requirements, it is necessary, with the rising number of EU-authorized GMOs, to perform an increasing number of analyses. In addition to this, it is necessary to test products for the potential presence of EU-unauthorized GMOs. Analysis for EU-authorized and -unauthorized GMOs in animal feed has thus become laborious and expensive. Initial screening steps may reduce the number of GMO identification methods that need to be applied, but with the increasing diversity also screening with GMO elements has become more complex. For the present study, the application of an informative detailed 24-element screening and subsequent identification strategy was applied in 50 animal feed samples. Almost all feed samples were labeled as containing GMO-derived materials. The main goal of the study was therefore to investigate if a detailed screening strategy would reduce the number of subsequent identification analyses. An additional goal was to test the samples in this way for the potential presence of EU-unauthorized GMOs. Finally, to test the robustness of the approach, eight of the samples were tested in a concise interlaboratory study. No significant differences were found between the results of the two laboratories.

  5. Genetic differentiation and genetic diversity of Castanopsis (Fagaceae), the dominant tree species in Japanese broadleaved evergreen forests, revealed by analysis of EST-associated microsatellites.

    Science.gov (United States)

    Aoki, Kyoko; Ueno, Saneyoshi; Kamijo, Takashi; Setoguchi, Hiroaki; Murakami, Noriaki; Kato, Makoto; Tsumura, Yoshihiko

    2014-01-01

    The broadleaved evergreen forests of the East Asian warm temperate zone are characterised by their high biodiversity and endemism, and there is therefore a need to extend our understanding of its genetic diversity and phylogeographic patterns. Castanopsis (Fagaceae) is one of the dominant tree species in the broadleaved evergreen forests of Japan. In this study we investigate the genetic diversity, genetic structure and leaf epidermal morphology of 63 natural populations of C. sieboldii and C. cuspidata, using 32 Expressed Sequence Tag associated microsatellites. The overall genetic differentiation between populations was low (GST = 0.069 in C. sieboldii and GST = 0.057 in C. cuspidata). Neighbor-joining tree and Bayesian clustering analyses revealed that the populations of C. sieboldii and C. cuspidata were genetically clearly differentiated, a result which is consistent with the morphology of their epidermal cell layers. This suggests that C. sieboldii and C. cuspidata should be treated as independent species, although intermediate morphologies are often observed, especially at sites where the two species coexist. The higher level of genetic diversity observed in the Kyushu region (for both species) and the Ryukyu Islands (for C. sieboldii) is consistent with the available fossil pollen data for Castanopsis-type broadleaved evergreen trees during the Last Glacial Maximum and suggests the existence of refugia for Castanopsis forests in southern Japan. Within the C. sieboldii populations, Bayesian clustering analyses detected three clusters, in the western and eastern parts of the main islands and in the Ryukyu Islands. The west-east genetic differentiation observed for this species in the main islands, a pattern which is also found in several plant and animal species inhabiting Castanopsis forests in Japan, suggests that they have been isolated from each other in the western and eastern populations for an extended period of time, and may imply the

  6. Screening Out Controversy: Human Genetics, Emerging Techniques of Diagnosis, and the Origins of the Social Issues Committee of the American Society of Human Genetics, 1964-1973.

    Science.gov (United States)

    Mitchell, M X

    2017-05-01

    In the years following World War II, and increasingly during the 1960s and 1970s, professional scientific societies developed internal sub-committees to address the social implications of their scientific expertise (Moore, Disrupting Science: Social Movements, American Scientists, and the Politics of the Military, 1945-1975. Princeton: Princeton University Press, 2008). This article explores the early years of one such committee, the American Society of Human Genetics' "Social Issues Committee," founded in 1967. Although the committee's name might suggest it was founded to increase the ASHG's public and policy engagement, exploration of the committee's early years reveals a more complicated reality. Affronted by legislators' recent unwillingness to seek the expert advice of human geneticists before adopting widespread neonatal screening programs for phenylketonuria (PKU), and feeling pressed to establish their relevance in an increasingly resource-scarce funding environment, committee members sought to increase the discipline's expert authority. Painfully aware of controversy over abortion rights and haunted by the taint of the discipline's eugenic past, however, the committee proceeded with great caution. Seeking to harness interest in and assert professional control over emerging techniques of genetic diagnosis, the committee strove to protect the society's image by relegating ethical and policy questions about their use to the individual consciences of member scientists. It was not until 1973, after the committee's modest success in organizing support for a retrospective public health study of PKU screening and following the legalization of abortion on demand, that the committee decided to take a more publicly engaged stance.

  7. Differential genetic susceptibility to child risk at birth in predicting observed maternal behavior.

    Directory of Open Access Journals (Sweden)

    Keren Fortuna

    Full Text Available This study examined parenting as a function of child medical risks at birth and parental genotype (dopamine D4 receptor; DRD4. Our hypothesis was that the relation between child risks and later maternal sensitivity would depend on the presence/absence of a genetic variant in the mothers, thus revealing a gene by environment interaction (GXE. Risk at birth was defined by combining risk indices of children's gestational age at birth, birth weight, and admission to the neonatal intensive care unit. The DRD4-III 7-repeat allele was chosen as a relevant genotype as it was recently shown to moderate the effect of environmental stress on parental sensitivity. Mothers of 104 twin pairs provided DNA samples and were observed with their children in a laboratory play session when the children were 3.5 years old. Results indicate that higher levels of risk at birth were associated with less sensitive parenting only among mothers carrying the 7-repeat allele, but not among mothers carrying shorter alleles. Moreover, mothers who are carriers of the 7-repeat allele and whose children scored low on the risk index were observed to have the highest levels of sensitivity. These findings provide evidence for the interactive effects of genes and environment (in this study, children born at higher risk on parenting, and are consistent with a genetic differential susceptibility model of parenting by demonstrating that some parents are inherently more susceptible to environmental influences, both good and bad, than are others.

  8. Establishing a diagnostic system for detecting Ralstonia solanacearum and genetic differentiation using RAPD molecular markers

    Directory of Open Access Journals (Sweden)

    Edisson Chavarro Mesa

    2007-02-01

    Full Text Available A polymerase chain reaction-based diagnostic test (PCR has been developed for amplifying a región and obtaining a 292 bp product by using specific 16S rDNA primers for the rapid and precise identification of the causative agent (Ralstonia solanacearum of bacterial withering of potato in asymptomatic tubers. The bacteria was isolated from potato tubers and banana fruit using culturing techniques and immunological and molecular ELISA-NCM and PCR tests, respectively. PCR detected the presence of R. solanacearum on asymptomatic tubers by contrast with ELISA-NCM which did not detect this pathogen. Analysing random amplified polymorphic DNA (RAPD led to differentiating and grouping R. solanacearum by geographical región and bacterial strain, suggesting that differences exist amongst existing collections according to their place of origin, presenting high genetic variability. The results showed that PCR is a sensitive and specific test for detecting R. solanacearum and can therefore be implemented as a method for controlling this pathogen in seed production and certification programmes in áreas free of the disease. The pathogen has been shown to be genetically heterogeneous according to the samples' geographical área thereby hampering control in áreas of Colombia experiencing phytosanitary problems with R. solanacearum in potato crops Key words: bacterial withered, moko, PCR-16S rADN, ELISA-NCM, PCR-RAPD.

  9. Indirect Evidence for Genetic Differentiation in Vulnerability to Embolism in Pinus halepensis.

    Science.gov (United States)

    David-Schwartz, Rakefet; Paudel, Indira; Mizrachi, Maayan; Delzon, Sylvain; Cochard, Hervé; Lukyanov, Victor; Badel, Eric; Capdeville, Gaelle; Shklar, Galina; Cohen, Shabtai

    2016-01-01

    Climate change is increasing mean temperatures and in the eastern Mediterranean is expected to decrease annual precipitation. The resulting increase in aridity may be too rapid for adaptation of tree species unless their gene pool already possesses variation in drought resistance. Vulnerability to embolism, estimated by the pressure inducing 50% loss of xylem hydraulic conductivity (P 50), is strongly associated with drought stress resistance in trees. Yet, previous studies on various tree species reported low intraspecific genetic variation for this trait, and therefore limited adaptive capacities to increasing aridity. Here we quantified differences in hydraulic efficiency (xylem hydraulic conductance) and safety (resistance to embolism) in four contrasting provenances of Pinus halepensis (Aleppo pine) in a provenance trial, which is indirect evidence for genetic differences. Results obtained with three techniques (bench dehydration, centrifugation and X-ray micro-CT) evidenced significant differentiation with similar ranking between provenances. Inter-provenance variation in P 50 correlated with pit anatomical properties (torus overlap and pit aperture size). These results suggest that adaptation of P. halepensis to xeric habitats has been accompanied by modifications of bordered pit function driven by variation in pit aperture. This study thus provides evidence that appropriate exploitation of provenance differences will allow continued forestry with P. halepensis in future climates of the Eastern Mediterranean.

  10. Indirect evidence for genetic differentiation in vulnerability to embolism in Pinus halepensis

    Directory of Open Access Journals (Sweden)

    Rakefet eDavid-Schwartz

    2016-06-01

    Full Text Available Climate change is increasing mean temperatures and in the eastern Mediterranean is expected to decrease annual precipitation. The resulting increase in aridity may be too rapid for adaptation of tree species unless their gene pool already possesses variation in drought resistance. Vulnerability to embolism, estimated by the pressure inducing 50% loss of xylem hydraulic conductivity (P50, is strongly associated with drought stress resistance in trees. Yet, previous studies on various tree species reported low intraspecific genetic variation for this trait, and therefore limited adaptive capacities to increasing aridity. Here we quantified differences in hydraulic efficiency (xylem hydraulic conductance and safety (resistance to embolism in four contrasting provenances of Pinus halepensis (Aleppo pine in a provenance trial, which is indirect evidence for genetic differences. Results obtained with three techniques (bench dehydration, centrifugation and X-ray micro-CT evidenced significant differentiation with similar ranking between provenances. Inter-provenance variation in P50 correlated with pit anatomical properties (torus overlap and pit aperture size. These results suggest that adaptation of P. halepensis to xeric habitats has been accompanied by modifications of bordered pit function driven by variation in pit aperture. This study thus provides evidence that appropriate exploitation of provenance differences will allow continued forestry with P. halepensis in future climates of the Eastern Mediterranean.

  11. Genetic differentiation of charcoal rot pathogen, Macrophomina phaseolina, into specific groups using URP-PCR.

    Science.gov (United States)

    Jana, T K; Singh, N K; Koundal, K R; Sharma, T R

    2005-02-01

    Forty isolates of Macrophomina phaseolina, a pathogen causing charcoal dry root rot of soybean, cotton, and chickpea, were genetically characterized with universal rice primers (URP; primers derived from DNA repeat sequences in the rice genome) using polymerase chain reaction (URP-PCR). Out of 12 URPs used in this study, 5 primers were effective in producing polymorphic fingerprint patterns from the DNA of M. phaseolina isolates. Three primers (URP-2F, URP-6R, and URP-30F) were quite informative and produced high levels of polymorphism among the isolates of M. phaseolina. Analysis of the entire fingerprint profiles using unweighted pair-group method with arithmetic averages (UPGMA) clearly differentiated M. phaseolina isolates obtained from soybean, cotton, and chickpea hosts into specific groups. In this study, we found for the first time transferability and use of PCR primers derived from plant genomes to generate host-specific fingerprint profiles of M. phaseolina, a broad host range plant pathogenic fungus. These results demonstrate that URPs are sensitive and technically simple to use for assaying genetic variability in M. phaseolina populations.

  12. Genetic engineering of Trypanosoma (Dutonella vivax and in vitro differentiation under axenic conditions.

    Directory of Open Access Journals (Sweden)

    Simon D'Archivio

    2011-12-01

    Full Text Available Trypanosoma vivax is one of the most common parasites responsible for animal trypanosomosis, and although this disease is widespread in Africa and Latin America, very few studies have been conducted on the parasite's biology. This is in part due to the fact that no reproducible experimental methods had been developed to maintain the different evolutive forms of this trypanosome under laboratory conditions. Appropriate protocols were developed in the 1990s for the axenic maintenance of three major animal Trypanosoma species: T. b. brucei, T. congolense and T. vivax. These pioneer studies rapidly led to the successful genetic manipulation of T. b. brucei and T. congolense. Advances were made in the understanding of these parasites' biology and virulence, and new drug targets were identified. By contrast, challenging in vitro conditions have been developed for T. vivax in the past, and this per se has contributed to defer both its genetic manipulation and subsequent gene function studies. Here we report on the optimization of non-infective T. vivax epimastigote axenic cultures and on the process of parasite in vitro differentiation into metacyclic infective forms. We have also constructed the first T. vivax specific expression vector that drives constitutive expression of the luciferase reporter gene. This vector was then used to establish and optimize epimastigote transfection. We then developed highly reproducible conditions that can be used to obtain and select stably transfected mutants that continue metacyclogenesis and are infectious in immunocompetent rodents.

  13. CD24: from a Hematopoietic Differentiation Antigen to a Genetic Risk Factor for Multiple Autoimmune Diseases.

    Science.gov (United States)

    Tan, Yixin; Zhao, Ming; Xiang, Bo; Chang, Christopher; Lu, Qianjin

    2016-02-01

    The autoantibody is an essential characteristic of inflammatory disorders, including autoimmune diseases. Although the exact pathogenic mechanisms of these diseases remain elusive, accumulated evidence has implicated that genetic factors play important roles in autoimmune inflammation. Among these factors, CD24 was first identified as a heat-stable antigen in 1978 and first successfully cloned in 1990. Thereafter, its functional roles have been intensively investigated in various human diseases, especially autoimmune diseases and cancers. It is currently known that CD24 serves as a costimulatory factor of T cells that regulate their homeostasis and proliferation, while in B cells, CD24 is functionally involved in cell activation and differentiation. CD24 can enhance autoimmune diseases in terms of its protective role in the clonal deletion of autoreactive thymocytes. Furthermore, CD24 deficiency has been linked to mouse experimental autoimmune encephalomyelitis. Finally, CD24 genetic variants, including single-nucleotide polymorphisms and deletions, are etiologically relevant to autoimmune diseases, such as multiple sclerosis and systemic lupus erythematosus. Therefore, CD24 is a promising biomarker and novel therapeutic target for autoimmune diseases.

