Direct-to-Consumer Genetic Testing: Helping Patients Make Informed Choices
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Science.gov (United States)

Mahon, Suzanne M

2018-02-01

Using direct-to-consumer genetic testing (DTCGT), individuals can order a genetic test, collect and submit a saliva sample, and obtain results about their genetic risk for a variety of traits and health conditions without involving a healthcare provider. Potential benefits of DTCGT include personal control over genetic information and health management decisions, whereas potential risks include misinterpretation of results, psychosocial distress, and lack of informed consent. Oncology nurses can provide education, support, and advocacy to enable patients to truly understand the positives and negatives associated with DTCGT.
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Health-related direct-to-consumer genetic testing: a review of companies' policies with regard to genetic testing in minors.

Science.gov (United States)

Borry, Pascal; Howard, Heidi C; Sénécal, Karine; Avard, Denise

2010-03-01

More and more companies are advertising and selling genetic tests directly to consumers. Considering the ethical, legal, and psychological concerns surrounding genetic testing in minors, a study of companies' websites was performed in order to describe and analyze their policies with respect to this issue. Of the 29 companies analyzed, 13 did not provide any information about this matter, eight companies allowed genetic testing upon parental request, four companies stated that their website is not directed to children under 18 years, and four companies suggested that in order to be tested, applicants should have reached the age of legal majority. If private companies offer genetic tests which are also offered in a clinical setting, can they be expected to adhere to the existing clinical guidelines with regard to these tests? If so, a certain ambiguity exists. Many companies are emphasizing in their disclaimers that their services are not medical services and should not be used as a basis for making medical decisions. Nonetheless, it remains debatable whether genetic testing in minors would be appropriate in this context. In line with the Advisory Committee on Genetic Testing, the Human Genetics Commission addressed the problem of non-consensual testing and recommended not to supply genetic testing services directly to those under the age of 16 or to those not able to make a competent decision regarding testing.

Direct and maternal genetic effects for preweaning growth in Retinta cattle estimated by a longitudinal approach throughout the calving trajectory of the cow.

Science.gov (United States)

Morales, R; Menéndez-Buxadera, A; Avilés, C; Molina, A

2013-12-01

The direct and maternal genetic effects were estimated for the preweaning growth of Retinta calves with a multitrait model across parities, using a longitudinal approach with random regression models (RRM). The 120 (P120) and 180 days (P180) weights (5972 calves) were considered as different traits in each calving. The heritability of direct effect across parities was on average 0.37 for P120 and 0.58 for P180, slightly higher than the estimates by univariate (0.30 and 0.56) and bivariate models (0.30 and 0.51, respectively). The heritability for maternal effects was 0.16 for P120 and 0.26 for P180 and very similar by uni- (0.16 and 0.23) and multivariate model (0.16 and 0.22, respectively). The correlation between direct and maternal effects by RRM showed a pronounced antagonism -0.64 for P120 and -0.78 for P180), likewise uni- (-0.62 and -0.72) and multivariate case (-0.64 and -0.74, respectively). The preweaning weights should be considered as different traits across parities, because the genetic correlations were different from unity. The RRM also allowed us to estimate all the parameters throughout the calving trajectory of the cow. The use of multiple traits RRM across parities can provide very useful information for the breeding programmes. © 2013 Blackwell Verlag GmbH.

Internet-Based Direct-to-Consumer Genetic Testing: A Systematic Review.

Science.gov (United States)

Covolo, Loredana; Rubinelli, Sara; Ceretti, Elisabetta; Gelatti, Umberto

2015-12-14

Direct-to-consumer genetic tests (DTC-GT) are easily purchased through the Internet, independent of a physician referral or approval for testing, allowing the retrieval of genetic information outside the clinical context. There is a broad debate about the testing validity, their impact on individuals, and what people know and perceive about them. The aim of this review was to collect evidence on DTC-GT from a comprehensive perspective that unravels the complexity of the phenomenon. A systematic search was carried out through PubMed, Web of Knowledge, and Embase, in addition to Google Scholar according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist with the key term "Direct-to-consumer genetic test." In the final sample, 118 articles were identified. Articles were summarized in five categories according to their focus on (1) knowledge of, attitude toward use of, and perception of DTC-GT (n=37), (2) the impact of genetic risk information on users (n=37), (3) the opinion of health professionals (n=20), (4) the content of websites selling DTC-GT (n=16), and (5) the scientific evidence and clinical utility of the tests (n=14). Most of the articles analyzed the attitude, knowledge, and perception of DTC-GT, highlighting an interest in using DTC-GT, along with the need for a health care professional to help interpret the results. The articles investigating the content analysis of the websites selling these tests are in agreement that the information provided by the companies about genetic testing is not completely comprehensive for the consumer. Given that risk information can modify consumers' health behavior, there are surprisingly few studies carried out on actual consumers and they do not confirm the overall concerns on the possible impact of DTC-GT. Data from studies that investigate the quality of the tests offered confirm that they are not informative, have little predictive power, and do not measure genetic risk

Risk assesment in the context of EC directives on genetically modified organisms

Energy Technology Data Exchange (ETDEWEB)

Meer, P.J. van der [Ministry for the Environment (Netherlands)

1992-07-01

The introduction of these new molecular technologies initiated an international discussion on the safety in biotechnology. In 1974 one of the pioneers of this new technology, Paul Berg, expressed his view on the potential risks of recombinant DNA applications in the famous 'Berg letter', leading to a self-imposed moratorium on certain experiments. Following the Berg letter and the Asilomar convention, much international attention has been given to the question of safety in biotechnology. This attention resulted in hundreds of documents, research programmes, guidelines and regulations. This resulted, among others, in two EC Directives on genetically modified organisms: the EC Directive 90/219/EEC on the contained use of genetically modified micro-organisms, and Directive 90/220/EEC on the release of genetically modified organisms. These directives lay down a system for harmonization of risk assessment and risk management with regard to the safety for human health and the environment.

Risk assesment in the context of EC directives on genetically modified organisms

International Nuclear Information System (INIS)

Meer, P.J. van der

1992-01-01

The introduction of these new molecular technologies initiated an international discussion on the safety in biotechnology. In 1974 one of the pioneers of this new technology, Paul Berg, expressed his view on the potential risks of recombinant DNA applications in the famous 'Berg letter', leading to a self-imposed moratorium on certain experiments. Following the Berg letter and the Asilomar convention, much international attention has been given to the question of safety in biotechnology. This attention resulted in hundreds of documents, research programmes, guidelines and regulations. This resulted, among others, in two EC Directives on genetically modified organisms: the EC Directive 90/219/EEC on the contained use of genetically modified micro-organisms, and Directive 90/220/EEC on the release of genetically modified organisms. These directives lay down a system for harmonization of risk assessment and risk management with regard to the safety for human health and the environment

Direct-to-consumer genetic testing: perceptions, problems, and policy responses.

Science.gov (United States)

Caulfield, Timothy; McGuire, Amy L

2012-01-01

Direct-to-consumer (DTC) genetic testing has attracted a great amount of attention from policy makers, the scientific community, professional groups, and the media. Although it is unclear what the public demand is for these services, there does appear to be public interest in personal genetic risk information. As a result, many commentators have raised a variety of social, ethical, and regulatory issues associated with this emerging industry, including privacy issues, ensuring that DTC companies provide accurate information about the risks and limitations of their services, the possible adverse impact of DTC genetic testing on healthcare systems, and concern about how individuals may interpret and react to genetic risk information.

Direct to consumer genetic testing-law and policy concerns in Ireland.

Science.gov (United States)

de Paor, Aisling

2017-11-25

With rapid scientific and technological advances, the past few years has witnessed the emergence of a new genetic era and a growing understanding of the genetic make-up of human beings. These advances have propelled the introduction of companies offering direct to consumer (DTC) genetic testing, which facilitates the direct provision of such tests to consumers, (for example, via the internet). Although DTC genetic testing offers benefits by enhancing consumer accessibility to such technology, promoting proactive healthcare and increasing genetic awareness, it presents a myriad of challenges, from an ethical, legal and regulatory perspective. As DTC genetic testing usually eliminates the need for a medical professional in accessing genetic tests, this lack of professional guidance and counselling may result in misinterpretation and confusion regarding results. In addition, an evident concern relates to the scientific validity and quality of these tests. A further problem arising is the lack or inadequacy of regulation in this field. Despite the increasing accessibility of DTC genetic testing, this legislative vacuum is apparent in Ireland, where there is no concrete legislation. This article explores the main ethical, legal and regulatory issues arising with the advent of rapid advances in DTC genetic testing in Ireland. Further, with inevitable future advances in genetic science, as well as increasing internet accessibility, the challenges presented are likely to become more amplified. In consideration of the ethical and legal challenges, this paper highlights the regulation of DTC genetic testing as a growing concern in Ireland, recognising its importance to both the scientific community as well as in respect of enhancing consumer confidence in such technologies.

Exploring dispositional tendencies to seek online information about direct-to-consumer genetic testing.

Science.gov (United States)

Paquin, Ryan S; Richards, Adam S; Koehly, Laura M; McBride, Colleen M

2012-12-01

Varying perspectives exist regarding the implications of genetic susceptibility testing for common disease, with some anticipating adverse effects and others expecting positive outcomes; however, little is known about the characteristics of people who are most likely to be interested in direct-to-consumer genetic testing. To that end, this study examines the association of individual dispositional differences with health risk perceptions and online information seeking related to a free genetic susceptibility test. Healthy adults enrolled in a large health maintenance organization were surveyed by telephone. Eligible participants (N = 1,959) were given access to a secure website that provided risk and benefit information about a genetic susceptibility test and given the option to be tested. Neuroticism was associated with increased perceptions of disease risk but not with logging on. Those scoring high in conscientiousness were more likely to log on. We found no evidence that neuroticism, a dispositional characteristic commonly linked to adverse emotional response, was predictive of online genetic information seeking in this sample of healthy adults.

Ethical and clinical practice considerations for genetic counselors related to direct-to-consumer marketing of genetic tests.

Science.gov (United States)

Wade, Christopher H; Wilfond, Benjamin S

2006-11-15

Several companies utilize direct-to-consumer (DTC) advertising for genetic tests and some, but not all, bypass clinician involvement by offering DTC purchase of the tests. This article examines how DTC marketing strategies may affect genetic counselors, using available cardiovascular disease susceptibility tests as an illustration. The interpretation of these tests is complex and includes consideration of clinical validity and utility, and the further complications of gene-environment interactions and pleiotropy. Although it is unclear to what extent genetic counselors will encounter clients who have been exposed to DTC marketing strategies, these strategies may influence genetic counseling interactions if they produce directed interest in specific tests and unrealistic expectations for the tests' capacity to predict disease. Often, a client's concern about risk for cardiovascular diseases is best addressed by established clinical tests and a family history assessment. Ethical dilemmas may arise for genetic counselors who consider whether to accept clients who request test interpretation or to order DTC-advertised tests that require a clinician's authorization. Genetic counselors' obligations to care for clients extend to interpreting DTC tests, although this obligation may be fulfilled by referral or consultation with specialists. Genetic counselors do not have an obligation to order DTC-advertised tests that have minimal clinical validity and utility at a client's request. This can be a justified restriction on autonomy based on consideration of risks to the client, the costs, and the implications for society. Published 2006 Wiley-Liss, Inc.

Internet-Based Direct-to-Consumer Genetic Testing: A Systematic Review

Science.gov (United States)

Rubinelli, Sara; Ceretti, Elisabetta; Gelatti, Umberto

2015-01-01

Background Direct-to-consumer genetic tests (DTC-GT) are easily purchased through the Internet, independent of a physician referral or approval for testing, allowing the retrieval of genetic information outside the clinical context. There is a broad debate about the testing validity, their impact on individuals, and what people know and perceive about them. Objective The aim of this review was to collect evidence on DTC-GT from a comprehensive perspective that unravels the complexity of the phenomenon. Methods A systematic search was carried out through PubMed, Web of Knowledge, and Embase, in addition to Google Scholar according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist with the key term “Direct-to-consumer genetic test.” Results In the final sample, 118 articles were identified. Articles were summarized in five categories according to their focus on (1) knowledge of, attitude toward use of, and perception of DTC-GT (n=37), (2) the impact of genetic risk information on users (n=37), (3) the opinion of health professionals (n=20), (4) the content of websites selling DTC-GT (n=16), and (5) the scientific evidence and clinical utility of the tests (n=14). Most of the articles analyzed the attitude, knowledge, and perception of DTC-GT, highlighting an interest in using DTC-GT, along with the need for a health care professional to help interpret the results. The articles investigating the content analysis of the websites selling these tests are in agreement that the information provided by the companies about genetic testing is not completely comprehensive for the consumer. Given that risk information can modify consumers’ health behavior, there are surprisingly few studies carried out on actual consumers and they do not confirm the overall concerns on the possible impact of DTC-GT. Data from studies that investigate the quality of the tests offered confirm that they are not informative, have little predictive

Modification of genetic effect of gamma-irradiation by electric current

International Nuclear Information System (INIS)

Grigor'eva, N.N.; Shakhbazov, V.G.

1983-01-01

The effect of direct current of different polarity on genetic sequels of #betta#-radiation of Vicia faba seedlings is studied. It is established that weak current might modify genetic sequels of #betta#-radiation. Protective current effect on irradiated meristem cells of seedlings manifests at negative polarization of the meristem before radiation and at positive polarization-after radiation. Modifying effect of electric current is brought about at the expense of redistribution of anions and cations between the meristem and other root zones

Genetic effects of ionizing radiation and repair processes

International Nuclear Information System (INIS)

Tuschl, H.

1986-11-01

Since DNA (=desoxyribonucleic acid) is the largest molecule within the cell it is the most important target for direct and indirect radiation effects. Within DNA the total genetic information is stored, thus damage to DNA in germ cells causes genetic disorders and damage in somatic cells is implicated in cancer and immunodeficiences. Alterations of DNA structure are not only due to ionizing radiation effects, but also to spontaneous DNA modifications and damage from interactions with environmental ultraviolet light and chemical agents. To maintain its genetic integrity, each organism had to develop different repair systems able to recognize and remove DNA damage. Repeated exposure to a DNA damaging agent can even lead to adaptation processes and increased resistance to the same agent. At normal function of repair systems it can be assumed that the capacity of those systems is adequate to scope with the effects of low radiation doses. (Author)

Assumed genetic effects of low level irradiation on man

International Nuclear Information System (INIS)

Dutrillaux, B.

1976-01-01

The significance of human genetic pathology is stated and a study is made of the assumed effect of low level ionizing radiations. The theoretical notions thus derived are compared to experimental data which are poor. A quick survey of the literature shows that is has not yet been possible to establish a direct relationship between an increase of exposure and any genetic effect on man. However, this must not lead to conclude on the innoxiousness of radiation but rather shows how such analyses are difficult in as much as the effect investigated is necessarily low [fr

The effect of direct-to-consumer genetic tests on anticipated affect and health-seeking behaviors: a pilot survey.

Science.gov (United States)

Bansback, Nick; Sizto, Sonia; Guh, Daphne; Anis, Aslam H

2012-10-01

Numerous websites offer direct-to-consumer (DTC) genetic testing, yet it is unknown how individuals will react to genetic risk profiles online. The objective of this study was to determine the feasibility of using a web-based survey and conjoint methods to elicit individuals' interpretations of genetic risk profiles by their anticipated worry/anxiousness and health-seeking behaviors. A web-based survey was developed using conjoint methods. Each survey presented 12 hypothetical genetic risk profiles describing genetic test results for four diseases. Test results were characterized by the type of disease (eight diseases), individual risk (five levels), and research confidence (three levels). After each profile, four questions were asked regarding anticipated worry and health-seeking behaviors. Probabilities of response outcomes based on attribute levels were estimated from logistic regression models, adjusting for covariates. Overall, 319 participants (69%) completed 3828 unique genetic risk profiles. Across all profiles, most participants anticipated making doctor's appointments (63%), lifestyle changes (57%), and accessing screening (57%); 40% anticipated feeling more worried and anxious. Higher levels of disease risk were significantly associated with affirmative responses. Conjoint methods may be used to elicit reactions to genetic information online. Preliminary results suggest that genetic information may increase worry/anxiousness and health-seeking behaviors among consumers of DTC tests. Further research is planned to determine the appropriateness of these affects and behaviors.

Modification of genetic effect of gamma irradiation by electric current

International Nuclear Information System (INIS)

Grigor'eva, N.N.; Shakhbazov, V.G.

1985-01-01

The effect of direct electric current of different value and polarity on genetic sequences of γ-irradiation of Vicia faba seedlings has been studied. The previously found modifying effect of direct electric current is confirmed. The extent and character of this effect depend on the value and polarity of current as well as time between irradiation and electric effects. Current effect modes having no effect on irradiated seedlings protecting cells from injury and the modes aggravating radiation effect have been found. At certain modes the effects of direct electric current on irradiated seedlings changes in the rearrangement spectrum are observed, particularly the number of bridges is increased

Estimating directional epistasis

Science.gov (United States)

Le Rouzic, Arnaud

2014-01-01

Epistasis, i.e., the fact that gene effects depend on the genetic background, is a direct consequence of the complexity of genetic architectures. Despite this, most of the models used in evolutionary and quantitative genetics pay scant attention to genetic interactions. For instance, the traditional decomposition of genetic effects models epistasis as noise around the evolutionarily-relevant additive effects. Such an approach is only valid if it is assumed that there is no general pattern among interactions—a highly speculative scenario. Systematic interactions generate directional epistasis, which has major evolutionary consequences. In spite of its importance, directional epistasis is rarely measured or reported by quantitative geneticists, not only because its relevance is generally ignored, but also due to the lack of simple, operational, and accessible methods for its estimation. This paper describes conceptual and statistical tools that can be used to estimate directional epistasis from various kinds of data, including QTL mapping results, phenotype measurements in mutants, and artificial selection responses. As an illustration, I measured directional epistasis from a real-life example. I then discuss the interpretation of the estimates, showing how they can be used to draw meaningful biological inferences. PMID:25071828

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

Science.gov (United States)

Cermeño Zambrano, Fernando G De J

2002-01-01

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

Direct to consumer genetic testing and the libertarian right to test.

Science.gov (United States)

Loi, Michele

2016-09-01

I sketch a libertarian argument for the right to test in the context of 'direct to consumer' (DTC) genetic testing. A libertarian right to genetic tests, as defined here, relies on the idea of a moral right to self-ownership. I show how a libertarian right to test can be inferred from this general libertarian premise, at least as a prima facie right, shifting the burden of justification on regulators. I distinguish this distinctively libertarian position from some arguments based on considerations of utility or autonomy, which are sometimes labelled 'libertarian' because they oppose a tight regulation of the direct to consumer genetic testing sector. If one takes the libertarian right to test as a starting point, the whole discussion concerning autonomy and personal utility may be sidestepped. Finally, I briefly consider some considerations that justify the regulation of the DTC genetic testing market, compatible with the recognition of a prima facie right to test. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Social genetic effects for growth in pigs differ between boars and gilts

DEFF Research Database (Denmark)

Nielsen, Hanne M.; Ask, Birgitte; Madsen, Per

2018-01-01

between boars and gilts and that accounting for these differences will improve the predictive ability of a social genetic effects model (SGM). Our data consisted of ADG from 30 to 94 kg for 32,212 uncastrated males (boars) and 48,252 gilts that were raised in sex-specific pens. Data were analyzed using......Average daily gain (ADG) in pigs is affected by the so-called social (or indirect) genetic effects (SGE). However, SGE may differ between sexes because boars grow faster than gilts and their social behaviours differ. We hypothesized that direct genetic effects (DGE) and SGE for ADG in pigs differ...

Directed genetic modification of African horse sickness virus by reverse genetics

Directory of Open Access Journals (Sweden)

Elaine Vermaak

2015-07-01

Full Text Available African horse sickness virus (AHSV, a member of the Orbivirus genus in the family Reoviridae, is an arthropod-transmitted pathogen that causes a devastating disease in horses with a mortality rate greater than 90%. Fundamental research on AHSV and the development of safe, efficacious vaccines could benefit greatly from an uncomplicated genetic modification method to generate recombinant AHSV. We demonstrate that infectious AHSV can be recovered by transfection of permissive mammalian cells with transcripts derived in vitro from purified AHSV core particles. These findings were expanded to establish a genetic modification system for AHSV that is based on transfection of the cells with a mixture of purified core transcripts and a synthetic T7 transcript. This approach was applied successfully to recover a directed cross-serotype reassortant AHSV and to introduce a marker sequence into the viral genome. The ability to manipulate the AHSV genome and engineer specific mutants will increase understanding of AHSV replication and pathogenicity, as well as provide a tool for generating designer vaccine strains.

Ontogeny of additive and maternal genetic effects: lessons from domestic mammals.

Science.gov (United States)

Wilson, Alastair J; Reale, Denis

2006-01-01

Evolution of size and growth depends on heritable variation arising from additive and maternal genetic effects. Levels of heritable (and nonheritable) variation might change over ontogeny, increasing through "variance compounding" or decreasing through "compensatory growth." We test for these processes using a meta-analysis of age-specific weight traits in domestic ungulates. Generally, mean standardized variance components decrease with age, consistent with compensatory growth. Phenotypic convergence among adult sheep occurs through decreasing environmental and maternal genetic variation. Maternal variation similarly declines in cattle. Maternal genetic effects are thus reduced with age (both in absolute and relative terms). Significant trends in heritability (decreasing in cattle, increasing in sheep) result from declining maternal and environmental components rather than from changing additive variation. There was no evidence for increasing standardized variance components. Any compounding must therefore be masked by more important compensatory processes. While extrapolation of these patterns to processes in natural population is difficult, our results highlight the inadequacy of assuming constancy in genetic parameters over ontogeny. Negative covariance between direct and maternal genetic effects was common. Negative correlations with additive and maternal genetic variances indicate that antagonistic pleiotropy (between additive and maternal genetic effects) may maintain genetic variance and limit responses to selection.

Genetic effects of ionising radiation in man

International Nuclear Information System (INIS)

Sankaranarayanan, K.

1991-01-01

A review is given of genetic risk estimation in man. Topics covered include the methods used, the germ cell stages and radiation conditions relevant for genetic risk estimation, doubling dose estimates, the classification and prevalence of naturally-occurring genetic disorders, the source of data used in the direct method of risk estimation, the genetic risk estimates from the mid-1970s to the present, the estimates of genetic risk used in ICRP 26 in 1977 and ICRP's current assessment of genetic risks. (UK)

Modification of the genetic effect of gamma irradiation by electric current

International Nuclear Information System (INIS)

Grigor'eva, N.N.; Shakhbazov, V.G.

1985-01-01

The authors study the effect of direct current of varying strength and polarity on the genetic damage due to gamma irradiation of Vicia faba seedlings. The modificational effect of direct current observed earlier is confirmed here. The extent and nature of this effect depends on the strength and polarity of the current as well as interval between irradiation and exposure to the electric field. Conditions having no effect on the irradiated seedlings, those protecting the cells from damage and enhancing the irradiation effect, are identified

Trends and Gaps in Awareness of Direct-to-Consumer Genetic Tests From 2007 to 2014.

Science.gov (United States)

Apathy, Nate C; Menser, Terri; Keeran, Lindsay M; Ford, Eric W; Harle, Christopher A; Huerta, Timothy R

2018-06-01

Direct-to-consumer genetic tests for inherited disease risks have gained recent approvals from the Food and Drug Administration, and interest in these tests has continued to grow. Broad use of these tests coupled with planning and discussion with health providers regarding genetic risks and potential protective behavior changes have been proposed as preventive tools to reduce health disparities and improve equity in health outcomes. However, awareness of direct-to-consumer genetic testing has historically demonstrated differences by education, income, and race; these disparities could jeopardize potential benefits by limiting access and use. The national survey data from the Health Information National Trends Survey was analyzed to understand how overall awareness of direct-to-consumer genetic testing and disparities in awareness across sociodemographic groups have changed since 2007. The findings showed persistent disparities, as well as a widening gap in awareness between Hispanics and non-Hispanic whites (OR 2007 =1.52, OR 2014 =0.58, p change =0.0056), despite overall increases in awareness over time. Given these findings, policies regulating direct-to-consumer genetic tests should prioritize equitable distribution of benefits by including provisions that counteract prevailing disparities in awareness. Copyright © 2018 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Analysis of conditional genetic effects and variance components in developmental genetics.

Science.gov (United States)

Zhu, J

1995-12-01

A genetic model with additive-dominance effects and genotype x environment interactions is presented for quantitative traits with time-dependent measures. The genetic model for phenotypic means at time t conditional on phenotypic means measured at previous time (t-1) is defined. Statistical methods are proposed for analyzing conditional genetic effects and conditional genetic variance components. Conditional variances can be estimated by minimum norm quadratic unbiased estimation (MINQUE) method. An adjusted unbiased prediction (AUP) procedure is suggested for predicting conditional genetic effects. A worked example from cotton fruiting data is given for comparison of unconditional and conditional genetic variances and additive effects.

Autobiologies on YouTube: Narratives of Direct-to-Consumer Genetic Testing

Science.gov (United States)

Harris, Anna; Kelly, Susan E.; Wyatt, Sally

2014-01-01

Despite a growing personal genomics market, little is known about how people engage with the possibilities offered by direct-to-consumer (DTC) genetic testing. In order to help address this gap, this study deploys narrative analysis of YouTube videos posted by individuals who have purchased DTC genetic testing for disease. Genetic testing is said to be contributing to new states of illness, where individuals may become “patients-in-waiting.” In the videos analyzed, we found a new form of storytelling about this ambiguous state of illness, which we refer to as autobiology. Autobiology – the study of, and story about, one's own biology – concerns narratives of sense-making through forms of biological practice, as well as wayfaring narratives which interweave genetic markers and family histories of disease. These autobiologies – part of a broader shift toward public stories about genetics and other healthcare technologies – exhibit playfulness, as well as being bound with consumerist practices. PMID:24772003

The genetic effects induced by an irradiation in low doses at Drosophila melanogaster

International Nuclear Information System (INIS)

Zajnullin, V.G.; Taskaev, A.I.; Moskalev, A.A.; Shaposhnikov, M.V.

2006-01-01

The review generalizes the results obtained in researches of genetic radiation effects for Drosophila melanogaster from contamination regions near the Chernobylsk NPP. The results of laboratory investigations of low dose irradiation effects on genotype variability and lifetime of Drosophila are presented too. It supposed that the main effect of low dose irradiation is caused by the induced genetic instability against the background of which the realization of different-directed radiobiological reactions is possible [ru

Limits to behavioral evolution: the quantitative genetics of a complex trait under directional selection.

Science.gov (United States)

Careau, Vincent; Wolak, Matthew E; Carter, Patrick A; Garland, Theodore

2013-11-01

Replicated selection experiments provide a powerful way to study how "multiple adaptive solutions" may lead to differences in the quantitative-genetic architecture of selected traits and whether this may translate into differences in the timing at which evolutionary limits are reached. We analyze data from 31 generations (n=17,988) of selection on voluntary wheel running in house mice. The rate of initial response, timing of selection limit, and height of the plateau varied significantly between sexes and among the four selected lines. Analyses of litter size and realized selection differentials seem to rule out counterposing natural selection as a cause of the selection limits. Animal-model analyses showed that although the additive genetic variance was significantly lower in selected than control lines, both before and after the limits, the decrease was not sufficient to explain the limits. Moreover, directional selection promoted a negative covariance between additive and maternal genetic variance over the first 10 generations. These results stress the importance of replication in selection studies of higher-level traits and highlight the fact that long-term predictions of response to selection are not necessarily expected to be linear because of the variable effects of selection on additive genetic variance and maternal effects. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

Pharmacogenetic testing through the direct-to-consumer genetic testing company 23andMe.

Science.gov (United States)

Lu, Mengfei; Lewis, Cathryn M; Traylor, Matthew

2017-06-19

Rapid advances in scientific research have led to an increase in public awareness of genetic testing and pharmacogenetics. Direct-to-consumer (DTC) genetic testing companies, such as 23andMe, allow consumers to access their genetic information directly through an online service without the involvement of healthcare professionals. Here, we evaluate the clinical relevance of pharmacogenetic tests reported by 23andMe in their UK tests. The research papers listed under each 23andMe report were evaluated, extracting information on effect size, sample size and ethnicity. A wider literature search was performed to provide a fuller assessment of the pharmacogenetic test and variants were matched to FDA recommendations. Additional evidence from CPIC guidelines, PharmGKB, and Dutch Pharmacogenetics Working Group was reviewed to determine current clinical practice. The value of the tests across ethnic groups was determined, including information on linkage disequilibrium between the tested SNP and causal pharmacogenetic variant, where relevant. 23andMe offers 12 pharmacogenetic tests to their UK customers, some of which are in standard clinical practice, and others which are less widely applied. The clinical validity and clinical utility varies extensively between tests. The variants tested are likely to have different degrees of sensitivity due to different risk allele frequencies and linkage disequilibrium patterns across populations. The clinical relevance depends on the ethnicity of the individual and variability of pharmacogenetic markers. Further research is required to determine causal variants and provide more complete assessment of drug response and side effects. 23andMe reports provide some useful pharmacogenetics information, mirroring clinical tests that are in standard use. Other tests are unspecific, providing limited guidance and may not be useful for patients without professional interpretation. Nevertheless, DTC companies like 23andMe act as a powerful

The genetics of indirect ecological effects - plant parasites and aphid herbivores

Directory of Open Access Journals (Sweden)

Jennifer K Rowntree

2014-04-01

Full Text Available When parasitic plants and aphid herbivores share a host, both direct and indirect ecological effects (IEEs can influence evolutionary processes. We used a hemiparasitic plant (Rhinanthus minor, a grass host (Hordeum vulgare and a cereal aphid (Sitobion avenae to investigate the genetics of IEEs between the aphid and the parasitic plant, and looked to see how these might affect or be influenced by the genetic diversity of the host plants. Survival of R. minor depended on the parasite’s population of origin, the genotypes of the aphids sharing the host and the genetic diversity in the host plant community. Hence the indirect effects of the aphids on the parasitic plants depended on the genetic environment of the system. Here, we show that genetic variation can be important in determining the outcome of IEEs. Therefore, IEEs have the potential to influence evolutionary processes and the continuity of species interactions over time.

Legislation on direct-to-consumer genetic testing in seven European countries.

Science.gov (United States)

Borry, Pascal; van Hellemondt, Rachel E; Sprumont, Dominique; Jales, Camilla Fittipaldi Duarte; Rial-Sebbag, Emmanuelle; Spranger, Tade Matthias; Curren, Liam; Kaye, Jane; Nys, Herman; Howard, Heidi

2012-07-01

An increasing number of private companies are now offering direct-to-consumer (DTC) genetic testing services. Although a lot of attention has been devoted to the regulatory framework of DTC genetic testing services in the USA, only limited information about the regulatory framework in Europe is available. We will report on the situation with regard to the national legislation on DTC genetic testing in seven European countries (Belgium, the Netherlands, Switzerland, Portugal, France, Germany, the United Kingdom). The paper will address whether these countries have legislation that specifically address the issue of DTC genetic testing or have relevant laws that is pertinent to the regulatory control of these services in their countries. The findings show that France, Germany, Portugal and Switzerland have specific legislation that defines that genetic tests can only be carried out by a medical doctor after the provision of sufficient information concerning the nature, meaning and consequences of the genetic test and after the consent of the person concerned. In the Netherlands, some DTC genetic tests could fall under legislation that provides the Minister the right to refuse to provide a license to operate if a test is scientifically unsound, not in accordance with the professional medical practice standards or if the expected benefit is not in balance with the (potential) health risks. Belgium and the United Kingdom allow the provision of DTC genetic tests.

Estimation of total genetic effects for survival time in crossbred laying hens showing cannibalism, using pedigree or genomic information

NARCIS (Netherlands)

Brinker, T.; Raymond, B.; Bijma, P.; Vereijken, A.; Ellen, E.D.

2017-01-01

Mortality of laying hens due to cannibalism is a major problem in the egg-laying industry. Survival depends on two genetic effects: the direct genetic effect of the individual itself (DGE) and the indirect genetic effects of its group mates (IGE). For hens housed in sire-family groups, DGE and

Attitudes about regulation among direct-to-consumer genetic testing customers.

Science.gov (United States)

Bollinger, Juli Murphy; Green, Robert C; Kaufman, David

2013-05-01

The first regulatory rulings by the U.S. Food and Drug Administration on direct-to-consumer (DTC) genetic testing services are expected soon. As the process of regulating these and other genetic tests moves ahead, it is important to understand the preferences of DTC genetic testing customers about the regulation of these products. An online survey of customers of three DTC genetic testing companies was conducted 2-8 months after they had received their results. Participants were asked about the importance of regulating the companies selling DTC genetic tests. Most of the 1,046 respondents responded that it would be important to have a nongovernmental (84%) or governmental agency (73%) monitor DTC companies' claims to ensure the consistency with scientific evidence. However, 66% also felt that it was important that DTC tests be available without governmental oversight. Nearly, all customers favored a policy to ensure that insurers and law enforcement officials could not access their information. Although many DTC customers want access to genetic testing services without restrictions imposed by the government regulation, most also favor an organization operating alongside DTC companies that will ensure that the claims made by the companies are consistent with sound scientific evidence. This seeming contradiction may indicate that DTC customers want to ensure that they have unfettered access to high-quality information. Additionally, policies to help ensure privacy of data would be welcomed by customers, despite relatively high confidence in the companies.

Rural-urban and racial-ethnic differences in awareness of direct-to-consumer genetic testing.

Science.gov (United States)

Salloum, Ramzi G; George, Thomas J; Silver, Natalie; Markham, Merry-Jennifer; Hall, Jaclyn M; Guo, Yi; Bian, Jiang; Shenkman, Elizabeth A

2018-02-23

Access to direct-to-consumer genetic testing services has increased in recent years. However, disparities in knowledge and awareness of these services are not well documented. We examined awareness of genetic testing services by rural/urban and racial/ethnic status. Analyses were conducted using pooled cross-sectional data from 4 waves (2011-2014) of the Health Information National Trends Survey (HINTS). Descriptive statistics compared sample characteristics and information sources by rural/urban residence. Logistic regression was used to examine the relationship between geography, racial/ethnic status, and awareness of genetic testing, controlling for sociodemographic characteristics. Of 13,749 respondents, 16.7% resided in rural areas, 13.8% were Hispanic, and 10.1% were non-Hispanic black. Rural residents were less likely than urban residents to report awareness of genetic testing (OR = 0.74, 95% CI = 0.63-0.87). Compared with non-Hispanic whites, racial/ethnic minorities were less likely to be aware of genetic testing: Hispanic (OR = 0.68, 95% CI = 0.56-0.82); and non-Hispanic black (OR = 0.74, 95% CI = 0.61-0.90). Rural-urban and racial-ethnic differences exist in awareness of direct-to-consumer genetic testing. These differences may translate into disparities in the uptake of genetic testing, health behavior change, and disease prevention through precision and personalized medicine.

Genetic effects of radiation in man

International Nuclear Information System (INIS)

Freire-Maia, N.

1978-01-01

Information obtained through three different surveys among Brazilian physicians is presented. Data have been classified according to survey, medical specialty, protection used and pregnancy order. Events under consideration are abortions, stillbirths, neo-natal mortality, infant-juvenile mortality, marbidity and sex ratio. A number of statistically sugnificant diferences have been found in the direction expected according to the radio-genetics theory and a few ones against it. Two of the surveys revealed an effect of the pregnancy order on abortions which was larger inthe exposed samples than in the control ones [pt

Genetic effects from internally deposited radionuclides

International Nuclear Information System (INIS)

Anon.

1987-01-01

It was learned in the late 1920's that ionizing radiation could produce genetic effects such as gene mutations and chromosome aberrations. However, at least until 1945, the focus on interest in radiation protection was primarily on somatic effects manifested in the individual exposed. Studies of the genetic effects of radiation using drosophila, however, refocused attention on effects transmitted to the exposed individuals offspring and concern over fallout in the 1950's resulted in efforts to estimate the genetic effects from exposure of human populations to internally deposited radionuclides. No human populations have been identified with burdens of internally deposited radioactive materials which have been shown to produce evidence of transmissible genetic damage. As a result, the research approach has been one in which macromolecular, cellular, and whole animal genetic studies have been combined to estimate genetic effects on humans following the deposition of radioactive materials in the body. The purpose of this report is to update the information available from animal and cellular experiments that relates genetic effects to deposited activity and dose from internally deposited radioactive materials

Somatic and genetic effects

International Nuclear Information System (INIS)

Broerse, J.J.; Barendsen, G.W.; Kal, H.B.; Kogel, A.J. van der

1983-01-01

This book contains the extended abstracts of the contributions of the poster workshop sessions on somatic and genetic effects of the 7th international congress of radiation research. They cover the following main topics: haematopoietic and immune systems, mechanisms of late effects in various tissues, endogenous and exogenous factors in radiation carcinogenesis, teratogenic effects, genetic effects, in vitro transformation, tumour induction in different tissues, carcinogenesis in incorporated tissues, cancer epidemology and risk assessment. refs.; figs.; tabs

[Direct-to-consumer genetic testing through Internet: marketing, ethical and social issues].

Science.gov (United States)

Ducournau, Pascal; Gourraud, Pierre-Antoine; Rial-Sebbag, Emmanuelle; Bulle, Alexandre; Cambon-Thomsen, Anne

2011-01-01

We probably did not anticipate all the consequences of the direct to consumer genetic tests on Internet, resulting from the combined skills of communication and genomic advances. What are the commercial strategies used by the companies offering direct-to-consumer genetic tests on Internet and what are the different social expectations on which they focus? Through a quantitative and qualitative analysis of the web sites offering such tests, it seems that these companies target a triple market based on: the "healthism" which raises health and hygiene to the top of the social values; the contemporary demands of the users to become actual actors of health decisions; and finally on the need for bio-social relationships. These three commercial strategies underlie various ethical and societal issues justifying a general analysis.

"Be ready against cancer, now": direct-to-consumer advertising for genetic testing.

Science.gov (United States)

William-Jones, Bryn

2006-04-01

A recent addition to the debate about the benefits and harms of direct-to-consumer (DTC) advertising of medicines and pharmaceuticals is a growing critique of DTC marketing and sale of genetic tests. Academic and policy literatures exploring this issue have, however, tended to focus on the sale of genetic tests, paying rather less attention to the particular implications of advertising. The globalization of broadcast media and ever increasing access to the Internet mean that public exposure to advertising for medical technologies is a reality that national regulatory bodies will be hard pressed to constrain. Working through a case study detailing Myriad Genetics' 2002 pilot advertising campaign for their BRACAnalysis genetic susceptibility test for hereditary breast and ovarian cancer, this paper highlights some of the diverse and often overlooked and unregulated approaches to DTC advertising, and the associated social, ethical and policy implications.

Genetic effects of the atomic bombs: a reappraisal

International Nuclear Information System (INIS)

Schull, W.J.; Otake, M.; Neel, J.V.

1981-01-01

Data are presented on four indicators of genetic effects from studies of children born to survivors of the atomic bombings of Hiroshima and Nagasaki. The indicators are frequency of untoward pregnancy outcomes (stillbirth, major congenital defect, death during the first postnatal weak); occurrence of death in live-born children, through an average of life expectancy of 17 years; frequency of children with sex chromosome aneuploidy; and frequency of children with mutation resulting in an eletrophoretic variant. In no instance is there a statistically significant effect of parental exposure; but for all indicators the observed effect is in the direction suggested by the hypothesis that genetic damage resulted from the exposure. On the basis of assumptions concerning the contribution that spontaneous mutation in the preceding generation makes to the indicators in question, it is possible to estimate the genetic doubling dose for radiation for the first three indicators (the data base is still too small for the fourth). The average of these estimates is 156 rems. This is some four times higher than the results from experimental studies on the mouse with comparable radiation sources, which have been the principal guide to the presumed human sensitivities. The relevance of these data in setting permissible limits for human exposures is discussed briefly

Genetic effects of the atomic bombs: a reappraisal

International Nuclear Information System (INIS)

Schull, W.J.; Otake, M.; Neel, J.V.

1981-01-01

Data are presented on four indicators of genetic effects from studies of children born to survivors of the atomic bombings of Hiroshima and Negasaki. The indicators are frequency of un toward pregnancy outcomes (stillbirth, major congenital defect, death during first postnatal week); occurrence of death in live-born children, through an average life expectancy of 17 years; frequency of children with sex chromosome aneuploidy; and frequency of children with mutation resulting in an electrophoretic variant. In no instance is there a statistically significant effect of parental exposure; but for all indicators the observed effect is in the direction suggested by the hypothesis that genetic damage resulted from the exposure. On the basis of assumptions concerning the contribution that spontaneous mutation in the preceding generation makes to the indicators in question, it is possible to estimate the genetic doubling dose for radiation for the first three indicators (the data base is still too small for the fourth). The average of these estimates is 156 rems. This is some four times higher than the results from experimental studies on the mouse with comparable radiation sources, which have been the principal guide to the presumed human sensitivities. The relevance of these data in setting permissible limits for human exposures is discussed briefly

Genetic effects of ionizing radiation

International Nuclear Information System (INIS)

Myers, D.K.; Childs, J.D.

1980-01-01

The genetic material in living organisms is susceptible to damage from a wide variety of causes including radiation exposure. Most of this damage is repaired by the organism; the residual damage and damage which is not correctly repaired can lead to genetic changes such as mutations. In lower organisms, most offspring carry an unaltered copy of the genetic information that was present in the parental organism, most of the genetic changes which do occur are not caused by natural background radiation, and the increase in frequency of genetic changes after irradiation at low-dose rates is directly proportional to total radiation dose. The same principles appear to be valid in mammals and other higher organisms. About 105 out of every 1000 humans born suffer from some genetic or partly-genetic condition requiring medical attention at some time. It has been estimated that approximately 1 person in every 2000 born carry a deleterious genetic mutation that was caused by the continued exposure of many generations of our ancestors to natural background radiation. On the same basis, it is predicted that the incidence of genetic diseases would be increased to 106 per 1000 in the children and grandchildren of radiation workers who were exposed to 1 rem per year commencing at age 18. However, there was no detectable change in the health and fitness of mice whose male ancestors were repeatedly exposed to high radiation doses up to 900 rem per generation. (auth)

Genetic Allee effects and their interaction with ecological Allee effects.

Science.gov (United States)

Wittmann, Meike J; Stuis, Hanna; Metzler, Dirk

2018-01-01

It is now widely accepted that genetic processes such as inbreeding depression and loss of genetic variation can increase the extinction risk of small populations. However, it is generally unclear whether extinction risk from genetic causes gradually increases with decreasing population size or whether there is a sharp transition around a specific threshold population size. In the ecological literature, such threshold phenomena are called 'strong Allee effects' and they can arise for example from mate limitation in small populations. In this study, we aim to (i) develop a meaningful notion of a 'strong genetic Allee effect', (ii) explore whether and under what conditions such an effect can arise from inbreeding depression due to recessive deleterious mutations, and (iii) quantify the interaction of potential genetic Allee effects with the well-known mate-finding Allee effect. We define a strong genetic Allee effect as a genetic process that causes a population's survival probability to be a sigmoid function of its initial size. The inflection point of this function defines the critical population size. To characterize survival-probability curves, we develop and analyse simple stochastic models for the ecology and genetics of small populations. Our results indicate that inbreeding depression can indeed cause a strong genetic Allee effect, but only if individuals carry sufficiently many deleterious mutations (lethal equivalents). Populations suffering from a genetic Allee effect often first grow, then decline as inbreeding depression sets in and then potentially recover as deleterious mutations are purged. Critical population sizes of ecological and genetic Allee effects appear to be often additive, but even superadditive interactions are possible. Many published estimates for the number of lethal equivalents in birds and mammals fall in the parameter range where strong genetic Allee effects are expected. Unfortunately, extinction risk due to genetic Allee effects

The impact of direct-to-consumer marketing of cancer genetic testing on women according to their genetic risk.

Science.gov (United States)

Lowery, Jan T; Byers, Tim; Axell, Lisen; Ku, Lisa; Jacobellis, Jillian

2008-12-01

To assess the impact of direct-to-consumer marketing for genetic testing among women of varying genetic risk for breast and ovarian cancer. Telephone surveys were conducted with 315 women in Denver, Colorado, one target audience for the Myriad BRACAnalysis ad campaign. Genetic risk was determined from personal and family history and grouped by probability of having a BRCA1/2 mutation (low or =10%). High-risk women were more knowledgeable about BRACAnalysis and more likely to recall the media ads than were low-risk women (60 vs. 39%, P audience. Concern about breast cancer was not appreciably increased. A large percentage of low-risk women (not candidates for testing) expressed interest in testing, suggesting the campaign was too broad. A campaign targeted at high-risk women, who may benefit from testing might be preferred.

Vitamin D: direct effects of vitamin D metabolites on bone: lessons from genetically modified mice

NARCIS (Netherlands)

Eisman, J.A.; Bouillon, R.

2014-01-01

The vitamin D endocrine system has clear beneficial effects on bone as demonstrated by prevention of rickets in children and by reducing the risk of osteomalacia or osteoporosis in adults or elderly subjects. Depending on the design of the study of genetically modified animals, however, 1,25(OH)2D

State of play in direct-to-consumer genetic testing for lifestyle-related diseases: market, marketing content, user experiences and regulation.

Science.gov (United States)

Saukko, Paula

2013-02-01

Direct-to-consumer (DTC) genetic tests have aroused controversy. Critics have argued many of the tests are not backed by scientific evidence, misguide their customers and should be regulated more stringently. Proponents suggest that finding out genetic susceptibilities for diseases could encourage healthier behaviours and makes the results of genetics research available to the public. This paper reviews the state of play in DTC genetic testing, focusing on tests identifying susceptibilities for lifestyle-related diseases. It will start with mapping the market for the tests. The paper will review (1) research on the content of the online marketing of DTC tests, (2) studies on the effects of DTC genetic tests on customers and (3) academic and policy proposals on how to regulate the tests. Current studies suggest that the marketing of DTC genetic tests often exaggerates their predictive powers, which could misguide consumers. However, research indicates that the tests do not seem to have major negative effects (worry and confusion) but neither do they engender positive effects (lifestyle change) on current users. Research on regulation of the tests has most commonly suggested regulating the marketing claims of the companies. In conclusion, the risks and benefits of DTC genetic tests are less significant than what has been predicted by critics and proponents, which will be argued reflects broader historical trends transforming health and medicine.

ATM directs DNA damage responses and proteostasis via genetically separable pathways.

Science.gov (United States)

Lee, Ji-Hoon; Mand, Michael R; Kao, Chung-Hsuan; Zhou, Yi; Ryu, Seung W; Richards, Alicia L; Coon, Joshua J; Paull, Tanya T

2018-01-09

The protein kinase ATM is a master regulator of the DNA damage response but also responds directly to oxidative stress. Loss of ATM causes ataxia telangiectasia, a neurodegenerative disorder with pleiotropic symptoms that include cerebellar dysfunction, cancer, diabetes, and premature aging. We genetically separated the activation of ATM by DNA damage from that by oxidative stress using separation-of-function mutations. We found that deficient activation of ATM by the Mre11-Rad50-Nbs1 complex and DNA double-strand breaks resulted in loss of cell viability, checkpoint activation, and DNA end resection in response to DNA damage. In contrast, loss of oxidative activation of ATM had minimal effects on DNA damage-related outcomes but blocked ATM-mediated initiation of checkpoint responses after oxidative stress and resulted in deficiencies in mitochondrial function and autophagy. In addition, expression of a variant ATM incapable of activation by oxidative stress resulted in widespread protein aggregation. These results indicate a direct relationship between the mechanism of ATM activation and its effects on cellular metabolism and DNA damage responses in human cells and implicate ATM in the control of protein homeostasis. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Evolution of genetic architecture under directional selection.

Science.gov (United States)

Hansen, Thomas F; Alvarez-Castro, José M; Carter, Ashley J R; Hermisson, Joachim; Wagner, Günter P

2006-08-01

We investigate the multilinear epistatic model under mutation-limited directional selection. We confirm previous results that only directional epistasis, in which genes on average reinforce or diminish each other's effects, contribute to the initial evolution of mutational effects. Thus, either canalization or decanalization can occur under directional selection, depending on whether positive or negative epistasis is prevalent. We then focus on the evolution of the epistatic coefficients themselves. In the absence of higher-order epistasis, positive pairwise epistasis will tend to weaken relative to additive effects, while negative pairwise epistasis will tend to become strengthened. Positive third-order epistasis will counteract these effects, while negative third-order epistasis will reinforce them. More generally, gene interactions of all orders have an inherent tendency for negative changes under directional selection, which can only be modified by higher-order directional epistasis. We identify three types of nonadditive quasi-equilibrium architectures that, although not strictly stable, can be maintained for an extended time: (1) nondirectional epistatic architectures; (2) canalized architectures with strong epistasis; and (3) near-additive architectures in which additive effects keep increasing relative to epistasis.

Genetic trends of selection for pelt traits in Karakul sheep I. Direct ...

African Journals Online (AJOL)

Genetic trends of selection for pelt traits in Karakul sheep. I. Direct ... development in the Karakul Wereestimated with the Animal Model in four selection lines and in a control flock over ..... Selection experiments in laboratory and domestic.

Genetic effects of iodine 131 incorporation in mammals

International Nuclear Information System (INIS)

Bajrakova, A.

1988-01-01

The translocation yield after single treatment of male mice with iodine 131 (55,5 - 222,0 kBq/g b.w.) was investigated. The results of the cytogenetic analysis of the gonad cells revealed the effectiveness only of the highest activity, distroying the thyroid gland. The so-called direct method was also used for determination of the risk coefficients for the expected new carriers of balanced and unbalanced translocations in the first generation - the genetic effects which could be expected from the use of iodine-131-diagnostics in a hypothetic population

Direct-to-consumer genetic testing in Slovenia: availability, ethical dilemmas and legislation.

Science.gov (United States)

Vrecar, Irena; Peterlin, Borut; Teran, Natasa; Lovrecic, Luca

2015-01-01

Over the last few years, many private companies are advertising direct-to-consumer genetic testing (DTC GT), mostly with no or only minor clinical utility and validity of tests and without genetic counselling. International professional community does not approve provision of DTC GT and situation in some EU countries has been analysed already. The aim of our study was to analyse current situation in the field of DTC GT in Slovenia and related legal and ethical issues. Information was retrieved through internet search, performed independently by two authors, structured according to individual private company and the types of offered genetic testing. Five private companies and three Health Insurance Companies offer DTC GT and it is provided without genetic counselling. Available tests include testing for breast cancer, tests with other health-related information (complex diseases, drug responses) and other tests (nutrigenetic, ancestry, paternity). National legislation is currently being developed and Council of Experts in Medical Genetics has issued an opinion about Genetic Testing and Commercialization of Genetic Tests in Slovenia. Despite the fact that Slovenia has signed the Additional protocol to the convention on human rights and biomedicine, concerning genetic testing for health purposes, DTC GT in Slovenia is present and against all international recommendations. There is lack of or no medical supervision, clinical validity and utility of tests and inappropriate genetic testing of minors is available. There is urgent need for regulation of ethical, legal, and social aspects. National legislation on DTC GT is being prepared.

Genetics and ionizing radiations. 2. The genetic effects of ionizing radiations

International Nuclear Information System (INIS)

Dutrillaux, B.

1980-01-01

Ionizing radiations are the best known mutagenic agents. Their relative importance as compared to other mutagens cannot be determined. Experiments show that male germinal cells are more sensitive than female germinal cells. This sensitivity is determined by the cell phase at the time of agression. Acute X-exposure results in a mutation rate of about 1.7x10 -7 rad -1 per gamete and per gene in the male. This rate is lower in case of chronic exposure. Pathological effects will appear in the first (dominant genes, and unbalanced chromosomal anomalies) or n-th generation (recessive genes and balanced chromosomal rearrangements). Direct studies on humans have brought contradictory results. Only X or γ-emitters induce a true genetic risk, the other radiations being too little penetrating to reach the gonads. The doubling dose of the mutation rate is estimated at over 100 rad in males and over 1,000 rad in females. However, one cannot conclude that low doses are not harmless because their effects are difficult to demonstrate. The individual risk, that remains low, must be distinguished from the collective risk for which the safeguard of the quality of the genetic material of our species must remain our prime purpose [fr

[Scientific potential of phenomics - functional direction of genetics].

