Estimation of genetic variability and heritability of wheat agronomic traits resulted from some gamma rays irradiation techniques

International Nuclear Information System (INIS)

Wijaya Murti Indriatama; Trikoesoemaningtyas; Syarifah Iis Aisyah; Soeranto Human

2016-01-01

Gamma irradiation techniques have significant effect on frequency and spectrum of macro-mutation but the study of its effect on micro-mutation that related to genetic variability on mutated population is very limited. The aim of this research was to study the effect of gamma irradiation techniques on genetic variability and heritability of wheat agronomic characters at M2 generation. This research was conducted from July to November 2014, at Cibadak experimental station, Indonesian Center for Agricultural Biotechnology and Genetic Resources Research and Development, Ministry of Agriculture. Three introduced wheat breeding lines (F-44, Kiran-95 & WL-711) were treated by 3 gamma irradiation techniques (acute, fractionated and intermittent). M1 generation of combination treatments were planted and harvested its spike individually per plants. As M2 generation, seeds of 75 M1 spike were planted at the field with one row one spike method and evaluated on the agronomic characters and its genetic components. The used of gamma irradiation techniques decreased mean but increased range values of agronomic traits in M2 populations. Fractionated irradiation induced higher mean and wider range on spike length and number of spike let per spike than other irradiation techniques. Fractionated and intermittent irradiation resulted greater variability of grain weight per plant than acute irradiation. The number of tillers, spike weight, grain weight per spike and grain weight per plant on M2 population resulted from induction of three gamma irradiation techniques have high estimated heritability and broad sense of genetic variability coefficient values. The three gamma irradiation techniques increased genetic variability of agronomic traits on M2 populations, except plant height. (author)

Genetic variability in Sudanese Acacia senegal (L.) assessed by ...

African Journals Online (AJOL)

TUOYO

2010-07-26

Jul 26, 2010 ... Full Length Research Paper. Genetic variability in Sudanese Acacia senegal (L.) assessed by random amplified polymorphic DNA. Rami S. Habeballa*, Nada B. Hamza and Eisa I. El Gaali. Commission for Biotechnology and Genetic Engineering, National Centre for Research, Khartoum, Sudan. P. O. Box.

Genetic variability of six French meat sheep breeds in relation to their genetic management.

Science.gov (United States)

Huby, Marie; Griffon, Laurent; Moureaux, Sophie; De Rochambeau, Hubert; Danchin-Burge, Coralie; Verrier, Etienne

2003-01-01

Some demographic parameters, the genetic structure and the evolution of the genetic variability of six French meat sheep breeds were analysed in relation with their management. Four of these breeds are submitted to more or less intense selection: the Berrichon du Cher (BCH), Blanc du Massif Central (BMC), Charollais (CHA) and Limousin (LIM); the other two breeds are under conservation: the Roussin de La Hague (RLH) and Solognot (SOL). Genealogical data of the recorded animals born from 1970 to 2000 and of their known ancestors were used. The most balanced contributions of the different flocks to the sire-daughter path was found in the SOL. In the BCH, a single flock provided 43% of the sire-AI sire path, whereas the contributions of the flocks were more balanced in the BMC and LIM (the only other breeds where AI is used to a substantial amount). The distribution of the expected genetic contribution of the founder animals was found to be unbalanced, especially in the BCH and LIM. The effective numbers of ancestors (founders or not) for the ewes born from 1996 to 2000 were equal to 35 (BCH), 144 (BMC), 112 (CHA), 69 (LIM), 40 (RLH) and 49 (SOL). Inbreeding was not analysed in the BMC, due to incomplete pedigree information. From 1980 on, the rates of inbreeding, in percentage points per year, were +0.112 (BCH), +0.045 (CHA), +0.036 (LIM), +0.098 (RLH) and +0.062 (SOL). The implications of the observed trends on genetic variability are discussed in relation to the genetic management of each breed. The need for a larger selection basis in the BCH, the efficiency of the rules applied in the SOL to preserve the genetic variability and the need for a more collective organisation in the CHA and RLH are outlined.

Genetic variability of six French meat sheep breeds in relation to their genetic management

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Coralie Danchin-Burge

2003-11-01

Full Text Available Abstract Some demographic parameters, the genetic structure and the evolution of the genetic variability of six French meat sheep breeds were analysed in relation with their management. Four of these breeds are submitted to more or less intense selection: the Berrichon du Cher (BCH, Blanc du Massif Central (BMC, Charollais (CHA and Limousin (LIM; the other two breeds are under conservation: the Roussin de La Hague (RLH and Solognot (SOL. Genealogical data of the recorded animals born from 1970 to 2000 and of their known ancestors were used. The most balanced contributions of the different flocks to the sire-daughter path was found in the SOL. In the BCH, a single flock provided 43% of the sire-AI sire path, whereas the contributions of the flocks were more balanced in the BMC and LIM (the only other breeds where AI is used to a substantial amount. The distribution of the expected genetic contribution of the founder animals was found to be unbalanced, especially in the BCH and LIM. The effective numbers of ancestors (founders or not for the ewes born from 1996 to 2000 were equal to 35 (BCH, 144 (BMC, 112 (CHA, 69 (LIM, 40 (RLH and 49 (SOL. Inbreeding was not analysed in the BMC, due to incomplete pedigree information. From 1980 on, the rates of inbreeding, in percentage points per year, were +0.112 (BCH, +0.045 (CHA, +0.036 (LIM, +0.098 (RLH and +0.062 (SOL. The implications of the observed trends on genetic variability are discussed in relation to the genetic management of each breed. The need for a larger selection basis in the BCH, the efficiency of the rules applied in the SOL to preserve the genetic variability and the need for a more collective organisation in the CHA and RLH are outlined.

ABCB1 genetic variability and methadone dosage requirements in opioid-dependent individuals.

Science.gov (United States)

Coller, Janet K; Barratt, Daniel T; Dahlen, Karianne; Loennechen, Morten H; Somogyi, Andrew A

2006-12-01

The most common treatment for opioid dependence is substitution therapy with another opioid such as methadone. The methadone dosage is individualized but highly variable, and program retention rates are low due in part to nonoptimal dosing resulting in withdrawal symptoms and further heroin craving and use. Methadone is a substrate for the P-glycoprotein transporter, encoded by the ABCB1 gene, which regulates central nervous system exposure. This retrospective study aimed to investigate the influence of ABCB1 genetic variability on methadone dose requirements. Genomic deoxyribonucleic acid was isolated from opioid-dependent subjects (n = 60) and non-opioid-dependent control subjects (n = 60), and polymerase chain reaction-restriction fragment length polymorphism and allele-specific polymerase chain reaction were used to determine the presence of single nucleotide polymorphisms at positions 61, 1199, 1236, 2677, and 3435. ABCB1 haplotypes were inferred with PHASE software (version 2.1). There were no significant differences in the allele or genotype frequencies of the individual single nucleotide polymorphisms or haplotypes between the 2 populations. ABCB1 genetic variability influenced daily methadone dose requirements, such that subjects carrying 2 copies of the wild-type haplotype required higher doses compared with those with 1 copy and those with no copies (98.3 +/- 10.4, 58.6 +/- 20.9, and 55.4 +/- 26.1 mg/d, respectively; P = .029). In addition, carriers of the AGCTT haplotype required significantly lower doses than noncarriers (38.0 +/- 16.8 and 61.3 +/- 24.6 mg/d, respectively; P = .04). Although ABCB1 genetic variability is not related to the development of opioid dependence, identification of variant haplotypes may, after larger prospective studies have been performed, provide clinicians with a tool for methadone dosage individualization.

Genetic Influence on Slope Variability in a Childhood Reflexive Attention Task.

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Rebecca A Lundwall

Full Text Available Individuals are not perfectly consistent, and interindividual variability is a common feature in all varieties of human behavior. Some individuals respond more variably than others, however, and this difference may be important to understanding how the brain works. In this paper, we explore genetic contributions to response time (RT slope variability on a reflexive attention task. We are interested in such variability because we believe it is an important part of the overall picture of attention that, if understood, has the potential to improve intervention for those with attentional deficits. Genetic association studies are valuable in discovering biological pathways of variability and several studies have found such associations with a sustained attention task. Here, we expand our knowledge to include a reflexive attention task. We ask whether specific candidate genes are associated with interindividual variability on a childhood reflexive attention task in 9-16 year olds. The genetic makers considered are on 11 genes: APOE, BDNF, CHRNA4, COMT, DRD4, HTR4, IGF2, MAOA, SLC5A7, SLC6A3, and SNAP25. We find significant associations with variability with markers on nine and we discuss the results in terms of neurotransmitters associated with each gene and the characteristics of the associated measures from the reflexive attention task.

Genetic variability in common wheat germplasm based on coefficients of parentage

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Fernanda Bered

2002-01-01

Full Text Available The characterization of genetic variability and an estimate of the genetic relationship among varieties are essential to any breeding program, because artificial crosses among less similar parents allow a larger segregation and the combination of different favorable alleles. Genetic variability can be evaluated in different ways, including the Coefficient of Parentage (COP, which estimates the probability of two alleles in two different individuals being identical by descent. In this study, we evaluated the degree of genetic relationship among 53 wheat genotypes, and identified the ancestor genotypes which contributed the most to the current wheat germplasm, as a prediction of the width of the genetic base of this cereal. The results revealed a mean COP of 0.07 and the formation of 22 similarity groups. The ancestor genotypes Ciano 67 and Mentana were those which contributed the most to the current wheat germplasm. According to the COP analyses, the genetic base of wheat rests on a small number of ancestral genotypes.

Genetic variability assessment in the genus Passiflora by SSR markers

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Claudia Lougon Paiva

2014-09-01

Full Text Available The genus Passiflora encompasses many species that are endemic to the Brazilian territory, including some with economic value. Studies on genetic diversity in this genus are fundamental because they allow understanding genetic variability and distance. The present study aimed to determine the genetic variability and distances among 10 species of the genus Passiflora by using microsatellite markers (Simple Sequence Repeat, SSR. Twenty-eight heterologous microsatellite markers were tested, but only 12 were used in the diversity analysis because they amplified in at least 80% of the species. A clear separation was observed among the subgenuses studied, as well as wide variation among the accessions of Passiflora. This knowledge enables breeders to explore diversity and transfer favorable alleles found in wild species.

Use of the IRAP marker to study genetic variability in Pseudocercospora fijiensis populations.

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de Queiroz, Casley Borges; Santana, Mateus Ferreira; da Silva, Gilvan Ferreira; Mizubuti, Eduardo Seiti Gomide; de Araújo, Elza Fernandes; de Queiroz, Marisa Vieira

2014-03-01

Pseudocercospora fijiensis is the etiological agent of black Sigatoka, which is currently considered as one of the most destructive banana diseases in all locations where it occurs. It is estimated that a large portion of the P. fijiensis genome consists of transposable elements, which allows researchers to use transposon-based molecular markers in the analysis of genetic variability in populations of this pathogen. In this context, the inter-retrotransposon-amplified polymorphism (IRAP) was used to study the genetic variability in P. fijiensis populations from different hosts and different geographical origins in Brazil. A total of 22 loci were amplified and 77.3 % showed a polymorphism. Cluster analysis revealed two major groups in Brazil. The observed genetic diversity (H E) was 0.22, and through molecular analysis of variance, it was determined that the greatest genetic variability occurs within populations. The discriminant analysis of principal components revealed no structuring related to the geographical origin of culture of the host. The IRAP-based marker system is a suitable tool for the study of genetic variability in P. fijiensis.

Genetic variability of broodstocks of restocking programs in Brazil

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Nelson Lopera-Barrero

2015-09-01

Full Text Available Objective. The aim of this study was evaluate the genetic diversity of the following broodstocks: piapara (Leporinus elongatus, dourado (Salminus brasiliensis, jundiá (Rhamdia quelen and cachara (Pseudoplatystoma fasciatum already useful for restocking programs in the Paranapanema, Iguaçu and Paraná Brazilian Rivers. Materials and methods. Samples from the caudal fin of 122 fish were analyzed. DNA was extracted by NaCl protocol. PCR products were separated by a horizontal agarose gel electrophoresis. The fragments were visualized by staining with ethidium bromide. Results. The amplification of 25 primers generated different fragments in studied species that allowed characterizing 440 fragments of 100-2900 bp. High percentage of polymorphic fragments (66.67 to 86.29, Shannon index (0.365 to 0.486 and genetic diversity of Nei (0.248 to 0.331 were detected. Conclusions. The level of genetic variability in the broodstocks was adequate for allowing their use in restocking programs in the studied Rivers. However, periodical monitoring studies of genetic variability in these stocks, the mating system, reproductive system and general management must be made to guarantee the preservation of wild populations.

Increased genetic variance of BMI with a higher prevalence of obesity

DEFF Research Database (Denmark)

Rokholm, Benjamin; Silventoinen, Karri; Ängquist, Lars

2011-01-01

populations. Several recent studies suggest that the genetic effects on adiposity may be stronger when combined with presumed risk factors for obesity. We tested the hypothesis that a higher prevalence of obesity and overweight and a higher BMI mean is associated with a larger genetic variation in BMI....

NOTE - Characterization of genetic variability among common bean genotypes by morphological descriptors

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Marilene Santos de Lima

2012-01-01

Full Text Available The purpose of this study was to characterize the genetic variability in 100 genotypes of the Active Germplasm Bank of common bean of the Federal University of Viçosa, by morphological descriptors, classify them in groups of genetic similarity and to identify the degree of relevance of descriptors of genetic divergence. The genotypes were evaluated based on 22 quantitative and qualitative morphological descriptors. The highyielding genotypes V 7936, Gold Gate, LM 95103904, 1829 S 349 Venezuela, and PF 9029975, CNFC 9454 andFe 732015, with upright growth, have potential for use as parents in common bean breeding programs. By genetic divergence analysis, the genotypes were clustered in eight groups of genetic dissimilarity. By methods of principal components, 9 of the 22 descriptors were eliminated, for being redundant or little variable, suggesting that 10-20 morphological descriptors can be used in studies of characterization of genetic variation.

Ecological Risk Assessment of Genetically Modified Higher Plants (GMHP)

DEFF Research Database (Denmark)

Kjær, C.; Damgaard, C.; Kjellsson, G.

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

Variables Affecting Secondary School Students' Willingness to Eat Genetically Modified Food Crops

Science.gov (United States)

Maes, Jasmien; Bourgonjon, Jeroen; Gheysen, Godelieve; Valcke, Martin

2017-04-01

A large-scale cross-sectional study (N = 4002) was set up to determine Flemish secondary school students' willingness to eat genetically modified food (WTE) and to link students' WTE to previously identified key variables from research on the acceptance of genetic modification (GM). These variables include subjective and objective knowledge about genetics and biotechnology, perceived risks and benefits of GM food crops, trust in information from different sources about GM, and food neophobia. Differences between WTE-related variables based on students' grade level, educational track, and gender were analyzed. The students displayed a rather indecisive position toward GM food and scored weakly on a genetics and biotechnology knowledge test. WTE correlated most strongly with perceived benefits and subjective and objective knowledge. The results have clear implications for education, as they reiterate the need to strengthen students' scientific knowledge base and to introduce a GM-related debate at a much earlier stage in their school career.

Genetic variability of Artemisia capillaris (Wormwood capillary) by ...

African Journals Online (AJOL)

The genetic variability among individuals of Artemisia capillaris from state of Terengganu, Malaysia was examined by using the random amplified polymorphic DNA (RAPD) technique. The samples were collected from differences regional in Terengganu State. The genomic DNA was extracted from the samples leaves.

Assessment of genetic variability of maize inbred lines and their ...

African Journals Online (AJOL)

Assessment of genetic variability of maize inbred lines and their hybrids under normal and drought conditions. ... Nigeria Agricultural Journal ... Analysis of variance revealed significant differences for most of the characters under study which indicates the presence of sufficient amount of variability offering ample scope for ...

Temporal dynamics of genetic variability in a mountain goat (Oreamnos americanus) population.

Science.gov (United States)

Ortego, Joaquín; Yannic, Glenn; Shafer, Aaron B A; Mainguy, Julien; Festa-Bianchet, Marco; Coltman, David W; Côté, Steeve D

2011-04-01

The association between population dynamics and genetic variability is of fundamental importance for both evolutionary and conservation biology. We combined long-term population monitoring and molecular genetic data from 123 offspring and their parents at 28 microsatellite loci to investigate changes in genetic diversity over 14 cohorts in a small and relatively isolated population of mountain goats (Oreamnos americanus) during a period of demographic increase. Offspring heterozygosity decreased while parental genetic similarity and inbreeding coefficients (F(IS) ) increased over the study period (1995-2008). Immigrants introduced three novel alleles into the population and matings between residents and immigrants produced more heterozygous offspring than local crosses, suggesting that immigration can increase population genetic variability. The population experienced genetic drift over the study period, reflected by a reduced allelic richness over time and an 'isolation-by-time' pattern of genetic structure. The temporal decline of individual genetic diversity despite increasing population size probably resulted from a combination of genetic drift due to small effective population size, inbreeding and insufficient counterbalancing by immigration. This study highlights the importance of long-term genetic monitoring to understand how demographic processes influence temporal changes of genetic diversity in long-lived organisms. © 2011 Blackwell Publishing Ltd.

Variability and population genetic structure in Achyrocline flaccida (Weinm. DC., a species with high value in folk medicine in South America.

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Juliana da Rosa

Full Text Available Better knowledge of medicinal plant species and their conservation is an urgent need worldwide. Decision making for conservation strategies can be based on the knowledge of the variability and population genetic structure of the species and on the events that may influence these genetic parameters. Achyrocline flaccida (Weinm. DC. is a native plant from the grassy fields of South America with high value in folk medicine. In spite of its importance, no genetic and conservation studies are available for the species. In this work, microsatellite and ISSR (inter-simple sequence repeat markers were used to estimate the genetic variability and structure of seven populations of A. flaccida from southern Brazil. The microsatellite markers were inefficient in A. flaccida owing to a high number of null alleles. After the evaluation of 42 ISSR primers on one population, 10 were selected for further analysis of seven A. flaccida populations. The results of ISSR showed that the high number of exclusive absence of loci might contribute to the inter-population differentiation. Genetic variability of the species was high (Nei's diversity of 0.23 and Shannon diversity of 0.37. AMOVA indicated higher genetic variability within (64.7% than among (33.96% populations, and the variability was unevenly distributed (FST 0.33. Gene flow among populations ranged from 1.68 to 5.2 migrants per generation, with an average of 1.39. The results of PCoA and Bayesian analyses corroborated and indicated that the populations are structured. The observed genetic variability and population structure of A. flaccida are discussed in the context of the vegetation formation history in southern Brazil, as well as the possible anthropogenic effects. Additionally, we discuss the implications of the results in the conservation of the species.

Hookworm infection, anaemia and genetic variability of the New Zealand sea lion.

Science.gov (United States)

Acevedo-Whitehouse, Karina; Petetti, Laura; Duignan, Padraig; Castinel, Aurelie

2009-10-07

Hookworms are intestinal blood-feeding nematodes that parasitize and cause high levels of mortality in a wide range of mammals, including otariid pinnipeds. Recently, an empirical study showed that inbreeding (assessed by individual measures of multi-locus heterozygosity) is associated with hookworm-related mortality of California sea lions. If inbreeding increases susceptibility to hookworms, effects would expectedly be stronger in small, fragmented populations. We tested this assumption in the New Zealand sea lion, a threatened otariid that has low levels of genetic variability and high hookworm infection rates. Using a panel of 22 microsatellites, we found that average allelic diversity (5.9) and mean heterozygosity (0.72) were higher than expected for a small population with restricted breeding, and we found no evidence of an association between genetic variability and hookworm resistance. However, similar to what was observed for the California sea lion, homozygosity at a single locus explained the occurrence of anaemia and thrombocytopenia in hookworm-infected pups (generalized linear model, F = 11.81, p < 0.001) and the effect was apparently driven by a particular allele (odds ratio = 34.95%; CI: 7.12-162.41; p < 0.00001). Our study offers further evidence that these haematophagus parasites exert selective pressure on otariid blood-clotting processes.

genetic variability among landraces of sesame in ethiopia abstract

African Journals Online (AJOL)

journal

Modified Rogers' Distances (MRD) and a principal coordinate analysis based on a ... Moreover, existence of great genetic variability between the landraces is a good starting point of sesame ...... among and within CIMMYT wheat landrace.

Genetic characterization of Toxoplasma gondii isolates from Portugal, Austria, and Israel reveals higher genetic variability within the type II lineage

Science.gov (United States)

This study compared genetic diversity of Toxoplasma gondii isolates from Portugal, Austria and Israel. For this, we genotyped 90 T. gondii isolates (16 from Portugal, 67 from Austria and 7 from Israel) using 10 nested PCR-restriction length polymorphism (RFLP) genetic markers and 15 microsatellite (...

Genetic variability among landraces of sesame in Ethiopia ...

African Journals Online (AJOL)

African Crop Science Journal ... Sesame (Sesamum indicum L.) is an ancient oil crop that has been referred to as the 'Queen of oilseeds' by virtue of its high quality oil. ... Moreover, existence of great genetic variability between the landraces is a good starting point of sesame crop improvement programs in Ethiopia.

Genetic Variability in Barley (Hordeum vulgare l.) Landraces from ...

African Journals Online (AJOL)

segregating progenies with maximum genetic variability for selection. .... cultivar Clipper applied in slots of the first two, the tenth, and the last ... solution (50 ml glacial acetic acid, 200 ml methanol and 250 ml distilled water) ...... Adelaide, South.

Genetic variability and inter-character associations in the mutants of Indian mustard

International Nuclear Information System (INIS)

Labana, K.S.; Chaurasia, B.D.; Singh, Balwant

1980-01-01

To study the genetic variability and the inter-character associations in Indian mustard [Brassica juncea (Linn.)Czern. and Coss. subsp. juncea Linn.], 104 radiation-induced mutants (including 'RLM 198') and 'RL 18' were grown during winter season of 1976-77 at the experimental farm of the Punjab Agricultural University. Analysis of variance revealed significant differences between the mutant genotypes for all the characters under study except for the primary branch number and siliqua number of main shoot, which were non-significant. High estimates of phenotypic coefficients of variation (pcv) and genetic coefficients of variation (gcv) were observed for secondary branch number, seed yield/plant, main shoot length and seed number/siliqua. In general, pcv estimates were higher than gcv estimates. The high estimates of both heritability and genetic advance were recorded in similar order for the plant height, seed number/siliqua, main shoot length and seed yield, in which the genetic progress could be achieved through mass selection. Seed yield was positively correlated with the primary branch number, the secondary branch number and the siliqua number of main shoot and negatively with the plant height. Shorter plant height w;.th more number of primary and secondary branches and more siliquae on main shoot were found to be good selection criteria for isolating high-yielding strains. (auth.)

Mycoplasma hyopneumoniae genetic variability within a swine operation.

Science.gov (United States)

Pantoja, Lucina Galina; Pettit, Kalie; Dos Santos, Lucas F; Tubbs, Rick; Pieters, Maria

2016-03-01

The objective of our study was to characterize the Mycoplasma hyopneumoniae genetic diversity within a swine operation comingling weaned pigs. Bronchial swabs and tracheal aspirates were collected from 3 nursery-to-finish farms. During the finishing production stages, samples were obtained from mortalities and from live coughing pigs in rooms where mortality was not observed. A total of 105 samples were examined by a M. hyopneumoniae real-time polymerase chain reaction and subjected to genetic typing using a multilocus variable number tandem repeat analysis (MLVA) assay. The MLVA was used to identify genetic variants based on the number of repeats in 2 variable number tandem repeats loci, namely P97 and P146, thought to mediate adherence of M. hyopneumoniae to swine cilia. Four distinguishable M. hyopneumoniae variants were identified: MVLA variants 9-15, 11-21, 9-21, and 7-15. Variant 9-15 was the most prevalent, observed in 79% of rooms, and detected on all 3 farms. Variant 11-21 was present in 37% of the rooms on 2 of the 3 farms. Only one 9-21 variant was identified in 1 farm, and all samples of variant 7-15 were recovered from another farm. Based on the low prevalence and limited geographic distribution of the last 2 variants, it is hypothesized that they might be the result of in-situ recombination. All variants detected in this investigation appeared to belong to 3 clusters. Overall, a limited number of variants and clusters were identified in a system that comingles pigs from different sources, suggesting limited M. hyopneumoniae genetic variation within commercial swine production environments. © 2016 The Author(s).

Genetic variability, correlation and path analysis in sponge gourd ...

African Journals Online (AJOL)

Windows-7

2013-02-06

Feb 6, 2013 ... fiber used in industries for filter and cleaning the motor car, glass wares, kitchen ... The fibrous vascular system inside the fruit after been separated from the skin, ... was carried out to gather information on genetic variability ...

Genetic Variability Under the Seedbank Coalescent.

Science.gov (United States)

Blath, Jochen; González Casanova, Adrián; Eldon, Bjarki; Kurt, Noemi; Wilke-Berenguer, Maite

2015-07-01

We analyze patterns of genetic variability of populations in the presence of a large seedbank with the help of a new coalescent structure called the seedbank coalescent. This ancestral process appears naturally as a scaling limit of the genealogy of large populations that sustain seedbanks, if the seedbank size and individual dormancy times are of the same order as those of the active population. Mutations appear as Poisson processes on the active lineages and potentially at reduced rate also on the dormant lineages. The presence of "dormant" lineages leads to qualitatively altered times to the most recent common ancestor and nonclassical patterns of genetic diversity. To illustrate this we provide a Wright-Fisher model with a seedbank component and mutation, motivated from recent models of microbial dormancy, whose genealogy can be described by the seedbank coalescent. Based on our coalescent model, we derive recursions for the expectation and variance of the time to most recent common ancestor, number of segregating sites, pairwise differences, and singletons. Estimates (obtained by simulations) of the distributions of commonly employed distance statistics, in the presence and absence of a seedbank, are compared. The effect of a seedbank on the expected site-frequency spectrum is also investigated using simulations. Our results indicate that the presence of a large seedbank considerably alters the distribution of some distance statistics, as well as the site-frequency spectrum. Thus, one should be able to detect from genetic data the presence of a large seedbank in natural populations. Copyright © 2015 by the Genetics Society of America.

Inter- and intra-population genetic variability of introduced silkworm (Bombyx mori L. strains raised in Bulgaria

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Teodora Staykova

2013-01-01

Full Text Available The genetic variability of four populations belonging to two introduced silkworm strains (Bombyx mori L. of various origins has been studied using isoenzymic analysis of six enzyme systems. Nonspecific esterases, phosphoglucomutase, malate dehydrogenase, acid phosphatase, alkaline phosphatase and hexokinase from different tissue of larvae 5th instar have been analysed using PAGE. Polymorphism in six from a total of nine loci has been found. Inter- and intra-population differences have been ascertained expressed in different allele composition of the gene pool and different frequencies of alleles. A higher degree of inter-population variability has been reported on the acid phosphatase and a lower one – on the phosphoglucomutase.

Genetic variability assessment of accessions of Corchorus olitorius L ...

African Journals Online (AJOL)

SAM

2014-05-14

May 14, 2014 ... genetic variabilities among 14 accessions of the species using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Seven polypeptide bands were obtained ranging from. 9.73 to 88.79 KDa thus depicting variations in the banding patterns of the accessions. The unweighted.

Genetic distance estimates and variable factors distinguishing between goat Kacang, Muara and Samosir

Science.gov (United States)

Hamdan; Saputra, H.; Mirwandhono, E.; Hasnudi; Sembiring, I.; Umar, S.; Ginting, N.; Alwiyah

2018-02-01

The purpose of this research was to look the genetic distance and factors distinguishing variable betwen types of goats in North Sumatera. This research have been conducted in PayaBakung, Hamparan Perak and Klambir Lima village, Deli Serdang district, Batu Binumbun, Aritonang, HutaGinjang village, Muarasubdistrict, North Tapanuli district and ParbabaDolok, Siopat Sosor, Sinabulan village, Ronggur Nihuta Pangururan village, Sitonggi-tonggi village in the subdistrict RonggurNihuta, Samosir district of the month of July 2016. The data was analyzed using descriptive, discriminants, canonical, Principal Component Analysis, Distance genetic and Tree Phylogenetic. The result showed that the nearest genetic distance goat found in Kacang and Samosir (1.973), and the farthest genetic distnace find in Samosir and Muara (8.671). The variables made it difference was goat race Base Rim Horn (0.856) and Long Horn (0.878). Genetic distance values most far between Muaragoat with Samosir goat was (8.671). The conclude that the crossing superior result, must be cross between two goat types with value genetics most distance. It will have a better chance heterosis in cross result.

Morphological Characterization and Assessment of Genetic Variability, Character Association, and Divergence in Soybean Mutants

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M. A. Malek

2014-01-01

Full Text Available Genetic diversity is important for crop improvement. An experiment was conducted during 2011 to study genetic variability, character association, and genetic diversity among 27 soybean mutants and four mother genotypes. Analysis of variance revealed significant differences among the mutants and mothers for nine morphological traits. Eighteen mutants performed superiorly to their mothers in respect to seed yield and some morphological traits including yield attributes. Narrow differences between phenotypic and genotypic coefficients of variation (PCV and GCV for most of the characters revealed less environmental influence on their expression. High values of heritability and genetic advance with high GCV for branch number, plant height, pod number, and seed weight can be considered as favorable attributes for soybean improvement through phenotypic selection and high expected genetic gain can be achieved. Pod and seed number and maturity period appeared to be the first order traits for higher yield and priority should be given in selection due to their strong associations and high magnitudes of direct effects on yield. Cluster analysis grouped 31 genotypes into five groups at the coefficient value of 235. The mutants/genotypes from cluster I and cluster II could be used for hybridization program with the mutants of clusters IV and V in order to develop high yielding mutant-derived soybean varieties for further improvement.

Variability, heritability and genetic advance in F2 populations of aromatic rice involving induced mutants and Basmati varieties

International Nuclear Information System (INIS)

Hasib, K.M.; Ganguli, P.K.; Kole, P.C.

2000-01-01

The F 2 generation of five cross-combinations of aromatic rice involving two induced mutants 124-17-4 and 21-6-1 of aromatic tall Indica cultivar Gobindabhog and three basmati varieties was studied for mean performance, variability, heritability and genetic advance. The cross 21-6-1/Pakistan Basmati showed higher mean values for grain yield plant, and several yield components. Wide variability was observed for panicle number plant, filled grains panicle, test weight, dry matter production plant, harvest index and grain yield plant. Among the traits, filled grains panicle and test weight in all the crosses, grain yield plant, in five crosses and harvest index in two crosses had high heritability coupled with high genetic advance indicating predominant role of additive gene action. The crosses 21-6-1/Pakistan Basmati and 124-17-4/Pusa Basmati I could be exploited for isolation of promising aromatic recombinants. (author)

Variability and genetic differentiation among Anopheles (Ano. intermedius Chagas, 1908 and Anopheles (Ano. mattogrossensis Lutz & Neiva, 1911 (Diptera: Culicidae from the Brazilian Amazon

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Joselita Maria Mendes dos Santos

2005-10-01

Full Text Available Anopheles (Anopheles intermedius and Anopheles (Ano. mattogrossensis are Brazilian anopheline species belonging to the scarcely studied Anopheles subgenus. Few studies have been done on the genetic differentiation of these species. Both species have been found infected by Plasmodium and are sympatric with other anopheline species from the Nyssorhynchus subgenus. Eighteen enzymatic loci were analyzed in larval specimens of An. intermedius and An. mattogrossensis aiming to estimate the variability and genetic differentiation between these species. An. mattogrossensis population showed higher genetic variability (P = 44.4 and Ho = 0.081 ± 0.031 than that of An. intermedius (P = 33.3 and Ho = 0.048 ± 0.021. Most analyzed loci showed genotypic frequencies according to Hardy-Weinberg equilibrium, except for LAP1 and LAP2 in An. intermedius, and EST1 and PGM loci in An. mattogrossensis. The genetic distance between these species (D = 0.683 was consistent with the inter-specific values reported for Anopheles subgenus. We verified that the polymorphism and heterozygosity percentile values found in both species and compared to those in the literature, showed no relation between the level of isozyme variability and geographical distribution. The low variability found in these two species is probably more related to the niche they occupy than to their geographic distribution.

The value of small habitat islands for the conservation of genetic variability in a steppe grass species

Science.gov (United States)

Wódkiewicz, Maciej; Dembicz, Iwona; Moysiyenko, Ivan I.

2016-10-01

The habitat loss and fragmentation due to agricultural land-conversion affected the steppe throughout its range. In Ukraine, 95% of steppe was destroyed in the last two centuries. Remaining populations are confined to few refuges, like nature reserves, loess ravines, and kurgans (small burial mounds), the latter being often subject to destruction by archeological excavations. Stipa capillata L. is a typical grass species of Eurasian steppes and extrazonal dry grasslands, that was previously used as a model species in studies on steppe ecology. The aim of our research was to assess genetic diversity of S. capillata populations within different types of steppe refuges (loess ravines, biosphere reserve, kurgan) and to evaluate the value of the latter group for the preservation of genetic diversity in the study species. We assessed genetic diversity of 266 individuals from 15 populations (nine from kurgans, three from loess ravines and three from Askania-Nova Biosphere Reserve) with eight Universal Rice Primers (URPs). Studied populations showed high intra-population variability (I: 0.262-0.419, PPB: 52.08-82.64%). Populations from kurgans showed higher genetic differentiation (ΦST = 0.247) than those from loess ravines (ΦST = 0.120) and the biosphere reserve (ΦST = 0.142). Although the diversity metrics were to a small extent lower for populations from kurgans than from larger refugia we conclude that all studied populations of the species still preserve high genetic variability and are valuable for protection. To what extent this pattern holds true under continuous fragmentation in the future must be carefully monitored.

Analysis of genetic variability in the Czech Dachshund population using microsatellite markers

Czech Academy of Sciences Publication Activity Database

Přibáňová, M.; Horák, Pavel; Schröffelová, D.; Urban, T.; Bechyňová, Renata; Musilová, L.

2009-01-01

Roč. 126, - (2009), s. 311-318 ISSN 0931-2668 R&D Projects: GA AV ČR 1QS500450578; GA ČR GD523/03/H076 Institutional research plan: CEZ:AV0Z50450515 Keywords : dachshund * dog * genetic variability * microsatellite Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.706, year: 2009

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

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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.

Joint analysis of phenotypic and molecular diversity provides new insights on the genetic variability of the Brazilian physic nut germplasm bank.

Science.gov (United States)

Alves, Alexandre Alonso; Bhering, Leonardo Lopes; Rosado, Tatiana Barbosa; Laviola, Bruno Galvêas; Formighieri, Eduardo Fernandes; Cruz, Cosme Damião

2013-09-01

The genetic variability of the Brazilian physic nut (Jatropha curcas) germplasm bank (117 accessions) was assessed using a combination of phenotypic and molecular data. The joint dissimilarity matrix showed moderate correlation with the original matrices of phenotypic and molecular data. However, the correlation between the phenotypic dissimilarity matrix and the genotypic dissimilarity matrix was low. This finding indicated that molecular markers (RAPD and SSR) did not adequately sample the genomic regions that were relevant for phenotypic differentiation of the accessions. The dissimilarity values of the joint dissimilarity matrix were used to measure phenotypic + molecular diversity. This diversity varied from 0 to 1.29 among the 117 accessions, with an average dissimilarity among genotypes of 0.51. Joint analysis of phenotypic and molecular diversity indicated that the genetic diversity of the physic nut germplasm was 156% and 64% higher than the diversity estimated from phenotypic and molecular data, respectively. These results show that Jatropha genetic variability in Brazil is not as limited as previously thought.

Estimates of genetic variability in mutated population of triticum aestivum

International Nuclear Information System (INIS)

Larik, A.S.; Siddiqui, K.A.; Soomoro, A.H.

1980-01-01

M 2 populations of four cultivars of Mexican origin (Mexipak-65, Nayab, Pak-70 and 6134 x C-271) and two locally bred cultivars (H-68 and C-591) of bread wheat, triticum aestivum (2n = 6x = AA BB DD) derived from six irradiation treatments (gamma rays 60sub(Co); 10, 15 and 20 kR and fast neutrons; 300, 600 and 900 RADS) were critically examined for spike length, spikelets per spike, grains per spike and grain yield. Genotypes varied significantly (p>=0.01) for all the characters. Irradiation treatment were instrumental in creating significant variability for all the characters, indicating that varieties did not perform uniformly across different gamma rays as well as fast neutron treatments. In the M 2 generation there was a considerable increase in variance for all the four metrical traits. Comparisons were made between controls and treated populations. Mutagenic treatments shifted the mean values mostly towards the negative direction, but the shift was not unidirectional nor equally effective for all the characters. The differences in mean values and the nature of variability observed in M 2 indicated a possible preference of selection M 3 generation. In general, estimates of genetic variability and heritability (b.s) increased with increasing doses of gamma rays and fast neutrons. Genetic advance also exhibited similar trend. The observed variability can be utilized in the evolution of new varieties. (authors)

Genetic variability in five species of Anostomidae (Ostariophysi - Characiformes

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Chiari Lucimara

1999-01-01

Full Text Available Genetic variability was studied in five fish species (Anostomidae: Schizodon intermedius and S. nasutus and Leporinus friderici, L. elongatus and L. obtusidens, collected at one location on the Tibagi River (Paraná, Brazil. The protein data from seven systems coded collectively for 19 loci in the liver, muscle and heart. Nine of these loci were polymorphic. The estimated proportion of polymorphism loci ( varied from 16.7% in S. intermedius to 36.9% in L. friderici; the mean heterozygosity observed (o was 0.027 ± 0.015 and 0.109 ± 0.042, respectively. The estimated value of the genetic identity among L. friderici and S. intermedius (0.749 and S. nasutus (0.787 suggested that these are "congeneric" species. Morphological characteristics indicate that these species belong to distinct genera, while isoenzymatic data show that they are very similar at the genetic/biochemical level.

Genetic fidelity and variability of micropropagated cassava plants (Manihot esculenta Crantz) evaluated using ISSR markers.

Science.gov (United States)

Vidal, Á M; Vieira, L J; Ferreira, C F; Souza, F V D; Souza, A S; Ledo, C A S

2015-07-14

Molecular markers are efficient for assessing the genetic fidelity of various species of plants after in vitro culture. In this study, we evaluated the genetic fidelity and variability of micropropagated cassava plants (Manihot esculenta Crantz) using inter-simple sequence repeat markers. Twenty-two cassava accessions from the Embrapa Cassava & Fruits Germplasm Bank were used. For each accession, DNA was extracted from a plant maintained in the field and from 3 plants grown in vitro. For DNA amplification, 27 inter-simple sequence repeat primers were used, of which 24 generated 175 bands; 100 of those bands were polymorphic and were used to study genetic variability among accessions of cassava plants maintained in the field. Based on the genetic distance matrix calculated using the arithmetic complement of the Jaccard's index, genotypes were clustered using the unweighted pair group method using arithmetic averages. The number of bands per primer was 2-13, with an average of 7.3. For most micropropagated accessions, the fidelity study showed no genetic variation between plants of the same accessions maintained in the field and those maintained in vitro, confirming the high genetic fidelity of the micropropagated plants. However, genetic variability was observed among different accessions grown in the field, and clustering based on the dissimilarity matrix revealed 7 groups. Inter-simple sequence repeat markers were efficient for detecting the genetic homogeneity of cassava plants derived from meristem culture, demonstrating the reliability of this propagation system.

Adaptive genetic variability and differentiation of Croatian and Austrian Quercus robur L. populations at a drought prone field trial

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Saša Bogdan

2017-07-01

Full Text Available Provenance trials, where populations of different geographical origin are tested in a common environment (common garden test, are a tool suited to allow the study of intraspecific adaptive genetic variation. Research of pedunculate oak (Quercus robur L. adaptive genetic variability through analyses of populations in common garden tests has a long tradition. However, pedunculated oak populations originating south-eastern from the Alps have been scarcely studied in this way. This study addresses the adaptive genetic variability and differentiation of pedunculate oak populations originating from Austria and Croatia in a provenance/progeny field trial. Studied plants were six years old and were growing at the trial for three years. After two years of unusually low precipitations height and survival were analysed. The total mean height of all plants in the trial was 137.8 cm and ranged from 123.0 cm to 151.8 cm. The overall mean survival rate was rather high (0.85. Mean population survival ranged from 0.64 to 0.94. Individual narrow-sense heritabilities (hi2, family mean heritabilities (hf2, the coefficients of additive genetic variation (CVA and quantitative genetic differentiation coefficients (QST were calculated. A multivariate regression tree (MRT analysis was used to determine the pattern of genetic differentiation of the populations. Individual heritabilities for height ranged between 0.00 and 0.39. Family mean heritabilities for height were rather low in most populations as well (<0.5. Family mean heritabilities for survival were higher than for height (ranging between 0.00 and 0.77. Calculated QST coefficients (0.25 for height and 0.14 for survival indicated between-population genetic differentiation. The populations were separated into two clusters by MRT analysis regarding a climatic variable, namely Hargreaves’ reference evapotranspiration. Populations originating from comparatively more humid habitats were grouped in the first

Genetic variability of Indonesian local chili pepper: The facts

Science.gov (United States)

Arumingtyas, Estri Laras; Kusnadi, Joni; Sari, Dewi Ratih Tirto; Ratih, Nursita

2017-11-01

Chili pepper (Capsicum frutescens) is one species of Solanaceae family that is very popular in Indonesia and some other tropical countries because of its pungency. Chili pepper is an important spice in Indonesia and is also eaten fresh as a pickle to increase appetite. In Indonesia, there are various local names for chili pepper includingcabai, cengek, lombok, pedesan etc. These varied local names represent the various morphological shapes of the chili pepper fruit. We have investigated the variability of some chili cultivars based on morphological characteristics, molecular markers, pungency, and capsaicin content. Some biological facts, such as the tendency of chili pepper to outbreed, have also been found. In this paper, the source of variability and the possible mechanism of increasing genetic variability of Indonesian local chili pepper are also discussed.

Variability in seed traits, oil content and genetic diversity in local and ...

African Journals Online (AJOL)

Variability in seed traits, oil content and genetic diversity of Jatropha curcas L. according to rainfall gradient in Senegal are hereby reported and discussed. Seed oil variability ranged from 58.61% in Sudanian zone to 46.94% in Sahelian zone. Seed oil content and seed thickness were correlated to rainfall with a correlation ...

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.

Genetic variability of tissue cultured Sorghum bicolor (L) Moench as ...

African Journals Online (AJOL)

To evaluate their performance for seedling traits at seedling stage (under hydroponics), plant water relations under water stress and ultimately grain yield, and to estimate the genetic variability of the regenerates, the parent plants of local sorghum cultivars in Kenya using simple sequence repeats (SSR) markers were ...

Variable selection in Logistic regression model with genetic algorithm.

Science.gov (United States)

Zhang, Zhongheng; Trevino, Victor; Hoseini, Sayed Shahabuddin; Belciug, Smaranda; Boopathi, Arumugam Manivanna; Zhang, Ping; Gorunescu, Florin; Subha, Velappan; Dai, Songshi

2018-02-01

Variable or feature selection is one of the most important steps in model specification. Especially in the case of medical-decision making, the direct use of a medical database, without a previous analysis and preprocessing step, is often counterproductive. In this way, the variable selection represents the method of choosing the most relevant attributes from the database in order to build a robust learning models and, thus, to improve the performance of the models used in the decision process. In biomedical research, the purpose of variable selection is to select clinically important and statistically significant variables, while excluding unrelated or noise variables. A variety of methods exist for variable selection, but none of them is without limitations. For example, the stepwise approach, which is highly used, adds the best variable in each cycle generally producing an acceptable set of variables. Nevertheless, it is limited by the fact that it commonly trapped in local optima. The best subset approach can systematically search the entire covariate pattern space, but the solution pool can be extremely large with tens to hundreds of variables, which is the case in nowadays clinical data. Genetic algorithms (GA) are heuristic optimization approaches and can be used for variable selection in multivariable regression models. This tutorial paper aims to provide a step-by-step approach to the use of GA in variable selection. The R code provided in the text can be extended and adapted to other data analysis needs.

Temporal stability of genetic variability and differentiation in the three-spined stickleback (Gasterosteus aculeatus).

Science.gov (United States)

DeFaveri, Jacquelin; Merilä, Juha

2015-01-01

Temporal variation in allele frequencies, whether caused by deterministic or stochastic forces, can inform us about interesting demographic and evolutionary phenomena occurring in wild populations. In spite of the continued surge of interest in the genetics of three-spined stickleback (Gasterosteus aculeatus) populations, little attention has been paid towards the temporal stability of allele frequency distributions, and whether there are consistent differences in effective size (Ne) of local populations. We investigated temporal stability of genetic variability and differentiation in 15 microsatellite loci within and among eight collection sites of varying habitat type, surveyed twice over a six-year time period. In addition, Nes were estimated with the expectation that they would be lowest in isolated ponds, intermediate in larger lakes and largest in open marine sites. In spite of the marked differences in genetic variability and differentiation among the study sites, the temporal differences in allele frequencies, as well as measures of genetic diversity and differentiation, were negligible. Accordingly, the Ne estimates were temporally stable, but tended to be lower in ponds than in lake or marine habitats. Hence, we conclude that allele frequencies in putatively neutral markers in three-spined sticklebacks seem to be temporally stable - at least over periods of few generations - across a wide range of habitat types differing markedly in levels of genetic variability, effective population size and gene flow.

Temporal stability of genetic variability and differentiation in the three-spined stickleback (Gasterosteus aculeatus.

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Jacquelin DeFaveri

Full Text Available Temporal variation in allele frequencies, whether caused by deterministic or stochastic forces, can inform us about interesting demographic and evolutionary phenomena occurring in wild populations. In spite of the continued surge of interest in the genetics of three-spined stickleback (Gasterosteus aculeatus populations, little attention has been paid towards the temporal stability of allele frequency distributions, and whether there are consistent differences in effective size (Ne of local populations. We investigated temporal stability of genetic variability and differentiation in 15 microsatellite loci within and among eight collection sites of varying habitat type, surveyed twice over a six-year time period. In addition, Nes were estimated with the expectation that they would be lowest in isolated ponds, intermediate in larger lakes and largest in open marine sites. In spite of the marked differences in genetic variability and differentiation among the study sites, the temporal differences in allele frequencies, as well as measures of genetic diversity and differentiation, were negligible. Accordingly, the Ne estimates were temporally stable, but tended to be lower in ponds than in lake or marine habitats. Hence, we conclude that allele frequencies in putatively neutral markers in three-spined sticklebacks seem to be temporally stable - at least over periods of few generations - across a wide range of habitat types differing markedly in levels of genetic variability, effective population size and gene flow.

Effects of Amerindian Genetic Ancestry on Clinical Variables and Therapy in Patients with Rheumatoid Arthritis.

Science.gov (United States)

Sánchez, Elena; García de la Torre, Ignacio; Sacnún, Mónica; Goñi, Mario; Berbotto, Guillermo; Paira, Sergio; Musuruana, Jorge Luis; Graf, César; Alvarellos, Alejandro; Messina, Osvaldo D; Babini, Alejandra; Strusberg, Ingrid; Marcos, Juan Carlos; Scherbarth, Hugo; Spindler, Alberto; Quinteros, Ana; Toloza, Sergio; Moreno, José Luis C; Catoggio, Luis J; Tate, Guillermo; Eimon, Alicia; Citera, Gustavo; Pellet, Antonio Catalán; Nasswetter, Gustavo; Cardiel, Mario H; Miranda, Pedro; Ballesteros, Francisco; Esquivel-Valerio, Jorge A; Maradiaga-Ceceña, Marco A; Acevedo-Vásquez, Eduardo M; García, Conrado García; Tusié-Luna, Teresa; Pons-Estel, Bernardo A; Alarcón-Riquelme, Marta E

2017-12-01

To define whether Amerindian genetic ancestry correlates with clinical and therapeutic variables in admixed individuals with rheumatoid arthritis (RA) from Latin America. Patients with RA (n = 1347) and healthy controls (n = 1012) from Argentina, Mexico, Chile, and Peru were included. Samples were genotyped for the Immunochip v1 using the Illumina platform. Clinical data were obtained through interviews or the clinical history. Percentage of Amerindian ancestry was comparable between cases and controls. Morning stiffness (p ancestry after Bonferroni correction. Higher Amerindian ancestry correlated only with weight loss (p Bonferroni ancestry correlated with higher doses of azathioprine (p ancestry protects against most major clinical criteria of RA, but regarding the association of RF with increased European ancestry, age, sex, and smoking are modifiers. Ancestry also correlates with the therapeutic profiles.

Climate variables explain neutral and adaptive variation within salmonid metapopulations: The importance of replication in landscape genetics

Science.gov (United States)

Hand, Brian K.; Muhlfeld, Clint C.; Wade, Alisa A.; Kovach, Ryan; Whited, Diane C.; Narum, Shawn R.; Matala, Andrew P.; Ackerman, Michael W.; Garner, B. A.; Kimball, John S; Stanford, Jack A.; Luikart, Gordon

2016-01-01

Understanding how environmental variation influences population genetic structure is important for conservation management because it can reveal how human stressors influence population connectivity, genetic diversity and persistence. We used riverscape genetics modelling to assess whether climatic and habitat variables were related to neutral and adaptive patterns of genetic differentiation (population-specific and pairwise FST) within five metapopulations (79 populations, 4583 individuals) of steelhead trout (Oncorhynchus mykiss) in the Columbia River Basin, USA. Using 151 putatively neutral and 29 candidate adaptive SNP loci, we found that climate-related variables (winter precipitation, summer maximum temperature, winter highest 5% flow events and summer mean flow) best explained neutral and adaptive patterns of genetic differentiation within metapopulations, suggesting that climatic variation likely influences both demography (neutral variation) and local adaptation (adaptive variation). However, we did not observe consistent relationships between climate variables and FST across all metapopulations, underscoring the need for replication when extrapolating results from one scale to another (e.g. basin-wide to the metapopulation scale). Sensitivity analysis (leave-one-population-out) revealed consistent relationships between climate variables and FST within three metapopulations; however, these patterns were not consistent in two metapopulations likely due to small sample sizes (N = 10). These results provide correlative evidence that climatic variation has shaped the genetic structure of steelhead populations and highlight the need for replication and sensitivity analyses in land and riverscape genetics.

Bayesian methods for meta-analysis of causal relationships estimated using genetic instrumental variables

DEFF Research Database (Denmark)

Burgess, Stephen; Thompson, Simon G; Thompson, Grahame

2010-01-01

Genetic markers can be used as instrumental variables, in an analogous way to randomization in a clinical trial, to estimate the causal relationship between a phenotype and an outcome variable. Our purpose is to extend the existing methods for such Mendelian randomization studies to the context o...

The Generalized Higher Criticism for Testing SNP-Set Effects in Genetic Association Studies

Science.gov (United States)

Barnett, Ian; Mukherjee, Rajarshi; Lin, Xihong

2017-01-01

It is of substantial interest to study the effects of genes, genetic pathways, and networks on the risk of complex diseases. These genetic constructs each contain multiple SNPs, which are often correlated and function jointly, and might be large in number. However, only a sparse subset of SNPs in a genetic construct is generally associated with the disease of interest. In this article, we propose the generalized higher criticism (GHC) to test for the association between an SNP set and a disease outcome. The higher criticism is a test traditionally used in high-dimensional signal detection settings when marginal test statistics are independent and the number of parameters is very large. However, these assumptions do not always hold in genetic association studies, due to linkage disequilibrium among SNPs and the finite number of SNPs in an SNP set in each genetic construct. The proposed GHC overcomes the limitations of the higher criticism by allowing for arbitrary correlation structures among the SNPs in an SNP-set, while performing accurate analytic p-value calculations for any finite number of SNPs in the SNP-set. We obtain the detection boundary of the GHC test. We compared empirically using simulations the power of the GHC method with existing SNP-set tests over a range of genetic regions with varied correlation structures and signal sparsity. We apply the proposed methods to analyze the CGEM breast cancer genome-wide association study. Supplementary materials for this article are available online. PMID:28736464

Higher Complexity of Infection and Genetic Diversity of Plasmodium vivax Than Plasmodium falciparum across all Malaria Transmission Zones of Papua New Guinea

Science.gov (United States)

Fola, Abebe A.; Harrison, G. L. Abby; Hazairin, Mita Hapsari; Barnadas, Céline; Hetzel, Manuel W.; Iga, Jonah; Siba, Peter M.; Mueller, Ivo; Barry, Alyssa E.

2017-01-01

Plasmodium falciparum and Plasmodium vivax have varying transmission dynamics that are informed by molecular epidemiology. This study aimed to determine the complexity of infection and genetic diversity of P. vivax and P. falciparum throughout Papua New Guinea (PNG) to evaluate transmission dynamics across the country. In 2008–2009, a nationwide malaria indicator survey collected 8,936 samples from all 16 endemic provinces of PNG. Of these, 892 positive P. vivax samples were genotyped at PvMS16 and PvmspF3, and 758 positive P. falciparum samples were genotyped at Pfmsp2. The data were analyzed for multiplicity of infection (MOI) and genetic diversity. Overall, P. vivax had higher polyclonality (71%) and mean MOI (2.32) than P. falciparum (20%, 1.39). These measures were significantly associated with prevalence for P. falciparum but not for P. vivax. The genetic diversity of P. vivax (PvMS16: expected heterozygosity = 0.95, 0.85–0.98; PvMsp1F3: 0.78, 0.66–0.89) was higher and less variable than that of P. falciparum (Pfmsp2: 0.89, 0.65–0.97). Significant associations of MOI with allelic richness (rho = 0.69, P = 0.009) and expected heterozygosity (rho = 0.87, P < 0.001) were observed for P. falciparum. Conversely, genetic diversity was not correlated with polyclonality nor mean MOI for P. vivax. The results demonstrate higher complexity of infection and genetic diversity of P. vivax across the country. Although P. falciparum shows a strong association of these parameters with prevalence, a lack of association was observed for P. vivax and is consistent with higher potential for outcrossing of this species. PMID:28070005

Detection genetic variability of secale cereale L. by scot markers

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Lenka Petrovičová

2017-01-01

Full Text Available Rye (Secale cereale L. is our traditional cereal used for baking. The genetic variability of grown rye has been reduced by modern agronomic practices, which subsequently prompted the importance of search for species that could be useful as a gene pool for the improving of flour quality for human consumption or for other industrial uses. Therefore, the aim of this study was to detect genetic variability among the set of 45 rye genotypes using 8 SCoT markers. Amplification of genomic DNA of 45 genotypes, using SCoT analysis, yielded 114 fragments, with an average of 14.25 polymorphic fragments per primer. The most polymorphic primer was SCoT 36, where 21 polymorphic amplification products were detected. In contract the lowest polymorphic primer was SCoT 45 with 5 polymorphic products. Genetic polymorphism was characterized based on diversity index (DI, probability of identity (PI and polymorphic information content (PIC. The hierarchical cluster analysis showed that the rye genotypes were divided into 2 main clusters. One rye genotype Motto, origin from Poland formed a separate subcluster (1b. Subscluster 2a included only genotype Valtické (CSK. In this experiment, SCoT proved to be a rapid, reliable and practicable method for revealing of polymorphism in the rye cultivars. Normal 0 21 false false false EN-GB X-NONE X-NONE

Components of genetic variability of ear length of silage maize

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Sečanski Mile

2006-01-01

Full Text Available The objective of this study was to evaluate following parameters of the ear length of silage maize: variability of inbred lines and their diallel hybrids, superior-parent heterosis and genetic components of variability and habitability on the basis of a diallel set. The analysis of genetic variance shows that the additive component (D was lower than the dominant (H1 and H2 genetic variances, while the frequency of dominant genes (u for this trait was greater than the frequency of recessive genes (v Furthermore, this is also confirmed by the dominant to recessive genes ratio in parental inbreeds for the ear length (Kd/Kr> 1, which is greater than unity during both investigation years. The calculated value of the average degree of dominance √H1/D is greater than unity, pointing out to superdominance in inheritance of this trait in both years of investigation, which is also confirmed by the results of Vr/Wr regression analysis of inheritance of the ear length. As a presence of the non-allelic interaction was established it is necessary to study effects of epitasis as it can have a greater significance in certain hybrids. A greater value of dominant than additive variance resulted in high broad-sense habitability for ear length in both investigation years.