  14. Breeding system, colony structure, and genetic differentiation in the Camponotus festinatus species complex of carpenter ants.

    Science.gov (United States)

    Goodisman, Michael A D; Hahn, Daniel A

    2005-10-01

    All social insects live in highly organized societies. However, different social insect species display striking variation in social structure. This variation can significantly affect the genetic structure within populations and, consequently, the divergence between species. The purpose of this study was to determine if variation in social structure was associated with species diversification in the Camponotus festinatus desert carpenter ant species complex. We used polymorphic DNA microsatellite markers to dissect the breeding system of these ants and to determine if distinct C. festinatus forms hybridized in their natural range. Our analysis of single-queen colonies established in the laboratory revealed that queens typically mated with only a single male. The genotypes of workers sampled from a field population suggested that multiple, related queens occasionally reproduced within colonies and that colonies inhabited multiple nests. Camponotus festinatus workers derived from colonies of the same form originating at different locales were strongly differentiated, suggesting that gene flow was geographically restricted. Overall, our data indicate that C. festinatus populations are highly structured. Distinct C. festinatus forms possess similar social systems but are genetically isolated. Consequently, our data suggest that diversification in the C. festinatus species complex is not necessarily associated with a shift in social structure.

  15. Strong genetic differentiation but not local adaptation toward the range limit of a coastal dune plant.

    Science.gov (United States)

    Samis, Karen E; López-Villalobos, Adriana; Eckert, Christopher G

    2016-11-01

    All species have limited geographic distributions; but the ecological and evolutionary mechanisms causing range limits are largely unknown. That many species' geographic range limits are coincident with niche limits suggests limited evolutionary potential of marginal populations to adapt to conditions experienced beyond the range. We provide a test of range limit theory by combining population genetic analysis of microsatellite polymorphisms with a transplant experiment within, at the edge of, and 60 km beyond the northern range of a coastal dune plant. Contrary to expectations, lifetime fitness increased toward the range limit with highest fitness achieved by most populations at and beyond the range edge. Genetic differentiation among populations was strong, with very low, nondirectional gene flow suggesting range limitation via constraints to dispersal. In contrast, however, local adaptation was negligible, and a distance-dependent decline in fitness only occurred for those populations furthest from home when planted beyond the range limit. These results challenge a commonly held assumption that stable range limits match niche limits, but also raise questions about the unique value of peripheral populations in expanding species' geographical ranges.

  16. Inference of selection based on temporal genetic differentiation in the study of highly polymorphic multigene families.

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    Mark McMullan

    Full Text Available The co-evolutionary arms race between host immune genes and parasite virulence genes is known as Red Queen dynamics. Temporal fluctuations in allele frequencies, or the 'turnover' of alleles at immune genes, are concordant with predictions of the Red Queen hypothesis. Such observations are often taken as evidence of host-parasite co-evolution. Here, we use computer simulations of the Major Histocompatibility Complex (MHC of guppies (Poecilia reticulata to study the turnover rate of alleles (temporal genetic differentiation, G'(ST. Temporal fluctuations in MHC allele frequencies can be ≥≤order of magnitude larger than changes observed at neutral loci. Although such large fluctuations in the MHC are consistent with Red Queen dynamics, simulations show that other demographic and population genetic processes can account for this observation, these include: (1 overdominant selection, (2 fluctuating population size within a metapopulation, and (3 the number of novel MHC alleles introduced by immigrants when there are multiple duplicated genes. Synergy between these forces combined with migration rate and the effective population size can drive the rapid turnover in MHC alleles. We posit that rapid allelic turnover is an inherent property of highly polymorphic multigene families and that it cannot be taken as evidence of Red Queen dynamics. Furthermore, combining temporal samples in spatial F(ST outlier analysis may obscure the signal of selection.

  17. Genetic diversity and differentiation of Pinus sylvestris L. from the IUFRO 1982 provenance trial revealed by AFLP analysis

    Directory of Open Access Journals (Sweden)

    Androsiuk Piotr

    2015-01-01

    Full Text Available DNA markers have become effective tools in genetic diversity studies of forest trees. However, molecular marker analyses are associated with laborious and costly effort. One of the possibilities to overcome these constraints is to analyze bulked samples per population, rather than individual plants. We have used bulked DNA-based AFLP analysis to investigate genetic variations in Pinus sylvestris L. (Scots pine from the IUFRO 1982 provenance trial in Kórnik (western Poland. Four AFLP primer combinations yielded a total of 309 bands, of which 208 (67.31% were polymorphic. Thirty-six (11.65% unique alleles were deployed randomly among the populations. Estimated genetic diversity and differentiation was high, as expressed by He = 0.238 and I = 0.356, and by genetic distance values which ranged from 0.154 to 0.363. A geographic pattern of interpopulation differentiation was observed, pointing to the individual character of populations from northeastern Europe. In the light of available data, we discuss the influence of historical migration routes, gene flow and human activity on observed genetic diversity and differentiation of Scots pine in Europe. Our results indicate that the AFLP method applied to DNA templates extracted from bulked leaf samples provides an efficient approach to elucidate genetic diversity and relationships among Scots pine populations.

  18. Genetic differentiation across multiple spatial scales of the Red Sea of the corals Stylophora pistillata and Pocillopora verrucosa

    KAUST Repository

    Monroe, Alison

    2015-12-01

    Observing populations at different spatial scales gives greater insight into the specific processes driving genetic differentiation and population structure. Here we determined population connectivity across multiple spatial scales in the Red Sea to determine the population structures of two reef building corals Stylophora pistillata and Pocillopora verrucosa. The Red sea is a 2,250 km long body of water with extremely variable latitudinal environmental gradients. Mitochondrial and microsatellite markers were used to determine distinct lineages and to look for genetic differentiation among sampling sites. No distinctive population structure across the latitudinal gradient was discovered within this study suggesting a phenotypic plasticity of both these species to various environments. Stylophora pistillata displayed a heterogeneous distribution of three distinct genetic populations on both a fine and large scale. Fst, Gst, and Dest were all significant (p-value<0.05) and showed moderate genetic differentiation between all sampling sites. However this seems to be byproduct of the heterogeneous distribution, as no distinct genetic population breaks were found. Stylophora pistillata showed greater population structure on a fine scale suggesting genetic selection based on fine scale environmental variations. However, further environmental and oceanographic data is needed to make more inferences on this structure at small spatial scales. This study highlights the deficits of knowledge of both the Red Sea and coral plasticity in regards to local environmental conditions.

  19. Bulinus globosus (Planorbidae; Gastropoda) populations in the Lake Victoria basin and coastal Kenya show extreme nuclear genetic differentiation.

    Science.gov (United States)

    Nyakaana, Silvester; Stothard, J Russell; Nalugwa, Allen; Webster, Bonnie L; Lange, Charles N; Jørgensen, Aslak; Rollinson, David; Kristensen, Thomas K

    2013-11-01

    Bulinus globosus, a key intermediate host for Schistosoma haematobium that causes urinary schistosomiasis, is a hermaphroditic freshwater Planorbid snail species that inhabits patchy and transient water bodies prone to large seasonal variations in water availability. Although capable of self-fertilizing, this species has been reported to be preferentially out crossing. In this study, we characterized the population genetic structure of 19 B. globosus populations sampled across the Lake Victoria basin and coastal Kenya using four polymorphic microsatellite loci. Population genetic structure was characterized and quantified using FST statistics and Bayesian clustering algorithms. The four loci used in this study contained sufficient statistical power to detect low levels of population genetic differentiation and were highly polymorphic with the number of alleles per locus across populations ranging from 16 to 22. Average observed and expected heterozygosities across loci in each population ranged from 0.13 to 0.69 and from 0.39 to 0.79, respectively. Twenty-five of the seventy-six possible population-locus comparisons significantly deviated from Hardy-Weinberg equilibrium proportions after Bonferroni corrections, mostly due to the deficiency of heterozygotes. Significant genetic differentiation was observed between populations and Bayesian inferences identified 15 genetic clusters. The excess homozygosity, significant inbreeding and population genetic differentiation observed in B. globosus populations are likely to be due to the habitat patchiness, mating system and the proneness to cyclic extinction and recolonization in transient habitats.

  20. Genetic evidence for differential selection of grain and embryo weight during wheat evolution under domestication.

    Science.gov (United States)

    Golan, Guy; Oksenberg, Adi; Peleg, Zvi

    2015-09-01

    Wheat is one of the Neolithic founder crops domesticated ~10 500 years ago. Following the domestication episode, its evolution under domestication has resulted in various genetic modifications. Grain weight, embryo weight, and the interaction between those factors were examined among domesticated durum wheat and its direct progenitor, wild emmer wheat. Experimental data show that grain weight has increased over the course of wheat evolution without any parallel change in embryo weight, resulting in a significantly reduced (30%) embryo weight/grain weight ratio in domesticated wheat. The genetic factors associated with these modifications were further investigated using a population of recombinant inbred substitution lines that segregated for chromosome 2A. A cluster of loci affecting grain weight and shape was identified on the long arm of chromosome 2AL. Interestingly, a novel locus controlling embryo weight was mapped on chromosome 2AS, on which the wild emmer allele promotes heavier embryos and greater seedling vigour. To the best of our knowledge, this is the first report of a QTL for embryo weight in wheat. The results suggest a differential selection of grain and embryo weight during the evolution of domesticated wheat. It is argued that conscious selection by early farmers favouring larger grains and smaller embryos appears to have resulted in a significant change in endosperm weight/embryo weight ratio in the domesticated wheat. Exposing the genetic factors associated with endosperm and embryo size improves our understanding of the evolutionary dynamics of wheat under domestication and is likely to be useful for future wheat-breeding efforts.

  1. Genetic differentiation and species cohesion in two widespread Central American Begonia species.

    Science.gov (United States)

    Twyford, A D; Kidner, C A; Ennos, R A

    2014-04-01

    Begonia is one of the ten largest plant genera, with over 1500 species. This high species richness may in part be explained by weak species cohesion, which has allowed speciation by divergence in allopatry. In this study, we investigate species cohesion in the widespread Central American Begonia heracleifolia and Begonia nelumbiifolia, by genotyping populations at microsatellite loci. We then test for post-zygotic reproductive barriers using experimental crosses, and assess whether sterility barriers are related to intraspecific changes in genome size, indicating major genome restructuring between isolated populations. Strong population substructure was found for B. heracleifolia (FST=0.364, F'ST=0.506) and B. nelumbiifolia (FST=0.277, F'ST=0.439), and Bayesian admixture analysis supports the division of most populations into discrete genetic clusters. Moderate levels of inferred selfing (B. heracleifolia s=0.40, B. nelumbiifolia s=0.62) and dispersal limitation are likely to have contributed to significant genetic differentiation (B. heracleifolia Jost's D=0.274; B. nelumbiifolia D=0.294). Interpopulation crosses involving a divergent B. heracleifolia population with a genome size ∼10% larger than the species mean had a ∼20% reduction in pollen viability compared with other outcrosses, supporting reproductive isolation being polymorphic within the species. The population genetic data suggest that Begonia populations are only weakly connected by gene flow, allowing reproductive barriers to accumulate between the most isolated populations. This supports allopatric divergence in situ being the precursor of speciation in Begonia, and may also be a common speciation mechanism in other tropical herbaceous plant groups.

  2. The genetic differentiation of Colocasia esculenta growing in gold mining areas with arsenic contamination.

    Science.gov (United States)

    Boonmee, Sirilak; Neeratanaphan, Lamyai; Tanee, Tawatchai; Khamon, Prodpran

    2015-05-01

    Arsenic is a heavy metal found in contaminated gold mining areas and which can affect plant and animal species. This study aims to determine the concentration of As in the aquatic plant Colocasia esculenta as well as this plant's genetic variability. Sediment and C. esculenta samples were collected from three studied sites at the edge of a stream around a gold mine. The arsenic concentrations in sediment and C. esculenta samples were analyzed using induction coupled plasma-mass spectrometry (ICP-MS). Genetic differentiations were studied by random amplified polymorphic DNA (RAPD) with dendrogram construction and analysis of genetic similarity (S). The results showed that the arsenic concentrations in sediment and C. esculenta samples ranged from 4.547 ± 0.318 to 229.964 ± 0.978 and 0.108 ± 0.046 to 0.406 ± 0.174 mg kg(-1), respectively. To compare the samples studied to the reference site, RAPD fingerprints from 26 primers successfully produced 2301 total bands used for dendrogram construction and S value analysis. The dendrogram construction separates C. esculenta into four clusters corresponding to their sampling sites. The S values of the studied sample sites compared to the reference site are 0.676-0.779, 0.739-0.791, and 0.743-0.783 for sites 1, 2, and 3, respectively, whereas the values of the individuals within each site are as high as 0.980. These results suggest that As accumulation in aquatic plant species should be of concern because of the potential effects of As on aquatic plants as well as humans.

  3. Amplified fragment length polymorphism: an adept technique for genome mapping, genetic differentiation, and intraspecific variation in protozoan parasites.