Science.gov (United States)

Marasanov, A V; Valtseva, E A

In this paper on the based on the integration of known theories, doctrines and concepts - principles of consistency and self-regulation of physiological functions (Pavlov I.P., 1950), the theory offunctional systems (Anokhin P.K., 1973), the theory of adaptive reactions (Selye H., 1960 ; Garkavi LKh et al, 1979), the doctrine of the dominant (Ukhtomsky A.A., 1966), doctrine on health (Baevsky R.M.), doctrine on the body type of the human by Merlin VS. conception on the “the interrelationship between the function and genetic apparatus” by Meyerson F.Z., Pshennikova M.G., Platonov V.N., and others, there is proposed to select phenomics - functional division of genetics considering the poolability of specific mechanisms of the body in an integral system of the adaptive act in favor of the development of a personalized approach to the diagnosis and prevention of non-communicable diseases, increasing life expectancy of working age into the particular scientific direction. The task of phenomics is the establishment of the phenotypic characteristics of the person, norms of the response of systems of his body, determination of the deviation of the level of the functioning of the each system from the norm of its response and the elaboration of the tactics for the correction of the functional state of the organism (the optimization of its life activity), with taking into account the directedness of the interaction of body systems. The description of the shaping of the mechanism of stereotyped response of the organism generated an important contribution to the development of phenomics. Stereotyped response being initiated by the non-specific response of the body is aimed at the shaping of the activity of its systems after a fashion of norms of the activity, promotes the recovery of the specificity of the body, plays an important role in the establishment of cause-effect relations of the disease.

Genotype by environment interaction effects in genetic evaluation of preweaning gain for Line 1 Hereford cattle from Miles City, Montana.

Science.gov (United States)

MacNeil, M D; Cardoso, F F; Hay, E

2017-09-01

It has long been recognized that genotype × environment interaction potentially influences genetic evaluation of beef cattle. However, this recognition has largely been ignored in systems for national cattle evaluation. The objective of this investigation was to determine if direct and maternal genetic effects on preweaning gain would be reranked depending on an environmental gradient as determined by year effects. Data used were from the 76-yr selection experiment with the Line 1 Hereford cattle raised at Miles City, MT. The data comprised recorded phenotypes from 7,566 animals and an additional 1,862 ancestral records included in the pedigree. The presence of genotype × environment interaction was examined using reaction norms wherein year effects on preweaning gain were hypothesized to linearly influence the EBV. Estimates of heritability for direct and maternal effects, given the average environment, were 10 ± 2 and 26 ± 3%, respectively. In an environment that is characterized by the 5th (95th) percentile of the distribution of year effects, the corresponding estimates of heritability were 18 ± 3 (22 ± 3%) and 30 ± 3% (30 ± 3%), respectively. Rank correlations of direct and maternal EBV appropriate to the 5th and 95th percentiles of the year effects were 0.67 and 0.92, respectively. In the average environment, the genetic trends were 255 ± 1 g/yr for direct effects and 557 ± 3 g/yr for maternal effects. In the fifth percentile environment, the corresponding estimates of genetic trend were 271 ± 1 and 540 ± 3 g/yr, respectively, and in the 95th percentile environment, they were 236 ± 1 and 578 ± 3 g/yr, respectively. Linear genetic trends in environmental sensitivity were observed for both the direct (-8.06 × 10 ± 0.49 × 10) and maternal (8.72 × 10 ± 0.43 × 10) effects. Therefore, changing systems of national cattle evaluation to more fully account for potential genotype × environment interaction would improve the assessment of breeding

Awareness and uptake of direct-to-consumer genetic testing among cancer cases, their relatives, and controls: the Northwest Cancer Genetics Network.

Science.gov (United States)

Hall, Taryn O; Renz, Anne D; Snapinn, Katherine W; Bowen, Deborah J; Edwards, Karen L

2012-07-01

To determine if awareness of, interest in, and use of direct-to-consumer (DTC) genetic testing is greater in a sample of high-risk individuals (cancer cases and their relatives), compared to controls. Participants were recruited from the Northwest Cancer Genetics Network. A follow-up survey was mailed to participants to assess DTC genetic testing awareness, interest, and use. One thousand two hundred sixty-seven participants responded to the survey. Forty-nine percent of respondents were aware of DTC genetic testing. Of those aware, 19% indicated interest in obtaining and testing. Additional information supplied by respondents who reported use of DTC genetic tests indicated that 55% of these respondents likely engaged in clinical genetic testing, rather than DTC genetic testing. Awareness of DTC genetic testing was greater in our sample of high-risk individuals than in controls and population-based studies. Although interest in and use of these tests among cases in our sample were equivalent to other population-based studies, interest in testing was higher among relatives and people who self-referred for a registry focused on cancer than among cases and controls. Additionally, our results suggest that there may be some confusion about what constitutes DTC genetic testing.

[Advantages and disadvantages of direct-to-consumer genetic tests].

Science.gov (United States)

Christiansen, Camilla Worm; Gerdes, Anne-Marie Axø

2017-03-13

Direct-to-consumer genetic tests are sold over the internet to consumers all over the world - including Denmark. No regulation of these tests has been introduced neither in Denmark nor in Europe, even though they have been on the market since 2007. Such tests have several advantages, but indeed also a long list of potential disadvantages, which are most often ignored, and among these is insufficient training of general practitioners in performing the necessary counselling but also the risk of increased expenses to unnecessary follow-up consultations.

Genetics and sport performance: current challenges and directions to the future

Directory of Open Access Journals (Sweden)

João Paulo Limongi França GUILHERME

2014-03-01

Full Text Available In recent years there has been a great progress in molecular biology techniques, which has facilitated the researches on influence of genetics on human performance. There are specific regions of DNA that can vary between individuals. Such variations (i.e., polymorphisms may, in part, explain why some individuals have differentiated responses to certain stimuli, including the responses to sports training. In a particular sport, the presence of specific polymorphisms may contribute to high levels of performance. Since 1998, several polymorphisms have been associated with athletic phenotypes; however the accumulation of information generated over these 15 years shows that the influence of genetics to sport is extremely complex. In this review, we will summarise the current status of the field, discussing the implications of available knowledge for the practice of professionals involved with the sport and suggesting future directions for research. We also discuss topics related to the importance of polygenic profile characterization of athletes, methods for the identification of new polymorphisms associated with physical performance, the use of genetic testing for predicting competitive success, and how crucial is the genetic profile for the success athletes in competition.

Prediction of direct and indirect genetic gains and genotypic correlations in rubber tree progenies

Directory of Open Access Journals (Sweden)

Cecília Khusala Verardi

2011-09-01

Full Text Available The objective of this work was to estimate the genetic parameters, genotypic and phenotypic correlations, and direct and indirect genetic gains among and within rubber tree (Hevea brasiliensis progenies. The experiment was set up at the Municipality of Jaú, SP, Brazil. A randomized complete block design was used, with 22 treatments (progenies, 6 replicates, and 10 plants per plot at a spacing of 3x3 m. Three‑year‑old progenies were assessed for girth, rubber yield, and bark thickness by direct and indirect gains and genotypic correlations. The number of latex vessel rings showed the best correlations, correlating positively and significantly with girth and bark thickness. Selection gains among progenies were greater than within progeny for all the variables analyzed. Total gains obtained were high, especially for girth increase and rubber yield, which were 93.38 and 105.95%, respectively. Young progeny selection can maximize the expected genetic gains, reducing the rubber tree selection cycle.

Effect of direct-to-consumer genetic tests on health behaviour and anxiety: a survey of consumers and potential consumers.

Science.gov (United States)

Egglestone, Corin; Morris, Anne; O'Brien, Ann

2013-10-01

Direct-to-consumer (DTC) genetic tests can be purchased over the internet. Some companies claim to provide relative genetic risks for various diseases and thus encourage healthy behaviour. There are concerns that exposure to such information may actually discourage healthy behaviour or increase health anxiety. An online survey was conducted (n = 275). Respondents were composed of individuals who had purchased a DTC genetic test and received their results (consumers, n = 189), as well as individuals who were either awaiting test results or considering purchasing a test (potential consumers, n = 86). Consumers were asked if their health behaviour or health anxiety had changed after receiving their results. Respondents' current health behaviour and health anxiety were queried and compared. In total, 27.3 % of consumers claimed a change in health behaviour, all either positive or neutral, with no reported cessation of any existing health behaviour. A change in health anxiety was claimed by 24.6 % of consumers, 85.3 % of which were a reduction. Consumers had significantly better health behaviour scores than potential consumers (p = 0.02), with no significant difference in health anxiety. This study points towards an association between receipt of DTC genetic test results and increased adoption of healthy behaviours for a minority of consumers based on self-report, with more mixed results in relation to health anxiety.

Current ethical and legal issues in health-related direct-to-consumer genetic testing.

Science.gov (United States)

Niemiec, Emilia; Kalokairinou, Louiza; Howard, Heidi Carmen

2017-09-01

A variety of health-related genetic testing is currently advertized directly to consumers. This article provides a timely overview of direct-to-consumer genetic testing (DTC GT) and salient ethical issues, as well as an analysis of the impact of the recently adopted regulation on in vitro diagnostic medical devices on DTC GT. DTC GT companies currently employ new testing approaches, report on a wide spectrum of conditions and target new groups of consumers. Such activities raise ethical issues including the questionable analytic and clinical validity of tests, the adequacy of informed consent, potentially misleading advertizing, testing in children, research uses and commercialization of genomic data. The recently adopted regulation on in vitro diagnostic medical devices may limit the offers of predisposition DTC GT in the EU market.

Genetic and perinatal effects of abused substances

Energy Technology Data Exchange (ETDEWEB)

Brande, M.C.; Zimmerman, A.M.

1987-01-01

This book provides an overview of the effects of several abused drugs, including opiates, cannabinoids, alcohol, nicotine, and cocaine, with special emphasis on the actions of these substances at the molecular and cellular levels. The first half deals with genetic effects, including molecular genetics, biochemical genetics, pharmacogenetics, cytogenetics, and genetic toxicity. The second half focuses on perinatal effects and covers: drug abuse during pregnancy; biochemical aspects of marihuana on male reproduction; and long-term behavioral and neuroendocrine effects of perinatal alcohol exposure.

Effectiveness of ancestral irradiation on the direct and correlated responses to selection for body weight in rats

International Nuclear Information System (INIS)

Gianola, D.

1975-01-01

The effects of ancestral irradiation of rat spermatogonia (a cumulative total of 4050 r of x-rays) were studied in a highly inbred line of rats to explore the feasibility of using irradiation to enhance the effectiveness of selection. Six generations after irradiation was terminated, a selection experiment for body weight at six weeks of age was started in both ancestrally irradiated and non-irradiated populations. There were two non-contemporaneous replicates in each of the populations. Within each of the ancestral treatment-replicate combinations one line was selected for high, one for low body weight at six weeks of age, and a third line was maintained by random selection. In each line, avoidance of mating of animals with grandparents in common was attempted. Data on the first ten progeny generations of selection were included in this study. Five types of covariances among relatives were used to estimate causal components of variance for five different genetic models within the ''non-irradiated'' and ''irradiated'' randomly selected models. The parameters in the genetic models were estimated by generalized least-squares. This analysis suggested that a genetic model including direct genetic and maternal genetic effects was adequate to describe the body weights at 3, 6 and 10 weeks of age and the weight gains between these ages. Ancestral irradiation seemed to have enhanced the maternal genetic variance and the covariance between the direct genetic and the maternal genetic effects. On the basis of the above analysis, it was deduced that mass selection should have been more effective in the descendants of irradiated males than in those of the non-irradiated males as a consequence of greater phenotypic variability in their progeny and an enhancement in the regression of the genetic value on the selection criterion

Age-related decline in brain resources modulates genetic effects on cognitive functioning

Directory of Open Access Journals (Sweden)

Ulman Lindenberger

2008-12-01

Full Text Available Individual differences in cognitive performance increase from early to late adulthood, likely reflecting influences of a multitude of factors. We hypothesize that losses in neurochemical and anatomical brain resources in normal aging modulate the effects of common genetic variations on cognitive functioning. Our hypothesis is based on the assumption that the function relating brain resources to cognition is nonlinear, so that genetic differences exert increasingly large effects on cognition as resources recede from high to medium levels in the course of aging.Direct empirical support for this hypothesis comes from a study by Nagel et al. (2008, who reported that the effects of the Catechol-O-Methyltransferase (COMT gene on cognitive performance are magnified in old age and interacted with the Brain-Derived Neurotrophic Factor (BDNF gene. We conclude that common genetic polymorphisms contribute to the increasing heterogeneity of cognitive functioning in old age. Extensions of the hypothesis to other polymorphisms are discussed.

Behavioural changes, sharing behaviour and psychological responses after receiving direct-to-consumer genetic test results: a systematic review and meta-analysis.

Science.gov (United States)

Stewart, Kelly F J; Wesselius, Anke; Schreurs, Maartje A C; Schols, Annemie M W J; Zeegers, Maurice P

2018-01-01

It has been hypothesised that direct-to-consumer genetic tests (DTC-GTs) could stimulate health behaviour change. However, genetic testing may also lead to anxiety and distress or unnecessarily burden the health care system. The aim is to review and meta-analyse the effects of DTC-GT on (1) behaviour change, (2) psychological response and (3) medical consumption. A systematic literature search was performed in three databases, using "direct-to-consumer genetic testing" as a key search term. Random effects meta-analyses were performed when at least two comparable outcomes were available. After selection, 19 articles were included involving 11 unique studies. Seven studies involved actual consumers who paid the retail price, whereas four included participants who received free genetic testing as part of a research trial (non-actual consumers). In meta-analysis, 23% had a positive lifestyle change. More specifically, improved dietary and exercise practices were both reported by 12%, whereas 19% quit smoking. Seven percent of participants had subsequent preventive checks. Thirty-three percent shared their results with any health care professional and 50% with family and/or friends. Sub-analyses show that behaviour change was more prevalent among non-actual consumers, whereas sharing was more prevalent among actual consumers. Results on psychological responses showed that anxiety, distress and worry were low or absent and that the effect faded with time. DTC-GT has potential to be effective as a health intervention, but the right audience needs to be addressed with tailored follow-up. Research is needed to identify consumers who do and do not change behaviour or experience adverse psychological responses.

Longitudinal analysis of direct and indirect effects on average daily gain in rabbits using a structured antedependence model.

Science.gov (United States)

David, Ingrid; Sánchez, Juan-Pablo; Piles, Miriam

2018-05-10

Indirect genetic effects (IGE) are important components of various traits in several species. Although the intensity of social interactions between partners likely vary over time, very few genetic studies have investigated how IGE vary over time for traits under selection in livestock species. To overcome this issue, our aim was: (1) to analyze longitudinal records of average daily gain (ADG) in rabbits subjected to a 5-week period of feed restriction using a structured antedependence (SAD) model that includes IGE and (2) to evaluate, by simulation, the response to selection when IGE are present and genetic evaluation is based on a SAD model that includes IGE or not. The direct genetic variance for ADG (g/d) increased from week 1 to 3 [from 8.03 to 13.47 (g/d) 2 ] and then decreased [6.20 (g/d) 2 at week 5], while the indirect genetic variance decreased from week 1 to 4 [from 0.43 to 0.22 (g/d) 2 ]. The correlation between the direct genetic effects of different weeks was moderate to high (ranging from 0.46 to 0.86) and tended to decrease with time interval between measurements. The same trend was observed for IGE for weeks 2 to 5 (correlations ranging from 0.62 to 0.91). Estimates of the correlation between IGE of week 1 and IGE of the other weeks did not follow the same pattern and correlations were lower. Estimates of correlations between direct and indirect effects were negative at all times. After seven generations of simulated selection, the increase in ADG from selection on EBV from a SAD model that included IGE was higher (~ 30%) than when those effects were omitted. Indirect genetic effects are larger just after mixing animals at weaning than later in the fattening period, probably because of the establishment of social hierarchy that is generally observed at that time. Accounting for IGE in the selection criterion maximizes genetic progress.

Genetic effects of radiation

International Nuclear Information System (INIS)

Selby, P.B.

1977-01-01

Many of the most important findings concerning the genetic effects of radiation have been obtained in the Biology Division of Oak Ridge National Laboratory. The paper focuses on some of the major discoveries made in the Biology Division and on a new method of research that assesses damage to the skeletons of mice whose fathers were irradiated. The results discussed have considerable influence upon estimates of genetic risk in humans from radiation, and an attempt is made to put the estimated amount of genetic damage caused by projected nuclear power development into its proper perspective

Closure of population biobanks and direct-to-consumer genetic testing companies.

Science.gov (United States)

Zawati, Ma'n H; Borry, Pascal; Howard, Heidi Carmen

2011-09-01

Genetic research gained new momentum with the completion of the Human Genome Project in 2003. Formerly centered on the investigation of single-gene disorders, genetic research is increasingly targeting common complex diseases and in doing so is studying the whole genome, the environment and its impact on genomic variation. Consequently, biobanking initiatives have emerged around the world as a tool to sustain such progress. Whether they are small scale or longitudinal, public or private, commercial or non-commercial, biobanks should consider the possibility of closure. Interestingly, while raising important ethical issues, this topic has hardly been explored in the literature. Indeed, ethical issues associated with sale, insolvency, end of funding, or transfer of materials to other entities (which are all issues either related to or possible consequences of closure) are seldom the subject of discussion. In an attempt to fill this gap, this paper will discuss-using population and direct-to-consumer (DTC) genetic testing companies' biobanks as case studies-(1) international and national normative documents addressing the issue of closure and (2) the internal policies of population biobanks and DTC genetic testing companies. The analysis will inform the debate on biobank closure and elucidate the underlying ethical issues, which include, but are not limited to informed consent, storage and privacy.

Genetic effects of ionising radiation

International Nuclear Information System (INIS)

Saunders, P.

1981-01-01

The mutagenic effects of ionising radiation on germ cells with resulting genetic abnormalities in subsequent generations, are considered. Having examined a simple model to explain the interaction of ionising radiation with genetic material and discussed its limitations, the methods whereby mutations are transmitted are discussed. Methods of estimating genetic risks and the results of such studies are examined. (U.K.)

Genetic effects of nonionizing electromagnetic fields

International Nuclear Information System (INIS)

Lai, Henry

2001-01-01

Due to the increased use of electricity and wireless communication devices, there is a concern on whether exposure to nonionizing electromagnetic fields (50/60 Hz fields and radiofrequency radiation) can lead to harmful health effects, particularly, genetic effects and cancer development. This presentation will review recent research on genetic effects of power line frequency and radiofrequency electromagnetic fields. Even though the mechanism of interaction is still unknown, there is increasing evidence that these electromagnetic fields at low intensities can cause genetic damage in cells. There is also evidence suggesting that the effects are caused by oxidative stress. (author)

Variance components and genetic parameters for body weight and ...

African Journals Online (AJOL)

model included a direct as well as a maternal additive genetic effect, while only the direct additive genetic eff'ect had a sig- .... deviations from the log likelihood value obtained under the ... (1995).lt would therefore be fair to assume that a.

The association between scalp hair-whorl direction, handedness and hemispheric language dominance: is there a common genetic basis of lateralization?

Science.gov (United States)

Jansen, Andreas; Lohmann, Hubertus; Scharfe, Stefanie; Sehlmeyer, Christina; Deppe, Michael; Knecht, Stefan

2007-04-01

The hemispheres of the human brain are functionally asymmetric. The left hemisphere tends to be dominant for language and superior in the control of manual dexterity. The mechanisms underlying these asymmetries are not known. Genetic as well as environmental factors are discussed. Recently, atypical anticlockwise hair-whorl direction has been related to an increased probability for non-right-handedness and atypical hemispheric language dominance. These findings are fascinating and important since hair-whorl direction is a structural marker of lateralization and could provide a readily observable anatomical clue to functional brain lateralization. Based on data on handedness and hair-whorl direction, Amar Klar proposed a genetic model ("random-recessive model") in that a single gene with two alleles controls both handedness and hair-whorl orientation (Klar, A.J.S., 2003. Human handedness and scalp hair-whorl direction develop from a common genetic mechanism. Genetics 165, 269-276). The present study was designed to further investigate the relationship between scalp hair-whorl direction with handedness and hemispheric language dominance. 1212 subjects were investigated for scalp hair-whorl direction and handedness. Additionally, we determined hemispheric language dominance (as assessed by a word generation task) in a subgroup of 212 subjects using functional transcranial Doppler sonography (fTCD). As for the single attributes - hair-whorl direction, handedness, and language dominance - we reproduced previously published results. However, we found no association between hair-whorl direction and either language dominance or handedness. These results strongly argue against a common genetic basis of handedness or language lateralization with scalp hair-whorl direction. Inspection of hair patterns will not help us to determine language dominance.

Direct to consumer genetic testing and the libertarian right to test.

Science.gov (United States)

Bonython, Wendy Elizabeth; Arnold, Bruce Baer

2017-08-20

Loi recently proposed a libertarian right to direct to consumer genetic testing (DTCGT)- independent of autonomy or utility-reflecting Cohen's work on self-ownership and Hohfeld's model of jural relations. Cohen's model of libertarianism dealt principally with self-ownership of the physical body. Although Loi adequately accounts for the physical properties of DNA, DNA is also an informational substrate, highly conserved within families. Information about the genome of relatives of the person undergoing testing may be extrapolated without requiring direct engagement with their personal physical copy of the genome, triggering rights and interests of relatives that may differ from the rights and interests of others, that is, individual consumers, testing providers and regulators. Loi argued that regulatory interference with exercise of the right required justification, whereas prima facie exercise of the right did not. Justification of regulatory interference could include 'conflict with other people's rights', 'aggressive' use of the genome and 'harming others'. Harms potentially experienced by relatives as a result of the individual's exercise of a right to test include breach of genetic privacy, violation of their right to determine when, and if, they undertake genetic testing and discrimination. Such harms may justify regulatory intervention, in the event they are recognised; motives driving 'aggressive' use of the genome may also be relevant. Each of the above criteria requires clarification, as potential redundancies and tensions exist between them, with different implications affecting different groups of rights holders. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Estimation of genetic parameters and genetic trends for weight and body measurements at birth in sheep populations in Thailand

Directory of Open Access Journals (Sweden)

China Supakorn

2013-02-01

Full Text Available The main objective of this study was to estimate the genetic parameters and genetic trends for birth weight (BW,heart girth (HG, and body length (BL at birth of sheep populations in Thailand. Data were collected during 1998 to 2011 fromfour livestock research and testing stations. Fixed effect testing showed that sex, herd, contemporary group and breed groupgreatly influenced on the investigated traits (P<0.05. The log likelihood ratio test showed that all traits significantly affectedby maternal additive genetic effect as well as covariance between animal effects. Estimated direct heritabilities from multivariate analysis of the model for BW, HG and BL were 0.32, 0.52 and 0.54, while estimated maternal heritabilities were 0.23,0.14 and 0.14, respectively. Positive correlations were found among direct additive genetic (0.29 to 0.97, maternal additivegenetic (0.23 to 0.95, and phenotype (0.18 to 0.96. Direct-maternal correlations within traits (-0.68 for BW, -0.92 for HG and-0.89 for BL and between traits (-0.89 to -0.08 were antagonistic effect. Direct additive genetic trends for BW, HG and BL inthe second period (2005 to 2011 were significantly increased (0.02 kg/year, 0.89 and 0.73 cm/year while maternal additivegenetic trends characteristically depicted significantly decreased (-0.01 kg/year, -0.92 and -0.72 cm/year.

Estimation of genetic effects in the presence of multicollinearity in multibreed beef cattle evaluation.

Science.gov (United States)

Roso, V M; Schenkel, F S; Miller, S P; Schaeffer, L R

2005-08-01

Breed additive, dominance, and epistatic loss effects are of concern in the genetic evaluation of a multibreed population. Multiple regression equations used for fitting these effects may show a high degree of multicollinearity among predictor variables. Typically, when strong linear relationships exist, the regression coefficients have large SE and are sensitive to changes in the data file and to the addition or deletion of variables in the model. Generalized ridge regression methods were applied to obtain stable estimates of direct and maternal breed additive, dominance, and epistatic loss effects in the presence of multicollinearity among predictor variables. Preweaning weight gains of beef calves in Ontario, Canada, from 1986 to 1999 were analyzed. The genetic model included fixed direct and maternal breed additive, dominance, and epistatic loss effects, fixed environmental effects of age of the calf, contemporary group, and age of the dam x sex of the calf, random additive direct and maternal genetic effects, and random maternal permanent environment effect. The degree and the nature of the multicollinearity were identified and ridge regression methods were used as an alternative to ordinary least squares (LS). Ridge parameters were obtained using two different objective methods: 1) generalized ridge estimator of Hoerl and Kennard (R1); and 2) bootstrap in combination with cross-validation (R2). Both ridge regression methods outperformed the LS estimator with respect to mean squared error of predictions (MSEP) and variance inflation factors (VIF) computed over 100 bootstrap samples. The MSEP of R1 and R2 were similar, and they were 3% less than the MSEP of LS. The average VIF of LS, R1, and R2 were equal to 26.81, 6.10, and 4.18, respectively. Ridge regression methods were particularly effective in decreasing the multicollinearity involving predictor variables of breed additive effects. Because of a high degree of confounding between estimates of maternal

Genetic effects of ionising radiation

International Nuclear Information System (INIS)

Saunders, P.A.H.

1991-12-01

Ionizing radiation effects on the gem cells, which can result in genetic abnormalities, are described. The basic mechanisms of radiation interactions with chromosomes, or specifically DNA, which can result in radiation induced mutation are discussed. Methods of estimating genetic risks, and some values for quantitative risk estimates are given. (U.K.). 13 refs., 2 figs., 1 tab

Indirect Genetic Effects for group-housed animals

DEFF Research Database (Denmark)

Alemu, Setegn Worku

This thesis investigated social interactions in group-housed animals. The main findings of this thesis: 1) Statistical methods to estimate indirect genetic effects when interactions differ between kin vs. non-kin were developed. 2) Indirect genetic effects contribute a substantial amount...... of heritable variation for bite mark traits in group-housed min. 3) Indirect genetic effects estimation needs to take into account systematic interactions due to sex or kin for bite mark trait in group-housed min. 4) Genomic selection can be used to increase the response to selection for survival time in Brown...

Variance components for direct and maternal effects on body weights of Katahdin lambs

Science.gov (United States)

The aim of this study was to estimate genetic parameters for BW in Katahdin lambs. Six animal models were used to study direct and maternal effects on birth (BWT), weaning (WWT) and postweaning (PWWT) weights using 41,066 BWT, 33,980 WWT, and 22,793 PWWT records collected over 17 yr in 100 flocks. F...

Testing for biases in selection on avian reproductive traits and partitioning direct and indirect selection using quantitative genetic models.

Science.gov (United States)

Reed, Thomas E; Gienapp, Phillip; Visser, Marcel E

2016-10-01

Key life history traits such as breeding time and clutch size are frequently both heritable and under directional selection, yet many studies fail to document microevolutionary responses. One general explanation is that selection estimates are biased by the omission of correlated traits that have causal effects on fitness, but few valid tests of this exist. Here, we show, using a quantitative genetic framework and six decades of life-history data on two free-living populations of great tits Parus major, that selection estimates for egg-laying date and clutch size are relatively unbiased. Predicted responses to selection based on the Robertson-Price Identity were similar to those based on the multivariate breeder's equation (MVBE), indicating that unmeasured covarying traits were not missing from the analysis. Changing patterns of phenotypic selection on these traits (for laying date, linked to climate change) therefore reflect changing selection on breeding values, and genetic constraints appear not to limit their independent evolution. Quantitative genetic analysis of correlational data from pedigreed populations can be a valuable complement to experimental approaches to help identify whether apparent associations between traits and fitness are biased by missing traits, and to parse the roles of direct versus indirect selection across a range of environments. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

Evaluating online direct-to-consumer marketing of genetic tests: informed choices or buyers beware?

Science.gov (United States)

Geransar, Rose; Einsiedel, Edna

2008-03-01

Commercialization of genetic technologies is expanding the horizons for the marketing and sales of genetic tests direct-to-consumers (DTCs). This study assesses the information provision and access requirements that are in place for genetic tests that are being advertised DTC over the Internet. Sets of key words specific to DTC genetic testing were entered into popular Internet search engines to generate a list of 24 companies engaging in DTC advertising. Company requirements for physician mediation, genetic counseling arrangements, and information provision were coded to develop categories for quantitative analysis within each variable. Results showed that companies offering risk assessment and diagnostic testing were most likely to require that testing be mediated by a clinician, and to recommend physician-arranged counseling. Companies offering enhancement testing were less likely to require physician mediation of services and more likely to provide long-distance genetic counseling. DTC advertisements often provided information on disease etiology; this was most common in the case of multifactorial diseases. The majority of companies cited outside sources to support the validity of claims about clinical utility of the tests being advertised; companies offering risk assessment tests most frequently cited all information sources. DTC advertising for genetic tests that lack independent professional oversight raises troubling questions about appropriate use and interpretation of these tests by consumers and carries implications for the standards of patient care. These implications are discussed in the context of a public healthcare system.

Direct-to-consumer genetic testing for predicting sports performance and talent identification: Consensus statement

Science.gov (United States)

Webborn, Nick; Williams, Alun; McNamee, Mike; Bouchard, Claude; Pitsiladis, Yannis; Ahmetov, Ildus; Ashley, Euan; Byrne, Nuala; Camporesi, Silvia; Collins, Malcolm; Dijkstra, Paul; Eynon, Nir; Fuku, Noriyuki; Garton, Fleur C; Hoppe, Nils; Holm, Søren; Kaye, Jane; Klissouras, Vassilis; Lucia, Alejandro; Maase, Kamiel; Moran, Colin; North, Kathryn N; Pigozzi, Fabio; Wang, Guan

2015-01-01

The general consensus among sport and exercise genetics researchers is that genetic tests have no role to play in talent identification or the individualised prescription of training to maximise performance. Despite the lack of evidence, recent years have witnessed the rise of an emerging market of direct-to-consumer marketing (DTC) tests that claim to be able to identify children's athletic talents. Targeted consumers include mainly coaches and parents. There is concern among the scientific community that the current level of knowledge is being misrepresented for commercial purposes. There remains a lack of universally accepted guidelines and legislation for DTC testing in relation to all forms of genetic testing and not just for talent identification. There is concern over the lack of clarity of information over which specific genes or variants are being tested and the almost universal lack of appropriate genetic counselling for the interpretation of the genetic data to consumers. Furthermore independent studies have identified issues relating to quality control by DTC laboratories with different results being reported from samples from the same individual. Consequently, in the current state of knowledge, no child or young athlete should be exposed to DTC genetic testing to define or alter training or for talent identification aimed at selecting gifted children or adolescents. Large scale collaborative projects, may help to develop a stronger scientific foundation on these issues in the future. PMID:26582191

Sex-specific genetic effects in physical activity: results from a quantitative genetic analysis.

Science.gov (United States)

Diego, Vincent P; de Chaves, Raquel Nichele; Blangero, John; de Souza, Michele Caroline; Santos, Daniel; Gomes, Thayse Natacha; dos Santos, Fernanda Karina; Garganta, Rui; Katzmarzyk, Peter T; Maia, José A R

2015-08-01

The objective of this study is to present a model to estimate sex-specific genetic effects on physical activity (PA) levels and sedentary behaviour (SB) using three generation families. The sample consisted of 100 families covering three generations from Portugal. PA and SB were assessed via the International Physical Activity Questionnaire short form (IPAQ-SF). Sex-specific effects were assessed by genotype-by-sex interaction (GSI) models and sex-specific heritabilities. GSI effects and heterogeneity were tested in the residual environmental variance. SPSS 17 and SOLAR v. 4.1 were used in all computations. The genetic component for PA and SB domains varied from low to moderate (11% to 46%), when analyzing both genders combined. We found GSI effects for vigorous PA (p = 0.02) and time spent watching television (WT) (p < 0.001) that showed significantly higher additive genetic variance estimates in males. The heterogeneity in the residual environmental variance was significant for moderate PA (p = 0.02), vigorous PA (p = 0.006) and total PA (p = 0.001). Sex-specific heritability estimates were significantly higher in males only for WT, with a male-to-female difference in heritability of 42.5 (95% confidence interval: 6.4, 70.4). Low to moderate genetic effects on PA and SB traits were found. Results from the GSI model show that there are sex-specific effects in two phenotypes, VPA and WT with a stronger genetic influence in males.

Changing public perceptions of genetically modified foods: Effects of consumer information and direct product experience

DEFF Research Database (Denmark)

Scholderer, Joachim; Bech-Larsen, Tino; Grunert, Klaus G.

and values. Two policies can be adopted in such a situation: (a) consumers can be actively informed regarding the risks and benefits and (b) consumers can be given the opportunity to evaluate products on the basis of direct experience. The effectiveness of both policies was tested in two experiments....... In experiment 1, attitude change experiments were conducted with consumers from Denmark, Germany, Italy and the UK (N=1650). Different information strategies were tested against a control group for their ability to change consumers' attitudes and their influence on product choice. Results indicate...... that no attitude change occured. Instead, all stategies seemed to bolster pre-existing attitudes, thereby significantly decreasing consumers' preferences for GM products. The effect did not occur when consumers only saw a labeled product example. In experiment 2, we tested the effects of direct experience...

Indirect Genetic Effects and the Spread of Infectious Disease: Are We Capturing the Full Heritable Variation Underlying Disease Prevalence?

Science.gov (United States)

Lipschutz-Powell, Debby; Woolliams, John A.; Bijma, Piter; Doeschl-Wilson, Andrea B.

2012-01-01

Reducing disease prevalence through selection for host resistance offers a desirable alternative to chemical treatment. Selection for host resistance has proven difficult, however, due to low heritability estimates. These low estimates may be caused by a failure to capture all the relevant genetic variance in disease resistance, as genetic analysis currently is not taylored to estimate genetic variation in infectivity. Host infectivity is the propensity of transmitting infection upon contact with a susceptible individual, and can be regarded as an indirect effect to disease status. It may be caused by a combination of physiological and behavioural traits. Though genetic variation in infectivity is difficult to measure directly, Indirect Genetic Effect (IGE) models, also referred to as associative effects or social interaction models, allow the estimation of this variance from more readily available binary disease data (infected/non-infected). We therefore generated binary disease data from simulated populations with known amounts of variation in susceptibility and infectivity to test the adequacy of traditional and IGE models. Our results show that a conventional model fails to capture the genetic variation in infectivity inherent in populations with simulated infectivity. An IGE model, on the other hand, does capture some of the variation in infectivity. Comparison with expected genetic variance suggests that there is scope for further methodological improvement, and that potential responses to selection may be greater than values presented here. Nonetheless, selection using an index of estimated direct and indirect breeding values was shown to have a greater genetic selection differential and reduced future disease risk than traditional selection for resistance only. These findings suggest that if genetic variation in infectivity substantially contributes to disease transmission, then breeding designs which explicitly incorporate IGEs might help reduce disease

You want to do what? My mother's choice to have direct-to-consumer genetic testing.

Science.gov (United States)

Varga, Elizabeth A

2012-06-01

As a genetic counselor, I had mixed opinions when my mother told me of her intent to undergo genomewide, SNP-based direct-to-consumer (DTC) genetic testing. I cautioned her that results could be misleading, could increase anxiety and were often of limited clinical validity or utility. I warned of the possibility of learning unintended health information and expressed concerns about how the information might be used by a private company. I told her about the variability in results among companies. Yet, she persisted in her desire, reminding me that she was an informed consumer. After reviewing her goals and understanding of the information she might receive, she elected to proceed. Despite my insistence that I would not be her personal genetic counselor, when the results came back, I found myself immersed in her genetic data. In this manuscript, I will examine how this personal experience challenged my perceptions of DTC testing.

Genetic parameter estimates for weaning weight and Kleiber ratio in goats

Directory of Open Access Journals (Sweden)

China Supakorn

2012-04-01

Full Text Available The research was conducted to evaluate the factors affecting on weaning weight (WW and Kleiber ratio (KR and toestimate genetic parameters for two traits in goats. The fixed factors affecting both traits indicated that year-season of birth,sex, birth type and regression of the Thai Native (TN, Boer (BO and Saanen (SA influenced on WW and KR (P<0.05. Malesin this population were heavier (P<0.05 than females. Weaning weights and KR of single kid were significantly higher (P<0.05 than other birth rearing types. Bivariate analysis of three models (Model 1: without maternal genetic effect, Model 2:with maternal genetic effect and am = 0, and Model 3: with maternal genetic effect and am  0 were used to estimate geneticparameters for this research. Estimated direct heritabilities from all models were 0.26 to 0.38 for WW, and 0.22 to 0.35 for KR.Estimated maternal heritabilities from Model 2 and 3 were 0.09 and 0.12 for WW and 0.08 and 0.11 for KR, respectively. Thedirect genetic and phenotypic correlations between WW and KR were positive and moderate values. Maternal genetic correlationsbetween them were positive and of low values. An antagonistic direct-maternal correlations from Model 3 withintraits and between traits indicated that offspring of does with superior maternal abilities probably may provide an inferiordirect genetic effect in the same trait and between traits. It was therefore possible to rapidly improve WW and KR in thisgoat population through selection, while the adverse effects of direct-maternal correlation within and between traits shouldbe considered. The best fit model would be a model including maternal genetic effect without a direct-maternal genetic covariance.

Long-term genetic monitoring of a riverine dragonfly, Orthetrum coerulescens (Odonata: Libellulidae]: Direct anthropogenic impact versus climate change effects.

Science.gov (United States)

Herzog, Rebecca; Hadrys, Heike

2017-01-01

Modern conservationists call for long term genetic monitoring datasets to evaluate and understand the impact of human activities on natural ecosystems and species on a global but also local scale. However, long-term monitoring datasets are still rare but in high demand to correctly identify, evaluate and respond to environmental changes. In the presented study, a population of the riverine dragonfly, Orthetrum coerulescens (Odonata: Libellulidae), was monitored over a time period from 1989 to 2013. Study site was an artificial irrigation ditch in one of the last European stone steppes and "nature heritage", the Crau in Southern France. This artificial riverine habitat has an unusual high diversity of odonate species, prominent indicators for evaluating freshwater habitats. A clearing of the canal and destruction of the bank vegetation in 1996 was assumed to have great negative impact on the odonate larval and adult populations. Two mitochondrial markers (CO1 & ND1) and a panel of nuclear microsatellite loci were used to assess the genetic diversity. Over time they revealed a dramatic decline in diversity parameters between the years 2004 and 2007, however not between 1996 and 1997. From 2007 onwards the population shows a stabilizing trend but has not reached the amount of genetic variation found at the beginning of this survey. This decline cannot be referred to the clearing of the canal or any other direct anthropogenic impact. Instead, it is most likely that the populations' decay was due to by extreme weather conditions during the specific years. A severe drought was recorded for the summer months of these years, leading to reduced water levels in the canal causing also other water parameters to change, and therefore impacting temperature sensitive riverine habitat specialists like the O. coerulescens in a significant way. The data provide important insights into population genetic dynamics and metrics not always congruent with traditional monitoring data (e

Direct and inverted repeats elicit genetic instability by both exploiting and eluding DNA double-strand break repair systems in mycobacteria.

Directory of Open Access Journals (Sweden)

Ewelina A Wojcik

Full Text Available Repetitive DNA sequences with the potential to form alternative DNA conformations, such as slipped structures and cruciforms, can induce genetic instability by promoting replication errors and by serving as a substrate for DNA repair proteins, which may lead to DNA double-strand breaks (DSBs. However, the contribution of each of the DSB repair pathways, homologous recombination (HR, non-homologous end-joining (NHEJ and single-strand annealing (SSA, to this sort of genetic instability is not fully understood. Herein, we assessed the genome-wide distribution of repetitive DNA sequences in the Mycobacterium smegmatis, Mycobacterium tuberculosis and Escherichia coli genomes, and determined the types and frequencies of genetic instability induced by direct and inverted repeats, both in the presence and in the absence of HR, NHEJ, and SSA. All three genomes are strongly enriched in direct repeats and modestly enriched in inverted repeats. When using chromosomally integrated constructs in M. smegmatis, direct repeats induced the perfect deletion of their intervening sequences ~1,000-fold above background. Absence of HR further enhanced these perfect deletions, whereas absence of NHEJ or SSA had no influence, suggesting compromised replication fidelity. In contrast, inverted repeats induced perfect deletions only in the absence of SSA. Both direct and inverted repeats stimulated excision of the constructs from the attB integration sites independently of HR, NHEJ, or SSA. With episomal constructs, direct and inverted repeats triggered DNA instability by activating nucleolytic activity, and absence of the DSB repair pathways (in the order NHEJ>HR>SSA exacerbated this instability. Thus, direct and inverted repeats may elicit genetic instability in mycobacteria by 1 directly interfering with replication fidelity, 2 stimulating the three main DSB repair pathways, and 3 enticing L5 site-specific recombination.

Direct and inverted repeats elicit genetic instability by both exploiting and eluding DNA double-strand break repair systems in mycobacteria.

Science.gov (United States)

Wojcik, Ewelina A; Brzostek, Anna; Bacolla, Albino; Mackiewicz, Pawel; Vasquez, Karen M; Korycka-Machala, Malgorzata; Jaworski, Adam; Dziadek, Jaroslaw

2012-01-01

Repetitive DNA sequences with the potential to form alternative DNA conformations, such as slipped structures and cruciforms, can induce genetic instability by promoting replication errors and by serving as a substrate for DNA repair proteins, which may lead to DNA double-strand breaks (DSBs). However, the contribution of each of the DSB repair pathways, homologous recombination (HR), non-homologous end-joining (NHEJ) and single-strand annealing (SSA), to this sort of genetic instability is not fully understood. Herein, we assessed the genome-wide distribution of repetitive DNA sequences in the Mycobacterium smegmatis, Mycobacterium tuberculosis and Escherichia coli genomes, and determined the types and frequencies of genetic instability induced by direct and inverted repeats, both in the presence and in the absence of HR, NHEJ, and SSA. All three genomes are strongly enriched in direct repeats and modestly enriched in inverted repeats. When using chromosomally integrated constructs in M. smegmatis, direct repeats induced the perfect deletion of their intervening sequences ~1,000-fold above background. Absence of HR further enhanced these perfect deletions, whereas absence of NHEJ or SSA had no influence, suggesting compromised replication fidelity. In contrast, inverted repeats induced perfect deletions only in the absence of SSA. Both direct and inverted repeats stimulated excision of the constructs from the attB integration sites independently of HR, NHEJ, or SSA. With episomal constructs, direct and inverted repeats triggered DNA instability by activating nucleolytic activity, and absence of the DSB repair pathways (in the order NHEJ>HR>SSA) exacerbated this instability. Thus, direct and inverted repeats may elicit genetic instability in mycobacteria by 1) directly interfering with replication fidelity, 2) stimulating the three main DSB repair pathways, and 3) enticing L5 site-specific recombination.

The effect of selection on genetic parameter estimates

African Journals Online (AJOL)

Unknown

The South African Journal of Animal Science is available online at ... A simulation study was carried out to investigate the effect of selection on the estimation of genetic ... The model contained a fixed effect, random genetic and random.

Direct and indirect genetic effects of sex-specific mitonuclear epistasis on reproductive ageing

DEFF Research Database (Denmark)

Immonen, Elina; Collet, Marie; Goenaga, Julieta

2016-01-01

Mitochondria are involved in ageing and their function requires coordinated action of both mitochondrial and nuclear genes. Epistasis between the two genomes can influence lifespan but whether this also holds for reproductive senescence is unclear. Maternal inheritance of mitochondria predicts sex...... to slower senescence relative to novel mitonuclear combinations. We found no evidence for mitonuclear coadaptation in males. Mitonuclear epistasis not only affected age-specific ejaculate weight, but also influenced male age-dependent indirect effects on traits expressed by their female partners (fecundity...... beetle Callosobruchus maculatus, using introgression lines harbouring distinct mitonuclear genotypes. Our results reveal both direct and indirect sex-specific effects of mitonuclear epistasis on reproductive ageing. Females harbouring coadapted mitonuclear genotypes showed higher lifetime fecundity due...

Analysis of genetic effects of nuclear-cytoplasmic interaction on quantitative traits: genetic model for diploid plants.

Science.gov (United States)

Han, Lide; Yang, Jian; Zhu, Jun

2007-06-01

A genetic model was proposed for simultaneously analyzing genetic effects of nuclear, cytoplasm, and nuclear-cytoplasmic interaction (NCI) as well as their genotype by environment (GE) interaction for quantitative traits of diploid plants. In the model, the NCI effects were further partitioned into additive and dominance nuclear-cytoplasmic interaction components. Mixed linear model approaches were used for statistical analysis. On the basis of diallel cross designs, Monte Carlo simulations showed that the genetic model was robust for estimating variance components under several situations without specific effects. Random genetic effects were predicted by an adjusted unbiased prediction (AUP) method. Data on four quantitative traits (boll number, lint percentage, fiber length, and micronaire) in Upland cotton (Gossypium hirsutum L.) were analyzed as a worked example to show the effectiveness of the model.

Effectiveness of an online curriculum for medical students on genetics, genetic testing and counseling

Directory of Open Access Journals (Sweden)

Mary P. Metcalf

2010-01-01

Full Text Available Background: It is increasingly important that physicians have a thorough understanding of the basic science of human genetics and the ethical, legal and social implications (ELSI associated with genetic testing and counseling. Methods: The authors developed a series of web-based courses for medical students on these topics. The course modules are interactive, emphasize clinical case studies, and can easily be incorporated into existing medical school curricula. Results: Results of a ‘real world’ effectiveness trial indicate that the courses have a statistically significant effect on knowledge, attitude, intended behavior and self-efficacy related to genetic testing (p<0.001; N varies between 163 and 596 for each course. Conclusions: The results indicate that this curriculum is an effective tool for educating medical students on the ELSI associated with genetic testing and for promoting positive changes in students' confidence, counseling attitudes and behaviors.

What Is Genetic Ancestry Testing?

Science.gov (United States)

... consumer genetic testing? What kinds of direct-to-consumer genetic tests are available? What is genetic ancestry testing? What are the benefits and risks of direct-to-consumer genetic testing? ...

Genetic parameters of body weight and ascites in broilers: effect of different incidence rates of ascites syndrome.

Science.gov (United States)

Ahmadpanah, J; Ghavi Hossein-Zadeh, N; Shadparvar, A A; Pakdel, A

2017-02-01

1. The objectives of the current study were to investigate the effect of incidence rate (5%, 10%, 20%, 30% and 50%) of ascites syndrome on the expression of genetic characteristics for body weight at 5 weeks of age (BW5) and AS and to compare different methods of genetic parameter estimation for these traits. 2. Based on stochastic simulation, a population with discrete generations was created in which random mating was used for 10 generations. Two methods of restricted maximum likelihood and Bayesian approach via Gibbs sampling were used for the estimation of genetic parameters. A bivariate model including maternal effects was used. The root mean square error for direct heritabilities was also calculated. 3. The results showed that when incidence rates of ascites increased from 5% to 30%, the heritability of AS increased from 0.013 and 0.005 to 0.110 and 0.162 for linear and threshold models, respectively. 4. Maternal effects were significant for both BW5 and AS. Genetic correlations were decreased by increasing incidence rates of ascites in the population from 0.678 and 0.587 at 5% level of ascites to 0.393 and -0.260 at 50% occurrence for linear and threshold models, respectively. 5. The RMSE of direct heritability from true values for BW5 was greater based on a linear-threshold model compared with the linear model of analysis (0.0092 vs. 0.0015). The RMSE of direct heritability from true values for AS was greater based on a linear-linear model (1.21 vs. 1.14). 6. In order to rank birds for ascites incidence, it is recommended to use a threshold model because it resulted in higher heritability estimates compared with the linear model and that BW5 could be one of the main components of selection goals.

Direct-to-consumer genetic testing for predicting sports performance and talent identification: Consensus statement.

Science.gov (United States)

Webborn, Nick; Williams, Alun; McNamee, Mike; Bouchard, Claude; Pitsiladis, Yannis; Ahmetov, Ildus; Ashley, Euan; Byrne, Nuala; Camporesi, Silvia; Collins, Malcolm; Dijkstra, Paul; Eynon, Nir; Fuku, Noriyuki; Garton, Fleur C; Hoppe, Nils; Holm, Søren; Kaye, Jane; Klissouras, Vassilis; Lucia, Alejandro; Maase, Kamiel; Moran, Colin; North, Kathryn N; Pigozzi, Fabio; Wang, Guan

2015-12-01

The general consensus among sport and exercise genetics researchers is that genetic tests have no role to play in talent identification or the individualised prescription of training to maximise performance. Despite the lack of evidence, recent years have witnessed the rise of an emerging market of direct-to-consumer marketing (DTC) tests that claim to be able to identify children's athletic talents. Targeted consumers include mainly coaches and parents. There is concern among the scientific community that the current level of knowledge is being misrepresented for commercial purposes. There remains a lack of universally accepted guidelines and legislation for DTC testing in relation to all forms of genetic testing and not just for talent identification. There is concern over the lack of clarity of information over which specific genes or variants are being tested and the almost universal lack of appropriate genetic counselling for the interpretation of the genetic data to consumers. Furthermore independent studies have identified issues relating to quality control by DTC laboratories with different results being reported from samples from the same individual. Consequently, in the current state of knowledge, no child or young athlete should be exposed to DTC genetic testing to define or alter training or for talent identification aimed at selecting gifted children or adolescents. Large scale collaborative projects, may help to develop a stronger scientific foundation on these issues in the future. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Indirect genetic effects contribute substantially to heritable variation in aggression-related traits in group-housed mink (Neovison vison)

DEFF Research Database (Denmark)

Alemu, Setegn Worku; Bijma, Peter; Møller, Steen Henrik

2014-01-01

Background Since the recommendations on group housing of mink (Neovison vison) were adopted by the Council of Europe in 1999, it has become common in mink production in Europe. Group housing is advantageous from a production perspective, but can lead to aggression between animals and thus raises...... a welfare issue. Bite marks on the animals are an indicator of this aggressive behaviour and thus selection against frequency of bite marks should reduce aggression and improve animal welfare. Bite marks on one individual reflect the aggression of its group members, which means that the number of bite marks...... genetic effects contribute to variation in number of bite marks in group-housed mink. Thus, a genetic selection design that includes both direct genetic and indirect genetic effects could reduce the frequency of bite marks and probably aggression behaviour in group-housed mink....

Genetic and phenotypic parameters of body weight in Zandi sheep

African Journals Online (AJOL)

DR. TONUKARI NYEROVWO

2011-11-02

Nov 2, 2011 ... In the mating season, artificial insemination (AI) was initially performed, but animals ... direct additive genetic effects; m = maternal genetic effects; c = per- .... food intake and performance in the young lamb; although this trend ...

Using human genetics to predict the effects and side-effects of drugs

DEFF Research Database (Denmark)

Stender, Stefan; Tybjærg-Hansen, Anne

2016-01-01

PURPOSE OF REVIEW: 'Genetic proxies' are increasingly being used to predict the effects of drugs. We present an up-to-date overview of the use of human genetics to predict effects and adverse effects of lipid-targeting drugs. RECENT FINDINGS: LDL cholesterol lowering variants in HMG-Coenzyme A re...

In search of genetic constraints limiting the evolution of egg size: direct and correlated responses to artificial selection on a prenatal maternal effector.

