WorldWideScience

Sample records for history molecular genetics

  1. The history of Old World camelids in the light of molecular genetics.

    Science.gov (United States)

    Burger, Pamela Anna

    2016-06-01

    Old World camels have come into the focus as sustainable livestock species, unique in their morphological and physiological characteristics and capable of providing vital products even under extreme environmental conditions. The evolutionary history of dromedary and Bactrian camels traces back to the middle Eocene (around 40 million years ago, mya), when the ancestors of Camelus emerged on the North American continent. While the genetic status of the two domestic species has long been established, the wild two-humped camel has only recently been recognized as a separate species, Camelus ferus, based on molecular genetic data. The demographic history established from genome drafts of Old World camels shows the independent development of the three species over the last 100,000 years with severe bottlenecks occurring during the last glacial period and in the recent past. Ongoing studies involve the immune system, relevant production traits, and the global population structure and domestication of Old World camels. Based on the now available whole genome drafts, specific metabolic pathways have been described shedding new light on the camels' ability to adapt to desert environments. These new data will also be at the origin for genome-wide association studies to link economically relevant phenotypes to genotypes and to conserve the diverse genetic resources in Old World camelids.

  2. Molecular genetics

    International Nuclear Information System (INIS)

    Parkinson, D.R.; Krontiris, T.G.

    1986-01-01

    In this chapter the authors review new findings concerning the molecular genetics of malignant melanoma in the context of other information obtained from clinical, epidemiologic, and cytogenetic studies in this malignancy. These new molecular approaches promise to provide a more complete understanding of the mechanisms involved in the development of melanoma, thereby suggesting new methods for its treatment and prevention

  3. From playfulness and self-centredness via grand expectations to normalisation: a psychoanalytical rereading of the history of molecular genetics.

    Science.gov (United States)

    Zwart, H A E

    2013-11-01

    In this paper, I will reread the history of molecular genetics from a psychoanalytical angle, analysing it as a case history. Building on the developmental theories of Freud and his followers, I will distinguish four stages, namely: (1) oedipal childhood, notably the epoch of model building (1943-1953); (2) the latency period, with a focus on the development of basic skills (1953-1989); (3) adolescence, exemplified by the Human Genome Project, with its fierce conflicts, great expectations and grandiose claims (1989-2003) and (4) adulthood (2003-present) during which revolutionary research areas such as molecular biology and genomics have achieved a certain level of normalcy--have evolved into a normal science. I will indicate how a psychoanalytical assessment conducted in this manner may help us to interpret and address some of the key normative issues that have been raised with regard to molecular genetics over the years, such as 'relevance', 'responsible innovation' and 'promise management'.

  4. Glioblastoma, a brief review of history, molecular genetics, animal models and novel therapeutic strategies.

    Science.gov (United States)

    Agnihotri, Sameer; Burrell, Kelly E; Wolf, Amparo; Jalali, Sharzhad; Hawkins, Cynthia; Rutka, James T; Zadeh, Gelareh

    2013-02-01

    Glioblastoma (GBM) is the most common and lethal primary brain tumor. Over the past few years tremendous genomic and proteomic characterization along with robust animal models of GBM have provided invaluable data that show that "GBM", although histologically indistinguishable from one another, are comprised of molecularly heterogenous diseases. In addition, robust pre-clinical models and a better understanding of the core pathways disrupted in GBM are providing a renewed optimism for novel strategies targeting these devastating tumors. Here, we summarize a brief history of the disease, our current molecular knowledge, lessons from animal models and emerging concepts of angiogenesis, invasion, and metabolism in GBM that may lend themselves to therapeutic targeting.

  5. Molecular genetics

    International Nuclear Information System (INIS)

    Kubitschek, H.E.

    1975-01-01

    Progress is reported on studies on the nature and action of lethal and mutagenic lesions in DNA and the mechanisms by which these are produced in bacteria by ionizing radiation or by decay of radioisotopes incorporated in DNA. Studies of radioisotope decay provide the advantages that the original lesion is localized in the genetic material and the immediate physical and chemical changes that occur at decay are known. Specific types of DNA damage were related to characteristic decay properties of several radioisotopes. Incorporated 125 I, for example, induces a double-stranded break in DNA with almost every decay, but causes remarkably little damage of any other kind to the DNA. (U.S.)

  6. Review of the Lynch syndrome: history, molecular genetics, screening, differential diagnosis, and medicolegal ramifications

    Science.gov (United States)

    Lynch, HT; Lynch, PM; Lanspa, SJ; Snyder, CL; Lynch, JF; Boland, CR

    2010-01-01

    More than one million patients will manifest colorectal cancer (CRC) this year of which, conservatively, approximately 3% (~30,700 cases) will have Lynch syndrome (LS), the most common hereditary CRC predisposing syndrome. Each case belongs to a family with clinical needs that require genetic counseling, DNA testing for mismatch repair genes (most frequently MLH1 or MSH2) and screening for CRC. Colonoscopy is mandated, given CRC’s proximal occurrence (70–80% proximal to the splenic flexure). Due to its early age of onset (average 45 years of age), colonoscopy needs to start by age 25, and because of its accelerated carcinogenesis, it should be repeated every 1 to 2 years through age 40 and then annually thereafter. Should CRC occur, subtotal colectomy may be necessary, given the marked frequency of synchronous and metachronous CRC. Because 40–60% of female patients will manifest endometrial cancer, tailored management is essential. Additional extracolonic cancers include ovary, stomach, small bowel, pancreas, hepatobiliary tract, upper uroepithelial tract, brain (Turcot variant) and sebaceous adenomas/carcinomas (Muir-Torre variant). LS explains only 10–25% of familial CRC. PMID:19659756

  7. Molecular Population Genetics.

    Science.gov (United States)

    Casillas, Sònia; Barbadilla, Antonio

    2017-03-01

    Molecular population genetics aims to explain genetic variation and molecular evolution from population genetics principles. The field was born 50 years ago with the first measures of genetic variation in allozyme loci, continued with the nucleotide sequencing era, and is currently in the era of population genomics. During this period, molecular population genetics has been revolutionized by progress in data acquisition and theoretical developments. The conceptual elegance of the neutral theory of molecular evolution or the footprint carved by natural selection on the patterns of genetic variation are two examples of the vast number of inspiring findings of population genetics research. Since the inception of the field, Drosophila has been the prominent model species: molecular variation in populations was first described in Drosophila and most of the population genetics hypotheses were tested in Drosophila species. In this review, we describe the main concepts, methods, and landmarks of molecular population genetics, using the Drosophila model as a reference. We describe the different genetic data sets made available by advances in molecular technologies, and the theoretical developments fostered by these data. Finally, we review the results and new insights provided by the population genomics approach, and conclude by enumerating challenges and new lines of inquiry posed by increasingly large population scale sequence data. Copyright © 2017 Casillas and Barbadilla.

  8. History of the molecular biology of cytomegaloviruses.

    Science.gov (United States)

    Stinski, Mark F

    2014-01-01

    The history of the molecular biology of cytomegaloviruses from the purification of the virus and the viral DNA to the cloning and expression of the viral genes is reviewed. A key genetic element of cytomegalovirus (the CMV promoter) contributed to our understanding of eukaryotic cell molecular biology and to the development of lifesaving therapeutic proteins. The study of the molecular biology of cytomegaloviruses also contributed to the development of antivirals to control the viral infection.

  9. Molecular ecology of the big brown bat (Eptesicus fuscus): Genetic and natural history variation in a hybrid zone

    Science.gov (United States)

    Neubaum, M.A.; Douglas, M.R.; Douglas, M.E.; O'Shea, T.J.

    2007-01-01

    Several geographically distinct mitochondrial DNA (mtDNA) lineages of the big brown bat (Eptesicus fuscus) have been documented in North America. Individuals from 2 of these lineages, an eastern and a western form, co-occur within maternity colonies in Colorado. The discovery of 2 divergent mtDNA lineages in sympatry prompted a set of questions regarding possible biological differences between haplotypes. We captured big brown bats at maternity roosts in Colorado and recorded data on body size, pelage color, litter size, roosting and overwintering behaviors, and local distributions. Wing biopsies were collected for genetic analysis. The ND2 region of the mtDNA molecule was used to determine lineage of the bats. In addition, nuclear DNA (nDNA) intron 1 of the ??-globin gene was used to determine if mtDNA lineages are hybridizing. Eastern and western mtDNA lineages differed by 10.3% sequence divergence and examination of genetic data suggests recent population expansion for both lineages. Differences in distribution occur along the Colorado Front Range, with an increasing proportion of western haplotypes farther south. Results from nDNA analyses demonstrated hybridization between the 2 lineages. Additionally, no outstanding distinctiveness was found between the mtDNA lineages in natural history characters examined. We speculate that historical climate changes separated this species into isolated eastern and western populations, and that secondary contact with subsequent interbreeding was facilitated by European settlement. ?? 2007 American Society of Mammalogists.

  10. Evolution of man in the light of molecular genetics: a review. Part I. Our evolutionary history and genomics.

    Science.gov (United States)

    Portin, Petter

    2007-07-01

    The discovery in the mid 1970s of efficient methods of DNA sequencing and their subsequent development into more and more rapid procedures followed by sequencing the genomes of many species, including man in 2001, revolutionised the whole of biology. Remarkably, new light could be cast on the evolutionary relations of different species, and the tempo and mode of evolution within a given species, notably man, could quantitatively be illuminated including ongoing evolution possibly involving also the size of the brains. This review is a short summary of the results of the molecular genetic investigations of human evolution including the time and place of the formation of our species, our evolutionary relation to the closest living species relatives as well as extinct forms of the genus Homo. The nature and amount of genetic polymorphism in man is also considered with special emphasis on the causes of this variation, and the role of natural selection in human evolution. A consensus about the mosaic nature of our genome and the rather dynamic structure of our ancestral population is gradually emerging. The modern gene pool has most likely been contributed to several different ancestral demes either before or after the emergence of the anatomically modern human phenotype in the extent that even the nature of the evolutionary lineage leading to the anatomically modern man as a distinct biological species is disputable. Regulation of the function of genes, as well as the evolution of brains will be dealt with in the second part of this review.

  11. The History of Patenting Genetic Material.

    Science.gov (United States)

    Sherkow, Jacob S; Greely, Henry T

    2015-01-01

    The US Supreme Court's recent decision in Association for Molecular Pathology v. Myriad Genetics, Inc. declared, for the first time, that isolated human genes cannot be patented. Many have wondered how genes were ever the subjects of patents. The answer lies in a nuanced understanding of both legal and scientific history. Since the early twentieth century, "products of nature" were not eligible to be patented unless they were "isolated and purified" from their surrounding environment. As molecular biology advanced, and the capability to isolate genes both physically and by sequence came to fruition, researchers (and patent offices) began to apply patent-law logic to genes themselves. These patents, along with other biological patents, generated substantial social and political criticism. Myriad Genetics, a company with patents on BRCA1 and BRCA2, two genes critical to assessing early-onset breast and ovarian cancer risk, and with a particularly controversial business approach, became the antagonist in an ultimately successful campaign to overturn gene patents in court. Despite Myriad's defeat, some questions concerning the rights to monopolize genetic information remain. The history leading to that defeat may be relevant to these future issues.

  12. Molecular genetics of breast cancer

    International Nuclear Information System (INIS)

    Radice, P.; Pierotti, M. A.

    1997-01-01

    In the last two decades, molecular studies have enlightened the complexity of the genetic alterations that occur in breast cancer cells. To date, more than 40 different genes or loci have been found to be altered in breast carcinomas. Although some of these genes, as for example ERBB2, appear to be mutated in a high proportion of cases, their mechanism of action and their role in the different stages of cancer development are still poorly understood. More recently, two major determinants of the inherited predisposition to breast cancer, BRCA1 and BRCA2, have been isolated. As a consequence, it is now possible to screen families with a positive history of breast carcinomas for the identification of mutations carriers, in order to address these individuals into adequate programs of cancer surveillance and prevention

  13. [The role of the genetics history in genetics teaching].

    Science.gov (United States)

    Li, Ming-Hui

    2006-08-01

    The research of the scientific history and development status reflect the science and technology level of a nation. The genetic history is one of the branches of the life science and the 21st century is life science century. The genetics history in the teaching of genetics not only can help students get familiar with the birth and development of genetics, but also enhance their thinking ability and scientific qualities. The roles and approaches of teaching are discussed in this paper.

  14. Molecular genetics made simple

    Directory of Open Access Journals (Sweden)

    Heba Sh. Kassem

    2012-07-01

    Full Text Available Genetics have undoubtedly become an integral part of biomedical science and clinical practice, with important implications in deciphering disease pathogenesis and progression, identifying diagnostic and prognostic markers, as well as designing better targeted treatments. The exponential growth of our understanding of different genetic concepts is paralleled by a growing list of genetic terminology that can easily intimidate the unfamiliar reader. Rendering genetics incomprehensible to the clinician however, defeats the very essence of genetic research: its utilization for combating disease and improving quality of life. Herein we attempt to correct this notion by presenting the basic genetic concepts along with their usefulness in the cardiology clinic. Bringing genetics closer to the clinician will enable its harmonious incorporation into clinical care, thus not only restoring our perception of its simple and elegant nature, but importantly ensuring the maximal benefit for our patients.

  15. Molecular genetics made simple

    Science.gov (United States)

    Kassem, Heba Sh.; Girolami, Francesca; Sanoudou, Despina

    2012-01-01

    Abstract Genetics have undoubtedly become an integral part of biomedical science and clinical practice, with important implications in deciphering disease pathogenesis and progression, identifying diagnostic and prognostic markers, as well as designing better targeted treatments. The exponential growth of our understanding of different genetic concepts is paralleled by a growing list of genetic terminology that can easily intimidate the unfamiliar reader. Rendering genetics incomprehensible to the clinician however, defeats the very essence of genetic research: its utilization for combating disease and improving quality of life. Herein we attempt to correct this notion by presenting the basic genetic concepts along with their usefulness in the cardiology clinic. Bringing genetics closer to the clinician will enable its harmonious incorporation into clinical care, thus not only restoring our perception of its simple and elegant nature, but importantly ensuring the maximal benefit for our patients. PMID:25610837

  16. Genetic Structure and Molecular Diversity of Cacao Plants Established as Local Varieties for More than Two Centuries: The Genetic History of Cacao Plantations in Bahia, Brazil.

    Science.gov (United States)

    Santos, Elisa S L; Cerqueira-Silva, Carlos Bernard M; Mori, Gustavo M; Ahnert, Dário; Mello, Durval L N; Pires, José Luis; Corrêa, Ronan X; de Souza, Anete P

    2015-01-01

    Bahia is the most important cacao-producing state in Brazil, which is currently the sixth-largest country worldwide to produce cacao seeds. In the eighteenth century, the Comum, Pará and Maranhão varieties of cacao were introduced into southern Bahia, and their descendants, which are called 'Bahian cacao' or local Bahian varieties, have been cultivated for over 200 years. Comum plants have been used to start plantations in African countries and extended as far as countries in South Asia and Oceania. In Brazil, two sets of clones selected from Bahian varieties and their mutants, the Agronomic Institute of East (SIAL) and Bahian Cacao Institute (SIC) series, represent the diversity of Bahian cacao in germplasm banks. Because the genetic diversity of Bahian varieties, which is essential for breeding programs, remains unknown, the objective of this work was to assess the genetic structure and diversity of local Bahian varieties collected from farms and germplasm banks. To this end, 30 simple sequence repeat (SSR) markers were used to genotype 279 cacao plants from germplasm and local farms. The results facilitated the identification of 219 cacao plants of Bahian origin, and 51 of these were SIAL or SIC clones. Bahian cacao showed low genetic diversity. It could be verified that SIC and SIAL clones do not represent the true diversity of Bahian cacao, with the greatest amount of diversity found in cacao trees on the farms. Thus, a core collection to aid in prioritizing the plants to be sampled for Bahian cacao diversity is suggested. These results provide information that can be used to conserve Bahian cacao plants and applied in breeding programs to obtain more productive Bahian cacao with superior quality and tolerance to major diseases in tropical cacao plantations worldwide.

  17. [When history meets molecular medicine: molecular history of human tuberculosis].

    Science.gov (United States)

    Ottini, Laura; Falchetti, Mario

    2010-01-01

    Tuberculosis represents one of the humankind's most socially devastating diseases. Despite a long history of medical research and the development of effective therapies, this disease remains a global health danger even in the 21st century. Tuberculosis may cause death but infected people with effective immunity may remain healthy for years, suggesting long-term host-pathogen co-existence. Because of its antiquity, a supposed association with human settlements and the tendency to leave typical lesions on skeletal and mummified remains, tuberculosis has been the object of intensive multidisciplinary studies, including paleo-pathological research. During the past 10 years molecular paleo-pathology developed as a new scientific discipline allowing the study of ancient pathogens by direct detection of their DNA. In this work, we reviewed evidences for tuberculosis in ancient human remains, current methods for identifying ancient mycobacterial DNA and explored current theories of Mycobacterium tuberculosis evolution and their implications in the global development of tuberculosis looking into the past and present at the same time.

  18. Molecular genetics in neurology.

    Science.gov (United States)

    Martin, J B

    1993-12-01

    There has been remarkable progress in the identification of mutations in genes that cause inherited neurological disorders. Abnormalities in the genes for Huntington disease, neurofibromatosis types 1 and 2, one form of familial amyotrophic lateral sclerosis, fragile X syndrome, myotonic dystrophy, Kennedy syndrome, Menkes disease, and several forms of retinitis pigmentosa have been elucidated. Rare disorders of neuronal migration such as Kallmann syndrome, Miller-Dieker syndrome, and Norrie disease have been shown to be due to specific gene defects. Several muscle disorders characterized by abnormal membrane excitability have been defined as mutations of the muscle sodium or chloride channels. These advances provide opportunity for accurate molecular diagnosis of at-risk individuals and are the harbinger of new approaches to therapy of these diseases.

  19. Molecular genetics of craniosynostosis

    Science.gov (United States)

    Caterine; Auerkari, Elza Ibrahim

    2018-03-01

    Tight regulation process and complex interplay occur along the osteogenic interfaces of the cranial sutures in normal growth and development of the skull. Cranial sutures serve as sites of bone growth while maintaining a state of patency to accommodate the developing brain. Cranial sutures are fibro-cellular structures that separate the rigid plates of the skull bones. Premature fusion of one or more cranial sutures leads to a condition known as craniosynostosis. Craniosynostosis is one of the most common craniofacial anomalies with a prevalence of 1 in 2,500 newborns. Several genes have been identified in the pathogenesis of craniosynostosis. Molecular signaling events and the intracellular signal transduction pathways implicated in the suture pathobiology will provide a useful approach for therapeutic targeting.

  20. Heredity before genetics: a history.

    Science.gov (United States)

    Cobb, Matthew

    2006-12-01

    Two hundred years ago, biologists did not recognize that there was such a thing as 'heredity'. By the 1830s, however, insights from medicine and agriculture had indicated that something is passed from generation to generation, creating the context for the brilliant advances of Mendel and Darwin. Recent work on the history and philosophy of science has shed light on how seventeenth-, eighteenth- and nineteenth-century thinkers sought to understand similarities between parents and offspring.

  1. Molecular Genetic of Atopic dermatitis: An Update

    Science.gov (United States)

    Al-Shobaili, Hani A.; Ahmed, Ahmed A.; Alnomair, Naief; Alobead, Zeiad Abdulaziz; Rasheed, Zafar

    2016-01-01

    Atopic dermatitis (AD) is a chronic multifactorial inflammatory skin disease. The pathogenesis of AD remains unclear, but the disease results from dysfunctions of skin barrier and immune response, where both genetic and environmental factors play a key role. Recent studies demonstrate the substantial evidences that show a strong genetic association with AD. As for example, AD patients have a positive family history and have a concordance rate in twins. Moreover, several candidate genes have now been suspected that play a central role in the genetic background of AD. In last decade advanced procedures similar to genome-wide association (GWA) and single nucleotide polymorphism (SNP) have been applied on different population and now it has been clarified that AD is significantly associated with genes of innate/adaptive immune systems, human leukocyte antigens (HLA), cytokines, chemokines, drug-metabolizing genes or various other genes. In this review, we will highlight the recent advancements in the molecular genetics of AD, especially on possible functional relevance of genetic variants discovered to date. PMID:27004062

  2. Molecular genetic studies on obligate anaerobic bacteria

    International Nuclear Information System (INIS)

    Woods, D.R.

    1982-01-01

    Molecular genetic studies on obligate anaerobic bacteria have lagged behind similar studies in aerobes. However, the current interest in biotechnology, the involvement of anaerobes in disease and the emergence of antibioticresistant strains have focused attention on the genetics of anaerobes. This article reviews molecular genetic studies in Bacteroides spp., Clostridium spp. and methanogens. Certain genetic systems in some anaerobes differ from those in aerobes and illustrate the genetic diversity among bacteria

  3. Event History Analysis in Quantitative Genetics

    DEFF Research Database (Denmark)

    Maia, Rafael Pimentel

    Event history analysis is a clas of statistical methods specially designed to analyze time-to-event characteristics, e.g. the time until death. The aim of the thesis was to present adequate multivariate versions of mixed survival models that properly represent the genetic aspects related to a given...

  4. Great ape genetic diversity and population history

    DEFF Research Database (Denmark)

    Prado-Martinez, Javier; Sudmant, Peter H; Kidd, Jeffrey M

    2013-01-01

    Most great ape genetic variation remains uncharacterized; however, its study is critical for understanding population history, recombination, selection and susceptibility to disease. Here we sequence to high coverage a total of 79 wild- and captive-born individuals representing all six great ape...

  5. A genetic atlas of human admixture history

    Science.gov (United States)

    Hellenthal, Garrett; Busby, George B.J.; Band, Gavin; Wilson, James F.; Capelli, Cristian

    2014-01-01

    Modern genetic data combined with appropriate statistical methods have the potential to contribute substantially to our understanding of human history. We have developed an approach that exploits the genomic structure of admixed populations to date and characterize historical mixture events at fine scales. We used this to produce an atlas of worldwide human admixture history, constructed using genetic data alone and encompassing over 100 events occurring over the past 4,000 years. We identify events whose dates and participants suggest they describe genetic impacts of the Mongol Empire, Arab slave trade, Bantu expansion, first millennium CE migrations in eastern Europe, and European colonialism, as well as unrecorded events, revealing admixture to be an almost universal force shaping human populations. PMID:24531965

  6. A genetic atlas of human admixture history.

    Science.gov (United States)

    Hellenthal, Garrett; Busby, George B J; Band, Gavin; Wilson, James F; Capelli, Cristian; Falush, Daniel; Myers, Simon

    2014-02-14

    Modern genetic data combined with appropriate statistical methods have the potential to contribute substantially to our understanding of human history. We have developed an approach that exploits the genomic structure of admixed populations to date and characterize historical mixture events at fine scales. We used this to produce an atlas of worldwide human admixture history, constructed by using genetic data alone and encompassing over 100 events occurring over the past 4000 years. We identified events whose dates and participants suggest they describe genetic impacts of the Mongol empire, Arab slave trade, Bantu expansion, first millennium CE migrations in Eastern Europe, and European colonialism, as well as unrecorded events, revealing admixture to be an almost universal force shaping human populations.

  7. The genetic history of Peninsular Malaysia.

    Science.gov (United States)

    Norhalifah, Hanim Kamis; Syaza, Fatnin Hisham; Chambers, Geoffrey Keith; Edinur, Hisham Atan

    2016-07-15

    This article explores the genetic history of the various sub-populations currently living in Peninsular Malaysia. This region has received multiple waves of migrants like the Orang Asli in prehistoric times and the Chinese, Indians, Europeans and Arabs during historic times. There are three highly distinct lineages that make up the Orang Asli; Semang, Senoi and Proto-Malays. The Semang, who have 'Negrito' characteristics, represent the first human settlers in Peninsular Malaysia arriving from about 50,000ya. The Senoi later migrated from Indochina and are a mix between an Asian Neolithic population and the Semang. These Asian genomes probably came in before Austroasiatic languages arrived between 5000 and 4000years ago. Semang and Senoi both now speak Austro-Asiatic languages indicative of cultural diffusion from Senoi to Semang. In contrast, the Proto-Malays who came last to the southern part of this region speak Austronesian language and are Austronesians with some Negrito admixture. It is from this group that the contemporary Malays emerged. Here we provide an overview of the best available genetic evidences (single nucleotide polymorphisms, mitochondrial DNA, Y-chromosome, blood groups, human platelet antigen, human leukocyte antigen, human neutrophil antigen and killer-cell immunoglobulin-like receptor) supporting the complex genetic history of Peninsular Malaysia. Large scale sampling and high throughput genetic screening programmes such as those using genome-wide single nucleotide polymorphism analyses have provided insights into various ancestral and admixture genetic fractions in this region. Given the now extensive admixture present in the contemporary descendants of ancient sub-populations in Peninsular Malaysia, improved reconstruction of human migration history in this region will require new evidence from ancient DNA in well-preserved skeletons. All other aspects of the highly diverse and complex genetic makeup in Peninsular Malaysia should be

  8. RESEARCH NOTE Molecular genetic analysis of consanguineous ...

    Indian Academy of Sciences (India)

    Navya

    Molecular genetic analysis of consanguineous families with primary microcephaly ... Translational Research Institute, Academic Health System, Hamad Medical ..... bridging the gap between homozygosity mapping and deep sequencing.

  9. On the History of Cattle Genetic Resources

    Directory of Open Access Journals (Sweden)

    Marleen Felius

    2014-11-01

    Full Text Available Cattle are our most important livestock species because of their production and role in human culture. Many breeds that differ in appearance, performance and environmental adaptation are kept on all inhabited continents, but the historic origin of the diverse phenotypes is not always clear. We give an account of the history of cattle by integrating archaeological record and pictorial or written sources, scarce until 300 years ago, with the recent contributions of DNA analysis. We describe the domestication of their wild ancestor, migrations to eventually all inhabited continents, the developments during prehistory, the antiquity and the Middle Ages, the relatively recent breed formation, the industrial cattle husbandry in the Old and New World and the current efforts to preserve the cattle genetic resources. Surveying the available information, we propose three main and overlapping phases during the development of the present genetic diversity: (i domestication and subsequent wild introgression; (ii natural adaptation to a diverse agricultural habitat; and (iii breed development.

  10. Genetic history of the African Sahelian populations.

    Science.gov (United States)

    Černý, V; Kulichová, I; Poloni, E S; Nunes, J M; Pereira, L; Mayor, A; Sanchez-Mazas, A

    2018-03-01

    From a biogeographic perspective, Africa is subdivided into distinct horizontal belts. Human populations living along the Sahel/Savannah belt south of the Sahara desert have often been overshadowed by extensive studies focusing on other African populations such as hunter-gatherers or Bantu in particular. However, the Sahel together with the Savannah bordering it in the south is a challenging region where people had and still have to cope with harsh climatic conditions and show resilient behaviours. Besides exponentially growing urban populations, several local groups leading various lifestyles and speaking languages belonging to three main linguistic families still live in rural localities across that region today. Thanks to several years of consistent population sampling throughout this area, the genetic history of the African Sahelian populations has been largely reconstructed and a deeper knowledge has been acquired regarding their adaptation to peculiar environments and/or subsistence modes. Distinct exposures to pathogens-in particular, malaria-likely contributed to their genetic differentiation for HLA genes. In addition, although food-producing strategies spread within the Sahel/Savannah belt relatively recently, during the last five millennia according to recent archaeological and archaeobotanical studies, remarkable amounts of genetic differences are also observed between sedentary farmers and more mobile pastoralists at multiple neutral and selected loci, reflecting both demographic effects and genetic adaptations to distinct cultural traits, such as dietary habits. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. From Mendel to epigenetics: History of genetics.

    Science.gov (United States)

    Gayon, Jean

    2016-01-01

    The origins of genetics are to be found in Gregor Mendel's memoir on plant hybridization (1865). However, the word 'genetics' was only coined in 1906, to designate the new science of heredity. Founded upon the Mendelian method for analyzing the products of crosses, this science is distinguished by its explicit purpose of being a general 'science of heredity', and by the introduction of totally new biological concepts (in particular those of gene, genotype, and phenotype). In the 1910s, Mendelian genetics fused with the chromosomal theory of inheritance, giving rise to what is still called 'classical genetics'. Within this framework, the gene is simultaneously a unit of function and transmission, a unit of recombination, and of mutation. Until the early 1950s, these concepts of the gene coincided. But when DNA was found to be the material basis of inheritance, this congruence dissolved. Then began the venture of molecular biology, which has never stopped revealing the complexity of the way in which hereditary material functions. Copyright © 2016 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  12. Advances in genetics. Volume 22: Molecular genetics of plants

    International Nuclear Information System (INIS)

    Scandalios, J.G.; Caspari, E.W.

    1984-01-01

    This book contains the following four chapters: Structural Variation in Mitochondrial DNA; The Structure and Expression of Nuclear Genes in Higher Plants; Chromatin Structure and Gene Regulation in Higher Plants; and The Molecular Genetics of Crown Gall Tumorigenesis

  13. Genetics and molecular biology of breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    King, M.C. [California Univ., Berkeley, CA (United States); Lippman, M. [Georgetown Univ. Medical Center, Washington, DC (United States)] [comps.

    1992-12-31

    This volume contains the abstracts of oral presentations and poster sessions presented at the Cold Springs Harbor Meeting on Cancer Cells, this meeting entitled Genetics and Molecular Biology of Breast Cancer.

  14. Protocols in human molecular genetics

    National Research Council Canada - National Science Library

    Mathew, Christopher G

    1991-01-01

    ... sequences has led to the development of DNA fingerprinting. The application of these techniques to the study of the human genome has culminated in major advances such as the cloning of the cystic fibrosis gene, the construction of genetic linkage maps of each human chromosome, the mapping of many genes responsible for human inherited disorders, genet...

  15. Molecular diversity and genetic relationships in Secale

    Indian Academy of Sciences (India)

    Molecular diversity and genetic relationships in Secale. E. Santos, M. Matos, P. Silva, A. M. Figueiras, C. Benito and O. Pinto-Carnide. J. Genet. 95, 273–281. Table 1. RAPD and ISSR primers used in this study. Primer. 5 –3. Primer. 5 –3. RAPDs (Operon). A1. CAGGCCCTTC. C5. CATGACCGCC. A4. AATCGGGCTG. C6.

  16. The genetic history of Ice Age Europe

    Science.gov (United States)

    Fu, Qiaomei; Posth, Cosimo; Hajdinjak, Mateja; Petr, Martin; Mallick, Swapan; Fernandes, Daniel; Furtwängler, Anja; Haak, Wolfgang; Meyer, Matthias; Mittnik, Alissa; Nickel, Birgit; Peltzer, Alexander; Rohland, Nadin; Slon, Viviane; Talamo, Sahra; Lazaridis, Iosif; Lipson, Mark; Mathieson, Iain; Schiffels, Stephan; Skoglund, Pontus; Derevianko, Anatoly P.; Drozdov, Nikolai; Slavinsky, Vyacheslav; Tsybankov, Alexander; Cremonesi, Renata Grifoni; Mallegni, Francesco; Gély, Bernard; Vacca, Eligio; González Morales, Manuel R.; Straus, Lawrence G.; Neugebauer-Maresch, Christine; Teschler-Nicola, Maria; Constantin, Silviu; Moldovan, Oana Teodora; Benazzi, Stefano; Peresani, Marco; Coppola, Donato; Lari, Martina; Ricci, Stefano; Ronchitelli, Annamaria; Valentin, Frédérique; Thevenet, Corinne; Wehrberger, Kurt; Grigorescu, Dan; Rougier, Hélène; Crevecoeur, Isabelle; Flas, Damien; Semal, Patrick; Mannino, Marcello A.; Cupillard, Christophe; Bocherens, Hervé; Conard, Nicholas J.; Harvati, Katerina; Moiseyev, Vyacheslav; Drucker, Dorothée G.; Svoboda, Jiří; Richards, Michael P.; Caramelli, David; Pinhasi, Ron; Kelso, Janet; Patterson, Nick; Krause, Johannes; Pääbo, Svante; Reich, David

    2016-01-01

    Modern humans arrived in Europe ~45,000 years ago, but little is known about their genetic composition before the start of farming ~8,500 years ago. We analyze genome-wide data from 51 Eurasians from ~45,000-7,000 years ago. Over this time, the proportion of Neanderthal DNA decreased from 3–6% to around 2%, consistent with natural selection against Neanderthal variants in modern humans. Whereas the earliest modern humans in Europe did not contribute substantially to present-day Europeans, all individuals between ~37,000 and ~14,000 years ago descended from a single founder population which forms part of the ancestry of present-day Europeans. A ~35,000 year old individual from northwest Europe represents an early branch of this founder population which was then displaced across a broad region, before reappearing in southwest Europe during the Ice Age ~19,000 years ago. During the major warming period after ~14,000 years ago, a new genetic component related to present-day Near Easterners appears in Europe. These results document how population turnover and migration have been recurring themes of European pre-history. PMID:27135931

  17. Unraveling the genetic history of the European wild goats

    Science.gov (United States)

    Ureña, I.; Ersmark, E.; Samaniego, J. A.; Galindo-Pellicena, M. A.; Crégut-Bonnoure, E.; Bolívar, H.; Gómez-Olivencia, A.; Rios-Garaizar, J.; Garate, D.; Dalén, L.; Arsuaga, J. L.; Valdiosera, C. E.

    2018-04-01

    The population history of the Iberian wild goat and the Alpine ibex has been closely related to that of humans since the Palaeolithic. Current molecular and paleontological studies differ substantially on the phylogenetic origin of the European wild goats, possibly due the loss of genetic variation through time. We investigated the phylogenetic relationship between the Alpine ibex (Capra ibex) and the Iberian wild goat (Capra pyrenaica) including different Iberian wild goat subspecies by applying ancient DNA techniques combined with Next Generation Sequencing technologies. We analysed the cytochrome b gene of the mitochondrial genome in 33 ancient and modern European wild goats from Spain and France together with publicly available genetic information of modern wild goats. This work uncovers for the first time ancient genetic information of the Iberian wild goat and the Alpine ibex, spanning a time range of approximately 40,000 years to the present. Our results suggest genetic continuity between ancient and modern populations and indicate a monophyletic origin of the Alpine ibex and the Iberian wild goat when compared to other Capra species. The monophyly of both species is in agreement with other molecular studies based only on modern populations, therefore supporting one-wave migration of wild goats into Western Europe followed by possible allopatric speciation. We observe three major clades of wild goats in Western Europe: Capra ibex, Capra pyrenaica pyrenaica and the group containing the subspecies Capra pyrenaica hispanica and Capra pyrenaica victoriae. This genetic structure recognizes the distinctiveness of the bucardo (C. p. pyrenaica) from the rest of Iberian wild goats and thus supports the idea that this group is an Evolutionary Significant Unit. The divergence time estimated here indicates an almost contemporaneous split between the three clades around 50,000-90,000 years BP.

  18. Lessons learned from family history in ocular genetics.

    Science.gov (United States)

    Marino, Meghan J

    2015-07-01

    Given the vast genetic and phenotypic heterogeneity seen in ocular genetic disorders, considering a patient's clinical phenotype in the context of the family history is essential. Clinicians can improve patient care by appropriately incorporating a patient's family history into their evaluation. Obtaining, reviewing, and accurately interpreting the pedigree are skills geneticists and genetic counselors possess. However, with the field of ophthalmic genetics vastly growing, it is becoming essential for ophthalmologists to understand the utility of the pedigree and develop their abilities in eliciting this information. By not considering a patient's clinical history in the context of the family history, diagnoses can be missed or inaccurate. The purpose of this review is to inform ophthalmologists on the importance of the family history and highlight how the pedigree can aid in establishing an accurate genetic diagnosis. This review also provides to ophthalmologists helpful tips on eliciting and interpreting a patient's family history.

  19. Cystic fibrosis, molecular genetics for all life

    Directory of Open Access Journals (Sweden)

    Ausilia Elce

    2015-10-01

    Full Text Available Cystic fibrosis (CF is the most frequent lethal autosomal recessive disorder among Caucasians (incidence: 1:2,500 newborn. In the last two decades CF prognosis considerably improved and many patients well survive into their adulthood. Furthermore, milder CF with a late onset was described. CF is a challenge for laboratory of molecular genetics that greatly contributes to the natural history of the disease since fetal age. Carrier screening and prenatal diagnosis, also by non-invasive analysis of maternal blood fetal DNA, are now available, and many labs offer preimplantation diagnosis. The major criticism in prenatal medicine is the lack of an effective multidisciplinary counseling that helps the couples to plan their reasoned reproductive choice. Most countries offer newborn screening that significantly reduce CF morbidity but different protocols based on blood trypsin, molecular analysis and sweat chloride cause a variable efficiency of the screening programs. Again, laboratory is crucial for CF diagnosis in symptomatic patients: sweat chloride is the diagnostic golden standard, but different methodologies and the lack of quality control in most labs reduce its effectiveness. Molecular analysis contributes to confirm diagnosis in symptomatic subjects; furthermore, it helps to predict the disease outcome on the basis of the mutation (genotype-phenotype correlation and mutations in a myriad of genes, inherited independently by CF transmembrane conductance regulator (CFTR, which may modulate the clinical expression of the disease in each single patient (modifier genes. More recently, the search of the CFTR mutations gained a role in selecting CF patients that may benefit from biological therapy based on correctors and potentiators that are effective in patients bearing specific mutations (personalized therapy. All such applications of molecular diagnostics confirm the “uniqueness” of each CF patient, offering to laboratory medicine the

  20. Reconstructing the genetic history of late Neanderthals.

    Science.gov (United States)

    Hajdinjak, Mateja; Fu, Qiaomei; Hübner, Alexander; Petr, Martin; Mafessoni, Fabrizio; Grote, Steffi; Skoglund, Pontus; Narasimham, Vagheesh; Rougier, Hélène; Crevecoeur, Isabelle; Semal, Patrick; Soressi, Marie; Talamo, Sahra; Hublin, Jean-Jacques; Gušić, Ivan; Kućan, Željko; Rudan, Pavao; Golovanova, Liubov V; Doronichev, Vladimir B; Posth, Cosimo; Krause, Johannes; Korlević, Petra; Nagel, Sarah; Nickel, Birgit; Slatkin, Montgomery; Patterson, Nick; Reich, David; Prüfer, Kay; Meyer, Matthias; Pääbo, Svante; Kelso, Janet

    2018-03-29

    Although it has previously been shown that Neanderthals contributed DNA to modern humans, not much is known about the genetic diversity of Neanderthals or the relationship between late Neanderthal populations at the time at which their last interactions with early modern humans occurred and before they eventually disappeared. Our ability to retrieve DNA from a larger number of Neanderthal individuals has been limited by poor preservation of endogenous DNA and contamination of Neanderthal skeletal remains by large amounts of microbial and present-day human DNA. Here we use hypochlorite treatment of as little as 9 mg of bone or tooth powder to generate between 1- and 2.7-fold genomic coverage of five Neanderthals who lived around 39,000 to 47,000 years ago (that is, late Neanderthals), thereby doubling the number of Neanderthals for which genome sequences are available. Genetic similarity among late Neanderthals is well predicted by their geographical location, and comparison to the genome of an older Neanderthal from the Caucasus indicates that a population turnover is likely to have occurred, either in the Caucasus or throughout Europe, towards the end of Neanderthal history. We find that the bulk of Neanderthal gene flow into early modern humans originated from one or more source populations that diverged from the Neanderthals that were studied here at least 70,000 years ago, but after they split from a previously sequenced Neanderthal from Siberia around 150,000 years ago. Although four of the Neanderthals studied here post-date the putative arrival of early modern humans into Europe, we do not detect any recent gene flow from early modern humans in their ancestry.

  1. The molecular genetics of holoprosencephaly.

    Science.gov (United States)

    Roessler, Erich; Muenke, Maximilian

    2010-02-15

    Holoprosencephaly (HPE) has captivated the imagination of Man for millennia because its most extreme manifestation, the single-eyed cyclopic newborn infant, brings to mind the fantastical creature Cyclops from Greek mythology. Attempting to understand this common malformation of the forebrain in modern medical terms requires a systematic synthesis of genetic, cytogenetic, and environmental information typical for studies of a complex disorder. However, even with the advances in our understanding of HPE in recent years, there are significant obstacles remaining to fully understand its heterogeneity and extensive variability in phenotype. General lessons learned from HPE will likely be applicable to other malformation syndromes. Here we outline the common, and rare, genetic and environmental influences on this conserved developmental program of forebrain development and illustrate the similarities and differences between these malformations in humans and those of animal models. 2010 Wiley-Liss, Inc.

  2. [Colorectal cancer (CCR): genetic and molecular alterations].

    Science.gov (United States)

    Juárez-Vázquez, Clara Ibet; Rosales-Reynoso, Mónica Alejandra

    2014-01-01

    The aim of this review is to present a genetic and molecular overview of colorectal carcinogenesis (sporadic and hereditary origin) as a multistage process, where there are a number of molecular mechanisms associated with the development of colorectal cancer and genomic instability that allows the accumulation of mutations in proto-oncogenes and tumor suppressor genes, chromosomal instability, and methylation and microsatellite instability, and the involvement of altered expression of microRNAs' prognosis factors.

  3. Molecular species identification and population genetics of ...

    African Journals Online (AJOL)

    Molecular genetic techniques, such as DNA barcoding and genotyping, are increasingly being used to assist with the conservation and management of chondrichthyans worldwide. Southern Africa is a shark biodiversity hotspot, with a large number of endemic species. According to the IUCN Red List, a quarter of South ...

  4. A molecular genetic toolbox for Yarrowia lipolytica

    DEFF Research Database (Denmark)

    Bredeweg, Erin L.; Pomraning, Kyle R.; Dai, Ziyu

    2017-01-01

    used these tools to build the "Yarrowia lipolytica Cell Atlas," a collection of strains with endogenous fluorescently tagged organelles in the same genetic background, in order to define organelle morphology in live cells. Conclusions: These molecular and isogenetic tools are useful for live assessment...

  5. Molecular markers unravel intraspecific and interspecific genetic ...

    Indian Academy of Sciences (India)

    [Kotwal S., Dhar M. K., Kour B., Raj K. and Kaul S. 2013 Molecular markers unravel intraspecific and interspecific genetic variability in ... of bowel problems including chronic constipation, amoebic ..... while to select parents from accessions, Pov80 and Pov79 ... nology (DBT), Govt. of India, for financial assistance in the form.

  6. Molecular diversity and genetic relationships in Secale

    Indian Academy of Sciences (India)

    The objective of this study was to quantify the molecular diversity and to determine the genetic relationships amongSecalespp. and among cultivars ofSecale ... Faculty of Sciences, Campo Grande, Lisboa, Portugal; Departamento de Genética, Facultad de Biologia, Universidad Complutense, C/ José Antonio Novais, 12, ...

  7. Molecular genetics in affective illness

    Energy Technology Data Exchange (ETDEWEB)

    Mendlewicz, J.; Sevy, S.; Mendelbaum, K. (Erasme Univ. Hospital, Brussels (Belgium))

    1993-01-01

    Genetic transmission in manic depressive illness (MDI) has been explored in twins, adoption, association, and linkage studies. The X-linked transmission hypothesis has been tested by using several markers on chromosome X: Xg blood group, color blindness, glucose-6-phosphate dehydrogenase (G6PD), factor IX (hemophilia B), and DNA probes such as DXS15, DXS52, F8C, ST14. The hypothesis of autosomal transmission has been tested by association studies with the O blood group located on chromosome 9, as well as linkage studies on chromosome 6 with the Human Leucocyte Antigens (HLA) haplotypes and on Chromosome 11 with DNA markers for the following genes: D2 dopamine receptor, tyrosinase, C-Harvey-Ras-A (HRAS) oncogene, insuline (ins), and tyrosine hydroxylase (TH). Although linkage studies support the hypothesis of a major locus for the transmission of MDI in the Xq27-28 region, several factors are limiting the results, and are discussed in the present review. 105 refs., 1 fig., 2 tabs.

  8. The Molecular Genetics of von Willebrand Disease

    Directory of Open Access Journals (Sweden)

    Ergül Berber

    2012-12-01

    Full Text Available Quantitative and/or qualitative deficiency of von Willebrand factor (vWF is associated with the most common inherited bleeding disease von Willebrand disease (vWD. vWD is a complex disease with clinical and genetic heterogeneity. Incomplete penetrance and variable expression due to genetic and environmental factors contribute to its complexity. vWD also has a complex molecular pathogenesis. Some vWF gene mutations are associated with the affected vWF biosynthesis and multimerization, whereas others are associated with increased clearance and functional impairment. Moreover, in addition to a particular mutation, type O blood may result in the more severe phenotype. The present review aimed to provide a summary of the current literature on the molecular genetics of vWD.

  9. The molecular genetics of von Willebrand disease.

    Science.gov (United States)

    Berber, Ergül

    2012-12-01

    Quantitative and/or qualitative deficiency of von Willebrand factor (vWF) is associated with the most common inherited bleeding disease von Willebrand disease (vWD). vWD is a complex disease with clinical and genetic heterogeneity. Incomplete penetrance and variable expression due to genetic and environmental factors contribute to its complexity. vWD also has a complex molecular pathogenesis. Some vWF gene mutations are associated with the affected vWF biosynthesis and multimerization, whereas others are associated with increased clearance and functional impairment. Moreover, in addition to a particular mutation, type O blood may result in the more severe phenotype. The present review aimed to provide a summary of the current literature on the molecular genetics of vWD. None declared.

  10. Molecular genetics of dyslexia: an overview.

    Science.gov (United States)

    Carrion-Castillo, Amaia; Franke, Barbara; Fisher, Simon E

    2013-11-01

    Dyslexia is a highly heritable learning disorder with a complex underlying genetic architecture. Over the past decade, researchers have pinpointed a number of candidate genes that may contribute to dyslexia susceptibility. Here, we provide an overview of the state of the art, describing how studies have moved from mapping potential risk loci, through identification of associated gene variants, to characterization of gene function in cellular and animal model systems. Work thus far has highlighted some intriguing mechanistic pathways, such as neuronal migration, axon guidance, and ciliary biology, but it is clear that we still have much to learn about the molecular networks that are involved. We end the review by highlighting the past, present, and future contributions of the Dutch Dyslexia Programme to studies of genetic factors. In particular, we emphasize the importance of relating genetic information to intermediate neurobiological measures, as well as the value of incorporating longitudinal and developmental data into molecular designs. Copyright © 2013 John Wiley & Sons, Ltd.

  11. Guidelines on the use of molecular genetics in reintroduction programs

    Science.gov (United States)

    Michael K. Schwartz

    2005-01-01

    The use of molecular genetics can play a key role in reintroduction efforts. Prior to the introduction of any individuals, molecular genetics can be used to identify the most appropriate source population for the reintroduction, ensure that no relic populations exist in the reintroduction area, and guide captive breeding programs. The use of molecular genetics post-...

  12. Molecular marker systems for Oenothera genetics.

    Science.gov (United States)

    Rauwolf, Uwe; Golczyk, Hieronim; Meurer, Jörg; Herrmann, Reinhold G; Greiner, Stephan

    2008-11-01

    The genus Oenothera has an outstanding scientific tradition. It has been a model for studying aspects of chromosome evolution and speciation, including the impact of plastid nuclear co-evolution. A large collection of strains analyzed during a century of experimental work and unique genetic possibilities allow the exchange of genetically definable plastids, individual or multiple chromosomes, and/or entire haploid genomes (Renner complexes) between species. However, molecular genetic approaches for the genus are largely lacking. In this study, we describe the development of efficient PCR-based marker systems for both the nuclear genome and the plastome. They allow distinguishing individual chromosomes, Renner complexes, plastomes, and subplastomes. We demonstrate their application by monitoring interspecific exchanges of genomes, chromosome pairs, and/or plastids during crossing programs, e.g., to produce plastome-genome incompatible hybrids. Using an appropriate partial permanent translocation heterozygous hybrid, linkage group 7 of the molecular map could be assigned to chromosome 9.8 of the classical Oenothera map. Finally, we provide the first direct molecular evidence that homologous recombination and free segregation of chromosomes in permanent translocation heterozygous strains is suppressed.

  13. Accuracy of family history of cancer : clinical genetic implications

    NARCIS (Netherlands)

    Sijmons, RH; Boonstra, AE; Reefhuis, J; Hordijk-Hos, JM; de Walle, HEK; Oosterwijk, JC; Cornel, MC

    Family medical history is the cornerstone of clinical genetic diagnosis and management in cases of familial cancer. The soundness of medical decisions can be compromised if reports by the family on affected relatives are inaccurate. Although very time consuming, family medical histories are

  14. Uncovering the Genetic History of the Present Day Greenlandic Population

    DEFF Research Database (Denmark)

    Moltke, Ida; Fumagalli, Matteo; Korneliussen, Thorfinn S

    2015-01-01

    Because of past limitations in samples and genotyping technologies, important questions about the history of the present-day Greenlandic population remain unanswered. In an effort to answer these questions and in general investigate the genetic history of the Greenlandic population, we analyzed...

  15. Medulloblastoma: Molecular Genetics and Animal Models

    Directory of Open Access Journals (Sweden)

    Corey Raffel

    2004-07-01

    Full Text Available Medulloblastoma is a primary brain tumor found in the cerebellum of children. The tumor occurs in association with two inherited cancer syndromes: Turcot syndrome and Gorlin syndrome. Insights into the molecular biology of the tumor have come from looking at alterations in the genes altered in these syndromes, PTC and APC, respectively. Murine models of medulloblastoma have been constructed based on these alterations. Additional murine models that, while mimicking the appearance of the human tumor, seem unrelated to the human tumor's molecular alterations have been made. In this review, the clinical picture, origin, molecular biology, murine models of medulloblastoma are discussed. Although a great deal has been discovered about this tumor, the genetic alterations responsible for tumor development in a majority of patients have yet to be described.

  16. The genetic history of Ice Age Europe

    DEFF Research Database (Denmark)

    Fu, Qiaomei; Posth, Cosimo; Hajdinjak, Mateja

    2016-01-01

    Modern humans arrived in Europe ~45,000 years ago, but little is known about their genetic composition before the start of farming ~8,500 years ago. Here we analyse genome-wide data from 51 Eurasians from ~45,000–7,000 years ago. Over this time, the proportion of Neanderthal DNA decreased from 3–...... ~19,000 years ago. During the major warming period after ~14,000 years ago, a genetic component related to present-day Near Easterners became widespread in Europe. These results document how population turnover and migration have been recurring themes of European prehistory....

  17. The genetic history of Ice Age Europe

    Czech Academy of Sciences Publication Activity Database

    Fu, Q.; Posth, C.; Hajdinjak, M.; Petr, M.; Mallick, S.; Fernandes, D.; Furtwängler, A.; Haak, W.; Meyer, M.; Mittnik, A.; Nickel, B.; Peltzer, A.; Rohland, N.; Slon, V.; Talamo, S.; Lazaridis, I.; Lipson, M.; Mathieson, I.; Schiffels, S.; Skoglund, P.; Derevianko, A. P.; Drozdov, N.; Slavinsky, V.; Tsybankov, A.; Cremonesi, R. G.; Mallegni, F.; Gély, B.; Vacca, E.; Morales, M. R. G.; Straus, L. G.; Neugebauer-Maresch, Ch.; Teschler-Nicola, M.; Constantin, S.; Moldovan, O. T.; Benazzi, S.; Peresani, M.; Coppola, D.; Lari, M.; Ricci, S.; Ronchitelli, A.; Valentin, F.; Thevenet, C.; Wehrberger, K.; Grigorescu, D.; Rougier, H.; Crevecoeur, I.; Flas, D.; Semal, P.; Mannino, M. A.; Cupillard, Ch.; Bocherens, H.; Conard, N. J.; Harvati, K.; Moiseyev, V.; Drucker, D. G.; Svoboda, Jiří; Richards, M. P.; Caramelli, D.; Pinhasi, R.; Kelso, J.; Patterson, N.; Krause, J.; Pääbo, S.; Reich, D.

    2016-01-01

    Roč. 534, č. 7606 (2016), s. 200-205 ISSN 0028-0836 Institutional support: RVO:68081758 Keywords : genetics * Pleistocene * Europe * modern humans * Neanderthal Subject RIV: AC - Archeology, Anthropology, Ethnology OBOR OECD: Archaeology Impact factor: 40.137, year: 2016

  18. The genetic history of Ice Age Europe.

    Science.gov (United States)

    Fu, Qiaomei; Posth, Cosimo; Hajdinjak, Mateja; Petr, Martin; Mallick, Swapan; Fernandes, Daniel; Furtwängler, Anja; Haak, Wolfgang; Meyer, Matthias; Mittnik, Alissa; Nickel, Birgit; Peltzer, Alexander; Rohland, Nadin; Slon, Viviane; Talamo, Sahra; Lazaridis, Iosif; Lipson, Mark; Mathieson, Iain; Schiffels, Stephan; Skoglund, Pontus; Derevianko, Anatoly P; Drozdov, Nikolai; Slavinsky, Vyacheslav; Tsybankov, Alexander; Cremonesi, Renata Grifoni; Mallegni, Francesco; Gély, Bernard; Vacca, Eligio; Morales, Manuel R González; Straus, Lawrence G; Neugebauer-Maresch, Christine; Teschler-Nicola, Maria; Constantin, Silviu; Moldovan, Oana Teodora; Benazzi, Stefano; Peresani, Marco; Coppola, Donato; Lari, Martina; Ricci, Stefano; Ronchitelli, Annamaria; Valentin, Frédérique; Thevenet, Corinne; Wehrberger, Kurt; Grigorescu, Dan; Rougier, Hélène; Crevecoeur, Isabelle; Flas, Damien; Semal, Patrick; Mannino, Marcello A; Cupillard, Christophe; Bocherens, Hervé; Conard, Nicholas J; Harvati, Katerina; Moiseyev, Vyacheslav; Drucker, Dorothée G; Svoboda, Jiří; Richards, Michael P; Caramelli, David; Pinhasi, Ron; Kelso, Janet; Patterson, Nick; Krause, Johannes; Pääbo, Svante; Reich, David

    2016-06-09

    Modern humans arrived in Europe ~45,000 years ago, but little is known about their genetic composition before the start of farming ~8,500 years ago. Here we analyse genome-wide data from 51 Eurasians from ~45,000-7,000 years ago. Over this time, the proportion of Neanderthal DNA decreased from 3-6% to around 2%, consistent with natural selection against Neanderthal variants in modern humans. Whereas there is no evidence of the earliest modern humans in Europe contributing to the genetic composition of present-day Europeans, all individuals between ~37,000 and ~14,000 years ago descended from a single founder population which forms part of the ancestry of present-day Europeans. An ~35,000-year-old individual from northwest Europe represents an early branch of this founder population which was then displaced across a broad region, before reappearing in southwest Europe at the height of the last Ice Age ~19,000 years ago. During the major warming period after ~14,000 years ago, a genetic component related to present-day Near Easterners became widespread in Europe. These results document how population turnover and migration have been recurring themes of European prehistory.

  19. Molecular and genetic mechanisms of environmental mutagens

    International Nuclear Information System (INIS)

    Kubitschek, H.E.; Derstine, P.L.; Griego, V.M.; Matsushita, T.; Peak, J.G.; Peak, M.J.; Reynolds, P.R.; Webb, R.B.; Williams-Hill, D.

    1981-01-01

    This program is primarily concerned with elucidation of the nature of DNA lesions produced by environmental and energy related mutagens, their mechanisms of action, and their repair. The main focus is on actions of chemical mutagens and electromagnetic radiations. Synergistic interactions between mutagens and the mutational processes that lead to synergism are being investigated. Mutagens are chosen for study on the basis of their potential for analysis of mutation (as genetic probes), for development of procedures for reducing mutational damage, for their potential importance to risk assessment, and for development of improved mutagen testing systems. Bacterial cells are used because of the rapidity and clarity of scientific results that can be obtained, the detailed genetic maps, and the many well-defined mutand strains available. The conventional tools of microbial and molecular genetics are used, along with intercomparison of genetically related strains. Advantage is taken of tcollective dose commitment will result in more attention being paid to potential releases of radionuclides at relatively short times after disposal

  20. Molecular genetic studies of bacteroides fragilis

    International Nuclear Information System (INIS)

    Southern, J.A.

    1986-03-01

    This study aimed at providing a means for probing the molecular genetic organization of B.fragilis, particularly those strains where the DNA repair mechanisms had been described. The following routes of investigation were followed: the bacteriocin of B.fragilis BF-1; the investigation of any plasmids which might be discovered, with the aim of constructing a hybrid plasmid which might replicate in both E.coli and B.fragilis; and the preparation of a genetic library which could be screened for Bacteroides genes which might function in E.coli. Should any genes be isolated by screening the library they were to be studied with regard to their expression and regulation in E.coli. The above assays make use of radioactive markers such as 14 C, 35 S, 32 P, and 3 H in the labelling of RNA, plasmids and probes

  1. Genetics and molecular biology of hypotension

    Science.gov (United States)

    Robertson, D.

    1994-01-01

    Major strides in the molecular biology of essential hypertension are currently underway. This has tended to obscure the fact that a number of inherited disorders associated with low blood pressure exist and that these diseases may have milder and underrecognized phenotypes that contribute importantly to blood pressure variation in the general population. This review highlights some of the gene products that, if abnormal, could cause hypotension in some individuals. Diseases due to abnormalities in the catecholamine enzymes are discussed in detail. It is likely that genetic abnormalities with hypotensive phenotypes will be as interesting and diverse as those that give rise to hypertensive disorders.

  2. Molecular beam epitaxy a short history

    CERN Document Server

    Orton, J W

    2015-01-01

    This volume describes the development of molecular beam epitaxy from its origins in the 1960s through to the present day. It begins with a short historical account of other methods of crystal growth, both bulk and epitaxial, to set the subject in context, emphasising the wide range of semiconductor materials employed. This is followed by an introduction to molecular beams and their use in the Stern-Gerlach experiment and the development of the microwave MASER.

  3. Teaching molecular genetics: Chapter 1--Background principles and methods of molecular biology.

    NARCIS (Netherlands)

    Knoers, N.V.A.M.; Monnens, L.A.H.

    2006-01-01

    In this first chapter of the series "Teaching molecular genetics," an introduction to molecular genetics is presented. We describe the structure of DNA and genes and explain in detail the central dogma of molecular biology, that is, the flow of genetic information from DNA via RNA to polypeptide

  4. Implementation of molecular karyotyping in clinical genetics

    Directory of Open Access Journals (Sweden)

    Luca Lovrecic

    2013-11-01

    Full Text Available Rapid development of technologies for the study of the human genome is an expected step after the discovery and sequencing of the entire human genome. Chromosomal microarrays, which allow us to perform tens of thousands of previously individual experiments simultaneously, are being utilized in all areas of human genetics and genomics. Initially, this was applicable only for research purposes, but in the last few years their clinical diagnostic purposes are becoming more and more relevant. Using molecular karyotyping (also chromosomal microarray, comparative genomic hybridization with microarray, aCGH, one can analyze microdeletions / microduplications in the whole human genome at once. It is a first-tier cytogenetic diagnostic test instead of G-banded karyotyping in patients with developmental delay and/or congenital anomalies. Molecular karyotyping is used as a diagnostic test in patients with unexplained developmental delay and/or idiopathic intellectual disability and/or dysmorphic features and/or multiple congenital anomalies (DD/ID/DF/MCA. In addition, the method is used in prenatal diagnostics and in some centres also in preimplantation genetic diagnosis.The aim of this paper is to inform the professional community in the field about this new diagnostic method and its implementation in Slovenia, and to define the clinical situations where the method is appropriate.

  5. Chum and pink salmon genetics - Genetic and life history variation of southern chum and pink salmon

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The distribution of genetic and life history variation in chum (Oncorhynchus keta) and pink (O. gorbuscha) salmon in their southern range in North America is key to...

  6. Molecular Genetic Identification Of Some Flax Mutants

    International Nuclear Information System (INIS)

    AMER, I.M.; MOUSTAFA, H.A.M.

    2009-01-01

    Five flax genotypes (Linum usitatissimum L.) i.e., commercial cultivar Sakha 2, the mother variety Giza 4 and three mutant types induced by gamma rays, were screened for their salinity tolerance in field experiments (salinity concentration was 8600 and 8300 ppm for soil and irrigation water, respectively). Mutation 6 was the most salt tolerant as compared to the other four genotypes.RAPD technique was used to detect some molecular markers associated with salt tolerance in flax (Mut 6), RAPD-PCR results using 12 random primers exhibited 149 amplified fragments; 91.9% of them were polymorphic and twelve molecular markers (8.1%) for salt tolerant (mutant 6) were identified with molecular size ranged from 191 to 4159 bp and only eight primers successes to amplify these specific markers. Concerning the other mutants, Mut 15 and Mut 25 exhibited 4.3% and 16.2% specific markers, respectively. The induced mutants exhibited genetic similarity to the parent variety were about 51%, 58.3% and 61.1% for Mut 25, Mut 6 and Mut 15, respectively. These specific markers (SM) are used for identification of the induced mutations and it is important for new variety registration.

  7. Molecular characterization and assessment of genetic diversity of ...

    African Journals Online (AJOL)

    R Madhusudhana

    genetic diversity available at molecular level among a set of phenotypically different ... allele matching and cluster analysis based on unweighted neighbor- joining (Gascuel, 1997) ..... on isozyme data-a simulation study. Theor. Appl. Genet.

  8. Molecular characterization of genetic diversity in some durum wheat ...

    African Journals Online (AJOL)

    Molecular characterization of genetic diversity in some durum wheat ... African Journal of Biotechnology ... Thus, RAPD offer a potentially simple, rapid and reliable method to evaluate genetic variation and relatedness among ten wheat ...

  9. Molecular & Genetic Investigation of Tau in Chronic Traumatic Encephalopathy

    Science.gov (United States)

    2015-10-01

    AWARD NUMBER: W81XWH-14-1-0399 TITLE: Molecular & Genetic Investigation of Tau in Chronic Traumatic Encephalopathy PRINCIPAL INVESTIGATOR: John F...Include area code) October 2015 Annual Report 30 Sep 2014 - 29 Sep 2015 Molecular & Genetic Investigation of Tau in Chronic Traumatic Encephalopathy John... encephalopathy (CTE), but the underlying molecular changes remain unclear. Here, biochemical and genetic studies that deepen our understanding of the

  10. Population genetic structure and demographic history of small ...

    African Journals Online (AJOL)

    Population genetic structure and demographic history of small yellow croaker, ... diversity (0.0112 ± 0.0061 to 0.0141 ± 0.0075) were detected in the species. ... into two closely related clades, but did not appear to have any geographic ...

  11. From pesticides to genetically modified plants : history, economics and politics

    NARCIS (Netherlands)

    Zadoks, J.C.; Waibel, H.

    2000-01-01

    Two technologies of crop protection are compared, crop protection by pesticides and by Genetically Modified Plants (GMPs). The history of pesticides provides lessons relevant to the future of GMPs; (1) high pesticide usage is counter-productive, (2) the technology requires intensive regulation and

  12. Molecular research on the genetic diversity of Tunisian date palm ...

    African Journals Online (AJOL)

    Molecular research on the genetic diversity of Tunisian date palm ( Phoenix dactylifera L.) using the random amplified microsatellite polymorphism (RAMPO) and amplified fragment length polymorphism (AFLP) methods.

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

    Science.gov (United States)

    Kitchen, Andrew

    2008-01-01

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

  14. Molecular Genetic Studies of Some Eye Diseases Affecting the ...

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Molecular Genetic Studies of Some Eye Diseases Affecting the Indian Population. Single gene disorders. Complex eye diseases. Genotype-phenotype correlation. Molecular diagnostics.

  15. Chondrosarcoma: With Updates on Molecular Genetics

    Directory of Open Access Journals (Sweden)

    Mi-Jung Kim

    2011-01-01

    Full Text Available Chondrosarcoma (CHS is a malignant cartilage-forming tumor and usually occurs within the medullary canal of long bones and pelvic bones. Based on the morphologic feature alone, a correct diangosis of CHS may be difficult, Therefore, correlation of radiological and clinicopathological features is mandatory in the diagnosis of CHS. The prognosis of CHS is closely related to histologic grading, however, histologic grading may be subjective with high inter-observer variability. In this paper, we present histologic grading system and clinicopathological and radiological findings of conventional CHS. Subtypes of CHSs, such as dedifferentiated, mesenchymal, and clear cell CHSs are also presented. In addition, we introduce updated cytogenetic and molecular genetic findings to expand our understanding of CHS biology. New markers of cell differentiation, proliferation, and cell signaling might offer important therapeutic and prognostic information in near future.

  16. Eco-genetic modeling of contemporary life-history evolution.

    Science.gov (United States)

    Dunlop, Erin S; Heino, Mikko; Dieckmann, Ulf

    2009-10-01

    We present eco-genetic modeling as a flexible tool for exploring the course and rates of multi-trait life-history evolution in natural populations. We build on existing modeling approaches by combining features that facilitate studying the ecological and evolutionary dynamics of realistically structured populations. In particular, the joint consideration of age and size structure enables the analysis of phenotypically plastic populations with more than a single growth trajectory, and ecological feedback is readily included in the form of density dependence and frequency dependence. Stochasticity and life-history trade-offs can also be implemented. Critically, eco-genetic models permit the incorporation of salient genetic detail such as a population's genetic variances and covariances and the corresponding heritabilities, as well as the probabilistic inheritance and phenotypic expression of quantitative traits. These inclusions are crucial for predicting rates of evolutionary change on both contemporary and longer timescales. An eco-genetic model can be tightly coupled with empirical data and therefore may have considerable practical relevance, in terms of generating testable predictions and evaluating alternative management measures. To illustrate the utility of these models, we present as an example an eco-genetic model used to study harvest-induced evolution of multiple traits in Atlantic cod. The predictions of our model (most notably that harvesting induces a genetic reduction in age and size at maturation, an increase or decrease in growth capacity depending on the minimum-length limit, and an increase in reproductive investment) are corroborated by patterns observed in wild populations. The predicted genetic changes occur together with plastic changes that could phenotypically mask the former. Importantly, our analysis predicts that evolutionary changes show little signs of reversal following a harvest moratorium. This illustrates how predictions offered by

  17. The history of genetics in Mexico in the light of A Cultural History of Heredity.

    Science.gov (United States)

    Barahona, Ana

    2013-01-01

    In this paper I analyze the conditions for scientific research and the social relationships that allowed the establishment of genetics in Mexico, in the laboratory, the clinic and in agronomy. I give three examples to illustrate how the cultural history of heredity has enlightened this work: the introduction and institutionalization of Mendelism in Mexico, the hereditarian ideas of medical doctors in the late nineteenth century, and the introduction of medical genetics in Mexico.