    Science.gov (United States)

    Kumar, Awanish; Misra, Pragya; Dube, Anuradha

    2013-02-01

    With the advent of polymerase chain reaction (PCR), genetic markers are now accessible for all organisms, including parasites. Amplified fragment length polymorphism (AFLP) is a PCR-based marker for the rapid screening of genetic diversity and intraspecific variation. It is a potent fingerprinting technique for genomic DNAs of any origin or complexity and rapidly generates a number of highly replicable markers that allow high-resolution genotyping. AFLPs are convenient and reliable in comparison to other markers like random amplified polymorphic DNA, restriction fragment length polymorphism, and simple sequence repeat in terms of time and cost efficiency, reproducibility, and resolution as it does not require template DNA sequencing. In addition, AFLP essentially probes the entire genome at random, without prior sequence knowledge. So, AFLP markers have emerged as an advance type of genetic marker with broad application in genomic mapping, population genetics, and DNA fingerprinting and are ideally suited as screening tool for molecular markers linked with biological and clinical traits. This review describes the AFLP procedure and its applications and overview in the fingerprinting of a genome, which has been currently used in parasite genome research. We outline the AFLP procedure adapted for Leishmania genome study and discuss the benefits of AFLPs for assessing genetic variation and genome mapping over other existing molecular techniques. We highlight the possible use of AFLPs as genetic markers with its broad application in parasitological research because it allows random screening of the entire genome for linkage with genetic and clinical properties of the parasite. In this review, we have taken a pragmatic approach on the study of AFLP for genome mapping and polymorphism in protozoan parasites and conclude that AFLP is a very useful tool.

  4. [The significance of pedigree genetic screening and rapid immunological parameters in the diagnosis of primary hemophagocytic lymphohistiocytosis].

    Science.gov (United States)

    Zhang, J; Wang, Y N; Wang, J S; Wu, L; Wei, N; Fu, L; Gao, Z; Chen, J H; Pei, R J; Wang, Z

    2016-07-01

    To investigate the significance of pedigree genetic screening and rapid immunological parameters in the diagnosis of primary hemophagocytic lymphohistiocytosis (HLH). Four cases of primary HLH patients with PRF1, UNC13D and SH2D1A gene mutations were conducted pedigree investigation, including family genetic screening and detections of immunological parameters (NK cell activity, CD107a degranulation and expression of HLH related defective protein), to evaluate the significance of these different indicators in the diagnosis of primary HLH and explore their correlations. The DNA mutations of the four families included missense mutation c.T172C (p.S58P) and non- frameshift deletions c.1083_1094del (p.361_365del), missense mutation c.C1349T (p.T450M) and frameshift mutation c.1090_1091delCT (p.T364fsX93) in PRF1 gene, missense mutation c.G2588A (p.G863D) in UNC13D gene and hemizygous mutation c.32T>G (p.I11S) in SH2D1A gene. The patients and their family members presented decreased NK cell activities. Individuals who carried mutations of PRF1 gene and SH2D1A gene showed low expression of perforin (PRF1) and signaling lymphocytic activation molecule associated protein (SAP). And the patient with UNC13D gene mutation and his family member with identical mutation showed significant reducing cytotoxic degranulation function (expression of CD107a). Pedigree genetic screening and rapid detection of immunological parameters might play an important role in the diagnosis of primary HLH, and both of them had good consistency. As an efficient detection means, the rapid immunological detection indicators would provide reliable basis for the early diagnosis of the primary HLH.

  5. A genetic analysis of intersex, a gene regulating sexual differentiation in Drosophila melanogaster females

    Energy Technology Data Exchange (ETDEWEB)

    Chase, B.A. [Stanford Univ., CA (United States)]|[Univ. of Nebraska, Omaha, NE (United States); Baker, B.S. [Stanford Univ., CA (United States)

    1995-04-01

    Sex-type in Drosophila melanogaster is controlled by a hierarchically acting set of regulatory genes. At the terminus of this hierarchy lie those regulatory genes responsible for implementing sexual differentiation: genes that control the activity of target loci whose products give rise to sexually dimorphic phenotypes. The genetic analysis of the intersex (ix) gene presented here demonstrates that ix is such a terminally positioned regulatory locus. The ix locus has been localized to the cytogenetic interval between 47E3-6 and 47F11-18. A comparison of the morphological and behavioral phenotypes of homozygotes and hemizygotes for three point mutations at ix indicates that the null phenotypes of homozygotes diplo-X animals into intersexes while leaving haplo-X animals unaffected. Analysis of X-ray induced, mitotic recombination clones lacking ix{sup +} function in the abdomen of diplo-X individuals indicates that the ix{sup +} product functions in a cell-autonomous manner and that it is required at least until the termination of cell division in this tissue. Taken together with previous analyses, our results indicate that the ix{sup +} product is required to function with the female-specific product of doublesex to implement appropriate female sexual differentiation in diplo-X animals. 55 refs., 4 figs., 4 tabs.

  6. Host plant use drives genetic differentiation in syntopic populations of Maculinea alcon

    Directory of Open Access Journals (Sweden)

    András Tartally

    2016-03-01

    Full Text Available The rare socially parasitic butterfly Maculinea alcon occurs in two forms, which are characteristic of hygric or xeric habitats and which exploit different host plants and host ants. The status of these two forms has been the subject of considerable controversy. Populations of the two forms are usually spatially distinct, but at Răscruci in Romania both forms occur on the same site (syntopically. We examined the genetic differentiation between the two forms using eight microsatellite markers, and compared with a nearby hygric site, Şardu. Our results showed that while the two forms are strongly differentiated at Răscruci, it is the xeric form there that is most similar to the hygric form at Şardu, and Bayesian clustering algorithms suggest that these two populations have exchanged genes relatively recently. We found strong evidence for population substructuring, caused by high within host ant nest relatedness, indicating very limited dispersal of most ovipositing females, but not association with particular host ant species. Our results are consistent with the results of larger scale phylogeographic studies that suggest that the two forms represent local ecotypes specialising on different host plants, each with a distinct flowering phenology, providing a temporal rather than spatial barrier to gene flow.

  7. Psychopathic personality traits and environmental contexts: Differential correlates, gender differences, and genetic mediation.

    Science.gov (United States)

    Hicks, Brian M; Carlson, Marie D; Blonigen, Daniel M; Patrick, Christopher J; Iacono, William G; Mgue, Matt

    2012-07-01

    Theorists have speculated that primary psychopathy (or Factor 1 affective-interpersonal features) is prominently heritable whereas secondary psychopathy (or Factor 2 social deviance) is more environmentally determined. We tested this differential heritability hypothesis using a large adolescent twin sample. Trait-based proxies of primary and secondary psychopathic tendencies were assessed using Multidimensional Personality Questionnaire (MPQ) estimates of Fearless Dominance and Impulsive Antisociality, respectively. The environmental contexts of family, school, peers, and stressful life events were assessed using multiple raters and methods. Consistent with prior research, MPQ Impulsive Antisociality was robustly associated with each environmental risk factor, and these associations were significantly greater than those for MPQ Fearless Dominance. However, MPQ Fearless Dominance and Impulsive Antisociality exhibited similar heritability, and genetic effects mediated the associations between MPQ Impulsive Antisociality and the environmental measures. Results were largely consistent across male and female twins. We conclude that gene-environment correlations rather than main effects of genes and environments account for the differential environmental correlates of primary and secondary psychopathy.

  8. [Establishment of a human laryngeal carcinoma Hep-2/5-Fu cell line and the screening of differentially expressed genes].

    Science.gov (United States)

    Chen, Jie; Wang, Jiadong

    2012-12-01

    To establish a Hep-2/5-Fu of human drug-resistant laryngeal carcinoma cell line, and to screen the possible drug resistance-associated genes. Hep-2/5-Fu of a human drug resistant laryngeal carcinoma cell line was induced by continuously exposing human laryngeal carcinoma cells to gradually increasing concentrations of 5-Fu. The growth law was observed and the growth curve was protracted. The drug resistance of Hep-2/5-Fu was measured by MTT assay and the drug resistant index RI was calculated. Genes expressed differentially between Hep-2/5-Fu and its parent cell line Hep-2 were screened using a gene chip, and several selected drug resistance associated genes were confirmed by reverse transcription-polymerase chain reaction (RT-PCR). Compared with its parental cells, the drug resistance cell line had slower growth rate and larger size. The Hep-2/5-Fu cell line showed cross drug resistance to 5-Fu, cisplatin and vincristine. There were 1210 differentially expressed genes possibly associated with drug resistance by the gene chip screening method. The possible drug resistance-related genes included Cyclin D, IGF-BP3, CASP9, and CDK4/6. The expression of Cyclin D in the Hep-2/5-Fu cell line was 6.5997 times of that in the parent cell line. RT-PCR results were consistent with the gene chip results. The altered biological properties of Hep-2/5-Fu may be related to its drug resistance phenotype. Several genes, such as Cyclin D, are possibly involved in the mechanism of drug resistance in this cell line.

  9. Low genetic differentiation across three major ocean populations of the whale shark, Rhincodon typus.

    Directory of Open Access Journals (Sweden)

    Jennifer V Schmidt

    Full Text Available BACKGROUND: Whale sharks are a declining species for which little biological data is available. While these animals are protected in many parts of their range, they are fished legally and illegally in some countries. Baseline biological and ecological data are needed to allow the formulation of an effective conservation plan for whale sharks. It is not known, for example, whether the whale shark is represented by a single worldwide panmictic population or by numerous, reproductively isolated populations. Genetic analysis of population structure is one essential component of the baseline data required for whale shark conservation. METHODOLOGY/PRINCIPAL FINDINGS: We have identified 8 polymorphic microsatellites in the whale shark and used these markers to assess genetic variation and population structure in a panel of whale sharks covering a broad geographic region. This is the first record of microsatellite loci in the whale shark, which displayed an average of 9 alleles per locus and mean H(o = 0.66 and H(e = 0.69. All but one of the eight loci meet the expectations of Hardy-Weinberg equilibrium. Analysis of these loci in whale sharks representing three major portions of their range, the Pacific (P, Caribbean (C, and Indian (I Oceans, determined that there is little population differentiation between animals sampled in different geographic regions, indicating historical gene flow between populations. F(ST values for inter-ocean comparisons were low (PxC = 0.0387, CxI = 0.0296 and PxI = -0.0022, and only CxI approached statistical significance (p = 0.0495. CONCLUSIONS/SIGNIFICANCE: We have shown only low levels of genetic differentiation between geographically distinct whale shark populations. Existing satellite tracking data have revealed both regional and long-range migration of whale sharks throughout their range, which supports the finding of gene flow between populations. Whale sharks traverse geographic and political boundaries during their

  10. Microbioreactor arrays for full factorial screening of exogenous and paracrine factors in human embryonic stem cell differentiation.

    Directory of Open Access Journals (Sweden)

    Drew M Titmarsh

    Full Text Available Timed exposure of pluripotent stem cell cultures to exogenous molecules is widely used to drive differentiation towards desired cell lineages. However, screening differentiation conditions in conventional static cultures can become impractical in large parameter spaces, and is intrinsically limited by poor spatiotemporal control of the microenvironment that also makes it impossible to determine whether exogenous factors act directly or through paracrine-dependent mechanisms. We detail here the development of a continuous flow microbioreactor array platform that combines full-factorial multiplexing of input factors with progressive accumulation of paracrine factors through serially-connected culture chambers, and further, the use of this system to explore the combinatorial parameter space of both exogenous and paracrine factors involved in human embryonic stem cell (hESC differentiation to a MIXL1-GFP(+ primitive streak-like population. We show that well known inducers of primitive streak (BMP, Activin and Wnt signals do not simply act directly on hESC to induce MIXL1 expression, but that this requires accumulation of surplus, endogenous factors; and, that conditioned medium or FGF-2 supplementation is able to offset this. Our approach further reveals the presence of a paracrine, negative feedback loop to the MIXL1-GFP(+ population, which can be overcome with GSK-3β inhibitors (BIO or CHIR99021, implicating secreted Wnt inhibitory signals such as DKKs and sFRPs as candidate effectors. Importantly, modulating paracrine effects identified in microbioreactor arrays by supplementing FGF-2 and CHIR in conventional static culture vessels resulted in improved differentiation outcomes. We therefore demonstrate that this microbioreactor array platform uniquely enables the identification and decoding of complex soluble factor signalling hierarchies, and that this not only challenges prevailing strategies for extrinsic control of hESC differentiation, but

  11. Microbioreactor arrays for full factorial screening of exogenous and paracrine factors in human embryonic stem cell differentiation.