Science.gov (United States)

Pick, J L; Hutter, P; Tschirren, B

2016-06-01

Maternal effects are an important force in nature, but the evolutionary dynamics of the traits that cause them are not well understood. Egg size is known to be a key mediator of prenatal maternal effects with an established genetic basis. In contrast to theoretical expectations for fitness-related traits, there is a large amount of additive genetic variation in egg size observed in natural populations. One possible mechanism for the maintenance of this variation is through genetic constraints caused by a shared genetic basis among traits. Here we created replicated, divergent selection lines for maternal egg investment in Japanese quail (Coturnix japonica) to quantify the role of genetic constraints in the evolution of egg size. We found that egg size responds rapidly to selection, accompanied by a strong response in all egg components. Initially, we observed a correlated response in body size, but this response declined over time, showing that egg size and body size can evolve independently. Furthermore, no correlated response in fecundity (measured as the proportion of days on which a female laid an egg) was observed. However, the response to selection was asymmetrical, with egg size plateauing after one generation of selection in the high but not the low investment lines. We attribute this pattern to the presence of genetic asymmetries, caused by directional dominance or unequal allele frequencies. Such asymmetries may contribute to the evolutionary stasis in egg size observed in natural populations, despite a positive association between egg size and fitness.

Genetic parameters and genetic trends in the Chinese × European Tiameslan composite pig line. II. Genetic trends

Directory of Open Access Journals (Sweden)

Legault Christian

2000-01-01

Full Text Available Abstract The Tiameslan line was created between 1983 and 1985 by mating Meishan × Jiaxing crossbred Chinese boars with sows from the Laconie composite male line. The Tiameslan line has been selected since then on an index combining average backfat thickness (ABT and days from 20 to 100 kg (DT. Direct and correlated responses to 11 years of selection were estimated using BLUP methodology applied to a multiple trait animal model. A total of 11 traits were considered, i.e.: ABT, DT, body weight at 4 (W4w, 8 (W8w and 22 (W22w weeks of age, teat number (TEAT, number of good teats (GTEAT, total number of piglets born (TNB, born alive (NBA and weaned (NW per litter, and birth to weaning survival rate (SURV. Performance data from a total of 4 881 males and 4 799 females from 1 341 litters were analysed. The models included both direct and maternal effects for ABT, W4w and W8w. Male and female performances were considered as different traits for W22w, DT and ABT. Genetic parameters estimated in another paper (Zhang et al., Genet. Sel. Evol. 32 (2000 41-56 were used to perform the analyses. Favourable phenotypic (ΔP and direct genetic trends (ΔGd were obtained for post-weaning growth traits and ABT. Trends for maternal effects were limited. Phenotypic and genetic trends were larger in females than in males for ABT (e.g. ΔGd = -0.48 vs. -0.38 mm/year, were larger in males for W22w (ΔGd = 0.90 vs. 0.58 kg/year and were similar in both sexes for DT (ΔGd = -0.54 vs. -0.55 day/year. Phenotypic and genetic trends were slightly favourable for W4w, W8w, TEAT and GTEAT and close to zero for reproductive traits.

The perspective from EASAC and FEAM on direct-to-consumer genetic testing for health-related purposes

NARCIS (Netherlands)

Fears, R.; Boccia, S.; Cornel, M.C.; Delpech, M.; Estivill, X.; Hansson, M.; Karalis, K.; Metspalu, A.; Nothen, M.; Propping, P.; Sequeiros, J.; Zimmem, R.; ter Meulen, V.

2013-01-01

Direct-to-consumer (DTC) genetic testing services raise scientific, regulatory and ethical questions. A report was prepared by consultation with an expert Working Group and published by the academies of science (European Academies of Science Advisory Council, EASAC) and medicine (Federation of

Genetic Evaluation and Ranking of Different Animal Models Using ...

African Journals Online (AJOL)

An animal model utilizes all relationships available in a given data set. Estimates for variance components for additive direct, additive maternal, maternal environmental and direct environmental effects, and their covariances between direct and maternal genetic effects for post weaning growth traits have been obtained with ...

Genetic and chromosomal effects of ionizing radiation

International Nuclear Information System (INIS)

Anon.

1981-01-01

The genetic and chromosomal effects of ionizing radiations deal with those effects in the descendants of the individuals irradiated. The information base concerning genetic and chromosomal injury to humans from radiation is less adequate than is the information base for cancer and leukemia. As a result, it is not possible to make the kinds of quantitative estimates that have been made for carcinogenesis in previous chapters of this book. The chapter includes a detailed explanation of various types of genetic injuries such as chromosomal diseases, x-linked diseases, autosomal dominant diseases, recessive diseases, and irregularly inherited diseases. Quantitative estimates of mutation rates and incidences are given based on atomic bomb survivors data

Genetics in endocrinology: genetic variation in deiodinases: a systematic review of potential clinical effects in humans.

Science.gov (United States)

Verloop, Herman; Dekkers, Olaf M; Peeters, Robin P; Schoones, Jan W; Smit, Johannes W A

2014-09-01

Iodothyronine deiodinases represent a family of selenoproteins involved in peripheral and local homeostasis of thyroid hormone action. Deiodinases are expressed in multiple organs and thyroid hormone affects numerous biological systems, thus genetic variation in deiodinases may affect multiple clinical endpoints. Interest in clinical effects of genetic variation in deiodinases has clearly increased. We aimed to provide an overview for the role of deiodinase polymorphisms in human physiology and morbidity. In this systematic review, studies evaluating the relationship between deiodinase polymorphisms and clinical parameters in humans were eligible. No restrictions on publication date were imposed. The following databases were searched up to August 2013: Pubmed, EMBASE (OVID-version), Web of Science, COCHRANE Library, CINAHL (EbscoHOST-version), Academic Search Premier (EbscoHOST-version), and ScienceDirect. Deiodinase physiology at molecular and tissue level is described, and finally the role of these polymorphisms in pathophysiological conditions is reviewed. Deiodinase type 1 (D1) polymorphisms particularly show moderate-to-strong relationships with thyroid hormone parameters, IGF1 production, and risk for depression. D2 variants correlate with thyroid hormone levels, insulin resistance, bipolar mood disorder, psychological well-being, mental retardation, hypertension, and risk for osteoarthritis. D3 polymorphisms showed no relationship with inter-individual variation in serum thyroid hormone parameters. One D3 polymorphism was associated with risk for osteoarthritis. Genetic deiodinase profiles only explain a small proportion of inter-individual variations in serum thyroid hormone levels. Evidence suggests a role of genetic deiodinase variants in certain pathophysiological conditions. The value for determination of deiodinase polymorphism in clinical practice needs further investigation. © 2014 European Society of Endocrinology.

Genetic effects of radiation. Annex I

International Nuclear Information System (INIS)

1982-01-01

This Annex is aimed at an updating of the 1977 UNSCEAR report, which presented a detailed review of the genetic effects of ionizing radiation, especially those parts that require significant revisions in the light of new data. There is an extensive bibliography with over 1000 references. Particular emphasis is given to those data that are relevant to the evaluation of genetic radiation hazards in man.

Genetic analysis of body weight in South African Angora kids and ...

African Journals Online (AJOL)

Variance and covariance components and ratios pertaining to direct additive genetic variation, maternal additive genetic variation, maternal permanent environmental variation, and the relationship between direct and maternal effects for birth weight (BW; kg), weaning weight (WW; kg) and body weight at 8, 12 and 16 ...

Genetic effects of ionizing radiation – some questions with no answers

International Nuclear Information System (INIS)

Mosse, Irma B.

2012-01-01

There are a lot of questions about genetic effects of ionizing radiation, the main one is does ionizing radiation induce mutations in humans? There is no direct evidence that exposure of parents to radiation leads to excess heritable disease in offspring. What is the difference between human and other species in which radiation induced mutations are easily registered? During evolution germ cell selection ex vivo has been changed to a selection in vivo and we cannot observe such selection of radiation damaged cells in human. Low radiation doses – are they harmful or beneficial? The “hormesis” phenomenon as well as radioadaptive response proves positive effects of low radiation dose. Can analysis of chromosomal aberration rate in lymphocytes be used for dosimetry? Many uncontrolled factors may be responsible for significant mistakes of this method. Why did evolution preserve the bystander effect? This paper is discussion one and its goal is to pay attention on some effects of ionizing radiation. - Highlights: ► There are a lot of questions about genetic effects of ionizing radiation. ► Does ionizing radiation induce mutations in human? ► During evolution germ cell selection ex vivo has been changed to a selection in vivo. ► Radioadaptive response proves positive effects of low radiation doses. ► Many uncontrolled factors may be responsible for significant biodosimetry mistakes.

Genetic evaluations for growth heat tolerance in Angus cattle.

Science.gov (United States)

Bradford, H L; Fragomeni, B O; Bertrand, J K; Lourenco, D A L; Misztal, I

2016-10-01

The objectives were to assess the impact of heat stress and to develop a model for genetic evaluation of growth heat tolerance in Angus cattle. The American Angus Association provided weaning weight (WW) and yearling weight (YW) data, and records from the Upper South region were used because of the hot climatic conditions. Heat stress was characterized by a weaning (yearling) heat load function defined as the mean temperature-humidity index (THI) units greater than 75 (70) for 30 (150) d prior to the weigh date. Therefore, a weaning (yearling) heat load of 5 units corresponded to 80 (75) for the corresponding period prior to the weigh date. For all analyses, 82,669 WW and 69,040 YW were used with 3 ancestral generations in the pedigree. Univariate models were a proxy for the Angus growth evaluation, and reaction norms using 2 B-splines for heat load were fit separately for weaning and yearling heat loads. For both models, random effects included direct genetic, maternal genetic, maternal permanent environment (WW only), and residual. Fixed effects included a linear age covariate, age-of-dam class (WW only), and contemporary group for both models and fixed regressions on the B-splines in the reaction norm. Direct genetic correlations for WW were strong for modest heat load differences but decreased to less than 0.50 for large differences. Reranking of proven sires occurred for only WW direct effects for the reaction norms with extreme heat load differences. Conversely, YW results indicated little effect of heat stress on genetic merit. Therefore, weaning heat tolerance was a better candidate for developing selection tools. Maternal heritabilities were consistent across heat loads, and maternal genetic correlations were greater than 0.90 for nearly all heat load combinations. No evidence existed for a genotype × environment interaction for the maternal component of growth. Overall, some evidence exists for phenotypic plasticity for the direct genetic effects of WW

Functional genetics of intraspecific ecological interactions in Arabidopsis thaliana.

Science.gov (United States)

Wolf, Jason B; Mutic, Joshua J; Kover, Paula X

2011-05-12

Studying the genetic basis of traits involved in ecological interactions is a fundamental part of elucidating the connections between evolutionary and ecological processes. Such knowledge allows one to link genetic models of trait evolution with ecological models describing interactions within and between species. Previous work has shown that connections between genetic and ecological processes in Arabidopsis thaliana may be mediated by the fact that quantitative trait loci (QTL) with 'direct' effects on traits of individuals also have pleiotropic 'indirect' effects on traits expressed in neighbouring plants. Here, we further explore these connections by examining functional relationships between traits affected directly and indirectly by the same QTL. We develop a novel approach using structural equation models (SEMs) to determine whether observed pleiotropic effects result from traits directly affected by the QTL in focal individuals causing the changes in the neighbours' phenotypes. This hypothesis was assessed using SEMs to test whether focal plant phenotypes appear to mediate the connection between the focal plants' genotypes and the phenotypes of their neighbours, or alternatively, whether the connection between the focal plants' genotypes and the neighbours' phenotypes is mediated by unmeasured traits. We implement this analysis using a QTL of major effect that maps to the well-characterized flowering locus, FRIGIDA. The SEMs support the hypothesis that the pleiotropic indirect effects of this locus arise from size and developmental timing-related traits in focal plants affecting the expression of developmental traits in their neighbours. Our findings provide empirical insights into the genetics and nature of intraspecific ecological interactions. Our technique holds promise in directing future work into the genetic basis and functional relationship of traits mediating and responding to ecological interactions.

Estimation of Genetic Effects from Generation Means in Maize (Zea mays L.)

International Nuclear Information System (INIS)

Ligeyo, D.O.; Ayiecho, P.O.

1999-01-01

Estimates of mean, additive, dominance, additive * additive, additive * dominance and dominance * dominance genetic effects were obtained for six crosses from four inbred lines of maize for grain yield. All the genetic effects contributed to the inheritance of yield. However not all genetic effects are present in all crosses at all locations. Both additive dominance genetic effects were responsible for the manifestation variability in grain yield, though the dominance genetic effect was preponderant in all cases. In most cases additive * additive and additive * dominance effects were more important contributors to inheritance than dominance * dominance gene effects at all locations.In all cases the manifestation of various genetic effects varied according to crosses and experimental sites

Effect of genetic variants and traits related to glucose metabolism and their interaction with obesity on breast and colorectal cancer risk among postmenopausal women.

Science.gov (United States)

Jung, Su Yon; Sobel, Eric M; Papp, Jeanette C; Zhang, Zuo-Feng

2017-04-26

Impaired glucose metabolism-related genetic variants and traits likely interact with obesity and related lifestyle factors, influencing postmenopausal breast and colorectal cancer (CRC), but their interconnected pathways are not fully understood. By stratifying via obesity and lifestyles, we partitioned the total effect of glucose metabolism genetic variants on cancer risk into two putative mechanisms: 1) indirect (risk-associated glucose metabolism genetic variants mediated by glucose metabolism traits) and 2) direct (risk-associated glucose metabolism genetic variants through pathways other than glucose metabolism traits) effects. Using 16 single-nucleotide polymorphisms (SNPs) associated with glucose metabolism and data from 5379 postmenopausal women in the Women's Health Initiative Harmonized and Imputed Genome-Wide Association Studies, we retrospectively assessed the indirect and direct effects of glucose metabolism-traits (fasting glucose, insulin, and homeostatic model assessment-insulin resistance [HOMA-IR]) using two quantitative tests. Several SNPs were associated with breast cancer and CRC risk, and these SNP-cancer associations differed between non-obese and obese women. In both strata, the direct effect of cancer risk associated with the SNP accounted for the majority of the total effect for most SNPs, with roughly 10% of cancer risk due to the SNP that was from an indirect effect mediated by glucose metabolism traits. No apparent differences in the indirect (glucose metabolism-mediated) effects were seen between non-obese and obese women. It is notable that among obese women, 50% of cancer risk was mediated via glucose metabolism trait, owing to two SNPs: in breast cancer, in relation to GCKR through glucose, and in CRC, in relation to DGKB/TMEM195 through HOMA-IR. Our findings suggest that glucose metabolism genetic variants interact with obesity, resulting in altered cancer risk through pathways other than those mediated by glucose metabolism traits.

Estimates of genetic parameters of body weight in descendants of x-irradiated rat spermatogonia

International Nuclear Information System (INIS)

Gianola, D.; Chapman, A.B.; Rutledge, J.J.

1977-01-01

Effects of nine generations of 450 R per generation of ancestral spermatogonial x irradiation of inbred rats on genetic parameters of body weight at 3, 6 and 10 weeks of age and of weight gains between these periods were studied. Covariances among relatives were estimated by mixed model and regression techniques in randomly selected lines with (R) and without (C) radiation history. Analyses of the data were based on five linear genetic models combining additive direct, additive indirect (maternal), dominance and environmental effects. Parameters in these models were estimated by generalized least-squares. A model including direct and indirect genetic effects fit more closely to the data in both R and C lines. Overdominance of induced mutations did not seem to be present. Ancestral irradiation increased maternal additive genetic variances of body weights and gains but not direct genetic variances. Theoretically, due to a negative direct-maternal genetic correlation, within full-sib family selection would be ineffective in increasing body weight at six weeks in both R and C lines. However, progress from mass selection would be expected to be faster in the R lines

Interactions between Genetic and Ecological Effects on the Evolution of Life Cycles.

Science.gov (United States)

Rescan, Marie; Lenormand, Thomas; Roze, Denis

2016-01-01

Sexual reproduction leads to an alternation between haploid and diploid phases, whose relative length varies widely across taxa. Previous genetical models showed that diploid or haploid life cycles may be favored, depending on dominance interactions and on effective recombination rates. By contrast, niche differentiation between haploids and diploids may favor biphasic life cycles, in which development occurs in both phases. In this article, we explore the interplay between genetical and ecological factors, assuming that deleterious mutations affect the competitivity of individuals within their ecological niche and allowing different effects of mutations in haploids and diploids (including antagonistic selection). We show that selection on a modifier gene affecting the relative length of both phases can be decomposed into a direct selection term favoring the phase with the highest mean fitness (due to either ecological differences or differential effects of mutations) and an indirect selection term favoring the phase in which selection is more efficient. When deleterious alleles occur at many loci and in the presence of ecological differentiation between haploids and diploids, evolutionary branching often occurs and leads to the stable coexistence of alleles coding for haploid and diploid cycles, while temporal variations in niche sizes may stabilize biphasic cycles.

Bayesian inference on genetic merit under uncertain paternity

Directory of Open Access Journals (Sweden)

Tempelman Robert J

2003-09-01

Full Text Available Abstract A hierarchical animal model was developed for inference on genetic merit of livestock with uncertain paternity. Fully conditional posterior distributions for fixed and genetic effects, variance components, sire assignments and their probabilities are derived to facilitate a Bayesian inference strategy using MCMC methods. We compared this model to a model based on the Henderson average numerator relationship (ANRM in a simulation study with 10 replicated datasets generated for each of two traits. Trait 1 had a medium heritability (h2 for each of direct and maternal genetic effects whereas Trait 2 had a high h2 attributable only to direct effects. The average posterior probabilities inferred on the true sire were between 1 and 10% larger than the corresponding priors (the inverse of the number of candidate sires in a mating pasture for Trait 1 and between 4 and 13% larger than the corresponding priors for Trait 2. The predicted additive and maternal genetic effects were very similar using both models; however, model choice criteria (Pseudo Bayes Factor and Deviance Information Criterion decisively favored the proposed hierarchical model over the ANRM model.

[Direct to consumer genetic testing: is it the moment?].

Science.gov (United States)

Lamoril, Jérôme; Bogard, Marc

2016-01-01

Since the development of new human genome sequencing technologies at the beginning of the 2000, commercial companies have developped direct to consumer genomic services, which means without medical prescription. From 2007 to 2013, many companies have offered services assesing associated risk with human public health in the world especially in the United States. This kind of company is forbidden in France. From 2009 to 2013, in United States, under the pressure of national or state health administrations, these companies have been progressively forbidden. However, in certain parts of the world, companies are still offering such services. The latter raise many different questions such as ethical, juridical, medical, scientific, educative, professional one. Many studies and debates have demonstrated their limit and the lack of usefulness and advantage in the field of human health for the time being. The commercialization of this type of services has arrived all too soon et is not yet ripe. In our time of globalization, with the lack of international rules controlling direct access to genetic services in the field of human health, there is an urgent need to regulate. International administrations and politicians must act fast. Inevitably, under the pressure of lobbies and citizens, companies (multinational or not) will develop especially as 1) new sequencing technologies evolve rapidly, 2) are cheaper from year to year, 3) scientific and medical knowledges are progressing quickly, 4) services are spreading faster through the web and other networks.

Indirect genetic effects and kin recognition

DEFF Research Database (Denmark)

Alemu, Setegn Worku; Berg, Peer; Janss, Luc

2014-01-01

Social interactions among individuals are widespread, both in natural and domestic populations. As a result, trait values of individuals may be affected by genes in other individuals, a phenomenon known as indirect genetic effects (IGEs). IGEs can be estimated using linear mixed models. The tradi......Social interactions among individuals are widespread, both in natural and domestic populations. As a result, trait values of individuals may be affected by genes in other individuals, a phenomenon known as indirect genetic effects (IGEs). IGEs can be estimated using linear mixed models...... present a reduced model that yields estimates of the total heritable effects on kin, on non-kin and on all social partners of an individual, as well as the total heritable variance for response to selection. Finally we discuss the consequences of analysing data in which IGEs depend on relatedness using...

Direct-to-consumer online genetic testing and the four principles: an analysis of the ethical issues.

Science.gov (United States)

Wasson, Katherine; Cook, E David; Helzlsouer, Kathy

2006-01-01

The development of genetic tests marketed and sold direct-to-consumers (DTC) via the internet raises moral concerns and debate about their appropriateness and ethical and clinical significance. These tests are offered for a wide range of diseases and conditions, and the mutations have variable penetrance and associated risk. A number of these tests lack data on their accuracy and reliability, making interpretation of results difficult. DTC genetic testing is undertaken outside the context of the physician-patient relationship and may lack appropriate individual and family genetic counseling, leaving the consumer vulnerable to potential harms, such as misinterpretation of results, including false positive or false reassurance, with limited or no benefits. Beauchamp and Childress's four principles of biomedical ethics provide a framework for analyzing the ethical issues raised by DTC genetic testing. We argue that the potential harms outweigh the potential benefits of such tests, that respect for autonomy should be limited in light of potential harm from DTC testing, and that the availability of genetic testing over the internet may be considered unfair and unjust and affect resource allocation by placing an unfair burden on primary care physicians. In light of the moral issues posed by these tests, practical responses are suggested in the areas of consumer education, medical education, and interaction with commercial companies.

Genetic effects

International Nuclear Information System (INIS)

Bender, M.A.; Abrahamson, S.; Denniston, C.; Schull, W.J.

1989-01-01

In this chapter, we present a comprehensive analysis of the major classes of genetic diseases that would be increased as a result of an increased gonadal radiation exposure to a human population. The risk analysis takes on two major forms: the increase in genetic disease that would be observed in the immediate offspring of the exposed population, and the subsequent transmission of the newly induced mutations through future generations. The major classes of genetic disease will be induced at different frequencies, and will also impact differentially in terms of survivability and fertility on the affected individuals and their descendants. Some classes of disease will be expected to persist for only a few generations at most. Other types of genetic disease will persist through a longer period. The classes of genetic diseases studied are: dominant gene mutation, X-linked gene mutation, chromosome disorders and multifactorial disorders which involve the interaction of many mutant genes and environmental factors. For each of these classes we have derived the general equations of mutation induction for the male and female germ cells of critical importance in the mutation process. The frequency of induced mutations will be determined initially by the dose received, the type of radiation and, to some extent at high dose, by the manner in which the dose is received. We have used the modeling analyses to predict the outcomes for two nuclear power plant accident scenarios, the first in which the population receives a chronic dose of 0.1 Gy (10 rad) over a 50-year period, the second in which an equivalent population receives an acute dose of 2 Gy. In both cases the analyses are projected over a period of five generations

Genetic effects of low level radiation

International Nuclear Information System (INIS)

Sumner, D.

1988-01-01

The author outlines the evidence for genetic effects. The incidence of congenital abnormalities, stillbirths and child deaths has been examined in 70,000 pregnancies in Hiroshima and Nagasaki and compared with pregnancies in an unirradiated control group. No difference was detected in incidence of congenital abnormalities of stillbirths, but there was a small insignificant increase in child deaths when both parents were exposed. The number of children born with chromosome aberrations was slightly higher, but insignificant in the exposed group compared with controls. However, surveys of congenital malformations in children of radiologists and in children of Hanford workers suggest a genetic effect of radiation. Absolute and relative methods of calculating risks and the ICRP risk factor is also briefly discussed. (U.K.)

A systems genetics approach provides a bridge from discovered genetic variants to biological pathways in rheumatoid arthritis.

Directory of Open Access Journals (Sweden)

Hirofumi Nakaoka

Full Text Available Genome-wide association studies (GWAS have yielded novel genetic loci underlying common diseases. We propose a systems genetics approach to utilize these discoveries for better understanding of the genetic architecture of rheumatoid arthritis (RA. Current evidence of genetic associations with RA was sought through PubMed and the NHGRI GWAS catalog. The associations of 15 single nucleotide polymorphisms and HLA-DRB1 alleles were confirmed in 1,287 cases and 1,500 controls of Japanese subjects. Among these, HLA-DRB1 alleles and eight SNPs showed significant associations and all but one of the variants had the same direction of effect as identified in the previous studies, indicating that the genetic risk factors underlying RA are shared across populations. By receiver operating characteristic curve analysis, the area under the curve (AUC for the genetic risk score based on the selected variants was 68.4%. For seropositive RA patients only, the AUC improved to 70.9%, indicating good but suboptimal predictive ability. A simulation study shows that more than 200 additional loci with similar effect size as recent GWAS findings or 20 rare variants with intermediate effects are needed to achieve AUC = 80.0%. We performed the random walk with restart (RWR algorithm to prioritize genes for future mapping studies. The performance of the algorithm was confirmed by leave-one-out cross-validation. The RWR algorithm pointed to ZAP70 in the first rank, in which mutation causes RA-like autoimmune arthritis in mice. By applying the hierarchical clustering method to a subnetwork comprising RA-associated genes and top-ranked genes by the RWR, we found three functional modules relevant to RA etiology: "leukocyte activation and differentiation", "pattern-recognition receptor signaling pathway", and "chemokines and their receptors".These results suggest that the systems genetics approach is useful to find directions of future mapping strategies to illuminate

A genome-wide survey of transgenerational genetic effects in autism.

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Kathryn M Tsang

Full Text Available Effects of parental genotype or parent-offspring genetic interaction are well established in model organisms for a variety of traits. However, these transgenerational genetic models are rarely studied in humans. We have utilized an autism case-control study with 735 mother-child pairs to perform genome-wide screening for maternal genetic effects and maternal-offspring genetic interaction. We used simple models of single locus parent-child interaction and identified suggestive results (P<10(-4 that cannot be explained by main effects, but no genome-wide significant signals. Some of these maternal and maternal-child associations were in or adjacent to autism candidate genes including: PCDH9, FOXP1, GABRB3, NRXN1, RELN, MACROD2, FHIT, RORA, CNTN4, CNTNAP2, FAM135B, LAMA1, NFIA, NLGN4X, RAPGEF4, and SDK1. We attempted validation of potential autism association under maternal-specific models using maternal-paternal comparison in family-based GWAS datasets. Our results suggest that further study of parental genetic effects and parent-child interaction in autism is warranted.

Genetic effects of high LET radiations

International Nuclear Information System (INIS)

Grahn, D.; Garriott, M.L.; Farrington, B.H.; Lee, C.H.; Russell, J.J.

1981-01-01

The objectives of this project are: (1) to assess genetic hazards from testicular burdens of 239 Pu and determine its retention and microdistribution in the testis; (2) to compare effects of 239 Pu with single, weekly, and continuous 60 Co gamma irradiation and single and weekly fission neutron irradiation to develop a basis for estimating relative biological effectiveness (RBE); and (3) to develop detailed dose-response data for genetic end points of concern at low doses of neutrons and gamma rays. Comparatively short-term genetic end points are used, namely: (1) the dominant lethal mutation rate in premeiotic and postmeiotic cell stages; (2) the frequency of abnormal sperm head morphology measured at various times after irradiation; and (3) the frequency of reciprocal chromosome translocations induced in spermatogonia and measured at first meiotic metaphase. Male hybrid B6CF 1 mice, 120 days old, are used for all studies. Measures of the retention, microdistributionand pollutant related changes. Assessment of human risk associated with nuclearing collective dose commitment will result in more attention being paid to potential releases of radionuclides at relatively short times after disposal

Effect of Coping-Therapy on Mental Health of Mothers with Genetic and Non Genetic Mentally Retarded Children

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M Alagheband

2011-04-01

Full Text Available Introdution: Presence of mentally retarded children as a source of pressure can jeopardize the general health of parents, especially mothers. The range of effect depends on the recognitive evaluation and the individual. The aim of this study was to investigate the effect of coping-therapy on mental health of mothers with genetically and non genetically mentally retarded children referring to Yazd clinical center. Methods: This study was semi experimental and included 40 mothers with mentally retarded children studying in schools supported by the welfare organization of Yazd in 2009- 2010 and were selected by available sampling method. They were divided to two groups; case and control. Before any therapy, all of the mothers answered a general health questionnaire(GHQ28. In the next step, coping-therapy was performed on the case group. In the end, all of the mothers answered the same questionnaire(GHQ28 and data were analyzed by covariance method and t test. Results: The research indicated that coping-therapy has a positive effect on the mental health of mothers with genetically mentally retarded children. This effect is similar on mothers of children with non genetically mental retarded children. Coping-therapy decreases the somatic signs of depression in mothers and improves their sleeping and social efficacy. There was no association of age and educational level of mothers with coping-therapy. Conclusion: Coping-therapy can improve the mental health of mothers of both genetically and non genetically mentally retarded children

Genetically-directed, cell type-specific sparse labeling for the analysis of neuronal morphology.

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Thomas Rotolo

Full Text Available In mammals, genetically-directed cell labeling technologies have not yet been applied to the morphologic analysis of neurons with very large and complex arbors, an application that requires extremely sparse labeling and that is only rendered practical by limiting the labeled population to one or a few predetermined neuronal subtypes.In the present study we have addressed this application by using CreER technology to non-invasively label very small numbers of neurons so that their morphologies can be fully visualized. Four lines of IRES-CreER knock-in mice were constructed to permit labeling selectively in cholinergic or catecholaminergic neurons [choline acetyltransferase (ChAT-IRES-CreER or tyrosine hydroxylase (TH-IRES-CreER], predominantly in projection neurons [neurofilament light chain (NFL-IRES-CreER], or broadly in neurons and some glia [vesicle-associated membrane protein2 (VAMP2-IRES-CreER]. When crossed to the Z/AP reporter and exposed to 4-hydroxytamoxifen in the early postnatal period, the number of neurons expressing the human placental alkaline phosphatase reporter can be reproducibly lowered to fewer than 50 per brain. Sparse Cre-mediated recombination in ChAT-IRES-CreER;Z/AP mice shows the full axonal and dendritic arbors of individual forebrain cholinergic neurons, the first time that the complete morphologies of these very large neurons have been revealed in any species.Sparse genetically-directed, cell type-specific neuronal labeling with IRES-creER lines should prove useful for studying a wide variety of questions in neuronal development and disease.

Genetic consequences of nuclear war

International Nuclear Information System (INIS)

Oftedal, P.

1986-01-01

In the aftermath of a nuclear war, genetic effects may appear trivial in comparison with the enormity of the catastrophic development in the survivors' health and the environment. Gross effects are immediately or subtly demonstrable on the basis of diverse war scenarios. On the other hand, in a great number of organisms, genetic effects of radiation have been shown to occur according to a no-threshold dose-effect curve, thus implying that effects may be found even in situations and population groups where other direct effects are small. The discussions on the effects of nuclear war have indicated that whatever sector of effects is focused on, closer examination has, in each case - be it treatment of casualties, effects on climate, or effects on world trade - led to a picture of possible and often probable catastrophic collapse

Genetic effects at pleiotropic loci are context-dependent with consequences for the maintenance of genetic variation in populations.

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Heather A Lawson

2011-09-01

Full Text Available Context-dependent genetic effects, including genotype-by-environment and genotype-by-sex interactions, are a potential mechanism by which genetic variation of complex traits is maintained in populations. Pleiotropic genetic effects are also thought to play an important role in evolution, reflecting functional and developmental relationships among traits. We examine context-dependent genetic effects at pleiotropic loci associated with normal variation in multiple metabolic syndrome (MetS components (obesity, dyslipidemia, and diabetes-related traits. MetS prevalence is increasing in Western societies and, while environmental in origin, presents substantial variation in individual response. We identify 23 pleiotropic MetS quantitative trait loci (QTL in an F(16 advanced intercross between the LG/J and SM/J inbred mouse strains (Wustl:LG,SM-G16; n = 1002. Half of each family was fed a high-fat diet and half fed a low-fat diet; and additive, dominance, and parent-of-origin imprinting genotypic effects were examined in animals partitioned into sex, diet, and sex-by-diet cohorts. We examine the context-dependency of the underlying additive, dominance, and imprinting genetic effects of the traits associated with these pleiotropic QTL. Further, we examine sequence polymorphisms (SNPs between LG/J and SM/J as well as differential expression of positional candidate genes in these regions. We show that genetic associations are different in different sex, diet, and sex-by-diet settings. We also show that over- or underdominance and ecological cross-over interactions for single phenotypes may not be common, however multidimensional synthetic phenotypes at loci with pleiotropic effects can produce situations that favor the maintenance of genetic variation in populations. Our findings have important implications for evolution and the notion of personalized medicine.

Direct results of recent multidisciplinary ethno-genetic research of the Serbs and the Serbian population (in Aleksandrovac district

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Todorović Ivica

2014-01-01

Full Text Available The paper presents immediate results of a multidisciplinary research into ethno genesis, that is, the origin of the Serbs and the Serbian population, based on genetic indicators. The most direct results of the carried out survey are 85 haplotypes with 17 DYS markers/locuses of the respondents from Aleksandrovac district, a representative area as it is in the very centre of Serbian, Kosovo-Resava linguistic and cultural zone. Unlike previous texts that the authors have written on this subject, this paper, for the first time, presents actual results which correlate ethnological facts - starting from older up to latest records on origin - with genetic results obtained owing to the cooperation of the SASA Institute of Ethnography and the Laboratory for DNA analysis of the National forensic centre at the Ministry of Interior, Republic of Serbia. In this way, new findings, which could have been summoned only by parallel use of ethnological and genetic information (and which are given in the paper as clear proofs of necessity and effectiveness of the applied methodological approach, are being obtained and presented. Among other things, the given results of the preliminary survey (compared with the latest relevant surveys by other authors and institutions indicate the dominance of 12a and R1a haplogroups, decisive in the ethnogenesis of the Slavs, which matches common Serbian perception of the Serbs as of a nation of the Slav language and origin.

Genetic effects of organic mercury compounds

Energy Technology Data Exchange (ETDEWEB)

Ramel, C

1967-01-01

Studies on the genetic and developmental effects of organic mercury compounds on lilies, drosophila, and ice were carried out. It was found that chromosomal and developmental abnormalities were correlated with the administration of mercury compounds.

Comparison of a constraint directed search to a genetic algorithm in a scheduling application

International Nuclear Information System (INIS)

Abbott, L.

1993-01-01

Scheduling plutonium containers for blending is a time-intensive operation. Several constraints must be taken into account; including the number of containers in a dissolver run, the size of each dissolver run, and the size and target purity of the blended mixture formed from these runs. Two types of algorithms have been used to solve this problem: a constraint directed search and a genetic algorithm. This paper discusses the implementation of these two different approaches to the problem and the strengths and weaknesses of each algorithm

Is there a doctor in the house? : The presence of physicians in the direct-to-consumer genetic testing context.

Science.gov (United States)

Howard, Heidi Carmen; Borry, Pascal

2012-04-01

Over the last couple of years, many commercial companies, the majority of which are based in the USA, have been advertising and offering direct-to-consumer (DTC) genetic testing services outside of the established health care system, and often without any involvement from a health care professional. In the last year, however, a number of DTC genetic testing companies have changed their provision model such that consumers must now contact a health care professional before being able to order the genetic testing service. In discussing the advent of this new model of service provision, this article also reviews the ethical and social issues surrounding DTC genetic testing and addresses the potential motivations for change, some barriers to achieving truly appropriate medical supervision and the present reality of DTC genetic testing for some psychiatric and neurological disorders. Since the advent of these commercial activities, critics have pointed a finger at the lack of medical supervision surrounding these services. The discussion herein, however, reveals how difficult it may be, despite the addition of a physician, to actually achieve adequate medical supervision within the present context of DTC genetic testing.

Differential network analysis reveals genetic effects on catalepsy modules.

Directory of Open Access Journals (Sweden)

Ovidiu D Iancu

Full Text Available We performed short-term bi-directional selective breeding for haloperidol-induced catalepsy, starting from three mouse populations of increasingly complex genetic structure: an F2 intercross, a heterogeneous stock (HS formed by crossing four inbred strains (HS4 and a heterogeneous stock (HS-CC formed from the inbred strain founders of the Collaborative Cross (CC. All three selections were successful, with large differences in haloperidol response emerging within three generations. Using a custom differential network analysis procedure, we found that gene coexpression patterns changed significantly; importantly, a number of these changes were concordant across genetic backgrounds. In contrast, absolute gene-expression changes were modest and not concordant across genetic backgrounds, in spite of the large and similar phenotypic differences. By inferring strain contributions from the parental lines, we are able to identify significant differences in allelic content between the selected lines concurrent with large changes in transcript connectivity. Importantly, this observation implies that genetic polymorphisms can affect transcript and module connectivity without large changes in absolute expression levels. We conclude that, in this case, selective breeding acts at the subnetwork level, with the same modules but not the same transcripts affected across the three selections.

Population size, center-periphery, and seed dispersers' effects on the genetic diversity and population structure of the Mediterranean relict shrub Cneorum tricoccon.

Science.gov (United States)

Lázaro-Nogal, Ana; Matesanz, Silvia; García-Fernández, Alfredo; Traveset, Anna; Valladares, Fernando

2017-09-01

The effect of population size on population genetic diversity and structure has rarely been studied jointly with other factors such as the position of a population within the species' distribution range or the presence of mutualistic partners influencing dispersal. Understanding these determining factors for genetic variation is critical for conservation of relict plants that are generally suffering from genetic deterioration. Working with 16 populations of the vulnerable relict shrub Cneorum tricoccon throughout the majority of its western Mediterranean distribution range, and using nine polymorphic microsatellite markers, we examined the effects of periphery (peripheral vs. central), population size (large vs. small), and seed disperser (introduced carnivores vs. endemic lizards) on the genetic diversity and population structure of the species. Contrasting genetic variation ( H E : 0.04-0.476) was found across populations. Peripheral populations showed lower genetic diversity, but this was dependent on population size. Large peripheral populations showed high levels of genetic diversity, whereas small central populations were less diverse. Significant isolation by distance was detected, indicating that the effect of long-distance gene flow is limited relative to that of genetic drift, probably due to high selfing rates ( F IS  = 0.155-0.887), restricted pollen flow, and ineffective seed dispersal. Bayesian clustering also supported the strong population differentiation and highly fragmented structure. Contrary to expectations, the type of disperser showed no significant effect on either population genetic diversity or structure. Our results challenge the idea of an effect of periphery per se that can be mainly explained by population size, drawing attention to the need of integrative approaches considering different determinants of genetic variation. Furthermore, the very low genetic diversity observed in several small populations and the strong among

Are the kids really all right? Direct-to-consumer genetic testing in children: are company policies clashing with professional norms?

Science.gov (United States)

Howard, Heidi Carmen; Avard, Denise; Borry, Pascal

2011-01-01

The genetic testing of minors within the direct-to-consumer (DTC) genetic testing (GT) context has been given relatively little attention. The issue of testing healthy children for diseases that would only develop in adulthood raises many important ethical, legal and social issues. As genetic testing is now available outside of the traditional health care system, often without even the intermediate of a health care professional, we surveyed 37 DTC GT companies regarding their policies for testing in children. Although the response rate is relatively low (35%, 13/37), our findings reveal that a clear majority of companies do perform genetic testing in minors. As such, companies testing for adult onset diseases are acting in contradiction of established professional guidelines, which state, among others, that, for predictive genetic testing, the availability of therapeutic or preventive measures is necessary for testing to be performed in asymptomatic minors. The community of stakeholders in children's health care and genetic testing should, therefore, decide which standards need to be upheld by DTC GT companies and ensure that these are met. PMID:21629297

Are the kids really all right? Direct-to-consumer genetic testing in children: are company policies clashing with professional norms?

Science.gov (United States)

Howard, Heidi Carmen; Avard, Denise; Borry, Pascal

2011-11-01

The genetic testing of minors within the direct-to-consumer (DTC) genetic testing (GT) context has been given relatively little attention. The issue of testing healthy children for diseases that would only develop in adulthood raises many important ethical, legal and social issues. As genetic testing is now available outside of the traditional health care system, often without even the intermediate of a health care professional, we surveyed 37 DTC GT companies regarding their policies for testing in children. Although the response rate is relatively low (35%, 13/37), our findings reveal that a clear majority of companies do perform genetic testing in minors. As such, companies testing for adult onset diseases are acting in contradiction of established professional guidelines, which state, among others, that, for predictive genetic testing, the availability of therapeutic or preventive measures is necessary for testing to be performed in asymptomatic minors. The community of stakeholders in children's health care and genetic testing should, therefore, decide which standards need to be upheld by DTC GT companies and ensure that these are met.

Enhanced genetic characterization of influenza A(H3N2) viruses and vaccine effectiveness by genetic group, 2014–2015

Science.gov (United States)

Flannery, Brendan; Zimmerman, Richard K.; Gubareva, Larisa V.; Garten, Rebecca J.; Chung, Jessie R.; Nowalk, Mary Patricia; Jackson, Michael L.; Jackson, Lisa A.; Monto, Arnold S.; Ohmit, Suzanne E.; Belongia, Edward A.; McLean, Huong Q.; Gaglani, Manjusha; Piedra, Pedro A.; Mishin, Vasiliy P.; Chesnokov, Anton P.; Spencer, Sarah; Thaker, Swathi N.; Barnes, John R.; Foust, Angie; Sessions, Wendy; Xu, Xiyan; Katz, Jacqueline; Fry, Alicia M.

2018-01-01

Background During the 2014–15 US influenza season, expanded genetic characterization of circulating influenza A(H3N2) viruses was used to assess the impact of genetic variability of influenza A(H3N2) viruses on influenza vaccine effectiveness (VE). Methods A novel pyrosequencing assay was used to determine genetic group based on hemagglutinin (HA) gene sequences of influenza A(H3N2) viruses from patients enrolled US Flu Vaccine Effectiveness network sites. Vaccine effectiveness was estimated using a test-negative design comparing vaccination among patients infected with influenza A(H3N2) viruses and uninfected patients. Results Among 9710 enrollees, 1868 (19%) tested positive for influenza A(H3N2); genetic characterization of 1397 viruses showed 1134 (81%) belonged to one HA genetic group (3C.2a) of antigenically drifted H3N2 viruses. Effectiveness of 2014–15 influenza vaccination varied by A(H3N2) genetic group from 1% (95% confidence interval [CI], −14% to 14%) against illness caused by antigenically drifted A(H3N2) group 3C.2a viruses versus 44% (95% CI, 16% to 63%) against illness caused by vaccine-like A(H3N2) group 3C.3b viruses. Conclusion Effectiveness of 2014–15 influenza vaccination varied by genetic group of influenza A(H3N2) virus. Changes in hemagglutinin genes related to antigenic drift were associated with reduced vaccine effectiveness. PMID:27190176

Plant traits correlated with generation time directly affect inbreeding depression and mating system and indirectly genetic structure

Directory of Open Access Journals (Sweden)

Hardy Olivier J

2009-07-01

Full Text Available Abstract Background Understanding the mechanisms that control species genetic structure has always been a major objective in evolutionary studies. The association between genetic structure and species attributes has received special attention. As species attributes are highly taxonomically constrained, phylogenetically controlled methods are necessary to infer causal relationships. In plants, a previous study controlling for phylogenetic signal has demonstrated that Wright's FST, a measure of genetic differentiation among populations, is best predicted by the mating system (outcrossing, mixed-mating or selfing and that plant traits such as perenniality and growth form have only an indirect influence on FST via their association with the mating system. The objective of this study is to further outline the determinants of plant genetic structure by distinguishing the effects of mating system on gene flow and on genetic drift. The association of biparental inbreeding and inbreeding depression with population genetic structure, mating system and plant traits are also investigated. Results Based on data from 263 plant species for which estimates of FST, inbreeding (FIS and outcrossing rate (tm are available, we confirm that mating system is the main influencing factor of FST. Moreover, using an alternative measure of FST unaffected by the impact of inbreeding on effective population size, we show that the influence of tm on FST is due to its impact on gene flow (reduced pollen flow under selfing and on genetic drift (higher drift under selfing due to inbreeding. Plant traits, in particular perenniality, influence FST mostly via their effect on the mating system but also via their association with the magnitude of selection against inbred individuals: the mean inbreeding depression increases from short-lived herbaceous to long-lived herbaceous and then to woody species. The influence of perenniality on mating system does not seem to be related to

Characterisation of genetic markers in Mungbean using direct amplification of length polymorphisms (DALP)

International Nuclear Information System (INIS)

Kumar, S.V.; Tan, S.G.; Quah, S.C.

2000-01-01

A newly developed technique, Direct Amplification of Length Polymorphisms (DALP), developed by Desmarais and co-workers in 1998 was successfully used to identify and characterise new genetic markers in mungbean (Vigyia radiata). DALP uses an arbitrarily primed PCR (AP-PCR) to produce genomic fingerprints and is specifically designed to enable direct sequencing of polymorphic bands. In this study, an oligonucleotide pair DALP235 and DAPLR were tested on four varieties of mungbean (V3476, P4281, V5973 and V5784) and produced, through PCR, specific multibanded fingerprints which showed polymorphisms. These polymorphic bands are the result of length polymorphisms as well as absence and presence of bands. Some of the polymorphic zones may be codominantly inherited and may be potential microsatellites. The success of DALP in characterising new polymorphic loci and its ability to discover microsatellites without the use of priori knowledge of the mungbean genome is revolutionary. This would greatly facilitate the breeding and improvement of the crop. (author)

Informed Choice in Direct-to-Consumer Genetic Testing for Alzheimer and Other Diseases: Lessons from Two Cases.

Science.gov (United States)

Messner, Donna A

2011-01-01

Health-related direct-to-consumer (DTC) genetic testing has been a controversial practice. Especially problematic is predictive testing for Alzheimer disease (AD), since the disease is incurable, prevention is inconclusive, and testing does not definitively predict an individual's future disease status. In this paper, I examine two contrasting cases of subjects who learn through genetic testing that they have an elevated risk of developing AD later in life. In these cases, the subject's emotional response to the result is related to how well prepared she was for the real-life personal implications of possible test results. Analysis leads to the conclusion that when groups of health-related genetic tests are offered as packages by DTC companies, informed consumer choice is rendered impossible. Moreover, I argue, this marketing approach contravenes U.S. Federal Trade Commission policies for non-deceptive commercial communications. I conclude by suggesting ways to improve the prospects for informed consumer choice in DTC testing.

Genetic gatekeepers: regulating direct-to-consumer genomic services in an era of participatory medicine.

Science.gov (United States)

Palmer, Jessica Elizabeth

2012-01-01

Should consumers be able to obtain information about their own bodies, even if it has no proven medical value? Direct-to-consumer ("DTC") genomic companies offer consumers two services: generation of the consumer's personal genetic sequence, and interpretation of that sequence in light of current research. Concerned that consumers will misunderstand genomic information and make ill-advised health decisions, regulators, legislators and scholars have advocated restricted access to DTC genomic services. The Food and Drug Administration, which has historically refrained from regulating most genetic tests, has announced its intent to treat DTC genomic services as medical devices because they make "medical claims." This Article argues that FDA regulation of genomic services as medical devices would be counterproductive. Clinical laboratories conducting genetic tests are already overseen by a federal regime administered by the Centers for Medicare and Medicaid Services. While consumers and clinicians would benefit from clearer communication of test results and their health implications, FDA's gatekeeping framework is ill-suited to weigh the safety and efficacy of genomic information that is not medically actionable in traditional ways. Playing gatekeeper would burden FDA's resources, conflict with the patient-empowering policies promoted by personalized medicine initiatives, impair individuals' access to information in which they have powerful autonomy interests, weaken novel participatory research infrastructures, and set a poor precedent for the future regulation of medical information. Rather than applying its risk-based regulatory framework to genetic information, FDA should ameliorate regulatory uncertainty by working with the Federal Trade Commission and Centers for Medicare and Medicaid Services to ensure that DTC genomic services deliver analytically valid data, market and implement their services in a truthful manner, and fully disclose the limitations of their

Comprehension and Data-Sharing Behavior of Direct-To-Consumer Genetic Test Customers.

Science.gov (United States)

McGrath, Scott P; Coleman, Jason; Najjar, Lotfollah; Fruhling, Ann; Bastola, Dhundy R

2016-01-01

The aim of this study was to evaluate current direct-to-consumer (DTC) genetic customers' ability to interpret and comprehend test results and to determine if honest brokers are needed. One hundred and twenty-two customers of the DTC genetic testing company 23andMe were polled in an online survey. The subjects were asked about their personal test results and to interpret the results of two mock test cases (type 2 diabetes and multiple sclerosis), where results were translated into disease probability for an individual compared to the public. When asked to evaluate the risk, 72.1% correctly assessed the first case and 77% were correct on the second case. Only 23.8% of those surveyed were able to interpret both cases correctly. x03C7;2 and logistic regression were used to interpret the results. Participants who took the time to read the DTC test-provided supplemental material were 3.93 times (p = 0.040) more likely to correctly interpret the test results than those who did not. The odds for correctly interpreting the test cases were 3.289 times (p = 0.011) higher for those who made more than USD 50,000 than those who made less. Survey results were compared to the Health Information National Trends Survey (HINTS) phase 4 cycle 3 data to evaluate national trends. Most of the subjects were able to correctly interpret the test cases, yet a majority did not share their results with a health-care professional. As the market for DTC genetic testing grows, test comprehension will become more critical. Involving more health professionals in this process may be necessary to ensure proper interpretations. © 2016 S. Karger AG, Basel.

Exploring Genetic and Environmental Effects in Dysphonia: A Twin Study

Science.gov (United States)

Simberg, Susanna; Santtila, Pekka; Soveri, Anna; Varjonen, Markus; Sala, Eeva; Sandnabba, N. Kenneth

2009-01-01

Purpose: To explore the existence of genetic effects as well as the interaction between potential genetic effects and a voice-demanding occupation on dysphonia. Method: One thousand seven hundred and twenty-eight Finnish twins (555 male; 1,173 female) born between 1961 and 1989 completed a questionnaire concerning vocal symptoms and occupation.…

Genetic and environmental effects of mortality before age 70 years

DEFF Research Database (Denmark)

Petersen, Liselotte; Andersen, Per Kragh; Sørensen, Thorkild I.A.

2008-01-01

BACKGROUND:: There is a familial influence on risk of many diseases and on mortality in general, which, according to studies of twins, is due to a combination of genetic and environmental effects. Adoption studies, which rest on different assumptions, may also be used to estimate separately...... the genetic and environmental effects on rate of dying. METHODS:: The genetic influence on the rate of dying before age 70 years was investigated by estimation of the associations in total and cause-specific mortality of Danish adoptees and their biologic full and half siblings. Familial environmental...

The Effects of Meiosis/Genetics Integration and Instructional Sequence on College Biology Student Achievement in Genetics.

Science.gov (United States)

Browning, Mark

The purpose of the research was to manipulate two aspects of genetics instruction in order to measure their effects on college, introductory biology students' achievement in genetics. One instructional sequence that was used dealt first with monohybrid autosomal inheritance patterns, then sex-linkage. The alternate sequence was the reverse.…

Effect of genetic polymorphisms on development of gout.

Science.gov (United States)

Urano, Wako; Taniguchi, Atsuo; Inoue, Eisuke; Sekita, Chieko; Ichikawa, Naomi; Koseki, Yumi; Kamatani, Naoyuki; Yamanaka, Hisashi

2013-08-01

To validate the association between genetic polymorphisms and gout in Japanese patients, and to investigate the cumulative effects of multiple genetic factors on the development of gout. Subjects were 153 Japanese male patients with gout and 532 male controls. The genotypes of 11 polymorphisms in the 10 genes that have been indicated to be associated with serum uric acid levels or gout were determined. The cumulative effects of the genetic polymorphisms were investigated using a weighted genotype risk score (wGRS) based on the number of risk alleles and the OR for gout. A model to discriminate between patients with gout and controls was constructed by incorporating the wGRS and clinical factors. C statistics method was applied to evaluate the capability of the model to discriminate gout patients from controls. Seven polymorphisms were shown to be associated with gout. The mean wGRS was significantly higher in patients with gout (15.2 ± 2.01) compared to controls (13.4 ± 2.10; p gout. A prediction model for gout that incorporates genetic and clinical factors may be useful for identifying individuals who are at risk of gout.