  18. Molecular genetics of follicular cell thyroid carcinoma

    Directory of Open Access Journals (Sweden)

    Valentina D. Yakushina

    2016-09-01

    Full Text Available Thyroid cancer is the most frequent endocrine malignancy. In the most cases thyroid cancer arises from follicular cells. Diagnosis of the cancer is based on the cytological analysis of fine needle aspiration biopsy of thyroid nodes. But the accuracy of the cytological diagnosis is about 80% that leads to the false positive and false negative cases and wrong strategy of treatment. Identification of genetic and epigenetic markers in the biopsies will allow to improve diagnostic accuracy. This article describes mutations, aberrant DNA methylation and abnormal microRNA expression constituting the core of molecular genetics of follicular cell thyroid cancer. The mutations given in the article includes point mutations, fusions and copy number variation. Besides frequent and well described driver mutations in genes of МАРK, PI3K/Akt and Wnt signaling pathways, as well as TP53 and TERT genes, we introduce here less frequent mutations appeared in the literature during the past two years. In addition the article contains examples of diagnostic panels applying these markers.

  19. Teaching molecular genetics: Chapter 1--Background principles and methods of molecular biology.

    Science.gov (United States)

    Knoers, Nine V A M; Monnens, Leo A H

    2006-02-01

    In this first chapter of the series "Teaching molecular genetics," an introduction to molecular genetics is presented. We describe the structure of DNA and genes and explain in detail the central dogma of molecular biology, that is, the flow of genetic information from DNA via RNA to polypeptide (protein). In addition, several basic and frequently used general molecular tools, such as restriction enzymes, Southern blotting, DNA amplification and sequencing are discussed, in order to lay the foundations for the forthcoming chapters.

  20. Child Development and Molecular Genetics: 14 Years Later

    Science.gov (United States)

    Plomin, Robert

    2013-01-01

    Fourteen years ago, the first article on molecular genetics was published in this journal: "Child Development, Molecular Genetics, and What to Do With Genes Once They Are Found" (R. Plomin & M. Rutter, 1998). The goal of the article was to outline what developmentalists can do with genes once they are found. These new directions for developmental…

  1. Application of molecular genetic tools for forest pathology

    Science.gov (United States)

    Mee-Sook Kim; John Hanna; Amy Ross-Davis; Ned Klopfenstein

    2012-01-01

    In recent years, advances in molecular genetics have provided powerful tools to address critical issues in forest pathology to help promote resilient forests. Although molecular genetic tools are initially applied to understand individual components of forest pathosystems, forest pathosystems involve dynamic interactions among biotic and abiotic components of the...

  2. Molecular genetic studies in flax (Linum usitatissimum L.)

    NARCIS (Netherlands)

    Vromans, J.

    2006-01-01

    In this thesis five molecular genetic studies on flax ( Linum usitatissimum L.) are described, of which two chapters aim to characterize the genetic structure and the amount of genetic diversity in the primary and secondary gene pool of the crop species. Three chapters describe the development of

  3. Inference of population history and patterns from molecular data

    DEFF Research Database (Denmark)

    Tataru, Paula

    , the existing mathematical models and computational methods need to be reformulated. I address this from an inference perspective in two areas of bioinformatics. Population genetics studies the influence exerted by various factors on the dynamics of a population's genetic variation. These factors cover...... evolutionary forces, such as mutation and selection, but also changes in population size. The aim in population genetics is to untangle the history of a population from observed genetic variation. This subject is dominated by two dual models, the Wright-Fisher and coalescent. I first introduce a new...... approximation to the Wright-Fisher model, which I show to accurately infer split times between populations. This approximation can potentially be applied for inference of mutation rates and selection coefficients. I then illustrate how the coalescent process is the natural framework for detecting traces...

  4. Molecular genetic researches on the radiation genetics of Drosophila in JINR

    International Nuclear Information System (INIS)

    Afanas'eva, K.P.; Aleksandrova, M.V.; Aleksandrov, I.D.

    2016-01-01

    Molecular genetic studies of radiation-induced heritable DNA lesions are carried out by the genetic group of Laboratory of nuclear problem in Joint Institute for Nuclear Research. The first results of molecular analysis of γ –ray- and neutron-induced vestigial mutations using PCR and sequencing will be presented. (authors)

  5. MODY in Siberia – molecular genetics and clinical characteristics

    Directory of Open Access Journals (Sweden)

    Alla Konstantinovna Ovsyannikova

    2017-05-01

    Full Text Available The diagnosis of maturity onset diabetes of the young (MODY has high clinical significance in young patients (no absolute need for exogenous insulin; normoglycaemia in most patients achieved by dieting or taking oral hypoglycaemic agents and their relatives (high probability of first-degree relatives being carriers of mutations, which requires a thorough collection of family history and determination of the parameters of carbohydrate metabolism. Aim. This study aimed was to determine the clinical characteristics of different subtypes of MODY in a Siberian region. Materials and Methods. We performed an examination, biochemical and hormonal blood tests, ultrasound and molecular genetic testing of 20 patients with a clinical diagnosis of MODY. Results. Four subtypes of MODY were verified: MODY2 in 11 patients, MODY3 in two, MODY8 in one and MODY12 in two. Eleven patients (69% exhibited no clinical manifestations of carbohydrate metabolism disorders, and one patient showed weight loss during early stage of the disease. Comorbidities included dyslipidemia, thyroid gland disorders and arterial hypertension. One patient (6% exhibited diabetic nephropathy; two (13%, diabetic retinopathy and three (19%, peripheral neuropathy of lower legs. All patients achieved the target carbohydrate metabolism; the level of C-peptide was within the reference range. Conclusion. Four different subtypes of MODY (2, 3, 8, 12 were diagnosed in the present study, which differed in their clinical characteristics, presence of complications and treatment strategies. Our knowledge of monogenic forms of diabetes is expanding with the development in molecular genetics, but several aspects related to them require further study.

  6. The Genetic Structure and History of Africans and African Americans

    Science.gov (United States)

    Tishkoff, Sarah A.; Reed, Floyd A.; Friedlaender, Françoise R.; Ehret, Christopher; Ranciaro, Alessia; Froment, Alain; Hirbo, Jibril B.; Awomoyi, Agnes A.; Bodo, Jean-Marie; Doumbo, Ogobara; Ibrahim, Muntaser; Juma, Abdalla T.; Kotze, Maritha J.; Lema, Godfrey; Moore, Jason H.; Mortensen, Holly; Nyambo, Thomas B.; Omar, Sabah A.; Powell, Kweli; Pretorius, Gideon S.; Smith, Michael W.; Thera, Mahamadou A.; Wambebe, Charles; Weber, James L.; Williams, Scott M.

    2010-01-01

    Africa is the source of all modern humans, but characterization of genetic variation and of relationships among populations across the continent has been enigmatic. We studied 121 African populations, four African American populations, and 60 non-African populations for patterns of variation at 1327 nuclear microsatellite and insertion/deletion markers. We identified 14 ancestral population clusters in Africa that correlate with self-described ethnicity and shared cultural and/or linguistic properties. We observed high levels of mixed ancestry in most populations, reflecting historical migration events across the continent. Our data also provide evidence for shared ancestry among geographically diverse hunter-gatherer populations (Khoesan speakers and Pygmies). The ancestry of African Americans is predominantly from Niger-Kordofanian (~71%), European (~13%), and other African (~8%) populations, although admixture levels varied considerably among individuals. This study helps tease apart the complex evolutionary history of Africans and African Americans, aiding both anthropological and genetic epidemiologic studies. PMID:19407144

  7. The molecular genetic basis of age-related macular degeneration ...

    Indian Academy of Sciences (India)

    2009-12-10

    Dec 10, 2009 ... this review, we have provided an overview on the underlying molecular genetic mechanisms in AMD worldwide and highlight ..... eases like diabetes (Scott et al. ...... 2006 Systematic review and meta-analysis of.

  8. A genetic analysis of segregation distortion revealed by molecular ...

    Indian Academy of Sciences (India)

    Journal of Genetics, Vol. 90, No. ... Segregation analysis was based on 64 molecular markers, including 26 .... FHB of RIL populations was controlled by quantitative trait ... The authors acknowledge financial support by the National Basic.

  9. Phenotypic and molecular genetic analysis of Pyruvate Kinase ...

    African Journals Online (AJOL)

    Phenotypic and molecular genetic analysis of Pyruvate Kinase deficiency in a Tunisian family. Jaouani Mouna, Hamdi Nadia, Chaouch Leila, Kalai Miniar, Mellouli Fethi, Darragi Imen, Boudriga Imen, Chaouachi Dorra, Bejaoui Mohamed, Abbes Salem ...

  10. Molecular Genetic and Gene Therapy Studies of the Musculoskeletal System

    National Research Council Canada - National Science Library

    Baylink, David

    2004-01-01

    The primary goal of the proposed work is to apply several state of the art molecular genetic and gene therapy technologies to address fundamental questions in bone biology with a particular emphasis on attempting: l...

  11. NEW MOLECULAR TECHNOLOGIES IN GENETIC DIAGNOSIS OF MALE INFERTILITY

    Directory of Open Access Journals (Sweden)

    V. B. Chernykh

    2017-01-01

    Full Text Available In recent years, the accelerated development of technologies in the field of molecular genetics and cytogenetics has led to significant opportunities of the research and diagnosis of mutations and variations of the genome. This article provides a brief review of new molecular technology, also as the results of their use in reproductive medicine and their perspectives in the genetic diagnosis of male infertility. 

  12. Endometrial cancer : from a molecular genetic perspective

    NARCIS (Netherlands)

    E. Smid-Koopman (Ellen)

    2002-01-01

    textabstractThe first observations indicative of a role of genetic factors in carcinogenesis were made as early as 1912, when Rous demonstrated that a filterable agent (i.e. virus) could induce cancer in chicken (Rous 1965). In 1914, Boveri postulated a "genetic" theory on carcinogenesis by

  13. Molecular and Genetic Basis of Stress

    Directory of Open Access Journals (Sweden)

    Bakir Mehić

    2012-05-01

    Full Text Available A person’s reaction to trauma depends on the traumatic situation itself, personality characteristics of the person exposed to trauma, and posttraumatic social environment. Stressor must be extreme event that is extremely dangerous or fatal nature, and which is outside normal human experience [1].Studies investigating psychological consequences of military and civil trauma confirmed the correlation between the nature and intensity of trauma, previous traumatic experience, and psychological consequences. Stress causes the autonomic nervous system hyperactivity. If the stress is extreme or constant symptoms of hyperactivity, increased heart rate, increased respiration, sweating, muscle tension, insomnia and increased anxiety are becoming significant for the prolonging the symptoms of PTSD. Our cells are well adapted to exposure to a mild stress for a short time. In contrast there are potentially serious consequences of exposure to the prolonged stress[2].Various damages arising from the war in Bosnia (1992 - 1995 are almost undetectable, and the consequences for the mental health of the population of Bosnia and Herzegovina are long and painful. It is estimated that in Bosnia and Herzegovina there are 1.75 million people who have some stress-related mental disorders, of which 1 million in the Federation.PTSD may be represented by mutations that must be carried by many genes. There may even be epigenetic reasons for the disorder that have nothing to do with heritable mutations per se. Epigenetic means related to functional changes in the genome that can be regulated by external environmental events that do not involve alterations in the genetic code. One epigenetic mechanism is called “methylation,” a molecular process that affects the activity of a large percentage of genes. Epigenetic investigations say that methylation may be involved in the development of stress regulation in early life[3].A number of longitudinal studies have looked at

  14. Assessing Date Palm Genetic Diversity Using Different Molecular Markers.

    Science.gov (United States)

    Atia, Mohamed A M; Sakr, Mahmoud M; Adawy, Sami S

    2017-01-01

    Molecular marker technologies which rely on DNA analysis provide powerful tools to assess biodiversity at different levels, i.e., among and within species. A range of different molecular marker techniques have been developed and extensively applied for detecting variability in date palm at the DNA level. Recently, the employment of gene-targeting molecular marker approaches to study biodiversity and genetic variations in many plant species has increased the attention of researchers interested in date palm to carry out phylogenetic studies using these novel marker systems. Molecular markers are good indicators of genetic distances among accessions, because DNA-based markers are neutral in the face of selection. Here we describe the employment of multidisciplinary molecular marker approaches: amplified fragment length polymorphism (AFLP), start codon targeted (SCoT) polymorphism, conserved DNA-derived polymorphism (CDDP), intron-targeted amplified polymorphism (ITAP), simple sequence repeats (SSR), and random amplified polymorphic DNA (RAPD) to assess genetic diversity in date palm.

  15. Supplementary data: Molecular assessment of genetic diversity in ...

    Indian Academy of Sciences (India)

    Molecular assessment of genetic diversity in cluster bean. (Cyamopsis tetragonoloba) genotypes. Rakesh Pathak, S. K. Singh, Manjit Singh and A. Henry. J. Genet. 89, 243–246. Figure 1. RAPD profile of 1–16 Cyamopsis tetragonoloba genotypes amplified with arbitrary primer OPA-16. Figure 2. RAPD profile of 17–32 ...

  16. Molecular evaluation of genetic diversity and association studies in ...

    Indian Academy of Sciences (India)

    Molecular evaluation of genetic diversity and association studies in rice. (Oryza sativa L.) C. Vanniarajan, K. K. Vinod and Andy Pereira. J. Genet. 91, 9–19. Table 1. Chromosome-wise distribution of SSR alleles and their number (k), polymorphic information content (PIC) and allele discrimination index (Dm). Chromosome.

  17. Molecular research and genetic engineering of resistance to ...

    African Journals Online (AJOL)

    This paper reviews the recent research progress on genetic methods of resistance, the status and existing problems, traditional breeding, the main resistance mechanism, molecular markers and genetic engineering of resistance genes. It is hoped that new breeding methods and new varieties resistant to Verticillium wilt will ...

  18. Use of molecular genetics and historical records to reconstruct the ...

    African Journals Online (AJOL)

    Recent advances in molecular genetics made the inference of past demographic events through the analysis of gene pools from modern populations possible. The technology uses genetic markers to provide previously unavailable resolution into questions of human evolution, migration and the historical relationship of ...

  19. Molecular Darwinism: The Contingency of Spontaneous Genetic Variation

    OpenAIRE

    Arber, Werner

    2011-01-01

    The availability of spontaneously occurring genetic variants is an important driving force of biological evolution. Largely thanks to experimental investigations by microbial geneticists, we know today that several different molecular mechanisms contribute to the overall genetic variations. These mechanisms can be assigned to three natural strategies to generate genetic variants: 1) local sequence changes, 2) intragenomic reshuffling of DNA segments, and 3) acquisition of a segment of foreign...

  20. Autosomal dominant cyclic hematopoiesis: Genetics, phenotype, and natural history

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, S.E.; Stephens, K.; Dale, D.C. [Univ. of Washington, Seattle, WA (United States)

    1994-09-01

    Autosomal dominant cyclic hematopoiesis (ADCH; cyclic neutropenia) is a rare disorder manifested by transient neutropenia that recurs every three weeks. To facilitate mapping the ADCH gene by genetic linkage analysis, we studied 9 ADCH families with 42 affected individuals. Pedigrees revealed AD inheritance with no evidence for decreased penetrance. Similar intra- and interfamilial variable expression was observed, with no evidence to support heterogeneity. At least 3 families displayed apparent new mutations. Many adults developed chronic neutropenia, while offspring always cycled during childhood. Children displayed recurrent oral ulcers, gingivitis, lymphadenopathy, fever, and skin and other infections with additional symptoms. Interestingly, there were no cases of neonatal infection. Some children required multiple hospitalizations for treatment. Four males under age 18 died of Clostridium sepsis following necrotizing enterocolitis; all had affected mothers. No other deaths due to ADCH were found; most had improvement of symptoms and infections as adults. Adults experienced increased tooth loss prior to age 30 (16 out of 27 adults, with 9 edentulous). No increase in myelodysplasia, malignancy, or congenital anomalies was observed. Recombinant G-CSF treatment resulted in dramatic improvement of symptoms and infections. The results suggest that ADCH is not a benign disorder, especially in childhood, and abdominal pain requires immediate evaluation. Diagnosis of ADCH requires serial blood counts in the proband and at least one CBC in relatives to exclude similar disorders. Genetic counseling requires specific histories as well as CBCs of each family member at risk to determine status regardless of symptom history, especially to assess apparent new mutations.

  1. Molecular Study of the Amazonian Macabea Cattle History.

    Science.gov (United States)

    Vargas, Julio; Landi, Vincenzo; Martínez, Amparo; Gómez, Mayra; Camacho, María Esperanza; Álvarez, Luz Ángela; Aguirre, Lenin; Delgado, Juan Vicente

    2016-01-01

    Macabea cattle are the only Bos taurus breed that have adapted to the wet tropical conditions of the Amazon. This breed has integrated into the culture of the indigenous Shuar-Asuar nations probably since its origins, being one of the few European zoogenetic resources assimilated by the deep-jungle Amazon communities. Despite its potential for local endogenous sustainable development, this breed is currently endangered. The present study used molecular genetics tools to investigate the within- and between-breeds diversity, in order to characterize the breed population, define its associations with other breeds, and infer its origin and evolution. The within-breed genetic diversity showed high values, as indicated by all genetic parameters, such as the mean number of alleles (MNA = 7.25±2.03), the observed heterozygosity (Ho = 0.72±0.02) and the expected heterozygosity (He = 0.72±0.02). The between-breeds diversity analysis, which included factorial correspondence analysis, Reynolds genetic distance, neighbor-joining analysis, and genetic structure analysis, showed that the Macabea breed belongs to the group of the American Creoles, with a Southern-Spain origin. Our outcomes demonstrated that the Macabea breed has a high level of purity and null influences of exotic cosmopolitan breeds with European or Asiatic origin. This breed is an important zoogenetic resource of Ecuador, with relevant and unique attributes; therefore, there is an urgent need to develop conservation strategies for the Macabea breed.

  2. Micropropagation, genetic engineering, and molecular biology of Populus

    Science.gov (United States)

    N. B. Klopfenstein; Y. W. Chun; M. -S. Kim; M. A. Ahuja; M. C. Dillon; R. C. Carman; L. G. Eskew

    1997-01-01

    Thirty-four Populus biotechnology chapters, written by 85 authors, are comprised in 5 sections: 1) in vitro culture (micropropagation, somatic embryogenesis, protoplasts, somaclonal variation, and germplasm preservation); 2) transformation and foreign gene expression; 3) molecular biology (molecular/genetic characterization); 4) biotic and abiotic resistance (disease,...

  3. Molecular and genetic study of wheat rusts

    African Journals Online (AJOL)

    Nicholas Le Maitre

    Phylogenetic trees were created for leaf and stem rust pathotypes. Field isolates of ... Key words: Prevalence, microsatellite, amplified fragment length polymorphisms (AFLP), phylogeny, Puccinia. INTRODUCTION. Puccinia triticina Eriks ..... Genetic distances and reconstruction phylogenetic trees from microsatellite DNA.

  4. Dissecting molecular stress networks: identifying nodes of divergence between life-history phenotypes.

    Science.gov (United States)

    Schwartz, Tonia S; Bronikowski, Anne M

    2013-02-01

    The complex molecular network that underlies physiological stress response is comprised of nodes (proteins, metabolites, mRNAs, etc.) whose connections span cells, tissues and organs. Variable nodes are points in the network upon which natural selection may act. Thus, identifying variable nodes will reveal how this molecular stress network may evolve among populations in different habitats and how it might impact life-history evolution. Here, we use physiological and genetic assays to test whether laboratory-born juveniles from natural populations of garter snakes (Thamnophis elegans), which have diverged in their life-history phenotypes, vary concomitantly at candidate nodes of the stress response network, (i) under unstressed conditions and (ii) in response to an induced stress. We found that two common measures of stress (plasma corticosterone and liver gene expression of heat shock proteins) increased under stress in both life-history phenotypes. In contrast, the phenotypes diverged at four nodes both under unstressed conditions and in response to stress: circulating levels of reactive oxygen species (superoxide, H(2)O(2)); liver gene expression of GPX1 and erythrocyte DNA damage. Additionally, allele frequencies for SOD2 diverge from neutral markers, suggesting diversifying selection on SOD2 alleles. This study supports the hypothesis that these life-history phenotypes have diverged at the molecular level in how they respond to stress, particularly in nodes regulating oxidative stress. Furthermore, the differences between the life-history phenotypes were more pronounced in females. We discuss the responses to stress in the context of the associated life-history phenotype and the evolutionary pressures thought to be responsible for divergence between the phenotypes. © 2012 Blackwell Publishing Ltd.

  5. Molecular diversity and genetic relationships in Secale

    Indian Academy of Sciences (India)

    2001); and molecular methods such as amplified fragment length polymorphism ... to the maintenance and rational use of germplasm resources in the improvement of ... study of diversity of ScMATE1 gene in different species of. Secale genus.

  6. Assessing individual risk for AMD with genetic counseling, family history, and genetic testing.

    Science.gov (United States)

    Cascella, R; Strafella, C; Longo, G; Manzo, L; Ragazzo, M; De Felici, C; Gambardella, S; Marsella, L T; Novelli, G; Borgiani, P; Sangiuolo, F; Cusumano, A; Ricci, F; Giardina, E

    2018-02-01

    PurposeThe goal was to develop a simple model for predicting the individual risk profile for age-related macular degeneration (AMD) on the basis of genetic information, disease family history, and smoking habits.Patients and methodsThe study enrolled 151 AMD patients following specific clinical and environmental inclusion criteria: age >55 years, positive family history for AMD, presence of at least one first-degree relative affected by AMD, and smoking habits. All of the samples were genotyped for rs1061170 (CFH) and rs10490924 (ARMS2) with a TaqMan assay, using a 7500 Fast Real Time PCR device. Statistical analysis was subsequently employed to calculate the real individual risk (OR) based on the genetic data (ORgn), family history (ORf), and smoking habits (ORsm).Results and conclusionThe combination of ORgn, ORf, and ORsm allowed the calculation of the Ort that represented the realistic individual risk for developing AMD. In this report, we present a computational model for the estimation of the individual risk for AMD. Moreover, we show that the average distribution of risk alleles in the general population and the knowledge of parents' genotype can be decisive to assess the real disease risk. In this contest, genetic counseling is crucial to provide the patients with an understanding of their individual risk and the availability for preventive actions.

  7. Molecular genetics of hemophilia A: Clinical perspectives

    African Journals Online (AJOL)

    Azza A.G. Tantawy

    Evaluation of an individual with a suspected bleeding disorder includes: platelet count .... information for genetic counseling of at-risk family members. It is indicated for ... Patients with blood group O and a low von Willebrand antigen level have a ..... [4] Husain N. Carrier analysis for hemophilia A: ideal versus acceptable.

  8. Molecular markers: a potential resource for ginger genetic diversity studies.

    Science.gov (United States)

    Ismail, Nor Asiah; Rafii, M Y; Mahmud, T M M; Hanafi, M M; Miah, Gous

    2016-12-01

    Ginger is an economically important and valuable plant around the world. Ginger is used as a food, spice, condiment, medicine and ornament. There is available information on biochemical aspects of ginger, but few studies have been reported on its molecular aspects. The main objective of this review is to accumulate the available molecular marker information and its application in diverse ginger studies. This review article was prepared by combing material from published articles and our own research. Molecular markers allow the identification and characterization of plant genotypes through direct access to hereditary material. In crop species, molecular markers are applied in different aspects and are useful in breeding programs. In ginger, molecular markers are commonly used to identify genetic variation and classify the relatedness among varieties, accessions, and species. Consequently, it provides important input in determining resourceful management strategies for ginger improvement programs. Alternatively, a molecular marker could function as a harmonizing tool for documenting species. This review highlights the application of molecular markers (isozyme, RAPD, AFLP, SSR, ISSR and others such as RFLP, SCAR, NBS and SNP) in genetic diversity studies of ginger species. Some insights on the advantages of the markers are discussed. The detection of genetic variation among promising cultivars of ginger has significance for ginger improvement programs. This update of recent literature will help researchers and students select the appropriate molecular markers for ginger-related research.

  9. HNPCC (Lynch Syndrome: Differential Diagnosis, Molecular Genetics and Management - a Review

    Directory of Open Access Journals (Sweden)

    Lynch Henry T

    2003-12-01

    Full Text Available Abstract HNPCC (Lynch syndrome is the most common form of hereditary colorectal cancer (CRC, wherein it accounts for between 2-7 percent of the total CRC burden. When considering the large number of extracolonic cancers integral to the syndrome, namely carcinoma of the endometrium, ovary, stomach, hepatobiliary system, pancreas, small bowel, brain tumors, and upper uroepithelial tract, these estimates of its frequency are likely to be conservative. The diagnosis is based upon its natural history in concert with a comprehensive cancer family history inclusive of all anatomic sites. In order for surveillance and management to be effective and, indeed, lifesaving, among these high-risk patients, the linchpin to cancer control would be the physician, who must be knowledgeable about hereditary cancer syndromes, their molecular and medical genetics, genetic counseling, and, most importantly, the natural history of the disorders, so that the entirety of this knowledge can be melded to highly-targeted management.

  10. HNPCC (Lynch Syndrome): Differential Diagnosis, Molecular Genetics and Management - a Review

    Science.gov (United States)

    2003-01-01

    HNPCC (Lynch syndrome) is the most common form of hereditary colorectal cancer (CRC), wherein it accounts for between 2-7 percent of the total CRC burden. When considering the large number of extracolonic cancers integral to the syndrome, namely carcinoma of the endometrium, ovary, stomach, hepatobiliary system, pancreas, small bowel, brain tumors, and upper uroepithelial tract, these estimates of its frequency are likely to be conservative. The diagnosis is based upon its natural history in concert with a comprehensive cancer family history inclusive of all anatomic sites. In order for surveillance and management to be effective and, indeed, lifesaving, among these high-risk patients, the linchpin to cancer control would be the physician, who must be knowledgeable about hereditary cancer syndromes, their molecular and medical genetics, genetic counseling, and, most importantly, the natural history of the disorders, so that the entirety of this knowledge can be melded to highly-targeted management.

  11. Molecular discrimination and genetic relationships between some ...

    African Journals Online (AJOL)

    Cucurbita pepo ssp. pepo; zucchini group is a widely grown and economically important group belonging to genus Cucurbita, and being one of the easiest groups to cultivate in temperate climate with overwhelming production. Since, RAPD analysis provides a fast and reliable method for molecular characterization and ...

  12. Genetics of asthma: a molecular biologist perspective

    OpenAIRE

    Ghosh Balaram; Kumar Amrendra

    2009-01-01

    Abstract Asthma belongs to the category of classical allergic diseases which generally arise due to IgE mediated hypersensitivity to environmental triggers. Since its prevalence is very high in developed or urbanized societies it is also referred to as "disease of civilizations". Due to its increased prevalence among related individuals, it was understood quite long back that it is a genetic disorder. Well designed epidemiological studies reinforced these views. The advent of modern biologica...

  13. Medical Genetics at McGill: The History of a Pioneering Research Group.

    Science.gov (United States)

    Canning, Christopher; Weisz, George; Tone, Andrea; Cambrosio, Alberto

    2013-01-01

    The McGill Group in Medical Genetics was formed in 1972, supported by the Medical Research Council and successor Canadian Institutes for Health Research until September 2009, making it the longest active biomedical research group in the history of Canada. We document the history of the McGill Group and situate its research within a broader history of medical genetics. Drawing on original oral histories with the Group's members, surviving documents, and archival materials, we explore how the Group's development was structured around epistemological trends in medical genetics, policy choices made by research agencies, and the development of genetics at McGill University and its hospitals.

  14. Molecular and Genetic Determinants of Glioma Cell Invasion

    Directory of Open Access Journals (Sweden)

    Kenta Masui

    2017-12-01

    Full Text Available A diffusely invasive nature is a major obstacle in treating a malignant brain tumor, “diffuse glioma”, which prevents neurooncologists from surgically removing the tumor cells even in combination with chemotherapy and radiation. Recently updated classification of diffuse gliomas based on distinct genetic and epigenetic features has culminated in a multilayered diagnostic approach to combine histologic phenotypes and molecular genotypes in an integrated diagnosis. However, it is still a work in progress to decipher how the genetic aberrations contribute to the aggressive nature of gliomas including their highly invasive capacity. Here we depict a set of recent discoveries involving molecular genetic determinants of the infiltrating nature of glioma cells, especially focusing on genetic mutations in receptor tyrosine kinase pathways and metabolic reprogramming downstream of common cancer mutations. The specific biology of glioma cell invasion provides an opportunity to explore the genotype-phenotype correlation in cancer and develop novel glioma-specific therapeutic strategies for this devastating disease.

  15. History, genetics, and strategies for cancer prevention in Lynch syndrome.

    Science.gov (United States)

    Kastrinos, Fay; Stoffel, Elena M

    2014-05-01

    Colorectal cancer (CRC) is the most common gastrointestinal malignancy and the third cause of cancer death in men and women in the United States. The majority of CRC cases diagnosed annually are due to sporadic events, but up to 6% are attributed to known monogenic disorders that confer a markedly increased risk for the development of CRC and multiple extracolonic malignancies. Lynch syndrome is the most common inherited CRC syndrome and is associated with mutations in DNA mismatch repair genes, mainly MLH1 and MSH2 but also MSH6, PMS2, and EPCAM. Although the risk of CRC and endometrial cancer may approach near 75% and 50%, respectively, in gene mutation carriers, the identification of these individuals and at-risk family members through predictive genetic testing provides opportunities for cancer prevention including specialized cancer screening, intensified surveillance, and/or prophylactic surgeries. This article will provide a review of the major advances in risk assessment, molecular genetics, DNA mutational analyses, and cancer prevention and management made since Lynch syndrome was first described 100 years ago. Copyright © 2014 AGA Institute. Published by Elsevier Inc. All rights reserved.

  16. Primer on molecular genetics. DOE Human Genome Program

    Energy Technology Data Exchange (ETDEWEB)

    1992-04-01

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

  17. Molecular, metabolic, and genetic control: An introduction

    Science.gov (United States)

    Tyson, John J.; Mackey, Michael C.

    2001-03-01

    The living cell is a miniature, self-reproducing, biochemical machine. Like all machines, it has a power supply, a set of working components that carry out its necessary tasks, and control systems that ensure the proper coordination of these tasks. In this Special Issue, we focus on the molecular regulatory systems that control cell metabolism, gene expression, environmental responses, development, and reproduction. As for the control systems in human-engineered machines, these regulatory networks can be described by nonlinear dynamical equations, for example, ordinary differential equations, reaction-diffusion equations, stochastic differential equations, or cellular automata. The articles collected here illustrate (i) a range of theoretical problems presented by modern concepts of cellular regulation, (ii) some strategies for converting molecular mechanisms into dynamical systems, (iii) some useful mathematical tools for analyzing and simulating these systems, and (iv) the sort of results that derive from serious interplay between theory and experiment.

  18. Advances in molecular genetic studies of primary dystonia

    Directory of Open Access Journals (Sweden)

    MA Ling-yan

    2013-07-01

    Full Text Available Dystonias are heterogeneous hyperkinetic movement disorders characterized by involuntary muscle contractions which result in twisting, repetitive movements and abnormal postures. In recent years, there was a great advance in molecular genetic studies of primary dystonia. This paper will review the clinical characteristics and molecular genetic studies of primary dystonia, including early-onset generalized torsion dystonia (DYT1, whispering dysphonia (DYT4, dopa-responsive dystonia (DYT5, mixed-type dystonia (DYT6, paroxysmal kinesigenic dyskinesia (DYT10, myoclonus-dystonia syndrome (DYT11, rapid-onset dystonia parkinsonism (DYT12, adult-onset cervical dystonia (DYT23, craniocervical dystonia (DYT24 and primary torsion dystonia (DYT25.

  19. Molecular genetics of inherited eye disorders.

    Science.gov (United States)

    MacDonald, I M; Sasi, R

    1994-10-01

    In the past 10 y, there have been considerable advances in the mapping, isolation, and characterization of many genes for important ocular conditions: retinitis pigmentosa, Norrie disease, Waardenburg syndrome, choroideremia, aniridia, retinoblastoma, and others. The candidate gene approach has now supplemented classical linkage studies and positional cloning in the investigation of ocular disorders. Developmentally expressed genes and animal models have provided insights as to the etiology of other disorders. With this knowledge at hand, genetic counselling for heritable eye diseases has been greatly improved.

  20. Use of molecular genetics and historical records to reconstruct the ...

    African Journals Online (AJOL)

    GRACE

    2006-12-29

    Dec 29, 2006 ... paternally inherited counterpart, the Y chromosome have been widely used for the ... for studies of maternal genetic history (Peričić et al.,. 2005). For the Y .... regarding its interactions with the other commu-nities living in the ...

  1. Molecular genetics of pituitary development in zebrafish.

    Science.gov (United States)

    Pogoda, Hans-Martin; Hammerschmidt, Matthias

    2007-08-01

    The pituitary gland of vertebrates consists of two major parts, the neurohypophysis (NH) and the adenohypophysis (AH). As a central part of the hypothalamo-hypophyseal system (HHS), it constitutes a functional link between the nervous and the endocrine system to regulate basic body functions, such as growth, metabolism and reproduction. The development of the AH has been intensively studied in mouse, serving as a model for organogenesis and differential cell specification. However, given that the AH is a relatively recent evolutionary advance of the chordate phylum, it is also interesting to understand its development in lower chordate systems. In recent years, the zebrafish has emerged as a powerful lower vertebrate system for developmental studies, being amenable for large-scale genetic approaches, embryological manipulations, and in vivo imaging. Here, we present an overview of current knowledge of the mechanisms and genetic control of pituitary formation during zebrafish development. First, we describe the components of the zebrafish HHS, and the different pituitary cell types and hormones, followed by a description of the different steps of normal pituitary development. The central part of the review deals with the genes found to be essential for zebrafish AH development, accompanied by a description of the corresponding mutant phenotypes. Finally, we discuss future directions, with particular focus on evolutionary aspects, and some novel functional aspects with growing medical and social relevance.

  2. Molecular genetics and epigenetics of CACTA elements

    KAUST Repository

    Fedoroff, Nina V.

    2013-08-21

    The CACTA transposons, so named for a highly conserved motif at element ends, comprise one of the most abundant superfamilies of Class 2 (cut-and-paste) plant transposons. CACTA transposons characteristically include subterminal sequences of several hundred nucleotides containing closely spaced direct and inverted repeats of a short, conserved sequence of 14-15 bp. The Supressor-mutator (Spm) transposon, identified and subjected to detailed genetic analysis by Barbara McClintock, remains the paradigmatic element of the CACTA family. The Spm transposon encodes two proteins required for transposition, the transposase (TnpD) and a regulatory protein (TnpA) that binds to the subterminal repeats. Spm expression is subject to both genetic and epigenetic regulation. The Spm-encoded TnpA serves as an activator of the epigenetically inactivated, methylated Spm, stimulating both transient and heritable activation of the transposon. TnpA also serves as a negative regulator of the demethylated active element promoter and is required, in addition to the TnpD, for transposition. © Springer Science+Business Media, New York 2013.

  3. Genetic factors and molecular mechanisms in dry eye disease.

    Science.gov (United States)

    Lee, Ling; Garrett, Qian; Flanagan, Judith; Chakrabarti, Subhabrata; Papas, Eric

    2018-04-01

    Dry eye disease (DED) is a complex condition with a multifactorial etiology that can be difficult to manage successfully. While external factors are modifiable, treatment success is limited if genetic factors contribute to the disease. The purpose of this review is to compile research describing normal and abnormal ocular surface function on a molecular level, appraise genetic studies involving DED or DED-associated diseases, and introduce the basic methods used for conducting genetic epidemiology studies. Copyright © 2018 Elsevier Inc. All rights reserved.

  4. Genetic Breeding and Diversity of the Genus Passiflora: Progress and Perspectives in Molecular and Genetic Studies

    Directory of Open Access Journals (Sweden)

    Carlos Bernard M. Cerqueira-Silva

    2014-08-01

    Full Text Available Despite the ecological and economic importance of passion fruit (Passiflora spp., molecular markers have only recently been utilized in genetic studies of this genus. In addition, both basic genetic researches related to population studies and pre-breeding programs of passion fruit remain scarce for most Passiflora species. Considering the number of Passiflora species and the increasing use of these species as a resource for ornamental, medicinal, and food purposes, the aims of this review are the following: (i to present the current condition of the passion fruit crop; (ii to quantify the applications and effects of using molecular markers in studies of Passiflora; (iii to present the contributions of genetic engineering for passion fruit culture; and (iv to discuss the progress and perspectives of this research. Thus, the present review aims to summarize and discuss the relationship between historical and current progress on the culture, breeding, and molecular genetics of passion fruit.

  5. Molecular Darwinism: the contingency of spontaneous genetic variation.

    Science.gov (United States)

    Arber, Werner

    2011-01-01

    The availability of spontaneously occurring genetic variants is an important driving force of biological evolution. Largely thanks to experimental investigations by microbial geneticists, we know today that several different molecular mechanisms contribute to the overall genetic variations. These mechanisms can be assigned to three natural strategies to generate genetic variants: 1) local sequence changes, 2) intragenomic reshuffling of DNA segments, and 3) acquisition of a segment of foreign DNA. In these processes, specific gene products are involved in cooperation with different nongenetic elements. Some genetic variations occur fully at random along the DNA filaments, others rather with a statistical reproducibility, although at many possible sites. We have to be aware that evolution in natural ecosystems is of higher complexity than under most laboratory conditions, not at least in view of symbiotic associations and the occurrence of horizontal gene transfer. The encountered contingency of genetic variation can possibly best ensure a long-term persistence of life under steadily changing living conditions.

  6. Asymmetry in family history implicates nonstandard genetic mechanisms: application to the genetics of breast cancer.

    Directory of Open Access Journals (Sweden)

    Clarice R Weinberg

    2014-03-01

    Full Text Available Genome-wide association studies typically target inherited autosomal variants, but less studied genetic mechanisms can play a role in complex disease. Sex-linked variants aside, three genetic phenomena can induce differential risk in maternal versus paternal lineages of affected individuals: 1. maternal effects, reflecting the maternal genome's influence on prenatal development; 2. mitochondrial variants, which are inherited maternally; 3. autosomal genes, whose effects depend on parent of origin. We algebraically show that small asymmetries in family histories of affected individuals may reflect much larger genetic risks acting via those mechanisms. We apply these ideas to a study of sisters of women with breast cancer. Among 5,091 distinct families of women reporting that exactly one grandmother had breast cancer, risk was skewed toward maternal grandmothers (p<0.0001, especially if the granddaughter was diagnosed between age 45 and 54. Maternal genetic effects, mitochondrial variants, or variant genes with parent-of-origin effects may influence risk of perimenopausal breast cancer.

  7. Avoiding Pitfalls in Molecular Genetic Testing: Case Studies of High-Resolution Array Comparative Genomic Hybridization Testing in the Definitive Diagnosis of Mowat-Wilson Syndrome

    OpenAIRE

    Kluk, Michael Joseph; An, Yu; James, Philip; Coulter, David; Harris, David; Wu, Bai-Lin; Shen, Yiping

    2011-01-01

    The molecular testing options available for the diagnosis of genetic disorders are numerous and include a variety of different assay platforms. The consultative input of molecular pathologists and cytogeneticists, working closely with the ordering clinicians, is often important for definitive diagnosis. Herein, we describe two patients who had long histories of unexplained signs and symptoms with a high clinical suspicion of an underlying genetic etiology. Initial molecular testing in both ca...

  8. Molecular Models of Genetic and Organismic Structures

    CERN Document Server

    Baianu, I C

    2004-01-01

    In recent studies we showed that the earlier relational theories of organismic sets (Rashevsky,1967), Metabolic-Replication (M,R)-systems (Rosen,1958)and molecular sets (Bartholomay,1968) share a joint foundation that can be studied within a unified categorical framework of functional organismic structures (Baianu,1980. This is possible because all relational theories have a biomolecular basis, that is, complex structures such as genomes, cells,organs and biological organisms are mathematically represented in terms of biomolecular properties and entities,(that are often implicit in their representation axioms. The definition of organismic sets, for example, requires that certain essential quantities be determined from experiment: these are specified by special sets of values of general observables that are derived from physicochemical measurements(Baianu,1970; Baianu,1980; Baianu et al, 2004a.)Such observables are context-dependent and lead directly to natural transformations in categories and Topoi, that are...

  9. Study of human genetic diversity : inferences on population origin and history

    OpenAIRE

    Haber, Marc, 1980-

    2013-01-01

    Patterns of human genetic diversity suggest that all modern humans originated from a small population in Africa that expanded rapidly 50,000 years ago to occupy the whole world. While moving into new environments, genetic drift and natural selection affected populations differently, creating genetic structure. By understanding the genetic structure of human populations, we can reconstruct human history and understand the genetic basis of diseases. The work presented here contributes to the on...

  10. Isolation and molecular genetic characterization of a yeast strain ...

    African Journals Online (AJOL)

    The yeast was identified by molecular genetics technique based on sequence analysis of the variable D1/D2 domain of the large subunit (26S) ribosomal DNA. Subsequent 26S rRNA gene sequencing showed 100% base sequence homology and it was identified as Candida viswanathii. The degradation of PAHs

  11. Cytogenetics and molecular genetics of Wilms' tumor of childhood

    NARCIS (Netherlands)

    Slater, R. M.; Mannens, M. M.

    1992-01-01

    We describe the way in which application of cytogenetic and molecular genetic techniques to the study of Wilms' tumor (WT) of the kidney and the associated congenital disorders, such as sporadic aniridia and the Beckwith-Wiedemann syndrome, has led to identification of two regions on the short arm

  12. Molecular markers for genetic diversity and phylogeny research of ...

    African Journals Online (AJOL)

    Brazilian sheep descended from several breeds brought to the New World by Portuguese and Spanish colonists, and they have evolved and adapted to local climatic variations and acquired tolerance or resistance to many diseases. Molecular markers are widely used in analyzing genetic variability, and markers such as ...

  13. Construction of intergeneric conjugal transfer for molecular genetic ...

    African Journals Online (AJOL)

    SAM

    2014-03-26

    Mar 26, 2014 ... The attB integration site in the S. mobaraensis genome was detected as a single attB ... present study, to promote the molecular genetic study of. S. mobaraensis .... further increase in the number of E. coli donor cells. (≥1.25 × 108) (Choi et .... rational mutagenesis and random mutagenesis. Appl. Microbiol.

  14. Molecular genetics of hemophilia A: Clinical perspectives | Tantawy ...

    African Journals Online (AJOL)

    Since the publication of the sequence of the factor VIII (F8) gene in 1984, a large number of mutations that cause hemophilia A have been identified and a significant progress has been made in translating this knowledge for clinical diagnostic and therapeutic purposes. Molecular genetic testing is used to determine the ...

  15. History of Science as an Instructional Context: Student Learning in Genetics and Nature of Science

    Science.gov (United States)

    Kim, Sun Young; Irving, Karen E.

    2010-01-01

    This study (1) explores the effectiveness of the contextualized history of science on student learning of nature of science (NOS) and genetics content knowledge (GCK), especially interrelationships among various genetics concepts, in high school biology classrooms; (2) provides an exemplar for teachers on how to utilize history of science in…

  16. Employing Genetic "Moments" in the History of Mathematics in Classroom Activities

    Science.gov (United States)

    Farmaki, Vassiliki; Paschos, Theodorus

    2007-01-01

    The integration of history into educational practice can lead to the development of activities through the use of genetic "moments" in the history of mathematics. In the present paper, we utilize Oresme's genetic ideas--developed during the fourteenth century, including ideas on the velocity-time graphical representation as well as geometric…

  17. The molecular genetics of crown gall tumorigenesis

    International Nuclear Information System (INIS)

    Hooykaas, P.J.J.; Schilperoort, R.A.

    1984-01-01

    The phytopathogenic bacteria Agrobacterium tumefaciens and A. rhizogenes are the causative agents of the widespread plant diseases ''crown gall'' and ''hairy root'' respectively. It is now well established that virulent strains of these bacterial species transfer a piece of bacterial DNA into plant cells, thereby transforming these into tumor cells. In research much attention has been paid to the agrobacteria for several reasons. First is the desire to develop a system for the genetic engineering of plant cells based on the natural system for gene transfer between Agrobacterium species and plant cells. Second, there is a striking resemblance between the etiology of animal cancers and the plant cancer crown gall that was recognized as early as in 1927. This led to basic studies on the process of plant tumor induction and on the recovery of plant cells from the tumorous state. A third important interest lies in crown gall as a disease that is the cause of economically important losses in agriculture an horticulture in Europe, North America, and Austrailia. Research has been aimed at finding means to prevent crown gall and to cure plants of this disease

  18. Intelligent DNA-based molecular diagnostics using linked genetic markers

    Energy Technology Data Exchange (ETDEWEB)

    Pathak, D.K.; Perlin, M.W.; Hoffman, E.P.

    1994-12-31

    This paper describes a knowledge-based system for molecular diagnostics, and its application to fully automated diagnosis of X-linked genetic disorders. Molecular diagnostic information is used in clinical practice for determining genetic risks, such as carrier determination and prenatal diagnosis. Initially, blood samples are obtained from related individuals, and PCR amplification is performed. Linkage-based molecular diagnosis then entails three data analysis steps. First, for every individual, the alleles (i.e., DNA composition) are determined at specified chromosomal locations. Second, the flow of genetic material among the individuals is established. Third, the probability that a given individual is either a carrier of the disease or affected by the disease is determined. The current practice is to perform each of these three steps manually, which is costly, time consuming, labor-intensive, and error-prone. As such, the knowledge-intensive data analysis and interpretation supersede the actual experimentation effort as the major bottleneck in molecular diagnostics. By examining the human problem solving for the task, we have designed and implemented a prototype knowledge-based system capable of fully automating linkage-based molecular diagnostics in X-linked genetic disorders, including Duchenne Muscular Dystrophy (DMD). Our system uses knowledge-based interpretation of gel electrophoresis images to determine individual DNA marker labels, a constraint satisfaction search for consistent genetic flow among individuals, and a blackboard-style problem solver for risk assessment. We describe the system`s successful diagnosis of DMD carrier and affected individuals from raw clinical data.

  19. Molecular genetic studies on irradiated wheat plants

    International Nuclear Information System (INIS)

    Saleh, O.M.

    2002-01-01

    Composite genotype(octamer hybrid) was obtained from crossing among eight Egyptian hexaploid wheat cultivars differing in their tolerance to drought stress to produce a genotype, which can economize on the irrigation water requirements or can tolerate drought stress. Gamma irradiation with 10-Krad was used to induce mutations, which could improve drought tolerance for this composite. From eight Egyptian wheat cultivars, two were chosen as drought tolerant and drought sensitive genotypes (G-160 and Sk-61, respectively. They were evaluated along with their F1 and F2 for their relative drought tolerance for some yield-related traits. Bulked segregating analysis developed some RAPD and SSR markers with different primers, which were considered as molecular for drought tolerance in wheat. Hal 2-like gene was introduced into Egyptian wheat cultivar G-164 via micro projectile bombardment. Two putative transgenic plants were successfully detected by leaf painting with the herbicide basta. PCR/ Southern blotting analysis indicated the presence of both/either bar and/or Hal 2-like genes in the genomic background of the two transgenic plants

  20. Corn Storage Protein - A Molecular Genetic Model

    Energy Technology Data Exchange (ETDEWEB)

    Messing, Joachim [Rutgers Univ., Piscataway, NJ (United States)

    2013-05-31

    Corn is the highest yielding crop on earth and probably the most valuable agricultural product of the United States. Because it converts sun energy through photosynthesis into starch and proteins, we addressed energy savings by focusing on protein quality. People and animals require essential amino acids derived from the digestion of proteins. If proteins are relatively low in certain essential amino acids, the crop becomes nutritionally defective and has to be supplemented. Such deficiency affects meat and fish production and countries where corn is a staple. Because corn seed proteins have relatively low levels of lysine and methionine, a diet has to be supplemented with soybeans for the missing lysine and with chemically synthesized methionine. We therefore have studied genes expressed during maize seed development and their chromosomal organization. A critical technical requirement for the understanding of the molecular structure of genes and their positional information was DNA sequencing. Because of the length of sequences, DNA sequencing methods themselves were insufficient for this type of analysis. We therefore developed the so-called “DNA shotgun sequencing” strategy, where overlapping DNA fragments were sequenced in parallel and used to reconstruct large DNA molecules via overlaps. Our publications became the most frequently cited ones during the decade of 1981-1990 and former Associate Director of Science for the Office of Basic Energy Sciences Patricia M. Dehmer presented our work as one of the great successes of this program. A major component of the sequencing strategy was the development of bacterial strains and vectors, which were also used to develop the first biotechnology crops. These crops possessed new traits thanks to the expression of foreign genes in plants. To enable such expression, chimeric genes had to be constructed using our materials and methods by the industry. Because we made our materials and methods freely available to

  1. Demographic history and biologically relevant genetic variation of Native Mexicans inferred from whole-genome sequencing

    OpenAIRE

    Romero-Hidalgo, Sandra; Ochoa-Leyva, Adrián; Garcíarrubio, Alejandro; Acuña-Alonzo, Victor; Antúnez-Argüelles, Erika; Balcazar-Quintero, Martha; Barquera-Lozano, Rodrigo; Carnevale, Alessandra; Cornejo-Granados, Fernanda; Fernández-López, Juan Carlos; García-Herrera, Rodrigo; García-Ortíz, Humberto; Granados-Silvestre, Ángeles; Granados, Julio; Guerrero-Romero, Fernando

    2017-01-01

    Understanding the genetic structure of Native American populations is important to clarify their diversity, demographic history, and to identify genetic factors relevant for biomedical traits. Here, we show a demographic history reconstruction from 12 Native American whole genomes belonging to six distinct ethnic groups representing the three main described genetic clusters of Mexico (Northern, Southern, and Maya). Effective population size estimates of all Native American groups remained bel...

  2. Genetic diversity analysis of common beans based on molecular markers

    Directory of Open Access Journals (Sweden)

    Homar R. Gill-Langarica

    Full Text Available A core collection of the common bean (Phaseolus vulgaris L., representing genetic diversity in the entire Mexican holding, is kept at the INIFAP (Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias, Mexico Germplasm Bank. After evaluation, the genetic structure of this collection (200 accessions was compared with that of landraces from the states of Oaxaca, Chiapas and Veracruz (10 genotypes from each, as well as a further 10 cultivars, by means of four amplified fragment length polymorphisms (AFLP +3/+3 primer combinations and seven simple sequence repeats (SSR loci, in order to define genetic diversity, variability and mutual relationships. Data underwent cluster (UPGMA and molecular variance (AMOVA analyses. AFLP analysis produced 530 bands (88.5% polymorphic while SSR primers amplified 174 alleles, all polymorphic (8.2 alleles per locus. AFLP indicated that the highest genetic diversity was to be found in ten commercial-seed classes from two major groups of accessions from Central Mexico and Chiapas, which seems to be an important center of diversity in the south. A third group included genotypes from Nueva Granada, Mesoamerica, Jalisco and Durango races. Here, SSR analysis indicated a reduced number of shared haplotypes among accessions, whereas the highest genetic components of AMOVA variation were found within accessions. Genetic diversity observed in the common-bean core collection represents an important sample of the total Phaseolus genetic variability at the main Germplasm Bank of INIFAP. Molecular marker strategies could contribute to a better understanding of the genetic structure of the core collection as well as to its improvement and validation.

  3. Genetic diversity analysis of common beans based on molecular markers

    Directory of Open Access Journals (Sweden)

    Homar R. Gill-Langarica

    2011-01-01

    Full Text Available A core collection of the common bean (Phaseolus vulgaris L., representing genetic diversity in the entire Mexican holding, is kept at the INIFAP (Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias, Mexico Germplasm Bank. After evaluation, the genetic structure of this collection (200 accessions was compared with that of landraces from the states of Oaxaca, Chiapas and Veracruz (10 genotypes from each, as well as a further 10 cultivars, by means of four amplified fragment length polymorphisms (AFLP +3/+3 primer combinations and seven simple sequence repeats (SSR loci, in order to define genetic diversity, variability and mutual relationships. Data underwent cluster (UPGMA and molecular variance (AMOVA analyses. AFLP analysis produced 530 bands (88.5% polymorphic while SSR primers amplified 174 alleles, all polymorphic (8.2 alleles per locus. AFLP indicated that the highest genetic diversity was to be found in ten commercial-seed classes from two major groups of accessions from Central Mexico and Chiapas, which seems to be an important center of diversity in the south. A third group included genotypes from Nueva Granada, Mesoamerica, Jalisco and Durango races. Here, SSR analysis indicated a reduced number of shared haplotypes among accessions, whereas the highest genetic components of AMOVA variation were found within accessions. Genetic diversity observed in the common-bean core collection represents an important sample of the total Phaseolus genetic variability at the main Germplasm Bank of INIFAP. Molecular marker strategies could contribute to a better understanding of the genetic structure of the core collection as well as to its improvement and validation.

  4. Genetic diversity analysis of common beans based on molecular markers.

    Science.gov (United States)

    Gill-Langarica, Homar R; Muruaga-Martínez, José S; Vargas-Vázquez, M L Patricia; Rosales-Serna, Rigoberto; Mayek-Pérez, Netzahualcoyotl

    2011-10-01

    A core collection of the common bean (Phaseolus vulgaris L.), representing genetic diversity in the entire Mexican holding, is kept at the INIFAP (Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias, Mexico) Germplasm Bank. After evaluation, the genetic structure of this collection (200 accessions) was compared with that of landraces from the states of Oaxaca, Chiapas and Veracruz (10 genotypes from each), as well as a further 10 cultivars, by means of four amplified fragment length polymorphisms (AFLP) +3/+3 primer combinations and seven simple sequence repeats (SSR) loci, in order to define genetic diversity, variability and mutual relationships. Data underwent cluster (UPGMA) and molecular variance (AMOVA) analyses. AFLP analysis produced 530 bands (88.5% polymorphic) while SSR primers amplified 174 alleles, all polymorphic (8.2 alleles per locus). AFLP indicated that the highest genetic diversity was to be found in ten commercial-seed classes from two major groups of accessions from Central Mexico and Chiapas, which seems to be an important center of diversity in the south. A third group included genotypes from Nueva Granada, Mesoamerica, Jalisco and Durango races. Here, SSR analysis indicated a reduced number of shared haplotypes among accessions, whereas the highest genetic components of AMOVA variation were found within accessions. Genetic diversity observed in the common-bean core collection represents an important sample of the total Phaseolus genetic variability at the main Germplasm Bank of INIFAP. Molecular marker strategies could contribute to a better understanding of the genetic structure of the core collection as well as to its improvement and validation.

  5. Neutral mutation as the source of genetic variation in life history traits.

    Science.gov (United States)

    Brcić-Kostić, Krunoslav

    2005-08-01

    The mechanism underlying the maintenance of adaptive genetic variation is a long-standing question in evolutionary genetics. There are two concepts (mutation-selection balance and balancing selection) which are based on the phenotypic differences between alleles. Mutation - selection balance and balancing selection cannot properly explain the process of gene substitution, i.e. the molecular evolution of quantitative trait loci affecting fitness. I assume that such loci have non-essential functions (small effects on fitness), and that they have the potential to evolve into new functions and acquire new adaptations. Here I show that a high amount of neutral polymorphism at these loci can exist in real populations. Consistent with this, I propose a hypothesis for the maintenance of genetic variation in life history traits which can be efficient for the fixation of alleles with very small selective advantage. The hypothesis is based on neutral polymorphism at quantitative trait loci and both neutral and adaptive gene substitutions. The model of neutral - adaptive conversion (NAC) assumes that neutral alleles are not neutral indefinitely, and that in specific and very rare situations phenotypic (relative fitness) differences between them can appear. In this paper I focus on NAC due to phenotypic plasticity of neutral alleles. The important evolutionary consequence of NAC could be the increased adaptive potential of a population. Loci responsible for adaptation should be fast evolving genes with minimally discernible phenotypic effects, and the recent discovery of genes with such characteristics implicates them as suitable candidates for loci involved in adaptation.

  6. Unravelling the genetic history of Negritos and indigenous populations of Southeast Asia.

    Science.gov (United States)

    Aghakhanian, Farhang; Yunus, Yushima; Naidu, Rakesh; Jinam, Timothy; Manica, Andrea; Hoh, Boon Peng; Phipps, Maude E

    2015-04-14

    Indigenous populations of Malaysia known as Orang Asli (OA) show huge morphological, anthropological, and linguistic diversity. However, the genetic history of these populations remained obscure. We performed a high-density array genotyping using over 2 million single nucleotide polymorphisms in three major groups of Negrito, Senoi, and Proto-Malay. Structural analyses indicated that although all OA groups are genetically closest to East Asian (EA) populations, they are substantially distinct. We identified a genetic affinity between Andamanese and Malaysian Negritos which may suggest an ancient link between these two groups. We also showed that Senoi and Proto-Malay may be admixtures between Negrito and EA populations. Formal admixture tests provided evidence of gene flow between Austro-Asiatic-speaking OAs and populations from Southeast Asia (SEA) and South China which suggest a widespread presence of these people in SEA before Austronesian expansion. Elevated linkage disequilibrium (LD) and enriched homozygosity found in OAs reflect isolation and bottlenecks experienced. Estimates based on Ne and LD indicated that these populations diverged from East Asians during the late Pleistocene (14.5 to 8 KYA). The continuum in divergence time from Negritos to Senoi and Proto-Malay in combination with ancestral markers provides evidences of multiple waves of migration into SEA starting with the first Out-of-Africa dispersals followed by Early Train and subsequent Austronesian expansions. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  7. Genetic diversity of popcorn genotypes using molecular analysis.

    Science.gov (United States)

    Resh, F S; Scapim, C A; Mangolin, C A; Machado, M F P S; do Amaral, A T; Ramos, H C C; Vivas, M

    2015-08-19

    In this study, we analyzed dominant molecular markers to estimate the genetic divergence of 26 popcorn genotypes and evaluate whether using various dissimilarity coefficients with these dominant markers influences the results of cluster analysis. Fifteen random amplification of polymorphic DNA primers produced 157 amplified fragments, of which 65 were monomorphic and 92 were polymorphic. To calculate the genetic distances among the 26 genotypes, the complements of the Jaccard, Dice, and Rogers and Tanimoto similarity coefficients were used. A matrix of Dij values (dissimilarity matrix) was constructed, from which the genetic distances among genotypes were represented in a more simplified manner as a dendrogram generated using the unweighted pair-group method with arithmetic average. Clusters determined by molecular analysis generally did not group material from the same parental origin together. The largest genetic distance was between varieties 17 (UNB-2) and 18 (PA-091). In the identification of genotypes with the smallest genetic distance, the 3 coefficients showed no agreement. The 3 dissimilarity coefficients showed no major differences among their grouping patterns because agreement in determining the genotypes with large, medium, and small genetic distances was high. The largest genetic distances were observed for the Rogers and Tanimoto dissimilarity coefficient (0.74), followed by the Jaccard coefficient (0.65) and the Dice coefficient (0.48). The 3 coefficients showed similar estimations for the cophenetic correlation coefficient. Correlations among the matrices generated using the 3 coefficients were positive and had high magnitudes, reflecting strong agreement among the results obtained using the 3 evaluated dissimilarity coefficients.

  8. MEGA X: Molecular Evolutionary Genetics Analysis across Computing Platforms.

    Science.gov (United States)

    Kumar, Sudhir; Stecher, Glen; Li, Michael; Knyaz, Christina; Tamura, Koichiro

    2018-06-01

    The Molecular Evolutionary Genetics Analysis (Mega) software implements many analytical methods and tools for phylogenomics and phylomedicine. Here, we report a transformation of Mega to enable cross-platform use on Microsoft Windows and Linux operating systems. Mega X does not require virtualization or emulation software and provides a uniform user experience across platforms. Mega X has additionally been upgraded to use multiple computing cores for many molecular evolutionary analyses. Mega X is available in two interfaces (graphical and command line) and can be downloaded from www.megasoftware.net free of charge.

  9. Enhancing genetic gain in the era of molecular breeding.

    Science.gov (United States)

    Xu, Yunbi; Li, Ping; Zou, Cheng; Lu, Yanli; Xie, Chuanxiao; Zhang, Xuecai; Prasanna, Boddupalli M; Olsen, Michael S

    2017-05-17

    As one of the important concepts in conventional quantitative genetics and breeding, genetic gain can be defined as the amount of increase in performance that is achieved annually through artificial selection. To develop pro ducts that meet the increasing demand of mankind, especially for food and feed, in addition to various industrial uses, breeders are challenged to enhance the potential of genetic gain continuously, at ever higher rates, while they close the gaps that remain between the yield potential in breeders' demonstration trials and the actual yield in farmers' fields. Factors affecting genetic gain include genetic variation available in breeding materials, heritability for traits of interest, selection intensity, and the time required to complete a breeding cycle. Genetic gain can be improved through enhancing the potential and closing the gaps, which has been evolving and complemented with modern breeding techniques and platforms, mainly driven by molecular and genomic tools, combined with improved agronomic practice. Several key strategies are reviewed in this article. Favorable genetic variation can be unlocked and created through molecular and genomic approaches including mutation, gene mapping and discovery, and transgene and genome editing. Estimation of heritability can be improved by refining field experiments through well-controlled and precisely assayed environmental factors or envirotyping, particularly for understanding and controlling spatial heterogeneity at the field level. Selection intensity can be significantly heightened through improvements in the scale and precision of genotyping and phenotyping. The breeding cycle time can be shortened by accelerating breeding procedures through integrated breeding approaches such as marker-assisted selection and doubled haploid development. All the strategies can be integrated with other widely used conventional approaches in breeding programs to enhance genetic gain. More transdisciplinary

  10. Molecular evaluation of genetic variability of wheat elite breeding material

    Directory of Open Access Journals (Sweden)

    Brbaklić Ljiljana

    2009-01-01

    Full Text Available Estimation of genetic variability of breeding material is essential for yield improvement in wheat cultivars. Modern techniques based on molecular markers application are more efficient and precise in genetic variability evaluation then conventional methods. Variability of 96 wheat cultivars and lines was analyzed using four microsatellite markers (Gwm11, Gwm428, Psp3200, Psp3071. The markers were chosen according to their potential association with important agronomical traits indicated in the literature. Total of 31 alleles were detected with maximum number of alleles (11 in Xgwm11 locus. The highest polymorphism information content (PIC value (0,831 was found in the locus Xpsp3071. The genotypes were grouped into three subpopulations based on their similarity in the analyzed loci. The results have indicated wide genetic variability of the studied material and possibility of its application in further breeding process after validation of marker-trait association. .

  11. Hamartomatous polyps - a clinical and molecular genetic study

    DEFF Research Database (Denmark)

    Jelsig, Anne Marie

    2016-01-01

    the knowledge on clinical course and molecular genetics in patients with HPs and HPS, and to investigate research participants' attitude towards the results of extensive genetic testing. Paper I: In the first paper we investigated the occurrence, anatomic distribution, and other demographics of juvenile polyps...... appearance. Patients with one or a few juvenile polyps are usually not offered clinical follow-up as the polyp(s) are considered not to harbour any malignant potential. Nevertheless, it is important to note that juvenile polyps and HPs are also found in patients with hereditary hamartomatous polyposis......-Jeghers syndrome, and the PTEN hamartoma tumour syndrome. Currently, the HPS diagnoses are based on clinical criteria and are often assisted with genetic testing as candidate genes have been described for each syndrome. This thesis is based on six scientific papers. The overall aim of the studies was to expand...

  12. Molecular Genetics of Beauveria bassiana Infection of Insects.

    Science.gov (United States)

    Ortiz-Urquiza, A; Keyhani, N O

    2016-01-01

    Research on the insect pathogenic filamentous fungus, Beauveria bassiana has witnessed significant growth in recent years from mainly physiological studies related to its insect biological control potential, to addressing fundamental questions regarding the underlying molecular mechanisms of fungal development and virulence. This has been in part due to a confluence of robust genetic tools and genomic resources for the fungus, and recognition of expanded ecological interactions with which the fungus engages. Beauveria bassiana is a broad host range insect pathogen that has the ability to form intimate symbiotic relationships with plants. Indeed, there is an increasing realization that the latter may be the predominant environmental interaction in which the fungus participates, and that insect parasitism may be an opportunist lifestyle evolved due to the carbon- and nitrogen-rich resources present in insect bodies. Here, we will review progress on the molecular genetics of B. bassiana, which has largely been directed toward identifying genetic pathways involved in stress response and virulence assumed to have practical applications in improving the insect control potential of the fungus. Important strides have also been made in understanding aspects of B. bassiana development. Finally, although increasingly apparent in a number of studies, there is a need for progressing beyond phenotypic mutant characterization to sufficiently investigate the molecular mechanisms underlying B. bassiana's unique and diverse lifestyles as saprophyte, insect pathogen, and plant mutualist. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. 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.

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

    Directory of Open Access Journals (Sweden)

    Felix C Tropf

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

  15. Update on the Cytogenetics and Molecular Genetics of Chordoma

    Directory of Open Access Journals (Sweden)

    Larizza Lidia

    2005-02-01

    Full Text Available Abstract Chordoma is a rare mesenchymal tumour of complex biology for which only histologic and immunohistochemical criteria have been defined, but no biomarkers predicting the clinical outcome and response to treatment have yet been recognised. We herein review the interdisciplinary information achieved by epidemiologists, neurosurgeons and basic scientists on chordoma, usually a sporadic tumour, which also includes a small fraction of familial cases. Main focus is on the current knowledge of the genetic alterations which might pinpoint candidate genes and molecular mechanisms shared by sporadic and familiar chordomas. Due to the scarcity of the investigated tumour specimens and the multiple chromosome abnormalities found in tumours with aberrant karyotypes, conventional cytogenetics and Fluorescence In Situ Hybridization failed to detect recurrent chordoma-specific chromosomal rearrangements. Genome-wide approaches such as Comparative Genomic Hybridization (CGH are yet at an initial stage of application and should be implemented using BAC arrays either genome-wide or targeting selected genomic regions, disclosed by Loss of Heterozygosity (LOH studies. An LOH region was shown by a systematic study on a consistent number of chordomas to encompass 1p36, a genomic interval where a candidate gene was suggested to reside. Despite the rarity of multiplex families with chordoma impaired linkage studies, a chordoma locus could be mapped to chromosome 7q33 by positive lod score in three independent families. The role in chordomagenesis of the Tuberous Sclerosis Complex (TSC genes has been proved, but the extent of involvement of TSC1 and TSC2 oncosuppressors in chordoma remains to be assessed. In spite of the scarce knowledge on the genetics and molecular biology of chordoma, recent initiation of clinical trials using molecular-targeted therapy, should validate new molecular targets and predict the efficacy of a given therapy. Comparative genetic and

  16. Mammalian life histories: their evolution and molecular-genetic mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Sacher, G.A.