    Science.gov (United States)

    Titmarsh, Drew M; Hudson, James E; Hidalgo, Alejandro; Elefanty, Andrew G; Stanley, Edouard G; Wolvetang, Ernst J; Cooper-White, Justin J

    2012-01-01

    Timed exposure of pluripotent stem cell cultures to exogenous molecules is widely used to drive differentiation towards desired cell lineages. However, screening differentiation conditions in conventional static cultures can become impractical in large parameter spaces, and is intrinsically limited by poor spatiotemporal control of the microenvironment that also makes it impossible to determine whether exogenous factors act directly or through paracrine-dependent mechanisms. We detail here the development of a continuous flow microbioreactor array platform that combines full-factorial multiplexing of input factors with progressive accumulation of paracrine factors through serially-connected culture chambers, and further, the use of this system to explore the combinatorial parameter space of both exogenous and paracrine factors involved in human embryonic stem cell (hESC) differentiation to a MIXL1-GFP(+) primitive streak-like population. We show that well known inducers of primitive streak (BMP, Activin and Wnt signals) do not simply act directly on hESC to induce MIXL1 expression, but that this requires accumulation of surplus, endogenous factors; and, that conditioned medium or FGF-2 supplementation is able to offset this. Our approach further reveals the presence of a paracrine, negative feedback loop to the MIXL1-GFP(+) population, which can be overcome with GSK-3β inhibitors (BIO or CHIR99021), implicating secreted Wnt inhibitory signals such as DKKs and sFRPs as candidate effectors. Importantly, modulating paracrine effects identified in microbioreactor arrays by supplementing FGF-2 and CHIR in conventional static culture vessels resulted in improved differentiation outcomes. We therefore demonstrate that this microbioreactor array platform uniquely enables the identification and decoding of complex soluble factor signalling hierarchies, and that this not only challenges prevailing strategies for extrinsic control of hESC differentiation, but also is

  12. Adaptive genetic variability and differentiation of Croatian and Austrian Quercus robur L. populations at a drought prone field trial

    Directory of Open Access Journals (Sweden)

    Saša Bogdan

    2017-07-01

    Full Text Available Provenance trials, where populations of different geographical origin are tested in a common environment (common garden test, are a tool suited to allow the study of intraspecific adaptive genetic variation. Research of pedunculate oak (Quercus robur L. adaptive genetic variability through analyses of populations in common garden tests has a long tradition. However, pedunculated oak populations originating south-eastern from the Alps have been scarcely studied in this way. This study addresses the adaptive genetic variability and differentiation of pedunculate oak populations originating from Austria and Croatia in a provenance/progeny field trial. Studied plants were six years old and were growing at the trial for three years. After two years of unusually low precipitations height and survival were analysed. The total mean height of all plants in the trial was 137.8 cm and ranged from 123.0 cm to 151.8 cm. The overall mean survival rate was rather high (0.85. Mean population survival ranged from 0.64 to 0.94. Individual narrow-sense heritabilities (hi2, family mean heritabilities (hf2, the coefficients of additive genetic variation (CVA and quantitative genetic differentiation coefficients (QST were calculated. A multivariate regression tree (MRT analysis was used to determine the pattern of genetic differentiation of the populations. Individual heritabilities for height ranged between 0.00 and 0.39. Family mean heritabilities for height were rather low in most populations as well (<0.5. Family mean heritabilities for survival were higher than for height (ranging between 0.00 and 0.77. Calculated QST coefficients (0.25 for height and 0.14 for survival indicated between-population genetic differentiation. The populations were separated into two clusters by MRT analysis regarding a climatic variable, namely Hargreaves’ reference evapotranspiration. Populations originating from comparatively more humid habitats were grouped in the first

  13. Greater Genetic Diversity in Spatially Restricted Coral Reef Fishes Suggests Secondary Contact among Differentiated Lineages

    Directory of Open Access Journals (Sweden)

    M. Julian Caley

    2011-09-01

    Full Text Available The maintenance of genetic diversity is a central goal of conservation. It is the raw material for evolutionary change and if lost, can accelerate extinction of species. According to theory, total genetic diversity should be less in species with restricted ranges and in populations on the margins of distributional ranges, making such species or populations more vulnerable to environmental perturbations. Using mtDNA and nuclear Inter Simple Sequence Repeat (ISSR data we investigated how the genetic diversity and structure of three con-generic species pairs of coral reef fishes (Pomacentridae was related to species’ range size and position of populations within these ranges. Estimates of genetic structure did not differ significantly among species, but mtDNA and nucDNA genetic diversities were up to 10 times greater in spatially restricted species compared to their widespread congeners. In two of the three species pairs, the distribution of genetic variation indicated secondary contact among differentiated lineages in the spatially restricted species. In contrast, the widespread species displayed a typical signature of population expansion suggesting recent genetic bottlenecks, possibly associated with the (re colonization of the Great Barrier Reef. These results indicate that historical processes, involving hybridization and founder effects, possibly associated with Pleistocene sea level fluctuations, have differentially influenced the widespread and spatially restricted coral reef damselfish species studied here.

  14. A genome-wide RNAi screen reveals MAP kinase phosphatases as key ERK pathway regulators during embryonic stem cell differentiation.

    Directory of Open Access Journals (Sweden)

    Shen-Hsi Yang

    Full Text Available Embryonic stem cells and induced pluripotent stem cells represent potentially important therapeutic agents in regenerative medicine. Complex interlinked transcriptional and signaling networks control the fate of these cells towards maintenance of pluripotency or differentiation. In this study we have focused on how mouse embryonic stem cells begin to differentiate and lose pluripotency and, in particular, the role that the ERK MAP kinase and GSK3 signaling pathways play in this process. Through a genome-wide siRNA screen we have identified more than 400 genes involved in loss of pluripotency and promoting the onset of differentiation. These genes were functionally associated with the ERK and/or GSK3 pathways, providing an important resource for studying the roles of these pathways in controlling escape from the pluripotent ground state. More detailed analysis identified MAP kinase phosphatases as a focal point of regulation and demonstrated an important role for these enzymes in controlling ERK activation kinetics and subsequently determining early embryonic stem cell fate decisions.

  15. Identification of differentially expressed genes in esophageal cancer through SSH in com- bination with high throughput reverse Northern screening

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    To understand the molecular mechanisms of carcinogenesis of esophagus and to isolate genes with different expression levels in esophageal cancer, suppression subtractive hybridization (SSH) was combined with PCR-based cDNA synthesis and reverse Northern on the cancer tissues and matched almost normal mucosa using 5 microgram of total RNA as starting marterial. Eight genes were found expressed differentially in esophageal cancer, in which 5 were known genes and 3 were novel ones; and 6 were down-regulated in cancer tissues, while 2 were up-regulated; 6 were of mid-high abundance and 2 were of low abundance in esophagus. The results revealed that alteration in expression level of multiple genes underlied the initiation and development of esophageal cancer. The differentially expressed genes identified in this study such as liporcotinⅠ, cystatin A, cystatin B, cytokeratin 13 may play roles in dedifferentiation, transformation and malignant proliferation of esophageal cancer. The combination of SSH with PCR-based double- strand cDNA synthesis and high throughput reverse Northern screening is an efficient way to isolate differentially expressed genes from microgram of total RNA.

  16. Screening of Cytotoxic B. cereus on Differentiated Caco-2 Cells and in Co-Culture with Mucus-Secreting (HT29-MTX) Cells.

    Science.gov (United States)

    Castiaux, Virginie; Laloux, Laurie; Schneider, Yves-Jacques; Mahillon, Jacques

    2016-11-05

    B. cereus is an opportunistic foodborne pathogen able to cause diarrhoea. However, the diarrhoeal potential of a B. cereus strain remains difficult to predict, because no simple correlation has yet been identified between the symptoms and a unique or a specific combination of virulence factors. In this study, 70 B. cereus strains with different origins (food poisonings, foods and environment) have been selected to assess their enterotoxicity. The B. cereus cell-free supernatants have been tested for their toxicity in vitro, on differentiated (21 day-old) Caco-2 cells, using their ATP content, LDH release and NR accumulation. The genetic determinants of the main potential enterotoxins and virulence factors (ces, cytK, entFM, entS, hbl, nhe, nprA, piplC and sph) have also been screened by PCR. This analysis showed that none of these genes was able to fully explain the enterotoxicity of B. cereus strains. Additionally, in order to assess a possible effect of the mucus layer in vitro, a cytotoxicity comparison between a monoculture (Caco-2 cells) and a co-culture (Caco-2 and HT29-MTX mucus-secreting cells) model has been performed with selected B. cereus supernatants. It appeared that, in these conditions, the mucus layer had no notable influence on the cytotoxicity of B. cereus supernatants.

  17. High acceptance of an early dyslexia screening test involving genetic analyses in Germany

    National Research Council Canada - National Science Library

    Wilcke, Arndt; Müller, Bent; Schaadt, Gesa; Kirsten, Holger; Boltze, Johannes

    2016-01-01

    ... the end of the 2nd grade, resulting in the loss of several years for early therapy. Currently, research is focusing on the development of early tests for dyslexia, which may be based on EEG and genetics...

  18. Genetic differentiation in Gammarus fossarum and G. caparti (Crustacea, Amphipoda) with reference to G. pulex pulex in northwestern Europe

    NARCIS (Netherlands)

    Scheepmaker, Maarten; Dalfsen, van Jan

    1989-01-01

    Genetic differentiation among G. fossarum Koch, 1835 from different stations in Germany, Switzerland, Belgium and northern France, and the closely related Belgian form G. caparti Pètre-Stroobants, 1980 was investigated by electrophoresis at 20 enzyme loci. Although morphologically variable,

  19. Genetic differentiation, origin and dispersal of Gammarus gauthieri from the Iberian peninsula and North Africa (Crustacea, Amphipoda)

    NARCIS (Netherlands)

    Scheepmaker, Maarten

    1990-01-01

    Genetic differentiation among population samples of G. gauthieri on both sides of the Strait of Gibraltar was investigated by enzyme electrophoresis at 20 enzyme loci with reference to G. gauthieri and G. ibericus from different areas in the Iberian peninsula. Levels of divergence resolved suggest t

  20. Decoding directional genetic dependencies through orthogonal CRISPR/Cas screens | Office of Cancer Genomics

    Science.gov (United States)

    Genetic interaction studies are a powerful approach to identify functional interactions between genes. This approach can reveal networks of regulatory hubs and connect uncharacterized genes to well-studied pathways. However, this approach has previously been limited to simple gene inactivation studies. Here, we present an orthogonal CRISPR/Cas-mediated genetic interaction approach that allows the systematic activation of one gene while simultaneously knocking out a second gene in the same cell.

  1. Genetic differentiation and recombination among geographic populations of the fungal pathogen Colletotrichum truncatum from chili peppers in China.

    Science.gov (United States)

    Diao, Yongzhao; Zhang, Can; Xu, Jianping; Lin, Dong; Liu, Li; Mtung'e, Olivo G; Liu, Xili

    2015-01-01

    Colletotrichum truncatum is an extremely important fungal pathogen. It can cause diseases both in humans and in over 460 plant species. However, little is known about its genetic diversity within and among populations. One of the major plant hosts of C. truncatum is pepper, and China is one of the main pepper-producing countries in the world. Here, we propose the hypotheses that geography has a major influence on the relationships among populations of C. truncatum in China and that infections in different populations need to be managed differently. To test these hypotheses, we obtained and analyzed 266 C. truncatum isolates from 13 regions representing the main pepper-growing areas throughout China. The analysis based on nine microsatellite markers identified high intrapopulation genetic diversity, evidence of sexual recombination, and geographic differentiation. The genetic differentiation was positively correlated with geographic distance, with the southern and northern China populations grouped in two distinct clusters. Interestingly, isolates collected from the pepper-breeding center harbored the most private alleles. The results suggest that the geographic populations of C. truncatum on peppers in China are genetically differentiated and should be managed accordingly. Our study also provides a solid foundation from which to further explore the global genetic epidemiology of C. truncatum in both plants and humans.

  2. Gene variation and genetic differentiation among populations of the solitary mud dauber wasp Trypoxylon (Trypargilum albitarse Fabricius 1804 (Hymenoptera, Crabronidae

    Directory of Open Access Journals (Sweden)

    Antonio C.B. Bergamaschi

    2015-01-01

    Full Text Available Abstract Trypoxylon is a genus of solitary crabronid wasps whose population genetics is poorly known. The purpose of the present study was to investigate the genetic variation and differentiation among five populations of Trypoxylon albitarse, a species widely distributed throughout the Neotropics, with records from Panama to northern Argentina. Eight species-specific microsatellite loci were used for genotyping 96 adult wasps (one female per nest sampled at five sites in Brazil. The analysis of allelic richness and private alleles indicated high genetic diversity in the populations sampled. Pairwise comparisons using the Fst and Dest indices revealed significant differentiation for all, but one pair of populations. Fst, Dest, AMOVA and assignment test values pointed to inter-population differentiation. Additionally, the analysis of population structure using Bayesian and PCA methods characterized two alternative genetic groups. The Mantel test indicated no correlation between genetic and geographic distances. Despite evidence of considerable dispersal capacity for T. albitarse, the data indicate low to moderate population structuring in this species.

  3. Scale-dependent effects of a heterogeneous landscape on genetic differentiation in the Central American squirrel monkey (Saimiri oerstedii).

    Science.gov (United States)

    Blair, Mary E; Melnick, Don J

    2012-01-01

    Landscape genetic studies offer a fine-scale understanding of how habitat heterogeneity influences population genetic structure. We examined population genetic structure and conducted a landscape genetic analysis for the endangered Central American Squirrel Monkey (Saimiri oerstedii) that lives in the fragmented, human-modified habitats of the Central Pacific region of Costa Rica. We analyzed non-invasively collected fecal samples from 244 individuals from 14 groups for 16 microsatellite markers. We found two geographically separate genetic clusters in the Central Pacific region with evidence of recent gene flow among them. We also found significant differentiation among groups of S. o. citrinellus using pairwise F(ST) comparisons. These groups are in fragments of secondary forest separated by unsuitable "matrix" habitats such as cattle pasture, commercial African oil palm plantations, and human residential areas. We used an individual-based landscape genetic approach to measure spatial patterns of genetic variance while taking into account landscape heterogeneity. We found that large, commercial oil palm plantations represent moderate barriers to gene flow between populations, but cattle pastures, rivers, and residential areas do not. However, the influence of oil palm plantations on genetic variance was diminished when we restricted analyses to within population pairs, suggesting that their effect is scale-dependent and manifests during longer dispersal events among populations. We show that when landscape genetic methods are applied rigorously and at the right scale, they are sensitive enough to track population processes even in species with long, overlapping generations such as primates. Thus landscape genetic approaches are extremely valuable for the conservation management of a diverse array of endangered species in heterogeneous, human-modified habitats. Our results also stress the importance of explicitly considering the heterogeneity of matrix habitats in

  4. Scale-dependent effects of a heterogeneous landscape on genetic differentiation in the Central American squirrel monkey (Saimiri oerstedii.