Genetic variability in mitochondrial and nuclear genes of Larus dominicanus (Charadriiformes, Laridae from the Brazilian coast

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Gisele Pires de Mendonça Dantas

2012-01-01

Full Text Available Several phylogeographic studies of seabirds have documented low genetic diversity that has been attributed to bottleneck events or individual capacity for dispersal. Few studies have been done in seabirds on the Brazilian coast and all have shown low genetic differentiation on a wide geographic scale. The Kelp Gull is a common species with a wide distribution in the Southern Hemisphere. In this study, we used mitochondrial and nuclear markers to examine the genetic variability of Kelp Gull populations on the Brazilian coast and compared this variability with that of sub-Antarctic island populations of this species. Kelp Gulls showed extremely low genetic variability for mitochondrial markers (cytb and ATPase and high diversity for a nuclear locus (intron 7 of the β-fibrinogen. The intraspecific evolutionary history of Kelp Gulls showed that the variability found in intron 7 of the β-fibrinogen gene was compatible with the variability expected under neutral evolution but suggested an increase in population size during the last 10,000 years. However, none of the markers revealed evidence of a bottleneck population. These findings indicate that the recent origin of Kelp Gulls is the main explanation for their nuclear diversity, although selective pressure on the mtDNA of this species cannot be discarded.

Agrobiodiversity Genetic Variability Utilization in Organic Food Production

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Dimitrijević Miodrag

2018-03-01

Full Text Available The food production at the global level is about to meet its border. Industrialization of agriculture correlates with an explosive enlargement of human population, during XX and at the beginning of XXI centuries. An ongoing process of environmental erosion has been speeding up during that period, not only in our physical surrounding, but also in biodiversity. A new direction in agricultural food production is in demand. Organic food production has been recognized as the way of providing safety and quality food, preserving the environment in the same time. In the other hand new land areas have to be explored for agricultural use, in order to enhance food quantity to meeting the increasing demand for food. These targets set new requirements in plant breeding. To fulfill these requirements the genetic variability harbored in genetic resources has to be preserved, examined and put to good use.

Multi-taxa integrated landscape genetics for zoonotic infectious diseases: deciphering variables influencing disease emergence.

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Leo, Sarah S T; Gonzalez, Andrew; Millien, Virginie

2016-05-01

Zoonotic disease transmission systems involve sets of species interacting with each other and their environment. This complexity impedes development of disease monitoring and control programs that require reliable identification of spatial and biotic variables and mechanisms facilitating disease emergence. To overcome this difficulty, we propose a framework that simultaneously examines all species involved in disease emergence by integrating concepts and methods from population genetics, landscape ecology, and spatial statistics. Multi-taxa integrated landscape genetics (MTILG) can reveal how interspecific interactions and landscape variables influence disease emergence patterns. We test the potential of our MTILG-based framework by modelling the emergence of a disease system across multiple species dispersal, interspecific interaction, and landscape scenarios. Our simulations showed that both interspecific-dependent dispersal patterns and landscape characteristics significantly influenced disease spread. Using our framework, we were able to detect statistically similar inter-population genetic differences and highly correlated spatial genetic patterns that imply species-dependent dispersal. Additionally, species that were assigned coupled-dispersal patterns were affected to the same degree by similar landscape variables. This study underlines the importance of an integrated approach to investigating emergence of disease systems. MTILG is a robust approach for such studies and can identify potential avenues for targeted disease management strategies.

Susceptibility of Biomphalaria spp. to infection with Schistosoma mansoni in sympatric and allopatric combinations with observations on the genetic variability between snails.

Science.gov (United States)

Mostafa, Osama M S; El-Dafrawy, Shadia M

2011-08-25

This investigation was carried out to study the susceptibility of Saudi Biomphalaria arabica to Egyptian Schistosoma mansoni in comparison with the susceptibility of Egyptian Biomphalaria alexandrina to the same parasite. This was in order to know the possibility that the parasite might be able to spread into Saudi Arabia and to determine the genetic variability between Egyptian B. alexandrina and Saudi Biomphalaria arabica snails. Lab bred Egyptian B. alexandrina and Saudi B. arabica snails were exposed individually to 10 freshly hatched Egyptian S. mansoni miracidia/snail. The mortality rate, infection rate, prepatent period, duration of cercarial shedding and cercariae production per snail were recorded in both the sympatric couple (Egyptian B. alexandrina and Egyptian S. mansoni) and in the allopatric combination (Saudi B. arabica and Egyptian S. mansoni). The results revealed that, the survival rate of snails exposed to Egyptian S. mansoni miracidia at 34th day post-exposure (at first cercarial shedding) was higher in B. arabica than in B. alexandrina. After shedding, the mortality rate was higher in the B. arabica, compared to B. alexandrina. The infection rate was higher in B. arabica than B. alexandrina; the mean of prepatent period was shorter in the B. arabica than in the B. alexandrina. However, the duration of cercarial shedding was longer in the Egyptian snails and the cercarial production per snail was higher in B. alexandrina snails than in B. arabica. To study the genetic variability between B. alexandrina and B. arabica, RAPD-PCR on the genomic DNA of snails was done. RAPD-PCR revealed significant variation between the two snail species. In conclusion, the results suggest that B. arabica can play a role in the transmission of Egyptian S. mansoni in Saudi Arabia and therefore this parasite might be able to spread into the Kingdom. In addition, the RAPD-PCR results demonstrated genetic variability between the two species which may be related to the

STUDY OF GENETIC VARIABILITY OF TRITICALE VARIETIES BY SSR MARKERS

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Jana Ondroušková

2013-04-01

Full Text Available For the detection of genetic variability ten genotypes of winter triticale (×Triticosecale Wittmack, 2n = 6x = 42; BBAARR were selected: nine varieties and one breeding line with good bread-making quality KM 4-09 with the chromosome translocation 1R.1D 5+10-2. 25 microsatellites markers located in the genome A, B, D and R were chosen for analysis. Eighty-four alleles were detected with an average of 3.36 alleles per locus were detected. For each microsatellite statistical values were calculated diversity index (DI, probabilities of identity (PI and polymorphic information content (PIC were calculated and averages statistical values are: DI 0.55, PI 0.27 and 0.5 PIC. Overall dendrogram based on the UPGMA method (Jaccards similarity coefficient significantly distinguished two groups of genotypes and these groups were divided into sub-clusters. A set of 5 SSR markers (Xwms0752, Xbarc128, Xrems1237, Xwms0861 and Xbrac170 which have the calculated PIC value higher than 0.68 that are sufficient for the identification of the analyzed genotypes was described.

Genetic variability in uptake of nitrogen at various growth stages of barley and wheat under dryland conditions

International Nuclear Information System (INIS)

Della, A.; Hadjichristodoulou, A.

1976-01-01

Protein and dry matter in a number of high protein and commercial varieties of barley and wheat were tested at various growth stages and at two locations. Large genetic variability was found in uptake of nitrogen, which was taken up generally before heading. High protein yields were not associated with high protein content but with higher dry matter yields. Nitrogen fertilization increased protein content and protein yield at a low protein location only. It was concluded that it is possible to breed for both high grain and high straw protein varieties. (author)

Comparative assessment of genetic variability in cryptolepis buchananii, tylophora hirsuta and wattakaka volubilis

International Nuclear Information System (INIS)

Mahmood, T.; Azir, N.; Abbasi, B.H.; Naqvi, S.

2011-01-01

Asclepiadaceae is an economically important family with great medicinal value. However, very little work has been carried out on the genetic variability of Asclepiadaceae members especially on some medicinally important species like Tylophora hirsuta, Wattakaka volubilis and Cryptolepis buchananii. Keeping in view the importance of these species, a study was designed to explore the genetic diversity of these 3 species of Asclepiadaceae and the plant material was collected from Quaid-i-Azam university campus, Islamabad. To assess the genetic variability and polymorphism among these species, randomly amplified polymorphic DNA (RAPD) markers were used. Sixty RAPD primers from OPA, OPC, OPF and OPG series were used; only 8 primers of OPC series gave amplification. Maximum polymorphism at interspecific and intraspecific levels was shown by OPC9 and minimum polymorphism was observed in OPC5. The data was analyzed using NTSYS software pc version 2.02. Low genetic diversification was observed at intraspecific and interspecific level. Moreover, during cluster analysis Tylophora hirsuta and Wattakaka volubilis were found to be present in the same cluster showing a close relationship whereas Cryptolepis buchananii appeared in a separate cluster. (author)

Genetic variability of Pantaneiro horse using RAPD-PCR markers

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Egito,Andréa Alves do; Fuck,Beatriz Helena; McManus,Concepta; Paiva,Samuel Rezende; Albuquerque,Maria do Socorro Maués; Santos,Sandra Aparecida; Abreu,Urbano Gomes Pinto de; Silva,Joaquim Augusto da; Sereno,Fabiana Tavares Pires de Souza; Mariante,Arthur da Silva

2007-01-01

Blood samples were collected from Pantaneiro Horses in five regions of Mato Grosso do Sul and Mato Grosso States. Arabian, Mangalarga Marchador and Thoroughbred were also included to estimate genetic distances and the existing variability among and within these breeds by RAPD-PCR (Random Amplified Polymorphic DNA - Polymerase Chain Reaction) molecular markers. From 146 primers, 13 were chosen for amplification and 44 polymorphic bands were generated. The analysis of molecular variance (AMOVA)...

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

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

2011-12-01

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

Genetic variability of European honey bee, Apis mellifera in mid hills ...

African Journals Online (AJOL)

To observe the genetic variability in European honey bee, A. mellifera, PCR was run separately with five primers and analysis of the banding pattern was worked out to investigate the molecular profile of honey bee genotypes collected from different locations having random amplified polymorphic DNA (RAPD) primers.

Genetic variability for different quantitative traits in M2 generations of opium poppy (Papaver somniferum L.)

International Nuclear Information System (INIS)

Chatterjee, A.; Shukla, S.; Singh, S.P.

2004-01-01

An experiment on induced mutation in two varieties of opium poppy was laid out to create new genetic variability for isolation of high yielding genotypes. Varieties NBRI-1 and NBRI-5 were subjected to irradiation for five doses of gamma rays and NBRI-5 was also treated with four doses of EMS and 20 mixed doses of EMS plus gamma rays. The data were recorded on 15 plants/treatment for 10 polygenic characters as pooled in M1 and M2 generations separately as well as in each dose-wise in M2 population. The results indicated that GCV, heritability and genetic advance were higher in M1 than M2 in both the varieties for all the traits except for opium and seed yield. The genetic advance was consistently high for opium yield, seed yield and capsule weight in all the doses for both the varieties with some exception. The dose level of kR10 and kR30 in NBRI-1 revealed high GCV, heritability and genetic advance for seed weight. These treatment levels also had high values of all these three genetic parameters for capsules per plant, capsule size and capsule weight. The values of these three parameters were also high for all the doses in M2 generations of both the varieties for opium yield, seed weight, capsule weight and capsule size in comparison to control. The GCV, heritability and genetic advance were consistently high for all the mixed doses in NBRI-5 for opium yield, seed weight and capsule weight, with some exception [it

Evaluating Genetic Variability of Sorghum Mutant Lines Tolerant to Acid Soil

International Nuclear Information System (INIS)

Puspitasari, W.; Human, S.; Wirnas, D.; Trikoesoemaningtyas

2012-01-01

High rainfall in some parts in Indonesia causes soil become acidic. The main constraint of acid soil is phosphor (P) deficiency and aluminum (Al) toxicity which decrease plant productivity. To overcome this problem, it is important to develop a crop variety tolerant to such conditions. Sorghum is probably one of the potential crops to meet that objective. Sorghum has been reported to have wide adaptability to various agro-ecology and can be used as food and animal feed. Unfortunately, sorghum is not Indonesian origin so its genetic variability is still low. From previous breeding works with induced mutation, some promising mutant lines have been developed. These mutant lines were included in the experiment carried out in Tenjo with soil condition was classified as acid soil with pH 4.8 and exchangeable-Al content 2.43 me/100 g. The objectives of this experiment were to study the magnitude of genetic variability of agronomy and grain quality characters in sorghum in order to facilitate the breeding improvement of the species. Plant materials used in this study were ten genotypes, including 6 mutant lines and 4 control varieties. The randomized block design with three replications was used in the experiment. The genetic variabilities of agronomic and grain quality characters existed among genotypes, such as plant height, number of leaves, stalk diameter, biomass weight, panicle length, grain yield per plant, 100 seed weight and tannin content in the grain. The broad sense heritabilities of agronomic characters were estimated ranging from medium to high. Grain yield showed significantly positive correlation with agronomic characters observed, but it was negatively correlated with protein content (author)

Variable-number-of-tandem-repeats analysis of genetic diversity in Pasteuria ramosa.

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Mouton, L; Ebert, D

2008-05-01

Variable-number-of-tandem-repeats (VNTR) markers are increasingly being used in population genetic studies of bacteria. They were recently developed for Pasteuria ramosa, an endobacterium that infects Daphnia species. In the present study, we genotyped P. ramosa in 18 infected hosts from the United Kingdom, Belgium, and two lakes in the United States using seven VNTR markers. Two Daphnia species were collected: D. magna and D. dentifera. Six loci showed length polymorphism, with as many as five alleles identified for a single locus. Similarity coefficient calculations showed that the extent of genetic variation between pairs of isolates within populations differed according to the population, but it was always less than the genetic distances among populations. Analysis of the genetic distances performed using principal component analysis revealed strong clustering by location of origin, but not by host Daphnia species. Our study demonstrated that the VNTR markers available for P. ramosa are informative in revealing genetic differences within and among populations and may therefore become an important tool for providing detailed analysis of population genetics and epidemiology.

Genetic variability of Echinococcus granulosus based on the mitochondrial 16S ribosomal RNA gene.

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Wang, Ning; Wang, Jiahai; Hu, Dandan; Zhong, Xiuqin; Jiang, Zhongrong; Yang, Aiguo; Deng, Shijin; Guo, Li; Tsering, Dawa; Wang, Shuxian; Gu, Xiaobin; Peng, Xuerong; Yang, Guangyou

2015-06-01

Echinococcus granulosus is the etiological agent of cystic echinococcosis, a major zoonotic disease of both humans and animals. In this study, we assessed genetic variability and genetic structure of E. granulosus in the Tibet plateau, using the complete mitochondrial 16 S ribosomal RNA gene for the first time. We collected and sequenced 62 isolates of E. granulosus from 3 populations in the Tibet plateau. A BLAST analysis indicated that 61 isolates belonged to E. granulosus sensu stricto (genotypes G1-G3), while one isolate belonged to E. canadensis (genotype G6). We detected 16 haplotypes with a haplotype network revealing a star-like expansion, with the most common haplotype occupying the center of the network. Haplotype diversity and nucleotide diversity were low, while negative values were observed for Tajima's D and Fu's Fs. AMOVA results and Fst values revealed that the three geographic populations were not genetically differentiated. Our results suggest that a population bottleneck or population expansion has occurred in the past, and that this explains the low genetic variability of E. granulosus in the Tibet Plateau.

Variability, heritability, character association and genetic divergence studies in M2 generation of gamma irradiated upland paddy

International Nuclear Information System (INIS)

Mehetre, S.S.; Patil, P.A.; Mahajan, C.R.; Shinde, R.B.

1996-01-01

The extent of coefficient of variation indicated that sterility percentage showed highest genotypic coefficients of variability (gcv) followed by grain yield/plant, plant height, spikelets/plant and tillers/plant, which proved existence of high genetic variability in induced varieties. High genetic estimates were recorded in all the characters studied. High genetic advance was observed in plant height and spikelets/panicle. Path coefficient analysis revealed that days to 50% flowering and days to maturity had largest positive direct effect on grain yield in induced varieties. (author). 10 refs., 3 tabs

Assessment of genetic variability in somaclonal population of sugarcane

International Nuclear Information System (INIS)

Seema, N.; Raza, S.; Yasmeen, S.; Bibi, S.; Nizamani, G.S.

2014-01-01

In the present study plant tissue culture technique was used to create the genetic variability in three sugarcane clones NIA98, BL4 and AEC82-1026. Callus induced in these clones in media containing MS + 2, 4 D (2mg 1it-1) and Dicamba (1mg1it-1). The embryogenic calli then regenerated in media containing MS basal media + Kinetin (2mg1it-1) + IBA (2mg1it-1) + IAA (2mglit-1). After shooting and rooting, plants were exposed to green house and acclimatization of the somaclones in the field condition. RAPD markers were used to evaluate the genetic variation at DNA level between parents and somaclones of NIA98, BL4 and AEC82-1026 developed through callus culture. Fourteen RAPD primer chosen randomly were used to amplify DNA from plant material to assess the genetic variation between parents and regenerated somaclones. The highest similarity was obtained between BL4 parent and BL4 somaclone (96%). While minimum similarity found between NIA-98 parent and AEC82-1026 somaclone (69%). In this study, we used RAPD to investigate the somaclonal variation in sugarcane clones derived from callus cultures. (author)

Estimation of genetic variability level in inbred CF1 mouse lines ...

Indian Academy of Sciences (India)

To estimate the genetic variability levels maintained by inbred lines selected for body weight and to compare them with a nonselected population from which the lines were derived, we calculated the per cent polymorphic loci (P) and marker diversity (MD) index from data on 43 putative loci of inter simple sequence repeats ...

Competitive advantage and higher fitness in native populations of genetically structured planktonic diatoms.

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Sildever, Sirje; Sefbom, Josefin; Lips, Inga; Godhe, Anna

2016-12-01

It has been shown that the planktonic diatom Skeletonema from neighbouring areas are genetically differentiated despite absence of physical dispersal barriers. We revisited two sites, Mariager Fjord and Kattegat, NE Atlantic, and isolated new strains. Microsatellite genotyping and F-statistics revealed that the populations were genetically differentiated. An experiment was designed to investigate if populations are locally adapted and have a native competitive advantage. Ten strains from each location were grown individually in native and foreign water to investigate differences in produced biomass. Additionally, we mixed six pairs, one strain from each site, and let them grow together in native and foreign water. Strains from Mariager Fjord and Kattegat produced higher biomass in native water. In the competition experiment, strains from both sites displayed higher relative abundance and demonstrated competitive advantage in their native water. The cause of the differentiated growth is unknown, but could possibly be attributed to differences in silica concentration or viruses in the two water types. Our data show that dispersal potential does not influence the genetic structure of the populations. We conclude that genetic adaptation has not been overruled by gene flow, but instead the responses to different selection conditions are enforcing the observed genetic structure. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

Heterozygosity level and its relationship with genetic variability mechanisms in beans

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Rita Carolina de Melo

Full Text Available ABSTRACT Heterozygosity is an extremely important resource in early breeding programs using autogamous plants because it is usually associated with the presence of genetic variability. Induced mutation and artificial hybridization can increase distinctly the proportion of loci in heterozygosis. This study aimed to compare segregating and mutant populations and relate the mechanisms used to generate variability with their respective heterozygosity levels tested. The treatments mutant populations (M2, M3, M4, M5, M6 and M7, segregating populations (F4, F5 and F6 and lines (BRS Pérola and IPR Uirapuru were evaluated by multivariate analysis and compared by orthogonal contrasts. The canonical discriminant analysis revealed which response variables contributed to differentiate the treatments assessed. All orthogonal contrasts involving the mutant populations showed significant differences, except the contrast between M2 vs. M3, M4, M5, M6, M7. The orthogonal contrast between the mutant and segregating populations denotes a significant variation in the interest in genetic breeding. The traits stem diameter (1.41 and number of legumes per plant (2.72 showed the highest canonical weight in this contrast. Conversely, number of grains per plant (-3.58 approached the mutant and segregating populations. No significant difference was observed in the linear comparison of means F5 vs. F6. The traits are fixed early in the segregant populations, unlike the mutant populations. Comparatively, induced mutation provides more loci in heterozygosis than artificial hybridization. Selection pressure should vary according to the variability creation mechanism used at the beginning of the breeding program.

Variability of individual genetic load: consequences for the detection of inbreeding depression.

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Restoux, Gwendal; Huot de Longchamp, Priscille; Fady, Bruno; Klein, Etienne K

2012-03-01

Inbreeding depression is a key factor affecting the persistence of natural populations, particularly when they are fragmented. In species with mixed mating systems, inbreeding depression can be estimated at the population level by regressing the average progeny fitness by the selfing rate of their mothers. We applied this method using simulated populations to investigate how population genetic parameters can affect the detection power of inbreeding depression. We simulated individual selfing rates and genetic loads from which we computed fitness values. The regression method yielded high statistical power, inbreeding depression being detected as significant (5 % level) in 92 % of the simulations. High individual variation in selfing rate and high mean genetic load led to better detection of inbreeding depression while high among-individual variation in genetic load made it more difficult to detect inbreeding depression. For a constant sampling effort, increasing the number of progenies while decreasing the number of individuals per progeny enhanced the detection power of inbreeding depression. We discuss the implication of among-mother variability of genetic load and selfing rate on inbreeding depression studies.

Genetic Diversity Studies Based on Morphological Variability, Pathogenicity and Molecular Phylogeny of the Sclerotinia sclerotiorum Population From Indian Mustard (Brassica juncea

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Pankaj Sharma

2018-06-01

in a clade-specific manner. Together this analysis observed the existence of higher heterogeneity and genetic variability in S. sclerotiorum isolates collection and indicates the presence of clonal and sexual progenies of the pathogen in the mustard growing regions of India surveyed in this study. With a higher level of genetic variability and diversity among the S. sclerotiorum population needs robust screening approaches to identify the donor parent and utilize them in resistance breeding program for effectively counter the menace of stem rot disease in Brassica.

Epigenetic variability in the genetically uniform forest tree species Pinus pinea L.

Science.gov (United States)

Sáez-Laguna, Enrique; Guevara, María-Ángeles; Díaz, Luis-Manuel; Sánchez-Gómez, David; Collada, Carmen; Aranda, Ismael; Cervera, María-Teresa

2014-01-01

There is an increasing interest in understanding the role of epigenetic variability in forest species and how it may contribute to their rapid adaptation to changing environments. In this study we have conducted a genome-wide analysis of cytosine methylation pattern in Pinus pinea, a species characterized by very low levels of genetic variation and a remarkable degree of phenotypic plasticity. DNA methylation profiles of different vegetatively propagated trees from representative natural Spanish populations of P. pinea were analyzed with the Methylation Sensitive Amplified Polymorphism (MSAP) technique. A high degree of cytosine methylation was detected (64.36% of all scored DNA fragments). Furthermore, high levels of epigenetic variation were observed among the studied individuals. This high epigenetic variation found in P. pinea contrasted with the lack of genetic variation based on Amplified Fragment Length Polymorphism (AFLP) data. In this manner, variable epigenetic markers clearly discriminate individuals and differentiates two well represented populations while the lack of genetic variation revealed with the AFLP markers fail to differentiate at both, individual or population levels. In addition, the use of different replicated trees allowed identifying common polymorphic methylation sensitive MSAP markers among replicates of a given propagated tree. This set of MSAPs allowed discrimination of the 70% of the analyzed trees.

Genetic variability and heritability in cultivated okra [Abel moschus esculentus (L.) Moench

Energy Technology Data Exchange (ETDEWEB)

Nwangburuka, C. C.; Denton, O. A.; Khinde, O. B.; Ojo, D. K.; Popoola, A. R.

2012-11-01

Twenty-nine okra accessions from different agro-ecological regions in Nigeria were grown during the rainy and dry seasons, between 2006 and 2007 at Abeokuta (derived savanah) and Ilishan (rainforest) and assessed to determine their genetic variability, heritability and genetic advance from eight yield related characters. The experiment was laid out in a Randomized Complete Block Design with five replications. There was high genotypic coefficient of variability, % broad-sense heritability and genetic advance in traits such as plant height (26.2, 90.7, 51.5), fresh pod length (23.9, 98.5, 48.8), fresh pod width (23.9, 98.5, 48.8), mature pod length (28.6, 98.5, 52.3), branching per plant (29.3, 82.3, 54.8) and pod weight per plant (33.9, 90.0, 63.3), suggesting the effect of additive genes and reliability of selection based on phenotype of these traits for crop improvement. The positive and significant phenotypic and genotypic correlation between plant height at maturity, fresh pod width, seeds per pod and pods per plant, branches per plant with seed weight per plant and pod weight per plant, suggests that selection on the basis of the phenotype of these characters will lead to high seed and pod yield in okra. (Author) 26 refs.

Epigenetic variability in the genetically uniform forest tree species Pinus pinea L.

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Enrique Sáez-Laguna

Full Text Available There is an increasing interest in understanding the role of epigenetic variability in forest species and how it may contribute to their rapid adaptation to changing environments. In this study we have conducted a genome-wide analysis of cytosine methylation pattern in Pinus pinea, a species characterized by very low levels of genetic variation and a remarkable degree of phenotypic plasticity. DNA methylation profiles of different vegetatively propagated trees from representative natural Spanish populations of P. pinea were analyzed with the Methylation Sensitive Amplified Polymorphism (MSAP technique. A high degree of cytosine methylation was detected (64.36% of all scored DNA fragments. Furthermore, high levels of epigenetic variation were observed among the studied individuals. This high epigenetic variation found in P. pinea contrasted with the lack of genetic variation based on Amplified Fragment Length Polymorphism (AFLP data. In this manner, variable epigenetic markers clearly discriminate individuals and differentiates two well represented populations while the lack of genetic variation revealed with the AFLP markers fail to differentiate at both, individual or population levels. In addition, the use of different replicated trees allowed identifying common polymorphic methylation sensitive MSAP markers among replicates of a given propagated tree. This set of MSAPs allowed discrimination of the 70% of the analyzed trees.

Deltamethrin flea-control preserves genetic variability of black-tailed prairie dogs during a plague outbreak

Science.gov (United States)

Jones, P.H.; Biggins, D.E.; Eads, D.A.; Eads, S.L.; Britten, H.B.

2012-01-01

Genetic variability and structure of nine black-tailed prairie dog (BTPD, Cynomys ludovicianus) colonies were estimated with 15 unlinked microsatellite markers. A plague epizootic occurred between the first and second years of sampling and our study colonies were nearly extirpated with the exception of three colonies in which prairie dog burrows were previously dusted with an insecticide, deltamethrin, used to control fleas (vectors of the causative agent of plague, Yersinia pestis). This situation provided context to compare genetic variability and structure among dusted and non-dusted colonies pre-epizootic, and among the three dusted colonies pre- and post-epizootic. We found no statistical difference in population genetic structures between dusted and non-dusted colonies pre-epizootic. On dusted colonies, gene flow and recent migration rates increased from the first (pre-epizootic) year to the second (post-epizootic) year which suggested dusted colonies were acting as refugia for prairie dogs from surrounding colonies impacted by plague. Indeed, in the dusted colonies, estimated densities of adult prairie dogs (including dispersers), but not juveniles (non-dispersers), increased from the first year to the second year. In addition to preserving BTPDs and many species that depend on them, protecting colonies with deltamethrin or a plague vaccine could be an effective method to preserve genetic variability of prairie dogs. ?? 2011 Springer Science+Business Media B.V.

Improved Genetic Algorithm with Two-Level Approximation for Truss Optimization by Using Discrete Shape Variables

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Shen-yan Chen

2015-01-01

Full Text Available This paper presents an Improved Genetic Algorithm with Two-Level Approximation (IGATA to minimize truss weight by simultaneously optimizing size, shape, and topology variables. On the basis of a previously presented truss sizing/topology optimization method based on two-level approximation and genetic algorithm (GA, a new method for adding shape variables is presented, in which the nodal positions are corresponding to a set of coordinate lists. A uniform optimization model including size/shape/topology variables is established. First, a first-level approximate problem is constructed to transform the original implicit problem to an explicit problem. To solve this explicit problem which involves size/shape/topology variables, GA is used to optimize individuals which include discrete topology variables and shape variables. When calculating the fitness value of each member in the current generation, a second-level approximation method is used to optimize the continuous size variables. With the introduction of shape variables, the original optimization algorithm was improved in individual coding strategy as well as GA execution techniques. Meanwhile, the update strategy of the first-level approximation problem was also improved. The results of numerical examples show that the proposed method is effective in dealing with the three kinds of design variables simultaneously, and the required computational cost for structural analysis is quite small.

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

International Nuclear Information System (INIS)

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

2016-01-01

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

[Genetic variability and differentiation of three Russian populations of yellow potato cyst nematode Globodera rostochiensis as revealed by nuclear markers].

Science.gov (United States)

Khrisanfova, G G; Kharchevnikov, D A; Popov, I O; Zinov'eva, S V; Semenova, S K

2008-05-01

Genetic variability of yellow potato cyst nematode G. rostochiensis from three Russian populations (Karelia, Vladimir oblast, and Moscow oblast) was investigated using two types of nuclear markers. Using RAPD markers identified with the help of six random primers (P-29, OPA-10, OPT-14, OPA-11, OPB-11, and OPH-20), it was possible to distinguish Karelian population from the group consisting of the populations from two adjacent regions (Moscow oblast and Vladimir oblast). Based on the combined matrix, containing 294 RAPD fragments, dendrogram of genetic differences was constructed, and the indices of genetic divergence and partition (P, H, and G(st)), as well as the gene flow indices N(m) between the nematode samples examined, were calculated. The dendrogram structure, genetic diversity indices, and variations of genetic distances between single individuals in each population from Karelia and Central Russia pointed to genetic isolation and higher genetic diversity of the nematodes from Karelia. Based on polymorphism of rDNA first intergenic spacer ITS1, attribution of all populations examined to the species G. rostochiensis was proved. Small variations of the ITS1 sequence in different geographic populations of nematodes from different regions of the species world range did not allow isolation of separate groups within the species. Possible factors (including interregional transportations of seed potato) affecting nematode population structure in Russia are discussed.

[Environmental and genetic variables related with alterations in language acquisition in early childhood].

Science.gov (United States)

Moriano-Gutierrez, A; Colomer-Revuelta, J; Sanjuan, J; Carot-Sierra, J M

2017-01-01

A great deal of research has addressed problems in the correct acquisition of language, but with few overall conclusions. The reasons for this lie in the individual variability, the existence of different measures for assessing language and the fact that a complex network of genetic and environmental factors are involved in its development. To review the environmental and genetic variables that have been studied to date, in order to gain a better under-standing of the causes of specific language impairment and create new evidence that can help in the development of screening systems for the early detection of these disorders. The environmental variables related with poorer early child language development include male gender, low level of education of the mother, familial history of problems with language or psychiatric problems, perinatal problems and health problems in early childhood. Bilingualism seems to be a protective factor. Temperament and language are related. Within the genetic factors there are several specific genes associated with language, two of which have a greater influence on its physiological acquisition: FOXP2 and CNTNAP2. The other genes that are most related with specific language disorders are ATP2C2, CMIP, ROBO2, ZNF277 and NOP9. The key to comprehending the development of specific language disorders lies in reaching an understanding of the true role played by genes in the ontogenesis, in the regulation of the different developmental processes, and how this role is modulated by the environment.

Foot-and-Mouth Disease Virus Serotype O Phylodynamics: Genetic Variability Associated with Epidemiological Factors in Pakistan

DEFF Research Database (Denmark)

Brito, B. P.; Perez, A. M.; Jamal, S. M.

2013-01-01

One of the most challenging aspects of foot-and-mouth disease (FMD) control is the high genetic variability of the FMD virus (FMDV). In endemic settings such as the Indian subcontinent, this variability has resulted in the emergence of pandemic strains that have spread widely and caused devastating...... outbreaks in disease-free areas. In countries trying to control and eradicate FMD using vaccination strategies, the constantly evolving and wide diversity of field FMDV strains is an obstacle for identifying vaccine strains that are successful in conferring protection against infection with field viruses....... Consequently, quantitative knowledge on the factors that are associated with variability of the FMDV is prerequisite for preventing and controlling FMD in the Indian subcontinent. A hierarchical linear model was used to assess the association between time, space, host species and the genetic variability...

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

Science.gov (United States)

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

2017-11-28

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

A colony of dog guides: analysis of the genetic variability assessed by pedigree data

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Roberta Ciampolini

2010-01-01

Full Text Available The study presents the analysis of the genetic variability in a colony of dog guides. Three breeds, Labrador (L, Golden Retriever (GR, and German Shepherd (GS, were evaluated. Pedigrees data on 370 L, 260 GR, and 85 GS dogs bred for guide by the National Guide Dog School (SNCG of Scandicci (Florence, Italy were used. Data were available beginning from 1994. The average coefficient of coancestry and the mean F were 0.8% and 0.45% in GR, 0.7% and 0.38% in L, 1.0% and 0.49% in GS, respectively. The rate of increase in inbreeding was lower in L population (0.17 than in GR population (0.54, while in GS only the dogs with 5 e 7 traced generations resulted inbred. The results of this research point out that the genetic management of the dogs seems to be carefully and rationally monitored. Nevertheless, the population that may require a greater attention seems to be the GR, where a higher increase of the coefficient of inbreeding per generation is observed; therefore, the importation of germplasm from other working dogs is desirable in order to avoid in future an excessive increase of the inbreeding that could lead to adverse consequences for dogs health and fertility.

Genetic Variability in Glucosinolates in Seed of Brassica juncea: Interest in Mustard Condiment

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Othmane Merah

2015-01-01

Full Text Available Brassica juncea is mostly used for oil production which implies selection of genotypes with low glucosinolates level and high oil content. In contrast, condiment production needs varieties with high level in some glucosinolates including sinigrin. The genetic variability was studied mostly by molecular tools. The objectives were almost the decrease of glucosinolates level in order to use the oilcake for animal feed. The aim of this work is to study the genetic variability for different glucosinolates and their relationships with agronomical traits within a large collection of Brassica juncea genotypes for condiment uses. A collection of 190 genotypes from different origins was studied in Dijon (France. Oil content and total glucosinolates, and sinigrin and gluconapin levels were measured. Flowering and maturation durations, seed yield, and yield components were also measured. Large variability was observed between genotypes for the measured traits within the studied collection. Total glucosinolates varied twofold between extreme genotypes. Values of sinigrin content varied from 0 to more than 134 µmol·g−1. Correlations between glucosinolates traits and both phenological and agronomical characters are presented and discussed for their potential for industrial condiment uses.

Is the higher rate of parental child homicide in stepfamilies an effect of non-genetic relatedness?

Institute of Scientific and Technical Information of China (English)

Hans TEMRIN; Johanna NORDLUND; Mikael RYING; Birgitta S. TULLBERG

2011-01-01

In an evolutionary perspective individuals are expected to vary the degree of parental love and care in relation to the fitness value that a child represents. Hence, stepparents are expected to show less solicitude than genetically related parents, and this lack of genetic relatedness has been used to explain the higher frequencies of child abuse and homicide found in stepfamilies.However, other factors than non-genetic relatedness may cause this over-representation in stepfamilies. Here we use a 45-year data set of parental child homicides in Sweden to test two hypotheses related to the higher incidence in stepfamilies: 1) adults in different types of family differ in their general disposition to use violence, and 2) parents are more likely to kill stepchildren than genetically related children. Of the 152 perpetrators in biparental families there was an overrepresentation of perpetrators in stepfamilies (n=27) compared with the general population. We found support for the first hypothesis in that both general and violent crime rates were higher in stepfamilies, both in the general population and among perpetrators of child homicide. However, we found no support for the second hypothesis because of the 27 perpetrators in stepfamilies the perpetrator killed a genetically related child in 13 cases, a stepchild in 13 cases and both types of children in one case. Moreover, out of the 12 families where the perpetrator lived with both stepchildren and genetic children, there was no bias towards killing stepchildren. Thus, we found no evidence for an effect of non-genetic relatedness per se [Current Zoology 57 (3): 253-59, 2011].

Cytogenetic variability in pinus sylvestris L. populations experiencing anthropogenic influence

International Nuclear Information System (INIS)

Oudalova, A.; Geras'kin, S.; Vasiliev, D.; Dikarev, V.

2004-01-01

Techno-genic pollution has become one of the most significant ecological factors determining biosphere existence and development. An analysis of genetic consequences of the radiation accidents in the South Urals and Chernobyl has shown that mutation and recombination processes are considerably accelerated in plant and animal's populations experiencing techno-genic influence. This implies that there are complicated adaptation processes leading to changes in genetic structure of populations and increasing genetic load. Pinus sylvestris L. populations growing at the territory of the 'radon' Leningrad regional radioactive waste reprocessing enterprise and Sosnovy Bor town were monitored 6 years (1997-2002) by a set of cyto-genetical and morphological tests. Cytogenetic damage levels within intercalary meristem of needle as well as in root meristem of seedlings were found to significantly exceed corresponding controls. A higher radioresistance of the Scots pine seeds analyzed was demonstrated with an acute γ-radiation that also revealed a selection process directed at an enhancement of repair efficiency and resulting in a shift of mean values of radioresistance in populations towards higher values. An enlargement of variance of studied cytogenetic parameters was found in the populations experiencing techno-genic influence. This indicates, with an account of phenomenon of the enhanced radioresistance, that there are processes of cyto-genetical adaptation in the investigated regions. An analysis of the structure of ecological-genetical variability was carried out with the purpose of separating two components in the inter-population variability - the first is engaged to the genetically determined variability of biological characteristics intrinsic for this species, and the second is responsible for the variability originating from anthropogenic contamination of the natural habitat. Changes of these two types of variability were studied in dependence on time and techno

Cytogenetic variability in pinus sylvestris L. populations experiencing anthropogenic influence

Energy Technology Data Exchange (ETDEWEB)

Oudalova, A.; Geras' kin, S.; Vasiliev, D.; Dikarev, V. [Russian Institute of Agricultural Radiology and Agroecology, Obninsk (Russian Federation)

2004-07-01

Techno-genic pollution has become one of the most significant ecological factors determining biosphere existence and development. An analysis of genetic consequences of the radiation accidents in the South Urals and Chernobyl has shown that mutation and recombination processes are considerably accelerated in plant and animal's populations experiencing techno-genic influence. This implies that there are complicated adaptation processes leading to changes in genetic structure of populations and increasing genetic load. Pinus sylvestris L. populations growing at the territory of the 'radon' Leningrad regional radioactive waste reprocessing enterprise and Sosnovy Bor town were monitored 6 years (1997-2002) by a set of cyto-genetical and morphological tests. Cytogenetic damage levels within intercalary meristem of needle as well as in root meristem of seedlings were found to significantly exceed corresponding controls. A higher radioresistance of the Scots pine seeds analyzed was demonstrated with an acute {gamma}-radiation that also revealed a selection process directed at an enhancement of repair efficiency and resulting in a shift of mean values of radioresistance in populations towards higher values. An enlargement of variance of studied cytogenetic parameters was found in the populations experiencing techno-genic influence. This indicates, with an account of phenomenon of the enhanced radioresistance, that there are processes of cyto-genetical adaptation in the investigated regions. An analysis of the structure of ecological-genetical variability was carried out with the purpose of separating two components in the inter-population variability - the first is engaged to the genetically determined variability of biological characteristics intrinsic for this species, and the second is responsible for the variability originating from anthropogenic contamination of the natural habitat. Changes of these two types of variability were studied in dependence on

The use of random amplified polymorphic DNA to evaluate the genetic variability of Ponkan mandarin (Citrus reticulata Blanco accessions

Directory of Open Access Journals (Sweden)

Coletta Filho Helvécio Della

2000-01-01

Full Text Available RAPD analysis of 19 Ponkan mandarin accessions was performed using 25 random primers. Of 112 amplification products selected, only 32 were polymorphic across five accessions. The absence of genetic variability among the other 14 accessions suggested that they were either clonal propagations with different local names, or that they had undetectable genetic variability, such as point mutations which cannot be detected by RAPD.

Association of genetic and phenotypic variability with geography and climate in three southern California oaks.

Science.gov (United States)

Riordan, Erin C; Gugger, Paul F; Ortego, Joaquín; Smith, Carrie; Gaddis, Keith; Thompson, Pam; Sork, Victoria L

2016-01-01

Geography and climate shape the distribution of organisms, their genotypes, and their phenotypes. To understand historical and future evolutionary and ecological responses to climate, we compared the association of geography and climate of three oak species (Quercus engelmannii, Quercus berberidifolia, and Quercus cornelius-mulleri) in an environmentally heterogeneous region of southern California at three organizational levels: regional species distributions, genetic variation, and phenotypic variation. We identified climatic variables influencing regional distribution patterns using species distribution models (SDMs), and then tested whether those individual variables are important in shaping genetic (microsatellite) and phenotypic (leaf morphology) variation. We estimated the relative contributions of geography and climate using multivariate redundancy analyses (RDA) with variance partitioning. The modeled distribution of each species was influenced by climate differently. Our analysis of genetic variation using RDA identified small but significant associations between genetic variation with climate and geography in Q. engelmannii and Q. cornelius-mulleri, but not in Q. berberidifolia, and climate explained more of the variation. Our analysis of phenotypic variation in Q. engelmannii indicated that climate had more impact than geography, but not in Q. berberidifolia. Throughout our analyses, we did not find a consistent pattern in effects of individual climatic variables. Our comparative analysis illustrates that climate influences tree response at all organizational levels, but the important climate factors vary depending on the level and on the species. Because of these species-specific and level-specific responses, today's sympatric species are unlikely to have similar distributions in the future. © 2016 Botanical Society of America.

Resolving the Complex Genetic Basis of Phenotypic Variation and Variability of Cellular Growth.

Science.gov (United States)

Ziv, Naomi; Shuster, Bentley M; Siegal, Mark L; Gresham, David

2017-07-01

In all organisms, the majority of traits vary continuously between individuals. Explaining the genetic basis of quantitative trait variation requires comprehensively accounting for genetic and nongenetic factors as well as their interactions. The growth of microbial cells can be characterized by a lag duration, an exponential growth phase, and a stationary phase. Parameters that characterize these growth phases can vary among genotypes (phenotypic variation), environmental conditions (phenotypic plasticity), and among isogenic cells in a given environment (phenotypic variability). We used a high-throughput microscopy assay to map genetic loci determining variation in lag duration and exponential growth rate in growth rate-limiting and nonlimiting glucose concentrations, using segregants from a cross of two natural isolates of the budding yeast, Saccharomyces cerevisiae We find that some quantitative trait loci (QTL) are common between traits and environments whereas some are unique, exhibiting gene-by-environment interactions. Furthermore, whereas variation in the central tendency of growth rate or lag duration is explained by many additive loci, differences in phenotypic variability are primarily the result of genetic interactions. We used bulk segregant mapping to increase QTL resolution by performing whole-genome sequencing of complex mixtures of an advanced intercross mapping population grown in selective conditions using glucose-limited chemostats. We find that sequence variation in the high-affinity glucose transporter HXT7 contributes to variation in growth rate and lag duration. Allele replacements of the entire locus, as well as of a single polymorphic amino acid, reveal that the effect of variation in HXT7 depends on genetic, and allelic, background. Amplifications of HXT7 are frequently selected in experimental evolution in glucose-limited environments, but we find that HXT7 amplifications result in antagonistic pleiotropy that is absent in naturally

High Levels of Genetic Diversity of Plasmodium falciparum Populations in Papua New Guinea despite Variable Infection Prevalence

Science.gov (United States)

Barry, Alyssa E.; Schultz, Lee; Senn, Nicholas; Nale, Joe; Kiniboro, Benson; Siba, Peter M.; Mueller, Ivo; Reeder, John C.

2013-01-01

High levels of genetic diversity in Plasmodium falciparum populations are an obstacle to malaria control. Here, we investigate the relationship between local variation in malaria epidemiology and parasite genetic diversity in Papua New Guinea (PNG). Cross-sectional malaria surveys were performed in 14 villages spanning four distinct malaria-endemic areas on the north coast, including one area that was sampled during the dry season. High-resolution msp2 genotyping of 2,147 blood samples identified 761 P. falciparum infections containing a total of 1,392 clones whose genotypes were used to measure genetic diversity. Considerable variability in infection prevalence and mean multiplicity of infection was observed at all of the study sites, with the area sampled during the dry season showing particularly striking local variability. Genetic diversity was strongly associated with multiplicity of infection but not with infection prevalence. In highly endemic areas, differences in infection prevalence may not translate into a decrease in parasite population diversity. PMID:23400571

Economic Statistical Design of Variable Sampling Interval X¯$\\overline X $ Control Chart Based on Surrogate Variable Using Genetic Algorithms

Directory of Open Access Journals (Sweden)

Lee Tae-Hoon

2016-12-01

Full Text Available In many cases, a X¯$\\overline X $ control chart based on a performance variable is used in industrial fields. Typically, the control chart monitors the measurements of a performance variable itself. However, if the performance variable is too costly or impossible to measure, and a less expensive surrogate variable is available, the process may be more efficiently controlled using surrogate variables. In this paper, we present a model for the economic statistical design of a VSI (Variable Sampling Interval X¯$\\overline X $ control chart using a surrogate variable that is linearly correlated with the performance variable. We derive the total average profit model from an economic viewpoint and apply the model to a Very High Temperature Reactor (VHTR nuclear fuel measurement system and derive the optimal result using genetic algorithms. Compared with the control chart based on a performance variable, the proposed model gives a larger expected net income per unit of time in the long-run if the correlation between the performance variable and the surrogate variable is relatively high. The proposed model was confined to the sample mean control chart under the assumption that a single assignable cause occurs according to the Poisson process. However, the model may also be extended to other types of control charts using a single or multiple assignable cause assumptions such as VSS (Variable Sample Size X¯$\\overline X $ control chart, EWMA, CUSUM charts and so on.

CRISPR/Cas9 gene drives in genetically variable and nonrandomly mating wild populations.

Science.gov (United States)

Drury, Douglas W; Dapper, Amy L; Siniard, Dylan J; Zentner, Gabriel E; Wade, Michael J

2017-05-01

Synthetic gene drives based on CRISPR/Cas9 have the potential to control, alter, or suppress populations of crop pests and disease vectors, but it is unclear how they will function in wild populations. Using genetic data from four populations of the flour beetle Tribolium castaneum , we show that most populations harbor genetic variants in Cas9 target sites, some of which would render them immune to drive (ITD). We show that even a rare ITD allele can reduce or eliminate the efficacy of a CRISPR/Cas9-based synthetic gene drive. This effect is equivalent to and accentuated by mild inbreeding, which is a characteristic of many disease-vectoring arthropods. We conclude that designing such drives will require characterization of genetic variability and the mating system within and among targeted populations.

Is the higher rate of parental child homicide in stepfamilies an effect of non-genetic relatedness?

Directory of Open Access Journals (Sweden)

Hans TEMRIN, Johanna NORDLUND, Mikael RYING, Birgitta S. TULLBERG

2011-06-01

Full Text Available In an evolutionary perspective individuals are expected to vary the degree of parental love and care in relation to the fitness value that a child represents. Hence, stepparents are expected to show less solicitude than genetically related parents, and this lack of genetic relatedness has been used to explain the higher frequencies of child abuse and homicide found in stepfamilies. However, other factors than non-genetic relatedness may cause this over-representation in stepfamilies. Here we use a 45-year data set of parental child homicides in Sweden to test two hypotheses related to the higher incidence in stepfamilies: 1 adults in different types of family differ in their general disposition to use violence, and 2 parents are more likely to kill stepchildren than genetically related children. Of the 152 perpetrators in biparental families there was an overrepresentation of perpetrators in stepfamilies (n=27 compared with the general population. We found support for the first hypothesis in that both general and violent crime rates were higher in stepfamilies, both in the general population and among perpetrators of child homicide. However, we found no support for the second hypothesis because of the 27 perpetrators in stepfamilies the perpetrator killed a genetically related child in 13 cases, a stepchild in 13 cases and both types of children in one case. Moreover, out of the 12 families where the perpetrator lived with both stepchildren and genetic children, there was no bias towards killing stepchildren. Thus, we found no evidence for an effect of non-genetic relatedness per se [Current Zoology 57 (3: 253–259, 2011].

Genetic variability in Brazilian wheat cultivars assessed by microsatellite markers

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Ivan Schuster

2009-01-01

Full Text Available Wheat (Triticum aestivum is one of the most important food staples in the south of Brazil. Understanding genetic variability among the assortment of Brazilian wheat is important for breeding. The aim of this work was to molecularly characterize the thirty-six wheat cultivars recommended for various regions of Brazil, and to assess mutual genetic distances, through the use of microsatellite markers. Twenty three polymorphic microsatellite markers (PMM delineated all 36 of the samples, revealing a total of 74 simple sequence repeat (SSR alleles, i.e. an average of 3.2 alleles per locus. Polymorphic information content (PIC value calculated to assess the informativeness of each marker ranged from 0.20 to 0.79, with a mean of 0.49. Genetic distances among the 36 cultivars ranged from 0.10 (between cultivars Ocepar 18 and BRS 207 to 0.88 (between cultivars CD 101 and Fudancep 46, the mean distance being 0.48. Twelve groups were obtained by using the unweighted pair-group method with arithmetic means analysis (UPGMA, and thirteen through the Tocher method. Both methods produced similar clusters, with one to thirteen cultivars per group. The results indicate that these tools may be used to protect intellectual property and for breeding and selection programs.

Genetic variability of Echinococcus granulosus from the Tibetan plateau inferred by mitochondrial DNA sequences.

Science.gov (United States)

Yan, Ning; Nie, Hua-Ming; Jiang, Zhong-Rong; Yang, Ai-Guo; Deng, Shi-Jin; Guo, Li; Yu, Hua; Yan, Yu-Bao; Tsering, Dawa; Kong, Wei-Shu; Wang, Ning; Wang, Jia-Hai; Xie, Yue; Fu, Yan; Yang, De-Ying; Wang, Shu-Xian; Gu, Xiao-Bin; Peng, Xue-Rong; Yang, Guang-You

2013-09-01

To analyse genetic variability and population structure, 84 isolates of Echinococcus granulosus (Cestoda: Taeniidae) collected from various host species at different sites of the Tibetan plateau in China were sequenced for the whole mitochondrial nad1 (894 bp) and atp6 (513 bp) genes. The vast majority were classified as G1 genotype (n=82), and two samples from human patients in Sichuan province were identified as G3 genotype. Based on the concatenated sequences of nad1+atp6, 28 different haplotypes (NA1-NA28) were identified. A parsimonious network of the concatenated sequence haplotypes showed star-like features in the overall population, with NA1 as the major haplotype in the population networks. By AMOVA it was shown that variation of E. granulosus within the overall population was the main pattern of the total genetic variability. Neutrality indexes of the concatenated sequence (nad1+atp6) were computed by Tajima's D and Fu's Fs tests and showed high negative values for E. granulosus, indicating significant deviations from neutrality. FST and Nm values suggested that the populations were not genetically differentiated. Copyright © 2013 Elsevier B.V. All rights reserved.

Genetic Variability of Macrophomina phaseolina Isolates from Dry Beans in Turkey

OpenAIRE

Serkan Yeşil; Kubilay Kurtuluş Baştaş

2016-01-01

Charcoal rot is a soil and seed borne, economically important fungal disease on dry bean in Turkey. Twenty bean isolates of M. phaseolina collected from different locations in Turkey during 2008 and 2012 years were studied for genetic variability using random amplified polymorphic DNA (RAPD) assay, chlorate sensitivity on medium supplemented with 120mM of potassium, phenotype of colony, and pathogenicity. Isolates were identified as M. phaseolina based on morhological features and PCR assays ...

Evolution of the genetic variability of eight French dairy cattle breeds assessed by pedigree analysis.

Science.gov (United States)

Danchin-Burge, C; Leroy, G; Brochard, M; Moureaux, S; Verrier, E

2012-06-01

A pedigree analysis was performed on eight French dairy cattle breeds to assess their change in genetic variability since a first analysis completed in 1996. The Holstein, Normande and Montbéliarde breeds are selected internationally with over hundreds of thousands cows registered in the performance recording system. Three breeds are internationally selected but with limited numbers of cows in France (Brown Swiss, French Simmental and French Red Pied). The last two remaining breeds (Abondance and Tarentaise) are raised at regional level. The effective numbers of ancestors of cows born between 2004 and 2007 varied between 15 (Abondance and Tarentaise) and 51 (French Red Pied). The effective population sizes (classical approach) varied between 53 (Abondance) and 197 (French Red Pied). This article also compares the genetic variability of the ex situ (collections of the French National Cryobank) and in situ populations. The results were commented in regard to the recent history of gene flows in the different breeds as well as the existence of more or less stringent bottlenecks. Our results showed that whatever the size of the breeds, their genetic diversity impoverished quite rapidly since 1996 and they all could be considered as quite poor from a genetic diversity point of view. It shows the need for setting up cryobanks as gene reservoirs as well as sustainable breeding programmes that include loss of genetic diversity as an integrated control parameter. © 2011 Blackwell Verlag GmbH.

Genetic variability in maned wolf based on heterologous short-tandem repeat markers from domestic dog.

Science.gov (United States)

Salim, D C; Akimoto, A A; Carvalho, C B; Oliveira, S F; Grisolia, C K; Moreira, J R; Klautau-Guimarães, M N

2007-06-20

The maned wolf (Chrysocyon brachyurus) is the largest South American canid. Habitat loss and fragmentation, due to agricultural expansion and predatory hunting, are the main threats to this species. It is included in the official list of threatened wildlife species in Brazil, and is also protected by IUCN and CITES. Highly variable genetic markers such as microsatellites have the potential to resolve genetic relationships at all levels of the population structure (among individuals, demes or metapopulations) and also to identify the evolutionary unit for strategies for the conservation of the species. Tests were carried out to verify whether a class of highly polymorphic tetranucleotide repeats described for the domestic dog effectively amplifies DNA in the maned wolf. All five loci studied were amplified; however, one of these, was shown to be monomorphic in 69 maned wolf samples. The average allele number and estimated heterozygosity per polymorphic locus were 4.3 and 67%, respectively. The genetic variability found for this species, which is considered threatened with extinction, showed similar results when compared to studies of other canids.