    1978-01-01

    Survival curves for various species of mammals are discussed and a table is presented to show recorded maximum life spans of about 30 species of mammals. The range of longevities is from one year for shrews and moles up to more than 80 years for the fin whale. The constitutional correlates of longevity are discussed with regard to body size, brain weight,metabolic rates, and body temperature. It is concluded that longevity evolved as a positive trait, associated with the evolution of large body size and brain size. Life table data for man, the thorough-bred horse, beagle dogs, and the laboratory rodents, Mus musculus and Peromyscus leucopus are discussed. The data show a pattern of exponential increase of death rate with age. A laboratory model using Mus musculus and Peromyscus leucopus for the study of the longevity-assurance mechanisms is described. (HLW)

  17. Reliable prediction of adsorption isotherms via genetic algorithm molecular simulation.

    Science.gov (United States)

    LoftiKatooli, L; Shahsavand, A

    2017-01-01

    Conventional molecular simulation techniques such as grand canonical Monte Carlo (GCMC) strictly rely on purely random search inside the simulation box for predicting the adsorption isotherms. This blind search is usually extremely time demanding for providing a faithful approximation of the real isotherm and in some cases may lead to non-optimal solutions. A novel approach is presented in this article which does not use any of the classical steps of the standard GCMC method, such as displacement, insertation, and removal. The new approach is based on the well-known genetic algorithm to find the optimal configuration for adsorption of any adsorbate on a structured adsorbent under prevailing pressure and temperature. The proposed approach considers the molecular simulation problem as a global optimization challenge. A detailed flow chart of our so-called genetic algorithm molecular simulation (GAMS) method is presented, which is entirely different from traditions molecular simulation approaches. Three real case studies (for adsorption of CO 2 and H 2 over various zeolites) are borrowed from literature to clearly illustrate the superior performances of the proposed method over the standard GCMC technique. For the present method, the average absolute values of percentage errors are around 11% (RHO-H 2 ), 5% (CHA-CO 2 ), and 16% (BEA-CO 2 ), while they were about 70%, 15%, and 40% for the standard GCMC technique, respectively.

  18. Empirical Refinements of a Molecular Genetics Learning Progression: The Molecular Constructs

    Science.gov (United States)

    Todd, Amber; Kenyon, Lisa

    2016-01-01

    This article describes revisions to four of the eight constructs of the Duncan molecular genetics learning progression [Duncan, Rogat, & Yarden, (2009)]. As learning progressions remain hypothetical models until validated by multiple rounds of empirical studies, these revisions are an important step toward validating the progression. Our…

  19. Three Women Scientists and Their Role in the History of Genetics.

    Science.gov (United States)

    Venville, Grady; Milne, Catherine

    1999-01-01

    Draws on an array of historical documents to delve into the history of genetics and the lives and scientific accomplishments of female geneticists that include Nettie Stevens, Rosalind Franklin, and Barbara McClintock. (Contains 20 references.) (Author/WRM)

  20. Molecular genetics and livestock selection. Approaches, opportunities and risks

    International Nuclear Information System (INIS)

    Williams, J.L.

    2005-01-01

    Following domestication, livestock were selected both naturally through adaptation to their environments and by man so that they would fulfil a particular use. As selection methods have become more sophisticated, rapid progress has been made in improving those traits that are easily measured. However, selection has also resulted in decreased diversity. In some cases, improved breeds have replaced local breeds, risking the loss of important survival traits. The advent of molecular genetics provides the opportunity to identify the genes that control particular traits by a gene mapping approach. However, as with selection, the early mapping studies focused on traits that are easy to measure. Where molecular genetics can play a valuable role in livestock production is by providing the means to select effectively for traits that are difficult to measure. Identifying the genes underpinning particular traits requires a population in which these traits are segregating. Fortunately, several experimental populations have been created that have allowed a wide range of traits to be studied. Gene mapping work in these populations has shown that the role of particular genes in controlling variation in a given trait can depend on the genetic background. A second finding is that the most favourable alleles for a trait may in fact. be present in animals that perform poorly for the trait. In the long term, knowledge of -the genes controlling particular traits, and the way they interact with the genetic background, will allow introgression between breeds and the assembly of genotypes that are best suited to particular environments, producing animals with the desired characteristics. If used wisely, this approach will maintain genetic diversity while improving performance over a wide range of desired traits. (author)

  1. 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

  2. Phylogeography, genetic diversity and demographic history of the ...

    Indian Academy of Sciences (India)

    FATAH ZAREI

    loop region of individuals representing four Kurdish groups from Iran .... research studies were performed on the origin and genetic landscape of the Kurds, ... haplogroups were determined on the basis of diagnostic sites using the PhyloTree 16 ...

  3. Molecular genetics: Step by step implementation in maize breeding

    Directory of Open Access Journals (Sweden)

    Konstantinov Kosana

    2007-01-01

    Full Text Available Efficiency in plant breeding is determined primarily by the ability to screen for genetic polymorphism, productivity and yield stability early in program. Dependent on the knowledge about the biochemical bases of the trait and nature of its genetic control, trait could be modified either through mutagenesis of genes controlling it or through the transfer of already existing mutant genes, controlling desired trait to different plant genotypes by classic crossing. Objective of this report is to present partly results on the investigation of the possibilities to apply ionizing radiations (fast neutrons, γ -rays and chemical mutagens (EI, iPMS, EMS, ENU to get maize and wheat mutants with increased amount and improved protein quality. Besides this approach in mutation breeding, results on the very early investigation of biochemical background of opaque -2 mutation including use of coupled cell - free RNA and protein synthesis containing components from both wild and opaque - 2 maize genotypes (chromatin, RNA polymerase, microsomall fraction, protein bodies will be presented. Partial results on opaque - 2 gene incorporation in different genetic background are reviewed. Part of report is dealing with different classes of molecular markers (proteins, RFLP, AFLP, RAPD, and SSR application in maize genome polymorphism investigation. Besides application of different molecular markers classes in the investigation of heterosis phenomena they are useful in biochemical pathway of important traits control determination as well. .

  4. Nasopharyngeal angiofibroma: review of the genetic and molecular aspects

    Directory of Open Access Journals (Sweden)

    Oliveira, Viviane Boaventura de

    2008-09-01

    Full Text Available Introduction: Juvenile nasopharyngeal angiofibroma (JNA is a rare fibrovascular tumor of unknown etiology, with few studies analyzing its pathogenesis. Objective: Reviewing JNA's pathogenesis, emphasizing genetic and molecular aspects. Method: All the relevant articles indexed in PUBMED and LILACS, besides reference book chapters, published between 1959 and 2007 were reviewed. Results: The sex selectivity seen in JNA may be explained by intranuclear accumulation of androgen receptor and beta-catenin, a co-activator which increases the tumor sensitivity to androgynous. The genetic alterations seen in JNA are most frequently located in sexual chromosomes. A number of growth factors seem to be related to the tumor pathogenesis. The insulin-like growth factor II is highly expressed while the vascular endothelial growth factor and the transforming growth factor beta are released by stromal cells and may influence the JNA's growth and vascularization. Conclusion: In spite of the scarce data describing the JNA etiology and pathogenesis, genetic and molecular factors seem to collaborate to the understanding of the disease's many clinical and morphological features. Knowledge regarding these specific issues could contribute for the establishment of potential therapeutic targets in the future.

  5. Molecular genetic identification of some wheat cultivars in the sudan

    International Nuclear Information System (INIS)

    Mekki, I. I; El Amin, H. B.

    2002-01-01

    Four wheat (Triticum aestivum L.) cultivars, namely condor, El-Nellene, Wadi El Neil and Debeira were characterized on biochemical and molecular bases. The biochemical ones were protein-banding patterns, using sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and isozymes to identify the biochemical genetic fingerprint of the four cultivars. Water-soluble protein-banding pattern showed no polymorphisms among the tested cultivars. The data from starch gel electrophoresis of enzymes, malate dehydrogenase (MDH), esterase (EST) and acid phosphate (ACPH) showed that the cultivars are monomorphic. Further trials to identify the molecular genetic fingerprints of the studied cultivars were carried out using RAPD-PCR twenty-five primers were tested to perform. RAPD-PCR analysis. From the PCR products, a phylogenetic map, i.e, dendrogram, was constructed for the studied cultivars which depicted tow groups. The first group contained Wadi El Neil and Deberia with 48.4% similarity, and the second group contained Condor and El Neileen with 100% similarity. There was no similarity between Condor and Debeira (100% dissimilarity). Therefor, these data can be used subsequently for genetic engineering research and for wheat breeding programmes in the Sudan.(Author)

  6. Phylogeography, risk factors and genetic history of hepatitis C virus in Gabon, central Africa.

    Directory of Open Access Journals (Sweden)

    Richard Njouom

    Full Text Available BACKGROUND: The epidemiological and molecular characteristics of hepatitis C virus (HCV infection in the general population have been poorly investigated in Africa. The aim of this study was to determine the prevalence, genotype distribution and epidemic history of HCV in the Gabonese general population. METHODS/PRINCIPAL FINDINGS: A total of 4042 sera collected from adults in 220 villages in all nine administrative areas of the country were screened for antibodies to HCV. HCV NS5B region sequencing was performed for molecular characterization and population genetic analyses. Of 4042 tested sera, 455 (11.2% were positive. The seroprevalence of HCV varied significantly by administrative area, with the highest rate in Ogooué-Lolo province (20.4% and the lowest in Ogooué-Maritine province (3.7%. History of parenteral injections, past hospital admission and age over 55 years were independent risk factors for HCV infection (p<0.0001. Phylogenetic analyses showed that 91.9% of the strains were genotype 4 (HCV-4, 5.7% genotype 1 and 2.2% genotype 2. HCV-4 strains were highly heterogeneous, with more than eight subtypes; subtype 4e predominated (57.3%. Coalescence analyses indicated that subtype 4e was the oldest, with an estimated most recent common ancestor of 1702 [95% CI, 1418-1884]. The epidemic profile indicated that it spread exponentially during the first part of the 20th century, probably by iatrogenic transmission. CONCLUSIONS/SIGNIFICANCE: These results confirm the endemicity of HCV subtype 4e in Gabon and show that its spread is due to a cohort effect, with previous, possibly iatrogenic events. More extensive epidemiological studies are needed to better characterize the route of transmission and the dissemination of HCV in Gabon.

  7. Molecular genetics of aging in the fly: is this the end of the beginning?

    Science.gov (United States)

    Helfand, Stephen L; Rogina, Blanka

    2003-02-01

    How we age and what we can do about it have been uppermost in human thought since antiquity. The many false starts have frustrated experimentalists and theoretical arguments pronouncing the inevitability of the process have created a nihilistic climate among scientists and the public. The identification of single gene alterations that substantially extend life span in nematodes and flies however, have begun to reinvigorate the field. Drosophila's long history of contributions to aging research, rich storehouse of genetic information, and powerful molecular techniques make it an excellent system for studying the molecular mechanisms underlying the process of aging. In recent years, Drosophila has been used to test current theories on aging and explore new directions of potential importance to the biology of aging. One such example is the surprising finding that, as opposed to the commonly held assumption that adult life is a period of random passive decline in which all things are thought to fall apart, the molecular life of the adult fly appears to be a state of dynamic well-regulated change. In the fly, the level of expression of many different genes changes in an invariant, often age-dependent, manner. These as well as other molecular genetic studies and demographic analyses using the fly have begun to challenge widely held ideas about aging providing evidence that aging may be a much more dynamic and malleable process than anticipated. With the enormous success that Drosophila molecular genetics has demonstrated in helping understand complex biological phenomena such as development there is much optimism that similar approaches can be adapted to assist in understanding the process of aging. Copyright 2003 Wiley Periodicals, Inc.

  8. Different Histories, Different Destinies‒Impact of Evolutionary History and Population Genetic Structure on Extinction Risk of the Adriatic Spined Loaches (Genus Cobitis; Cypriniformes, Actinopterygii.

    Directory of Open Access Journals (Sweden)

    Ivana Buj

    Full Text Available The region of Balkans is often considered as an ichthyologic "hot spot", with a great number of species and high portion of endemics living in fresh waters in a relatively small area. The Adriatic watershed in Croatia and Herzegovina is inhabited by six spined loach species (genus Cobitis whose extinction risk estimations were based solely on their extent of occurrence (and/or area of occupancy and its fragmentation, and conservation proposals do not consider diversity below species level. In this investigation we employed molecular genetic methods to describe present genetic structure of the Adriatic spined loaches and reveal their demographic history. The divergence of the Adriatic lineages inside the genus Cobitis started in Miocene and lasted until Pleistocene epoch. Geological events responsible for shaping recent diversity of spined loaches in the Adriatic basin are: the Dinarid Mountains upwelling, the evolution of Dinaric Lake system, local tectonic activity, river connections during glaciations and differences in sea level. Even though all the investigated species inhabit karstic rivers located in the same geographic area and that were subject of similar geological events, the results obtained reveal great differences in their genetic diversity and structure and point out the necessity of different conservation measures to ensure their future viability. High level of genetic polymorphism is characteristic for species located more to the south. Two species comprised of more than one population have completely different intraspecific structure; populations of C. illyrica are genetically distinct and represent separate evolutionary significant units, whereas intraspecific structure of C. narentana corresponds to metapopulational pattern. Without population genetic data, evolutionary significant units could be easily misidentified. Furthermore, the obtained results affirm that population genetic measurements are able to detect differences

  9. A Baseline Algorithm for Molecular Diagnosis of Genetic Eye Diseases: Ophthalmologist’s Perspective

    Directory of Open Access Journals (Sweden)

    Hande Taylan Şekeroğlu

    2016-12-01

    Full Text Available To the Editor: Genetic eye diseases constitute a large and heterogeneous group. Individual diseases may cause multiple structural/functional anomalies and developmental features. Family history may be suggestive; however, it may also be challenging, particularly in late-onset conditions or in cases of variable expression. In the current era of genetic advances, diagnosis of a genetic eye disease is facilitated by well-established collaboration between ophthalmologists and geneticists, as increasingly more patients will be asking for genetic counseling and prenatal diagnosis in addition to ophthalmologic management. Molecular investigation of a genetic eye disease requires customized analysis and advanced technology in addition to the requisite detailed family history and accurate ophthalmological diagnosis. A common indication for genetic testing is the validation of a preliminary diagnosis made in clinical practice. The need to determine the prognostic implications of the genotype, assessment of the recurrence risk and in particular, the possibility of specific gene therapy in the near future encourages clinicians to pursue genetic research. We present here a baseline algorithm covering common genetic mechanisms in order to outline a basic molecular approach for ophthalmologists. The first step of the flow chart, a prudent clinical examination with complete description of the phenotype, is indispensible for making a precise and accurate preliminary diagnosis (Figure 1. If the phenotype is pathognomonic, Sanger sequencing is preferred for confirmation.1 A previously established genotype-phenotype correlation may add to the value, either by providing accurate prognostic information or by indicating which particular mutation to look for. One such example may be electroretinographic supranormal rod response, indicating KCNV2 mutation type cone dystrophy, which can be precisely detected by Sanger sequencing or qPCR.2 Conventional karyotyping reveals

  10. Phylogeography, genetic diversity and demographic history of the ...

    Indian Academy of Sciences (India)

    FATAH ZAREI

    mutations), and analyses of molecular variance (AMOVA) based on different criteria .... high and low levels of mean number of pairwise differences. Population ..... east frontiers of the country against the constant inroads of the Turkmen and ...

  11. Classical and molecular genetics of malignant melanoma and dysplastic naevi

    International Nuclear Information System (INIS)

    Traupe, H.; Macher, E.

    1988-01-01

    The authors conclude that the prevailing concept of monogenic autosomaldominant inheritance of dysplastic naevi and familial melanoma is not compatible with the principles of formal (Mendelian) genetics. The concept of polygenic inheritance offers instead a sound basis to explain familial aggregation of dysplastic naevi and melanoma. The various genes involved have not yet been identified at the molecular level. The recent advances made possible by modern DNA technology have given us a new view of carcinogenesis. In human malignant melanoma, chromosomes 1, 6, 7 are of particular interest and oncogenes located on these chromosomes may be involved with the initiation, promotion and progression of melanoma. Carcinogenesis is viewed as a multistep process and even tumour initiation requires the input of at least two independent oncogenes. Molecular genetics thus adds an important argument for the existence of a polygenic predisposition to melanoma. The concept of polygenic inheritance is not restricted to familial melanoma, but implies that all melanomas basically share the same predisposition and are due to similar genetic mechanisms. In some patients an inherited genetic predisposition is of great importance, whereas in others (the majority) environmental factors (e.g. UV-light-induced mutations) will be the cause of initial steps in the malignant transformation. The concept of polygenic inheritance has consequences for the management of our patients. In contrast to simple Mendelian inheritance, the risk for dysplastic naevi and melanoma is not constantly 50%, but increases with the number of family members already affected. Persons belonging to families with more that 2 affected close relatives should be considered at high risk regardless of the dysplastic naevus status. Strict surveillance of this patient group is warranted for melanoma prevention

  12. Genetic History of Xinjiang's Uyghurs Suggests Bronze Age Multiple-Way Contacts in Eurasia.

    Science.gov (United States)

    Feng, Qidi; Lu, Yan; Ni, Xumin; Yuan, Kai; Yang, Yajun; Yang, Xiong; Liu, Chang; Lou, Haiyi; Ning, Zhilin; Wang, Yuchen; Lu, Dongsheng; Zhang, Chao; Zhou, Ying; Shi, Meng; Tian, Lei; Wang, Xiaoji; Zhang, Xi; Li, Jing; Khan, Asifullah; Guan, Yaqun; Tang, Kun; Wang, Sijia; Xu, Shuhua

    2017-10-01

    The Uyghur people residing in Xinjiang, a territory located in the far west of China and crossed by the Silk Road, are a key ethnic group for understanding the history of human dispersion in Eurasia. Here we assessed the genetic structure and ancestry of 951 Xinjiang's Uyghurs (XJU) representing 14 geographical subpopulations. We observed a southwest and northeast differentiation within XJU, which was likely shaped jointly by the Tianshan Mountains, which traverses from east to west as a natural barrier, and gene flow from both east and west directions. In XJU, we identified four major ancestral components that were potentially derived from two earlier admixed groups: one from the West, harboring European (25-37%) and South Asian ancestries (12-20%), and the other from the East, with Siberian (15-17%) and East Asian (29-47%) ancestries. By using a newly developed method, MultiWaver, the complex admixture history of XJU was modeled as a two-wave admixture. An ancient wave was dated back to ∼3,750 years ago (ya), which is much earlier than that estimated by previous studies, but fits within the range of dating of mummies that exhibited European features that were discovered in the Tarim basin, which is situated in southern Xinjiang (4,000-2,000 ya); a more recent wave occurred around 750 ya, which is in agreement with the estimate from a recent study using other methods. We unveiled a more complex scenario of ancestral origins and admixture history in XJU than previously reported, which further suggests Bronze Age massive migrations in Eurasia and East-West contacts across the Silk Road. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. Molecular genetics of glioblastomas: defining subtypes and understanding the biology.

    Science.gov (United States)

    Renault, Ilana Zalcberg; Golgher, Denise

    2015-02-01

    Despite comprehensive therapy, which includes surgery, radiotherapy, and chemotherapy, the prognosis of glioblastoma multiforme is very poor. Diagnosed individuals present an average of 12 to 18 months of life. This article provides an overview of the molecular genetics of these tumors. Despite the overwhelming amount of data available, so far little has been translated into real benefits for the patient. Because this is such a complex topic, the goal is to point out the main alterations in the biological pathways that lead to tumor formation, and how this can contribute to the development of better therapies and clinical care. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Molecular and genetic aspects of odontogenic tumors: a review.

    Science.gov (United States)

    Garg, Kavita; Chandra, Shaleen; Raj, Vineet; Fareed, Wamiq; Zafar, Muhammad

    2015-06-01

    Odontogenic tumors contain a heterogeneous collection of lesions that are categorized from hamartomas to benign and malignant neoplasms of inconstant aggressiveness. Odontogenic tumors are usually extraordinary with assessed frequency of short of 0.5 cases/100,000 population for every year. The lesions such as odontogenic tumors are inferred from the components of the tooth-structuring contraption. They are discovered solely inside the maxillary and mandibular bones. This audit speaks to experiences and cooperation of the molecular and genetic variations connected to the development and movement of odontogenic tumors which incorporate oncogenes, tumor-silencer genes, APC gene, retinoblastoma genes, DNA repair genes, onco-viruses, development components, telomerase, cell cycle controllers, apoptosis-related elements, and regulators/conttrollers of tooth development. The reasonable and better understanding of the molecular components may prompt new ideas for their detection and administrating a better prognosis of odontogenic tumors.

  15. Molecular and genetic aspects of odontogenic tumors: a review

    Directory of Open Access Journals (Sweden)

    Kavita Garg

    2015-06-01

    Full Text Available Odontogenic tumors contain a heterogeneous collection of lesions that are categorized from hamartomas to benign and malignant neoplasms of inconstant aggressiveness. Odontogenic tumors are usually extraordinary with assessed frequency of short of 0.5 cases/100,000 population for every year. The lesions such as odontogenic tumors are inferred from the components of the tooth-structuring contraption. They are discovered solely inside the maxillary and mandibular bones. This audit speaks to experiences and cooperation of the molecular and genetic variations connected to the development and movement of odontogenic tumors which incorporate oncogenes, tumor-silencer genes, APC gene, retinoblastoma genes, DNA repair genes, onco-viruses, development components, telomerase, cell cycle controllers, apoptosis-related elements, and regulators/controllers of tooth development. The reasonable and better understanding of the molecular components may prompt new ideas for their detection and administrating a better prognosis of odontogenic tumors.

  16. Testicular germ cell tumors: Molecular genetic and clinicomorphological aspects

    Directory of Open Access Journals (Sweden)

    M. V. Nemtsova

    2015-03-01

    Full Text Available Testicular tumors are the most common form of solid cancer in young men. According to the 2004 WHO classification, testicular germ cell tumors (TGCT may present with different histological types. Embryonic cells of varying grade may be a source of TGCT and the occurrence of this type of tumors is directly related to the formation of a pool of male sex cells and gametogenesis. The paper gives information on mo- lecular stages for the process of formation of male sex cells in health, as well as ways of their impairments leading to TGCT. An investigation of the profiles of gene expression and the spectrum of molecular damages revealed genes responsible for a predisposition to the sporadic and hereditary forms of TGCT. The paper presents the current molecular genetic and clinicomorphological characteristics of TGCT. 

  17. Sending family history questionnaires to patients before a colonoscopy improves genetic counseling for hereditary colorectal cancer.

    Science.gov (United States)

    Kessels, Koen; Eisinger, Joey D; Letteboer, Tom G; Offerhaus, G Johan A; Siersema, Peter D; Moons, Leon M G

    2017-06-01

    To investigate whether sending a family history questionnaire to patients prior to undergoing colonoscopy results in an increased availability of family history and better genetic counseling. A questionnaire was mailed to patients before they underwent outpatient colonoscopy at a university hospital in 2013. These patients' additional characteristics and referral for genetic evaluation were retrieved from the electronic medical records. Patients undergoing inpatient coloboscopy, with confirmed hereditary colorectal cancer (CRC) or inflammatory bowel disease were excluded. All study patients from 2010 to 2013 were matched with the database of the genetics department to determine who consulted a geneticist. A total of 6163 patients underwent colonoscopy from 2010 to 2013. Of 1421 who underwent colonoscopy in 2013, 53 (3.7%) consulted a geneticist, while 75 (1.6%) of 4742 patients undergoing colonoscopy between 2010 and 2012 did so (P history was not recorded in the electronic medical records of 393 (40.3%). In 129 (32.8%), family history was obtained from the completed questionnaire. In 2013, 49 (60.5%) out of 81 patients referred for genetic counseling were referred based on their family history. Eight (9.9%) patients were referred based on the completed questionnaire. Screening for hereditary CRC in a population undergoing outpatient colonoscopy with a questionnaire sent by mail resulted in an increased availability of family histories and genetic counseling. © 2017 Chinese Medical Association Shanghai Branch, Chinese Society of Gastroenterology, Renji Hospital Affiliated to Shanghai Jiaotong University School of Medicine and John Wiley & Sons Australia, Ltd.

  18. Implication of Gastric Cancer Molecular Genetic Markers in Surgical Practice.

    Science.gov (United States)

    Nemtsova, Marina V; Strelnikov, Vladimir V; Tanas, Alexander S; Bykov, Igor I; Zaletaev, Dmitry V; Rudenko, Viktoria V; Glukhov, Alexander I; Kchorobrich, Tatiana V; Li, Yi; Tarasov, Vadim V; Barreto, George E; Aliev, Gjumrakch

    2017-10-01

    We have investigated aberrant methylation of genes CDH1, RASSF1A, MLH1, N33, DAPK, expression of genes hTERT, MMP7, MMP9, BIRC5 (survivin), PTGS2, and activity of telomerase of 106 gastric tumor samples obtained intra-operatively and 53 gastric tumor samples from the same group of patients obtained endoscopically before surgery. Biopsy specimens obtained from 50 patients with chronic calculous cholecystitis were used as a control group. Together with tissue samples obtained from different sites remote to tumors, a total of 727 samples have been studied. The selected parameters comprise a system of molecular markers that can be used in both diagnostics of gastric cancer and in dynamic monitoring of patients after surgery. Special attention was paid to the use of molecular markers for the diagnostics of malignant process in the material obtained endoscopically since the efficacy of morphological diagnostics in biopsies is compromised by intratumoral heterogeneity, which may prevent reliable identification of tumor cells in the sampling. Our data indicated that certain molecular genetic events provided more sensitive yet specific markers of the tumor. We demonstrated that molecular profiles detected in preoperative biopsies were confirmed by the material obtained intra-operatively. The use of endoscopic material facilitates gastric tumors pre-operative diagnostics, improving early detection of gastric cancer and potential effective treatment strategies.

  19. Genetic structure and evolutionary history of three alpine sclerophyllous oaks in East Himalaya-Hengduan Mountains and adjacent regions

    Directory of Open Access Journals (Sweden)

    Li Feng

    2016-11-01

    Full Text Available The East Himalaya-Hengduan Mountains (EH-HM region has a high biodiversity and harbours numerous endemic alpine plants. This is probably the result of combined orographic and climate oscillations occurring since late Tertiary. Here, we determined the genetic structure and evolutionary history of alpine oak species (including Q. spinosa, Q. aquifolioides and Q. rehderiana using both cytoplasmic-nuclear markers and ecological niche models (ENMs, and elucidated the impacts of climate oscillations and environmental heterogeneity on their population demography. Our results indicate there were mixed genetic structure and asymmetric contemporary gene flow within them. The ENMs revealed a similar demographic history for the three species expanded their ranges from the last interglacial (LIG to the last glacial maximum (LGM, which was consistent with effective population sizes changes. Effects of genetic drift and fragmentation of habitats were responsible for the high differentiation and the lack of phylogeographic structure. Our results support that geological and climatic factors since Miocene triggered the differentiation, evolutionary origin and range shifts of the three oak species in the studied area and also emphasize that a multidisciplinary approach combining molecular markers, ENMs and population genetics can yield deep insights into diversification and evolutionary dynamics of species.

  20. Genetic Structure and Evolutionary History of Three Alpine Sclerophyllous Oaks in East Himalaya-Hengduan Mountains and Adjacent Regions.

    Science.gov (United States)

    Feng, Li; Zheng, Qi-Jian; Qian, Zeng-Qiang; Yang, Jia; Zhang, Yan-Ping; Li, Zhong-Hu; Zhao, Gui-Fang

    2016-01-01

    The East Himalaya-Hengduan Mountains (EH-HM) region has a high biodiversity and harbors numerous endemic alpine plants. This is probably the result of combined orographic and climate oscillations occurring since late Tertiary. Here, we determined the genetic structure and evolutionary history of alpine oak species (including Quercus spinosa, Quercus aquifolioides , and Quercus rehderiana ) using both cytoplasmic-nuclear markers and ecological niche models (ENMs), and elucidated the impacts of climate oscillations and environmental heterogeneity on their population demography. Our results indicate there were mixed genetic structure and asymmetric contemporary gene flow within them. The ENMs revealed a similar demographic history for the three species expanded their ranges from the last interglacial (LIG) to the last glacial maximum (LGM), which was consistent with effective population sizes changes. Effects of genetic drift and fragmentation of habitats were responsible for the high differentiation and the lack of phylogeographic structure. Our results support that geological and climatic factors since Miocene triggered the differentiation, evolutionary origin and range shifts of the three oak species in the studied area and also emphasize that a multidisciplinary approach combining molecular markers, ENMs and population genetics can yield deep insights into diversification and evolutionary dynamics of species.

  1. Enclaves of genetic diversity resisted Inca impacts on population history.

    Science.gov (United States)

    Barbieri, Chiara; Sandoval, José R; Valqui, Jairo; Shimelman, Aviva; Ziemendorff, Stefan; Schröder, Roland; Geppert, Maria; Roewer, Lutz; Gray, Russell; Stoneking, Mark; Fujita, Ricardo; Heggarty, Paul

    2017-12-12

    The Inca Empire is claimed to have driven massive population movements in western South America, and to have spread Quechua, the most widely-spoken language family of the indigenous Americas. A test-case is the Chachapoyas region of northern Peru, reported as a focal point of Inca population displacements. Chachapoyas also spans the environmental, cultural and demographic divides between Amazonia and the Andes, and stands along the lowest-altitude corridor from the rainforest to the Pacific coast. Following a sampling strategy informed by linguistic data, we collected 119 samples, analysed for full mtDNA genomes and Y-chromosome STRs. We report a high indigenous component, which stands apart from the network of intense genetic exchange in the core central zone of Andean civilization, and is also distinct from neighbouring populations. This unique genetic profile challenges the routine assumption of large-scale population relocations by the Incas. Furthermore, speakers of Chachapoyas Quechua are found to share no particular genetic similarity or gene-flow with Quechua speakers elsewhere, suggesting that here the language spread primarily by cultural diffusion, not migration. Our results demonstrate how population genetics, when fully guided by the archaeological, historical and linguistic records, can inform multiple disciplines within anthropology.

  2. 76 FR 18227 - Molecular and Clinical Genetics Panel of the Medical Devices Advisory Committee; Notice of...

    Science.gov (United States)

    2011-04-01

    ...] Molecular and Clinical Genetics Panel of the Medical Devices Advisory Committee; Notice of Meeting... comment period for the notice announcing a meeting of the Molecular and Clinical Genetics Panel (the panel... Clinical Genetics Panel of the Medical Devices Advisory Committee, and the opening of a public docket to...

  3. Genetic structure and domestication history of the grape

    Science.gov (United States)

    Myles, Sean; Boyko, Adam R.; Owens, Christopher L.; Brown, Patrick J.; Grassi, Fabrizio; Aradhya, Mallikarjuna K.; Prins, Bernard; Reynolds, Andy; Chia, Jer-Ming; Ware, Doreen; Bustamante, Carlos D.; Buckler, Edward S.

    2011-01-01

    The grape is one of the earliest domesticated fruit crops and, since antiquity, it has been widely cultivated and prized for its fruit and wine. Here, we characterize genome-wide patterns of genetic variation in over 1,000 samples of the domesticated grape, Vitis vinifera subsp. vinifera, and its wild relative, V. vinifera subsp. sylvestris from the US Department of Agriculture grape germplasm collection. We find support for a Near East origin of vinifera and present evidence of introgression from local sylvestris as the grape moved into Europe. High levels of genetic diversity and rapid linkage disequilibrium (LD) decay have been maintained in vinifera, which is consistent with a weak domestication bottleneck followed by thousands of years of widespread vegetative propagation. The considerable genetic diversity within vinifera, however, is contained within a complex network of close pedigree relationships that has been generated by crosses among elite cultivars. We show that first-degree relationships are rare between wine and table grapes and among grapes from geographically distant regions. Our results suggest that although substantial genetic diversity has been maintained in the grape subsequent to domestication, there has been a limited exploration of this diversity. We propose that the adoption of vegetative propagation was a double-edged sword: Although it provided a benefit by ensuring true breeding cultivars, it also discouraged the generation of unique cultivars through crosses. The grape currently faces severe pathogen pressures, and the long-term sustainability of the grape and wine industries will rely on the exploitation of the grape's tremendous natural genetic diversity. PMID:21245334

  4. Molecular evolution and the natural history of select virus epidemics

    DEFF Research Database (Denmark)

    Bruhn, Christian Anders Wathne

    Molecular evolution of pathogenic viruses with RNA based genomes is most often fast enough to leave an informative genomic sequence signal within a timeframe that is relevant for the study of both recent and on-­‐going epidemics (and epizootics). The true power of molecular evolutionary methodolo...

  5. Plant genetic and molecular responses to water deficit

    Directory of Open Access Journals (Sweden)

    Silvio Salvi

    2011-02-01

    Full Text Available Plant productivity is severely affected by unfavourable environmental conditions (biotic and abiotic stresses. Among others, water deficit is the plant stress condition which mostly limits the quality and the quantity of plant products. Tolerance to water deficit is a polygenic trait strictly dependent on the coordinated expression of a large set of genes coding for proteins directly involved in stress-induced protection/repair mechanisms (dehydrins, chaperonins, enzymes for the synthesis of osmoprotectants and detoxifying compounds, and others as well as genes involved in transducing the stress signal and regulating gene expression (transcription factors, kinases, phosphatases. Recently, research activities in the field evolved from the study of single genes directly involved in cellular stress tolerance (functional genes to the identification and characterization of key regulatory genes involved in stress perception and transduction and able to rapidly and efficiently activate the complex gene network involved in the response to stress. The complexity of the events occurring in response to stress have been recently approached by genomics tools; in fact the analysis of transcriptome, proteome and metabolome of a plant tissue/cell in response to stress already allowed to have a global view of the cellular and molecular events occurring in response to water deficit, by the identification of genes activated and co-regulated by the stress conditions and the characterization of new signalling pathways. Moreover the recent application of forward and reverse genetic approaches, trough mutant collection development, screening and characterization, is giving a tremendous impulse to the identification of gene functions with key role in stress tolerance. The integration of data obtained by high-throughput genomic approaches, by means of powerful informatic tools, is allowing nowadays to rapidly identify of major genes/QTLs involved in stress tolerance

  6. The rapid evolution of molecular genetic diagnostics in neuromuscular diseases.

    Science.gov (United States)

    Volk, Alexander E; Kubisch, Christian

    2017-10-01

    The development of massively parallel sequencing (MPS) has revolutionized molecular genetic diagnostics in monogenic disorders. The present review gives a brief overview of different MPS-based approaches used in clinical diagnostics of neuromuscular disorders (NMDs) and highlights their advantages and limitations. MPS-based approaches like gene panel sequencing, (whole) exome sequencing, (whole) genome sequencing, and RNA sequencing have been used to identify the genetic cause in NMDs. Although gene panel sequencing has evolved as a standard test for heterogeneous diseases, it is still debated, mainly because of financial issues and unsolved problems of variant interpretation, whether genome sequencing (and to a lesser extent also exome sequencing) of single patients can already be regarded as routine diagnostics. However, it has been shown that the inclusion of parents and additional family members often leads to a substantial increase in the diagnostic yield in exome-wide/genome-wide MPS approaches. In addition, MPS-based RNA sequencing just enters the research and diagnostic scene. Next-generation sequencing increasingly enables the detection of the genetic cause in highly heterogeneous diseases like NMDs in an efficient and affordable way. Gene panel sequencing and family-based exome sequencing have been proven as potent and cost-efficient diagnostic tools. Although clinical validation and interpretation of genome sequencing is still challenging, diagnostic RNA sequencing represents a promising tool to bypass some hurdles of diagnostics using genomic DNA.

  7. GENETICS AND MOLECULAR BIOLOGY AND PIG MEAT QUALITY IMPROVEMENT

    Directory of Open Access Journals (Sweden)

    J. BULLA

    2007-05-01

    Full Text Available The main goals in pig breeding have for many years been to improve growth rate, feedconversion and carcass composition. There have been less efforts to improve meat qualityparameters (WHC, pH, tenderness, colour etc. but the main contribution has been areduction of stress susceptibility and PSE meat. Unfortunately, the quantitative geneticapproach has yielded few clues regarding the fundamental genetic changes that accompaniedthe selection of animal for superior carcass attributes. While mapping efforts are makingsignificant major effects on carcass and his quality composition DNA test would be availableto detect some positive or negative alleles. There are clear breed effects on meat quality,which in some cases are fully related to the presence of a single gene with major effect (RYR1,MYF4, H-FABP, LEPR, IGF2. Molecular biology methods provides excellent opportunitiesto improve meat quality in selection schemes within breeds and lines. Selection on majorgenes will not only increase average levels of quality but also decrease variability (ei increaseuniformity. The aim of this paper is to discuss there genetic and non-genetic opportunities.

  8. GENETICS AND MOLECULAR BIOLOGY AND PIG MEAT QUALITY IMPROVEMENT

    Directory of Open Access Journals (Sweden)

    BULLA, J.

    2007-01-01

    Full Text Available The main goals in pig breeding have for many years been to improve growth rate, feedconversion and carcass composition. There have been less efforts to improve meat qualityparameters (WHC, pH, tenderness, colour etc. but the main contribution has been areduction of stress susceptibility and PSE meat. Unfortunately, the quantitative geneticapproach has yielded few clues regarding the fundamental genetic changes that accompaniedthe selection of animal for superior carcass attributes. While mapping efforts are makingsignificant major effects on carcass and his quality composition DNA test would be availableto detect some positive or negative alleles. There are clear breed effects on meat quality,which in some cases are fully related to the presence of a single gene with major effect (RYR1,MYF4, H-FABP, LEPR, IGF2. Molecular biology methods provides excellent opportunitiesto improve meat quality in selection schemes within breeds and lines. Selection on majorgenes will not only increase average levels of quality but also decrease variability (ei increaseuniformity. The aim of this paper is to discuss there genetic and non-genetic opportunities.

  9. [Malignant Melanoma - from Classical Histology towards Molecular Genetic Testing].

    Science.gov (United States)

    Ryška, A; Horký, O; Berkovcová, J; Tichá, I; Kalinová, M; Matějčková, M; Bóday, Á; Drábek, J; Martínek, P; Šimová, J; Sieglová, K; Vošmiková, H

    Malignant melanoma is - in comparison with other skin tumors - a relatively rare malignant neoplasm with highly aggressive biologic behavior and variable prognosis. Recent data in pathology and molecular diagnostics indicate that malignant melanoma is in fact not a single entity but a group of different neoplasms with variable etiopathogenesis, biologic behavior and prognosis. New therapeutic options using targeted treatment blocking MAPK signaling pathway require testing of BRAF gene mutation status. This helps to select patients with highest probability of benefit from this treatment. This article summarizes information on the correlation of morphological findings with genetic changes, discusses the representation of individual genetic types in various morphological subgroups and deals with the newly proposed genetic classification of melanoma and the current possibilities, pitfalls and challenges in BRAF testing of malignant melanoma. It also describes the current testing situation in the Czech Republic - the methods used, the representation of BRAF mutations in the tested population and the future of testing. It also shows the limitations of the BRAF and MEK targeted treatment concept resulting from the heterogeneity of the tumor population. Mechanisms of acquired resistance to MAPK pathway inhibitors, possibilities of their detection, and issues of combination of targeted therapy and immunotherapy are discussed.Key words: malignant melanoma - BRAF - mutation - molecular targeted therapy - tumor microenvironment - tumor heterogeneity This work was supported by projects PROGRES Q40/11, BBMRICZ LM2015089, SVV 260398 and GACR 17-10331S. The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.Submitted: 28. 3. 2017Accepted: 16. 5. 2017.

  10. Catecholaminergic systems in stress: structural and molecular genetic approaches.

    Science.gov (United States)

    Kvetnansky, Richard; Sabban, Esther L; Palkovits, Miklos

    2009-04-01

    Stressful stimuli evoke complex endocrine, autonomic, and behavioral responses that are extremely variable and specific depending on the type and nature of the stressors. We first provide a short overview of physiology, biochemistry, and molecular genetics of sympatho-adrenomedullary, sympatho-neural, and brain catecholaminergic systems. Important processes of catecholamine biosynthesis, storage, release, secretion, uptake, reuptake, degradation, and transporters in acutely or chronically stressed organisms are described. We emphasize the structural variability of catecholamine systems and the molecular genetics of enzymes involved in biosynthesis and degradation of catecholamines and transporters. Characterization of enzyme gene promoters, transcriptional and posttranscriptional mechanisms, transcription factors, gene expression and protein translation, as well as different phases of stress-activated transcription and quantitative determination of mRNA levels in stressed organisms are discussed. Data from catecholamine enzyme gene knockout mice are shown. Interaction of catecholaminergic systems with other neurotransmitter and hormonal systems are discussed. We describe the effects of homotypic and heterotypic stressors, adaptation and maladaptation of the organism, and the specificity of stressors (physical, emotional, metabolic, etc.) on activation of catecholaminergic systems at all levels from plasma catecholamines to gene expression of catecholamine enzymes. We also discuss cross-adaptation and the effect of novel heterotypic stressors on organisms adapted to long-term monotypic stressors. The extra-adrenal nonneuronal adrenergic system is described. Stress-related central neuronal regulatory circuits and central organization of responses to various stressors are presented with selected examples of regulatory molecular mechanisms. Data summarized here indicate that catecholaminergic systems are activated in different ways following exposure to distinct

  11. Permanent Genetic Resources added to Molecular Ecology Resources Database 1 December 2012 - 31 January 2013

    Czech Academy of Sciences Publication Activity Database

    Mendel, Jan; Urbánková, Soňa; Vyskočilová, M.

    2013-01-01

    Roč. 13, č. 3 (2013), s. 546-549 ISSN 1755-098X Institutional support: RVO:68081766 Keywords : genetic database * microsatellite marker loci Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.626, year: 2013

  12. [Long QT syndrome. History, genetics, clinical symptoms, causes and therapy].

    Science.gov (United States)

    Krönauer, T; Friederich, P

    2015-08-01

    The long QT syndrome is caused by a change in cardiac repolarization due to functional ion channel defects. A differentiation is made between a congenital (cLQTS) and an acquired (aLQTS) form of the disease. The disease results in the name-giving prolongation of the QT interval in the electrocardiogram and represents a predisposition for cardiac arrhythmia and sudden cardiac death. This article summarizes the current knowledge on the history, pathophysiology, clinical symptoms and therapy of cLQTS and aLQTS. This knowledge of pathophysiological features of the symptoms allows the underlying anesthesiological approach for individualized perioperative concepts for patients suffering from LQTS to be derived.

  13. Italian Common Bean Landraces: History, Genetic Diversity and Seed Quality

    Directory of Open Access Journals (Sweden)

    Angela R. Piergiovanni

    2010-05-01

    Full Text Available The long tradition of common bean cultivation in Italy has allowed the evolution of many landraces adapted to restricted areas. Nowadays, in response to market demands, old landraces are gradually being replaced by improved cultivars. However, landraces still survive in marginal areas of several Italian regions. Most of them appear severely endangered with risk of extinction due to the advanced age of the farmers and the socio-cultural context where they are cultivated. The present contribution is an overview of the state of the art about the knowledge of Italian common bean germplasm, describing the most important and recent progresses made in its characterization, including genetic diversity and nutritional aspects.

  14. A Molecular Genetic Basis Explaining Altered Bacterial Behavior in Space.

    Directory of Open Access Journals (Sweden)

    Luis Zea

    Full Text Available Bacteria behave differently in space, as indicated by reports of reduced lag phase, higher final cell counts, enhanced biofilm formation, increased virulence, and reduced susceptibility to antibiotics. These phenomena are theorized, at least in part, to result from reduced mass transport in the local extracellular environment, where movement of molecules consumed and excreted by the cell is limited to diffusion in the absence of gravity-dependent convection. However, to date neither empirical nor computational approaches have been able to provide sufficient evidence to confirm this explanation. Molecular genetic analysis findings, conducted as part of a recent spaceflight investigation, support the proposed model. This investigation indicated an overexpression of genes associated with starvation, the search for alternative energy sources, increased metabolism, enhanced acetate production, and other systematic responses to acidity-all of which can be associated with reduced extracellular mass transport.

  15. A Molecular Genetic Basis Explaining Altered Bacterial Behavior in Space

    Science.gov (United States)

    Prasad, Nripesh; Levy, Shawn E.; Stodieck, Louis; Jones, Angela; Shrestha, Shristi; Klaus, David

    2016-01-01

    Bacteria behave differently in space, as indicated by reports of reduced lag phase, higher final cell counts, enhanced biofilm formation, increased virulence, and reduced susceptibility to antibiotics. These phenomena are theorized, at least in part, to result from reduced mass transport in the local extracellular environment, where movement of molecules consumed and excreted by the cell is limited to diffusion in the absence of gravity-dependent convection. However, to date neither empirical nor computational approaches have been able to provide sufficient evidence to confirm this explanation. Molecular genetic analysis findings, conducted as part of a recent spaceflight investigation, support the proposed model. This investigation indicated an overexpression of genes associated with starvation, the search for alternative energy sources, increased metabolism, enhanced acetate production, and other systematic responses to acidity—all of which can be associated with reduced extracellular mass transport. PMID:27806055

  16. Blacktip reef sharks, Carcharhinus melanopterus, have high genetic structure and varying demographic histories in their Indo-Pacific range

    KAUST Repository

    Vignaud, Thomas M.; Mourier, Johann; Maynard, Jeffrey Allen; Leblois, Raphaë l; Spaet, Julia L.Y.; Clua, É ric; Neglia, Valentina; Planes, Serge

    2014-01-01

    For free-swimming marine species like sharks, only population genetics and demographic history analyses can be used to assess population health/status as baseline population numbers are usually unknown. We investigated the population genetics

  17. Molecular genetics of early-onset Alzheimer's disease revisited.

    Science.gov (United States)

    Cacace, Rita; Sleegers, Kristel; Van Broeckhoven, Christine

    2016-06-01

    As the discovery of the Alzheimer's disease (AD) genes, APP, PSEN1, and PSEN2, in families with autosomal dominant early-onset AD (EOAD), gene discovery in familial EOAD came more or less to a standstill. Only 5% of EOAD patients are carrying a pathogenic mutation in one of the AD genes or a apolipoprotein E (APOE) risk allele ε4, most of EOAD patients remain unexplained. Here, we aimed at summarizing the current knowledge of EOAD genetics and its role in ongoing approaches to understand the biology of AD and disease symptomatology as well as developing new therapeutics. Next, we explored the possible molecular mechanisms that might underlie the missing genetic etiology of EOAD and discussed how the use of massive parallel sequencing technologies triggered novel gene discoveries. To conclude, we commented on the relevance of reinvestigating EOAD patients as a means to explore potential new avenues for translational research and therapeutic discoveries. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  18. Introductory guide to the statistics of molecular genetics.

    Science.gov (United States)

    Eley, Thalia C; Rijsdijk, Frühling

    2005-10-01

    This introductory guide presents the main two analytical approaches used by molecular geneticists: linkage and association. Traditional linkage and association methods are described, along with more recent advances in methodologies such as those using a variance components approach. New methods are being developed all the time but the core principles of linkage and association remain the same. The basis of linkage is the transmission of a marker along with a disease within families, whereas association is based on the comparison of marker frequencies in case and control groups. It is becoming increasingly clear that effect sizes of individual markers on diseases and traits are likely to be very small. As such, much greater power is needed, and correspondingly greater sample sizes. Although non-replication is still a problem, molecular genetic studies in some areas such as attention deficit/hyperactivity disorder (ADHD) are starting to show greater convergence. Epidemiologists and other researchers with large well-characterized samples will be well placed to use these methods. Inter-disciplinary studies can then ask far more interesting questions such as those relating to developmental, multivariate and gene-environment interaction hypotheses.

  19. Biochemical and molecular genetic studies on some cyanobacterial isolates

    International Nuclear Information System (INIS)

    Kamal, E.A.R.; Ebrahim, S.A.A.

    2011-01-01

    In the present study, the isolation and purification of a set of Cyanobacteria strains belonging to genus Oscillatoria was undertaken, followed by the analyses of phylogenetic relationships using different biochemical and molecular genetic techniques (SOS-PAGE and RAPO-PCR). A total of 45 protein bands were observed within the studied Osci/latoria isolates by SOS-PAGE (only three unique bands, eight monomorphic bands and 37 polymorphic bands). On the other hand, extracted ONA from isolates was used to identify the molecular fingerprints. A sum of 94 polymorphic bands was generated by these primers in the Ocsi/laloria genotypes under study. A total of 20 unique bands were identified out of the polymorphic ones. These unique bands were used to discriminate among the studied Ocsi/latoria isolates. Most isolates of Ocsi/latoria genotypes were discriminated by one or more unique bands. Numerical taxonomic using 45 protein attributes of 19 isolates and RAPO markers on five isolates. Two methods -Clustering (UPGMA) and Principal Component Analysis (PCA) were used for these analyses. The similarities and clusters produced between the studied isolates were discussed.

  20. Biochemical and molecular genetic studies on some cyanobacterial isolates

    Energy Technology Data Exchange (ETDEWEB)

    Kamal, E A.R. [Umm Al-Qura University, Makkah (Saudi Arabia). Dept. of Biology; Ebrahim, S A.A. [Ain Sham University, Cairo (Egypt). Dept. of Cytogenetic

    2011-11-15

    In the present study, the isolation and purification of a set of Cyanobacteria strains belonging to genus Oscillatoria was undertaken, followed by the analyses of phylogenetic relationships using different biochemical and molecular genetic techniques (SOS-PAGE and RAPO-PCR). A total of 45 protein bands were observed within the studied Osci/latoria isolates by SOS-PAGE (only three unique bands, eight monomorphic bands and 37 polymorphic bands). On the other hand, extracted ONA from isolates was used to identify the molecular fingerprints. A sum of 94 polymorphic bands was generated by these primers in the Ocsi/laloria genotypes under study. A total of 20 unique bands were identified out of the polymorphic ones. These unique bands were used to discriminate among the studied Ocsi/latoria isolates. Most isolates of Ocsi/latoria genotypes were discriminated by one or more unique bands. Numerical taxonomic using 45 protein attributes of 19 isolates and RAPO markers on five isolates. Two methods -Clustering (UPGMA) and Principal Component Analysis (PCA) were used for these analyses. The similarities and clusters produced between the studied isolates were discussed.

  1. Pathogenesis of Gastric Cancer: Genetics and Molecular Classification.

    Science.gov (United States)

    Figueiredo, Ceu; Camargo, M C; Leite, Marina; Fuentes-Pananá, Ezequiel M; Rabkin, Charles S; Machado, José C

    Gastric cancer is the fifth most incident and the third most common cause of cancer-related death in the world. Infection with Helicobacter pylori is the major risk factor for this disease. Gastric cancer is the final outcome of a cascade of events that takes decades to occur and results from the accumulation of multiple genetic and epigenetic alterations. These changes are crucial for tumor cells to expedite and sustain the array of pathways involved in the cancer development, such as cell cycle, DNA repair, metabolism, cell-to-cell and cell-to-matrix interactions, apoptosis, angiogenesis, and immune surveillance. Comprehensive molecular analyses of gastric cancer have disclosed the complex heterogeneity of this disease. In particular, these analyses have confirmed that Epstein-Barr virus (EBV)-positive gastric cancer is a distinct entity. The identification of gastric cancer subtypes characterized by recognizable molecular profiles may pave the way for a more personalized clinical management and to the identification of novel therapeutic targets and biomarkers for screening, prognosis, prediction of response to treatment, and monitoring of gastric cancer progression.

  2. Genetic engineering in Cowpea (Vigna unguiculata): history, status and prospects.

    Science.gov (United States)

    Citadin, Cristiane T; Ibrahim, Abdulrazak B; Aragão, Francisco J L

    2011-01-01

    In the last three decades, a number of attempts have been made to develop reproducible protocols for generating transgenic cowpea that permit the expression of genes of agronomic importance. Pioneer works focused on the development of such systems vis-à-vis an in vitro culture system that would guarantee de novo regeneration of transgenic cowpea arising from cells amenable to one form of gene delivery system or another, but any such system has eluded researchers over the years. Despite this apparent failure, significant progress has been made in generating transgenic cowpea, bringing researchers much nearer to their goal than thirty years ago. Now, various researchers have successfully established transgenic procedures for cowpea with evidence of inherent transgenes of interest, effected by progenies in a Mendelian fashion. New opportunities have thus emerged to optimize existing protocols and devise new strategies to ensure the development of transgenic cowpea with desirable agronomic traits. This review chronicles the important milestones in the last thirty years that have marked the evolution of genetic engineering of cowpea. It also highlights the progress made and describes new strategies that have arisen, culminating in the current status of transgenic technologies for cowpea.

  3. Can genetics help us understand Indian social history?

    Science.gov (United States)

    Thapar, Romila

    2014-06-26

    Attempts have been made recently to determine the identity of the so-called "Aryans" as components of the Indian population by using DNA analysis. This is largely to ascertain whether they were indigenous to India or were foreign arrivals. Similar attempts have been made to trace the origins of caste groups on the basis of varna identities and record their distribution. The results so far have been contradictory and, therefore, not of much help to social historians. There are problems in the defining of categories and the techniques of analysis. Aryan is a linguistic and cultural category and not a biological one. Caste groups have no well-defined and invariable boundaries despite marriage codes. Various other categories have been assimilated into particular castes as part of the evolution of social history on the subcontinent. A few examples of these are discussed. The problems with using DNA analysis are also touched on. Copyright © 2014 Cold Spring Harbor Laboratory Press; all rights reserved.

  4. Molecular genetic approach for screening of hereditary non-polyposis colorectal cancer

    Directory of Open Access Journals (Sweden)

    Metka Ravnik-Glavač

    2005-07-01

    Full Text Available Background: The main goal of knowledge concerning human diseases is to transfer as much as possible useful information into clinical applications. Hereditary non-polyposis colorectal cancer (HNPCC is the most common autosomal dominant inherited predisposition for colorectal cancer, accounting for 1–2% of all bowel cancer. The only way to diagnose HNPCC is by a family history consistent with the disease defined by International Collaborative Group on HNPCC (Amsterdam criteria I and II. The main molecular cause of HNPCC is a constitutional mutation in one of the mismatch repair (MMR genes. Since HNPCC mutations have been detected also in families that did not fulfil the Amsterdam criteria, molecular genetic characteristics of HNPCC cancers have been proposed as valuable first step in HNPCC identification. Microsatellite instability is present in about 90% of cancers of HNPCC patients. However, of all MSI colorectal cancers 80– 90% are sporadic. Several molecular mechanisms have been uncovered that enable distinguishing to some extent between sporadic and HNPCC cancers with MSI including hypermethylation of hMLH1 promoter and frequent mutations in BAX and TGFBR2 in sporadic CRC with MSI-H.Conclusions: The determination of MSI status and careful separation of MSI positive colorectal cancer into sporadic MSIL, sporadic MSI-H, and HNPCC MSI-H followed by mutation detection in MMR genes is important for prevention, screening and management of colorectal cancer. In some studies we and others have already shown that large-scale molecular genetic analysis for HNPCC can be done and is sensitive enough to approve population screening. Population screening includes also colonoscopy which is restricted only to the obligate carriers of the mutation. This enables that the disease is detected in earlier stages which would greatly decrease medical treatment costs and most importantly decrease mortality. In Slovenia we have started population screening based

  5. Improving Molecular Genetic Test Utilization through Order Restriction, Test Review, and Guidance.

    Science.gov (United States)

    Riley, Jacquelyn D; Procop, Gary W; Kottke-Marchant, Kandice; Wyllie, Robert; Lacbawan, Felicitas L

    2015-05-01

    The ordering of molecular genetic tests by health providers not well trained in genetics may have a variety of untoward effects. These include the selection of inappropriate tests, the ordering of panels when the assessment of individual or fewer genes would be more appropriate, inaccurate result interpretation and inappropriate patient guidance, and significant unwarranted cost expenditure. We sought to improve the utilization of molecular genetic tests by requiring providers without specialty training in genetics to use genetic counselors and molecular genetic pathologists to assist in test selection. We used a genetic and genomic test review process wherein the laboratory-based genetic counselor performed the preanalytic assessment of test orders and test triage. Test indication and clinical findings were evaluated against the test panel composition, methods, and test limitations under the supervision of the molecular genetic pathologist. These test utilization management efforts resulted in a decrease in genetic test ordering and a gross cost savings of $1,531,913 since the inception of these programs in September 2011 through December 2013. The combination of limiting the availability of complex genetic tests and providing guidance regarding appropriate test strategies is an effective way to improve genetic tests, contributing to judicious use of limited health care resources. Copyright © 2015 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

  6. The endemic gastropod fauna of Lake Titicaca: correlation between molecular evolution and hydrographic history.

    Science.gov (United States)

    Kroll, Oliver; Hershler, Robert; Albrecht, Christian; Terrazas, Edmundo M; Apaza, Roberto; Fuentealba, Carmen; Wolff, Christian; Wilke, Thomas

    2012-07-01

    Lake Titicaca, situated in the Altiplano high plateau, is the only ancient lake in South America. This 2- to 3-My-old (where My is million years) water body has had a complex history that included at least five major hydrological phases during the Pleistocene. It is generally assumed that these physical events helped shape the evolutionary history of the lake's biota. Herein, we study an endemic species assemblage in Lake Titicaca, composed of members of the microgastropod genus Heleobia, to determine whether the lake has functioned as a reservoir of relic species or the site of local diversification, to evaluate congruence of the regional paleohydrology and the evolutionary history of this assemblage, and to assess whether the geographic distributions of endemic lineages are hierarchical. Our phylogenetic analyses indicate that the Titicaca/Altiplano Heleobia fauna (together with few extralimital taxa) forms a species flock. A molecular clock analysis suggests that the most recent common ancestor (MRCAs) of the Altiplano taxa evolved 0.53 (0.28-0.80) My ago and the MRCAs of the Altiplano taxa and their extralimital sister group 0.92 (0.46-1.52) My ago. The endemic species of Lake Titicaca are younger than the lake itself, implying primarily intralacustrine speciation. Moreover, the timing of evolutionary branching events and the ages of two precursors of Lake Titicaca, lakes Cabana and Ballivián, is congruent. Although Lake Titicaca appears to have been the principal site of speciation for the regional Heleobia fauna, the contemporary spatial patterns of endemism have been masked by immigration and/or emigration events of local riverine taxa, which we attribute to the unstable hydrographic history of the Altiplano. Thus, a hierarchical distribution of endemism is not evident, but instead there is a single genetic break between two regional clades. We also discuss our findings in relation to studies of other regional biota and suggest that salinity tolerance was

  7. Molecular surface science of heterogeneous catalysis. History and perspective

    International Nuclear Information System (INIS)

    Somorjai, G.A.

    1983-08-01

    A personal account is given of how the author became involved with modern surface science and how it was employed for studies of the chemistry of surfaces and heterogeneous catalysis. New techniques were developed for studying the properties of the surface monolayers: Auger electron spectroscopy, LEED, XPS, molecular beam surface scattering, etc. An apparatus was developed and used to study hydrocarbon conversion reactions on Pt, CO hydrogenation on Rh and Fe, and NH 3 synthesis on Fe. A model has been developed for the working Pt reforming catalyst. The three molecular ingredients that control catalytic properties are atomic surface structure, an active carbonaceous deposit, and the proper oxidation state of surface atoms. 40 references, 21 figures

  8. Molecular surface science of heterogeneous catalysis. History and perspective

    Energy Technology Data Exchange (ETDEWEB)

    Somorjai, G.A.

    1983-08-01

    A personal account is given of how the author became involved with modern surface science and how it was employed for studies of the chemistry of surfaces and heterogeneous catalysis. New techniques were developed for studying the properties of the surface monolayers: Auger electron spectroscopy, LEED, XPS, molecular beam surface scattering, etc. An apparatus was developed and used to study hydrocarbon conversion reactions on Pt, CO hydrogenation on Rh and Fe, and NH/sub 3/ synthesis on Fe. A model has been developed for the working Pt reforming catalyst. The three molecular ingredients that control catalytic properties are atomic surface structure, an active carbonaceous deposit, and the proper oxidation state of surface atoms. 40 references, 21 figures. (DLC)

  9. Introducing medical genetics services in Ethiopia using the MiGene Family History App.

    Science.gov (United States)

    Quinonez, Shane C; Yeshidinber, Abate; Lourie, Michael A; Bekele, Delayehu; Mekonnen, Yemisrach; Nigatu, Balkachew; Metaferia, Gesit; Jebessa, Solomie

    2018-06-11

    Almost all low-income countries and many middle-income countries lack the capacity to deliver medical genetics services. We developed the MiGene Family History App (MFHA), which assists doctors with family history collection and population-level epidemiologic analysis. The MFHA was studied at St. Paul's Hospital in Addis Ababa, Ethiopia. A needs assessment was used to assess Ethiopian physicians' experience with genetics services. The MFHA then collected patient data over a 6-month period. The majority of doctors provide genetics services, with only 16% reporting their genetics knowledge is sufficient. A total of 1699 patients from the pediatric ward (n = 367), neonatal intensive care unit (NICU) (n = 477), and antenatal clinic (n = 855) were collected using the MFHA with a 4% incidence of a MFHA-screened condition present. The incidence was 11.7% in the pediatric ward, 3% in the NICU, and 0.5% in the antenatal clinic. Heart malformations (5.5% of patients) and trisomy 21 (4.4% of patients) were the most common conditions in the pediatric ward. Medical genetics services are needed in Ethiopia. As other countries increase their genetics capacity, the MFHA can provide fundamental genetics services and collect necessary epidemiologic data.

  10. Genética molecular: avanços e problemas Molecular genetics: advances and problems

    Directory of Open Access Journals (Sweden)

    Eloi S. Garcia

    1996-03-01

    Full Text Available Este artigo traz a discussão sobre genética molecular em saúde ao campo da saúde pública. Com a revolução produzida pela chegada da engenharia genética, é importante discutir alguns dos avanços e problemas desta tecnologia para a sociedade. Está na hora de se fazer uma avaliação clara e bem informada acerca do que já se conseguiu e do que ainda podemos conseguir através desta tecnologia. A sociedade precisa compreender as implicações éticas e práticas de uma tecnologia capaz de produzir drogas milagrosas, dagnósticos modernos e a cura de todas as doenças. Alguns pontos particularmente delicados pertinentes às questões sociais ligadas à biologia molecular e ao projeto genoma humano são discutidos.This article is an attempt to draw the discussion on molecular genetics in health into the public health domain. Now that the genetic engineering revolution has arrived, it is important to point out the advances and problems this technology poses for society. It is time for a clear, informed assessment of what we have already achieved and may soon achieve using this technology. Clearly, society needs to understand the ethical and practical implications of a technology which can produce miracle drugs and modern diagnoses and cure virtually every disease. Important points from sensitive social issues raised by molecular biology and the human genome project are discussed.

  11. 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

  12. Genetic structure and demographic history of Colletotrichum gloeosporioides sensu lato and C. truncatum isolates from Trinidad and Mexico.

    Science.gov (United States)

    Rampersad, Sephra N; Perez-Brito, Daisy; Torres-Calzada, Claudia; Tapia-Tussell, Raul; Carrington, Christine V F

    2013-06-22

    C. gloeosporioides sensu lato is one of the most economically important post-harvest diseases affecting papaya production worldwide. There is currently no information concerning the genetic structure or demographic history of this pathogen in any of the affected countries. Knowledge of molecular demographic parameters for different populations will improve our understanding of the biogeographic history as well as the evolutionary and adaptive potential of these pathogens. In this study, sequence data for ACT, GPDH, β-TUB and ITS gene regions were analyzed for C. gloeosporioides sensu lato and C. truncatum isolates infecting papaya in Trinidad and Mexico in order to determine the genetic structure and demographic history of these populations. The data indicated that Mexico is the ancestral C. gloeosporioides sensu lato population with asymmetrical migration to Trinidad. Mexico also had the larger effective population size but, both Mexico and Trinidad populations exhibited population expansion. Mexico also had greater nucleotide diversity and high levels of diversity for each gene. There was significant sub-division of the Trinidad and Mexico populations and low levels of genetic divergence among populations for three of the four gene regions; β-TUB was shown to be under positive selection. There were also dissimilar haplotype characteristics for both populations. Mutation may play a role in shaping the population structure of C. gloeosporioides sensu lato isolates from Trinidad and from Mexico, especially with respect to the ACT and GPDH gene regions. There was no evidence of gene flow between the C. truncatum populations and it is possible that the Mexico and Trinidad populations emerged independently of each other. The study revealed relevant information based on the genetic structure as well as the demographic history of two fungal pathogens infecting papaya, C. gloeosporioides sensu lato and C. truncatum, in Trinidad and Mexico. Understanding the genetic

  13. Quadratic genetic modifications: a streamlined route to cosmological simulations with controlled merger history

    Science.gov (United States)

    Rey, Martin P.; Pontzen, Andrew

    2018-02-01

    Recent work has studied the interplay between a galaxy's history and its observable properties using `genetically modified' cosmological zoom simulations. The approach systematically generates alternative histories for a halo, while keeping its cosmological environment fixed. Applications to date altered linear properties of the initial conditions, such as the mean overdensity of specified regions; we extend the formulation to include quadratic features, such as local variance, that determines the overall importance of smooth accretion relative to mergers in a galaxy's history. We introduce an efficient algorithm for this new class of modification and demonstrate its ability to control the variance of a region in a one-dimensional toy model. Outcomes of this work are twofold: (i) a clarification of the formulation of genetic modifications and (ii) a proof of concept for quadratic modifications leading the way to a forthcoming implementation in cosmological simulations.