Genetic and Environmental Effects on Vocal Symptoms and Their Intercorrelations

Science.gov (United States)

Nybacka, Ida; Simberg, Susanna; Santtila, Pekka; Sala, Eeva; Sandnabba, N. Kenneth

2012-01-01

Purpose: Recently, Simberg et al. (2009) found genetic effects on a composite variable consisting of 6 vocal symptom items measuring dysphonia. The purpose of the present study was to determine genetic and environmental effects on the individual vocal symptoms in a population-based sample of Finnish twins. Method: The sample comprised 1,728 twins…

Direct genetic transformation of Hibiscus sabdariffa L.

African Journals Online (AJOL)

Administrator

After 60 days evaluation point, the assessment of the transformation by PCR revealed that H. sabdariffa line tested, carried the nptII gene. Key words: Hibiscus sabdariffa, genetic transformation. INTRODUCTION. Hibiscus sabdariffa is a crop widely cultivated in Sub. Saharan Africa, growing on sandy soils after the harvest.

[Quality assurance in human genetic testing].

Science.gov (United States)

Stuhrmann-Spangenberg, Manfred

2015-02-01

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

Genetic basis and detection of unintended effects in genetically modified crop plants

NARCIS (Netherlands)

Ladics, G.S.; Bartholomaeus, A.; Bregitzer, P.; Doerrer, N.G.; Gray, A.; Holzhauzer, T.; Jordan, M.; Keese, P.; Kok, E.J.; Macdonald, P.; Parrott, W.; Privalle, L.; Raybould, A.; Rhee, S.Y.; Rice, E.; Romeis, J.; Vaughn, J.; Wal, J.M.; Glenn, K.

2015-01-01

In January 2014, an international meeting sponsored by the International Life Sciences Institute/Health and Environmental Sciences Institute and the Canadian Food Inspection Agency titled “Genetic Basis of Unintended Effects in Modified Plants” was held in Ottawa, Canada, bringing together over 75

Awareness, attitudes and perspectives of direct-to-consumer genetic testing in Greece: a survey of potential consumers.

Science.gov (United States)

Mavroidopoulou, Vasiliki; Xera, Ellie; Mollaki, Vasiliki

2015-09-01

Direct-to-consumer genetic testing (DTCGT) is now offered by numerous companies. The present survey aimed to explore awareness, interest, reasons to take and refuse DTCGT, and understanding of results amongst 725 higher education students in Greece. A third of the responders were aware of DTCGT and interest was dependent on cost. More than 60% of the participants would undergo DTCGT to learn more about their health, to warn their children, so that their doctor can monitor their health and change their lifestyle. Nevertheless, they would prefer to consult their doctor first and expressed concerned about their personal data. After receiving results from a hypothetical DTC genetic test predicting higher risk for colon cancer, 59.5% of the responders thought that they could understand the results but 46.1% believed that the results have diagnostic value. In total, 83.6% of the participants would ask their doctor to explain the results and 70.4% would discuss results with their family. In conclusion, the majority of higher education students in Greece appreciate the benefits of genetic testing but with the involvement of their doctor. A physician's participation in the process and informing the public about the true value of genetic testing, are crucial to avoid misinterpretation of DTCGT results.

Public Awareness of Direct-to-Consumer Genetic Tests: Findings from the 2013 U.S. Health Information National Trends Survey.

Science.gov (United States)

Agurs-Collins, Tanya; Ferrer, Rebecca; Ottenbacher, Allison; Waters, Erika A; O'Connell, Mary E; Hamilton, Jada G

2015-12-01

Although the availability of direct-to-consumer (DTC) genetic testing has increased in recent years, the general public's awareness of this testing is not well understood. This study examined levels of public awareness of DTC genetic testing, sources of information about testing, and psychosocial factors associated with awareness of testing in the USA. Data were obtained from the nationally representative 2013 U.S. Health Information National Trends Survey. Guided by a social-cognitive conceptual framework, univariable and multivariable logistic regressions were conducted to identify factors associated with awareness of DTC genetic tests. Of 3185 participants, 35.6% were aware of DTC genetic tests, with the majority learning about these tests through radio, television, and the Internet. In the final adjusted model, participants with annual incomes of $99,999 or less had lower odds of being aware of DTC genetic testing (ORs ranging from 0.46-0.61) than did those participants with incomes of $100,000 or more. The odds of awareness of DTC genetic tests were significantly higher for those who actively seek cancer information (OR=1.91, 95% CI=1.36-2.69), use the Internet (OR=1.81, 95% CI=1.05-3.13), and have high numeracy skills (OR=1.67, 95% CI=1.17-2.38). It will be critical for healthcare researchers and practitioners to understand predictors and consequences of the public's awareness of DTC genetic tests, as well as how such awareness may translate into DTC genetic testing uptake, health behavior change, and ultimately disease prevention.

Genetic effects of heavy ion irradiation in maize and soybean

International Nuclear Information System (INIS)

Yatou, Osamu; Amano, Etsuo; Takahashi, Tan.

1992-01-01

Somatic mutation on leaves of maize and soybean were observed to investigate genetic effects of heavy ion irradiation. Maize seeds were irradiated with N, Fe and U ions and soybean seeds were irradiated with N ions. This is a preliminary report of the experiment, 1) to examine the mutagenic effects of the heavy ion irradiation, and 2) to evaluate the genetic effects of cosmic ray exposure in a space ship outside the earth. (author)

On the genetic effects of low-level tritium

International Nuclear Information System (INIS)

Hori, Tada-aka; Nakai, Sayaka

1976-01-01

Genetic risk assessment for potential hazard from environmental tritium to man becomes important with increasing nuclear-power industry. The purpose of this short review is to discuss the possible genetic effects of tritium from a view of genetic risk estimation. The discussion is based mainly on our experimental results on the chromosome aberrations induced in human lymphocytes by tritium at the very low-level. The types of chromosome aberrations induced by radiation from tritium incorporated into the cells are mostly chromatid types. The most interesting finding is that the dose-response relationship observed in both tritiated-water and tritiated-thymidine is composed of two phases. The examination on the nature of two-phase dose-response relationship is very important not only for the mechanisms of chromosome aberrations, but also for the evaluation of genetic risk from low-level radiation. (auth.)

Evolving Landscapes: the Effect of Genetic Variation on Salt Marsh Erosion

Science.gov (United States)

Bernik, B. M.; Blum, M. J.

2014-12-01

Ecogeomorphic studies have demonstrated that biota can exert influence over geomorphic processes, such as sediment transport, which in turn have biotic consequences and generate complex feedbacks. However, little attention has been paid to the potential for feedback to arise from evolutionary processes as population genetic composition changes in response to changing physical landscapes. In coastal ecosystems experiencing land loss, for example, shoreline erosion entails reduced plant survival and reproduction, and thereby represents a geomorphic response with inherent consequences for evolutionary fitness. To get at this topic, we examined the effect of genetic variation in the saltmarsh grass Spartina alterniflora, a renowned ecosystem engineer, on rates of shoreline erosion. Field transplantation studies and controlled greenhouse experiments were conducted to compare different genotypes from both wild and cultivated populations. Plant traits, soil properties, accretion/subsidence, and rates of land loss were measured. We found significant differences in rates of erosion between field plots occupied by different genotypes. Differences in erosion corresponded to variation in soil properties including critical shear stress and subsidence. Plant traits that differed across genotypes included belowground biomass, root tensile strength, and C:N ratios. Our results demonstrate the importance of genetic variation to salt marsh functioning, elucidating the relationship between evolutionary processes and ecogeomorphic dynamics in these systems. Because evolutionary processes can occur on ecological timescales, the direction and strength of ecogeomorphic feedbacks may be more dynamic than previously accounted for.

Genetic and somatic effects of ionizing radiation

International Nuclear Information System (INIS)

1986-01-01

This is the ninth substantive report of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) to the General Assembly. This report contains reviews on three special topics in the field of biological effects of ionizing radiation that are among those presently under consideration by the Committee: genetic effects of radiation, dose-response relationships for radiation-induced cancer and biological effects of pre-natal irradiation

Genetic effects of ionizing radiations in Eucaryocytes

International Nuclear Information System (INIS)

Jullien, Pierre

1976-01-01

The litterature on the genetic effects of ionizing radiations is reviewed, especially as concerns specific loci or chromosome mutations. Extrapolation from one species to another is considered as well as extra-nuclear mutations [fr

Distributions of Mutational Effects and the Estimation of Directional Selection in Divergent Lineages of Arabidopsis thaliana.

Science.gov (United States)

Park, Briton; Rutter, Matthew T; Fenster, Charles B; Symonds, V Vaughan; Ungerer, Mark C; Townsend, Jeffrey P

2017-08-01

Mutations are crucial to evolution, providing the ultimate source of variation on which natural selection acts. Due to their key role, the distribution of mutational effects on quantitative traits is a key component to any inference regarding historical selection on phenotypic traits. In this paper, we expand on a previously developed test for selection that could be conducted assuming a Gaussian mutation effect distribution by developing approaches to also incorporate any of a family of heavy-tailed Laplace distributions of mutational effects. We apply the test to detect directional natural selection on five traits along the divergence of Columbia and Landsberg lineages of Arabidopsis thaliana , constituting the first test for natural selection in any organism using quantitative trait locus and mutation accumulation data to quantify the intensity of directional selection on a phenotypic trait. We demonstrate that the results of the test for selection can depend on the mutation effect distribution specified. Using the distributions exhibiting the best fit to mutation accumulation data, we infer that natural directional selection caused divergence in the rosette diameter and trichome density traits of the Columbia and Landsberg lineages. Copyright © 2017 by the Genetics Society of America.

Increasing Public Awareness of Direct-to-Consumer Genetic Tests: Health Care Access, Internet Use, and Population Density Correlates.

Science.gov (United States)

Finney Rutten, Lila J; Gollust, Sarah E; Naveed, Sana; Moser, Richard P

2012-01-01

Uncertainty around the value of and appropriate regulatory models for direct-to-consumer (DTC) genetic testing underscores the importance of tracking public awareness of these services. We analyzed nationally representative, cross-sectional data from the Health Information National Trends Survey in 2008 (n = 7, 674) and 2011 (n = 3, 959) to assess population-level changes in awareness of DTC genetic testing in the U.S. and to explore sociodemographic, health care, Internet use, and population density correlates. Overall, awareness increased significantly from 29% in 2008 to 37% in 2011. The observed increase in awareness from 2008 to 2011 remained significant (OR = 1.39) even when adjusted for sociodemographic variables, health care access, Internet use, and population density. Independent of survey year, the odds of awareness of DTC genetic tests were significantly higher for those aged 50-64 (OR = 1.64), and 65-74 (OR = 1.60); college graduates (OR = 2.02); those with a regular source of health care (OR = 1.27); those with a prior cancer diagnosis (OR = 1.24); those who use the Internet (OR = 1.27); and those living in urban areas (OR = 1.25). Surveillance of awareness-along with empirical data on use of and response to genetic risk information-can inform public health and policy efforts to maximize benefits and minimize risks of DTC genetic testing.

Increasing Public Awareness of Direct-to-Consumer Genetic Tests: Health Care Access, Internet Use, and Population Density Correlates

International Nuclear Information System (INIS)

Rutten, L. J. F.; Gollust, S. E.; Naveed, S.; Moser, R. P.

2012-01-01

Uncertainty around the value of and appropriate regulatory models for direct-to-consumer (DTC) genetic testing underscores the importance of tracking public awareness of these services. We analyzed nationally representative, cross-sectional data from the Health Information National Trends Survey in 2008 (n=7, 674) and 2011 (n=3, 959) to assess population-level changes in awareness of DTC genetic testing in the U.S. and to explore socio demographic, health care, Internet use, and population density correlates. Overall, awareness increased significantly from 29% in 2008 to 37% in 2011. The observed increase in awareness from 2008 to 2011 remained significant (OR=1.39) even when adjusted for socio demographic variables, health care access, Internet use, and population density. Independent of survey year, the odds of awareness of DTC genetic tests were significantly higher for those aged 50-64 (OR=1.64), and 65-74 (O R=1.60); college graduates (OR=2.02 ); those with a regular source of health care (OR=1.27); those with a prior cancer diagnosis (OR=1.24); those who use the Internet (OR=1.27); and those living in urban areas ( OR=1.25). Surveillance of awareness-along with empirical data on use of and response to genetic risk information-can inform public health and policy efforts to maximize benefits and minimize risks of DTC genetic testing.

Increasing Public Awareness of Direct-to-Consumer Genetic Tests: Health Care Access, Internet Use, and Population Density Correlates

Directory of Open Access Journals (Sweden)

Lila J. Finney Rutten

2012-01-01

Full Text Available Uncertainty around the value of and appropriate regulatory models for direct-to-consumer (DTC genetic testing underscores the importance of tracking public awareness of these services. We analyzed nationally representative, cross-sectional data from the Health Information National Trends Survey in 2008 (n=7,674 and 2011 (n=3,959 to assess population-level changes in awareness of DTC genetic testing in the U.S. and to explore sociodemographic, health care, Internet use, and population density correlates. Overall, awareness increased significantly from 29% in 2008 to 37% in 2011. The observed increase in awareness from 2008 to 2011 remained significant (OR=1.39 even when adjusted for sociodemographic variables, health care access, Internet use, and population density. Independent of survey year, the odds of awareness of DTC genetic tests were significantly higher for those aged 50–64 (OR=1.64, and 65–74 (OR=1.60; college graduates (OR=2.02; those with a regular source of health care (OR=1.27; those with a prior cancer diagnosis (OR=1.24; those who use the Internet (OR=1.27; and those living in urban areas (OR=1.25. Surveillance of awareness—along with empirical data on use of and response to genetic risk information—can inform public health and policy efforts to maximize benefits and minimize risks of DTC genetic testing.

Effect of Duplicate Genes on Mouse Genetic Robustness: An Update

Directory of Open Access Journals (Sweden)

Zhixi Su

2014-01-01

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

The genetic influence on the cortical processing of experimental pain and the moderating effect of pain status.

Directory of Open Access Journals (Sweden)

Helen Vossen

Full Text Available BACKGROUND: Research suggests that the COMT Val(158Met, BDNF Val(66Met and OPRM1 A(118G polymorphisms moderate the experience of pain. In order to obtain experimental confirmation and extension of findings, cortical processing of experimentally-induced pain was used. METHOD: A sample of 78 individuals with chronic low back pain complaints and 37 healthy controls underwent EEG registration. Event-Related Potentials were measured in response to electrical nociceptive stimuli and moderation by COMT Val(158Met, BDNF Val(66Met and OPRM1 A(118G polymorphisms was assessed. RESULTS: Genetic variation did not have a direct effect on cortical processing of experimental pain. However, genetic effects (COMT Val(158Met and BDNF Val(66Met on experimental pain were moderated by the presence of chronic pain. In the presence of chronic pain, the COMT Met allele and the BDNF Met allele augmented cortical pain processing, whilst reducing pain processing in pain-free controls. No significant effects were found concerning the OPRM1 A(118G polymorphism. CONCLUSIONS: The current study suggests that chronic experience of pain enhances genetic sensitivity to experimentally induced mildly painful stimuli, possibly through a process of epigenetic modification.

Measuring the genetic influence on human life span: gene-environment interaction and sex-specific genetic effects

DEFF Research Database (Denmark)

Tan, Qihua; De Benedictis, G; Yashin, Annatoli

2001-01-01

New approaches are needed to explore the different ways in which genes affect the human life span. One needs to assess the genetic effects themselves, as well as gene–environment interactions and sex dependency. In this paper, we present a new model that combines both genotypic and demographicinf......New approaches are needed to explore the different ways in which genes affect the human life span. One needs to assess the genetic effects themselves, as well as gene–environment interactions and sex dependency. In this paper, we present a new model that combines both genotypic...

Estimation of genetic parameters related to eggshell strength using random regression models.

Science.gov (United States)

Guo, J; Ma, M; Qu, L; Shen, M; Dou, T; Wang, K

2015-01-01

This study examined the changes in eggshell strength and the genetic parameters related to this trait throughout a hen's laying life using random regression. The data were collected from a crossbred population between 2011 and 2014, where the eggshell strength was determined repeatedly for 2260 hens. Using random regression models (RRMs), several Legendre polynomials were employed to estimate the fixed, direct genetic and permanent environment effects. The residual effects were treated as independently distributed with heterogeneous variance for each test week. The direct genetic variance was included with second-order Legendre polynomials and the permanent environment with third-order Legendre polynomials. The heritability of eggshell strength ranged from 0.26 to 0.43, the repeatability ranged between 0.47 and 0.69, and the estimated genetic correlations between test weeks was high at > 0.67. The first eigenvalue of the genetic covariance matrix accounted for about 97% of the sum of all the eigenvalues. The flexibility and statistical power of RRM suggest that this model could be an effective method to improve eggshell quality and to reduce losses due to cracked eggs in a breeding plan.

Genetic effects

International Nuclear Information System (INIS)

Abrahamson, S.; Bender, M.; Denniston, C.; Schull, W.

1985-01-01

Modeling analyses are used to predict the outcomes for two nuclear power plant accident scenarios, the first in which the population received a chronic dose of 0.1 Gy (10 rad) over a 50 year period, the second in which an equivalent population receives acute dose of 2 Gy. In both cases the analyses are projected over a period of five generations. The risk analysis takes on two major forms: the increase in genetic disease that would be observed in the immediate offspring of the exposed population, and the subsequent transmission of the newly induced mutations through future generations. The classes of genetic diseases studied are: dominant gene mutation, X-linked gene mutation, chromosome disorders and multifactorial disorders which involve the interaction of many mutant genes and environmental factors. 28 references, 3 figures, 5 tables

Statistical methods and challenges in connectome genetics

KAUST Repository

Pluta, Dustin

2018-03-12

The study of genetic influences on brain connectivity, known as connectome genetics, is an exciting new direction of research in imaging genetics. We here review recent results and current statistical methods in this area, and discuss some of the persistent challenges and possible directions for future work.

Understanding the relative contributions of direct environmental effects and passive genotype-environment correlations in the association between familial risk factors and child disruptive behavior disorders.

Science.gov (United States)

Bornovalova, M A; Cummings, J R; Hunt, E; Blazei, R; Malone, S; Iacono, W G

2014-03-01

Previous work reports an association between familial risk factors stemming from parental characteristics and offspring disruptive behavior disorders (DBDs). This association may reflect (a) the direct effects of familial environment and (b) a passive gene-environment correlation (r(GE)), wherein the parents provide both the genes and the environment. The current study examined the contributions of direct environmental influences and passive r(GE) by comparing the effects of familial risk factors on child DBDs in genetically related (biological) and non-related (adoptive) families. Participants were 402 adoptive and 204 biological families. Familial environment was defined as maternal and paternal maladaptive parenting and antisociality, marital conflict and divorce; offspring DBDs included attention deficit hyperactivity disorder (ADHD), conduct disorder (CD) and oppositional defiant disorder (ODD). Mixed-level regressions estimated the main effects of familial environment, adoption status and the familial environment by adoption status interaction term, which tested for the presence of passive r(GE). There was a main effect of maternal and paternal maladaptive parenting and marital discord on child DBDs, indicating a direct environmental effect. There was no direct environmental effect of maternal or paternal antisociality, but maternal and paternal antisociality had stronger associations with child DBDs in biological families than adoptive families, indicating the presence of a passive r(GE). Many familial risk factors affected children equally across genetically related and non-related families, providing evidence for direct environmental effects. The relationship of parental antisociality and offspring DBDs was best explained by a passive r(GE), where a general vulnerability toward externalizing psychopathology is passed down by the parents to the children.

A maternal-effect genetic incompatibility in Caenorhabditis elegans

OpenAIRE

Burga, Alejandro; Ben-David, Eyal; Kruglyak, Leonid

2017-01-01

Selfish genetic elements spread in natural populations and have an important role in genome evolution. We discovered a selfish element causing a genetic incompatibility between strains of the nematode Caenorhabditis elegans . The element is made up of sup-35 , a maternal-effect toxin that kills developing embryos, and pha-1 , its zygotically expressed antidote. pha-1 has long been considered essential for pharynx development based on its mutant phenotype, but this phenotype in fact arises fro...

Broad Bandwidth or High Fidelity? Evidence from the Structure of Genetic and Environmental Effects on the Facets of the Five Factor Model

Science.gov (United States)

Briley, Daniel A.; Tucker-Drob, Elliot M.

2017-01-01

The Five Factor Model (FFM) of personality is well-established at the phenotypic level, but much less is known about the coherence of the genetic and environmental influences within each personality domain. Univariate behavioral genetic analyses have consistently found the influence of additive genes and nonshared environment on multiple personality facets, but the extent to which genetic and environmental influences on specific facets reflect more general influences on higher order factors is less clear. We applied a multivariate quantitative-genetic approach to scores on the CPI-Big Five facets for 490 monozygotic and 317 dizygotic twins who took part in the National Merit Twin Study. Our results revealed a complex genetic structure for facets composing all five factors, with both domain-general and facet-specific genetic and environmental influences. Models that required common genetic and environmental influences on each facet to occur by way of effects on a higher order trait did not fit as well as models allowing for common genetic and environmental effects to act directly on the facets for three of the Big Five domains. These results add to the growing body of literature indicating that important variation in personality occurs at the facet level which may be overshadowed by aggregating to the trait level. Research at the facet level, rather than the factor level, is likely to have pragmatic advantages in future research on the genetics of personality. PMID:22695681

The effect of interactions between genetics and cannabis use on neurocognition. A review.

Science.gov (United States)

Cosker, E; Schwitzer, T; Ramoz, N; Ligier, F; Lalanne, L; Gorwood, P; Schwan, R; Laprévote, V

2018-03-02

Cannabis is one of the most widely-used drugs in industrialized countries. It is now well established that cannabis use impacts neurocognition. In the intoxication period time episodic memory, working memory and attention are impacted and impulsivity is increased. The long-term effects of cannabis use tend to be similar. Various internal factors, such as sex differences, modulate this impact. It is unclear whether genetic variations can also influence the impact of cannabis on neurocognition. We set out to examine the impact of genetic variations on neurocognition in cannabis users. We conducted a search via the PubMed, Web of Science, and ScienceDirect databases to identify studies measuring neurocognition and assessing genotypes in the context of cannabis use. We included 13 articles. We found that working memory, verbal and visual memory and sustained attention are more impacted during intoxication in subjects with the Val COMT allele. COMT gene could also modulate sustained attention in regular use. The CNR1, AKT1, DBH and 5-HTT/SLC6A4 genes may also modulate effects. Most of these genes are linked to schizophrenia. A fuller understanding of their impact on the effects of cannabis on neurocognition would thus help elucidate the mechanisms linking cannabis and psychosis. However, evidence is still scant, and more research is needed. Copyright © 2017. Published by Elsevier Inc.

Germ cell toxicity: significance in genetic and fertility effects of radiation and chemicals

International Nuclear Information System (INIS)

Oakberg, E.F.

1983-01-01

The response of the male and female to radiation and chemicals is different. Any loss of oocytes in the female cannot be replaced, and if severe enough, will result in a shortening of the reproductive span. In the male, a temporary sterile period may be induced owing to destruction of the differentiating spermatogonia, but the stem cells are the most resistant spermatogonial type, are capable of repopulating the seminiferous epithelium, and fertility usually returns. The response of both the male and female changes with development of the embryonic to the adult gonad, and with differentiation and maturation in the adult. The primordial germ cells, early oocytes, and differentiating spermatogonia of the adult male are unusually sensitive to the cytotoxic action of noxious agents, but each agent elicits a specific response owing to the intricate biochemical and physiological changes associated with development and maturation of the gametes. The relationship of germ cell killing to fertility is direct, and long-term fertility effects can be predicted from histological analysis of the gonads. The relationship to genetic effects, on the other hand, is indirect, and acts primarily by limiting the cell stages available for testing, by affecting the distribution of mitotically active stem cells among the different stages of the mitotic cycle, and thereby, changing both the type and frequency of genetic effects observed. 100 references, 38 figures, 7 tables

A longitudinal twin study of the direction of effects between ADHD symptoms and IQ.

Science.gov (United States)

Rommel, Anna Sophie; Rijsdijk, Frühling; Greven, Corina U; Asherson, Philip; Kuntsi, Jonna

2015-01-01

While the negative association between ADHD symptoms and IQ is well documented, our knowledge about the direction and aetiology of this association is limited. Here, we examine the association of ADHD symptoms with verbal and performance IQ longitudinally in a population-based sample of twins. In a population-based sample of 4,771 twin pairs, DSM-IV ADHD symptoms were obtained from the Conners' Parent Rating Scale-Revised. Verbal (vocabulary) and performance (Raven's Progressive Matrices) IQ were assessed online. ADHD symptom ratings and IQ scores were obtained at ages 12, 14 and 16 years. Making use of the genetic sensitivity and time-ordered nature of our data, we use a cross-lagged model to examine the direction of effects, while modelling the aetiologies of the association between ADHD symptoms with vocabulary and Raven's scores over time. Although time-specific aetiological influences emerged for each trait at ages 14 and 16 years, the aetiological factors involved in the association between ADHD symptoms and IQ were stable over time. ADHD symptoms and IQ scores significantly predicted each other over time. ADHD symptoms at age 12 years were a significantly stronger predictor of vocabulary and Raven's scores at age 14 years than vice versa, whereas no differential predictive effects emerged from age 14 to 16 years. The results suggest that ADHD symptoms may put adolescents at risk for decreased IQ scores. Persistent genetic influences seem to underlie the association of ADHD symptoms and IQ over time. Early intervention is likely to be key to reducing ADHD symptoms and the associated risk for lower IQ.

Reducing bias in population and landscape genetic inferences: the effects of sampling related individuals and multiple life stages.

Science.gov (United States)

Peterman, William; Brocato, Emily R; Semlitsch, Raymond D; Eggert, Lori S

2016-01-01

In population or landscape genetics studies, an unbiased sampling scheme is essential for generating accurate results, but logistics may lead to deviations from the sample design. Such deviations may come in the form of sampling multiple life stages. Presently, it is largely unknown what effect sampling different life stages can have on population or landscape genetic inference, or how mixing life stages can affect the parameters being measured. Additionally, the removal of siblings from a data set is considered best-practice, but direct comparisons of inferences made with and without siblings are limited. In this study, we sampled embryos, larvae, and adult Ambystoma maculatum from five ponds in Missouri, and analyzed them at 15 microsatellite loci. We calculated allelic richness, heterozygosity and effective population sizes for each life stage at each pond and tested for genetic differentiation (F ST and D C ) and isolation-by-distance (IBD) among ponds. We tested for differences in each of these measures between life stages, and in a pooled population of all life stages. All calculations were done with and without sibling pairs to assess the effect of sibling removal. We also assessed the effect of reducing the number of microsatellites used to make inference. No statistically significant differences were found among ponds or life stages for any of the population genetic measures, but patterns of IBD differed among life stages. There was significant IBD when using adult samples, but tests using embryos, larvae, or a combination of the three life stages were not significant. We found that increasing the ratio of larval or embryo samples in the analysis of genetic distance weakened the IBD relationship, and when using D C , the IBD was no longer significant when larvae and embryos exceeded 60% of the population sample. Further, power to detect an IBD relationship was reduced when fewer microsatellites were used in the analysis.

Reducing bias in population and landscape genetic inferences: the effects of sampling related individuals and multiple life stages

Directory of Open Access Journals (Sweden)

William Peterman

2016-03-01

Full Text Available In population or landscape genetics studies, an unbiased sampling scheme is essential for generating accurate results, but logistics may lead to deviations from the sample design. Such deviations may come in the form of sampling multiple life stages. Presently, it is largely unknown what effect sampling different life stages can have on population or landscape genetic inference, or how mixing life stages can affect the parameters being measured. Additionally, the removal of siblings from a data set is considered best-practice, but direct comparisons of inferences made with and without siblings are limited. In this study, we sampled embryos, larvae, and adult Ambystoma maculatum from five ponds in Missouri, and analyzed them at 15 microsatellite loci. We calculated allelic richness, heterozygosity and effective population sizes for each life stage at each pond and tested for genetic differentiation (FST and DC and isolation-by-distance (IBD among ponds. We tested for differences in each of these measures between life stages, and in a pooled population of all life stages. All calculations were done with and without sibling pairs to assess the effect of sibling removal. We also assessed the effect of reducing the number of microsatellites used to make inference. No statistically significant differences were found among ponds or life stages for any of the population genetic measures, but patterns of IBD differed among life stages. There was significant IBD when using adult samples, but tests using embryos, larvae, or a combination of the three life stages were not significant. We found that increasing the ratio of larval or embryo samples in the analysis of genetic distance weakened the IBD relationship, and when using DC, the IBD was no longer significant when larvae and embryos exceeded 60% of the population sample. Further, power to detect an IBD relationship was reduced when fewer microsatellites were used in the analysis.

Genetic and environmental effects on mortality before age 70 years

DEFF Research Database (Denmark)

Petersen, L.; Andersen, Per Kragh; Sørensen, Thorkild I.A.

2008-01-01

There is a familial influence on risk of many diseases and on mortality in general, which, according to studies of twins, is due to a combination of genetic and environmental effects. Adoption studies, which rest on different assumptions, may also be used to estimate separately the genetic...

Effects of UV radiation on genetic recombination

International Nuclear Information System (INIS)

Vlahovic, K.; Zahradka, D.; Petranovic, M.; Petranovic, D.

1996-01-01

We have used the model consisting of Escherichia coli cells and l phage to study the effects of UV radiation on genetic recombination. We found two radiation induced processes that reduce or inhibit genetic recombination. One such process leads to the inability of prophage to excise itself from the irradiated bacterial chromosome by the site-specific recombination. The other process was shown to inhibit a type of general recombination by which the prophage transfers one of its genetic markers to the infecting homologous phage. Loss of the prophage ability to take part in both site-specific and general recombination was shown to develop in recB + but not in recB cells. From this we infer that the loss of prophage recombinogenicity in irradiated cells is a consequence of one process in which RecBCD enzyme (the product of recB, recC and recD genes) plays an essential role. (author)

Estimation of Genetic Parameters of Kleiber Ratio and Growth Traits in Kurdish Sheep

Directory of Open Access Journals (Sweden)

Davoud Ali Saghi

2016-11-01

restricted maximum likelihood (REML method fitting six animal models using WOMBAT (18: y =Xb+Zaa+e Model 1 y=Xb+Zaa+Zpepe+e Model 2 y =Xb+Zaa+Zmm+e\tCov(a,m=0\tModel 3 y =Xb+Zaa+Zmm+e\tCov(a,m=Aσam\tModel 4 y =Xb+Zaa+Zmm+Zpepe+e\tCov(a,m=0\tModel 5 y =Xb+Zaa+Zmm+Zpepe+e\tCov(a,m= Aσam\tModel 6 where y: is a vector of records, b: is a vector of fixed effects, a: is a vector of direct additive genetic effects, m: is a vector of maternal additive genetic effects, pe: is a vector of permanent environmental effects due to ewe, X, Za, Zm and Zpe are corresponding design matrices relating the fixed effects, direct additive genetic effects, maternal additive genetic effects and permanent environmental effects due to ewe to vector of y, respectively, e: is a vector of residual effects, and Cov(a,m: is the covariance between direct additive genetic and maternal additive genetic effects. Akaike’s Information Criterion (AIC was used for selecting the best model among the tested models (3: Where logLi: is the maximized log likelihood of model i at convergence and pi: is the number of the parameters in each model. Model with the lowest AIC was considered as the best model for each trait. Estimation of genetic and phenotypic correlations was accomplished using multi-trait analysis (with model 1. The fixed effects included in the multi-trait animal models were those in single-trait analyses. Results and Discussion The pre-weaning average daily gain in Kurdish lambs was 215.33±0.96 g, while this trait in post-weaning periods had a decreased trend. These values (especially in pre-weaning period indicated that Kurdish lambs have a good potential for growth. Results from the analysis of variance of ADG and KR in different ages showed that birth year and sex of the lambs significantly influenced studied traits (P< 0.01. Type of birth had significant effect (P< 0.01 on ADG0-3, ADG3-6, KR1 and KR2. The effect of ewe age was significant for ADG0-3 and KR1. The significant effects of fixed

Childhood socioeconomic status amplifies genetic effects on adult intelligence.

Science.gov (United States)

Bates, Timothy C; Lewis, Gary J; Weiss, Alexander

2013-10-01

Studies of intelligence in children reveal significantly higher heritability among groups with high socioeconomic status (SES) than among groups with low SES. These interaction effects, however, have not been examined in adults, when between-families environmental effects are reduced. Using 1,702 adult twins (aged 24-84) for whom intelligence assessment data were available, we tested for interactions between childhood SES and genetic effects, between-families environmental effects, and unique environmental effects. Higher SES was associated with higher mean intelligence scores. Moreover, the magnitude of genetic influences on intelligence was proportional to SES. By contrast, environmental influences were constant. These results suggest that rather than setting lower and upper bounds on intelligence, genes multiply environmental inputs that support intellectual growth. This mechanism implies that increasing SES may raise average intelligence but also magnifies individual differences in intelligence.

Genetic and environmental effects on performance traits of ...

African Journals Online (AJOL)

Genetic and environmental effects on performance traits of Simmentaler cattle on the Transvaal Highveld. Tina Rust*. Highveld Region Agricultural Development Institute, .... ef'fect of the mtt' management system (m = 1,2,3,4),. bW = linear regression of the appropriate deviation from the mean of individual age at weaning (in ...

Cost-Effectiveness Analysis of Different Genetic Testing Strategies for Lynch Syndrome in Taiwan.

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Ying-Erh Chen

Full Text Available Patients with Lynch syndrome (LS have a significantly increased risk of developing colorectal cancer (CRC and other cancers. Genetic screening for LS among patients with newly diagnosed CRC aims to identify mutations in the disease-causing genes (i.e., the DNA mismatch repair genes in the patients, to offer genetic testing for relatives of the patients with the mutations, and then to provide early prevention for the relatives with the mutations. Several genetic tests are available for LS, such as DNA sequencing for MMR genes and tumor testing using microsatellite instability and immunohistochemical analyses. Cost-effectiveness analyses of different genetic testing strategies for LS have been performed in several studies from different countries such as the US and Germany. However, a cost-effectiveness analysis for the testing has not yet been performed in Taiwan. In this study, we evaluated the cost-effectiveness of four genetic testing strategies for LS described in previous studies, while population-specific parameters, such as the mutation rates of the DNA mismatch repair genes and treatment costs for CRC in Taiwan, were used. The incremental cost-effectiveness ratios based on discounted life years gained due to genetic screening were calculated for the strategies relative to no screening and to the previous strategy. Using the World Health Organization standard, which was defined based on Taiwan's Gross Domestic Product per capita, the strategy based on immunohistochemistry as a genetic test followed by BRAF mutation testing was considered to be highly cost-effective relative to no screening. Our probabilistic sensitivity analysis results also suggest that the strategy has a probability of 0.939 of being cost-effective relative to no screening based on the commonly used threshold of $50,000 to determine cost-effectiveness. To the best of our knowledge, this is the first cost-effectiveness analysis for evaluating different genetic testing

Genetic effects of radiation in man: a critical analysis of methodology with examples from three surveys among Brazilian physicians

International Nuclear Information System (INIS)

Freire-Maia, N.

1978-01-01

Information obtained through three different surveys (two via mail and one through personal interviews) made among Brazilian physicians in presented. Data have been classified according to survey, medical speciality, protection used and pregnancy order. Events under consideration are abortions, stillbirths, neo-natal mortality, infant-juvenile mortality (under two criteria) and sex ratio. A number of statistically significant diferences have been found in the direction expected according to the radio-genetics theory and a few ones against it. Two of the surveys reveal an effect of the pregnancy order an abortions which was larger in the exposed samples than in the control ones. This fact could be due to radiation-induced genetic damage, especially chromosome aberrations [pt

Assessment of Direct-to-Consumer Genetic Testing Policy in Korea Based on Consumer Preference.

Science.gov (United States)

Jeong, Gicheol

2017-01-01

In June 2016, Korea permitted direct-to-consumer genetic testing (DTC-GT) on 42 genes. However, both the market and industry have not yet been fully activated. Considering the aforementioned context, this study provides important insights. The Korean DTC-GT policy assessment is based on consumer preference analysis using a discrete choice experiment. In August 2016, a web-based survey was conducted to collect data from 1,200 respondents. The estimation results show that consumers prefer a DTC-GT product that is cheap, tests various items or genes, offers accurate test results, and guarantees the confidentiality of all information. However, consumers are not entirely satisfied by current DTC-GT products due to the existence of insufficient and/or inadequate policies. First, the permitted testing of 42 genes is insufficient to satisfy consumers' curiosity regarding their genes. Second, the accuracy of the DTC-GT products has not been fully verified, assessed, and communicated to consumers. Finally, regulatory loopholes that allow information leaks in the DTC-GT process can occur. These findings imply that DTC-GT requires an improvement in government policy-making criteria and the implementation of practical measures to guarantee test accuracy and genetic information. © 2017 S. Karger AG, Basel.

Traditional Amerindian cultivators combine directional and ideotypic selection for sustainable management of cassava genetic diversity.

Science.gov (United States)

Duputié, A; Massol, F; David, P; Haxaire, C; McKey, D

2009-06-01

Plant domestication provides striking examples of rapid evolution. Yet, it involves more complex processes than plain directional selection. Understanding the dynamics of diversity in traditional agroecosystems is both a fundamental goal in evolutionary biology and a practical goal in conservation. We studied how Amerindian cultivators maintain dynamically evolving gene pools in cassava. Farmers purposely maintain diversity in the form of phenotypically distinct, clonally propagated landraces. Landrace gene pools are continuously renewed by incorporating seedlings issued from spontaneous sexual reproduction. This poses two problems: agronomic quality may decrease because some seedlings are inbred, and landrace identity may be progressively lost through the incorporation of unrelated seedlings. Using a large microsatellite dataset, we show that farmers solve these problems by applying two kinds of selection: directional selection against inbred genotypes, and counter-selection of off-type phenotypes, which maintains high intra-landrace relatedness. Thus, cultural elements such as ideotypes (a representation of the ideal phenotype of a landrace) can shape genetic diversity.

A genetically optimized kinetic model for ethanol electro-oxidation on Pt-based binary catalysts used in direct ethanol fuel cells

Science.gov (United States)

Sánchez-Monreal, Juan; García-Salaberri, Pablo A.; Vera, Marcos

2017-09-01

A one-dimensional model is proposed for the anode of a liquid-feed direct ethanol fuel cell. The complex kinetics of the ethanol electro-oxidation reaction is described using a multi-step reaction mechanism that considers free and adsorbed intermediate species on Pt-based binary catalysts. The adsorbed species are modeled using coverage factors to account for the blockage of the active reaction sites on the catalyst surface. The reaction rates are described by Butler-Volmer equations that are coupled to a one-dimensional mass transport model, which incorporates the effect of ethanol and acetaldehyde crossover. The proposed kinetic model circumvents the acetaldehyde bottleneck effect observed in previous studies by incorporating CH3CHOHads among the adsorbed intermediates. A multi-objetive genetic algorithm is used to determine the reaction constants using anode polarization and product selectivity data obtained from the literature. By adjusting the reaction constants using the methodology developed here, different catalyst layers could be modeled and their selectivities could be successfully reproduced.

Genetic Engineering and Human Mental Ecology: Interlocking Effects and Educational Considerations

OpenAIRE

Affifi, Ramsey

2017-01-01

This paper describes some likely semiotic consequences of genetic engineering on what Gregory Bateson has called ?the mental ecology? (1979) of future humans, consequences that are less often raised in discussions surrounding the safety of GMOs (genetically modified organisms). The effects are as follows: an increased 1) habituation to the presence of GMOs in the environment, 2) normalization of empirically false assumptions grounding genetic reductionism, 3) acceptance that humans are capabl...

Assessment of genetic results of ionizing radiation effect on hydrobionts population

International Nuclear Information System (INIS)

Pechkurenkov, V.L.; Pokrovskaya, L.G.; Fetisov, A.N.

1987-01-01

The effect of dose value and rate on genetic results of chronic radiation with the low dose rate is estimated. At such irradiation the yield of abberant anaphases of embryos is determined by the dose value and it does not depend on the dose rate. The threshold radiation dose rate of the developing fish roe equals 2-3 cGy/h when ignoring the medium modifying factors. The estimation of possible limits of modification of genetic effects of radiation with the low rate when changing environmental factors is given. The model allowing to forecast the appearance of genetic effects of radiation with the low dose rate is constructed. The correspondence between the data obtained in laboratory experiments using organisms living in water reservoirs contaminated experimentally by radionuclides is marked

Determining causes of genetic isolation in a large carnivore (Ursus americanus population to direct contemporary conservation measures.

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Agnès Pelletier

Full Text Available The processes leading to genetic isolation influence a population's local extinction risk, and should thus be identified before conservation actions are implemented. Natural or human-induced circumstances can result in historical or contemporary barriers to gene flow and/or demographic bottlenecks. Distinguishing between these hypotheses can be achieved by comparing genetic diversity and differentiation in isolated vs. continuous neighboring populations. In Ontario, American black bears (Ursus americanus are continuously distributed, genetically diverse, and exhibit an isolation-by-distance structuring pattern, except on the Bruce Peninsula (BP. To identify the processes that led to the genetic isolation of BP black bears, we modelled various levels of historical and contemporary migration and population size reductions using forward simulations. We compared simulation results with empirical genetic indices from Ontario black bear populations under different levels of geographic isolation, and conducted additional simulations to determine if translocations could help achieve genetic restoration. From a genetic standpoint, conservation concerns for BP black bears are warranted because our results show that: i a recent demographic bottleneck associated with recently reduced migration best explains the low genetic diversity on the BP; and ii under sustained isolation, BP black bears could lose between 70% and 80% of their rare alleles within 100 years. Although restoring migration corridors would be the most effective method to enhance long-term genetic diversity and prevent inbreeding, it is unrealistic to expect connectivity to be re-established. Current levels of genetic diversity could be maintained by successfully translocating 10 bears onto the peninsula every 5 years. Such regular translocations may be more practical than landscape restoration, because areas connecting the peninsula to nearby mainland black bear populations have been

Erosion of Brassica incana Genetic Resources: Causes and Effects

Science.gov (United States)

Muscolo, A.; Settineri, G.; Mallamaci, C.; Papalia, T.; Sidari, M.

2017-07-01

Brassica incana Ten., possessing a number of useful agronomic traits, represents a precious genetic resource to be used in plant breeding programs to broaden the genetic base in most Brassica crop species. B. incana that grows on limestone cliffs is at risk of genetic erosion for environmental constraints and human activities. We studied the pedological conditions of a Calabrian site where the B. incana grows, and we correlated the soil properties to the physiological and biochemical aspects of B. incana to identify the causes and effects of the genetic erosion of this species. Our results evidenced that physical soil conditions did not affect B. incana growth and nutraceutical properties; conversely, biological soil properties modified its properties. We identified leaf pigments and secondary metabolites that can be used routinely as early warning indicators of plant threat, to evaluate in a short term the dynamic behavior of plants leading to species extinction.

Genetic effects of low-dose irradiation in Drosophila Melanogaster

International Nuclear Information System (INIS)

Zajnulin, V.G.; Shaposhnikov, M.V.; Yuraneva, I.N.

2000-01-01

Influence of chronic γ-irradiation at the dose rate of 0.17 cGy/h on the rate of genetic variability in the laboratory strains of Drosophila Melanogaster with genotypic distinguishes by families of mobile genetic elements and of systems of hybrid disgenesis and also violations in reparation processes control mechanisms. It was shown that the rates of induction of recessive lethal mutations depended on genotype of investigated strains. In the different strains an increase as well as a decrease of the mutation rate were observed. Also in was established that irradiation leads to the increase in frequencies of the gonads sterility and mutability of the sn w and h(w + ) in the P-M and H-E dysgenic crosses. Obtained results suggest that mobile genetic elements play an important role in the forming of genetic effects in response to low dose irradiation [ru

Adults' perceptions of genetic counseling and genetic testing.

Science.gov (United States)

Houfek, Julia Fisco; Soltis-Vaughan, Brigette S; Atwood, Jan R; Reiser, Gwendolyn M; Schaefer, G Bradley

2015-02-01

This study described the perceptions of genetic counseling and testing of adults (N = 116) attending a genetic education program. Understanding perceptions of genetic counseling, including the importance of counseling topics, will contribute to patient-focused care as clinical genetic applications for common, complex disorders evolve. Participants completed a survey addressing: the importance of genetic counseling topics, benefits and negative effects of genetic testing, and sharing test results. Topics addressing practical information about genetic conditions were rated most important; topics involving conceptual genetic/genomic principles were rated least important. The most frequently identified benefit and negative effect of testing were prevention/early detection/treatment and psychological distress. Participants perceived that they were more likely to share test results with first-degree than other relatives. Findings suggest providing patients with practical information about genetic testing and genetic contributions to disease, while also determining whether their self-care abilities would be enhanced by teaching genetic/genomic principles. Copyright © 2014 Elsevier Inc. All rights reserved.

Genetic Properties of Some Economic Traits in Isfahan Native Fowl Using Bayesian and REML Methods

Directory of Open Access Journals (Sweden)

Salehinasab M

2015-12-01

Full Text Available The objective of the present study was to estimate heritability values for some performance and egg quality traits of native fowl in Isfahan breeding center using REML and Bayesian approaches. The records were about 51521 and 975 for performance and egg quality traits, respectively. At the first step, variance components were estimated for body weight at hatch (BW0, body weight at 8 weeks of age (BW8, weight at sexual maturity (WSM, egg yolk weight (YW, egg Haugh unit and eggshell thickness, via REML approach using ASREML software. At the second step, the same traits were analyzed via Bayesian approach using Gibbs3f90 software. In both approaches six different animal models were applied and the best model was determined using likelihood ratio test (LRT and deviance information criterion (DIC for REML and Bayesian approaches, respectively. Heritability estimates for BW0, WSM and ST were the same in both approaches. For BW0, LRT and DIC indexes confirmed that the model consisting maternal genetic, permanent environmental and direct genetic effects was significantly better than other models. For WSM, a model consisting of maternal permanent environmental effect in addition to direct genetic effect was the best. For shell thickness, the basic model consisting direct genetic effect was the best. The results for BW8, YW and Haugh unit, were different between the two approaches. The reason behind this tiny differences was that the convergence could not be achieved for some models in REML approach and thus for these traits the Bayesian approach estimated the variance components more accurately. The results indicated that ignoring maternal effects, overestimates the direct genetic variance and heritability for most of the traits. Also, the Bayesian-based software could take more variance components into account.

Application of preimplantation genetic diagnosis in equine blastocysts

Directory of Open Access Journals (Sweden)

Grady ST

2016-08-01

Full Text Available Pre-implantation genetic diagnosis (PGD is a procedure used to screen in vitroproduced embryos or embryos recovered after uterine flush to determine genetic traits by DNA testing prior to transfer into the uterus. Biopsy methods to obtain a sample of cells for genetic analysis before implantation have been successful in small embryos (morulae and blastocysts 300 µm diameter. The successful biopsy of expanded equine blastocysts via micromanipulation, with subsequent normal pregnancy rates, was first reported in 2010. Direct PCR may be performed when evaluating only one gene, such as for embryo sexing, while whole genome amplification is effective for subsequent multiplex PCR of multiple genes.

Modelling the co-evolution of indirect genetic effects and inherited variability.

Science.gov (United States)

Marjanovic, Jovana; Mulder, Han A; Rönnegård, Lars; Bijma, Piter

2018-03-28

When individuals interact, their phenotypes may be affected not only by their own genes but also by genes in their social partners. This phenomenon is known as Indirect Genetic Effects (IGEs). In aquaculture species and some plants, however, competition not only affects trait levels of individuals, but also inflates variability of trait values among individuals. In the field of quantitative genetics, the variability of trait values has been studied as a quantitative trait in itself, and is often referred to as inherited variability. Such studies, however, consider only the genetic effect of the focal individual on trait variability and do not make a connection to competition. Although the observed phenotypic relationship between competition and variability suggests an underlying genetic relationship, the current quantitative genetic models of IGE and inherited variability do not allow for such a relationship. The lack of quantitative genetic models that connect IGEs to inherited variability limits our understanding of the potential of variability to respond to selection, both in nature and agriculture. Models of trait levels, for example, show that IGEs may considerably change heritable variation in trait values. Currently, we lack the tools to investigate whether this result extends to variability of trait values. Here we present a model that integrates IGEs and inherited variability. In this model, the target phenotype, say growth rate, is a function of the genetic and environmental effects of the focal individual and of the difference in trait value between the social partner and the focal individual, multiplied by a regression coefficient. The regression coefficient is a genetic trait, which is a measure of cooperation; a negative value indicates competition, a positive value cooperation, and an increasing value due to selection indicates the evolution of cooperation. In contrast to the existing quantitative genetic models, our model allows for co-evolution of

A longitudinal twin study of the direction of effects between ADHD symptoms and IQ.

Directory of Open Access Journals (Sweden)

Anna Sophie Rommel

Full Text Available While the negative association between ADHD symptoms and IQ is well documented, our knowledge about the direction and aetiology of this association is limited. Here, we examine the association of ADHD symptoms with verbal and performance IQ longitudinally in a population-based sample of twins. In a population-based sample of 4,771 twin pairs, DSM-IV ADHD symptoms were obtained from the Conners' Parent Rating Scale-Revised. Verbal (vocabulary and performance (Raven's Progressive Matrices IQ were assessed online. ADHD symptom ratings and IQ scores were obtained at ages 12, 14 and 16 years. Making use of the genetic sensitivity and time-ordered nature of our data, we use a cross-lagged model to examine the direction of effects, while modelling the aetiologies of the association between ADHD symptoms with vocabulary and Raven's scores over time. Although time-specific aetiological influences emerged for each trait at ages 14 and 16 years, the aetiological factors involved in the association between ADHD symptoms and IQ were stable over time. ADHD symptoms and IQ scores significantly predicted each other over time. ADHD symptoms at age 12 years were a significantly stronger predictor of vocabulary and Raven's scores at age 14 years than vice versa, whereas no differential predictive effects emerged from age 14 to 16 years. The results suggest that ADHD symptoms may put adolescents at risk for decreased IQ scores. Persistent genetic influences seem to underlie the association of ADHD symptoms and IQ over time. Early intervention is likely to be key to reducing ADHD symptoms and the associated risk for lower IQ.

Modeling genetic imprinting effects of DNA sequences with multilocus polymorphism data

Directory of Open Access Journals (Sweden)

Staud Roland

2009-08-01

Full Text Available Abstract Single nucleotide polymorphisms (SNPs represent the most widespread type of DNA sequence variation in the human genome and they have recently emerged as valuable genetic markers for revealing the genetic architecture of complex traits in terms of nucleotide combination and sequence. Here, we extend an algorithmic model for the haplotype analysis of SNPs to estimate the effects of genetic imprinting expressed at the DNA sequence level. The model provides a general procedure for identifying the number and types of optimal DNA sequence variants that are expressed differently due to their parental origin. The model is used to analyze a genetic data set collected from a pain genetics project. We find that DNA haplotype GAC from three SNPs, OPRKG36T (with two alleles G and T, OPRKA843G (with alleles A and G, and OPRKC846T (with alleles C and T, at the kappa-opioid receptor, triggers a significant effect on pain sensitivity, but with expression significantly depending on the parent from which it is inherited (p = 0.008. With a tremendous advance in SNP identification and automated screening, the model founded on haplotype discovery and statistical inference may provide a useful tool for genetic analysis of any quantitative trait with complex inheritance.

Analysis of the Threat of Genetically Modified Organisms for Biological Warfare

Science.gov (United States)

2011-05-01

biological warfare. The primary focus of the framework are those aspects of the technology directly affecting humans by inducing virulent infectious disease...applications. Simple organisms such as fruit flies have been used to study the effects of genetic changes across generations. Transgenic mice are...Analysis * Multi-cell pathogens * Toxins (Chemical products of living cells.) * Fungi (Robust organism; no genetic manipulation needed

Exchange effects in direct reactions

International Nuclear Information System (INIS)

LeMere, M.; Kanellopoulos, E.J.; Suenkel, W.; Tang, Y.C.