Quantizing higher-spin gravity in free-field variables

Science.gov (United States)

Campoleoni, Andrea; Fredenhagen, Stefan; Raeymaekers, Joris

2018-02-01

We study the formulation of massless higher-spin gravity on AdS3 in a gauge in which the fundamental variables satisfy free field Poisson brackets. This gauge choice leaves a small portion of the gauge freedom unfixed, which should be further quotiented out. We show that doing so leads to a bulk version of the Coulomb gas formalism for W N CFT's: the generators of the residual gauge symmetries are the classical limits of screening charges, while the gauge-invariant observables are classical W N charges. Quantization in these variables can be carried out using standard techniques and makes manifest a remnant of the triality symmetry of W ∞[λ]. This symmetry can be used to argue that the theory should be supplemented with additional matter content which is precisely that of the Prokushkin-Vasiliev theory. As a further application, we use our formulation to quantize a class of conical surplus solutions and confirm the conjecture that these are dual to specific degenerate W N primaries, to all orders in the large central charge expansion.

Genetic variability of concentration of microelements in wild sunflower species and hybrids

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Kastori Rudolf R.

2010-01-01

Full Text Available The aim of this work was to investigate genetic specificity of sunflower nutrition with microelements. Therefore, concentrations of essential (Zn, B, Mn, Cu, Fe and Ni and non-essential (Cr, Al, Cd, As, Pb and Ba micronutrients were analyzed. Five sunflower hybrids the most grown in Serbia and different populations of wild sunflower species originating from North America: Helianthus neglectus Heiser (3, Helianthus agrophyllus T&G (3, Helianthus petiolaris Nutt. (2, Helianthus annuus L. (4 were included in the experiment. Populations of wild sunflower species and hybrids differed significantly with respect to the concentration of analyzed elements. Manganese concentration was significantly higher in hybrids than in wild species. In all genotypes Fe, B and Mn had the highest concentration. Coefficient of variation of microelement concentration depended on genotype and particular element. In wild populations, for essential microelements, it was between 3.7 and 59.5, whereas in hybrids it varied from 10.0 to 48.8. Coefficient of variation of concentration of non-essential microelements in wild populations varied from 7.7 to 73.8, and in hybrids from 15.1 to 48.8. Average coefficient of variation in both wild species and hybrids was the lowest for Mn and Pb. It was the highest for Cr, Ni, and Zn in hybrids and for Cd, Ni, and Cr in wild species. The results suggest that genetic specificity with respect to uptake of microelements in wild species and hybrids is highly expressed. Broad genetic variability of concentrations of microelements in wild species and hybrids indicate that their reactions to deficiency and/or excess of those elements probably are not the same either. This finding may be used in breeding process aimed specifically at improvement of tolerance and capacity to accumulate microelements in sunflower. Phytoremediation technology designed to reduce the amount of microelements in the soil could thus be advanced by utilization of such

Genetic variability of a population of Aedes aegypti from Paraná, Brazil, using the mitochondrial ND4 gene

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Adriana L. Twerdochlib

2012-06-01

Full Text Available Genetic variability of a population of Aedes aegypti from Paraná, Brazil, using the mitochondrial ND4 gene. To analyze the genetic variability of populations of Aedes aegypti, 156 samples were collected from 10 municipalities in the state of Paraná, Brazil. A 311 base pairs (bp region of the NADH dehydrogenase subunit 4 (ND4 mitochondrial gene was examined. An analysis of this fragment identified eight distinct haplotypes. The mean genetic diversity was high (h = 0.702; p = 0.01556. AMOVA analysis indicated that most of the variation (67% occurred within populations and the F ST value (0.32996 was highly significant. F ST values were significant in most comparisons among cities. The isolation by distance was not significant (r = -0.1216 and p = 0, 7550, indicating that genetic distance is not related to geographic distance. Neighbor-joining analysis showed two genetically distinct groups within Paraná. The DNA polymorphism and AMOVA data indicate a decreased gene flow in populations from Paraná, which can result in increased vectorial competence.

IN SITU COMPARISON OF TREE-RING RESPONSES TO CLIMATE AND POPULATION GENETICS: THE NEED TO CONTROL FOR LOCAL CLIMATE AND SITE VARIABLES

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Johann Mathias Housset

2016-10-01

Full Text Available Tree species responses to climate change will be greatly influenced by their evolutionary potential and their phenotypic plasticity. Investigating tree-rings responses to climate and population genetics at the regional scale is therefore crucial in assessing the tree behaviour to climate change. This study combined in situ dendroclimatology and population genetics over a latitudinal gradient and compared the variations between the two at the intra- and inter-population levels. This approach was applied on the northern marginal populations of Thuja occidentalis (eastern white-cedar in the Canadian boreal forest. We aimed first to assess the radial growth variability (response functional trait within populations across the gradient and to compare it with the genetic diversity (microsatellites. Second, we investigated the variability in the growth response to climate at the regional scale through the radial growth-climate relationships, and tested its correlation with environmental variables and population genetic structure. Model selection based on the Akaike Information Criteria revealed that the growth synchronicity between pairs of trees of a population covariates with both the genetic diversity of this population and the amount of precipitation (inverse correlation, although these variables only explained a small fraction of the observed variance. At the regional scale, variance partitioning and partial redundancy analysis indicate that the growth response to climate was greatly modulated by stand environmental variables, suggesting predominant plastic variations in growth-response to climate. Combining in situ dendroclimatology and population genetics is a promising way to investigate species’ response capacity to climate change in natural stands. We stress the need to control for local climate and site conditions effects on dendroclimatic response to climate to avoid misleading conclusions regarding the associations with genetic variables.

Variability of Cutaneous Leishmaniasis Lesions Is Not Associated with Genetic Diversity of Leishmania tropica in Khyber Pakhtunkhwa Province of Pakistan.

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Khan, Nazma Habib; Llewellyn, Martin S; Schönian, Gabriele; Sutherland, Colin J

2017-11-01

Leishmania tropica is the causative agent of cutaneous leishmaniasis in Pakistan. Here, intraspecific diversity of L. tropica from northern Pakistan was investigated using multilocus microsatellite typing. Fourteen polymorphic microsatellite markers were typed in 34 recently collected L. tropica isolates from Pakistan along with 158 archival strains of diverse Afro-Eurasian origins. Previously published profiles for 145 strains of L. tropica originating from different regions of Africa, Central Asia, Iran, and Middle East were included for comparison. Six consistently well-supported genetic groups were resolved: 1) Asia, 2) Morroco A, 3) Namibia and Kenya A, 4) Kenya B/Tunisia and Galilee, 5) Morocco B, and 6) Middle East. Strains from northern Pakistan were assigned to Asian cluster except for three that were placed in a geographically distant genetic group; Morocco A. Lesion variability among these Pakistani strains was not associated with specific L. tropica genetic profile. Pakistani strains showed little genetic differentiation from strains of Iraq, Afghanistan, and Syria (F ST = 0.00-0.06); displayed evidence of modest genetic flow with India (F ST = 0.14). Furthermore, genetic structuring within these isolates was not geographically defined. Pak-Afghan cluster was in significant linkage disequilibrium (I A = 1.43), had low genetic diversity, and displayed comparatively higher heterozygosity (F IS = -0.62). Patterns of genetic diversity observed suggest dominance of a minimally diverse clonal lineage within northern Pakistan. This is surprising as a wide clinical spectrum was observed in patients, suggesting the importance of host and other factors. Further genotyping studies of L. tropica isolates displaying different clinical phenotypes are required to validate this potentially important observation.

Genetic Variability of Show Jumping Attributes in Young Horses Commencing Competing

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Tomasz Próchniak

2015-08-01

Full Text Available The aim of the study was to select traits that may constitute a prospective criterion for breeding value prediction of young horses. The results of 1,232 starts of 894 four-, five-, six-, and seven-year-old horses, obtained during jumping championships for young horses which had not been evaluated in, alternative to championships, training centres were analyed. Nine traits were chosen of those recorded: ranking in the championship, elimination (y/n, conformation, rating of style on day one, two, and three, and penalty points on day one, two, and three of a championship. (Covariance components were estimated via the Gibbs sampling procedure and adequate (covariance component ratios were calculated. Statistical classifications were trait dependent but all fitted random additive genetic and permanent environment effects. It was found that such characteristics as penalty points and jumping style are potential indicators of jumping ability, and the genetic variability of the traits was within the range of 14% to 27%. Given the low genetic correlations between the conformation and other results achieved on the parkour, the relevance of assessment of conformation in four-years-old horses has been questioned.

Genetic Variability of Macrophomina phaseolina Isolates from Dry Beans in Turkey

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Serkan Yeşil

2016-04-01

Full Text Available Charcoal rot is a soil and seed borne, economically important fungal disease on dry bean in Turkey. Twenty bean isolates of M. phaseolina collected from different locations in Turkey during 2008 and 2012 years were studied for genetic variability using random amplified polymorphic DNA (RAPD assay, chlorate sensitivity on medium supplemented with 120mM of potassium, phenotype of colony, and pathogenicity. Isolates were identified as M. phaseolina based on morhological features and PCR assays using species-specific primers (MPKF1and MPKR1. Isolates of M. phaseolina were analysed for their aggressiveness on the susceptible bean cv. Akman 98, by soil inoculation method. Isolates exhibiting a dense chlorate phenotype were chlorate-resistant, while those possessing feathery and restricted chlorate phenotypes were chlorate-sensitive. More than half of the isolates (55% were resistant to chlorate and produced dense phenotype, while 35% isolates showed feathery and two isolates (10% showed restricted growth. DNA from 20 isolates was subjected to genetic diversity analysis by the RAPD method using 14 randomly chosen 10-base random primers, and low genetic diversity (33.3% was observed among the tested isolates.

Genetic variability, trait association and path analysis of yield and yield components in mungbean (vigna radiata (L.) wilczek)

International Nuclear Information System (INIS)

Tabasum, A.; Saleem, M.; Aziz, I.

2010-01-01

Genetic variability, heritability along with genetic advance of traits, their association and direct and indirect effects on yield are essential for crop improvement. Ten mungbean genotypes were studied to assess variability and degree to which various plant traits associate with seed yield. Primary and secondary branches, pods per cluster and pod length showed lesser variability while clusters per plant, 100 seed weight and harvest index exhibited intermediate range of variability. Sufficient genetic variability was observed for plant height, pods per plant, total plant weight and seed yield. Moderate to high heritability estimates were found for all traits. Primary and secondary branches per plant, pod length and 100-seed weight exhibited negative and non significant genotypic and phenotypic correlations with seed yield. Plant height showed positive non-significant and significant genotypic and phenotypic correlation. Pods per cluster correlated significantly negative with seed yield. Clusters per plant, pods per plant, total plant weight and harvest index showed positive significant genotypic and phenotypic correlations with seed yield. Positive direct effects were exerted through secondary branches, pods per plant, pod length, 100 seed weight, total plant weight and harvest index while primary branches, plant height, clusters per plant and pods per cluster had negative direct effects. The present findings could be useful for establishing selection criteria for high seed yield in the mungbean breeding. (author)

Genetic variability and differentiation among populations of the Azorean endemic gymnosperm Juniperus brevifolia: baseline information for a conservation and restoration perspective.

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Silva, Luís; Elias, Rui B; Moura, Mónica; Meimberg, Harald; Dias, Eduardo

2011-12-01

The Azorean endemic gymnosperm Juniperus brevifolia (Seub.) Antoine is a top priority species for conservation in Macaronesia, based on its ecological significance in natural plant communities. To evaluate genetic variability and differentiation among J. brevifolia populations from the Azorean archipelago, we studied 15 ISSR and 15 RAPD markers in 178 individuals from 18 populations. The average number of polymorphic bands per population was 65 for both ISSR and RAPD. The majority of genetic variability was found within populations and among populations within islands, and this partitioning of variability was confirmed by AMOVA. The large majority of population pairwise F(ST) values were above 0.3 and below 0.6. The degree of population genetic differentiation in J. brevifolia was relatively high compared with other species, including Juniperus spp. The genetic differentiation among populations suggests that provenance should be considered when formulating augmentation or reintroduction strategies.

Genetic variability of the pattern of night melatonin blood levels in relation to coat changes development in rabbits

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Chemineau Philippe

2004-03-01

Full Text Available Abstract To assess the genetic variability in both the nocturnal increase pattern of melatonin concentration and photoresponsiveness in coat changes, an experiment on 422 Rex rabbits (from 23 males raised under a constant light programme from birth was performed. The animals were sampled at 12 weeks of age, according to 4 periods over a year. Blood samples were taken 7 times during the dark phase and up to 1 h after the lighting began. Maturity of the fur was assessed at pelting. Heritability estimates of blood melatonin concentration (0.42, 0.17 and 0.11 at mid-night, 13 and 15 h after lights-out respectively and strong genetic correlations between fur maturity and melatonin levels at the end of the dark phase (-0.64 indicates that (i the variability of the nocturnal pattern of melatonin levels is under genetic control and (ii the duration of the nocturnal melatonin increase is a genetic component of photoresponsiveness in coat changes.

Recent habitat fragmentation caused by major roads leads to reduction of gene flow and loss of genetic variability in ground beetles.

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Keller, Irene; Largiadèr, Carlo R

2003-02-22

Although habitat fragmentation is suspected to jeopardize the long-term survival of many species, few data are available on its impact on the genetic variability of invertebrates. We assess the genetic population structure of the flightless ground beetle Carabus violaceus L., 1758 in a Swiss forest, which is divided into several fragments by a highway and two main roads. Eight samples were collected from different forest fragments and analysed at six microsatellite loci. The largest genetic differentiation was observed between samples separated by roads and in particular by the highway. The number of roads between sites explained 44% of the variance in pairwise F(ST) estimates, whereas the age of the road and the geographical distance between locations were not significant factors. Furthermore, a comparison of allelic richness showed that the genetic variability in a small forest fragment isolated by the highway was significantly lower than in the rest of the study area. These findings strongly support the hypothesis that large roads are absolute barriers to gene flow in C. violaceus, which may lead to a loss of genetic variability in fragmented populations.

Genetical variability of Gladioli as the result of gamma-radiation

International Nuclear Information System (INIS)

Jakota, L.I.; Murin, A.V.

1994-01-01

In the starting material of Gladioli, got in the result of Y-radiation, the forms with white spots on the petals were observed. The Gladioli form 165-81 is distinguished by low growth and middle early flowering. The flower form is triangular. Basic pigmentation is red. White spots of different size on the petals were observed. The investigation was made in 1992 in the field of genetical variability of Gladioli. The Gladioli form 165-81 was irradiated with gamma-radiation dose 30 Gr. As a result the depression of biometric indicators was observed. Consequently, 30 Gr is a mutant dose for Gladioli

Genetic variability and identification of the intermediate snail hosts of Schistosoma mansoni

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Teofânia HDA Vidigal

1998-01-01

Full Text Available Studies based on shell or reproductive organ morphology and genetic considerations suggest extensive intraspecific variation in Biomphalaria snails. The high variability at the morphological and genetic levels, as well as the small size of some specimens and similarities between species complicate the correct identification of these snails. Here we review our work using methods based on polymerase chain reaction (PCR amplification for analysis of genetic variation and identification of Biomphalaria snails from Brazil, Argentina, Uruguay and Paraguay. Arbitrarily primed-PCR revealed that the genome of B. glabrata exihibits a remarkable degree of intraespecific polymorphism. Low stringency-PCR using primers for 18S rRNA permited the identification of B. glabrata, B. tenagophila and B. occidentalis. The study of individuals obtained from geographically distinct populations exhibits significant intraspecific DNA polymorphism, however specimens from the same species, exhibit some species specific LSPs. We also showed that PCR-restriction fragment of length polymorphism of the internal transcribed spacer region of Biomphalaria rDNA, using DdeI permits the differentiation of the three intermediate hosts of Schistosoma mansoni. The molecular biological techniques used in our studies are very useful for the generation of new knowledge concerning the systematics and population genetics of Biomphalaria snails.

Genetic variability in Melipona scutellaris from Recôncavo, Bahia, Brazil.

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Viana, J L; Francisco, A K; Carvalho, C A L; Waldschmidt, A M

2013-09-10

Bees play a key role in pollination and thereby help maintain plant diversity. The stingless bee Melipona scutellaris is an important pollinator in northeastern Brazil because it is endemic to this region. Both deforestation and timber harvesting have reduced the nesting sites for this species, thus reducing its population and range. Genetic studies may help reverse this process by providing important tools for their proper management with a view to conservation of this species. Microsatellite markers have proven to be ideal for mapping genes and population genetic studies. Our aim was to study, using microsatellite markers, the interpopulation genetic variability of M. scutellaris in different parts of the Recôncavo region in Bahia State, Brazil. In all, 95 adult workers from 11 localities in Recôncavo Baiano (Amargosa, Cabaceiras do Paraguaçu, Conceição da Feira, Conceição do Almeida, Domingos Macedo Costa, Governador Mangabeira, Jaguaripe, Jiquiriça, Maragojipe, São Felipe, and Vera Cruz) were analyzed using 10 pairs of microsatellite primers developed for different Meliponini species. The total number of alleles, allele richness, and genetic diversity ranged from 2 to 7 per locus (average = 4.4), 1.00 to 4.88, and 0.0 to 0.850, respectively. The expected and observed heterozygosities varied from 0.0 to 0.76 and 0.0 to 0.84, respectively. No locus showed deviation from the expected frequencies in the chi-square test or linkage disequilibrium. The fixation index, analysis of molecular variance, and unweighted pair-group method using the arithmetic average revealed the effects of human activities on the populations of M. scutellaris, as little genetic structure was detected.

Global issues of genetic diversity.

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Vida, G

1994-01-01

Genetic diversity within species is highly significant during their adaptation to environmental changes and, consequently, for their long-term survival. The genetic variability of species is also the basis for the evolution of higher levels of biodiversity, the evolution of species, and it might be an indispensible prerequisite for the functioning of our biosphere. Studies which promote understanding of the maintenance and the functional aspects of biodiversity at any level are therefore essential for the future welfare of mankind.

Genetic variability of garlic accessions as revealed by agro-morphological traits evaluated under different environments.

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Hoogerheide, E S S; Azevedo Filho, J A; Vencovsky, R; Zucchi, M I; Zago, B W; Pinheiro, J B

2017-05-31

The cultivated garlic (Allium sativum L.) displays a wide phenotypic diversity, which is derived from natural mutations and phenotypic plasticity, due to dependence on soil type, moisture, latitude, altitude and cultural practices, leading to a large number of cultivars. This study aimed to evaluate the genetic variability shown by 63 garlic accessions belonging to Instituto Agronômico de Campinas and the Escola Superior de Agricultura "Luiz de Queiroz" germplasm collections. We evaluated ten quantitative characters in experimental trials conducted under two localities of the State of São Paulo: Monte Alegre do Sul and Piracicaba, during the agricultural year of 2007, in a randomized blocks design with five replications. The Mahalanobis distance was used to measure genetic dissimilarities. The UPGMA method and Tocher's method were used as clustering procedures. Results indicated significant variation among accessions (P < 0.01) for all evaluated characters, except for the percentage of secondary bulb growth in MAS, indicating the existence of genetic variation for bulb production, and germplasm evaluation considering different environments is more reliable for the characterization of the genotypic variability among garlic accessions, since it diminishes the environmental effects in the clustering of genotypes.

Genetic Variability among Lucerne Cultivars Based on Biochemical (SDS-PAGE) and Morphological Markers

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Farshadfar, M.; Farshadfar, E.

The present research was conducted to determine the genetic variability of 18 Lucerne cultivars, based on morphological and biochemical markers. The traits studied were plant height, tiller number, biomass, dry yield, dry yield/biomass, dry leaf/dry yield, macro and micro elements, crude protein, dry matter, crude fiber and ash percentage and SDS- PAGE in seed and leaf samples. Field experiments included 18 plots of two meter rows. Data based on morphological, chemical and SDS-PAGE markers were analyzed using SPSSWIN soft ware and the multivariate statistical procedures: cluster analysis (UPGMA), principal component. Analysis of analysis of variance and mean comparison for morphological traits reflected significant differences among genotypes. Genotype 13 and 15 had the greatest values for most traits. The Genotypic Coefficient of Variation (GCV), Phenotypic Coefficient of Variation (PCV) and Heritability (Hb) parameters for different characters raged from 12.49 to 26.58% for PCV, hence the GCV ranged from 6.84 to 18.84%. The greatest value of Hb was 0.94 for stem number. Lucerne genotypes could be classified, based on morphological traits, into four clusters and 94% of the variance among the genotypes was explained by two PCAs: Based on chemical traits they were classified into five groups and 73.492% of variance was explained by four principal components: Dry matter, protein, fiber, P, K, Na, Mg and Zn had higher variance. Genotypes based on the SDS-PAGE patterns all genotypes were classified into three clusters. The greatest genetic distance was between cultivar 10 and others, therefore they would be suitable parent in a breeding program.

Genetic Variability in DNA Repair Proteins in Age-Related Macular Degeneration

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Janusz Blasiak

2012-10-01

Full Text Available The pathogenesis of age-related macular degeneration (AMD is complex and involves interactions between environmental and genetic factors, with oxidative stress playing an important role inducing damage in biomolecules, including DNA. Therefore, genetic variability in the components of DNA repair systems may influence the ability of the cell to cope with oxidative stress and in this way contribute to the pathogenesis of AMD. However, few reports have been published on this subject so far. We demonstrated that the c.977C>G polymorphism (rs1052133 in the hOGG1 gene and the c.972G>C polymorphism (rs3219489 in the MUTYH gene, the products of which play important roles in the repair of oxidatively damaged DNA, might be associated with the risk of AMD. Oxidative stress may promote misincorporation of uracil into DNA, where it is targeted by several DNA glycosylases. We observed that the g.4235T>C (rs2337395 and c.−32A>G (rs3087404 polymorphisms in two genes encoding such glycosylases, UNG and SMUG1, respectively, could be associated with the occurrence of AMD. Polymorphisms in some other DNA repair genes, including XPD (ERCC2, XRCC1 and ERCC6 (CSB have also been reported to be associated with AMD. These data confirm the importance of the cellular reaction to DNA damage, and this may be influenced by variability in DNA repair genes, in AMD pathogenesis.

Population growth rate and genetic variability of small and large populations of Red flour beetle (Tribolium castaneum) following multigenerational exposure to copper.

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Laskowski, Ryszard; Radwan, Jacek; Kuduk, Katarzyna; Mendrok, Magdalena; Kramarz, Paulina

2015-07-01

We reared large (1000 individuals) and small (20 individuals) populations of Tribolium castaneum on diet contaminated with copper in order to determine if the size of a population affects its ability to adapt to adverse environmental conditions. After 10 generations, we used microsatellite markers to estimate and subsequently compare the genetic variability of the copper-treated populations with that of the control populations, which were reared on uncontaminated medium. Additionally, we conducted a full cross-factorial experiment which evaluated the effects of 10 generations of "pre-exposure" to copper on a population's fitness in control and copper-contaminated environments. In order to distinguish results potentially arising from genetic adaptation from those due to non-genetic effects associated to parental exposure to copper, we subjected also F11 generation, originating from parents not exposed to copper, to the same cross-factorial experiment. The effects of long-term exposure to copper depended on population size: the growth rates of small populations that were pre-exposed to copper were inhibited compared to those of small populations reared in uncontaminated environments. Large Cu-exposed populations had a higher growth rate in the F10 generation compared to the control groups, while the growth rate of the F11 generation was unaffected by copper exposure history. The only factor that had a significant effect on genetic variability was population size, but this was to be expected given the large difference in the number of individuals between large and small populations. Neither copper contamination nor its interaction with population size affected the number of microsatellite alleles retained in the F10 generation.

Genetic variability, heritability and genetic advance of quantitative ...

African Journals Online (AJOL)

ONOS

2010-05-10

May 10, 2010 ... coefficient of variation; h2, heritability; GA, genetic advance;. EMS, ethyl methane ... The analysis of variance (ANOVA) revealed the significance degree among the ... fullest extent. The estimates of range, phenotypic and.

Loss of genetic variability in a hatchery strain of Senegalese sole (Solea senegalensis revealed by sequence data of the mitochondrial DNA control region and microsatellite markers

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Pablo Sánchez

2012-06-01

Full Text Available Comparisons of the levels of genetic variation within and between a hatchery F1 (FAR, n=116 of Senegalese sole, Solea senegalensis, and its wild donor population (ATL, n = 26, both native to the SW Atlantic coast of the Iberian peninsula, as well as between the wild donor population and a wild western Mediterranean sample (MED, n=18, were carried out by characterizing 412 base pairs of the nucleotide sequence of the mitochondrial DNA control region I, and six polymorphic microsatellite loci. FAR showed a substantial loss of genetic variability (haplotypic diversity, h=0.49±0.066; nucleotide diversity, π=0.006±0.004; private allelic richness, pAg=0.28 to its donor population ATL (h=0.69±0.114; π=0.009±0.006; pAg=1.21. Pairwise FST values of microsatellite data were highly significant (P < 0.0001 between FAR and ATL (0.053 and FAR and MED (0.055. The comparison of wild samples revealed higher values of genetic variability in MED than in ATL, but only with mtDNA CR-I sequence data (h=0.948±0.033; π=0.030±0.016. However, pairwise ΦST and FST values between ATL and MED were highly significant (P < 0.0001 with mtDNA CR-I (0.228 and with microsatellite data (0.095, respectively. While loss of genetic variability in FAR could be associated with the sampling error when the broodstock was established, the results of parental and sibship inference suggest that most of these losses can be attributed to a high variance in reproductive success among members of the broodstock, particularly among females.

Study of the genetic variability of isolated belonging to the group B of the Respiratory Virus Human Sincicial

International Nuclear Information System (INIS)

Delfraro, A.

1998-07-01

The study allows analyzing the genetic variability of stumps belonging to the group B of the Breathing Virus Sincicial (Vrs), isolated in Uruguay among the years 1990 and 1996. They were evidenced by sequence the nucleotides changes and the changes were determined that take place at level of amino acids, the following ones were used technical: enzyme immunoassay, of extraction of viral RNA, of reverse transcription and Pcr, of purification of DNA and electrophoresis of nucleic acids. The result proven in the entirety of the isolated virus the genetic variability, enlarging and confirming the evolution pattern proposed by Sullender and collaborators, (1991) for the group B of Vrs [es

Impact of strong selection for the PrP major gene on genetic variability of four French sheep breeds (Open Access publication

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Pantano Thais

2008-11-01

Full Text Available Abstract Effective selection on the PrP gene has been implemented since October 2001 in all French sheep breeds. After four years, the ARR "resistant" allele frequency increased by about 35% in young males. The aim of this study was to evaluate the impact of this strong selection on genetic variability. It is focussed on four French sheep breeds and based on the comparison of two groups of 94 animals within each breed: the first group of animals was born before the selection began, and the second, 3–4 years later. Genetic variability was assessed using genealogical and molecular data (29 microsatellite markers. The expected loss of genetic variability on the PrP gene was confirmed. Moreover, among the five markers located in the PrP region, only the three closest ones were affected. The evolution of the number of alleles, heterozygote deficiency within population, expected heterozygosity and the Reynolds distances agreed with the criteria from pedigree and pointed out that neutral genetic variability was not much affected. This trend depended on breed, i.e. on their initial states (population size, PrP frequencies and on the selection strategies for improving scrapie resistance while carrying out selection for production traits.

Genetic variability in elite barley genotypes based on the agro-morphological characteristics evaluated under irrigated system

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Renato Fernando Amabile

Full Text Available ABSTRACT Recently, researches have shown that the Brazilian savannah has a great potential to supply the demand for barley grains. The purpose of this study was to assess the genetic variability in 39 elite barley (Hordeum vulgare L. genotypes based on the agro-morphological traits of a crop irrigated in the savannah system. An irrigation experiment in the design of complete randomized block with four replicates was conducted at Federal District - Brazil. The evaluated traits were: distance from the last knot to the rachis, distance from the flag leaf to rachis, spike length, number of grains by ear, flag leaf area, plant height, silking, lodging, grain yield, thousand-seed weight, protein content and grain commercial classification. After using analysis of variance the means were used to estimate the genetic dissimilarity among all genotypes pairs based on the Mahalanobis’ generalized distance. Cluster analysis using genetic distance matrix was performed having Unweighted Pair Group Method using Arithmetic Means method (UPGMA as the criteria. Highly significant differences were found among the genotypes for all traits evaluated. The high coefficient of genetic variation indicates the possibility of having genetic gains for all traits. The traits that most contributed to the variability were the flag leaf area and silking, while the protein content and lodging were the traits that contributed the least. Based on the cluster analysis, at least three major groups of similarity were found. There was a clustering trend of two and six-rowed materials. The most divergent genotypes were PFC 2005123, Antártica-1, Nandi and FM 404.

Clinical Characteristics and Genetic Variability of Human Rhinovirus in Mexico

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Hilda Montero

2012-01-01

Full Text Available Human rhinovirus (HRV is a leading cause of acute respiratory infection (ARI in young children and infants worldwide and has a high impact on morbidity and mortality in this population. Initially, HRV was classified into two species: HRV-A and HRV-B. Recently, a species called HRV-C and possibly another species, HRV-D, were identified. In Mexico, there is little information about the role of HRV as a cause of ARI, and the presence and importance of species such as HRV-C are not known. The aim of this study was to determine the clinical characteristics and genetic variability of HRV in Mexican children. Genetic characterization was carried out by phylogenetic analysis of the 5′-nontranslated region (5′-NTR of the HRV genome. The results show that the newly identified HRV-C is circulating in Mexican children more frequently than HRV-B but not as frequently as HRV-A, which was the most frequent species. Most of the cases of the three species of HRV were in children under 2 years of age, and all species were associated with very mild and moderate ARI.

Genetic variability and bottleneck analyses of Kanni adu goat population using microsatellite markers [Also published in The Indian Journal of Small Ruminants, 2015, 21(2): 216-22

International Nuclear Information System (INIS)

Jeyakumar, M.; Thiruvenkadan, R.; Saravana, R.; Periasamy, K.

2016-01-01

Full text: Microsatellite data on 25 loci were generated and utilized to evaluate the genetic architecture and mutation drift equilibrium of Kanni Adu goats of southern Tamil Nadu. The genetic diversity analysis of Kanni Adu goats displayed higher level of within breed variability in terms of mean number of alleles per locus (11.24±0.87) and heterozygosity values (Ho= 0.677±0.041, He=0.857±0.016). Within population inbreeding estimate (FIS=0.215±0.040) showed moderate level of inbreeding, which warrant adoption of appropriate breeding strategies under field conditions. The polymorphism information content (PIC) value ranged from 0.531 to 0.915 suggested higher polymorphism in this breed. In general, the sign, standardized differences and Wilcoxon rank tests indicated heterozygosity excess in Kanni Adu goat population in infinite alleles and two-phase model and non-significant in stepwise mutation model. Hence, the mode-shift indicator test was utilized and it indicated the absence of genetic bottleneck in the recent past in Kanni Adu goats. It suggests that any unique alleles present in this breed may not have been lost. The study indicated that Kanni adu goats exhibited substantial amount of genetic variation as reflected from the heterozygosity and number of alleles per locus. (author)

Genetic variability in the endophytic fungus Guignardia citricarpa isolated from citrus plants

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Chirlei Glienke-Blanco

2002-01-01

Full Text Available During some phases of of their life-cycle endophytic fungi colonize plants asymptomatically being found most frequently inside the aerial part of plant tissues. After surface disinfection of apparently healthy leaves from three varieties of mandarin orange and one tangor, and after incubation on appropriate culture medium, 407 fungal isolates were obtained, giving a total infection frequency of 81%. No fungal growth was observed from disinfected seeds, indicating that fungi are probably not transmitted via seeds. Of the fungal isolates, 27% belonged to the genus Guignardia, with 12 isolates being identified as Guignardia citricarpa Kiely, which is described as a citrus pathogen. The isolates were variable in respect to the presence of sexual structures and growth rates. Most of the isolates produces mature asci, supporting the hypothesis that they are nonpathogenic endophytes, which recently were identified as G. mangiferae. High intraspecific genetic variability (an average similarity coefficient of 0.6 was detected using random amplified polymorphic DNA (RAPD markers generated by seven different primers. The highest similarity coefficient (0.9 was between isolates P15 and M86 and the smallest (0.22 between isolates P15 and C145. These results did not allow us to establish an association between genetic similarity of the fungal isolates and the citrus varieties from which they were obtained.

Hybrid Model Based on Genetic Algorithms and SVM Applied to Variable Selection within Fruit Juice Classification

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C. Fernandez-Lozano

2013-01-01

Full Text Available Given the background of the use of Neural Networks in problems of apple juice classification, this paper aim at implementing a newly developed method in the field of machine learning: the Support Vector Machines (SVM. Therefore, a hybrid model that combines genetic algorithms and support vector machines is suggested in such a way that, when using SVM as a fitness function of the Genetic Algorithm (GA, the most representative variables for a specific classification problem can be selected.

Environmental carcinogenesis and genetic variability

International Nuclear Information System (INIS)

Knudsen, A.G. Jr

1977-01-01

It was found that carcinogenesis in man may involve the interaction of genetic and environmental forces, and that mutation, whether germinal or somatic, seems to be involved in the origin of many, perhaps all cancers. The cancers of man may be visualized as occurring in four groups of individuals according to whether (1) neither genetic nor environmental factors are dominant, i.e. 'background' or 'spontaneous' cancer, (2) heredity alone is dominant, (3) environment alone is important, or (4) both are operating (Knudsen, 1977). The last two groups together are widely thought to contribute 70-80% of cancer cases in the United States; the relative contribution of each group is a major question to be answered

Genetic variability of Pantaneiro horse using RAPD-PCR markers Variabilidade genética do cavalo Pantaneiro utilizando marcadores RAPD-PCR

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Andréa Alves do Egito

2007-08-01

Full Text Available Blood samples were collected from Pantaneiro Horses in five regions of Mato Grosso do Sul and Mato Grosso States. Arabian, Mangalarga Marchador and Thoroughbred were also included to estimate genetic distances and the existing variability among and within these breeds by RAPD-PCR (Random Amplified Polymorphic DNA - Polymerase Chain Reaction molecular markers. From 146 primers, 13 were chosen for amplification and 44 polymorphic bands were generated. The analysis of molecular variance (AMOVA indicated that the greatest portion of detected variability was due to differences between individuals within populations (75.47%. Analysis of the genetic variability between pairs of populations presented higher estimates for the five Pantaneiro populations with the Arabian breed, while lowest estimates were presented by pairs formed among the Pantaneiro populations with the Mangalarga Marchador. Highest genic diversity was shown by the Pantaneiro (0.3396, which also showed highest genetic distance with the Arabian and lowest with Mangalarga Marchador breed. UPGMA dendrogram showed distinct differences between naturalized (Pantaneiro and Mangalarga Marchador and exotic (Arabian and Thoroughbred breeds. In the dendrogram generated by UPGMA method, the similarity matrix generated by the Jaccard coefficient showed distinction between the naturalised breeds, Pantaneiro and Mangalarga Marchador, and the exotic breeds, Árab and English Thoroughbred. Results suggest that the Pantaneiro presents a higher genetic variability than the other studied breeds and has a close relationship with the Mangalarga Marchador.Amostras de sangue foram coletadas de cavalos Pantaneiros de cinco regiões dos estados de Mato Grosso do Sul e Mato Grosso. As raças Mangalarga Marchador, Árabe e Puro-Sangue Inglês (PSI usando marcadores moleculares RAPD-PCR (Random Amplified Polymorphic DNA - Polymerase Chain Reaction foram incluídas no intuito de se calcular as distâncias gen

Bayesian inference for the genetic control of water deficit tolerance in spring wheat by stochastic search variable selection.

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Safari, Parviz; Danyali, Syyedeh Fatemeh; Rahimi, Mehdi

2018-06-02

Drought is the main abiotic stress seriously influencing wheat production. Information about the inheritance of drought tolerance is necessary to determine the most appropriate strategy to develop tolerant cultivars and populations. In this study, generation means analysis to identify the genetic effects controlling grain yield inheritance in water deficit and normal conditions was considered as a model selection problem in a Bayesian framework. Stochastic search variable selection (SSVS) was applied to identify the most important genetic effects and the best fitted models using different generations obtained from two crosses applying two water regimes in two growing seasons. The SSVS is used to evaluate the effect of each variable on the dependent variable via posterior variable inclusion probabilities. The model with the highest posterior probability is selected as the best model. In this study, the grain yield was controlled by the main effects (additive and non-additive effects) and epistatic. The results demonstrate that breeding methods such as recurrent selection and subsequent pedigree method and hybrid production can be useful to improve grain yield.

GENETIC VARIABILITY OF CULTURED PLANT TISSUES UNDER NORMAL CONDITIONS AND UNDER STRESS

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Dolgikh Yu.I.

2012-08-01

Full Text Available The genetic variability induced by in vitro conditions known as somaclonal variation is of practical interest due to its potential uses in plant breeding but, on the other hand, if clonal propagation or transformation is main goal, it becomes an unwelcome phenomenon. Thus, it is important to know frequency, the genomic distribution, the mechanisms and factors influencing somaclonal variation. We studied variability of PCR-based DNA markers of cultured tissues and regenerated plants of maize and bread wheat. The original A188 line of maize and the somaclones obtained were tested using 38 RAPD and 10 ISSR primers. None of the A188 plants showed variation in the RAPD and ISSR spectra for any of the primers used. However, the PCR spectra obtained from the somaclones demonstrated some variations, i.e., 22 RAPD primers and 6 ISSR primers differentiated at least one somaclonal variant from the progenitor line. Six SCAR markers were developed based on several RAPD and ISSR fragments. The inheritance of these SCAR markers was verified in the selfing progeny of each somaclone in the R1–R4 generations and in the hybrids, with A188 as the parental line in the F1 and F2 generations. These markers were sequenced and bioinformatic searches were performed to understand the molecular events that may underlie the variability observed in the somaclones. All changes were found in noncoding sequences and were induced by different molecular events, such as the insertion of long terminal repeat transposon, precise miniature inverted repeat transposable element (MITE excision, microdeletion, recombination, and a change in the pool of mitochondrial DNA. In two groups of independently produced somaclones, the same features (morphological, molecular were variable, which confirms the theory of ‘hot spots’ occurring in the genome. The presence of the same molecular markers in the somaclones and in different non-somaclonal maize variants suggests that in some cases

Genetic variability and heritability for resistance to black stem (Phoma macdonaldii) in sunflower (Helianthus annuus L.)

International Nuclear Information System (INIS)

Abou Al Fadil, T.; Dechamp-Guillaume, G.; Poormohammad Kiani, S.; Sarrafi, A.

2004-01-01

Black stem, caused by Phoma macdonaldii, is one of the most important diseases of sunflower in many Countries. In order to study the genetic control of the disease, seeds of the inbred line AS-613 were exposed to 75 Grays of gamma rays and M1 and M2 plants were self-pollinated to obtain the M3 generation. Among M3 mutants, M3-8, a relatively resistant line to black stem, was crossed with AS-613. Seeds from this cross were grown and F1 plants were self-pollinated to produce F2 seeds from which the F3 generation was produced. Eighty-eight F3 families and two parents were used to determine the genetic variability of partial resistance to black stem in sunflower. Twelve-day-old seedlings were inoculated at the junction of the cotyledon petiole and hypocotyl with 20 micronl of pycniospore suspension. Seven days after inoculation, both cotyledon petioles of the seedling were scored according to the percentage of petiole area exhibiting symptoms (necrosis). Significant difference in resistance between the two parents, M3-8 and AS-613, indicates that mutagenesis can be considered as important tool to produce genetic variation for resistance to Phoma in sunflower. Results showed that F3 families included extreme genotypes with a relatively high resistance rate compared with the parents. Ten percent of F3 families showed a resistance rate higher than the one of the best parent, indicating transgressive segregation for resistance to black stem among families. The percentage of heritability was 69.6, which indicates that progeny selection for resistance to the disease is possible [it

Evaluating the Genetics of Common Variable Immunodeficiency: Monogenetic Model and Beyond

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Guillem de Valles-Ibáñez

2018-05-01

Full Text Available Common variable immunodeficiency (CVID is the most frequent symptomatic primary immunodeficiency characterized by recurrent infections, hypogammaglobulinemia and poor response to vaccines. Its diagnosis is made based on clinical and immunological criteria, after exclusion of other diseases that can cause similar phenotypes. Currently, less than 20% of cases of CVID have a known underlying genetic cause. We have analyzed whole-exome sequencing and copy number variants data of 36 children and adolescents diagnosed with CVID and healthy relatives to estimate the proportion of monogenic cases. We have replicated an association of CVID to p.C104R in TNFRSF13B and reported the second case of homozygous patient to date. Our results also identify five causative genetic variants in LRBA, CTLA4, NFKB1, and PIK3R1, as well as other very likely causative variants in PRKCD, MAPK8, or DOCK8 among others. We experimentally validate the effect of the LRBA stop-gain mutation which abolishes protein production and downregulates the expression of CTLA4, and of the frameshift indel in CTLA4 producing expression downregulation of the protein. Our results indicate a monogenic origin of at least 15–24% of the CVID cases included in the study. The proportion of monogenic patients seems to be lower in CVID than in other PID that have also been analyzed by whole exome or targeted gene panels sequencing. Regardless of the exact proportion of CVID monogenic cases, other genetic models have to be considered for CVID. We propose that because of its prevalence and other features as intermediate penetrancies and phenotypic variation within families, CVID could fit with other more complex genetic scenarios. In particular, in this work, we explore the possibility of CVID being originated by an oligogenic model with the presence of heterozygous mutations in interacting proteins or by the accumulation of detrimental variants in particular immunological pathways, as well as

Genetic variability in Cynara cardunculus L. domestic and wild types for grain oil production and fatty acids composition

International Nuclear Information System (INIS)

Raccuia, Salvatore Antonino; Piscioneri, Ilario; Sharma, Neeta; Melilli, Maria Grazia

2011-01-01

This paper aimed to study the genetic variability within different types of Cynara cardunculus L., domestic and wild types, for their grain oil amount and oil fatty acid composition. The grain oils were extracted from 8 domestic cardoons and 4 wild cardoons, by Soxhlet method, and obtained oils were characterized for palmitic, stearic, oleic and linoleic acids by gas chromatography. The oil amount, resulted on average of accessions 216 g kg -1 DM with a good range of variability (CV = 11.7%). Unsaturated acids (oleic and linoleic) predominated over saturated ones (stearic and palmitic acids), the chemical characterization of extracted oil, showed the main compound (as % of analysed fatty acids), averaged for all populations, was linoleic acid (44.5%), followed by oleic acid (42.6%), palmitic acid (9.8%) and stearic acid (3.1%). In particular referring the oleic acid wild cardoon populations showed a mean value of 289 g kg -1 oil, against a mean value of 472 g kg -1 oil showed by domestic cardoon accessions. Three of the studied domestic cardoon ('DC1', 'DC3' and 'DC7') showed values higher than 795 g kg -1 oil, while all the other accessions had concentration lower than 370 g kg -1 oil. The three types of domestic cardoon 'DC1', 'DC3' and 'DC7' showed a fatty acids profile similar to genetic modified sunflower oil, representing new genetic material that potentially could be used for high quality biodiesel production, characterised by a low Iodine Number. -- Highlights: → The grain oils from 12 cardoons were characterized for fatty acids composition. → The oil amount, resulted on average of accessions 216 g kg -1 DM. → Oleic and linoleic acids predominated over stearic and palmitic acids. → Three domestic cardoons grain oil showed high oleic acid content (795 g kg -1 oil). → This oil could be used for high quality biodiesel production, with a low IN.

Variables associated with achievement in higher education: A systematic review of meta-analyses.

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Schneider, Michael; Preckel, Franzis

2017-06-01

The last 2 decades witnessed a surge in empirical studies on the variables associated with achievement in higher education. A number of meta-analyses synthesized these findings. In our systematic literature review, we included 38 meta-analyses investigating 105 correlates of achievement, based on 3,330 effect sizes from almost 2 million students. We provide a list of the 105 variables, ordered by the effect size, and summary statistics for central research topics. The results highlight the close relation between social interaction in courses and achievement. Achievement is also strongly associated with the stimulation of meaningful learning by presenting information in a clear way, relating it to the students, and using conceptually demanding learning tasks. Instruction and communication technology has comparably weak effect sizes, which did not increase over time. Strong moderator effects are found for almost all instructional methods, indicating that how a method is implemented in detail strongly affects achievement. Teachers with high-achieving students invest time and effort in designing the microstructure of their courses, establish clear learning goals, and employ feedback practices. This emphasizes the importance of teacher training in higher education. Students with high achievement are characterized by high self-efficacy, high prior achievement and intelligence, conscientiousness, and the goal-directed use of learning strategies. Barring the paucity of controlled experiments and the lack of meta-analyses on recent educational innovations, the variables associated with achievement in higher education are generally well investigated and well understood. By using these findings, teachers, university administrators, and policymakers can increase the effectivity of higher education. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Detecting Major Genetic Loci Controlling Phenotypic Variability in Experimental Crosses

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Rönnegård, Lars; Valdar, William

2011-01-01

Traditional methods for detecting genes that affect complex diseases in humans or animal models, milk production in livestock, or other traits of interest, have asked whether variation in genotype produces a change in that trait’s average value. But focusing on differences in the mean ignores differences in variability about that mean. The robustness, or uniformity, of an individual’s character is not only of great practical importance in medical genetics and food production but is also of scientific and evolutionary interest (e.g., blood pressure in animal models of heart disease, litter size in pigs, flowering time in plants). We describe a method for detecting major genes controlling the phenotypic variance, referring to these as vQTL. Our method uses a double generalized linear model with linear predictors based on probabilities of line origin. We evaluate our method on simulated F2 and collaborative cross data, and on a real F2 intercross, demonstrating its accuracy and robustness to the presence of ordinary mean-controlling QTL. We also illustrate the connection between vQTL and QTL involved in epistasis, explaining how these concepts overlap. Our method can be applied to a wide range of commonly used experimental crosses and may be extended to genetic association more generally. PMID:21467569

Higher-order Peregrine combs and Peregrine walls for the variable-coefficient Lenells-Fokas equation

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Wang, Zi-Qi; Wang, Xin; Wang, Lei; Sun, Wen-Rong; Qi, Feng-Hua

2017-02-01

In this paper, we study the variable-coefficient Lenells-Fokas (LF) model. Under large periodic modulations in the variable coefficients of the LF model, the generalized Akhmediev breathers develop into the breather multiple births (BMBs) from which we obtain the Peregrine combs (PCs). The PCs can be considered as the limiting case of the BMBs and be transformed into the Peregrine walls (PWs) with a specific amplitude of periodic modulation. We further investigate the spatiotemporal characteristics of the PCs and PWs analytically. Based on the second-order breather and rogue-wave solutions, we derive the corresponding higher-order structures (higher-order PCs and PWs) under proper periodic modulations. What is particularly noteworthy is that the second-order PC can be converted into the Peregrine pyramid which exhibits the higher amplitude and thickness. Our results could be helpful for the design of experiments in the optical fiber communications.

Genetic variability, correlation and path coefficients of yield and its components analysis in pumpkin (Cucurbita moschata Duch Ex Poir

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GM Mohsin

2017-06-01

Full Text Available Genetic variability, correlation and path coefficient were studied for yield and yield component traits in twenty one diverse genotypes of pumpkin. Highest genotypic coefficient of variation was recorded for fruit length (cm, single fruit weight (kg, Brix (% and yield per plant (kg. Heritability estimates in broad sense were higher for almost all the characters. The characters namely, fruit length, single fruit weight, yield per plant and brix% had high genotypic coefficient of variation coupled with heritability gave high genetic advance expressed as percentage of mean ranged from 76.84 to 96.06 which indicated that these characters were less influenced by environment confirming additive gene action, and therefore, selection of these characters would be more effective for yield improvement of pumpkins. Total six traits likely fruit length, fruit diameter, flesh thickness, single fruit weight and number of fruits per plant were positively and significantly associated with yield per plant. Path coefficient analysis also revealed maximum contribution of single fruit weight (0.869 to yield and this was followed by the contribution of number of fruit per plant (0.527 at genotypic level.

Morphological and agronomical characterization and estimates of genetic parameters of sesbania Scop. (Leguminosae accessions

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Veasey E.A.

1999-01-01

Full Text Available Twenty-two accessions of seven Sesbania (Leguminosae species: S. emerus, S. rostrata, S. tetraptera, S. exasperata (annuals, S. grandiflora, S. sesban and S. virgata (perennials, used for ruminant fodder, firewood, wood products, soil improvement, and human food, were investigated, with the aim of characterizing both inter- and intraspecific genetic variability, estimating genetic parameters for the characters evaluated and appraising the forage potential of the accessions. These were planted at the Instituto de Zootecnia, Nova Odessa, SP, Brazil, in a randomized complete block design with 22 treatments and four replications. Seventeen morphological and 17 agronomic characters were evaluated. Genetic parameters coefficient of intraspecific genetic diversity (bi and coefficient of intraspecific genetic variation (CVgi were obtained for the species represented by more than one accession. Highly significant differences were observed among as well as within species for most characters, showing considerable genetic variability. S. exasperata showed intraspecific genetic variability for the largest number of morphological characters. The same was observed for S. sesban for the agronomic characters. Most of the characters gave high bi values, above 0.80, indicating the possibility of selecting superior genotypes. The CVgi values, on the other hand, which indicate the magnitude of the existing genetic variability relative to the character mean, varied according to the species and character evaluated. Differences between annual and perennial species were observed, with higher biomass yields presented by the annuals at the first cut and by the perennials after the second cut, reaching the highest yield at the third cut. The annual species had higher seed production. Accession NO 934 of S. sesban gave the highest biomass yields and regrowth vigor, showing promise as a forage legume plant.

Determination of genetic variability of traditional varieties of Brazilian rice using microsatellite markers

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Claudio Brondani

2006-01-01

Full Text Available The rice (Oryza sativa breeding program of the Rice and Bean research center of the Brazilian agricultural company Empresa Brasileira de Pesquisa Agropecuária (Embrapa is well established and provides new cultivars every year to attend the demand for improved high yielding varieties with tolerance to biotic and abiotic stresses. However, the elite genitors used to compose new populations for selection are closely related, contributing to the yield plateau reached in the last 20 years. To overcome this limit, it is necessary to broaden the genetic basis of the cultivars using diverse germplasm such as wild relatives or traditional varieties, with the latter being more practical because they are more easily crossed with elite germplasm to accelerate the recovery of modern plant types in the breeding lines. The objective of our study was to characterize the allelic diversity of 192 traditional varieties of Brazilian rice using 12 simple sequence repeat (SSR or microsatellite markers. The germplasm was divided into 39 groups by common name similarity. A total of 176 alleles were detected, 30 of which (from 23 accessions were exclusive. The number of alleles per marker ranged from 6 to 22, with an average of 14.6 alleles per locus. We identified 16 accessions as a mixture of pure lines or heterozygous plants. Dendrogram analysis identified six clusters of identical accessions with different common names and just one cluster with identical accessions with the same common name, indicating that SSR markers are fundamental to determining the genetic relationship between landraces. A subset of 24 landraces, representatives of the 13 similarity groups plus the 11 accessions not grouped, was the most variable set of genotypes analyzed. These accessions can be used as genitors to increase the genetic variability available to rice breeding programs.

Genetic and virulence variability among Erwinia tracheiphila strains recovered from different cucurbit hosts.

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Rojas, E Saalau; Dixon, P M; Batzer, J C; Gleason, M L

2013-09-01

The causal agent of cucurbit bacterial wilt, Erwinia tracheiphila, has a wide host range in the family Cucurbitaceae, including economically important crops such as muskmelon (Cucumis melo), cucumber (C. sativus), and squash (Cucurbita spp.). Genetic variability of 69 E. tracheiphila strains was investigated by repetitive-element polymerase chain reaction (rep-PCR) using BOXA1R and ERIC1-2 primers. Fingerprint profiles revealed significant variability associated with crop host; strains isolated from Cucumis spp. were clearly distinguishable from Cucurbita spp.-isolated strains regardless of geographic origin. Twelve E. tracheiphila strains isolated from muskmelon, cucumber, or summer squash were inoculated onto muskmelon and summer squash seedlings, followed by incubation in a growth chamber. Wilt symptoms were assessed over 3 weeks, strains were reisolated, and rep-PCR profiles were compared with the inoculated strains. Wilting occurred significantly faster when seedlings were inoculated with strains that originated from the same crop host genus (P<0.001). In the first run of the experiment, cucumber and muskmelon strains caused wilting on muskmelon seedlings at a median of 7.8 and 5.6 days after inoculation (dai), respectively. Summer squash seedlings wilted 18.0, 15.7, and 5.7 dai when inoculated with muskmelon-, cucumber-, and squash-origin strains, respectively. In a second run of the experiment, cucumber and muskmelon strains caused wilting on muskmelon at 7.0 and 6.9 dai, respectively, whereas summer squash seedlings wilted at 23.6, 29.0 and 9.0 dai when inoculated with muskmelon-, cucumber-, and squash-origin strains, respectively. Our results provide the first evidence of genetic diversity within E. tracheiphila and suggest that strain specificity is associated with plant host. This advance is a first step toward understanding the genetic and population structure of E. tracheiphila.

Variable-coefficient higher-order nonlinear Schroedinger model in optical fibers: Variable-coefficient bilinear form, Baecklund transformation, brightons and symbolic computation

International Nuclear Information System (INIS)

Tian Bo; Gao Yitian; Zhu Hongwu

2007-01-01

Symbolically investigated in this Letter is a variable-coefficient higher-order nonlinear Schroedinger (vcHNLS) model for ultrafast signal-routing, fiber laser systems and optical communication systems with distributed dispersion and nonlinearity management. Of physical and optical interests, with bilinear method extend, the vcHNLS model is transformed into a variable-coefficient bilinear form, and then an auto-Baecklund transformation is constructed. Constraints on coefficient functions are analyzed. Potentially observable with future optical-fiber experiments, variable-coefficient brightons are illustrated. Relevant properties and features are discussed as well. Baecklund transformation and other results of this Letter will be of certain value to the studies on inhomogeneous fiber media, core of dispersion-managed brightons, fiber amplifiers, laser systems and optical communication links with distributed dispersion and nonlinearity management

Radiation induced genetic variability studies in M2 and F2M2 generation in chilli (Capsicum annum L.)

International Nuclear Information System (INIS)

Rangaiah, S.; Manjunath, A.; Naik, Puttarama; Gangappa, E.

2002-01-01

Chilli (Capsicum annum L.) is an important commercial crop in India. Mutation breeding is one of the effective tool to create new variability. Since, yield and its component characters show polygenic inheritance, information on amount of heritable portion of variability created through mutation for these characters is needed to use the induced variability for crop improvement. To harness more variability mutation has been superimposed on hybridization in several crops. The present study is undertaken to estimate the genetic variability induced through gamma irradiation for the polygenically inherited productive traits of chilli in M 2 and F 2 M 2 generation

EVALUATION OF GENETIC VARIABILITY OF FRESHWATER PRAWN COLLECTED FROM MAKASSAR-SULAWESI, PANGKALANBUNKALIMANTAN, JAMBI-SUMATRA, SUKABUMI-JAVA, AND GIMacro USING mtDNA CO-I MARKERS

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Estu Nugroho

2009-06-01

Full Text Available The objective of this research is to evaluate the genetic variability of freshwater prawn, Macrobrachium rosenbergii. The genetic variability of freshwater prawn collected from Makassar-Sulawesi, Pangkalanbun-Kalimantan, Jambi-Sumatra, Sukabumi-Java, and GIMacro strain was examined using polymorphism of the mitochondria DNA (mtDNA markers. Twelve composite haplotypes were detected following digestion of CO1 sequences with four endonucleases: Hae III, Rsa I, Mbo I, and Taq I. The average haplotype diversity was 0.217. Significant genetic difference was observed among freshwater prawn populations, especially among Makassar-Sulawesi population and others. Makassar-Sulawesi strain has future prospect for genetic resources in breeding program.