  14. Tracing the origin of 'blue Weimaraner' dogs by molecular genetics.

    Science.gov (United States)

    Gerding, W M; Schreiber, S; Dekomien, G; Epplen, J T

    2011-04-01

    Weimaraner dogs are defined by light brown coat colour termed grey including several shadings ranging from silver and deer to mouse grey. In contrast, the so-called blue Weimaraners (BW) with lightened black-pigmented coat have been proposed to represent spontaneous revertants in the Weimaraner breed. In order to investigate the genetic determinants of the characteristic grey coat colour versus those of BW, known variation in coat colour genes including TYRP1 and MLPH were analysed in a number of grey and blue dogs. Variations at the B locus cause grey coat colour in Weimaraners via two non-functional TYRP1 copies (bb) including the b(s), b(d) and b(c) alleles. In all BW, at least one functional TYRP1 allele (Bb or BB genotype) was identified. Defined microsatellite alleles in TYRP1 intron 4 are linked to this functional B allele in BW. These alleles were also detected in various other dog breeds, but not in grey Weimaraners. The combination of a dominant trait for blue versus grey together with a specific TYRP1 haplotype in BW suggests that blue coat colour is not the result of spontaneous (back-) mutation in grey Weimaraners. This inference is even emphasized by the presence of a unique Y-chomosomal haplotype in a male offspring of the supposed ancestor of the BW population which - according to pedigree information - carries a copy of the original Y chromosome. Thus, molecular genetic analyses of coat colours combined with Y-chromosomal haplotypes allow tracing the origin of atypical dogs in respective canine populations. © 2010 Blackwell Verlag GmbH.

  15. Phylogeographic analyses and genetic structure illustrate the complex evolutionary history of Phragmites australis in Mexico.

    Science.gov (United States)

    Colin, Ricardo; Eguiarte, Luis E

    2016-05-01

    Genetic data suggest that three lineages of Phragmites australis are found in North America: the Native North American lineage, the Gulf Coast lineage, and the Invasive lineage. In Mexico, P. australis is a common species, but nothing is known about the distribution or ecology of these lineages. We examined the phylogeography of P. australis to analyze the current geographic distribution of genetic variation, demographic history, and dispersal patterns to better understand its evolutionary history in Mexico. We sampled 427 individuals from 28 populations. We used two noncoding regions of chloroplast DNA to estimate the levels of genetic variation and identified the genetic groups across the species' geographical range in Mexico. We compared the genealogical relationships among haplotypes with those previously reported. A hypothesis of demographic expansion was also tested for the Mexican P. australis lineages. We found 13 new haplotypes native to Mexico that might be undergoing an active process of expansion and diversification. Genealogical analyses provided evidence that two independent lineages of P. australis are present in Mexico. The invasive lineage was not detected with our sampling. Our estimates of population expansions in Mexico ranged from 0.202 to 0.726 mya. Phragmites australis is a native species that has been in Mexico for thousands of years. Genetic data suggest that climatic changes during the Pleistocene played an important role in the demographic expansion of the populations that constitute the different genetic groups of P. australis in Mexico. © 2016 Botanical Society of America.

  16. MOLECULAR GENETIC MARKERS AND METHODS OF THEIR IDENTIFICATION IN MODERN FISH-FARMING

    Directory of Open Access Journals (Sweden)

    I. Hrytsyniak

    2014-03-01

    Full Text Available Purpose. The application of molecular genetic markers has been widely used in modern experimental fish-farming in recent years. This methodology is currently presented by a differentiated approach with individual mechanisms and clearly defined possibilities. Numerous publications in the scientific literature that are dedicated to molecular genetic markers for the most part offer purely practical data. Thus, the synthesis and analysis of existing information on the general principles of action and the limits of the main methods of using molecular genetic markers is an actual problem. In particular, such a description will make it possible to plan more effectively the experiment and to obtain the desired results with high reliability. Findings. The main types of variable parts of DNA that can be used as molecular genetic markers in determining the level of stock hybridization, conducting genetic inventory of population and solving other problems in modern fish-farming are described in this paper. Also, the article provides an overview of principal modern methods that can be used to identify molecular genetic markers. Originality. This work is a generalization of modern ideas about the mechanisms of experiments with molecular genetic markers in fish-farming. Information is provided in the form of consistent presentation of the principles and purpose of each method, as well as significant advances during their practical application. Practical value. The proposed review of classic and modern literature data on molecular genetic markers can be used for planning, modernization and correction of research activity in modern fish-farming.

  17. A proposition on the genetic history of visceral Leishmaniasis:glimpses from the side of parasite

    International Nuclear Information System (INIS)

    Ibrahim, Muntasir E.

    1999-01-01

    The recorded history of diseases affecting man, contains hardly any reliable information on their state beyond few centuries ago. This is particularly true for diseases having symptoms common to others as is typically the case of visceral Leishmaniasis. Our increased understanding of the biology and epidemiology of VL during the last hundred years or so, nevertheless, raise more questions than answers. For example: what is the possible role played by such disease in shaping the population structure and range of expaion of their human host. Could resistance of certain populations to disease be explained by the distribution of less virulent parasite strains e.g. (Leishmania infantum) or by ancient episodes of strong selection? data obtained from molecular analysis of parasites isolated from patients in Sudan, indicates that the current outbreak is probably a recent event caused by stocks of closely related parasites. More recently, mitochondrial hapoltypes analysis gave further support to the homogeneity of these parasite populations. Cladistic analysis of Leishmania donovani strains from different continents make a clear distinction between two clades; one containing parasites of the infantum group in different continents and the other includes members of the donovani group in Africa and Asia. Furthermore, we did not encounter-a-presence-of Leishmania infantum specific sequence within paraite population sampled in the areas, covered by the outbreaks. The parasites from Sudan presented with the most ancestral haplotypes. The disease in Sudan may have passed through short periods of protraction and expansion, which may have resulted in stability of the parasite genetic population structure, but rather a fragile host-parasite relationship. Studying host sequence may reveal equally interesting situations and shed more light on these-aspects.(Author)

  18. Molecular Phylogenetic: Organism Taxonomy Method Based on Evolution History

    Directory of Open Access Journals (Sweden)

    N.L.P Indi Dharmayanti

    2011-03-01

    Full Text Available Phylogenetic is described as taxonomy classification of an organism based on its evolution history namely its phylogeny and as a part of systematic science that has objective to determine phylogeny of organism according to its characteristic. Phylogenetic analysis from amino acid and protein usually became important area in sequence analysis. Phylogenetic analysis can be used to follow the rapid change of a species such as virus. The phylogenetic evolution tree is a two dimensional of a species graphic that shows relationship among organisms or particularly among their gene sequences. The sequence separation are referred as taxa (singular taxon that is defined as phylogenetically distinct units on the tree. The tree consists of outer branches or leaves that represents taxa and nodes and branch represent correlation among taxa. When the nucleotide sequence from two different organism are similar, they were inferred to be descended from common ancestor. There were three methods which were used in phylogenetic, namely (1 Maximum parsimony, (2 Distance, and (3 Maximum likehoood. Those methods generally are applied to construct the evolutionary tree or the best tree for determine sequence variation in group. Every method is usually used for different analysis and data.

  19. Molecular genetic transfection of the coccidian parasite Sarcocystis neurona.

    Science.gov (United States)

    Gaji, Rajshekhar Y; Zhang, Deqing; Breathnach, Cormac C; Vaishnava, Shipra; Striepen, Boris; Howe, Daniel K

    2006-11-01

    Sarcocystis neurona is an apicomplexan parasite that is the major cause of equine protozoal myeloencephalitis (EPM). The biology of this pathogen remains poorly understood in part due to unavailability of molecular genetic tools. Hence, with an objective to develop DNA transfection capabilities for S. neurona, the 5' flanking region of the SnSAG1 gene was isolated from a genomic library and used to construct expression plasmids. In transient assays, the reporter molecules beta-galactosidase (beta-gal) and yellow fluorescent protein (YFP) could be detected in electroporated S. neurona, thereby confirming the feasibility of transgene expression in this organism. Stable transformation of S. neurona was achieved using a mutant dihydrofolate reductase thymidylate synthase (DHFR-TS) gene of Toxoplasma gondii that confers resistance to pyrimethamine. This selection system was used to create transgenic S. neurona that stably express beta-gal and YFP. As shown in this study, these transgenic clones can be useful for analyzing growth rate of parasites in vitro and for assessing drug sensitivities. More importantly, the DNA transfection methods described herein should greatly facilitate studies examining intracellular parasitism by this important coccidian pathogen.

  20. Genetic, functional and molecular features of glucocorticoid receptor binding.

    Directory of Open Access Journals (Sweden)

    Francesca Luca

    Full Text Available Glucocorticoids (GCs are key mediators of stress response and are widely used as pharmacological agents to treat immune diseases, such as asthma and inflammatory bowel disease, and certain types of cancer. GCs act mainly by activating the GC receptor (GR, which interacts with other transcription factors to regulate gene expression. Here, we combined different functional genomics approaches to gain molecular insights into the mechanisms of action of GC. By profiling the transcriptional response to GC over time in 4 Yoruba (YRI and 4 Tuscans (TSI lymphoblastoid cell lines (LCLs, we suggest that the transcriptional response to GC is variable not only in time, but also in direction (positive or negative depending on the presence of specific interacting transcription factors. Accordingly, when we performed ChIP-seq for GR and NF-κB in two YRI LCLs treated with GC or with vehicle control, we observed that features of GR binding sites differ for up- and down-regulated genes. Finally, we show that eQTLs that affect expression patterns only in the presence of GC are 1.9-fold more likely to occur in GR binding sites, compared to eQTLs that affect expression only in its absence. Our results indicate that genetic variation at GR and interacting transcription factors binding sites influences variability in gene expression, and attest to the power of combining different functional genomic approaches.

  1. Molecular genetic analysis of phosphomannomutase genes in Triticum monococcum

    Institute of Scientific and Technical Information of China (English)

    Chunmei; Yu; Xinyan; Liu; Qian; Zhang; Xinyu; He; Wan; Huai; Baohua; Wang; Yunying; Cao; Rong; Zhou

    2015-01-01

    In higher plants, phosphomannomutase(PMM) is essential for synthesizing the antioxidant ascorbic acid through the Smirnoff–Wheeler pathway. Previously, we characterized six PMM genes(Ta PMM-A1, A2, B1, B2, D1 and D2) in common wheat(Triticum aestivum, AABBDD).Here, we report a molecular genetic analysis of PMM genes in Triticum monococcum(AmAm), a diploid wheat species whose Amgenome is closely related to the A genome of common wheat. Two distinct PMM genes, Tm PMM-1 and Tm PMM-2, were found in T. monococcum. The coding region of Tm PMM-1 was intact and highly conserved. In contrast, two main Tm PMM-2 alleles were identified, with Tm PMM-2a possessing an intact coding sequence and Tm PMM-2b being a pseudogene. The transcript level of Tm PMM-2a was much higher than that of Tm PMM-2b, and a bacterially expressed Tm PMM-2a recombinant protein displayed relatively high PMM activity. In general, the total transcript level of PMM was substantially higher in accessions carrying Tm PMM-1 and Tm PMM-2a than those harboring Tm PMM-1 and Tm PMM-2b. However, total PMM protein and activity levels did not differ drastically between the two genotypes. This work provides new information on PMM genes in T. monococcum and expands our understanding on Triticeae PMM genes, which may aid further functional and applied studies of PMM in crop plants.

  2. [Molecular, genetic and physiological analysis of photoinhibition and photosynthetic

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    A major goal of this project is to use a combined molecular genetic, biochemical and physiological approach to understand the relationship between photosynthetic performance and the structure of the multifunctional D1 reaction center protein of Photosystem II encoded by the chloroplast psbA gene. Relative to other chloroplast proteins, turover of D1 is rapid and highly light dependent and de novo synthesis of D1 is required for a plant's recovery from short term exposure to irradiances which induce photoinhibitory damage. These observations have led to models for a damage/repair cycle of PSII involving the targeted degradation and replacement of photodamaged D1. To investigate the effects of perturbing the D1 cycle on photosynthesis and autotrophic growth under high and low irradiance, we have examined the consequences of site-specific mutations of the psbA and 16S rRNA genes affecting synthesis, maturation and function/stability of the D1 protein introduced into the chloroplast genome of wildtype strain of the green alga Chlamydomonas reinhardtii using biolistic transformation.

  3. Molecular genetics of human primary microcephaly: an overview

    Science.gov (United States)

    2015-01-01

    Autosomal recessive primary microcephaly (MCPH) is a neurodevelopmental disorder that is characterised by microcephaly present at birth and non-progressive mental retardation. Microcephaly is the outcome of a smaller but architecturally normal brain; the cerebral cortex exhibits a significant decrease in size. MCPH is a neurogenic mitotic disorder, though affected patients demonstrate normal neuronal migration, neuronal apoptosis and neural function. Twelve MCPH loci (MCPH1-MCPH12) have been mapped to date from various populations around the world and contain the following genes: Microcephalin, WDR62, CDK5RAP2, CASC5, ASPM, CENPJ, STIL, CEP135, CEP152, ZNF335, PHC1 and CDK6. It is predicted that MCPH gene mutations may lead to the disease phenotype due to a disturbed mitotic spindle orientation, premature chromosomal condensation, signalling response as a result of damaged DNA, microtubule dynamics, transcriptional control or a few other hidden centrosomal mechanisms that can regulate the number of neurons produced by neuronal precursor cells. Additional findings have further elucidated the microcephaly aetiology and pathophysiology, which has informed the clinical management of families suffering from MCPH. The provision of molecular diagnosis and genetic counselling may help to decrease the frequency of this disorder. PMID:25951892

  4. Constructing Masculinity through Genetic Legacies: Family Histories, Y-Chromosomes, and “Viking Identities”

    Directory of Open Access Journals (Sweden)

    Marc Scully

    2018-02-01

    Full Text Available The contemporary popularity of genetic genealogy has been accompanied by concerns about its potential reifying of identity. This has referred in particular to ethnicity, but also to gender, with fears that looking at the past through the lens of popular genetics reinforces patriarchal views of the family and traditional heteronormative understandings of masculinity and femininity. This study investigates whether such understandings are drawn upon by male participants in a population genetics study. Discursive analysis of 128 responses to a participant motivation survey and 18 follow-up interviews explores how participants construct masculinity when discussing genetics and their own family history. It is argued that while there is some evidence for the “patriarchal” argument, a subtler form of masculine legacy creation and maintenance is the primary narrative.

  5. Land, language, and loci: mtDNA in Native Americans and the genetic history of Peru.

    Science.gov (United States)

    Lewis, Cecil M; Tito, Raúl Y; Lizárraga, Beatriz; Stone, Anne C

    2005-07-01

    Despite a long history of complex societies and despite extensive present-day linguistic and ethnic diversity, relatively few populations in Peru have been sampled for population genetic investigations. In order to address questions about the relationships between South American populations and about the extent of correlation between genetic distance, language, and geography in the region, mitochondrial DNA (mtDNA) hypervariable region I sequences and mtDNA haplogroup markers were examined in 33 individuals from the state of Ancash, Peru. These sequences were compared to those from 19 American Indian populations using diversity estimates, AMOVA tests, mismatch distributions, a multidimensional scaling plot, and regressions. The results show correlations between genetics, linguistics, and geographical affinities, with stronger correlations between genetics and language. Additionally, the results suggest a pattern of differential gene flow and drift in western vs. eastern South America, supporting previous mtDNA and Y chromosome investigations. (c) 2004 Wiley-Liss, Inc

  6. Molecular evidence for the early history of living amphibians.

    Science.gov (United States)

    Feller, A E; Hedges, S B

    1998-06-01

    The evolutionary relationships of the three orders of living amphibians (lissamphibians) has been difficult to resolve, partly because of their specialized morphologies. Traditionally, frogs and salamanders are considered to be closest relatives, and all three orders are thought to have arisen in the Paleozoic (>250 myr). Here, we present evidence from the DNA sequences of four mitochondrial genes (2.7 kilobases) that challenges the conventional hypothesis and supports a salamander-caecilian relationship. This, in light of the fossil record and distribution of the families, suggests a more recent (Mesozoic) origin for salamanders and caecilians directly linked to the initial breakup of the supercontinent Pangaea. We propose that this single geologic event isolated salamanders and archaeobatrachian frogs on the northern continents (Laurasia) and the caecilians and neobatrachian frogs on the southern continents (Gondwana). Among the neobatrachian frog families, molecular evidence supports a South American clade and an African clade, inferred here to be the result of mid-Cretaceous vicariance. Copyright 1998 Academic Press.

  7. Genetic dissimilarity among sweet potato genotypes using morphological and molecular descriptors

    Directory of Open Access Journals (Sweden)

    Elisângela Knoblauch Viega de Andrade

    2017-08-01

    Full Text Available This study aimed to evaluate the genetic dissimilarity among sweet potato genotypes using morphological and molecular descriptors. The experiment was conducted in the Olericulture Sector at Federal University of Jequitinhonha and Mucuri Valleys (UFVJM and evaluated 60 sweet potato genotypes. For morphological characterization, 24 descriptors were used. For molecular characterization, 11 microsatellite primers specific for sweet potatoes were used, obtaining 210 polymorphic bands. Morphological and molecular diversity was obtained by dissimilarity matrices based on the coefficient of simple matching and the Jaccard index for morphological and molecular data, respectively. From these matrices, dendrograms were built. There is a large amount of genetic variability among sweet potato genotypes of the germplasm bank at UFVJM based on morphological and molecular characterizations. There was no duplicate suspicion or strong association between morphological and molecular analyses. Divergent accessions have been identified by molecular and morphological analyses, which can be used as parents in breeding programmes to produce progenies with high genetic variability.

  8. Geographic, genetic and life-history variability in a sex-changing fish

    Directory of Open Access Journals (Sweden)

    Chiara Benvenuto

    2015-11-01

    Full Text Available Sequential hermaphroditism, commonly referred to as sex change or sex reversal, is a striking phenomenon in mating-system evolution and the most remarkable example of sexual plasticity. Among vertebrates, it is specific to teleosts. Some fish species reproduce initially as females and then change into males (protogynous hermaphrodites or vice versa (protandrous hermaphrodites. The white sea bream, Diplodus sargus, exhibits a high degree of sexual plasticity: populations have been reported to be gonochoristic, protandrous or digynic (with primary females, derived from intersexual juveniles, and secondary females, derived from males. We analysed populations collected from eight different locations across the species distribution range (between the Mediterranean and the North-Eastern Atlantic. These populations are characterized by different degrees of connectivity, spatial demographics and life histories. Using individual-based analyses, we linked the genetic structure of each specimen with environmental heterogeneity, life-history traits and reproductive modes. Our aim is to gather a better understanding of the variation in reproductive life-history strategies in this sexually plastic species. Diplodus sargus is a valuable candidate organism to investigate sequential hermaphroditism and it also has a commercial value. The application of population genetics tools against the background of life-history theory can bring valuable insights for the management of marine resources. The geographical patterns of sex change (and of age- and size-at-sex change linked with population genetics can be pivotal for both theoretical investigations and conservation and management plans in marine areas.

  9. [Molecular genetic diagnostics and screening of hereditary hemochromatosis].

    Science.gov (United States)

    Zlocha, J; Kovács, L; Pozgayová, S; Kupcová, V; Durínová, S

    2006-06-01

    identified through biochemical testing for iron overload using serum transferrin saturation and genetic testing for C282Y homozygosity. DNA analysis is recommended in patients whose transferrin saturation is 45% or more on a repeated test. General population screening has been waived in preference to targeting high-risk groups such as first-degree relatives of affected individuals and those with secondary iron overload, especially patients with chronic liver disorders and chronic anemia. This screening strategy is likely to continue until uncertainties regarding the natural history of the disease, age-related penetrance, and management of asymptomatic individuals are clarified.

  10. Novel molecular markers of Chlamydia pecorum genetic diversity in the koala (Phascolarctos cinereus)

    Science.gov (United States)

    2011-01-01

    Background Chlamydia pecorum is an obligate intracellular bacterium and the causative agent of reproductive and ocular disease in several animal hosts including koalas, sheep, cattle and goats. C. pecorum strains detected in koalas are genetically diverse, raising interesting questions about the origin and transmission of this species within koala hosts. While the ompA gene remains the most widely-used target in C. pecorum typing studies, it is generally recognised that surface protein encoding genes are not suited for phylogenetic analysis and it is becoming increasingly apparent that the ompA gene locus is not congruent with the phylogeny of the C. pecorum genome. Using the recently sequenced C. pecorum genome sequence (E58), we analysed 10 genes, including ompA, to evaluate the use of ompA as a molecular marker in the study of koala C. pecorum genetic diversity. Results Three genes (incA, ORF663, tarP) were found to contain sufficient nucleotide diversity and discriminatory power for detailed analysis and were used, with ompA, to genotype 24 C. pecorum PCR-positive koala samples from four populations. The most robust representation of the phylogeny of these samples was achieved through concatenation of all four gene sequences, enabling the recreation of a "true" phylogenetic signal. OmpA and incA were of limited value as fine-detailed genetic markers as they were unable to confer accurate phylogenetic distinctions between samples. On the other hand, the tarP and ORF663 genes were identified as useful "neutral" and "contingency" markers respectively, to represent the broad evolutionary history and intra-species genetic diversity of koala C. pecorum. Furthermore, the concatenation of ompA, incA and ORF663 sequences highlighted the monophyletic nature of koala C. pecorum infections by demonstrating a single evolutionary trajectory for koala hosts that is distinct from that seen in non-koala hosts. Conclusions While the continued use of ompA as a fine

  11. Novel molecular markers of Chlamydia pecorum genetic diversity in the koala (Phascolarctos cinereus

    Directory of Open Access Journals (Sweden)

    Timms Peter

    2011-04-01

    Full Text Available Abstract Background Chlamydia pecorum is an obligate intracellular bacterium and the causative agent of reproductive and ocular disease in several animal hosts including koalas, sheep, cattle and goats. C. pecorum strains detected in koalas are genetically diverse, raising interesting questions about the origin and transmission of this species within koala hosts. While the ompA gene remains the most widely-used target in C. pecorum typing studies, it is generally recognised that surface protein encoding genes are not suited for phylogenetic analysis and it is becoming increasingly apparent that the ompA gene locus is not congruent with the phylogeny of the C. pecorum genome. Using the recently sequenced C. pecorum genome sequence (E58, we analysed 10 genes, including ompA, to evaluate the use of ompA as a molecular marker in the study of koala C. pecorum genetic diversity. Results Three genes (incA, ORF663, tarP were found to contain sufficient nucleotide diversity and discriminatory power for detailed analysis and were used, with ompA, to genotype 24 C. pecorum PCR-positive koala samples from four populations. The most robust representation of the phylogeny of these samples was achieved through concatenation of all four gene sequences, enabling the recreation of a "true" phylogenetic signal. OmpA and incA were of limited value as fine-detailed genetic markers as they were unable to confer accurate phylogenetic distinctions between samples. On the other hand, the tarP and ORF663 genes were identified as useful "neutral" and "contingency" markers respectively, to represent the broad evolutionary history and intra-species genetic diversity of koala C. pecorum. Furthermore, the concatenation of ompA, incA and ORF663 sequences highlighted the monophyletic nature of koala C. pecorum infections by demonstrating a single evolutionary trajectory for koala hosts that is distinct from that seen in non-koala hosts. Conclusions While the continued use of

  12. Molecular phylogeny and evolutionary history of Moricandia DC (Brassicaceae

    Directory of Open Access Journals (Sweden)

    Francisco Perfectti

    2017-10-01

    Full Text Available Background The phylogeny of tribe Brassiceae (Brassicaceae has not yet been resolved because of its complex evolutionary history. This tribe comprises economically relevant species, including the genus Moricandia DC. This genus is currently distributed in North Africa, Middle East, Central Asia and Southern Europe, where it is associated with arid and semi-arid environments. Although some species of Moricandia have been used in several phylogenetic studies, the phylogeny of this genus is not well established. Methods Here we present a phylogenetic analysis of the genus Moricandia using a nuclear (the internal transcribed spacers of the ribosomal DNA and two plastidial regions (parts of the NADH dehydrogenase subunit F gene and the trnT-trnF region. We also included in the analyses members of their sister genus Rytidocarpus and from the close genus Eruca. Results The phylogenetic analyses showed a clear and robust phylogeny of the genus Moricandia. The Bayesian inference tree was concordant with the maximum likelihood and timing trees, with the plastidial and nuclear trees showing only minor discrepancies. The genus Moricandia appears to be formed by two main lineages: the Iberian clade including three species, and the African clade including the four species inhabiting the Southern Mediterranean regions plus M. arvensis. Discussion We dated the main evolutionary events of this genus, showing that the origin of the Iberian clade probably occurred after a range expansion during the Messinian period, between 7.25 and 5.33 Ma. In that period, an extensive African-Iberian floral and faunal interchange occurred due to the existence of land bridges between Africa and Europa in what is, at present-days, the Strait of Gibraltar. We have demonstrated that a Spanish population previously ascribed to Rytidocarpus moricandioides is indeed a Moricandia species, and we propose to name it as M. rytidocarpoides sp. nov. In addition, in all the phylogenetic

  13. Landscape attributes and life history variability shape genetic structure of trout populations in a stream network

    Science.gov (United States)

    Neville, H.M.; Dunham, J.B.; Peacock, M.M.

    2006-01-01

    Spatial and temporal landscape patterns have long been recognized to influence biological processes, but these processes often operate at scales that are difficult to study by conventional means. Inferences from genetic markers can overcome some of these limitations. We used a landscape genetics approach to test hypotheses concerning landscape processes influencing the demography of Lahontan cutthroat trout in a complex stream network in the Great Basin desert of the western US. Predictions were tested with population- and individual-based analyses of microsatellite DNA variation, reflecting patterns of dispersal, population stability, and local effective population sizes. Complementary genetic inferences suggested samples from migratory corridors housed a mixture of fish from tributaries, as predicted based on assumed migratory life histories in those habitats. Also as predicted, populations presumed to have greater proportions of migratory fish or from physically connected, large, or high quality habitats had higher genetic variability and reduced genetic differentiation from other populations. Populations thought to contain largely non-migratory individuals generally showed the opposite pattern, suggesting behavioral isolation. Estimated effective sizes were small, and we identified significant and severe genetic bottlenecks in several populations that were isolated, recently founded, or that inhabit streams that desiccate frequently. Overall, this work suggested that Lahontan cutthroat trout populations in stream networks are affected by a combination of landscape and metapopulation processes. Results also demonstrated that genetic patterns can reveal unexpected processes, even within a system that is well studied from a conventional ecological perspective. ?? Springer 2006.

  14. Molecular analysis of genetic diversity in elite II synthetic hexaploid ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-07-20

    Jul 20, 2009 ... The presence of sufficient genetic diversity in the germplam is an important ..... Figure 1. PCR amplification profile of Elite-II SH Wheat using the primer OPG-2. .... genetic relationships among cowpea breeding lines and local.

  15. Molecular genetic analysis of consanguineous families with primary ...

    Indian Academy of Sciences (India)

    MUZAMMIL AHMAD KHAN

    3Institute of Human Genetics, Medical University of Graz, Graz 8010, Austria. 4Department of Cell and ... Materials and methods. Family recruitment and sample collection ..... 2014 A Drosophila genetic resource of mutats to study mechanism ...

  16. Genetic Analysis of Oncorhynchus Nerka : Life History and Genetic Analysis of Redfish Lake Oncorhynchus Nerka, 1993-1994 Completion Report.

    Energy Technology Data Exchange (ETDEWEB)

    Brannon, E.L.; Thorgaard, G.H.; Cummings, S.A.

    1994-10-01

    The study has shown through life history examination and DNA analysis that three forms of O. nerka are present in Redfish Lake. The three forms are closely related, but may be sufficiently different to be considered three separate stocks. Fishhook Creek kokanee are temporally isolated from the beach spawners, and may represent the gene pool most similar to the historic sockeye population that once spawned there. Fishhook Creek offers the best spawning area available in the lake system, and should be considered for use in reestablishing an anadromous Fishhook Creek sockeye swain. The resident beach spawning strain of O. nerka is likewise the most similar genetic form of the companion anadromous beach spawning O. nerka, and needs to be considered the most appropriate genetic source to help minimize reduced fitness of the sockeye from inbreeding.

  17. Uncovering the genetic history of the present-day greenlandic population

    DEFF Research Database (Denmark)

    Moltke, Ida; Fumagalli, Matteo; Korneliussen, Thorfinn Sand

    2015-01-01

    Because of past limitations in samples and genotyping technologies, important questions about the history of the present-day Greenlandic population remain unanswered. In an effort to answer these questions and in general investigate the genetic history of the Greenlandic population, we analyzed...... between the Norse Vikings who lived in Greenland for a limited period ∼600-1,000 years ago and the Inuit, we found no evidence supporting this hypothesis. Similarly, we found no evidence supporting a previously hypothesized admixture event between the Inuit in East Greenland and the Dorset people, who...

  18. Molecular mechanism and genetic determinants of buprofezin degradation.

    Science.gov (United States)

    Chen, Xueting; Ji, Junbin; Zhao, Leizhen; Qiu, Jiguo; Dai, Chen; Wang, Weiwu; He, Jian; Jiang, Jiandong; Hong, Qing; Yan, Xin

    2017-07-14

    . However, the molecular mechanism and genetic determinants of microbial degradation of buprofezin has not been well identified. This work revealed that gene cluster bfzBA3A4A1A2C is responsible for the upstream catabolic pathway of buprofezin in R. qingshengii YL-1. The products of bfzBA3A4A1A2C could also degrade bifenthrin, a widely used pyrethroid insecticide. These findings enhance our understanding of the microbial degradation mechanism of buprofezin and benefit the application of strain YL-1 and bfzBA3A4A1A2C in the bioremediation of buprofezin contamination. Copyright © 2017 American Society for Microbiology.

  19. Ordering molecular genetic tests and reporting results: practices in laboratory and clinical settings.

    Science.gov (United States)

    Lubin, Ira M; Caggana, Michele; Constantin, Carolyn; Gross, Susan J; Lyon, Elaine; Pagon, Roberta A; Trotter, Tracy L; Wilson, Jean Amos; McGovern, Margaret M

    2008-09-01

    Previous studies have suggested that patient care may be compromised as a consequence of poor communication between clinicians and laboratory professionals in cases in which molecular genetic test results are reported. To understand better the contributing factors to such compromised care, we investigated both pre- and postanalytical processes using cystic fibrosis mutation analysis as our model. We found that although the majority of test requisition forms requested patient/family information that was necessary for the proper interpretation of test results, in many cases, these data were not provided by the individuals filling out the forms. We found instances in which result reports for simulated diagnostic testing described individuals as carriers where only a single mutation was found with no comment pertaining to a diagnosis of cystic fibrosis. Similarly, reports based on simulated scenarios for carrier testing were problematic when no mutations were identified, and the patient's race/ethnicity and family history were not discussed in reference to residual risk of disease. Remarkably, a pilot survey of obstetrician-gynecologists revealed that office staff, including secretaries, often helped order genetic tests and reported test results to patients, raising questions about what efforts are undertaken to ensure personnel competency. These findings are reviewed in light of what efforts should be taken to improve the quality of test-ordering and result-reporting practices.

  20. Neuroblastoma: morphological pattern, molecular genetic features, and prognostic factors

    Directory of Open Access Journals (Sweden)

    A. M. Stroganova

    2016-01-01

    Full Text Available Neuroblastoma, the most common extracranial tumor of childhood, arises from the developing neurons of the sympathetic nervous system (neural cress stem cells and has various biological and clinical characteristics. The mean age at disease onset is 18 months. Neuroblastoma has a number of unique characteristics: a capacity for spontaneous regression in babies younger than 12 months even in the presence of distant metastases, for differentiation (maturation into ganglioneuroma in infants after the first year of life, and for swift aggressive development and rapid metastasis. There are 2 clinical classifications of neuroblastoma: the International neuroblastoma staging system that is based on surgical results and the International Neuroblastoma Risk Group Staging System. One of the fundamentally important problems for the clinical picture of neuroblastoma is difficulties making its prognosis. Along with clinical parameters (a patient’s age, tumor extent and site, some histological, molecular biochemical (ploidy and genetic (chromosomal aberrations, MYCN gene status, deletion of the locus 1p36 and 11q, the longer arm of chromosome 17, etc. characteristics of tumor cells are of considerable promise. MYCN gene amplification is observed in 20–30 % of primary neuroblastomas and it is one of the major indicators of disease aggressiveness, early chemotherapy resistance, and a poor prognosis. There are 2 types of MYCN gene amplification: extrachromosomal (double acentric chromosomes and intrachromosomal (homogenically painted regions. Examination of double acentric chromosomes revealed an interesting fact that it may be eliminated (removed from the nucleus through the formation of micronuclei. MYCN oncogene amplification is accompanied frequently by 1p36 locus deletion and longer 17q arm and less frequently by 11q23 deletion; these are poor prognostic factors for the disease. The paper considers in detail the specific, unique characteristics of the

  1. The Mouse House: A brief history of the ORNL mouse-genetics program, 1947–2009

    Energy Technology Data Exchange (ETDEWEB)

    Russell, Liane B.

    2013-10-01

    The large mouse genetics program at the Oak Ridge National Lab is often re-membered chiefly for the germ-cell mutation-rate data it generated and their uses in estimating the risk of heritable radiation damage. In fact, it soon became a multi-faceted research effort that, over a period of almost 60 years, generated a wealth of information in the areas of mammalian mutagenesis, basic genetics (later enriched by molecular techniques), cytogenetics, reproductive biology, biochemistry of germ cells, and teratology. Research in the area of germ-cell mutagenesis explored the important physical and biological factors that affect the frequency and nature of induced mutations and made several unexpected discoveries, such as the major importance of the perigametic interval (the zygote stage) for the origin of spontaneous mutations and for the sensitivity to induced genetic change. Of practical value was the discovery that ethylnitrosourea was a supermutagen for point mutations, making high-efficiency mutagenesis in the mouse feasible worldwide. Teratogenesis findings resulted in recommendations still generally accepted in radiological practice. Studies supporting the mutagenesis research added whole bodies of information about mammalian germ-cell development and about molecular targets in germ cells. The early decision to not merely count but propagate genetic variants of all sorts made possible further discoveries, such as the Y-Chromosome s importance in mammalian sex determination and the identification of rare X-autosome translocations, which, in turn, led to the formulation of the single-active-X hypothesis and provided tools for studies of functional mosaicism for autosomal genes, male sterility, and chromosome-pairing mechanism. Extensive genetic and then molecular analyses of large numbers of induced specific-locus mutants resulted in fine-structure physical and correlated functional mapping of significant portions of the mouse genome and constituted a valuable

  2. The Mouse House: a brief history of the ORNL mouse-genetics program, 1947-2009.

    Science.gov (United States)

    Russell, Liane B

    2013-01-01

    The large mouse genetics program at the Oak Ridge National Laboratory (ORNL) is often remembered chiefly for the germ-cell mutation-rate data it generated and their uses in estimating the risk of heritable radiation damage. In fact, it soon became a multi-faceted research effort that, over a period of almost 60 years, generated a wealth of information in the areas of mammalian mutagenesis, basic genetics (later enriched by molecular techniques), cytogenetics, reproductive biology, biochemistry of germ cells, and teratology. Research in the area of germ-cell mutagenesis explored the important physical and biological factors that affect the frequency and nature of induced mutations and made several unexpected discoveries, such as the major importance of the perigametic interval (the zygote stage) for the origin of spontaneous mutations and for the sensitivity to induced genetic change. Of practical value was the discovery that ethylnitrosourea was a supermutagen for point mutations, making high-efficiency mutagenesis in the mouse feasible worldwide. Teratogenesis findings resulted in recommendations still generally accepted in radiological practice. Studies supporting the mutagenesis research added whole bodies of information about mammalian germ-cell development and about molecular targets in germ cells. The early decision to not merely count but propagate genetic variants of all sorts made possible further discoveries, such as the Y-chromosome's importance in mammalian sex determination and the identification of rare X-autosome translocations, which, in turn, led to the formulation of the single-active-X hypothesis and provided tools for studies of functional mosaicism for autosomal genes, male sterility, and chromosome-pairing mechanism. Extensive genetic and then molecular analyses of large numbers of induced specific-locus mutants resulted in fine-structure physical and correlated functional mapping of significant portions of the mouse genome and constituted a

  3. Population genetic structure and demographic history of Atrina pectinata based on mitochondrial DNA and microsatellite markers.

    Directory of Open Access Journals (Sweden)

    Dong-Xiu Xue

    Full Text Available The pen shell, Atrina pectinata, is one of the commercial bivalves in East Asia and thought to be recently affected by anthropogenic pressure (habitat destruction and/or fishing pressure. Information on its population genetic structure is crucial for the conservation of A. pectinata. Considering its long pelagic larval duration and iteroparity with high fecundity, the genetic structure for A. pectinata could be expected to be weak at a fine scale. However, the unusual oceanography in the coasts of China and Korea suggests potential for restricted dispersal of pelagic larvae and geographical differentiation. In addition, environmental changes associated with Pleistocene sea level fluctuations on the East China Sea continental shelf may also have strongly influenced historical population demography and genetic diversity of marine organisms. Here, partial sequences of the mitochondrial Cytochrome c oxidase subunit I (COI gene and seven microsatellite loci were used to estimate population genetic structure and demographic history of seven samples from Northern China coast and one sample from North Korea coast. Despite high levels of genetic diversity within samples, there was no genetic differentiation among samples from Northern China coast and low but significant genetic differentiation between some of the Chinese samples and the North Korean sample. A late Pleistocene population expansion, probably after the Last Glacial Maximum, was also demonstrated for A. pectinata samples. No recent genetic bottleneck was detected in any of the eight samples. We concluded that both historical recolonization (through population range expansion and demographic expansion in the late Pleistocene and current gene flow (through larval dispersal were responsible for the weak level of genetic structure detected in A. pectinata.

  4. Sex determination of Pohnpei Micronesian kingfishers using morphological and molecular genetic techniques

    Science.gov (United States)

    Kesler, Dylan C.; Lopes, I.F.; Haig, Susan M.

    2006-01-01

    Conservation-oriented studies of Micronesian Kingfishers (Todiramphus cinnamominus) have been hindered by a lack of basic natural history information, despite the status of the Guam subspecies (T. c. cinnamominus) as one of the most endangered species in the world. We used tissue samples and morphometric measures from museum specimens and wild-captured Pohnpei Micronesian Kingfishers (T. c. reichenbachii) to develop methods for sex determination. We present a modified molecular protocol and a discriminant function that yields the probability that a particular individual is male or female. Our results revealed that females were significantly larger than males, and the discriminant function correctly predicted sex in 73% (30/41) of the individuals. The sex of 86% (18/21) of individuals was correctly assigned when a moderate reliability threshold was set. Sex determination using molecular genetic techniques was more reliable than methods based on morphology. Our results will facilitate recovery efforts for the critically endangered Guam Micronesian Kingfisher and provide a basis for sex determination in the 11 other endangered congeners in the Pacific Basin.

  5. MEGA5: Molecular Evolutionary Genetics Analysis Using Maximum Likelihood, Evolutionary Distance, and Maximum Parsimony Methods

    Science.gov (United States)

    Tamura, Koichiro; Peterson, Daniel; Peterson, Nicholas; Stecher, Glen; Nei, Masatoshi; Kumar, Sudhir

    2011-01-01

    Comparative analysis of molecular sequence data is essential for reconstructing the evolutionary histories of species and inferring the nature and extent of selective forces shaping the evolution of genes and species. Here, we announce the release of Molecular Evolutionary Genetics Analysis version 5 (MEGA5), which is a user-friendly software for mining online databases, building sequence alignments and phylogenetic trees, and using methods of evolutionary bioinformatics in basic biology, biomedicine, and evolution. The newest addition in MEGA5 is a collection of maximum likelihood (ML) analyses for inferring evolutionary trees, selecting best-fit substitution models (nucleotide or amino acid), inferring ancestral states and sequences (along with probabilities), and estimating evolutionary rates site-by-site. In computer simulation analyses, ML tree inference algorithms in MEGA5 compared favorably with other software packages in terms of computational efficiency and the accuracy of the estimates of phylogenetic trees, substitution parameters, and rate variation among sites. The MEGA user interface has now been enhanced to be activity driven to make it easier for the use of both beginners and experienced scientists. This version of MEGA is intended for the Windows platform, and it has been configured for effective use on Mac OS X and Linux desktops. It is available free of charge from http://www.megasoftware.net. PMID:21546353

  6. A methodological overview on molecular preimplantation genetic diagnosis and screening: a genomic future?

    Science.gov (United States)

    Vendrell, Xavier; Bautista-Llácer, Rosa

    2012-12-01

    The genetic diagnosis and screening of preimplantation embryos generated by assisted reproduction technology has been consolidated in the prenatal care framework. The rapid evolution of DNA technologies is tending to molecular approaches. Our intention is to present a detailed methodological view, showing different diagnostic strategies based on molecular techniques that are currently applied in preimplantation genetic diagnosis. The amount of DNA from one single, or a few cells, obtained by embryo biopsy is a limiting factor for the molecular analysis. In this sense, genetic laboratories have developed molecular protocols considering this restrictive condition. Nevertheless, the development of whole-genome amplification methods has allowed preimplantation genetic diagnosis for two or more indications simultaneously, like the selection of histocompatible embryos plus detection of monogenic diseases or aneuploidies. Moreover, molecular techniques have permitted preimplantation genetic screening to progress, by implementing microarray-based comparative genome hybridization. Finally, a future view of the embryo-genetics field based on molecular advances is proposed. The normalization, cost-effectiveness analysis, and new technological tools are the next topics for preimplantation genetic diagnosis and screening. Concomitantly, these additions to assisted reproduction technologies could have a positive effect on the schedules of preimplantation studies.

  7. Molecular genetic contributions to socioeconomic status and intelligence.

    Science.gov (United States)

    Marioni, Riccardo E; Davies, Gail; Hayward, Caroline; Liewald, Dave; Kerr, Shona M; Campbell, Archie; Luciano, Michelle; Smith, Blair H; Padmanabhan, Sandosh; Hocking, Lynne J; Hastie, Nicholas D; Wright, Alan F; Porteous, David J; Visscher, Peter M; Deary, Ian J

    2014-05-01

    Education, socioeconomic status, and intelligence are commonly used as predictors of health outcomes, social environment, and mortality. Education and socioeconomic status are typically viewed as environmental variables although both correlate with intelligence, which has a substantial genetic basis. Using data from 6815 unrelated subjects from the Generation Scotland study, we examined the genetic contributions to these variables and their genetic correlations. Subjects underwent genome-wide testing for common single nucleotide polymorphisms (SNPs). DNA-derived heritability estimates and genetic correlations were calculated using the 'Genome-wide Complex Trait Analyses' (GCTA) procedures. 21% of the variation in education, 18% of the variation in socioeconomic status, and 29% of the variation in general cognitive ability was explained by variation in common SNPs (SEs ~ 5%). The SNP-based genetic correlations of education and socioeconomic status with general intelligence were 0.95 (SE 0.13) and 0.26 (0.16), respectively. There are genetic contributions to intelligence and education with near-complete overlap between common additive SNP effects on these traits (genetic correlation ~ 1). Genetic influences on socioeconomic status are also associated with the genetic foundations of intelligence. The results are also compatible with substantial environmental contributions to socioeconomic status.

  8. Avoiding pitfalls in molecular genetic testing: case studies of high-resolution array comparative genomic hybridization testing in the definitive diagnosis of Mowat-Wilson syndrome.

    Science.gov (United States)

    Kluk, Michael Joseph; An, Yu; James, Philip; Coulter, David; Harris, David; Wu, Bai-Lin; Shen, Yiping

    2011-05-01

    The molecular testing options available for the diagnosis of genetic disorders are numerous and include a variety of different assay platforms. The consultative input of molecular pathologists and cytogeneticists, working closely with the ordering clinicians, is often important for definitive diagnosis. Herein, we describe two patients who had long histories of unexplained signs and symptoms with a high clinical suspicion of an underlying genetic etiology. Initial molecular testing in both cases was negative, but the application of high-resolution array comparative genomic hybridization technology lead to definitive diagnosis in both cases. We summarize the clinical findings and molecular testing in each case, discuss the differential diagnoses, and review the clinical and pathological findings of Mowat-Wilson syndrome. This report highlights the importance for those involved in molecular testing to know the nature of the underlying genetic abnormalities associated with the suspected diagnosis, to recognize the limitations of each testing platform, and to persistently pursue repeat testing using high-resolution technologies when indicated. This concept is applicable to both germline and somatic molecular genetic testing. Copyright © 2011 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

  9. Demographic histories, isolation and social factors as determinants of the genetic structure of Alpine linguistic groups.

    Science.gov (United States)

    Coia, Valentina; Capocasa, Marco; Anagnostou, Paolo; Pascali, Vincenzo; Scarnicci, Francesca; Boschi, Ilaria; Battaggia, Cinzia; Crivellaro, Federica; Ferri, Gianmarco; Alù, Milena; Brisighelli, Francesca; Busby, George B J; Capelli, Cristian; Maixner, Frank; Cipollini, Giovanna; Viazzo, Pier Paolo; Zink, Albert; Destro Bisol, Giovanni

    2013-01-01

    Great European mountain ranges have acted as barriers to gene flow for resident populations since prehistory and have offered a place for the settlement of small, and sometimes culturally diverse, communities. Therefore, the human groups that have settled in these areas are worth exploring as an important potential source of diversity in the genetic structure of European populations. In this study, we present new high resolution data concerning Y chromosomal variation in three distinct Alpine ethno-linguistic groups, Italian, Ladin and German. Combining unpublished and literature data on Y chromosome and mitochondrial variation, we were able to detect different genetic patterns. In fact, within and among population diversity values observed vary across linguistic groups, with German and Italian speakers at the two extremes, and seem to reflect their different demographic histories. Using simulations we inferred that the joint effect of continued genetic isolation and reduced founding group size may explain the apportionment of genetic diversity observed in all groups. Extending the analysis to other continental populations, we observed that the genetic differentiation of Ladins and German speakers from Europeans is comparable or even greater to that observed for well known outliers like Sardinian and Basques. Finally, we found that in south Tyroleans, the social practice of Geschlossener Hof, a hereditary norm which might have favored male dispersal, coincides with a significant intra-group diversity for mtDNA but not for Y chromosome, a genetic pattern which is opposite to those expected among patrilocal populations. Together with previous evidence regarding the possible effects of "local ethnicity" on the genetic structure of German speakers that have settled in the eastern Italian Alps, this finding suggests that taking socio-cultural factors into account together with geographical variables and linguistic diversity may help unveil some yet to be understood

  10. Demographic histories, isolation and social factors as determinants of the genetic structure of Alpine linguistic groups.

    Directory of Open Access Journals (Sweden)

    Valentina Coia

    Full Text Available Great European mountain ranges have acted as barriers to gene flow for resident populations since prehistory and have offered a place for the settlement of small, and sometimes culturally diverse, communities. Therefore, the human groups that have settled in these areas are worth exploring as an important potential source of diversity in the genetic structure of European populations. In this study, we present new high resolution data concerning Y chromosomal variation in three distinct Alpine ethno-linguistic groups, Italian, Ladin and German. Combining unpublished and literature data on Y chromosome and mitochondrial variation, we were able to detect different genetic patterns. In fact, within and among population diversity values observed vary across linguistic groups, with German and Italian speakers at the two extremes, and seem to reflect their different demographic histories. Using simulations we inferred that the joint effect of continued genetic isolation and reduced founding group size may explain the apportionment of genetic diversity observed in all groups. Extending the analysis to other continental populations, we observed that the genetic differentiation of Ladins and German speakers from Europeans is comparable or even greater to that observed for well known outliers like Sardinian and Basques. Finally, we found that in south Tyroleans, the social practice of Geschlossener Hof, a hereditary norm which might have favored male dispersal, coincides with a significant intra-group diversity for mtDNA but not for Y chromosome, a genetic pattern which is opposite to those expected among patrilocal populations. Together with previous evidence regarding the possible effects of "local ethnicity" on the genetic structure of German speakers that have settled in the eastern Italian Alps, this finding suggests that taking socio-cultural factors into account together with geographical variables and linguistic diversity may help unveil some yet

  11. Classification of rare missense substitutions, using risk surfaces, with genetic- and molecular-epidemiology applications.

    Science.gov (United States)

    Tavtigian, Sean V; Byrnes, Graham B; Goldgar, David E; Thomas, Alun

    2008-11-01

    Many individually rare missense substitutions are encountered during deep resequencing of candidate susceptibility genes and clinical mutation screening of known susceptibility genes. BRCA1 and BRCA2 are among the most resequenced of all genes, and clinical mutation screening of these genes provides an extensive data set for analysis of rare missense substitutions. Align-GVGD is a mathematically simple missense substitution analysis algorithm, based on the Grantham difference, which has already contributed to classification of missense substitutions in BRCA1, BRCA2, and CHEK2. However, the distribution of genetic risk as a function of Align-GVGD's output variables Grantham variation (GV) and Grantham deviation (GD) has not been well characterized. Here, we used data from the Myriad Genetic Laboratories database of nearly 70,000 full-sequence tests plus two risk estimates, one approximating the odds ratio and the other reflecting strength of selection, to display the distribution of risk in the GV-GD plane as a series of surfaces. We abstracted contours from the surfaces and used the contours to define a sequence of missense substitution grades ordered from greatest risk to least risk. The grades were validated internally using a third, personal and family history-based, measure of risk. The Align-GVGD grades defined here are applicable to both the genetic epidemiology problem of classifying rare missense substitutions observed in known susceptibility genes and the molecular epidemiology problem of analyzing rare missense substitutions observed during case-control mutation screening studies of candidate susceptibility genes. (c) 2008 Wiley-Liss, Inc.

  12. Genetic studies and a search for molecular markers that are linked ...

    African Journals Online (AJOL)

    SERVER

    Instead, linkage analysis resulted in the construction of a molecular marker linkage map consisting of 45 ..... This limits the application of this marker type, particularly in ... primer design when one uses RAPDs. .... Concepts of Genetics. Fourth.

  13. Regional Genetic Structuring and Evolutionary History of the Impala Aepyceros melampus

    DEFF Research Database (Denmark)

    Lorenzen, Eline Deirdre; Arctander, Peter; Siegismund, Hans Redlef

    2006-01-01

    Samples of 162 impala antelope (Aepyceros melampus) from throughout its distribution range in sub-Saharan Africa were surveyed using eight polymorphic microsatellite loci. Furthermore, 155 previously published mitochondrial DNA (mtDNA) sequences from the same localities were reanalyzed. Two...... subspecies of impala are presently recognized-the isolated black-faced impala (Aepyceros melampus petersi) in southwest Africa and the common impala (Aepyceros melampus melampus) abundant in southern and east Africa. All tests performed indicated significant genetic differentiation at the subspecific level....... Furthermore, individual-based analyses split the common impala subspecies into two distinct genetic groups, conforming with regional geographic affiliation to southern or east Africa. This was supported by assignment tests, genetic distance measures, pairwise values, and analysis of molecular variance. We...

  14. Using Genetic Buffering Relationships Identified in Fission Yeast To Elucidate the Molecular Pathology of Tuberous Sclerosis

    Science.gov (United States)

    2016-07-01

    tsc1 and tsc2 loss of function mutations in Schizosaccharomyces pombe. Northeast Regional Yeast Meeting, June 16-17, University at Buffalo, The State...AWARD NUMBER: W81XWH-14-1-0169 TITLE: Using Genetic Buffering Relationships Identified in Fission Yeast To Elucidate the Molecular Pathology of...SUBTITLE Using Genetic Buffering Relationships Identified in Fission 5a. CONTRACT NUMBER W81XWH-14-1-0169 Yeast to Elucidate the Molecular Pathology

  15. EMQN/CMGS best practice guidelines for the molecular genetic testing of Huntington disease

    OpenAIRE

    Losekoot, Monique; van Belzen, Martine J; Seneca, Sara; Bauer, Peter; Stenhouse, Susan A R; Barton, David E

    2012-01-01

    Huntington disease (HD) is caused by the expansion of an unstable polymorphic trinucleotide (CAG)n repeat in exon 1 of the HTT gene, which translates into an extended polyglutamine tract in the protein. Laboratory diagnosis of HD involves estimation of the number of CAG repeats. Molecular genetic testing for HD is offered in a wide range of laboratories both within and outside the European community. In order to measure the quality and raise the standard of molecular genetic testing in these ...

  16. Morphological and molecular genetic diversity of Syrian indigenous ...

    African Journals Online (AJOL)

    Domestic goats in Syria may provide an interesting source of genetic variability due to its proximity to the centers of domestication. This study aimed to assess the morphological variation, genetic diversity and population substructure of the Syrian goat populations. Commonly, three goat genotypes are distinguished in Syria, ...

  17. Molecular and pro-inflammatory genetic profile in gastric carcinomas

    NARCIS (Netherlands)

    Sitarz, R.

    2009-01-01

    Gastric cancer is a result from the combination of environmental factors and an accumulation of specific genetic alterations, and affects mainly the older population. It is known that genetic factors play a more important role in early onset gastric cancers than in conventional gastric cancer

  18. Molecular based assessment of genetic diversity of xoconostle ...

    African Journals Online (AJOL)

    aghomotsegin

    2014-01-08

    Jan 8, 2014 ... Xoconostle or acidic prickly pear is an important fruit in Mexico; it is produced by a ... study, we report for the first time the estimation of genetic diversity within a set ... demonstrates the high genetic variation among genotypes of .... O. leucotricha Salm-Dyck × O. joconostle F.A.C Weber Zacatecas Wild Stock.

  19. Molecular epidemiology and evolutionary genetics of Mycobacterium tuberculosis in Taipei.

    Science.gov (United States)

    Dou, Horng-Yunn; Tseng, Fan-Chen; Lin, Chih-Wei; Chang, Jia-Ru; Sun, Jun-Ren; Tsai, Wen-Shing; Lee, Shi-Yi; Su, Ih-Jen; Lu, Jang-Jih

    2008-12-22

    The control of tuberculosis in densely populated cities is complicated by close human-to-human contacts and potential transmission of pathogens from multiple sources. We conducted a molecular epidemiologic analysis of 356 Mycobacterium tuberculosis (MTB) isolates from patients presenting pulmonary tuberculosis in metropolitan Taipei. Classical antibiogram studies and genetic characterization, using mycobacterial interspersed repetitive-unit-variable-number tandem-repeat (MIRU-VNTR) typing and spoligotyping, were applied after culture. A total of 356 isolates were genotyped by standard spoligotyping and the strains were compared with in the international spoligotyping database (SpolDB4). All isolates were also categorized using the 15 loci MIRU-VNTR typing method and combin with NTF locus and RD deletion analyses. Of 356 isolates spoligotyped, 290 (81.4%) displayed known spoligotypes and 66 were not identified in the database. Major spoligotypes found were Beijing lineages (52.5%), followed by Haarlem lineages (13.5%) and EAI plus EAI-like lineages (11%). When MIRU-VNTR was employed, 140 patterns were identified, including 36 clusters by 252 isolates and 104 unique patterns, and the largest cluster comprised 95 isolates from the Beijing family. The combination of spoligotyping and MIRU-VNTR revealed that 236 (67%) of the 356 isolates were clustered in 43 genotypes. Strains of the Beijing family was more likely to be of modern strain and a higher percentage of multiple drug resistance than other families combined (P = 0.08). Patients infected with Beijing strains were younger than those with other strains (mean 58.7 vs. 64.2, p = 0.02). Moreover, 85.3% of infected persons younger than 25 years had Beijing modern strain, suggesting a possible recent spread in the young population by this family of TB strain in Taipei. Our data on MTB genotype in Taipei suggest that MTB infection has not been optimally controlled. Control efforts should be reinforced in view of the

  20. [The development of molecular human genetics and its significance for perspectives of modern medicine].

    Science.gov (United States)

    Coutelle, C; Speer, A; Grade, K; Rosenthal, A; Hunger, H D

    1989-01-01

    The introduction of molecular human genetics has become a paradigma for the application of genetic engineering in medicine. The main principles of this technology are the isolation of molecular probes, their application in hybridization reactions, specific gene-amplification by the polymerase chain reaction, and DNA sequencing reactions. These methods are used for the analysis of monogenic diseases by linkage studies and the elucidation of the molecular defect causing these conditions, respectively. They are also the basis for genomic diagnosis of monogenic diseases, introduced into the health care system of the GDR by a national project on Duchenne/Becker muscular dystrophy, Cystic Fibrosis and Phenylketonuria. The rapid development of basic research on the molecular analysis of the human genome and genomic diagnosis indicates, that human molecular genetics is becoming a decisive basic discipline of modern medicine.

  1. Alternative life histories in the Atlantic salmon: genetic covariances within the sneaker sexual tactic in males.

    Science.gov (United States)

    Páez, David James; Bernatchez, Louis; Dodson, Julian J

    2011-07-22

    Alternative reproductive tactics are ubiquitous in many species. Tactic expression often depends on whether an individual's condition surpasses thresholds that are responsible for activating particular developmental pathways. Two central goals in understanding the evolution of reproductive tactics are quantifying the extent to which thresholds are explained by additive genetic effects, and describing their covariation with condition-related traits. We monitored the development of early sexual maturation that leads to the sneaker reproductive tactic in Atlantic salmon (Salmo salar L.). We found evidence for additive genetic variance in the timing of sexual maturity (which is a measure of the surpassing of threshold values) and body-size traits. This suggests that selection can affect the patterns of sexual development by changing the timing of this event and/or body size. Significant levels of covariation between these traits also occurred, implying a potential for correlated responses to selection. Closer examination of genetic covariances suggests that the detected genetic variation is distributed along at least five directions of phenotypic variation. Our results show that the potential for evolution of the life-history traits constituting this reproductive phenotype is greatly influenced by their patterns of genetic covariance.

  2. Pollution breaks down the genetic architecture of life history traits in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Morgan Dutilleul

    Full Text Available When pollution occurs in an environment, populations present suffer numerous negative and immediate effects on their life history traits. Their evolutionary potential to live in a highly stressful environment will depend on the selection pressure strengths and on the genetic structure, the trait heritability, and the genetic correlations between them. If expression of this structure changes in a stressful environment, it becomes necessary to quantify these changes to estimate the evolutionary potential of the population in this new environment. We studied the genetic structure for survival, fecundity, and early and late growth in isogenic lines of a Caenorhabditis elegans population subject to three different environments: a control environment, an environment polluted with uranium, and a high salt concentration environment. We found a heritability decrease in the polluted environments for fecundity and early growth, two traits that were the most heritable in the control environment. The genetic structure of the traits was particularly affected in the uranium polluted environment, probably due to generally low heritability in this environment. This could prevent selection from acting on traits despite the strong selection pressures exerted on them. Moreover, phenotypic traits were more strongly affected in the salt than in the uranium environment and the heritabilities were also lower in the latter environment. Consequently the decrease in heritability was not proportional to the population fitness reduction in the polluted environments. Our results suggest that pollution can alter the genetic structure of a C. elegans population, and thus modify its evolutionary potential.

  3. Management of insect pests: Nuclear and related molecular and genetic techniques

    International Nuclear Information System (INIS)

    1993-01-01

    The conference was organized in eight sessions: opening, genetic engineering and molecular biology, genetics, operational programmes, F 1 sterility and insect behaviour, biocontrol, research and development on the tsetse fly, and quarantine. The 64 individual contributions have been indexed separately for INIS. Refs, figs and tabs

  4. 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...

  5. Genetic and Environmental Influences on Achievement Outcomes Based on Family History of Learning Disabilities Status.

    Science.gov (United States)

    Erbeli, Florina; Hart, Sara A; Taylor, Jeanette

    2018-05-01

    A risk to develop a learning disability has been shown to run in families. Having a positive family history of learning disability seems to account for mean differences in achievement outcomes (reading, math) in that children with a positive family history score significantly lower compared to their peers with no such family history. However, the role of family history status in explaining etiological (genetic and environmental) differences among these subgroups of children has yet to be established. The present study of 872 twins ( M age = 13.30, SD age = 1.40) from the Florida Twin Project on Reading, Behavior, and Environment utilized a multigroup approach to examine etiological differences on reading, spelling, and math among two subgroups defined by family history status. Results showed significant mean differences on all achievement outcomes, aside from math; however, no significant etiological differences on any achievement outcome were found among the two subgroups. Results support previous literature that the risk for developing a learning disability is transmitted through a family, but this is seemingly not manifested by differential etiology.

  6. Cystic fibrosis genetics: from molecular understanding to clinical application

    Science.gov (United States)

    Cutting, Garry R.

    2015-01-01

    The availability of the human genome sequence and tools for interrogating individual genomes provide an unprecedented opportunity to apply genetics to medicine. Mendelian conditions, which are caused by dysfunction of a single gene, offer powerful examples that illustrate how genetics can provide insights into disease. Cystic fibrosis, one of the more common lethalautosomal recessive Mendelian disorders, is presented here as an example. Recent progress in elucidating disease mechanism and causes of phenotypic variation, as well as in the development of treatments, demonstrates that genetics continues to play an important part in cystic fibrosis research 25 years after the d iscove1y of the disease-causing gene. PMID:25404111

  7. Genetic variation assessment of acid lime accessions collected from south of Iran using SSR and ISSR molecular markers.

    Science.gov (United States)

    Sharafi, Ata Allah; Abkenar, Asad Asadi; Sharafi, Ali; Masaeli, Mohammad

    2016-01-01

    Iran has a long history of acid lime cultivation and propagation. In this study, genetic variation in 28 acid lime accessions from five regions of south of Iran, and their relatedness with other 19 citrus cultivars were analyzed using Simple Sequence Repeat (SSR) and Inter-Simple Sequence Repeat (ISSR) molecular markers. Nine primers for SSR and nine ISSR primers were used for allele scoring. In total, 49 SSR and 131 ISSR polymorphic alleles were detected. Cluster analysis of SSR and ISSR data showed that most of the acid lime accessions (19 genotypes) have hybrid origin and genetically distance with nucellar of Mexican lime (9 genotypes). As nucellar of Mexican lime are susceptible to phytoplasma, these acid lime genotypes can be used to evaluate their tolerance against biotic constricts like lime "witches' broom disease".

  8. Molecular characterization and genetic diversity of different genotypes of Oryza sativa and Oryza glaberrima

    Directory of Open Access Journals (Sweden)

    Caijin Chen

    2017-11-01

    Conclusions: Genetic diversity studies revealed that 50 rice types were clustered into different subpopulations whereas three genotypes were admixtures. Molecular fingerprinting and 10 specific markers were obtained to identify the 53 rice genotypes. These results can facilitate the potential utilization of sibling species in rice breeding and molecular classification of O. sativa and O. glaberrima germplasms.

  9. Candidate gene molecular markers as tools for analyzing genetic susceptibility to morbillivirus infection in stranded Cetaceans

    Czech Academy of Sciences Publication Activity Database

    Stejskalová, K.; Bayerova, Z.; Futas, J.; Hrazdilová, K.; Klumplerova, M.; Oppelt, J.; Šplíchalová, P.; Di Guardo, G.; Mazzariol, S.; Di Francesco, C. E.; Di Francesco, G.; Terracciano, G.; Paiu, R.M.; Ursache, T. D.; Modrý, David; Horin, P.

    2017-01-01

    Roč. 90, č. 6 (2017), s. 343-353 ISSN 2059-2302 Institutional support: RVO:60077344 Keywords : Cetacea * haplotype * immunity * innate * mhc-dqb * Phocoena phocoena * polymorphism * single nucleotide * Stenella coeruleoalba Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Biochemistry and molecular biology

  10. Permanent genetic resources added to molecular ecology resources database 1 February 2013-31 March 2013

    Czech Academy of Sciences Publication Activity Database

    Arias, M. C.; Atteke, C.; Augusto, S. C.; Bailey, J.; Bazaga, P.; Beheregaray, L. B.; Benoit, L.; Blatrix, R.; Born, C.; Brito, R. M.; Chen, H.-K.; Covarrubias, S.; de Vega, C.; Djiéto-Lordon, C.; Dubois, M.-P.; Francisco, F. O.; García, C.; Concalves, P. H. P.; González, C.; Gutiérrez-Rodríguez, C.; Hammer, M. P.; Herrera, C. M.; Itoh, H.; Kamimura, S.; Karaoglu, H.; Kojima, S.; Li, S.-L.; Ling, H. J.; Matos Maravi, Pavel F.; McKey, D.; Mezui-M’Eko, J.; Ornelas, J. F.; Park, R. F.; Pozo, M. I.; Ramula, S.; Rigueiro, C.; Sandoval-Castillo, J.; Santiago, L. R.; Seino, M. M.; Song, C.-B.; Takeshima, H.; Vasemägi, A.; Wellings, C. R.; Yan, J.; Du, Y.-Z.; Zhang, C.-R.; Zhang, T.-Y.

    2013-01-01

    Roč. 13, č. 4 (2013), s. 760-762 ISSN 1755-098X Institutional support: RVO:60077344 Keywords : molecular ecology Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.626, year: 2013 http://onlinelibrary.wiley.com/doi/10.1111/1755-0998.12121/pdf

  11. Molecular Genetics Techniques to Develop New Treatments for Brain Cancers

    Energy Technology Data Exchange (ETDEWEB)

    Fox, Jacob; Fathallan-Shaykh, Hassan

    2006-09-22

    The objectives of this report are: (1) to devise novel molecular gene therapies for malignant brain tumors, (2) advance our understanding of the immune system in the central nervous system; and (3) apply genomics to find molecular probes to diagnose brain tumors, predict prognosis, biological behavior and their response to treatment.

  12. Molecular genetic analysis of consanguineous families with primary ...

    Indian Academy of Sciences (India)

    RESEARCH NOTE Volume 96 Issue 2 June 2017 pp 383-387 ... Autosomal recessive primary microcephaly is a rare genetic disorder that is ... Department of Cell and Developmental Biology, School of Life Sciences, University of Science and ...

  13. A unifying study of phenotypic and molecular genetic variability in ...

    Indian Academy of Sciences (India)

    2014-04-25

    Apr 25, 2014 ... future studies from the authors. The remaining leaves ... βij the random contribution for the jth individual of the ith biogeographic province ... quantifying genetic structure accounting for the complexities of spatial correlation in ...

  14. Phenotypic and molecular evaluation of genetic diversity of rapeseed

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-05

    Oct 5, 2009 ... basis of elite oilseed rape breeding material has been narrowed by an intensive .... breeding programs was the basic reason for detailed genetic analysis. ...... A periodical of Scientific Research on Field and. Vegetable Crops ...

  15. Molecular genetics of schizophrenia: past, present and future

    Indian Academy of Sciences (India)

    Unknown

    leucocyte antigen; IDDM, insulin dependent diabetes mellitus; MAO, monoamine oxidase; MHC, ... In this review, we summarize the evolution of schizophrenia genetics from ...... K, Yeh J I and Hsiao K J 1999 Systematic mutation analysis.

  16. Advances in genetics and molecular breeding of three legume crops ...

    Indian Academy of Sciences (India)

    2012-10-15

    Oct 15, 2012 ... 3. Genomic resources for SAT legumes. In the past, for genetic diversity analysis, a range of ... DNA libraries, (b) sequencing and mining the BAC (bacterial ..... spiration efficiency, biomass, specific leaf area, pod weight,.