    Directory of Open Access Journals (Sweden)

    Mary E Blair

    Full Text Available Landscape genetic studies offer a fine-scale understanding of how habitat heterogeneity influences population genetic structure. We examined population genetic structure and conducted a landscape genetic analysis for the endangered Central American Squirrel Monkey (Saimiri oerstedii that lives in the fragmented, human-modified habitats of the Central Pacific region of Costa Rica. We analyzed non-invasively collected fecal samples from 244 individuals from 14 groups for 16 microsatellite markers. We found two geographically separate genetic clusters in the Central Pacific region with evidence of recent gene flow among them. We also found significant differentiation among groups of S. o. citrinellus using pairwise F(ST comparisons. These groups are in fragments of secondary forest separated by unsuitable "matrix" habitats such as cattle pasture, commercial African oil palm plantations, and human residential areas. We used an individual-based landscape genetic approach to measure spatial patterns of genetic variance while taking into account landscape heterogeneity. We found that large, commercial oil palm plantations represent moderate barriers to gene flow between populations, but cattle pastures, rivers, and residential areas do not. However, the influence of oil palm plantations on genetic variance was diminished when we restricted analyses to within population pairs, suggesting that their effect is scale-dependent and manifests during longer dispersal events among populations. We show that when landscape genetic methods are applied rigorously and at the right scale, they are sensitive enough to track population processes even in species with long, overlapping generations such as primates. Thus landscape genetic approaches are extremely valuable for the conservation management of a diverse array of endangered species in heterogeneous, human-modified habitats. Our results also stress the importance of explicitly considering the heterogeneity of

  5. Characterization of new bacterial catabolic genes and mobile genetic elements by high throughput genetic screening of a soil metagenomic library.

    Science.gov (United States)

    Jacquiod, Samuel; Demanèche, Sandrine; Franqueville, Laure; Ausec, Luka; Xu, Zhuofei; Delmont, Tom O; Dunon, Vincent; Cagnon, Christine; Mandic-Mulec, Ines; Vogel, Timothy M; Simonet, Pascal

    2014-11-20

    A mix of oligonucleotide probes was used to hybridize soil metagenomic DNA from a fosmid clone library spotted on high density membranes. The pooled radio-labeled probes were designed to target genes encoding glycoside hydrolases GH18, dehalogenases, bacterial laccases and mobile genetic elements (integrases from integrons and insertion sequences). Positive hybridizing spots were affiliated to the corresponding clones in the library and the metagenomic inserts were sequenced. After assembly and annotation, new coding DNA sequences related to genes of interest were identified with low protein similarity against the closest hits in databases. This work highlights the sensitivity of DNA/DNA hybridization techniques as an effective and complementary way to recover novel genes from large metagenomic clone libraries. This study also supports that some of the identified catabolic genes might be associated with horizontal transfer events.

  6. RNA sequencing of Sleeping Beauty transposon-induced tumors detects transposon-RNA fusions in forward genetic cancer screens

    Science.gov (United States)

    Temiz, Nuri A.; Moriarity, Branden S.; Wolf, Natalie K.; Riordan, Jesse D.; Dupuy, Adam J.; Largaespada, David A.; Sarver, Aaron L.

    2016-01-01

    Forward genetic screens using Sleeping Beauty (SB)-mobilized T2/Onc transposons have been used to identify common insertion sites (CISs) associated with tumor formation. Recurrent sites of transposon insertion are commonly identified using ligation-mediated PCR (LM-PCR). Here, we use RNA sequencing (RNA-seq) data to directly identify transcriptional events mediated by T2/Onc. Surprisingly, the majority (∼80%) of LM-PCR identified junction fragments do not lead to observable changes in RNA transcripts. However, in CIS regions, direct transcriptional effects of transposon insertions are observed. We developed an automated method to systematically identify T2/Onc-genome RNA fusion sequences in RNA-seq data. RNA fusion-based CISs were identified corresponding to both DNA-based CISs (Cdkn2a, Mycl1, Nf2, Pten, Sema6d, and Rere) and additional regions strongly associated with cancer that were not observed by LM-PCR (Myc, Akt1, Pth, Csf1r, Fgfr2, Wisp1, Map3k5, and Map4k3). In addition to calculating recurrent CISs, we also present complementary methods to identify potential driver events via determination of strongly supported fusions and fusions with large transcript level changes in the absence of multitumor recurrence. These methods independently identify CIS regions and also point to cancer-associated genes like Braf. We anticipate RNA-seq analyses of tumors from forward genetic screens will become an efficient tool to identify causal events. PMID:26553456

  7. RNA sequencing of Sleeping Beauty transposon-induced tumors detects transposon-RNA fusions in forward genetic cancer screens.

    Science.gov (United States)

    Temiz, Nuri A; Moriarity, Branden S; Wolf, Natalie K; Riordan, Jesse D; Dupuy, Adam J; Largaespada, David A; Sarver, Aaron L

    2016-01-01

    Forward genetic screens using Sleeping Beauty (SB)-mobilized T2/Onc transposons have been used to identify common insertion sites (CISs) associated with tumor formation. Recurrent sites of transposon insertion are commonly identified using ligation-mediated PCR (LM-PCR). Here, we use RNA sequencing (RNA-seq) data to directly identify transcriptional events mediated by T2/Onc. Surprisingly, the majority (∼80%) of LM-PCR identified junction fragments do not lead to observable changes in RNA transcripts. However, in CIS regions, direct transcriptional effects of transposon insertions are observed. We developed an automated method to systematically identify T2/Onc-genome RNA fusion sequences in RNA-seq data. RNA fusion-based CISs were identified corresponding to both DNA-based CISs (Cdkn2a, Mycl1, Nf2, Pten, Sema6d, and Rere) and additional regions strongly associated with cancer that were not observed by LM-PCR (Myc, Akt1, Pth, Csf1r, Fgfr2, Wisp1, Map3k5, and Map4k3). In addition to calculating recurrent CISs, we also present complementary methods to identify potential driver events via determination of strongly supported fusions and fusions with large transcript level changes in the absence of multitumor recurrence. These methods independently identify CIS regions and also point to cancer-associated genes like Braf. We anticipate RNA-seq analyses of tumors from forward genetic screens will become an efficient tool to identify causal events.

  8. Screening of CACNA1A and ATP1A2 genes in hemiplegic migraine: clinical, genetic, and functional studies

    Science.gov (United States)

    Carreño, Oriel; Corominas, Roser; Serra, Selma Angèlica; Sintas, Cèlia; Fernández-Castillo, Noèlia; Vila-Pueyo, Marta; Toma, Claudio; Gené, Gemma G; Pons, Roser; Llaneza, Miguel; Sobrido, María-Jesús; Grinberg, Daniel; Valverde, Miguel Ángel; Fernández-Fernández, José Manuel; Macaya, Alfons; Cormand, Bru

    2013-01-01

    Hemiplegic migraine (HM) is a rare and severe subtype of autosomal dominant migraine, characterized by a complex aura including some degree of motor weakness. Mutations in four genes (CACNA1A, ATP1A2, SCN1A and PRRT2) have been detected in familial and in sporadic cases. This genetically and clinically heterogeneous disorder is often accompanied by permanent ataxia, epileptic seizures, mental retardation, and chronic progressive cerebellar atrophy. Here we report a mutation screening in the CACNA1A and ATP1A2 genes in 18 patients with HM. Furthermore, intragenic copy number variant (CNV) analysis was performed in CACNA1A using quantitative approaches. We identified four previously described missense CACNA1A mutations (p.Ser218Leu, p.Thr501Met, p.Arg583Gln, and p.Thr666Met) and two missense changes in the ATP1A2 gene, the previously described p.Ala606Thr and the novel variant p.Glu825Lys. No structural variants were found. This genetic screening allowed the identification of more than 30% of the disease alleles, all present in a heterozygous state. Functional consequences of the CACNA1A-p.Thr501Met mutation, previously described only in association with episodic ataxia, and ATP1A2-p.Glu825Lys, were investigated by means of electrophysiological studies, cell viability assays or Western blot analysis. Our data suggest that both these variants are disease-causing. PMID:24498617

  9. Pre-implantation genetic screening using fluorescence in situ hybridization in couples of Indian ethnicity: Is there a scope?

    Directory of Open Access Journals (Sweden)

    Shailaja Gada Saxena

    2014-01-01

    Full Text Available Context: There is a high incidence of numerical chromosomal aberration in couples with repeated in vitro fertilization (IVF failure, advanced maternal age, repeated unexplained abortions, severe male factor infertility and unexplained infertility. Pre-implantation genetic screening (PGS, a variant of pre-implantation genetic diagnosis, screens numerical chromosomal aberrations in couples with normal karyotype, experiencing poor reproductive outcome. The present study includes the results of the initial pilot study on 9 couples who underwent 10 PGS cycles. Aim: The aim of the present study was to evaluate the beneficial effects of PGS in couples with poor reproductive outcome. Settings and Design: Data of initial 9 couples who underwent 10 PGS for various indications was evaluated. Subjects and Methods: Blastomere biopsy was performed on cleavage stage embryos and subjected to two round fluorescence in situ hybridization (FISH testing for chromosomes 13, 18, 21, X and Y as a two-step procedure. Results: Six of the 9 couples (10 PGS cycles conceived, including a twin pregnancy in a couple with male factor infertility, singleton pregnancies in a couple with secondary infertility, in three couples with adverse obstetric outcome in earlier pregnancies and in one couple with repeated IVF failure. Conclusion: In the absence of availability of array-comparative genomic hybridization in diagnostic clinical scenario for PGS and promising results with FISH based PGS as evident from the current pilot study, it is imperative to offer the best available services in the present scenario for better pregnancy outcome for patients.

  10. [Microsatellite data verify low genetic differentiation between western and eastern subspecies of the common crane Grusgrus L. (Gruidae, Aves)].

    Science.gov (United States)

    Mudrik, E A; Kashentseva, T A; Redchuk, P S; Politov, D V

    2015-01-01

    Using a set of 10 microsatellite loci (Gram-22, Gram-30, Gpa-12, Gpa-38, Gpa-39, Gj-M15, Gj-M34, Gj-4066, Gj-8077, Gj-2298) a high level of genetic variability (N(A) = 10.2, H(O) = = 0.684, H(E) = 0.728) and low genetic differentiation (F(ST) = 0.011) in the Common crane (Grus grus L.) was detected throughout its range. Genetic diversity in disputed western (G. g. grus) and eastern (G. g. lilfordi) sub- species was shown to be similar. Spatial distribution of multi-locus individual genotypes has not been revealed (R(XY) = 0.017). Despite low differentiation, subspecies and local populations of the Common crane should be considered as separate conservational units. Organization of programs for gene pool conservation and monitor- ing requires more detailed analysis based on combined analysis of various molecular markers.

  11. Human genetics in rheumatoid arthritis guides a high-throughput drug screen of the CD40 signaling pathway.

    Directory of Open Access Journals (Sweden)

    Gang Li

    2013-05-01

    Full Text Available Although genetic and non-genetic studies in mouse and human implicate the CD40 pathway in rheumatoid arthritis (RA, there are no approved drugs that inhibit CD40 signaling for clinical care in RA or any other disease. Here, we sought to understand the biological consequences of a CD40 risk variant in RA discovered by a previous genome-wide association study (GWAS and to perform a high-throughput drug screen for modulators of CD40 signaling based on human genetic findings. First, we fine-map the CD40 risk locus in 7,222 seropositive RA patients and 15,870 controls, together with deep sequencing of CD40 coding exons in 500 RA cases and 650 controls, to identify a single SNP that explains the entire signal of association (rs4810485, P = 1.4×10(-9. Second, we demonstrate that subjects homozygous for the RA risk allele have ∼33% more CD40 on the surface of primary human CD19+ B lymphocytes than subjects homozygous for the non-risk allele (P = 10(-9, a finding corroborated by expression quantitative trait loci (eQTL analysis in peripheral blood mononuclear cells from 1,469 healthy control individuals. Third, we use retroviral shRNA infection to perturb the amount of CD40 on the surface of a human B lymphocyte cell line (BL2 and observe a direct correlation between amount of CD40 protein and phosphorylation of RelA (p65, a subunit of the NF-κB transcription factor. Finally, we develop a high-throughput NF-κB luciferase reporter assay in BL2 cells activated with trimerized CD40 ligand (tCD40L and conduct an HTS of 1,982 chemical compounds and FDA-approved drugs. After a series of counter-screens and testing in primary human CD19+ B cells, we identify 2 novel chemical inhibitors not previously implicated in inflammation or CD40-mediated NF-κB signaling. Our study demonstrates proof-of-concept that human genetics can be used to guide the development of phenotype-based, high-throughput small-molecule screens to identify potential novel

  12. Human Genetics in Rheumatoid Arthritis Guides a High-Throughput Drug Screen of the CD40 Signaling Pathway

    Science.gov (United States)

    Li, Gang; Diogo, Dorothée; Wu, Di; Spoonamore, Jim; Dancik, Vlado; Franke, Lude; Kurreeman, Fina; Rossin, Elizabeth J.; Duclos, Grant; Hartland, Cathy; Zhou, Xuezhong; Li, Kejie; Liu, Jun; De Jager, Philip L.; Siminovitch, Katherine A.; Zhernakova, Alexandra; Raychaudhuri, Soumya; Bowes, John; Eyre, Steve; Padyukov, Leonid; Gregersen, Peter K.; Worthington, Jane; Gupta, Namrata; Clemons, Paul A.; Stahl, Eli; Tolliday, Nicola; Plenge, Robert M.