Population structure and genetic variability of mainland and insular populations of the Neotropical water rat, Nectomys squamipes (Rodentia, Sigmodontinae

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Francisca C. Almeida

2005-12-01

Full Text Available Seven microsatellite loci were used to investigate the genetic variability and structure of six mainland and two island populations of the Neotropical water rat Nectomys squamipes, a South American semi-aquatic rodent species with a wide distribution. High levels of variability were found within mainland populations while island populations were less variable but the more differentiated in respect to allele number and frequency. The time of biological divergence between mainland and island populations coincided with geological data. A significant geographic structure was found in mainland populations (theta = 0.099; rho = 0.086 although the degree of differentiation was relatively low in respect to the distance between surveyed localities (24 to 740 km. Genetic and geographic distances were not positively correlated as previously found with random amplified polymorphic DNA (RAPD markers. Significant but low genetic differentiation in the mainland and lack of isolation by distance can be explained by large population size and/or recent population expansion. Additionally, the agreement between the age of geologic events (sea level fluctuations and divergence times for insular populations points to a good reference for molecular clock calibration to associate recent environmental changes and the distribution pattern of small mammals in the Brazilian Atlantic Forest.

Genetic relatedness of commensal Escherichia coli from nursery pigs in intensive pig production in Denmark and molecular characterization of genetically different strains

DEFF Research Database (Denmark)

Herrero Fresno, Ana; Larsen, Inge; Olsen, John Elmerdahl

2015-01-01

AIMS: To determine the genetic relatedness and the presence of virulence and antibiotic resistance genes in commensal Escherichia coli from nursery pigs in Danish intensive production. METHODS AND RESULTS: The genetic diversity of 1000 E. coli strains randomly picked (N = 50 isolates) from cultured...... in depth the genetic variability of commensal E. coli from pigs in Danish intensive pig production. A tendency for higher diversity was observed with in nursery pigs that were treated with zinc oxide only, in absence of other antimicrobials. Strains with potential to disseminate virulence and antibiotic...

Genetic variability of Amorphophallus muelleri Blume in Java based on Random Amplified Polymorphic DNA

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DIYAH MARTANTI

2008-10-01

Full Text Available Amorphophallus muelleri Blume (Araceae is valued for its glucomanan content for use in food industry (healthy diet food, paper industry, pharmacy and cosmetics. The species is triploid (2n=3x=39 and the seed is developed apomictically. The present research is aimed to identify genetic variability of six population of A. muelleri from Java (consisted of 50 accessions using random amplified polymorphic DNA (RAPD. The six populations of the species are: East Java: (1 Silo-Jember, (2 Saradan-Madiun, (3 IPB (cultivated, from Saradan-Madiun, (4 Panti-Jember, (5 Probolinggo; and Central Java: (6 Cilacap. The results showed that five RAPD primers generated 42 scorable bands of which 29 (69.05% were polymorphic. Size of the bands varied from 300bp to 1.5kbp. The 50 accessions of A. muelleri were divided into two main clusters, some of them were grouped based on their populations, and some others were not. The range of individual genetic dissimilarity was from 0.02 to 0.36. The results showed that among six populations investigated, Saradan population showed the highest levels of genetic variation with mean values of na = 1.500+ 0.5061, ne = 1.3174 + 0.3841, PLP = 50% and He = 0, 0.1832+0.2054, whereas Silo-Jember population showed the lowest levels of genetic variation with mean values na = 1.2619+ 0.4450, ne = 1.1890 + 0.3507, PLP = 26.19% and He = 0.1048+0.1887. Efforts to conserve, domesticate, cultivate and improve genetically should be based on the genetic properties of each population and individual within population, especially Saradan population which has the highest levels of genetic variation, need more attention for its conservation.

Genetic variability in the Florida manatee (Trichechus manatus)

Science.gov (United States)

McClenaghan, Leroy R.; O'Shea, Thomas J.

1988-01-01

Tissue was obtained from 59 manatee (Trichechus manatus) carcasses salvaged from 20 counties in Florida. Allozyme phenotypes at 24 structural loci were determined by gel electrophoresis. Averages for the proportion of polymorphic loci and mean heterozygosity were 0.300 (range, 0.167-0.417) and 0.050 (range, 0.028-0.063), respectively. These estimates are equivalent to or higher than those generally reported for other species of marine mammals and do not support the hypothesis that body size and heterozygosity in mammals are related inversely. Among-region gene diversity accounted for only 4% of the total diversity. High rates of gene flow probably account for genetic homogeneity across regions. An F-statistic analysis revealed a general tendency toward excess homozygosity within regions. Management efforts to prevent future reductions in population size that would erode existing genic diversity should continue.

Genetic variability among 18 cultivars of cooking bananas and plantains by RAPD and ISSR markers

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YUYU SURYASARI POERBA

2010-07-01

Full Text Available Poerba YS, Ahmad F (2010 Genetic variability among 18 cultivars of cooking bananas and plantains by RAPD and ISSR markers. Biodiversitas 11: 118-123. This study was done to assess the molecular diversity of 36 accessions (18 cultivars of the plantain and cooking bananas (Musa acuminata x M. balbisiana, AAB, ABB subgroups based on Random amplified polymorphic DNA (RAPD and and Inter Simple Sequence Repeats (ISSR markers and to determine genetic relationships in the bananas. RAPD and ISSR fingerprinting of these banana varieties was carried out by five primers of RAPDs and two primers of ISSRs. RAPD primers produced 63 amplified fragments varying from 250 to 2500 bp in size. 96.82% of the amplification bands were polymorphic. ISSR primers produced 26 amplified fragments varying from 350 bp to 2000 bp in size. The results showed that 92.86% of the amplification bands were polymorphic. The range of genetic distance of 18 cultivars was from 0.06-0.67.

Challenging behavior: Behavioral phenotypes of some genetic syndromes

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Buha Nataša

2014-01-01

Full Text Available Challenging behavior in individuals with mental retardation (MR is relatively frequent, and represents a significant obstacle to adaptive skills. The frequency of specific forms and manifestations of challenging behavior can depend on a variety of personal and environmental factors. There are several prominent theoretical models regarding the etiology of challenging behavior and psychopathology in persons with MR: behavioral, developmental, socio-cultural and biological. The biological model emphasizes the physiological, biochemical and genetic factors as the potential source of challenging behavior. The progress in the field of genetics and neuroscience has opened the opportunity to study and discover the neurobiological basis of phenotypic characteristics. Genetic syndromes associated with MR can be followed by a specific set of problems and disorders which constitutes their behavioral phenotype. The aim of this paper was to present challenging behaviors that manifest in the most frequently studied syndromes: Down syndrome, Fragile X syndrome, Williams syndrome, Prader-Willi syndrome and Angelman syndrome. The concept of behavioral phenotype implies a higher probability of manifesting specific developmental characteristics and specific behaviors in individuals with a certain genetic syndrome. Although the specific set of (possible problems and disorders is distinctive for the described genetic syndromes, the connection between genetics and behavior should be viewed through probabilistic dimension. The probabilistic concept takes into consideration the possibility of intra-syndrome variability in the occurrence, intensity and time onset of behavioral characteristics, at which the higher variability the lower is the specificity of the genetic syndrome. Identifying the specific pattern of behavior can be most important for the process of early diagnosis and prognosis. In addition, having knowledge about behavioral phenotype can be a landmark in

High Interannual Variability in Connectivity and Genetic Pool of a Temperate Clingfish Matches Oceanographic Transport Predictions

Science.gov (United States)

Teixeira, Sara; Assis, Jorge; Serrão, Ester A.; Gonçalves, Emanuel J.; Borges, Rita

2016-01-01

Adults of most marine benthic and demersal fish are site-attached, with the dispersal of their larval stages ensuring connectivity among populations. In this study we aimed to infer spatial and temporal variation in population connectivity and dispersal of a marine fish species, using genetic tools and comparing these with oceanographic transport. We focused on an intertidal rocky reef fish species, the shore clingfish Lepadogaster lepadogaster, along the southwest Iberian Peninsula, in 2011 and 2012. We predicted high levels of self-recruitment and distinct populations, due to short pelagic larval duration and because all its developmental stages have previously been found near adult habitats. Genetic analyses based on microsatellites countered our prediction and a biophysical dispersal model showed that oceanographic transport was a good explanation for the patterns observed. Adult sub-populations separated by up to 300 km of coastline displayed no genetic differentiation, revealing a single connected population with larvae potentially dispersing long distances over hundreds of km. Despite this, parentage analysis performed on recruits from one focal site within the Marine Park of Arrábida (Portugal), revealed self-recruitment levels of 2.5% and 7.7% in 2011 and 2012, respectively, suggesting that both long- and short-distance dispersal play an important role in the replenishment of these populations. Population differentiation and patterns of dispersal, which were highly variable between years, could be linked to the variability inherent in local oceanographic processes. Overall, our measures of connectivity based on genetic and oceanographic data highlight the relevance of long-distance dispersal in determining the degree of connectivity, even in species with short pelagic larval durations. PMID:27911952

A higher-order nonlinear Schrödinger equation with variable coefficients

OpenAIRE

Carvajal, X.; Linares, F.

2003-01-01

We study the initial value problem (IVP) associated to a higher-order nonlinear Schrödinger equation with variable coefficients. Under some regularity on its coefficients we establish local well-posedness for the IVP for data in $H^s(\\mathbb R)$, $s\\ge1/4$, improving previous results [22]. The main ingredient in our proof is an estimate of the maximal function associated to the linear solution similar to the sharp one obtained for linear solutions of the Schrödinger and K...

Genetic variability and divergence studies in seed traits and oil content of Jatropha (Jatropha curcas L.) accessions

Energy Technology Data Exchange (ETDEWEB)

Kaushik, N.; Kumar, Krishan; Kumar, Sushil [CCS HAU, Regional Research Station, Bawal (Rewari) (India); Kaushik, Nutan; Roy, S. [The Energy Resource Institute, New Delhi (India)

2007-07-15

Variability in seed traits and oil content of 24 accessions of Jatropha curcas collected from different agroclimatic zones of Haryana state, India were assessed. There were significant differences (P<0.05) in seed size, 100-seed weight and oil content between accessions. Maximum seed weight was recorded in seeds collected from IC-520602 and the least weight was recorded in IC-520587. Oil variability ranged from 28.00% in IC-520589 to 38.80% in IC-520601. In general phenotypic coefficient of variation was higher than the genotypic coefficient of variation indicating the predominant role of environment. High heritability and genetic gain were recorded for oil content (99.00% and 18.90%) and seed weight (96.00% and 18.00%), respectively, indicating the additive gene action. Seed weight had positive correlation with seed length, breadth, thickness and oil content. On the basis of non-hierarchical Euclidian cluster analysis, six clusters were obtained with highest number of accession falling under cluster III. Maximum and minimum intra cluster distance was observed for cluster VI (2.499) and for cluster III (2.252), respectively. Whereas maximum inter-cluster distance was observed between cluster VI and IV (5.129) and minimum between cluster III and II (2.472). Among the six clusters formed cluster IV showed maximum cluster value for seed size whereas, cluster VI showed maximum value for oil content and seed weight. Thus on the basis of present finding it is suggested that the crossing between accessions of cluster IV and VI will result in wide spectrum of variability in subsequent generations. (author)

SOUR CHERRY (Prunus cerasus L. GENETIC VARIABILITY AND PHOTOSYNTHETIC EFFICIENCY DURING DROUGHT

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Marija Viljevac

2012-12-01

Full Text Available Sour cherry is an important fruit in Croatian orchards. Cultivar Oblačinska is predominant in existing orchards with noted intracultivar phenotypic heterogeneity. In this study, the genetic variability of 22 genotypes of cvs. Oblačinska, Maraska and Cigančica, as well as standard cvs. Kelleris 14, Kelleris 16, Kereška, Rexelle and Heimann conserved were investigated. Two types of molecular markers were used: microsatellite markers (SSR in order to identify intercultivar, and AFLP in order to identify intracultivar variabilities. A set of 12 SSR markers revealed small genetic distance between cvs. Maraska and Oblačinska while cv. Cigančica is affined to cv. Oblačinska. Furthermore, cvs. Oblačinska, Cigančica and Maraska were characterized compared to standard ones. AFLP markers didn`t confirm significant intracultivar variability of cv. Oblačinska although the variability has been approved at the morphological, chemical and pomological level. Significant corelation between SSR and AFLP markers was found. Identification of sour cherry cultivars tolerant to drought will enable the sustainability of fruit production with respect to the climate change in the future. For this purpose, the tolerance of seven sour cherry genotypes (cvs. Kelleris 16, Maraska, Cigančica and Oblačinska represented by 4 genotypes: OS, 18, D6 and BOR to drought conditions was tested in order to isolate genotypes with the desired properties. In the greenhouse experiment, cherry plants were exposed to drought stress. The leaf relative water content, OJIP test parameters which specify efficiency of the photosynthetic system based on measurements of chlorophyll a fluorescence, and concentrations of photo-synthetic pigments during the experiment were measured as markers of drought tolerance. Photosynthetic performance index (PIABS comprises three key events in the reaction centre of photosystem II affecting the photosynthetic activity: the absorption of energy

Genetic variability, partial regression, Co-heritability studies and their implication in selection of high yielding potato gen

International Nuclear Information System (INIS)

Iqbal, Z.M.; Khan, S.A.

2003-01-01

Partial regression coefficient, genotypic and phenotypic variabilities, heritability co-heritability and genetic advance were studied in 15 Potato varieties of exotic and local origin. Both genotypic and phenotypic coefficients of variations were high for scab and rhizoctonia incidence percentage. Significant partial regression coefficient for emergence percentage indicated its relative importance in tuber yield. High heritability (broadsense) estimates coupled with high genetic advance for plant height, number of stems per plant and scab percentage revealed substantial contribution of additive genetic variance in the expression of these traits. Hence, the selection based on these characters could play a significant role in their improvement the dominance and epistatic variance was more important for character expression of yield ha/sup -1/, emergence and rhizoctonia percentage. This phenomenon is mainly due to the accumulative effects of low heritability and low to moderate genetic advance. The high co-heritability coupled with negative genotypic and phenotypic covariance revealed that selection of varieties having low scab and rhizoctonia percentage resulted in more potato yield. (author)

Genetic variability of Taenia solium cysticerci recovered from experimentally infected pigs and from naturally infected pigs using microsatellite markers.

Science.gov (United States)

Pajuelo, Mónica J; Eguiluz, María; Roncal, Elisa; Quiñones-García, Stefany; Clipman, Steven J; Calcina, Juan; Gavidia, Cesar M; Sheen, Patricia; Garcia, Hector H; Gilman, Robert H; Gonzalez, Armando E; Zimic, Mirko

2017-12-01

The adult Taenia solium, the pork tapeworm, usually lives as a single worm in the small intestine of humans, its only known definitive host. Mechanisms of genetic variation in T. solium are poorly understood. Using three microsatellite markers previously reported [1], this study explored the genetic variability of T. solium from cysts recovered from experimentally infected pigs. It then explored the genetic epidemiology and transmission in naturally infected pigs and adult tapeworms recovered from human carriers from an endemic rural community in Peru. In an initial study on experimental infection, two groups of three piglets were each infected with proglottids from one of two genetically different tapeworms for each of the microsatellites. After 7 weeks, pigs were slaughtered and necropsy performed. Thirty-six (92.3%) out of 39 cysts originated from one tapeworm, and 27 (100%) out of 27 cysts from the other had exactly the same genotype as the parental tapeworm. This suggests that the microsatellite markers may be a useful tool for studying the transmission of T. solium. In the second study, we analyzed the genetic variation of T. solium in cysts recovered from eight naturally infected pigs, and from adult tapeworms recovered from four human carriers; they showed genetic variability. Four pigs had cysts with only one genotype, and four pigs had cysts with two different genotypes, suggesting that multiple infections of genetically distinct parental tapeworms are possible. Six pigs harbored cysts with a genotype corresponding to one of the identified tapeworms from the human carriers. In the dendrogram, cysts appeared to cluster within the corresponding pigs as well as with the geographical origin, but this association was not statistically significant. We conclude that genotyping of microsatellite size polymorphisms is a potentially important tool to trace the spread of infection and pinpoint sources of infection as pigs spread cysts with a shared parental genotype.

Genetic variability of Taenia solium cysticerci recovered from experimentally infected pigs and from naturally infected pigs using microsatellite markers.

Directory of Open Access Journals (Sweden)

Mónica J Pajuelo

2017-12-01

Full Text Available The adult Taenia solium, the pork tapeworm, usually lives as a single worm in the small intestine of humans, its only known definitive host. Mechanisms of genetic variation in T. solium are poorly understood. Using three microsatellite markers previously reported [1], this study explored the genetic variability of T. solium from cysts recovered from experimentally infected pigs. It then explored the genetic epidemiology and transmission in naturally infected pigs and adult tapeworms recovered from human carriers from an endemic rural community in Peru. In an initial study on experimental infection, two groups of three piglets were each infected with proglottids from one of two genetically different tapeworms for each of the microsatellites. After 7 weeks, pigs were slaughtered and necropsy performed. Thirty-six (92.3% out of 39 cysts originated from one tapeworm, and 27 (100% out of 27 cysts from the other had exactly the same genotype as the parental tapeworm. This suggests that the microsatellite markers may be a useful tool for studying the transmission of T. solium. In the second study, we analyzed the genetic variation of T. solium in cysts recovered from eight naturally infected pigs, and from adult tapeworms recovered from four human carriers; they showed genetic variability. Four pigs had cysts with only one genotype, and four pigs had cysts with two different genotypes, suggesting that multiple infections of genetically distinct parental tapeworms are possible. Six pigs harbored cysts with a genotype corresponding to one of the identified tapeworms from the human carriers. In the dendrogram, cysts appeared to cluster within the corresponding pigs as well as with the geographical origin, but this association was not statistically significant. We conclude that genotyping of microsatellite size polymorphisms is a potentially important tool to trace the spread of infection and pinpoint sources of infection as pigs spread cysts with a shared

T-cell receptor variable genes and genetic susceptibility to celiac disease: an association and linkage study.

Science.gov (United States)

Roschmann, E; Wienker, T F; Gerok, W; Volk, B A

1993-12-01

Genetic susceptibility of celiac disease is primarily associated with a particular combination of and HLA-DQA1/DQB1 gene; however, this does not fully account for the genetic predisposition. Therefore, the aim of this study was to examine whether T-cell receptor (TCR) genes may be susceptibility genes in celiac disease. HLA class II typing was performed by polymerase chain reaction amplification in combination with sequence-specific oligonucleotide hybridization. TCR alpha (TCRA), TCR gamma (TCRG), and TCR beta (TCRB) loci were investigated by restriction fragment length polymorphism analysis. Allelic frequencies of TCRA, TCRG, and TCRB variable genes were compared between patients with celiac disease (n = 53) and control patients (n = 67), and relative risk (RR) estimates were calculated. The RR was 1.67 for allele C1 at TCRA1, 3.35 for allele D2 at TCRA2, 1.66 for allele B2 at TCRG, and 1.35 for allele B at TCRB, showing no significant association. Additionally, linkage analysis was performed in 23 families. The logarithm of odd scores for celiac disease vs. the TCR variable genes at TCRA, TCRG, and TCRB showed no significant linkage. These data suggest that the analyzed TCR variable gene segments V alpha 1.2, V gamma 11, and V beta 8 do not play a major role in susceptibility to celiac disease.

Variability, heritability and genetic association in vegetable amaranth (Amaranthus tricolor L.)

Energy Technology Data Exchange (ETDEWEB)

Sarker, U.; Islam, Md T.; Rabbani, Md G.; Oba, S.

2015-07-01

Forty three vegetable amaranth (Amaranthus tricolor L.) genotypes selected from different eco-geographic regions of Bangladesh were evaluated during 3 years (2012-2014) for genetic variability, heritability and genetic association among mineral elements and quality and agronomic traits in randomized complete block design (RCBD) with five replications. The analysis showed that vegetable amaranth is a rich source of K, Ca, Mg, proteins and dietary fibre with average values among the 43 genotypes (1.014%, 2.476%, 2.984, 1.258% and 7.81%, respectively). Six genotypes (VA13, VA14, VA16, VA18, VA26, VA27) showed a biological yield >2000 g/m2 and high mineral, protein and dietary fibre contents; eleven genotypes had high amount of minerals, protein and dietary fibre with above average biological yield; nine genotypes had below average biological yield but were rich in minerals, protein and dietary fibre. Biological yield exhibited a strong positive correlation with leaf area, shoot weight, shoot/root weight and stem base diameter. Insignificant genotypic correlation was observed among mineral, quality and agronomic traits, except K vs. Mg, protein vs. dietary fibre and stem base diameter vs. Ca. Some of these genotypes can be used for improvement of vegetable amaranth regarding mineral, protein and dietary fibre content without compromising yield loss. (Author)

Morphology and genetic variability within Taenia multiceps in ruminants from Italy.

Science.gov (United States)

Varcasia, Antonio; Pipia, Anna Paola; Dessì, Giorgia; Zidda, Antonella; Tamponi, Claudia; Pau, Marco; Scala, Antonio; Boufana, Belgees

2016-06-15

The aim of this study was to investigate the genetic variability and population structure of Taenia multiceps, and to correlate morphological features of individual coenuri with haplotypes. A total of 92 animals (86 sheep; 4 goats; 1 cattle; 1 mouflon, Ovis musimon) aged between 6-36 months showing clinical symptoms of cerebral coenurosis were included in this study. T. multiceps coenuri (n=118) sampled from live animals during routine surgery procedures or at post-mortem inspections were examined morphologically and molecularly identified. Morphological features of the 52 coenuri selected for this study (number and size of large and small hooks) were within the range reported in the literature. Fifty-two of the molecularly confirmed T. multiceps coenuri harboured by 47 animals (sheep=41; cattle=1; goats=4; mouflon=1) were used to determine gene genealogies and population genetic indices and were compared to the 3 T. multiceps genetic variants, Tm1-Tm3 previously described from Sardinia, Italy. For the 379 bp cox1 dataset we identified 11 polymorphic sites of which 8 were parsimony informative. A high haplotype diversity (0.664±0.067) was recorded for the cox1 sequences defining 10 haplotypes (TM01-TM10). The comparison of haplotypes generated in this study with published T. multiceps Tm1 variant pointed to the possible existence of a common lineage for T. multiceps. No correlation was detected between the size of the small and large hooks and the cox 1 haplotypes. Polycystic infestation (2-9 coenuri) was recorded in 27.7% of animals (13/47). No statistical correlation between polycystic T. multiceps infection and haplotypes was detected. Copyright © 2016 Elsevier B.V. All rights reserved.

Genetic variability of attachment (G and Fusion (F protein genes of human metapneumovirus strains circulating during 2006-2009 in Kolkata, Eastern India

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Chawla-Sarkar Mamta

2011-02-01

Full Text Available Abstract Background Human metapneumovirus (hMPV is associated with the acute respiratory tract infection (ARTI in all the age groups. However, there is limited information on prevalence and genetic diversity of human metapneumovirus (hMPV strains circulating in India. Objective To study prevalence and genomic diversity of hMPV strains among ARTI patients reporting in outpatient departments of hospitals in Kolkata, Eastern India. Methods Nasal and/or throat swabs from 2309 patients during January 2006 to December 2009, were screened for the presence of hMPV by RT-PCR of nucleocapsid (N gene. The G and F genes of representative hMPV positive samples were sequenced. Results 118 of 2309 (5.11% clinical samples were positive for hMPV. The majority (≈80% of the positive cases were detected during July−November all through the study period. Genetic analysis revealed that 77% strains belong to A2 subgroup whereas rest clustered in B1 subgroup. G sequences showed higher diversity at the nucleotide and amino acid level. In contrast, less than 10% variation was observed in F gene of representative strains of all four years. Sequence analysis also revealed changes in the position of stop codon in G protein, which resulted in variable length (217-231 aa polypeptides. Conclusion The study suggests that approximately 5% of ARTI in the region were caused by hMPV. This is the first report on the genetic variability of G and F gene of hMPV strains from India which clearly shows that the G protein of hMPV is continuously evolving. Though the study partially fulfills lacunae of information, further studies from other regions are necessary for better understanding of prevalence, epidemiology and virus evolution in Indian subcontinent.

Genetic variability and cadmium metabolism and toxicity

OpenAIRE

Rentschler, Gerda

2014-01-01

Abstract: Cadmium (Cd) is ubiquitous in the environment. Human exposure in non-smokers occurs mainly via intake of healthy food like vegetables, cereals, and shellfish. Adverse health effects on kidney and bone at low-level environmental Cd exposure are well-documented in adults. There is considerable inter-individual variation in both metabolism (toxicokinetics) and toxicity (toxicodynamics) of Cd. This may be due to genetic factors. The aim of this thesis was to identify genetic fact...

Living in Heterogeneous Woodlands - Are Habitat Continuity or Quality Drivers of Genetic Variability in a Flightless Ground Beetle?

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Tamar Marcus

Full Text Available Although genetic diversity is one of the key components of biodiversity, its drivers are still not fully understood. While it is known that genetic diversity is affected both by environmental parameters as well as habitat history, these factors are not often tested together. Therefore, we analyzed 14 microsatellite loci in Abax parallelepipedus, a flightless, forest dwelling ground beetle, from 88 plots in two study regions in Germany. We modeled the effects of historical and environmental variables on allelic richness, and found for one of the regions, the Schorfheide-Chorin, a significant effect of the depth of the litter layer, which is a main component of habitat quality, and of the sampling effort, which serves as an inverse proxy for local population size. For the other region, the Schwäbische Alb, none of the potential drivers showed a significant effect on allelic richness. We conclude that the genetic diversity in our study species is being driven by current local population sizes via environmental variables and not by historical processes in the studied regions. This is also supported by lack of genetic differentiation between local populations sampled from ancient and from recent woodlands. We suggest that the potential effects of former fragmentation and recolonization processes have been mitigated by the large and stable local populations of Abax parallelepipedus in combination with the proximity of the ancient and recent woodlands in the studied landscapes.

Gene variants associated with antisocial behaviour: a latent variable approach.

Science.gov (United States)

Bentley, Mary Jane; Lin, Haiqun; Fernandez, Thomas V; Lee, Maria; Yrigollen, Carolyn M; Pakstis, Andrew J; Katsovich, Liliya; Olds, David L; Grigorenko, Elena L; Leckman, James F

2013-10-01

The aim of this study was to determine if a latent variable approach might be useful in identifying shared variance across genetic risk alleles that is associated with antisocial behaviour at age 15 years. Using a conventional latent variable approach, we derived an antisocial phenotype in 328 adolescents utilizing data from a 15-year follow-up of a randomized trial of a prenatal and infancy nurse-home visitation programme in Elmira, New York. We then investigated, via a novel latent variable approach, 450 informative genetic polymorphisms in 71 genes previously associated with antisocial behaviour, drug use, affiliative behaviours and stress response in 241 consenting individuals for whom DNA was available. Haplotype and Pathway analyses were also performed. Eight single-nucleotide polymorphisms (SNPs) from eight genes contributed to the latent genetic variable that in turn accounted for 16.0% of the variance within the latent antisocial phenotype. The number of risk alleles was linearly related to the latent antisocial variable scores. Haplotypes that included the putative risk alleles for all eight genes were also associated with higher latent antisocial variable scores. In addition, 33 SNPs from 63 of the remaining genes were also significant when added to the final model. Many of these genes interact on a molecular level, forming molecular networks. The results support a role for genes related to dopamine, norepinephrine, serotonin, glutamate, opioid and cholinergic signalling as well as stress response pathways in mediating susceptibility to antisocial behaviour. This preliminary study supports use of relevant behavioural indicators and latent variable approaches to study the potential 'co-action' of gene variants associated with antisocial behaviour. It also underscores the cumulative relevance of common genetic variants for understanding the aetiology of complex behaviour. If replicated in future studies, this approach may allow the identification of a

Genetic variability of wild populations of Leporinus elongatus in the São Domingos River - MS Brazil: a preliminary view on the construction of the hydroelectric plant

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Ricardo Pereira Ribeiro

2016-09-01

Full Text Available Most of the electricity used in Brazil comes from hydroelectric plants, mainly due to the great availability of its water resources. However, the construction of these plants denotes serious problems related to migration of native fish and the genetic conservation of stocks. Current study evaluates two wild population of Leporinus elongatus (piapara located downstream (Population A - PopA and upstream (Population B - PopB of the Cachoeira Branca before the construction of the São Domingos hydroelectric plant (HPP in the Mato Grosso do Sul State, Brazil. Thirty samples from caudal fins were collected and analyzed for each population. Eighty-nine fragments, including 72 polymorphic ones (80.9%, were analyzed. Low fragments (less than 0.100 in both populations (PopA = 2 and PopB = 3 were identified. Nine fixed fragments (frequency 1.000 (PopA = 3 and PopB = 6, and four exclusive fragments (PopA = 3 and PopB = 1 were also reported. The genetic variability within populations, calculated by Shannon Index and by percentage of polymorphic fragments, indicated high rates of intrapopulation variability (PopA = 0.309 and 61.80% and PopB = 0.392 and 71.90%, respectively. Genetic distance and identity rates (0.089 and 0.915, respectively were different between populations, whilst AMOVA showed that most variations lie within the populations and not between them. Fst and Nm rates showed moderate genetic differentiation with low numbers of migrants. Results reveal populations with high intra-population genetic variability and genetic differentiation, with low gene flow. The passage ladders of São Domingos HPP should control fish transposition to preserve genetic variability.

Genetic variability, heritability, character association and path analysis in F/sub 1/ hybrids of tomato

International Nuclear Information System (INIS)

Saleem, M.Y.; Iqbal, Q.; Asghar, M.

2013-01-01

Twenty-five F/sub 1/ hybrids generated from 5*5 diallel crosses were evaluated to study the quantitative genetics of yield and some yield related traits during 2009-10. Worth of room was realized for improvement due to highly significant genetic variations among all traits studied. The highest estimates of genotypic and phenotypic coefficients of variability were recorded for number of fruits per plant while fruit width was the most heritable trait. Plant height, number of fruits per plant and fruit weight revealed significant positive genotypic and phenotypic association along with direct positive effect on fruit yield per plant. It is therefore, recommended that fruit weight, number of fruits per plant and plant height should be given due importance in selection of promising crosses to develop commercial hybrid variety in tomato. (author)

Genome-wide prediction of traits with different genetic architecture through efficient variable selection.

Science.gov (United States)

Wimmer, Valentin; Lehermeier, Christina; Albrecht, Theresa; Auinger, Hans-Jürgen; Wang, Yu; Schön, Chris-Carolin

2013-10-01

In genome-based prediction there is considerable uncertainty about the statistical model and method required to maximize prediction accuracy. For traits influenced by a small number of quantitative trait loci (QTL), predictions are expected to benefit from methods performing variable selection [e.g., BayesB or the least absolute shrinkage and selection operator (LASSO)] compared to methods distributing effects across the genome [ridge regression best linear unbiased prediction (RR-BLUP)]. We investigate the assumptions underlying successful variable selection by combining computer simulations with large-scale experimental data sets from rice (Oryza sativa L.), wheat (Triticum aestivum L.), and Arabidopsis thaliana (L.). We demonstrate that variable selection can be successful when the number of phenotyped individuals is much larger than the number of causal mutations contributing to the trait. We show that the sample size required for efficient variable selection increases dramatically with decreasing trait heritabilities and increasing extent of linkage disequilibrium (LD). We contrast and discuss contradictory results from simulation and experimental studies with respect to superiority of variable selection methods over RR-BLUP. Our results demonstrate that due to long-range LD, medium heritabilities, and small sample sizes, superiority of variable selection methods cannot be expected in plant breeding populations even for traits like FRIGIDA gene expression in Arabidopsis and flowering time in rice, assumed to be influenced by a few major QTL. We extend our conclusions to the analysis of whole-genome sequence data and infer upper bounds for the number of causal mutations which can be identified by LASSO. Our results have major impact on the choice of statistical method needed to make credible inferences about genetic architecture and prediction accuracy of complex traits.

Studies of genetic variability of the glucose transporter 2 promoter in patients with type 2 diabetes mellitus

DEFF Research Database (Denmark)

Møller, A M; Jensen, N M; Pildal, J

2001-01-01

This study was performed to test the hypothesis that genetic variation in the promoter of the glucose transporter 2 (GLUT2) might predispose to prediabetic phenotypes or type 2 diabetes. A total of 1611 bp comprising the minimal promoter region of the GLUT2 gene were examined by combined single-s......-tolerant subjects. In conclusion, we found no evidence supporting the hypothesis that genetic variability in the minimal promoter of the GLUT2 is associated with type 2 diabetes or prediabetic phenotypes in the Danish population.......This study was performed to test the hypothesis that genetic variation in the promoter of the glucose transporter 2 (GLUT2) might predispose to prediabetic phenotypes or type 2 diabetes. A total of 1611 bp comprising the minimal promoter region of the GLUT2 gene were examined by combined single...

Stochastic search in structural optimization - Genetic algorithms and simulated annealing

Science.gov (United States)

Hajela, Prabhat

1993-01-01

An account is given of illustrative applications of genetic algorithms and simulated annealing methods in structural optimization. The advantages of such stochastic search methods over traditional mathematical programming strategies are emphasized; it is noted that these methods offer a significantly higher probability of locating the global optimum in a multimodal design space. Both genetic-search and simulated annealing can be effectively used in problems with a mix of continuous, discrete, and integer design variables.

Genetic variability among advanced lines of brassica

International Nuclear Information System (INIS)

Ullah, N.; Farhatullah, A.; Rahman, H.U.; Fayyaz, L.

2015-01-01

Genetic variability for morphological and biochemical traits among six advanced lines (F10:11) of brassica was studied at The University of Agriculture Peshawar during crop season of 2012-13. These lines were developed through interspecific hybridization. Significant differences at (p=0.01) for plant height, main, pods main raceme-1, pod length, seed yield plant-1 and protein content at (p=0.05) for 100-seed weight, oil content were recorded. The advanced line, AUP-05 produced the maximum seed yield plant-1 (19.73 g), protein content (24.56%), 100-seed weight (0.64 g). Advanced line AUP-04 had the highest erucic acid (50.31%), linolenic acid (10.60%) and was late maturing (179.33). Advanced line AUP-06 produced the high oil content (48.82%). Advanced line AUP-03 produced comparatively longer main raceme (69.32 cm). Environmental variance was smaller than genotypic variance for majority of the traits. Genotypic and phenotypic coefficients of variation ranged from 2.45 to 25.67% and 2.50 to 27.68%, respectively. Heritability was high for majority of the traits. The maximum heritability was recorded for plant height (0.61), main raceme length (0.81), pods main raceme-1 (0.74), seed yield plant-1 (0.86) and protein content (0.77). Moderate heritability was observed for oil (0.58) contents. Heritability for 100-seed weight (0.30) was the lowest. These lines may be released as new improved varieties for specific parameters. (author)

Genetic analysis of glucosinolate variability in broccoli florets using genome-anchored single nucleotide polymorphisms.

Science.gov (United States)

Brown, Allan F; Yousef, Gad G; Reid, Robert W; Chebrolu, Kranthi K; Thomas, Aswathy; Krueger, Christopher; Jeffery, Elizabeth; Jackson, Eric; Juvik, John A

2015-07-01

The identification of genetic factors influencing the accumulation of individual glucosinolates in broccoli florets provides novel insight into the regulation of glucosinolate levels in Brassica vegetables and will accelerate the development of vegetables with glucosinolate profiles tailored to promote human health. Quantitative trait loci analysis of glucosinolate (GSL) variability was conducted with a B. oleracea (broccoli) mapping population, saturated with single nucleotide polymorphism markers from a high-density array designed for rapeseed (Brassica napus). In 4 years of analysis, 14 QTLs were associated with the accumulation of aliphatic, indolic, or aromatic GSLs in floret tissue. The accumulation of 3-carbon aliphatic GSLs (2-propenyl and 3-methylsulfinylpropyl) was primarily associated with a single QTL on C05, but common regulation of 4-carbon aliphatic GSLs was not observed. A single locus on C09, associated with up to 40 % of the phenotypic variability of 2-hydroxy-3-butenyl GSL over multiple years, was not associated with the variability of precursor compounds. Similarly, QTLs on C02, C04, and C09 were associated with 4-methylsulfinylbutyl GSL concentration over multiple years but were not significantly associated with downstream compounds. Genome-specific SNP markers were used to identify candidate genes that co-localized to marker intervals and previously sequenced Brassica oleracea BAC clones containing known GSL genes (GSL-ALK, GSL-PRO, and GSL-ELONG) were aligned to the genomic sequence, providing support that at least three of our 14 QTLs likely correspond to previously identified GSL loci. The results demonstrate that previously identified loci do not fully explain GSL variation in broccoli. The identification of additional genetic factors influencing the accumulation of GSL in broccoli florets provides novel insight into the regulation of GSL levels in Brassicaceae and will accelerate development of vegetables with modified or enhanced GSL

Genetic variability in Asparagus racemosus (Willd.) from Madhya ...

African Journals Online (AJOL)

Random amplified polymorphic DNA (RAPD) markers were used to assess genetic diversity in Asparagus racemosus (Willd.) an important medicinal plant collected from 7 different locations covering Madhya Pradesh. High level of genetic similarity was observed in the collected accessions. 4 random primers generated a ...

Biological pathways and genetic variables involved in pain

NARCIS (Netherlands)

Shi, Qiuling; Cleeland, Charles S.; Klepstad, Pål; Miaskowski, Christine; Pedersen, Nancy L.; Abernethy, Amy P.; Baas, Frank; Barsevick, Andrea M.; Bartels, Meike; Boomsma, Dorret I.; Chauhan, Cynthia; Dueck, Amylou C.; Frost, Marlene H.; Hall, Per; Halyard, Michele Y.; Martin, Nicholas G.; Mosing, Miriam; Movsas, Benjamin; van Noorden, Cornelis J. F.; Patrick, Donald L.; Ropka, Mary E.; Shinozaki, Gen; Singh, Jasvinder A.; Sloan, Jeff A.; Sprangers, Mirjam A. G.; Veenhoven, Ruut; Yang, Ping; Zwinderman, Ailko H.

2010-01-01

Purpose This paper summarizes current knowledge of pain-related and analgesic-related pathways as well as genetic variations involved in pain perception and management. Methods The pain group of the GENEQOL Consortium was given the task of summarizing the current status of research on genetic

Variability of yield traits and disease resistance in winter triticale genetic resources accessions

Directory of Open Access Journals (Sweden)

Wanda Kociuba

2014-07-01

Full Text Available A systematic gathering of winter triticale accessions was started in Poland in 1982 by the Institute of Genetics, Breeding and Seed Science at the Agricultural University in Lublin (at present its name is: Institute of Genetics, Breeding and Plant Biotechnology at the University of Life Sciences in Lublin. First, breeding lines obtained in local breeding stations were gathered. Next, accessions were imported from the following world gene banks: Beltsville, Gatersleben, and VIR. Interesting hybrid materials obtained in research centers were also included in the collection. Now, the collection includes 2349 accessions (1329 of winter triticale and 1020 of spring triticale. The evaluation is conducted in a 4-year cycle of field experiments using the same methods. The gathered accessions represent a large range of variability of both morphological and commercial traits. The large differentiation of accessions especially concerns traits such as: plant height, number and weight of grains per spi- ke, protein content in grain, field resistance to powdery mildew, brown rust and leaf and spike diseases.

Exploring the mitochondrial DNA variability of the Amazonian Yanomami.

Science.gov (United States)

Varano, Sara; Scorrano, Gabriele; Martínez-Labarga, Cristina; Finocchio, Andrea; Rapone, Cesare; Berti, Andrea; Rickards, Olga

2016-11-01

The aim of this study was to explore the mitochondrial variability in the Yanomami population to reconstruct its demographic history and explore its genetic composition in relation to its cultural and linguistic features. A total of 174 human head hair shafts -collected in 1958- belonging to individuals from a Yanomami group living in Santa Isabel, Brazil, were analyzed. Automated extraction of the hairs was performed, and several methods were applied to optimize the analysis of the degraded DNA. The mtDNA hypervariable segments I-II, along with the 9-bp COII-tRNA Lys deletion, were investigated. Using published data from the Yanomami and other Amazonian populations, several statistical analyses were carried out to explore the genetic variability within the study population. Ninety eight percent of the mitochondrial DNA (mtDNA) sequences analyzed belonged to Native American haplogroups, while 2% belonged to African haplogroups. Compared with the Yanomami groups previously studied, the Santa Isabel sample seemed more genetically similar to other Amazonian populations. Among the Yanomami samples studied to date, the Santa Isabel Yanomami show a higher genetic heterogeneity. This could be due to gene flow with non-Yanomami populations, as well as to the introduction of new mitochondrial haplotypes by gold miners. In both cases, the geographic location of Santa Isabel might have made this Yanomami village less isolated than the others, suggesting that the Rio Negro played a central role in increasing its genetic variability. On the whole, the Yanomami were quite genetically diversified, probably mirroring their great linguistic heterogeneity. Am. J. Hum. Biol. 28:846-856, 2016. © 2016Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Using variable combination population analysis for variable selection in multivariate calibration.

Science.gov (United States)

Yun, Yong-Huan; Wang, Wei-Ting; Deng, Bai-Chuan; Lai, Guang-Bi; Liu, Xin-bo; Ren, Da-Bing; Liang, Yi-Zeng; Fan, Wei; Xu, Qing-Song

2015-03-03

Variable (wavelength or feature) selection techniques have become a critical step for the analysis of datasets with high number of variables and relatively few samples. In this study, a novel variable selection strategy, variable combination population analysis (VCPA), was proposed. This strategy consists of two crucial procedures. First, the exponentially decreasing function (EDF), which is the simple and effective principle of 'survival of the fittest' from Darwin's natural evolution theory, is employed to determine the number of variables to keep and continuously shrink the variable space. Second, in each EDF run, binary matrix sampling (BMS) strategy that gives each variable the same chance to be selected and generates different variable combinations, is used to produce a population of subsets to construct a population of sub-models. Then, model population analysis (MPA) is employed to find the variable subsets with the lower root mean squares error of cross validation (RMSECV). The frequency of each variable appearing in the best 10% sub-models is computed. The higher the frequency is, the more important the variable is. The performance of the proposed procedure was investigated using three real NIR datasets. The results indicate that VCPA is a good variable selection strategy when compared with four high performing variable selection methods: genetic algorithm-partial least squares (GA-PLS), Monte Carlo uninformative variable elimination by PLS (MC-UVE-PLS), competitive adaptive reweighted sampling (CARS) and iteratively retains informative variables (IRIV). The MATLAB source code of VCPA is available for academic research on the website: http://www.mathworks.com/matlabcentral/fileexchange/authors/498750. Copyright © 2015 Elsevier B.V. All rights reserved.

Radiation induced mutants in elite genetic background for the augmentation of genetic diversity

International Nuclear Information System (INIS)

Kumar, V.; Bhagwat, S.G.

2011-01-01

Rice (Oryza sativa L.), an important food crop for India, shows large genetic diversity. However, despite the large genetic resource, high genetic similarity is reported in cultivated varieties indicating genetic erosion. Radiation induced mutations provide genetic variability in elite background. In the present study, twenty gamma ray induced mutants of rice variety WL112 (carrying sd-1 semi-dwarfing gene) were analysed for genetic diversity using microsatellite markers. The high range of genetic diversity among mutants indicated that the mutants possess potential for enhancing variability in rice. Cluster analysis showed presence of five clusters having small sub-clusters. Earliness, semi-dwarf stature or resistance to blast disease observed among the mutants showed that these will be useful in breeding programmes. (author)

Genetic variability of the whitefly Bemisia tabaci and its secondary endosymbionts in the Arabian Peninsula

KAUST Repository

Ragab, Alaa I.

2013-05-01

the Q biotype. All endosymbionts were detected, with Hamiltonella as the most predominant. Several instances of co-infection by two or more endosymbionts were observed. Samples from the geographically isolated and mountainous region of Fayfa demonstrated higher genetic variability compared to the other locations, leading to the possible identification of a new haplotype, as well as the first time identification of the A biotype in the region.

HLA-DRB and HLA-DQ genetic variability in patients with aspirin-exacerbated respiratory disease.

Science.gov (United States)

Esmaeilzadeh, Hossein; Nabavi, Mohammad; Amirzargar, Ali Akbar; Aryan, Zahra; Arshi, Saba; Bemanian, Mohammad Hassan; Fallahpour, Morteza; Mortazavi, Negar; Rezaei, Nima

2015-01-01

Major histocompatibility complex (MHC) class II is involved in T-cell activation, cytokine secretion, and induction of immune responses. Cytokines, staphylococcus super antigens, and eosinophil activation are proposed to play important roles in aspirin-exacerbated respiratory disease (AERD). This study is aimed at investigating the association of HLA-DRB and DQ genetic variabilities in patients with AERD. A genetic association analysis in three different groups, including 33 patients with AERD, 17 patients with aspirin-tolerant asthma (ATA), and 100 healthy controls was performed. Oral aspirin challenge (OAC) test was performed to identify aspirin hypersensitivity. Pulmonary function test (PFT) was performed for all patients. Eosinophil percentage in nasal smear and peripheral blood and serum immunoglobin (Ig)E were investigated. HLA-DRB, HLA-DQA1, and HLA-DQB1 were genotyped using polymerase chain reaction. HLA-DQB1*0302 (OR, 5.49, 95% confidence interval [CI],(2.40-12.59)), HLA-DQA1*0301 (OR, 2.90, 95% CI, (1.49-5.67)), HLA-DRB4 (OR, 2.94, 95% CI, (1.61-5.36)), and HLA-DRB1*04 (OR, 3.19, 95% CI, (1.57-6.47)) were higher in patients with AERD compared with controls. In patients with AERD, HLA-DQB1*0301 (OR,0.22, 95% CI, (0.09-0.54)), HLA-DQA1*0501 (OR, 0.42, 95% CI, (0.21-0.81)), HLA-DRB1*11 (OR, 0.30, 95% CI, (0.12-0.73)), and HLA-DRB3 (OR, 0.38, 95% CI, (0.21-0.70)) were significantly lower compared with healthy controls. Patients with AERD had lower frequencies of HLA-DQB1*0301 (OR, 0.27, 95% CI, (0.08-0.86)), and HLA-DRB1*011 (OR, 0.27, 95% CI, (0.08-0.86)) compared with ATA. Haplotypes of HLA-DRB1*04/ DQA1*0301/ DQB1*0302 (OR, 4.25, 95% CI, (1.94-9.29)) and HLA-DRB1*07 /DQA1*0201/ DQB1*0201 (OR, 3.52, 95% CI, (1.54-8.06)) were higher in patients with AERD compared with controls (all p < 0.05). Results of this study suggest that HLA-DQB1*0302 and HLA-DRB1*04 and their related haplotypes are genes involved in predisposing patients to AERD, whereas HLA-DQB1

Genetic variability of a Brazilian Capsicum frutescens germplasm collection using morphological characteristics and SSR markers.

Science.gov (United States)

Carvalho, S I C; Bianchetti, L B; Ragassi, C F; Ribeiro, C S C; Reifschneider, F J B; Buso, G S C; Faleiro, F G

2017-07-06

Characterization studies provide essential information for the conservation and use of germplasm in plant breeding programs. In this study, 103 Capsicum frutescens L. accessions from the Active Germplasm Bank of Embrapa Hortaliças, representative of all five Brazilian geographic regions, were characterized based on morphological characteristics and microsatellite (or simple sequence repeat - SSR) molecular markers. Morphological characterization was carried out using 57 descriptors, and molecular characterization was based on 239 alleles from 24 microsatellite loci. From the estimates of genetic distances among accessions, based on molecular characterization, a cluster analysis was carried out, and a dendrogram was established. Correlations between morphological and molecular variables were also estimated. Twelve morphological descriptors were monomorphic for the set of C. frutescens accessions, and those with the highest degree of polymorphism were stem length (14.0 to 62.0 cm), stem diameter (1.0 to 4.2 cm), days to flowering (90 to 129), days to fruiting (100 to 140), fruit weight (0.1 to 1.4 g), fruit length (0.6 to 4.6 cm), and fruit wall thickness (0.25 to 1.5 mm). The polymorphism information content for the SSR loci varied from 0.36 (EPMS 417) to 0.75 (CA49), with an overall mean of 0.57. The correlation value between morphological and molecular characterization data was 0.6604, which was statistically significant. Fourteen accessions were described as belonging to the morphological type tabasco, 85 were described as malagueta, and four were malaguetinha, a morphological type confirmed in this study. The typical morphological pattern of malagueta was described. Six similarity groups were established for C. frutescens based on the dendrogram and are discussed individually. The genetic variability analyzed in the study highlights the importance of characterizing genetic resources available for the development of new C. frutescens cultivars with the potential

Comparison of genetic variability between Czech and foreign isolates of phytopathogenic bacteria Clavibacter michiganensis subsp. sepedonicus by Rep-PCR technique

Czech Academy of Sciences Publication Activity Database

Fousek, Jan; Mráz, Ivan; Petrzik, Karel

2002-01-01

Roč. 47, - (2002), s. 450-454 ISSN 0015-5632 R&D Projects: GA ČR GA522/00/0887 Keywords : Clavibacter michiganensis * genetic variability Subject RIV: EE - Microbiology, Virology Impact factor: 0.979, year: 2002

First evidence of genetic intraspecific variability and occurrence of Entamoeba gingivalis in HIV(+/AIDS.

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Sibeli B S Cembranelli

Full Text Available Entamoeba gingivalis is considered an oral commensal but demonstrates a pathogenic potential associated with periodontal disease in immunocompromised individuals. Therefore, this study evaluated the occurrence, opportunistic conditions, and intraspecific genetic variability of E. gingivalis in HIV(+/AIDS patients. Entamoeba gingivalis was studied using fresh examination (FE, culture, and PCR from bacterial plaque samples collected from 82 HIV(+/AIDS patients. Genetic characterization of the lower ribosomal subunit of region 18S (18S-SSU rRNA was conducted in 9 positive samples using low-stringency single specific primer PCR (LSSP-PCR and sequencing analysis. Entamoeba gingivalis was detected in 63.4% (52/82 of the samples. No association was detected between the presence of E. gingivalis and the CD4(+ lymphocyte count (≤200 cells/mm(3 (p = 0.912 or viral load (p = 0.429. The LSSP-PCR results helped group E. gingivalis populations into 2 polymorphic groups (68.3% similarity: group I, associated with 63.6% (7/11 of the samples, and group II, associated with 36.4% (4/11 of the samples, which shared 74% and 83.7% similarity and association with C and E isolates from HIV(- individuals, respectively. Sequencing of 4 samples demonstrated 99% identity with the reference strain ATCC 30927 and also showed 2 divergent clusters, similar to those detected by LSSP-PCR. Opportunistic behavior of E. gingivalis was not detected, which may be related to the use of highly active antiretroviral therapy by all HIV(+/AIDS patients. The high occurrence of E. gingivalis in these patients can be influenced by multifactorial components not directly related to the CD4(+ lymphocyte counts, such as cholesterol and the oral microbiota host, which could mask the potential opportunistic ability of E. gingivalis. The identification of the 18S SSU-rRNA polymorphism by LSSP-PCR and sequencing analysis provides the first evidence of genetic variability in E. gingivalis

Mitochondrial DNA variability among eight Tikúna villages: evidence for an intratribal genetic heterogeneity pattern.

Science.gov (United States)

Mendes-Junior, Celso Teixeira; Simões, Aguinaldo Luiz

2009-11-01

To study the genetic structure of the Tikúna tribe, four major Native American mitochondrial DNA (mtDNA) founder haplogroups were analyzed in 187 Amerindians from eight Tikúna villages located in the Brazilian Amazon. The central position of these villages in the continent makes them relevant for attempts to reconstruct population movements in South America. In this geographic region, there is particular concern regarding the genetic structure of the Tikúna tribe, formerly designated "enigmatic" due to its remarkable degree of intratribal homogeneity and the scarcity of private protein variants. In spite of its large population size and geographic distribution, the Tikúna tribe presents marked genetic and linguistic isolation. All individuals presented indigenous mtDNA haplogroups. An intratribal genetic heterogeneity pattern characterized by two highly homogeneous Tikúna groups that differ considerably from each other was observed. Such a finding was unexpected, since the Tikúna tribe is characterized by a social system that favors intratribal exogamy and patrilocality that would lead to a higher female migration rate and homogenization of the mtDNA gene pool. Demographic explosions and religious events, which significantly changed the sizes and compositions of many Tikúna villages, may be reflected in the genetic results presented here.

Seedling vigor and genetic variability for rice seed, seedling emergence and seedling traits

International Nuclear Information System (INIS)

Ali, S.S.; Jafri, S.J.H.; Jamil, M.; Ijaz, M.

1994-01-01

Eleven local rice cultivars including Basmati 370 were evaluated for seedling vigor. Three groups of traits were evaluated viz; seed traits (Seed density, seed volume see weight, paddy length and grain length), seed emergence traits (emergence %, emergence index and emergence rate index), and seedling traits (fresh root length, dry root weight, emergence percentage, root length, dry root weight, seed weight and relative root weight were observed significant, respectively. Seed density, relative root weight, emergence rate index and root to shoot ratio were relatively more amenable to improvement. Relative expected genetic advance was the function of heritability and coefficient of phenotypic variability, latter being more important. (author)

Genetic variability and resistance of cultivars of cowpea [Vigna unguiculata (L.) Walp] to cowpea weevil (Callosobruchus maculatus Fabr.).

Science.gov (United States)

Vila Nova, M X; Leite, N G A; Houllou, L M; Medeiros, L V; Lira Neto, A C; Hsie, B S; Borges-Paluch, L R; Santos, B S; Araujo, C S F; Rocha, A A; Costa, A F

2014-03-31

The cowpea weevil (Callosobruchus maculatus Fabr.) is the most destructive pest of the cowpea bean; it reduces seed quality. To control this pest, resistance testing combined with genetic analysis using molecular markers has been widely applied in research. Among the markers that show reliable results, the inter-simple sequence repeats (ISSRs) (microsatellites) are noteworthy. This study was performed to evaluate the resistance of 27 cultivars of cowpea bean to cowpea weevil. We tested the resistance related to the genetic variability of these cultivars using ISSR markers. To analyze the resistance of cultivars to weevil, a completely randomized test design with 4 replicates and 27 treatments was adopted. Five pairs of the insect were placed in 30 grains per replicate. Analysis of variance showed that the number of eggs and emerged insects were significantly different in the treatments, and the means were compared by statistical tests. The analysis of the large genetic variability in all cultivars resulted in the formation of different groups. The test of resistance showed that the cultivar Inhuma was the most sensitive to both number of eggs and number of emerged adults, while the TE96-290-12-G and MNC99-537-F4 (BRS Tumucumaque) cultivars were the least sensitive to the number of eggs and the number of emerged insects, respectively.