  17. Chronic Stress and Neuropathology: Neurochemical, Molecular, and Genetic Factors

    National Research Council Canada - National Science Library

    Koob, George F; Zorrilla, Eric P

    2005-01-01

    ... to selective breeding in the rat. Genetic differences in stress responsiveness in replicate line 1 were associated with differences in anxiety-like behavior, body weight gain and voluntary intake of sweet solutions and ethanol...

  18. Molecular evaluation of genetic diversity and association studies in ...

    Indian Academy of Sciences (India)

    2012-04-05

    Apr 5, 2012 ... Phenotypic data were collected for yield and component traits. Pattern of ...... ical isolation, evolutionary time gaps, mutation, selection and genetic drift ..... along chromosome 1 of maize (Zea mays ssp. mays L.). Proc. Natl.

  19. Molecular-genetic analysis of two cases with retinoblastoma ...

    Indian Academy of Sciences (India)

    Unknown

    Effective counselling and management of retinoblastoma families using genetic information is presently practised in many parts of ... to chromosomal deletion, single-nucleotide alteration, microdeletion, loss ... informed consent of the parent.

  20. Genetic, molecular and functional analyses of complement factor I deficiency

    DEFF Research Database (Denmark)

    Nilsson, S.C.; Trouw, L.A.; Renault, N.

    2009-01-01

    Complete deficiency of complement inhibitor factor I (FI) results in secondary complement deficiency due to uncontrolled spontaneous alternative pathway activation leading to susceptibility to infections. Current genetic examination of two patients with near complete FI deficiency and three patie...

  1. Molecular genetic diversity in cocoa clones with potential for ...

    African Journals Online (AJOL)

    Adeilson

    2016-11-02

    Nov 2, 2016 ... This study aimed to assess the genetic variability in groups of 11 ... INTRODUCTION .... Iquitos Maraño (or Mixed) Calabacilo ... method (Doyle and Doyle, 1990; Bertolde et al., 2010). ..... Further studies on a concise list of.

  2. Molecular approaches for genetic improvement of seed quality and characterization of genetic diversity in soybean: a critical review.

    Science.gov (United States)

    Tripathi, Niraj; Khare, Dhirendra

    2016-10-01

    Soybean is an economically important leguminous crop. Genetic improvements of soybeans have focused on enhancement of seed and oil yield, development of varieties suited to different cropping systems, and breeding resistant/tolerant varieties for various biotic and abiotic stresses. Plant breeders have used conventional breeding techniques for the improvement of these traits in soybean. The conventional breeding process can be greatly accelerated through the application of molecular and genomic approaches. Molecular markers have proved to be a new tool in soybean breeding by enhancing selection efficiency in a rapid and time-bound manner. An overview of molecular approaches for the genetic improvement of soybean seed quality parameters, considering recent applications of marker-assisted selection and 'omics' research, is provided in this article.

  3. Best practice guidelines for the molecular genetic diagnosis of Type 1 (HFE-related hereditary haemochromatosis

    Directory of Open Access Journals (Sweden)

    Barton David E

    2006-11-01

    Full Text Available Abstract Background Hereditary haemochromatosis (HH is a recessively-inherited disorder of iron over-absorption prevalent in Caucasian populations. Affected individuals for Type 1 HH are usually either homozygous for a cysteine to tyrosine amino acid substitution at position 282 (C282Y of the HFE gene, or compound heterozygotes for C282Y and for a histidine to aspartic acid change at position 63 (H63D. Molecular genetic testing for these two mutations has become widespread in recent years. With diverse testing methods and reporting practices in use, there was a clear need for agreed guidelines for haemochromatosis genetic testing. The UK Clinical Molecular Genetics Society has elaborated a consensus process for the development of disease-specific best practice guidelines for genetic testing. Methods A survey of current practice in the molecular diagnosis of haemochromatosis was conducted. Based on the results of this survey, draft guidelines were prepared using the template developed by UK Clinical Molecular Genetics Society. A workshop was held to develop the draft into a consensus document. The consensus document was then posted on the Clinical Molecular Genetics Society website for broader consultation and amendment. Results Consensus or near-consensus was achieved on all points in the draft guidelines. The consensus and consultation processes worked well, and outstanding issues were documented in an appendix to the guidelines. Conclusion An agreed set of best practice guidelines were developed for diagnostic, predictive and carrier testing for hereditary haemochromatosis and for reporting the results of such testing.

  4. EMQN/CMGS best practice guidelines for the molecular genetic testing of Huntington disease.

    Science.gov (United States)

    Losekoot, Monique; van Belzen, Martine J; Seneca, Sara; Bauer, Peter; Stenhouse, Susan A R; Barton, David E

    2013-05-01

    Huntington disease (HD) is caused by the expansion of an unstable polymorphic trinucleotide (CAG)n repeat in exon 1 of the HTT gene, which translates into an extended polyglutamine tract in the protein. Laboratory diagnosis of HD involves estimation of the number of CAG repeats. Molecular genetic testing for HD is offered in a wide range of laboratories both within and outside the European community. In order to measure the quality and raise the standard of molecular genetic testing in these laboratories, the European Molecular Genetics Quality Network has organized a yearly external quality assessment (EQA) scheme for molecular genetic testing of HD for over 10 years. EQA compares a laboratory's output with a fixed standard both for genotyping and reporting of the results to the referring physicians. In general, the standard of genotyping is very high but the clarity of interpretation and reporting of the test result varies more widely. This emphasizes the need for best practice guidelines for this disorder. We have therefore developed these best practice guidelines for genetic testing for HD to assist in testing and reporting of results. The analytical methods and the potential pitfalls of molecular genetic testing are highlighted and the implications of the different test outcomes for the consultand and his or her family members are discussed.

  5. Genetic Diversity Analysis in 27 Tomato Accessions Using Morphological and Molecular Markers

    Directory of Open Access Journals (Sweden)

    Catur Herison

    2018-02-01

    Full Text Available Genetic diversity is the most important aspect in tomato breeding activities. Better assessment on the diversity of the collected accessions will come up with better result of the cultivar development. This study aimed at analyzing the genetic diversity of 27 tomato accessions by morphological and molecular markers. Twenty seven accessions collected from various regions of Indonesia were planted in the field and evaluated for their morphological traits, and RAPD analyzed for their molecular markers. The UPGMA clustering analyzes, elaborating the combination of morphological and molecular data, indicated that the tomato accessions could be grouped into 5 major groups with 70 % genetic similarity levels. Current study indicated that although many accessions came from different locations, they congregated into the same group. Cherry, Kudamati 1 and Lombok 3 were the farthest genetic distant accessions to the others. Those three genotypes will be the most valuable accessions, when they were crossed with other accessions, for designing a prospective breeding program in the future.

  6. The molecular genetics of inflammatory, autoimmune, and infectious diseases of the sinonasal tract: a review.

    Science.gov (United States)

    Montone, Kathleen T

    2014-06-01

    The sinonasal tract is frequently affected by a variety of nonneoplastic inflammatory disease processes that are often multifactorial in their etiology but commonly have a molecular genetic component. To review the molecular genetics of a variety of nonneoplastic inflammatory diseases of the sinonasal tract. Inflammatory lesions of the sinonasal tract can be divided into 3 main categories: (1) chronic rhinosinusitis, (2) infectious diseases, and (3) autoimmune diseases/vasculitides. The molecular diagnosis and pathways of a variety of these inflammatory lesions are currently being elucidated and will shed light on disease pathogenesis and treatment. The sinonasal tract is frequently affected by inflammatory lesions that arise through complex interactions of environmental, infectious, and genetic factors. Because these lesions are all inflammatory in nature, the molecular pathology surrounding them is most commonly due to upregulation and down-regulation of genes that affect inflammatory responses and immune regulation.

  7. History and future of genetically engineered food animal regulation: an open request.

    Science.gov (United States)

    Wells, Kevin D

    2016-06-01

    Modern biotechnology resulted from of a series of incremental improvements in the understanding of DNA and the enzymes that nature evolved to manipulate it. As the potential impact of genetic engineering became apparent, scientists began the process of trying to identify the potential unintended consequences. Restrictions to recombinant DNA experimentation were at first self-imposed. Collaborative efforts between scientists and lawyers formalized an initial set of guidelines. These guidelines have been used to promulgate regulations around world. However, the initial guidelines were only intended as a starting point and were motivated by a specific set of concerns. As new data became available, the guidelines and regulations should have been adapted to the new knowledge. Instead, other social drivers drove the development of regulations. For most species and most applications, the framework that was established has slowly allowed some products to reach the market. However, genetically engineered livestock that are intended for food have been left in a regulatory state of limbo. To date, no genetically engineered food animal is available in the marketplace. A short history and a U.S.-based genetic engineer's perspective are presented. In addition, a request to regulatory agencies is presented for consideration as regulation continues to evolve. Regulators appear to have shown preference for the slow, random progression of evolution over the efficiency of intentional design.

  8. Genetics of the pig tapeworm in madagascar reveal a history of human dispersal and colonization.

    Science.gov (United States)

    Yanagida, Tetsuya; Carod, Jean-François; Sako, Yasuhito; Nakao, Minoru; Hoberg, Eric P; Ito, Akira

    2014-01-01

    An intricate history of human dispersal and geographic colonization has strongly affected the distribution of human pathogens. The pig tapeworm Taenia solium occurs throughout the world as the causative agent of cysticercosis, one of the most serious neglected tropical diseases. Discrete genetic lineages of T. solium in Asia and Africa/Latin America are geographically disjunct; only in Madagascar are they sympatric. Linguistic, archaeological and genetic evidence has indicated that the people in Madagascar have mixed ancestry from Island Southeast Asia and East Africa. Hence, anthropogenic introduction of the tapeworm from Southeast Asia and Africa had been postulated. This study shows that the major mitochondrial haplotype of T. solium in Madagascar is closely related to those from the Indian Subcontinent. Parasitological evidence presented here, and human genetics previously reported, support the hypothesis of an Indian influence on Malagasy culture coinciding with periods of early human migration onto the island. We also found evidence of nuclear-mitochondrial discordance in single tapeworms, indicating unexpected cross-fertilization between the two lineages of T. solium. Analyses of genetic and geographic populations of T. solium in Madagascar will shed light on apparently rapid evolution of this organism driven by recent (<2,000 yr) human migrations, following tens of thousands of years of geographic isolation.

  9. Molecular Markers for Genetic Diversity Studies of European Hare (Lepus europaeus Pallas, 1778 Populations

    Directory of Open Access Journals (Sweden)

    Noémi Soós

    2015-05-01

    Full Text Available The purpose of this article is to give an overview of different molecular techniques which have been used in studies concerning population genetic issues of Lepus species and specifically of L. europaeus. The importance of these researches is ever-growing as the European populations of the brown hare have suffered several falloffs as a consequent upon both natural and anthropogenic effects. With developing tools and techniques molecular genetics have become the centrepiece of population genetics and conservation biology. Nucleic acid methods based on both bi- and uniparentally inherited DNA (allozymes, microsatellites, Y chromosome, mtDNA are often used to study genetic structure, diversity and phylogeography of different species’ populations due to their effectiveness in identifying genetic variability

  10. Molecular genetic diversity in populations of the stingless bee Plebeia remota: A case study

    Directory of Open Access Journals (Sweden)

    Flávio de Oliveira Francisco

    2013-01-01

    Full Text Available Genetic diversity is a major component of the biological diversity of an ecosystem. The survival of a population may be seriously threatened if its genetic diversity values are low. In this work, we measured the genetic diversity of the stingless bee Plebeia remota based on molecular data obtained by analyzing 15 microsatellite loci and sequencing two mitochondrial genes. Population structure and genetic diversity differed depending on the molecular marker analyzed: microsatellites showed low population structure and moderate to high genetic diversity, while mitochondrial DNA (mtDNA showed high population structure and low diversity in three populations. Queen philopatry and male dispersal behavior are discussed as the main reasons for these findings.

  11. The impact of advances in human molecular biology on radiation genetic risk estimation in man

    International Nuclear Information System (INIS)

    Sankaranarayanan, K.

    1996-01-01

    This paper provides an overview of the conceptual framework, the data base, methods and assumptions used thus far to assess the genetic risks of exposure of human populations to ionising radiation. These are then re-examined in the contemporary context of the rapidly expanding knowledge of the molecular biology of human mendelian diseases. This re-examination reveals that (i) many of the assumptions used thus far in radiation genetic risk estimation may not be fully valid and (ii) the current genetic risk estimates are probably conservative, but provide an adequate margin of safety for radiological protection. The view is expressed that further advances in the field of genetic risk estimation will be largely driven by advances in the molecular biology of human genetic diseases. (author). 37 refs., 5 tabs

  12. Molecular phylogeography and evolutionary history of Poropuntius huangchuchieni (Cyprinidae in Southwest China.

    Directory of Open Access Journals (Sweden)

    Xiaoyun Wu

    Full Text Available The evolution of the Yunnan Plateau's drainages network during the Pleistocene was dominated by the intense uplifts of the Qinghai-Tibetan Plateau. In the present study, we investigated the association between the evolutionary histories of three main drainage systems and the geographic patterns of genetic differentiation of Poropuntius huangchuchieni.We sequenced the complete sequences of mitochondrial control region for 304 specimens and the sequences of Cytochrome b gene for 15 specimens of the species P. huangchuchieni and 5 specimens of Poropuntius opisthoptera. Phylogenetic analysis identified five major lineages, of which lineages MK-A and MK-B constrained to the Mekong River System, lineages RL and LX to the Red River System, and lineage SW to the Salween River System. The genetic distance and network analysis detected significant divergences among these lineages. Mismatch distribution analysis implied that the population of P. huangchuchieni underwent demographic stability and the lineage MK-B, sublineages MK-A1 and LX-1 underwent a recent population expansion. The divergence of the 5 major lineages was dated back to 0.73-1.57 MYA.Our results suggest that P. opisthoptera was a paraphyletic group of P. huangchuchieni. The phylogenetic pattern of P. huangchuchieni was mostly associated with the drainage's structures and the geomorphological history of the Southwest Yunnan Plateau. Also the differentiation of the major lineages among the three drainages systems coincides with the Kunlun-Yellow River Movement (1.10-0.60 MYA. The genetic differentiation within river basins and recent demographical expansions that occurred in some lineages and sublineages are consistent with the palaeoclimatic oscillations during the Pleistocene. Additionally, our results also suggest that the populations of P. huangchuchieni had keep long term large effective population sizes and demographic stability in the recent evolutionary history, which may be

  13. Molecular population genetics of inversion breakpoint regions in Drosophila pseudoobscura.

    Science.gov (United States)

    Wallace, Andre G; Detweiler, Don; Schaeffer, Stephen W

    2013-07-08

    Paracentric inversions in populations can have a profound effect on the pattern and organization of nucleotide variability along a chromosome. Regions near inversion breakpoints are expected to have greater levels of differentiation because of reduced genetic exchange between different gene arrangements whereas central regions in the inverted segments are predicted to have lower levels of nucleotide differentiation due to greater levels of genetic flux among different karyotypes. We used the inversion polymorphism on the third chromosome of Drosophila pseudoobscura to test these predictions with an analysis of nucleotide diversity of 18 genetic markers near and away from inversion breakpoints. We tested hypotheses about how the presence of different chromosomal arrangements affects the pattern and organization of nucleotide variation. Overall, markers in the distal segment of the chromosome had greater levels of nucleotide heterozygosity than markers within the proximal segment of the chromosome. In addition, our results rejected the hypothesis that the breakpoints of derived inversions will have lower levels of nucleotide variability than breakpoints of ancestral inversions, even when strains with gene conversion events were removed. High levels of linkage disequilibrium were observed within all 11 breakpoint regions as well as between the ends of most proximal and distal breakpoints. The central region of the chromosome had the greatest levels of linkage disequilibrium compared with the proximal and distal regions because this is the region that experiences the highest level of recombination suppression. These data do not fully support the idea that genetic exchange is the sole force that influences genetic variation on inverted chromosomes.

  14. The population genomic landscape of human genetic structure, admixture history and local adaptation in Peninsular Malaysia.

    Science.gov (United States)

    Deng, Lian; Hoh, Boon Peng; Lu, Dongsheng; Fu, Ruiqing; Phipps, Maude E; Li, Shilin; Nur-Shafawati, Ab Rajab; Hatin, Wan Isa; Ismail, Endom; Mokhtar, Siti Shuhada; Jin, Li; Zilfalil, Bin Alwi; Marshall, Christian R; Scherer, Stephen W; Al-Mulla, Fahd; Xu, Shuhua

    2014-09-01

    Peninsular Malaysia is a strategic region which might have played an important role in the initial peopling and subsequent human migrations in Asia. However, the genetic diversity and history of human populations--especially indigenous populations--inhabiting this area remain poorly understood. Here, we conducted a genome-wide study using over 900,000 single nucleotide polymorphisms (SNPs) in four major Malaysian ethnic groups (MEGs; Malay, Proto-Malay, Senoi and Negrito), and made comparisons of 17 world-wide populations. Our data revealed that Peninsular Malaysia has greater genetic diversity corresponding to its role as a contact zone of both early and recent human migrations in Asia. However, each single Orang Asli (indigenous) group was less diverse with a smaller effective population size (N(e)) than a European or an East Asian population, indicating a substantial isolation of some duration for these groups. All four MEGs were genetically more similar to Asian populations than to other continental groups, and the divergence time between MEGs and East Asian populations (12,000--6,000 years ago) was also much shorter than that between East Asians and Europeans. Thus, Malaysian Orang Asli groups, despite their significantly different features, may share a common origin with the other Asian groups. Nevertheless, we identified traces of recent gene flow from non-Asians to MEGs. Finally, natural selection signatures were detected in a batch of genes associated with immune response, human height, skin pigmentation, hair and facial morphology and blood pressure in MEGs. Notable examples include SYN3 which is associated with human height in all Orang Asli groups, a height-related gene (PNPT1) and two blood pressure-related genes (CDH13 and PAX5) in Negritos. We conclude that a long isolation period, subsequent gene flow and local adaptations have jointly shaped the genetic architectures of MEGs, and this study provides insight into the peopling and human migration

  15. Portuguese crypto-Jews: the genetic heritage of a complex history

    Science.gov (United States)

    Nogueiro, Inês; Teixeira, João C.; Amorim, António; Gusmão, Leonor; Alvarez, Luis

    2015-01-01

    The first documents mentioning Jewish people in Iberia are from the Visigothic period. It was also in this period that the first documented anti-Judaic persecution took place. Other episodes of persecution would happen again and again during the long troubled history of the Jewish people in Iberia and culminated with the Decrees of Expulsion and the establishment of the Inquisition: some Jews converted to Catholicism while others resisted and were forcedly baptized, becoming the first Iberian Crypto-Jews. In the 18th century the official discrimination and persecution carried out by the Inquisition ended and several Jewish communities emerged in Portugal. From a populational genetics point of view, the worldwide Diaspora of contemporary Jewish communities has been intensely studied. Nevertheless, very little information is available concerning Sephardic and Iberian Crypto-Jewish descendants. Data from the Iberian Peninsula, the original geographic source of Sephardic Jews, is limited to two populations in Portugal, Belmonte, and Bragança district, and the Chueta community from Mallorca. Belmonte was the first Jewish community studied for uniparental markers. The construction of a reference model for the history of the Portuguese Jewish communities, in which the genetic and classical historical data interplay dynamically, is still ongoing. Recently an enlarged sample covering a wide region in the Northeast Portugal was undertaken, allowing the genetic profiling of male and female lineages. A Jewish specific shared female lineage (HV0b) was detected between the community of Belmonte and Bragança. In contrast to what was previously described as a hallmark of the Portuguese Jews, an unexpectedly high polymorphism of lineages was found in Bragança, showing a surprising resistance to the erosion of genetic diversity typical of small-sized isolate populations, as well as signs of admixture with the Portuguese host population. PMID:25699075

  16. Portuguese crypto-Jews: the genetic heritage of a complex history.

    Science.gov (United States)

    Nogueiro, Inês; Teixeira, João C; Amorim, António; Gusmão, Leonor; Alvarez, Luis

    2015-01-01

    The first documents mentioning Jewish people in Iberia are from the Visigothic period. It was also in this period that the first documented anti-Judaic persecution took place. Other episodes of persecution would happen again and again during the long troubled history of the Jewish people in Iberia and culminated with the Decrees of Expulsion and the establishment of the Inquisition: some Jews converted to Catholicism while others resisted and were forcedly baptized, becoming the first Iberian Crypto-Jews. In the 18th century the official discrimination and persecution carried out by the Inquisition ended and several Jewish communities emerged in Portugal. From a populational genetics point of view, the worldwide Diaspora of contemporary Jewish communities has been intensely studied. Nevertheless, very little information is available concerning Sephardic and Iberian Crypto-Jewish descendants. Data from the Iberian Peninsula, the original geographic source of Sephardic Jews, is limited to two populations in Portugal, Belmonte, and Bragança district, and the Chueta community from Mallorca. Belmonte was the first Jewish community studied for uniparental markers. The construction of a reference model for the history of the Portuguese Jewish communities, in which the genetic and classical historical data interplay dynamically, is still ongoing. Recently an enlarged sample covering a wide region in the Northeast Portugal was undertaken, allowing the genetic profiling of male and female lineages. A Jewish specific shared female lineage (HV0b) was detected between the community of Belmonte and Bragança. In contrast to what was previously described as a hallmark of the Portuguese Jews, an unexpectedly high polymorphism of lineages was found in Bragança, showing a surprising resistance to the erosion of genetic diversity typical of small-sized isolate populations, as well as signs of admixture with the Portuguese host population.

  17. PORTUGUESE CRYPTO-JEWS: THE GENETIC HERITAGE OF A COMPLEX HISTORY

    Directory of Open Access Journals (Sweden)

    Inês Pires Nogueiro

    2015-02-01

    Full Text Available The first documents mentioning Jewish people in Iberia are from the Visigothic period. It was also in this period that the first documented anti-Judaic persecution took place. Other episodes of persecution would happen again and again during the long troubled history of the Jewish people in Iberia and culminated with the Decrees of Expulsion and the establishment of the Inquisition: some Jews converted to Catholicism while others resisted and were forcedly baptized, becoming the first Iberian Crypto-Jews. In the 18th century the official discrimination and persecution carried out by the Inquisition ended and several Jewish communities emerged in Portugal. From a populational genetics point of view, the worldwide Diaspora of contemporary Jewish communities has been intensely studied. Nevertheless, very little information is available concerning Sephardic and Iberian Crypto-Jewish descendants. Data from the Iberian Peninsula, the original geographic source of Sephardic Jews, is limited to two populations in Portugal, Belmonte and Bragança district, and the Chueta community from Mallorca. Belmonte was the first Jewish community studied for uniparental markers. The construction of a reference model for the history of the Portuguese Jewish communities, in which the genetic and classical historical data interplay dynamically, is still ongoing. Recently an enlarged sample covering a wide region in the Northeast Portugal was undertaken, allowing the genetic profiling of male and female lineages. A Jewish specific shared female lineage (HV0b was detected between the community of Belmonte and Bragança. In contrast to what was previously described as a hallmark of the Portuguese Jews, an unexpectedly high polymorphism of lineages’ was found in Bragança, showing a surprising resistance to the erosion of genetic diversity typical of small-sized isolate populations, as well as signs of admixture with the Portuguese host population.

  18. Genetic influences on attention deficit hyperactivity disorder symptoms from age 2 to 3: A quantitative and molecular genetic investigation

    Directory of Open Access Journals (Sweden)

    Saudino Kimberly J

    2010-12-01

    Full Text Available Abstract Background A twin study design was used to assess the degree to which additive genetic variance influences ADHD symptom scores across two ages during infancy. A further objective in the study was to observe whether genetic association with a number of candidate markers reflects results from the quantitative genetic analysis. Method We have studied 312 twin pairs at two time-points, age 2 and age 3. A composite measure of ADHD symptoms from two parent-rating scales: The Child Behavior Checklist/1.5 - 5 years (CBCL hyperactivity scale and the Revised Rutter Parent Scale for Preschool Children (RRPSPC was used for both quantitative and molecular genetic analyses. Results At ages 2 and 3 ADHD symptoms are highly heritable (h2 = 0.79 and 0.78, respectively with a high level of genetic stability across these ages. However, we also observe a significant level of genetic change from age 2 to age 3. There are modest influences of non-shared environment at each age independently (e2 = 0.22 and 0.21, respectively, with these influences being largely age-specific. In addition, we find modest association signals in DAT1 and NET1 at both ages, along with suggestive specific effects of 5-HTT and DRD4 at age 3. Conclusions ADHD symptoms are heritable at ages 2 and 3. Additive genetic variance is largely shared across these ages, although there are significant new effects emerging at age 3. Results from our genetic association analysis reflect these levels of stability and change and, more generally, suggest a requirement for consideration of age-specific genotypic effects in future molecular studies.

  19. TAXONOMY AND GENETIC RELATIONSHIPS OF PANGASIIDAE, ASIAN CATFISHES, BASED ON MORPHOLOGICAL AND MOLECULAR ANALYSES

    Directory of Open Access Journals (Sweden)

    Rudhy Gustiano

    2007-12-01

    Full Text Available Pangasiids are economically important riverine catfishes generally residing in freshwater from the Indian subcontinent to the Indonesian Archipelago. The systematics of this family are still poorly known. Consequently, lack of such basic information impedes the understanding of the biology of the Pangasiids and the study of their aquaculture potential as well as improvement of seed production and growth performance. The objectives of the present study are to clarify phylogeny of this family based on a biometric analysis and molecular evidence using 12S ribosomal mtDNA on the total of 1070 specimens. The study revealed that 28 species are recognised as valid in Pangasiidae. Four genera are also recognized as Helicophagus Bleeker 1858, Pangasianodon Chevey 1930, Pteropangasius Fowler 1937, and Pangasius Valenciennes 1840 instead of two as reported by previous workers. The phylogenetic analysis demonstrated the recognised genera, and genetic relationships among taxa. Overall, trees from the different analyses show similar topologies and confirm the hypothesis derived from geological history, palaeontology, and similar models in other taxa of fishes from the same area. The oldest genus may already have existed when the Asian mainland was still connected to the islands in the southern part about 20 million years ago.

  20. Toward molecular pathogenesis of an autoimmune disease: Refined genetic mapping of autoimmune polyglandular disease type I (APECED)

    Energy Technology Data Exchange (ETDEWEB)

    Aaltonen, J.; Bjoerses, P.; Peltonen, L. [National Public Health Institute, Helsinki (Finland)] [and others

    1994-09-01

    Autoimmune reactions encoupled to many human diseases are still only partially understood. Unravelling the molecular pathogenesis of inherited diseases with a strong autoimmune component in their clinical expression could help to dissect individual components in the molecular background of abnormal immune response. One such genetic disorder is autosomal recessive autoimmune polyglandular disease type I (PGD I), also known as autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED, MIM 240300). The disease is especially enriched in the genetically isolated population of Finland and we have assigned the APECED locus to human chromosome 21q22.3 in 14 Finnish families by linkage analyses. The best positional lod score of 6.49 was observed with marker D21S49. Based on the history of the Finns, the gene pool of this population clearly demonstrates the consequences of a founder effect and consequent isolation. In the Finnish population, we can take advantage of linkage disequilibrium and allelic association studies to more precisely define the critical DNA region for our disease gene of interest than would be possible by linkage analyses alone. We are now able to define the chromosomal region of interest between two flanking markers locating 1 cM apart. Linkage disequilibrium is observed with three of the markers used in the analyses and this suggests a distance of less than 500 kb to the disease locus, well approachable with molecular cloning techniques. Overlapping YAC and cosmid clones spanning our region of interest will facilitate the cloning of APECED gene in the near future.

  1. The genetic variance but not the genetic covariance of life-history traits changes towards the north in a time-constrained insect.

    Science.gov (United States)

    Sniegula, Szymon; Golab, Maria J; Drobniak, Szymon M; Johansson, Frank

    2018-03-22

    Seasonal time constraints are usually stronger at higher than lower latitudes and can exert strong selection on life-history traits and the correlations among these traits. To predict the response of life-history traits to environmental change along a latitudinal gradient, information must be obtained about genetic variance in traits and also genetic correlation between traits, that is the genetic variance-covariance matrix, G. Here, we estimated G for key life-history traits in an obligate univoltine damselfly that faces seasonal time constraints. We exposed populations to simulated native temperatures and photoperiods and common garden environmental conditions in a laboratory set-up. Despite differences in genetic variance in these traits between populations (lower variance at northern latitudes), there was no evidence for latitude-specific covariance of the life-history traits. At simulated native conditions, all populations showed strong genetic and phenotypic correlations between traits that shaped growth and development. The variance-covariance matrix changed considerably when populations were exposed to common garden conditions compared with the simulated natural conditions, showing the importance of environmentally induced changes in multivariate genetic structure. Our results highlight the importance of estimating variance-covariance matrixes in environments that mimic selection pressures and not only trait variances or mean trait values in common garden conditions for understanding the trait evolution across populations and environments. © 2018 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2018 European Society For Evolutionary Biology.

  2. Molecular analysis of genetic diversity in elite II synthetic hexaploid ...

    African Journals Online (AJOL)

    The present study was conducted to assess the genetic diversity of Elite-II synthetic hexaploid (SH) wheat by genome DNA fingerprinting as revealed by random amplified polymorphic DNA (RAPD) analysis. Ten decamer RAPD primers (OPG-1, OPG-2, OPG-3, OPG-4, OPG-5, OPA-3, OPA-4, OPA-5, OPA-8, and OPA-15) ...

  3. Genetic diversity and molecular characterization of physic nut ...

    African Journals Online (AJOL)

    ajl

    2013-02-27

    Feb 27, 2013 ... 2Department of Plant Science, Federal University of Viçosa, Viçosa, Minas Gerais, Brazil. ... primers were used to characterize toxicity alleles, and none of the accessions presented patterns ... accessions from India (Gupta et al., 2008; Gohil and. Pandya .... ISSR primers, generally low genetic diversity was.

  4. Molecular genetic diversity study of Lepidium sativum population ...

    African Journals Online (AJOL)

    Vostro 2520

    Generally, Tigray and Amhara regions showed moderate to high diversity in ISSR analysis. ... other crops. The main purpose of its cultivation in. Ethiopia is to use it as a medicinal plant. It is used for human abdominal ache and diarrhea. Moreover, L. ... of 10 primers were obtained from the Genetic Research Laboratory.

  5. Molecular and genetic basis of freezing tolerance in crucifer species

    NARCIS (Netherlands)

    Heo, J.

    2014-01-01

    Understanding genetic variation for freezing tolerance is important for unraveling an adaptative strategy of species and for finding out an effective way to improve crop productivity to unfavorable winter environments. The aim of this thesis was to examine natural variation for

  6. Genetic and molecular markers of proteinuria and glomerulosclerosis

    NARCIS (Netherlands)

    IJpelaar, Daphne Hubertina Thea

    2009-01-01

    The clinical course of renal diseases depends on the type of renal disorder, genetic factors, environmental influences, and the severity of renal fibrosis. Proteinuria is the abnormal amount of proteins present in the urine. Proteinuria is an independent risk factor for development of renal

  7. Molecular evaluation of genetic diversity and association studies in ...

    Indian Academy of Sciences (India)

    In the present study, we tested rice genotypes that included un(der)exploited landraces of Tamil Nadu along with indica and japonica test cultivars to ascertain their genetic diversity structure. Highly polymorphic microsatellite markers were used for generating marker segregation data. A novel measure, allele discrimination ...

  8. Preliminary molecular analysis of the genetic diversity of some ...

    African Journals Online (AJOL)

    In the arid and semi arid areas, salt bush (Atriplex) represents an important forage resource. The characterization of the genetic diversity of these species is useful for their classification, their conservation and their improvement. In this context, we used the random amplified polymorphic DNA-polymerase chain reaction ...

  9. Construction of intersubspecific molecular genetic map of lentil

    Indian Academy of Sciences (India)

    Lentil (Lens culinaris ssp. culinaris), is a self-pollinating diploid ( 2 n = 2 x = 14 ), cool-season legume crop and is consumed worldwide as a rich source of protein (∼24.0%), largely in vegetarian diets. Here we report development of a genetic linkage map of Lens using 114 F2 plants derived from the intersubspecific cross ...

  10. A unifying study of phenotypic and molecular genetic variability in ...

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... Home; Journals; Journal of Genetics; Volume 93; Issue 1 ... Populations from the Paranaense biogeographic province showed the highest mean value of number of seeds per fruit making them valuable as well with regard to the exploitation of management strategies as a ... Please take note of this change.

  11. Molecular and genetic characterization of OSH6 ( Oryza sativa ...

    African Journals Online (AJOL)

    Genetic studies of dissociation (Ds) insertion mutant rice plants indicated that ectopic expression of truncated OSH6 (Oryza sativa Homeobox 6) mRNA may be responsible for the mutant phenotype of knotted leaf formation at the peduncle. Additionally, ectopic expression of truncated OSH6 mRNA in the OSH6-Ds mutant ...

  12. Molecular genetic analysis of the Chinese Erhualian pig breed | Yue ...

    African Journals Online (AJOL)

    The Chinese Erhualian is one of the most prolific pig breeds in the world, but it is in danger of being replaced by other exotic pig breeds because of its slow growth rate and high fat content in the body. To obtain some genetic information for conservation, we analysed the Erhualian pigs by using a PCR-RFLP for the ...

  13. Genetic variability of hull-less barley accessions based on molecular and quantitative data

    Directory of Open Access Journals (Sweden)

    Ricardo Meneses Sayd

    2015-02-01

    Full Text Available The objective of this work was to characterize and quantify the genetic, molecular, and agronomic variability of hull-less barley genotypes, for the selection of parents and identification of genotypes adapted to the irrigated production system in the Brazilian Cerrado. Eighteen hull-less barley accessions were evaluated, and three covered barley accessions served as reference. The characterization was based on 157 RAPD molecular markers and ten agronomic traits. Genetic distance matrices were obtained based on molecular markers and quantitative traits. Graphic grouping and dispersion analyses were performed. Genetic, molecular, and agronomic variability was high among genotypes. Ethiopian accessions were genetically more similar, and the Brazilian ones were genetically more distant. For agronomic traits, two more consistent groupings were obtained, one with the most two-rowed materials, and the other with six-rowed materials. The more diverging materials were the two-rowed CI 13453, CN Cerrado 5, CN Cerrado 1, and CN Cerrado 2. The PI 356466, CN Cerrado 1, PI 370799, and CI 13453 genotypes show agronomic traits of interest and, as genetically different genotypes, they are indicated for crossing, in breeding programs.

  14. Genetic diversity and population history of a critically endangered primate, the northern muriqui (Brachyteles hypoxanthus).

    Science.gov (United States)

    Chaves, Paulo B; Alvarenga, Clara S; Possamai, Carla de B; Dias, Luiz G; Boubli, Jean P; Strier, Karen B; Mendes, Sérgio L; Fagundes, Valéria

    2011-01-01

    Social, ecological, and historical processes affect the genetic structure of primate populations, and therefore have key implications for the conservation of endangered species. The northern muriqui (Brachyteles hypoxanthus) is a critically endangered New World monkey and a flagship species for the conservation of the Atlantic Forest hotspot. Yet, like other neotropical primates, little is known about its population history and the genetic structure of remnant populations. We analyzed the mitochondrial DNA control region of 152 northern muriquis, or 17.6% of the 864 northern muriquis from 8 of the 12 known extant populations and found no evidence of phylogeographic partitions or past population shrinkage/expansion. Bayesian and classic analyses show that this finding may be attributed to the joint contribution of female-biased dispersal, demographic stability, and a relatively large historic population size. Past population stability is consistent with a central Atlantic Forest Pleistocene refuge. In addition, the best scenario supported by an Approximate Bayesian Computation analysis, significant fixation indices (Φ(ST) = 0.49, Φ(CT) = 0.24), and population-specific haplotypes, coupled with the extirpation of intermediate populations, are indicative of a recent geographic structuring of genetic diversity during the Holocene. Genetic diversity is higher in populations living in larger areas (>2,000 hectares), but it is remarkably low in the species overall (θ = 0.018). Three populations occurring in protected reserves and one fragmented population inhabiting private lands harbor 22 out of 23 haplotypes, most of which are population-exclusive, and therefore represent patchy repositories of the species' genetic diversity. We suggest that these populations be treated as discrete units for conservation management purposes.

  15. Genetic diversity and population history of a critically endangered primate, the northern muriqui (Brachyteles hypoxanthus.

    Directory of Open Access Journals (Sweden)

    Paulo B Chaves

    Full Text Available Social, ecological, and historical processes affect the genetic structure of primate populations, and therefore have key implications for the conservation of endangered species. The northern muriqui (Brachyteles hypoxanthus is a critically endangered New World monkey and a flagship species for the conservation of the Atlantic Forest hotspot. Yet, like other neotropical primates, little is known about its population history and the genetic structure of remnant populations. We analyzed the mitochondrial DNA control region of 152 northern muriquis, or 17.6% of the 864 northern muriquis from 8 of the 12 known extant populations and found no evidence of phylogeographic partitions or past population shrinkage/expansion. Bayesian and classic analyses show that this finding may be attributed to the joint contribution of female-biased dispersal, demographic stability, and a relatively large historic population size. Past population stability is consistent with a central Atlantic Forest Pleistocene refuge. In addition, the best scenario supported by an Approximate Bayesian Computation analysis, significant fixation indices (Φ(ST = 0.49, Φ(CT = 0.24, and population-specific haplotypes, coupled with the extirpation of intermediate populations, are indicative of a recent geographic structuring of genetic diversity during the Holocene. Genetic diversity is higher in populations living in larger areas (>2,000 hectares, but it is remarkably low in the species overall (θ = 0.018. Three populations occurring in protected reserves and one fragmented population inhabiting private lands harbor 22 out of 23 haplotypes, most of which are population-exclusive, and therefore represent patchy repositories of the species' genetic diversity. We suggest that these populations be treated as discrete units for conservation management purposes.

  16. Genetic diversity in cultivated carioca common beans based on molecular marker analysis

    Directory of Open Access Journals (Sweden)

    Juliana Morini Küpper Cardoso Perseguini

    2011-01-01

    Full Text Available A wide array of molecular markers has been used to investigate the genetic diversity among common bean species. However, the best combination of markers for studying such diversity among common bean cultivars has yet to be determined. Few reports have examined the genetic diversity of the carioca bean, commercially one of the most important common beans in Brazil. In this study, we examined the usefulness of two molecular marker systems (simple sequence repeats - SSRs and amplified fragment length polymorphisms - AFLPs for assessing the genetic diversity of carioca beans. The amount of information provided by Roger's modified genetic distance was used to analyze SSR data and Jaccards similarity coefficient was used for AFLP data. Seventy SSRs were polymorphic and 20 AFLP primer combinations produced 635 polymorphic bands. Molecular analysis showed that carioca genotypes were quite diverse. AFLPs revealed greater genetic differentiation and variation within the carioca genotypes (Gst = 98% and Fst = 0.83, respectively than SSRs and provided better resolution for clustering the carioca genotypes. SSRs and AFLPs were both suitable for assessing the genetic diversity of Brazilian carioca genotypes since the number of markers used in each system provided a low coefficient of variation. However, fingerprint profiles were generated faster with AFLPs, making them a better choice for assessing genetic diversity in the carioca germplasm.

  17. Molecular genetic diversity and genetic structure of Vietnamese indigenous pig populations

    DEFF Research Database (Denmark)

    Pham, L. D.; Do, Duy Ngoc; Nam, L. Q.

    2014-01-01

    The study characterized genetic diversity and genetic structure of five indigenous pig populations (Ha Lang, Muong Te, Mong Cai, Lung and Lung Pu), two wild pig populations (Vietnamese and Thai wild pigs) and an exotic pig breed (Yorkshire) using FAO/ISAG recommended 16 microsatellite markers...

  18. Panel 4: Recent Advances in Otitis Media in Molecular Biology, Biochemistry, Genetics, and Animal Models

    Science.gov (United States)

    Li, Jian-Dong; Hermansson, Ann; Ryan, Allen F.; Bakaletz, Lauren O.; Brown, Steve D.; Cheeseman, Michael T.; Juhn, Steven K.; Jung, Timothy T. K.; Lim, David J.; Lim, Jae Hyang; Lin, Jizhen; Moon, Sung-Kyun; Post, J. Christopher

    2014-01-01

    Background Otitis media (OM) is the most common childhood bacterial infection and also the leading cause of conductive hearing loss in children. Currently, there is an urgent need for developing novel therapeutic agents for treating OM based on full understanding of molecular pathogenesis in the areas of molecular biology, biochemistry, genetics, and animal model studies in OM. Objective To provide a state-of-the-art review concerning recent advances in OM in the areas of molecular biology, biochemistry, genetics, and animal model studies and to discuss the future directions of OM studies in these areas. Data Sources and Review Methods A structured search of the current literature (since June 2007). The authors searched PubMed for published literature in the areas of molecular biology, biochemistry, genetics, and animal model studies in OM. Results Over the past 4 years, significant progress has been made in the areas of molecular biology, biochemistry, genetics, and animal model studies in OM. These studies brought new insights into our understanding of the molecular and biochemical mechanisms underlying the molecular pathogenesis of OM and helped identify novel therapeutic targets for OM. Conclusions and Implications for Practice Our understanding of the molecular pathogenesis of OM has been significantly advanced, particularly in the areas of inflammation, innate immunity, mucus overproduction, mucosal hyperplasia, middle ear and inner ear interaction, genetics, genome sequencing, and animal model studies. Although these studies are still in their experimental stages, they help identify new potential therapeutic targets. Future preclinical and clinical studies will help to translate these exciting experimental research findings into clinical applications. PMID:23536532

  19. Phenotypic and molecular evaluation of genetic diversity of rapeseed

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-05

    Oct 5, 2009 ... seed yield per plant, 1000-seed weight, oil content and protein content) were analyzed in a three-year ... regard to many characters of value for breeding process. (Cowling ..... tances determined by molecular markers and heterosis ..... Comparative analysis of cultivated melon groups (Cucumis melo L.).

  20. Advances in genetics and molecular breeding of three legume crops ...

    Indian Academy of Sciences (India)

    Molecular markers are the most powerful genomic tools to increase the efficiency and precision of breeding practices for crop improvement. Progress in the development of genomic resources in the leading legume crops of the semi-arid tropics (SAT), namely, chickpea (Cicer arietinum), pigeonpea (Cajanus cajan) and ...

  1. Molecular dissection of white pine genetic resistance to Cronartium ribicola

    Science.gov (United States)

    Jun-Jun Liu; Richard Sniezko

    2011-01-01

    Pinus monticola (Dougl. ex D. Don.) maintains a complex defence system that detects white pine blister rust pathogen (Cronartium ribicola J.C.Fisch.) and activates resistance responses. A thorough understanding of how it functions at the molecular level would provide us new strategies for creating forest trees with durable disease resistance. Our research focuses on...

  2. Indel Group in Genomes (IGG) Molecular Genetic Markers1[OPEN

    Science.gov (United States)

    Burkart-Waco, Diana; Kuppu, Sundaram; Britt, Anne; Chetelat, Roger

    2016-01-01

    Genetic markers are essential when developing or working with genetically variable populations. Indel Group in Genomes (IGG) markers are primer pairs that amplify single-locus sequences that differ in size for two or more alleles. They are attractive for their ease of use for rapid genotyping and their codominant nature. Here, we describe a heuristic algorithm that uses a k-mer-based approach to search two or more genome sequences to locate polymorphic regions suitable for designing candidate IGG marker primers. As input to the IGG pipeline software, the user provides genome sequences and the desired amplicon sizes and size differences. Primer sequences flanking polymorphic insertions/deletions are produced as output. IGG marker files for three sets of genomes, Solanum lycopersicum/Solanum pennellii, Arabidopsis (Arabidopsis thaliana) Columbia-0/Landsberg erecta-0 accessions, and S. lycopersicum/S. pennellii/Solanum tuberosum (three-way polymorphic) are included. PMID:27436831

  3. MAJOR MOLECULAR GENETIC DRIVERS IN SPORADIC PRIMARY HYPERPARATHYROIDISM.

    Science.gov (United States)

    Arnold, Andrew

    2016-01-01

    Primary hyperparathyroidism is primarily due to a solitary parathyroid adenoma but multi-gland disease, parathyroid carcinoma, and ectopic parathyroid hormone production can occur. Although primary hyperparathyroidism mostly presents sporadically, strong familial predispositions also exist. Much is known about heritable genetic mutations responsible for these syndromes, including multiple endocrine neoplasia types 1 and 2A, hyperparathyroidism-jaw tumor syndrome, and familial hypocalciuric hypercalcemia. Acquired mutations in common sporadic hyperparathyroidism have also been discovered. Here we focus on the most common and well-established genetic drivers: 1) involvement of the oncogene cyclin D1 in human neoplasia was first established in parathyroid adenomas, followed by recognition of its importance in other tumor types including breast cancer and B-lymphoid malignancy; and 2) somatic mutation of the MEN1 gene, first identified as the source of pathogenic germline mutations in patients with familial endocrinopathies, is found in a substantial fraction of non-familial parathyroid adenomas.

  4. Involvement of genetic variants associated with primary open-angle glaucoma in pathogenic mechanisms and family history of glaucoma.

    Science.gov (United States)

    Mabuchi, Fumihiko; Sakurada, Yoichi; Kashiwagi, Kenji; Yamagata, Zentaro; Iijima, Hiroyuki; Tsukahara, Shigeo

    2015-03-01

    To investigate the associations between the non-intraocular pressure (IOP)-related genetic variants (genetic variants associated with vulnerability of the optic nerve independent of IOP) and primary open-angle glaucoma (POAG), including normal-tension glaucoma (NTG) and high-tension glaucoma (HTG), and between the non-IOP-related genetic variants and a family history of glaucoma. Case-control study. Japanese patients with NTG (n = 213) and HTG (n = 212) and 191 control subjects were genotyped for 5 non-IOP-related genetic variants predisposing to POAG near the SRBD1, ELOVL5, CDKN2B/CDKN2B-AS1, SIX1/SIX6, and ATOH7 genes. The load of these genetic variants was compared between the control subjects and patients with NTG or HTG and between the POAG patients with and without a family history of glaucoma. The total number of POAG risk alleles and the product of the odds ratios (POAG risk) of these genetic variants were significantly larger (P product of the odds ratios increased (P = .012 and P = .047, respectively). Non-IOP-related genetic variants contribute to the pathogenesis of HTG as well as NTG. A positive family history of glaucoma in cases of POAG is thought to reflect the influence of genetic variants predisposing to POAG. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Genetics and Molecular Diagnostics in Retinoblastoma--An Update.

    Science.gov (United States)

    Soliman, Sameh E; Racher, Hilary; Zhang, Chengyue; MacDonald, Heather; Gallie, Brenda L

    2017-01-01

    Retinoblastoma is the prototype genetic cancer: in one or both eyes of young children, most retinoblastomas are initiated by biallelic mutation of the retinoblastoma tumor suppressor gene, RB1, in a developing retinal cell. All those with bilateral retinoblastoma have heritable cancer, although 95% have not inherited the RB1 mutation. Non-heritable retinoblastoma is always unilateral, with 98% caused by loss of both RB1 alleles from the tumor, whereas 2% have normal RB1 in tumors initiated by amplification of the MYCN oncogene. Good understanding of retinoblastoma genetics supports optimal care for retinoblastoma children and their families. Retinoblastoma is the first cancer to officially acknowledge the seminal role of genetics in cancer, by incorporating "H" into the eighth edition of cancer staging (2017): those who carry the RB1 cancer-predisposing gene are H1; those proven to not carry the familial RB1 mutation are H0; and those at unknown risk are HX. We suggest H0* be used for those with residual <1% risk to carry a RB1 mutation due to undetectable mosaicism. Loss of RB1 from a susceptible developing retinal cell initiates the benign precursor, retinoma. Progressive genomic changes result in retinoblastoma, and cancer progression ensues with increasing genomic disarray. Looking forward, novel therapies are anticipated from studies of retinoblastoma and metastatic tumor cells and the second primary cancers that the carriers of RB1 mutations are at high risk to develop. Here, we summarize the concepts of retinoblastoma genetics for ophthalmologists in a question/answer format to assist in the care of patients and their families. Copyright 2017 Asia-Pacific Academy of Ophthalmology.

  6. Quantitative genetic analysis of life-history traits of Caenorhabditis elegans in stressful environments

    Directory of Open Access Journals (Sweden)

    Shorto Alison

    2008-01-01

    Full Text Available Abstract Background Organisms live in environments that vary. For life-history traits that vary across environments, fitness will be maximised when the phenotype is appropriately matched to the environmental conditions. For the free-living nematode Caenorhabditis elegans, we have investigated how two major life-history traits, (i the development of environmentally resistant dauer larvae and (ii reproduction, respond to environmental stress (high population density and low food availability, and how these traits vary between lines and the genetic basis of this variation. Results We found that lines of C. elegans vary in their phenotypic plasticity of dauer larva development, i.e. there is variation in the likelihood of developing into a dauer larva for the same environmental change. There was also variation in how lifetime fecundity and the rate of reproduction changed under conditions of environmental stress. These traits were related, such that lines that are highly plastic for dauer larva development also maintain a high population growth rate when stressed. We identified quantitative trait loci (QTL on two chromosomes that control the dauer larva development and population size phenotypes. The QTLs affecting the dauer larva development and population size phenotypes on chromosome II are closely linked, but are genetically separable. This chromosome II QTL controlling dauer larva development does not encompass any loci previously identified to control dauer larva development. This chromosome II region contains many predicted 7-transmembrane receptors. Such proteins are often involved in information transduction, which is clearly relevant to the control of dauer larva development. Conclusion C. elegans alters both its larval development and adult reproductive strategy in response to environmental stress. Together the phenotypic and genotypic data suggest that these two major life-history traits are co-ordinated responses to environmental stress

  7. Dating Antarctic ice sheet collapse: Proposing a molecular genetic approach

    Science.gov (United States)

    Strugnell, Jan M.; Pedro, Joel B.; Wilson, Nerida G.

    2018-01-01

    Sea levels at the end of this century are projected to be 0.26-0.98 m higher than today. The upper end of this range, and even higher estimates, cannot be ruled out because of major uncertainties in the dynamic response of polar ice sheets to a warming climate. Here, we propose an ecological genetics approach that can provide insight into the past stability and configuration of the West Antarctic Ice Sheet (WAIS). We propose independent testing of the hypothesis that a trans-Antarctic seaway occurred at the last interglacial. Examination of the genomic signatures of bottom-dwelling marine species using the latest methods can provide an independent window into the integrity of the WAIS more than 100,000 years ago. Periods of connectivity facilitated by trans-Antarctic seaways could be revealed by dating coalescent events recorded in DNA. These methods allow alternative scenarios to be tested against a fit to genomic data. Ideal candidate taxa for this work would need to possess a circumpolar distribution, a benthic habitat, and some level of genetic structure indicated by phylogeographical investigation. The purpose of this perspective piece is to set out an ecological genetics method to help resolve when the West Antarctic Ice Shelf last collapsed.

  8. The molecular genetic makeup of acute lymphoblastic leukemia.

    Science.gov (United States)

    Mullighan, Charles G

    2012-01-01

    Genomic profiling has transformed our understanding of the genetic basis of acute lymphoblastic leukemia (ALL). Recent years have seen a shift from microarray analysis and candidate gene sequencing to next-generation sequencing. Together, these approaches have shown that many ALL subtypes are characterized by constellations of structural rearrangements, submicroscopic DNA copy number alterations, and sequence mutations, several of which have clear implications for risk stratification and targeted therapeutic intervention. Mutations in genes regulating lymphoid development are a hallmark of ALL, and alterations of the lymphoid transcription factor gene IKZF1 (IKAROS) are associated with a high risk of treatment failure in B-ALL. Approximately 20% of B-ALL cases harbor genetic alterations that activate kinase signaling that may be amenable to treatment with tyrosine kinase inhibitors, including rearrangements of the cytokine receptor gene CRLF2; rearrangements of ABL1, JAK2, and PDGFRB; and mutations of JAK1 and JAK2. Whole-genome sequencing has also identified novel targets of mutation in aggressive T-lineage ALL, including hematopoietic regulators (ETV6 and RUNX1), tyrosine kinases, and epigenetic regulators. Challenges for the future are to comprehensively identify and experimentally validate all genetic alterations driving leukemogenesis and treatment failure in childhood and adult ALL and to implement genomic profiling into the clinical setting to guide risk stratification and targeted therapy.

  9. Principles, exemplars, and uses of history in early 20th century genetics.

    Science.gov (United States)

    Skopek, Jeffrey M

    2011-06-01

    This paper is concerned with the uses of history in science. It focuses in particular on Anglo-American genetics and on university textbooks--where the canon of a science is consolidated, as the heterogeneous approaches and controversies of its practice are rendered unified for its reproduction. Tracing the emergence and eventual standardization of geneticists' use of a case-based method of teaching in the 1920s-1950s, this paper argues that geneticists created historical environments in their textbooks-spaces in which students developed an understanding of the laws of genetics through simulations of their discovery and use. Witnessing the unfolding of Mendel's and Morgan's experiments and performing genetic crosses on paper, students learned not only the rules that were explicitly taught as such, but also the experientially-based, tacit skills needed to find and follow these rules. This didactic system taught them how to go on when confronting new situations, and in doing so, provided geneticists with an important disciplinary tool, freeing the first steps of their student's enculturation from the physical infrastructure of the laboratory. Copyright © 2010 Elsevier Ltd. All rights reserved.

  10. The genetic theory of infectious diseases: a brief history and selected illustrations.

    Science.gov (United States)

    Casanova, Jean-Laurent; Abel, Laurent

    2013-01-01

    Until the mid-nineteenth century, life expectancy at birth averaged 20 years worldwide, owing mostly to childhood fevers. The germ theory of diseases then gradually overcame the belief that diseases were intrinsic. However, around the turn of the twentieth century, asymptomatic infection was discovered to be much more common than clinical disease. Paradoxically, this observation barely challenged the newly developed notion that infectious diseases were fundamentally extrinsic. Moreover, interindividual variability in the course of infection was typically explained by the emerging immunological (or somatic) theory of infectious diseases, best illustrated by the impact of vaccination. This powerful explanation is, however, best applicable to reactivation and secondary infections, particularly in adults; it can less easily account for interindividual variability in the course of primary infection during childhood. Population and clinical geneticists soon proposed a complementary hypothesis, a germline genetic theory of infectious diseases. Over the past century, this idea has gained some support, particularly among clinicians and geneticists, but has also encountered resistance, particularly among microbiologists and immunologists. We present here the genetic theory of infectious diseases and briefly discuss its history and the challenges encountered during its emergence in the context of the apparently competing but actually complementary microbiological and immunological theories. We also illustrate its recent achievements by highlighting inborn errors of immunity underlying eight life-threatening infectious diseases of children and young adults. Finally, we consider the far-reaching biological and clinical implications of the ongoing human genetic dissection of severe infectious diseases.

  11. The Genetic Theory of Infectious Diseases: A Brief History and Selected Illustrations

    Science.gov (United States)

    Casanova, Jean-Laurent; Abel, Laurent

    2016-01-01

    Until the mid-nineteenth century, life expectancy at birth averaged 20 years worldwide, owing mostly to childhood fevers. The germ theory of diseases then gradually overcame the belief that diseases were intrinsic. However, around the turn of the twentieth century, asymptomatic infection was discovered to be much more common than clinical disease. Paradoxically, this observation barely challenged the newly developed notion that infectious diseases were fundamentally extrinsic. Moreover, interindividual variability in the course of infection was typically explained by the emerging immunological (or somatic) theory of infectious diseases, best illustrated by the impact of vaccination. This powerful explanation is, however, best applicable to reactivation and secondary infections, particularly in adults; it can less easily account for interindividual variability in the course of primary infection during childhood. Population and clinical geneticists soon proposed a complementary hypothesis, a germline genetic theory of infectious diseases. Over the past century, this idea has gained some support, particularly among clinicians and geneticists, but has also encountered resistance, particularly among microbiologists and immunologists. We present here the genetic theory of infectious diseases and briefly discuss its history and the challenges encountered during its emergence in the context of the apparently competing but actually complementary microbiological and immunological theories. We also illustrate its recent achievements by highlighting inborn errors of immunity underlying eight life-threatening infectious diseases of children and young adults. Finally, we consider the far-reaching biological and clinical implications of the ongoing human genetic dissection of severe infectious diseases. PMID:23724903

  12. Genetic structure in the Amazonian catfish Brachyplatystoma rousseauxii: influence of life history strategies.

    Science.gov (United States)

    Carvajal-Vallejos, F M; Duponchelle, F; Desmarais, E; Cerqueira, F; Querouil, S; Nuñez, J; García, C; Renno, J-F

    2014-08-01

    The Dorado or Plateado (Gilded catfish) Brachyplatystoma rousseauxii (Pimelodidae, Siluriformes) is a commercially valuable migratory catfish performing the largest migration in freshwaters: from the Amazonian headwaters in the Andean foothills (breeding area) to the Amazon estuary (nursery area). In spite of its importance to inform management and conservation efforts, the genetic variability of this species has only recently begun to be studied. The aim of the present work was to determine the population genetic structure of B. rousseauxii in two regions: the Upper Madera Basin (five locations in the Bolivian Amazon) and the Western Amazon Basin (one regional sample from the Uyucalí-Napo-Marañon-Amazon basin, Peru). Length polymorphism at nine microsatellite loci (284 individuals) was used to determine genetic variability and to identify the most probable panmictic units (using a Bayesian approach), after a significant departure from Hardy-Weinberg equilibrium was observed in the overall dataset (Western Amazon + Upper Madera). Bayesian analyses revealed at least three clusters in admixture in the five locations sampled in the Bolivian Amazon, whereas only two of these clusters were observed in the Western Amazon. Considering the migratory behaviour of B. rousseauxii, different life history strategies, including homing, are proposed to explain the cluster distribution. Our results are discussed in the light of the numerous threats to the species survival in the Madera basin, in particular dam and reservoir construction.

  13. Global mtDNA genetic structure and hypothesized invasion history of a major pest of citrus, Diaphorina citri (Hemiptera: Liviidae).

    Science.gov (United States)

    Luo, Yufa; Agnarsson, Ingi

    2018-01-01

    The Asian citrus psyllid Diaphorina citri Kuwayama is a key pest of citrus as the vector of the bacterium causing the "huanglongbing" disease (HLB). To assess the global mtDNA population genetic structure, and possible dispersal history of the pest, we investigated genetic variation at the COI gene collating newly collected samples with all previously published data. Our dataset consists of 356 colonies from 106 geographic sites worldwide. High haplotype diversity (H-mean = 0.702 ± 0.017), low nucleotide diversity (π-mean = 0.003), and significant positive selection (Ka/Ks = 32.92) were observed. Forty-four haplotypes (Hap) were identified, clustered into two matrilines: Both occur in southeastern and southern Asia, North and South America, and Africa; lineages A and B also occur in eastern and western Asia, respectively. The most abundant haplotypes were Hap4 in lineage A (35.67%), and Hap9 in lineage B (41.29%). The haplotype network identified them as the ancestral haplotypes within their respective lineages. Analysis of molecular variance showed significant genetic structure ( F ST  = 0.62, p  analysis suggests geographic structuring. We hypothesize a southern and/or southeastern Asia origin, three dispersal routes, and parallel expansions of two lineages. The hypothesized first route involved the expansion of lineage B from southern Asia into North America via West Asia. The second, the expansion of some lineage A individuals from Southeast Asia into East Asia, and the third involved both lineages from Southeast Asia spreading westward into Africa and subsequently into South America. To test these hypotheses and gain a deeper understanding of the global history of D. citri , more data-rich approaches will be necessary from the ample toolkit of next-generation sequencing (NGS). However, this study may serve to guide such sampling and in the development of biological control programs against the global pest D. citri .

  14. The Genetic Essence of Houses and People: History as Idealization and Appropriation of an Imagined Timelessness

    Directory of Open Access Journals (Sweden)

    Pierini Francesca

    2016-12-01

    Full Text Available Marina Fiorato’s The Glassblower of Murano (2008 tells the story of Eleonora, a young woman who travels to Venice in search of her genealogical past and existential roots. Coming from London, Eleonora incarnates a “modern” outlook on what she assumes to be the timeless life and culture of Venice. At one point in the novel, admiring the old houses on the Canal Grande, Eleonora is “on fire with enthusiasm for this culture where the houses and the people kept their genetic essence so pure for millennia that they look the same now as in the Renaissance” (2008, 15. This discourse of pure origins and unbroken continuities is a fascinating fantasizing on characteristics that extend from the urban territory to the people who inhabit it. Within narratives centred on this notion, Italian culture, perceived as holding a privileged relation with history and the past, is often contrasted with the displacement and rootlessness that seem to characterize the modern places and people of England and North America. Through a discussion of two Anglo-American popular novels set in Italy, and several relocation narratives, this paper proposes an exploration of the notion according to which history is the force cementing the identities of societies perceived as less modern and frozen in a timeless dimension. From a point in time when the dialectics of history have been allegedly transcended, Anglo-American popular narratives observe Italy as a timeless, pre-modern other.

  15. Understanding invasion history and predicting invasive niches using genetic sequencing technology in Australia: case studies from Cucurbitaceae and Boraginaceae.

    Science.gov (United States)

    Shaik, Razia S; Zhu, Xiaocheng; Clements, David R; Weston, Leslie A

    2016-01-01

    Part of the challenge in dealing with invasive plant species is that they seldom represent a uniform, static entity. Often, an accurate understanding of the history of plant introduction and knowledge of the real levels of genetic diversity present in species and populations of importance is lacking. Currently, the role of genetic diversity in promoting the successful establishment of invasive plants is not well defined. Genetic profiling of invasive plants should enhance our understanding of the dynamics of colonization in the invaded range. Recent advances in DNA sequencing technology have greatly facilitated the rapid and complete assessment of plant population genetics. Here, we apply our current understanding of the genetics and ecophysiology of plant invasions to recent work on Australian plant invaders from the Cucurbitaceae and Boraginaceae. The Cucurbitaceae study showed that both prickly paddy melon ( Cucumis myriocarpus ) and camel melon ( Citrullus lanatus ) were represented by only a single genotype in Australia, implying that each was probably introduced as a single introduction event. In contrast, a third invasive melon, Citrullus colocynthis , possessed a moderate level of genetic diversity in Australia and was potentially introduced to the continent at least twice. The Boraginaceae study demonstrated the value of comparing two similar congeneric species; one, Echium plantagineum , is highly invasive and genetically diverse, whereas the other, Echium vulgare , exhibits less genetic diversity and occupies a more limited ecological niche. Sequence analysis provided precise identification of invasive plant species, as well as information on genetic diversity and phylogeographic history. Improved sequencing technologies will continue to allow greater resolution of genetic relationships among invasive plant populations, thereby potentially improving our ability to predict the impact of these relationships upon future spread and better manage invaders

  16. Genetically modified crops: the fastest adopted crop technology in the history of modern agriculture

    Directory of Open Access Journals (Sweden)

    Khush Gurdev S

    2012-09-01

    Full Text Available Abstract The major scientific advances of the last century featured the identification of the structure of DNA, the development of molecular biology and the technology to exploit these advances. These breakthroughs gave us new tools for crop improvement, including molecular marker-aided selection (MAS and genetic modification (GM. MAS improves the efficiency of breeding programs, and GM allows us to accomplish breeding objectives not possible through conventional breeding approaches. MAS is not controversial and is now routinely used in crop improvement programs. However, the international debate about the application of genetic manipulation to crop improvement has slowed the adoption of GM crops in developing as well as in European countries. Since GM crops were first introduced to global agriculture in 1996, Clive James has published annual reports on the global status of commercialized GM crops as well as special reports on individual GM crops for The International Service for the Acquisition of Agri-biotech Applications (ISAAA. His 34th report, Global Status of Commercialized Biotech/ GM crops: 2011 [1] is essential reading for those who are concerned about world food security.

  17. Study of inter species diversity and population structure by molecular genetic method in Iranian Artemia

    OpenAIRE

    Hajirostamloo, Mahbobeh

    2005-01-01

    Artemia is a small crustacean that adapted to live in brine water and has been seen in different brine water sources in Iran. Considering the importance of genetic studies manifest inter population differences in species, to estimate genetic structure, detect difference at molecular level and separate different Artemia populations of Iran, also study of phylogenic relationships among them, samples of Artemia were collected from nine region: Urmia lake in West Azerbaijan, Sh...

  18. Update on Anaplastic Thyroid Carcinoma: Morphological, Molecular, and Genetic Features of the Most Aggressive Thyroid Cancer

    Directory of Open Access Journals (Sweden)

    Moira Ragazzi

    2014-01-01

    Full Text Available Anaplastic thyroid carcinoma (ATC is the most aggressive form of thyroid cancer. It shows a wide spectrum of morphological presentations and the diagnosis could be challenging due to its high degree of dedifferentiation. Molecular and genetic features of ATC are widely heterogeneous as well and many efforts have been made to find a common profile in order to clarify its cancerogenetic process. A comprehensive review of the current literature is here performed, focusing on histopathological and genetic features.

  19. Clinical, Molecular, and Genetic Characteristics of PAPA Syndrome: A Review

    Science.gov (United States)

    Smith, Elisabeth J; Allantaz, Florence; Bennett, Lynda; Zhang, Dongping; Gao, Xiaochong; Wood, Geryl; Kastner, Daniel L; Punaro, Marilynn; Aksentijevich, Ivona; Pascual, Virginia; Wise, Carol A

    2010-01-01

    PAPA syndrome (Pyogenic Arthritis, Pyoderma gangrenosum, and Acne) is an autosomal dominant, hereditary auto-inflammatory disease arising from mutations in the PSTPIP1/CD2BP1 gene on chromosome 15q. These mutations produce a hyper-phosphorylated PSTPIP1 protein and alter its participation in activation of the “inflammasome” involved in interleukin-1 (IL-1β) production. Overproduction of IL-1β is a clear molecular feature of PAPA syndrome. Ongoing research is implicating other biochemical pathways that may be relevant to the distinct pyogenic inflammation of the skin and joints characteristic of this disease. This review summarizes the recent and rapidly accumulating knowledge on these molecular aspects of PAPA syndrome and related disorders. PMID:21532836

  20. [Wolfram syndrome: clinical features, molecular genetics of WFS1 gene].