1979-01-01

The effect of antisymmetrization in direct reactions is examined by studying the properties of the coupling-normalization kernel function occurring in a resonating-group formulation. From this study, one obtains useful information concerning the general behavior of direct-reactiion processes and some justification for the use of three-body models in phenomenological analyses

Including nonadditive genetic effects in mating programs to maximize dairy farm profitability.

Science.gov (United States)

Aliloo, H; Pryce, J E; González-Recio, O; Cocks, B G; Goddard, M E; Hayes, B J

2017-02-01

We compared the outcome of mating programs based on different evaluation models that included nonadditive genetic effects (dominance and heterozygosity) in addition to additive effects. The additive and dominance marker effects and the values of regression on average heterozygosity were estimated using 632,003 single nucleotide polymorphisms from 7,902 and 7,510 Holstein cows with calving interval and production (milk, fat, and protein yields) records, respectively. Expected progeny values were computed based on the estimated genetic effects and genotype probabilities of hypothetical progeny from matings between the available genotyped cows and the top 50 young genomic bulls. An index combining the traits based on their economic values was developed and used to evaluate the performance of different mating scenarios in terms of dollar profit. We observed that mating programs with nonadditive genetic effects performed better than a model with only additive effects. Mating programs with dominance and heterozygosity effects increased milk, fat, and protein yields by up to 38, 1.57, and 1.21 kg, respectively. The inclusion of dominance and heterozygosity effects decreased calving interval by up to 0.70 d compared with random mating. The average reduction in progeny inbreeding by the inclusion of nonadditive genetic effects in matings compared with random mating was between 0.25 to 1.57 and 0.64 to 1.57 percentage points for calving interval and production traits, respectively. The reduction in inbreeding was accompanied by an average of A$8.42 (Australian dollars) more profit per mating for a model with additive, dominance, and heterozygosity effects compared with random mating. Mate allocations that benefit from nonadditive genetic effects can improve progeny performance only in the generation where it is being implemented, and the gain from specific combining abilities cannot be accumulated over generations. Continuous updating of genomic predictions and mate

The Environmental Benefits and Costs of Genetically Modified (GM) Crops

NARCIS (Netherlands)

Wesseler, J.H.H.; Scatasta, S.; Fall, E.H.

2011-01-01

The widespread introduction of genetically modified (GM) crops may change the effect of agriculture on the environment. The magnitude and direction of expected effects are still being hotly debated, and the interests served in this discussion arena are often far from those of science and social

The genetic and economic effect of preliminary culling in the seedling orchard

Science.gov (United States)

Don E. Riemenschneider

1977-01-01

The genetic and economic effects of two stages of truncation selection in a white spruce seedling orchard were investigated by computer simulation. Genetic effects were computed by assuming a bivariate distribution of juvenile and mature traits and volume was used as the selection criterion. Seed production was assumed to rise in a linear fashion to maturity and then...

Cancer-related direct-to-consumer advertising: a critical review.

Science.gov (United States)

Kontos, Emily Z; Viswanath, K

2011-02-01

The direct-to-consumer advertising (DTCA) phenomenon has received attention because of its attempt to reach out to consumers by bypassing important gatekeepers such as physicians. The emergence of new information platforms and the introduction of genetic tests directly to the consumer have heightened the concern with DTCA and its potential consequences. These effects of DTCA are particularly important given the communication inequalities among social groups, with class, race and ethnicity influencing how people access, seek, process and act on information. This Science and Society article reviews the major issues regarding general and cancer-related DTCA and also offers data from a national survey in the United States as an example of the communication inequalities in genetic testing awareness.

Which lessons can we learn from the European Union legal framework of medicines for the regulation of direct-to-consumer genetic tests?

Science.gov (United States)

van Hellemondt, Rachèl; Hendriks, Aart; Breuning, Martijn

2012-01-01

The legal framework of the European Union (EU) for regulating access to and supply of direct-to-consumer (DTC) genetic tests is very liberal compared to the legal and regulatory framework for (internet) medicines. Nevertheless, both health related products can cause equally serious damage to the well being of individuals. In this contribution we examine whether the legal framework of the EU for the safety and responsible use of (internet) medicines could be an example for regulating access to and supply of DTC genetic tests. The EU laws governing medicines can, notwithstanding their shortcomings, serve as an example for (central) authorising the marketing of DTC genetic tests on the internal market in accordance with strict criteria regarding predictive value and clinical usefulness. Furthermore, a legal framework controlling DTC genetic tests also should introduce system supervision as well as quality criteria with respect to the information to be provided to consumers in order to enhance health protection. However, DTC genetic tests purchased through online ordering are difficult to supervise by any agency. Adequately protecting individuals against questionable testing kits calls for international vigilance and comprehensive measures by the international community. For Europe, it is important to rank the regulation of DTC genetic tests on the European regulatory agenda.

Estimating non-genetic and genetic parameters of pre-weaning growth traits in Raini Cashmere goat.

Science.gov (United States)

Barazandeh, Arsalan; Moghbeli, Sadrollah Molaei; Vatankhah, Mahmood; Mohammadabadi, Mohammadreza

2012-04-01

Data and pedigree information used in the present study were 3,022 records of kids obtained from the breeding station of Raini goat. The studied traits were birth weight (BW), weaning weight (WW), average daily gain from birth to weaning (ADG) and Kleiber ratio at weaning (KR). The model included the fixed effects of sex of kid, type of birth, age of dam, year of birth, month of birth, and age of kid (days) as covariate that had significant effects, and random effects direct additive genetic, maternal additive genetic, maternal permanent environmental effects and residual. (Co) variance components were estimated using univariate and multivariate analysis by WOMBAT software applying four animal models including and ignoring maternal effects. Likelihood ratio test used to determine the most appropriate models. Heritability (h(a)(2)) estimates for BW, WW, ADG, and KR according to suitable model were 0.12 ± 0.05, 0.08 ± 0.06, 0.10 ± 0.06, and 0.06 ± 0.05, respectively. Estimates of the proportion of maternal permanent environmental effect to phenotypic variance (c(2)) were 0.17 ± 0.03, 0.07 ± 0.03, and 0.07 ± 0.03 for BW, WW, and ADG, respectively. Genetic correlations among traits were positive and ranged from 0.53 (BW-ADG) to 1.00 (WW-ADG, WW-KR, and ADG-KR). The maternal permanent environmental correlations between BW-WW, BW-ADG, and WW-ADG were 0.54, 0.48, and 0.99, respectively. Results indicated that maternal effects, especially maternal permanent environmental effects are an important source of variation in pre-weaning growth trait and ignoring those in the model redound incorrect genetic evaluation of kids.

New approaches to evaluating the genetic effects of the atomic bombs

International Nuclear Information System (INIS)

Neel, J.V.

1995-01-01

In the aftermath of the atomic bombings of Hiroshima and Nagasaki fifty years ago, one of the compelling biomedical questions that arose concerned the genetic effects of this exposure. More recently, revelations of the extent of industrial or accidental exposures in the former Soviet Union and charges that employment in the Sellafield Nuclear Reprocessing Plant in West Cumbria, England has resulted in a gene-mediated increase in children of plant employees have served to keep in the public mind the issue of the genetic risks of exposure to ionizing radiation. The study of the genetic effects of the atomic bombs has moved from the gross morphological level of congenital malformations to the examination of DNA. However, were the need for such genetic studies to arise in the foreseeable future, despite this impressive progress in DNA-oriented systems, the documentation of congenital defect, genetic disease and child survival would still be an essential component of any future study. Whatever the geneticists may think, the phenotypic well-being and survival of children are still the primary indicators on which the public, who ultimately supports these studies, will base its judgement of risk. 28 refs

Intrinsic Value and the Genetic Engineering of Animals.

NARCIS (Netherlands)

Vries, R.B.M. de

2008-01-01

The concept of intrinsic value is often invoked to articulate objections to the genetic engineering of animals, particularly those objections that are not directed at the negative effects the technique might have on the health and welfare of the modified animals. However, this concept was not

Genetic Engineering and the Amelioration of Genetic Defect

Science.gov (United States)

Lederberg, Joshua

1970-01-01

Discusses the claims for a brave new world of genetic manipulation" and concludes that if we could agree upon applying genetic (or any other effective) remedies to global problems we probably would need no rescourse to them. Suggests that effective methods of preventing genetic disease are prevention of mutations and detection and…

Trapped in the extinction vortex? Strong genetic effects in a declining vertebrate population

Directory of Open Access Journals (Sweden)

Larsson Mikael

2010-02-01

Full Text Available Abstract Background Inbreeding and loss of genetic diversity are expected to increase the extinction risk of small populations, but detailed tests in natural populations are scarce. We combine long-term population and fitness data with those from two types of molecular markers to examine the role of genetic effects in a declining metapopulation of southern dunlins Calidris alpina schinzii, an endangered shorebird. Results The decline is associated with increased pairings between related individuals, including close inbreeding (as revealed by both field observations of parentage and molecular markers. Furthermore, reduced genetic diversity seems to affect individual fitness at several life stages. Higher genetic similarity between mates correlates negatively with the pair's hatching success. Moreover, offspring produced by related parents are more homozygous and suffer from increased mortality during embryonic development and possibly also after hatching. Conclusions Our results demonstrate strong genetic effects in a rapidly declining population, emphasizing the importance of genetic factors for the persistence of small populations.

Health-related direct-to-consumer genetic tests: a public health assessment and analysis of practices related to Internet-based tests for risk of thrombosis.

Science.gov (United States)

Goddard, K A B; Robitaille, J; Dowling, N F; Parrado, A R; Fishman, J; Bradley, L A; Moore, C A; Khoury, M J

2009-01-01

Recent years have seen increased concern about direct-to-consumer (DTC) genetic testing (i.e., the sale and use of genetic tests without involving a health care provider). Numerous professional organizations have developed policies in this area. However, little systematic evidence exists to inform public policy about these tests. We conducted a systematic search to identify genetic tests that are sold DTC without involving a health care provider. We evaluated the practices of companies offering DTC genetic tests for risk of thrombosis using criteria from multiple sources and a minimal set of key practices. We identified 84 instances of currently available health-related DTC genetic tests sold on 27 Web sites; the most common were for pharmacogenomics (12), risk of thrombosis (10), and nutrigenomics (10). For the DTC genetic tests for risk of thrombosis, we found low adherence to recommendations. Online information was frequently incomplete and had low agreement with professional recommendations. Our findings document the rapid growth in the availability of health-related DTC genetic tests and highlight the need to improve the delivery of DTC genetic tests. A major implication of this study is the need for the scientific and medical community to develop consistent recommendations to increase their impact. Copyright 2008 S. Karger AG, Basel.

Analyzing age-specific genetic effects on human extreme age survival in cohort-based longitudinal studies

DEFF Research Database (Denmark)

Tan, Qihua; Jacobsen, Rune; Sørensen, Mette

2013-01-01

The analysis of age-specific genetic effects on human survival over extreme ages is confronted with a deceleration pattern in mortality that deviates from traditional survival models and sparse genetic data available. As human late life is a distinct phase of life history, exploring the genetic...... effects on extreme age survival can be of special interest to evolutionary biology and health science. We introduce a non-parametric survival analysis approach that combines population survival information with individual genotype data in assessing the genetic effects in cohort-based longitudinal studies...

Cardiometabolic effects of genetic upregulation of the interleukin 1 receptor antagonist

DEFF Research Database (Denmark)

2015-01-01

BACKGROUND: To investigate potential cardiovascular and other effects of long-term pharmacological interleukin 1 (IL-1) inhibition, we studied genetic variants that produce inhibition of IL-1, a master regulator of inflammation. METHODS: We created a genetic score combining the effects of alleles...... of two common variants (rs6743376 and rs1542176) that are located upstream of IL1RN, the gene encoding the IL-1 receptor antagonist (IL-1Ra; an endogenous inhibitor of both IL-1α and IL-1β); both alleles increase soluble IL-1Ra protein concentration. We compared effects on inflammation biomarkers...... of this genetic score with those of anakinra, the recombinant form of IL-1Ra, which has previously been studied in randomised trials of rheumatoid arthritis and other inflammatory disorders. In primary analyses, we investigated the score in relation to rheumatoid arthritis and four cardiometabolic diseases (type...

Directional genetic selection by pulp mill effluent on multiple natural populations of three-spined stickleback (Gasterosteus aculeatus).

Science.gov (United States)

Lind, Emma E; Grahn, Mats

2011-05-01

Contamination can cause a rapid environmental change which may require populations to respond with evolutionary changes. To evaluate the effects of pulp mill effluents on population genetics, we sampled three-spined sticklebacks (Gasterosteus aculeatus) near four pulp mills and four adjacent reference sites and analyzed Amplified Fragment Length Polymorphism (AFLP) to compare genetic variability. A fine scale genetic structure was detected and samples from polluted sites separated from reference sites in multidimensional scaling plots (Pselection. When removing 13 F(ST)-outlier loci, significant at the Pselective agent on natural populations of G. aculeatus, causing a convergence in genotype composition change at multiple sites in an open environment. © The Author(s) 2011. This article is published with open access at Springerlink.com

Empirical evidence of direct rebound effect in Catalonia

International Nuclear Information System (INIS)

Freire Gonzalez, Jaume

2010-01-01

This paper reviews the empirical literature concerning the direct rebound effect in households; it briefly analyzes the main theoretical and methodological aspects, and finally estimates the magnitude of direct rebound effect for all energy services using electricity in households of Catalonia (Spain) using econometric techniques. The main results show an estimated direct rebound effect of 35% in the short term and 49% in the long term. The existence of a rebound effect reduces the effectiveness of energy efficiency policies.

Genetic estimation of hot carcass weight in indigenous Matebele ...

African Journals Online (AJOL)

Genetic parameter estimation for simple carcass traits has been confined to the improved goat breeds worldwide unlike in the unimproved breeds in developing countries where goats are numerous. Variance components for additive direct, additive maternal, permanent environmental maternal effects, the covariance ...

GENETIC CONTRIBUTION OF RAM ON LITTER SIZE IN ŠUMAVA SHEEP

Directory of Open Access Journals (Sweden)

Jitka Schmidová

2015-09-01

Full Text Available The objective of the present study was to quantify the service sire effect in terms of (co variance components of born and weaned lambs number and to propose models for the potential inclusion of this effect in the linear equations for breeding value estimation. The database with 21,324 lambings in Šumava sheep from 1992- 2013 was used. The basic model equation for the analysis of variance of litter size contained effects of ewe´s age at lambing, contemporary group, permanent environmental effect of ewe and direct additive genetic effect of ewe. Two modifications of the basic model were used for estimation of service sire effect. The proportions of variance for the service sire effect for number of born and weaned lambs were 2.1% and 2.0%, when service sire was not included into relationship matrix; while included into the relationship matrix and dividing effect into genetic contribution and permanent environment effect refer that nongenetic effect seems to be bigger than genetic (0.013 vs. 0.009 for number of born and 0.017 vs. 0.004 for number of weaned. Changes in other variance components were relatively low, except of contemporary group. Model including service sire effect as a simple random effect without genetic relationship matrix inclusion is recommended for genetic evaluation of litter size traits.

Race, Genetic Ancestry and Response to Antidepressant Treatment for Major Depression

Science.gov (United States)

Murphy, Eleanor; Hou, Liping; Maher, Brion S; Woldehawariat, Girma; Kassem, Layla; Akula, Nirmala; Laje, Gonzalo; McMahon, Francis J

2013-01-01

The Sequenced Treatment Alternatives to Relieve Depression (STAR*D) Study revealed poorer antidepressant treatment response among black compared with white participants. This racial disparity persisted even after socioeconomic and baseline clinical factors were taken into account. Some studies have suggested genetic contributions to this disparity, but none have attempted to disentangle race and genetic ancestry. Here we used genome-wide single-nucleotide polymorphism (SNP) data to examine independent contributions of race and genetic ancestry to citalopram response. Secondary data analyses included 1877 STAR*D participants who completed an average of 10 weeks of citalopram treatment and provided DNA samples. Participants reported their race as White (n=1464), black (n=299) or other/mixed (n=114). Genetic ancestry was estimated by multidimensional scaling (MDS) analyses of about 500 000 SNPs. Ancestry proportions were estimated by STRUCTURE. Structural equation modeling was used to examine the direct and indirect effects of observed and latent predictors of response, defined as change in the Quick Inventory of Depressive Symptomatology (QIDS) score from baseline to exit. Socioeconomic and baseline clinical factors, race, and anxiety significantly predicted response, as previously reported. However, direct effects of race disappeared in all models that included genetic ancestry. Genetic African ancestry predicted lower treatment response in all models. Although socioeconomic and baseline clinical factors drive racial differences in antidepressant response, genetic ancestry, rather than self-reported race, explains a significant fraction of the residual differences. Larger samples would be needed to identify the specific genetic mechanisms that may be involved, but these findings underscore the importance of including more African-American patients in drug trials. PMID:23827886

Effectiveness of students worksheet based on mastery learning in genetics subject

Science.gov (United States)

Megahati, R. R. P.; Yanti, F.; Susanti, D.

2018-05-01

Genetics is one of the subjects that must be followed by students in Biology education department. Generally, students do not like the genetics subject because of genetics concepts difficult to understand and the unavailability of a practical students worksheet. Consequently, the complete learning process (mastery learning) is not fulfilled and low students learning outcomes. The aim of this study develops student worksheet based on mastery learning that practical in genetics subject. This research is a research and development using 4-D models. The data analysis technique used is the descriptive analysis that describes the results of the practicalities of students worksheets based on mastery learning by students and lecturer of the genetic subject. The result is the student worksheet based on mastery learning on genetics subject are to the criteria of 80,33% and 80,14%, which means that the students worksheet practical used by lecturer and students. Student’s worksheet based on mastery learning effective because it can increase the activity and student learning outcomes.

Genetic parameters of body weight and prolificacy in pigeons

Directory of Open Access Journals (Sweden)

Beaumont Catherine

2000-07-01

Full Text Available Abstract Genetic parameters of body weight at weaning and of prolificacy were estimated in three commercial lines of pigeons selected by BLUP (Best Linear Unbiased Prediction on both traits. The model of analysis took into account the direct genetic effects for both traits and the effect of parental permanent environment for body weight. Depending on the line considered, body weight varied from 556.7 g to 647.6 g and prolificacy ranged from 12.5 to 16.8 pigeons weaned per couple of parents per year. Heritability of body weight was high, varying between 0.46 and 0.60, and permanent environment was responsible for 6% to 9% of the total variability. On the contrary, prolificacy was poorly heritable (0.04 to 0.12. They were highly and negatively correlated (-0.77 to -0.82. Body weight showed significant genetic trends in lines B and C. No significant genetic difference could be observed between males and females for both traits.

Informed choice in direct-to-consumer genetic testing (DTCGT) websites: a content analysis of benefits, risks, and limitations.

Science.gov (United States)

Singleton, Amanda; Erby, Lori Hamby; Foisie, Kathryn V; Kaphingst, Kimberly A

2012-06-01

An informed choice about health-related direct-to-consumer genetic testing (DTCGT) requires knowledge of potential benefits, risks, and limitations. To understand the information that potential consumers of DTCGT services are exposed to on company websites, we conducted a content analysis of 23 health-related DTCGT websites. Results revealed that benefit statements outweighed risk and limitation statements 6 to 1. The most frequently described benefits were: 1) disease prevention, 2) consumer education, 3) personalized medical recommendations, and 4) the ability to make health decisions. Thirty-five percent of websites also presented at least one risk of testing. Seventy-eight percent of websites mentioned at least one limitation of testing. Based on this information, potential consumers might get an inaccurate picture of genetic testing which could impact their ability to make an informed decision. Practices that enhance the presentation of balanced information on DTCGT company websites should be encouraged.

Communication is the key. : Part 2 : Direct to consumer genetics in our future daily life ?

Science.gov (United States)

Perbal, Bernard

2014-12-01

The considerable advances of genome sequencing over the past decades have had a profound impact on our daily life and opened up new avenues for the public to have access to their genetic information and learn more about their ancestry, genealogy and other traits that make each of us unique individuals. A very large number of individual single nucleotide polymorphisms (SNPs) have been associated to diseases whereas others have no known phenotype. For example, among the SNPs mapped within ccn1(cyr61), ccn2(ctgf), ccn3(nov), ccn4(wisp-1), ccn5(wisp-2) and ccn6 (wisp-3), only mutations within ccn4 were associated to PPD (the autosomal recessive skeletal disorder Progressive Pseudorheumatoid Dysplasia). On the occasion of this JCCS special issue on the roles of hormetic responses in adaptation, and response of living species to the modifications of their environment, it appeared that it was a good time to briefly review a topic that has been the subject of passionate discussions for the past few years, that is Direct to Consumer genetic tests (DTC GT). Based on the use of DNA analysis and identification of polymorphisms, DTC GT have been developed by several companies in the USA and in countries where there was no legal obstacle for customers to have direct access to their genetic information and manage their healthcare. Problems that arose and decisions that have been taken by regulatory agencies are presented and discussed in this editorial. The « freeze » of health-oriented DTC GT in the USA neither implies the end of DNA analysis nor « fun » applications, which are not aimed at providing risks estimates for particular illnesses. As shown in the example which is discussed in this editorial, DTC GT for cosmetic applications might be considered a fun application of great interest for companies such as L'Oréal, who recently developed the Makeup Genius mobile application. Other fun applications of DTC GT are discussed but there is no doubt that nothing will stop

Coalgebraic structure of genetic inheritance.

Science.gov (United States)

Tian, Jianjun; Li, Bai-Lian

2004-09-01

Although in the broadly defined genetic algebra, multiplication suggests a forward direction of from parents to progeny, when looking from the reverse direction, it also suggests to us a new algebraic structure-coalge- braic structure, which we call genetic coalgebras. It is not the dual coalgebraic structure and can be used in the construction of phylogenetic trees. Math- ematically, to construct phylogenetic trees means we need to solve equations x([n]) = a, or x([n]) = b. It is generally impossible to solve these equations inalgebras. However, we can solve them in coalgebras in the sense of tracing back for their ancestors. A thorough exploration of coalgebraic structure in genetics is apparently necessary. Here, we develop a theoretical framework of the coalgebraic structure of genetics. From biological viewpoint, we defined various fundamental concepts and examined their elementary properties that contain genetic significance. Mathematically, by genetic coalgebra, we mean any coalgebra that occurs in genetics. They are generally noncoassociative and without counit; and in the case of non-sex-linked inheritance, they are cocommutative. Each coalgebra with genetic realization has a baric property. We have also discussed the methods to construct new genetic coalgebras, including cocommutative duplication, the tensor product, linear combinations and the skew linear map, which allow us to describe complex genetic traits. We also put forward certain theorems that state the relationship between gametic coalgebra and gametic algebra. By Brower's theorem in topology, we prove the existence of equilibrium state for the in-evolution operator.

Destabilizing protein polymorphisms in the genetic background direct phenotypic expression of mutant SOD1 toxicity.

Directory of Open Access Journals (Sweden)

Tali Gidalevitz

2009-03-01

Full Text Available Genetic background exerts a strong modulatory effect on the toxicity of aggregation-prone proteins in conformational diseases. In addition to influencing the misfolding and aggregation behavior of the mutant proteins, polymorphisms in putative modifier genes may affect the molecular processes leading to the disease phenotype. Mutations in SOD1 in a subset of familial amyotrophic lateral sclerosis (ALS cases confer dominant but clinically variable toxicity, thought to be mediated by misfolding and aggregation of mutant SOD1 protein. While the mechanism of toxicity remains unknown, both the nature of the SOD1 mutation and the genetic background in which it is expressed appear important. To address this, we established a Caenorhabditis elegans model to systematically examine the aggregation behavior and genetic interactions of mutant forms of SOD1. Expression of three structurally distinct SOD1 mutants in C. elegans muscle cells resulted in the appearance of heterogeneous populations of aggregates and was associated with only mild cellular dysfunction. However, introduction of destabilizing temperature-sensitive mutations into the genetic background strongly enhanced the toxicity of SOD1 mutants, resulting in exposure of several deleterious phenotypes at permissive conditions in a manner dependent on the specific SOD1 mutation. The nature of the observed phenotype was dependent on the temperature-sensitive mutation present, while its penetrance reflected the specific combination of temperature-sensitive and SOD1 mutations. Thus, the specific toxic phenotypes of conformational disease may not be simply due to misfolding/aggregation toxicity of the causative mutant proteins, but may be defined by their genetic interactions with cellular pathways harboring mildly destabilizing missense alleles.

The genetic effects of radio-activity in man and other organisms

International Nuclear Information System (INIS)

Parry, J.M.

1979-01-01

The changes that occur in the chromosomal information and which give rise to observable genetic effects stem from the induction by radiation of a number of lesions within the DNA. The relative frequencies of single and double strand breaks induced in DNA is dependent upon the type of radiation exposure given. Radiation sensitivity of a variety of different species of bacteria irradiated with gamma rays in air are given. The effect of dose rate upon radiation induced genetic damage indicates that at low dose rates the cells are capable of handling or repairing a higher proportion of the radiation induced DNA lesions before they undergo the events leading to chromosome and chromatid aberration. The radiation quality, expressed in terms of LET (linear energy transfer) also influence the induction of genetic damage. (U.K.)

Arthropod Genetics.

Science.gov (United States)

Zumwalde, Sharon

2000-01-01

Introduces an activity on arthropod genetics that involves phenotype and genotype identification of the creature and the construction process. Includes a list of required materials and directions to build a model arthropod. (YDS)

Statistical methods and challenges in connectome genetics

KAUST Repository

Pluta, Dustin; Yu, Zhaoxia; Shen, Tong; Chen, Chuansheng; Xue, Gui; Ombao, Hernando

2018-01-01

The study of genetic influences on brain connectivity, known as connectome genetics, is an exciting new direction of research in imaging genetics. We here review recent results and current statistical methods in this area, and discuss some

Mapping the Plasticity of the E. coli Genetic Code with Orthogonal Pair Directed Sense Codon Reassignment.

Science.gov (United States)

Schmitt, Margaret A; Biddle, Wil; Fisk, John Domenic

2018-04-18

The relative quantitative importance of the factors that determine the fidelity of translation is largely unknown, which makes predicting the extent to which the degeneracy of the genetic code can be broken challenging. Our strategy of using orthogonal tRNA/aminoacyl tRNA synthetase pairs to precisely direct the incorporation of a single amino acid in response to individual sense and nonsense codons provides a suite of related data with which to examine the plasticity of the code. Each directed sense codon reassignment measurement is an in vivo competition experiment between the introduced orthogonal translation machinery and the natural machinery in E. coli. This report discusses 20 new, related genetic codes, in which a targeted E. coli wobble codon is reassigned to tyrosine utilizing the orthogonal tyrosine tRNA/aminoacyl tRNA synthetase pair from Methanocaldococcus jannaschii. One at a time, reassignment of each targeted sense codon to tyrosine is quantified in cells by measuring the fluorescence of GFP variants in which the essential tyrosine residue is encoded by a non-tyrosine codon. Significantly, every wobble codon analyzed may be partially reassigned with efficiencies ranging from 0.8% to 41%. The accumulation of the suite of data enables a qualitative dissection of the relative importance of the factors affecting the fidelity of translation. While some correlation was observed between sense codon reassignment and either competing endogenous tRNA abundance or changes in aminoacylation efficiency of the altered orthogonal system, no single factor appears to predominately drive translational fidelity. Evaluation of relative cellular fitness in each of the 20 quantitatively-characterized proteome-wide tyrosine substitution systems suggests that at a systems level, E. coli is robust to missense mutations.

BREEDING AND GENETICS SYMPOSIUM: Resilience and lessons from studies in genetics of heat stress.

Science.gov (United States)

Misztal, I

2017-04-01

Production environments are expected to change, mostly to a hotter climate but also possibly more extreme and drier. Can the current generation of farm animals cope with the changes or should it be specifically selected for changing conditions? In general, genetic selection produces animals with a smaller environmental footprint but also with smaller environmental flexibility. Some answers are coming from heat-stress research across species, with heat tolerance partly understood as a greater environmental flexibility. Specific studies in various species show the complexities of defining and selecting for heat tolerance. In Holsteins, the genetic component for effect of heat stress on production approximately doubles in second and quadruples in third parity. Cows with elevated body temperature have the greatest production under heat stress but probably are at risk for increased mortality. In hot but less intensive environments, the effect of heat stress on production is minimal, although the negative effect on fertility remains. Mortality peaks under heat stress and increases with parity. In Angus, the effect of heat stress is stronger only in selected regions, probably because of adaptation of calving seasons to local conditions and crossbreeding. Genetically, the direct effect shows variability because of heat stress, but the maternal effect does not, probably because dams shield calves from environmental challenges. In pigs, the effect of heat stress is strong for commercial farms but almost nothing for nucleus farms, which have lower pig density and better heat abatement. Under intensive management, heat stress is less evident in drier environments because of more efficient cooling. A genetic component of heat stress exists, but it is partly masked by improving management and selection based on data from elite farms. Genetic selection may provide superior identification of heat-tolerant animals, but a few cycles may be needed for clear results. Also, simple

Effects of trawl selectivity and genetic parameters on fish body length under long-term trawling

Science.gov (United States)

Yu, Yang; Sun, Peng; Cui, He; Sheng, Huaxiang; Zhao, Fenfang; Tang, Yanli; Chen, Zelin

2015-10-01

Long-term fishing pressure affects the biological characteristics of exploited fish stocks. The biological characteristics of hairtail ( Trichiurus lepturus) in the East China Sea are unable to recover because of long-term trawling. Fishing induces evolutionary effects on the fish's biological characteristics. Evidence of these changes includes small size at age, a shift to earlier age structure, and early maturation. Natural and artificial selection usually affect the fish's life history. Selection can induce different chances of reproduction, and individual fish can give a different genetic contribution to the next generation. In this study, analysis of time-dependent probability of significance and test of sensitivity were used to explore the effects of fish exploitation rate, mesh size, and heritability with long-term trawling. Results showed that fishing parameters were important drivers to exploited fish population. However, genetic traits altered by fishing were slow, and the changes in biological characteristics were weaker than those caused by fishing selection. Exploitation rate and mesh size exhibited similar evolutionary trend tendency under long-term fishing. The time-dependent probability of significance trend showed a gradual growth and tended to be stable. Therefore, the direction of fishing-induced evolution and successful management of fish species require considerable attention to contribute to sustainable fisheries in China.

Non-GMO genetically edited crop plants.

Science.gov (United States)

Kanchiswamy, Chidananda Nagamangala; Malnoy, Mickael; Velasco, Riccardo; Kim, Jin-Soo; Viola, Roberto

2015-09-01

Direct delivery of purified Cas9 protein with guide RNA into plant cells, as opposed to plasmid-mediated delivery, displays high efficiency and reduced off-target effects. Following regeneration from edited cells, the ensuing plant is also likely to bypass genetically modified organism (GMO) legislation as the genome editing complex is degraded in the recipient cells. Copyright © 2015 Elsevier Ltd. All rights reserved.

Mechano-genetic DNA hydrogels as a simple, reconstituted model to probe the effect of active fluctuations on gene transcription

Science.gov (United States)

Nguyen, Dan; Saleh, Omar

Active fluctuations - non-directed fluctuations attributable, not to thermal energy, but to non-equilibrium processes - are thought to influence biology by increasing the diffusive motion of biomolecules. Dense DNA regions within cells (i.e. chromatin) are expected to exhibit such phenomena, as they are cross-linked networks that continually experience propagating forces arising from dynamic cellular activity. Additional agitation within these gene-encoding DNA networks could have potential genetic consequences. By changing the local mobility of transcriptional machinery and regulatory proteins towards/from their binding sites, and thereby influencing transcription rates, active fluctuations could prove to be a physical means of modulating gene expression. To begin probing this effect, we construct genetic DNA hydrogels, as a simple, reconstituted model of chromatin, and quantify transcriptional output from these hydrogels in the presence/absence of active fluctuations.

A two-locus model of spatially varying stabilizing or directional selection on a quantitative trait.

Science.gov (United States)

Geroldinger, Ludwig; Bürger, Reinhard

2014-06-01

The consequences of spatially varying, stabilizing or directional selection on a quantitative trait in a subdivided population are studied. A deterministic two-locus two-deme model is employed to explore the effects of migration, the degree of divergent selection, and the genetic architecture, i.e., the recombination rate and ratio of locus effects, on the maintenance of genetic variation. The possible equilibrium configurations are determined as functions of the migration rate. They depend crucially on the strength of divergent selection and the genetic architecture. The maximum migration rates are investigated below which a stable fully polymorphic equilibrium or a stable single-locus polymorphism can exist. Under stabilizing selection, but with different optima in the demes, strong recombination may facilitate the maintenance of polymorphism. However usually, and in particular with directional selection in opposite direction, the critical migration rates are maximized by a concentrated genetic architecture, i.e., by a major locus and a tightly linked minor one. Thus, complementing previous work on the evolution of genetic architectures in subdivided populations subject to diversifying selection, it is shown that concentrated architectures may aid the maintenance of polymorphism. Conditions are obtained when this is the case. Finally, the dependence of the phenotypic variance, linkage disequilibrium, and various measures of local adaptation and differentiation on the parameters is elaborated. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Genetic inhibition of CETP, ischemic vascular disease and mortality, and possible adverse effects

DEFF Research Database (Denmark)

Johannsen, Trine Holm; Frikke-Schmidt, Ruth; Schou, Jesper

2012-01-01

This study tested whether genetic variation in the CETP gene is consistent with a protective effect of cholesteryl ester transfer protein (CETP) inhibition on risk of ischemic events and on total mortality, without the adverse effects reported for torcetrapib.......This study tested whether genetic variation in the CETP gene is consistent with a protective effect of cholesteryl ester transfer protein (CETP) inhibition on risk of ischemic events and on total mortality, without the adverse effects reported for torcetrapib....

Direction of Wording Effects in Balanced Scales.

Science.gov (United States)

Miller, Timothy R.; Cleary, T. Anne

1993-01-01

The degree to which statistical item selection reduces direction-of-wording effects in balanced affective measures developed from relatively small item pools was investigated with 171 male and 228 female undergraduate and graduate students at 2 U.S. universities. Clearest direction-of-wording effects result from selection of items with high…

Environment Changes Genetic Effects on Respiratory Conditions and Allergic Phenotypes

DEFF Research Database (Denmark)

Song, Yong; Schwager, Michelle J; Backer, Vibeke

2017-01-01

The prevalence of asthma and allergic diseases is disproportionately distributed among different populations, with an increasing trend observed in Western countries. Here we investigated how the environment affected genotype-phenotype association in a genetically homogeneous, but geographically...... separated population. We evaluated 18 single nucleotide polymorphisms (SNPs) corresponding to 8 genes (ADAM33, ALOX5, LT-α, LTC4S, NOS1, ORMDL3, TBXA2R and TNF-α), the lung function and five respiratory/allergic conditions (ever asthma, bronchitis, rhinitis, dermatitis and atopy) in two populations of Inuit......-phenotype associations relating to bronchitis and allergy susceptibility are dependent on the environment and that environmental factors/lifestyles modify genetic predisposition and change the genetic effects on diseases....

Cause and effect analysis by fuzzy relational equations and a genetic algorithm

International Nuclear Information System (INIS)

Rotshtein, Alexander P.; Posner, Morton; Rakytyanska, Hanna B.

2006-01-01

This paper proposes using a genetic algorithm as a tool to solve the fault diagnosis problem. The fault diagnosis problem is based on a cause and effect analysis which is formally described by fuzzy relations. Fuzzy relations are formed on the basis of expert assessments. Application of expert fuzzy relations to restore and identify the causes through the observed effects requires the solution to a system of fuzzy relational equations. In this study this search for a solution amounts to solving a corresponding optimization problem. An optimization algorithm is based on the application of genetic operations of crossover, mutation and selection. The genetic algorithm suggested here represents an application in expert systems of fault diagnosis and quality control

Prediction of crack growth direction by Strain Energy Sih's Theory on specimens SEN under tension-compression biaxial loading employing Genetic Algorithms

International Nuclear Information System (INIS)

Rodriguez-MartInez R; Lugo-Gonzalez E; Urriolagoitia-Calderon G; Urriolagoitia-Sosa G; Hernandez-Gomez L H; Romero-Angeles B; Torres-San Miguel Ch

2011-01-01

Crack growth direction has been studied in many ways. Particularly Sih's strain energy theory predicts that a fracture under a three-dimensional state of stress spreads in direction of the minimum strain energy density. In this work a study for angle of fracture growth was made, considering a biaxial stress state at the crack tip on SEN specimens. The stress state applied on a tension-compression SEN specimen is biaxial one on crack tip, as it can observed in figure 1. A solution method proposed to obtain a mathematical model considering genetic algorithms, which have demonstrated great capacity for the solution of many engineering problems. From the model given by Sih one can deduce the density of strain energy stored for unit of volume at the crack tip as dW = [1/2E(σ 2 x + σ 2 y ) - ν/E(σ x σy)]dV (1). From equation (1) a mathematical deduction to solve in terms of θ of this case was developed employing Genetic Algorithms, where θ is a crack propagation direction in plane x-y. Steel and aluminium mechanical properties to modelled specimens were employed, because they are two of materials but used in engineering design. Obtained results show stable zones of fracture propagation but only in a range of applied loading.

Genetic and environmental effects on performance traits of ...

African Journals Online (AJOL)

Genetic and environmental effects on performance traits of Simmentaler cattle on the Transvaal Highveld. Tina Rust, J van der Westhuizen. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals Online. HOW TO USE ...

Use of Contemporary Genetics in Cardiovascular Diagnosis

Science.gov (United States)

George, Alfred L.

2015-01-01

An explosion of knowledge regarding the genetic and genomic basis for rare and common diseases has provided a framework for revolutionizing the practice of medicine. Achieving the reality of a genomic medicine era requires that basic discoveries are effectively translated into clinical practice through implementation of genetic and genomic testing. Clinical genetic tests have become routine for many inherited disorders and can be regarded as the standard-of-care in many circumstances including disorders affecting the cardiovascular system. New, high-throughput methods for determining the DNA sequence of all coding exons or complete genomes are being adopted for clinical use to expand the speed and breadth of genetic testing. Along with these extraordinary advances have emerged new challenges to practicing physicians for understanding when and how to use genetic testing along with how to appropriately interpret test results. This review will acquaint readers with general principles of genetic testing including newer technologies, test interpretation and pitfalls. The focus will be on testing genes responsible for monogenic disorders and on other emerging applications such as pharmacogenomic profiling. The discussion will be extended to the new paradigm of direct-to-consumer genetic testing and the value of assessing genomic risk for common diseases. PMID:25421045

Detrimental effect of selection for milk yield on genetic tolerance to heat stress in purebred Zebu cattle: Genetic parameters and trends.

Science.gov (United States)

Santana, M L; Pereira, R J; Bignardi, A B; Filho, A E Vercesi; Menéndez-Buxadera, A; El Faro, L

2015-12-01

In an attempt to determine the possible detrimental effects of continuous selection for milk yield on the genetic tolerance of Zebu cattle to heat stress, genetic parameters and trends of the response to heat stress for 86,950 test-day (TD) milk yield records from 14,670 first lactations of purebred dairy Gir cows were estimated. A random regression model with regression on days in milk (DIM) and temperature-humidity index (THI) values was applied to the data. The most detrimental effect of THI on milk yield was observed in the stage of lactation with higher milk production, DIM 61 to 120 (-0.099kg/d per THI). Although modest variations were observed for the THI scale, a reduction in additive genetic variance as well as in permanent environmental and residual variance was observed with increasing THI values. The heritability estimates showed a slight increase with increasing THI values for any DIM. The correlations between additive genetic effects across the THI scale showed that, for most of the THI values, genotype by environment interactions due to heat stress were less important for the ranking of bulls. However, for extreme THI values, this type of genotype by environment interaction may lead to an important error in selection. As a result of the selection for milk yield practiced in the dairy Gir population for 3 decades, the genetic trend of cumulative milk yield was significantly positive for production in both high (51.81kg/yr) and low THI values (78.48kg/yr). However, the difference between the breeding values of animals at high and low THI may be considered alarming (355kg in 2011). The genetic trends observed for the regression coefficients related to general production level (intercept of the reaction norm) and specific ability to respond to heat stress (slope of the reaction norm) indicate that the dairy Gir population is heading toward a higher production level at the expense of lower tolerance to heat stress. These trends reflect the genetic

Sample design effects in landscape genetics

Science.gov (United States)

Oyler-McCance, Sara J.; Fedy, Bradley C.; Landguth, Erin L.

2012-01-01

An important research gap in landscape genetics is the impact of different field sampling designs on the ability to detect the effects of landscape pattern on gene flow. We evaluated how five different sampling regimes (random, linear, systematic, cluster, and single study site) affected the probability of correctly identifying the generating landscape process of population structure. Sampling regimes were chosen to represent a suite of designs common in field studies. We used genetic data generated from a spatially-explicit, individual-based program and simulated gene flow in a continuous population across a landscape with gradual spatial changes in resistance to movement. Additionally, we evaluated the sampling regimes using realistic and obtainable number of loci (10 and 20), number of alleles per locus (5 and 10), number of individuals sampled (10-300), and generational time after the landscape was introduced (20 and 400). For a simulated continuously distributed species, we found that random, linear, and systematic sampling regimes performed well with high sample sizes (>200), levels of polymorphism (10 alleles per locus), and number of molecular markers (20). The cluster and single study site sampling regimes were not able to correctly identify the generating process under any conditions and thus, are not advisable strategies for scenarios similar to our simulations. Our research emphasizes the importance of sampling data at ecologically appropriate spatial and temporal scales and suggests careful consideration for sampling near landscape components that are likely to most influence the genetic structure of the species. In addition, simulating sampling designs a priori could help guide filed data collection efforts.

Direct-to-consumer advertising of predictive genetic tests: a health belief model based examination of consumer response.

Science.gov (United States)

Rollins, Brent L; Ramakrishnan, Shravanan; Perri, Matthew

2014-01-01

Direct-to-consumer (DTC) advertising of predictive genetic tests (PGTs) has added a new dimension to health advertising. This study used an online survey based on the health belief model framework to examine and more fully understand consumers' responses and behavioral intentions in response to a PGT DTC advertisement. Overall, consumers reported moderate intentions to talk with their doctor and seek more information about PGTs after advertisement exposure, though consumers did not seem ready to take the advertised test or engage in active information search. Those who perceived greater threat from the disease, however, had significantly greater behavioral intentions and information search behavior.

Geographical gradients in selection can reveal genetic constraints for evolutionary responses to ocean acidification.

Science.gov (United States)

Gaitán-Espitia, Juan Diego; Marshall, Dustin; Dupont, Sam; Bacigalupe, Leonardo D; Bodrossy, Levente; Hobday, Alistair J

2017-02-01

Geographical gradients in selection can shape different genetic architectures in natural populations, reflecting potential genetic constraints for adaptive evolution under climate change. Investigation of natural pH/pCO 2 variation in upwelling regions reveals different spatio-temporal patterns of natural selection, generating genetic and phenotypic clines in populations, and potentially leading to local adaptation, relevant to understanding effects of ocean acidification (OA). Strong directional selection, associated with intense and continuous upwellings, may have depleted genetic variation in populations within these upwelling regions, favouring increased tolerances to low pH but with an associated cost in other traits. In contrast, diversifying or weak directional selection in populations with seasonal upwellings or outside major upwelling regions may have resulted in higher genetic variances and the lack of genetic correlations among traits. Testing this hypothesis in geographical regions with similar environmental conditions to those predicted under climate change will build insights into how selection may act in the future and how populations may respond to stressors such as OA. © 2017 The Author(s).

Genetic analysis of growth traits in Polled Nellore cattle raised on pasture in tropical region using Bayesian approaches.

Science.gov (United States)

Lopes, Fernando Brito; Magnabosco, Cláudio Ulhôa; Paulini, Fernanda; da Silva, Marcelo Corrêa; Miyagi, Eliane Sayuri; Lôbo, Raysildo Barbosa

2013-01-01

Components of (co)variance and genetic parameters were estimated for adjusted weights at ages 120 (W120), 240 (W240), 365 (W365) and 450 (W450) days of Polled Nellore cattle raised on pasture and born between 1987 and 2010. Analyses were performed using an animal model, considering fixed effects: herd-year-season of birth and calf sex as contemporary groups and the age of cow as a covariate. Gibbs Samplers were used to estimate (co)variance components, genetic parameters and additive genetic effects, which accounted for great proportion of total variation in these traits. High direct heritability estimates for the growth traits were revealed and presented mean 0.43, 0.61, 0.72 and 0.67 for W120, W240, W365 and W450, respectively. Maternal heritabilities were 0.07 and 0.08 for W120 and W240, respectively. Direct additive genetic correlations between the weight at 120, 240, 365 and 450 days old were strong and positive. These estimates ranged from 0.68 to 0.98. Direct-maternal genetic correlations were negative for W120 and W240. The estimates ranged from -0.31 to -0.54. Estimates of maternal heritability ranged from 0.056 to 0.092 for W120 and from 0.064 to 0.096 for W240. This study showed that genetic progress is possible for the growth traits we studied, which is a novel and favorable indicator for an upcoming and promising Polled Zebu breed in Tropical regions. Maternal effects influenced the performance of weight at 120 and 240 days old. These effects should be taken into account in genetic analyses of growth traits by fitting them as a genetic or a permanent environmental effect, or even both. In general, due to a medium-high estimate of environmental (co)variance components, management and feeding conditions for Polled Nellore raised at pasture in tropical regions of Brazil needs improvement and growth performance can be enhanced.

Revised models and genetic parameter estimates for production and ...

African Journals Online (AJOL)

Genetic parameters for production and reproduction traits in the Elsenburg Dormer sheep stud were estimated using records of 11743 lambs born between 1943 and 2002. An animal model with direct and maternal additive, maternal permanent and temporary environmental effects was fitted for traits considered traits of the ...

Genetic engineering of microbial pesticides

Science.gov (United States)

Bruce C. Carlton

1985-01-01

Recent advances in genetics and molecular biology make possible the cloning and genetic manipulation of genes for insecticidal activities from natural insect pathogens. Using recombinant DNA methods and site-directed mutagenesis of specific gene regions, production of new and improved biorationals should be possible.

Statistics for Learning Genetics

Science.gov (United States)

Charles, Abigail Sheena

This study investigated the knowledge and skills that biology students may need to help them understand statistics/mathematics as it applies to genetics. The data are based on analyses of current representative genetics texts, practicing genetics professors' perspectives, and more directly, students' perceptions of, and performance in, doing statistically-based genetics problems. This issue is at the emerging edge of modern college-level genetics instruction, and this study attempts to identify key theoretical components for creating a specialized biological statistics curriculum. The goal of this curriculum will be to prepare biology students with the skills for assimilating quantitatively-based genetic processes, increasingly at the forefront of modern genetics. To fulfill this, two college level classes at two universities were surveyed. One university was located in the northeastern US and the other in the West Indies. There was a sample size of 42 students and a supplementary interview was administered to a select 9 students. Interviews were also administered to professors in the field in order to gain insight into the teaching of statistics in genetics. Key findings indicated that students had very little to no background in statistics (55%). Although students did perform well on exams with 60% of the population receiving an A or B grade, 77% of them did not offer good explanations on a probability question associated with the normal distribution provided in the survey. The scope and presentation of the applicable statistics/mathematics in some of the most used textbooks in genetics teaching, as well as genetics syllabi used by instructors do not help the issue. It was found that the text books, often times, either did not give effective explanations for students, or completely left out certain topics. The omission of certain statistical/mathematical oriented topics was seen to be also true with the genetics syllabi reviewed for this study. Nonetheless

STRESS, RELATIONSHIP SATISFACTION, AND HEALTH AMONG AFRICAN AMERICAN WOMEN: GENETIC MODERATION OF EFFECTS

Science.gov (United States)

Lei, Man-Kit; Beach, Steven R. H.; Simons, Ronald L.; Barr, Ashley B.; Cutrona, Carolyn E.; Philibert, Robert A.

2015-01-01

We examined whether romantic relationship satisfaction would serve as a link between early and later stressors which in turn would influence the Thyroid Function Index (TFI), an indicator of physiological stress response. Using the framework of genetic susceptibility theory combined with hypotheses derived from the vulnerability-stress-adaptation and stress-generation models, we tested whether the hypothesized mediational model would be conditioned by 5-HTTLPR genotype, with greater effects and stronger evidence of mediation among carriers of the “s” allele. In a sample of African American women in romantic relationships (n = 270), we found that 5-HTTLPR moderated each stage of the hypothesized mediational model in a “for better or for worse” manner. That is genetic polymorphisms function to exacerbate not only the detrimental impact of negative environments (i.e. “for worse effects”) but also the beneficial impact of positive environments (i.e. “for better effects”). The effect of early stress on relationship satisfaction was greater among carriers of the “short” allele than among those who did not carry the short allele, and was significantly different in both the “for better” and “for worse” direction. Likewise, the effect of relationship satisfaction on later stressors was moderated in a “for better” or “for worse” manner. Finally, impact on physiological stress, indexed using TFI level, indicated that the impact of later stressors on TFI level was greater in the presence of the short allele, and also followed a “for better” or “for worse” pattern. As expected, the proposed mediational model provided a better fit for “s” allele carriers. PMID:26376424

The effect of genetically engineered glucagon on glucose recovery after hypoglycaemia in man

DEFF Research Database (Denmark)

Hvidberg, A; Jørgensen, S; Hilsted, J

1992-01-01

To compare the effect on glucose recovery after insulin-induced hypoglycaemia of intramuscular genetically engineered glucagon, intramuscular glucagon from pancreatic extraction and intravenous glucose, we examined 10 healthy subjects during blockage of glucose counterregulation with somatostatin...... appearance rate were far more protracted after i.m. glucagon than after i.v. glucose. These results suggest that genetically engineered glucagon and glucagon from pancreatic extraction have a similar effect on hepatic glucose production rate. Due to the protracted effect of intramuscular glucagon, a combined......, propranolol and phentolamine. Each subject was studied on three separate occasions. Thirty min after a bolus injection of 0.075 iu soluble insulin per kilogram body weight the subjects received one of the following treatments: 1 mg glucagon from pancreatic extraction intramuscularly; 1 mg genetically...

Revealing life-history traits by contrasting genetic estimations with predictions of effective population size.

Science.gov (United States)

Greenbaum, Gili; Renan, Sharon; Templeton, Alan R; Bouskila, Amos; Saltz, David; Rubenstein, Daniel I; Bar-David, Shirli

2017-12-22

Effective population size, a central concept in conservation biology, is now routinely estimated from genetic surveys and can also be theoretically predicted from demographic, life-history, and mating-system data. By evaluating the consistency of theoretical predictions with empirically estimated effective size, insights can be gained regarding life-history characteristics and the relative impact of different life-history traits on genetic drift. These insights can be used to design and inform management strategies aimed at increasing effective population size. We demonstrated this approach by addressing the conservation of a reintroduced population of Asiatic wild ass (Equus hemionus). We estimated the variance effective size (N ev ) from genetic data (N ev =24.3) and formulated predictions for the impacts on N ev of demography, polygyny, female variance in lifetime reproductive success (RS), and heritability of female RS. By contrasting the genetic estimation with theoretical predictions, we found that polygyny was the strongest factor affecting genetic drift because only when accounting for polygyny were predictions consistent with the genetically measured N ev . The comparison of effective-size estimation and predictions indicated that 10.6% of the males mated per generation when heritability of female RS was unaccounted for (polygyny responsible for 81% decrease in N ev ) and 19.5% mated when female RS was accounted for (polygyny responsible for 67% decrease in N ev ). Heritability of female RS also affected N ev ; hf2=0.91 (heritability responsible for 41% decrease in N ev ). The low effective size is of concern, and we suggest that management actions focus on factors identified as strongly affecting Nev, namely, increasing the availability of artificial water sources to increase number of dominant males contributing to the gene pool. This approach, evaluating life-history hypotheses in light of their impact on effective population size, and contrasting

Prediction of genetic values of quantitative traits with epistatic effects in plant breeding populations.