Higher fine-scale genetic structure in peripheral than in core populations of a long-lived and mixed-mating conifer--eastern white cedar (Thuja occidentalis L.).

Science.gov (United States)

Pandey, Madhav; Rajora, Om P

2012-04-05

Fine-scale or spatial genetic structure (SGS) is one of the key genetic characteristics of plant populations. Several evolutionary and ecological processes and population characteristics influence the level of SGS within plant populations. Higher fine-scale genetic structure may be expected in peripheral than core populations of long-lived forest trees, owing to the differences in the magnitude of operating evolutionary and ecological forces such as gene flow, genetic drift, effective population size and founder effects. We addressed this question using eastern white cedar (Thuja occidentalis) as a model species for declining to endangered long-lived tree species with mixed-mating system. We determined the SGS in two core and two peripheral populations of eastern white cedar from its Maritime Canadian eastern range using six nuclear microsatellite DNA markers. Significant SGS ranging from 15 m to 75 m distance classes was observed in the four studied populations. An analysis of combined four populations revealed significant positive SGS up to the 45 m distance class. The mean positive significant SGS observed in the peripheral populations was up to six times (up to 90 m) of that observed in the core populations (15 m). Spatial autocorrelation coefficients and correlograms of single and sub-sets of populations were statistically significant. The extent of within-population SGS was significantly negatively correlated with all genetic diversity parameters. Significant heterogeneity of within-population SGS was observed for 0-15 m and 61-90 m between core and peripheral populations. Average Sp, and gene flow distances were higher in peripheral (Sp = 0.023, σg = 135 m) than in core (Sp = 0.014, σg = 109 m) populations. However, the mean neighborhood size was higher in the core (Nb = 82) than in the peripheral (Nb = 48) populations. Eastern white cedar populations have significant fine-scale genetic structure at short distances. Peripheral populations have several

Genetic variability in MCF-7 sublines: evidence of rapid genomic and RNA expression profile modifications

International Nuclear Information System (INIS)

Nugoli, Mélanie; Theillet, Charles; Chuchana, Paul; Vendrell, Julie; Orsetti, Béatrice; Ursule, Lisa; Nguyen, Catherine; Birnbaum, Daniel; Douzery, Emmanuel JP; Cohen, Pascale

2003-01-01

Both phenotypic and cytogenetic variability have been reported for clones of breast carcinoma cell lines but have not been comprehensively studied. Despite this, cell lines such as MCF-7 cells are extensively used as model systems. In this work we documented, using CGH and RNA expression profiles, the genetic variability at the genomic and RNA expression levels of MCF-7 cells of different origins. Eight MCF-7 sublines collected from different sources were studied as well as 3 subclones isolated from one of the sublines by limit dilution. MCF-7 sublines showed important differences in copy number alteration (CNA) profiles. Overall numbers of events ranged from 28 to 41. Involved chromosomal regions varied greatly from a subline to another. A total of 62 chromosomal regions were affected by either gains or losses in the 11 sublines studied. We performed a phylogenetic analysis of CGH profiles using maximum parsimony in order to reconstruct the putative filiation of the 11 MCF-7 sublines. The phylogenetic tree obtained showed that the MCF-7 clade was characterized by a restricted set of 8 CNAs and that the most divergent subline occupied the position closest to the common ancestor. Expression profiles of 8 MCF-7 sublines were analyzed along with those of 19 unrelated breast cancer cell lines using home made cDNA arrays comprising 720 genes. Hierarchical clustering analysis of the expression data showed that 7/8 MCF-7 sublines were grouped forming a cluster while the remaining subline clustered with unrelated breast cancer cell lines. These data thus showed that MCF-7 sublines differed at both the genomic and phenotypic levels. The analysis of CGH profiles of the parent subline and its three subclones supported the heteroclonal nature of MCF-7 cells. This strongly suggested that the genetic plasticity of MCF-7 cells was related to their intrinsic capacity to generate clonal heterogeneity. We propose that MCF-7, and possibly the breast tumor it was derived from, evolved

Genetic variability and population structure of Plasmodium falciparum parasite populations from different malaria ecological regions of Kenya.

Science.gov (United States)

Ingasia, Luicer A; Cheruiyot, Jelagat; Okoth, Sheila Akinyi; Andagalu, Ben; Kamau, Edwin

2016-04-01

Transmission intensity, movement of human and vector hosts, biogeographical features, and malaria control measures are some of the important factors that determine Plasmodium falciparum parasite genetic variability and population structure. Kenya has different malaria ecologies which might require different disease intervention methods. Refined parasite population genetic studies are critical for informing malaria control and elimination strategies. This study describes the genetic diversity and population structure of P. falciparum parasites from the different malaria ecological zones in Kenya. Twelve multi-locus microsatellite (MS) loci previously described were genotyped in 225 P. falciparum isolates collected between 2012 and 2013 from five sites; three in lowland endemic regions (Kisumu, Kombewa, and Malindi) and two in highland, epidemic regions (Kisii and Kericho). Parasites from the lowland endemic and highland epidemic regions of western Kenya had high genetic diversity compared to coastal lowland endemic region of Kenya [Malindi]. The Kenyan parasites had a mean genetic differentiation index (FST) of 0.072 (p=0.011). The multi-locus genetic analysis of the 12 MS revealed all the parasites had unique haplotypes. Significant linkage disequilibrium (LD) was observed in all the five parasite populations. Kisumu had the most significant index of association values (0.16; pKenya after introduction of the artemether-lumefantrine is important in refining the spread of drug resistant strains and malaria transmission for more effective control and eventual elimination of malaria in Kenya. Copyright © 2015. Published by Elsevier B.V.

Genetic variability in Sambucus nigra L. clones : a preliminary ...

Indian Academy of Sciences (India)

c Indian Academy of Sciences. ONLINE ... yield and production evaluations revealed that clones from ..... Population genetic software for teaching and research. Mol. Ecol. ... and genetic evaluation of interspecific hybrids within the genus.

Assessment of genetic variability in Trigonella foenum-graecum L. germplasm by SDS-page analysis

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Qadir Abdul

2017-01-01

Full Text Available The 96 genotypes of Trigonella foenum-graecum L. (Fenugreek were estimated by using Sodium Dodecyl Sulphate Poly Acrylamide Gel Electrophoresis (SDS-PAGE. The accessions were maintained from diverse ecological areas of the world. Total seed storage proteins were electrophoresis on 12.5% polyacrylamide gels. A total of 17 protein bands were detected, of which seven were highly polymorphic and six were moderate polymorphic and four were low polymorphic with molecular weight extending from of ~15 to ~180 kDa. The dendrogram based on similarity matrix using Unweighted Pair Group Method with Arithmetic Mean (UPGMA divided all the genotypes into four major clusters i.e., I, II, III and IV comprising 51, 24, 10 and 11 accessions, respectively. Although limited genetic diversity was detected amongst known germplasm but the presence/absence of polymorphic bands revealed a significant variances among different Trigonella genotypes. The differences exposed in this project work should be oppressed for the future breeding prospective of Trigonella genotypes by using other advanced molecular techniques. The SDS-PAGE per se seems inadequate tool for such kind of analysis, and may be integrated with other genetic and sequence based approaches for more precise estimation of the genetic variability within closely related accessions. Our results provide baseline for obtaining locally adapted and improved cultivars of fenugreek in Pakistan.

Genetic variability and health of Norway spruce stands in the Regional Directorate of the State Forests in Krosno

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Gutkowska Justyna

2017-03-01

Full Text Available The study was conducted in 2015 in six spruce stands situated in different forest districts administratively belonging to the Regional Directorate of State Forests in Krosno. Each spruce population was represented by 30 trees and assessed in terms of their current health status. Genetic analyses were performed on shoot samples from each tree using nine nuclear DNA markers and one mitochondrial DNA marker (nad1. The health status of the trees was described according to the classification developed by Szczepkowski and Tarasiuk (2005 and the correlation between health classes and the level of genetic variability was computed with STATISTICA (α = 0.05.

Genetic Variability of 27 Traits in a Core Collection of Flax (Linum usitatissimum L.).

Science.gov (United States)

You, Frank M; Jia, Gaofeng; Xiao, Jin; Duguid, Scott D; Rashid, Khalid Y; Booker, Helen M; Cloutier, Sylvie

2017-01-01

Assessment of genetic variability of plant core germplasm is needed for efficient germplasm utilization in breeding improvement. A total of 391 accessions of a flax core collection, which preserves the variation present in the world collection of 3,378 accessions maintained by Plant Gene Resources of Canada (PGRC) and represents a broad range of geographical origins, different improvement statuses and two morphotypes, was evaluated in field trials in up to 8 year-location environments for 10 agronomic, eight seed quality, six fiber and three disease resistance traits. The large phenotypic variation in this subset was explained by morphotypes (22%), geographical origins (11%), and other variance components (67%). Both divergence and similarity between two basic morphotypes, namely oil or linseed and fiber types, were observed, whereby linseed accessions had greater thousand seed weight, seeds m -2 , oil content, branching capability and resistance to powdery mildew while fiber accessions had greater straw weight, plant height, protein content and resistance to pasmo and fusarium wilt diseases, but they had similar performance in many traits and some of them shared common characteristics of fiber and linseed types. Weak geographical patterns within either fiber or linseed accessions were confirmed, but specific trait performance was identified in East Asia for fiber type, and South Asia and North America for linseed type. Relatively high broad-sense heritability was obtained for seed quality traits, followed by agronomic traits and resistance to powdery mildew and fusarium wilt. Diverse phenotypic and genetic variability in the flax core collection constitutes a useful resource for breeding.

Inter- and intra-population genetic variability of introduced silkworm (Bombyx mori L.) strains raised in Bulgaria

OpenAIRE

Teodora Staykova

2013-01-01

The genetic variability of four populations belonging to two introduced silkworm strains (Bombyx mori L.) of various origins has been studied using isoenzymic analysis of six enzyme systems. Nonspecific esterases, phosphoglucomutase, malate dehydrogenase, acid phosphatase, alkaline phosphatase and hexokinase from different tissue of larvae 5th instar have been analysed using PAGE. Polymorphism in six from a total of nine loci has been found. Inter- and intra-population differences have been a...

A Multi-Faceted Approach to Analyse the Effects of Environmental Variables on Geographic Range and Genetic Structure of a Perennial Psammophilous Geophyte: The Case of the Sea Daffodil Pancratium maritimum L. in the Mediterranean Basin.

Science.gov (United States)

De Castro, Olga; Di Maio, Antonietta; Di Febbraro, Mirko; Imparato, Gennaro; Innangi, Michele; Véla, Errol; Menale, Bruno

2016-01-01

The Mediterranean coastline is a dynamic and complex system which owes its complexity to its past and present vicissitudes, e.g. complex tectonic history, climatic fluctuations, and prolonged coexistence with human activities. A plant species that is widespread in this habitat is the sea daffodil, Pancratium maritimum (Amaryllidaceae), which is a perennial clonal geophyte of the coastal sands of the Mediterranean and neighbouring areas, well adapted to the stressful conditions of sand dune environments. In this study, an integrated approach was used, combining genetic and environmental data with a niche modelling approach, aimed to investigate: (1) the effect of climate change on the geographic range of this species at different times {past (last inter-glacial, LIG; and last glacial maximum, LGM), present (CURR), near-future (FUT)} and (2) the possible influence of environmental variables on the genetic structure of this species in the current period. The genetic results show that 48 sea daffodil populations (867 specimens) display a good genetic diversity in which the marginal populations (i.e. Atlantic Sea populations) present lower values. Recent genetic signature of bottleneck was detected in few populations (8%). The molecular variation was higher within the populations (77%) and two genetic pools were well represented. Comparing the different climatic simulations in time, the global range of this plant increased, and a further extension is foreseen in the near future thanks to projections on the climate of areas currently-more temperate, where our model suggested a forecast for a climate more similar to the Mediterranean coast. A significant positive correlation was observed between the genetic distance and Precipitation of Coldest Quarter variable in current periods. Our analyses support the hypothesis that geomorphology of the Mediterranean coasts, sea currents, and climate have played significant roles in shaping the current genetic structure of the sea

Higher resting heart rate variability predicts skill in expressing some emotions.

Science.gov (United States)

Tuck, Natalie L; Grant, Rosemary C I; Sollers, John J; Booth, Roger J; Consedine, Nathan S

2016-12-01

Vagally mediated heart rate variability (vmHRV) is a measure of cardiac vagal tone, and is widely viewed as a physiological index of the capacity to regulate emotions. However, studies have not directly tested whether vmHRV is associated with the ability to facially express emotions. In extending prior work, the current report tested links between resting vmHRV and the objectively assessed ability to facially express emotions, hypothesizing that higher vmHRV would predict greater expressive skill. Eighty healthy women completed self-reported measures, before attending a laboratory session in which vmHRV and the ability to express six emotions in the face were assessed. A repeated measures analysis of variance revealed a marginal main effect for vmHRV on skill overall; individuals with higher resting vmHRV were only better able to deliberately facially express anger and interest. Findings suggest that differences in resting vmHRV are associated with the objectively assessed ability to facially express some, but not all, emotions, with potential implications for health and well-being. © 2016 Society for Psychophysiological Research.

Tomato second cycle hybrids as a source of genetic variability for fruit quality traits

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Pereira da Costa JH

2016-11-01

Full Text Available The objective of this study was to investigate the phenotypic and molecular variability in a F2 generation derived from a SCH (Second Cycle Hybrid in order to detect QTLs for some fruit traits of tomato. Genome coverage at different levels was achieved by three types of molecular markers (polypeptides, sequence-related amplified polymorphism-SRAP and amplified restriction fragment polymorphism - AFLP. Different degrees of polymorphism were detected by SRAP and AFLP at the DNA structure level and also by polypeptides at the DNA expression level. The first two markers, associated with phenotypic variation, detected QTLs involved in important agronomic traits such as fruit shelf life, soluble solids content, pH, and titratable acidity. New gene blocks originated by recombination during the first cycle of crossing were detected. This study confirmed that the observed phenotypic differences represent a new gene rearrangement and that these new gene blocks are responsible for the presence of the genetic variability detected for these traits.

GENETIC VARIABILITY OF THREE POPULATIONS OF FLYING FISH, Hirundichthy oxycephalus FROM MAKASSAR STRAIT

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Andi Parenrengi

2016-03-01

Full Text Available Flying fish, Hirundichthy oxycephalus is one of economically important marine species to Indonesia, particularly in Makassar Strait and Flores Sea. However, there is a limited published data on genetic variation in molecular marker level of this species. Random Amplified Polymorphic DNA (RAPD was employed in this study to determine the genetic variability of three populations of flying fish collected from Takalar, Pare-Pare, and Majene in Makassar Strait. Genomic DNA was isolated from preserved muscle tissue using phenol-chloroform technique. Two selected arbitrary primers (CA-01 and P-40 were performed to generate RAPD finger printing of flying fish populations. The two primers generated a total of 81 fragments (loci and 50 polymorphic fragments with size ranging from 125 to 1,250 bp. There were no significant differences in number of fragment and number of polymorphic fragment among populations. The high polymorphism (63.5±7.4% was obtained from Takalar population followed by Pare-Pare (58.3±19.6% and Majene population (57.7±0.8%. Similarity index of individuals was 0.60±0.17 for Takalar, 0.63±0.17 for Majene and 0.75±0.21 for Pare-Pare population. Seven fragments were identified as species-specific markers of H. oxycephalus. The UPGMA cluster analysis showed that the Takalar population was genetically closer to Pare-Pare population (D= 0.0812 than to Majene population (D= 0.1873.

Distribution of the Most Common Genetic Variants Associated with a Variable Drug Response in the Population of the Republic of Macedonia

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Nestorovska Kapedanovska A.

2014-12-01

Full Text Available Genetic variation in the regulation, expression and activity of genes coding for Phase I, Phase II drug metabolizing enzymes (DMEs and drug targets, can be defining factors for the variability in both the effectiveness and occurrence of drug therapy side effects. Information regarding the geographic structure and multi-ethnic distribution of clinically relevant genetic variations is becoming increasingly useful for improving drug therapy and explaining inter-individual and inter-ethnic differences in drug response.

Integrated biochemical, molecular genetic, and bioacoustical analysis of mesoscale variability of the euphausiid Nematoscelis difficilis in the California Current

Science.gov (United States)

Bucklin, Ann; Wiebe, Peter H.; Smolenack, Sara B.; Copley, Nancy J.; Clarke, M. Elizabeth

2002-03-01

Integrated assessment of the euphausiid Nematoscelis difficilis (Crustacea; Euphausiacea) and the zooplankton assemblage of the California Current was designed to investigate individual, population, and community responses to mesoscale variability in biological and physical characters of the ocean. Zooplankton samples and observational data were collected along a cross-shelf transect of the California Current in association with the California Cooperative Fisheries Investigations (CalCOFI) Survey during October 1996. The transect crossed three domains defined by temperature and salinity: nearshore, mid-Current, and offshore. Individual N. difficilis differed in physiological condition along the transect, with higher size-corrected concentrations of four central metabolic enzymes (citrate synthetase, hexokinase, lactate dehydrogenase (LDH), and phosphoglucose isomerase (PGI)) for euphausiids collected in nearshore waters than in mid-Current and offshore waters. There was little variation in the DNA sequences of the genes encoding PGI and LDH (all DNA changes were either silent or heterozygous base substitutions), suggesting that differences in enzyme concentration did not result from underlying molecular genetic variation. The population genetic makeup of N. difficilis varied from sample to sample based on haplotype frequencies of mitochondrial cytochrome oxidase I (mtCOI; P=0.029). There were significant differences between pooled nearshore and offshore samples, based on allele frequencies at two sites of common substitutions in the mtCOI sequence ( P=0.020 and 0.026). Silhouette and bioacoustical backscattering measurements of the zooplankton assemblage of the top 100 m showed marked diel vertical migration of the scattering layer, of which euphausiids were a small but significant fraction. The biochemical and molecular assays are used as indices of complex physiological (i.e., growth and condition) and genetic (i.e., mortality) processes; the bioacoustical

Therapeutic Vaccine Against HIV, Viral Variability, Cytotoxic T Lymphocyte Epitopes, and Genetics of Patients.

Science.gov (United States)

Fleury, Herve; Tumiotto, Camille; Bellecave, Pantxika; Recordon-Pinson, Patricia

2018-01-01

The scientific and medical community is seeking to cure HIV. Several pathways have been or are being explored including therapeutic vaccination. Viroimmunological studies on primary infection as well as on elite controllers have demonstrated the importance of the cytotoxic CD8 response and have mainly oriented research on vaccine constructs toward this type of response. The results of these trials are clearly not commensurate with the hope placed in them. Might there be one or more uncontrolled variables? The genetics of patients need to be taken into consideration, especially their human lymphocyte antigen (HLA) alleles. There is a need to find a balance between the conservation of cytotoxic T lymphocyte (CTL) epitopes and presentation by HLA alleles. The pathway is a narrow one between adaptation of the virus to HLA I restriction and the definition of conserved proviral CTL epitopes presentable by HLA I alleles. It is likely that the genetics of patients will need to be considered for HIV-1 vaccine studies and that multidisciplinary collaboration will be essential in this field of infectious diseases.

Microsatellite DNA typing for assessment of genetic variability in ...

Indian Academy of Sciences (India)

these microsatellite loci in measurement of genetic diversity indices in other Indian cattle breeds too. Various .... enced a recent reduction in the effective population size or a genetic ... by using the m p val.exe program (Garza and Williamson.

Genetic diversity for fermentable carbohydrates production in alfalfa

Energy Technology Data Exchange (ETDEWEB)

Castonguay, Y.; Bertrand, A.; Duceppe, M.O.; Dube, M.P.; Michaud, R. [Agriculture and Agri-Food Canada, Quebec City, PQ (Canada)

2009-07-01

Alfalfa has many attributes that renders it suitable for bioethanol production, including its adaptability to diverse environmental conditions without any need for nitrogen fertilizer. However research is needed to develop biofuel-type alfalfa with improved biomass production and standability, increased persistence, and better cell wall degradability. The ethanol conversion rates from alfalfa biomass could be increased by genetically improving the accumulation of readily fermentable non-structural carbohydrates (NSC). This presentation reported on a screening project where genotypes with superior cell wall degradability were identified. NSC accumulation within 300 genotypes was randomly selected within six genetic backgrounds from Europe and North America. Biochemical analyses of dried stems revealed a large genetic variability for NSC content, with concentrations ranging from 20 to 100 mg per g DW. NSC variability was considerably higher in a genetic background of European origin compared to the other populations, therefore emphasizing the potential for genetic improvement for that trait. A modified commercial enzymatic cocktail known as AcceleraseTM 1000 Genencor is being developed to optimize the degradation of alfalfa biomass. DNA extracted from genotypes with the highest and lowest cell wall degradability or NSC accumulation will be pooled and used for bulk segregant analysis of DNA polymorphisms using the PCR-based sequence-related amplified polymorphism technique. It was concluded that the commercial release of biofuel-type alfalfa can be accelerated if the genetic markers associated with these traits can be identified.

INDUCED GENETIC VARIABILITY AND SELECTION FOR HIGH YIELDING MUTANTS IN BREAD WHEAT(TRITICUM AESTIVUM L.)

International Nuclear Information System (INIS)

SOBIEH, S.EL-S.S.

2007-01-01

This study was conducted during the two winter seasons of 2004/2005 and 2005/2006 at the experimental farm belonging to Plant Research Department, Nuclear Research Centre, AEA, Egypt.The aim of this study is to determine the effect of gamma rays(150, 200 and 250 Gy) on means of yield and its attributes for exotic wheat variety (vir-25) and induction of genetic variability that permits to perform visual selection through the irradiated populations, as well as to determine difference in seed protein patterns between vir-25 parent variety and some selectants in M2 generation.The results showed that the different doses of gamma rays had non-significant effect on mean value of yield/plant and significant effect on mean values of it's attributes. 0n the other hand, the considered genetic variability was generated as result of applying gamma irradiation. The highest amount of induced genetic variability was detected for number of grains/ spike, spike length and number of spikes/plant. Additionally, these three traits exhibited strong association with grain yield/plant, hence, they were used as a criterion for selection.Some variant plants were selected from radiation treatment 250 Gy, with 2-10 spikes per plant.These variant plants exhibited increasing in spike length and number of gains/spike.The results also revealed that protein electrophoresis were varied in the number and position of bands from genotype to another and various genotypes share bands with molecular weights 31.4 and 3.2 KD.Many bands were found to be specific for the genotype and the nine wheat mutants were characterized by the presence of bands of molecular weights: 151.9, 125.7, 14.1 and 5.7 KD at M-167.4, 21.7 and 8.2 at M-299.7 KD at M-3136.1, 97.6, 49.8, 27.9 and 20.6 KD at M-4 135.2, 95.3 and 28.1 KD at M-5 135.5, 67.7, 47.1, 32.3, 21.9 and 9.6 KD at M-6 126.1, 112.1, 103.3, 58.8, 20.9 and 12.1 KD at M-7 127.7, 116.6, 93.9, 55.0 and 47.4 KD at M-8 141.7, 96.1, 79.8, 68.9, 42.1, 32.7, 22.0 and 13

High mutation rates explain low population genetic divergence at copy-number-variable loci in Homo sapiens.

Science.gov (United States)

Hu, Xin-Sheng; Yeh, Francis C; Hu, Yang; Deng, Li-Ting; Ennos, Richard A; Chen, Xiaoyang

2017-02-22

Copy-number-variable (CNV) loci differ from single nucleotide polymorphic (SNP) sites in size, mutation rate, and mechanisms of maintenance in natural populations. It is therefore hypothesized that population genetic divergence at CNV loci will differ from that found at SNP sites. Here, we test this hypothesis by analysing 856 CNV loci from the genomes of 1184 healthy individuals from 11 HapMap populations with a wide range of ancestry. The results show that population genetic divergence at the CNV loci is generally more than three times lower than at genome-wide SNP sites. Populations generally exhibit very small genetic divergence (G st  = 0.05 ± 0.049). The smallest divergence is among African populations (G st  = 0.0081 ± 0.0025), with increased divergence among non-African populations (G st  = 0.0217 ± 0.0109) and then among African and non-African populations (G st  = 0.0324 ± 0.0064). Genetic diversity is high in African populations (~0.13), low in Asian populations (~0.11), and intermediate in the remaining 11 populations. Few significant linkage disequilibria (LDs) occur between the genome-wide CNV loci. Patterns of gametic and zygotic LDs indicate the absence of epistasis among CNV loci. Mutation rate is about twice as large as the migration rate in the non-African populations, suggesting that the high mutation rates play dominant roles in producing the low population genetic divergence at CNV loci.

Genetic variability in the population of the endemic bee Anthophora ...

African Journals Online (AJOL)

The genetic diversity and spatial genetic population structure of the solitary bee Anthophora pauperata Walker 1871, a species endemic to St Katherine Protectorate, were studied by RAPD markers in seven wadis in the St Katherine Protectorate, South Sinai, Egypt. High levels of genetic diversity were found, mostly within ...

Higher fine-scale genetic structure in peripheral than in core populations of a long-lived and mixed-mating conifer - eastern white cedar (Thuja occidentalis L.)

Science.gov (United States)

2012-01-01

Background Fine-scale or spatial genetic structure (SGS) is one of the key genetic characteristics of plant populations. Several evolutionary and ecological processes and population characteristics influence the level of SGS within plant populations. Higher fine-scale genetic structure may be expected in peripheral than core populations of long-lived forest trees, owing to the differences in the magnitude of operating evolutionary and ecological forces such as gene flow, genetic drift, effective population size and founder effects. We addressed this question using eastern white cedar (Thuja occidentalis) as a model species for declining to endangered long-lived tree species with mixed-mating system. Results We determined the SGS in two core and two peripheral populations of eastern white cedar from its Maritime Canadian eastern range using six nuclear microsatellite DNA markers. Significant SGS ranging from 15 m to 75 m distance classes was observed in the four studied populations. An analysis of combined four populations revealed significant positive SGS up to the 45 m distance class. The mean positive significant SGS observed in the peripheral populations was up to six times (up to 90 m) of that observed in the core populations (15 m). Spatial autocorrelation coefficients and correlograms of single and sub-sets of populations were statistically significant. The extent of within-population SGS was significantly negatively correlated with all genetic diversity parameters. Significant heterogeneity of within-population SGS was observed for 0-15 m and 61-90 m between core and peripheral populations. Average Sp, and gene flow distances were higher in peripheral (Sp = 0.023, σg = 135 m) than in core (Sp = 0.014, σg = 109 m) populations. However, the mean neighborhood size was higher in the core (Nb = 82) than in the peripheral (Nb = 48) populations. Conclusion Eastern white cedar populations have significant fine-scale genetic structure at short distances. Peripheral

Higher fine-scale genetic structure in peripheral than in core populations of a long-lived and mixed-mating conifer - eastern white cedar (Thuja occidentalis L.

Directory of Open Access Journals (Sweden)

Pandey Madhav

2012-04-01

Full Text Available Abstract Background Fine-scale or spatial genetic structure (SGS is one of the key genetic characteristics of plant populations. Several evolutionary and ecological processes and population characteristics influence the level of SGS within plant populations. Higher fine-scale genetic structure may be expected in peripheral than core populations of long-lived forest trees, owing to the differences in the magnitude of operating evolutionary and ecological forces such as gene flow, genetic drift, effective population size and founder effects. We addressed this question using eastern white cedar (Thuja occidentalis as a model species for declining to endangered long-lived tree species with mixed-mating system. Results We determined the SGS in two core and two peripheral populations of eastern white cedar from its Maritime Canadian eastern range using six nuclear microsatellite DNA markers. Significant SGS ranging from 15 m to 75 m distance classes was observed in the four studied populations. An analysis of combined four populations revealed significant positive SGS up to the 45 m distance class. The mean positive significant SGS observed in the peripheral populations was up to six times (up to 90 m of that observed in the core populations (15 m. Spatial autocorrelation coefficients and correlograms of single and sub-sets of populations were statistically significant. The extent of within-population SGS was significantly negatively correlated with all genetic diversity parameters. Significant heterogeneity of within-population SGS was observed for 0-15 m and 61-90 m between core and peripheral populations. Average Sp, and gene flow distances were higher in peripheral (Sp = 0.023, σg = 135 m than in core (Sp = 0.014, σg = 109 m populations. However, the mean neighborhood size was higher in the core (Nb = 82 than in the peripheral (Nb = 48 populations. Conclusion Eastern white cedar populations have significant fine-scale genetic structure at short

Evaluation of genetic variability in potato cv. 'Parda-Pastusa' obtained through the physical mutagenic agents

International Nuclear Information System (INIS)

Angarita-Zerda, A.; Mosquera, T.; Nustez, C.

1997-01-01

'Parda-Pastusa' is probably the most important variety of potato in Colombia. Its susceptibility to frost and Phytophthora infestans can cause important losses in the crop. In order to induce genetic variability to select clones resistant to frost and late blight, disease-free micropropagated plantlets, obtained from meristem culture of indexed tubers were irradiated with gamma rays from a 60 Co source. Virus-free mericlones were initially irradiated with 0,25, 50, 75 and 100 Gy or with 0, 10, 20 and 30 Gy. The optimal radiation dose was found to be 20 Gy. A mass propagation was carried out, and plantlets were irradiated with the optimal radiation dose. Clones derived from irradiated material were propagated for selection under simulated frost conditions (-7 deg. C for 360 minutes) and co-cultured with extracts of fungus, Phytophthora infestans. The selected clones will be transferred to field conditions for evaluation of agronomic and genetic characteristics. (author). 1 ref

Evaluation of genetic variability in potato cv. `Parda-Pastusa` obtained through the physical mutagenic agents

Energy Technology Data Exchange (ETDEWEB)

Angarita-Zerda, A; Mosquera, T; Nustez, C [Tissue Culture Lab., Agronomy School, National Univ. of Colombia, Santafe de Bogota (Colombia)

1997-07-01

`Parda-Pastusa` is probably the most important variety of potato in Colombia. Its susceptibility to frost and Phytophthora infestans can cause important losses in the crop. In order to induce genetic variability to select clones resistant to frost and late blight, disease-free micropropagated plantlets, obtained from meristem culture of indexed tubers were irradiated with gamma rays from a {sup 60}Co source. Virus-free mericlones were initially irradiated with 0,25, 50, 75 and 100 Gy or with 0, 10, 20 and 30 Gy. The optimal radiation dose was found to be 20 Gy. A mass propagation was carried out, and plantlets were irradiated with the optimal radiation dose. Clones derived from irradiated material were propagated for selection under simulated frost conditions (-7 deg. C for 360 minutes) and co-cultured with extracts of fungus, Phytophthora infestans. The selected clones will be transferred to field conditions for evaluation of agronomic and genetic characteristics. (author). 1 ref.

Prevalence and genetic variability of Plesiomonas shigelloides in temperate climate surface waters of the Pannonian Plain

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Petrušić Milivoje

2018-01-01

Full Text Available Plesiomonas shigelloides, a Gram-negative bacterium and the causative agent of intestinal diseases and extraintestinal infections in humans and animals, is most frequently found in aquatic environments in tropical or subtropical areas. The present study was designed to establish the prevalence and genetic variability of P. shigelloides in surface waters (lakes, rivers, ponds, inlets and canals located in a temperate climate zone, namely the Pannonian Plain of the northern part of Serbia and southern part of Hungary. The strains were isolated directly by plating samples on inositol-brilliant green-bile agar with neutral red or phenol red as indicators. Our results indicate that phenol red effectively facilitates differentiation of P. shigelloides from other bacteria. A number of samples were enriched using alkaline peptone water broth, peptone inositolbile broth and tetrathionate broth. The recovery of the isolates was more successful with the first medium. Out of a total of 51 water samples collected from 28 different locations, 22 samples (43.1% were found positive for P. shigelloides. Among the 37 isolated strains, 34 were from lakes (Šatrinci, Ludaš, Panonija, Krivaja, Pecs, Kapetanski rit, Pavlovci, Kovacsszenaja, Dobrodol, Vranjaš, Borkovac, Hermann Otto, Sot, Šelevrenac, Zobnatica, Palić, Orfui, Jarkovci, Čonoplja and 3 were from rivers (Danube, Sava. The strains were identified by phenotypic characteristic or by the VITEK2 system and confirmed by PCR using 23S rRNA species-specific oligos. The strains showed a high genetic variability, displaying a variety of RAPD profiles. Our results reveal for the first time a high prevalence of genetically diverse P. shigelloides populations in surface waters located in the temperate climate of central and southeastern Europe. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. OI 172058

Genetic diversity and structure of Brazilian ginger germplasm (Zingiber officinale) revealed by AFLP markers.

Science.gov (United States)

Blanco, Eleonora Zambrano; Bajay, Miklos Maximiliano; Siqueira, Marcos Vinícius Bohrer Monteiro; Zucchi, Maria Imaculada; Pinheiro, José Baldin

2016-12-01

Ginger is a vegetable with medicinal and culinary properties widely cultivated in the Southern and Southeastern Brazil. The knowledge of ginger species' genetic variability is essential to direct correctly future studies of conservation and genetic improvement, but in Brazil, little is known about this species' genetic variability. In this study, we analyzed the genetic diversity and structure of 55 Brazilian accessions and 6 Colombian accessions of ginger, using AFLP (Amplified Fragment Length Polymorphism) molecular markers. The molecular characterization was based on 13 primers combinations, which generated an average of 113.5 polymorphic loci. The genetic diversity estimates of Nei (Hj), Shannon-Weiner index (I) and an effective number of alleles (n e ) were greater in the Colombian accessions in relation to the Brazilian accessions. The analysis of molecular variance showed that most of the genetic variation occurred between the two countries while in the Brazilian populations there is no genetic structure and probably each region harbors 100 % of genetic variation found in the samples. The bayesian model-based clustering and the dendrogram using the dissimilarity's coefficient of Jaccard were congruent with each other and showed that the Brazilian accessions are highly similar between themselves, regardless of the geographic region of origin. We suggested that the exploration of the interspecific variability and the introduction of new varieties of Z.officinale are viable alternatives for generating diversity in breeding programs in Brazil. The introduction of new genetic materials will certainly contribute to a higher genetic basis of such crop.

Exploring the Role of Genetic Variability and Lifestyle in Oxidative Stress Response for Healthy Aging and Longevity

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Giuseppe Passarino

2013-08-01

Full Text Available Oxidative stress is both the cause and consequence of impaired functional homeostasis characterizing human aging. The worsening efficiency of stress response with age represents a health risk and leads to the onset and accrual of major age-related diseases. In contrast, centenarians seem to have evolved conservative stress response mechanisms, probably derived from a combination of a diet rich in natural antioxidants, an active lifestyle and a favorable genetic background, particularly rich in genetic variants able to counteract the stress overload at the level of both nuclear and mitochondrial DNA. The integration of these factors could allow centenarians to maintain moderate levels of free radicals that exert beneficial signaling and modulator effects on cellular metabolism. Considering the hot debate on the efficacy of antioxidant supplementation in promoting healthy aging, in this review we gathered the existing information regarding genetic variability and lifestyle factors which potentially modulate the stress response at old age. Evidence reported here suggests that the integration of lifestyle factors (moderate physical activity and healthy nutrition and genetic background could shift the balance in favor of the antioxidant cellular machinery by activating appropriate defense mechanisms in response to exceeding external and internal stress levels, and thus possibly achieving the prospect of living a longer life.

Genetic variability of South African fiscal shrikes ( Lanius collaris ...

African Journals Online (AJOL)

Rogers' (1972) mean genetic distance (D) was 0.094, and Nei's (1978) mean unbiased genetic distance was 0.019. A phenogram (unweighted pair group method) and a phylogenetic tree (distance Wagner network), both based on Rogers' (1972) distance, showed some degree of geographical subgrouping. The high ...

Divergence and genetic variability among superior rubber tree genotypes Divergência e variabilidade genética de genótipos superiores de seringueira

Directory of Open Access Journals (Sweden)

Lígia Regina Lima Gouvêa

2010-02-01

Full Text Available The objective of this work was to estimate the genetic variability and divergence among 22 superior rubber tree (Hevea sp. genotypes of the IAC 400 series. Univariate and multivariate analyses were performed using eight quantitative traits (descriptors, including yield. In the univariate analyses, the estimated parameters were: genetic and environmental variances; genetic and environmental coefficients of variation; and the variation index. The Mahalanobis generalized distance, the Tocher agglomerative method and canonical variables were used for the multivariate analyses. In the univariate analyses, variability was verified among the genotypes for all the variables evaluated. The Tocher method grouped the genotypes into 11 clusters of dissimilarity. The first four canonical variables explained 87.93% of the cumulative variation. The highest genetic variability was found in rubber yield-related traits, which contributed the most to the genetic divergence. The most divergent pairs of genotypes are suggested for crossbreeding. The genotypes evaluated are suitable for breeding and may be used to continue the IAC rubber tree breeding program.O objetivo deste trabalho foi estimar a divergência e a variabilidade genética entre 22 genótipos superiores de seringueira (Hevea sp. da série IAC 400. Análises univariadas e multivariadas foram realizadas com oito caracteres quantitativos (descritores, incluindo produtividade. Na análise univariada, os parâmetros estimados foram: variâncias genética e ambiental, coeficientes de variação genética e ambiental, e índice de variação. A distância generalizada de Mahalanobis, o método aglomerativo de Tocher e variáveis canônicas foram utilizados nas análises multivariadas. Nas análises univariadas, verificou-se variabilidade entre os genótipos para todas as variáveis avaliadas. O método de Tocher agrupou os genótipos em 11 grupos de dissimilaridade. As quatro primeiras variáveis can

Deriving estimates of individual variability in genetic potentials of performance traits for 3 dairy breeds, using a model of lifetime nutrient partitioning

DEFF Research Database (Denmark)

Phuong, H N; Martin, O; de Boer, I J M

2015-01-01

, body reserve usage, and growth for different genotypes of cow. Moreover, it can be used to separate genetic variability in performance between individual cows from environmental noise. The model enables simulation of the effects of a genetic selection strategy on lifetime efficiency of individual cows......, which has a main advantage of including the rearing costs, and thus, can be used to explore the impact of future selection on animal performance and efficiency....

Genetic Variability of Bovine Viral Diarrhea Virus and Evidence for a Possible Genetic Bottleneck during Vertical Transmission in Persistently Infected Cattle.

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Natalie Dow

Full Text Available Bovine viral diarrhea virus (BVDV, a Pestivirus in the family Flaviviridae, is an economically important pathogen of cattle worldwide. The primary propagators of the virus are immunotolerant persistently infected (PI cattle, which shed large quantities of virus throughout life. Despite the absence of an acquired immunity against BVDV in these PI cattle there are strong indications of viral variability that are of clinical and epidemiological importance. In this study the variability of E2 and NS5B sequences in multiple body compartments of PI cattle were characterized using clonal sequencing. Phylogenetic analyses revealed that BVDV exists as a quasispecies within PI cattle. Viral variants were clustered by tissue compartment significantly more often than expected by chance alone with the central nervous system appearing to be a particularly important viral reservoir. We also found strong indications for a genetic bottleneck during vertical transmission from PI animals to their offspring. These quasispecies analyses within PI cattle exemplify the role of the PI host in viral propagation and highlight the complex dynamics of BVDV pathogenesis, transmission and evolution.

Experimental Population Genetics in the Introductory Genetics Laboratory Using "Drosophila" as a Model Organism

Science.gov (United States)

Johnson, Ronald; Kennon, Tillman

2009-01-01

Hypotheses of population genetics are derived and tested by students in the introductory genetics laboratory classroom as they explore the effects of biotic variables (physical traits of fruit flies) and abiotic variables (island size and distance) on fruit fly populations. In addition to this hypothesis-driven experiment, the development of…

GSTM1, GSTP1, and GSTT1 genetic variability in Turkish and worldwide populations.

Science.gov (United States)

Karaca, Sefayet; Karaca, Mehmet; Cesuroglu, Tomris; Erge, Sema; Polimanti, Renato

2015-01-01

Glutathione S-transferase (GST) variants have been widely investigated to better understand their role in several pathologic conditions. To our knowledge, no data about these genetic polymorphisms within the Turkish population are currently available. The aim of this study was to analyze GSTM1 positive/null, GSTT1 positive/null, GSTP1*I105V (rs1695), and GSTP1*A114V (rs1138272) variants in the general Turkish population, to provide information about its genetic diversity, and predisposition to GST-related diseases. Genotyping was performed in 500 Turkish individuals using the Sequenom MassARRAY platform. A comparative analysis was executed using the data from the HapMap and Human Genome Diversity Projects (HGDP). Sequence variation was deeply explored using the Phase 1 data of the 1,000 Genomes Project. The variability of GSTM1, GSTT1, and GSTP1 polymorphisms in the Turkish population was similar to that observed in Central Asian, European, and Middle Eastern populations. The high linkage disequilibrium between GSTP1*I105V and GSTP1*A114V in these populations may have a confounding effect on GSTP1 genetic association studies. In analyzing GSTM1, GSTT1, and GSTP1 sequence variation, we observed other common functional variants that may be candidates for associated studies of diseases related to GST genes (e.g., cancer, cardiovascular disease, and allergy). This study provides novel data about GSTM1 positive/null, GSTT1 positive/null, GSTP1*I105V, and GSTP1*A114V variants in the Turkish population, and other functional variants that may affect GSTM1, GSTT1, and GSTP1 functions among worldwide populations. This information can assist in the design of future genetic association studies investigating oxidative stress-related diseases. © 2014 Wiley Periodicals, Inc.

Genetic variability and population structure in loci related to milk production traits in native Argentine Creole and commercial Argentine Holstein cattle

Directory of Open Access Journals (Sweden)

Golijow C.D.

1999-01-01

Full Text Available Many cattle breeds have been subjected to high selection pressure for production traits. Consequently, population genetic structure and allelic distribution could differ in breeds under high selection pressure compared to unselected breeds. Analysis of k-casein, aS1-casein and prolactin gene frequencies was made for Argentine Creole (AC and Argentine Holstein (AH cattle herds. The calculated FST values measured the degree of genetic differentiation of subpopulations, depending on the variances of gene frequencies.The AC breed had considerably more variation among herds at the aS1-casein and k-casein loci. Conservation strategies should consider the entire AC population in order to maintain the genetic variability found in this native breed.

Higher-dimensional black holes: hidden symmetries and separation of variables

International Nuclear Information System (INIS)

Frolov, Valeri P; Kubiznak, David

2008-01-01

In this paper, we discuss hidden symmetries in rotating black hole spacetimes. We start with an extended introduction which mainly summarizes results on hidden symmetries in four dimensions and introduces Killing and Killing-Yano tensors, objects responsible for hidden symmetries. We also demonstrate how starting with a principal CKY tensor (that is a closed non-degenerate conformal Killing-Yano 2-form) in 4D flat spacetime one can 'generate' the 4D Kerr-NUT-(A)dS solution and its hidden symmetries. After this we consider higher-dimensional Kerr-NUT-(A)dS metrics and demonstrate that they possess a principal CKY tensor which allows one to generate the whole tower of Killing-Yano and Killing tensors. These symmetries imply complete integrability of geodesic equations and complete separation of variables for the Hamilton-Jacobi, Klein-Gordon and Dirac equations in the general Kerr-NUT-(A)dS metrics

Genetic variability within french race and riding horse breeds from genealogical data and blood marker polymorphisms

OpenAIRE

Moureaux, Sophie; Verrier, Etienne; Ricard, Anne; Meriaux, J-Claude

1996-01-01

The genetic variability of five horse breeds raised in France was analysed: Thoroughbred, Trotteur Français, Arab, Anglo-Arab and Selle Français. Genealogical data and genotypes at seven blood group and nine protein loci were used. Paternal family sizes were found to be unbalanced, especially in Trotteur français, Selle Franqais and Thoroughbred. Average coefficients of inbreeding for offspring born from 1989 to 1992 were 1.02 (Thoroughbred), 1.86 (Trotteur Français), 3.08 (Arab), 1.17 (...

Habitat variability does not generally promote metabolic network modularity in flies and mammals.

Science.gov (United States)

Takemoto, Kazuhiro

2016-01-01

The evolution of species habitat range is an important topic over a wide range of research fields. In higher organisms, habitat range evolution is generally associated with genetic events such as gene duplication. However, the specific factors that determine habitat variability remain unclear at higher levels of biological organization (e.g., biochemical networks). One widely accepted hypothesis developed from both theoretical and empirical analyses is that habitat variability promotes network modularity; however, this relationship has not yet been directly tested in higher organisms. Therefore, I investigated the relationship between habitat variability and metabolic network modularity using compound and enzymatic networks in flies and mammals. Contrary to expectation, there was no clear positive correlation between habitat variability and network modularity. As an exception, the network modularity increased with habitat variability in the enzymatic networks of flies. However, the observed association was likely an artifact, and the frequency of gene duplication appears to be the main factor contributing to network modularity. These findings raise the question of whether or not there is a general mechanism for habitat range expansion at a higher level (i.e., above the gene scale). This study suggests that the currently widely accepted hypothesis for habitat variability should be reconsidered. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Genetic variability induction in the size of the size of rice plantules by combined irradiation and temperature treatments

International Nuclear Information System (INIS)

Garcia, D.; Gonzalez, L.M.; Gumberra, R.

1993-01-01

Induced variability in the size of rice plantules was determined using the heritability calculation in a narrow sense, by means of the progenitor-descendant regression. Progenitor stands for the original variety, whereas descendant stands for plant population from CO6 0 gamma-rays irradiated seeds (at 100-600 Gy doses), treated at different temperatures. Results obtained: show the possibility to increase efficiency in variability induction by a combined course of action of both factors. In this experience, the best combination turned out to be 300 Gy-0 celsius grated, which of all the changes that it caused, some 75 percent was of a genetic nature

Genetic variability of cultivated cowpea in Benin assessed by ...

African Journals Online (AJOL)

STORAGESEVER

2008-12-17

Dec 17, 2008 ... Res. Crop Evol. 48: 559-566. Mignouna HD, Ng NQ, Ikea J, Thottapilly G (1998). Genetic diversity in cowpea as revealed by random amplified polymorphic DNA. J. Gen. Breed. 52: 151-159. Nei M, Li WH (1979). Mathematical model for studying genetic variation in terms of restriction endonucleases. Proc.

The influence of gamma rays irradiation on chlorophyll mutation and genetic variability of agronomic characters in soybean plant

International Nuclear Information System (INIS)

Ratma, Rivaie; Sumargono, A.M. Riyanti

1998-01-01

Seeds of soybean mutant line No. 13/PsJ with 12% moisture content were irradiated by 0,10;0,20;0.30 and 0.40 kGy of gamma rays treatment. Number of irradiated seed for each treatment was 1500 seeds. Irradiated of seeds were planted in the 4m X 5m plot size with 0,20m x 0,40m spacing and two seed each hole and were planted as M-1 plants in the wet season of 1996/1997 at PAIR field experiment in Pasar Jumat, Jakarta. The experiment was designed Randomized Block Design with three replication Plans of M-1 generation were harvested individuality and were planted as known M2 plants in the next generation in dry season of 1997 at PAIR field experiment. Seven days planting the chlorophyll mutation of plants were recorded by Frydenberg method and the genetic variability of plant height, number of fertile pods and nodes were calculated by Singh and Chaudhary formula. Results of the experiment showed that chlorophyll mutation and genetic variability of plant height and number of fertile pods could be improved be 0.10 and 0,20 kGy of gamma rays treatment. (authors)

Environmental interaction, additive and non-additive genetic variability is involved in the expression of tissue and whole-plant heat tolerance in upland cotton (Gossypium hirsutum. L

Directory of Open Access Journals (Sweden)

Hafeez-ur-Rahman

2006-01-01

Full Text Available Heat tolerance is measured at tissue level by cellular membrane thermostability (CMT and at the whole plant level by the heat tolerance index (HTI. Eight upland cotton cultivars and 15 crosses were used to determine the type and extent of genetic variability associated with the expression of these traits between and within environments. Heat stress and non-stress conditions were used as the CMT environments and years for HTI. The wide variation in heterotic expression and combining ability effects observed for CMT and HTI suggest multigenic inheritance of these traits. Significant genetic variability across environments was evident but the traits were not highly heritable because of substantial environmental interaction. The available genetic variability included both additive and non-additive components, but the proportion of additive genetic variability was high for HTI. The parental cultivars CRIS-19 and CIM-448 were good donor parents for high CMT under heat-stressed conditions, and MNH-552 and N-Karishma under non-stressed conditions. Cultivar FH-634 was a good donor parent for HTI. The results show two types of general combining ability (GCA inheritance among high CMT parents: positive GCA inheritance expressed by CRIS-19 in the presence of heat stress and MNH-552 and N-Karishma in the absence of heat stress; and negative GCA inheritance expressed by FH-900 in the presence of heat stress. It was also evident that genes controlling high CMT in cultivar CRIS-19 were different from those present in the MNH-552, N-Karishma and FH-900 cultivars. Similarly, among high HTI parents, FH-634 showed positive and CIM-443 negative GCA inheritance. No significant relationship due to genetic causes existed between tissue and whole plant heat tolerance, diminishing the likelihood of simultaneous improvement and selection of the two traits.

use of genetic variability estimates and interrelationships

African Journals Online (AJOL)

Prof. Adipala Ekwamu

of 11 agronomic and biochemical traits to water stress based on estimation of genetic ... of primary branches and 100 seed weight under W0, and number of primary ... selection of superior drought-tolerant genotype (LR1) with good yield ...

Antigenic and genetic variability of human metapneumoviruses

NARCIS (Netherlands)

S. Herfst (Sander); L. Sprong; P.A. Cane; E. Forleo-Neto; A.D.M.E. Osterhaus (Albert); R.A.M. Fouchier (Ron); R.L. de Swart (Rik); B.G. van den Hoogen (Bernadette)

2004-01-01

textabstractHuman metapneumovirus (HMPV) is a member of the subfamily Pneumovirinae within the family Paramyxo- viridae. Other members of this subfamily, respiratory syncytial virus and avian pneumovirus, can be divided into subgroups on the basis of genetic or antigenic differences or both. For

Brucella Genetic Variability in Wildlife Marine Mammals Populations Relates to Host Preference and Ocean Distribution.

Science.gov (United States)

Suárez-Esquivel, Marcela; Baker, Kate S; Ruiz-Villalobos, Nazareth; Hernández-Mora, Gabriela; Barquero-Calvo, Elías; González-Barrientos, Rocío; Castillo-Zeledón, Amanda; Jiménez-Rojas, César; Chacón-Díaz, Carlos; Cloeckaert, Axel; Chaves-Olarte, Esteban; Thomson, Nicholas R; Moreno, Edgardo; Guzmán-Verri, Caterina

2017-07-01

Intracellular bacterial pathogens probably arose when their ancestor adapted from a free-living environment to an intracellular one, leading to clonal bacteria with smaller genomes and less sources of genetic plasticity. Still, this plasticity is needed to respond to the challenges posed by the host. Members of the Brucella genus are facultative-extracellular intracellular bacteria responsible for causing brucellosis in a variety of mammals. The various species keep different host preferences, virulence, and zoonotic potential despite having 97-99% similarity at genome level. Here, we describe elements of genetic variation in Brucella ceti isolated from wildlife dolphins inhabiting the Pacific Ocean and the Mediterranean Sea. Comparison with isolates obtained from marine mammals from the Atlantic Ocean and the broader Brucella genus showed distinctive traits according to oceanic distribution and preferred host. Marine mammal isolates display genetic variability, represented by an important number of IS711 elements as well as specific IS711 and SNPs genomic distribution clustering patterns. Extensive pseudogenization was found among isolates from marine mammals as compared with terrestrial ones, causing degradation in pathways related to energy, transport of metabolites, and regulation/transcription. Brucella ceti isolates infecting particularly dolphin hosts, showed further degradation of metabolite transport pathways as well as pathways related to cell wall/membrane/envelope biogenesis and motility. Thus, gene loss through pseudogenization is a source of genetic variation in Brucella, which in turn, relates to adaptation to different hosts. This is relevant to understand the natural history of bacterial diseases, their zoonotic potential, and the impact of human interventions such as domestication. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

GENETIC VARIABILITY OF POLYMESODA EROSA POPULATION IN THE SEGARA ANAKAN CILACAP

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AGUS NURYANTO

2010-01-01

Full Text Available Mud clams, Polymesoda erosa, in the Segara Anakan Cilacap are highly exploited by the local communities for daily consumption. This is presumed causing population decline and potentially causing loss of genetic diversity. Genetic diversity level within population can be obtained by population genetic study using molecular marker such as randomly amplified polymorphic DNA (RAPD. Here we amplified RAPD marker using ten arbitrary primers to assess genetic diversity of P. erosa population in the Segara Anakan Cilacap to provide genetic data for its sustainable use. The results proved that the use of RAPD marker has high polymorphisms. The mud clam population also showed a high level of heterozygosity and genetic diversity. This has important implication for the management plan towards sustainable use of P. erosa in the Segara Anakan Cilacap.

Genetic variability of the length of postpartum anoestrus in Charolais cows and its relationship with age at puberty

Directory of Open Access Journals (Sweden)

Ménissier François

2000-07-01

Full Text Available Abstract Fertility records (n = 1 802 were collected from 615 Charolais primiparous and multiparous cows managed in an experimental herd over an 11-year period. The objectives of the study were to describe the genetic variability of the re-establishment of postpartum reproductive activity and the relationship with body weight (BW and body condition score (BCS at calving and age at puberty. The length of postpartum anoestrus was estimated based on weekly blood progesterone assays and on twice daily detection of oestrus behaviour. The first oestrus behaviour was observed 69 days (± 25 days s.d. post-calving and the first positive progesterone measurement (≥ 1 ng mL-1 was observed at 66 days (± 22 days s.d. for the group of easy-calving multiparous suckling cows. Estimates of heritability and repeatability were h2 = 0.12 and r = 0.38 respectively, for the interval from calving to first oestrus (ICO. Corresponding values were h2 = 0.35 and r = 0.60 for the interval from calving to the first positive progesterone test (ICP. The genetic correlation between both criteria was high (rg = 0.98. The genetic relationships between postpartum intervals and BW and BCS of the female at calving were negative: the genetic aptitude to be heavier at calving and to have high body reserves was related to shorter postpartum intervals. A favourable genetic correlation between age at puberty and postpartum intervals was found (rg between 0.45 and 0.70. The heifers which were genetically younger at puberty also had shorter postpartum intervals.

Could refuge theory and rivers acting as barriers explain the genetic variability distribution in the Atlantic Forest?