    Science.gov (United States)

    Tanabe, Katsuya; Matsunaga, Kimie; Hatanaka, Masayuki; Akiyama, Masaru; Tanizawa, Yukio

    2015-02-01

    Wolfram syndrome(WFS: OMIM 222300) is a rare recessive neuro-endocrine degenerative disorder, known as DIDMOAD(Diabetes Insipidus, early-onset Diabetes Mellitus, Optic Atrophy and Deafness) syndrome. Most affected individuals carry recessive mutations in the Wolfram syndrome 1 gene(WFS1). The WFS1 protein is an endoplasmic reticulum(ER) embedded protein, which functions in ER calcium homeostasis and unfolded protein responses. Dysregulation of these cellular processes results in the development of ER stress, leading to apoptosis. In addition, abundantly present WFS1 protein in insulin secretory granules plays a role in the intra-granular acidification. However, the phenotypic pleiomorphism and molecular complexity of this disease limit the understanding of WFS. Here we review clinical features, molecular mechanisms and mutations of WFS1 gene that relate to this syndrome.

  1. Molecular Mechanism and Genetic Determinants of Buprofezin Degradation

    OpenAIRE

    Chen, Xueting; Ji, Junbin; Zhao, Leizhen; Qiu, Jiguo; Dai, Chen; Wang, Weiwu; He, Jian; Jiang, Jiandong; Hong, Qing; Yan, Xin

    2017-01-01

    Buprofezin is a widely used insect growth regulator whose residue has been frequently detected in the environment, posing a threat to aquatic organisms and nontarget insects. Microorganisms play an important role in the degradation of buprofezin in the natural environment. However, the relevant catabolic pathway has not been fully characterized, and the molecular mechanism of catabolism is still completely unknown. Rhodococcus qingshengii YL-1 can utilize buprofezin as a sole source of carbon...

  2. Genetic and clinical characteristics of primary and secondary glioblastoma is associated with differential molecular subtype distribution

    OpenAIRE

    Li, Rui; Li, Hailin; Yan, Wei; Yang, Pei; Bao, Zhaoshi; Zhang, Chuanbao; Jiang, Tao; You, Yongping

    2015-01-01

    Glioblastoma multiforme (GBM) is classified into primary (pGBM) or secondary (sGBM) based on clinical progression. However, there are some limits to this classification for insight into genetically and clinically distinction between pGBM and sGBM. The aim of this study is to characterize pGBM and sGBM associating with differential molecular subtype distribution. Whole transcriptome sequencing data was used to assess the distribution of molecular subtypes and genetic alterations in 88 pGBM and...

  3. Fanconi anaemia: genetics, molecular biology, and cancer – implications for clinical management in children and adults.

    Science.gov (United States)

    Schneider, M; Chandler, K; Tischkowitz, M; Meyer, S

    2015-07-01

    Fanconi anaemia (FA) is an inherited disease with congenital and developmental abnormalities, cross-linker hypersensitivity and extreme cancer predisposition. With better understanding of the genetic and molecular basis of the disease, and improved clinical management, FA has been transformed from a life-limiting paediatric disease to an uncommon chronic condition that needs lifelong multidisciplinary management, and a paradigm condition for the understanding of the gene-environment interaction in the aetiology of congenital anomalies, haematopoiesis and cancer development. Here we review genetic, molecular and clinical aspects of FA, and discuss current controversies and future prospects. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Molecular genetic gene-environment studies using candidate genes in schizophrenia: a systematic review.

    Science.gov (United States)

    Modinos, Gemma; Iyegbe, Conrad; Prata, Diana; Rivera, Margarita; Kempton, Matthew J; Valmaggia, Lucia R; Sham, Pak C; van Os, Jim; McGuire, Philip

    2013-11-01

    The relatively high heritability of schizophrenia suggests that genetic factors play an important role in the etiology of the disorder. On the other hand, a number of environmental factors significantly influence its incidence. As few direct genetic effects have been demonstrated, and there is considerable inter-individual heterogeneity in the response to the known environmental factors, interactions between genetic and environmental factors may be important in determining whether an individual develops the disorder. To date, a considerable number of studies of gene-environment interactions (G×E) in schizophrenia have employed a hypothesis-based molecular genetic approach using candidate genes, which have led to a range of different findings. This systematic review aims to summarize the results from molecular genetic candidate studies and to review challenges and opportunities of this approach in psychosis research. Finally, we discuss the potential of future prospects, such as new studies that combine hypothesis-based molecular genetic candidate approaches with agnostic genome-wide association studies in determining schizophrenia risk. © 2013 Elsevier B.V. All rights reserved.

  5. Strengthening molecular genetics and training in craniosynostosis: The need of the hour

    Science.gov (United States)

    Barik, Mayadhar; Bajpai, Minu; Panda, Shasanka Shekhar; Malhotra, Arun; Samantaray, Jyotish Chandra; Dwivedi, Sada Nanda

    2014-01-01

    Craniosynostosis (CS) is premature fusion of skull. It is divided into two groups: Syndromic craniosynostosis (SCS) and non-syndromic craniosynostosis (NSC). Its incidence in Indian population is 1:1000 live births where as in the USA it is 1:2500 live births. Its incidence varies from country to country. Molecular genetics having great interest and relevance in medical students, faculty, scientist, pediatric neurosurgeon and staff nurses, our objective was to educate the medical students, residents, researchers, clinicians, pediatric neurosurgeon, anesthetists, pediatricians, staff nurses and paramedics. We summarized here including with diagnosis, investigations, surgical therapy, induction therapy, and molecular therapy. Molecular genetics training is needed to know the information regarding development of skull, cranial connective tissue, craniofacial dysplasia, frame work, network of receptors and its etiopathogenesis. The important part is clinically with molecular therapy (MT) how to manage CS in rural sector and metropolitan cities need a special attention. PMID:25288859

  6. Strengthening molecular genetics and training in craniosynostosis: The need of the hour

    Directory of Open Access Journals (Sweden)

    Mayadhar Barik

    2014-01-01

    Full Text Available Craniosynostosis (CS is premature fusion of skull. It is divided into two groups: Syndromic craniosynostosis (SCS and non-syndromic craniosynostosis (NSC. Its incidence in Indian population is 1:1000 live births where as in the USA it is 1:2500 live births. Its incidence varies from country to country. Molecular genetics having great interest and relevance in medical students, faculty, scientist, pediatric neurosurgeon and staff nurses, our objective was to educate the medical students, residents, researchers, clinicians, pediatric neurosurgeon, anesthetists, pediatricians, staff nurses and paramedics. We summarized here including with diagnosis, investigations, surgical therapy, induction therapy, and molecular therapy. Molecular genetics training is needed to know the information regarding development of skull, cranial connective tissue, craniofacial dysplasia, frame work, network of receptors and its etiopathogenesis. The important part is clinically with molecular therapy (MT how to manage CS in rural sector and metropolitan cities need a special attention.

  7. DataGenno: building a new tool to bridge molecular and clinical genetics

    Directory of Open Access Journals (Sweden)

    Fabricio F Costa

    2011-03-01

    Full Text Available Fabricio F Costa1,2, Luciano S Foly1, Marcelo P Coutinho11DataGenno Interactive Research Ltd., Itaperuna, Rio de Janeiro, Brazil; 2Cancer Biology and Epigenomics Program, Children's Memorial Research Center, Northwestern University's Feinberg School of Medicine, Chicago, IL, USAAbstract: Clinical genetics is one of the most challenging fields in medicine, with thousands of children born every year with congenital defects that have no satisfactory diagnosis. There are more than 6,000 known single-gene disorders that can cause birth defects or diseases in approximately 1 in every 200 births. Clinical and molecular information on genetic diseases and syndromes are widespread in the literature, and there are few databases combining this information. Therefore, it is very challenging for health care professionals and researchers to translate the latest advances in science and medicine into effective clinical interventions and new treatments. In order to overcome this obstacle and promote networking, we are building DataGenno, an online medical and scientific portal. DataGenno has been developed to be a source of information on genetic diseases and syndromes for the needs of all heath care professionals and researchers. Our database will be able to integrate both clinical and molecular aspects of genetic diseases in a fully interactive environment. DataGenno’s system already contains clinical and molecular information for 300 diseases, with approximately 6,000 signs and symptoms of these diseases in a database combined with a search engine. Our main goal is to cover all genetic diseases described to date, providing not only clinical information such as morphological and anatomical features but also the most comprehensive molecular genetics/genomics features and available testing information. We are also developing ways to connect DataGenno’s portal with Electronic Health Records in order to improve the efficiency of patient care. Additionally

  8. A Short History and Description of Drosophila melanogaster Classical Genetics: Chromosome Aberrations, Forward Genetic Screens, and the Nature of Mutations.

    Science.gov (United States)

    Kaufman, Thomas C

    2017-06-01

    The purpose of this chapter in FlyBook is to acquaint the reader with the Drosophila genome and the ways in which it can be altered by mutation. Much of what follows will be familiar to the experienced Fly Pusher but hopefully will be useful to those just entering the field and are thus unfamiliar with the genome, the history of how it has been and can be altered, and the consequences of those alterations. I will begin with the structure, content, and organization of the genome, followed by the kinds of structural alterations (karyotypic aberrations), how they affect the behavior of chromosomes in meiotic cell division, and how that behavior can be used. Finally, screens for mutations as they have been performed will be discussed. There are several excellent sources of detailed information on Drosophila husbandry and screening that are recommended for those interested in further expanding their familiarity with Drosophila as a research tool and model organism. These are a book by Ralph Greenspan and a review article by John Roote and Andreas Prokop, which should be required reading for any new student entering a fly lab for the first time. Copyright © 2017 by the Genetics Society of America.

  9. Molecular population genetics of the β-esterase gene cluster of ...

    Indian Academy of Sciences (India)

    We suggest that the demographic history (bottleneck and admixture of genetically differentiated populations) is the major factor shaping the pattern of nucleotide polymorphism in the -esterase gene cluster. However there are some 'footprints' of directional and balancing selection shaping specific distribution of nucleotide ...

  10. [Molecular genetics in chronic myeloid leukemia with variant Ph translocation].

    Science.gov (United States)

    Wu, Wei; Li, Jian-yong; Zhu, Yu; Qiu, Hai-rong; Pan, Jin-lan; Xu, Wei; Chen, Li-juan; Shen, Yun-feng; Xue, Yong-quan

    2007-08-01

    To explore the value of fluorescence in situ hybridization (FISH) and multiplex fluorescence in situ hybridization (M-FISH) techniques in the detection of genetic changes in chronic myeloid leukemia (CML) with variant Philadelphia translocation (vPh). Cytogenetic preparations from 10 CML patients with vPh confirmed by R banding were assayed with dual color dual fusion FISH technique. If only one fusion signal was detected in interphase cells, metaphase cells were observed to determine if there were derivative chromosome 9[der (9)] deletions. Meanwhile, the same cytogenetic preparations were assayed with M-FISH technique. Of the 10 CML patients with vPh, 5 were detected with der (9) deletions by FISH technique. M-FISH technique revealed that besides the chromosome 22, chromosomes 1, 3, 5, 6, 8, 10, 11 and 17 were also involved in the vPh. M-FISH technique also detected the abnormalities which were not found with conventional cytogenetics (CC), including two never reported abnormalities. The combination of CC, FISH and M-FISH technique could refine the genetic diagnosis of CML with vPh.

  11. Genetic and molecular dosimetry of HZE radiation (US-1 RADIAT)

    Science.gov (United States)

    Nelson, Gregory A.; Schubert, W. W.; Kazarians, G. A.; Richards, G. F.; Benton, E. V.; Benton, E. R.; Henke, R. P.

    1995-01-01

    In order to estimate radiation exposure in space, experiments were conducted during the 1st International Microgravity Laboratory (IML-1) mission in order to isolate genetic changes in animal cells caused by cosmic rays. The space measurements were evaluated against results from synthetic cosmic rays produced by particle accelerators on the ground. The biological material used was the tiny soil nematode, Caenorhabditis elegans. The measurements were made by thermoluminescent detectors and plastic nuclear track detectors. The development and the chromosome mechanics in microgravity were studied, and the mutagenesis induced by radiation exposure was analyzed. The results showed that there are no obvious differences in the development, behavior and chromosome mechanics, as a function of gravity unloading (reproduction, self-fertilization and mating of males with hermaphrodites, gross anatomy, symmetry and gametogenesis, pairing, disjoining and recombination of chromosomes). A variety of mutants were isolated, and it was noted that mutants isolated from regions of identified high particles were more severely affected than those isolated by random screening. Linear energy transfer particles seem to favor large scale genetic lesions.

  12. Molecular genetics of cancer and tumorigenesis: Drosophila models

    Institute of Scientific and Technical Information of China (English)

    Wu-Min Deng

    2011-01-01

    Why do some cells not respond to normal control of cell division and become tumorous? Which signals trigger some tumor cells to migrate and colonize other tissues? What genetic factors are responsible for tumorigenesis and cancer development? What environmental factors play a role in cancer formation and progression? In how many ways can our bodies prevent and restrict the growth of cancerous cells?How can we identify and deliver effective drugs to fight cancer? In the fight against cancer,which kills more people than any other disease,these and other questions have long interested researchers from a diverse range of fields.To answer these questions and to fight cancer more effectively,we must increase our understanding of basic cancer biology.Model organisms,including the fruit fly Drosophila melanogaster,have played instrumental roles in our understanding of this devastating disease and the search for effective cures.Drosophila and its highly effective,easy-touse,and ever-expanding genetic tools have contributed toand enriched our knowledge of cancer and tumor formation tremendously.

  13. Genetic diversity and molecular characterization of Saccharomyces cerevisiae strains from winemaking environments

    OpenAIRE

    Schuller, Dorit Elisabeth

    2004-01-01

    Tese de doutoramento em Ciências The principal aim of the present work is to assess the genetic diversity of fermenting Saccharomyces cerevisiae strains found in vineyards belonging to the Vinho Verde Region in order to create a strain collection representing the region’s biodiversity wealth as a basis for future strain selection and improvement programs. Validation of molecular techniques for accurate genotyping is an indispensable prerequisite for biogeographical surveys. Molecular ty...

  14. Physiological, Molecular and Genetic Mechanisms of Long-Term Habituation

    Energy Technology Data Exchange (ETDEWEB)

    Calin-Jageman, Robert J

    2009-09-12

    Work funded on this grant has explored the mechanisms of long-term habituation, a ubiquitous form of learning that plays a key role in basic cognitive functioning. Specifically, behavioral, physiological, and molecular mechanisms of habituation have been explored using a simple model system, the tail-elicited siphon-withdrawal reflex (T-SWR) in the marine mollusk Aplysia californica. Substantial progress has been made on the first and third aims, providing some fundamental insights into the mechanisms by which memories are stored. We have characterized the physiological correlates of short- and long-term habituation. We found that short-term habituation is accompanied by a robust sensory adaptation, whereas long-term habituation is accompanied by alterations in sensory and interneuron synaptic efficacy. Thus, our data indicates memories can be shifted between different sites in a neural network as they are consolidated from short to long term. At the molecular level, we have accomplished microarray analysis comparing gene expression in both habituated and control ganglia. We have identified a network of putatively regulated transcripts that seems particularly targeted towards synaptic changes (e.g. SNAP25, calmodulin) . We are now beginning additional work to confirm regulation of these transcripts and build a more detailed understanding of the cascade of molecular events leading to the permanent storage of long-term memories. On the third aim, we have fostered a nascent neuroscience program via a variety of successful initiatives. We have funded over 11 undergraduate neuroscience scholars, several of whom have been recognized at national and regional levels for their research. We have also conducted a pioneering summer research program for community college students which is helping enhance access of underrepresented groups to life science careers. Despite minimal progress on the second aim, this project has provided a) novel insight into the network mechanisms by

  15. Radiation mutagenesis from molecular and genetic points of view

    International Nuclear Information System (INIS)

    Chen, D.J.C.; Park, M.S.; Okinaka, R.T.; Jaberaboansari, A.

    1993-01-01

    An important biological effect of ionizing radiation on living organisms is mutation induction. Mutation is also a primary event in the etiology of cancer. The chain events, from induction of DNA damage by ionizing radiation to processing of these damages by the cellular repair/replication machinery, that lead to mutation are not well understood. The development of quantitative methods for measuring mutation-induction, such as the HPRT system, in cultured mammalian cells has provided an estimate of the mutagenic effects of x- and γ-rays as wen as of high LET radiation in both rodent and human cells. A major conclusion from these mutagenesis data is that high LET radiation induces mutations more efficiently than g-rays. Molecular analysis of mutations induced by sparsely ionizing radiation have detected major structural alterations at the gene level. Our molecular results based on analysis of human HPRT deficient mutants induced by γ-rays, α-particles and high energy charged particles indicate that higher LET radiation induce more total and large deletion mutations than γ-rays. Utilizing molecular techniques including polymerase chain reaction (PCR), Single-strand conformation polymorphism (SSCP), denaturing gradient gel electrophoresis (DGGE) and Direct DNA sequencing, mutational spectra induced by ionizing radiation have been compared in different cell systems. Attempts have also been made to determine the mutagenic potential and the nature of mutation induced by low dose rate γ-rays. Defective repair, in the form of either a diminished capability for repair or inaccurate repair, can lead to increased risk of heritable mutations from radiation exposure. Therefore, the effects of DNA repair deficiency on the mutation induction in mammalian cells is reviewed

  16. Molecular genetic studies on some irradiated medicinal plants

    Energy Technology Data Exchange (ETDEWEB)

    Alam el-din, H.F.M

    2007-07-01

    This thesis aimed to study the molecular characterization , the phylogenetic relationships among the four mentha and the three ocimum species and to get some species-specific markers. twenty-one RAPD and 10 ISSR primers were used which showed high polymorphism among the species and detected 150 molecular markers for these genotypes (100 using RAPD and 50 by ISSR-analyses). detection of the phylogenetic relationships based on the three studied systems (RAPD,ISSR and their combined analyses ) indicated that these techniques succeeded in separating the seven species into two main clusters of the two mentha and ocimum genera. SDS-protein patterns characterized the seven genotypes based on presence/ absence and staining intensities of 14 polypeptide bands into two main groups.the effect of four doses of gamma irradiation on eight active components of volatile oils and SDS-protein pattern of stems of mentha viridis indicated that low levels of gamma irradiation could improve the value of some active components of medicinal plants such as menthol in mentha viridis.

  17. Molecular Genetics of Metal Detoxification: Prospects for Phytoremediation

    Energy Technology Data Exchange (ETDEWEB)

    Ow, David W. ow@pgec.ams.usda.gov

    2000-09-01

    Unlike compounds that can be broken down, the remediation of most heavy metals and radionuclides requires physical extraction from contaminated sources. Plants can extract inorganics, but effective phytoextraction requires plants that produce high biomass, grow rapidly and possess high capacity-uptake for the inorganic substance. Either hyperaccumulator plants must be bred for increased growth and biomass or hyperaccumulation traits must be engineered into fast growing, high biomass plants. This latter approach requires fundamental knowledge of the molecular mechanisms in the uptake and storage of inorganics. Much has been learned in recent years on how plants and certain fungi chelate and transport selected heavy metals. This progress has been facilitated by the use of Schizosaccharomyces pombe as a model system. The use of a model organism for study permits rapid characterization of the molecular process. As target genes are identified in a model organism, their sequences can be modified for expression in a heterologous host or aid in the search of homologous genes in more complex organisms. Moreover, as plant nutrient uptake is intrinsically linked to the association with rhizospheric fungi, elucidating metal sequestration in this fungus permits additional opportunities for engineering rhizospheric microbes to assist in phytoextraction.

  18. An update on molecular genetics of Alkaptonuria (AKU).

    Science.gov (United States)

    Zatkova, Andrea

    2011-12-01

    Alkaptonuria (AKU) is an autosomal recessive disorder caused by a deficiency of homogentisate 1,2 dioxygenase (HGD) and characterized by homogentisic aciduria, ochronosis, and ochronotic arthritis. The defect is caused by mutations in the HGD gene, which maps to the human chromosome 3q21-q23. AKU shows a very low prevalence (1:100,000-250,000) in most ethnic groups, but there are countries such as Slovakia and the Dominican Republic in which the incidence of this disorder rises to as much as 1:19,000. In this work, we summarize the genetic aspects of AKU in general and the distribution of all known disease-causing mutations reported so far. We focus on special features of AKU in Slovakia, which is one of the countries with an increased incidence of this rare metabolic disorder.

  19. Distribution, ecology, life history, genetic variation, and risk of extinction of nonhuman primates from Costa Rica

    Directory of Open Access Journals (Sweden)

    María E Zaldívar

    2004-09-01

    Full Text Available We examined the association between geographic distribution, ecological traits, life history, genetic diversity, and risk of extinction in nonhuman primate species from Costa Rica. All of the current nonhuman primate species from Costa Rica are included in the study; spider monkeys (Ateles geoffroyi, howling monkeys (Alouatta palliata, capuchins (Cebus capucinus, and squirrel monkeys (Saimiri oerstedii. Geographic distribution was characterized accessing existing databases. Data on ecology and life history traits were obtained through a literature review. Genetic diversity was characterized using isozyme electrophoresis. Risk of extinction was assessed from the literature. We found that species differed in all these traits. Using these data, we conducted a Pearson correlation between risk of extinction and ecological and life history traits, and genetic variation, for widely distributed species. We found a negative association between risk of extinction and population birth and growth rates; indicating that slower reproducing species had a greater risk of extinction. We found a positive association between genetic variation and risk of extinction; i.e., species showing higher genetic variation had a greater risk of extinction. The relevance of these traits for conservation efforts is discussed. Rev. Biol. Trop. 52(3: 679-693. Epub 2004 Dic 15.Se estudió la asociación entre la distribución geográfica, algunos rasgos ecológicos, las historias de vida, la diversidad genética y el riesgo de extinción, en primates no humanos de Costa Rica. Se incluyen todas las especies de primates no humanos del país: los monos araña (Ateles geoffroyi, congo (Alouatta palliata, cara blanca (Cebus capucinus, y tití (Saimiri oerstedii. La distribución geográfica se caracterizó utilizando principalmente bases de datos existentes. Se obtuvo información acerca de sus características ecológicas y de historias de vida mediante una revisión bibliogr

  20. Molecular genetic techniques for gene manipulation in Candida albicans.

    Science.gov (United States)

    Xu, Qiu-Rong; Yan, Lan; Lv, Quan-Zhen; Zhou, Mi; Sui, Xue; Cao, Yong-Bing; Jiang, Yuan-Ying

    2014-05-15

    Candida albicans is one of the most common fungal pathogen in humans due to its high frequency as an opportunistic and pathogenic fungus causing superficial as well as invasive infections in immunocompromised patients. An understanding of gene function in C. albicans is necessary to study the molecular basis of its pathogenesis, virulence and drug resistance. Several manipulation techniques have been used for investigation of gene function in C. albicans, including gene disruption, controlled gene expression, protein tagging, gene reintegration, and overexpression. In this review, the main cassettes containing selectable markers used for gene manipulation in C. albicans are summarized; the advantages and limitations of these cassettes are discussed concerning the influences on the target gene expression and the virulence of the mutant strains.

  1. The molecular genetics of the telomere biology disorders.

    Science.gov (United States)

    Bertuch, Alison A

    2016-08-02

    The importance of telomere function for human health is exemplified by a collection of Mendelian disorders referred to as the telomere biology disorders (TBDs), telomeropathies, or syndromes of telomere shortening. Collectively, the TBDs cover a spectrum of conditions from multisystem disease presenting in infancy to isolated disease presentations in adulthood, most notably idiopathic pulmonary fibrosis. Eleven genes have been found mutated in the TBDs to date, each of which is linked to some aspect of telomere maintenance. This review summarizes the molecular defects that result from mutations in these genes, highlighting recent advances, including the addition of PARN to the TBD gene family and the discovery of heterozygous mutations in RTEL1 as a cause of familial pulmonary fibrosis.

  2. Genetic diversity, outcrossing rate, and demographic history along a climatic gradient in the ruderal plant Ruellia nudiflora (Acanthaceae)

    OpenAIRE

    Vargas-Mendoza, Carlos F.; Ortegón-Campos, Ilka; Marrufo-Zapata, Denis; Herrera, Carlos M.; Parra-Tabla, Víctor

    2015-01-01

    Ruellia nudiflora has shown a high potential to easily invade disturbed areas. Outcrossing rate and genetic structure and diversity in this species were examined along a climatic gradient in the Yucatán Peninsula (Mexico) in order to understand the effects of environmental heterogeneity - isolation by environment (IBE) - as well as correlation in herkogamy on genetic structure, diversity, and demographic history in this species. Nine populations were sampled along a temperature-precipitation ...

  3. Scarlet Fever Upsurge in England and Molecular-Genetic Analysis in North-West London, 2014

    Centers for Disease Control (CDC) Podcasts

    2016-08-16

    Sarah Gregory reads an abridged version of the article, Scarlet Fever Upsurge in England and Molecular-Genetic Analysis in North-West London, 2014.  Created: 8/16/2016 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 8/16/2016.

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

    Directory of Open Access Journals (Sweden)

    Li Hai-Long

    2011-06-01

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

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

    Science.gov (United States)

    Ai, Lin; Chen, Mu-Xin; Alasaad, Samer; Elsheikha, Hany M; Li, Juan; Li, Hai-Long; Lin, Rui-Qing; Zou, Feng-Cai; Zhu, Xing-Quan; Chen, Jia-Xu

    2011-06-10

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

  6. Studying Human Disease Genes in "Caenorhabditis Elegans": A Molecular Genetics Laboratory Project

    Science.gov (United States)

    Cox-Paulson, Elisabeth A.; Grana, Theresa M.; Harris, Michelle A.; Batzli, Janet M.

    2012-01-01

    Scientists routinely integrate information from various channels to explore topics under study. We designed a 4-wk undergraduate laboratory module that used a multifaceted approach to study a question in molecular genetics. Specifically, students investigated whether "Caenorhabditis elegans" can be a useful model system for studying genes…

  7. the genetic and molecular basis of bacterial invasion of epithelial cells

    African Journals Online (AJOL)

    DR. AMINU

    The pathogenic species of bacteria are of great medical importance as causative agents of infectious diseases. Moreover, as the condition of human existence have changed, so have the bacterial species that produce diseases. It is against this background that molecular genetics have now entered the field of microbial ...

  8. Molecular genetic diversity of Punica granatum L. (pomegranate) as revealed by microsatellite DNA markers

    Science.gov (United States)

    Pomegranate (Punica granatum L.) is one of the oldest known edible fruits and more and more it arouse interest of scientific community given its numerous biological activities. However, information about its genetic resources and characterization using reliable molecular markers are still scarce. In...

  9. Genetics and molecular pathology of Stargardt-like macular degeneration.

    Science.gov (United States)

    Vasireddy, Vidyullatha; Wong, Paul; Ayyagari, Radha

    2010-05-01

    Stargardt-like macular degeneration (STGD3) is an early onset, autosomal dominant macular degeneration. STGD3 is characterized by a progressive pathology, the loss of central vision, atrophy of the retinal pigment epithelium, and accumulation of lipofuscin, clinical features that are also characteristic of age-related macular degeneration. The onset of clinical symptoms in STGD3, however, is typically observed within the second or third decade of life (i.e., starting in the teenage years). The clinical profile at any given age among STGD3 patients can be variable suggesting that, although STGD3 is a single gene defect, other genetic or environmental factors may play a role in moderating the final disease phenotype. Genetic studies localized the STGD3 disease locus to a small region on the short arm of human chromosome 6, and application of a positional candidate gene approach identified protein truncating mutations in the elongation of very long chain fatty acids-4 gene (ELOVL4) in patients with this disease. The ELOVL4 gene encodes a protein homologous to the ELO group of proteins that participate in fatty acid elongation in yeast. Pathogenic mutations found in the ELOVL4 gene result in altered trafficking of the protein and behave with a dominant negative effect. Mice carrying an Elovl4 mutation developed photoreceptor degeneration and depletion of very long chain fatty acids (VLCFA). ELOVL4 protein participates in the synthesis of fatty acids with chain length longer than 26 carbons. Studies on ELOVL4 indicate that VLCFA may be necessary for normal function of the retina, and the defective protein trafficking and/or altered VLCFA elongation underlies the pathology associated with STGD3. Determining the role of VLCFA in the retina and discerning the implications of abnormal trafficking of mutant ELOVL4 and depleted VLCFA content in the pathology of STGD3 will provide valuable insight in understanding the retinal structure, function, and pathology underlying STGD3

  10. "Like sugar in milk": reconstructing the genetic history of the Parsi population.

    Science.gov (United States)

    Chaubey, Gyaneshwer; Ayub, Qasim; Rai, Niraj; Prakash, Satya; Mushrif-Tripathy, Veena; Mezzavilla, Massimo; Pathak, Ajai Kumar; Tamang, Rakesh; Firasat, Sadaf; Reidla, Maere; Karmin, Monika; Rani, Deepa Selvi; Reddy, Alla G; Parik, Jüri; Metspalu, Ene; Rootsi, Siiri; Dalal, Kurush; Khaliq, Shagufta; Mehdi, Syed Qasim; Singh, Lalji; Metspalu, Mait; Kivisild, Toomas; Tyler-Smith, Chris; Villems, Richard; Thangaraj, Kumarasamy

    2017-06-14

    The Parsis are one of the smallest religious communities in the world. To understand the population structure and demographic history of this group in detail, we analyzed Indian and Pakistani Parsi populations using high-resolution genetic variation data on autosomal and uniparental loci (Y-chromosomal and mitochondrial DNA). Additionally, we also assayed mitochondrial DNA polymorphisms among ancient Parsi DNA samples excavated from Sanjan, in present day Gujarat, the place of their original settlement in India. Among present-day populations, the Parsis are genetically closest to Iranian and the Caucasus populations rather than their South Asian neighbors. They also share the highest number of haplotypes with present-day Iranians and we estimate that the admixture of the Parsis with Indian populations occurred ~1,200 years ago. Enriched homozygosity in the Parsi reflects their recent isolation and inbreeding. We also observed 48% South-Asian-specific mitochondrial lineages among the ancient samples, which might have resulted from the assimilation of local females during the initial settlement. Finally, we show that Parsis are genetically closer to Neolithic Iranians than to modern Iranians, who have witnessed a more recent wave of admixture from the Near East. Our results are consistent with the historically-recorded migration of the Parsi populations to South Asia in the 7th century and in agreement with their assimilation into the Indian sub-continent's population and cultural milieu "like sugar in milk". Moreover, in a wider context our results support a major demographic transition in West Asia due to the Islamic conquest.

  11. Chad Genetic Diversity Reveals an African History Marked by Multiple Holocene Eurasian Migrations.

    Science.gov (United States)

    Haber, Marc; Mezzavilla, Massimo; Bergström, Anders; Prado-Martinez, Javier; Hallast, Pille; Saif-Ali, Riyadh; Al-Habori, Molham; Dedoussis, George; Zeggini, Eleftheria; Blue-Smith, Jason; Wells, R Spencer; Xue, Yali; Zalloua, Pierre A; Tyler-Smith, Chris

    2016-12-01

    Understanding human genetic diversity in Africa is important for interpreting the evolution of all humans, yet vast regions in Africa, such as Chad, remain genetically poorly investigated. Here, we use genotype data from 480 samples from Chad, the Near East, and southern Europe, as well as whole-genome sequencing from 19 of them, to show that many populations today derive their genomes from ancient African-Eurasian admixtures. We found evidence of early Eurasian backflow to Africa in people speaking the unclassified isolate Laal language in southern Chad and estimate from linkage-disequilibrium decay that this occurred 4,750-7,200 years ago. It brought to Africa a Y chromosome lineage (R1b-V88) whose closest relatives are widespread in present-day Eurasia; we estimate from sequence data that the Chad R1b-V88 Y chromosomes coalesced 5,700-7,300 years ago. This migration could thus have originated among Near Eastern farmers during the African Humid Period. We also found that the previously documented Eurasian backflow into Africa, which occurred ∼3,000 years ago and was thought to be mostly limited to East Africa, had a more westward impact affecting populations in northern Chad, such as the Toubou, who have 20%-30% Eurasian ancestry today. We observed a decline in heterozygosity in admixed Africans and found that the Eurasian admixture can bias inferences on their coalescent history and confound genetic signals from adaptation and archaic introgression. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  12. Microsatellite DNA analysis of northern pike ( Esox lucius L.) populations: insights into the genetic structure and demographic history of a genetically depauperate species

    DEFF Research Database (Denmark)

    Jacobsen, B. H.; Hansen, Michael Møller; Loeschcke, V.

    2005-01-01

    The northern pike Esox lucius L. is a freshwater fish exhibiting pronounced population subdivision and low genetic variability. However, there is limited knowledge on phylogeographical patterns within the species, and it is not known whether the low genetic variability reflects primarily current...... low effective population sizes or historical bottlenecks. We analysed six microsatellite loci in ten populations from Europe and North America. Genetic variation was low, with the average number of alleles within populations ranging from 2.3 to 4.0 per locus. Genetic differentiation among populations...... was high (overall theta(ST) = 0.51; overall rho(ST) = 0.50). Multidimensional scaling analysis of genetic distances between populations and spatial analysis of molecular variance suggested a single phylogeographical race within the sampled populations from northern Europe, whereas North American...

  13. Molecular genetics of a Chinese family with spinocerebellar ataxia

    Directory of Open Access Journals (Sweden)

    Dan-dan WU

    2015-10-01

    Full Text Available Objective To study the genotype of the members of a Chinese family with spinocerebellar ataxia (SCA. Methods The peripheral blood samples of 6 patients and 40 asymptomatic people belonged to the family were collected. Referring to the clinical manifestations of the proband and second-generation sequencing results, the CAG trinucleotide repeats of the pathogenic gene ATXN2 were amplified by polymerase chain reaction (PCR. The repeated times of the trinucleotide in normally and abnormally amplified alleles were defined by agarose gel electrophoresis and PCR products sequencing. Results Autosomal dominant heredity was the cause of the SCA in this family. Six out of 46 in the fourth-generation were SCA2 patients, 7 were the carriers of pathogenic allele. The repeated times of CAG trinucleotide were within the normal range in one of the two alleles of ATXN2, but they were in abnormal range in the another one. The repeated times of CAG trinucleotide were 40-46 in abnormal alleles of patients. Conclusion Autosomal dominant heredity SCA2 has been diagnosed in this family caused by the dynamic nutation of CAG trinucleotide repeats, and 7 pathogenic allele carriers in this family were confirmed by genetic diagnosis. DOI: 10.11855/j.issn.0577-7402.2015.08.07

  14. Testing advances in molecular discrimination among Chinook salmon life histories: evidence from a blind test.

    Science.gov (United States)

    Banks, Michael A; Jacobson, David P; Meusnier, Isabelle; Greig, Carolyn A; Rashbrook, Vanessa K; Ardren, William R; Smith, Christian T; Bernier-Latmani, Jeremiah; Van Sickle, John; O'Malley, Kathleen G

    2014-06-01

    The application of DNA-based markers toward the task of discriminating among alternate salmon runs has evolved in accordance with ongoing genomic developments and increasingly has enabled resolution of which genetic markers associate with important life-history differences. Accurate and efficient identification of the most likely origin for salmon encountered during ocean fisheries, or at salvage from fresh water diversion and monitoring facilities, has far-reaching consequences for improving measures for management, restoration and conservation. Near-real-time provision of high-resolution identity information enables prompt response to changes in encounter rates. We thus continue to develop new tools to provide the greatest statistical power for run identification. As a proof of concept for genetic identification improvements, we conducted simulation and blind tests for 623 known-origin Chinook salmon (Oncorhynchus tshawytscha) to compare and contrast the accuracy of different population sampling baselines and microsatellite loci panels. This test included 35 microsatellite loci (1266 alleles), some known to be associated with specific coding regions of functional significance, such as the circadian rhythm cryptochrome genes, and others not known to be associated with any functional importance. The identification of fall run with unprecedented accuracy was demonstrated. Overall, the top performing panel and baseline (HMSC21) were predicted to have a success rate of 98%, but the blind-test success rate was 84%. Findings for bias or non-bias are discussed to target primary areas for further research and resolution. © 2014 The Authors. Animal Genetics published by John Wiley & Sons Ltd on behalf of Stichting International Foundation for Animal Genetics.

  15. Impact of Professional Learning on Teachers' Representational Strategies and Students' Cognitive Engagement with Molecular Genetics Concepts

    Science.gov (United States)

    Nichols, Kim

    2018-01-01

    A variety of practices and specialised representational systems are required to understand, communicate and construct molecular genetics knowledge. This study describes teachers' use of multimodal representations of molecular genetics concepts and how their strategies and choice of resources were interpreted, understood and used by students to…

  16. 76 FR 6623 - Molecular and Clinical Genetics Panel of the Medical Devices Advisory Committee; Notice of Meeting

    Science.gov (United States)

    2011-02-07

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2011-N-0066] Molecular and Clinical Genetics Panel of the Medical Devices Advisory Committee; Notice of Meeting AGENCY... public. Name of Committee: Molecular and Clinical Genetics Panel of the Medical Devices Advisory...

  17. Higher molecular weight dissolved organic nitrogen turnover as affected by soil management history

    DEFF Research Database (Denmark)

    Lønne Enggrob, Kirsten

    of different management histories on the turnover of high Mw DON. Further, we distinguished between several classes of high Mw DON, i.e., 1-10 kDa and >10 kDa. 3. Materials and methods With the use of micro-lysimeters, the turnover of triple-labeled (15N, 14C and 13C) high Mw DON was studied in a sandy soil......High molecular weight dissolved organic nitrogen turnover as affected by soil management history *Kirsten Lønne Enggrob,1 Lars Elsgaard,1 and Jim Rasmussen1 1Aarhus University, Dept. of Agroecology, Foulum, Denmark 1. Introduction Dissolved organic nitrogen (DON) play an important role in soil N...... are presented for 14CO2 evolution during 14 days of incubation. 4. Results and conclusion Results showed that the turnover rate of high Mw DON was dependent on both the Mw size of DON and on the soil liming history. Evidence showing where in the DON Mw sizes the bottleneck lies will be presented....

  18. Congenital heart disease and genetic syndromes: new insights into molecular mechanisms.

    Science.gov (United States)

    Calcagni, Giulio; Unolt, Marta; Digilio, Maria Cristina; Baban, Anwar; Versacci, Paolo; Tartaglia, Marco; Baldini, Antonio; Marino, Bruno

    2017-09-01

    Advances in genetics allowed a better definition of the role of specific genetic background in the etiology of syndromic congenital heart defects (CHDs). The identification of a number of disease genes responsible for different syndromes have led to the identification of several transcriptional regulators and signaling transducers and modulators that are critical for heart morphogenesis. Understanding the genetic background of syndromic CHDs allowed a better characterization of the genetic basis of non-syndromic CHDs. In this sense, the well-known association of typical CHDs in Down syndrome, 22q11.2 microdeletion and Noonan syndrome represent paradigms as chromosomal aneuploidy, chromosomal microdeletion and intragenic mutation, respectively. Area covered: For each syndrome the anatomical features, distinctive cardiac phenotype and molecular mechanisms are discussed. Moreover, the authors include recent genetic findings that may shed light on some aspects of still unclear molecular mechanisms of these syndromes. Expert commentary: Further investigations are needed to enhance the translational approach in the field of genetics of CHDs. When there is a well-established definition of genotype-phenotype (reverse medicine) and genotype-prognosis (predictive and personalized medicine) correlations, hopefully preventive medicine will make its way in this field. Subsequently a reduction will be achieved in the morbidity and mortality of children with CHDs.

  19. Genetic Confirmation of Mungbean (Vigna radiata) and Mashbean (Vigna mungo) Interspecific Recombinants using Molecular Markers.

    Science.gov (United States)

    Abbas, Ghulam; Hameed, Amjad; Rizwan, Muhammad; Ahsan, Muhammad; Asghar, Muhammad J; Iqbal, Nayyer

    2015-01-01

    Molecular confirmation of interspecific recombinants is essential to overcome the issues like self-pollination, environmental influence, and inadequacy of morphological characteristics during interspecific hybridization. The present study was conducted for genetic confirmation of mungbean (female) and mashbean (male) interspecific crosses using molecular markers. Initially, polymorphic random amplified polymorphic DNA (RAPD), universal rice primers (URP), and simple sequence repeats (SSR) markers differentiating parent genotypes were identified. Recombination in hybrids was confirmed using these polymorphic DNA markers. The NM 2006 × Mash 88 was most successful interspecific cross. Most of true recombinants confirmed by molecular markers were from this cross combination. SSR markers were efficient in detecting genetic variability and recombination with reference to specific chromosomes and particular loci. SSR (RIS) and RAPD identified variability dispersed throughout the genome. In conclusion, DNA based marker assisted selection (MAS) efficiently confirmed the interspecific recombinants. The results provided evidence that MAS can enhance the authenticity of selection in mungbean improvement program.

  20. [Molecular biology of renal cancer: bases for genetic directed therapy in advanced disease].

    Science.gov (United States)

    Maroto Rey, José Pablo; Cillán Narvaez, Elena

    2013-06-01

    There has been expansion of therapeutic options in the management of metastatic renal cell carcinoma due to a better knowledge of the molecular biology of kidney cancers. There are different tumors grouped under the term renal cell carcinoma, being clear cell cancer the most frequent and accounting for 80% of kidney tumors. Mutations in the Von Hippel-Lindau gene can be identified in up to 80% of sporadic clear cell cancer, linking a genetically inheritable disease where vascular tumors are frequent, with renal cell cancer. Other histologic types present specific alterations in molecular pathways, like c-MET in papillary type I tumors, and Fumarase Hydratase in papillary type II tumors. Identification of the molecular alteration for a specific tumor may offer an opportunity for treatment selection based on biomarkers, and, in the future, for developing an engineering designed genetic treatment.

  1. Molecular genetic approaches to the study of cellular senescence.

    Science.gov (United States)

    Goletz, T J; Smith, J R; Pereira-Smith, O M

    1994-01-01

    Cellular senescence is an inability of cells to synthesize DNA and divide, which results in a terminal loss of proliferation despite the maintenance of basic metabolic processes. Senescence has been proposed as a model for the study of aging at the cellular level, and the basis for this model system and its features have been summarized. Although strong experimental evidence exists to support the hypothesis that cellular senescence is a dominant active process, the mechanisms responsible for this phenomenon remain a mystery. Investigators have taken several approaches to gain a better understanding of senescence. Several groups have documented the differences between young and senescent cells, and others have identified changes that occur during the course of a cell's in vitro life span. Using molecular and biochemical approaches, important changes in gene expression and function of cell-cycle-associated products have been identified. The active production of an inhibitor of DNA synthesis has been demonstrated. This may represent the final step in a cascade of events governing senescence. The study of immortal cells which have escaped senescence has also provided useful information, particularly with regard to the genes governing the senescence program. These studies have identified four complementation groups for indefinite division, which suggests that there are at least four genes or gene pathways in the senescence program. Through the use of microcell-mediated chromosome transfer, chromosomes encoding senescence genes have been identified; efforts to clone these genes are ongoing.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Thermal histories of chondrules in solar nebula shocks, including the effect of molecular line cooling

    Science.gov (United States)

    Morris, Melissa A.

    Chondrules are millimeter-sized, silicate (mostly ferromagnesian) igneous spheres found within chondritic meteorites. They are some of the oldest materials in our Solar System, having formed within a few million years of its birth. Chondrules were melted at high temperature (over 1800 K), while they were free-floating objects in the early solar nebula. Their petrology and chemistry constrain their formation, especially their thermal histories. Chondrules provide some of the most powerful constraints on conditions in the solar nebula. Models in which chondrule precursors melted by passage through solar nebula shocks are very promising, and meet most constraints on chondrule formation in broad brush. However, these models have been lacking in some of the relevant physics. Previous shock models have used incorrect approximations to the input radiation boundary condition, and the opacity of solids has been treated simply. Most important, a proper treatment of cooling due to molecular line emission has not been included. In this thesis, the shock model is significantly improved in order to determine if it remains consistent with observational constraints. The appropriate boundary condition for the input radiation and the proper method for calculation of the opacity of solids are determined, and a complete treatment of molecular line cooling due to water is included. Previous estimates of the effect of line cooling predicted chondrule cooling rates in excess of 10,000 K per hour. However, once molecular line cooling due to water was incorporated into the full shock model, it was found that line cooling has a minimal effect on the thermal histories of gas and chondrules. This behavior is attributed mostly to the thermal buffering of the gas due to hydrogen dissociation and recombination, which tends to keep the gas temperature at approximately 2000 K until the column densities of water become optically thick to line emission. Chondrule cooling rates in the range of 10

  3. Delusional disorder: molecular genetic evidence for dopamine psychosis.

    Science.gov (United States)

    Morimoto, Kiyoshi; Miyatake, Ryosuke; Nakamura, Mitsuo; Watanabe, Takemi; Hirao, Toru; Suwaki, Hiroshi

    2002-06-01

    Since delusional disorder is characterized by mono-symptomatic paranoid symptoms, it can be a good clinical model for investigating the dopaminergic mechanism responsible for paranoid symptoms. We examined neuroleptic responses, plasma homovanillic acid (pHVA) and genes of the dopamine receptor (DR) and its synthesizing enzyme (tyrosine hydroxylase: TH) in patients with delusional disorder and compared them with those of schizophrenic patients and healthy controls. (1) A relatively small dose of haloperidol was more effective for delusional disorder than for schizophrenia. (2) The pretreatment level of pHVA was higher in patients with persecution-type, but not in those with jealousy-type delusional disorder, compared with age- and sex-matched controls. This increased pHVA level was decreased eight weeks after successful haloperidol treatment. (3) The genotype frequency of the DRD2 gene Ser311Cys was significantly higher in patients with persecution-type delusional disorder (21%), compared with schizophrenic patients (6%) or controls (6%). (4) Patients homozygous for the DRD3 gene Ser9Ser had higher pretreatment levels of pHVA than those heterozygous for Ser9Gly. (v) A significant positive correlation was found between the polymorphic (TCAT)(n) repeat in the first intron of the TH gene and pretreatment levels of pHVA in delusional disorder. We suggest that delusional disorder, especially the persecution-type, includes a "dopamine psychosis," and that polymorphism of the DRD2, DRD3 and/or TH gene is part of the genetic basis underlying the hyperdopaminergic state that produces paranoid symptoms. Further studies on a large sample size are required.

  4. Evolutionary history of genus Macrobrachium inferred from mitochondrial markers: a molecular clock approach.

    Science.gov (United States)

    Jose, Deepak; Harikrishnan, Mahadevan

    2018-04-17

    Caridea, an infraorder of shrimps coming under Pleocyemata was first reported from the oceans before 417 million years followed by their radiation recorded during the Permian period. Hitherto, about 3877 extant caridean species were accounted within which one quarter constitute freshwater species. Freshwater prawns of genus Macrobrachium (Infraorder Caridea; Family Palaemonidae), with more than 240 species are inhabitants of diverse aquatic habitats like coastal lagoons, lakes, tropical streams, ponds and rivers. Previous studies on Macrobrachium relied on the highly variable morphological characters which were insufficient for accurate diagnosis of natural species groups. Present study focuses on the utility of molecular markers (viz. COI and 16S rRNA) for resolving the evolutionary history of genus Macrobrachium using a combination of phylogeny and timescale components. It is for the first time a molecular clock approach had been carried out towards genus Macrobrachium in a broad aspect with the incorporation of congeners inhabiting diverse geographical realms including endemic species M. striatum from South West coast of India. Molecular results obtained revealed the phylogenetic relationships between congeners of genus Macrobrachium at intra/inter-continental level along with the corresponding evolutionary time estimates.

  5. Molecular and genetic substrates linking stress and addiction.

    Science.gov (United States)

    Briand, Lisa A; Blendy, Julie A

    2010-02-16

    Drug addiction is one of the top three health concerns in the United States in terms of economic and health care costs. Despite this, there are very few effective treatment options available. Therefore, understanding the causes and molecular mechanisms underlying the transition from casual drug use to compulsive drug addiction could aid in the development of treatment options. Studies in humans and animal models indicate that stress can lead to both vulnerability to develop addiction, and increased drug taking and relapse in addicted individuals. Exposure to stress or drugs of abuse results in long-term adaptations in the brain that are likely to involve persistent alterations in gene expression or activation of transcription factors, such as the cAMP Response Element Binding (CREB) protein. The signaling pathways controlled by CREB have been strongly implicated in drug addiction and stress. Many potential CREB target genes have been identified based on the presence of a CRE element in promoter DNA sequences. These include, but are not limited to CRF, BDNF, and dynorphin. These genes have been associated with initiation or reinstatement of drug reward and are altered in one direction or the other following stress. While many reviews have examined the interactions between stress and addiction, the goal of this review was to focus on specific molecules that play key roles in both stress and addiction and are therefore posed to mediate the interaction between the two. Focus on these molecules could provide us with new targets for pharmacological treatments for addiction. Copyright 2009 Elsevier B.V. All rights reserved.

  6. Strongly enhanced colorectal cancer risk stratification by combining family history and genetic risk score

    Directory of Open Access Journals (Sweden)

    Weigl K

    2018-01-01

    Full Text Available Korbinian Weigl,1,2 Jenny Chang-Claude,3,4 Phillip Knebel,5 Li Hsu,6 Michael Hoffmeister,1 Hermann Brenner1,2,7 1Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ, Heidelberg, 2German Cancer Consortium (DKTK, German Cancer Research Center (DKFZ, Heidelberg, 3Unit of Genetic Epidemiology, German Cancer Research Center (DKFZ, Heidelberg, 4University Cancer Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, 5Department for General, Visceral and Transplantation Surgery, University Heidelberg, Heidelberg, Germany; 6Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA; 7Division of Preventive Oncology, German Cancer Research Center (DKFZ and National Center for Tumor Diseases (NCT, Heidelberg, Germany Background and aim: Family history (FH and genetic risk scores (GRSs are increasingly used for risk stratification for colorectal cancer (CRC screening. However, they were mostly considered alternatively rather than jointly. The aim of this study was to assess the potential of individual and joint risk stratification for CRC by FH and GRS.Patients and methods: A GRS was built based on the number of risk alleles in 53 previously identified single-nucleotide polymorphisms among 2,363 patients with a first diagnosis of CRC and 2,198 controls in DACHS [colorectal cancer: chances for prevention through screening], a population-based case-control study in Germany. Associations between GRS and FH with CRC risk were quantified by multiple logistic regression.Results: A total of 316 cases (13.4% and 214 controls (9.7% had a first-degree relative (FDR with CRC (adjusted odds ratio [aOR] 1.86, 95% CI 1.52–2.29. A GRS in the highest decile was associated with a 3.0-fold increased risk of CRC (aOR 3.00, 95% CI 2.24–4.02 compared with the lowest decile. This association was tentatively more pronounced in older age groups. FH and GRS were essentially unrelated, and their

  7. Molecular mechanisms of the genetic risk factors in pathogenesis of Alzheimer disease.

    Science.gov (United States)

    Kanatsu, Kunihiko; Tomita, Taisuke

    2017-01-01

    Alzheimer disease (AD) is a neurodegenerative disease characterized by the extensive deposition of senile plaques and neurofibrillary tangles. Until recently, only the APOE gene had been known as a genetic risk factor for late-onset AD (LOAD), which accounts for more than 95% of all AD cases. However, in addition to this well-established genetic risk factor, genome-wide association studies have identified several single nucleotide polymorphisms as genetic risk factors of LOAD, such as PICALM and BIN1 . In addition, whole genome sequencing and exome sequencing have identified rare variants associated with LOAD, including TREM2 . We review the recent findings related to the molecular mechanisms by which these genetic risk factors contribute to AD, and our perspectives regarding the etiology of AD for the development of therapeutic agents.

  8. Genetic diversity and structure of tea plant in Qinba area in China by three types of molecular markers.

    Science.gov (United States)

    Zhang, Yu; Zhang, Xiaojuan; Chen, Xi; Sun, Wang; Li, Jiao

    2018-01-01

    Qinba area has a long history of tea planting and is a northernmost region in China where Camellia sinensis L. is grown. In order to provide basic data for selection and optimization of molecular markers of tea plants. 118 markers, including 40 EST-SSR, 40 SRAP and 38 SCoT markers were used to evaluate the genetic diversity of 50 tea plant ( Camellia sinensis. ) samples collected from Qinb. tea germplasm, assess population structure. In this study, a total of 414 alleles were obtained using 38 pairs of SCoT primers, with an average of 10.89 alleles per primer. The percentage of polymorphic bands (PPB), polymorphism information content (PIC), resolving power (Rp), effective multiplex ratio (EMR), average band informativeness (Ib av ), and marker index (MI) were 96.14%, 0.79, 6.71, 10.47, 0.58, and 6.07 respectively. 338 alleles were amplified via 40 pairs of SRAP (8.45 per primer), with PPB, PIC, Rp, EMR, Ib av, and MI values of 89.35%, 0.77, 5.11, 7.55, 0.61, and 4.61, respectively. Furthermore, 320 alleles have been detected using 40 EST-SSR primers (8.00 per primer), with PPB, PIC, Rp, EMR, Ib av , and MI values of 94.06%, 0.85, 4.48, 7.53, 0.56, and 4.22 respectively. These results indicated that SCoT markers had higher efficiency.Mantel test was used to analyze the genetic distance matrix generated by EST-SSRs, SRAPs and SCoTs. The results showed that the correlation between the genetic distance matrix based on EST-SSR and that based on SRAP was very small ( r  = 0.01), followed by SCoT and SRAP ( r  = 0.17), then by SCoT and EST-SSR ( r  = 0.19).The 50 tea samples were divided into two sub-populations using STRUCTURE, Neighbor-joining (NJ) method and principal component analyses (PCA). The results produced by STRUCTURE were completely consistent with the PCA analysis. Furthermore, there is no obvious relationship between the results produced using sub-populational and geographical data. Among the three types of markers, SCoT markers has many

  9. Chemical Genetics — A Versatile Method to Combine Science and Higher Level Teaching in Molecular Genetics

    Directory of Open Access Journals (Sweden)

    Björn Sandrock

    2012-10-01

    Full Text Available Phosphorylation is a key event in many cellular processes like cell cycle, transformation of environmental signals to transcriptional activation or polar growth. The chemical genetics approach can be used to analyse the effect of highly specific inhibition in vivo and is a promising method to screen for kinase targets. We have used this approach to study the role of the germinal centre kinase Don3 during the cell division in the phytopathogenic fungus Ustilago maydis. Due to the easy determination of the don3 phenotype we have chosen this approach for a genetic course for M.Sc. students and for IMPRS (International Max-Planck research school students. According to the principle of “problem-based learning” the aim of this two-week course is to transfer knowledge about the broad spectrum of kinases to the students and that the students acquire the ability to design their own analog-sensitive kinase of interest. In addition to these training goals, we benefit from these annual courses the synthesis of basic constructs for genetic modification of several kinases in our model system U. maydis.

  10. An ancient Mediterranean melting pot: investigating the uniparental genetic structure and population history of sicily and southern Italy.

    Directory of Open Access Journals (Sweden)

    Stefania Sarno

    Full Text Available Due to their strategic geographic location between three different continents, Sicily and Southern Italy have long represented a major Mediterranean crossroad where different peoples and cultures came together over time. However, its multi-layered history of migration pathways and cultural exchanges, has made the reconstruction of its genetic history and population structure extremely controversial and widely debated. To address this debate, we surveyed the genetic variability of 326 accurately selected individuals from 8 different provinces of Sicily and Southern Italy, through a comprehensive evaluation of both Y-chromosome and mtDNA genomes. The main goal was to investigate the structuring of maternal and paternal genetic pools within Sicily and Southern Italy, and to examine their degrees of interaction with other Mediterranean populations. Our findings show high levels of within-population variability, coupled with the lack of significant genetic sub-structures both within Sicily, as well as between Sicily and Southern Italy. When Sicilian and Southern Italian populations were contextualized within the Euro-Mediterranean genetic space, we observed different historical dynamics for maternal and paternal inheritances. Y-chromosome results highlight a significant genetic differentiation between the North-Western and South-Eastern part of the Mediterranean, the Italian Peninsula occupying an intermediate position therein. In particular, Sicily and Southern Italy reveal a shared paternal genetic background with the Balkan Peninsula and the time estimates of main Y-chromosome lineages signal paternal genetic traces of Neolithic and post-Neolithic migration events. On the contrary, despite showing some correspondence with its paternal counterpart, mtDNA reveals a substantially homogeneous genetic landscape, which may reflect older population events or different demographic dynamics between males and females. Overall, both uniparental genetic

  11. Regulating Intracellular Calcium in Plants: From Molecular Genetics to Physiology

    International Nuclear Information System (INIS)

    Sze, Heven

    2008-01-01

    To grow, develop, adapt, and reproduce, plants have evolved mechanisms to regulate the uptake, translocation and sorting of calcium ions into different cells and subcellular compartments. Yet how plants accomplish this remarkable feat is still poorly understood. The spatial and temporal changes in intracellular (Ca2+) during growth and during responses to hormonal and environmental stimuli indicate that Ca2+ influx and efflux transporters are diverse and tightly regulated in plants. The specific goals were to determine the biological roles of multiple Ca pumps (ECAs) in the model plant Arabidopsis thaliana. We had pioneered the use of K616 yeast strain to functionally express plant Ca pumps, and demonstrated two distinct types of Ca pumps in plants (Sze et al., 2000. Annu Rev Plant Biol. 51,433). ACA2 represented one type that was auto-inhibited by the N-terminal region and stimulated by calmodulin. ECA1 represented another type that was not sensitive to calmodulin and phylogenetically distinct from ACAs. The goal to determine the biological roles of multiple ECA-type Ca pumps in Arabidopsis has been accomplished. Although we demonstrated ECA1 was a Ca pump by functional expression in yeast, the in vivo roles of ECAs was unclear. A few highlights are described. ECA1 and/or ECA4 are Ca/Mn pumps localized to the ER and are highly expressed in all cell types. Using homozygous T-DNA insertional mutants of eca1, we demonstrated that the ER-bound ECA1 supports growth and confers tolerance of plants growing on medium low in Ca or containing toxic levels of Mn. This is the first genetic study to determine the in vivo function of a Ca pump in plants. A phylogenetically distinct ECA3 is also a Ca/Mn pump that is localized to endosome, such as post-Golgi compartments. Although it is expressed at lower levels than ECA1, eca3 mutants are impaired in Ca-dependent root growth and in pollen tube elongation. Increased secretion of wall proteins in mutants suggests that Ca and Mn

  12. Molecular and genetic epidemiology of cancer in low- and medium-income countries.

    Science.gov (United States)

    Malhotra, Jyoti

    2014-01-01

    Genetic and molecular factors can play an important role in an individual's cancer susceptibility and response to carcinogen exposure. Cancer susceptibility and response to carcinogen exposure can be either through inheritance of high penetrance but rare germline mutations that constitute heritable cancer syndromes, or it can be inherited as common genetic variations or polymorphisms that are associated with low to moderate risk for development of cancer. These polymorphisms can interact with environmental exposures and can influence an individual's cancer risk through multiple pathways, including affecting the rate of metabolism of carcinogens or the immune response to these toxins. Thus, these genetic polymorphisms can account for some of the geographical differences seen in cancer prevalence between different populations. This review explores the role of molecular epidemiology in the field of cancer prevention and control in low- and medium-income countries. Using data from Human Genome Project and HapMap Project, genome-wide association studies have been able to identify multiple susceptibility loci for different cancers. The field of genetic and molecular epidemiology has been further revolutionized by the discovery of newer, faster, and more efficient DNA-sequencing technologies including next-generation sequencing. The new DNA-sequencing technologies can play an important role in planning and implementation of cancer prevention and screening strategies. More research is needed in this area, especially in investigating new biomarkers and measuring gene-environment interactions. Copyright © 2014 Icahn School of Medicine at Mount Sinai. Published by Elsevier Inc. All rights reserved.

  13. Genetic and life-history trait variation of the amphipod Melita plumulosa from polluted and unpolluted waterways in eastern Australia

    International Nuclear Information System (INIS)

    Chung, Pann Pann; Hyne, Ross V.; Mann, Reinier M.; Ballard, J. William O.

    2008-01-01

    To monitor genetic diversity and environmental contamination in eastern Australia, toxicity studies have employed the sensitive benthic amphipod Melita plumulosa. The goal of this study was to examine the genetic and life-history variability of natural populations of M. plumulosa from the Parramatta (polluted) and Hawkesbury (unpolluted) Rivers. The underlying genetics of the populations in these distinct waterways was examined at one mitochondrial (cytochrome c oxidase subunit I (COI)) and one nuclear (ribosomal internal transcribed spacer region 1 (ITS1)) locus. Seven unique haplotypes for COI were found amongst animals from the Parramatta River, while animals from the Hawkesbury River showed a complete absence of genetic variation at this locus. At ITS1 a total of two sequence variants were found amongst Parramatta River amphipods and three sequence variants among Hawkesbury River animals, with no common variants across the two river systems. To establish whether genetic differences were associated with organismal responses to toxicant exposure, two life-history trait variables (female head length as an estimator of amphipod size and female fecundity) were analyzed. Life-history trait analyses showed that females from the Hawkesbury River were significantly larger and more fecund. These data have critical implications for toxicity tests, the use of laboratory cultures for testing purposes, and environmental contamination in Sydney Harbor

  14. Genetic and life-history trait variation of the amphipod Melita plumulosa from polluted and unpolluted waterways in eastern Australia

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Pann Pann [Evolution and Ecology Research Centre, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney 2052 (Australia); Hyne, Ross V. [Ecotoxicology and Environmental Contaminants Section, NSW Department of Environment and Climate Change, PO Box 29, Lidcombe, NSW 1825 (Australia); Mann, Reinier M. [Centre for Ecotoxicology, Department of Environmental Sciences, University of Technology-Sydney, C/-PO Box 29, Lidcombe, NSW 1825 (Australia); Ballard, J. William O. [Evolution and Ecology Research Centre, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney 2052 (Australia)], E-mail: w.ballard@unsw.edu.au

    2008-09-15

    To monitor genetic diversity and environmental contamination in eastern Australia, toxicity studies have employed the sensitive benthic amphipod Melita plumulosa. The goal of this study was to examine the genetic and life-history variability of natural populations of M. plumulosa from the Parramatta (polluted) and Hawkesbury (unpolluted) Rivers. The underlying genetics of the populations in these distinct waterways was examined at one mitochondrial (cytochrome c oxidase subunit I (COI)) and one nuclear (ribosomal internal transcribed spacer region 1 (ITS1)) locus. Seven unique haplotypes for COI were found amongst animals from the Parramatta River, while animals from the Hawkesbury River showed a complete absence of genetic variation at this locus. At ITS1 a total of two sequence variants were found amongst Parramatta River amphipods and three sequence variants among Hawkesbury River animals, with no common variants across the two river systems. To establish whether genetic differences were associated with organismal responses to toxicant exposure, two life-history trait variables (female head length as an estimator of amphipod size and female fecundity) were analyzed. Life-history trait analyses showed that females from the Hawkesbury River were significantly larger and more fecund. These data have critical implications for toxicity tests, the use of laboratory cultures for testing purposes, and environmental contamination in Sydney Harbor.

  15. Teaching Molecular Biology with Microcomputers.

    Science.gov (United States)

    Reiss, Rebecca; Jameson, David

    1984-01-01

    Describes a series of computer programs that use simulation and gaming techniques to present the basic principles of the central dogma of molecular genetics, mutation, and the genetic code. A history of discoveries in molecular biology is presented and the evolution of these computer assisted instructional programs is described. (MBR)

  16. The Molecular Epidemiology and Genetic Environment of Carbapenemases Detected in Africa.

    Science.gov (United States)

    Sekyere, John Osei; Govinden, Usha; Essack, Sabiha

    2016-01-01

    Research articles describing carbapenemases and their genetic environments in Gram-negative bacteria were reviewed to determine the molecular epidemiology of carbapenemases in Africa. The emergence of resistance to the carbapenems, the last resort antibiotic for difficult to treat bacterial infections, affords clinicians few therapeutic options, with a resulting increase in morbidities, mortalities, and healthcare costs. However, the molecular epidemiology of carbapenemases throughout Africa is less described. Research articles and conference proceedings describing the genetic environment and molecular epidemiology of carbapenemases in Africa were retrieved from Google Scholar, Scifinder, Pubmed, Web of Science, and Science Direct databases. Predominant carbapenemase genes so far described in Africa include the blaOXA-48 type, blaIMP, blaVIM, and blaNDM in Acinetobacter baumannii, Klebsiella pneumoniae, Enterobacter cloacae, Citrobacter spp., and Escherichia coli carried on various plasmid types and sizes, transposons, and integrons. Class D and class B carbapenemases, mainly prevalent in A. baumannii, K. pneumoniae, E. cloacae, Citrobacter spp., and E. coli were the commonest carbapenemases. Carbapenemases are mainly reported in North and South Africa as under-resourced laboratories, lack of awareness and funding preclude the detection and reporting of carbapenemase-mediated resistance. Consequently, the true molecular epidemiology of carbapenemases and their genetic environment in Africa is still unknown.

  17. Molecular genetics and genomics generate new insights into invertebrate pest invasions.

    Science.gov (United States)

    Kirk, Heather; Dorn, Silvia; Mazzi, Dominique

    2013-07-01

    Invertebrate pest invasions and outbreaks are associated with high social, economic, and ecological costs, and their significance will intensify with an increasing pressure on agricultural productivity as a result of human population growth and climate change. New molecular genetic and genomic techniques are available and accessible, but have been grossly underutilized in studies of invertebrate pest invasions, despite that they are useful tools for applied pest management and for understanding fundamental features of pest invasions including pest population demographics and adaptation of pests to novel and/or changing environments. Here, we review current applications of molecular genetics and genomics in the study of invertebrate pest invasions and outbreaks, and we highlight shortcomings from the current body of research. We then discuss recent conceptual and methodological advances in the areas of molecular genetics/genomics and data analysis, and we highlight how these advances will further our understanding of the demographic, ecological, and evolutionary features of invertebrate pest invasions. We are now well equipped to use molecular data to understand invertebrate dispersal and adaptation, and this knowledge has valuable applications in agriculture at a time when these are critically required.

  18. Impacts of biogeographic history and marginal population genetics on species range limits: a case study of Liriodendron chinense.

    Science.gov (United States)

    Yang, Aihong; Dick, Christopher W; Yao, Xiaohong; Huang, Hongwen

    2016-05-10

    Species ranges are influenced by past climate oscillations, geographical constraints, and adaptive potential to colonize novel habitats at range limits. This study used Liriodendron chinense, an important temperate Asian tree species, as a model system to evaluate the roles of biogeographic history and marginal population genetics in determining range limits. We examined the demographic history and genetic diversity of 29 L. chinense populations using both chloroplast and nuclear microsatellite loci. Significant phylogeographic structure was recovered with haplotype clusters coinciding with major mountain regions. Long-term demographical stability was suggested by mismatch distribution analyses, neutrality tests, and ecological niche models (ENM) and suggested the existence of LGM refuges within mountain regions. Differences in genetic diversity between central and marginal populations were not significant for either genomic region. However, asymmetrical gene flow was inferred from central populations to marginal populations, which could potentially limit range adaptation and expansion of L. chinense.