    2013-01-01

    Although genetic and non-genetic studies in mouse and human implicate the CD40 pathway in rheumatoid arthritis (RA), there are no approved drugs that inhibit CD40 signaling for clinical care in RA or any other disease. Here, we sought to understand the biological consequences of a CD40 risk variant in RA discovered by a previous genome-wide association study (GWAS) and to perform a high-throughput drug screen for modulators of CD40 signaling based on human genetic findings. First, we fine-map the CD40 risk locus in 7,222 seropositive RA patients and 15,870 controls, together with deep sequencing of CD40 coding exons in 500 RA cases and 650 controls, to identify a single SNP that explains the entire signal of association (rs4810485, P = 1.4×10−9). Second, we demonstrate that subjects homozygous for the RA risk allele have ∼33% more CD40 on the surface of primary human CD19+ B lymphocytes than subjects homozygous for the non-risk allele (P = 10−9), a finding corroborated by expression quantitative trait loci (eQTL) analysis in peripheral blood mononuclear cells from 1,469 healthy control individuals. Third, we use retroviral shRNA infection to perturb the amount of CD40 on the surface of a human B lymphocyte cell line (BL2) and observe a direct correlation between amount of CD40 protein and phosphorylation of RelA (p65), a subunit of the NF-κB transcription factor. Finally, we develop a high-throughput NF-κB luciferase reporter assay in BL2 cells activated with trimerized CD40 ligand (tCD40L) and conduct an HTS of 1,982 chemical compounds and FDA–approved drugs. After a series of counter-screens and testing in primary human CD19+ B cells, we identify 2 novel chemical inhibitors not previously implicated in inflammation or CD40-mediated NF-κB signaling. Our study demonstrates proof-of-concept that human genetics can be used to guide the development of phenotype-based, high-throughput small-molecule screens to identify potential novel therapies in

  13. Genetic Variance for Autism Screening Items in an Unselected Sample of Toddler-Age Twins

    Science.gov (United States)

    Stilp, Rebecca L. H.; Gernsbacher, Morton Ann; Schweigert, Emily K.; Arneson, Carrie L.; Goldsmith, H. Hill

    2010-01-01

    Objective: Twin and family studies of autistic traits and of cases diagnosed with autism suggest high heritability; however, the heritability of autistic traits in toddlers has not been investigated. Therefore, this study's goals were (1) to screen a statewide twin population using items similar to the six critical social and communication items…

  14. Genetical studies of resistance to Phytophthora porri in Allium porrum, using a new early screening method.

    NARCIS (Netherlands)

    Smilde, W.D.; Nes, van M.; Reinink, K.; Kik, C.

    1997-01-01

    A new screening method was developed to evaluate resistance of leek (Allium porrum) to Phytophthora porri, based on inoculation by 24 h-immersion of leek plantlets in the 3–6 leaf stage in a suspension of ca. 100 zoospores.ml-1. The immersion test was used for identifying new sources of resistance a

  15. Screening a core collection of citrus genetic resources for resistance to Fusarium solani (Mart) Sacc

    Science.gov (United States)

    A causal agent for Dry root rot (DRR) of citrus has not been definitively identified, but the organism most consistently associated with DRR is Fusarium solani (Mart.) Sacc. To efficiently screen a citrus germplasm collection for resistance to F. solani, a core subset of the collection was evaluated...

  16. Effects and Costs of Breast Cancer screening in women with a familial or genetic predisposition

    NARCIS (Netherlands)

    A.J. Rijnsburger (Rian)

    2005-01-01

    textabstract"Women with a BRCA1 or BRCA2 mutation, who have a considerable increased risk of developing breast cancer, now face the choice of intensive screening, prophylactic surgery or chemoprevention. The efficacy of the various medical options and the durability of its effects are of major

  17. Genetic diversity and differentiation of masu salmon (Oncorhynchus masou masou) between and within cultured populations inferred from microsatellite DNA analysis

    Institute of Scientific and Technical Information of China (English)

    Zhiying JIA; Yuyong ZHANG; Shuqiang CHEN; Lianyu SHI

    2012-01-01

    Masu salmon,Oncorhynchus masou masou,is one of the most valuable fishery species that has been introduced to China,though to date no studies on the genetic diversity and genetic relationship among hatchery populations has been performed with molecular markers.We undertook such a study and sampled 120 individuals from three hatchery stocks and analyzed 20 microsatellite loci.All loci were polymorphic and a total of 91 alleles were detected.A relatively low level of genetic diversity was revealed with effective number of allele of 3.1094,3.3299 and 3.1894 and expected heterozygosity of 0.6600,0.6648 and 0.6638 in the three stocks,respectively.Deviations from Hardy-Weinberg equilibrium were found due to heterozygote deficit.Accordingly,evidence of genetic bottlenecks were found in the three stocks.An individual assignment test demonstrated that 85% of individuals were correctly assigned into their original stocks.Pairwise Fst revealed that significant differentiation occurred between these three stocks.The results of the study indicated that disequilibrium of genetic structure and differentiation has occurred in all three stocks.This information collectively provides a basis for measures to avoid of loss of genetic diversity and introgression in Chinese aquaculture.

  18. Screening differentially expressed genes in an amphipod (Hyalella azteca) exposed to fungicide vinclozolin by suppression subtractive hybridization.

    Science.gov (United States)

    Wu, Yun H; Wu, Tsung M; Hong, Chwan Y; Wang, Yei S; Yen, Jui H

    2014-01-01

    Vinclozolin, a dicarboximide fungicide, is an endocrine disrupting chemical that competes with an androgenic endocrine disruptor compound. Most research has focused on the epigenetic effect of vinclozolin in humans. In terms of ecotoxicology, understanding the effect of vinclozolin on non-target organisms is important. The expression profile of a comprehensive set of genes in the amphipod Hyalella azteca exposed to vinclozolin was examined. The expressed sequence tags in low-dose vinclozolin-treated and -untreated amphipods were isolated and identified by suppression subtractive hybridization. DNA dot blotting was used to confirm the results and establish a subtracted cDNA library for comparing all differentially expressed sequences with and without vinclozolin treatment. In total, 494 differentially expressed genes, including hemocyanin, heatshock protein, cytochrome, cytochrome oxidase and NADH dehydrogenase were detected. Hemocyanin was the most abundant gene. DNA dot blotting revealed 55 genes with significant differential expression. These genes included larval serum protein 1 alpha, E3 ubiquitin-protein ligase, mitochondrial cytochrome c oxidase, mitochondrial protein, proteasome inhibitor, hemocyanin, zinc-finger-containing protein, mitochondrial NADH-ubiquinone oxidoreductase and epididymal sperm-binding protein. Vinclozolin appears to upregulate stress-related genes and hemocyanin, related to immunity. Moreover, vinclozolin downregulated NADH dehydrogenase, related to respiration. Thus, even a non-lethal concentration of vinclozolin still has an effect at the genetic level in H. azteca and presents a potential risk, especially as it would affect non-target organism hormone metabolism.

  19. [Morphogenesis and differentiation of the female genital tract. Genetic determinism and epithelium-stromal interactions].

    Science.gov (United States)

    Amălinei, Cornelia

    2007-01-01

    The epithelium-stromal interaction is important in the process of morphogenesis, differentiation, and hormone response, in female genital tract. This review is organized in four sections: i) female genital tract morphogenesis, based on genetic determinism; ii) hormonal control of endometrial proliferation; iii) TGF-beta key-role in epithelium-stromal communication; iv) endometrial apoptosis. Female genital tract derives from the Müllerian ducts, a number of genes being involved in its regulation, like Lim1, Lhx9, Emx, Pax-2, Hox-A9, Hox-A10, Hox-A11, Hox-A13, Wnt-4, Wnt-7, WT1, SF-1, and GATA-4. TGF-beta, whose expression is modulated by ovarian steroids, regulates cell growth, differentiation, apoptosis, inflammatory and immune responses, extracellular matrix deposition, adhesion molecules, proteases, and protease inhibitor expression. In the endometrium, TGF-beta regulates its own expression, and that of extracellular matrix, adhesion molecules and proteases implicated in trophoblast invasion, angiogenesis, and tumor metastasis during embryo implantation, endometriosis, irregular bleeding, and endometrial cancer. Cellular response elicited by TGF-beta, mediated through a serine/threonine kinase receptor, induces the recruitment of multiple intracellular signals, specifically Smads, whose activation and subsequent translocation into the nucleus results in gene expression. Ubiquitin is involved in the degradation of short lived, regulatory or misfolded proteins, by tagging them to be taken to the proteasome. In the endometrium, ubiquitin may allow cells of stromal origin to grow, survive and evade T-cell mediated disposal, showing a functional duality. A complete understanding of the complex regulatory endometrial epithelium-stromal mechanism, concertating genes, hormones, and cytokines, may provide new therapeutic targets in female reproductive tract pathology.

  20. Recombinant differential anchorage probes that tower over the spatial dimension of intracellular signals for high content screening and analysis.

    Science.gov (United States)

    Schembri, Laura; Zanese, Marion; Depierre-Plinet, Gaelle; Petit, Muriel; Elkaoukabi-Chaibi, Assia; Tauzin, Loic; Florean, Cristina; Lartigue, Lydia; Medina, Chantal; Rey, Christophe; Belloc, Francis; Reiffers, Josy; Ichas, François; De Giorgi, Francesca

    2009-12-01

    Recombinant fluorescent probes allow the detection of molecular events inside living cells. Many of them exploit the intracellular space to provide positional signals and, thus, require detection by single cell imaging. We describe here a novel strategy based on probes capable of encoding the spatial dimension of intracellular signals into "all-or-none" fluorescence intensity changes (differential anchorage probes, DAPs). The resulting signals can be acquired in single cells at high throughput by automated flow cytometry, (i) bypassing image acquisition and analysis, (ii) providing a direct quantitative readout, and (iii) allowing the exploration of large experimental series. We illustrate our purpose with DAPs for Bax and the effector caspases 3 and 7, which are keys players in apoptotic cell death, and show applications in basic research, high content multiplexed library screening, compound characterization, and drug profiling.

  1. Anomaly metrics to differentiate threat sources from benign sources in primary vehicle screening.

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, Israel Dov; Mengesha, Wondwosen

    2011-09-01

    Discrimination of benign sources from threat sources at Port of Entries (POE) is of a great importance in efficient screening of cargo and vehicles using Radiation Portal Monitors (RPM). Currently RPM's ability to distinguish these radiological sources is seriously hampered by the energy resolution of the deployed RPMs. As naturally occurring radioactive materials (NORM) are ubiquitous in commerce, false alarms are problematic as they require additional resources in secondary inspection in addition to impacts on commerce. To increase the sensitivity of such detection systems without increasing false alarm rates, alarm metrics need to incorporate the ability to distinguish benign and threat sources. Principal component analysis (PCA) and clustering technique were implemented in the present study. Such techniques were investigated for their potential to lower false alarm rates and/or increase sensitivity to weaker threat sources without loss of specificity. Results of the investigation demonstrated improved sensitivity and specificity in discriminating benign sources from threat sources.

  2. Development of a qualitative, multiplex real-time PCR kit for screening of genetically modified organisms (GMOs).

    Science.gov (United States)

    Dörries, Hans-Henno; Remus, Ivonne; Grönewald, Astrid; Grönewald, Cordt; Berghof-Jäger, Kornelia

    2010-03-01

    The number of commercially available genetically modified organisms (GMOs) and therefore the diversity of possible target sequences for molecular detection techniques are constantly increasing. As a result, GMO laboratories and the food production industry currently are forced to apply many different methods to reliably test raw material and complex processed food products. Screening methods have become more and more relevant to minimize the analytical effort and to make a preselection for further analysis (e.g., specific identification or quantification of the GMO). A multiplex real-time PCR kit was developed to detect the 35S promoter of the cauliflower mosaic virus, the terminator of the nopaline synthase gene of Agrobacterium tumefaciens, the 35S promoter from the figwort mosaic virus, and the bar gene of the soil bacterium Streptomyces hygroscopicus as the most widely used sequences in GMOs. The kit contains a second assay for the detection of plant-derived DNA to control the quality of the often processed and refined sample material. Additionally, the plant-specific assay comprises a homologous internal amplification control for inhibition control. The determined limits of detection for the five assays were 10 target copies/reaction. No amplification products were observed with DNAs of 26 bacterial species, 25 yeasts, 13 molds, and 41 not genetically modified plants. The specificity of the assays was further demonstrated to be 100% by the specific amplification of DNA derived from reference material from 22 genetically modified crops. The applicability of the kit in routine laboratory use was verified by testing of 50 spiked and unspiked food products. The herein described kit represents a simple and sensitive GMO screening method for the reliable detection of multiple GMO-specific target sequences in a multiplex real-time PCR reaction.

  3. DRD2 genetic variation in relation to smoking and obesity in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial.

    Science.gov (United States)

    Morton, Lindsay M; Wang, Sophia S; Bergen, Andrew W; Chatterjee, Nilanjan; Kvale, Paul; Welch, Robert; Yeager, Meredith; Hayes, Richard B; Chanock, Stephen J; Caporaso, Neil E

    2006-12-01

    Cigarette smoking is the leading cause of morbidity and mortality worldwide. We investigated the association between smoking behavior and genetic variations in the D2 dopamine receptor (DRD2), which mediates nicotine dependence. To assess the specificity of genetic effects, we also investigated other reward-motivated characteristics (obesity, alcohol consumption). Four single nucleotide polymorphisms in DRD2 were genotyped in 2374 participants selected randomly from the screening arm of the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial after stratifying by sex, age, and smoking status. Smoking, obesity, and alcohol consumption were assessed by questionnaire. Single nucleotide polymorphism and haplotype associations were estimated using odds ratios (ORs) and 95% confidence intervals derived from conditional logistic regression models, adjusted for race/ethnicity. DRD2 polymorphisms were associated with the risk of remaining a current smoker and obesity. Current smokers were more likely than former smokers to possess the variant TaqIA allele (rsmusical sharp1800497) in a dose-dependent model (ORCT=1.2, ORTT=1.5, P for linear trend=0.007). The DRD2 haplotype T-C-T-A [TaqIA(C/T)-957(T/C)-IVS6-83(G/T)- -50977(A/G)] was more common among current than former smokers (OR=1.3, P=0.006), particularly among heavy smokers (21+ cigarettes per day; OR=1.6, P=0.006), and was more common among obese than normal weight individuals (OR=1.4, P=0.02). Genetic variation in DRD2 is a modifier of the reward-motivated characteristics, smoking and obesity. As fewer than 15% of smokers who attempt to quit are able to maintain abstinence for greater than 3 months, our results support that DRD2 is an appropriate molecular target for smoking cessation treatments. Our results further support evaluation of DRD2 antagonists for obesity therapies.