Science.gov (United States)

Cazé, Ana Luiza R; Mäder, Geraldo; Nunes, Teonildes S; Queiroz, Luciano P; de Oliveira, Guilherme; Diniz-Filho, José Alexandre F; Bonatto, Sandro L; Freitas, Loreta B

2016-08-01

The Atlantic Forest is one of the most species-rich ecoregions in the world. The historical origins of this richness and the evolutionary processes that produced diversification and promoted speciation in this ecosystem remain poorly understood. In this context, focusing on Passiflora contracta, an endemic species from the Atlantic Forest distributed exclusively at sea level along forest edges, this study aimed to characterize the patterns of genetic variability and explore two hypotheses that attempt to explain the possible causes of the genetic diversity in this region: the refuge and riverine barrier theories. We employed Bayesian methods combined with niche modeling to identify genetically homogeneous groups, to determine the diversification age, and identify long-term climate stability areas to species survival. The analyses were performed using molecular markers from nuclear and plastid genomes, with samples collected throughout the entire geographic distribution of the species, and comparisons with congeners species. The results indicated that populations were genetically structured and provided evidence of demographic stability. The molecular markers indicated the existence of a clear structure and the presence of five homogeneous groups. Interestingly, the separation of the groups coincides with the geographical locations of local rivers, corroborating the hypothesis of rivers acting as barriers to gene flow in this species. The highest levels of genetic diversity and the areas identified as having long-term climate stability were found in the same region reported for other species as a possible refuge area during the climatic changes of the Quaternary. Copyright © 2016 Elsevier Inc. All rights reserved.

NOTE - Genetic variability among cassava accessions based on SSR markers

Directory of Open Access Journals (Sweden)

Márcia de Nazaré Oliveira Ribeiro

2011-01-01

Full Text Available The aim of this study was to characterize and estimate the genetic similarity among 93 cassava accessions. The DNAamplification was performed with 14 microsatellite primers. The amplification products were separated by a polyacrylamide gelelectrophoresis, showing a polymorphism formation, through which the accessions were discriminated against. The genetic similarityamong accessions of cassava was estimated by the Dice coefficient. Cluster analysis was carried out using the UPGMA method. Thepolymorphic primers amplified a total of 26 alleles with 2-4 alleles per loci. The genetic similarity ranged from 0.16 to 0.96. Theaverage values for observed and expected heterozygosity were 0.18 and 0.46, respectively. Twenty genetic similarity clusters weredetermined, demonstrating diversity among accessions, suggesting the possibility of heterotic hybrid generation.

Genetic variability of Herpailurus yagouaroundi, Puma concolor and Panthera onca (Mammalia, Felidae studied using Felis catus microsatellites

Directory of Open Access Journals (Sweden)

Vanessa Roma Moreno

2006-01-01

Full Text Available We used four microsatellite loci (Fca08, Fca45, Fca77 and Fca96 from the domestic cat, Felis catus, to investigate genetic variability in specimens of Herpailurus yagouaroundi (jaguarundi, otter cat, eyra, Puma concolor (cougar, mountain lion, puma and Panthera onca (jaguar held in various Brazilian zoos. Samples of DNA from the cats were PCR amplified and then sequenced before being analyzed using the CERVUS program. Our results show a mean polymorphic information content (PIC of 0.83 for H. yagouaroundi, 0.66 for P. concolor and 0.69 for P. onca and a mean of 10.3 alleles for the Fca08 locus, 5.3 for Fca 45, 9 for Fca 77 and 14 for Fca 96. These results indicate a relatively high level of genetic diversity for the specimens studied.

Studies of genetic variability of the glucose transporter 2 promoter in patients with type 2 diabetes mellitus

DEFF Research Database (Denmark)

Møller, A M; Jensen, N M; Pildal, J

2001-01-01

This study was performed to test the hypothesis that genetic variation in the promoter of the glucose transporter 2 (GLUT2) might predispose to prediabetic phenotypes or type 2 diabetes. A total of 1611 bp comprising the minimal promoter region of the GLUT2 gene were examined by combined single......-tolerant subjects. In conclusion, we found no evidence supporting the hypothesis that genetic variability in the minimal promoter of the GLUT2 is associated with type 2 diabetes or prediabetic phenotypes in the Danish population.......-strand conformational polymorphism and heteroduplex analysis followed by direct sequencing of identified variants on genomic DNA from 96 randomly recruited Danish type 2 diabetic patients. We identified 4 nucleotide variants, -447g-->a, -149c-->a, -122t-->c, and -44g-->a. None of the variants were positioned in known...

Reproductive strategies and genetic variability in tropical freshwater fish

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Maria Dolores Peres Lassala

2007-01-01

Full Text Available We estimated the genetic variability of nine fish species from the Brazilian upper Paraná River floodplain (Astyanax altiparanae, Hoplias malabaricus, Leporinus lacustris, Loricariichthys platymetopon, Parauchenipterus galeatus, Pimelodus maculatus, Rhaphiodon vulpinus, Roeboides paranensis and Serrasalmus marginatus based on data for 36 putative allozyme loci obtained using corn starch gel electrophoresis of 13 enzymatic systems: aspartate aminotransferase (EC 2.6.1.1, acid phosphatase (EC 3.1.3.2, esterase (EC 3.1.1.1, glycerol-3-phosphate dehydrogenase (EC 1.1.1.8, glucose-6-phosphate dehydrogenase (EC 1.1.1.49, glucose-6-phosphate isomerase (EC 5.3.1.9, Iditol dehydrogenase (EC 1.1.1.14, isocitrate dehydrogenase - NADP+ (EC 1.1.1.42, L-lactate dehydrogenase (EC 1.1.1.27, malate dehydrogenase (EC 1.1.1.37, malate dehydrogenase-NADP+ (EC 1.1.1.40, phosphoglucomutase (EC 5.4.2.2 and superoxide dismutase, (EC 1.15.1.1. The mean expected heterozygosity varied from zero to 0.147. When data from the literature for 75 species of tropical fish were added to the nine species of this study, the heterozygosity values differed significantly among the groups of different reproductive strategies. The highest mean heterozygosity was for the non-migratory without parental care, followed by the long-distance migratory, and the lowest mean was for the non-migratory with parental care or internal fecundation.

The estimation of genetic distance and discriminant variables on breed of duck (Alabio, Bali, Khaki Campbell, Mojosari and Pegagan by morphological analysis

Directory of Open Access Journals (Sweden)

B Brahmantiyo

2003-03-01

Full Text Available A study on morphological body conformation of Alabio, Bali, Khaki Campbell, Mojosari and Pegagan ducks was carried out to determine the genetic distance and discriminant variables. This research was held in Research Institute for Animal Production, Ciawi, Bogor using 65 Alabio ducks, 40 Bali ducks, 36 Khaki Campbell ducks, 60 Mojosari ducks and 30 Pegagan ducks. Seven different body parts were measured, they were the length of femur, tibia, tarsometatarsus, the circumference of tarsometatarsus, the length of third digits, wing and maxilla. General Linear Models and simple discriminant analysis were used in this observation (SAS package program. Male and female Pegagan ducks had morphological size bigger than Alabio, Bali, Khaki Campbell and Mojosari ducks. Khaki Campbell ducks were mixed with Bali ducks (47.22% and Pegagan ducks from isolated location in South Sumatera were lightly mixed with Alabio and Bali. Mahalanobis genetic distance showed that Bali and Khaki Campbell ducks, also, Alabio and Mojosari ducks had similarity, with genetic distance of 1.420 and 1.548, respectively. Results from canonical analysis showed that the most discriminant variables were obtained from the length of femur, tibia and third digits.

A Multi-Faceted Approach to Analyse the Effects of Environmental Variables on Geographic Range and Genetic Structure of a Perennial Psammophilous Geophyte: The Case of the Sea Daffodil Pancratium maritimum L. in the Mediterranean Basin.

Directory of Open Access Journals (Sweden)

Olga De Castro

Full Text Available The Mediterranean coastline is a dynamic and complex system which owes its complexity to its past and present vicissitudes, e.g. complex tectonic history, climatic fluctuations, and prolonged coexistence with human activities. A plant species that is widespread in this habitat is the sea daffodil, Pancratium maritimum (Amaryllidaceae, which is a perennial clonal geophyte of the coastal sands of the Mediterranean and neighbouring areas, well adapted to the stressful conditions of sand dune environments. In this study, an integrated approach was used, combining genetic and environmental data with a niche modelling approach, aimed to investigate: (1 the effect of climate change on the geographic range of this species at different times {past (last inter-glacial, LIG; and last glacial maximum, LGM, present (CURR, near-future (FUT} and (2 the possible influence of environmental variables on the genetic structure of this species in the current period. The genetic results show that 48 sea daffodil populations (867 specimens display a good genetic diversity in which the marginal populations (i.e. Atlantic Sea populations present lower values. Recent genetic signature of bottleneck was detected in few populations (8%. The molecular variation was higher within the populations (77% and two genetic pools were well represented. Comparing the different climatic simulations in time, the global range of this plant increased, and a further extension is foreseen in the near future thanks to projections on the climate of areas currently-more temperate, where our model suggested a forecast for a climate more similar to the Mediterranean coast. A significant positive correlation was observed between the genetic distance and Precipitation of Coldest Quarter variable in current periods. Our analyses support the hypothesis that geomorphology of the Mediterranean coasts, sea currents, and climate have played significant roles in shaping the current genetic structure of

GENETIC, PATHOGENIC AND TOXIGENIC VARIABILITY OF F

African Journals Online (AJOL)

Vesna Krnjaja

2012-03-08

Mar 8, 2012 ... The same authors concluded that natural populations of F. proliferatum in Iran were probably genetically divergent and included isolates representing a potential risk for disease development. Elmer (1991) and Elmer et al. (1999) collected 110 and. 77 isolates of F. proliferatum from asparagus originating.

Genetic variability in environmental isolates of Legionella pneumophila from Comunidad Valenciana (Spain).

Science.gov (United States)

Coscollá, Mireia; Gosalbes, María José; Catalán, Vicente; González-Candelas, Fernando

2006-06-01

Legionella pneumophila is associated to recurrent outbreaks in several Comunidad Valenciana (Spain) localities, especially in Alcoi, where social and climatic conditions seem to provide an excellent environment for bacterial growth. We have analysed the nucleotide sequences of three loci from 25 environmental isolates from Alcoi and nearby locations sampled over 3 years. The analysis of these isolates has revealed a substantial level of genetic variation, with consistent patterns of variability across loci, and comparable to that found in a large, European-wide sampling of clinical isolates. Among the tree loci studied, fliC showed the highest level of nucleotide diversity. The analysis of isolates sampled in different years revealed a clear differentiation, with samples from 2001 being significantly distinct from those obtained in 2002 and 2003. Furthermore, although linkage disequilibrium measures indicate a clonal nature for population structure in this sample, the presence of some recombination events cannot be ruled out.

Genetic variability of Echinococcus granulosus complex in various geographical populations of Iran inferred by mitochondrial DNA sequences.

Science.gov (United States)

Spotin, Adel; Mahami-Oskouei, Mahmoud; Harandi, Majid Fasihi; Baratchian, Mehdi; Bordbar, Ali; Ahmadpour, Ehsan; Ebrahimi, Sahar

2017-01-01

To investigate the genetic variability and population structure of Echinococcus granulosus complex, 79 isolates were sequenced from different host species covering human, dog, camel, goat, sheep and cattle as of various geographical sub-populations of Iran (Northwestern, Northern, and Southeastern). In addition, 36 sequences of other geographical populations (Western, Southeastern and Central Iran), were directly retrieved from GenBank database for the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene. The confirmed isolates were grouped as G1 genotype (n=92), G6 genotype (n=14), G3 genotype (n=8) and G2 genotype (n=1). 50 unique haplotypes were identified based on the analyzed sequences of cox1. A parsimonious network of the sequence haplotypes displayed star-like features in the overall population containing IR23 (22: 19.1%) as the most common haplotype. According to the analysis of molecular variance (AMOVA) test, the high value of haplotype diversity of E. granulosus complex was shown the total genetic variability within populations while nucleotide diversity was low in all populations. Neutrality indices of the cox1 (Tajima's D and Fu's Fs tests) were shown negative values in Western-Northwestern, Northern and Southeastern populations which indicating significant divergence from neutrality and positive but not significant in Central isolates. A pairwise fixation index (Fst) as a degree of gene flow was generally low value for all populations (0.00647-0.15198). The statistically Fst values indicate that Echinococcus sensu stricto (genotype G1-G3) populations are not genetically well differentiated in various geographical regions of Iran. To appraise the hypothetical evolutionary scenario, further study is needed to analyze concatenated mitogenomes and as well a panel of single locus nuclear markers should be considered in wider areas of Iran and neighboring countries. Copyright © 2016 Elsevier B.V. All rights reserved.

Higher-dimensional cosmological model with variable gravitational ...

Indian Academy of Sciences (India)

variable G and bulk viscosity in Lyra geometry. Exact solutions for ... a comparative study of Robertson–Walker models with a constant deceleration .... where H is defined as H =(˙A/A)+(1/3)( ˙B/B) and β0,H0 are representing present values of β ...

Higher-dimensional cosmological model with variable gravitational ...

Indian Academy of Sciences (India)

We have studied five-dimensional homogeneous cosmological models with variable and bulk viscosity in Lyra geometry. Exact solutions for the field equations have been obtained and physical properties of the models are discussed. It has been observed that the results of new models are well within the observational ...

Genetic variability in the human cannabinoid receptor 1 is associated with resting state EEG theta power in humans.

Science.gov (United States)

Heitland, I; Kenemans, J L; Böcker, K B E; Baas, J M P

2014-11-01

It has long been postulated that exogenous cannabinoids have a profound effect on human cognitive functioning. These cannabinoid effects are thought to depend, at least in parts, on alterations of phase-locking of local field potential neuronal firing. The latter can be measured as activity in the theta frequency band (4-7Hz) by electroencephalogram. Theta oscillations are supposed to serve as a mechanism in neural representations of behaviorally relevant information. However, it remains unknown whether variability in endogenous cannabinoid activity is involved in theta rhythms and therefore, may serve as an individual differences index of human cognitive functioning. To clarify this issue, we recorded resting state EEG activity in 164 healthy human subjects and extracted EEG power across frequency bands (δ, θ, α, and β). To assess variability in the endocannabinoid system, two genetic polymorphisms (rs1049353, rs2180619) within the cannabinoid receptor 1 (CB1) were determined in all participants. As expected, we observed significant effects of rs1049353 on EEG power in the theta band at frontal, central and parietal electrode regions. Crucially, these effects were specific for the theta band, with no effects on activity in the other frequency bands. Rs2180619 showed no significant associations with theta power after Bonferroni correction. Taken together, we provide novel evidence in humans showing that genetic variability in the cannabinoid receptor 1 is associated with resting state EEG power in the theta frequency band. This extends prior findings of exogenous cannabinoid effects on theta power to the endogenous cannabinoid system. Copyright © 2014 Elsevier B.V. All rights reserved.

Discordant patterns of genetic and phenotypic differentiation in five grasshopper species codistributed across a microreserve network.

Science.gov (United States)

Ortego, Joaquín; García-Navas, Vicente; Noguerales, Víctor; Cordero, Pedro J

2015-12-01

Conservation plans can be greatly improved when information on the evolutionary and demographic consequences of habitat fragmentation is available for several codistributed species. Here, we study spatial patterns of phenotypic and genetic variation among five grasshopper species that are codistributed across a network of microreserves but show remarkable differences in dispersal-related morphology (body size and wing length), degree of habitat specialization and extent of fragmentation of their respective habitats in the study region. In particular, we tested the hypothesis that species with preferences for highly fragmented microhabitats show stronger genetic and phenotypic structure than codistributed generalist taxa inhabiting a continuous matrix of suitable habitat. We also hypothesized a higher resemblance of spatial patterns of genetic and phenotypic variability among species that have experienced a higher degree of habitat fragmentation due to their more similar responses to the parallel large-scale destruction of their natural habitats. In partial agreement with our first hypothesis, we found that genetic structure, but not phenotypic differentiation, was higher in species linked to highly fragmented habitats. We did not find support for congruent patterns of phenotypic and genetic variability among any studied species, indicating that they show idiosyncratic evolutionary trajectories and distinctive demographic responses to habitat fragmentation across a common landscape. This suggests that conservation practices in networks of protected areas require detailed ecological and evolutionary information on target species to focus management efforts on those taxa that are more sensitive to the effects of habitat fragmentation. © 2015 John Wiley & Sons Ltd.

EPSPS variability, gene expression, and enzymatic activity in glyphosate-resistant biotypes of Digitaria insularis.

Science.gov (United States)

Galeano, E; Barroso, A A M; Vasconcelos, T S; López-Rubio, A; Albrecht, A J P; Victoria Filho, R; Carrer, H

2016-08-12

Weed resistance to herbicides is a natural phenomenon that exerts selection on individuals in a population. In Brazil, glyphosate resistance was recently detected in Digitaria insularis. The objective of this study was to elucidate mechanisms of weed resistance in this plant, including genetic variability, allelism, amino acid substitutions, gene expression, and enzymatic activity levels. Most of these have not previously been studied in this species. D. insularis DNA sequences were used to analyze genetic variability. cDNA from resistant and susceptible plants was used to identify mutations, alleles, and 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) expression, using real-time quantitative reverse transcription-polymerase chain reaction. In addition, EPSPS activity was measured. We found a decrease in genetic variability between populations related to glyphosate application. Substitutions from proline to threonine and tyrosine to cysteine led to a decrease in EPSPS affinity for the glyphosate. In addition, the EPSPS enzymatic activity was slightly higher in resistant plants, whereas EPSPS gene expression was almost identical in both biotypes, suggesting feedback regulation at different levels. To conclude, our results suggest new molecular mechanisms used by D. insularis to increase glyphosate resistance.

Genetic variability, correlation and path analysis of yield contributing characters in sweet potato (ipomoea batatas lam.)

International Nuclear Information System (INIS)

Hossain, M.D.; Rabbani, M.G.; Mollah, M.L.R.

2000-01-01

Evaluation of 30 sweet potato (Ipomoea batatas Lam.) genotypes for yield contributing characters and tuber yield per plant revealed high phenotypic and genotypic coefficient of variation (PCV and GCV, respectively) for number of tubers per plant, average tuber weight and tuber yield per plant. The heritability and genetic advance were higher for tuber yield per plant, average tuber weight and number of tubers per plant. These three characters also reflected high heritability as well as high genetic advance. As high positive significant correlation, as well as positive direct effect of average tuber weight and number of tubers per plant on tuber yield per plant were found, these characters should be given prime importance for selecting high yielding sweet potato genotypes. (author)

Olfactory map formation in the Drosophila brain: genetic specificity and neuronal variability.

Science.gov (United States)

Brochtrup, Anna; Hummel, Thomas

2011-02-01

The development of the Drosophila olfactory system is a striking example of how genetic programs specify a large number of different neuron types and assemble them into functional circuits. To ensure precise odorant perception, each sensory neuron has to not only select a single olfactory receptor (OR) type out of a large genomic repertoire but also segregate its synaptic connections in the brain according to the OR class identity. Specification and patterning of second-order interneurons in the olfactory brain center occur largely independent of sensory input, followed by a precise point-to-point matching of sensory and relay neurons. Here we describe recent progress in the understanding of how cell-intrinsic differentiation programs and context-dependent cellular interactions generate a stereotyped sensory map in the Drosophila brain. Recent findings revealed an astonishing morphological diversity among members of the same interneuron class, suggesting an unexpected variability in local microcircuits involved in insect sensory processing. Copyright © 2010 Elsevier Ltd. All rights reserved.

Genetic variability of Cordia alliodora (R. and P.) Oken progenies

International Nuclear Information System (INIS)

Marulanda, Marta Leonor; Lopez, Ana Maria; Uribe, Marcela; Ospina, Carlos Mario

2011-01-01

Cordia alliodora is a well-known wood producer tree of tropical areas of Latin America and the Caribbean characterized for producing valuable wood and by its fast growth rate. In Colombia, it is frequent on agro-forestall systems with coffee. This species, like most forest species have biological problems for genetic improvement programs, such as long regeneration periods and high costs for supporting a population in a long term. The molecular assisted markers in plant breeding programs have had a great impact on genetic improvement, due to the fact they minimize their intervals of regeneration, increase the genetic gain by generation and allow the evaluation of the genetic information essential for the species. In this work, 60 genotypes of C. alliodora were characterized, belonging to the provenance and progenies tests established by the program of genetic improvement of Cenicafe. The characterization was carried out through micro satellite markers, after developing a genomic library enriched with micro satellites of the species. Finally, 24 specific micro satellites were evaluated, 20 of which allowed the detection of 28 polymorphic and multiallelic loci. These results provide a guide for orienting the policies of sustainable production and conservation of this valuable species; also, it provides a useful tool for the identification of clones with commercial interest.

Genetic variability of Passiflora spp. from commercial fields in the Federal District, Brazil Variabilidade genética de Passiflora spp. em plantios comerciais do Distrito Federal, Brasil

Directory of Open Access Journals (Sweden)

Ana Paula Gomes de Castro

2011-06-01

Full Text Available This study aimed to characterize the genetic variability in commercial accessions of passion fruit from the Federal District, Brazil, by RAPD markers. Genetic analyses were done with leaf samples of 30 accessions. DNA samples were amplified by RAPD technique, and respective markers converted into a binary matrix, from which the genetic distances between the accessions were estimated. Clustering analyis based on genetic distances allowed to detect a wide range of genetic variabillity among the accessions of sour passion fruit, and to separate them from the two sweet passion fruit. The graphical positioning of 'BRS Ouro Vermelho' confirms its potential to improve the genetic variability of commercial varieties of sour passion fruit. Dispersal of genetic distances among commercial accessions of sour passion fruit supports evidence for different genetic origins of the materials planted in the Federal District. The verified genetic variability indicates the potential success of future breeding programs for this region.Este estudo teve como objetivo caracterizar a variabilidade genética de acessos de maracujá comerciais no Distrito Federal por meio de marcadores RAPD. Análises genéticas foram feitas com amostras foliares de 30 acessos. As amostras de DNA foram amplificadas pela técnica de RAPD e os respectivos marcadores convertidos em uma matriz binária, a partir da qual as distâncias genéticas entre os acessos foram estimadas. Análises de agrupamento baseadas em distâncias genéticas permitiram detectar uma ampla gama de variabilidade genética entre os acessos de maracujazeiro-azedo, bem como para separá-los dos dois de maracujazeiro-doce. O posicionamento gráfico de 'BRS Ouro Vermelho' confirma a sua importante contribuição para aumentar a variabilidade genética das atuais variedades comerciais de maracujazeiro-azedo. A dispersão das distâncias genéticas entre os acessos comerciais de maracujazeiro-azedo suportam as evid

Variability assesment of some morphological traits among blue pine (pinus wallichiana) communities in hindukush ranges of Swat, Pakistan

International Nuclear Information System (INIS)

Rahman, I. U.; Khan, N.; Ali, K.

2017-01-01

Pinus wallichiana dominated forest communities, located in the Hindukush ranges of Swat, Pakistan were analysed for variability in the cone and seed traits. The results disclosed significant variability in mean values, critical difference, co-efficient of variation, broad sense heritability, genetic gain and genetic advance. Genotypic variance (Vg) and genotypic coefficient of variance (GCV) were noted to be lower than the corresponding environmental variance (Ve) and environmental coefficient of variability (ECV) for most of the parameters which clearly shows that these traits are under the control of environment. Both Number of male clusters/branch and 100 seeds weight are heritable traits as having higher genotypic variance and genotypic coefficient of variance. Traits like 100 seeds weight, Number of male cluster/branch, number of female cones/tree, female cone weight and number of sterile scales/cone showed moderate to high percentage of heritability indicates that these traits are under strong genetic control. These heritable additive genetic traits can be used for future breeding and tree improvement plans for the species. It is further concluded that the alleged traits should be given priority while selecting superior genotypes. (author)

Higher Energy Intake Variability as Predisposition to Obesity: Novel Approach Using Interquartile Range.

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Forejt, Martin; Brázdová, Zuzana Derflerová; Novák, Jan; Zlámal, Filip; Forbelská, Marie; Bienert, Petr; Mořkovská, Petra; Zavřelová, Miroslava; Pohořalá, Aneta; Jurášková, Miluše; Salah, Nabil; Bienertová-Vašků, Julie

2017-12-01

It is known that total energy intake and its distribution during the day influences human anthropometric characteristics. However, possible association between variability in total energy intake and obesity has thus far remained unexamined. This study was designed to establish the influence of energy intake variability of each daily meal on the anthropometric characteristics of obesity. A total of 521 individuals of Czech Caucasian origin aged 16–73 years (390 women and 131 men) were included in the study, 7-day food records were completed by all study subjects and selected anthropometric characteristics were measured. The interquartile range (IQR) of energy intake was assessed individually for each meal of the day (as a marker of energy intake variability) and subsequently correlated with body mass index (BMI), body fat percentage (%BF), waist-hip ratio (WHR), and waist circumference (cW). Four distinct models were created using multiple logistic regression analysis and backward stepwise logistic regression. The most precise results, based on the area under the curve (AUC), were observed in case of the %BF model (AUC=0.895) and cW model (AUC=0.839). According to the %BF model, age (p<0.001) and IQR-lunch (p<0.05) seem to play an important prediction role for obesity. Likewise, according to the cW model, age (p<0.001), IQR-breakfast (p<0.05) and IQR-dinner (p <0.05) predispose patients to the development of obesity. The results of our study show that higher variability in the energy intake of key daily meals may increase the likelihood of obesity development. Based on the obtained results, it is necessary to emphasize the regularity in meals intake for maintaining proper body composition. Copyright© by the National Institute of Public Health, Prague 2017

Variabilidade genética em biotipos de leiteiro de Londrina/PR Genetic variability among Euphorbia heterophylla

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Maria José V. de Vasconcelos

2000-08-01

size, which can vary among and within populations. This variability suggested to several authors that E. heterophylla was, in fact, formed by different species. To systematize the study of E. heterophylla and to determine if the phenotypic variability correspond to modifications at the DNA level, we analyzed 10 different plants collected in the soybean field in Londrina (Parana, Brazil. The plants were transplanted to the greenhouse and leaf DNA was extracted for RAPD technique analysis. Twenty-six RAPD "primers" different amplified 102 DNA bands, 38 of them being polymorphic. Genetic distances among the individuals were calculated based on the presence (1 or absence (0 of those bands. Cluster analyses divided the plants into two distinct groups considering an upper limit of 22% relative genetic distance. The genetic distances among the plants were between 1 and 39%, in agreement with the variability obseved at the morphological level.

Genetic parameters and estimated genetic gains in young rubber tree progenies

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Cecília Khusala Verardi

2013-04-01

Full Text Available The objective of this work was to assess the genetic parameters and to estimate genetic gains in young rubber tree progenies. The experiments were carried out during three years, in a randomized block design, with six replicates and ten plants per plot, in three representative Hevea crop regions of the state of São Paulo, Brazil. Twenty-two progenies were evaluated, from three to five years old, for rubber yield and annual girth growth. Genetic gain was estimated with the multi-effect index (MEI. Selection by progenies means provided greater estimated genetic gain than selection based on individuals, since heritability values of progeny means were greater than the ones of individual heritability, for both evaluated variables, in all the assessment years. The selection of the three best progenies for rubber yield provided a selection gain of 1.28 g per plant. The genetic gains estimated with MEI using data from early assessments (from 3 to 5-year-old were generally high for annual girth growth and rubber yield. The high genetic gains for annual girth growth in the first year of assessment indicate that progenies can be selected at the beginning of the breeding program. Population effective size was consistent with the three progenies selected, showing that they were not related and that the population genetic variability is ensured. Early selection with the genetic gains estimated by MEI can be made on rubber tree progenies.

Genetic variability for tuber yield, quality, and virus disease complex ...

African Journals Online (AJOL)

Some cultivars e.g. Munyeera, New Kawogo, Silk and Sowola which showed high flowering ability failed to fertilise and set seed when crossed to specific cultivars. Preliminary genetic analysis for yield and quality following crossing elite 7 female and 6 male cultivars in a North Carolina 2 mating design showed wide genetic ...

Genetic variability and heritability estimates of some polygenic traits in upland cotton

International Nuclear Information System (INIS)

Baloch, M.J.

2004-01-01

Plant breeders are more interested in genetic variance rather than phenotypic variance because it is amenable to selection and bring further improvement in the character. Twenty-eight F/sub 2/ progenies were tested in two environments so as to predict genetic variances, heritability estimates and genetic gains. Mean squares for locations were significant for all the five traits suggesting that genotypes performed differently under varying environments. Genetic variances, in most cases, however, were about equal to that of phenotypic variances consequently giving high heritability estimates and significant genetic gains. The broad sense heritability estimates were; 94.2, 92.9, 33.6, 81.9 and 86.9% and genetic gains were; 30.19, 10.55,0.20,0.89 and 1.76 in seed cotton yield, bolls per plant, lint %, fibre length and fibre uniformity ratio, respectively. Substantial genetic variances and high heritability estimates implied that these characters could be improved through selection from segregating populations. (author)

Genetic characterization of canine parvovirus from dogs in Pakistan.

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Shabbir, M Z; Sohail, M U; Chaudhary, U N; Yaqub, W; Rashid, I; Saleem, M H; Munir, M

Canine parvoviruses (CPV) exist as antigenic variants with varying frequencies and genetic variabilities across the globe. Given the endemicity and high prevalence in Pakistan, we characterized the CPVs originating from dogs-population to elucidate viral diversity and evolution. Fecal samples from clinically diseased pups (n = 17) of different breeds and age (2-6 months) were processed for hemagglutination assay (HA), and later for partial amplification of VP2 gene sequence and amino acid analysis. A total of 11 samples (64.71%) were found positive both in hemagglutination and PCR assays. Phylogenetic and evolutionary analysis demonstrated higher genetic heterogeneity in studied strains and constituted seven clusters within the CPV-2a group, however, they shared high level of identity with Chinese strains. Further studies are necessary to elucidate genetic analysis and epidemiology of CPV variants across a wide geographical area of the country.

Conspicuous plumage colours are highly variable.

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Delhey, Kaspar; Szecsenyi, Beatrice; Nakagawa, Shinichi; Peters, Anne

2017-01-25

Elaborate ornamental traits are often under directional selection for greater elaboration, which in theory should deplete underlying genetic variation. Despite this, many ornamental traits appear to remain highly variable and how this essential variation is maintained is a key question in evolutionary biology. One way to address this question is to compare differences in intraspecific variability across different types of traits to determine whether high levels of variation are associated with specific trait characteristics. Here we assess intraspecific variation in more than 100 plumage colours across 55 bird species to test whether colour variability is linked to their level of elaboration (indicated by degree of sexual dichromatism and conspicuousness) or their condition dependence (indicated by mechanism of colour production). Conspicuous colours had the highest levels of variation and conspicuousness was the strongest predictor of variability, with high explanatory power. After accounting for this, there were no significant effects of sexual dichromatism or mechanisms of colour production. Conspicuous colours may entail higher production costs or may be more sensitive to disruptions during production. Alternatively, high variability could also be related to increased perceptual difficulties inherent to discriminating highly elaborate colours. Such psychophysical effects may constrain the exaggeration of animal colours. © 2017 The Author(s).

Rapid and inexpensive analysis of genetic variability in Arapaima gigas by PCR multiplex panel of eight microsatellites.

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Hamoy, I G; Santos, E J M; Santos, S E B

2008-01-22

The aim of the present study was the development of a multiplex genotyping panel of eight microsatellite markers of Arapaima gigas, previously described. Specific primer pairs were developed, each one of them marked with either FAM-6, HEX or NED. The amplification conditions using the new primers were standardized for a single reaction. The results obtained demonstrate high heterozygosity (average of 0.69) in a Lower Amazon population. The multiplex system described can thus be considered a fast, efficient and inexpensive method for the investigation of genetic variability in Arapaima populations.

Characterization of casein gene complex and genetic diversity analysis in Indian goats.

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Rout, P K; Kumar, A; Mandal, A; Laloe, D; Singh, S K; Roy, R

2010-04-01

Milk protein polymorphism plays an important role in genetic diversity analysis, phylogenetic studies, establishing geographical diversity, conservation decision, and improving breeding goals. Milk protein polymorphism in Indian goat breeds has not been well studied; therefore, an investigation was carried out to analyze the genetic structure of the casein gene and milk protein diversity at six milk protein loci in nine Indian goat breeds/genetic groups from varied agro-climatic zones. Milk protein genotyping was carried out in 1098 individual milk samples by SDS-PAGE at alphaS1-CN (CSN1S1), beta-CN (CSN2), alphaS2-CN (CSN1S2), kappa-CN (CSN3), beta-LG, and alpha-LA loci. Indian goats exhibited alphaS1-casein A allele in higher frequency in the majority of breeds except Ganjam and local goats. The alphaS1-casein A allele frequencies varied from 0.45 to 0.77. A total of 16 casein haplotypes were observed in seven breeds and breed specific haplotypes were observed with respect to geographic region. The average number of alleles was lowest in Ganjam (1.66 +/- 0.81) and highest in Sirohi goats (2.50 +/- 1.05). Expected heterozygosity at six different loci demonstrated genetic diversity and breed fragmentation. Neighbor-Joining tree was built basing on Nei's distance. There was about 16.95% variability due to differences between breeds, indicating a strong subdivision. Principal component analysis was carried out to highlight the relationship among breeds. The variability among goat breeds was contributed by alphaS2-CN, beta-LG and alphaS1-CN. The Indian goats exhibited alphaS1-CN (CSN1S1) A allele in higher frequency in all the breeds indicating the higher casein yield in their milk.

Sequence determinants of human microsatellite variability

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Jakobsson Mattias

2009-12-01

Full Text Available Abstract Background Microsatellite loci are frequently used in genomic studies of DNA sequence repeats and in population studies of genetic variability. To investigate the effect of sequence properties of microsatellites on their level of variability we have analyzed genotypes at 627 microsatellite loci in 1,048 worldwide individuals from the HGDP-CEPH cell line panel together with the DNA sequences of these microsatellites in the human RefSeq database. Results Calibrating PCR fragment lengths in individual genotypes by using the RefSeq sequence enabled us to infer repeat number in the HGDP-CEPH dataset and to calculate the mean number of repeats (as opposed to the mean PCR fragment length, under the assumption that differences in PCR fragment length reflect differences in the numbers of repeats in the embedded repeat sequences. We find the mean and maximum numbers of repeats across individuals to be positively correlated with heterozygosity. The size and composition of the repeat unit of a microsatellite are also important factors in predicting heterozygosity, with tetra-nucleotide repeat units high in G/C content leading to higher heterozygosity. Finally, we find that microsatellites containing more separate sets of repeated motifs generally have higher heterozygosity. Conclusions These results suggest that sequence properties of microsatellites have a significant impact in determining the features of human microsatellite variability.

Studies on the application of radiation for genetic transformation in higher plants

International Nuclear Information System (INIS)

Lee, Young Il; Song, Hi Sup; Kim, Jae Sung; Shin, In Chul; Lee, Sang Jae; Lee, Ki Woon; Lim, Yong Taek

1992-02-01

Present research carried out to develop the radiation application on the mutation research of genetic engineering. Some variants selected in M1 generation derived from the plantlet by the nodal stem culture of three potato cultivars irradiated with gamma rays, and the optimum dosage for mutation induction was revealed the range of 30 - 50 Gy of gamma ray. In the rice anther culture of the plant irradiated with gamma rays at different developmental stage of microspore, the haploidy callus formation rates were much higher in gamma ray irradiated anthers than those of non-irradiated, and the occurrence of a typical pollen was significantly increased up to 47% in the anthers irradiated with 30 Gy of gamma ray compared with 11% of non-irradiated anthers at the stage of pollen mother cell. A lot of variants were selected in rice, soybean, perilla and red pepper irradiated with gamma rays for breeding of earliness, short culm, high yielding and disease resistant mutant. (Author)

Wolbachia and genetic variability in the birdnest blowfly Protocalliphora sialia.

Science.gov (United States)

Baudry, E; Bartos, J; Emerson, K; Whitworth, T; Werren, J H

2003-07-01

Wolbachia are widespread cytoplasmically inherited bacteria that induce various reproductive alterations in host arthropods, including cytoplasmic incompatibility (CI), an incompatibility between sperm and egg that typically results in embryonic death. CI has been invoked as a possible mechanism for reproductive isolation and speciation in arthropods, by restricting gene flow and promoting maintenance (and evolution) of genetic divergence between populations. Here we investigate patterns of Wolbachia infection and nuclear and mitochondrial differentiation in geographical populations of the birdnest blowfly Protocalliphora sialia. Blowflies in western North America are infected with two A-group Wolbachia, with some individuals singly and others doubly infected. Individuals in eastern North America mostly show single infections with a B-group Wolbachia. Populations in the Midwest are polymorphic for infections and show A- or B-group infection. There is a low level of mitochondrial divergence and perfect concordance of mitochondrial haplotype with infection type, suggesting that two Wolbachia-associated selective sweeps of the mitochondrion have occurred in this species. Amplified fragment length polymorphism analysis of nuclear genetic variation shows genetic differentiation between the eastern-Midwestern and western populations. Both Midwestern and eastern flies infected with A-Wolbachia show eastern nuclear genetic profiles. Current results therefore suggest that Wolbachia has not acted as a major barrier to gene flow between western and eastern-Midwestern populations, although some genetic differentiation between A-Wolbachia infected and B-Wolbachia infected individuals in eastern-Midwestern populations cannot be ruled out.

Dark solitons for a variable-coefficient higher-order nonlinear Schrödinger equation in the inhomogeneous optical fiber

Science.gov (United States)

Sun, Yan; Tian, Bo; Wu, Xiao-Yu; Liu, Lei; Yuan, Yu-Qiang

2017-04-01

Under investigation in this paper is a variable-coefficient higher-order nonlinear Schrödinger equation, which has certain applications in the inhomogeneous optical fiber communication. Through the Hirota method, bilinear forms, dark one- and two-soliton solutions for such an equation are obtained. We graphically study the solitons with d1(z), d2(z) and d3(z), which represent the variable coefficients of the group-velocity dispersion, third-order dispersion and fourth-order dispersion, respectively. With the different choices of the variable coefficients, we obtain the parabolic, periodic and V-shaped dark solitons. Head-on and overtaking collisions are depicted via the dark two soliton solutions. Velocities of the dark solitons are linearly related to d1(z), d2(z) and d3(z), respectively, while the amplitudes of the dark solitons are not related to such variable coefficients.

Intraspecific morphological and genetic variation of common species predicts ranges of threatened ones

Science.gov (United States)

Fuller, Trevon L.; Thomassen, Henri A.; Peralvo, Manuel; Buermann, Wolfgang; Milá, Borja; Kieswetter, Charles M.; Jarrín-V, Pablo; Devitt, Susan E. Cameron; Mason, Eliza; Schweizer, Rena M.; Schlunegger, Jasmin; Chan, Janice; Wang, Ophelia; Schneider, Christopher J.; Pollinger, John P.; Saatchi, Sassan; Graham, Catherine H.; Wayne, Robert K.; Smith, Thomas B.

2013-01-01

Predicting where threatened species occur is useful for making informed conservation decisions. However, because they are usually rare, surveying threatened species is often expensive and time intensive. Here, we show how regions where common species exhibit high genetic and morphological divergence among populations can be used to predict the occurrence of species of conservation concern. Intraspecific variation of common species of birds, bats and frogs from Ecuador were found to be a significantly better predictor for the occurrence of threatened species than suites of environmental variables or the occurrence of amphibians and birds. Fully 93 per cent of the threatened species analysed had their range adequately represented by the geographical distribution of the morphological and genetic variation found in seven common species. Both higher numbers of threatened species and greater genetic and morphological variation of common species occurred along elevation gradients. Higher levels of intraspecific divergence may be the result of disruptive selection and/or introgression along gradients. We suggest that collecting data on genetic and morphological variation in common species can be a cost effective tool for conservation planning, and that future biodiversity inventories include surveying genetic and morphological data of common species whenever feasible. PMID:23595273

Genetic variation of the greenhouse whitefly, Trialeurodes vaporariorum (Hemiptera: Aleyrodidae), among populations from Serbia and neighbouring countries, as inferred from COI sequence variability.

Science.gov (United States)

Prijović, M; Skaljac, M; Drobnjaković, T; Zanić, K; Perić, P; Marčić, D; Puizina, J

2014-06-01

The greenhouse whitefly Trialeurodes vaporariorum Westwood, 1856 (Hemiptera: Aleyrodidae) is an invasive and highly polyphagous phloem-feeding pest of vegetables and ornamentals. Trialeurodes vaporariorum causes serious damage due to direct feeding and transmits several important plant viruses. Excessive use of insecticides has resulted in significantly reduced levels of susceptibility of various T. vaporariorum populations. To determine the genetic variability within and among populations of T. vaporariorum from Serbia and to explore their genetic relatedness with other T. vaporariorum populations, we analysed the mitochondrial cytochrome c oxidase I (COI) sequences of 16 populations from Serbia and six neighbouring countries: Montenegro (three populations), Macedonia (one population) and Croatia (two populations), for a total of 198 analysed specimens. A low overall level of sequence divergence and only five variable nucleotides and six haplotypes were found. The most frequent haplotype, H1, was identified in all Serbian populations and in all specimens from distant localities in Croatia and Macedonia. The COI sequence data that was retrieved from GenBank and the data from our study indicated that H1 is the most globally widespread T. vaporariorum haplotype. A lack of spatial genetic structure among the studied T. vaporariorum populations, as well as two demographic tests that we performed (Tajima's D value and Fu's Fs statistics), indicate a recent colonisation event and population growth. Phylogenetic analyses of the COI haplotypes in this study and other T. vaporariorum haplotypes that were retrieved from GenBank were performed using Bayesian inference and median-joining (MJ) network analysis. Two major haplogroups with only a single unique nucleotide difference were found: haplogroup 1 (containing the five Serbian haplotypes and those previously identified in India, China, the Netherlands, the United Kingdom, Morocco, Reunion and the USA) and haplogroup 3

Inferring genetic connectivity in real populations, exemplified by coastal and oceanic Atlantic cod.

Science.gov (United States)

Spies, Ingrid; Hauser, Lorenz; Jorde, Per Erik; Knutsen, Halvor; Punt, André E; Rogers, Lauren A; Stenseth, Nils Chr

2018-04-19

Genetic data are commonly used to estimate connectivity between putative populations, but translating them to demographic dispersal rates is complicated. Theoretical equations that infer a migration rate based on the genetic estimator F ST , such as Wright's equation, F ST ≈ 1/(4 N e m + 1), make assumptions that do not apply to most real populations. How complexities inherent to real populations affect migration was exemplified by Atlantic cod in the North Sea and Skagerrak and was examined within an age-structured model that incorporated genetic markers. Migration was determined under various scenarios by varying the number of simulated migrants until the mean simulated level of genetic differentiation matched a fixed level of genetic differentiation equal to empirical estimates. Parameters that decreased the N e / N t ratio (where N e is the effective and N t is the total population size), such as high fishing mortality and high fishing gear selectivity, increased the number of migrants required to achieve empirical levels of genetic differentiation. Higher maturity-at-age and lower selectivity increased N e / N t and decreased migration when genetic differentiation was fixed. Changes in natural mortality, fishing gear selectivity, and maturity-at-age within expected limits had a moderate effect on migration when genetic differentiation was held constant. Changes in population size had the greatest effect on the number of migrants to achieve fixed levels of F ST , particularly when genetic differentiation was low, F ST ≈ 10 -3 Highly variable migration patterns, compared with constant migration, resulted in higher variance in genetic differentiation and higher extreme values. Results are compared with and provide insight into the use of theoretical equations to estimate migration among real populations. Copyright © 2018 the Author(s). Published by PNAS.

AFLP marker analysis revealing genetic structure of the tree Parapiptadenia rigida (Benth. Brenan (Leguminosae-Mimosoideae in the southern Brazilian Tropical Rainforest

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Laís Bérgamo de Souza

2013-01-01

Full Text Available Parapiptadenia rigida is a tropical early secondary succession tree characteristic of the Tropical Atlantic Rainforest. This species is of great ecological importance in the recovery of degraded areas. In this study we investigated the variability and population genetic structure of eight populations of P. rigida. Five AFLP primer combinations were used in a sample of 159 individuals representing these eight populations, rendering a total of 126 polymorphic fragments. The averages of percentage of polymorphic loci, gene diversity, and Shannon index were 60.45%, 0.217, and 0.322, respectively. A significant correlation between the population genetic variability and the population sizes was observed. The genetic variability within populations (72.20% was higher than between these (22.80%. No perfect correlation was observed between geographic and genetic distances, which might be explained by differences in deforestation intensities that occurred in these areas. A dendrogram constructed by the UPGMA method revealed the formation of two clusters, these also confirmed by Bayesian analysis for the number of K cluster. These results show that it is necessary to develop urgent management strategies for the conservation of certain populations of P. rigida, while other populations still preserve reasonably high levels of genetic variability.

Infection dynamics and genetic variability of Mycoplasma hyopneumoniae in self-replacement gilts.

Science.gov (United States)

Takeuti, Karine L; de Barcellos, David E S N; de Andrade, Caroline P; de Almeida, Laura L; Pieters, Maria

2017-09-01

The aim of this study was to assess the longitudinal pattern of M. hyopneumoniae detection in self-replacement gilts at various farms and to characterize the genetic diversity among samples. A total of 298 gilts from three M. hyopneumoniae positive farms were selected at 150days of age (doa). Gilts were tested for M. hyopneumoniae antibodies by ELISA, once in serum at 150 doa and for M. hyopneumoniae detection in laryngeal swabs by real time PCR two or three times. Also, 425 piglets were tested for M. hyopneumoniae detection in laryngeal swabs. A total of 103 samples were characterized by Multiple Locus Variable-number tandem repeats Analysis. Multiple comparison tests were performed and adjusted using Bonferroni correction to compare prevalences of positive gilts by ELISA and real time PCR. Moderate to high prevalence of M. hyopneumoniae in gilts was detected at 150 doa, which decreased over time, and different detection patterns were observed among farms. Dam-to-piglet transmission of M. hyopneumoniae was not detected. The characterization of M. hyopneumoniae showed 17 different variants in all farms, with two identical variants detected in two of the farms. ELISA testing showed high prevalence of seropositive gilts at 150 doa in all farms. Results of this study showed that circulation of M. hyopneumoniae in self-replacement gilts varied among farms, even under similar production and management conditions. In addition, the molecular variability of M. hyopneumoniae detected within farms suggests that in cases of minimal replacement gilt introduction bacterial diversity maybe farm specific. Copyright © 2017 Elsevier B.V. All rights reserved.

Genetically uniform strains of fish as laboratory models for experimental studies of the effects of ionizing radiation

International Nuclear Information System (INIS)

Woodhead, A.D.; Setlow, R.B.; Hart, R.W.

1979-01-01

The advantages are discussed of using a genetically uniform test animal such as the amazon molly, Poecilia formosa, to reduce the biotic variability in experimental determination of the effects of ionizing radiation on aquatic ecosystems. Besides a cost reduction from using less organisms for these radiation-effect studies, another significant advantage of the higher precision responses due to homozygous genetic material is the assessment of radiation effects at the molecular and cellular levels. (author)

Results of Evolution Supervised by Genetic Algorithms

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Lorentz JÄNTSCHI

2010-09-01

Full Text Available The efficiency of a genetic algorithm is frequently assessed using a series of operators of evolution like crossover operators, mutation operators or other dynamic parameters. The present paper aimed to review the main results of evolution supervised by genetic algorithms used to identify solutions to agricultural and horticultural hard problems and to discuss the results of using a genetic algorithms on structure-activity relationships in terms of behavior of evolution supervised by genetic algorithms. A genetic algorithm had been developed and implemented in order to identify the optimal solution in term of estimation power of a multiple linear regression approach for structure-activity relationships. Three survival and three selection strategies (proportional, deterministic and tournament were investigated in order to identify the best survival-selection strategy able to lead to the model with higher estimation power. The Molecular Descriptors Family for structure characterization of a sample of 206 polychlorinated biphenyls with measured octanol-water partition coefficients was used as case study. Evolution using different selection and survival strategies proved to create populations of genotypes living in the evolution space with different diversity and variability. Under a series of criteria of comparisons these populations proved to be grouped and the groups were showed to be statistically different one to each other. The conclusions about genetic algorithm evolution according to a number of criteria were also highlighted.

Genetic diversity and genetic structure of farmed and wild Chinese mitten crab (Eriocheir sinensis) populations from three major basins by mitochondrial DNA COI and Cyt b gene sequences.

Science.gov (United States)

Zhang, Cheng; Li, Qingqing; Wu, Xugan; Liu, Qing; Cheng, Yongxu

2017-11-20

The Chinese mitten crab, Eriocheir sinensis, is one of the important native crab species in East Asian region, which has been widely cultured throughout China, particularly in river basins of Yangtze, Huanghe and Liaohe. This study was designed to evaluate the genetic diversity and genetic structure of cultured and wild E. sinensis populations from the three river basins based on mitochondrial DNA (mtDNA) cytochrome oxidase subunit I (COI) and cytochrome b (Cyt b). The results showed that there were 62 variable sites and 30 parsimony informative sites in the 647 bp of sequenced mtDNA COI from 335 samples. Similarly, a 637 bp segment of Cyt b provided 59 variable sites and 26 parsimony informative sites. AMOVA showed that the levels of genetic differentiation were low among six populations. Although the haplotype diversity and nucleotide diversity of Huanghe wild population had slightly higher than the other populations, there were no significant differences. There was no significant differentiation between the genetic and geographic distance of the six populations, and haplotype network diagram indicated that there may exist genetic hybrids of E. sinensis from different river basins. The results of clustering and neutrality tests revealed that the distance of geographical locations were not completely related to their genetic distance values for the six populations. In conclusion, these results have great significance for the evaluation and exploitation of germplasm resources of E. sinensis.

Assessment of Genetic Variability in Sorghum Accessions (Sorghum ...

African Journals Online (AJOL)

ADOWIE PERE

The polymorphic information content (PIC) of individual primer ranged from 0.34 to 0.70 with a mean value of 0.54 indicating enough ... Keywords: Sorghum; Simple Sequence Repeat markers; Genetic variation; Polymorphic Information Content;. Coefficient of ... based techniques include Restriction Fragment Length.

Variability of resistance in Black Bengal goats naturally infected with Haemonchus contortus.

Science.gov (United States)

Kumar, Ratnesh; Ranjan, Sanjeev; Vishnu, P Guru; Negi, Mamta; Senapati, P K; Charita, V Gnani

2015-03-01

A total 290 Black Bengal goats (6 buck, 109 doe and 175 kids born from 11 sires) were studied to evaluate the variability of resistance in Black Bengal goats naturally infected with Haemonchus contortus. The variability of resistance in Black Bengal goat was studied for both genetic and non-genetic factors like village, sex, age dam, sire, dam resistance group and offspring resistance group. Male kids have slightly higher resistance than female kids although it was not significant. Resistance of kids was increased as age increases and kid population showed significantly different resistance status among the offspring resistant groups. The doe population showed significantly different LEPG as per the resistance group in all the collections. The present study found that the resistance of kids under sire were varied significantly and observed that the kids under sire 1, 6-8 were significantly more resistant than the kids of the sire 2, 5 and 11 in 3rd collection and it is also noticed that maternal genetic effect has a very little impact on resistance of kids. Males (buck) were most resistant and the kids were least resistant and the resistance of dam was in between the male and kids population.

Behavioral Variability and Somatic Mosaicism: A Cytogenomic Hypothesis.

Science.gov (United States)

Vorsanova, Svetlana G; Zelenova, Maria A; Yurov, Yuri B; Iourov, Ivan Y

2018-04-01

Behavioral sciences are inseparably related to genetics. A variety of neurobehavioral phenotypes are suggested to result from genomic variations. However, the contribution of genetic factors to common behavioral disorders (i.e. autism, schizophrenia, intellectual disability) remains to be understood when an attempt to link behavioral variability to a specific genomic change is made. Probably, the least appreciated genetic mechanism of debilitating neurobehavioral disorders is somatic mosaicism or the occurrence of genetically diverse (neuronal) cells in an individual's brain. Somatic mosaicism is assumed to affect directly the brain being associated with specific behavioral patterns. As shown in studies of chromosome abnormalities (syndromes), genetic mosaicism is able to change dynamically the phenotype due to inconsistency of abnormal cell proportions. Here, we hypothesize that brain-specific postzygotic changes of mosaicism levels are able to modulate variability of behavioral phenotypes. More precisely, behavioral phenotype variability in individuals exhibiting somatic mosaicism might correlate with changes in the amount of genetically abnormal cells throughout the lifespan. If proven, the hypothesis can be used as a basis for therapeutic interventions through regulating levels of somatic mosaicism to increase functioning and to improve overall condition of individuals with behavioral problems.

Population genetic structure and life history variability in Oncorhynchus nerka from the Snake River basin. Final report

International Nuclear Information System (INIS)

Waples, R.S.; Aebersold, P.B.; Winans, G.A.

1997-05-01

The authors used protein electrophoresis to examine genetic relationships among samples of sockeye salmon and kokanee (Oncorhynchus nerka) from the Snake River basin. A few collections from elsewhere in the Pacific Northwest were also included to add perspective to the analysis. After combining temporal samples that did not differ statistically within and between years, 32 different populations were examined for variation at 64 gene loci scored in all populations. Thirty-five (55%) of these gene loci surveyed were polymorphic in at least one population. Average heterozygosities were relatively low (0.006--0.041), but genetic differentiation among populations was pronounced: the value of Wright's F ST of 0.244 is higher than has been reported in any other study of Pacific salmon

Ethnicity-dependent influence of innate immune genetic markers on morphine PCA requirements and adverse effects in postoperative pain.

Science.gov (United States)

Somogyi, Andrew A; Sia, Alex T; Tan, Ene-Choo; Coller, Janet K; Hutchinson, Mark R; Barratt, Daniel T

2016-11-01

Although several genetic factors have been associated with postsurgical morphine requirements, those involving the innate immune system and cytokines have not been well investigated. The aim of this study was to investigate the contribution of genetic variability in innate immune signalling pathways to variability in morphine dosage after elective caesarean section under spinal anaesthesia in 133 Indian, 230 Malay, and 598 Han Chinese women previously studied. Twenty single nucleotide polymorphisms in 14 genes involved in glial activation (TLR2, TLR4, MYD88, MD2), inflammatory signalling (IL2, IL6, IL10, IL1B, IL6R, TNFA, TGFB1, CRP, CASP1), and neuronal regulation (BDNF) were newly investigated, in addition to OPRM1, COMT, and ABCB1 genetic variability identified previously. Postsurgical patient-controlled analgesia morphine use (mg/24 hours) was binned into 6 normally distributed groups and scored 0 to 5 to facilitate step-down multiple linear regression analysis of genetic predictors, controlling for ethnicity and nongenetic variables. Ethnicity, OPRM1 rs1799971 (increased), TLR2 rs3804100 (decreased), and an interaction between ethnicity and IL1B rs1143634 (increased), predicted 9.8% of variability in morphine use scores in the entire cohort. In the Indian cohort, 14.5% of the variance in morphine use score was explained by IL1B rs1143634 (increased) and TGFB1 rs1800469 (decreased). In Chinese patients, the incidence of postsurgical pain was significantly higher in variant COMT rs4680 genotypes (P = 0.0007) but not in the Malay or Indian cohorts. Innate immune genetics may contribute to variability in postsurgical opioid requirements in an ethnicity-dependent manner.

Chemical Genetics — A Versatile Method to Combine Science and Higher Level Teaching in Molecular Genetics

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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.

A rangewide population genetic study of trumpeter swans

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Oyler-McCance, S.J.; Ransler, F.A.; Berkman, L.K.; Quinn, T.W.