  19. Genetic Diversity Analysis of Tagetes Species Using PCR Based Molecular Markers

    International Nuclear Information System (INIS)

    Shahzadi, I.; Ahmad, R.; Waheed, U.; Shah, M. F.

    2016-01-01

    Tagetes is a genus of medicinally important wild and cultivated plants containing several chemical compounds. Lack of information on variation at molecular level present in Tagetes species is paramount to understand the genetic basis of medicinally important compounds. Current study aims at finding genetic variability in Tagetes species using random and specific molecular markers. Two primer systems including 25 RAPD and 3 STS (limonene gene) were used to ascertain genetic diversity of 15 Tagetes genotypes belonging to different species. We found that 20 of the 25 tested RAPD primers generated stable band patterns with 167 loci of amplification products. The proportion of polymorphic bands was 95.21 percent for RAPD primers. Three STS primers generated a total of 29 amplification products, of which 96.55 percent were polymorphic. Homology of genotypes was 53.18 percent and 51.11 percent with RAPD and STS primers respectively. The dendrogram obtained revealed that the range of overall genetic distances estimated was 22 percent to 100 percent through RAPD and 9 percent to 100 percent through STS markers. The findings help to establish that PCR-based assay such as RAPD and STS could be used successfully for estimation of genetic diversity of different genotypes of Tagetes that can be used for selection of parents for improvement of the species. (author)

  20. Molecular Insights into the Genetic Diversity of Garcinia cambogia Germplasm Accessions

    Directory of Open Access Journals (Sweden)

    C Tharachand

    2015-10-01

    Full Text Available ABSTRACTIn this work, the genetic relationship among twelveGarcinia cambogia (Gaertn. Desr. accessions were evaluated using Random Amplified Polymorphic DNA markers. The samples were part of the germplasm collected and maintained at NBPGR Regional station, Thrissur, India. Out of thirty RAPD primers used for screening, seven primers produced a total of 128 polymorphic markers in twelve accessions. The Polymorphic Information Content (PIC ranged from 0.28 (OPA18 to 0.37 (OPA9 and Marker Index (MI ranged between 3.61 (OPA12 and 5.93 (OPA3 among the primers used. Jaccard's coefficient of genetic similarity ranged between 0.07 and 0.64. The dendrogram constructed based on the similarity matrix generated from the molecular and morphological data showed the genetic relationship among the sampled accessions. Mantel matrix test showed a positive correlation (r = 0.49 between the cluster analysis of RAPD data and morphological data. The clustering pattern in the molecular dendrogram and Principle Coordinate Analysis (PCoA showed that the genotypes were diverse, which was in congruence with the similarity index values and morphological dendrogram. High frequency of similarity values in the range of 0.11 to 0.17 suggested the existence of high genetic diversity among the accessions. The high level of genetic diversity among the studied accessions ofG.cambogia was also supported by the large variation in the morphological characters observed in the flowers, leaves, fruits and seeds of these sampled accessions. This is the first report for the molecular based genetic diversity studies for these accessions.

  1. Molecular and genetic insights into an infantile epileptic encephalopathy – CDKL5 disorder

    Science.gov (United States)

    Zhou, Ailing; Han, Song

    2017-01-01

    Background The discovery that mutations in cyclin-dependent kinase-like 5 (CDKL5) gene are associated with infantile epileptic encephalopathy has stimulated world-wide research effort to understand the molecular and genetic basis of CDKL5 disorder. Given the large number of literature published thus far, this review aims to summarize current genetic studies, draw a consensus on proposed molecular functions, and point to gaps of knowledge in CDKL5 research. Methods A systematic review process was conducted using the PubMed search engine focusing on CDKL5 studies in the recent ten years. We analyzed these publications and summarized the findings into four sections: genetic studies, CDKL5 expression patterns, molecular functions, and animal models. We also discussed challenges and future directions in each section. Results On the clinical side, CDKL5 disorder is characterized by early onset epileptic seizures, intellectual disability, and stereotypical behaviors. On the research side, a series of molecular and genetic studies in human patients, cell cultures and animal models have established the causality of CDKL5 to the infantile epileptic encephalopathy, and pointed to a key role for CDKL5 in regulating neuronal function in the brain. Mouse models of CDKL5 disorder have also been developed, and notably, manifest behavioral phenotypes, mimicking numerous clinical symptoms of CDKL5 disorder and advancing CDKL5 research to the preclinical stage. Conclusions Given what we have learned thus far, future identification of robust, quantitative, and sensitive outcome measures would be the key in animal model studies, particularly in heterozygous females. In the meantime, molecular and cellular studies of CDKL5 should focus on mechanism-based investigation and aim to uncover druggable targets that offer the potential to rescue or ameliorate CDKL5 disorder-related phenotypes. PMID:28580010

  2. Molecular and genetic insights into an infantile epileptic encephalopathy - CDKL5 disorder.

    Science.gov (United States)

    Zhou, Ailing; Han, Song; Zhou, Zhaolan Joe

    2017-02-01

    The discovery that mutations in cyclin-dependent kinase-like 5 ( CDKL5 ) gene are associated with infantile epileptic encephalopathy has stimulated world-wide research effort to understand the molecular and genetic basis of CDKL5 disorder. Given the large number of literature published thus far, this review aims to summarize current genetic studies, draw a consensus on proposed molecular functions, and point to gaps of knowledge in CDKL5 research. A systematic review process was conducted using the PubMed search engine focusing on CDKL5 studies in the recent ten years. We analyzed these publications and summarized the findings into four sections: genetic studies, CDKL5 expression patterns, molecular functions, and animal models. We also discussed challenges and future directions in each section. On the clinical side, CDKL5 disorder is characterized by early onset epileptic seizures, intellectual disability, and stereotypical behaviors. On the research side, a series of molecular and genetic studies in human patients, cell cultures and animal models have established the causality of CDKL5 to the infantile epileptic encephalopathy, and pointed to a key role for CDKL5 in regulating neuronal function in the brain. Mouse models of CDKL5 disorder have also been developed, and notably, manifest behavioral phenotypes, mimicking numerous clinical symptoms of CDKL5 disorder and advancing CDKL5 research to the preclinical stage. Given what we have learned thus far, future identification of robust, quantitative, and sensitive outcome measures would be the key in animal model studies, particularly in heterozygous females. In the meantime, molecular and cellular studies of CDKL5 should focus on mechanism-based investigation and aim to uncover druggable targets that offer the potential to rescue or ameliorate CDKL5 disorder-related phenotypes.

  3. Molecular and genetic insights into an infantile epileptic encephalopathy-CDKL5 disorder

    Institute of Scientific and Technical Information of China (English)

    Ailing Zhou; Song Han; Zhaolan Joe Zhou

    2017-01-01

    BACKGROUND:The discovery that mutations in cyclin-dependent kinase-like 5 (CDKL5) gene are associated with infantile epileptic encephalopathy has stimulated world-wide research effort to understand the molecular and genetic basis of CDKL5 disorder.Given the large number of literature published thus far,this review aims to summarize current genetic studies,draw a consensus on proposed molecular functions,and point to gaps of knowledge in CDKL5 research.METHODS:A systematic review process was conducted using the PubMed search engine focusing on CDKL5 studies in the recent ten years.We analyzed these publications and summarized the findings into four sections:genetic studies,CDKL5 expression pattems,molecular functions,and animal models.We also discussed challenges and future directions in each section.RESULTS:On the clinical side,CDKL5 disorder is characterized by early onset epileptic seizures,intellectual disability,and stereotypical behaviors.On the research side,a series of molecular and genetic studies in human patients,cell cultures and animal models have established the causality of CDKL5 to the infantile epileptic encephalopathy,and pointed to a key role for CDKL5 in regulating neuronal function in the brain.Mouse models of CDKL5 disorder have also been developed,and notably,manifest behavioral phenotypes,mimicking numerous clinical symptoms of CDKL5 disorder and advancing CDKL5 research to the preclinical stage.CONCLUSIONS:Given what we have leamed thus far,future identification of robust,quantitative,and sensitive outcome measures would be the key in animal model studies,particularly in heterozygous females.In the meantime,molecular and cellular studies of CDKL5 should focus on mechanism-based investigation and aim to uncover druggable targets that offer the potential to rescue or ameliorate CDKL5 disorder-related phenotypes.

  4. Environmental Catastrophes in the Earth's History Due to Solar Systems Encounters with Giant Molecular Clouds

    Science.gov (United States)

    Pavlov, Alexander A.

    2011-01-01

    In its motion through the Milky Way galaxy, the solar system encounters an average density (>=330 H atoms/cubic cm) giant molecular cloud (GMC) approximately every 108 years, a dense (approx 2 x 103 H atoms/cubic cm) GMC every approx 109 years and will inevitably encounter them in the future. However, there have been no studies linking such events with severe (snowball) glaciations in Earth history. Here we show that dramatic climate change can be caused by interstellar dust accumulating in Earth's atmosphere during the solar system's immersion into a dense (approx ,2 x 103 H atoms/cubic cm) GMC. The stratospheric dust layer from such interstellar particles could provide enough radiative forcing to trigger the runaway ice-albedo feedback that results in global snowball glaciations. We also demonstrate that more frequent collisions with less dense GMCs could cause moderate ice ages.

  5. Targeted association mapping demonstrating the complex molecular genetics of fatty acid formation in soybean.

    Science.gov (United States)

    Li, Ying-hui; Reif, Jochen C; Ma, Yan-song; Hong, Hui-long; Liu, Zhang-xiong; Chang, Ru-zhen; Qiu, Li-juan

    2015-10-23

    The relative abundance of five dominant fatty acids (FAs) (palmitic, stearic, oleic, linoleic and linolenic acids) is a major factor determining seed quality in soybean. To clarify the currently poorly understood genetic architecture of FAs in soybean, targeted association analysis was conducted in 421 diverse accessions phenotyped in three environments and genotyped using 1536 pre-selected SNPs. The population of 421 soybean accessions displayed significant genetic variation for each FA. Analysis of the molecular data revealed three subpopulations, which reflected a trend depending on latitude of cultivation. A total of 37 significant (p seed quality of soybean with benefits for human health and for food processing.

  6. Molecular genetic diversity of the Saccharomyces yeasts in Taiwan: Saccharomyces arboricola, Saccharomyces cerevisiae and Saccharomyces kudriavzevii.

    Science.gov (United States)

    Naumov, Gennadi I; Lee, Ching-Fu; Naumova, Elena S

    2013-01-01

    Genetic hybridization, sequence and karyotypic analyses of natural Saccharomyces yeasts isolated in different regions of Taiwan revealed three biological species: Saccharomyces arboricola, Saccharomyces cerevisiae and Saccharomyces kudriavzevii. Intraspecies variability of the D1/D2 and ITS1 rDNA sequences was detected among S. cerevisiae and S. kudriavzevii isolates. According to molecular and genetic analyses, the cosmopolitan species S. cerevisiae and S. kudriavzevii contain local divergent populations in Taiwan, Malaysia and Japan. Six of the seven known Saccharomyces species are documented in East Asia: S. arboricola, S. bayanus, S. cerevisiae, S. kudriavzevii, S. mikatae, and S. paradoxus.

  7. Molecular markers for genetic diversity, gene flow and genetic population structure of freshwater mussel species

    Directory of Open Access Journals (Sweden)

    AB Choupina

    Full Text Available Freshwater mussel species are in global decline. Anthropogenic changes of river channels and the decrease of autochthonous fish population, the natural hosts of mussels larval stages (glochidia, are the main causes. Therefore, the conservation of mussel species depends not only on habitat conservation, but also on the availability of the fish host. In Portugal, information concerning most of the mussel species is remarkably scarce. One of the most known species, Unio pictorum is also in decline however, in the basins of the rivers Tua and Sabor (Northeast of Portugal, there is some indication of relatively large populations. The aforementioned rivers can be extremely important for this species conservation not only in Portugal, but also in the remaining Iberian Peninsula. Thus, it is important to obtain data concerning Unio pictorum bioecology (distribution, habitat requirements, population structure, genetic variability, reproductive cycle and recruitment rates, as well as the genetic variability and structure of the population. Concomitantly, information concerning fish population structure, the importance of the different fish species as “glochidia” hosts and their appropriate density to allow effective mussel recruitment, will also be assessed. The achieved data is crucial to obtain information to develop effective management measures in order to promote the conservation of this bivalve species, the conservation of autochthonous fish populations, and consequently the integrity of the river habitats.

  8. Epidemiology, genetic, natural history and clinical presentation of giant cerebral aneurysms.

    Science.gov (United States)

    Lonjon, M; Pennes, F; Sedat, J; Bataille, B

    2015-12-01

    Giant cerebral aneurysms represent 5% of intracranial aneurysms, and become symptomatic between 40 and 70 years with a female predominance. In the paediatric population, the giant aneurysm rate is higher than in the adult population. Classified as saccular, fusiform and serpentine, the natural history of giant cerebral aneurysms is characterized by thrombosis, growth and rupture. The pathogenesis of these giant aneurysms is influenced by a number of risk factors, including genetic variables. Genome-wide association studies have identified some chromosomes highlighting candidate genes. Although these giant aneurysms can occur at the same locations as their smaller counterparts, a predilection for the cavernous location has been observed. Giant aneurysms present with symptoms caused by a mass effect depending on their location or by rupture; ischemic manifestations rarely reveal the aneurysm. If the initial clinical descriptions have been back up by imagery, the clinical context with a pertinent analysis of the risk factors remain the cornerstone for the management decisions of these lesions. Five year cumulative rupture rates for patients with giant aneurysm were 40% for those located on the anterior part of circle of Willis and 50% for those on the posterior part. The poor outcome of untreated patients justifies the therapeutic risks. Copyright © 2015. Published by Elsevier Masson SAS.

  9. The genomic ancestry, landscape genetics and invasion history of introduced mice in New Zealand

    Science.gov (United States)

    Russell, James C.; King, Carolyn M.

    2018-01-01

    The house mouse (Mus musculus) provides a fascinating system for studying both the genomic basis of reproductive isolation, and the patterns of human-mediated dispersal. New Zealand has a complex history of mouse invasions, and the living descendants of these invaders have genetic ancestry from all three subspecies, although most are primarily descended from M. m. domesticus. We used the GigaMUGA genotyping array (approximately 135 000 loci) to describe the genomic ancestry of 161 mice, sampled from 34 locations from across New Zealand (and one Australian city—Sydney). Of these, two populations, one in the south of the South Island, and one on Chatham Island, showed complete mitochondrial lineage capture, featuring two different lineages of M. m. castaneus mitochondrial DNA but with only M. m. domesticus nuclear ancestry detectable. Mice in the northern and southern parts of the North Island had small traces (approx. 2–3%) of M. m. castaneus nuclear ancestry, and mice in the upper South Island had approximately 7–8% M. m. musculus nuclear ancestry including some Y-chromosomal ancestry—though no detectable M. m. musculus mitochondrial ancestry. This is the most thorough genomic study of introduced populations of house mice yet conducted, and will have relevance to studies of the isolation mechanisms separating subspecies of mice. PMID:29410804

  10. The genomic ancestry, landscape genetics and invasion history of introduced mice in New Zealand.

    Science.gov (United States)

    Veale, Andrew J; Russell, James C; King, Carolyn M

    2018-01-01

    The house mouse ( Mus musculus ) provides a fascinating system for studying both the genomic basis of reproductive isolation, and the patterns of human-mediated dispersal. New Zealand has a complex history of mouse invasions, and the living descendants of these invaders have genetic ancestry from all three subspecies, although most are primarily descended from M. m. domesticus . We used the GigaMUGA genotyping array (approximately 135 000 loci) to describe the genomic ancestry of 161 mice, sampled from 34 locations from across New Zealand (and one Australian city-Sydney). Of these, two populations, one in the south of the South Island, and one on Chatham Island, showed complete mitochondrial lineage capture, featuring two different lineages of M. m. castaneus mitochondrial DNA but with only M. m. domesticus nuclear ancestry detectable. Mice in the northern and southern parts of the North Island had small traces (approx. 2-3%) of M. m. castaneus nuclear ancestry, and mice in the upper South Island had approximately 7-8% M. m. musculus nuclear ancestry including some Y-chromosomal ancestry-though no detectable M. m. musculus mitochondrial ancestry. This is the most thorough genomic study of introduced populations of house mice yet conducted, and will have relevance to studies of the isolation mechanisms separating subspecies of mice.

  11. Natural and molecular history of prolactinoma: insights from a Prlr-/- mouse model.

    Science.gov (United States)

    Bernard, Valérie; Villa, Chiara; Auguste, Aurélie; Lamothe, Sophie; Guillou, Anne; Martin, Agnès; Caburet, Sandrine; Young, Jacques; Veitia, Reiner A; Binart, Nadine

    2018-01-19

    Lactotroph adenoma, also called prolactinoma, is the most common pituitary tumor but little is known about its pathogenesis. Mouse models of prolactinoma can be useful to better understand molecular mechanisms involved in abnormal lactotroph cell proliferation and secretion. We have previously developed a prolactin receptor deficient ( Prlr -/- ) mouse, which develops prolactinoma. The present study aims to explore the natural history of prolactinoma formation in Prlr -/- mice, using hormonal, radiological, histological and molecular analyses to uncover mechanisms involved in lactotroph adenoma development. Prlr -/- females develop large secreting prolactinomas from 12 months of age, with a penetrance of 100%, mimicking human aggressive densely granulated macroprolactinoma, which is a highly secreting subtype. Mean blood PRL measurements reach 14 902 ng/mL at 24 months in Prlr -/- females while PRL levels were below 15 ng/mL in control mice ( p model in ACI rats, we pinpointed 218 concordantly differentially expressed (DE) genes involved in cell cycle, mitosis, cell adhesion molecules, dopaminergic synapse and estrogen signaling. Pathway/gene-set enrichment analyses suggest that the transcriptomic dysregulation in both models of prolactinoma might be mediated by a limited set of transcription factors (i.e., STAT5, STAT3, AhR, ESR1, BRD4, CEBPD, YAP, FOXO1) and kinases (i.e., JAK2, AKT1, BRAF, BMPR1A, CDK8, HUNK, ALK, FGFR1, ILK). Our experimental results and their bioinformatic analysis provide insights into early genomic changes in murine models of the most frequent human pituitary tumor.

  12. Abundant genetic overlap between blood lipids and immune-mediated diseases indicates shared molecular genetic mechanisms.

    Directory of Open Access Journals (Sweden)

    Ole A Andreassen

    Full Text Available Epidemiological studies suggest a relationship between blood lipids and immune-mediated diseases, but the nature of these associations is not well understood. We used genome-wide association studies (GWAS to investigate shared single nucleotide polymorphisms (SNPs between blood lipids and immune-mediated diseases. We analyzed data from GWAS (n~200,000 individuals, applying new False Discovery Rate (FDR methods, to investigate genetic overlap between blood lipid levels [triglycerides (TG, low density lipoproteins (LDL, high density lipoproteins (HDL] and a selection of archetypal immune-mediated diseases (Crohn's disease, ulcerative colitis, rheumatoid arthritis, type 1 diabetes, celiac disease, psoriasis and sarcoidosis. We found significant polygenic pleiotropy between the blood lipids and all the investigated immune-mediated diseases. We discovered several shared risk loci between the immune-mediated diseases and TG (n = 88, LDL (n = 87 and HDL (n = 52. Three-way analyses differentiated the pattern of pleiotropy among the immune-mediated diseases. The new pleiotropic loci increased the number of functional gene network nodes representing blood lipid loci by 40%. Pathway analyses implicated several novel shared mechanisms for immune pathogenesis and lipid biology, including glycosphingolipid synthesis (e.g. FUT2 and intestinal host-microbe interactions (e.g. ATG16L1. We demonstrate a shared genetic basis for blood lipids and immune-mediated diseases independent of environmental factors. Our findings provide novel mechanistic insights into dyslipidemia and immune-mediated diseases and may have implications for therapeutic trials involving lipid-lowering and anti-inflammatory agents.

  13. Genetic diversity and structure related to expansion history and habitat isolation: stone marten populating rural-urban habitats.

    Science.gov (United States)

    Wereszczuk, Anna; Leblois, Raphaël; Zalewski, Andrzej

    2017-12-22

    Population genetic diversity and structure are determined by past and current evolutionary processes, among which spatially limited dispersal, genetic drift, and shifts in species distribution boundaries have major effects. In most wildlife species, environmental modifications by humans often lead to contraction of species' ranges and/or limit their dispersal by acting as environmental barriers. However, in species well adapted to anthropogenic habitat or open landscapes, human induced environmental changes may facilitate dispersal and range expansions. In this study, we analysed whether isolation by distance and deforestation, among other environmental features, promotes or restricts dispersal and expansion in stone marten (Martes foina) populations. We genotyped 298 martens from eight sites at twenty-two microsatellite loci to characterize the genetic variability, population structure and demographic history of stone martens in Poland. At the landscape scale, limited genetic differentiation between sites in a mosaic of urban, rural and forest habitats was mostly influenced by isolation by distance. Statistical clustering and multivariate analyses showed weak genetic structuring with two to four clusters and a high rate of gene flow between them. Stronger genetic differentiation was detected for one stone marten population (NE1) located inside a large forest complex. Genetic differentiation between this site and all others was 20% higher than between other sites separated by similar distances. The genetic uniqueness index of NE1 was also twofold higher than in other sites. Past demographic history analyses showed recent expansion of this species in north-eastern Poland. A decrease in genetic diversity from south to north, and MIGRAINE analyses indicated the direction of expansion of stone marten. Our results showed that two processes, changes in species distribution boundaries and limited dispersal associated with landscape barriers, affect genetic diversity and

  14. Deciphering molecular circuits from genetic variation underlying transcriptional responsiveness to stimuli.

    Science.gov (United States)

    Gat-Viks, Irit; Chevrier, Nicolas; Wilentzik, Roni; Eisenhaure, Thomas; Raychowdhury, Raktima; Steuerman, Yael; Shalek, Alex K; Hacohen, Nir; Amit, Ido; Regev, Aviv

    2013-04-01

    Individual genetic variation affects gene responsiveness to stimuli, often by influencing complex molecular circuits. Here we combine genomic and intermediate-scale transcriptional profiling with computational methods to identify variants that affect the responsiveness of genes to stimuli (responsiveness quantitative trait loci or reQTLs) and to position these variants in molecular circuit diagrams. We apply this approach to study variation in transcriptional responsiveness to pathogen components in dendritic cells from recombinant inbred mouse strains. We identify reQTLs that correlate with particular stimuli and position them in known pathways. For example, in response to a virus-like stimulus, a trans-acting variant responds as an activator of the antiviral response; using RNA interference, we identify Rgs16 as the likely causal gene. Our approach charts an experimental and analytic path to decipher the mechanisms underlying genetic variation in circuits that control responses to stimuli.

  15. Tracing the Trans-Pacific Evolutionary History of a Domesticated Seaweed (Gracilaria chilensis) with Archaeological and Genetic Data

    Science.gov (United States)

    Guillemin, Marie-Laure; Valero, Myriam; Faugeron, Sylvain; Nelson, Wendy; Destombe, Christophe

    2014-01-01

    The history of a domesticated marine macroalga is studied using archaeological, phylogeographic and population genetic tools. Phylogeographic and population genetic analyses demonstrated that the cultivated red alga Gracilaria chilensis colonised the Chilean coast from New Zealand. Combining archaeological observations with phylogeographic data provided evidence that exchanges between New Zealand and Chile have occurred at least before the Holocene, likely at the end of the Last Glacial Maximum (LGM) and we suggest that migration probably occurred via rafting. Furthermore, the remarkably low microsatellite diversity found in the Chilean populations compared to those in New Zealand is consistent with a recent genetic bottleneck as a result of over-exploitation of natural populations and/or the process of domestication. Therefore, the aquaculture of this seaweed, based essentially on clonal propagation, is occurring from genetically depressed populations and may be driving the species to an extinction vortex in Chile. PMID:25501717

  16. Molecular epidemiology and evolutionary genetics of Mycobacterium tuberculosis in Taipei

    OpenAIRE

    Su Ih-Jen; Lee Shi-Yi; Tsai Wen-Shing; Sun Jun-Ren; Chang Jia-Ru; Lin Chih-Wei; Tseng Fan-Chen; Dou Horng-Yunn; Lu Jang-Jih

    2008-01-01

    Abstract Background The control of tuberculosis in densely populated cities is complicated by close human-to-human contacts and potential transmission of pathogens from multiple sources. We conducted a molecular epidemiologic analysis of 356 Mycobacterium tuberculosis (MTB) isolates from patients presenting pulmonary tuberculosis in metropolitan Taipei. Classical antibiogram studies and genetic characterization, using mycobacterial interspersed repetitive-unit-variable-number tandem-repeat (M...

  17. A Report on Molecular Diagnostic Testing for Inherited Retinal Dystrophies by Targeted Genetic Analyses.

    Science.gov (United States)

    Ramkumar, Hema L; Gudiseva, Harini V; Kishaba, Kameron T; Suk, John J; Verma, Rohan; Tadimeti, Keerti; Thorson, John A; Ayyagari, Radha

    2017-02-01

    To test the utility of targeted sequencing as a method of clinical molecular testing in patients diagnosed with inherited retinal degeneration (IRD). After genetic counseling, peripheral blood was drawn from 188 probands and 36 carriers of IRD. Single gene testing was performed on each patient in a Clinical Laboratory Improvement Amendment (CLIA) certified laboratory. DNA was isolated, and all exons in the gene of interest were analyzed along with 20 base pairs of flanking intronic sequence. Genetic testing was most often performed on ABCA4, CTRP5, ELOV4, BEST1, CRB1, and PRPH2. Pathogenicity of novel sequence changes was predicted by PolyPhen2 and sorting intolerant from tolerant (SIFT). Of the 225 genetic tests performed, 150 were for recessive IRD, and 75 were for dominant IRD. A positive molecular diagnosis was made in 70 (59%) of probands with recessive IRD and 19 (26%) probands with dominant IRD. Analysis confirmed 12 (34%) of individuals as carriers of familial mutations associated with IRD. Thirty-two novel variants were identified; among these, 17 sequence changes in four genes were predicted to be possibly or probably damaging including: ABCA4 (14), BEST1 (2), PRPH2 (1), and TIMP3 (1). Targeted analysis of clinically suspected genes in 225 subjects resulted in a positive molecular diagnosis in 26% of patients with dominant IRD and 59% of patients with recessive IRD. Novel damaging mutations were identified in four genes. Single gene screening is not an ideal method for diagnostic testing given the phenotypic and genetic heterogeneity among IRD cases. High-throughput sequencing of all genes associated with retinal degeneration may be more efficient for molecular diagnosis.

  18. Molecular causes and consequences of genetic instability with respect to the FA/BRCA Caretaker Pathway

    OpenAIRE

    Neveling, Kornelia

    2012-01-01

    In the context of this thesis, I investigated the molecular causes and functional consequences of genetic instability using a human inherited disease, Fanconi anemia. FA patients display a highly variable clinical phenotype, including congenital abnormalities, progressive bone marrow failure and a high cancer risk. The FA cellular phenotype is characterized by spontaneous and inducible chromosomal instability, and a typical S/G2 phase arrest after exposure to DNA-damaging agents. So far, 13 g...

  19. The influence of small dose radiation on some molecular and genetic parameters of peripheral blood lymphocytes

    International Nuclear Information System (INIS)

    Mel'nov, S.B.; Morozik, P.M.

    2001-01-01

    About 70% of Chernobyl radionuclide fallout was spread on the territory of Belarus. As a result, 2,5 million people now are living in contaminated areas under the pressure of the additional influence of low dose radiation. The aim of the current research is to definite the effects of this factor on some molecular and genetic characteristics of the children - prominent residents of the contaminated areas

  20. [Noonan syndrome can be diagnosed clinically and through molecular genetic analyses].

    Science.gov (United States)

    Henningsen, Marie Krab; Jelsig, Anne Marie; Andersen, Helle; Brusgaard, Klaus; Ousager, Lilian Bomme; Hertz, Jens Michael

    2015-08-03

    Noonan syndrome is part of the group of RASopathies caused by germ line mutations in genes involved in the RAS/MAPK pathway. There is substantial phenotypic overlap among the RASopathies. Diagnosis of Noonan syndrome is often based on clinical features including dysmorphic facial features, short stature and congenital heart disease. Rapid advances in sequencing technology have made molecular genetic analyses a helpful tool in diagnosing and distinguishing Noonan syndrome from other RASopathies.

  1. Molecular and Genetic Investigation of Tau in Chronic Traumatic Encephalopathy (Log No. 13267017)

    Science.gov (United States)

    2017-10-01

    AWARD NUMBER: W81XWH-14-1-0399 TITLE: Molecular & Genetic Investigation of Tau in Chronic Traumatic Encephalopathy (Log No. 13267017) PRINCIPAL...this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data ...sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden

  2. Molecular Genetic Insights on Cheetah (Acinonyx jubatus) Ecology and Conservation in Namibia

    OpenAIRE

    Marker, Laurie L.; Wilkerson, Alison J. Pearks; Sarno, Ronald J.; Martenson, Janice; Breitenmoser-Würsten, Christian; O'Brien, Stephen J.; Johnson, Warren E.

    2017-01-01

    The extent and geographic patterns of molecular genetic diversity of the largest remaining free-ranging cheetah population were described in a survey of 313 individuals from throughout Namibia. Levels of relatedness, including paternity/maternity (parentage), were assessed across all individuals using 19 polymorphic microsatellite loci, and unrelated cheetahs (n = 89) from 7 regions were genotyped at 38 loci to document broad geographical patterns. There was limited differentiation among regi...

  3. Molecular Genetic Methods Implementation for Phytopathogen Identification in Forest Stands and Nurseries of the Russian Federation

    Directory of Open Access Journals (Sweden)

    T. S. Alimova

    2014-08-01

    Full Text Available The results of the application of molecular genetics methods for the analysis of the plant pathogens present in forest plantations and nurseries of the Russian Federation, including doughnut fungus and annosum root rot are presented. The prospects and benefits of using DNA analysis for early diagnosis of plant diseases without isolation of the pathogen in pure culture, shortening time of analysis, and the possibility of mass screening are discussed.

  4. Quality control in mutation analysis: the European Molecular Genetics Quality Network (EMQN).

    Science.gov (United States)

    Müller, C R

    2001-08-01

    The demand for clinical molecular genetics testing has steadily grown since its introduction in the 1980s. In order to reach and maintain the agreed quality standards of laboratory medicine, the same internal and external quality assurance (IQA/EQA) criteria have to be applied as for "conventional" clinical chemistry or pathology. In 1996 the European Molecular Genetics Quality Network (EMQN) was established in order to spread QA standards across Europe and to harmonise the existing national activities. EMQN is operated by a central co-ordinator and 17 national partners from 15 EU countries; since 1998 it is being funded by the EU commission for a 3-year period. EMQN promotes QA by two tools: by providing disease-specific best practice meetings (BPM) and EQA schemes. A typical BPM is focussed on one disease or group of related disorders. International experts report on the latest news of gene characterisation and function and the state-of-the-art techniques for mutation detection. Disease-specific EQA schemes are provided by experts in the field. DNA samples are sent out together with mock clinical referrals and a diagnostic question is asked. Written reports must be returned which are marked for genotyping and interpretation. So far, three BPMs have been held and six EQA schemes are in operation at various stages. Although mutation types and diagnostic techniques varied considerably between schemes, the overall technical performance showed a high diagnostic standard. Nevertheless, serious genotyping errors have been occurred in some schemes which underline the necessity of quality assurance efforts. The European Molecular Genetics Quality Network provides a necessary platform for the internal and external quality assurance of molecular genetic testing.

  5. Molecular genetic analysis of activation-tagged transcription factors thought to be involved in photomorphogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Neff, Michael M.

    2011-06-23

    This is a final report for Department of Energy Grant No. DE-FG02-08ER15927 entitled “Molecular Genetic Analysis of Activation-Tagged Transcription Factors Thought to be Involved in Photomorphogenesis”. Based on our preliminary photobiological and genetic analysis of the sob1-D mutant, we hypothesized that OBP3 is a transcription factor involved in both phytochrome and cryptochrome-mediated signal transduction. In addition, we hypothesized that OBP3 is involved in auxin signaling and root development. Based on our preliminary photobiological and genetic analysis of the sob2-D mutant, we also hypothesized that a related gene, LEP, is involved in hormone signaling and seedling development.

  6. Progress in the molecular and genetic modification breeding of beef cattle in China.

    Science.gov (United States)

    Tong, Bin; Zhang, Li; Li, Guang-Peng

    2017-11-20

    The studies of beef cattle breeding in China have been greatly improved with the rapid development of the international beef cattle industrialization. The beef cattle breeding technologies have rapidly transformed from traditional breeding to molecular marker-assisted breeding, genomic selection and genetic modification breeding. Hundreds of candidate genes and molecular markers associated with growth, meat quality, reproduction performance and diseases resistance have been identified, and some of them have already been used in cattle breeding. Genes and molecular markers associated with growth and development are focused on the growth hormone, muscle regulatory factors, myostatin and insulin-like growth factors. Meat quality is mediated by fatty acid transport and deposition related signals, calpains and calpain system, muscle regulatory factors and muscle growth regulation pathways. Reproduction performance is regulated by GnRH-FSH-LH, growth differentiation factor 9, prolactin receptor and forkhead box protein O1. Disease resistance is modulated by the major histocompatibility complex gene family, toll-like receptors, mannose-binding lectin and interferon gene signals. In this review, we summarize the most recent progress in beef cattle breeding in marker-assisted selection, genome-wide selection and genetic modification breeding, aiming to provide a reference for further genetic breeding research of beef cattle in China.

  7. Genetic structure and hierarchical population divergence history of Acer mono var. mono in South and Northeast China.

    Directory of Open Access Journals (Sweden)

    Chunping Liu

    Full Text Available Knowledge of the genetic structure and evolutionary history of tree species across their ranges is essential for the development of effective conservation and forest management strategies. Acer mono var. mono, an economically and ecologically important maple species, is extensively distributed in Northeast China (NE, whereas it has a scattered and patchy distribution in South China (SC. In this study, the genetic structure and demographic history of 56 natural populations of A. mono var. mono were evaluated using seven nuclear microsatellite markers. Neighbor-joining tree and STRUCTURE analysis clearly separated populations into NE and SC groups with two admixed-like populations. Allelic richness significantly decreased with increasing latitude within the NE group while both allelic richness and expected heterozygosity showed significant positive correlation with latitude within the SC group. Especially in the NE region, previous studies in Quercus mongolica and Fraxinus mandshurica have also detected reductions in genetic diversity with increases in latitude, suggesting this pattern may be common for tree species in this region, probably due to expansion from single refugium following the last glacial maximum (LGM. Approximate Bayesian Computation-based analysis revealed two major features of hierarchical population divergence in the species' evolutionary history. Recent divergence between the NE group and the admixed-like group corresponded to the LGM period and ancient divergence of SC groups took place during mid-late Pleistocene period. The level of genetic differentiation was moderate (FST  = 0.073; G'ST  = 0.278 among all populations, but significantly higher in the SC group than the NE group, mirroring the species' more scattered distribution in SC. Conservation measures for this species are proposed, taking into account the genetic structure and past demographic history identified in this study.

  8. A portrait of a sucker using landscape genetics: how colonization and life history undermine the idealized dendritic metapopulation.

    Science.gov (United States)

    Salisbury, Sarah J; McCracken, Gregory R; Keefe, Donald; Perry, Robert; Ruzzante, Daniel E

    2016-09-01

    Dendritic metapopulations have been attributed unique properties by in silico studies, including an elevated genetic diversity relative to a panmictic population of equal total size. These predictions have not been rigorously tested in nature, nor has there been full consideration of the interacting effects among contemporary landscape features, colonization history and life history traits of the target species. We tested for the effects of dendritic structure as well as the relative importance of life history, environmental barriers and historical colonization on the neutral genetic structure of a longnose sucker (Catostomus catostomus) metapopulation in the Kogaluk watershed of northern Labrador, Canada. Samples were collected from eight lakes, genotyped with 17 microsatellites, and aged using opercula. Lakes varied in differentiation, historical and contemporary connectivity, and life history traits. Isolation by distance was detected only by removing two highly genetically differentiated lakes, suggesting a lack of migration-drift equilibrium and the lingering influence of historical factors on genetic structure. Bayesian analyses supported colonization via the Kogaluk's headwaters. The historical concentration of genetic diversity in headwaters inferred by this result was supported by high historical and contemporary effective sizes of the headwater lake, T-Bone. Alternatively, reduced allelic richness in headwaters confirmed the dendritic structure's influence on gene flow, but this did not translate to an elevated metapopulation effective size. A lack of equilibrium and upstream migration may have dampened the effects of dendritic structure. We suggest that interacting historical and contemporary factors prevent the achievement of the idealized traits of a dendritic metapopulation in nature. © 2016 John Wiley & Sons Ltd.

  9. Genetic structure and hierarchical population divergence history of Acer mono var. mono in South and Northeast China.

    Science.gov (United States)

    Liu, Chunping; Tsuda, Yoshiaki; Shen, Hailong; Hu, Lijiang; Saito, Yoko; Ide, Yuji

    2014-01-01

    Knowledge of the genetic structure and evolutionary history of tree species across their ranges is essential for the development of effective conservation and forest management strategies. Acer mono var. mono, an economically and ecologically important maple species, is extensively distributed in Northeast China (NE), whereas it has a scattered and patchy distribution in South China (SC). In this study, the genetic structure and demographic history of 56 natural populations of A. mono var. mono were evaluated using seven nuclear microsatellite markers. Neighbor-joining tree and STRUCTURE analysis clearly separated populations into NE and SC groups with two admixed-like populations. Allelic richness significantly decreased with increasing latitude within the NE group while both allelic richness and expected heterozygosity showed significant positive correlation with latitude within the SC group. Especially in the NE region, previous studies in Quercus mongolica and Fraxinus mandshurica have also detected reductions in genetic diversity with increases in latitude, suggesting this pattern may be common for tree species in this region, probably due to expansion from single refugium following the last glacial maximum (LGM). Approximate Bayesian Computation-based analysis revealed two major features of hierarchical population divergence in the species' evolutionary history. Recent divergence between the NE group and the admixed-like group corresponded to the LGM period and ancient divergence of SC groups took place during mid-late Pleistocene period. The level of genetic differentiation was moderate (FST  = 0.073; G'ST  = 0.278) among all populations, but significantly higher in the SC group than the NE group, mirroring the species' more scattered distribution in SC. Conservation measures for this species are proposed, taking into account the genetic structure and past demographic history identified in this study.

  10. Genetic Structure and Hierarchical Population Divergence History of Acer mono var. mono in South and Northeast China

    Science.gov (United States)

    Shen, Hailong; Hu, Lijiang; Saito, Yoko; Ide, Yuji

    2014-01-01

    Knowledge of the genetic structure and evolutionary history of tree species across their ranges is essential for the development of effective conservation and forest management strategies. Acer mono var. mono, an economically and ecologically important maple species, is extensively distributed in Northeast China (NE), whereas it has a scattered and patchy distribution in South China (SC). In this study, the genetic structure and demographic history of 56 natural populations of A. mono var. mono were evaluated using seven nuclear microsatellite markers. Neighbor-joining tree and STRUCTURE analysis clearly separated populations into NE and SC groups with two admixed-like populations. Allelic richness significantly decreased with increasing latitude within the NE group while both allelic richness and expected heterozygosity showed significant positive correlation with latitude within the SC group. Especially in the NE region, previous studies in Quercus mongolica and Fraxinus mandshurica have also detected reductions in genetic diversity with increases in latitude, suggesting this pattern may be common for tree species in this region, probably due to expansion from single refugium following the last glacial maximum (LGM). Approximate Bayesian Computation-based analysis revealed two major features of hierarchical population divergence in the species’ evolutionary history. Recent divergence between the NE group and the admixed-like group corresponded to the LGM period and ancient divergence of SC groups took place during mid-late Pleistocene period. The level of genetic differentiation was moderate (FST = 0.073; G′ST = 0.278) among all populations, but significantly higher in the SC group than the NE group, mirroring the species’ more scattered distribution in SC. Conservation measures for this species are proposed, taking into account the genetic structure and past demographic history identified in this study. PMID:24498039

  11. Molecular marker studies in riverine buffaloes, for characterization and diagnosis of genetic defects

    International Nuclear Information System (INIS)

    Yadav, B.R.

    2005-01-01

    The buffalo is probably the last livestock species to have been domesticated, with many genetic, physiological and behavioural traits not yet well understood. Molecular markers have been used for characterizing animals and breeds, diagnosing diseases and identifying anatomical and physiological anomalies. RFLP studies showed low heterozygosity, but genomic and oligonucleotide probes showed species-specific bands useful for identification of carcass or other unknown samples. Use of RAPD revealed band frequencies, band sharing frequencies, genetic distances, and genetic and identity indexes in different breeds. Bovine microsatellite primers indicate that 70.9% of bovine loci were conserved in buffalo. Allele numbers, sizes, frequencies, heterozygosity and polymorphism information content showed breed-specific patterns. Different marker types - genomic and oligonucleotide probes, RAPD and microsatellites - are useful in parent identification. Individual specific DNA fingerprinting techniques were applied with twin-born animal (XX/XY) chimerism, sex identification, anatomically defective and XO individuals. Molecular markers are a potential tool for geneticists and breeders to evaluate existing germplasm and to manipulate it to develop character-specific strains and to provide the basis for effective genetic conservation. (author)

  12. Population genetic structure of rare and endangered plants using molecular markers

    Science.gov (United States)

    Raji, Jennifer; Atkinson, Carter T.

    2013-01-01

    This study was initiated to assess the levels of genetic diversity and differentiation in the remaining populations of Phyllostegia stachyoides and Melicope zahlbruckneri in Hawai`i Volcanoes National Park and determine the extent of gene flow to identify genetically distinct individuals or groups for conservation purposes. Thirty-six Amplified Fragment Length Polymorphic (AFLP) primer combinations generated a total of 3,242 polymorphic deoxyribonucleic acid (DNA) fragments in the P. stachyoides population with a percentage of polymorphic bands (PPB) ranging from 39.3 to 65.7% and 2,780 for the M. zahlbruckneri population with a PPB of 18.8 to 64.6%. Population differentiation (Fst) of AFLP loci between subpopulations of P. stachyoides was low (0.043) across populations. Analysis of molecular variance of P. stachyoides showed that 4% of the observed genetic differentiation occurred between populations in different kīpuka and 96% when individuals were pooled from all kīpuka. Moderate genetic diversity was detected within the M. zahlbruckneri population. Bayesian and multivariate analyses both classified the P. stachyoides and M. zahlbruckneri populations into genetic groups with considerable sub-structuring detected in the P. stachyoides population. The proportion of genetic differentiation among populations explained by geographical distance was estimated by Mantel tests. No spatial correlation was found between genetic and geographic distances in both populations. Finally, a moderate but significant gene flow that could be attributed to insect or bird-mediated dispersal of pollen across the different kīpuka was observed. The results of this study highlight the utility of a multi-allelic DNA-based marker in screening a large number of polymorphic loci in small and closely related endangered populations and revealed the presence of genetically unique groups of individuals in both M. zahlbruckneri and P. stachyoides populations. Based on these findings

  13. Contemporary genetic structure and postglacial demographic history of the black scorpionfish, Scorpaena porcus, in the Mediterranean and the Black Seas.

    Science.gov (United States)

    Boissin, E; Micu, D; Janczyszyn-Le Goff, M; Neglia, V; Bat, L; Todorova, V; Panayotova, M; Kruschel, C; Macic, V; Milchakova, N; Keskin, Ç; Anastasopoulou, A; Nasto, I; Zane, L; Planes, S

    2016-05-01

    Understanding the distribution of genetic diversity in the light of past demographic events linked with climatic shifts will help to forecast evolutionary trajectories of ecosystems within the current context of climate change. In this study, mitochondrial sequences and microsatellite loci were analysed using traditional population genetic approaches together with Bayesian dating and the more recent approximate Bayesian computation scenario testing. The genetic structure and demographic history of a commercial fish, the black scorpionfish, Scorpaena porcus, was investigated throughout the Mediterranean and Black Seas. The results suggest that the species recently underwent population expansions, in both seas, likely concomitant with the warming period following the Last Glacial Maximum, 20 000 years ago. A weak contemporaneous genetic differentiation was identified between the Black Sea and the Mediterranean Sea. However, the genetic diversity was similar for populations of the two seas, suggesting a high number of colonizers entered the Black Sea during the interglacial period and/or the presence of a refugial population in the Black Sea during the glacial period. Finally, within seas, an east/west genetic differentiation in the Adriatic seems to prevail, whereas the Black Sea does not show any structured spatial genetic pattern of its population. Overall, these results suggest that the Black Sea is not that isolated from the Mediterranean, and both seas revealed similar evolutionary patterns related to climate change and changes in sea level. © 2016 John Wiley & Sons Ltd.

  14. The influence of life-history strategy on genetic differentiation and lineage divergence in darters (Percidae: Etheostomatinae).

    Science.gov (United States)

    Fluker, Brook L; Kuhajda, Bernard R; Harris, Phillip M

    2014-11-01

    Recent studies determined that darters with specialized breeding strategies can exhibit deep lineage divergence over fine geographic scales without apparent physical barriers to gene flow. However, the extent to which intrinsic characteristics interact with extrinsic factors to influence population divergence and lineage diversification in darters is not well understood. This study employed comparative phylogeographic and population genetic methods to investigate the influence of life history on gene flow, dispersal ability, and lineage divergence in two sympatric sister darters with differing breeding strategies. Our results revealed highly disparate phylogeographic histories, patterns of genetic structure, and dispersal abilities between the two species suggesting that life history may contribute to lineage diversification in darters, especially by limiting dispersal among large river courses. Both species also showed striking differences in demographic history, indicating that extrinsic factors differentially affected each species during the Pleistocene. Collectively, our results indicate that intrinsic and extrinsic factors have influenced levels of gene flow among populations within both species examined. However, we suggest that life-history strategy may play a more important role in lineage diversification in darters than previously appreciated, a finding that has potentially important implications for understanding diversification of the rich North American freshwater fish fauna. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  15. DNA Re-EvolutioN: a game for learning molecular genetics and evolution.

    Science.gov (United States)

    Miralles, Laura; Moran, Paloma; Dopico, Eduardo; Garcia-Vazquez, Eva

    2013-01-01

    Evolution is a main concept in biology, but not many students understand how it works. In this article we introduce the game DNA Re-EvolutioN as an active learning tool that uses genetic concepts (DNA structure, transcription and translation, mutations, natural selection, etc.) as playing rules. Students will learn about molecular evolution while playing a game that mixes up theory and entertainment. The game can be easily adapted to different educational levels. The main goal of this play is to arrive at the end of the game with the longest protein. Students play with pawns and dices, a board containing hypothetical events (mutations, selection) that happen to molecules, "Evolution cards" with indications for DNA mutations, prototypes of a DNA and a mRNA chain with colored "nucleotides" (plasticine balls), and small pieces simulating t-RNA with aminoacids that will serve to construct a "protein" based on the DNA chain. Students will understand how changes in DNA affect the final protein product and may be subjected to positive or negative selection, using a didactic tool funnier than classical theory lectures and easier than molecular laboratory experiments: a flexible and feasible game to learn and enjoy molecular evolution at no-cost. The game was tested by majors and non-majors in genetics from 13 different countries and evaluated with pre- and post-tests obtaining very positive results. © 2013 by The International Union of Biochemistry and Molecular Biology.

  16. Bull trout life history, genetics, habitat needs, and limiting factors in Central and Northeast Oregon. Annual report 1996

    International Nuclear Information System (INIS)

    Bellerud, B.L.; Gunkel, S.; Hemmingsen, A.R.; Buchanan, D.V.; Howell, P.J.

    1997-10-01

    This study is part of a multi-year research project studying aspects of bull trout life history, ecology and genetics. This report covers the activities of the project in 1996. Results and analysis are presented in the following five areas: (1) analysis of the genetic structure of Oregon bull trout populations; (2) distribution and habitat use of bull trout and brook trout in streams containing both species; (3) bull trout spawning surveys; (4) summary and analysis of historical juvenile bull trout downstream migrant trap catches in the Grande Ronde basin; and (5) food habits and feeding behavior of bull trout alone and in sympatry with brook trout

  17. Bull Trout Life History, Genetics, Habitat Needs, and Limiting Factors in Central and Northeast Oregon. Annual Report 1996.

    Energy Technology Data Exchange (ETDEWEB)

    Bellerud, Blane L.; Gunckel, Stephanie; Hemmingsen, Alan R.; Buchanan, David V.; Howell, Philip J.

    1997-10-01

    This study is part of a multi-year research project studying aspects of bull trout life history, ecology and genetics. This report covers the activities of the project in 1996. Results and analysis are presented in the following five areas: (1) analysis of the genetic structure of Oregon bull trout populations; (2) distribution and habitat use of bull trout and brook trout in streams containing both species; (3) bull trout spawning surveys; (4) summary and analysis of historical juvenile bull trout downstream migrant trap catches in the Grande Ronde basin; and (5) food habits and feeding behavior of bull trout alone and in sympatry with brook trout.

  18. Medical genetic issues in clinical of pediatric neurology practice:a history of pediatrics in Peking University First Hospital.

    Science.gov (United States)

    Wu, Xi-ru

    2006-02-18

    The Department of Pediatrics of Peking University First Hospital has a long term of outstanding history. It was established about 60 years ago. After the division of pediatric neurology (DPN) had been established in 1960s, it had been assigned to cover genetic disorders. During the recent 20 years, efforts have been put on three aspects: (1) Pediatric neurology clinical service and education; (2) research studies of childhood epilepsies and pediatric neurogenetic disorders; and (3) development of a strong DPN team to establish a comprehensive pediatric neurological program. In this paper, we reviewed the history of the pediatric neurology division in our department, our clinical and research work and achievements for neurogenetic diseases.

  19. Molecular genetic markers for thyroid FNAB. Established assays and future perspective.

    Science.gov (United States)

    Musholt, Thomas J; Musholt, P B

    2015-01-01

    Thyroid nodules > 1 cm are observed in about 12% of unselected adult employees aged 18-65 years screened by ultrasound scan (40). While intensive ultrasound screening leads to early detection of thyroid diseases, the determination of benign or malignant behaviour remains uncertain and may trigger anxieties in many patients and their physicians. A considerable number of thyroid resections are consecutively performed due to suspicion of malignancy in the detected nodes. Fine needle aspiration biopsy (FNAB) has been recommended for the assessment of thyroid nodules to facilitate detection of thyroid carcinomas but also to rule out malignancy and thereby avoid unnecessary thyroid resections. However, cytology results are dependent on experience of the respective cytologist and unfortunately inconclusive in many cases. Molecular genetic markers are already used nowadays to enhance sensitivity and specificity of FNAB cytology in some centers in Germany. The most clinically relevant molecular genetic markers as pre-operative diagnostic tools and the clinical implications for the intraoperative and postoperative management were reviewed. Molecular genetic markers predominantly focus on the preoperative detection of thyroid malignancies rather than the exclusion of thyroid carcinomas. While some centers routinely assess FNABs, other centers concentrate on FNABs with cytology results of follicular neoplasia or suspicion of thyroid carcinoma. Predominantly mutations of BRAF, RET/PTC, RAS, and PAX8/PPARγ or expression of miRNAs are analyzed. However, only the detection of BRAF mutations predicts the presence of (papillary) thyroid malignancy with almost 98% probability, indicating necessity of oncologic thyroid resections irrespective of the cytology result. Other genetic alterations are associated with thyroid malignancy with varying frequency and achieve less impact on the clinical management. Molecular genetic analysis of FNABs is increasingly performed in Germany

  20. Genetic diversity among Korean bermudagrass (Cynodon spp.) ecotypes characterized by morphological, cytological and molecular approaches.

    Science.gov (United States)

    Kang, Si-Yong; Lee, Geung-Joo; Lim, Ki Byung; Lee, Hye Jung; Park, In Sook; Chung, Sung Jin; Kim, Jin-Baek; Kim, Dong Sub; Rhee, Hye Kyung

    2008-04-30

    The genus Cynodon comprises ten species. The objective of this study was to evaluate the genetic diversity of Korean bermudagrasses at the morphological, cytological and molecular levels. Morphological parameters, the nuclear DNA content and ploidy levels were observed in 43 bermudagrass ecotypes. AFLP markers were evaluated to define the genetic diversity, and chromosome counts were made to confirm the inferred cytotypes. Nuclear DNA contents were in the ranges 1.42-1.56, 1.94-2.19, 2.54, and 2.77-2.85 pg/2C for the triploid, tetraploid, pentaploid, and hexaploid accessions, respectively. The inferred cytotypes were triploid (2n = 3x = 27), tetraploid (2n = 4x = 36), pentaploid (2n = 5x = 45), and hexaploid (2n = 6x = 54), but the majority of the collections were tetraploid (81%). Mitotic chromosome counts verified the corresponding ploidy levels. The fast growing fine-textured ecotypes had lower ploidy levels, while the pentaploids and hexaploids were coarse types. The genetic similarity ranged from 0.42 to 0.94 with an average of 0.64. UPGMA cluster analysis and principle coordinate analysis separated the ecotypes into 6 distinct groups. The genetic similarity suggests natural hybridization between the different cytotypes, which could be useful resources for future breeding and genetic studies.

  1. Molecular genetics of colorectal cancer Genética molecular del cáncer colorrectal

    Directory of Open Access Journals (Sweden)

    D. Cruz-Bustillo Clarens

    2004-01-01

    Full Text Available Colorectal tumours constitute an excellent system to study carcinogenesis and the molecular events implicated in the development of cancer. Attending to the way it is transmitted, colorectal cancer may appear in one of three forms: sporadic, familial, and hereditary. The sporadic form is most common and has no familial or hereditary associated factor thus far, while familial and hereditary forms show the same inheritance pattern. Hereditary colorectal cancers develop by means of defined stages that go from lesions in the crypt of the colon through adenomas to manifest cancer. They are characterised by the accumulation of multiple mutations in tumour suppressor genes and oncogenes that affect the balance between cell proliferation and apoptosis. The colorectal carcinogenesis pathway is not unique and there are probably several ways for the initiation, development and progression of colorectal tumours.Los tumores colorrectales constituyen un excelente sistema para estudiar la carcinogénesis y los eventos moleculares involucrados en el desarrollo de un tumor. El cáncer colorrectal puede presentarse en tres formas, según su forma de transmisión: esporádico, familiar y hereditario. La forma esporádica que es la mayoritaria, no tiene hasta el momento ningún factor familiar o hereditario asociado, mientras que las formas familiares y hereditarias siguen un patrón de herencia en la propensión familiar a padecerlo. Los cánceres colorrectales hereditarios se desarrollan mediante etapas definidas que van desde lesiones en la cripta del colon a través de adenomas hasta manifestar el cáncer y se caracterizan por la acumulación de múltiples mutaciones en genes supresores de tumor y oncogenes que afectan el balance entre la proliferación celular y la apoptosis. La vía de carcinogénesis colorrectal no es una sola y probablemente existan varios caminos para el inicio, desarrollo y progresión de un tumor colorrectal.

  2. Determination of genetic structure of germplasm collections: are traditional hierarchical clustering methods appropriate for molecular marker data?

    NARCIS (Netherlands)

    Odong, T.L.; Heerwaarden, van J.; Jansen, J.; Hintum, van T.J.L.; Eeuwijk, van F.A.

    2011-01-01

    Despite the availability of newer approaches, traditional hierarchical clustering remains very popular in genetic diversity studies in plants. However, little is known about its suitability for molecular marker data. We studied the performance of traditional hierarchical clustering techniques using

  3. Inferring Genetic Variation and Demographic History of Michelia yunnanensis Franch. (Magnoliaceae from Chloroplast DNA Sequences and Microsatellite Markers

    Directory of Open Access Journals (Sweden)

    Shikang Shen

    2017-04-01

    Full Text Available Michelia yunnanensis Franch., is a traditional ornamental, aromatic, and medicinal shrub that endemic to Yunnan Province in southwest China. Although the species has a large distribution pattern and is abundant in Yunnan Province, the populations are dramatically declining because of overexploitation and habitat destruction. Studies on the genetic variation and demography of endemic species are necessary to develop effective conservation and management strategies. To generate such knowledge, we used 3 pairs of universal cpDNA markers and 10 pairs of microsatellite markers to assess the genetic diversity, genetic structure, and demographic history of 7 M. yunnanensis populations. We calculated a total of 88 alleles for 10 polymorphic loci and 10 haplotypes for a combined 2,089 bp of cpDNA. M. yunnanensis populations showed high genetic diversity (Ho = 0.551 for nuclear markers and Hd = 0.471 for cpDNA markers and low genetic differentiation (FST = 0.058. Geographical structure was not found among M. yunnanensis populations. Genetic distance and geographic distance were not correlated (P > 0.05, which indicated that geographic isolation is not the primary cause of the low genetic differentiation of M. yunnanensis. Additionally, M. yunnanensis populations contracted ~20,000–30,000 years ago, and no recent expansion occurred in current populations. Results indicated that the high genetic diversity of the species and within its populations holds promise for effective genetic resource management and sustainable utilization. Thus, we suggest that the conservation and management of M. yunnanensis should address exotic overexploitation and habitat destruction.

  4. High-resolution molecular epidemiology and evolutionary history of HIV-1 subtypes in Albania.

    Directory of Open Access Journals (Sweden)

    Marco Salemi

    2008-01-01

    Full Text Available HIV-1 epidemic in Western Europe is largely due to subtype B. Little is known about the HIV-1 in Eastern Europe, but a few studies have shown that non-B subtypes are quite common. In Albania, where a recent study estimated a ten-fold increase of AIDS incidence during the last six years, subtype A and B account for 90% of the know infections.We investigated the demographic history of HIV-1 subtype A and B in Albania by using a statistical framework based on coalescent theory and phylogeography. High-resolution phylogenetic and molecular clock analysis showed a limited introduction to the Balkan country of subtype A during the late 1980s followed by an epidemic outburst in the early 1990 s. In contrast, subtype B was apparently introduced multiple times between the mid-1970s and mid-1980s. Both subtypes are growing exponentially, although the HIV-1A epidemic displays a faster growth rate, and a significantly higher basic reproductive number R(0. HIV-1A gene flow occurs primarily from the capital Tirane, in the center of the country, to the periphery, while HIV-1B flow is characterized by a balanced exchange between center and periphery. Finally, we calculated that the actual number of infections in Albania is at least two orders of magnitude higher than previously thought.Our analysis demonstrates the power of recently developed computational tools to investigate molecular epidemiology of pathogens, and emphasize the complex factors involved in the establishment of HIV-1 epidemics. We suggest that a significant correlation exists between HIV-1 exponential spread and the socio-political changes occurred during the Balkan wars. The fast growth of a relatively new non-B epidemic in the Balkans may have significant consequences for the evolution of HIV-1 epidemiology in neighboring countries in Eastern and Western Europe.

  5. Assessing the evolutionary history of the class Synurophyceae (Heterokonta) using molecular, morphometric, and paleobiological approaches.

    Science.gov (United States)

    Siver, Peter A; Jo, Bok Yeon; Kim, Jong Im; Shin, Woongghi; Lott, Anne Marie; Wolfe, Alexander P

    2015-06-01

    Heterokont algae of the class Synurophyceae, characterized by distinctive siliceous scales that cover the surface of the cell, are ecologically important in inland waters, yet their evolutionary history remains enigmatic. We explore phylogenetic relationships within this group of algae relative to geologic time, with a focus on evolution of siliceous components. We combined an expansive five-gene and time-calibrated molecular phylogeny of synurophyte algae with an extensive array of fossil specimens from the middle Eocene to infer evolutionary trends within the group. The group originated in the Jurassic approximately 157 million years ago (Ma), with the keystone genera Mallomonas and Synura diverging during the Early Cretaceous at 130 Ma. Mallomonas further splits into two major subclades, signaling the evolution of the V-rib believed to aid in the spacing and organization of scales on the cell covering. Synura also diverges into two primary subclades, separating taxa with forward-projecting spines on the scale from those with a keel positioned on the scale proper. Approximately one third of the fossil species are extinct, whereas the remaining taxa are linked to modern congeners. The taxonomy of synurophytes, which relies extensively on the morphology of the siliceous components, is largely congruent with molecular analyses. Scales of extinct synurophytes were significantly larger than those of modern taxa and may have played a role in their demise. In contrast, many fossil species linked to modern lineages were smaller in the middle Eocene, possibly reflecting growth in the greenhouse climatic state that characterized this geologic interval. © 2015 Botanical Society of America, Inc.

  6. Molecular genetic and molecular evolutionary studies on the bacteriochlorophyll synthesis genes of Rhodobacter capsulatus

    Energy Technology Data Exchange (ETDEWEB)

    Burke-Agueero, D.H.

    1992-08-01

    Rhodobacter capsulatus, purple bacterium capable of either aerobic or photosynthetic growth, has proven to be very useful in genetic studies of photosynthesis. Forty-four genes clustered together within a 46 kilobase region are required to establish photosynthetic ability in R. capsulatus. Approximately twenty of these genes are involved in bacteriochlorophyll synthesis of which eight bch'' genes are the subject of this thesis. Six of these genes were found to code for the two ring reductases. The first converts protochlorophyllide (PChlide) into a chlorin, the immediate precursor to chlorophyll a, and then into a bacteriochlorin. Each reductase is shown to be made up of three subunits. PChlide reductase is coded by the genes bchN, bchB, and bchL. Proteins with amino acid sequences markedly similar to those of bchN and bchL have been shown in other organisms to be required for chlorophyll synthesis; hence, their designation as chlN and chlB. A third chloroplast-encoded gene of heretofore unknown function shares amino acid identities with bchB and is probably the third subunit of the plant PChlide reductase. The bchA locus, which encodes the chlorin reductase, is found to be made up of three separate, translationally coupled genes, referred to as bchX, bchY, and bchZ. Amino acid similarities between bchX, bchL, and the nitrogenase reductase protein nifH suggest that all three classes of proteins share certain three-dimensional structural features, including elements that are central to the enzymatic mechanism of nifH. PChlide reductase and chlorin reductase are clearly derived from a common ancestor. Several lines of analysis suggests the ancestor of both enzyme systems reduced PChlide twice to produce bacteriochlorophyll supporting the concept bacteriochlorophyll as the ancestral reaction center pigment.

  7. Molecular genetic and molecular evolutionary studies on the bacteriochlorophyll synthesis genes of Rhodobacter capsulatus

    Energy Technology Data Exchange (ETDEWEB)

    Burke-Agueero, Donald H. [Univ. of California, Berkeley, CA (United States)

    1992-08-01

    Rhodobacter capsulatus, purple bacterium capable of either aerobic or photosynthetic growth, has proven to be very useful in genetic studies of photosynthesis. Forty-four genes clustered together within a 46 kilobase region are required to establish photosynthetic ability in R. capsulatus. Approximately twenty of these genes are involved in bacteriochlorophyll synthesis of which eight ``bch`` genes are the subject of this thesis. Six of these genes were found to code for the two ring reductases. The first converts protochlorophyllide (PChlide) into a chlorin, the immediate precursor to chlorophyll a, and then into a bacteriochlorin. Each reductase is shown to be made up of three subunits. PChlide reductase is coded by the genes bchN, bchB, and bchL. Proteins with amino acid sequences markedly similar to those of bchN and bchL have been shown in other organisms to be required for chlorophyll synthesis; hence, their designation as chlN and chlB. A third chloroplast-encoded gene of heretofore unknown function shares amino acid identities with bchB and is probably the third subunit of the plant PChlide reductase. The bchA locus, which encodes the chlorin reductase, is found to be made up of three separate, translationally coupled genes, referred to as bchX, bchY, and bchZ. Amino acid similarities between bchX, bchL, and the nitrogenase reductase protein nifH suggest that all three classes of proteins share certain three-dimensional structural features, including elements that are central to the enzymatic mechanism of nifH. PChlide reductase and chlorin reductase are clearly derived from a common ancestor. Several lines of analysis suggests the ancestor of both enzyme systems reduced PChlide twice to produce bacteriochlorophyll supporting the concept bacteriochlorophyll as the ancestral reaction center pigment.

  8. Global Genetics and Invasion History of the Potato Powdery Scab Pathogen, Spongospora subterranea f.sp. subterranea

    OpenAIRE

    Gau, Rebecca D.; Merz, Ueli; Falloon, Richard E.; Brunner, Patrick C.

    2013-01-01

    Spongospora subterranea f. sp. subterranea (Sss) causes two diseases on potato (Solanum tuberosum), lesions on tubers and galls on roots, which are economically important worldwide. Knowledge of global genetic diversity and population structure of pathogens is essential for disease management including resistance breeding. A combination of microsatellite and DNA sequence data was used to investigate the structure and invasion history of Sss. South American populations (four countries, 132 sam...

  9. The impact of genetic counselling on risk perception and mental health in women with a family history of breast cancer.

    Science.gov (United States)

    Watson, M; Lloyd, S; Davidson, J; Meyer, L; Eeles, R; Ebbs, S; Murday, V

    1999-02-01

    The present study investigated: (1) perception of genetic risk and, (2) the psychological effects of genetic counselling in women with a family history of breast cancer. Using a prospective design, with assessment pre- and post-genetic counselling at clinics and by postal follow-up at 1, 6 and 12 months, attenders at four South London genetic clinics were assessed. Participants included 282 women with a family history of breast cancer. Outcome was measured in terms of mental health, cancer-specific distress and risk perception. High levels of cancer-specific distress were found pre-genetic counselling, with 28% of participants reporting that they worried about breast cancer 'frequently or constantly' and 18% that worry about breast cancer was 'a severe or definite problem'. Following genetic counselling, levels of cancer-specific distress were unchanged. General mental health remained unchanged over time (33% psychiatric cases detected pre-genetic counselling, 27% at 12 months after genetic counselling). Prior to their genetics consultation, participants showed poor knowledge of their lifetime risk of breast cancer since there was no association between their perceived lifetime risk (when they were asked to express this as a 1 in x odds ratio) and their actual risk, when the latter was calculated by the geneticist at the clinic using the CASH model. In contrast, women were more accurate about their risk of breast cancer pre-genetic counselling when this was assessed in broad categorical terms (i.e. very much lower/very much higher than the average woman) with a significant association between this rating and the subsequently calculated CASH risk figure (P = 0.001). Genetic counselling produced a modest shift in the accuracy of perceived lifetime risk, expressed as an odds ratio, which was maintained at 12 months' follow-up. A significant minority failed to benefit from genetic counselling; 77 women continued to over-estimate their risk and maintain high levels of

  10. Behavioural mediators of genetic life-history trade-offs: a test of the pace-of-life syndrome hypothesis in field crickets.