Science.gov (United States)

Wang, D; Salah El-Basyoni, I; Stephen Baenziger, P; Crossa, J; Eskridge, K M; Dweikat, I

2012-11-01

Though epistasis has long been postulated to have a critical role in genetic regulation of important pathways as well as provide a major source of variation in the process of speciation, the importance of epistasis for genomic selection in the context of plant breeding is still being debated. In this paper, we report the results on the prediction of genetic values with epistatic effects for 280 accessions in the Nebraska Wheat Breeding Program using adaptive mixed least absolute shrinkage and selection operator (LASSO). The development of adaptive mixed LASSO, originally designed for association mapping, for the context of genomic selection is reported. The results show that adaptive mixed LASSO can be successfully applied to the prediction of genetic values while incorporating both marker main effects and epistatic effects. Especially, the prediction accuracy is substantially improved by the inclusion of two-locus epistatic effects (more than onefold in some cases as measured by cross-validation correlation coefficient), which is observed for multiple traits and planting locations. This points to significant potential in using non-additive genetic effects for genomic selection in crop breeding practices.

Evolution of branched regulatory genetic pathways: directional selection on pleiotropic loci accelerates developmental system drift.

Science.gov (United States)

Johnson, Norman A; Porter, Adam H

2007-01-01

Developmental systems are regulated by a web of interacting loci. One common and useful approach in studying the evolution of development is to focus on classes of interacting elements within these systems. Here, we use individual-based simulations to study the evolution of traits controlled by branched developmental pathways involving three loci, where one locus regulates two different traits. We examined the system under a variety of selective regimes. In the case where one branch was under stabilizing selection and the other under directional selection, we observed "developmental system drift": the trait under stabilizing selection showed little phenotypic change even though the loci underlying that trait showed considerable evolutionary divergence. This occurs because the pleiotropic locus responds to directional selection and compensatory mutants are then favored in the pathway under stabilizing selection. Though developmental system drift may be caused by other mechanisms, it seems likely that it is accelerated by the same underlying genetic mechanism as that producing the Dobzhansky-Muller incompatibilities that lead to speciation in both linear and branched pathways. We also discuss predictions of our model for developmental system drift and how different selective regimes affect probabilities of speciation in the branched pathway system.

Apparent directional selection by biased pleiotropic mutation.

Science.gov (United States)

Tanaka, Yoshinari

2010-07-01

Pleiotropic effects of deleterious mutations are considered to be among the factors responsible for genetic constraints on evolution by long-term directional selection acting on a quantitative trait. If pleiotropic phenotypic effects are biased in a particular direction, mutations generate apparent directional selection, which refers to the covariance between fitness and the trait owing to a linear association between the number of mutations possessed by individuals and the genotypic values of the trait. The present analysis has shown how the equilibrium mean value of the trait is determined by a balance between directional selection and biased pleiotropic mutations. Assuming that genes act additively both on the trait and on fitness, the total variance-standardized directional selection gradient was decomposed into apparent and true components. Experimental data on mutation bias from the bristle traits of Drosophila and life history traits of Daphnia suggest that apparent selection explains a small but significant fraction of directional selection pressure that is observed in nature; the data suggest that changes induced in a trait by biased pleiotropic mutation (i.e., by apparent directional selection) are easily compensated for by (true) directional selection.

Cytoplasmic-genetic male sterility gene provides direct evidence for some hybrid rice recently evolving into weedy rice

Science.gov (United States)

Zhang, Jingxu; Lu, Zuomei; Dai, Weimin; Song, Xiaoling; Peng, Yufa; Valverde, Bernal E.; Qiang, Sheng

2015-01-01

Weedy rice infests paddy fields worldwide at an alarmingly increasing rate. There is substantial evidence indicating that many weedy rice forms originated from or are closely related to cultivated rice. There is suspicion that the outbreak of weedy rice in China may be related to widely grown hybrid rice due to its heterosis and the diversity of its progeny, but this notion remains unsupported by direct evidence. We screened weedy rice accessions by both genetic and molecular marker tests for the cytoplasmic male sterility (CMS) genes (Wild abortive, WA, and Boro type, BT) most widely used in the production of indica and japonica three-line hybrid rice as a diagnostic trait of direct parenthood. Sixteen weedy rice accessions of the 358 tested (4.5%) contained the CMS-WA gene; none contained the CMS-BT gene. These 16 accessions represent weedy rices recently evolved from maternal hybrid rice derivatives, given the primarily maternal inheritance of this trait. Our results provide key direct evidence that hybrid rice can be involved in the evolution of some weedy rice accessions, but is not a primary factor in the recent outbreak of weedy rice in China. PMID:26012494

Cytoplasmic-genetic male sterility gene provides direct evidence for some hybrid rice recently evolving into weedy rice.

Science.gov (United States)

Zhang, Jingxu; Lu, Zuomei; Dai, Weimin; Song, Xiaoling; Peng, Yufa; Valverde, Bernal E; Qiang, Sheng

2015-05-27

Weedy rice infests paddy fields worldwide at an alarmingly increasing rate. There is substantial evidence indicating that many weedy rice forms originated from or are closely related to cultivated rice. There is suspicion that the outbreak of weedy rice in China may be related to widely grown hybrid rice due to its heterosis and the diversity of its progeny, but this notion remains unsupported by direct evidence. We screened weedy rice accessions by both genetic and molecular marker tests for the cytoplasmic male sterility (CMS) genes (Wild abortive, WA, and Boro type, BT) most widely used in the production of indica and japonica three-line hybrid rice as a diagnostic trait of direct parenthood. Sixteen weedy rice accessions of the 358 tested (4.5%) contained the CMS-WA gene; none contained the CMS-BT gene. These 16 accessions represent weedy rices recently evolved from maternal hybrid rice derivatives, given the primarily maternal inheritance of this trait. Our results provide key direct evidence that hybrid rice can be involved in the evolution of some weedy rice accessions, but is not a primary factor in the recent outbreak of weedy rice in China.

Effects of landscape fragmentation on genetic diversity of Stipa ...

African Journals Online (AJOL)

STORAGESEVER

2009-08-04

Aug 4, 2009 ... Effects of landscape fragmentation on genetic diversity of Stipa krylovii ..... nation plant tends to anemophily, this pollination mode enable it to have the .... sity on newly isolated tropical islands: a test of a null hypothesis and.

Human-directed social behaviour in dogs shows significant heritability.

Science.gov (United States)

Persson, M E; Roth, L S V; Johnsson, M; Wright, D; Jensen, P

2015-04-01

Through domestication and co-evolution with humans, dogs have developed abilities to attract human attention, e.g. in a manner of seeking assistance when faced with a problem solving task. The aims of this study were to investigate within breed variation in human-directed contact seeking in dogs and to estimate its genetic basis. To do this, 498 research beagles, bred and kept under standardized conditions, were tested in an unsolvable problem task. Contact seeking behaviours recorded included both eye contact and physical interactions. Behavioural data was summarized through a principal component analysis, resulting in four components: test interactions, social interactions, eye contact and physical contact. Females scored significantly higher on social interactions and physical contact and age had an effect on eye contact scores. Narrow sense heritabilities (h(2) ) of the two largest components were estimated at 0.32 and 0.23 but were not significant for the last two components. These results show that within the studied dog population, behavioural variation in human-directed social behaviours was sex dependent and that the utilization of eye contact seeking increased with age and experience. Hence, heritability estimates indicate a significant genetic contribution to the variation found in human-directed social interactions, suggesting that social skills in dogs have a genetic basis, but can also be shaped and enhanced through individual experiences. This research gives the opportunity to further investigate the genetics behind dogs' social skills, which could also play a significant part into research on human social disorders such as autism. © 2015 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

Non-Genetic Determinants of Mosquito Competence for Malaria Parasites

Science.gov (United States)

Lefèvre, Thierry; Vantaux, Amélie; Dabiré, Kounbobr R.; Mouline, Karine; Cohuet, Anna

2013-01-01

Understanding how mosquito vectors and malaria parasites interact is of fundamental interest, and it also offers novel perspectives for disease control. Both the genetic and environmental contexts are known to affect the ability of mosquitoes to support malaria development and transmission, i.e., vector competence. Although the role of environment has long been recognized, much work has focused on host and parasite genetic effects. However, the last few years have seen a surge of studies revealing a great diversity of ways in which non-genetic factors can interfere with mosquito-Plasmodium interactions. Here, we review the current evidence for such environmentally mediated effects, including ambient temperature, mosquito diet, microbial gut flora, and infection history, and we identify additional factors previously overlooked in mosquito-Plasmodium interactions. We also discuss epidemiological implications, and the evolutionary consequences for vector immunity and parasite transmission strategies. Finally, we propose directions for further research and argue that an improved knowledge of non-genetic influences on mosquito-Plasmodium interactions could aid in implementing conventional malaria control measures and contribute to the design of novel strategies. PMID:23818841

Non-genetic determinants of mosquito competence for malaria parasites.

Directory of Open Access Journals (Sweden)

Thierry Lefèvre

Full Text Available Understanding how mosquito vectors and malaria parasites interact is of fundamental interest, and it also offers novel perspectives for disease control. Both the genetic and environmental contexts are known to affect the ability of mosquitoes to support malaria development and transmission, i.e., vector competence. Although the role of environment has long been recognized, much work has focused on host and parasite genetic effects. However, the last few years have seen a surge of studies revealing a great diversity of ways in which non-genetic factors can interfere with mosquito-Plasmodium interactions. Here, we review the current evidence for such environmentally mediated effects, including ambient temperature, mosquito diet, microbial gut flora, and infection history, and we identify additional factors previously overlooked in mosquito-Plasmodium interactions. We also discuss epidemiological implications, and the evolutionary consequences for vector immunity and parasite transmission strategies. Finally, we propose directions for further research and argue that an improved knowledge of non-genetic influences on mosquito-Plasmodium interactions could aid in implementing conventional malaria control measures and contribute to the design of novel strategies.

Evolution of Genetic Variance during Adaptive Radiation.

Science.gov (United States)

Walter, Greg M; Aguirre, J David; Blows, Mark W; Ortiz-Barrientos, Daniel

2018-04-01

Genetic correlations between traits can concentrate genetic variance into fewer phenotypic dimensions that can bias evolutionary trajectories along the axis of greatest genetic variance and away from optimal phenotypes, constraining the rate of evolution. If genetic correlations limit adaptation, rapid adaptive divergence between multiple contrasting environments may be difficult. However, if natural selection increases the frequency of rare alleles after colonization of new environments, an increase in genetic variance in the direction of selection can accelerate adaptive divergence. Here, we explored adaptive divergence of an Australian native wildflower by examining the alignment between divergence in phenotype mean and divergence in genetic variance among four contrasting ecotypes. We found divergence in mean multivariate phenotype along two major axes represented by different combinations of plant architecture and leaf traits. Ecotypes also showed divergence in the level of genetic variance in individual traits and the multivariate distribution of genetic variance among traits. Divergence in multivariate phenotypic mean aligned with divergence in genetic variance, with much of the divergence in phenotype among ecotypes associated with changes in trait combinations containing substantial levels of genetic variance. Overall, our results suggest that natural selection can alter the distribution of genetic variance underlying phenotypic traits, increasing the amount of genetic variance in the direction of natural selection and potentially facilitating rapid adaptive divergence during an adaptive radiation.

Genetic effects of air pollution on forest tree species of the Carpathian Mountains

International Nuclear Information System (INIS)

Longauer, Roman; Goemoery, Dusan; Paule, Ladislav; Blada, Ioan; Popescu, Flaviu; Mankovska, Blanka; Mueller-Starck, Gerhard; Schubert, Roland; Percy, Kevin; Szaro, Robert C.; Karnosky, David F.

2004-01-01

The effects of air pollution on the genetic structure of Norway spruce, European silver fir and European beech were studied at four polluted sites in Slovakia, Romania and Czech Republic. In order to reduce potential effects of site heterogeneity on the health condition, pair-wise sampling of pollution-tolerant and sensitive trees was applied. Genotypes of sampled trees were determined at 21 isozyme gene loci of spruce, 18 loci of fir and 15 loci of beech. In comparison with Norway spruce, fewer genetic differences were revealed in beech and almost no differentiation between pollution-tolerant and sensitive trees was observed in fir. In adult stands of Norway spruce, sensitive trees exhibited higher genetic multiplicity and diversity. The decline of pollution-sensitive trees may result thus in a gradual genetic depletion of pollution-exposed populations of Norway spruce through the loss of less frequent alleles with potential adaptive significance to altered stressing regimes in the future. Comparison of the subsets of sensitive and tolerant Norway spruce individuals as determined by presence or absence of discolorations (''spruce yellowing'') revealed different heterozygosity at 3 out of 11 polymorphic loci. - Genetic effects of air pollution on main forest trees of the Carpathians are species- and site-specific

The effects of stress and sex on selection, genetic covariance, and the evolutionary response.

Science.gov (United States)

Holman, L; Jacomb, F

2017-10-01

The capacity of a population to adapt to selection (evolvability) depends on whether the structure of genetic variation permits the evolution of fitter trait combinations. Selection, genetic variance and genetic covariance can change under environmental stress, and males and females are not genetically independent, yet the combined effects of stress and dioecy on evolvability are not well understood. Here, we estimate selection, genetic (co)variance and evolvability in both sexes of Tribolium castaneum flour beetles under stressful and benign conditions, using a half-sib breeding design. Although stress uncovered substantial latent heritability, stress also affected genetic covariance, such that evolvability remained low under stress. Sexual selection on males and natural selection on females favoured a similar phenotype, and there was positive intersex genetic covariance. Consequently, sexual selection on males augmented adaptation in females, and intralocus sexual conflict was weak or absent. This study highlights that increased heritability does not necessarily increase evolvability, suggests that selection can deplete genetic variance for multivariate trait combinations with strong effects on fitness, and tests the recent hypothesis that sexual conflict is weaker in stressful or novel environments. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

The genetic architecture of leaf number and its genetic relationship to flowering time in maize.

Science.gov (United States)

Li, Dan; Wang, Xufeng; Zhang, Xiangbo; Chen, Qiuyue; Xu, Guanghui; Xu, Dingyi; Wang, Chenglong; Liang, Yameng; Wu, Lishuan; Huang, Cheng; Tian, Jinge; Wu, Yaoyao; Tian, Feng

2016-04-01

The number of leaves and their distributions on plants are critical factors determining plant architecture in maize (Zea mays), and leaf number is frequently used as a measure of flowering time, a trait that is key to local environmental adaptation. Here, using a large set of 866 maize-teosinte BC2 S3 recombinant inbred lines genotyped by using 19,838 single nucleotide polymorphism markers, we conducted a comprehensive genetic dissection to assess the genetic architecture of leaf number and its genetic relationship to flowering time. We demonstrated that the two components of total leaf number, the number of leaves above (LA) and below (LB) the primary ear, were under relatively independent genetic control and might be subject to differential directional selection during maize domestication and improvement. Furthermore, we revealed that flowering time and leaf number are commonly regulated at a moderate level. The pleiotropy of the genes ZCN8, dlf1 and ZmCCT on leaf number and flowering time were validated by near-isogenic line analysis. Through fine mapping, qLA1-1, a major-effect locus that specifically affects LA, was delimited to a region with severe recombination suppression derived from teosinte. This study provides important insights into the genetic basis of traits affecting plant architecture and adaptation. The genetic independence of LA from LB enables the optimization of leaf number for ideal plant architecture breeding in maize. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Genetic parameters of calving ease using sire-maternal grandsire model in Korean Holsteins

Directory of Open Access Journals (Sweden)

Mahboob Alam

2017-09-01

Full Text Available Objective Calving ease (CE is a complex reproductive trait of economic importance in dairy cattle. This study was aimed to investigate the genetic merits of CE for Holsteins in Korea. Methods A total of 297,614 field records of CE, from 2000 to 2015, from first parity Holstein heifers were recorded initially. After necessary data pruning such as age at first calving (18 to 42 mo, gestation length, and presence of sire information, final datasets for CE consisted of 147,526 and 132,080 records for service sire calving ease (SCE and daughter calving ease (DCE evaluations, respectively. The CE categories were ordered and scores ranged from CE1 to CE5 (CE1, easy; CE2, slight assistance; CE3, moderate assistance; CE4, difficult calving; CE5, extreme difficulty calving. A linear transformation of CE score was obtained on each category using Snell procedure, and a scaling factor was applied to attain the spread between 0 (CE5 and 100% (CE1. A sire-maternal grandsire model analysis was performed using ASREML 3.0 software package. Results The estimated direct heritability (h2 from SCE and DCE evaluations were 0.11±0.01 and 0.08±0.01, respectively. Maternal h2 estimates were 0.05±0.02 and 0.04±0.01 from SCE and DCE approaches, respectively. Estimates of genetic correlations between direct and maternal genetic components were −0.68±0.09 (SCE and −0.71±0.09 (DCE. The average direct genetic effect increased over time, whereas average maternal effect was low and consistent. The estimated direct predicted transmitting ability (PTA was desirable and increasing over time, but the maternal PTA was undesirable and decreasing. Conclusion The evidence on sufficient genetic variances in this study could reflect a possible selection improvement over time regarding ease of calving. It is expected that the estimated genetic parameters could be a valuable resource to formulate sire selection and breeding plans which would be directed towards the reduction of

Genetics

International Nuclear Information System (INIS)

Hubitschek, H.E.

1975-01-01

Progress is reported on the following research projects: genetic effects of high LET radiations; genetic regulation, alteration, and repair; chromosome replication and the division cycle of Escherichia coli; effects of radioisotope decay in the DNA of microorganisms; initiation and termination of DNA replication in Bacillus subtilis; mutagenesis in mouse myeloma cells; lethal and mutagenic effects of near-uv radiation; effect of 8-methoxypsoralen on photodynamic lethality and mutagenicity in Escherichia coli; DNA repair of the lethal effects of far-uv; and near uv irradiation of bacterial cells

Robust reactor power control system design by genetic algorithm

Energy Technology Data Exchange (ETDEWEB)

Lee, Yoon Joon; Cho, Kyung Ho; Kim, Sin [Cheju National University, Cheju (Korea, Republic of)

1998-12-31

The H{sub {infinity}} robust controller for the reactor power control system is designed by use of the mixed weight sensitivity. The system is configured into the typical two-port model with which the weight functions are augmented. Since the solution depends on the weighting functions and the problem is of nonconvex, the genetic algorithm is used to determine the weighting functions. The cost function applied in the genetic algorithm permits the direct control of the power tracking performances. In addition, the actual operating constraints such as rod velocity and acceleration can be treated as design parameters. Compared with the conventional approach, the controller designed by the genetic algorithm results in the better performances with the realistic constraints. Also, it is found that the genetic algorithm could be used as an effective tool in the robust design. 4 refs., 6 figs. (Author)

Robust reactor power control system design by genetic algorithm

Energy Technology Data Exchange (ETDEWEB)

Lee, Yoon Joon; Cho, Kyung Ho; Kim, Sin [Cheju National University, Cheju (Korea, Republic of)

1997-12-31

The H{sub {infinity}} robust controller for the reactor power control system is designed by use of the mixed weight sensitivity. The system is configured into the typical two-port model with which the weight functions are augmented. Since the solution depends on the weighting functions and the problem is of nonconvex, the genetic algorithm is used to determine the weighting functions. The cost function applied in the genetic algorithm permits the direct control of the power tracking performances. In addition, the actual operating constraints such as rod velocity and acceleration can be treated as design parameters. Compared with the conventional approach, the controller designed by the genetic algorithm results in the better performances with the realistic constraints. Also, it is found that the genetic algorithm could be used as an effective tool in the robust design. 4 refs., 6 figs. (Author)

The significant effects of puberty on the genetic diathesis of binge eating in girls.

Science.gov (United States)

Klump, Kelly L; Culbert, Kristen M; O'Connor, Shannon; Fowler, Natasha; Burt, S Alexandra

2017-08-01

Recent data show significant phenotypic and genetic associations between ovarian hormones and binge eating in adulthood. Theories of hormonal risk focus on puberty and the possibility that hormone activation induces changes in genetic effects that then lead to differential risk for binge eating in postpuberty and adulthood. Although this theory is difficult to test in humans, an indirect test is to examine whether genetic influences on binge eating increase during the pubertal period in girls. Prior work has shown pubertal increases in genetic influences on overall disordered eating symptoms, but no study to date has examined binge eating. The present study was the first to examine these increases for binge eating. Participants included 1,568 female twins (aged 8-25 years) from the Michigan State University Twin Registry. Binge eating and pubertal development were assessed with self-report questionnaires. Twin moderation models showed significant linear increases in genetic effects from prepuberty (5%) to postpuberty (42%), even after controlling for the effects of age and body mass index. Results provide critical support for increased genetic influences on binge eating during puberty. Additional studies are needed to identify hormonal mechanisms and fully test contemporary models of ovarian hormone risk. © 2017 Wiley Periodicals, Inc.

The genetic effects of the atomic bombs

International Nuclear Information System (INIS)

Neel, J.V.

1992-01-01

Studies on the genetic effects of the atomic bombs detonated over Hiroshima and Nagasaki have been in progress since 1946. The indicators of potential genetic damage in the children of exposees which have been employed are: (1) untoward pregnancy outcomes (major congenital defect and/or stillbirth and/or neonatal death), (2) death of liveborn infants prior to average age 28.8 years, (3) cancer of onset prior to age 20, (4) sex chromosome aneuploidy, (5) mutations affecting protein electrophoretic mobility and/or activity, (6) chromosomal reciprocal translocations, (7) sex-ratio in the children of exposed mothers, and (8) physical development at birth, at 9-months, and at school age. There is no statistically significant effect of parental exposure to the bombs on any of these indicators. The net regression of indicator(s) on dose is, however, positive. On the basis of these regressions and assumptions concerning the contribution of spontaneous mutation to the indicator values in the controls, the gametic doubling dose of acute ionizing radiation under these circumstances is estimated to be 2 Sv. With a dose rate factor of 2, which seems appropriate to these circumstances, the doubling dose for chronic radiation is placed at 4 Sv. This is a substantially higher estimate than previous extrapolations to man from murine experiments

The molecular genetic architecture of self-employment.

Science.gov (United States)

van der Loos, Matthijs J H M; Rietveld, Cornelius A; Eklund, Niina; Koellinger, Philipp D; Rivadeneira, Fernando; Abecasis, Gonçalo R; Ankra-Badu, Georgina A; Baumeister, Sebastian E; Benjamin, Daniel J; Biffar, Reiner; Blankenberg, Stefan; Boomsma, Dorret I; Cesarini, David; Cucca, Francesco; de Geus, Eco J C; Dedoussis, George; Deloukas, Panos; Dimitriou, Maria; Eiriksdottir, Guðny; Eriksson, Johan; Gieger, Christian; Gudnason, Vilmundur; Höhne, Birgit; Holle, Rolf; Hottenga, Jouke-Jan; Isaacs, Aaron; Järvelin, Marjo-Riitta; Johannesson, Magnus; Kaakinen, Marika; Kähönen, Mika; Kanoni, Stavroula; Laaksonen, Maarit A; Lahti, Jari; Launer, Lenore J; Lehtimäki, Terho; Loitfelder, Marisa; Magnusson, Patrik K E; Naitza, Silvia; Oostra, Ben A; Perola, Markus; Petrovic, Katja; Quaye, Lydia; Raitakari, Olli; Ripatti, Samuli; Scheet, Paul; Schlessinger, David; Schmidt, Carsten O; Schmidt, Helena; Schmidt, Reinhold; Senft, Andrea; Smith, Albert V; Spector, Timothy D; Surakka, Ida; Svento, Rauli; Terracciano, Antonio; Tikkanen, Emmi; van Duijn, Cornelia M; Viikari, Jorma; Völzke, Henry; Wichmann, H-Erich; Wild, Philipp S; Willems, Sara M; Willemsen, Gonneke; van Rooij, Frank J A; Groenen, Patrick J F; Uitterlinden, André G; Hofman, Albert; Thurik, A Roy

2013-01-01

Economic variables such as income, education, and occupation are known to affect mortality and morbidity, such as cardiovascular disease, and have also been shown to be partly heritable. However, very little is known about which genes influence economic variables, although these genes may have both a direct and an indirect effect on health. We report results from the first large-scale collaboration that studies the molecular genetic architecture of an economic variable-entrepreneurship-that was operationalized using self-employment, a widely-available proxy. Our results suggest that common SNPs when considered jointly explain about half of the narrow-sense heritability of self-employment estimated in twin data (σ(g)(2)/σ(P)(2) = 25%, h(2) = 55%). However, a meta-analysis of genome-wide association studies across sixteen studies comprising 50,627 participants did not identify genome-wide significant SNPs. 58 SNPs with pself-employment in an independent sample (p≥0.039). Our results are consistent with a highly polygenic molecular genetic architecture of self-employment, with many genetic variants of small effect. Although self-employment is a multi-faceted, heavily environmentally influenced, and biologically distal trait, our results are similar to those for other genetically complex and biologically more proximate outcomes, such as height, intelligence, personality, and several diseases.

Genetic Modification of the Lung Directed Toward Treatment of Human Disease.

Science.gov (United States)

Sondhi, Dolan; Stiles, Katie M; De, Bishnu P; Crystal, Ronald G

2017-01-01

Genetic modification therapy is a promising therapeutic strategy for many diseases of the lung intractable to other treatments. Lung gene therapy has been the subject of numerous preclinical animal experiments and human clinical trials, for targets including genetic diseases such as cystic fibrosis and α1-antitrypsin deficiency, complex disorders such as asthma, allergy, and lung cancer, infections such as respiratory syncytial virus (RSV) and Pseudomonas, as well as pulmonary arterial hypertension, transplant rejection, and lung injury. A variety of viral and non-viral vectors have been employed to overcome the many physical barriers to gene transfer imposed by lung anatomy and natural defenses. Beyond the treatment of lung diseases, the lung has the potential to be used as a metabolic factory for generating proteins for delivery to the circulation for treatment of systemic diseases. Although much has been learned through a myriad of experiments about the development of genetic modification of the lung, more work is still needed to improve the delivery vehicles and to overcome challenges such as entry barriers, persistent expression, specific cell targeting, and circumventing host anti-vector responses.

The 'horizontal direct effect' of EU international agreements

DEFF Research Database (Denmark)

Gáspár-Szilágyi, Szilárd

2015-01-01

This article looks at a less discussed topic in European legal scholarship: the horizontal direct effect of EU international agreements and the Court of Justice’s apparent reluctance to expressly confirm it. It is argued that the direct effect of EU international agreements has been confirmed...... in proceedings involving private individuals/professionals against the private regulatory bodies of a profession or a State owned and controlled entity. However, direct effect has not yet been expressly confirmed in cases involving veritable horizontal relationships, between private parties of equal positions...

Power assessment for genetic association study of human longevity using offspring of long-lived subjects

DEFF Research Database (Denmark)

Tan, Qihua; Zhao, Jing Hua; Li, Shuxia

2010-01-01

and the proportional hazard model for generating individual lifespan. Family genotype data is generated using a genetic linkage program for given SNP allele frequency. Power is estimated by setting the type I error rate at 0.05 and by calculating the Armitage's chi-squared test statistic for 200 replicate samples...... the direct approach. It also has low power in detecting non-additive effect genes. Indirect genetic association using offspring from families with both parents as nonagenarians is nearly as powerful as using offspring from families with one centenarian parent. In conclusion, the indirect design can be a good......Recently, an indirect genetic association approach that compares genotype frequencies in offspring of long-lived subjects and offspring from random families has been introduced to study gene-longevity associations. Although the indirect genetic association has certain advantages over the direct...

Estimation of genetic parameters for milk traits in Romanian local sheep breed

Directory of Open Access Journals (Sweden)

Pelmus RS

2014-03-01

Full Text Available Objective. Estimate the genetic parameters for milk traits in a Romanian local sheep population Teleorman Black Head. Material and methods. Records of 262 sheep belonging to 17 rams and 139 ewes were used in the study. The following traits were investigated: milk yield, fat yield, protein yield, fat percentage and protein percentage. The genetic parameters were estimated using the Restricted Maximum Likelihood method, with a model including maternal effects. Results. The results from our study revealed that direct heritability estimates were moderate for milk yield (0.449, fat yield (0.442, protein yield (0.386 while for protein percentage (0.708 and fat percentage (0.924 were high. The high direct and maternal genetic correlation was between milk yield and protein yield (0.979, 0.973 and between protein yield and fat yield (0.952, 0.913 while the phenotypic correlation between the milk yield and fat yield (0.968, the milk yield and protein yield (0.967, fat yield and protein yield (0.936 was high and positive. Conclusions. The genetic parameters are important in selection program on this breed for genetic improvement.

The sense and nonsense of direct-to-consumer genetic testing for cardiovascular disease

NARCIS (Netherlands)

A.C.J.W. Janssens (Cécile); A.A.M. Wilde (Arthur); I.M. van Langen (Irene)

2011-01-01

textabstractExpectations are high that increasing knowledge of the genetic basis of cardiovascular disease will eventually lead to personalised medicine-to preventive and therapeutic interventions that are targeted to at-risk individuals on the basis of their genetic profiles. Most cardiovascular

Evolution of the additive genetic variance–covariance matrix under continuous directional selection on a complex behavioural phenotype

Science.gov (United States)

Careau, Vincent; Wolak, Matthew E.; Carter, Patrick A.; Garland, Theodore

2015-01-01

Given the pace at which human-induced environmental changes occur, a pressing challenge is to determine the speed with which selection can drive evolutionary change. A key determinant of adaptive response to multivariate phenotypic selection is the additive genetic variance–covariance matrix (G). Yet knowledge of G in a population experiencing new or altered selection is not sufficient to predict selection response because G itself evolves in ways that are poorly understood. We experimentally evaluated changes in G when closely related behavioural traits experience continuous directional selection. We applied the genetic covariance tensor approach to a large dataset (n = 17 328 individuals) from a replicated, 31-generation artificial selection experiment that bred mice for voluntary wheel running on days 5 and 6 of a 6-day test. Selection on this subset of G induced proportional changes across the matrix for all 6 days of running behaviour within the first four generations. The changes in G induced by selection resulted in a fourfold slower-than-predicted rate of response to selection. Thus, selection exacerbated constraints within G and limited future adaptive response, a phenomenon that could have profound consequences for populations facing rapid environmental change. PMID:26582016

Evolution of the additive genetic variance-covariance matrix under continuous directional selection on a complex behavioural phenotype.

Science.gov (United States)

Careau, Vincent; Wolak, Matthew E; Carter, Patrick A; Garland, Theodore

2015-11-22

Given the pace at which human-induced environmental changes occur, a pressing challenge is to determine the speed with which selection can drive evolutionary change. A key determinant of adaptive response to multivariate phenotypic selection is the additive genetic variance-covariance matrix ( G: ). Yet knowledge of G: in a population experiencing new or altered selection is not sufficient to predict selection response because G: itself evolves in ways that are poorly understood. We experimentally evaluated changes in G: when closely related behavioural traits experience continuous directional selection. We applied the genetic covariance tensor approach to a large dataset (n = 17 328 individuals) from a replicated, 31-generation artificial selection experiment that bred mice for voluntary wheel running on days 5 and 6 of a 6-day test. Selection on this subset of G: induced proportional changes across the matrix for all 6 days of running behaviour within the first four generations. The changes in G: induced by selection resulted in a fourfold slower-than-predicted rate of response to selection. Thus, selection exacerbated constraints within G: and limited future adaptive response, a phenomenon that could have profound consequences for populations facing rapid environmental change. © 2015 The Author(s).

Genetic parameters and environmental effects on temperament score and reproductive traits of Nellore cattle.

Science.gov (United States)

Barrozo, D; Buzanskas, M E; Oliveira, J A; Munari, D P; Neves, H H R; Queiroz, S A

2012-01-01

Animal temperament is a trait of economic relevance and its use as a selection criterion requires the identification of environmental factors that influence this trait, as well as the estimation of its genetic variability and interrelationship with other traits. The objectives of this study were to evaluate the effect of the covariates dam age at calving (ADC), long yearling age (YA) and long yearling weight (YW) on temperament score (T) and to estimate genetic parameters for T, scrotal circumference (SC) at long YA and age at first calving (AFC) in Nellore cattle participating in a selection program. The traits were analyzed by the restricted maximum likelihood method under a multiple-trait animal model. For all traits, contemporary group was included as a fixed effect and additive genetic and residual as random effects. In addition to these effects, YA, YW and ADC were considered for analyzing T. In the case of SC and AFC, the effect of long YW was included as a covariate. Genetic parameters were estimated for and between traits. The three covariates significantly influenced T. The heritability estimates for T, SC and AFC were 0.18 ± 0.02, 0.53 ± 0.04 and 0.23 ± 0.08, respectively. The genetic correlations between T and SC, and T and AFC were -0.07 ± 0.17 and -0.06 ± 0.19, respectively. The genetic correlation estimated between SC and AFC was -0.57 ± 0.16. In conclusion, a response to selection for T, SC and AFC is expected and selection for T does not imply correlated responses with the other traits.

[Issues on business of genetic testing in near future].

Science.gov (United States)

Takada, Fumio

2009-06-01

Since 1990's, a business condition that company sells genetic testing services directly to consumers without through medical facility, so called "direct-to-consumers (DTC) genetic testing", has risen. They provide genetic testing for obesity, disease susceptibility or paternity, etc. There are serious problems in this kind of business. Most of the providers do not make sales with face-to-face selling, and do through internet instead. They do not provide genetic counseling by certified genetic counselor or clinical geneticist. Most DTC genetic testing services for disease susceptibility or predispositions including obesity, lack scientific validity, clinical validity and clinical utility. And also including paternity genetic testing, they all have risks of ethical legal and social issues (ELSI) in genetic discrimination and/or eugenics. The specific problem in Japan is that the healthcare section of the government still has not paid attention and not taken seriously the requirement to deploy safety net.

Chemotaxonomic markers of organic, natural, and genetically modified soybeans detected by direct infusion electrospray ionization mass spectrometry

International Nuclear Information System (INIS)

Santos, L.S.; Catharino, R.R.; Eberlin, M.N.; Tsai, S.M.

2006-01-01

The crude methanolic extracts of a single bean from samples of organic, natural or genetically modified (GM) soybeans [Glycine max. (Merrill) L.] were analyzed by direct infusion electrospray ionization mass spectrometry (ESI-MS). These extracts, containing the most polar natural products of soybeans (free aglycones, monoglucosides, diglucosides and esters including isoflavones and flavones) provide characteristic fingerprinting mass spectra owing to different proportions or sets of components. Spectra distinctiveness is confirmed by chemometric multivariate analysis of the ESIMS data, which place the three-types of beans into well-defined groups. When ESI-MS is applied, these polar components constitute therefore unique chemotaxonomic markers able to provide fast soybean typification. (author)

50. Brazilian congress on genetics. 50 years developing genetics. Abstracts

International Nuclear Information System (INIS)

2004-01-01

Use of radioisotopes and ionizing radiations in genetics is presented. Several aspects related to men, animals,plants and microorganisms are reported highlighting biological radiation effects, evolution, mutagenesis and genetic engineering. Genetic mapping, gene mutations, genetic diversity, DNA damages, plant cultivation and plant grow are studied as well

The sense and nonsense of direct-to-consumer genetic testing for cardiovascular disease

NARCIS (Netherlands)

Janssens, A. C. J. W.; Wilde, A. A. M.; van Langen, I. M.

2011-01-01

Expectations are high that increasing knowledge of the genetic basis of cardiovascular disease will eventually lead to personalised medicine-to preventive and therapeutic interventions that are targeted to at-risk individuals on the basis of their genetic profiles. Most cardiovascular diseases are

Genetical effects of radiations from products of nuclear explosions

Energy Technology Data Exchange (ETDEWEB)

Spiers, F W

1955-01-01

Relative radiation dose-rates to man and to Drosophila are discussed. Data previously presented by Prof. J.B.S. Haldane on the genetical effects of radiation resulting from nuclear explosions are reviewed. A reply from Prof. Haldane presents revised calculations of radiation dose rates.

Effect of Direction Type, Emotional Valence of Words And Gender on Directed Forgetting

OpenAIRE

Sayar, Filiz

2018-01-01

In the present study, the effects of emotional valence of words and gender on directed forgettingwere investigated. The directed forgetting effect was investigated by requiring from participants toforget the words that they have to recall and at the same time, to recall the words that they have toforget. The study was composed of two experiments. In the first experiment, the participants werepresented with a list of words consisting of neutral and emotional words once, while the participantsw...

Food safety evaluation of crops produced through genetic engineering--how to reduce unintended effects?

Science.gov (United States)

Jelenić, Srećko

2005-06-01

Scientists started applying genetic engineering techniques to improve crops two decades ago; about 70 varieties obtained via genetic engineering have been approved to date. Although genetic engineering offers the most precise and controllable genetic modification of crops in entire history of plant improvement, the site of insertion of a desirable gene cannot be predicted during the application of this technology. As a consequence, unintended effects might occur due to activation or silencing of genes, giving rise to allergic reactions or toxicity. Therefore, extensive chemical, biochemical and nutritional analyses are performed on each new genetically engineered variety. Since the unintended effects may be predictable on the basis of what is known about the insertion place of the transgenic DNA, an important aim of plant biotechnology is to define techniques for the insertion of transgene into the predetermined chromosomal position (gene targeting). Although gene targeting cannot be applied routinely in crop plants, given the recent advances, that goal may be reached in the near future.

Cardiometabolic effects of genetic upregulation of the interleukin 1 receptor antagonist: A Mendelian randomisation analysis

NARCIS (Netherlands)

C.M. Freitag (Christine); A.S. Butterworth (Adam); J. Willeit (Johann); J.M.M. Howson (Joanna M.M.); S. Burgess (Stephen); S. Kaptoge (Stephen); R. Young (Robin); W.K. Ho (Weang Kee); A.M. Wood (Angela); M. Sweeting (Michael); S. Spackman (Sarah); J.R. Staley (James R.); A. Ramond (Anna); E. Harshfield (Eric); S.F. Nielsen (Sune); P. Grande (Peer); L.A. Lange (Leslie); M.J. Bown (Matthew J.); G.T. Jones (Gregory); R.A. Scott (Robert); S. Bevan (Steve); E. Porcu (Eleonora); G. Thorleifsson (Gudmar); L. Zeng (Lingyao); T. Kessler (Thorsten); M. Nikpay (Majid); R. Do (Ron); W. Zhang (Weihua); J. Hopewell; M.E. Kleber (Marcus); G. Delgado; C.P. Nelson (Christopher P.); A. Goel (Anuj); J.C. Bis (Joshua); A. Dehghan (Abbas); S. Ligthart (Symen); G.D. Smith; L. Qu (Liming); F.N.G. Van 'T Hof (Femke); P.I.W. de Bakker (Paul); A.F. Baas (Annette); A.M. van Rij (Andre); G. Tromp (Gerard); H. Kuivaniemi (Helena); M.D. Ritchie (Marylyn D.); S.S. Verma (Shefali S.); D.C. Crawford (Dana); J. Malinowski (Jennifer); M. de Andrade (Mariza); I. Kullo (Iftikhar); P.L. Peissig (Peggy L.); C.A. McCarty (Catherine A.); E.P. Bottinger (Erwin); R.F. Gottesman (Rebecca); D.R. Crosslin (David); D.S. Carrell (David); L.J. Rasmussen-Torvik (Laura); J.A. Pacheco (Jennifer A.); J. Huang (Jie); N.J. Timpson (Nicholas); J. Kettunen (Johannes); M. Ala-Korpela (Mika); G.F. Mitchell (Gary); A. Parsa (Afshin); I.B. Wilkinson (Ian B.); M. Gorski (Mathias); Y. Li (Yong); N. Franceschini (Nora); M.F. Keller (Margaux); S.K. Ganesh (Santhi); C.D. Langefeld (Carl); L. Bruijn (Lucie); M.A. Brown (Matthew); D.M. Evans (David M.); S. Baltic (Svetlana); M.A. Ferreira (Manuel); H. Baurecht (Hansjörg); S. Weidinger (Stephan); A. Franke (Andre); S.A. Lubitz (Steven); M. Müller-Nurasyid (Martina); J.F. Felix (Janine); N.L. Smith (Nicholas); M. Sudman (Marc); S.D. Thompson (Susan D.); E. Zeggini (Eleftheria); K. Panoutsopoulou (Kalliope); M.A. Nalls (Michael); A. Singleton (Andrew); C. Polychronakos (Constantin); J.P. Bradfield (Jonathan); H. Hakonarson (Hakon); D.F. Easton (Douglas); D. Thompson (Deborah); I.P. Tomlinson (Ian); M. Dunlop (Malcolm); K. Hemminki (Kari); G. Morgan (Gareth); T. Eisen (Timothy); H. Goldschmidt (Hartmut); J.M. Allan (James); M. Henrion (Marc); N. Whiffin (Nicola); Y. Wang (Yufei); D. Chubb (Daniel); M.M. Iles (Mark M.); D.T. Bishop (David Timothy); M.H. Law (Matthew H.); N. Hayward (Nick); Y. Luo (Yang); S. Nejentsev (Sergey); M. Barbalic (maja); D. Crossman (David); S. Sanna (Serena); N. Soranzo (Nicole); H.S. Markus (Hugh); N.J. Wareham (Nick); D.J. Rader (Daniel); M.P. Reilly (Muredach); T.L. Assimes (Themistocles); T.B. Harris (Tamara B.); A. Hofman (Albert); O.H. Franco (Oscar); V. Gudnason (Vilmundur); R.P. Tracy (Russell); B.M. Psaty (Bruce); M. Farrall (Martin); H. Watkins (Hugh); A.S. Hall (Alistair); N.J. Samani (Nilesh); W. März (Winfried); R. Clarke (Robert); F.S. Collins (Francis); J.S. Kooner (Jaspal S.); J.C. Chambers (John C.); S. Kathiresan (Sekar); R. McPherson (Ruth); J. Erdmann (Jeanette); A. Kastrati (Adnan); H. Schunkert (Heribert); J-A. Zwart (John-Anker); U. Thorsteinsdottir (Unnur); J. Walston (Jeremy); A. Tybjaerg-Hansen; D.S. Alam (Dewan S.); A. Al Shafi Majumder (Abdullah); E.D. Angelantonio (Emanuele Di); R. Chowdhury (Rajiv); B.G. Nordestgaard (Børge); D. Saleheen; S.G. Thompson (Simon); J. Danesh (John); R. Houlston (Richard)

2015-01-01

textabstractTo investigate potential cardiovascular and other effects of long-term pharmacological interleukin 1 (IL-1) inhibition, we studied genetic variants that produce inhibition of IL-1, a master regulator of inflammation. Methods: We created a genetic score combining the effects of alleles of

Cardiometabolic effects of genetic upregulation of the interleukin 1 receptor antagonist : A Mendelian randomisation analysis

NARCIS (Netherlands)

Freitag, Daniel; Butterworth, Adam S.; Willeit, Peter; Howson, Joanna M M; Burgess, Stephen; Kaptoge, Stephen; Young, Robin; Ho, Weang Kee; Wood, Angela M.; Sweeting, Michael; Spackman, Sarah; Staley, James R.; Ramond, Anna; Harshfield, Eric; Nielsen, Sune F.; Grande, Peer; Lange, Leslie A.; Bown, Matthew J.; Jones, Gregory T.; Scott, Robert A.; Bevan, Steve; Porcu, Eleonora; Thorleifsson, Gudmar; Zeng, Lingyao; Kessler, Thorsten; Nikpay, Majid; Do, Ron; Zhang, Weihua; Hopewell, Jemma C.; Kleber, Marcus; Delgado, Graciela E.; Nelson, Christopher P.; Goel, Anuj; Bis, Joshua C.; Dehghan, Abbas; Ligthart, Symen; Smith, Albert V.; Qu, Liming; van 't Hof, Femke N G; de Bakker, Paul I W; Baas, Annette F.; van Rij, Andre; Tromp, Gerard; Kuivaniemi, Helena; Ritchie, Marylyn D.; Verma, Shefali S.; Crawford, Dana C.; Malinowski, Jennifer; de Andrade, Mariza; Kullo, Iftikhar J.; Peissig, Peggy L.; McCarty, Catherine A.; Böttinger, Erwin P.; Gottesman, Omri; Crosslin, David R.; Carrell, David S.; Rasmussen-Torvik, Laura J.; Pacheco, Jennifer A.; Huang, Jie; Timpson, Nicholas J.; Kettunen, Johannes; Ala-Korpela, Mika; Mitchell, Gary F.; Parsa, Afshin; Wilkinson, Ian B.; Gorski, Mathias; Li, Yong; Franceschini, Nora; Keller, Margaux F.; Ganesh, Santhi K.; Langefeld, Carl D.; Bruijn, Lucie; Brown, Matthew A.; Evans, David M.; Baltic, Svetlana; Ferreira, Manuel A.; Baurecht, Hansjörg; Weidinger, Stephan; Franke, Andre; Lubitz, Steven A.; Müller-Nurasyid, Martina; Felix, Janine F.; Smith, Nicholas L.; Sudman, Marc; Thompson, Susan D.; Zeggini, Eleftheria; Panoutsopoulou, Kalliope; Nalls, Mike A.; Singleton, Andrew; Polychronakos, Constantin; Bradfield, Jonathan P.; Hakonarson, Hakon; Easton, Douglas F.; Thompson, Deborah; Tomlinson, Ian P.; Dunlop, Malcolm; Hemminki, Kari; Morgan, Gareth; Eisen, Timothy; Goldschmidt, Hartmut; Allan, James M.; Henrion, Marc; Whiffin, Nicola; Wang, Yufei; Chubb, Daniel; Iles, Mark M.; Bishop, D. Timothy; Law, Matthew H.; Hayward, Nicholas K.; Luo, Yang; Nejentsev, Sergey; Barbalic, Maja; Crossman, David; Sanna, Serena; Soranzo, Nicole; Markus, Hugh S.; Wareham, Nicholas J.; Rader, Daniel J.; Reilly, Muredach; Assimes, Themistocles; Harris, Tamara B.; Hofman, Albert; Franco, Oscar H.; Gudnason, Vilmundur; Tracy, Russell; Psaty, Bruce M.; Farrall, Martin; Watkins, Hugh; Hall, Alistair S.; Samani, Nilesh J.; März, Winfried; Clarke, Robert; Collins, Rory; Kooner, Jaspal S.; Chambers, John C.; Kathiresan, Sekar; McPherson, Ruth; Erdmann, Jeanette; Kastrati, Adnan; Schunkert, Heribert; Stefánsson, Kári; Thorsteinsdottir, Unnur; Walston, Jeremy D.; Tybjærg-Hansen, Anne; Alam, Dewan S.; Al Shafi Majumder, Abdullah; Angelantonio, Emanuele Di; Chowdhury, Rajiv; Nordestgaard, Børge G.; Saleheen, Danish; Thompson, Simon G.; Danesh, John; Houlston, Richard S.

2015-01-01

To investigate potential cardiovascular and other effects of long-term pharmacological interleukin 1 (IL-1) inhibition, we studied genetic variants that produce inhibition of IL-1, a master regulator of inflammation. Methods: We created a genetic score combining the effects of alleles of two common

The Molecular Genetic Architecture of Self-Employment

Science.gov (United States)

van der Loos, Matthijs J. H. M.; Rietveld, Cornelius A.; Eklund, Niina; Koellinger, Philipp D.; Rivadeneira, Fernando; Abecasis, Gonçalo R.; Ankra-Badu, Georgina A.; Baumeister, Sebastian E.; Benjamin, Daniel J.; Biffar, Reiner; Blankenberg, Stefan; Boomsma, Dorret I.; Cesarini, David; Cucca, Francesco; de Geus, Eco J. C.; Dedoussis, George; Deloukas, Panos; Dimitriou, Maria; Eiriksdottir, Guðny; Eriksson, Johan; Gieger, Christian; Gudnason, Vilmundur; Höhne, Birgit; Holle, Rolf; Hottenga, Jouke-Jan; Isaacs, Aaron; Järvelin, Marjo-Riitta; Johannesson, Magnus; Kaakinen, Marika; Kähönen, Mika; Kanoni, Stavroula; Laaksonen, Maarit A.; Lahti, Jari; Launer, Lenore J.; Lehtimäki, Terho; Loitfelder, Marisa; Magnusson, Patrik K. E.; Naitza, Silvia; Oostra, Ben A.; Perola, Markus; Petrovic, Katja; Quaye, Lydia; Raitakari, Olli; Ripatti, Samuli; Scheet, Paul; Schlessinger, David; Schmidt, Carsten O.; Schmidt, Helena; Schmidt, Reinhold; Senft, Andrea; Smith, Albert V.; Spector, Timothy D.; Surakka, Ida; Svento, Rauli; Terracciano, Antonio; Tikkanen, Emmi; van Duijn, Cornelia M.; Viikari, Jorma; Völzke, Henry; Wichmann, H. -Erich; Wild, Philipp S.; Willems, Sara M.; Willemsen, Gonneke; van Rooij, Frank J. A.; Groenen, Patrick J. F.; Uitterlinden, André G.; Hofman, Albert; Thurik, A. Roy

2013-01-01

Economic variables such as income, education, and occupation are known to affect mortality and morbidity, such as cardiovascular disease, and have also been shown to be partly heritable. However, very little is known about which genes influence economic variables, although these genes may have both a direct and an indirect effect on health. We report results from the first large-scale collaboration that studies the molecular genetic architecture of an economic variable–entrepreneurship–that was operationalized using self-employment, a widely-available proxy. Our results suggest that common SNPs when considered jointly explain about half of the narrow-sense heritability of self-employment estimated in twin data (σg 2/σP 2 = 25%, h 2 = 55%). However, a meta-analysis of genome-wide association studies across sixteen studies comprising 50,627 participants did not identify genome-wide significant SNPs. 58 SNPs with pentrepreneurship reveal significant associations. Finally, SNP-based genetic scores that use results from the meta-analysis capture less than 0.2% of the variance in self-employment in an independent sample (p≥0.039). Our results are consistent with a highly polygenic molecular genetic architecture of self-employment, with many genetic variants of small effect. Although self-employment is a multi-faceted, heavily environmentally influenced, and biologically distal trait, our results are similar to those for other genetically complex and biologically more proximate outcomes, such as height, intelligence, personality, and several diseases. PMID:23593239

Genetic and histopathology studies on mice: Effect of fenugreek oil ...

African Journals Online (AJOL)

There is a growing interest in understanding the biological effect of medicinal plants. In the present investigation, the effects of fenugreek oil administration on the liver and ovarian activity genetically (i.e., meiotic progression in collected oocytes as well as changes in DNA and RNA content in the liver and ovarian tissues) ...

Genetic analysis of growth traits in Iranian Makuie sheep breed

Directory of Open Access Journals (Sweden)

Mohammad Farhadian

2012-01-01

Full Text Available The Makuie sheep is a fat-tailed sheep breed which can be found in the Azerbaijan province of Iran. In 1986, a Makuie sheep breeding station was established in the city of Maku in order to breed, protect and purify this breed. The genetic parameters for birth weight, weaning weight (3 months, 6-month, 9-month and yearling weight, and average daily gain from birth to weaning traits were estimated based on 25 years of data using DFREML software. Six different models were applied and a likelihood ratio test (LRT was used to select the appropriate model. Bivariate analysis was used to define the genetic correlation between studied traits. Based on the LRT, model II was selected as an appropriate model for all studied traits. Direct heritability estimates of birth, weaning, 6-month, 9-month and yearling weights and average daily gain from birth to weaning were 0.36, 0.41, 0.48, 0.42, 0.36 and 0.37, respectively. Estimates of direct genetic correlation between birth and weaning weights, birth and 6-month weights, birth and 9-month weights, as well as between birth and yearling weights were 0.57, 0.49, 0.46 and 0.32, respectively. The results suggest there is a substantial additive genetic variability for studied traits in the Makuie sheep breed population, and the direct additive effect and maternal permanent environment variance are the main source of phenotypic variance.