2007-01-01

For management purposes, the range of naturally occurring trumpeter swans (Cygnus buccinator) has been divided into two populations, the Pacific Coast Population (PP) and the Rocky Mountain Population (RMP). Little is known about the distribution of genetic variation across the species' range despite increasing pressure to make difficult management decisions regarding the two populations and flocks within them. To address this issue, we used rapidly evolving genetic markers (mitochondrial DNA sequence and 17 nuclear microsatellite loci) to elucidate the underlying genetic structure of the species. Data from both markers revealed a significant difference between the PP and RMP with the Yukon Territory as a likely area of overlap. Additionally, we found that the two populations have somewhat similar levels of genetic diversity (PP is slightly higher) suggesting that the PP underwent a population bottleneck similar to a well-documented one in the RMP. Both genetic structure and diversity results reveal that the Tri-State flock, a suspected unique, non-migratory flock, is not genetically different from the Canadian flock of the RMP and need not be treated as a unique population from a genetic standpoint. Finally, trumpeter swans appear to have much lower mitochondrial DNA variability than other waterfowl studied thus far which may suggest a previous, species-wide bottleneck. ?? 2007 Springer Science+Business Media, Inc.

Genetics educational needs in China: physicians' experience and knowledge of genetic testing.

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Li, Jing; Xu, Tengda; Yashar, Beverly M

2015-09-01

The aims of this study were to explore the relationship between physicians' knowledge and utilization of genetic testing and to explore genetics educational needs in China. An anonymous survey about experience, attitudes, and knowledge of genetic testing was conducted among physicians affiliated with Peking Union Medical College Hospital during their annual health evaluation. A personal genetics knowledge score was developed and predictors of personal genetics knowledge score were evaluated. Sixty-four physicians (33% male) completed the survey. Fifty-eight percent of them had used genetic testing in their clinical practice. Using a 4-point scale, mean knowledge scores of six common genetic testing techniques ranged from 1.7 ± 0.9 to 2.4 ± 1.0, and the average personal genetics knowledge score was 2.1 ± 0.8. In regression analysis, significant predictors of higher personal genetics knowledge score were ordering of genetic testing, utilization of pedigrees, higher medical degree, and recent genetics training (P education. This study demonstrated a sizable gap between Chinese physicians' knowledge and utilization of genetic testing. Participants had high self-perceived genetics educational needs. Development of genetics educational platforms is both warranted and desired in China.Genet Med 17 9, 757-760.

Applying genetic algorithms to set the optimal combination of forest fire related variables and model forest fire susceptibility based on data mining models. The case of Dayu County, China.

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Hong, Haoyuan; Tsangaratos, Paraskevas; Ilia, Ioanna; Liu, Junzhi; Zhu, A-Xing; Xu, Chong

2018-07-15

The main objective of the present study was to utilize Genetic Algorithms (GA) in order to obtain the optimal combination of forest fire related variables and apply data mining methods for constructing a forest fire susceptibility map. In the proposed approach, a Random Forest (RF) and a Support Vector Machine (SVM) was used to produce a forest fire susceptibility map for the Dayu County which is located in southwest of Jiangxi Province, China. For this purpose, historic forest fires and thirteen forest fire related variables were analyzed, namely: elevation, slope angle, aspect, curvature, land use, soil cover, heat load index, normalized difference vegetation index, mean annual temperature, mean annual wind speed, mean annual rainfall, distance to river network and distance to road network. The Natural Break and the Certainty Factor method were used to classify and weight the thirteen variables, while a multicollinearity analysis was performed to determine the correlation among the variables and decide about their usability. The optimal set of variables, determined by the GA limited the number of variables into eight excluding from the analysis, aspect, land use, heat load index, distance to river network and mean annual rainfall. The performance of the forest fire models was evaluated by using the area under the Receiver Operating Characteristic curve (ROC-AUC) based on the validation dataset. Overall, the RF models gave higher AUC values. Also the results showed that the proposed optimized models outperform the original models. Specifically, the optimized RF model gave the best results (0.8495), followed by the original RF (0.8169), while the optimized SVM gave lower values (0.7456) than the RF, however higher than the original SVM (0.7148) model. The study highlights the significance of feature selection techniques in forest fire susceptibility, whereas data mining methods could be considered as a valid approach for forest fire susceptibility modeling

Temperature-dependent behaviours are genetically variable in the nematode Caenorhabditis briggsae.

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Stegeman, Gregory W; de Mesquita, Matthew Bueno; Ryu, William S; Cutter, Asher D

2013-03-01

Temperature-dependent behaviours in Caenorhabditis elegans, such as thermotaxis and isothermal tracking, are complex behavioural responses that integrate sensation, foraging and learning, and have driven investigations to discover many essential genetic and neural pathways. The ease of manipulation of the Caenorhabditis model system also has encouraged its application to comparative analyses of phenotypic evolution, particularly contrasts of the classic model C. elegans with C. briggsae. And yet few studies have investigated natural genetic variation in behaviour in any nematode. Here we measure thermotaxis and isothermal tracking behaviour in genetically distinct strains of C. briggsae, further motivated by the latitudinal differentiation in C. briggsae that is associated with temperature-dependent fitness differences in this species. We demonstrate that C. briggsae performs thermotaxis and isothermal tracking largely similar to that of C. elegans, with a tendency to prefer its rearing temperature. Comparisons of these behaviours among strains reveal substantial heritable natural variation within each species that corresponds to three general patterns of behavioural response. However, intraspecific genetic differences in thermal behaviour often exceed interspecific differences. These patterns of temperature-dependent behaviour motivate further development of C. briggsae as a model system for dissecting the genetic underpinnings of complex behavioural traits.

Virulence factors and genetic variability of Staphylococcus aureus strains isolated from raw sheep's milk cheese.

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Spanu, Vincenzo; Spanu, Carlo; Virdis, Salvatore; Cossu, Francesca; Scarano, Christian; De Santis, Enrico Pietro Luigi

2012-02-01

Contamination of dairy products with Staphylococcus aureus can be of animal or human origin. The host pathogen relationship is an important factor determining genetic polymorphism of the strains and their potential virulence. The aim of the present study was to carry out an extensive characterization of virulence factors and to study the genetic variability of S. aureus strains isolated from raw ewe's milk cheese. A total of 100 S. aureus strains isolated from cheese samples produced in 10 artisan cheese factories were analyzed for the presence of enterotoxins (sea-see) and enterotoxins-like genes (seh, sek, sel, sem, seo, sep), leukocidins, exfoliatins, haemolysins, toxic shock syndrome toxin 1 (TSST-1) and the accessory gene regulator alleles (agr). Strains were also typed using pulsed-field gel electrophoresis (PFGE). AMOVA analysis carried out on PFGE and PCR data showed that the major component explaining genetic distance between strains was the dairy of origin. Of the total isolates 81% had a pathogenicity profile ascribable to "animal" biovar while 16% could be related to "human" biovar. The biovar allowed to estimate the most likely origin of the contamination. Minimum inhibitory concentrations (MICs) of nine antimicrobial agents and the presence of the corresponding genes coding for antibiotic resistance was also investigated. 18 strains carrying blaZ gene showed resistance to ampicillin and penicillin and 6 strains carrying tetM gene were resistant to tetracycline. The presence of mecA gene and methicillin resistance, typical of strains of human origin, was never detected. The results obtained in the present study confirm that S. aureus contamination in artisan cheese production is mainly of animal origin. Copyright © 2011. Published by Elsevier B.V.

STUDY OF PHENOTYPIC CHARACTERS VARIABILITY OF THE SILKMOTH COCOON FROM THE NATIVE GENETIC STOCK OF BOMBYX MORI L. SP.

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ALEXANDRA MATEI

2008-10-01

Full Text Available This study had aims the analysis of phenotypic characters variability of silkmoth cocoon within the native genetic stock of Bombyx mori L. sp. The biological material was represented by 72 races consisting of the gene stock of Bombyx mori sp., grouped by their origin. The main phenotypical ad quantitative parameters of the races that represent the gene stock of Bombyx mori sp., present the following values: raw cocoon weight (1.445-2.361 g, cocoon shell weight (0.240-0.520 g, fiber length (746-1356 m, metric number of fiber (2917-3764 m/g. Depending on the quantitative parameters value, the silkworm races are being used differently, entire genetic stock being destined for various technological levels, as follows: 4 active races (parents of hybrids, 4 candidate races for parents of hybrids, 64 races in preservation.

Predictive Variables of Success for Latino Enrollment in Higher Education

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Sanchez, Jafeth E.; Usinger, Janet; Thornton, Bill W.

2015-01-01

It is necessary to better understand the unique variables that serve as predictors of Latino students' postsecondary enrollment and success. Impacts of various variables were examined among 850 Latino and Caucasian students (76% and 24% of the sample, respectively). Gender, ethnicity, perceived affordability, high school grade point average, and…

Variability, heritability, character association, path analysis and morphological diversity in snake gourd

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A.S.M. Mahbubur Rahman Khan

2016-11-01

Full Text Available Genetic variability, heritability and path coefficient analysis were studied in 21 genotypes of snake gourd. The phenotypic coefficient of variations was found slightly higher than the genotypic coefficient of variations for all characters studied, indicating that the apparent variation is not only genetic but also influenced by the growing environment in the expression of the traits. The genotypic coefficient of variation was high for the fruit yield, number of fruits per vine, length of fruit and single fruit weight. High heritability coupled with high-to-moderate genetic advance was estimated for all characters studied. Correlation studies revealed that the fruit yield had a significant, positive correlation with the number of fruits per vine, length of fruit and single fruit weight. Importantly, more than 90% of the genotypic total variation was contributed by the characters included in the path analysis. The highest, direct, positive effect was recorded for the number of fruits per vine. The divergence value for cluster analysis indicated that the genotypes from clusters II and III had the highest inter-cluster distance and were expected to provide high heterosis in hybridization and to show wide variability in genetic architecture. The selection of high yielding genotypes should give emphasis to the number of fruits per vine, length of fruit and single fruit weight.

Assessing Extinction Risk: Integrating Genetic Information

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Jason Dunham

1999-06-01

Full Text Available Risks of population extinction have been estimated using a variety of methods incorporating information from different spatial and temporal scales. We briefly consider how several broad classes of extinction risk assessments, including population viability analysis, incidence functions, and ranking methods integrate information on different temporal and spatial scales. In many circumstances, data from surveys of neutral genetic variability within, and among, populations can provide information useful for assessing extinction risk. Patterns of genetic variability resulting from past and present ecological and demographic events, can indicate risks of extinction that are otherwise difficult to infer from ecological and demographic analyses alone. We provide examples of how patterns of neutral genetic variability, both within, and among populations, can be used to corroborate and complement extinction risk assessments.

Genetics and variation

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John R. Jones; Norbert V. DeByle

1985-01-01

The broad genotypic variability in quaking aspen (Populus tremuloides Michx.), that results in equally broad phenotypic variability among clones is important to the ecology and management of this species. This chapter considers principles of aspen genetics and variation, variation in aspen over its range, and local variation among clones. For a more...

Little genetic variability in resilience among cattle exists for a range of performance traits across herds in Ireland differing in Fasciola hepatica prevalence.

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Twomey, Alan J; Graham, David A; Doherty, Michael L; Blom, Astrid; Berry, Donagh P

2018-06-04

interval. Therefore, there was reranking of sires for fertility traits across different F. hepatica prevalence levels. In conclusion, there was little or no genetic variability in sensitivity to F. hepatica prevalence levels among cattle for milk production and carcass traits. But, some genetic variability in sensitivity among dairy cows did exist for fertility traits measured across herds differing in F. hepatica prevalence.

Scrub typhus in South India: clinical and laboratory manifestations, genetic variability, and outcome.

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Varghese, George M; Janardhanan, Jeshina; Trowbridge, Paul; Peter, John V; Prakash, John A J; Sathyendra, Sowmya; Thomas, Kurien; David, Thambu S; Kavitha, M L; Abraham, Ooriapadickal C; Mathai, Dilip

2013-11-01

This study sought to document the clinical and laboratory manifestations, genetic variability, and outcomes of scrub typhus, an often severe infection caused by Orientia tsutsugamushi, in South India. Patients admitted to a large teaching hospital with IgM ELISA-confirmed scrub typhus were evaluated. Clinical examination with a thorough search for an eschar, laboratory testing, chest X-ray, and outcome were documented and analyzed. Additionally, a 410-bp region of the 56-kDa type-specific antigen gene of O. tsutsugamushi was sequenced and compared with isolates from other regions of Asia. Most of the 154 patients evaluated presented with fever and non-specific symptoms. An eschar was found in 86 (55%) patients. Mild hepatic involvement was seen in most, with other organ involvement including respiratory, cardiovascular, and renal. Multi-organ dysfunction was noted in 59 (38.3%), and the fatality rate was 7.8%. Hypotension requiring vasoactive agents was found to be an independent predictor of mortality (p<0.001). The phylogeny of 26 samples showed 17 (65%) clustering with the Kato-like group and eight (31%) with the Karp-like group. The presentation of scrub typhus can be variable, often non-specific, but with potentially severe multi-organ dysfunction. Prompt recognition is key to specific treatment and good outcomes. Further study of the circulating strains is essential for the development of a successful vaccine and sensitive point-of-care testing. Copyright © 2013 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Foundations of genetic algorithms 1991

CERN Document Server

1991-01-01

Foundations of Genetic Algorithms 1991 (FOGA 1) discusses the theoretical foundations of genetic algorithms (GA) and classifier systems.This book compiles research papers on selection and convergence, coding and representation, problem hardness, deception, classifier system design, variation and recombination, parallelization, and population divergence. Other topics include the non-uniform Walsh-schema transform; spurious correlations and premature convergence in genetic algorithms; and variable default hierarchy separation in a classifier system. The grammar-based genetic algorithm; condition

Estimates of genetic parameters and path analysis in lentil (lens culinaris medik)

International Nuclear Information System (INIS)

Younis, N.; Hanif, M.; Sadiq, S.; Abbas, G.; Asghar, M.J.; Haq, M.A.

2008-01-01

These studies were conducted to determine the genetic parameters and character association in elite lines 0 lentil (Lens culinaris Medik).Genetic parameters like genotypic and phenotypic variances, coefficients of variation heritability, genetic advance, correlation coefficients and path coefficients were estimated. Significant variation was noted for all the traits. High heritability estimates were observed for all the traits except number of primary branches per plant. In general phenotypic coefficients of variability were greater than their corresponding genotypic coefficient of variability. Higher estimates of heritability and genetic advance were observed for seed yield (97.10%, 90.71%), harvest index (96.20%, 63.29%) and maturity days (95.90%, 63.39%) indicating the these characters are mainly controlled by additive genes and selection of such traits might be effective for the improvement of seed yield. Days to flower, plant height, number of primary branches, biological yield, harvest index and hundred seed weight had positive direct effect on seed yield. Biological yield, hundred seed weight and harvest index also had positive and highly significant genotypic and phenotypic correlation with seed yield. Hence these traits could be used for the improvement of seed yield resulting in the evolution of high yielding varieties 0 lentil. (author)

Genetics and intelligence differences: five special findings

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Plomin, R; Deary, I J

2015-01-01

Intelligence is a core construct in differential psychology and behavioural genetics, and should be so in cognitive neuroscience. It is one of the best predictors of important life outcomes such as education, occupation, mental and physical health and illness, and mortality. Intelligence is one of the most heritable behavioural traits. Here, we highlight five genetic findings that are special to intelligence differences and that have important implications for its genetic architecture and for gene-hunting expeditions. (i) The heritability of intelligence increases from about 20% in infancy to perhaps 80% in later adulthood. (ii) Intelligence captures genetic effects on diverse cognitive and learning abilities, which correlate phenotypically about 0.30 on average but correlate genetically about 0.60 or higher. (iii) Assortative mating is greater for intelligence (spouse correlations ~0.40) than for other behavioural traits such as personality and psychopathology (~0.10) or physical traits such as height and weight (~0.20). Assortative mating pumps additive genetic variance into the population every generation, contributing to the high narrow heritability (additive genetic variance) of intelligence. (iv) Unlike psychiatric disorders, intelligence is normally distributed with a positive end of exceptional performance that is a model for ‘positive genetics'. (v) Intelligence is associated with education and social class and broadens the causal perspectives on how these three inter-correlated variables contribute to social mobility, and health, illness and mortality differences. These five findings arose primarily from twin studies. They are being confirmed by the first new quantitative genetic technique in a century—Genome-wide Complex Trait Analysis (GCTA)—which estimates genetic influence using genome-wide genotypes in large samples of unrelated individuals. Comparing GCTA results to the results of twin studies reveals important insights into the genetic

Effect of oligonucleotide primers in determining viral variability within hosts

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Moya Andrés

2004-12-01

Full Text Available Abstract Background Genetic variability in viral populations is usually estimated by means of polymerase chain reaction (PCR based methods in which the relative abundance of each amplicon is assumed to be proportional to the frequency of the corresponding template in the initial sample. Although bias in template-to-product ratios has been described before, its relevance in describing viral genetic variability at the intrapatient level has not been fully assessed yet. Results To investigate the role of oligonucleotide design in estimating viral variability within hosts, genetic diversity in hepatitis C virus (HCV populations from eight infected patients was characterised by two parallel PCR amplifications performed with two slightly different sets of primers, followed by cloning and sequencing (mean = 89 cloned sequences per patient. Population genetics analyses of viral populations recovered by pairs of amplifications revealed that in seven patients statistically significant differences were detected between populations sampled with different set of primers. Conclusions Genetic variability analyses demonstrates that PCR selection due to the choice of primers, differing in their degeneracy degree at some nucleotide positions, can eclipse totally or partially viral variants, hence yielding significant different estimates of viral variability within a single patient and therefore eventually producing quite different qualitative and quantitative descriptions of viral populations within each host.

Effect of oligonucleotide primers in determining viral variability within hosts.

Science.gov (United States)

Bracho, Maria Alma; García-Robles, Inmaculada; Jiménez, Nuria; Torres-Puente, Manuela; Moya, Andrés; González-Candelas, Fernando

2004-12-09

Genetic variability in viral populations is usually estimated by means of polymerase chain reaction (PCR) based methods in which the relative abundance of each amplicon is assumed to be proportional to the frequency of the corresponding template in the initial sample. Although bias in template-to-product ratios has been described before, its relevance in describing viral genetic variability at the intrapatient level has not been fully assessed yet. To investigate the role of oligonucleotide design in estimating viral variability within hosts, genetic diversity in hepatitis C virus (HCV) populations from eight infected patients was characterised by two parallel PCR amplifications performed with two slightly different sets of primers, followed by cloning and sequencing (mean = 89 cloned sequences per patient). Population genetics analyses of viral populations recovered by pairs of amplifications revealed that in seven patients statistically significant differences were detected between populations sampled with different set of primers. Genetic variability analyses demonstrates that PCR selection due to the choice of primers, differing in their degeneracy degree at some nucleotide positions, can eclipse totally or partially viral variants, hence yielding significant different estimates of viral variability within a single patient and therefore eventually producing quite different qualitative and quantitative descriptions of viral populations within each host.

Genetic Diversity of Pinus nigra Arn. Populations in Southern Spain and Northern Morocco Revealed By Inter-Simple Sequence Repeat Profiles

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Oussama Ahrazem

2012-05-01

Full Text Available Eight Pinus nigra Arn. populations from Southern Spain and Northern Morocco were examined using inter-simple sequence repeat markers to characterize the genetic variability amongst populations. Pair-wise population genetic distance ranged from 0.031 to 0.283, with a mean of 0.150 between populations. The highest inter-population average distance was between PaCU from Cuenca and YeCA from Cazorla, while the lowest distance was between TaMO from Morocco and MA Sierra Mágina populations. Analysis of molecular variance (AMOVA and Nei’s genetic diversity analyses revealed higher genetic variation within the same population than among different populations. Genetic differentiation (Gst was 0.233. Cuenca showed the highest Nei’s genetic diversity followed by the Moroccan region, Sierra Mágina, and Cazorla region. However, clustering of populations was not in accordance with their geographical locations. Principal component analysis showed the presence of two major groups—Group 1 contained all populations from Cuenca while Group 2 contained populations from Cazorla, Sierra Mágina and Morocco—while Bayesian analysis revealed the presence of three clusters. The low genetic diversity observed in PaCU and YeCA is probably a consequence of inappropriate management since no estimation of genetic variability was performed before the silvicultural treatments. Data indicates that the inter-simple sequence repeat (ISSR method is sufficiently informative and powerful to assess genetic variability among populations of P. nigra.

The effects of socioeconomic status, clinical factors, and genetic ancestry on pulmonary tuberculosis disease in northeastern Mexico.

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Bonnie N Young

Full Text Available Diverse socioeconomic and clinical factors influence susceptibility to tuberculosis (TB disease in Mexico. The role of genetic factors, particularly those that differ between the parental groups that admixed in Mexico, is unclear. The objectives of this study are to identify the socioeconomic and clinical predictors of the transition from latent TB infection (LTBI to pulmonary TB disease in an urban population in northeastern Mexico, and to examine whether genetic ancestry plays an independent role in this transition. We recruited 97 pulmonary TB disease patients and 97 LTBI individuals from a public hospital in Monterrey, Nuevo León. Socioeconomic and clinical variables were collected from interviews and medical records, and genetic ancestry was estimated for a subset of 142 study participants from 291,917 single nucleotide polymorphisms (SNPs. We examined crude associations between the variables and TB disease status. Significant predictors from crude association tests were analyzed using multivariable logistic regression. We also compared genetic ancestry between LTBI individuals and TB disease patients at 1,314 SNPs in 273 genes from the TB biosystem in the NCBI BioSystems database. In crude association tests, 12 socioeconomic and clinical variables were associated with TB disease. Multivariable logistic regression analyses indicated that marital status, diabetes, and smoking were independently associated with TB status. Genetic ancestry was not associated with TB disease in either crude or multivariable analyses. Separate analyses showed that LTBI individuals recruited from hospital staff had significantly higher European genetic ancestry than LTBI individuals recruited from the clinics and waiting rooms. Genetic ancestry differed between individuals with LTBI and TB disease at SNPs located in two genes in the TB biosystem. These results indicate that Monterrey may be structured with respect to genetic ancestry, and that genetic

The effects of socioeconomic status, clinical factors, and genetic ancestry on pulmonary tuberculosis disease in northeastern Mexico.

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Young, Bonnie N; Rendón, Adrian; Rosas-Taraco, Adrian; Baker, Jack; Healy, Meghan; Gross, Jessica M; Long, Jeffrey; Burgos, Marcos; Hunley, Keith L

2014-01-01

Diverse socioeconomic and clinical factors influence susceptibility to tuberculosis (TB) disease in Mexico. The role of genetic factors, particularly those that differ between the parental groups that admixed in Mexico, is unclear. The objectives of this study are to identify the socioeconomic and clinical predictors of the transition from latent TB infection (LTBI) to pulmonary TB disease in an urban population in northeastern Mexico, and to examine whether genetic ancestry plays an independent role in this transition. We recruited 97 pulmonary TB disease patients and 97 LTBI individuals from a public hospital in Monterrey, Nuevo León. Socioeconomic and clinical variables were collected from interviews and medical records, and genetic ancestry was estimated for a subset of 142 study participants from 291,917 single nucleotide polymorphisms (SNPs). We examined crude associations between the variables and TB disease status. Significant predictors from crude association tests were analyzed using multivariable logistic regression. We also compared genetic ancestry between LTBI individuals and TB disease patients at 1,314 SNPs in 273 genes from the TB biosystem in the NCBI BioSystems database. In crude association tests, 12 socioeconomic and clinical variables were associated with TB disease. Multivariable logistic regression analyses indicated that marital status, diabetes, and smoking were independently associated with TB status. Genetic ancestry was not associated with TB disease in either crude or multivariable analyses. Separate analyses showed that LTBI individuals recruited from hospital staff had significantly higher European genetic ancestry than LTBI individuals recruited from the clinics and waiting rooms. Genetic ancestry differed between individuals with LTBI and TB disease at SNPs located in two genes in the TB biosystem. These results indicate that Monterrey may be structured with respect to genetic ancestry, and that genetic differences in TB

Nonequilibrium Conditions Explain Spatial Variability in Genetic Structuring of Little Penguin (Eudyptula minor)

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Peucker, Amanda J.; Valautham, Sureen K.; Styan, Craig A.; Dann, Peter

2015-01-01

Factors responsible for spatial structuring of population genetic variation are varied, and in many instances there may be no obvious explanations for genetic structuring observed, or those invoked may reflect spurious correlations. A study of little penguins (Eudyptula minor) in southeast Australia documented low spatial structuring of genetic variation with the exception of colonies at the western limit of sampling, and this distinction was attributed to an intervening oceanographic feature (Bonney Upwelling), differences in breeding phenology, or sea level change. Here, we conducted sampling across the entire Australian range, employing additional markers (12 microsatellites and mitochondrial DNA, 697 individuals, 17 colonies). The zone of elevated genetic structuring previously observed actually represents the eastern half of a genetic cline, within which structuring exists over much shorter spatial scales than elsewhere. Colonies separated by as little as 27 km in the zone are genetically distinguishable, while outside the zone, homogeneity cannot be rejected at scales of up to 1400 km. Given a lack of additional physical or environmental barriers to gene flow, the zone of elevated genetic structuring may reflect secondary contact of lineages (with or without selection against interbreeding), or recent colonization and expansion from this region. This study highlights the importance of sampling scale to reveal the cause of genetic structuring. PMID:25833231

Genetic variation facilitates seedling establishment but not population growth rate of a perennial invader.

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Li, Shou-Li; Vasemägi, Anti; Ramula, Satu

2016-01-01

Assessing the demographic consequences of genetic variation is fundamental to invasion biology. However, genetic and demographic approaches are rarely combined to explore the effects of genetic variation on invasive populations in natural environments. This study combined population genetics, demographic data and a greenhouse experiment to investigate the consequences of genetic variation for the population fitness of the perennial, invasive herb Lupinus polyphyllus. Genetic and demographic data were collected from 37 L. polyphyllus populations representing different latitudes in Finland, and genetic variation was characterized based on 13 microsatellite loci. Associations between genetic variation and population size, population density, latitude and habitat were investigated. Genetic variation was then explored in relation to four fitness components (establishment, survival, growth, fecundity) measured at the population level, and the long-term population growth rate (λ). For a subset of populations genetic variation was also examined in relation to the temporal variability of λ. A further assessment was made of the role of natural selection in the observed variation of certain fitness components among populations under greenhouse conditions. It was found that genetic variation correlated positively with population size, particularly at higher latitudes, and differed among habitat types. Average seedling establishment per population increased with genetic variation in the field, but not under greenhouse conditions. Quantitative genetic divergence (Q(ST)) based on seedling establishment in the greenhouse was smaller than allelic genetic divergence (F'(ST)), indicating that unifying selection has a prominent role in this fitness component. Genetic variation was not associated with average survival, growth or fecundity measured at the population level, λ or its variability. The study suggests that although genetic variation may facilitate plant invasions by

Genetic diversity of dispersed seeds is highly variable among leks of the long-wattled umbrellabird

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Ottewell, Kym; Browne, Luke; Cabrera, Domingo; Olivo, Jorge; Karubian, Jordan

2018-01-01

Frugivorous animals frequently generate clumped distributions of seeds away from source trees, but genetic consequences of this phenomenon remain poorly resolved. Seed dispersal of the palm Oenocarpus bataua by long-wattled umbrellabirds Cephalopterus penduliger generates high seed densities in leks (i.e., multi-male display sites), providing a suitable venue to investigate how dispersal by this frugivore may influence seed source diversity and genetic structure at local and landscape levels. We found moderate levels of maternal seed source diversity in primary seed rain across five leks in northwest Ecuador (unweighted mean alpha diversity α = 9.52, weighted mean αr = 3.52), with considerable variation among leks (αr range: 1.81-24.55). Qualitatively similar findings were obtained for allelic diversity and heterozygosity. Higher densities of O. bataua adults around leks were associated with higher values of αr and heterozygosity (non-significant trends) and allelic diversity (significant correlation). Seed source overlap between different leks was not common but did occur at low frequency, providing evidence for long-distance seed dispersal by umbrellabirds into leks. Our findings are consistent with the idea that seed pool diversity within leks may be shaped by the interaction between density of local trees, which can vary considerably between leks, and umbrellabird foraging ecology, particularly a lack of territorial defense of fruiting trees. Taken as a whole, this work adds to our growing appreciation of the ways resource distribution and associated frugivore foraging behaviors mechanistically shape seed dispersal outcomes and the distribution of plant genotypes across the landscape.

Influence of TFAP2B and KCTD15 genetic variability on personality dimensions in anorexia and bulimia nervosa.

Science.gov (United States)

Gamero-Villarroel, Carmen; González, Luz M; Rodríguez-López, Raquel; Albuquerque, David; Carrillo, Juan A; García-Herráiz, Angustias; Flores, Isalud; Gervasini, Guillermo

2017-09-01

TFAP2B and KCTD15 are obesity-related genes that interact to regulate feeding behavior. We hypothesize that variability in these loci, isolated or in combination, could also be related to the risk of eating disorders (ED) and/or associated psychological traits. We screened 425 participants (169 ED patients, 75 obese subjects, and 181 controls) for 10 clinically relevant and tag single-nucleotide polymorphisms (SNPs) in KCTD15 and TFAP2B by the Sequenom MassARRAY platform and direct sequencing. Psychometric evaluation was performed with EDI-2 and SCL-90R inventories. The KCTD15 rs287103 T variant allele was associated with increased risk of bulimia nervosa (BN) (OR = 4.34 [1.47-29.52]; p  = .003) and with scores of psychopathological scales of these patients. Haplotype *6 in KCTD15 was more frequent in controls (OR = 0.40 [0.20-0.80], p  = .009 for anorexia nervosa), while haplotype *4 in TFAP2B affected all three scales of the SCL-90R inventory in BN patients ( p  ≤ .01). Epistasis analyses revealed relevant interactions with body mass index of BN patients ( p  < .001). Genetic profiles in obese patients did not significantly differ from those found in ED patients. This is the first study that evaluates the combined role of TFAP2B and KCTD15 genes in ED. Our preliminary findings suggest that the interaction of genetic variability in these loci could influence the risk for ED and/or anthropometric and psychological parameters.

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

Science.gov (United States)

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

2013-09-01

Populations of widespread marine organisms are typically characterized by a low degree of genetic differentiation in neutral genetic markers, but much less is known about differentiation in genes whose functional roles are associated with specific selection regimes. To uncover possible adaptive population divergence and heterogeneous genomic differentiation in marine three-spined sticklebacks (Gasterosteus aculeatus), we used a candidate gene-based genome-scan approach to analyse variability in 138 microsatellite loci located within/close to (<6 kb) functionally important genes in samples collected from ten geographic locations. The degree of genetic differentiation in markers classified as neutral or under balancing selection-as determined with several outlier detection methods-was low (F(ST) = 0.033 or 0.011, respectively), whereas average FST for directionally selected markers was significantly higher (F(ST) = 0.097). Clustering analyses provided support for genomic and geographic heterogeneity in selection: six genetic clusters were identified based on allele frequency differences in the directionally selected loci, whereas four were identified with the neutral loci. Allelic variation in several loci exhibited significant associations with environmental variables, supporting the conjecture that temperature and salinity, but not optic conditions, are important drivers of adaptive divergence among populations. In general, these results suggest that in spite of the high degree of physical connectivity and gene flow as inferred from neutral marker genes, marine stickleback populations are strongly genetically structured in loci associated with functionally relevant genes. © 2013 John Wiley & Sons Ltd.

Genetic Structure in a Small Pelagic Fish Coincides with a Marine Protected Area: Seascape Genetics in Patagonian Fjords.

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Cristian B Canales-Aguirre

Full Text Available Marine environmental variables can play an important role in promoting population genetic differentiation in marine organisms. Although fjord ecosystems have attracted much attention due to the great oscillation of environmental variables that produce heterogeneous habitats, species inhabiting this kind of ecosystem have received less attention. In this study, we used Sprattus fuegensis, a small pelagic species that populates the inner waters of the continental shelf, channels and fjords of Chilean Patagonia and Argentina, as a model species to test whether environmental variables of fjords relate to population genetic structure. A total of 282 individuals were analyzed from Chilean Patagonia with eight microsatellite loci. Bayesian and non-Bayesian analyses were conducted to describe the genetic variability of S. fuegensis and whether it shows spatial genetic structure. Results showed two well-differentiated genetic clusters along the Chilean Patagonia distribution (i.e. inside the embayment area called TicToc, and the rest of the fjords, but no spatial isolation by distance (IBD pattern was found with a Mantel test analysis. Temperature and nitrate were correlated to the expected heterozygosities and explained the allelic frequency variation of data in the redundancy analyses. These results suggest that the singular genetic differences found in S. fuegensis from inside TicToc Bay (East of the Corcovado Gulf are the result of larvae retention bya combination of oceanographic mesoscale processes (i.e. the west wind drift current reaches the continental shelf exactly in this zone, and the local geographical configuration (i.e. embayment area, islands, archipelagos. We propose that these features generated an isolated area in the Patagonian fjords that promoted genetic differentiation by drift and a singular biodiversity, adding support to the existence of the largest marine protected area (MPA of continental Chile, which is the Tic-Toc MPA.

Genetic Structure in a Small Pelagic Fish Coincides with a Marine Protected Area: Seascape Genetics in Patagonian Fjords.

Science.gov (United States)

Canales-Aguirre, Cristian B; Ferrada-Fuentes, Sandra; Galleguillos, Ricardo; Hernández, Cristián E

2016-01-01

Marine environmental variables can play an important role in promoting population genetic differentiation in marine organisms. Although fjord ecosystems have attracted much attention due to the great oscillation of environmental variables that produce heterogeneous habitats, species inhabiting this kind of ecosystem have received less attention. In this study, we used Sprattus fuegensis, a small pelagic species that populates the inner waters of the continental shelf, channels and fjords of Chilean Patagonia and Argentina, as a model species to test whether environmental variables of fjords relate to population genetic structure. A total of 282 individuals were analyzed from Chilean Patagonia with eight microsatellite loci. Bayesian and non-Bayesian analyses were conducted to describe the genetic variability of S. fuegensis and whether it shows spatial genetic structure. Results showed two well-differentiated genetic clusters along the Chilean Patagonia distribution (i.e. inside the embayment area called TicToc, and the rest of the fjords), but no spatial isolation by distance (IBD) pattern was found with a Mantel test analysis. Temperature and nitrate were correlated to the expected heterozygosities and explained the allelic frequency variation of data in the redundancy analyses. These results suggest that the singular genetic differences found in S. fuegensis from inside TicToc Bay (East of the Corcovado Gulf) are the result of larvae retention bya combination of oceanographic mesoscale processes (i.e. the west wind drift current reaches the continental shelf exactly in this zone), and the local geographical configuration (i.e. embayment area, islands, archipelagos). We propose that these features generated an isolated area in the Patagonian fjords that promoted genetic differentiation by drift and a singular biodiversity, adding support to the existence of the largest marine protected area (MPA) of continental Chile, which is the Tic-Toc MPA.

Genetic variability of aryl hydrocarbon receptor (AhR)-mediated regulation of the human UDP glucuronosyltransferase (UGT) 1A4 gene

Energy Technology Data Exchange (ETDEWEB)

Erichsen, Thomas J; Ehmer, Ursula; Kalthoff, Sandra; Lankisch, Tim O; Mueller, Tordis M [Department of Gastroenterology, Hepatology and Endocrinology, Hannover, Medical School, Hannover (Germany); Munzel, Peter A [Department of Toxicology, Institute of Pharmacology and Toxicology, University of Tubingen, Tubingen (Germany); Manns, Michael P [Department of Gastroenterology, Hepatology and Endocrinology, Hannover, Medical School, Hannover (Germany); Strassburg, Christian P. [Department of Gastroenterology, Hepatology and Endocrinology, Hannover, Medical School, Hannover (Germany)], E-mail: strassburg.christian@mh-hannover.de

2008-07-15

UDP glucuronosyltransferases (UGTs) play an important role for drug detoxification and toxicity. UGT function is genetically modulated by single nucleotide polymorphisms (SNPs) which lead to the expression of functionally altered protein, or altered expression levels. UGT1A4 activity includes anticonvulsants, antidepressants and environmental mutagens. In this study the induction of the human UGT1A4 gene and a potential influence of genetic variation in its promoter region were analyzed. SNPs at bp - 219 and - 163 occurred in 9% among 109 blood donors reducing UGT1A4 transcription by 40%. UGT1A4 transcription was dioxin inducible. Reporter gene experiments identified 2 xenobiotic response elements (XRE), which were functionally confirmed by mutagenesis analyses, and binding was demonstrated by electromobility shift assays. Constitutive human UGT1A4 gene expression and induction was aryl hydrocarbon receptor (AhR)-dependent, and reduced in the presence of SNPs at bp - 219 and - 163. AhR-mediated regulation of the human UGT1A4 gene by two XRE and a modulation by naturally occurring genetic variability by SNPs is demonstrated, which indicates gene-environment interaction with potential relevance for drug metabolism.

Genetic variability of aryl hydrocarbon receptor (AhR)-mediated regulation of the human UDP glucuronosyltransferase (UGT) 1A4 gene

International Nuclear Information System (INIS)

Erichsen, Thomas J.; Ehmer, Ursula; Kalthoff, Sandra; Lankisch, Tim O.; Mueller, Tordis M.; Munzel, Peter A.; Manns, Michael P.; Strassburg, Christian P.

2008-01-01

UDP glucuronosyltransferases (UGTs) play an important role for drug detoxification and toxicity. UGT function is genetically modulated by single nucleotide polymorphisms (SNPs) which lead to the expression of functionally altered protein, or altered expression levels. UGT1A4 activity includes anticonvulsants, antidepressants and environmental mutagens. In this study the induction of the human UGT1A4 gene and a potential influence of genetic variation in its promoter region were analyzed. SNPs at bp - 219 and - 163 occurred in 9% among 109 blood donors reducing UGT1A4 transcription by 40%. UGT1A4 transcription was dioxin inducible. Reporter gene experiments identified 2 xenobiotic response elements (XRE), which were functionally confirmed by mutagenesis analyses, and binding was demonstrated by electromobility shift assays. Constitutive human UGT1A4 gene expression and induction was aryl hydrocarbon receptor (AhR)-dependent, and reduced in the presence of SNPs at bp - 219 and - 163. AhR-mediated regulation of the human UGT1A4 gene by two XRE and a modulation by naturally occurring genetic variability by SNPs is demonstrated, which indicates gene-environment interaction with potential relevance for drug metabolism

Genetic variation and correlation of agronomic traits in meadow bromegrass (Bromus riparius Rehm clones

Directory of Open Access Journals (Sweden)

Araújo Marcelo Renato Alves de

2004-01-01

Full Text Available Meadow bromegrass (Bromus riparius Rehm. is a recently introduced pasture grass in western Canada. Its leafy production and rapid regrowth have made it a major grass species for pasturing beef animals in this region. As relatively little breeding work has been done on this species, there is little information on its breeding behaviour. The main objective of this study was to estimate total genetic variability, broad-sense heritability, phenotypic and genetic correlations. Forty-four meadow bromegrass clones were evaluated for agronomic characters. Genetic variation for dry matter yield, seed yield, fertility index, harvest index, plant height, plant spread, crude protein, neutral detergent fiber and acid detergent fiber, was significant. Broad-sense heritability estimates exceeded 50% for all characters. Heritability estimates were at least 3.5 times greater than their standard errors. Phenotypic and genetic correlation between all possible characters were measured. There was general agreement in both sign and magnitude between genetic and phenotypic correlations. Correlations between the different characters demonstrated that it is possible to simultaneously improve seed and forage yield. Based on the results, it appears that the development of higher yielding cultivars with higher crude protein, and lower acid and neutral detergent fibers concentration should be possible.

Genetic variability and structure of an isolated population of ...

Indian Academy of Sciences (India)

Rosa-Laura Heredia-Bobadilla

2017-11-15

Nov 15, 2017 ... Journal of Genetics, Vol. 96, No. 6, December 2017 ... or international status of protection. The mole ... populations by a matrix of agriculture and urbanization, can be considered ...... BioScience 38, 471–479. Lemos-Espinal ...

Genetic variability of psychrotolerant Acidithiobacillus ferrivorans revealed by (meta)genomic analysis.

Science.gov (United States)

González, Carolina; Yanquepe, María; Cardenas, Juan Pablo; Valdes, Jorge; Quatrini, Raquel; Holmes, David S; Dopson, Mark

2014-11-01

Acidophilic microorganisms inhabit low pH environments such as acid mine drainage that is generated when sulfide minerals are exposed to air. The genome sequence of the psychrotolerant Acidithiobacillus ferrivorans SS3 was compared to a metagenome from a low temperature acidic stream dominated by an A. ferrivorans-like strain. Stretches of genomic DNA characterized by few matches to the metagenome, termed 'metagenomic islands', encoded genes associated with metal efflux and pH homeostasis. The metagenomic islands were enriched in mobile elements such as phage proteins, transposases, integrases and in one case, predicted to be flanked by truncated tRNAs. Cus gene clusters predicted to be involved in copper efflux and further Cus-like RND systems were predicted to be located in metagenomic islands and therefore, constitute part of the flexible gene complement of the species. Phylogenetic analysis of Cus clusters showed both lineage specificity within the Acidithiobacillus genus as well as niche specificity associated with an acidic environment. The metagenomic islands also contained a predicted copper efflux P-type ATPase system and a polyphosphate kinase potentially involved in polyphosphate mediated copper resistance. This study identifies genetic variability of low temperature acidophiles that likely reflects metal resistance selective pressures in the copper rich environment. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Journal of Genetics | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Genetics. ARMANDO SUNNY. Articles written in Journal of Genetics. Volume 96 Issue 6 December 2017 pp 873-883 RESEARCH ARTICLE. Genetic variability and structure of an isolated population of Ambystoma altamirani , a mole salamander that lives in the mountains of one of the largest ...

Genetic variation within three populations of Phycella australis (Phil. Ravenna from Biobío Region, Chile, evaluated using ISSR markers

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Cristian Flores

2013-03-01

Full Text Available Phycella australis (Phil. Ravenna is a Chilean plant with high ornamental potential; however, the intensive extraction as a cut flower might be detrimental for the conservational state by ignoring the state of genetic variation. The objective of this investigation was to assess genetic variability within and between three populations of P. australis in the Biobío Region using inter-simple sequence repeat (ISSR markers. The evaluated areas correspond to three locations in the province of Concepción, Biobío Region: Desembocadura (36°48' S, 73°10' W, Santa Juana (36°58' S, 72°58' W, and Lipinhue (37°00' S, 72°58' W. Six ISSR primers were used obtaining 51 fragments, from which 72.5% were polymorphic. From the three evaluated sites Santa Juana showed a higher percentage of polymorphic loci (76.47%. From this variability, 83% belong to within population variability and only 17% belong to variability between populations. The dendrogram generated using the unweighted pair group method with arithmetic mean (UPGMA method, grouped Lipinhue and Santa Juana sites together, which agrees with the geographic locations. This investigation proved that P. australis has high genetic variability despite the exploitation for economic purposes.

Genetic variability and relationship between MT-1 elephant grass ...

Indian Academy of Sciences (India)

tein, 28 to 40 per cent in crude fiber, 10 to 16 per cent in ash, 0.9 ... and forage production in the alley cropping system of agro- ... Keywords. genetic diversity; cluster analysis; DNA markers; Shannon information index; Pennisetum purpureum.

Regulation of Saccharomyces cerevisiae genetic engineering on the production of acetate esters and higher alcohols during Chinese Baijiu fermentation.

Science.gov (United States)

Li, Wei; Wang, Jian-Hui; Zhang, Cui-Ying; Ma, Hong-Xia; Xiao, Dong-Guang

2017-06-01

Acetate esters and higher alcohols greatly influence the quality and flavor profiles of Chinese Baijiu (Chinese liquor). Various mutants have been constructed to investigate the interactions of ATF1 overexpression, IAH1 deletion, and BAT2 deletion on the production of acetate esters and higher alcohols. The results showed that the overexpression of ATF1 under the control of the PGK1 promoter with BAT2 and IAH1 double-gene deletion led to a higher production of acetate esters and a lower production of higher alcohols than the overexpression of ATF1 with IAH1 deletion or overexpression of ATF1 with BAT2 deletion. Moreover, deletion of IAH1 in ATF1 overexpression strains effectively increased the production of isobutyl acetate and isoamyl acetate by reducing the hydrolysis of acetate esters. The decline in the production of higher alcohol by the ATF1 overexpression strains with BAT2 deletion is due to the interaction of ATF1 overexpression and BAT2 deletion. Mutants with varying abilities of producing acetate esters and higher alcohols were developed by genetic engineering. These strains have great potential for industrial application.

Multi-objective optimization in systematic conservation planning and the representation of genetic variability among populations.

Science.gov (United States)

Schlottfeldt, S; Walter, M E M T; Carvalho, A C P L F; Soares, T N; Telles, M P C; Loyola, R D; Diniz-Filho, J A F

2015-06-18

Biodiversity crises have led scientists to develop strategies for achieving conservation goals. The underlying principle of these strategies lies in systematic conservation planning (SCP), in which there are at least 2 conflicting objectives, making it a good candidate for multi-objective optimization. Although SCP is typically applied at the species level (or hierarchically higher), it can be used at lower hierarchical levels, such as using alleles as basic units for analysis, for conservation genetics. Here, we propose a method of SCP using a multi-objective approach. We used non-dominated sorting genetic algorithm II in order to identify the smallest set of local populations of Dipteryx alata (baru) (a Brazilian Cerrado species) for conservation, representing the known genetic diversity and using allele frequency information associated with heterozygosity and Hardy-Weinberg equilibrium. We worked in 3 variations for the problem. First, we reproduced a previous experiment, but using a multi-objective approach. We found that the smallest set of populations needed to represent all alleles under study was 7, corroborating the results of the previous study, but with more distinct solutions. In the 2nd and 3rd variations, we performed simultaneous optimization of 4 and 5 objectives, respectively. We found similar but refined results for 7 populations, and a larger portfolio considering intra-specific diversity and persistence with populations ranging from 8-22. This is the first study to apply multi-objective algorithms to an SCP problem using alleles at the population level as basic units for analysis.

First and higher order, heuristically based generalized perturbation theory (HGPT) with optional control reset variable

International Nuclear Information System (INIS)

Gandini, A.

1996-01-01

The heuristically based generalized perturbation theory (HGPT), to first and higher order, applied to the neutron field of a reactor system, is discussed in relation to the criticality reset procedure. This procedure is implicit within the GPT methodology, corresponding to the so called filtering of the importance function relevant to the neutron field from the fundamental mode contamination. It is common practice to use the so called ''lambda''-mode filter. In order to account for any possible reset option, a general definition is introduced of an intensive control variable (ρ) entering into the governing equations, and correspondingly a fundamental ρ-mode filtering of the importance function is defined, relevant to the real criticality reset (control) mechanism adopted. A simple example illustrates the need to take into account the correct filtering, so as to avoid significant inaccuracies in the sensitivity calculation results. The extension of this filtering technique to other functions entering into the GPT perturbative formulations at first and higher order is also discussed. (author)

Genetic disorders as collective phenomena

International Nuclear Information System (INIS)

Chela-Flores, J.

1987-05-01

Genetic disorders due to human chromosome aberrations in number are discussed from the point of view of Molecular Genetics. The etiology of trisomy is discussed in the light of the collective variables recently introduced and an age-dependent metabolic disorder is suggested as a possible etiological factor. (author). 11 refs

Utility of computer simulations in landscape genetics

Science.gov (United States)

Bryan K. Epperson; Brad H. McRae; Kim Scribner; Samuel A. Cushman; Michael S. Rosenberg; Marie-Josee Fortin; Patrick M. A. James; Melanie Murphy; Stephanie Manel; Pierre Legendre; Mark R. T. Dale

2010-01-01

Population genetics theory is primarily based on mathematical models in which spatial complexity and temporal variability are largely ignored. In contrast, the field of landscape genetics expressly focuses on how population genetic processes are affected by complex spatial and temporal environmental heterogeneity. It is spatially explicit and relates patterns to...

The African baobab (Adansonia digitata, Malvaceae): genetic resources in neglected populations of the Nuba Mountains, Sudan.

Science.gov (United States)

Wiehle, Martin; Prinz, Kathleen; Kehlenbeck, Katja; Goenster, Sven; Mohamed, Seifeldin Ali; Finkeldey, Reiner; Buerkert, Andreas; Gebauer, Jens

2014-09-01

• Adansonia digitata L. is one of the most important indigenous fruit trees of mainland Africa. Despite its significance for subsistence and income generation of local communities, little is known about the genetic and morphological variability of East African populations of A. digitata, including those of Sudan. The aim of the current study, therefore, was to analyze genetic and morphological variability of different baobab populations in Kordofan, Sudan and to estimate the effect of human intervention on genetic differentiation and diversity.• A total of 306 trees were randomly sampled from seven spatially separated locations in the Nuba Mountains, Sudan, to cover a wide range of differing environmental gradients and management regimes ('homesteads' and 'wild'). Genetic analyses were conducted using nine microsatellite markers. Because of the tetraploid nature of A. digitata, different approaches were applied to estimate patterns of genetic diversity. Investigations were completed by measurements of dendrometric and fruit morphological characters.• Genetic diversity was balanced and did not differ between locations or management regimes, although tendencies of higher diversity in 'homesteads' were observed. A Bayesian cluster approach detected two distinct gene pools in the sample set, mainly caused by one highly diverse population close to a main road. The variability of tree characters and fruit morphometries was high, and significantly different between locations.• Results indicated a rather positive effect with human intervention. The observed populations provide a promising gene pool and likely comprise ecotypes well-adapted to environmental conditions at the northern distribution range of the species, which should be considered in conservation and management programs. © 2014 Botanical Society of America, Inc.

The evolution of RNA viruses: A population genetics view

Science.gov (United States)

Moya, Andrés; Elena, Santiago F.; Bracho, Alma; Miralles, Rosario; Barrio, Eladio

2000-01-01

RNA viruses are excellent experimental models for studying evolution under the theoretical framework of population genetics. For a proper justification of this thesis we have introduced some properties of RNA viruses that are relevant for studying evolution. On the other hand, population genetics is a reductionistic theory of evolution. It does not consider or make simplistic assumptions on the transformation laws within and between genotypic and phenotypic spaces. However, such laws are minimized in the case of RNA viruses because the phenotypic space maps onto the genotypic space in a much more linear way than on higher DNA-based organisms. Under experimental conditions, we have tested the role of deleterious and beneficial mutations in the degree of adaptation of vesicular stomatitis virus (VSV), a nonsegmented virus of negative strand. We also have studied how effective population size, initial genetic variability in populations, and environmental heterogeneity shapes the impact of mutations in the evolution of vesicular stomatitis virus. Finally, in an integrative attempt, we discuss pros and cons of the quasispecies theory compared with classic population genetics models for haploid organisms to explain the evolution of RNA viruses. PMID:10860958

Higher incidence of nasopharyngeal carcinoma in some regions in the world confers for interplay between genetic factors and external stimuli.

Science.gov (United States)

Roy Chattopadhyay, Nabanita; Das, Piyanki; Chatterjee, Koustav; Choudhuri, Tathagata

2017-01-01

Nasopharyngeal carcinoma (NPC) is a rare variety of head and neck cancers. The risk factors include three major causes: genetic factors, viral infection, and environmental and dietary factors. The types of NPC show strong ethnic and geographic variations. The keratinizing and non-keratinizing types are prevalent in the lower incidence regions like North America and Europe; whereas the undifferentiated type is mostly found in the regions with higher incidences like China, North Africa, Arctic, and Nagaland of North-East India. These suggest a possible major role of the internal genetic factors for generation and promotion of this disease. Viral infections might accelerate the process of carcinogenesis by helping in cellular proliferation and loss of apoptosis. Diet and other environmental factors promote these neoplastic processes and further progression of the disease occurs.

Marine reserves help preserve genetic diversity after impacts derived from climate variability: Lessons from the pink abalone in Baja California

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Adrián Munguía-Vega

2015-07-01

Full Text Available Genetic diversity is crucial for the adaptation of exploited species like the pink abalone (Haliotis corrugata, faced with threats from climate change, overfishing and impacts associated with aquaculture production. While marine reserves are commonly used to mitigate risks to marine populations, the duration, size, location and larval connectivity needed for a reserve to help conserve genetic resources is still poorly understood. Here, we examine the effects of fishing, reserves, and restocking on the genetic diversity of 10 populations from central Baja California, Mexico, and Southern California, USA. We demonstrate that each population shows characteristic genetic signatures according to recent management decisions. We found high allelic diversity, particularly rare alleles, a larger effective population size and a lack of a recent genetic bottleneck in pink abalones within a small (0.8 km2, recently established (5 years reserve in Baja California, compared to other fished sites after a climatic bottleneck. Higher diversity may result from the presence of older animals in the reserve. Due to its location, the reserve may also act as an important hub connecting distant populations via larval dispersal. In contrast, a population from California showed genetic isolation, loss of allelic diversity and high relatedness, consistent with the collapse of fisheries in the 1990s and their lack of recovery thereafter. In addition, a fished area in Baja California with a history of restocking for over a decade showed an increase in frequency of related individuals and high genetic differentiation from nearby sites that were consistent with the production of larvae from a few adults in the laboratory. A network of strategically placed small marine reserves that considers ocean circulation patterns could help to maintain genetic diversity and connectivity of exploited populations.

Genetic Contributions to Clinical Pain and Analgesia: Avoiding Pitfalls in Genetic Research

Science.gov (United States)

Kim, Hyungsuk; Clark, David; Dionne, Raymond A.

2010-01-01

Understanding the genetic basis of human variations in pain is critical to elucidating the molecular basis of pain sensitivity, variable responses to analgesic drugs, and, ultimately, to individualized treatment of pain and improved public health. With the help of recently accumulated knowledge and advanced technologies, pain researchers hope to gain insight into genetic mechanisms of pain and eventually apply this knowledge to pain treatment. Perspective We critically reviewed the published literature to examine the strength of evidence supporting genetic influences on clinical and human experimental pain. Based on this evidence and the experience of false associations that have occurred in other related disciplines, we provide recommendations for avoiding pitfalls in pain genetic research. PMID:19559388

Genetic variability and effective population size when local extinction and recolonization of subpopulations are frequent

Science.gov (United States)

Maruyama, Takeo; Kimura, Motoo

1980-01-01

If a population (species) consists of n haploid lines (subpopulations) which reproduce asexually and each of which is subject to random extinction and subsequent replacement, it is shown that, at equilibrium in which mutational production of new alleles and their random extinction balance each other, the genetic diversity (1 minus the sum of squares of allelic frequencies) is given by 2Nev/(1 + 2Nev), where [Formula: see text] in which Ñ is the harmonic mean of the population size per line, n is the number of lines (assumed to be large), λ is the rate of line extinction, and v is the mutation rate (assuming the infinite neutral allele model). In a diploid population (species) consisting of n colonies, if migration takes place between colonies at the rate m (the island model) in addition to extinction and recolonization of colonies, it is shown that effective population size is [Formula: see text] If the rate of colony extinction (λ) is much larger than the migration rate of individuals, the effective population size is greatly reduced compared with the case in which no colony extinctions occur (in which case Ne = nÑ). The stepping-stone type of recolonization scheme is also considered. Bearing of these results on the interpretation of the level of genetic variability at the enzyme level observed in natural populations is discussed from the standpoint of the neutral mutation-random drift hypothesis. PMID:16592920

Journal of Genetics | Indian Academy of Sciences

Indian Academy of Sciences (India)

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

Form factors and complete spectrum of XXX antiperiodic higher spin chains by quantum separation of variables

Energy Technology Data Exchange (ETDEWEB)

Niccoli, G. [YITP, Stony Brook University, New York 11794-3840 (United States)

2013-05-15

The antiperiodic transfer matrices associated to higher spin representations of the rational 6-vertex Yang-Baxter algebra are analyzed by generalizing the approach introduced recently in the framework of Sklyanin's quantum separation of variables (SOV) for cyclic representations, spin-1/2 highest weight representations, and also for spin-1/2 representations of the 6-vertex reflection algebra. Such SOV approach allow us to derive exactly results which represent complicate tasks for more traditional methods based on Bethe ansatz and Baxter Q-operator. In particular, we both prove the completeness of the SOV characterization of the transfer matrix spectrum and its simplicity. Then, the derived characterization of local operators by Sklyanin's quantum separate variables and the expression of the scalar products of separate states by determinant formulae allow us to compute the form factors of the local spin operators by one determinant formulae similar to those of the scalar products.