    Science.gov (United States)

    Santostefano, Francesca; Wilson, Alastair J; Niemelä, Petri T; Dingemanse, Niels J

    2017-10-11

    The pace-of-life syndrome (POLS) hypothesis predicts associations between life history and 'risky' behaviours. Individuals with 'fast' lifestyles should develop faster, reproduce earlier, exhibit more risk-prone behaviours, and die sooner than those with 'slow' lifestyles. While support for POLS has been equivocal to date, studies have relied on individual-level (phenotypic) patterns in which genetic trade-offs may be masked by environmental effects on phenotypes. We estimated genetic correlations between life history (development, lifespan, size) and risky behaviours (exploration, aggression) in a pedigreed population of Mediterranean field crickets ( Gryllus bimaculatus ). Path analyses showed that behaviours mediated some genetic relationships between life history traits, though not those involved in trade-offs. Thus, while specific predictions of POLS theory were not supported, genetic integration of behaviour and life history was present. This implies a major role for risky behaviours in life history evolution. © 2017 The Author(s).

  11. Genética Molecular das Epidermólises Bolhosas Molecular Genetics of Epidermolysis Bullosa

    Directory of Open Access Journals (Sweden)

    Hiram Larangeira de Almeida Jr

    2002-10-01

    Full Text Available O estudo das alterações moleculares das epidermólises bolhosas tem contribuído para que se compreenda melhor essas enfermidades. Na epidermólise bolhosa simples a maioria dos casos está associada com alteração nas citoqueratinas basais 5 (gen KRT5 e 14 (gen KRT14, o que modifica o citoesqueleto na camada basal da epiderme, levando à degeneração dessa camada, formando bolha intra-epidérmica. Mutações na plectina (gen PLEC1, componente da placa interna do hemidesmossoma, levam também à clivagem intra-epidérmica. Na epidermólise bolhosa juncional vários gens estão envolvidos, em decorrência da complexidade da zona da membrana basal, todos levando ao descolamento dos queratinócitos basais na lâmina lúcida, pela disfunção da aderência entre esses e a lâmina densa. Alterações na laminina 5 (gens LAMA3, LAMB3 e LAMC2, integrina alfa6beta4 (gens ITGA6 e ITGB4 e colágeno XVII (gen COL17A1 foram descritas. Por fim, na epidermólise bolhosa distrófica apenas um gen está mutado, alterando o colágeno VII (gen COL7A1, principal componente das fibrilas ancorantes, produzindo clivagem abaixo da lâmina densa, variando fenotipicamente de acordo com a conseqüência da mutação. Outra aplicação importante dessas informações refere-se ao diagnóstico pré-natal, com a perspectiva no futuro da terapia gênica.New data regarding the molecular aspects of the heterogeneous group of epidermolysis bullosa has brought some important information about its pathogenesis. In epidermolysis bullosa simplex the majority of mutations are localized in the genes of the basal cytokeratin 5 (gene KRT5 and 14 (gene KRT14, cytolysis at this layer with intraepidermal blister is seen under light microscopy. Mutations of plectin (gene PLEC1, a protein found in the inner hemidesmosomal plaque, leads also to intraepidermal blisters. In junctional epidermolysis bullosa many proteins from the basal membrane zone are involved, such as laminin 5 (genes

  12. Do microplastic particles affect Daphnia magna at the morphological, life history and molecular level?

    Directory of Open Access Journals (Sweden)

    Hannes K Imhof

    Full Text Available Microplastic particles are ubiquitous not only in marine but also in freshwater ecosystems. However, the impacts of microplastics, consisting of a large variety of synthetic polymers, on freshwater organisms remains poorly understood. We examined the effects of two polymer mixtures on the morphology, life history and on the molecular level of the waterflea Daphnia magna (three different clones. Microplastic particles of ~40 μm were supplied at a low concentration (1% of the food particles leading to an average of ~30 particles in the digestive tract which reflects a high microplastic contamination but still resembles a natural situation. Neither increased mortality nor changes on the morphological (body length, width and tail spine length or reproductive parameters were observed for adult Daphnia. The analyses of juvenile Daphnia revealed a variety of small and rather subtle responses of morphological traits (body length, width and tail spine length. For adult Daphnia, alterations in expression of genes related to stress responses (i.e. HSP60, HSP70 & GST as well as of other genes involved in body function and body composition (i.e. SERCA were observed already 48h after exposure. We anticipate that the adverse effects of microplastic might be influenced by many additional factors like size, shape, type and even age of the particles and that the rather weak effects, as detected in a laboratory, may lead to reduced fitness in a natural multi-stressor environment.

  13. Molecular markers to assess genetic diversity and mutant identifications in Jatropha curcas

    International Nuclear Information System (INIS)

    Azhar Mohamad; Yie Min Kwan; Fatin Mastura Derani; Abdul Rahim Harun

    2010-01-01

    Jatropha curcas (Linnaeus) belongs to the Euphorbiaceae family, is a multipurpose use, drought resistant and perennial plant. It is an economic important crop, which generates wide interest in understanding the genetic diversity of the species towards selection and breeding of superior genotypes. Jatropha accessions are closely related family species. Thus, better understanding of the effectiveness of the different DNA-based markers is an important step towards plant germplasm characterization and evaluation. It is becoming a prerequisite for more effective application of marker techniques in breeding programs. Inter-simple sequence repeats (ISSRs) has shown rapid, simple, reproducible and inexpensive means in molecular taxonomy, conservation breeding and genetic diversity analysis. These markers were used to understand diversity and differentiate amongst accessions of Jatropha population and mutant lines generated by acute gamma radiation. The ISSR for marker applications are essential to facilitate management, conservation and genetic improvement programs towards improvement of bio-diesel production and medication substances. A total of 62 ISSR primers were optimized for polymorphism evaluations on five foreign accessions (Africa, India, Myanmar, Indonesia, Thailand), nine local accessions and two mutants of Jatropha. Optimization was resulted 54 ISSR primers affirmative for the polymorphism evaluation study, which encountered 12 ISSR primers, showed significance polymorphism amongst the accessions and mutants. Marker derived from ISSR profiling is a powerful method for identification and molecular classification of Jatropha from accession to generated mutant varieties. (author)

  14. [Clinical genealogical and molecular genetic study of patients with mental retardation].

    Science.gov (United States)

    Hryshchenko, N V; B'ichkova, A M; Lyvshyts, A B; Kravchenko, S A; Pampukha, V N; Solov'ev, A A; Kucherenko, A M; Tatarskiĭ, P F; Afanas'eva, N A; Dubrovskaia, E V; Patskun, Ie Y; Zymak-Zakutnaia, N O; Nykytchina, T V; Lohysh, S Iu; Lyvshyts, L A

    2012-01-01

    The results of clinical, genealogical, cytogenetic and molecular genetic studies of 113 patients from 96 families with different forms of mental retardation from Ukraine are presented. This study was held as part of the CHERISH project of the 7-th Framework Program. The aim of the project is to improve diagnostics of mental retardation in children in Eastern Europe and Central Asia through detailed analysis of known chromosomal and gene's aberrations and to find the new gene-candidates that cause mental retardation. All patients have normal chromosome number (46XY or 46XX). The cases with fragile-X syndrome were eliminated using molecular genetic methods. Genome rearrangements were found among 28 patients using cytogenetic analysis, multiplex ligation-dependent probe amplification (MLPA analysis) ofsubtelomeric regions and array-based comparative genomic hybridisation (array CGH screening). In 10 cases known pathogenic CNV's were identified, 11 cases are unknown aberrations; their pathogenicity is being determined. The rest cases are known nonpathogenic gene rearrangements. Obtained results show the strong genetic heterogeneity of hereditary forms of mental retardation. The further studies will allow to identificate genes candidates and certain mutations in these genes that may be associated with this pathology.

  15. Comparison of population genetic patterns in two widespread freshwater mussels with contrasting life histories in western North America.

    Science.gov (United States)

    Mock, K E; Brim Box, J C; Chong, J P; Furnish, J; Howard, J K

    2013-12-01

    We investigate population genetic structuring in Margaritifera falcata, a freshwater mussel native to western North America, across the majority of its geographical range. We find shallow rangewide genetic structure, strong population-level structuring and very low population diversity in this species, using both mitochondrial sequence and nuclear microsatellite data. We contrast these patterns with previous findings in another freshwater mussel species group (Anodonta californiensis/A. nuttalliana) occupying the same continental region and many of the same watersheds. We conclude that differences are likely caused by contrasting life history attributes between genera, particularly host fish requirements and hermaphroditism. Further, we demonstrate the occurrence of a 'hotspot' for genetic diversity in both groups of mussels, occurring in the vicinity of the lower Columbia River drainage. We suggest that stream hierarchy may be responsible for this pattern and may produce similar patterns in other widespread freshwater species. © 2013 John Wiley & Sons Ltd.

  16. New STS molecular markers for assessment of genetic diversity and DNA fingerprinting in hop (Humulus lupulus L.)

    Czech Academy of Sciences Publication Activity Database

    Patzak, J.; Vrba, Lukáš; Matoušek, Jaroslav

    2007-01-01

    Roč. 50, č. 1 (2007), s. 15-25 ISSN 0831-2796 R&D Projects: GA ČR GA521/03/0072 Institutional research plan: CEZ:AV0Z50510513 Keywords : hop (Humulus lupulus L.) * genetic diversity Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.785, year: 2007

  17. Molecular mechanisms of drug resistance in natural Leishmania populations vary with genetic background.

    Directory of Open Access Journals (Sweden)

    Saskia Decuypere

    Full Text Available The evolution of drug-resistance in pathogens is a major global health threat. Elucidating the molecular basis of pathogen drug-resistance has been the focus of many studies but rarely is it known whether a drug-resistance mechanism identified is universal for the studied pathogen; it has seldom been clarified whether drug-resistance mechanisms vary with the pathogen's genotype. Nevertheless this is of critical importance in gaining an understanding of the complexity of this global threat and in underpinning epidemiological surveillance of pathogen drug resistance in the field. This study aimed to assess the molecular and phenotypic heterogeneity that emerges in natural parasite populations under drug treatment pressure. We studied lines of the protozoan parasite Leishmania (L. donovani with differential susceptibility to antimonial drugs; the lines being derived from clinical isolates belonging to two distinct genetic populations that circulate in the leishmaniasis endemic region of Nepal. Parasite pathways known to be affected by antimonial drugs were characterised on five experimental levels in the lines of the two populations. Characterisation of DNA sequence, gene expression, protein expression and thiol levels revealed a number of molecular features that mark antimonial-resistant parasites in only one of the two populations studied. A final series of in vitro stress phenotyping experiments confirmed this heterogeneity amongst drug-resistant parasites from the two populations. These data provide evidence that the molecular changes associated with antimonial-resistance in natural Leishmania populations depend on the genetic background of the Leishmania population, which has resulted in a divergent set of resistance markers in the Leishmania populations. This heterogeneity of parasite adaptations provides severe challenges for the control of drug resistance in the field and the design of molecular surveillance tools for widespread

  18. History of safe use as applied to the safety assessment of novel foods and foods derived from genetically modified organisms.

    Science.gov (United States)

    Constable, A; Jonas, D; Cockburn, A; Davi, A; Edwards, G; Hepburn, P; Herouet-Guicheney, C; Knowles, M; Moseley, B; Oberdörfer, R; Samuels, F

    2007-12-01

    Very few traditional foods that are consumed have been subjected to systematic toxicological and nutritional assessment, yet because of their long history and customary preparation and use and absence of evidence of harm, they are generally regarded as safe to eat. This 'history of safe use' of traditional foods forms the benchmark for the comparative safety assessment of novel foods, and of foods derived from genetically modified organisms. However, the concept is hard to define, since it relates to an existing body of information which describes the safety profile of a food, rather than a precise checklist of criteria. The term should be regarded as a working concept used to assist the safety assessment of a food product. Important factors in establishing a history of safe use include: the period over which the traditional food has been consumed; the way in which it has been prepared and used and at what intake levels; its composition and the results of animal studies and observations from human exposure. This paper is aimed to assist food safety professionals in the safety evaluation and regulation of novel foods and foods derived from genetically modified organisms, by describing the practical application and use of the concept of 'history of safe use'.

  19. Molecular regulation and genetic improvement of seed oil content in Brassica napus L.

    Directory of Open Access Journals (Sweden)

    Wei HUA,Jing LIU,Hanzhong WANG

    2016-09-01

    Full Text Available As an important oil crop and a potential bioenergy crop, Brassica napus L. is becoming a model plant for basic research on seed lipid biosynthesis as well as seed oil content, which has always been the key breeding objective. In this review, we present current progress in understanding of the regulation of oil content in B. napus, including genetics, biosynthesis pathway, transcriptional regulation, maternal effects and QTL analysis. Furthermore, the history of breeding for high oil content in B. napus is summarized and the progress in breeding ultra-high oil content lines is described. Finally, prospects for breeding high oil content B. napus cultivars are outlined.

  20. Genetic Pattern and Demographic History of Salminus brasiliensis: Population Expansion in the Pantanal Region during the Pleistocene

    Directory of Open Access Journals (Sweden)

    Lívia A. de Carvalho Mondin

    2018-01-01

    Full Text Available Pleistocene climate changes were major historical events that impacted South American biodiversity. Although the effects of such changes are well-documented for several biomes, it is poorly known how these climate shifts affected the biodiversity of the Pantanal floodplain. Fish are one of the most diverse groups in the Pantanal floodplains and can be taken as a suitable biological model for reconstructing paleoenvironmental scenarios. To identify the effects of Pleistocene climate changes on Pantanal’s ichthyofauna, we used genetic data from multiple populations of a top-predator long-distance migratory fish, Salminus brasiliensis. We specifically investigated whether Pleistocene climate changes affected the demography of this species. If this was the case, we expected to find changes in population size over time. Thus, we assessed the genetic diversity of S. brasiliensis to trace the demographic history of nine populations from the Upper Paraguay basin, which includes the Pantanal floodplain, that form a single genetic group, employing approximate Bayesian computation (ABC to test five scenarios: constant population, old expansion, old decline, old bottleneck following by recent expansion, and old expansion following by recent decline. Based on two mitochondrial DNA markers, our inferences from ABC analysis, the results of Bayesian skyline plot, the implications of star-like networks, and the patterns of genetic diversity (high haplotype diversity and low-to-moderate nucleotide diversity indicated a sudden population expansion. ABC allowed us to make strong quantitative inferences about the demographic history of S. brasiliensis. We estimated a small ancestral population size that underwent a drastic fivefold expansion, probably associated with the colonization of newly formed habitats. The estimated time of this expansion was consistent with a humid and warm phase as inferred by speleothem growth phases and travertine records during

  1. Genetic characterization, molecular epidemiology, and phylogenetic relationships of insect-specific viruses in the taxon Negevirus.

    Science.gov (United States)

    Nunes, Marcio R T; Contreras-Gutierrez, María Angélica; Guzman, Hilda; Martins, Livia C; Barbirato, Mayla Feitoza; Savit, Chelsea; Balta, Victoria; Uribe, Sandra; Vivero, Rafael; Suaza, Juan David; Oliveira, Hamilton; Nunes Neto, Joaquin P; Carvalho, Valeria L; da Silva, Sandro Patroca; Cardoso, Jedson F; de Oliveira, Rodrigo Santo; da Silva Lemos, Poliana; Wood, Thomas G; Widen, Steven G; Vasconcelos, Pedro F C; Fish, Durland; Vasilakis, Nikos; Tesh, Robert B

    2017-04-01

    The recently described taxon Negevirus is comprised of a diverse group of insect-specific viruses isolated from mosquitoes and phlebotomine sandflies. In this study, a comprehensive genetic characterization, molecular, epidemiological and evolutionary analyses were conducted on nearly full-length sequences of 91 new negevirus isolates obtained in Brazil, Colombia, Peru, Panama, USA and Nepal. We demonstrated that these arthropod restricted viruses are clustered in two major phylogenetic groups with origins related to three plant virus genera (Cilevirus, Higrevirus and Blunevirus). Molecular analyses demonstrated that specific host correlations are not present with most negeviruses; instead, high genetic variability, wide host-range, and cross-species transmission were noted. The data presented here also revealed the existence of five novel insect-specific viruses falling into two arthropod-restrictive virus taxa, previously proposed as distinct genera, designated Nelorpivirus and Sandewavirus. Our results provide a better understanding of the molecular epidemiology, evolution, taxonomy and stability of this group of insect-restricted viruses. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Molecular phylogeny of Toxoplasmatinae: comparison between inferences based on mitochondrial and apicoplast genetic sequences

    Directory of Open Access Journals (Sweden)

    Michelle Klein Sercundes

    2016-03-01

    Full Text Available Abstract Phylogenies within Toxoplasmatinae have been widely investigated with different molecular markers. Here, we studied molecular phylogenies of the Toxoplasmatinae subfamily based on apicoplast and mitochondrial genes. Partial sequences of apicoplast genes coding for caseinolytic protease (clpC and beta subunit of RNA polymerase (rpoB, and mitochondrial gene coding for cytochrome B (cytB were analyzed. Laboratory-adapted strains of the closely related parasites Sarcocystis falcatula and Sarcocystis neurona were investigated, along with Neospora caninum, Neospora hughesi, Toxoplasma gondii (strains RH, CTG and PTG, Besnoitia akodoni, Hammondia hammondiand two genetically divergent lineages of Hammondia heydorni. The molecular analysis based on organellar genes did not clearly differentiate between N. caninum and N. hughesi, but the two lineages of H. heydorni were confirmed. Slight differences between the strains of S. falcatula and S. neurona were encountered in all markers. In conclusion, congruent phylogenies were inferred from the three different genes and they might be used for screening undescribed sarcocystid parasites in order to ascertain their phylogenetic relationships with organisms of the family Sarcocystidae. The evolutionary studies based on organelar genes confirm that the genusHammondia is paraphyletic. The primers used for amplification of clpC and rpoB were able to amplify genetic sequences of organisms of the genus Sarcocystisand organisms of the subfamily Toxoplasmatinae as well.

  3. EMQN best practice guidelines for the molecular genetic diagnosis of hereditary hemochromatosis (HH)

    Science.gov (United States)

    Porto, Graça; Brissot, Pierre; Swinkels, Dorine W; Zoller, Heinz; Kamarainen, Outi; Patton, Simon; Alonso, Isabel; Morris, Michael; Keeney, Steve

    2016-01-01

    Molecular genetic testing for hereditary hemochromatosis (HH) is recognized as a reference test to confirm the diagnosis of suspected HH or to predict its risk. The vast majority (typically >90%) of patients with clinically characterized HH are homozygous for the p.C282Y variant in the HFE gene, referred to as HFE-related HH. Since 1996, HFE genotyping was implemented in diagnostic algorithms for suspected HH, allowing its early diagnosis and prevention. However, the penetrance of disease in p.C282Y homozygotes is incomplete. Hence, homozygosity for p.C282Y is not sufficient to diagnose HH. Neither is p.C282Y homozygosity required for diagnosis as other rare forms of HH exist, generally referred to as non-HFE-related HH. These pose significant challenges when defining criteria for referral, testing protocols, interpretation of test results and reporting practices. We present best practice guidelines for the molecular genetic diagnosis of HH where recommendations are classified, as far as possible, according to the level and strength of evidence. For clarification, the guidelines' recommendations are preceded by a detailed description of the methodology and results obtained with a series of actions taken in order to achieve a wide expert consensus, namely: (i) a survey on the current practices followed by laboratories offering molecular diagnosis of HH; (ii) a systematic literature search focused on some identified controversial topics; (iii) an expert Best Practice Workshop convened to achieve consensus on the practical recommendations included in the guidelines. PMID:26153218

  4. Genetic variability, local selection and demographic history: genomic evidence of evolving towards allopatric speciation in Asian seabass.

    Science.gov (United States)

    Wang, Le; Wan, Zi Yi; Lim, Huan Sein; Yue, Gen Hua

    2016-08-01

    Genomewide analysis of genetic divergence is critically important in understanding the genetic processes of allopatric speciation. We sequenced RAD tags of 131 Asian seabass individuals of six populations from South-East Asia and Australia/Papua New Guinea. Using 32 433 SNPs, we examined the genetic diversity and patterns of population differentiation across all the populations. We found significant evidence of genetic heterogeneity between South-East Asian and Australian/Papua New Guinean populations. The Australian/Papua New Guinean populations showed a rather lower level of genetic diversity. FST and principal components analysis revealed striking divergence between South-East Asian and Australian/Papua New Guinean populations. Interestingly, no evidence of contemporary gene flow was observed. The demographic history was further tested based on the folded joint site frequency spectrum. The scenario of ancient migration with historical population size changes was suggested to be the best fit model to explain the genetic divergence of Asian seabass between South-East Asia and Australia/Papua New Guinea. This scenario also revealed that Australian/Papua New Guinean populations were founded by ancestors from South-East Asia during mid-Pleistocene and were completely isolated from the ancestral population after the last glacial retreat. We also detected footprints of local selection, which might be related to differential ecological adaptation. The ancient gene flow was examined and deemed likely insufficient to counteract the genetic differentiation caused by genetic drift. The observed genomic pattern of divergence conflicted with the 'genomic islands' scenario. Altogether, Asian seabass have likely been evolving towards allopatric speciation since the split from the ancestral population during mid-Pleistocene. © 2016 John Wiley & Sons Ltd.

  5. Genetic Alterations in the Molecular Subtypes of Bladder Cancer: Illustration in the Cancer Genome Atlas Dataset.

    Science.gov (United States)

    Choi, Woonyoung; Ochoa, Andrea; McConkey, David J; Aine, Mattias; Höglund, Mattias; Kim, William Y; Real, Francisco X; Kiltie, Anne E; Milsom, Ian; Dyrskjøt, Lars; Lerner, Seth P

    2017-09-01

    Recent whole genome mRNA expression profiling studies revealed that bladder cancers can be grouped into molecular subtypes, some of which share clinical properties and gene expression patterns with the intrinsic subtypes of breast cancer and the molecular subtypes found in other solid tumors. The molecular subtypes in other solid tumors are enriched with specific mutations and copy number aberrations that are thought to underlie their distinct progression patterns, and biological and clinical properties. The availability of comprehensive genomic data from The Cancer Genome Atlas (TCGA) and other large projects made it possible to correlate the presence of DNA alterations with tumor molecular subtype membership. Our overall goal was to determine whether specific DNA mutations and/or copy number variations are enriched in specific molecular subtypes. We used the complete TCGA RNA-seq dataset and three different published classifiers developed by our groups to assign TCGA's bladder cancers to molecular subtypes, and examined the prevalence of the most common DNA alterations within them. We interpreted the results against the background of what was known from the published literature about the prevalence of these alterations in nonmuscle-invasive and muscle-invasive bladder cancers. The results confirmed that alterations involving RB1 and NFE2L2 were enriched in basal cancers, whereas alterations involving FGFR3 and KDM6A were enriched in luminal tumors. The results further reinforce the conclusion that the molecular subtypes of bladder cancer are distinct disease entities with specific genetic alterations. Our observation showed that some of subtype-enriched mutations and copy number aberrations are clinically actionable, which has direct implications for the clinical management of patients with bladder cancer. Copyright © 2017 European Association of Urology. Published by Elsevier B.V. All rights reserved.

  6. Pangenesis as a source of new genetic information. The history of a now disproven theory.

    Science.gov (United States)

    Bergman, Gerald

    2006-01-01

    Evolution is based on natural selection of existing biological phenotypic traits. Natural selection can only eliminate traits. It cannot create new ones, requiring a theory to explain the origin of new genetic information. The theory of pangenesis was a major attempt to explain the source of new genetic information required to produce phenotypic variety. This theory, advocated by Darwin as the main source of genetic variety, has now been empirically disproved. It is currently a theory mainly of interest to science historians.

  7. Analysis of genetic diversity among rapeseed cultivars and breeding lines by srap and ssr molecular markers

    International Nuclear Information System (INIS)

    Channa, S.A.; Tian, H.

    2016-01-01

    The knowledge of genetic diversity is very important for developing new rapeseed (Brassica napus L.) cultivars. The genetic diversity among 77 rapeseed accessions, including 22 varieties and 55 advanced breeding lines were analyzed by 47 sequence-related amplified polymorphism (SRAP) and 56 simple sequence repeat (SSR) primers. A total of 270 SRAP and 194 SSR polymorphic fragments were detected with an average of 5.74 and 3.46 for SRAP and SSR primer, respectively. The cluster analysis grouped the 77 accessions into five major clusters. Cluster I contained spring and winter type varieties from Czech Republic and semi-winter varieties and their respective breeding lines from China. The 16 elite breeding lines discovered in Cluster II, III, IV and V indicated higher genetic distance than accessions in Cluster I. The principal component analysis and structure analysis exhibited similar results to the cluster analysis. Analysis of molecular variance revealed that genetic diversity of the selected breeding lines was comparable to the rapeseed varieties, and variation among varieties and lines was significant. The diverse and unique group of 16 elite breeding lines detected in this study can be utilized in the future breeding program as a source for development of commercial varieties with more desirable characters. (author)

  8. Quality assurance practices in Europe: a survey of molecular genetic testing laboratories

    Science.gov (United States)

    Berwouts, Sarah; Fanning, Katrina; Morris, Michael A; Barton, David E; Dequeker, Elisabeth

    2012-01-01

    In the 2000s, a number of initiatives were taken internationally to improve quality in genetic testing services. To contribute to and update the limited literature available related to this topic, we surveyed 910 human molecular genetic testing laboratories, of which 291 (32%) from 29 European countries responded. The majority of laboratories were in the public sector (81%), affiliated with a university hospital (60%). Only a minority of laboratories was accredited (23%), and 26% was certified. A total of 22% of laboratories did not participate in external quality assessment (EQA) and 28% did not use reference materials (RMs). The main motivations given for accreditation were to improve laboratory profile (85%) and national recognition (84%). Nearly all respondents (95%) would prefer working in an accredited laboratory. In accredited laboratories, participation in EQA (Pquality assurance (Pquality implementation score (QIS), we showed that accredited laboratories (average score 92) comply better than certified laboratories (average score 69, Pquality indicators. We conclude that quality practices vary widely in European genetic testing laboratories. This leads to a potentially dangerous situation in which the quality of genetic testing is not consistently assured. PMID:22739339

  9. Genetic diversity analysis of Chrysopidae family (Insecta, Neuroptera) via molecular markers.

    Science.gov (United States)

    Yari, Kheirollah; Mirmoayedi, Alinaghi; Marami, Marzieh; Kazemi, Elham; Kahrizi, Danial

    2014-09-01

    In entomology, improvement of molecular methods would be beneficial tools for accurate identification and detecting the genetic diversity of insect species to discover a corroborative evidence for the traditional classification based on morphology. The aim of this study was focused on RAPD-PCR method for distinguishing the genetic diversity between eight species of Chrysopidae family. In current research, many specimens were collected in different locations of Tehran province (Iran), between them 24 specimens were identified. The wing venation, male genitalia and other morphological characters were used for identification and also the sexing of species was recognized with study of external genitalia. Then, the DNA was extracted with CTAB method. The RAPD-PCR method was carried out with twenty random primers. The agarose gel electrophoresis was used for separation of the PCR products. Based on electrophoresis results, 133 bands were amplified and between them, 126 bands were poly-morph and others were mono-morph. Also, among the applied primers, the primers OPA02 with 19 bands and OPA03 with 8 bands were amplified the maximum and minimum of bands, respectively. The results showed that 80.35 and 73.21 % of genetic similarity existed between Chrysopa pallens-Chrysopa dubitans, and between the Chrysoperla kolthoffi and Chrysoperla carnea, respectively. The minimum (45.53 %) of genetic similarity was observed between C. kolthoffi and C. dubitans, and the maximum (0.80 %) was seen between C. pallens and C. dubitans.

  10. Molecular and Genetic Basis of Hereditary Connective-Tissue Diseases Accompanied by Frequent Fractures

    Directory of Open Access Journals (Sweden)

    G. T. Yakhyaeva

    2016-01-01

    Full Text Available Frequent bone fractures in infancy require the elimination of a large number (> 100 of genetic disorders. The modern diagnostic method of hereditary diseases characterized by debilitating course is a new generation sequencing. The article presents the results of molecular-genetic study conducted in 18 patients with clinical symptoms of connective tissue disorders. 10 (56% patients had mutations in the genes encoding type I collagen chains, leading to the development of osteogenesis imperfecta, 5 (28% — mutations in IV and V type collagen genes that are responsible for the development of Ehlers-Danlos syndrome. 3 (17% patients had mutations in the gene encoding fibrillin-1 protein, deficiency of which is manifested by Marfan syndrome. However, the correlation between patient's phenotype and discovered mutations in the investigated gene is established not in all cases.

  11. Search of molecular ground state via genetic algorithm: Implementation on a hybrid SIMD-MIMD platform

    International Nuclear Information System (INIS)

    Pucello, N.; D'Agostino, G.; Pisacane, F.

    1997-01-01

    A genetic algorithm for the optimization of the ground-state structure of a metallic cluster has been developed and ported on a SIMD-MIMD parallel platform. The SIMD part of the parallel platform is represented by a Quadrics/APE100 consisting of 512 floating point units, while the MIMD part is formed by a cluster of workstations. The proposed algorithm is composed by a part where the genetic operators are applied to the elements of the population and a part which performs a further local relaxation and the fitness calculation via Molecular Dynamics. These parts have been implemented on the MIMD and on the SIMD part, respectively. Results have been compared to those generated by using Simulated Annealing

  12. Molecular analysis and genetic diversity of Aedes albopictus (Diptera, Culicidae) from China.

    Science.gov (United States)

    Ruiling, Zhang; Peien, Leng; Xuejun, Wang; Zhong, Zhang

    2018-05-01

    Aedes albopictus is one of the most invasive species, which can carry Dengue virus, Yellow fever virus and more than twenty arboviruses. Based on mitochondrial gene cytochrome c oxidase I (COI) and samples collected from 17 populations, we investigated the molecular character and genetic diversity of Ae. albopictus from China. Altogether, 25 haplotypes were detected, including 10 shared haplotypes and 15 private haplotypes. H1 was the dominant haplotype, which is widely distributed in 13 populations. Tajima'D value of most populations was significantly negative, demonstrating that populations experienced rapid range expansion recently. Most haplotypes clustered together both in phylogenetic and median-joining network analysis without clear phylogeographic patterns. However, neutrality tests revealed shallow divergences among Hainan and Guangxi with other populations (0.15599 ≤ F ST ≤ 0.75858), which probably due to interrupted gene flow, caused by geographical isolations. In conclusion, Ae. albopictus populations showed low genetic diversity in China.

  13. Kazusa Marker DataBase: a database for genomics, genetics, and molecular breeding in plants

    Science.gov (United States)

    Shirasawa, Kenta; Isobe, Sachiko; Tabata, Satoshi; Hirakawa, Hideki

    2014-01-01

    In order to provide useful genomic information for agronomical plants, we have established a database, the Kazusa Marker DataBase (http://marker.kazusa.or.jp). This database includes information on DNA markers, e.g., SSR and SNP markers, genetic linkage maps, and physical maps, that were developed at the Kazusa DNA Research Institute. Keyword searches for the markers, sequence data used for marker development, and experimental conditions are also available through this database. Currently, 10 plant species have been targeted: tomato (Solanum lycopersicum), pepper (Capsicum annuum), strawberry (Fragaria × ananassa), radish (Raphanus sativus), Lotus japonicus, soybean (Glycine max), peanut (Arachis hypogaea), red clover (Trifolium pratense), white clover (Trifolium repens), and eucalyptus (Eucalyptus camaldulensis). In addition, the number of plant species registered in this database will be increased as our research progresses. The Kazusa Marker DataBase will be a useful tool for both basic and applied sciences, such as genomics, genetics, and molecular breeding in crops. PMID:25320561

  14. Molecular evidence and high genetic diversity of shrew-borne Seewis virus in Slovenia.

    Science.gov (United States)

    Resman, Katarina; Korva, Miša; Fajs, Luka; Zidarič, Tanja; Trilar, Tomi; Zupanc, Tatjana Avšič

    2013-10-01

    Seewis virus, the shrew-borne hantavirus from Sorex araneus, has been molecularly detected in reservoir hosts in many different central European countries and Russia. Slovenia is a known endemic country for rodent-borne hantaviruses, therefore the aim of the study was to investigate the presence of shrew-borne hantaviruses in insectivores. Viral L, S and M segment have been recovered only from tissue samples of 7 S. araneus, despite several shrew species were tested. Phylogenetic analysis showed high genetic diversity of SWSV in Slovenia, ranging from 3 to 19.4% for different viral segments. The most divergent were M segment sequences, with 19.4% nucleotide divergence among Slovenian strains. Above that, different SWSV strains from Slovenia do not group into separate geographic clusters. While three separate genetic clades were determined, two of them were simultaneously present in one location at the same time. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Genetic divergence through joint analysis of morphoagronomic and molecular characters in accessions of Jatropha curcas.

    Science.gov (United States)

    Pestana-Caldas, C N; Silva, S A; Machado, E L; de Souza, D R; Cerqueira-Pereira, E C; Silva, M S

    2016-10-05

    The aim of this study was to investigate the genetic divergence between accessions of Jatropha curcas through joint analysis of morphoagronomic and molecular characters. To this end, we investigated 11 morphoagronomic characters and performed molecular genotyping, using 23 inter-simple sequence repeat (ISSR) primers in 46 accessions of J. curcas. We calculated the contribution of each character on divergence using analysis of variance. The grouping among accessions was performed using the Ward-MLM (modified location model) method, using morphoagronomic and molecular data, whereas the cophenetic correlation was obtained based on Gower's algorithm. There were significant differences in all growth-related characteristics: number of primary and secondary branches per plant, plant height, and stem diameter. For characters related to grain production, differences were found for number of fruit clusters per plant and number of inflorescence clusters per plant and average number of seeds per fruit. The greatest phenotypic variation was found in plant height (59.67- 222.33 cm), whereas the smallest variation was found in average number of seeds per fruit (0-2.90), followed by the number of fruit clusters per plant (0-8.67). In total, 94 polymorphic ISSR fragments were obtained. The genotypic grouping identified six groups, indicating that there is genetic divergence among the accessions. The most promising crossings for future hybridization were identified among accessions UFRB60 and UFVJC45, and UFRB61 and UFVJC18. In conclusion, the joint analysis of morphoagronomic characters and ISSR markers is an efficient method to assess the genetic divergence in J. curcas.

  16. Application of Molecular Genetics to the Investigation of Inherited Bleeding Disorders

    DEFF Research Database (Denmark)

    Lethagen, Stefan Rune; Dunø, Morten; Nielsen, Lars Bo

    2013-01-01

    Hemophilia is an inherited bleeding disorder primarily caused by deficiency of coagulation factor (F)VIII (hemophilia A) or FIX (hemophilia B). Both conditions are X-linked. More than 2100 different F8 mutations have been described, the most common being a 500 kb inversion involving exon 1 to exo...... quality control systems in place, and participate in established external quality assessment programs....... the causative mutation is unknown. More rare bleeding disorders are generally recessively inherited, and are often caused by mutations that are specific for individual families, and mutations are scattered throughout the genes. Laboratories performing molecular genetic analyses must have validated internal...

  17. Recent advances in the molecular genetics of the lignin degrading fungus, phanerochaete chrysosporium

    International Nuclear Information System (INIS)

    Covert, S.F.

    1991-01-01

    During the past several years, molecular genetics research on phanerochaete chrysosporium, a white-rot basidiomycete, has increased dramatically. It is known that families of highly homologous, clustered genes encode the lignin peroxidases. The same appears to be true with the exocellobiohydrolase genes. Functional domains and active sites have been tentatively identified from the deduced amino acid sequences of these genes. Current investigations focus on elucidating the genomic organization of gene families, the mechanism(s) of gene regulation, and the role and interaction of specific gene products in lignocellulose degradation. (author)

  18. Phenotypic, genetic and molecular characterization of a maize low phytic acid mutant (lpa241)

    DEFF Research Database (Denmark)

    Pilu, R.; Panzeri, D.; Gavazzi, G.

    2003-01-01

    -nutritional factor for animals, and isolation of maize low phytic acid (lpa) mutants provides a novel approach to study its biochemical pathway and to tackle the nutritional problems associated with it. Following chemical mutagenesis of pollen, we have isolated a viable recessive mutant named lpa 241 showing about...... 90% reduction of phytic acid and about a tenfold increase in seed-free phosphate content. Although germination rate was decreased by about 30% compared to wild-type, developement of mutant plants was apparentely unaffected. The results of the genetic, biochemical and molecular characterization...

  19. Molecular genetics of experimental hypertension and the metabolic syndrome: from gene pathways to new therapies

    Czech Academy of Sciences Publication Activity Database

    Pravenec, Michal; Kurtz, T. W.

    2007-01-01

    Roč. 49, č. 5 (2007), s. 941-952 ISSN 0194-911X R&D Projects: GA MZd(CZ) NR8545; GA ČR(CZ) GA301/04/0390; GA ČR(CZ) GA301/06/0028 Grant - others:The Howard Hughes Institute(US) HHMI55005624 Institutional research plan: CEZ:AV0Z50110509 Keywords : SHR * CD36 * metabolic syndrome Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 7.194, year: 2007

  20. Biological chemistry as a foundation of DNA genealogy: the emergence of "molecular history".

    Science.gov (United States)

    Klyosov, A A

    2011-05-01

    foundation for "molecular history", in which the principal tool is high-technology analysis of DNA molecules of both our contemporaries and excavated ancient DNA samples, along with their biological kinetics.

  1. [Genetic polymorphism of flax Linum usitatissimum based on use of molecular cytogenetic markers].

    Science.gov (United States)

    Rachinskaia, O A; Lemesh, V A; Muravenko, O V; Iurkevich, O Iu; Guzenko, E V; Bol'sheva, N L; Bogdanova, M V; Samatadze, T E; Popov, K V; Malyshev, S V; Shostak, N G; Heller, K; Khotyleva, L V; Zelenin, A V

    2011-01-01

    Using a set of approaches based on the use of molecular cytogenetic markers (DAPI/C-banding, estimation of the total area of DAPI-positive regions in prophase nuclei, FISH with 26S and 5S rDNA probes) and the microsatellite (SSR-PCR) assay, we studied genomic polymorphism in 15 flax (Linum usitatissimum L.) varieties from different geographic regions belonging to three directions of selection (oil, fiber, and intermediate flaxes) and in the k-37 x Viking hybrid. All individual chromosomes have been identified in the karyotypes of these varieties on the basis of the patterns of differential DAPI/C-banding and the distribution of 26S and 5S rDNA, and idiograms of the chromosomes have been generated. Unlike the oil flax varieties, the chromosomes in the karyotypes of the fiber flax varieties have, as a rule, pericentromeric and telomeric DAPI-positive bands of smaller size, but contain larger intercalary regions. Two chromosomal rearrangements (chromosome 3 inversions) were discovered in the variety Luna and in the k-37 x Viking hybrid. In both these forms, no colocalization of 26S rDNA and 5S rDNA on the satellite chromosome was detected. The SSR assay with the use of 20 polymorphic pairs of primers revealed 22 polymorphic loci. Based on the SSR data, we analyzed genetic similarity of the flax forms studied and constructed a genetic similarity dendrogram. The genotypes studied here form three clusters. The oil varieties comprise an independent cluster. The genetically related fiber flax varieties Vita and Luna, as well as the landrace Lipinska XIII belonging to the intermediate type, proved to be closer to the oil varieties than the remaining fiber flax varieties. The results of the molecular chromosomal analysis in the fiber and oil flaxes confirm their very close genetic similarity. In spite of this, the combined use of the chromosomal and molecular markers has opened up unique possibilities for describing the genotypes of flax varieties and creating their genetic

  2. Molecular genetic analysis of a cattle population to reconstitute the extinct Algarvia breed

    Directory of Open Access Journals (Sweden)

    Rangel-Figueiredo Teresa

    2010-06-01

    Full Text Available Abstract Background Decisions to initiate conservation programmes need to account for extant variability, diversity loss and cultural and economic aspects. Molecular markers were used to investigate if putative Algarvia animals could be identified for use as progenitors in a breeding programme to recover this nearly extinct breed. Methods 46 individuals phenotypically representative of Algarvia cattle were genotyped for 27 microsatellite loci and compared with 11 Portuguese autochthonous and three imported breeds. Genetic distances and factorial correspondence analyses (FCA were performed to investigate the relationship among Algarvia and related breeds. Assignment tests were done to identify representative individuals of the breed. Y chromosome and mtDNA analyses were used to further characterize Algarvia animals. Gene- and allelic-based conservation analyses were used to determine breed contributions to overall genetic diversity. Results Genetic distance and FCA results confirmed the close relationship between Algarvia and southern Portuguese breeds. Assignment tests without breed information classified 17 Algarvia animals in this cluster with a high probability (q > 0.95. With breed information, 30 cows and three bulls were identified (q > 0.95 that could be used to reconstitute the Algarvia breed. Molecular and morphological results were concordant. These animals showed intermediate levels of genetic diversity (MNA = 6.0 ± 1.6, Rt = 5.7 ± 1.4, Ho = 0.63 ± 0.19 and He = 0.69 ± 0.10 relative to other Portuguese breeds. Evidence of inbreeding was also detected (Fis = 0.083, P st = 0.028, P > 0.05. Algarvia cattle provide an intermediate contribution (CB = 6.18, CW = -0.06 and D1 = 0.50 to the overall gene diversity of Portuguese cattle. Algarvia and seven other autochthonous breeds made no contribution to the overall allelic diversity. Conclusions Molecular analyses complemented previous morphological findings to identify 33 animals that

  3. New approaches to the treatment of orphan genetic disorders: Mitigating molecular pathologies using chemicals

    Directory of Open Access Journals (Sweden)

    RENATA V. VELHO

    2015-08-01

    Full Text Available With the advance and popularization of molecular techniques, the identification of genetic mutations that cause diseases has increased dramatically. Thus, the number of laboratories available to investigate a given disorder and the number of subsequent diagnosis have increased over time. Although it is necessary to identify mutations and provide diagnosis, it is also critical to develop specific therapeutic approaches based on this information. This review aims to highlight recent advances in mutation-targeted therapies with chemicals that mitigate mutational pathology at the molecular level, for disorders that, for the most part, have no effective treatment. Currently, there are several strategies being used to correct different types of mutations, including the following: the identification and characterization of translational readthrough compounds; antisense oligonucleotide-mediated splicing redirection; mismatch repair; and exon skipping. These therapies and other approaches are reviewed in this paper.

  4. New approaches to the treatment of orphan genetic disorders: Mitigating molecular pathologies using chemicals.

    Science.gov (United States)

    Velho, Renata V; Sperb-Ludwig, Fernanda; Schwartz, Ida V D

    2015-08-01

    With the advance and popularization of molecular techniques, the identification of genetic mutations that cause diseases has increased dramatically. Thus, the number of laboratories available to investigate a given disorder and the number of subsequent diagnosis have increased over time. Although it is necessary to identify mutations and provide diagnosis, it is also critical to develop specific therapeutic approaches based on this information. This review aims to highlight recent advances in mutation-targeted therapies with chemicals that mitigate mutational pathology at the molecular level, for disorders that, for the most part, have no effective treatment. Currently, there are several strategies being used to correct different types of mutations, including the following: the identification and characterization of translational readthrough compounds; antisense oligonucleotide-mediated splicing redirection; mismatch repair; and exon skipping. These therapies and other approaches are reviewed in this paper.

  5. Global genetics and invasion history of the potato powdery scab pathogen, Spongospora subterranea f.sp. subterranea.

    Science.gov (United States)

    Gau, Rebecca D; Merz, Ueli; Falloon, Richard E; Brunner, Patrick C

    2013-01-01

    Spongospora subterranea f. sp. subterranea (Sss) causes two diseases on potato (Solanum tuberosum), lesions on tubers and galls on roots, which are economically important worldwide. Knowledge of global genetic diversity and population structure of pathogens is essential for disease management including resistance breeding. A combination of microsatellite and DNA sequence data was used to investigate the structure and invasion history of Sss. South American populations (four countries, 132 samples) were consistently more diverse than those from all other regions (15 countries, 566 samples), in agreement with the hypothesis that Sss originated in South America where potato was domesticated. A substantial genetic differentiation was found between root and tuber-derived samples from South America. Estimates of past and recent gene flow suggested that Sss was probably introduced from South America into Europe. Subsequently, Europe is likely to have been the recent source of migrants of the pathogen, acting as a "bridgehead" for further global dissemination. Quarantine measures must continue to be focussed on maintaining low global genetic diversity and avoiding exchange of genetic material between the native and introduced regions. Nevertheless, the current low global genetic diversity of Sss allows potato breeders to select for resistance, which is likely to be durable.

  6. Global genetics and invasion history of the potato powdery scab pathogen, Spongospora subterranea f.sp. subterranea.

    Directory of Open Access Journals (Sweden)

    Rebecca D Gau

    Full Text Available Spongospora subterranea f. sp. subterranea (Sss causes two diseases on potato (Solanum tuberosum, lesions on tubers and galls on roots, which are economically important worldwide. Knowledge of global genetic diversity and population structure of pathogens is essential for disease management including resistance breeding. A combination of microsatellite and DNA sequence data was used to investigate the structure and invasion history of Sss. South American populations (four countries, 132 samples were consistently more diverse than those from all other regions (15 countries, 566 samples, in agreement with the hypothesis that Sss originated in South America where potato was domesticated. A substantial genetic differentiation was found between root and tuber-derived samples from South America. Estimates of past and recent gene flow suggested that Sss was probably introduced from South America into Europe. Subsequently, Europe is likely to have been the recent source of migrants of the pathogen, acting as a "bridgehead" for further global dissemination. Quarantine measures must continue to be focussed on maintaining low global genetic diversity and avoiding exchange of genetic material between the native and introduced regions. Nevertheless, the current low global genetic diversity of Sss allows potato breeders to select for resistance, which is likely to be durable.

  7. The conservation of forest genetic resources: case histories from Canada, Mexico, and the United States

    Science.gov (United States)

    F. Thomas Ledig; J. Jesús Vargas-Hernández; Kurt H. Johnsen

    1998-01-01

    The genetic codes of living organisms are natural resources no less than soil, air, and water. Genetic resources-from nucleotide sequences in DNA to selected genotypes, populations, and species-are the raw material in forestry: for breeders, for the forest manager who produces an economic crop, for society that reaps the environmental benefits provided by forests, and...

  8. The history and development of the Human Genetics Society of Australasia.

    Science.gov (United States)

    Sutherland, Grant R

    2008-08-01

    The Human Genetics Society of Australasia is a vibrant professional society with more than 900 members that promotes and regulates the practice of human and medical genetics in Australia and New Zealand. The growth of human genetics was stimulated by the development of diagnostic clinical cytogenetics laboratories in the early to mid 1960s. This coincided with the recognition by medical specialists, mainly pediatricians, that genetic disorders, especially inborn errors of metabolism and birth defects, were of clinical interest and potentially challenging areas for their skills. The organization of professionals in human genetics was slow to evolve. There was an early Western Australian Human Genetics Society, and the cytogenetics community had begun to meet annually from about 1966 but was coordinated by a mailing list rather than as a formal organization. In 1976, as part of the celebrations of the Centenary Year of the Adelaide Children's Hospital, a clinical genetics meeting involving several high profile international speakers and most of the senior medical geneticists in Australia and New Zealand along with the annual meeting of the loose-knit cytogeneticists group agreed that a small working group be charged with setting up a Human Genetics Society. The society was formally incorporated in South Australia in 1977.

  9. Children's History of Speech-Language Difficulties: Genetic Influences and Associations with Reading-Related Measures

    Science.gov (United States)

    DeThorne, Laura Segebart; Hart, Sara A.; Petrill, Stephen A.; Deater-Deckard, Kirby; Thompson, Lee Anne; Schatschneider, Chris; Davison, Megan Dunn

    2006-01-01

    Purpose: This study examined (a) the extent of genetic and environmental influences on children's articulation and language difficulties and (b) the phenotypic associations between such difficulties and direct assessments of reading-related skills during early school-age years. Method: Behavioral genetic analyses focused on parent-report data…

  10. Systems Genetics Reveals the Functional Context of PCOS Loci and Identifies Genetic and Molecular Mechanisms of Disease Heterogeneity

    Science.gov (United States)

    Xu, Ning; Cui, Jinrui; Mengesha, Emebet; Chen, Yii-Der I.; Taylor, Kent D.; Azziz, Ricardo; Goodarzi, Mark O.

    2015-01-01

    Genome wide association studies (GWAS) have revealed 11 independent risk loci for polycystic ovary syndrome (PCOS), a common disorder in young women characterized by androgen excess and oligomenorrhea. To put these risk loci and the single nucleotide polymorphisms (SNPs) therein into functional context, we measured DNA methylation and gene expression in subcutaneous adipose tissue biopsies to identify PCOS-specific alterations. Two genes from the LHCGR region, STON1-GTF2A1L and LHCGR, were overexpressed in PCOS. In analysis stratified by obesity, LHCGR was overexpressed only in non-obese PCOS women. Although not differentially expressed in the entire PCOS group, INSR was underexpressed in obese PCOS subjects only. Alterations in gene expression in the LHCGR, RAB5B and INSR regions suggest that SNPs in these loci may be functional and could affect gene expression directly or indirectly via epigenetic alterations. We identified reduced methylation in the LHCGR locus and increased methylation in the INSR locus, changes that are concordant with the altered gene expression profiles. Complex patterns of meQTL and eQTL were identified in these loci, suggesting that local genetic variation plays an important role in gene regulation. We propose that non-obese PCOS women possess significant alterations in LH receptor expression, which drives excess androgen secretion from the ovary. Alternatively, obese women with PCOS possess alterations in insulin receptor expression, with underexpression in metabolic tissues and overexpression in the ovary, resulting in peripheral insulin resistance and excess ovarian androgen production. These studies provide a genetic and molecular basis for the reported clinical heterogeneity of PCOS. PMID:26305227

  11. Systems Genetics Reveals the Functional Context of PCOS Loci and Identifies Genetic and Molecular Mechanisms of Disease Heterogeneity.

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    Michelle R Jones

    2015-08-01

    Full Text Available Genome wide association studies (GWAS have revealed 11 independent risk loci for polycystic ovary syndrome (PCOS, a common disorder in young women characterized by androgen excess and oligomenorrhea. To put these risk loci and the single nucleotide polymorphisms (SNPs therein into functional context, we measured DNA methylation and gene expression in subcutaneous adipose tissue biopsies to identify PCOS-specific alterations. Two genes from the LHCGR region, STON1-GTF2A1L and LHCGR, were overexpressed in PCOS. In analysis stratified by obesity, LHCGR was overexpressed only in non-obese PCOS women. Although not differentially expressed in the entire PCOS group, INSR was underexpressed in obese PCOS subjects only. Alterations in gene expression in the LHCGR, RAB5B and INSR regions suggest that SNPs in these loci may be functional and could affect gene expression directly or indirectly via epigenetic alterations. We identified reduced methylation in the LHCGR locus and increased methylation in the INSR locus, changes that are concordant with the altered gene expression profiles. Complex patterns of meQTL and eQTL were identified in these loci, suggesting that local genetic variation plays an important role in gene regulation. We propose that non-obese PCOS women possess significant alterations in LH receptor expression, which drives excess androgen secretion from the ovary. Alternatively, obese women with PCOS possess alterations in insulin receptor expression, with underexpression in metabolic tissues and overexpression in the ovary, resulting in peripheral insulin resistance and excess ovarian androgen production. These studies provide a genetic and molecular basis for the reported clinical heterogeneity of PCOS.

  12. Systems Genetics Reveals the Functional Context of PCOS Loci and Identifies Genetic and Molecular Mechanisms of Disease Heterogeneity.

    Science.gov (United States)

    Jones, Michelle R; Brower, Meredith A; Xu, Ning; Cui, Jinrui; Mengesha, Emebet; Chen, Yii-Der I; Taylor, Kent D; Azziz, Ricardo; Goodarzi, Mark O

    2015-08-01

    Genome wide association studies (GWAS) have revealed 11 independent risk loci for polycystic ovary syndrome (PCOS), a common disorder in young women characterized by androgen excess and oligomenorrhea. To put these risk loci and the single nucleotide polymorphisms (SNPs) therein into functional context, we measured DNA methylation and gene expression in subcutaneous adipose tissue biopsies to identify PCOS-specific alterations. Two genes from the LHCGR region, STON1-GTF2A1L and LHCGR, were overexpressed in PCOS. In analysis stratified by obesity, LHCGR was overexpressed only in non-obese PCOS women. Although not differentially expressed in the entire PCOS group, INSR was underexpressed in obese PCOS subjects only. Alterations in gene expression in the LHCGR, RAB5B and INSR regions suggest that SNPs in these loci may be functional and could affect gene expression directly or indirectly via epigenetic alterations. We identified reduced methylation in the LHCGR locus and increased methylation in the INSR locus, changes that are concordant with the altered gene expression profiles. Complex patterns of meQTL and eQTL were identified in these loci, suggesting that local genetic variation plays an important role in gene regulation. We propose that non-obese PCOS women possess significant alterations in LH receptor expression, which drives excess androgen secretion from the ovary. Alternatively, obese women with PCOS possess alterations in insulin receptor expression, with underexpression in metabolic tissues and overexpression in the ovary, resulting in peripheral insulin resistance and excess ovarian androgen production. These studies provide a genetic and molecular basis for the reported clinical heterogeneity of PCOS.

  13. Demographic History and Reproductive Output Correlates with Intraspecific Genetic Variation in Seven Species of Indo-Pacific Mangrove Crabs.

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    Sara Fratini

    Full Text Available The spatial distribution and the amount of intraspecific genetic variation of marine organisms are strongly influenced by many biotic and abiotic factors. Comparing biological and genetic data characterizing species living in the same habitat can help to elucidate the processes driving these variation patterns. Here, we present a comparative multispecies population genetic study on seven mangrove crabs co-occurring in the West Indian Ocean characterized by planktotrophic larvae with similar pelagic larval duration. Our main aim was to investigate whether a suite of biological, behavioural and ecological traits could affect genetic diversities of the study species in combination with historical demographic parameters. As possible current explanatory factors, we used the intertidal micro-habitat colonised by adult populations, various parameters of individual and population fecundity, and the timing of larval release. As the genetic marker, we used partial sequences of cytochrome oxidase subunit I gene. Genetic and ecological data were collected by the authors and/or gathered from primary literature. Permutational multiple regression models and ANOVA tests showed that species density and their reproductive output in combination with historical demographic parameters could explain the intraspecific genetic variation indexes across the seven species. In particular, species producing consistently less eggs per spawning event showed higher values of haplotype diversity. Moreover, Tajima's D parameters well explained the recorded values for haplotype diversity and average γst. We concluded that current intraspecific gene diversities in crabs inhabiting mangrove forests were affected by population fecundity as well as past demographic history. The results were also discussed in terms of management and conservation of fauna in the Western Indian Ocean mangroves.

  14. Demographic History and Reproductive Output Correlates with Intraspecific Genetic Variation in Seven Species of Indo-Pacific Mangrove Crabs.

    Science.gov (United States)

    Fratini, Sara; Ragionieri, Lapo; Cannicci, Stefano

    2016-01-01

    The spatial distribution and the amount of intraspecific genetic variation of marine organisms are strongly influenced by many biotic and abiotic factors. Comparing biological and genetic data characterizing species living in the same habitat can help to elucidate the processes driving these variation patterns. Here, we present a comparative multispecies population genetic study on seven mangrove crabs co-occurring in the West Indian Ocean characterized by planktotrophic larvae with similar pelagic larval duration. Our main aim was to investigate whether a suite of biological, behavioural and ecological traits could affect genetic diversities of the study species in combination with historical demographic parameters. As possible current explanatory factors, we used the intertidal micro-habitat colonised by adult populations, various parameters of individual and population fecundity, and the timing of larval release. As the genetic marker, we used partial sequences of cytochrome oxidase subunit I gene. Genetic and ecological data were collected by the authors and/or gathered from primary literature. Permutational multiple regression models and ANOVA tests showed that species density and their reproductive output in combination with historical demographic parameters could explain the intraspecific genetic variation indexes across the seven species. In particular, species producing consistently less eggs per spawning event showed higher values of haplotype diversity. Moreover, Tajima's D parameters well explained the recorded values for haplotype diversity and average γst. We concluded that current intraspecific gene diversities in crabs inhabiting mangrove forests were affected by population fecundity as well as past demographic history. The results were also discussed in terms of management and conservation of fauna in the Western Indian Ocean mangroves.

  15. A molecular, genetic and physiological analysis of plant aluminum tolerance (abstract)

    International Nuclear Information System (INIS)

    Pineros, M.

    2005-01-01

    Aluminum (Al) toxicity is an important agronomic trait, limiting crop production on acid soils that comprise up to 50% of the world's potentially arable lands. A significant genetic variation in Al tolerance exists in both crop plants and Arabidopsis. The exploitation of this genetic variation to breed crops with increased Al tolerance has been a productive and active area of research, however, the underlying molecular, genetic and physiological bases are still not well understood. Only very recently was the first Al tolerance gene, ALMT1, isolated in wheat and shown to be a novel Al-activated malate transporter. Work in our laboratory has focused on using integrated genomic (gene and protein expression profiling), molecular genetic and physiological approaches to identify novel Al tolerance genes and the physiological mechanisms they control in the cereal crops maize and sorghum, and also in arabidopsis. In sorghum we had previously shown that Al tolerance is the result of a single locus, Alt/sub SB/ which maps to the top of sorghum chromosome 3 in a region totally distinct from where the major Al tolerance maps in wheat and other related members of the Triticeae. Very recently, we have used map-based cloning techniques in sorghum to clone Alt/sub SB/ and have found it is a novel Al tolerance gene. Here we will present a molecular characterization of the Alt/sub SB/ gene and also the physiological mechanism of sorghum Al tolerance it controls. In arabidopsis, we have previously shown that Al tolerance is a quantitative trait and have identified two major Al tolerance QTL on chromosomes 1 and 5. These genes function to confer tolerance via Al via activated root malate release. We found that a member of the arabidopsis gene family that is a close homolog to wheat ALMT1 maps near the largest tolerance QTL on chromosome 1 and have also found this gene encodes the Al-activated malate transport involved in arabidopsis Al tolerance. However, we have clear molecular

  16. Genetic diversity analyses of Lasiodiplodia theobromae on Morus alba and Agave sisalana based on RAPD and ISSR molecular markers

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    Hong-hui Xie

    2016-10-01

    Full Text Available Genetic diversity of 23 Lasiodiplodia theobromae isolates on Morus alba and 6 isolates on Agave sisalana in Guangxi province, China, was studied by using random amplified polymorphic DNA and inter-simple sequence repeat molecular markers. Results of two molecular markers showed that the average percentage of polymorphic loci of all isolates was more than 93%. Both dendrograms of two molecular markers showed obvious relationship between groups and the geographical locations where those strains were collected, among which, the 23 isolates on M. alba were divided into 4 populations and the 6 isolates on A. sisalana were separated as a independent population. The average genetic identity and genetic distance of 5 populations were 0.7215, 0.3284 and 0.7915, 0.2347, respectively, which indicated that the genetic identity was high and the genetic distance was short in the 5 populations. Average value of the gene diversity index (H and the Shannon’s information index (I of 29 isolates were significantly higher than 5 populations which showed that genetic diversity of those isolates was richer than the populations and the degree of genetic differentiation of the isolates was higher. The Gst and Nm of 29 isolates were 0.4411, 0.6335 and 0.4756, 0.5513, respectively, which showed that the genetic diversity was rich in those isolates.

  17. Molecular Insights into the Genetic Diversity of Hemarthria compressa Germplasm Collections Native to Southwest China

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    Zhi-Hui Guo

    2014-12-01

    Full Text Available Start codon targeted polymorphism (SCoT analysis was employed to distinguish 37 whipgrass (Hemarthria compressa L. clones and assess the genetic diversity and population structure among these genotypes. The informativeness of markers was also estimated using various parameters. Using 25 highly reproducible primer sets, 368 discernible fragments were generated. Of these, 282 (77.21% were polymorphic. The number of alleles per locus ranged from five to 21, and the genetic variation indices varied. The polymorphism information content (PIC was 0.358, the Shannon diversity index (H was 0.534, the marker index (MI was 4.040, the resolving power (RP was 6.108, and the genotype index (GI was 0.782. Genetic similarity coefficients (GS between the accessions ranged from 0.563 to 0.872, with a mean of 0.685. Their patterns observed in a dendrogram constructed using the unweighted pair group method with arithmetic mean analysis (UPGMA based on GS largely confirmed the results of principal coordinate analysis (PCoA. PCoA was further confirmed by Bayesian model-based STRUCTURE analysis, which revealed no direct association between genetic relationship and geographical origins as validated by Mantel’s test (r = 0.2268, p = 0.9999. In addition, high-level genetic variation within geographical groups was significantly greater than that between groups, as determined by Shannon diversity analysis, analysis of molecular variance (AMOVA and Bayesian analysis. Overall, SCoT analysis is a simple, effective and reliable technique for characterizing and maintaining germplasm collections of whipgrass and related species.

  18. Molecular genetic features of polyploidization and aneuploidization reveal unique patterns for genome duplication in diploid Malus.

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    Michael J Considine

    Full Text Available Polyploidization results in genome duplication and is an important step in evolution and speciation. The Malus genome confirmed that this genus was derived through auto-polyploidization, yet the genetic and meiotic mechanisms for polyploidization, particularly for aneuploidization, are unclear in this genus or other woody perennials. In fact the contribution of aneuploidization remains poorly understood throughout Plantae. We add to this knowledge by characterization of eupolyploidization and aneuploidization in 27,542 F₁ seedlings from seven diploid Malus populations using cytology and microsatellite markers. We provide the first evidence that aneuploidy exceeds eupolyploidy in the diploid crosses, suggesting aneuploidization is a leading cause of genome duplication. Gametes from diploid Malus had a unique combinational pattern; ova preserved euploidy exclusively, while spermatozoa presented both euploidy and aneuploidy. All non-reduced gametes were genetically heterozygous, indicating first-division restitution was the exclusive mode for Malus eupolyploidization and aneuploidization. Chromosome segregation pattern among aneuploids was non-uniform, however, certain chromosomes were associated for aneuploidization. This study is the first to provide molecular evidence for the contribution of heterozygous non-reduced gametes to fitness in polyploids and aneuploids. Aneuploidization can increase, while eupolyploidization may decrease genetic diversity in their newly established populations. Auto-triploidization is important for speciation in the extant Malus. The features of Malus polyploidization confer genetic stability and diversity, and present heterozygosity, heterosis and adaptability for evolutionary selection. A protocol using co-dominant markers was proposed for accelerating apple triploid breeding program. A path was postulated for evolution of numerically odd basic chromosomes. The model for Malus derivation was considerably revised

  19. Molecular genetic features of polyploidization and aneuploidization reveal unique patterns for genome duplication in diploid Malus.

    Science.gov (United States)

    Considine, Michael J; Wan, Yizhen; D'Antuono, Mario F; Zhou, Qian; Han, Mingyu; Gao, Hua; Wang, Man

    2012-01-01

    Polyploidization results in genome duplication and is an important step in evolution and speciation. The Malus genome confirmed that this genus was derived through auto-polyploidization, yet the genetic and meiotic mechanisms for polyploidization, particularly for aneuploidization, are unclear in this genus or other woody perennials. In fact the contribution of aneuploidization remains poorly understood throughout Plantae. We add to this knowledge by characterization of eupolyploidization and aneuploidization in 27,542 F₁ seedlings from seven diploid Malus populations using cytology and microsatellite markers. We provide the first evidence that aneuploidy exceeds eupolyploidy in the diploid crosses, suggesting aneuploidization is a leading cause of genome duplication. Gametes from diploid Malus had a unique combinational pattern; ova preserved euploidy exclusively, while spermatozoa presented both euploidy and aneuploidy. All non-reduced gametes were genetically heterozygous, indicating first-division restitution was the exclusive mode for Malus eupolyploidization and aneuploidization. Chromosome segregation pattern among aneuploids was non-uniform, however, certain chromosomes were associated for aneuploidization. This study is the first to provide molecular evidence for the contribution of heterozygous non-reduced gametes to fitness in polyploids and aneuploids. Aneuploidization can increase, while eupolyploidization may decrease genetic diversity in their newly established populations. Auto-triploidization is important for speciation in the extant Malus. The features of Malus polyploidization confer genetic stability and diversity, and present heterozygosity, heterosis and adaptability for evolutionary selection. A protocol using co-dominant markers was proposed for accelerating apple triploid breeding program. A path was postulated for evolution of numerically odd basic chromosomes. The model for Malus derivation was considerably revised. Impacts of

  20. Molecular markers reveal limited population genetic structure in a North American corvid, Clark's nutcracker (Nucifraga columbiana.

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    Kimberly M Dohms

    Full Text Available The genetic impact of barriers and Pleistocene glaciations on high latitude resident species has not been widely investigated. The Clark's nutcracker is an endemic North American corvid closely associated with Pinus-dominated forests. The nutcracker's encompasses known barriers to dispersal for other species, and glaciated and unglaciated areas. Clark's nutcrackers also irruptively disperse long distances in search of pine seed crops, creating the potential for gene flow among populations. Using the highly variable mitochondrial DNA control region, seven microsatellite loci, and species distribution modeling, we examined the effects of glaciations and dispersal barriers on population genetic patterns and population structure of nutcrackers. We sequenced 900 bp of mitochondrial control region for 169 individuals from 15 populations and analysed seven polymorphic microsatellite loci for 13 populations across the Clark's nutcracker range. We used species distribution modeling and a range of phylogeographic analyses to examine evolutionary history. Clark's nutcracker populations are not highly differentiated throughout their range, suggesting high levels of gene flow among populations, though we did find some evidence of isolation by distance and peripheral isolation. Our analyses suggested expansion from a single refugium after the last glacial maximum, but patterns of genetic diversity and paleodistribution modeling of suitable habitat were inconclusive as to the location of this refugium. Potential barriers to dispersal (e.g. mountain ranges do not appear to restrict gene flow in Clark's nutcracker, and postglacial expansion likely occurred quickly from a single refugium located south of the ice sheets.