Applications of genetic data to improve management and conservation of river fishes and their habitats

Science.gov (United States)

Scribner, Kim T.; Lowe, Winsor H.; Landguth, Erin L.; Luikart, Gordon; Infante, Dana M.; Whelan, Gary; Muhlfeld, Clint C.

2015-01-01

Environmental variation and landscape features affect ecological processes in fluvial systems; however, assessing effects at management-relevant temporal and spatial scales is challenging. Genetic data can be used with landscape models and traditional ecological assessment data to identify biodiversity hotspots, predict ecosystem responses to anthropogenic effects, and detect impairments to underlying processes. We show that by combining taxonomic, demographic, and genetic data of species in complex riverscapes, managers can better understand the spatial and temporal scales over which environmental processes and disturbance influence biodiversity. We describe how population genetic models using empirical or simulated genetic data quantify effects of environmental processes affecting species diversity and distribution. Our summary shows that aquatic assessment initiatives that use standardized data sets to direct management actions can benefit from integration of genetic data to improve the predictability of disturbance–response relationships of river fishes and their habitats over a broad range of spatial and temporal scales.

A genome-wide association study of social genetic effects in Landrace pigs.

Science.gov (United States)

Hong, Joon Ki; Jeong, Yong Dae; Cho, Eun Seok; Choi, Tae Jeong; Kim, Yong Min; Cho, Kyu Ho; Lee, Jae Bong; Lim, Hyun Tae; Lee, Deuk Hwan

2018-06-01

The genetic effects of an individual on the phenotypes of its social partners, such as its pen mates, are known as social genetic effects. This study aims to identify the candidate genes for social (pen-mates') average daily gain (ADG) in pigs by using the genome-wide association approach. Social ADG (sADG) was the average ADG of unrelated pen-mates (strangers). We used the phenotype data (16,802 records) after correcting for batch (week), sex, pen, number of strangers (1 to 7 pigs) in the pen, full-sib rate (0% to 80%) within pen, and age at the end of the test. A total of 1,041 pigs from Landrace breeds were genotyped using the Illumina PorcineSNP60 v2 BeadChip panel, which comprised 61,565 single nucleotide polymorphism (SNP) markers. After quality control, 909 individuals and 39,837 markers remained for sADG in genome-wide association study. We detected five new SNPs, all on chromosome 6, which have not been associated with social ADG or other growth traits to date. One SNP was inside the prostaglandin F2α receptor ( PTGFR ) gene, another SNP was located 22 kb upstream of gene interferon-induced protein 44 ( IFI44 ), and the last three SNPs were between 161 kb and 191 kb upstream of the EGF latrophilin and seven transmembrane domain-containing protein 1 ( ELTD1 ) gene. PTGFR, IFI44, and ELTD1 were never associated with social interaction and social genetic effects in any of the previous studies. The identification of several genomic regions, and candidate genes associated with social genetic effects reported here, could contribute to a better understanding of the genetic basis of interaction traits for ADG. In conclusion, we suggest that the PTGFR, IFI44, and ELTD1 may be used as a molecular marker for sADG, although their functional effect was not defined yet. Thus, it will be of interest to execute association studies in those genes.

Genetic and somatic effects in animals maintained on tritiated water

International Nuclear Information System (INIS)

Carsten, A.L.; Commerford, S.L.; Cronkite, E.P.; Brooks, A.

1982-01-01

Somatic and genetic effects of the continuous ingestion of tritiated water (HTO) at concentrations of 0.3, 1.0 and 3.0 μCi/ml were investigated in mice of the Hale-Stoner-Brookhaven strain. At these levels, there was no measurable somatic effect. Although genetic effects as measured by dominant lethal mutation (DLM) assay indicated a significant effect (P>0.01) on the number of viable embryos and early deaths in the 3.0 μCi/ml HTO group and on the number of viable embryos in the 1.0 μCi/ml HTO group, no genetic effects were significantly noted in the 0.3 μCi/ml HTO group. Liver cytogenetic studies showed a significant increase in the number of abnormal cells in the 3.0 μCi/ml HTO group. A reduction in bone marrow stem cells, without an attendant reduction in total marrow cellularity, was noted in the 3.0 and 1.0 μCi/ml HTO groups. There was no significant difference in any of the DLM parameters between animals maintained on 3.0 μCi/ml of HTO and animals exposed to the equivalent 137 Cs gamma dose (22 hours/day exposure). Consideration of the relative amounts and biological half lives of tritium present in the nucleus as water, DNA and histone suggests that after transient exposure to tritiated water, nearly all significant radiation damage can be attributed to tritium present in the nucleus as water. These data suggest that hazards from tritium attendant with normal reactor operation should not at this time be considered as a deterrent to the further development of fission and/or fusion reactor technology. (Namekawa, K.)

Journal of Genetics | Indian Academy of Sciences

Indian Academy of Sciences (India)

polygenes; additive genetic variance; epistasis; dominance; selection ... seem to run out of genetic variability even after many generations of directional selection. ... Conspicuous examples are the small number of loci that changed teosinte to ...

Genetically contextual effects of smoking on genome wide DNA methylation.

Science.gov (United States)

Dogan, Meeshanthini V; Beach, Steven R H; Philibert, Robert A

2017-09-01

Smoking is the leading cause of death in the United States. It exerts its effects by increasing susceptibility to a variety of complex disorders among those who smoke, and if pregnant, to their unborn children. In prior efforts to understand the epigenetic mechanisms through which this increased vulnerability is conveyed, a number of investigators have conducted genome wide methylation analyses. Unfortunately, secondary to methodological limitations, these studies were unable to examine methylation in gene regions with significant amounts of genetic variation. Using genome wide genetic and epigenetic data from the Framingham Heart Study, we re-examined the relationship of smoking status to genome wide methylation status. When only methylation status is considered, smoking was significantly associated with differential methylation in 310 genes that map to a variety of biological process and cellular differentiation pathways. However, when SNP effects on the magnitude of smoking associated methylation changes are also considered, cis and trans-interaction effects were noted at a total of 266 and 4353 genes with no marked enrichment for any biological pathways. Furthermore, the SNP variation participating in the significant interaction effects is enriched for loci previously associated with complex medical illnesses. The enlarged scope of the methylome shown to be affected by smoking may better explicate the mediational pathways linking smoking with a myriad of smoking related complex syndromes. Additionally, these results strongly suggest that combined epigenetic and genetic data analyses may be critical for a more complete understanding of the relationship between environmental variables, such as smoking, and pathophysiological outcomes. © 2017 Wiley Periodicals, Inc.

Estimation and interpretation of genetic effects with epistasis using the NOIA model.

Science.gov (United States)

Alvarez-Castro, José M; Carlborg, Orjan; Rönnegård, Lars

2012-01-01

We introduce this communication with a brief outline of the historical landmarks in genetic modeling, especially concerning epistasis. Then, we present methods for the use of genetic modeling in QTL analyses. In particular, we summarize the essential expressions of the natural and orthogonal interactions (NOIA) model of genetic effects. Our motivation for reviewing that theory here is twofold. First, this review presents a digest of the expressions for the application of the NOIA model, which are often mixed with intermediate and additional formulae in the original articles. Second, we make the required theory handy for the reader to relate the genetic concepts to the particular mathematical expressions underlying them. We illustrate those relations by providing graphical interpretations and a diagram summarizing the key features for applying genetic modeling with epistasis in comprehensive QTL analyses. Finally, we briefly review some examples of the application of NOIA to real data and the way it improves the interpretability of the results.

Peripartum Cardiomyopathy: Moving Towards a More Central Role of Genetics#

Science.gov (United States)

Cemin, Roberto; Janardhanan, Rajesh; Donazzan, Luca; Daves, Massimo

2013-01-01

Peripartum cardiomyopathy (PCM) is a relatively rare disease with potentially devasting consequences requiring prompt identification and correct treatment. Overall prognosis is good in majority of the cases, although some patients may progress to irreversible heart failure. Early diagnosis is important and effective treatment reduces mortality rates and increases the chance of complete recovery of ventricular systolic function. The aetiology and pathogenesis seems to be multifactorial and poorly understood, with the available literature rather conflicting. In recent years, there has been increased interest in the role played by genetic predisposition in the development of PCM. It probably develops as a result of a complex interaction of pregnancy-associated factors and genetic factors and recently there have been many observations pointing out the central role played by a genetic predisposition. The direct and indirect observations on genetic susceptibility may offer new insights into the pathogenesis of PCM. However, larger studies are needed before advising routine genetic testing in these patients. PMID:23909634

Genetic autonomic disorders.

Science.gov (United States)

Axelrod, Felicia B

2013-03-01

Genetic disorders affecting the autonomic nervous system can result in abnormal development of the nervous system or they can be caused by neurotransmitter imbalance, an ion-channel disturbance or by storage of deleterious material. The symptoms indicating autonomic dysfunction, however, will depend upon whether the genetic lesion has disrupted peripheral or central autonomic centers or both. Because the autonomic nervous system is pervasive and affects every organ system in the body, autonomic dysfunction will result in impaired homeostasis and symptoms will vary. The possibility of genetic confirmation by molecular testing for specific diagnosis is increasing but treatments tend to remain only supportive and directed toward particular symptoms. Copyright © 2013 Elsevier Inc. All rights reserved.

Bayesian analyses of genetic parameters for growth traits in Nellore cattle raised on pasture.

Science.gov (United States)

Lopes, F B; Ferreira, J L; Lobo, R B; Rosa, G J M

2017-07-06

This study was carried out to investigate (co)variance components and genetic parameters for growth traits in beef cattle using a multi-trait model by Bayesian methods. Genetic and residual (co)variances and parameters were estimated for weights at standard ages of 120 (W120), 210 (W210), 365 (W365), and 450 days (W450), and for pre- and post-weaning daily weight gain (preWWG and postWWG) in Nellore cattle. Data were collected over 16 years (1993-2009), and all animals were raised on pasture in eight farms in the North of Brazil that participate in the National Association of Breeders and Researchers. Analyses were run by the Bayesian approach using Gibbs sampler. Additive direct heritabilities for W120, W210, W365, and W450 and for preWWG and postWWG were 0.28 ± 0.013, 0.32 ± 0.002, 0.31 ± 0.002, 0.50 ± 0.026, 0.61 ± 0.047, and 0.79 ± 0.055, respectively. The estimates of maternal heritability were 0.32 ± 0.012, 0.29 ± 0.004, 0.30 ± 0.005, 0.25 ± 0.015, 0.23 ± 0.017, and 0.22 ± 0.016, respectively, for W120, W210, W365, and W450 and for preWWG and postWWG. The estimates of genetic direct additive correlation among all traits were positive and ranged from 0.25 ± 0.03 (preWWG and postWWG) to 0.99 ± 0.00 (W210 and preWWG). The moderate to high estimates of heritability and genetic correlation for weights and daily weight gains at different ages is suggestive of genetic improvement in these traits by selection at an appropriate age. Maternal genetic effects seemed to be significant across the traits. When the focus is on direct and maternal effects, W210 seems to be a good criterium for the selection of Nellore cattle considering the importance of this breed as a major breed of beef cattle not only in Northern Brazil but all regions covered by tropical pastures. As in this study the genetic correlations among all traits were high, the selection based on weaning weight might be a good choice because at this age there are two important effects (maternal

Genetic parameters and genetic and phenotypic trends of performance traits of equines from the Brazilian Army

Directory of Open Access Journals (Sweden)

Mariana de Almeida Dornelles

2012-06-01

Full Text Available The objective of this research was to compare the magnitude of genetic parameters (coefficients of heritability and genetic correlation as estimated by the Restricted Maximum Likelihood (REML method and Bayesian Inference, and to estimate the genetic and phenotypic trends to the traits height at the withers (HW24 and weight at 24 months of age (W24. The average heritability estimated by Bayesian Inference to HW24 was 0.47, and it was lower than that obtained by REML bi-trait analysis (0.52; however, the value estimated to W24 (0.39 was higher than that obtained by REML bi-trait analysis (0.38. The genetic correlation estimate between W24 and HW24 traits obtained by the REML method (0.66 was lower than that obtained by the Bayesian Inference Method (0.72. From the regression of the average additive genetic merit in the year of birth of the animals, it was found that the averaged genetic values of the animals for HW24 showed a genetic trend near zero (-0.0008cm/year, and the averaged genetic values for W24 showed a negative trend of -0.38 kg/year. The values to the direct heritability estimated for HW24 and W24 suggest that the direct selection for these traits can provide genetic gain in this population. The genetic correlation between the traits, high and positive, suggests that the selection for HW24 should promote increase in W24 at this age. The genetic trends obtained for the traits studied, near zero, indicate that the selection performed produced a slight reduction of the weight of the animals at 24 months of age; however, it did not promote increase in height at the wither at this same age, in this population.

The potential use of genetics to increase the effectiveness of treatment programs for criminal offenders.

Science.gov (United States)

Beaver, Kevin M; Jackson, Dylan B; Flesher, Dillon

2014-01-01

During the past couple of decades, the amount of research examining the genetic underpinnings to antisocial behaviors, including crime, has exploded. Findings from this body of work have generated a great deal of information linking genetics to criminal involvement. As a partial result, there is now a considerable amount of interest in how these findings should be integrated into the criminal justice system. In the current paper, we outline the potential ways that genetic information can be used to increase the effectiveness of treatment programs designed to reduce recidivism among offenders. We conclude by drawing attention to how genetic information can be used by rehabilitation programs to increase program effectiveness, reduce offender recidivism rates, and enhance public safety.

Genetic Barrier to Direct Acting Antivirals in HCV Sequences Deposited in the European Databank.

Directory of Open Access Journals (Sweden)

Dimas Alexandre Kliemann

Full Text Available Development of resistance results from mutations in the viral genome, and the presence of selective drug pressure leads to the emergence of a resistant virus population. The aim of this study was to analyze the impact of genetic variability on the genetic barrier to drug resistance to DAAs.The genetic barrier was quantified based on the number and type of nucleotide mutations required to impart resistance, considering full-length HCV NS3, NS5A and NS5B regions segregated by genotype into subtypes 1a, 1b, 2a, 2b and 3a. This study analyzeds 789 NS3 sequences, 708 sequences and 536 NS5B sequences deposited in the European Hepatitis C Virus Database, in the following resistance-associated positions: NS3: F43/I/L/S/V, Q80K/R, R155K/G, A156G/S/T and D168A/C/E/G/H/N/T/V/Y; NS5A: L/M28A/T/V, Q30E/H/R, L31F/I/M/V, H58D or P58S and Y93C/F/H/N/S; NS5B: S282P/R/T, C316H/N/Y, S368T, Y448C/H, S556G/R, D559R.Variants that require only one transversion in NS3 were found in 4 positions and include F43S, R80K, R155K/G and A156T. The genetic barrier to resistance shows subtypic differences at position 155 of the NS3 gene where a single transition is necessary in subtype 1a. In the NS5A gene, 5 positions where only one nucleotide change can confer resistance were found, such as L31M which requires one transversion in all subtypes, except in 0.28% of 1b sequences; and R30H, generated by a single transition, which was found in 10.25% of the sequences of genotype 1b. Other subtypic differences were observed at position 58, where resistance is less likely in genotype 1a because a transversion is required to create the variant 58S. For the NS5B inhibitors, the genetic barrier at positions conferring resistance was nearly identical in subtypes 1a and 1b, and single transitions or transversions were necessary in 5 positions to generate a drug-resistant variant of HCV. The positions C316Y and S556D required only one transition in all genotypes, Y448H and S556 G

Study on the immunological and genetic effects induced by internal exposure to radionuclides

International Nuclear Information System (INIS)

Zhu Shoupeng; Wang Liuyi; Luan Meiling

1995-02-01

The immune system is the important part of defense mechanism in organism. Studies have demonstrated the high radiosensitivity of the immunocytes to internal radionuclide exposure. It is evident that serious functional disturbances and morphological changes of immune organs are induced by internal contamination of radionuclides, including suppression of division and proliferation of immunocytes, induction of irreversible sequelae, leading to injurious effects on both central and peripheral immune organs. In order to study the consequences of the injuries of genetic material caused by internal contamination of radionuclides, researches have developed from the harmful effects on parental generation to those on the offspring. The present paper reports the study on the genetic injuries of somatic and germ cells induced by internal radionuclide exposure. Emphasis is placed on the molecular basis of radio-genetic effect and the relations of the molecular basis of DNA injury to gene mutation and chromosome aberration

Quantification of the genetic risk of environmental mutagens

International Nuclear Information System (INIS)

Ehling, U.H.

1988-01-01

Screening methods are used for hazard identification. Assays for heritable mutations in mammals are used for the confirmation of short-term test results and for the quantification of the genetic risk. There are two main approaches in making genetic risk estimates. One of these, termed the direct method, expresses risk in terms of the expected frequency of genetic changes induced per unit. The other, referred to as the doubling dose method or the indirect method, expresses risk in relation to the observed incidence of genetic disorders now present in man. The indirect method uses experimental data only for the calculation of the doubling dose. The quality of the risk estimation depends on the assumption of persistence of the induced mutations and the ability to determine the current incidence of genetic diseases. The difficulties of improving the estimates of current incidences of genetic diseases or the persistence of the genes in the population led them to the development of an alternative method, the direct estimation of the genetic risk. The direct estimation uses experimental data for the induced frequency for dominant mutations in mice. For the verification of these quantifications one can use the data of Hiroshima and Nagasaki. According to the estimation with the direct method, one would expect less than 1 radiation-induced dominant cataract in 19,000 children with one or both parents exposed. The expected overall frequency of dominant mutations in the first generation would be 20-25, based on radiation-induced dominant cataract mutations. It is estimated that 10 times more recessive than dominant mutations are induced. The same approaches can be used to determine the impact of chemical mutagens

Safety of genetically engineered foods: approaches to assessing unintended health effects

National Research Council Canada - National Science Library

Committee on Identifying and Assessing Unintended Effects of Genetically Engineered Foods on Human Health, National Research Council

2004-01-01

Assists policymakers in evaluating the appropriate scientific methods for detecting unintended changes in food and assessing the potential for adverse health effects from genetically modified products...

Effects of Behavioral Genetic Evidence on Perceptions of Criminal Responsibility and Appropriate Punishment

Science.gov (United States)

Appelbaum, Paul S.; Scurich, Nicholas; Raad, Raymond

2015-01-01

Demonstrations of a link between genetic variants and criminal behavior have stimulated increasing use of genetic evidence to reduce perceptions of defendants’ responsibility for criminal behavior and to mitigate punishment. However, because only limited data exist regarding the impact of such evidence on decision makers and the public at large, we recruited a representative sample of the U.S. adult population (n=960) for a web-based survey. Participants were presented with descriptions of three legal cases and were asked to: determine the length of incarceration for a convicted murderer; adjudicate an insanity defense; and decide whether a defendant should receive the death penalty. A fully crossed, between-participants, factorial design was used, varying the type of evidence (none, genetic, neuroimaging, both), heinousness of the crime, and past criminal record, with sentence or verdict as the primary outcome. Also assessed were participants’ apprehension of the defendant, belief in free will, political ideology, and genetic knowledge. Across all three cases, genetic evidence had no significant effects on outcomes. Neuroimaging data showed an inconsistent effect in one of the two cases in which it was introduced. In contrast, heinousness of the offense and past criminal record were strongly related to participants’ decisions. Moreover, participants’ beliefs about the controllability of criminal behavior and political orientations were significantly associated with their choices. Our findings suggest that neither hopes that genetic evidence will modify judgments of culpability and punishment nor fears about the impact of genetic evidence on decision makers are likely to come to fruition. PMID:26240516

Effects of Behavioral Genetic Evidence on Perceptions of Criminal Responsibility and Appropriate Punishment.

Science.gov (United States)

Appelbaum, Paul S; Scurich, Nicholas; Raad, Raymond

2015-05-01

Demonstrations of a link between genetic variants and criminal behavior have stimulated increasing use of genetic evidence to reduce perceptions of defendants' responsibility for criminal behavior and to mitigate punishment. However, because only limited data exist regarding the impact of such evidence on decision makers and the public at large, we recruited a representative sample of the U.S. adult population (n=960) for a web-based survey. Participants were presented with descriptions of three legal cases and were asked to: determine the length of incarceration for a convicted murderer; adjudicate an insanity defense; and decide whether a defendant should receive the death penalty. A fully crossed, between-participants, factorial design was used, varying the type of evidence (none, genetic, neuroimaging, both), heinousness of the crime, and past criminal record, with sentence or verdict as the primary outcome. Also assessed were participants' apprehension of the defendant, belief in free will, political ideology, and genetic knowledge. Across all three cases, genetic evidence had no significant effects on outcomes. Neuroimaging data showed an inconsistent effect in one of the two cases in which it was introduced. In contrast, heinousness of the offense and past criminal record were strongly related to participants' decisions. Moreover, participants' beliefs about the controllability of criminal behavior and political orientations were significantly associated with their choices. Our findings suggest that neither hopes that genetic evidence will modify judgments of culpability and punishment nor fears about the impact of genetic evidence on decision makers are likely to come to fruition.

Genetic diversity and population structure of 20 North European cattle breeds

DEFF Research Database (Denmark)

kantanen, J; Olsaker, Ingrid; Holm, Lars-Erik

2000-01-01

Blood samples were collected from 743 animals from 15 indigenous, 2 old imported, and 3 commercial North European cattle breeds. The samples were analyzed for 11 erythrocyte antigen systems, 8 proteins, and 10 microsatellites, and used to assess inter- and intrabreed genetic variation and genetic......, allelic diversity has been reduced in several breeds, which was explained by limited effective population sizes over the course of man-directed breed development and demographic bottlenecks of indigenous breeds. A tree showing genetic relationships between breeds was constructed from a matrix of random...... drift-based genetic distance estimates. The breeds were classified on the basis of the tree topology into four major breed groups, defined as Northern indigenous breeds, Southern breeds, Ayrshire and Friesian breeds, and Jersey. Grouping of Nordic breeds was supported by documented breed history...

Genetic correlations between mature cow weight and productive and reproductive traits in Nellore cattle.

Science.gov (United States)

Regatieri, I C; Boligon, A A; Baldi, F; Albuquerque, L G

2012-08-29

We investigated genetic associations between mature cow weight (MW) and weaning weight (WW), yearling weight (YW), weight gain from birth to weaning (GBW), weight gain from weaning to yearling (GWY), weaning hip height (WHH), yearling hip height (YHH), scrotal circumference (SC), and age at first calving (AFC). Data from 127,104 Nellore animals born between 1993 and 2006, belonging to Agropecuária Jacarezinho Ltda., were analyzed. (Co)variance components were obtained by the restricted maximum likelihood method, applying an animal model in a multi-traits analysis. The model included direct genetic and residual effects as random effects, the fixed effects of contemporary group, and the linear and quadratic effects of animal age at recording (except for AFC, GBW, and GWY) and age of cow at calving as covariates (except for MW). The numbers of days from birth to weaning and from weaning to yearling were included as covariates for GBW and GWY, respectively. Estimated direct heritabilities were 0.43 ± 0.02 (MW), 0.33 ± 0.01 (WW), 0.36 ± 0.01 (YW), 0.28 ± 0.02 (GBW), 0.31 ± 0.01 (GWY), 0.44 ± 0.02 (WHH), 0.48 ± 0.02 (YHH), 0.44 ± 0.01 (SC), and 0.16 ± 0.03 (AFC). Genetic correlations between MW and productive traits were positive and of medium to high magnitude (ranging from 0.47 ± 0.03 to 0.71 ± 0.01). A positive and low genetic correlation was observed between MW and SC (0.24 ± 0.04). A negative genetic correlation (-0.19 ± 0.03) was estimated between MW and AFC. Selection to increase weight or weight gains at any age, as well as hip height, will change MW in the same direction. Selection for higher SC may lead to a long-term increase in MW. The AFC can be included in selection indices to improve the reproductive performance of beef cattle without significant changes in MW.

Integrating environmental and genetic effects to predict responses of tree populations to climate.

Science.gov (United States)

Wang, Tongli; O'Neill, Gregory A; Aitken, Sally N

2010-01-01

Climate is a major environmental factor affecting the phenotype of trees and is also a critical agent of natural selection that has molded among-population genetic variation. Population response functions describe the environmental effect of planting site climates on the performance of a single population, whereas transfer functions describe among-population genetic variation molded by natural selection for climate. Although these approaches are widely used to predict the responses of trees to climate change, both have limitations. We present a novel approach that integrates both genetic and environmental effects into a single "universal response function" (URF) to better predict the influence of climate on phenotypes. Using a large lodgepole pine (Pinus contorta Dougl. ex Loud.) field transplant experiment composed of 140 populations planted on 62 sites to demonstrate the methodology, we show that the URF makes full use of data from provenance trials to: (1) improve predictions of climate change impacts on phenotypes; (2) reduce the size and cost of future provenance trials without compromising predictive power; (3) more fully exploit existing, less comprehensive provenance tests; (4) quantify and compare environmental and genetic effects of climate on population performance; and (5) predict the performance of any population growing in any climate. Finally, we discuss how the last attribute allows the URF to be used as a mechanistic model to predict population and species ranges for the future and to guide assisted migration of seed for reforestation, restoration, or afforestation and genetic conservation in a changing climate.

Genetic risks of ionizing radiation

International Nuclear Information System (INIS)

Sankaranarayanan, K.

1990-01-01

Quantitative genetic risk estimation is made using two methods: the direct method, and the doubling dose (DD) method. The doubling dose currently used is 1 Gy for low LET, low dose, low dose rate irradiation, and is based on mouse data. Tables present the 1988 UNSCEAR estimates of genetic risk using both methods. (L.L.) (Tab.)

Reduced genetic variance among high fitness individuals: inferring stabilizing selection on male sexual displays in Drosophila serrata.

Science.gov (United States)

Sztepanacz, Jacqueline L; Rundle, Howard D

2012-10-01

Directional selection is prevalent in nature, yet phenotypes tend to remain relatively constant, suggesting a limit to trait evolution. However, the genetic basis of this limit is unresolved. Given widespread pleiotropy, opposing selection on a trait may arise from the effects of the underlying alleles on other traits under selection, generating net stabilizing selection on trait genetic variance. These pleiotropic costs of trait exaggeration may arise through any number of other traits, making them hard to detect in phenotypic analyses. Stabilizing selection can be inferred, however, if genetic variance is greater among low- compared to high-fitness individuals. We extend a recently suggested approach to provide a direct test of a difference in genetic variance for a suite of cuticular hydrocarbons (CHCs) in Drosophila serrata. Despite strong directional sexual selection on these traits, genetic variance differed between high- and low-fitness individuals and was greater among the low-fitness males for seven of eight CHCs, significantly more than expected by chance. Univariate tests of a difference in genetic variance were nonsignificant but likely have low power. Our results suggest that further CHC exaggeration in D. serrata in response to sexual selection is limited by pleiotropic costs mediated through other traits. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

Non-genetic effects on growth characteristics of Brahman cattle

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Nicacia Hernández-Hernández

2015-01-01

Full Text Available Objective. To determine how some non-genetic factors influence weights at birth (BW, weaning (WW and yearling (YW of Brahman calves. Materials and methods. Data corresponding to 58257, 57045 and 40364 for BW, WW and YW, respectively, were analyzed. The models included the effects of year and season of birth and sex, and were considered simple interactions. Results. All effects were significant (p0.05 on WW. The average general BW, WW and YW were 32±3.2, 188±37.7 and 291±56.8 kg, respectively. Variables evaluated that take into account the year of birth show a trend to increase weight each year. In relation to the birth season on BW and YW, it was observed that calves born during the rainy season were heavier than those born during the dry season. Similarly, male calves were heavier than females at birth, weaning and one year of age. The effects of the analyzed interactions were significant (p0.05 for BW and WW. Conclusions. The studied non-genetic factors were important and should be taken into account in management strategies when striving to increase the efficiency of the productive system.

A Genetic Algorithms Based Approach for Identification of Escherichia coli Fed-batch Fermentation

Directory of Open Access Journals (Sweden)

Olympia Roeva

2004-10-01

Full Text Available This paper presents the use of genetic algorithms for identification of Escherichia coli fed-batch fermentation process. Genetic algorithms are a directed random search technique, based on the mechanics of natural selection and natural genetics, which can find the global optimal solution in complex multidimensional search space. The dynamic behavior of considered process has known nonlinear structure, described with a system of deterministic nonlinear differential equations according to the mass balance. The parameters of the model are estimated using genetic algorithms. Simulation examples for demonstration of the effectiveness and robustness of the proposed identification scheme are included. As a result, the model accurately predicts the process of cultivation of E. coli.

Plant genetic variation mediates an indirect ecological effect between belowground earthworms and aboveground aphids.

Science.gov (United States)

Singh, Akanksha; Braun, Julia; Decker, Emilia; Hans, Sarah; Wagner, Agnes; Weisser, Wolfgang W; Zytynska, Sharon E

2014-10-21

Interactions between aboveground and belowground terrestrial communities are often mediated by plants, with soil organisms interacting via the roots and aboveground organisms via the shoots and leaves. Many studies now show that plant genetics can drive changes in the structure of both above and belowground communities; however, the role of plant genetic variation in mediating aboveground-belowground interactions is still unclear. We used an earthworm-plant-aphid model system with two aphid species (Aphis fabae and Acyrthosiphon pisum) to test the effect of host-plant (Vicia faba) genetic variation on the indirect interaction between the belowground earthworms (Eisenia veneta) on the aboveground aphid populations. Our data shows that host-plant variety mediated an indirect ecological effect of earthworms on generalist black bean aphids (A. fabae), with earthworms increasing aphid growth rate in three plant varieties but decreasing it in another variety. We found no effect of earthworms on the second aphid species, the pea aphid (A. pisum), and no effect of competition between the aphid species. Plant biomass was increased when earthworms were present, and decreased when A. pisum was feeding on the plant (mediated by plant variety). Although A. fabae aphids were influenced by the plants and worms, they did not, in turn, alter plant biomass. Previous work has shown inconsistent effects of earthworms on aphids, but we suggest these differences could be explained by plant genetic variation and variation among aphid species. This study demonstrates that the outcome of belowground-aboveground interactions can be mediated by genetic variation in the host-plant, but depends on the identity of the species involved.

Genetic effects on information processing speed are moderated by age--converging results from three samples.

Science.gov (United States)

Ising, M; Mather, K A; Zimmermann, P; Brückl, T; Höhne, N; Heck, A; Schenk, L A; Rujescu, D; Armstrong, N J; Sachdev, P S; Reppermund, S

2014-06-01

Information processing is a cognitive trait forming the basis of complex abilities like executive function. The Trail Making Test (TMT) is a well-established test of information processing with moderate to high heritability. Age of the individual also plays an important role. A number of genetic association studies with the TMT have been performed, which, however, did not consider age as a moderating factor. We report the results of genome-wide association studies (GWASs) on age-independent and age-dependent TMT performance in two population-representative community samples (Munich Antidepressant Response Signature, MARS: N1 = 540; Ludwig Maximilians University, LMU: N2 = 350). Age-dependent genome-wide findings were then evaluated in a third sample of healthy elderly subjects (Sydney Memory and Ageing Study, Sydney MAS: N3 = 448). While a meta-analysis on the GWAS findings did not reveal age-independent TMT associations withstanding correction for multiple testing, we found a genome-wide significant age-moderated effect between variants in the DSG1 gene region and TMT-A performance predominantly reflecting visual processing speed (rs2199301, P(meta-analysis) = 1.3 × 10(-7)). The direction of the interaction suggests for the minor allele a beneficial effect in younger adults turning into a detrimental effect in older adults. The detrimental effect of the missense single nucleotide polymorphism rs1426310 within the same DSG1 gene region could be replicated in Sydney MAS participants aged 70-79, but not in those aged 80 years and older, presumably a result of survivor bias. Our findings demonstrate opposing effects of DSG1 variants on information processing speed depending on age, which might be related to the complex processes that DSG1 is involved with, including cell adhesion and apoptosis. © 2014 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

Genetics of Age-Related Macular Degeneration: Current Concepts, Future Directions

Science.gov (United States)

DeAngelis, Margaret M.; Silveira, Alexandra C.; Carr, Elizabeth A.; Kim, Ivana K.

2014-01-01

Age-related macular degeneration (AMD) is a progressive degenerative disease which leads to blindness, affecting the quality of life of millions of Americans. More than 1.75 million individuals in the United States are affected by the advanced form of AMD. The etiological pathway of AMD is not yet fully understood, but there is a clear genetic influence on disease risk. To date, the 1q32 (CFH) and 10q26 (PLEKHA1/ARMS2/HTRA1) loci are the most strongly associated with disease; however, the variation in these genomic regions alone is unable to predict disease development with high accuracy. Therefore, current genetic studies are aimed at identifying new genes associated with AMD and their modifiers, with the goal of discovering diagnostic or prognostic biomarkers. Moreover, these studies provide the foundation for further investigation into the pathophysiology of AMD by utilizing a systems-biology-based approach to elucidate underlying mechanistic pathways. PMID:21609220

Genetic questions for environmental studies. Differential parenting and psychopathology in adolescence.

Science.gov (United States)

Reiss, D; Hetherington, E M; Plomin, R; Howe, G W; Simmens, S J; Henderson, S H; O'Connor, T J; Bussell, D A; Anderson, E R; Law, T

1995-11-01

Recent genetic evidence suggests that the most important environmental influences on normal and pathologic development are those that are not shared by siblings in the same family. We sought to determine the relationship between differences in parenting styles and depressive symptoms and antisocial behavior in adolescence, and to compare the influence of these nonshared experiences with genetic influences. We studied 708 families with at least two same-sexed adolescent siblings who were monozygotic twins (93 families), dizygotic twins (99 families), ordinary siblings (95 families), full siblings in step families (181 families), half siblings in step families (110 families), and genetically unrelated siblings in step families (130 families). Data on parenting style were collected by questionnaire and by video recording of interaction between parents and children. Almost 60% of variance in adolescent antisocial behavior and 37% of variance in depressive symptoms could be accounted for by conflictual and negative parental behavior directed specifically at the adolescent. In contrast, when a parent directed harsh, aggressive, explosive, and inconsistent parenting toward the sibling, we found less psychopathologic outcome in the adolescent. Parenting behavior directed specifically at each child in the family is a major correlate of symptoms in adolescents. Furthermore, harsh parental behavior directed at a sibling may have protective effects for adolescents, a phenomenon we call the "siblin barricade."

Prediction of crack growth direction by Strain Energy Sih's Theory on specimens SEN under tension-compression biaxial loading employing Genetic Algorithms

Energy Technology Data Exchange (ETDEWEB)

Rodriguez-MartInez R; Lugo-Gonzalez E; Urriolagoitia-Calderon G; Urriolagoitia-Sosa G; Hernandez-Gomez L H; Romero-Angeles B; Torres-San Miguel Ch, E-mail: rrodriguezm@ipn.mx, E-mail: urrio332@hotmail.com, E-mail: guiurri@hotmail.com, E-mail: luishector56@hotmail.com, E-mail: romerobeatriz98@hotmail.com, E-mail: napor@hotmail.com [INSTITUTO POLITECNICO NACIONAL Seccion de Estudios de Posgrado e Investigacion (SEPI), Escuela Superior de Ingenieria Mecanica y Electrica (ESIME), Edificio 5. 2do Piso, Unidad Profesional Adolfo Lopez Mateos ' Zacatenco' Col. Lindavista, C.P. 07738, Mexico, D.F. (Mexico)

2011-07-19

Crack growth direction has been studied in many ways. Particularly Sih's strain energy theory predicts that a fracture under a three-dimensional state of stress spreads in direction of the minimum strain energy density. In this work a study for angle of fracture growth was made, considering a biaxial stress state at the crack tip on SEN specimens. The stress state applied on a tension-compression SEN specimen is biaxial one on crack tip, as it can observed in figure 1. A solution method proposed to obtain a mathematical model considering genetic algorithms, which have demonstrated great capacity for the solution of many engineering problems. From the model given by Sih one can deduce the density of strain energy stored for unit of volume at the crack tip as dW = [1/2E({sigma}{sup 2}{sub x} + {sigma}{sup 2}{sub y}) - {nu}/E({sigma}{sub x}{sigma}{sub y})]dV (1). From equation (1) a mathematical deduction to solve in terms of {theta} of this case was developed employing Genetic Algorithms, where {theta} is a crack propagation direction in plane x-y. Steel and aluminium mechanical properties to modelled specimens were employed, because they are two of materials but used in engineering design. Obtained results show stable zones of fracture propagation but only in a range of applied loading.

Attitudes towards Social Networking and Sharing Behaviors among Consumers of Direct-to-Consumer Personal Genomics.

Science.gov (United States)

Lee, Sandra Soo-Jin; Vernez, Simone L; Ormond, K E; Granovetter, Mark

2013-10-14

Little is known about how consumers of direct-to-consumer personal genetic services share personal genetic risk information. In an age of ubiquitous online networking and rapid development of social networking tools, understanding how consumers share personal genetic risk assessments is critical in the development of appropriate and effective policies. This exploratory study investigates how consumers share personal genetic information and attitudes towards social networking behaviors. Adult participants aged 23 to 72 years old who purchased direct-to-consumer genetic testing from a personal genomics company were administered a web-based survey regarding their sharing activities and social networking behaviors related to their personal genetic test results. 80 participants completed the survey; of those, 45% shared results on Facebook and 50.9% reported meeting or reconnecting with more than 10 other individuals through the sharing of their personal genetic information. For help interpreting test results, 70.4% turned to Internet websites and online sources, compared to 22.7% who consulted their healthcare providers. Amongst participants, 51.8% reported that they believe the privacy of their personal genetic information would be breached in the future. Consumers actively utilize online social networking tools to help them share and interpret their personal genetic information. These findings suggest a need for careful consideration of policy recommendations in light of the current ambiguity of regulation and oversight of consumer initiated sharing activities.

Directional selection effects on patterns of phenotypic (co)variation in wild populations.

Science.gov (United States)

Assis, A P A; Patton, J L; Hubbe, A; Marroig, G

2016-11-30

Phenotypic (co)variation is a prerequisite for evolutionary change, and understanding how (co)variation evolves is of crucial importance to the biological sciences. Theoretical models predict that under directional selection, phenotypic (co)variation should evolve in step with the underlying adaptive landscape, increasing the degree of correlation among co-selected traits as well as the amount of genetic variance in the direction of selection. Whether either of these outcomes occurs in natural populations is an open question and thus an important gap in evolutionary theory. Here, we documented changes in the phenotypic (co)variation structure in two separate natural populations in each of two chipmunk species (Tamias alpinus and T. speciosus) undergoing directional selection. In populations where selection was strongest (those of T. alpinus), we observed changes, at least for one population, in phenotypic (co)variation that matched theoretical expectations, namely an increase of both phenotypic integration and (co)variance in the direction of selection and a re-alignment of the major axis of variation with the selection gradient. © 2016 The Author(s).

Safe genetically engineered plants

International Nuclear Information System (INIS)

Rosellini, D; Veronesi, F

2007-01-01

The application of genetic engineering to plants has provided genetically modified plants (GMPs, or transgenic plants) that are cultivated worldwide on increasing areas. The most widespread GMPs are herbicide-resistant soybean and canola and insect-resistant corn and cotton. New GMPs that produce vaccines, pharmaceutical or industrial proteins, and fortified food are approaching the market. The techniques employed to introduce foreign genes into plants allow a quite good degree of predictability of the results, and their genome is minimally modified. However, some aspects of GMPs have raised concern: (a) control of the insertion site of the introduced DNA sequences into the plant genome and of its mutagenic effect; (b) presence of selectable marker genes conferring resistance to an antibiotic or an herbicide, linked to the useful gene; (c) insertion of undesired bacterial plasmid sequences; and (d) gene flow from transgenic plants to non-transgenic crops or wild plants. In response to public concerns, genetic engineering techniques are continuously being improved. Techniques to direct foreign gene integration into chosen genomic sites, to avoid the use of selectable genes or to remove them from the cultivated plants, to reduce the transfer of undesired bacterial sequences, and make use of alternative, safer selectable genes, are all fields of active research. In our laboratory, some of these new techniques are applied to alfalfa, an important forage plant. These emerging methods for plant genetic engineering are briefly reviewed in this work

Safe genetically engineered plants

Energy Technology Data Exchange (ETDEWEB)

Rosellini, D; Veronesi, F [Dipartimento di Biologia Vegetale e Biotecnologie Agroambientali e Zootecniche, Universita degli Studi di Perugia, Borgo XX giugno 74, 06121 Perugia (Italy)

2007-10-03

The application of genetic engineering to plants has provided genetically modified plants (GMPs, or transgenic plants) that are cultivated worldwide on increasing areas. The most widespread GMPs are herbicide-resistant soybean and canola and insect-resistant corn and cotton. New GMPs that produce vaccines, pharmaceutical or industrial proteins, and fortified food are approaching the market. The techniques employed to introduce foreign genes into plants allow a quite good degree of predictability of the results, and their genome is minimally modified. However, some aspects of GMPs have raised concern: (a) control of the insertion site of the introduced DNA sequences into the plant genome and of its mutagenic effect; (b) presence of selectable marker genes conferring resistance to an antibiotic or an herbicide, linked to the useful gene; (c) insertion of undesired bacterial plasmid sequences; and (d) gene flow from transgenic plants to non-transgenic crops or wild plants. In response to public concerns, genetic engineering techniques are continuously being improved. Techniques to direct foreign gene integration into chosen genomic sites, to avoid the use of selectable genes or to remove them from the cultivated plants, to reduce the transfer of undesired bacterial sequences, and make use of alternative, safer selectable genes, are all fields of active research. In our laboratory, some of these new techniques are applied to alfalfa, an important forage plant. These emerging methods for plant genetic engineering are briefly reviewed in this work.

Direct Index Method of Beam Damage Location Detection Based on Difference Theory of Strain Modal Shapes and the Genetic Algorithms Application

Directory of Open Access Journals (Sweden)

Bao Zhenming

2012-01-01

Full Text Available Structural damage identification is to determine the structure health status and analyze the test results. The three key problems to be solved are as follows: the existence of damage in structure, to detect the damage location, and to confirm the damage degree or damage form. Damage generally changes the structure physical properties (i.e., stiffness, mass, and damping corresponding with the modal characteristics of the structure (i.e., natural frequencies, modal shapes, and modal damping. The research results show that strain mode can be more sensitive and effective for local damage. The direct index method of damage location detection is based on difference theory, without the modal parameter of the original structure. FEM numerical simulation to partial crack with different degree is done. The criteria of damage location detection can be obtained by strain mode difference curve through cubic spline interpolation. Also the genetic algorithm box in Matlab is used. It has been possible to identify the damage to a reasonable level of accuracy.

Molecular profiling techniques as tools to detect potential unintended effects in genetically engineered maize

CSIR Research Space (South Africa)

Barros, E

2010-05-01

Full Text Available Molecular Profiling Techniques as Tools to Detect Potential Unintended Effects in Genetically Engineered Maize Eugenia Barros Introduction In the early stages of production and commercialization of foods derived from genetically engineered (GE) plants... systems. In a recent paper published in Plant Biotechnology Journal,4 we compared two transgenic white maize lines with the non-transgenic counterpart to investigate two possible sources of variation: genetic engineering and environmental variation...

Genetic algorithm based reactive power dispatch for voltage stability improvement

Energy Technology Data Exchange (ETDEWEB)

Devaraj, D. [Department of Electrical and Electronics, Kalasalingam University, Krishnankoil 626 190 (India); Roselyn, J. Preetha [Department of Electrical and Electronics, SRM University, Kattankulathur 603 203, Chennai (India)

2010-12-15

Voltage stability assessment and control form the core function in a modern energy control centre. This paper presents an improved Genetic algorithm (GA) approach for voltage stability enhancement. The proposed technique is based on the minimization of the maximum of L-indices of load buses. Generator voltages, switchable VAR sources and transformer tap changers are used as optimization variables of this problem. The proposed approach permits the optimization variables to be represented in their natural form in the genetic population. For effective genetic processing, the crossover and mutation operators which can directly deal with the floating point numbers and integers are used. The proposed algorithm has been tested on IEEE 30-bus and IEEE 57-bus test systems and successful results have been obtained. (author)

Impact of Genetic Counseling and Connexin-26 and Connexin-30 Testing on Deaf Identity and Comprehension of Genetic Test Results in a Sample of Deaf Adults: A Prospective, Longitudinal Study

Science.gov (United States)

Palmer, Christina G. S.; Boudreault, Patrick; Baldwin, Erin E.; Sinsheimer, Janet S.

2014-01-01

Using a prospective, longitudinal study design, this paper addresses the impact of genetic counseling and testing for deafness on deaf adults and the Deaf community. This study specifically evaluated the effect of genetic counseling and Connexin-26 and Connexin-30 genetic test results on participants' deaf identity and understanding of their genetic test results. Connexin-26 and Connexin-30 genetic testing was offered to participants in the context of linguistically and culturally appropriate genetic counseling. Questionnaire data collected from 209 deaf adults at four time points (baseline, immediately following pre-test genetic counseling, 1-month following genetic test result disclosure, and 6-months after result disclosure) were analyzed. Four deaf identity orientations (hearing, marginal, immersion, bicultural) were evaluated using subscales of the Deaf Identity Development Scale-Revised. We found evidence that participants understood their specific genetic test results following genetic counseling, but found no evidence of change in deaf identity based on genetic counseling or their genetic test results. This study demonstrated that culturally and linguistically appropriate genetic counseling can improve deaf clients' understanding of genetic test results, and the formation of deaf identity was not directly related to genetic counseling or Connexin-26 and Connexin-30 genetic test results. PMID:25375116

Genetic load and transgenic mitigating genes in transgenic Brassica rapa (field mustard × Brassica napus (oilseed rape hybrid populations

Directory of Open Access Journals (Sweden)

Warwick Suzanne I

2009-10-01

Full Text Available Abstract Background One theoretical explanation for the relatively poor performance of Brassica rapa (weed × Brassica napus (crop transgenic hybrids suggests that hybridization imparts a negative genetic load. Consequently, in hybrids genetic load could overshadow any benefits of fitness enhancing transgenes and become the limiting factor in transgenic hybrid persistence. Two types of genetic load were analyzed in this study: random/linkage-derived genetic load, and directly incorporated genetic load using a transgenic mitigation (TM strategy. In order to measure the effects of random genetic load, hybrid productivity (seed yield and biomass was correlated with crop- and weed-specific AFLP genomic markers. This portion of the study was designed to answer whether or not weed × transgenic crop hybrids possessing more crop genes were less competitive than hybrids containing fewer crop genes. The effects of directly incorporated genetic load (TM were analyzed through transgene persistence data. TM strategies are proposed to decrease transgene persistence if gene flow and subsequent transgene introgression to a wild host were to occur. Results In the absence of interspecific competition, transgenic weed × crop hybrids benefited from having more crop-specific alleles. There was a positive correlation between performance and number of B. napus crop-specific AFLP markers [seed yield vs. marker number (r = 0.54, P = 0.0003 and vegetative dry biomass vs. marker number (r = 0.44, P = 0.005]. However under interspecific competition with wheat or more weed-like conditions (i.e. representing a situation where hybrid plants emerge as volunteer weeds in subsequent cropping systems, there was a positive correlation between the number of B. rapa weed-specific AFLP markers and seed yield (r = 0.70, P = 0.0001, although no such correlation was detected for vegetative biomass. When genetic load was directly incorporated into the hybrid genome, by inserting a

Genetics of body shape and armour variation in threespine sticklebacks.

Science.gov (United States)

Leinonen, T; Cano, J M; Merilä, J

2011-01-01

Patterns of genetic variation and covariation can influence the rate and direction of phenotypic evolution. We explored the possibility that the parallel morphological evolution seen in threespine stickleback (Gasterosteus aculeatus) populations colonizing freshwater environments is facilitated by patterns of genetic variation and covariation in the ancestral (marine) population. We estimated the genetic (G) and phenotypic (P) covariance matrices and directions of maximum additive genetic (g(max) ) and phenotypic (p(max) ) covariances of body shape and armour traits. Our results suggest a role for the ancestral G in explaining parallel morphological evolution in freshwater populations. We also found evidence of genetic constraints owing to the lack of variance in the ancestral G. Furthermore, strong genetic covariances and correlations among traits revealed that selective factors responsible for threespine stickleback body shape and armour divergence may be difficult to disentangle. The directions of g(max) and p(max) were correlated, but the correlations were not high enough to imply that phenotypic patterns of trait variation and covariation within populations are very informative of underlying genetic patterns. © 2010 The Authors. Journal of Evolutionary Biology © 2010 European Society For Evolutionary Biology.

The genetic consequences of selection in natural populations.

Science.gov (United States)

Thurman, Timothy J; Barrett, Rowan D H

2016-04-01

The selection coefficient, s, quantifies the strength of selection acting on a genetic variant. Despite this parameter's central importance to population genetic models, until recently we have known relatively little about the value of s in natural populations. With the development of molecular genetic techniques in the late 20th century and the sequencing technologies that followed, biologists are now able to identify genetic variants and directly relate them to organismal fitness. We reviewed the literature for published estimates of natural selection acting at the genetic level and found over 3000 estimates of selection coefficients from 79 studies. Selection coefficients were roughly exponentially distributed, suggesting that the impact of selection at the genetic level is generally weak but can occasionally be quite strong. We used both nonparametric statistics and formal random-effects meta-analysis to determine how selection varies across biological and methodological categories. Selection was stronger when measured over shorter timescales, with the mean magnitude of s greatest for studies that measured selection within a single generation. Our analyses found conflicting trends when considering how selection varies with the genetic scale (e.g., SNPs or haplotypes) at which it is measured, suggesting a need for further research. Besides these quantitative conclusions, we highlight key issues in the calculation, interpretation, and reporting of selection coefficients and provide recommendations for future research. © 2016 John Wiley & Sons Ltd.

Direct-to-consumer testing: more risks than opportunities.

Science.gov (United States)

Lippi, G; Favaloro, E J; Plebani, M

2011-12-01

As a result of incessant genetic discoveries and remarkable technological advancements, the availability and the consequent consumer's request for genetic testing are growing exponentially, leading to the development of a 'parallel' market, i.e. the direct-to-consumer (DTC) testing, also known as 'direct access testing' (DAT). Analogous to the traditional laboratory diagnostics, drawbacks of DTC testing might arise from any step characterising the total testing process, and include poor control of both appropriateness and preanalytical requirements, potential operation outside national or international regulation for in vitro diagnostic testing, little evidence of quality as well as the risk of transfer of genetic materials from the companies to other entities. Another important issue is the test panels offered to consumers, which are often based on preliminary, speculative or unsupported scientific information. Finally, the potential of this type of testing to generate anxiety or false reassurance should also be carefully considered. Although DTC testing carries some theoretical advantages (e.g. greater consumer autonomy and empowerment), solid clinical studies and costs vs. benefit analyses are needed to definitely establish whether DTC testing might be effective for decreasing the burden of diseases, delay their onset or modify their progression and therefore the clinical outcome. © 2011 Blackwell Publishing Ltd.

Genetic diversity, phylogeographic structure and effect of selection ...

Indian Academy of Sciences (India)

Abdulhakeem B. Ajibike

2017-12-11

Dec 11, 2017 ... RESEARCH ARTICLE. Genetic diversity, phylogeographic ... chickens as genetic resources towards ensuring food security. Keywords. genetic diversity ... PCR product as template DNA, 3.2 pmol of primer and. 8 μL of Big Dye ...

Environmental and geographic variables are effective surrogates for genetic variation in conservation planning.