  4. Polar body biopsy: a viable alternative to preimplantation genetic diagnosis and screening.

    Science.gov (United States)

    Montag, M; van der Ven, K; Rösing, B; van der Ven, H

    2009-01-01

    Polar body diagnosis (PBD) is a diagnostic method for the indirect genetic analysis of oocytes. Polar bodies are by-products of the meiotic cell cycle, which have no influence on further embryo development. The biopsy of polar bodies can be accomplished either by zona drilling or laser drilling within a very short time period. However, the paternal contribution to the genetic constitution of the developing embryo cannot be diagnosed by PBD. The major application of PBD is the detection of maternally derived chromosomal aneuploidies and translocations in oocytes. For these indications, PBD may offer a viable alternative to blastomere biopsy as the embryo's integrity remains unaffected, in contrast to preimplantation genetic diagnosis (PGD) by blastomere biopsy. The rapid pace of developments in the field of molecular diagnostics will also influence the advantages of PBD, and probably allow more general diagnostic applications in the future.

  5. Identification of Differentially Expressed Kinase and Screening Potential Anticancer Drugs in Papillary Thyroid Carcinoma

    Science.gov (United States)

    Zhang, Huairong

    2016-01-01

    Aim. We aim to identify protein kinases involved in the pathophysiology of papillary thyroid carcinoma (PTC) in order to provide potential therapeutic targets for kinase inhibitors and unfold possible molecular mechanisms. Materials and Methods. The gene expression profile of GSE27155 was analyzed to identify differentially expressed genes and mapped onto human protein kinases database. Correlation of kinases with PTC was addressed by systematic literature search, GO and KEGG pathway analysis. Results. The functional enrichment analysis indicated that “mitogen-activated protein kinases pathway” expression was extremely enriched, followed by “neurotrophin signaling pathway,” “focal adhesion,” and “GnRH signaling pathway.” MAPK, SRC, PDGFRa, ErbB, and EGFR were significantly regulated to correct these pathways. Kinases investigated by the literature on carcinoma were considered to be potential novel molecular therapeutic target in PTC and application of corresponding kinase inhibitors could be possible therapeutic tool. Conclusion. SRC, MAPK, and EGFR were the most important differentially expressed kinases in PTC. Combined inhibitors may have high efficacy in PTC treatment by targeting these kinases. PMID:27703281

  6. Genetic variation in Miscanthus x giganteus and the importance of estimating genetic distance tresholds for differentiating clones

    DEFF Research Database (Denmark)

    Glowacka, K; Clark, L; Adhikari, S;

    2015-01-01

    with samples of the parental species M. sacchariflorus and M. sinensis. Estimates of genotyping error rates were essential for distinguishing between experimental error and true genotypic differences among accessions. Given differences in estimated error rates and costs per marker for SSRs and RAD......-seq, the former is currently more cost-effective for determining if two accessions are genetically identical. We concluded that all of the Mxg legacy cultivars were derived via vegetative propagation from a single genet. In contrast with the Mxg legacy cultivars, genetic similarity to the type-specimen of eight...... new triploid Mxg progeny ranged from 0.46 to 0.56. Though genetic diversity among the Mxg legacy cultivars is critically low, new crosses can provide much-needed variation to growers...

  7. Mathematics is differentially related to reading comprehension and word decoding: Evidence from a genetically-sensitive design

    Science.gov (United States)

    Harlaar, Nicole; Kovas, Yulia; Dale, Philip S.; Petrill, Stephen A.; Plomin, Robert

    2013-01-01

    Although evidence suggests that individual differences in reading and mathematics skills are correlated, this relationship has typically only been studied in relation to word decoding or global measures of reading. It is unclear whether mathematics is differentially related to word decoding and reading comprehension. The current study examined these relationships at both a phenotypic and etiological level in a population-based cohort of 5162 twin pairs at age 12. Multivariate genetic analyses of latent phenotypic factors of mathematics, word decoding and reading comprehension revealed substantial genetic and shared environmental correlations among all three domains. However, the phenotypic and genetic correlations between mathematics and reading comprehension were significantly greater than between mathematics and word decoding. Independent of mathematics, there was also evidence for genetic and nonshared environmental links between word decoding and reading comprehension. These findings indicate that word decoding and reading comprehension have partly distinct relationships with mathematics in the middle school years. PMID:24319294

  8. Genetic differentiation and selection against migrants in evolutionarily replicated extreme environments.

    Science.gov (United States)

    Plath, Martin; Pfenninger, Markus; Lerp, Hannes; Riesch, Rüdiger; Eschenbrenner, Christoph; Slattery, Patrick A; Bierbach, David; Herrmann, Nina; Schulte, Matthias; Arias-Rodriguez, Lenin; Rimber Indy, Jeane; Passow, Courtney; Tobler, Michael

    2013-09-01

    We investigated mechanisms of reproductive isolation in livebearing fishes (genus Poecilia) inhabiting sulfidic and nonsulfidic habitats in three replicate river drainages. Although sulfide spring fish convergently evolved divergent phenotypes, it was unclear if mechanisms of reproductive isolation also evolved convergently. Using microsatellites, we found strongly reduced gene flow between adjacent populations from different habitat types, suggesting that local adaptation to sulfidic habitats repeatedly caused the emergence of reproductive isolation. Reciprocal translocation experiments indicate strong selection against immigrants into sulfidic waters, but also variation among drainages in the strength of selection against immigrants into nonsulfidic waters. Mate choice experiments revealed the evolution of assortative mating preferences in females from nonsulfidic but not from sulfidic habitats. The inferred strength of sexual selection against immigrants (RI(s)) was negatively correlated with the strength of natural selection (RI(m)), a pattern that could be attributed to reinforcement, whereby natural selection strengthens behavioral isolation due to reduced hybrid fitness. Overall, reproductive isolation and genetic differentiation appear to be replicated and direct consequences of local adaptation to sulfide spring environments, but the relative contributions of different mechanisms of reproductive isolation vary across these evolutionarily independent replicates, highlighting both convergent and nonconvergent evolutionary trajectories of populations in each drainage. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

  9. The application of genetics methods to differentiation of three Lactobacillus species of human origin.

    Science.gov (United States)

    Gosiewski, Tomasz; Chmielarczyk, Agnieszka; Strus, Magdalena; Brzychczy-Włoch, Monika; Heczko, Piotr B

    2012-12-01

    In recent decades, the interest in probiotics as diet supplements or drugs has increased. In order to determine a specific bacterial isolate to be probiotic, it is necessary to describe precisely its probiotic characteristics and taxonomic properties, including the strain level. Most of the well-known genotyping methods were designed for the commonly-found pathogenic bacteria. The objective of this study is to undertake an attempt at standardization of FISH, RAPD and PFGE methods to genotype and identify the bacteria belonging to Lactobacillus fermentum, L. gasseri and L. plantarum species. The FISH probes have been designed and tested for Lactobacillus fermentum, L. gasseri and L. plantarum species and an endeavor has been made at standardization of RAPD and PFGE methods for these bacterial species. Moreover, the MLST method was applied to differentiate Lactobacillus plantarum strains. L. plantarum isolated from humans could not be genetically diversified with the use of RAPD, PFGE or MLST methods; only the strains originating from plants have displayed diversification among themselves and have been different from the strains of human origin.

  10. Genetic differentiation among natural populations of the Nile tilapia Oreochromis niloticus (Teleostei, cichlidae).

    Science.gov (United States)

    Agnèse, J F; Adépo-Gourène, B; Abban, E K; Fermon, Y

    1997-07-01

    We analysed the genetic differentiation among 17 natural populations of the Nile tilapia Oreochromis niloticus (Linnaeus, 1758) using allozymes and restriction fragment length polymorphism (RFLP) of mitochondrial DNA (mtDNA). The populations studied, from the River Senegal to Lake Tana and from Lake Manzalla to Lake Baringo, represent all subspecies which have been previously described. Sixteen variable nuclear loci showed that these populations can be clustered in three groups: (1) West African populations (Senegal, Niger, Volta and Chad drainages), (2) Ethiopian Rift Valley populations (Lakes Awasa, Ziway, Koka and the Awash River) and (3) Nile drainage (Manzalla, Cairo, Lake Edward) and Kenyan Rift Valley populations (Lakes Turkana, Baringo and River Suguta). Nine different mtDNA haplotypes were found in the RFLP analysis of a 1 kb portion of the D-loop region. The network obtained showed that there are three geographically distinct groups; all West African populations and O. aureus are clustered, the two Ethiopian Rift Valley populations are distinct and between these two groups are the Kenyan and Ugandan Rift Valley populations. Nile populations show affinities both with West African populations and with specimens from Lakes Tana and Turkana. Taxonomic and biogeographical implications of these results are discussed.

  11. Screening Genetic Resources of Capsicum Peppers in Their Primary Center of Diversity in Bolivia and Peru.

    Directory of Open Access Journals (Sweden)

    Maarten van Zonneveld

    Full Text Available For most crops, like Capsicum, their diversity remains under-researched for traits of interest for food, nutrition and other purposes. A small investment in screening this diversity for a wide range of traits is likely to reveal many traditional varieties with distinguished values. One objective of this study was to demonstrate, with Capsicum as model crop, the application of indicators of phenotypic and geographic diversity as effective criteria for selecting promising genebank accessions for multiple uses from crop centers of diversity. A second objective was to evaluate the expression of biochemical and agromorphological properties of the selected Capsicum accessions in different conditions. Four steps were involved: 1 Develop the necessary diversity by expanding genebank collections in Bolivia and Peru; 2 Establish representative subsets of ~100 accessions for biochemical screening of Capsicum fruits; 3 Select promising accessions for different uses after screening; and 4 Examine how these promising accessions express biochemical and agromorphological properties when grown in different environmental conditions. The Peruvian Capsicum collection now contains 712 accessions encompassing all five domesticated species (C. annuum, C. chinense, C. frutescens, C. baccatum, and C. pubescens. The collection in Bolivia now contains 487 accessions, representing all five domesticates plus four wild taxa (C. baccatum var. baccatum, C. caballeroi, C. cardenasii, and C. eximium. Following the biochemical screening, 44 Bolivian and 39 Peruvian accessions were selected as promising, representing wide variation in levels of antioxidant capacity, capsaicinoids, fat, flavonoids, polyphenols, quercetins, tocopherols, and color. In Peru, 23 promising accessions performed well in different environments, while each of the promising Bolivian accessions only performed well in a certain environment. Differences in Capsicum diversity and local contexts led to distinct

  12. Screening Genetic Resources of Capsicum Peppers in Their Primary Center of Diversity in Bolivia and Peru.

    Science.gov (United States)

    van Zonneveld, Maarten; Ramirez, Marleni; Williams, David E; Petz, Michael; Meckelmann, Sven; Avila, Teresa; Bejarano, Carlos; Ríos, Llermé; Peña, Karla; Jäger, Matthias; Libreros, Dimary; Amaya, Karen; Scheldeman, Xavier

    2015-01-01

    For most crops, like Capsicum, their diversity remains under-researched for traits of interest for food, nutrition and other purposes. A small investment in screening this diversity for a wide range of traits is likely to reveal many traditional varieties with distinguished values. One objective of this study was to demonstrate, with Capsicum as model crop, the application of indicators of phenotypic and geographic diversity as effective criteria for selecting promising genebank accessions for multiple uses from crop centers of diversity. A second objective was to evaluate the expression of biochemical and agromorphological properties of the selected Capsicum accessions in different conditions. Four steps were involved: 1) Develop the necessary diversity by expanding genebank collections in Bolivia and Peru; 2) Establish representative subsets of ~100 accessions for biochemical screening of Capsicum fruits; 3) Select promising accessions for different uses after screening; and 4) Examine how these promising accessions express biochemical and agromorphological properties when grown in different environmental conditions. The Peruvian Capsicum collection now contains 712 accessions encompassing all five domesticated species (C. annuum, C. chinense, C. frutescens, C. baccatum, and C. pubescens). The collection in Bolivia now contains 487 accessions, representing all five domesticates plus four wild taxa (C. baccatum var. baccatum, C. caballeroi, C. cardenasii, and C. eximium). Following the biochemical screening, 44 Bolivian and 39 Peruvian accessions were selected as promising, representing wide variation in levels of antioxidant capacity, capsaicinoids, fat, flavonoids, polyphenols, quercetins, tocopherols, and color. In Peru, 23 promising accessions performed well in different environments, while each of the promising Bolivian accessions only performed well in a certain environment. Differences in Capsicum diversity and local contexts led to distinct outcomes in

  13. High acceptance of an early dyslexia screening test involving genetic analyses in Germany.

    Science.gov (United States)

    Wilcke, Arndt; Müller, Bent; Schaadt, Gesa; Kirsten, Holger; Boltze, Johannes

    2016-02-01

    Dyslexia is a developmental disorder characterized by severe problems in the acquisition of reading and writing skills. It has a strong neurobiological basis. Genetic influence is estimated at 50-70%. One of the central problems with dyslexia is its late diagnosis, normally not before the end of the 2nd grade, resulting in the loss of several years for early therapy. Currently, research is focusing on the development of early tests for dyslexia, which may be based on EEG and genetics. Our aim was to determine the acceptance of such a future test among parents. We conducted a representative survey in Germany with 1000 parents of children aged 3-7 years, with and without experience of dyslexia. 88.7% of the parents supported the introduction of an early test for dyslexia based on EEG and genetics; 82.8% would have their own children tested, and 57.9% were willing to pay for the test if health insurance did not cover the costs. Test acceptance was significantly higher if parents had prior experience with dyslexia. The perceived benefits of such a test were early recognition and remediation and, preventing deficits. Concerns regarded the precision of the test, its potentially stigmatizing effect and its costs. The high overall support for the test leads to the conclusion that parents would accept a test for dyslexia based on EEG and genetics.