Science.gov (United States)

Hanson, Jeffrey O; Rhodes, Jonathan R; Riginos, Cynthia; Fuller, Richard A

2017-11-28

Protected areas buffer species from anthropogenic threats and provide places for the processes that generate and maintain biodiversity to continue. However, genetic variation, the raw material for evolution, is difficult to capture in conservation planning, not least because genetic data require considerable resources to obtain and analyze. Here we show that freely available environmental and geographic distance variables can be highly effective surrogates in conservation planning for representing adaptive and neutral intraspecific genetic variation. We obtained occurrence and genetic data from the IntraBioDiv project for 27 plant species collected over the European Alps using a gridded sampling scheme. For each species, we identified loci that were potentially under selection using outlier loci methods, and mapped their main gradients of adaptive and neutral genetic variation across the grid cells. We then used the cells as planning units to prioritize protected area acquisitions. First, we verified that the spatial patterns of environmental and geographic variation were correlated, respectively, with adaptive and neutral genetic variation. Second, we showed that these surrogates can predict the proportion of genetic variation secured in randomly generated solutions. Finally, we discovered that solutions based only on surrogate information secured substantial amounts of adaptive and neutral genetic variation. Our work paves the way for widespread integration of surrogates for genetic variation into conservation planning.

Analytical strategies for discovery and replication of genetic effects in pharmacogenomic studies

Directory of Open Access Journals (Sweden)

Kohler JR

2014-08-01

Full Text Available Jared R Kohler, Tobias Guennel, Scott L MarshallBioStat Solutions, Inc., Frederick, MD, USAAbstract: In the past decade, the pharmaceutical industry and biomedical research sector have devoted considerable resources to pharmacogenomics (PGx with the hope that understanding genetic variation in patients would deliver on the promise of personalized medicine. With the advent of new technologies and the improved collection of DNA samples, the roadblock to advancements in PGx discovery is no longer the lack of high-density genetic information captured on patient populations, but rather the development, adaptation, and tailoring of analytical strategies to effectively harness this wealth of information. The current analytical paradigm in PGx considers the single-nucleotide polymorphism (SNP as the genomic feature of interest and performs single SNP association tests to discover PGx effects – ie, genetic effects impacting drug response. While it can be straightforward to process single SNP results and to consider how this information may be extended for use in downstream patient stratification, the rate of replication for single SNP associations has been low and the desired success of producing clinically and commercially viable biomarkers has not been realized. This may be due to the fact that single SNP association testing is suboptimal given the complexities of PGx discovery in the clinical trial setting, including: 1 relatively small sample sizes; 2 diverse clinical cohorts within and across trials due to genetic ancestry (potentially impacting the ability to replicate findings; and 3 the potential polygenic nature of a drug response. Subsequently, a shift in the current paradigm is proposed: to consider the gene as the genomic feature of interest in PGx discovery. The proof-of-concept study presented in this manuscript demonstrates that genomic region-based association testing has the potential to improve the power of detecting single SNP or

Neurocognitive functioning in parents of schizophrenia patients: Attentional and executive performance vary with genetic loading.

Science.gov (United States)

Schulze-Rauschenbach, Svenja; Lennertz, Leonhard; Ruhrmann, Stephan; Petrovsky, Nadine; Ettinger, Ulrich; Pukrop, Ralf; Dreher, Jan; Klosterkötter, Joachim; Maier, Wolfgang; Wagner, Michael

2015-12-30

Neuropsychological deficits are candidate endophenotypes of schizophrenia which can assist to explain the neurocognitive impact of genetic risk variants. The identification of endophenotypes is often based on the familiality of these phenotypes. Several studies demonstrate neuropsychological deficits in unaffected biological relatives of schizophrenia patients without differentiating between genetic and non-genetic factors underlying these deficits. We assessed N=129 unaffected biological parents of schizophrenia patients, N=28 schizophrenia patients (paranoid subtype), and N=143 controls without a family history of schizophrenia with an extensive neuropsychological test battery. Direct comparison of N=22 parents with an ancestral history of schizophrenia (more likely carriers, MLC) and N=17 of their spouses without such a history (less likely carriers, LLC) allowed the separation of genetic and non-genetic aspects in cognition. Overall, parents showed significant deficits in neuropsychological tasks from all cognitive domains with medium effect sizes. Direct comparisons of MLC- and LLC-parents showed that attentional and executive tasks were most strongly affected by genetic loading. To conclude, unaffected parents of schizophrenia patients showed modest yet significant impairments in attention, memory, and executive functioning. In particular, attentional and executive impairments varied most strongly with genetic loading for schizophrenia, prioritising these dysfunctions for genotype-endophenotype analyses. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Evaluation of type 2 diabetes genetic risk variants in Chinese adults

DEFF Research Database (Denmark)

Gan, Wei; Walters, Robin G; Holmes, Michael V

2016-01-01

: Association signals were directionally consistent between CKB and the original discovery GWAS: of 56 variants passing quality control, 48 showed the same direction of effect (binomial test, p = 2.3 × 10(-8)). We observed a consistent overall trend towards lower risk variant effect sizes in CKB than in case......-control samples of GWAS meta-analyses (mean 19-22% decrease in log odds, p ≤ 0.0048), likely to reflect correction of both 'winner's curse' and spectrum bias effects. The association with risk of diabetes of a genetic risk score, based on lead variants at 25 loci considered to act through beta cell function...

Genetic information, non-discrimination, and privacy protections in genetic counseling practice.

Science.gov (United States)

Prince, Anya E R; Roche, Myra I

2014-12-01

The passage of the Genetic Information Non Discrimination Act (GINA) was hailed as a pivotal achievement that was expected to calm the fears of both patients and research participants about the potential misuse of genetic information. However, 6 years later, patient and provider awareness of legal protections at both the federal and state level remains discouragingly low, thereby, limiting their potential effectiveness. The increasing demand for genetic testing will expand the number of individuals and families who could benefit from obtaining accurate information about the privacy and anti-discriminatory protections that GINA and other laws extend. In this paper we describe legal protections that are applicable to individuals seeking genetic counseling, review the literature on patient and provider fears of genetic discrimination and examine their awareness and understandings of existing laws, and summarize how genetic counselors currently discuss genetic discrimination. We then present three genetic counseling cases to illustrate issues of genetic discrimination and provide relevant information on applicable legal protections. Genetic counselors have an unprecedented opportunity, as well as the professional responsibility, to disseminate accurate knowledge about existing legal protections to their patients. They can strengthen their effectiveness in this role by achieving a greater knowledge of current protections including being able to identify specific steps that can help protect genetic information.

Improving Decision Making about Genetic Testing in the Clinic: An Overview of Effective Knowledge Translation Interventions.

Science.gov (United States)

Légaré, France; Robitaille, Hubert; Gane, Claire; Hébert, Jessica; Labrecque, Michel; Rousseau, François

2016-01-01

Knowledge translation (KT) interventions are attempts to change behavior in keeping with scientific evidence. While genetic tests are increasingly available to healthcare consumers in the clinic, evidence about their benefits is unclear and decisions about genetic testing are thus difficult for all parties. We sought to identify KT interventions that involved decisions about genetic testing in the clinical context and to assess their effectiveness for improving decision making in terms of behavior change, increased knowledge and wellbeing. We searched for trials assessing KT interventions in the context of genetic testing up to March 2014 in all systematic reviews (n = 153) published by two Cochrane review groups: Effective Practice and Organisation of Care (EPOC) and Consumers and Communication. We retrieved 2473 unique trials of which we retained only 28 (1%). Two EPOC reviews yielded two trials of KT interventions: audit and feedback (n = 1) and educational outreach (n = 1). Both targeted health professionals and the KT intervention they assessed was found to be effective. Four Consumers and Communication reviews yielded 26 trials: decision aids (n = 15), communication of DNA-based disease risk estimates (n = 7), personalized risk communication (n = 3) and mobile phone messaging (n = 1). Among these, 25 trials targeted only health consumers or patients and the KT interventions were found to be effective in four trials, partly effective in seven, and ineffective in four. Lastly, only one trial targeted both physicians and patients and was found to be effective. More research on the effectiveness of KT interventions regarding genetic testing in the clinical context may contribute to patients making informed value-based decisions and drawing the maximum benefit from clinical applications of genetic and genomic innovations.

Efeito da inclusão da covariância genética aditiva direta-materna no modelo de análise sobre a magnitude das estimativas de parâmetros e valores genéticos preditos para ganho de peso na raça Brangus Effect of genetic direct-maternal covariance inclusion in the model of analizys on the estimate of parameters and predicted genetic values for weight gain in Brangus breed

Directory of Open Access Journals (Sweden)

Luiz Felipe Waihrich Guterres

2007-06-01

this research was to study the effect of accouting for the covariance between the additive genetic direct and the maternal effects (covd-m on the estimates of genetic parameters and on predictions of genetic values (VG, for average daily gain from birth to weaning (GMDND and from weaning to 550 days of age (GMDDS. They were analyzed 28,949 records for GMDND and 11,884 for GMDDS of a Brangus breed population (58 Angus x 3/8 Nellore, collected from 1986 to 2002. The (covariance components were obtained by REML. In the animal model for GMDND, the additive genetic direct and maternal and residual effects were considered as random, and the effects of contemporaneous group at weaning (Gc²05, the interaction of the Nellore-Angus breed genetic percentage of the bull and cow (FGNA and the covariables, age of the cow at birth (IV and age at weaning (ID as fixed effects. For GMDDS, the model was the same, except that Gc²05 was substituted by contemporaneous group at 550 days of age (CG550 and ID by age at 550 days. In both models, permanent environmental effect of the cow was considered as a random effect. The heritabilities estimated for direct genetic effects ranged from 0.14 ± 0.03 to 0.21 ± 0.03 and for maternal effects from 0.00 ± 0.01 to 0.15 ± 0.02, the estimates had smaller values when covd-m was included in the model for GMDND. The correlations between genetic direct and maternal effects were negative -0.25 ± 0.12 (GMDND and -0.77 ± 0.19 (GMDDS. The likelihood ratio test showed that there is no significant diference, at 5% significance level, between the adopted models for boths characteristics. The rank correlation between the VG predicted by the two models, were 0.89 for GMDND and 0.98 for GMDND, suggesting that a slight change in the rank of the animals can happen, for GMDND.

Assessment of genetic risk for human exposure to radiation

International Nuclear Information System (INIS)

Sevcenko, V.A.; Rubanovic, A.V.

2002-01-01

Full text: The methodology of assessing the genetic risk of radiation exposure is based on the concept of 'hitting the target' in development of which N.V. Timofeeff-Ressovsky has played and important role. To predict genetic risk posed by irradiation, the U N Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) has worked out direct and indirect methods of assessment, extrapolation, integral and palpitation criteria of risk analysis that together permit calculating the risk from human exposure on the basis of data obtained for mice. Based on the reports of UNSCEAR for the period from 1958 to 2001 the paper presents a retrospective analysis of the use of direct methods and the doubling dose method for quantitative determination of the genetic risk of human exposure expressed as different hereditary diseases. As early as 1962 UNSCEAR estimated the doubling dose (a dose causing as many mutations as those occurring spontaneously during one generation) at 1 Gy for cases of exposure to ionizing radiations with low LET at a low dose rate and this value was confirmed in the next UNSCEAR reports up to now. For cases of acute irradiation the doubling dose was estimated at 0,3-0,4 Gy for the period under review. The paper considers the evolution of the concepts of human natural hereditary variability which is a basis for assessing the risk of exposure by the doubling dose method. The level of human natural genetic variability per 1 000 000 newborns is estimated at 738 000 hereditary diseases including mendelian, chromosomal and multifactorial ones. The greatest difficulties in assessing the doubling dose value were found to occur in the case of multifactorial diseases the pheno typical expression of which depends on mutational events in polygenic systems and on numerous environmental factors. The introduction in calculations of the potential recoverability correction factor (RPCF) made it possible to assess the genetic risk taking into account this class of

Education reduces the effects of genetic susceptibilities to poor physical health.

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Johnson, Wendy; Kyvik, Kirsten Ohm; Mortensen, Erik L; Skytthe, Axel; Batty, G David; Deary, Ian J

2010-04-01

Greater education is associated with better physical health. This has been of great concern to public health officials. Most demonstrations show that education influences mean levels of health. Little is known about the influence of education on variance in health status, or about how this influence may impact the underlying genetic and environmental sources of health problems. This study explored these influences. In a 2002 postal questionnaire, 21 522 members of same-sex pairs in the Danish Twin Registry born between 1931 and 1982 reported physical health in the 12-item Short Form Health Survey. We used quantitative genetic models to examine how genetic and environmental variance in physical health differed with level of education, adjusting for birth-year effects. and Conclusions As expected, greater education was associated with better physical health. Greater education was also associated with smaller variance in health status. In both sexes, 2 standard deviations (SDs) above mean educational level, variance in physical health was only about half that among those 2 SDs below. This was because fewer highly educated people reported poor health. There was less total variance in health primarily because there was less genetic variance. Education apparently reduced expression of genetic susceptibilities to poor health. The patterns of genetic and environmental correlations suggested that this might take place because more educated people manage their environments to protect their health. If so, fostering the personal charactieristics associated with educational attainment could be important in reducing the education-health gradient.

How well do you know your mutation? Complex effects of genetic background on expressivity, complementation, and ordering of allelic effects.

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Christopher H Chandler

2017-11-01

Full Text Available For a given gene, different mutations influence organismal phenotypes to varying degrees. However, the expressivity of these variants not only depends on the DNA lesion associated with the mutation, but also on factors including the genetic background and rearing environment. The degree to which these factors influence related alleles, genes, or pathways similarly, and whether similar developmental mechanisms underlie variation in the expressivity of a single allele across conditions and among alleles is poorly understood. Besides their fundamental biological significance, these questions have important implications for the interpretation of functional genetic analyses, for example, if these factors alter the ordering of allelic series or patterns of complementation. We examined the impact of genetic background and rearing environment for a series of mutations spanning the range of phenotypic effects for both the scalloped and vestigial genes, which influence wing development in Drosophila melanogaster. Genetic background and rearing environment influenced the phenotypic outcome of mutations, including intra-genic interactions, particularly for mutations of moderate expressivity. We examined whether cellular correlates (such as cell proliferation during development of these phenotypic effects matched the observed phenotypic outcome. While cell proliferation decreased with mutations of increasingly severe effects, surprisingly it did not co-vary strongly with the degree of background dependence. We discuss these findings and propose a phenomenological model to aid in understanding the biology of genes, and how this influences our interpretation of allelic effects in genetic analysis.

Effects of flow gradients on directional radiation of human voice.

Science.gov (United States)

Pulkki, Ville; Lähivaara, Timo; Huhtakallio, Ilkka

2018-02-01

In voice communication in windy outdoor conditions, complex velocity gradients appear in the flow field around the source, the receiver, and also in the atmosphere. It is commonly known that voice emanates stronger towards the downstream direction when compared with the upstream direction. In literature, the atmospheric effects are used to explain the stronger emanation in the downstream direction. This work shows that the wind also has an effect to the directivity of voice also favouring the downstream direction. The effect is addressed by measurements and simulations. Laboratory measurements are conducted by using a large pendulum with a loudspeaker mimicking the human head, whereas practical measurements utilizing the human voice are realized by placing a subject through the roof window of a moving car. The measurements and a simulation indicate congruent results in the speech frequency range: When the source faces the downstream direction, stronger radiation coinciding with the wind direction is observed, and when it faces the upstream direction, radiation is not affected notably. The simulated flow gradients show a wake region in the downstream direction, and the simulated acoustic field in the flow show that the region causes a wave-guide effect focusing the sound in the direction.

Isozymes and the genetic resources of forest trees

Science.gov (United States)

A. H. D. Brown; G. F. Moran

1981-01-01

Genetic data are an essential prerequisite for analysing the genetic structure of tree populations. The isozyme technique is the best currently available method for obtaining such data. Despite several shortcomings, isozyme data directly evaluate the genetic resources of forest trees, and can thus be used to monitor and manipulate these resources. For example,...

The limits of child effects: evidence for genetically mediated child effects on corporal punishment but not on physical maltreatment.

Science.gov (United States)

Jaffee, Sara R; Caspi, Avshalom; Moffitt, Terrie E; Polo-Tomas, Monica; Price, Thomas S; Taylor, Alan

2004-11-01

Research on child effects has demonstrated that children's difficult and coercive behavior provokes harsh discipline from adults. Using a genetically sensitive design, the authors tested the limits of child effects on adult behavior that ranged from the normative (corporal punishment) to the nonnormative (physical maltreatment). The sample was a 1994-1995 nationally representative birth cohort of 1,116 twins and their families who participated in the Environmental Risk Longitudinal Study. Results showed that environmental factors accounted for most of the variation in corporal punishment and physical maltreatment. However, corporal punishment was genetically mediated in part, and the genetic factors that influenced corporal punishment were largely the same as those that influenced children's antisocial behavior, suggesting a child effect. The authors conclude that risk factors for maltreatment are less likely to reside within the child and more likely to reside in characteristics that differ between families. (c) 2004 APA, all rights reserved

Cost-effectiveness of MODY genetic testing: translating genomic advances into practical health applications.

Science.gov (United States)

Naylor, Rochelle N; John, Priya M; Winn, Aaron N; Carmody, David; Greeley, Siri Atma W; Philipson, Louis H; Bell, Graeme I; Huang, Elbert S

2014-01-01

OBJECTIVE To evaluate the cost-effectiveness of a genetic testing policy for HNF1A-, HNF4A-, and GCK-MODY in a hypothetical cohort of type 2 diabetic patients 25-40 years old with a MODY prevalence of 2%. RESEARCH DESIGN AND METHODS We used a simulation model of type 2 diabetes complications based on UK Prospective Diabetes Study data, modified to account for the natural history of disease by genetic subtype to compare a policy of genetic testing at diabetes diagnosis versus a policy of no testing. Under the screening policy, successful sulfonylurea treatment of HNF1A-MODY and HNF4A-MODY was modeled to produce a glycosylated hemoglobin reduction of -1.5% compared with usual care. GCK-MODY received no therapy. Main outcome measures were costs and quality-adjusted life years (QALYs) based on lifetime risk of complications and treatments, expressed as the incremental cost-effectiveness ratio (ICER) (USD/QALY). RESULTS The testing policy yielded an average gain of 0.012 QALYs and resulted in an ICER of 205,000 USD. Sensitivity analysis showed that if the MODY prevalence was 6%, the ICER would be ~50,000 USD. If MODY prevalence was >30%, the testing policy was cost saving. Reducing genetic testing costs to 700 USD also resulted in an ICER of ~50,000 USD. CONCLUSIONS Our simulated model suggests that a policy of testing for MODY in selected populations is cost-effective for the U.S. based on contemporary ICER thresholds. Higher prevalence of MODY in the tested population or decreased testing costs would enhance cost-effectiveness. Our results make a compelling argument for routine coverage of genetic testing in patients with high clinical suspicion of MODY.

Genetic variation for parental effects on the propensity to gregarise in Locusta migratoria

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Foucart Antoine

2008-02-01

Full Text Available Abstract Background Environmental parental effects can have important ecological and evolutionary consequences, yet little is known about genetic variation among populations in the plastic responses of offspring phenotypes to parental environmental conditions. This type of variation may lead to rapid phenotypic divergence among populations and facilitate speciation. With respect to density-dependent phenotypic plasticity, locust species (Orthoptera: family Acrididae, exhibit spectacular developmental and behavioural shifts in response to population density, called phase change. Given the significance of phase change in locust outbreaks and control, its triggering processes have been widely investigated. Whereas crowding within the lifetime of both offspring and parents has emerged as a primary causal factor of phase change, less is known about intraspecific genetic variation in the expression of phase change, and in particular in response to the parental environment. We conducted a laboratory experiment that explicitly controlled for the environmental effects of parental rearing density. This design enabled us to compare the parental effects on offspring expression of phase-related traits between two naturally-occurring, genetically distinct populations of Locusta migratoria that differed in their historical patterns of high population density outbreak events. Results We found that locusts from a historically outbreaking population of L. migratoria expressed parentally-inherited density-dependent phase changes to a greater degree than those from a historically non-outbreaking population. Conclusion Because locusts from both populations were raised in a common environment during our experiment, a genetically-based process must be responsible for the observed variation in the propensity to express phase change. This result emphasizes the importance of genetic factors in the expression of phase traits and calls for further investigations on density

Genetic Variability, Correlation Studies and Path Coefficient Analysis in Gladiolus Alatus Cultivars

International Nuclear Information System (INIS)

Ramzan, A.; Nawab, N. N.; Tariq, M. S.; Ikram, S.; Ahad, A.

2016-01-01

A study was undertaken to find out the estimates of genetic variability, genetic parameters and character association among different flower traits between three gladiolus cultivars viz: Sancerre, Fado and Advanced Red. The experiment was repeated three times by using RCBD (Randomized complete block design) at Department of Horticulture, PMAS-UAAR, Rawalpindi. The highest genotypic coefficient variation (GCV) and phenotypic coefficient variation (PCV) magnitude was observed for spike length (16.00) and number of florets per spike (14.84) followed by number of leaves (10.00). Among the traits studied the highest heritability estimates was recorded in spike length (99.5 percent) followed by number of florets/spike (99.6 percent) and lowest in plant height (98.2 percent). The genetic advance as percent of mean was ranged from 2.8 percent to 24.75 percent. Genetic advance was highest for floret breadth (24.75 percent) and lowest for plant height (2.8 percent). High heritability combined with high genetic advance was noticed for number of florets per spike, spike length and floret breadth indicating additive gene action which suggested that improvement of these traits would be effective for further selection of superior genotypes. Plant height and number of florets per spike showed highly positive and significant association with spike length, number of leaves, leaf area, floret length and floret breadth while, spike length registered positive and significant correlation with number of leaves and floret breadth. The path coefficient analysis based on spike length, as responsible variable exposed that all of the traits exerted direct positive effect except leaf area and floret length. Spike length imparted maximum positive direct effect on the number of florets per spike. Hence, spike length and number of florets per spike may be considered for further improvement. However, Floret length and floret breadth may also be considered as a criterion for selection. (author)

Genetic analysis for grain quality traits in pakistani wheat varieties

International Nuclear Information System (INIS)

Minhas, N.M.; Ajmal, S.U.; Iqbal, Z.; Munir, M.

2014-01-01

A set of eight parental diallel involving seven commercial wheat cultivars and one breeding line was made to investigate the nature of gene action determining inheritance pattern of grain quality characters. Highly significant differences were observed among the genotypes for 1000 grain weight, protein content, wet gluten and lysine content. Adequacy tests were employed to estimate the fitness of data sets to additive dominance model. Both the tests i.e. analysis of uniformity of Wr, Vr and joint regression analysis validated the data of these traits for genetic analysis. Gene actions for grain quality traits were ascertained following Hayman's analysis of variance. Results of the genetic analysis revealed that both additive and dominance genetic components were involved in the manifestation of characters under study. However, additive gene effects were more pronounced in the genetic control of these traits. Non significance of b1, b2 and b3 values revealed the absence of directional dominance, symmetrical distribution of genes among the parental lines and absence of specific genes action respectively in all the traits. Maternal effects were also noted in 1000 grain weight, protein content and wet gluten percentage. It is concluded that additive effects are crucial in the expression of grain quality characters of wheat in germplasm under study and single plant selection may be recommended in segregating generations for effective improvement in these characters. (author)

Tabapuã breed in Northeastern Brazil: genetic progress and population structure

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Dirlane Novais Caires

2012-08-01

Full Text Available The objective of this study was to evaluate the history of the Tabapuã breed in Northeastern Brazil by determining its population structure and genetic progress. Pedigree information from animals born in the period between 1965 and 2006 and weight-adjusted data at 205 (W205, 365 (W365 and 550 (W550 days of age for bovines born between 1975 and 2006 were used. The (covariance components and genetic value were estimated using the application MTDFREML. Also, the software ENDOG was used for pedigree analysis and parameter estimation based on the probabilities of gene origin, inbreeding and average generation interval. The heritability coefficients for direct genetic effects were 0.21±0.03, 0.26±0.04 and 0.36±0.05 for W205, W365 and W550, respectively. During the first 20 years studied, the observed effective size was small. The generation intervals by gametic pathway were: 7.7±3.4 (sire-son, 7.8±3.7 (sire-daughter, 6.9±3.3 (dam-son, 6.8 ± 3.1 (dam-daughter, and mean interval of 7.3±3.4 years. The studied population showed moderate heritability coefficients, whereas the genetic gains based on the studied traits may be higher than those estimated by genetic tendencies. Reduced generation interval, increased effective size and continuous mating control of relatives are important strategies for the genetic progress of the Tabapuã breed in the region.

Direct maximum parsimony phylogeny reconstruction from genotype data

OpenAIRE

Sridhar, Srinath; Lam, Fumei; Blelloch, Guy E; Ravi, R; Schwartz, Russell

2007-01-01

Abstract Background Maximum parsimony phylogenetic tree reconstruction from genetic variation data is a fundamental problem in computational genetics with many practical applications in population genetics, whole genome analysis, and the search for genetic predictors of disease. Efficient methods are available for reconstruction of maximum parsimony trees from haplotype data, but such data are difficult to determine directly for autosomal DNA. Data more commonly is available in the form of ge...

Genetics Home Reference

Science.gov (United States)

... Page Search Home Health Conditions Genes Chromosomes & mtDNA Resources Help Me Understand Genetics Share: Email Facebook Twitter Genetics Home Reference provides consumer-friendly information about the effects of genetic variation on human health. Health Conditions More than 1,200 health ...

Commentary: a sociologist's view on community genetics

OpenAIRE

Raz, Aviad E.

2010-01-01

This commentary illustrates and discusses potential research directions for sociologists and anthropologists interested in the field of community genetics and its emerging networks of individuals genetically at risk. Community genetics—the application of medical genetics in community settings for the benefit of individuals—also involves social issues of lay-professional misunderstandings (and more recently also the different perspectives of various expert communities), stigmatization, discrim...

Shared genetic aetiology of puberty timing between sexes and with health-related outcomes.

Science.gov (United States)

Day, Felix R; Bulik-Sullivan, Brendan; Hinds, David A; Finucane, Hilary K; Murabito, Joanne M; Tung, Joyce Y; Ong, Ken K; Perry, John R B

2015-11-09

Understanding of the genetic regulation of puberty timing has come largely from studies of rare disorders and population-based studies in women. Here, we report the largest genomic analysis for puberty timing in 55,871 men, based on recalled age at voice breaking. Analysis across all genomic variants reveals strong genetic correlation (0.74, P=2.7 × 10(-70)) between male and female puberty timing. However, some loci show sex-divergent effects, including directionally opposite effects between sexes at the SIM1/MCHR2 locus (Pheterogeneity=1.6 × 10(-12)). We find five novel loci for puberty timing (Ppuberty, LEPR and KAL1. Finally, we identify genetic correlations that indicate shared aetiologies in both sexes between puberty timing and body mass index, fasting insulin levels, lipid levels, type 2 diabetes and cardiovascular disease.

Ecological Risk Assessment of Genetically Modified Higher Plants (GMHP)

DEFF Research Database (Denmark)

Kjær, C.; Damgaard, C.; Kjellsson, G.

Preface This publication is a first version of a manual identifying the data needs for ecological risk assessment of genetically modified higher plants (GMHP). It is the intention of the authors to stimulate further discussion of what data are needed in order to conduct a proper ecological risk...... of the project Biotechnology: elements in environmental risk assessment of genetically modified plants. December 1999 Christian Kjær Introduction In ecological risk assessment of transgenic plants, information on a wide range of subjects is needed for an effective and reliable assessment procedure...... in the amendment to the directive. This report suggests a structured way to identify the type of data needed to perform a sound ecological risk assessment for genetically modified higher plants (GMHP). The identified data types are intended to support the evaluation of the following risks: risk of invasion...

Personalized Genetic Testing and Norovirus Susceptibility

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Natalie Prystajecky

2014-01-01

Full Text Available BACKGROUND: The availability of direct-to-consumer personalized genetic testing has enabled the public to access and interpret their own genetic information. Various genetic traits can be determined including resistance to norovirus through a nonsense mutation (G428A in the FUT2 gene. Although this trait is believed to confer resistance to the most dominant norovirus genotype (GII.4, the spectrum of resistance to other norovirus strains is unknown. The present report describes a cluster of symptomatic norovirus GI.6 infection in a family identified to have norovirus resistance through personalized genetic testing.

Genetic and somatic effects in animals maintained on tritiated water

International Nuclear Information System (INIS)

Carsten, A.L.; Brooks, A.; Commerford, S.L.; Cronkite, E.P.

1981-01-01

The possible genetic (dominant lethal mutations (DLM) and cytogenetic changes in the regenerating liver) and somatic (hematopoietic stem cell changes, growth and nonspecific life time shortening) effects in mice maintained on tritiated water (HTO) over two generations was investigated. Results to date are summarized

Stress-induced variation in evolution: from behavioural plasticity to genetic assimilation.

Science.gov (United States)

Badyaev, Alexander V

2005-05-07

Extreme environments are closely associated with phenotypic evolution, yet the mechanisms behind this relationship are poorly understood. Several themes and approaches in recent studies significantly further our understanding of the importance that stress-induced variation plays in evolution. First, stressful environments modify (and often reduce) the integration of neuroendocrinological, morphological and behavioural regulatory systems. Second, such reduced integration and subsequent accommodation of stress-induced variation by developmental systems enables organismal 'memory' of a stressful event as well as phenotypic and genetic assimilation of the response to a stressor. Third, in complex functional systems, a stress-induced increase in phenotypic and genetic variance is often directional, channelled by existing ontogenetic pathways. This accounts for similarity among individuals in stress-induced changes and thus significantly facilitates the rate of adaptive evolution. Fourth, accumulation of phenotypically neutral genetic variation might be a common property of locally adapted and complex organismal systems, and extreme environments facilitate the phenotypic expression of this variance. Finally, stress-induced effects and stress-resistance strategies often persist for several generations through maternal, ecological and cultural inheritance. These transgenerational effects, along with both the complexity of developmental systems and stressor recurrence, might facilitate genetic assimilation of stress-induced effects. Accumulation of phenotypically neutral genetic variance by developmental systems and phenotypic accommodation of stress-induced effects, together with the inheritance of stress-induced modifications, ensure the evolutionary persistence of stress-response strategies and provide a link between individual adaptability and evolutionary adaptation.

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.

Improving Decision Making about Genetic Testing in the Clinic: An Overview of Effective Knowledge Translation Interventions.

Directory of Open Access Journals (Sweden)

France Légaré

Full Text Available Knowledge translation (KT interventions are attempts to change behavior in keeping with scientific evidence. While genetic tests are increasingly available to healthcare consumers in the clinic, evidence about their benefits is unclear and decisions about genetic testing are thus difficult for all parties.We sought to identify KT interventions that involved decisions about genetic testing in the clinical context and to assess their effectiveness for improving decision making in terms of behavior change, increased knowledge and wellbeing.We searched for trials assessing KT interventions in the context of genetic testing up to March 2014 in all systematic reviews (n = 153 published by two Cochrane review groups: Effective Practice and Organisation of Care (EPOC and Consumers and Communication.We retrieved 2473 unique trials of which we retained only 28 (1%. Two EPOC reviews yielded two trials of KT interventions: audit and feedback (n = 1 and educational outreach (n = 1. Both targeted health professionals and the KT intervention they assessed was found to be effective. Four Consumers and Communication reviews yielded 26 trials: decision aids (n = 15, communication of DNA-based disease risk estimates (n = 7, personalized risk communication (n = 3 and mobile phone messaging (n = 1. Among these, 25 trials targeted only health consumers or patients and the KT interventions were found to be effective in four trials, partly effective in seven, and ineffective in four. Lastly, only one trial targeted both physicians and patients and was found to be effective.More research on the effectiveness of KT interventions regarding genetic testing in the clinical context may contribute to patients making informed value-based decisions and drawing the maximum benefit from clinical applications of genetic and genomic innovations.

Genetic testing in the epilepsies—Report of the ILAE Genetics Commission

OpenAIRE

Ottman, Ruth; Hirose, Shinichi; Jain, Satish; Lerche, Holger; Lopes-Cendes, Iscia; Noebels, Jeffrey L.; Serratosa, José; Zara, Federico; Scheffer, Ingrid E.

2010-01-01

In this report, the International League Against Epilepsy (ILAE) Genetics Commission discusses essential issues to be considered with regard to clinical genetic testing in the epilepsies. Genetic research on the epilepsies has led to the identification of more than 20 genes with a major effect on susceptibility to idiopathic epilepsies. The most important potential clinical application of these discoveries is genetic testing: the use of genetic information, either to clarify the diagnosis in ...

Determinants of genetic structure in a nonequilibrium metapopulation of the plant Silene latifolia.

Directory of Open Access Journals (Sweden)

Peter D Fields

Full Text Available Population genetic differentiation will be influenced by the demographic history of populations, opportunities for migration among neighboring demes and founder effects associated with repeated extinction and recolonization. In natural populations, these factors are expected to interact with each other and their magnitudes will vary depending on the spatial distribution and age structure of local demes. Although each of these effects has been individually identified as important in structuring genetic variance, their relative magnitude is seldom estimated in nature. We conducted a population genetic analysis in a metapopulation of the angiosperm, Silene latifolia, from which we had more than 20 years of data on the spatial distribution, demographic history, and extinction and colonization of demes. We used hierarchical Bayesian methods to disentangle which features of the populations contributed to among population variation in allele frequencies, including the magnitude and direction of their effects. We show that population age, long-term size and degree of connectivity all combine to affect the distribution of genetic variance; small, recently-founded, isolated populations contributed most to increase FST in the metapopulation. However, the effects of population size and population age are best understood as being modulated through the effects of connectivity to other extant populations, i.e. FST diminishes as populations age, but at a rate that depends how isolated the population is. These spatial and temporal correlates of population structure give insight into how migration, founder effect and within-deme genetic drift have combined to enhance and restrict genetic divergence in a natural metapopulation.

Education reduces the effects of genetic susceptibilities to poor physical health

DEFF Research Database (Denmark)

Johnson, Wendy; Kyvik, Kirsten Ohm; Mortensen, Erik L

2010-01-01

BACKGROUND: Greater education is associated with better physical health. This has been of great concern to public health officials. Most demonstrations show that education influences mean levels of health. Little is known about the influence of education on variance in health status, or about how...... this influence may impact the underlying genetic and environmental sources of health problems. This study explored these influences. METHODS: In a 2002 postal questionnaire, 21 522 members of same-sex pairs in the Danish Twin Registry born between 1931 and 1982 reported physical health in the 12-item Short Form...... Health Survey. We used quantitative genetic models to examine how genetic and environmental variance in physical health differed with level of education, adjusting for birth-year effects. RESULTS: and Conclusions As expected, greater education was associated with better physical health. Greater education...

Advancement of researches on the malignant tumor radio-genetic therapy

International Nuclear Information System (INIS)

Tian Yue; Su Chenghai

2008-01-01

Radiotherapy is one of the routine methods of malignant tumor treatment and used in clinical many years, while gene therapy is one of the new therapy. But the formation of tumor is the complicated process effected by many factors and many genes. The effect of polygene therapy is not ideal. Therefore, radio-genetic therapy is the hot spot of the present study and will become one of the important direction of cancer therapy. (authors)

Implications of new technologies and shifting priorities on the understanding of genetic injury

International Nuclear Information System (INIS)

Grahn, D.

1988-01-01

Some areas of radiation genetics still contain gaps of knowledge, as these studies lost priority when the emphasis in experimental mutagenesis shifted toward the effect of chemical mutagens. This shifted emphasis, however, was accompanied by the development of a better understanding of genetic injury at the molecular level. At the opposite end of the spectrum, more attention was paid to estimates of the direct health costs of the genetic burden in humans and the capacity to make prenatal diagnoses, and to consider reasonable clinical and biochemical intervention. Although, as yet, there are no completely reliable direct methods to estimate the radiation-induced mutation rate in humans, we have come to rely upon data from experimental animals to predict event frequency and extrapolate from these data to predict human health consequences. What will the future offer? Certainly, we should develop a better understanding of molecular genetic damage and, possibly, a better extrapolation model for predicting mutation rate, but many aspects of expected health consequences may remain elusive. We still may have to rely upon (1) an inadequate human population genetic baseline, (2) sometimes arguable perceptions of man-mouse extrapolation models, (3) changing perceptions of gene-environment interactions, and (4) changing levels of short-term selection pressure against detrimental mutations

Genetics of Genome-Wide Recombination Rate Evolution in Mice from an Isolated Island.

Science.gov (United States)

Wang, Richard J; Payseur, Bret A

2017-08-01

Recombination rate is a heritable quantitative trait that evolves despite the fundamentally conserved role that recombination plays in meiosis. Differences in recombination rate can alter the landscape of the genome and the genetic diversity of populations. Yet our understanding of the genetic basis of recombination rate evolution in nature remains limited. We used wild house mice ( Mus musculus domesticus ) from Gough Island (GI), which diverged recently from their mainland counterparts, to characterize the genetics of recombination rate evolution. We quantified genome-wide autosomal recombination rates by immunofluorescence cytology in spermatocytes from 240 F 2 males generated from intercrosses between GI-derived mice and the wild-derived inbred strain WSB/EiJ. We identified four quantitative trait loci (QTL) responsible for inter-F 2 variation in this trait, the strongest of which had effects that opposed the direction of the parental trait differences. Candidate genes and mutations for these QTL were identified by overlapping the detected intervals with whole-genome sequencing data and publicly available transcriptomic profiles from spermatocytes. Combined with existing studies, our findings suggest that genome-wide recombination rate divergence is not directional and its evolution within and between subspecies proceeds from distinct genetic loci. Copyright © 2017 by the Genetics Society of America.

Attitudes towards Social Networking and Sharing Behaviors among Consumers of Direct-to-Consumer Personal Genomics

Directory of Open Access Journals (Sweden)

Mark Granovetter

2013-10-01

Full Text Available Little is known about how consumers of direct-to-consumer personal genetic services share personal genetic risk information. In an age of ubiquitous online networking and rapid development of social networking tools, understanding how consumers share personal genetic risk assessments is critical in the development of appropriate and effective policies. This exploratory study investigates how consumers share personal genetic information and attitudes towards social networking behaviors. Methods: Adult participants aged 23 to 72 years old who purchased direct-to-consumer genetic testing from a personal genomics company were administered a web-based survey regarding their sharing activities and social networking behaviors related to their personal genetic test results. Results: 80 participants completed the survey; of those, 45% shared results on Facebook and 50.9% reported meeting or reconnecting with more than 10 other individuals through the sharing of their personal genetic information. For help interpreting test results, 70.4% turned to Internet websites and online sources, compared to 22.7% who consulted their healthcare providers. Amongst participants, 51.8% reported that they believe the privacy of their personal genetic information would be breached in the future. Conclusion: Consumers actively utilize online social networking tools to help them share and interpret their personal genetic information. These findings suggest a need for careful consideration of policy recommendations in light of the current ambiguity of regulation and oversight of consumer initiated sharing activities.

Reverse genetics with animal viruses. NSV reverse genetics

International Nuclear Information System (INIS)

Mebatsion, T.

2005-01-01

New strategies to genetically manipulate the genomes of several important animal pathogens have been established in recent years. This article focuses on the reverse genetics techniques, which enables genetic manipulation of the genomes of non-segmented negative-sense RNA viruses. Recovery of a negative-sense RNA virus entirely from cDNA was first achieved for rabies virus in 1994. Since then, reverse genetic systems have been established for several pathogens of medical and veterinary importance. Based on the reverse genetics technique, it is now possible to design safe and more effective live attenuated vaccines against important viral agents. In addition, genetically tagged recombinant viruses can be designed to facilitate serological differentiation of vaccinated animals from infected animals. The approach of delivering protective immunogens of different pathogens using a single vector was made possible with the introduction of the reverse genetics system, and these novel broad-spectrum vaccine vectors have potential applications in improving animal health in developing countries. (author)

Illusions of scientific legitimacy: misrepresented science in the direct-to-consumer genetic-testing marketplace.

Science.gov (United States)

Vashlishan Murray, Amy B; Carson, Michael J; Morris, Corey A; Beckwith, Jon

2010-11-01

Marketers of genetic tests often openly or implicitly misrepresent the utility of genetic information. Scientists who are well aware of the current limitations to the utility of such tests are best placed to publicly counter misrepresentations of the science. Copyright © 2010 Elsevier Ltd. All rights reserved.

Genetics Home Reference: sitosterolemia

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... also helps regulate cholesterol levels in a similar fashion; normally about 50 percent of cholesterol in the ... 10 All Bulletins Features What is direct-to-consumer genetic testing? What are genome editing and CRISPR- ...

Direct-to-Consumer Genetic Testing and Personal Genomics Services: A Review of Recent Empirical Studies

Science.gov (United States)

Ostergren, Jenny

2013-01-01

Direct-to-consumer genetic testing (DTC-GT) has sparked much controversy and undergone dramatic changes in its brief history. Debates over appropriate health policies regarding DTC-GT would benefit from empirical research on its benefits, harms, and limitations. We review the recent literature (2011-present) and summarize findings across (1) content analyses of DTC-GT websites, (2) studies of consumer perspectives and experiences, and (3) surveys of relevant health care providers. Findings suggest that neither the health benefits envisioned by DTC-GT proponents (e.g., significant improvements in positive health behaviors) nor the worst fears expressed by its critics (e.g., catastrophic psychological distress and misunderstanding of test results, undue burden on the health care system) have materialized to date. However, research in this area is in its early stages and possesses numerous key limitations. We note needs for future studies to illuminate the impact of DTC-GT and thereby guide practice and policy regarding this rapidly evolving approach to personal genomics. PMID:24058877

Genetic variation in foundation species governs the dynamics of trophic interactions

Science.gov (United States)

Valencia-Cuevas, Leticia; Mussali-Galante, Patricia; Cano-Santana, Zenón; Pujade-Villar, Juli; Equihua-Martínez, Armando

2018-01-01

Abstract Various studies have demonstrated that the foundation species genetic diversity can have direct effects that extend beyond the individual or population level, affecting the dependent communities. Additionally, these effects may be indirectly extended to higher trophic levels throughout the entire community. Quercus castanea is an oak species with characteristics of foundation species beyond presenting a wide geographical distribution and being a dominant element of Mexican temperate forests. In this study, we analyzed the influence of population (He) and individual (HL) genetic diversity of Q. castanea on its canopy endophagous insect community and associated parasitoids. Specifically, we studied the composition, richness (S) and density of leaf-mining moths (Lepidoptera: Tischeridae, Citheraniidae), gall-forming wasps (Hymenoptera: Cynipidae), and canopy parasitoids of Q. castanea. We sampled 120 trees belonging to six populations (20/site) through the previously recognized gradient of genetic diversity. In total, 22 endophagous insect species belonging to three orders (Hymenoptera, Lepidoptera, and Diptera) and 20 parasitoid species belonging to 13 families were identified. In general, we observed that the individual genetic diversity of the host plant (HL) has a significant positive effect on the S and density of the canopy endophagous insect communities. In contrast, He has a significant negative effect on the S of endophagous insects. Additionally, indirect effects of HL were observed, affecting the S and density of parasitoid insects. Our results suggest that genetic variation in foundation species can be one of the most important factors governing the dynamics of tritrophic interactions that involve oaks, herbivores, and parasitoids. PMID:29492034

Genetic Manipulations of PPARs: Effects on Obesity and Metabolic Disease

Directory of Open Access Journals (Sweden)

Yaacov Barak

2007-01-01

Full Text Available The interest in genetic manipulations of PPARs is as old as their discovery as receptors of ligands with beneficial clinical activities. Considering the effects of PPAR ligands on critical aspects of systemic physiology, including obesity, lipid metabolism, insulin resistance, and diabetes, gene knockout (KO in mice is the ideal platform for both hypothesis testing and discovery of new PPAR functions in vivo. With the fervent pursuit of the magic bullet to eradicate the obesity epidemic, special emphasis has been placed on the impacts of PPARs on obesity and its associated diseases. As detailed in this review, understanding how PPARs regulate gene expression and basic metabolic pathways is a necessary intermediate en route to deciphering their effects on obesity. Over a decade and dozens of genetic modifications of PPARs into this effort, valuable lessons have been learned, but we are left with more questions to be answered. These lessons and future prospects are the subject of this review.

Genetic testing for breast and ovarian cancer susceptibility: evaluating direct-to-consumer marketing--Atlanta, Denver, Raleigh-Durham, and Seattle, 2003.

Science.gov (United States)

2004-07-16

Breast and ovarian cancer are the second and fifth leading causes of cancer death, respectively, among women in the United States. One in eight women will have breast cancer during their lifetimes, and one in 70 will have ovarian cancer. Mutations in two genes, BRCA1 and BRCA2 (BRCA1/2), are associated with predisposition for inherited breast and ovarian cancer and are identified in 5%-10% of women with breast or ovarian cancer (BOC). Since 1996, genetic testing for these mutations has been available clinically; however, population-based screening is not recommended because of the complexity of test interpretation and limited data on clinical validity and utility. Despite the test's limited applicability in the general population, the U.S. provider of clinical BRCA1/2 testing (Myriad Genetic Laboratories, Inc., Salt Lake City, Utah) conducted a pilot direct-to-consumer (DTC) marketing campaign in two cities (Atlanta, Georgia, and Denver, Colorado) during September 2002-February 2003. Although DTC advertisements have been used to raise consumer awareness about pharmaceuticals, this was the first time an established genetic test was marketed to the public. To assess the impact of the campaign on consumer behaviors and health-care provider practices, CDC and the respective state health departments for the pilot cities and two comparison cities (Raleigh-Durham, North Carolina, and Seattle, Washington) surveyed consumers and providers. This report summarizes results of those surveys, which indicated that consumer and provider awareness of BRCA1/2 testing increased in the pilot cities and that providers in these cities perceived an impact on their practice (e.g., more questions asked about testing, more BRCA1/2 tests requested, and more tests ordered). However, in all four cities, providers often lacked knowledge to advise patients about inherited BOC and testing. These findings underscore the need for evidence-based recommendations on appropriate use of genetic tests

Effects of teacher-directed versus student-directed instruction and cues versus no cues for improving spelling performance

OpenAIRE

Gettinger, Maribeth

1985-01-01

The purpose of this study was twofold: to examine the effects of imitating children's spelling errors alone and in combination with visual and verbal cues on spelling accuracy and retention among poor spellers and to compare the effectiveness of student-directed versus teacher-directed spelling instruction on children's spelling accuracy and retention. Nine children received four alternating experimental treatments during a 16-week spelling program. Results indicated that student-directed ins...

Genetic Toxicology in the 21st Century: Reflections and Future Directions

Science.gov (United States)

Mahadevan, Brinda; Snyder, Ronald D.; Waters, Michael D.; Benz, R. Daniel; Kemper, Raymond A.; Tice, Raymond R.; Richard, Ann M.

2011-01-01

A symposium at the 40th anniversary of the Environmental Mutagen Society, held from October 24–28, 2009 in St. Louis, MO, surveyed the current status and future directions of genetic toxicology. This article summarizes the presentations and provides a perspective on the future. An abbreviated history is presented, highlighting the current standard battery of genotoxicity assays and persistent challenges. Application of computational toxicology to safety testing within a regulatory setting is discussed as a means for reducing the need for animal testing and human clinical trials, and current approaches and applications of in silico genotoxicity screening approaches across the pharmaceutical industry were surveyed and are reported here. The expanded use of toxicogenomics to illuminate mechanisms and bridge genotoxicity and carcinogenicity, and new public efforts to use high-throughput screening technologies to address lack of toxicity evaluation for the backlog of thousands of industrial chemicals in the environment are detailed. The Tox21 project involves coordinated efforts of four U.S. Government regulatory/research entities to use new and innovative assays to characterize key steps in toxicity pathways, including genotoxic and nongenotoxic mechanisms for carcinogenesis. Progress to date, highlighting preliminary test results from the National Toxicology Program is summarized. Finally, an overview is presented of ToxCast™, a related research program of the U.S. Environmental Protection Agency, using a broad array of high throughput and high content technologies for toxicity profiling of environmental chemicals, and computational toxicology modeling. Progress and challenges, including the pressing need to incorporate metabolic activation capability, are summarized. PMID:21538556

Consumers report lower confidence in their genetics knowledge following direct-to-consumer personal genomic testing.

Science.gov (United States)

Carere, Deanna Alexis; Kraft, Peter; Kaphingst, Kimberly A; Roberts, J Scott; Green, Robert C

2016-01-01

The aim of this study was to measure changes to genetics knowledge and self-efficacy following personal genomic testing (PGT). New customers of 23andMe and Pathway Genomics completed a series of online surveys. We measured genetics knowledge (nine true/false items) and genetics self-efficacy (five Likert-scale items) before receipt of results and 6 months after results and used paired methods to evaluate change over time. Correlates of change (e.g., decision regret) were identified using linear regression. 998 PGT customers (59.9% female; 85.8% White; mean age 46.9 ± 15.5 years) were included in our analyses. Mean genetics knowledge score was 8.15 ± 0.95 (out of 9) at baseline and 8.25 ± 0.92 at 6 months (P = 0.0024). Mean self-efficacy score was 29.06 ± 5.59 (out of 35) at baseline and 27.7 ± 5.46 at 6 months (P reported lower self-efficacy following PGT. Change in self-efficacy was positively associated with health-care provider consultation (P = 0.0042), impact of PGT on perceived control over one's health (P consumers in response to receiving complex genetic information.Genet Med 18 1, 65-72.

Abstracts of the 48. Brazilian congress on genetics. Genetics in social inclusion

International Nuclear Information System (INIS)

2002-01-01

Use of radioisotopes and ionizing radiations in genetics is presented. Several aspects related to men, animals, plants and microorganisms are reported highlighting biological radiation effects, evolution, mutagenesis and genetic engineering. Genetic mapping, polymerase chain reaction, gene mutations, genetic diversity, DNA hybridization, DNA sequencing, plant cultivation and plant grow are studied as well

Methods to estimate the genetic risk

International Nuclear Information System (INIS)

Ehling, U.H.

1989-01-01

The estimation of the radiation-induced genetic risk to human populations is based on the extrapolation of results from animal experiments. Radiation-induced mutations are stochastic events. The probability of the event depends on the dose; the degree of the damage dose not. There are two main approaches in making genetic risk estimates. One of these, termed the direct method, expresses risk in terms of expected frequencies of genetic changes induced per unit dose. The other, referred to as the doubling dose method or the indirect method, expresses risk in relation to the observed incidence of genetic disorders now present in man. The advantage of the indirect method is that not only can Mendelian mutations be quantified, but also other types of genetic disorders. The disadvantages of the method are the uncertainties in determining the current incidence of genetic disorders in human and, in addition, the estimasion of the genetic component of congenital anomalies, anomalies expressed later and constitutional and degenerative diseases. Using the direct method we estimated that 20-50 dominant radiation-induced mutations would be expected in 19 000 offspring born to parents exposed in Hiroshima and Nagasaki, but only a small proportion of these mutants would have been detected with the techniques used for the population study. These methods were used to predict the genetic damage from the fallout of the reactor accident at Chernobyl in the vicinity of Southern Germany. The lack of knowledge for the interaction of chemicals with ionizing radiation and the discrepancy between the high safety standards for radiation protection and the low level of knowledge for the toxicological evaluation of chemical mutagens will be emphasized. (author)

Human genetics and sleep behavior.

Science.gov (United States)

Shi, Guangsen; Wu, David; Ptáček, Louis J; Fu, Ying-Hui

2017-06-01

Why we sleep remains one of the greatest mysteries in science. In the past few years, great advances have been made to better understand this phenomenon. Human genetics has contributed significantly to this movement, as many features of sleep have been found to be heritable. Discoveries about these genetic variations that affect human sleep will aid us in understanding the underlying mechanism of sleep. Here we summarize recent discoveries about the genetic variations affecting the timing of sleep, duration of sleep and EEG patterns. To conclude, we also discuss some of the sleep-related neurological disorders such as Autism Spectrum Disorder (ASD) and Alzheimer's Disease (AD) and the potential challenges and future directions of human genetics in sleep research. Copyright © 2017 Elsevier Ltd. All rights reserved.

Human Kin Investment as a Function of Genetic Relatedness and Lineage