  14. High acceptance of an early dyslexia screening test involving genetic analyses in Germany

    Science.gov (United States)

    Wilcke, Arndt; Müller, Bent; Schaadt, Gesa; Kirsten, Holger; Boltze, Johannes; Angela, h c; Friederici, D; Emmrich, Frank; Brauer, Jens; Wilcke, Arndt; Neef, Nicole; Boltze, Johannes; Skeide, Michael; Kirsten, Holger; Schaadt, Gesa; Müller, Bent; Kraft, Indra; Czepezauer, Ivonne; Bobovnikov, Nadin

    2016-01-01

    Dyslexia is a developmental disorder characterized by severe problems in the acquisition of reading and writing skills. It has a strong neurobiological basis. Genetic influence is estimated at 50–70%. One of the central problems with dyslexia is its late diagnosis, normally not before the end of the 2nd grade, resulting in the loss of several years for early therapy. Currently, research is focusing on the development of early tests for dyslexia, which may be based on EEG and genetics. Our aim was to determine the acceptance of such a future test among parents. We conducted a representative survey in Germany with 1000 parents of children aged 3–7 years, with and without experience of dyslexia. 88.7% of the parents supported the introduction of an early test for dyslexia based on EEG and genetics; 82.8% would have their own children tested, and 57.9% were willing to pay for the test if health insurance did not cover the costs. Test acceptance was significantly higher if parents had prior experience with dyslexia. The perceived benefits of such a test were early recognition and remediation and, preventing deficits. Concerns regarded the precision of the test, its potentially stigmatizing effect and its costs. The high overall support for the test leads to the conclusion that parents would accept a test for dyslexia based on EEG and genetics. PMID:26036858

  15. BRAF screening as a low-cost effective strategy for simplifying HNPCC genetic testing

    NARCIS (Netherlands)

    Domingo, E; Laiho, P; Ollikainen, M; Pinto, M; Wang, L; French, AJ; Westra, J.; Frebourg, T; Espin, E; Armengol, M; Hamelin, R; Yamamoto, H; Hofstra, RMW; Seruca, R; Lindblom, A; Peltomaki, P; Thibodeau, SN; Aaltonen, LA; Schwartz, S

    2004-01-01

    Background: According to the international criteria for hereditary non-polyposis colorectal cancer (HNPCC) diagnostics, cancer patients with a family history or early onset of colorectal tumours showing high microsatellite instability (MSI-H) should receive genetic counselling and be offered testing

  16. Development of quantitative duplex real-time PCR method for screening analysis of genetically modified maize.

    Science.gov (United States)

    Oguchi, Taichi; Onishi, Mari; Minegishi, Yasutaka; Kurosawa, Yasunori; Kasahara, Masaki; Akiyama, Hiroshi; Teshima, Reiko; Futo, Satoshi; Furui, Satoshi; Hino, Akihiro; Kitta, Kazumi

    2009-06-01

    A duplex real-time PCR method was developed for quantitative screening analysis of GM maize. The duplex real-time PCR simultaneously detected two GM-specific segments, namely the cauliflower mosaic virus (CaMV) 35S promoter (P35S) segment and an event-specific segment for GA21 maize which does not contain P35S. Calibration was performed with a plasmid calibrant specially designed for the duplex PCR. The result of an in-house evaluation suggested that the analytical precision of the developed method was almost equivalent to those of simplex real-time PCR methods, which have been adopted as ISO standard methods for the analysis of GMOs in foodstuffs and have also been employed for the analysis of GMOs in Japan. In addition, this method will reduce both the cost and time requirement of routine GMO analysis by half. The high analytical performance demonstrated in the current study would be useful for the quantitative screening analysis of GM maize. We believe the developed method will be useful for practical screening analysis of GM maize, although interlaboratory collaborative studies should be conducted to confirm this.

  17. The promises of genomic screening: building a governance infrastructure. Special issue: genetics and democracy.

    Science.gov (United States)

    Cornel, Martina C; van El, Carla G; Dondorp, Wybo J

    2012-04-01

    New screening possibilities become available at a high rate, both useful and unsound possibilities. All screening programmes do harm, and only few have more advantages than disadvantages at reasonable cost. Horizon scanning is needed to identify those few possibilities with more pros than cons. Attunement is needed between actors involved: scientists developing new high-throughput screening techniques and treatment, health care workers, patients and consumers and governmental agencies. The product of a process of attunement may be a quality mark as a norm for professional conduct, rather than legal measures, as the field is moving fast. As actors may have varying perspectives, a governance structure is needed to develop an agenda that is agreed upon by all or most actors involved. A standing committee might oversee the evaluation of benefits and disadvantages in an integrated approach, taking evidence, economics and ethics into account. A proactive role of governmental agencies is needed to facilitate agenda setting and attunement. Policy making has to be transparent and open to stakeholder engagement.

  18. Screening for FecGH Mutation of Growth Differentiation Factor 9 Gene in Iranian Ghezel Sheep Population

    Directory of Open Access Journals (Sweden)

    Mahzad Akbarpour

    2009-01-01

    Full Text Available Background: Ghezel sheep are highly prolific and one of the local sheep breeds in Iran andTurkey. Growth differentiation factor-9 (GDF9 gene has been found to be essential for growthand differentiation of early ovarian follicles. Novel mutations in GDF9 have been associated withincreased ovulation rates and high litter sizes in heterozygous carriers. Therefore, fecundity genefor GDF9 (FecGH mutation in GDF9 is considered as a possible candidate for the increased littersize observed in Ghezel ewes.Materials and Methods: The aim was to evaluate the frequency of recently reported SNP (FecGHusing polymerase chain reaction (PCR - single strand conformation polymorphism (SSCP in 110Ghezel ewes with a history of high litter size reproductive activity and 75 fertile ewes with normalreproductive activity.Results: The GDF9 gene exon II was investigated by this technique to screen whether they are FecGH(S395F carriers or not. SSCP analysis identified four fragments that contained conformationaldifferences; however the combined results with sequencing analysis data did not reveal the FecGHmutation (C to T in GDF9 gene in Iranian Ghezel ewes.Conclusion: Current results confirmed that FecGH mutation is not present in the selected IranianGhezel sheep population and is not associated with Ghezel sheep high prolificacy performance.Therefore, this SNP may not represent a molecular marker for marker assisted selection programsin this population.

  19. Proteomic Screening and Lasso Regression Reveal Differential Signaling in Insulin and Insulin-like Growth Factor I (IGF1) Pathways.

    Science.gov (United States)

    Erdem, Cemal; Nagle, Alison M; Casa, Angelo J; Litzenburger, Beate C; Wang, Yu-Fen; Taylor, D Lansing; Lee, Adrian V; Lezon, Timothy R

    2016-09-01

    Insulin and insulin-like growth factor I (IGF1) influence cancer risk and progression through poorly understood mechanisms. To better understand the roles of insulin and IGF1 signaling in breast cancer, we combined proteomic screening with computational network inference to uncover differences in IGF1 and insulin induced signaling. Using reverse phase protein array, we measured the levels of 134 proteins in 21 breast cancer cell lines stimulated with IGF1 or insulin for up to 48 h. We then constructed directed protein expression networks using three separate methods: (i) lasso regression, (ii) conventional matrix inversion, and (iii) entropy maximization. These networks, named here as the time translation models, were analyzed and the inferred interactions were ranked by differential magnitude to identify pathway differences. The two top candidates, chosen for experimental validation, were shown to regulate IGF1/insulin induced phosphorylation events. First, acetyl-CoA carboxylase (ACC) knock-down was shown to increase the level of mitogen-activated protein kinase (MAPK) phosphorylation. Second, stable knock-down of E-Cadherin increased the phospho-Akt protein levels. Both of the knock-down perturbations incurred phosphorylation responses stronger in IGF1 stimulated cells compared with insulin. Overall, the time-translation modeling coupled to wet-lab experiments has proven to be powerful in inferring differential interactions downstream of IGF1 and insulin signaling, in vitro.

  20. Genetic analysis of scattered populations of the Indian eri silkworm, Samia cynthia ricini Donovan: differentiation of subpopulations

    Directory of Open Access Journals (Sweden)

    Appukuttannair R. Pradeep

    2011-01-01

    Full Text Available Deforestation and exploitation has led to the fragmentation of habitats and scattering of populations of the economically important eri silkworm, Samia cynthia ricini, in north-east India. Genetic analysis of 15 eri populations, using ISSR markers, showed 98% inter-population, and 23% to 58% intra-population polymorphism. Nei's genetic distance between populations increased significantly with altitude (R² = 0.71 and geographic distance (R² = 0.78. On the dendrogram, the lower and upper Assam populations were clustered separately, with intermediate grouping of those from Barpathar and Chuchuyimlang, consistent with geographical distribution. The Nei's gene diversity index was 0.350 in total populations and 0.121 in subpopulations. The genetic differentiation estimate (Gst was 0.276 among scattered populations. Neutrality tests showed deviation of 118 loci from Hardy-Weinberg equilibrium. The number of loci that deviated from neutrality increased with altitude (R² = 0.63. Test of linkage disequilibrium showed greater contribution of variance among eri subpopulations to total variance. D'2IS exceeded D'2ST, showed significant contribution of random genetic drift to the increase in variance of disequilibrium in subpopulations. In the Lakhimpur population, the peripheral part was separated from the core by a genetic distance of 0.260. Patchy habitats promoted low genetic variability, high linkage disequilibrium and colonization by new subpopulations. Increased gene flow and habitat-area expansion are required to maintain higher genetic variability and conservation of the original S. c. ricini gene pool.

  1. Locally adapted fish populations maintain small-scale genetic differentiation despite perturbation by a catastrophic flood event

    Science.gov (United States)

    2010-01-01

    Background Local adaptation to divergent environmental conditions can promote population genetic differentiation even in the absence of geographic barriers and hence, lead to speciation. Perturbations by catastrophic events, however, can distort such parapatric ecological speciation processes. Here, we asked whether an exceptionally strong flood led to homogenization of gene pools among locally adapted populations of the Atlantic molly (Poecilia mexicana, Poeciliidae) in the Cueva del Azufre system in southern Mexico, where two strong environmental selection factors (darkness within caves and/or presence of toxic H2S in sulfidic springs) drive the diversification of P. mexicana. Nine nuclear microsatellites as well as heritable female life history traits (both as a proxy for quantitative genetics and for trait divergence) were used as markers to compare genetic differentiation, genetic diversity, and especially population mixing (immigration and emigration) before and after the flood. Results Habitat type (i.e., non-sulfidic surface, sulfidic surface, or sulfidic cave), but not geographic distance was the major predictor of genetic differentiation. Before and after the flood, each habitat type harbored a genetically distinct population. Only a weak signal of individual dislocation among ecologically divergent habitat types was uncovered (with the exception of slightly increased dislocation from the Cueva del Azufre into the sulfidic creek, El Azufre). By contrast, several lines of evidence are indicative of increased flood-induced dislocation within the same habitat type, e.g., between different cave chambers of the Cueva del Azufre. Conclusions The virtual absence of individual dislocation among ecologically different habitat types indicates strong natural selection against migrants. Thus, our current study exemplifies that ecological speciation in this and other systems, in which extreme environmental factors drive speciation, may be little affected by temporary

  2. Sewage treatment plant associated genetic differentiation in the blue mussel from the Baltic Sea and Swedish west coast

    Science.gov (United States)

    Lönn, Mikael; Lind, Emma E.; Świeżak, Justyna; Smolarz, Katarzyna; Grahn, Mats

    2016-01-01

    Human-derived environmental pollutants and nutrients that reach the aquatic environment through sewage effluents, agricultural and industrial processes are constantly contributing to environmental changes that serve as drivers for adaptive responses and evolutionary changes in many taxa. In this study, we examined how two types of point sources of aquatic environmental pollution, harbors and sewage treatment plants, affect gene diversity and genetic differentiation in the blue mussel in the Baltic Sea area and off the Swedish west coast (Skagerrak). Reference sites (REF) were geographically paired with sites from sewage treatments plant (STP) and harbors (HAR) with a nested sampling scheme, and genetic differentiation was evaluated using a high-resolution marker amplified fragment length polymorphism (AFLP). This study showed that genetic composition in the Baltic Sea blue mussel was associated with exposure to sewage treatment plant effluents. In addition, mussel populations from harbors were genetically divergent, in contrast to the sewage treatment plant populations, suggesting that there is an effect of pollution from harbors but that the direction is divergent and site specific, while the pollution effect from sewage treatment plants on the genetic composition of blue mussel populations acts in the same direction in the investigated sites.

  3. Sewage treatment plant associated genetic differentiation in the blue mussel from the Baltic Sea and Swedish west coast

    Directory of Open Access Journals (Sweden)

    Josefine Larsson

    2016-10-01

    Full Text Available Human-derived environmental pollutants and nutrients that reach the aquatic environment through sewage effluents, agricultural and industrial processes are constantly contributing to environmental changes that serve as drivers for adaptive responses and evolutionary changes in many taxa. In this study, we examined how two types of point sources of aquatic environmental pollution, harbors and sewage treatment plants, affect gene diversity and genetic differentiation in the blue mussel in the Baltic Sea area and off the Swedish west coast (Skagerrak. Reference sites (REF were geographically paired with sites from sewage treatments plant (STP and harbors (HAR with a nested sampling scheme, and genetic differentiation was evaluated using a high-resolution marker amplified fragment length polymorphism (AFLP. This study showed that genetic composition in the Baltic Sea blue mussel was associated with exposure to sewage treatment plant effluents. In addition, mussel populations from harbors were genetically divergent, in contrast to the sewage treatment plant populations, suggesting that there is an effect of pollution from harbors but that the direction is divergent and site specific, while the pollution effect from sewage treatment plants on the genetic composition of blue mussel populations acts in the same direction in the investigated sites.