Genetic characterization of Istrian goat: the key-point for a long-term conservation

Directory of Open Access Journals (Sweden)

Ante Ivanković

2018-01-01

Full Text Available Istrian goat is an autochthonous Croatian breed which inhabited Istrian peninsula and was important in milk production and human nutrition, especially for poor people. For centuries Istrian goat was a recognizable heraldic symbol of Istria, but in her real form almost disappeared from the breeding area. The revitalization and reaffirmation of Istrian goat began with several dozen remaining breeding animals, after a decade-long breeding ban. Genetic characterization of the Istrian goat population is necessary for providing insight into the state of genetically preserved structure within population as well as positioning Istrian goats within phylogenetically related breeds. Microsatellite and mtDNA analysis of reproductive individuals of Istrian goat and related breeds, Croatian White goat and Saanen goat was carried out. In the population of Istrian goat, higher allelic variability (nA = 9.7; AR = 7.4 were found as well as significant genetic distance (FST = 0.068 - 0.086 in relation to other two breeds. Such results indicated that Istrian goat constitutes a separate genetic identity. The observed ten haplotype sequences of the D-loop mtDNA also confirm the significant genetic richness of the maternal hereditary component. The observed haplotypes in the population of Istrian goat belong to lineage A. A smaller number of haplotypes shows similarity to the group of “white” goats, indicating traces of earlier limited but targeted crossing of Istrian goats. The genetic profile analysis of Istrian goats indicates a high level of genetic variability and provides guidelines for a long-term conservation program. The preserved genetic and promising potential of milk production of Istrian goat makes a significant basis for her economic reaffirmation. Orientation of the breed towards milk production could be an efficient strategy for its effective preservation.

Genetic variability of sorghum landraces from lower Eastern Kenya ...

African Journals Online (AJOL)

Reuben M. Muasya

2016-02-24

Feb 24, 2016 ... from the farmers and four improved varieties were analyzed using 20 SSR markers. All markers were polymorphic with ... Levels and patterns of diversity within and between cultivated and wild sorghum gene pools ..... environmental heterogeneity and/or farmer preferences and random genetic drift (Neal, ...

Studies on mutagenic effect on genetic variability in green gram (Vigna radiata (L. ) Wilczek)

Energy Technology Data Exchange (ETDEWEB)

Krishnaswami, S; Rathinam, M [Tamil Nadu Agricultural Univ. Coimbatore (India). Dept. of Agricultural Botany

1982-03-01

With a view to finding out the effect of mutagenic treatments on heritability in green gram, two cultivars, showing extremes of sensitivity to mutagen, were subjected to two levels each of gamma irradiation and EMS separately and conjointly and the M/sub 2/ generation raised. Families of the higher dose in each treatment were advanced to the M/sub 3/ and the genetic parameters of the various growth and yield attributes, besides seed yield, studied. Barring plant height, heritability of all other traits registered an increase under the mutagen effect. No consistency was evident in the superiority of one mutagen over the other, their behaviour varying with the cultivar and the character studied. Consequent to enhancement in heritability, correlations between the characters underwent alterations under the mutagens.

Adaptive genetic potential of coniferous forest tree species under climate change: implications for sustainable forest management

Science.gov (United States)

Mihai, Georgeta; Birsan, Marius-Victor; Teodosiu, Maria; Dumitrescu, Alexandru; Daia, Mihai; Mirancea, Ionel; Ivanov, Paula; Alin, Alexandru

2017-04-01

Mountain ecosystems are extremely vulnerable to climate change. The real potential for adaptation depends upon the existence of a wide genetic diversity in trees populations, upon the adaptive genetic variation, respectively. Genetic diversity offers the guarantee that forest species can survive, adapt and evolve under the influence of changing environmental conditions. The aim of this study is to evaluate the genetic diversity and adaptive genetic potential of two local species - Norway spruce and European silver fir - in the context of regional climate change. Based on data from a long-term provenance experiments network and climate variables spanning over more than 50 years, we have investigated the impact of climatic factors on growth performance and adaptation of tree species. Our results indicate that climatic and geographic factors significantly affect forest site productivity. Mean annual temperature and annual precipitation amount were found to be statistically significant explanatory variables. Combining the additive genetic model with the analysis of nuclear markers we obtained different images of the genetic structure of tree populations. As genetic indicators we used: gene frequencies, genetic diversity, genetic differentiation, genetic variance, plasticity. Spatial genetic analyses have allowed identifying the genetic centers holding high genetic diversity which will be valuable sources of gene able to buffer the negative effects of future climate change. Correlations between the marginal populations and in the optimal vegetation, between the level of genetic diversity and ecosystem stability, will allow the assessment of future risks arising from current genetic structure. Therefore, the strategies for sustainable forest management have to rely on the adaptive genetic variation and local adaptation of the valuable genetic resources. This work was realized within the framework of the project GENCLIM (Evaluating the adaptive potential of the main

Chicken meat quality: genetic variability and relationship with growth and muscle characteristics

Directory of Open Access Journals (Sweden)

Santé-Lhoutellier Véronique

2008-08-01

Full Text Available Abstract Background The qualitative properties of the meat are of major importance for poultry breeding, since meat is now widely consumed as cuts or as processed products. The aim of this study was to evaluate the genetic parameters of several breast meat quality traits and their genetic relationships with muscle characteristics in a heavy commercial line of broilers. Results Significant levels of heritability (averaging 0.3 were obtained for breast meat quality traits such as pH at 15 min post-slaughter, ultimate pH (pHu, color assessed by lightness L*, redness a* and yellowness b*, drip loss, thawing-cooking loss and shear-force. The rate of decrease in pH early post-mortem and the final pH of the meat were shown to be key factors of chicken meat quality. In particular, a decrease in the final pH led to paler, more exudative and tougher breast meat. The level of glycogen stored in breast muscle estimated by the Glycolytic Potential (GP at slaughter time was shown to be highly heritable (h2 0.43. There was a very strong negative genetic correlation (rg with ultimate meat pH (rg -0.97, suggesting a common genetic control for GP and pHu. While breast muscle weight was genetically positively correlated with fiber size (rg 0.76, it was negatively correlated with the level of glycogen stored in the muscle (rg -0.58, and as a consequence it was positively correlated with the final pH of the meat (rg 0.84. Conclusion This genetic study confirmed that selection should be useful to improve meat characteristics of meat-type chickens without impairing profitability because no genetic conflict was detected between meat quality and meat quantity. Moreover, the results suggested relevant selection criteria such as ultimate pH, which is strongly related to color, water-holding capacity and texture of the meat in this heavy chicken line.

Computational Integration of Human Genetic Data to Evaluate AOP-Specific Susceptibility

Science.gov (United States)

There is a need for approaches to efficiently evaluate human genetic variability and susceptibility related to environmental chemical exposure. Direct estimation of the genetic contribution to variability in susceptibility to environmental chemicals is only possible in special ca...

Identifying genetic signatures of selection in a non-model species, alpine gentian (Gentiana nivalis L.), using a landscape genetic approach

DEFF Research Database (Denmark)

Bothwell, H.; Bisbing, S.; Therkildsen, Nina Overgaard

2013-01-01

It is generally accepted that most plant populations are locally adapted. Yet, understanding how environmental forces give rise to adaptive genetic variation is a challenge in conservation genetics and crucial to the preservation of species under rapidly changing climatic conditions. Environmental...... loci, we compared outlier locus detection methods with a recently-developed landscape genetic approach. We analyzed 157 loci from samples of the alpine herb Gentiana nivalis collected across the European Alps. Principle coordinates of neighbor matrices (PCNM), eigenvectors that quantify multi...... variables identified eight more potentially adaptive loci than models run without spatial variables. 3) When compared to outlier detection methods, the landscape genetic approach detected four of the same loci plus 11 additional loci. 4) Temperature, precipitation, and solar radiation were the three major...

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

Variability in human body size

Science.gov (United States)

Annis, J. F.

1978-01-01

The range of variability found among homogeneous groups is described and illustrated. Those trends that show significantly marked differences between sexes and among a number of racial/ethnic groups are also presented. Causes of human-body size variability discussed include genetic endowment, aging, nutrition, protective garments, and occupation. The information is presented to aid design engineers of space flight hardware and equipment.

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.

The Status of Genetics Curriculum in Higher Education in the United States: Goals and Assessment

Science.gov (United States)

McElhinny, Teresa L.; Dougherty, Michael J.; Bowling, Bethany V.; Libarkin, Julie C.

2014-01-01

We review the state of genetics instruction in the United States through the lens of backward design, with particular attention to the goals and assessments that inform curricular practice. An analysis of syllabi and leading textbooks indicates that genetics instruction focuses most strongly on foundations of DNA and Mendelian genetics. At the…

Expression patterns of the aquaporin gene family during renal development: influence of genetic variability.

Science.gov (United States)

Parreira, Kleber S; Debaix, Huguette; Cnops, Yvette; Geffers, Lars; Devuyst, Olivier

2009-08-01

High-throughput analyses have shown that aquaporins (AQPs) belong to a cluster of genes that are differentially expressed during kidney organogenesis. However, the spatiotemporal expression patterns of the AQP gene family during tubular maturation and the potential influence of genetic variation on these patterns and on water handling remain unknown. We investigated the expression patterns of all AQP isoforms in fetal (E13.5 to E18.5), postnatal (P1 to P28), and adult (9 weeks) kidneys of inbred (C57BL/6J) and outbred (CD-1) mice. Using quantitative polymerase chain reaction (PCR), we evidenced two mRNA patterns during tubular maturation in C57 mice. The AQPs 1-7-11 showed an early (from E14.5) and progressive increase to adult levels, similar to the mRNA pattern observed for proximal tubule markers (Megalin, NaPi-IIa, OAT1) and reflecting the continuous increase in renal cortical structures during development. By contrast, AQPs 2-3-4 showed a later (E15.5) and more abrupt increase, with transient postnatal overexpression. Most AQP genes were expressed earlier and/or stronger in maturing CD-1 kidneys. Furthermore, adult CD-1 kidneys expressed more AQP2 in the collecting ducts, which was reflected by a significant delay in excreting a water load. The expression patterns of proximal vs. distal AQPs and the earlier expression in the CD-1 strain were confirmed by immunoblotting and immunostaining. These data (1) substantiate the clustering of important genes during tubular maturation and (2) demonstrate that genetic variability influences the regulation of the AQP gene family during tubular maturation and water handling by the mature kidney.

Uniform Selection as a Primary Force Reducing Population Genetic Differentiation of Cavitation Resistance across a Species Range

Science.gov (United States)

Lamy, Jean-Baptiste; Bouffier, Laurent; Burlett, Régis; Plomion, Christophe; Cochard, Hervé; Delzon, Sylvain

2011-01-01

Background Cavitation resistance to water stress-induced embolism determines plant survival during drought. This adaptive trait has been described as highly variable in a wide range of tree species, but little is known about the extent of genetic and phenotypic variability within species. This information is essential to our understanding of the evolutionary forces that have shaped this trait, and for evaluation of its inclusion in breeding programs. Methodology We assessed cavitation resistance (P 50), growth and carbon isotope composition in six Pinus pinaster populations in a provenance and progeny trial. We estimated the heritability of cavitation resistance and compared the distribution of neutral markers (F ST) and quantitative genetic differentiation (Q ST), for retrospective identification of the evolutionary forces acting on these traits. Results/Discussion In contrast to growth and carbon isotope composition, no population differentiation was found for cavitation resistance. Heritability was higher than for the other traits, with a low additive genetic variance (h2 ns = 0.43±0.18, CVA = 4.4%). Q ST was significantly lower than F ST, indicating uniform selection for P 50, rather than genetic drift. Putative mechanisms underlying QST

Genetic Structure of Bluefin Tuna in the Mediterranean Sea Correlates with Environmental Variables

Science.gov (United States)

Riccioni, Giulia; Stagioni, Marco; Landi, Monica; Ferrara, Giorgia; Barbujani, Guido; Tinti, Fausto

2013-01-01

Background Atlantic Bluefin Tuna (ABFT) shows complex demography and ecological variation in the Mediterranean Sea. Genetic surveys have detected significant, although weak, signals of population structuring; catch series analyses and tagging programs identified complex ABFT spatial dynamics and migration patterns. Here, we tested the hypothesis that the genetic structure of the ABFT in the Mediterranean is correlated with mean surface temperature and salinity. Methodology We used six samples collected from Western and Central Mediterranean integrated with a new sample collected from the recently identified easternmost reproductive area of Levantine Sea. To assess population structure in the Mediterranean we used a multidisciplinary framework combining classical population genetics, spatial and Bayesian clustering methods and a multivariate approach based on factor analysis. Conclusions FST analysis and Bayesian clustering methods detected several subpopulations in the Mediterranean, a result also supported by multivariate analyses. In addition, we identified significant correlations of genetic diversity with mean salinity and surface temperature values revealing that ABFT is genetically structured along two environmental gradients. These results suggest that a preference for some spawning habitat conditions could contribute to shape ABFT genetic structuring in the Mediterranean. However, further studies should be performed to assess to what extent ABFT spawning behaviour in the Mediterranean Sea can be affected by environmental variation. PMID:24260341

Genetic variability in Brazilian populations of Biomphalaria straminea complex detected by simple sequence repeat anchored polymerase chain reaction amplification

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Caldeira Roberta L

2001-01-01

Full Text Available Biomphalaria glabrata, B. tenagophila and B. straminea are intermediate hosts of Schistosoma mansoni, in Brazil. The latter is of epidemiological importance in the northwest of Brazil and, due to morphological similarities, has been grouped with B. intermedia and B. kuhniana in a complex named B. straminea. In the current work, we have standardized the simple sequence repeat anchored polymerase chain reaction (SSR-PCR technique, using the primers (CA8RY and K7, to study the genetic variability of these species. The similarity level was calculated using the Dice coefficient and genetic distance using the Nei and Li coefficient. The trees were obtained by the UPGMA and neighbor-joining methods. We have observed that the most related individuals belong to the same species and locality and that individuals from different localities, but of the same species, present clear heterogeneity. The trees generated using both methods showed similar topologies. The SSR-PCR technique was shown to be very efficient in intrapopulational and intraspecific studies of the B. straminea complex snails.

Preimplantation Genetic Screening and Preimplantation Genetic Diagnosis.

Science.gov (United States)

Sullivan-Pyke, Chantae; Dokras, Anuja

2018-03-01

Preimplantation genetic testing encompasses preimplantation genetic screening (PGS) and preimplantation genetic diagnosis (PGD). PGS improves success rates of in vitro fertilization by ensuring the transfer of euploid embryos that have a higher chance of implantation and resulting in a live birth. PGD enables the identification of embryos with specific disease-causing mutations and transfer of unaffected embryos. The development of whole genome amplification and genomic tools, including single nucleotide polymorphism microarrays, comparative genomic hybridization microarrays, and next-generation sequencing, has led to faster, more accurate diagnoses that translate to improved pregnancy and live birth rates. Copyright © 2017 Elsevier Inc. All rights reserved.

Vigorous physical activity predicts higher heart rate variability among younger adults.

Science.gov (United States)

May, Richard; McBerty, Victoria; Zaky, Adam; Gianotti, Melino

2017-06-14

Baseline heart rate variability (HRV) is linked to prospective cardiovascular health. We tested intensity and duration of weekly physical activity as predictors of heart rate variability in young adults. Time and frequency domain indices of HRV were calculated based on 5-min resting electrocardiograms collected from 82 undergraduate students. Hours per week of both moderate and vigorous activity were estimated using the International Physical Activity Questionnaire. In regression analyses, hours of vigorous physical activity, but not moderate activity, significantly predicted greater time domain and frequency domain indices of heart rate variability. Adjusted for weekly frequency, greater daily duration of vigorous activity failed to predict HRV indices. Future studies should test direct measurements of vigorous activity patterns as predictors of autonomic function in young adulthood.

Determination of interrill soil erodibility coefficient based on Fuzzy and Fuzzy-Genetic Systems

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Habib Palizvan Zand

2017-02-01

independent variables for development fuzzy and fuzzy- genetic models. For this reason their linguistic variables were defined and fuzzy models rules were written by Mamdani's fuzzy inference method. Then, the outputs of model defuzzified by centroid method. Once again, generation of membership functions and fuzzy rules base as well as optimization of fuzzy rule bases was performed by genetic algorithm, and the fuzzy functions were determined by optimized weight of membership functions and fuzzy rules. Results Discussion: Interrill erodibility parameters (Ki of the examined soils calculated at 3 rainfall rates using are listed in Table 2. The values ranged from 1.03 to 71.79 × 105 kg s m-4, depending on the soil and rainfall intensity. Results showed that the effect of rainfall intensity on Ki turned to be insignificant. This implies that Ki was independent of rainfall intensities. Results showed that the Triangular and Trapezoidal membership functions are better than the other membership functions for linguistic variables which used in this study. The values of R2, RMSE (Root mean square error and GMER (Geometric mean error ratio and GSDER (Geometric standard deviation of error ratio were 0.63, 592755, 1.31 and 1.38 for the fuzzy model, and, 0.70, 441942, 1.10 and 1.044 for the fuzzy- genetic model, respectively. Higher R2 and lower RMSE of the fuzzy – genetic model shows higher accuracy and efficiency of the fuzzy-genetic model. The GSDER criteria shows better matching of the fuzzy- genetic model estimated values with measured values. The GMER criteria shows lower over-estimation of the fuzzy- genetic model than fuzzy model. Conclusion: Fuzzy and fuzzy-genetic models which were designed with two input variables namely aggregates fractal dimensions and soil sand content, capable to predict of interrill erodibility coefficient of soils with reasonable accuracy. So using of these models for predicting of interrill erodibility is recommended.Optimization of fuzzy rule bases

The estimation of genetic distance and discriminant variables on breed of duck (Alabio, Bali, Khaki Campbell, Mojosari and Pegagan) by morphological analysis

OpenAIRE

B Brahmantiyo; L.H Prasetyo; A.R Setioko; R.H Mulyono

2003-01-01

A study on morphological body conformation of Alabio, Bali, Khaki Campbell, Mojosari and Pegagan ducks was carried out to determine the genetic distance and discriminant variables. This research was held in Research Institute for Animal Production, Ciawi, Bogor using 65 Alabio ducks, 40 Bali ducks, 36 Khaki Campbell ducks, 60 Mojosari ducks and 30 Pegagan ducks. Seven different body parts were measured, they were the length of femur, tibia, tarsometatarsus, the circumference of tarsometatarsu...

Phylogeography, genetic variability and structure of Acanthamoeba metapopulations in Iran inferred by 18S ribosomal RNA sequences: A systematic review and meta-analysis.

Science.gov (United States)

Spotin, Adel; Moslemzadeh, Hamid Reza; Mahami-Oskouei, Mahmoud; Ahmadpour, Ehsan; Niyyati, Maryam; Hejazi, Seyed Hossein; Memari, Fatemeh; Noori, Jafar

2017-09-01

To verify phylogeography and genetic structure of Acanthamoeba populations among the Iranian clinical isolates and natural/artificial environments distributed in various regions of the country. We searched electronic databases including Medline, PubMed, Science Direct, Scopus and Google Scholar from 2005 to 2016. To explore the genetic variability of Acanthamoeba sp, 205 sequences were retrieved from keratitis patients, immunosuppressed cases and environmental sources as of various geographies of Iran. T4 genotype was the predominant strain in Iran, and the rare genotypes belonged to T2, T3, T5 (Acanthamoeba lenticulata), T6, T9, T11, T13 and T15 (Acanthamoeba jacobsi). A total of 47 unique haplotypes of T4 were identified. A parsimonious network of the sequence haplotypes demonstrated star-like feature containing haplogroups IR6 (34.1%) and IR7 (31.2%) as the most common haplotypes. In accordance with the analysis of molecular variance, the high value of haplotype diversity (0.612-0.848) of Acanthamoeba T4 represented genetic variability within populations. Neutrality indices of the 18S ribosomal RNA demonstrated negative values in all populations which represented a considerable divergence from neutrality. The majority of genetic diversity belonged to the infected contact lens and dust samples in immunodeficiency and ophthalmology wards, which indicated potential routes for exposure to a pathogenic Acanthamoeba sp. in at-risk individuals. A pairwise fixation index (F ST ) was from low to high values (0.02433-0.41892). The statistically F ST points out that T4 is genetically differentiated between north-west, north-south and central-south metapopulations, but not differentiated between west-central, west-south, central-south, and north-central isolates. An occurrence of IR6 and IR7 displays that possibly a gene flow of Acanthamoeba T4 occurred after the founder effect or bottleneck experience through ecological changes or host mobility. This is the first

Patterns of ancestry and genetic diversity in reintroduced populations of the slimy sculpin: Implications for conservation

Science.gov (United States)

Huff, David D.; Miller, Loren M.; Vondracek, Bruce C.

2010-01-01

Reintroductions are a common approach for preserving intraspecific biodiversity in fragmented landscapes. However, they may exacerbate the reduction in genetic diversity initially caused by population fragmentation because the effective population size of reintroduced populations is often smaller and reintroduced populations also tend to be more geographically isolated than native populations. Mixing genetically divergent sources for reintroduction purposes is a practice intended to increase genetic diversity. We documented the outcome of reintroductions from three mixed sources on the ancestral composition and genetic variation of a North American fish, the slimy sculpin (Cottus cognatus). We used microsatellite markers to evaluate allelic richness and heterozygosity in the reintroduced populations relative to computer simulated expectations. Sculpins in reintroduced populations exhibited higher levels of heterozygosity and allelic richness than any single source, but only slightly higher than the single most genetically diverse source population. Simulations intended to mimic an ideal scenario for maximizing genetic variation in the reintroduced populations also predicted increases, but they were only moderately greater than the most variable source population. We found that a single source contributed more than the other two sources at most reintroduction sites. We urge caution when choosing whether to mix source populations in reintroduction programs. Genetic characteristics of candidate source populations should be evaluated prior to reintroduction if feasible. When combined with knowledge of the degree of genetic distinction among sources, simulations may allow the genetic diversity benefits of mixing populations to be weighed against the risks of outbreeding depression in reintroduced and nearby populations.

Ethnic variability in adiposity and cardiovascular risk: the variable disease selection hypothesis.

Science.gov (United States)

Wells, Jonathan C K

2009-02-01

Evidence increasingly suggests that ethnic differences in cardiovascular risk are partly mediated by adipose tissue biology, which refers to the regional distribution of adipose tissue and its differential metabolic activity. This paper proposes a novel evolutionary hypothesis for ethnic genetic variability in adipose tissue biology. Whereas medical interest focuses on the harmful effect of excess fat, the value of adipose tissue is greatest during chronic energy insufficiency. Following Neel's influential paper on the thrifty genotype, proposed to have been favoured by exposure to cycles of feast and famine, much effort has been devoted to searching for genetic markers of 'thrifty metabolism'. However, whether famine-induced starvation was the primary selective pressure on adipose tissue biology has been questioned, while the notion that fat primarily represents a buffer against starvation appears inconsistent with historical records of mortality during famines. This paper reviews evidence for the role played by adipose tissue in immune function and proposes that adipose tissue biology responds to selective pressures acting through infectious disease. Different diseases activate the immune system in different ways and induce different metabolic costs. It is hypothesized that exposure to different infectious disease burdens has favoured ethnic genetic variability in the anatomical location of, and metabolic profile of, adipose tissue depots.

[HIV-1 genetic variability in non Spaniard infected children].

Science.gov (United States)

Piñeiro Pérez, R; Mellado Peña, M J; Holguín, A; Cilleruelo, M J; García Hortelano, M; Villota, J; Martín Fontelos, P

2009-01-01

The prevalence of HIV-1 non-B subtypes (HIV-NBS) is increasing in Europe, because of emigration from countries where genetic variants are endemic. Although HIV-NBS could have a different clinical evolution and could respond differently to antiretrovirals (AR) than B-subtypes, these variant's response remain undocumented. To identify HIV-1 genetic variants and to determine clinical evolution in a non-Spaniard children infected with HIV-1. Children with HIV-1 infection from endemic countries were tested for HIV-1 subtypes between 1-1-1988 and 31-12-2006. Twelve children less than 18 years old and born abroad were selected. HIV-NBS were isolated in 5 children (42%): CRF2_AG recombinant in 3 cases (Equatorial Guinea), Subtype C in one (Equatorial Guinea) and CRF13_cpx in last one (India). Because of the increasing frequency of patients with HIV-NBS and their unknown long-term evolution, all children from endemic countries should be tested for HIV subtypes. We believe new studies with more patients during longer times could reveal differences in these patient's clinical, immunological and virological evolution.

Genetic structure and variability within and among populations of the ...

African Journals Online (AJOL)

Lalouta

2014-01-01

Jan 1, 2014 ... The clustering analysis performed with 'structure' detected the absence of .... tance of molecular information in the establishment of genetic improvement ... applied using a Markov Chain Monte Carlo simulation (100 batches,.

Population genetic characteristics of horse chestnut in Serbia

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Ocokoljić Mirjana

2013-01-01

Full Text Available The general population genetic characteristics of cultivated horse chestnut trees excelling in growth, phenotype characteristics, type of inflorescence, productivity and resistance to the leafminer Cameraria ohridella Deschka and Dimić were analyzed in Serbia. The analyzed population genetic parameters point to fundamental differences in the genetic structure among the cultivated populations in Serbia. The study shows the variability in all properties among the populations and inter-individual variability within the populations. The variability and differential characteristics were assessed using statistical parameters, taking into account the satisfactory reflection of the hereditary potential. The assessed differences in the vitality and evolution potential of different populations can determine the methods of horse chestnut gene pool collection, reconstruction and improvement. [Projekat Ministarstva nauke Republike Srbije, br. 31041: Establishment of Wood Plantations Intended for a forestation of Serbia

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...

Institutional Variables and Perceived Environmental Concerns in Higher Education.

Science.gov (United States)

Michael, Steve O.

1995-01-01

Discusses the effects of worsening financial constraints evident in all aspects of higher education institutions. Examines differences and similarities in institutional leaders' opinions regarding environmental concerns. All Alberta, Canada, higher education institutions are experiencing similar problems. There is no deliberate shift in government…

RAPD analysis of genetic variability in a multiprovenance base population of Eucalyptus grandis hill ex maiden Variabilidade genética através da técnica RAPD de uma população-base multiprocedências de Eucalyptus grandis hill ex maiden

Directory of Open Access Journals (Sweden)

Susi Meire Maximino Leite

2008-12-01

Full Text Available This study aimed to evaluate the genetic variability among individuals of a base population of Eucalyptus grandis and to build a molecular marker database for the analyzed populations. The Eucalyptus grandis base population comprised 327 individuals from Coff's Harbour, Atherton and Rio Claro. A few plants came from other sites (Belthorpe MT. Pandanus, Kenilworth, Yabbra, etc.. Since this base population had a heterogeneous composition, the groups were divided according to geographic localization (latitude and longitude, and genetic breeding level. Thus, the influence of those two factors (geographic localization and genetic breeding level on the genetic variability detected was discussed. The RAPD technique allowed the evaluation of 70 loci. The binary matrix was used to estimate the genetic similarity among individuals using Jaccard's Coefficient. Parametric statistical tests were used to compare within-group similarity of the means. The obtained results showed that the base population had wide genetic variability and a mean genetic similarity of 0.328. Sub-group 3 (wild materials from the Atherton region showed mean genetic similarity of 0.318. S.P.A. (from Coff's Harbour region had a mean genetic similarity of 0.322 and was found to be very important for maintenance of variation in the base population. This can be explained since the individuals from those groups accounted for most of the base population (48.3% for it. The base population plants with genetic similarity higher than 0.60 should be phenotypically analyzed again in order to clarify the tendency of genetic variability during breeding programs.Este estudo visou avaliar a variabilidade e distância genética dentro de uma população-base de melhoramento genético de Eucalyptus grandis. A avaliação da variabilidade genética tem como objetivos principais analisar a base genética da população-base e montar um banco de dados marcadores moleculares da população em an

Exploring Relationships Among Belief in Genetic Determinism, Genetics Knowledge, and Social Factors

Science.gov (United States)

Gericke, Niklas; Carver, Rebecca; Castéra, Jérémy; Evangelista, Neima Alice Menezes; Marre, Claire Coiffard; El-Hani, Charbel N.

2017-12-01

Genetic determinism can be described as the attribution of the formation of traits to genes, where genes are ascribed more causal power than what scientific consensus suggests. Belief in genetic determinism is an educational problem because it contradicts scientific knowledge, and is a societal problem because it has the potential to foster intolerant attitudes such as racism and prejudice against sexual orientation. In this article, we begin by investigating the very nature of belief in genetic determinism. Then, we investigate whether knowledge of genetics and genomics is associated with beliefs in genetic determinism. Finally, we explore the extent to which social factors such as gender, education, and religiosity are associated with genetic determinism. Methodologically, we gathered and analyzed data on beliefs in genetic determinism, knowledge of genetics and genomics, and social variables using the "Public Understanding and Attitudes towards Genetics and Genomics" (PUGGS) instrument. Our analyses of PUGGS responses from a sample of Brazilian university freshmen undergraduates indicated that (1) belief in genetic determinism was best characterized as a construct built up by two dimensions or belief systems: beliefs concerning social traits and beliefs concerning biological traits; (2) levels of belief in genetic determination of social traits were low, which contradicts prior work; (3) associations between knowledge of genetics and genomics and levels of belief in genetic determinism were low; and (4) social factors such as age and religiosity had stronger associations with beliefs in genetic determinism than knowledge. Although our study design precludes causal inferences, our results raise questions about whether enhancing genetic literacy will decrease or prevent beliefs in genetic determinism.

Wildlife translocation: the conservation implications of pathogen exposure and genetic heterozygosity

Science.gov (United States)

2011-01-01

Background A key challenge for conservation biologists is to determine the most appropriate demographic and genetic management strategies for wildlife populations threatened by disease. We explored this topic by examining whether genetic background and previous pathogen exposure influenced survival of translocated animals when captive-bred and free-ranging bighorn sheep (Ovis canadensis) were used to re-establish a population that had been extirpated in the San Andres Mountains in New Mexico, USA. Results Although the free-ranging source population had significantly higher multi-locus heterozygosity at 30 microsatellite loci than the captive bred animals, neither source population nor genetic background significantly influenced survival or cause of death. The presence of antibodies to a respiratory virus known to cause pneumonia was associated with increased survival, but there was no correlation between genetic heterozygosity and the presence of antibodies to this virus. Conclusions Although genetic theory predicts otherwise, increased heterozygosity was not associated with increased fitness (survival) among translocated animals. While heterosis or genetic rescue effects may occur in F1 and later generations as the two source populations interbreed, we conclude that previous pathogen exposure was a more important marker than genetic heterozygosity for predicting survival of translocated animals. Every wildlife translocation is an experiment, and whenever possible, translocations should be designed and evaluated to test hypotheses that will further improve our understanding of how pathogen exposure and genetic variability influence fitness. PMID:21284886

Wildlife translocation: the conservation implications of pathogen exposure and genetic heterozygosity

Directory of Open Access Journals (Sweden)

Penedo M Cecilia T

2011-02-01

Full Text Available Abstract Background A key challenge for conservation biologists is to determine the most appropriate demographic and genetic management strategies for wildlife populations threatened by disease. We explored this topic by examining whether genetic background and previous pathogen exposure influenced survival of translocated animals when captive-bred and free-ranging bighorn sheep (Ovis canadensis were used to re-establish a population that had been extirpated in the San Andres Mountains in New Mexico, USA. Results Although the free-ranging source population had significantly higher multi-locus heterozygosity at 30 microsatellite loci than the captive bred animals, neither source population nor genetic background significantly influenced survival or cause of death. The presence of antibodies to a respiratory virus known to cause pneumonia was associated with increased survival, but there was no correlation between genetic heterozygosity and the presence of antibodies to this virus. Conclusions Although genetic theory predicts otherwise, increased heterozygosity was not associated with increased fitness (survival among translocated animals. While heterosis or genetic rescue effects may occur in F1 and later generations as the two source populations interbreed, we conclude that previous pathogen exposure was a more important marker than genetic heterozygosity for predicting survival of translocated animals. Every wildlife translocation is an experiment, and whenever possible, translocations should be designed and evaluated to test hypotheses that will further improve our understanding of how pathogen exposure and genetic variability influence fitness.

Studies on heritability and genetic advance in chickpea (cicer arietinum L.)

International Nuclear Information System (INIS)

Yaqoob, M.; Bakhsh, A.; Zahid, M.A.

2010-01-01

Studies on estimation of heritability (h2) and genetic advance (GA) were carried out in twenty desi-type chickpea genotypes. The experiment was carried out at Agricultural Research Institute, Dera Ismail Khan, in RCBD with three repeats. The data were recorded on: days to 50% flowering, days to pod-maturity, plant height, number of branches, number of pods per plant, 1000-seed weight, no. of seeds per pod, plant biomass, grain yield and harvest index. The results of analysis-of-variance revealed significant differences among genotypes for 5 out of ten traits. Phenotypic coefficients of variability (PCV) were higher in magnitude than their respective genotypic coefficients of variability (GCV) in all the traits, thereby showing the dominant effect of environment. The maximum h2 estimates are obtained for 1000-seed weight, followed by number of seeds per pod, days to 500;0 flowering and days to pod- maturity. The grain yield, harvest index and plant biomass exhibited low heritability, which indicate the major role of environmental factors in the expression of these traits. High h2, coupled with high genetic advance, for 1000 grain weight and number of pods per plant indicated the additive gene effects determining these traits, whereas, high h2, coupled with low genetic advance, for number of seeds per pod indicated the involvement of dominant and epi static genetic effects for these traits. Selection for improvement of 1000-grain weight and number of pods per plant may be practiced in early germination, whereas it should be delayed in the case of seeds per pod. (author)

Hanseniaspora uvarum from winemaking environments show spatial and temporal genetic clustering

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Warren eAlbertin

2016-01-01

Full Text Available Hanseniaspora uvarum is one of the most abundant yeast species found on grapes and in grape must, at least before the onset of alcoholic fermentation which is usually performed by Saccharomyces species. The aim of this study was to characterise the genetic and phenotypic variability within the H. uvarum species. One hundred and fifteen strains isolated from winemaking environments in different geographical origins were analysed using 11 microsatellite markers and a subset of 47 strains were analysed by AFLP. H. uvarum isolates clustered mainly on the basis of their geographical localisation as revealed by microsatellites. In addition, a strong clustering based on year of isolation was evidenced, indicating that the genetic diversity of Hanseniaspora uvarum isolates was related to both spatial and temporal variations. Conversely, clustering analysis based on AFLP data provided a different picture with groups showing no particular characteristics, but provided higher strain discrimination. This result indicated that AFLP approaches are inadequate to establish the genetic relationship between individuals, but allowed good strain discrimination. At the phenotypic level, several extracellular enzymatic activities of enological relevance (pectinase, chitinase, protease, β-glucosidase were measured but showed low diversity. The impact of environmental factors of enological interest (temperature, anaerobia and copper addition on growth was also assessed and showed poor variation. Altogether, this work provided both new analytical tool (microsatellites and new insights into the genetic and phenotypic diversity of H. uvarum, a yeast species that has previously been identified as a potential candidate for co-inoculation in grape must, but whose intraspecific variability had never been fully assessed.

Determination of genetic variability of Asian rice (Oryza sativa L ...

African Journals Online (AJOL)

PRECIOUS

2009-11-02

Nov 2, 2009 ... diversity and relationship among thirty-five Asian cultivars of rice including 19 aromatic, 13 non- ... are promising and effective tools for measuring genetic .... efficients were employed by using Simqual sub-program in similarity.

Comparative Genetic Variability in HIV-1 Subtype C vpu Gene in Early Age Groups of Infants.

Science.gov (United States)

Sharma, Uma; Gupta, Poonam; Gupta, Sunil; Venkatesh, S; Husain, Mohammad

2018-01-01

Identifying the genetic variability in vertically transmitted viruses in early infancy is important to understand the disease progression. Being important in HIV-1 disease pathogenesis, vpu gene, isolated from young infants was investigated to understand the viral characteristics. Blood samples were obtained from 80 HIV-1 positive infants, categorized in two age groups; acute (6-18 months). A total of 77 PCR positive samples, amplified for vpu gene, were sequenced and analyzed. 73 isolates belonged to subtype C. Analysis of heterogeneity of amino acid sequences in infant groups showed that in the sequences of acute age group both insertions and deletions were present while in the early age group only deletions were present. In the acute age group, a deletion of 3 residues (RAE) in the first alfa helix in one sequence and insertions of 1-2 residues (DM, GH, G and H) in the second alfa helix in 4 sequences were observed. In the early age group, deletion of 2 residues (VN) in the cytoplasmic tail region in 2 sequences was observed. Length of the amino terminal was observed to be gradually increasing with the increasing age of the infants. Protein Variation Effect Analyzer software showed that deleterious mutations were more in the acute than the early age group. Entropy analysis revealed that heterogeneity of the residues was comparatively higher in the sequences of acute than the early age group. Mutations observed in the helixes may affect the conformation and lose the ability to degrade CD4 receptors. Heterogeneity was decreasing with the increasing ages of the infants, indicating positive selection for robust virion survival. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Detailed genetic structure of European bitterling populations in Central Europe

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Veronika Bartáková

2015-11-01

Full Text Available The European bitterling (Rhodeus amarus is a small cyprinid fish whose populations declined markedly between 1950 and 1980. However, its range currently expands, partly due to human-assisted introductions. We determined the genetic variability and detailed spatial structure among bitterling populations in Central Europe and tested alternative hypotheses about colonization of this area. Twelve polymorphic microsatellite loci on a large sample of 688 individuals had been used to analyse genetic variability and population structure. Samples originated from 27 localities with emphasis on area of the Czech Republic where three major sea drainages (Black, Baltic, and Northern Sea meet. Highly variable level of intrapopulation genetic variability had generally been detected and a recent decrease in numbers (“bottleneck” had been indicated by genetic data among six populations. High level of interpopulation differentiation was identified even within the basins. There was a significant role of genetic drift and indications of low dispersal ability of R. amarus. Surprisingly, the Odra River was inhabited by two distinct populations without any genetic signatures of a secondary contact. Czech part of the Odra (Baltic basin was colonized from the Danubian refugium (similarly to adjacent Danubian basin rivers including the Morava, while Polish part of the Odra was genetically similar to the populations in the Vistula River (Baltic basin, that has been colonized by a different (Eastern phylogeographic lineage of R. amarus. Most Czech R. amarus populations were colonized from the Danubian refugium, suggesting potential for a human-mediated colonization of the Odra or Elbe Rivers by R. amarus. One Elbe basin population was genetically mixed from the two (Danubian and Eastern phylogeographic lineages. In general the Czech populations of R. amarus were genetically stable except for a single population which has probably been recently introduced. This research

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 ...

Assessment of the genetic diversity and pattern of relationship of ...

African Journals Online (AJOL)

An understanding of the extent, distribution and patterns of genetic variation is useful for estimation of any possible loss of genetic diversity and assessment of genetic variability and its potential use in breeding programs, including establishment of heterotic groups. This study assessed patterns of genetic diversity and ...

Bivariate analysis of the genetic variability among some accessions of African Yam Bean (Sphenostylis stenocarpa (Hochst ex A. RichHarms

Directory of Open Access Journals (Sweden)

Solomon Tayo AKINYOSOYE

2017-12-01

Full Text Available Variability is an important factor to consider in crop improvement programmes. This study was conducted in two years to assess genetic variability and determine relationship between seed yield, its components and tuber production characters among twelve accessions of African yam bean. Data collected were subjected to combined analysis of variance (ANOVA, Principal Component Analysis (PCA, hierarchical and K-means clustering analyses. Results obtained revealed that genotype by year (G × Y interaction had significant effects on some of variables measured (days to first flowering, days to 50 % flowering, number of pod per plant, pod length, seed yield and tuber yield per plant in this study.The first five principal components (PC with Eigen values greater than 1.0 accounted for about 66.70 % of the total variation, where PC1 and PC 2 accounted for 39.48 % of variation and were associated with seed and tuber yield variables. Three heterotic groups were clearly delineated among genotypes with accessions AY03 and AY10 identified for high seed yield and tuber yield respectively. Non-significant relationship that existed between tuber and seed yield per plant of these accessions was recommended for further test in various agro-ecologies for their suitability, adaptability and possible exploitation of heterosis to further improve the accessions.

Quantitative effects of composting state variables on C/N ratio through GA-aided multivariate analysis

International Nuclear Information System (INIS)

Sun Wei; Huang, Guo H.; Zeng Guangming; Qin Xiaosheng; Yu Hui

2011-01-01

It is widely known that variation of the C/N ratio is dependent on many state variables during composting processes. This study attempted to develop a genetic algorithm aided stepwise cluster analysis (GASCA) method to describe the nonlinear relationships between the selected state variables and the C/N ratio in food waste composting. The experimental data from six bench-scale composting reactors were used to demonstrate the applicability of GASCA. Within the GASCA framework, GA searched optimal sets of both specified state variables and SCA's internal parameters; SCA established statistical nonlinear relationships between state variables and the C/N ratio; to avoid unnecessary and time-consuming calculation, a proxy table was introduced to save around 70% computational efforts. The obtained GASCA cluster trees had smaller sizes and higher prediction accuracy than the conventional SCA trees. Based on the optimal GASCA tree, the effects of the GA-selected state variables on the C/N ratio were ranged in a descending order as: NH 4 + -N concentration > Moisture content > Ash Content > Mean Temperature > Mesophilic bacteria biomass. Such a rank implied that the variation of ammonium nitrogen concentration, the associated temperature and the moisture conditions, the total loss of both organic matters and available mineral constituents, and the mesophilic bacteria activity, were critical factors affecting the C/N ratio during the investigated food waste composting. This first application of GASCA to composting modelling indicated that more direct search algorithms could be coupled with SCA or other multivariate analysis methods to analyze complicated relationships during composting and many other environmental processes. - Research Highlights: → A genetic algorithm aided stepwise cluster analysis method in food waste composting. → Nonlinear relationships between the selected state variables and the C/N ratio. → Introduced proxy tables save around 70% computational

Quantitative effects of composting state variables on C/N ratio through GA-aided multivariate analysis

Energy Technology Data Exchange (ETDEWEB)

Sun Wei [Faculty of Engineering and Applied Science, University of Regina, Regina, Saskatchewan, S4S 0A2 (Canada); Huang, Guo H., E-mail: huangg@iseis.org [Faculty of Engineering and Applied Science, University of Regina, Regina, Saskatchewan, S4S 0A2 (Canada); MOE Key Laboratory of Regional Energy Systems Optimization, Sino-Canada Energy and Environmental Research Academy, North China Electric Power University, Beijing, 102206 (China); Zeng Guangming [MOE Key Laboratory of Environmental Biology and Pollution Control, College of Environmental Science and Engineering, Hunan University, Changsha, Hunan, 410082 (China); Qin Xiaosheng [School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Yu Hui [Faculty of Engineering and Applied Science, University of Regina, Regina, Saskatchewan, S4S 0A2 (Canada)

2011-03-01

It is widely known that variation of the C/N ratio is dependent on many state variables during composting processes. This study attempted to develop a genetic algorithm aided stepwise cluster analysis (GASCA) method to describe the nonlinear relationships between the selected state variables and the C/N ratio in food waste composting. The experimental data from six bench-scale composting reactors were used to demonstrate the applicability of GASCA. Within the GASCA framework, GA searched optimal sets of both specified state variables and SCA's internal parameters; SCA established statistical nonlinear relationships between state variables and the C/N ratio; to avoid unnecessary and time-consuming calculation, a proxy table was introduced to save around 70% computational efforts. The obtained GASCA cluster trees had smaller sizes and higher prediction accuracy than the conventional SCA trees. Based on the optimal GASCA tree, the effects of the GA-selected state variables on the C/N ratio were ranged in a descending order as: NH{sub 4}{sup +}-N concentration > Moisture content > Ash Content > Mean Temperature > Mesophilic bacteria biomass. Such a rank implied that the variation of ammonium nitrogen concentration, the associated temperature and the moisture conditions, the total loss of both organic matters and available mineral constituents, and the mesophilic bacteria activity, were critical factors affecting the C/N ratio during the investigated food waste composting. This first application of GASCA to composting modelling indicated that more direct search algorithms could be coupled with SCA or other multivariate analysis methods to analyze complicated relationships during composting and many other environmental processes. - Research Highlights: {yields} A genetic algorithm aided stepwise cluster analysis method in food waste composting. {yields} Nonlinear relationships between the selected state variables and the C/N ratio. {yields} Introduced proxy tables

Human genetic factors in tuberculosis: an update.

Science.gov (United States)

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

2017-09-01

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

Genetic variability of cultivated cowpea in Benin assessed by random amplified polymorphic DNA

NARCIS (Netherlands)

Zannou, A.; Kossou, D.K.; Ahanchédé, A.; Zoundjihékpon, J.; Agbicodo, E.; Struik, P.C.; Sanni, A.

2008-01-01

Characterization of genetic diversity among cultivated cowpea [Vigna unguiculata (L.) Walp.] varieties is important to optimize the use of available genetic resources by farmers, local communities, researchers and breeders. Random amplified polymorphic DNA (RAPD) markers were used to evaluate the

Genetic Causal Attribution of Epilepsy and its Implications for Felt Stigma

Science.gov (United States)

Sabatello, Maya; Phelan, Jo C.; Hesdorffer, Dale C.; Shostak, Sara; Goldsmith, Jeff; Sorge, Shawn T.; Winawer, Melodie R.; Chung, Wendy K.; Ottman, Ruth

2015-01-01

Summary Objective Research in other disorders suggests that genetic causal attribution of epilepsy might be associated with increased stigma. We investigated this hypothesis in a unique sample of families containing multiple individuals with epilepsy. Methods 181 people with epilepsy and 178 biological relatives without epilepsy completed a self-administered survey. In people with epilepsy, felt stigma was assessed through the Epilepsy Stigma Scale (ESS), scored 1 to 7 with higher scores indicating more stigma and >4 indicating some felt stigma. Felt stigma related to having epilepsy in the family was assessed through the Family Epilepsy Stigma Scale (FESS), created by replacing “epilepsy” with “epilepsy in my family” in each ESS item. Genetic attribution was assessed through participants’ perceptions of the (1) role of genetics in causing epilepsy in the family, (2) chance they had an epilepsy-related mutation, and (3) (in people with epilepsy) influence of genetics in causing their epilepsy. Results Among people with epilepsy, 22% met criteria for felt stigma (ESS score >4). Scores were increased among individuals who were aged ≥60 years, were unemployed, reported epilepsy-related discrimination, or had seizures within the last year or >100 seizures in their lifetime. Adjusting for other variables, ESS scores in people with epilepsy were significantly higher among those who perceived genetics played a “medium” or “big” role in causing epilepsy in the family than in others (3.4 vs. 2.7, p=0.025). Only 4% of relatives without epilepsy had felt stigma. Scores in relatives were unrelated to genetic attribution. Significance In these unusual families, predictors of felt stigma in individuals with epilepsy are similar to those in other studies, and stigma levels are low in relatives without epilepsy. Felt stigma may be increased in people with epilepsy who believe epilepsy in the family has a genetic cause, emphasizing the need for sensitive

Evolution of genetic systems in filamentous ascomycetes

NARCIS (Netherlands)

Nauta, M.J.

1994-01-01

A great variety of genetic systems exist in filamentous ascomycetes. The transmission of genetic material does not only occur by (sexual or asexual) reproduction, but it can also follow vegetative fusion of different strains. In this thesis the evolution of this variability is studied,

Journal of Genetics | Indian Academy of Sciences

Indian Academy of Sciences (India)

Thirteen quantitative traits and eight nuclear microsatellite loci were examined in individuals from two biogeographic provinces of Argentina to determine the number and composition of genetically distinguishable groups of individuals and explore possible spatial patterns of the phenotypic and genetic variability. Means of ...

The use of reproductive vigor descriptors in studying genetic ...

African Journals Online (AJOL)

The use of reproductive vigor descriptors in studying genetic variability in nine Tunisian faba bean ( Vicia faba L.) populations. ... The dendrogram based on Nei's genetic distance of the 9 populations using UPGMA method, show some genetic drift between populations. Key words: Faba bean, agromorphological traits, ...

Genetic and environmental factors influencing the Placental Growth Factor (PGF variation in two populations.

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Rossella Sorice

Full Text Available Placental Growth Factor (PGF is a key molecule in angiogenesis. Several studies have revealed an important role of PGF primarily in pathological conditions (e.g.: ischaemia, tumour formation, cardiovascular diseases and inflammatory processes suggesting its use as a potential therapeutic agent. However, to date, no information is available regarding the genetics of PGF variability. Furthermore, even though the effect of environmental factors (e.g.: cigarette smoking on angiogenesis has been explored, no data on the influence of these factors on PGF levels have been reported so far. Here we have first investigated PGF variability in two cohorts focusing on non-genetic risk factors: a study sample from two isolated villages in the Cilento region, South Italy (N=871 and a replication sample from the general Danish population (N=1,812. A significant difference in PGF mean levels was found between the two cohorts. However, in both samples, we observed a strong correlation of PGF levels with ageing and sex, men displaying PGF levels significantly higher than women. Interestingly, smoking was also found to influence the trait in the two populations, although differently. We have then focused on genetic risk factors. The association between five single nucleotide polymorphisms (SNPs located in the PGF gene and the plasma levels of the protein was investigated. Two polymorphisms (rs11850328 and rs2268614 were associated with the PGF plasma levels in the Cilento sample and these associations were strongly replicated in the Danish sample. These results, for the first time, support the hypothesis of the presence of genetic and environmental factors influencing PGF plasma variability.

Speech-language pathologists' knowledge of genetics: perceived confidence, attitudes, knowledge acquisition and practice-based variables.

Science.gov (United States)

Tramontana, G Michael; Blood, Ingrid M; Blood, Gordon W

2013-01-01

The purpose of this study was to determine (a) the general knowledge bases demonstrated by school-based speech-language pathologists (SLPs) in the area of genetics, (b) the confidence levels of SLPs in providing services to children and their families with genetic disorders/syndromes, (c) the attitudes of SLPs regarding genetics and communication disorders, (d) the primary sources used by SLPs to learn about genetic disorders/syndromes, and (e) the association between general knowledge, confidence, attitudes, the number of years of experience working as an SLP, and the number of children currently provided services with genetic disorders/syndromes on SLPs' caseloads. Survey data from a nationwide sample of 533 SLPs was analyzed. Results showed SLPs earned a median knowledge score about genetics of 66% correct responses. Their mean confidence and attitude ratings were in the "unsure" categories while they reported they learned about genetics from three main sources, (a) self-study via web and internet-based searches, (b) on-the-job training and (c) popular press magazines and newspapers. Analyses revealed that Confidence summary scores, Attitude Summary scores, the number of children with genetic disorders/syndromes on SLPs' caseloads are positively associated with the ratings of participants with the highest Knowledge scores. Readers will be able to (a) explain the important links between developmental and communication disabilities and genetics, (b) describe the associations between knowledge about genetics and confidence, attitudes, and the number of children with genetic disorders/syndromes on their caseloads, and (c) outline the clinical and theoretical implications of the results from this study. Copyright © 2012 Elsevier Inc. All rights reserved.

Genetic characterization of early maturing maize hybrids (Zea mays L. obtained by protein and RAPD markers

Directory of Open Access Journals (Sweden)

Bauer Iva

2005-01-01

Full Text Available Knowledge of maize germplasm genetic diversity is important for planning breeding programmes, germplasm conservation per se etc. Genetic variability of maize hybrids grown in the fields is also very important because genetic uniformity implies risks of genetic vulnerability to stress factors and can cause great losts in yield. Early maturing maize hybrids are characterized by shorter vegetation period and they are grown in areas with shorter vegetation season. Because of different climatic conditions in these areas lines and hybrids are developed with different features in respect to drought resistance and disease resistance. The objective of our study was to characterize set of early maturing maize hybrids with protein and RAPD markers and to compare this clasification with their pedigree information. RAPD markers gave significantly higher rate of polymorphism than protein markers. Better corelation was found among pedigree information and protein markers.

Individual Differences in Scotopic Visual Acuity and Contrast Sensitivity: Genetic and Non-Genetic Influences.

Directory of Open Access Journals (Sweden)

Alex J Bartholomew

Full Text Available Despite the large amount of variation found in the night (scotopic vision capabilities of healthy volunteers, little effort has been made to characterize this variation and factors, genetic and non-genetic, that influence it. In the largest population of healthy observers measured for scotopic visual acuity (VA and contrast sensitivity (CS to date, we quantified the effect of a range of variables on visual performance. We found that young volunteers with excellent photopic vision exhibit great variation in their scotopic VA and CS, and this variation is reliable from one testing session to the next. We additionally identified that factors such as Circadian preference, iris color, astigmatism, depression, sex and education have no significant impact on scotopic visual function. We confirmed previous work showing that the amount of time spent on the vision test influences performance and that laser eye surgery results in worse scotopic vision. We also showed a significant effect of intelligence and photopic visual performance on scotopic VA and CS, but all of these variables collectively explain <30% of the variation in scotopic vision. The wide variation seen in young healthy volunteers with excellent photopic vision, the high test-retest agreement, and the vast majority of the variation in scotopic vision remaining unexplained by obvious non-genetic factors suggests a strong genetic component. Our preliminary genome-wide association study (GWAS of 106 participants ruled out any common genetic variants of very large effect and paves the way for future, larger genetic studies of scotopic vision.

Genetic variation in variability: phenotypic variability of fledging weight and its evolution in a songbird population

NARCIS (Netherlands)

Mulder, H.A.; Gienapp, P; Visser, ME

2016-01-01

Variation in traits is essential for natural selection to operate and genetic and environmental effects can contribute to this phenotypic variation. From domesticated populations, we know that families can differ in their level of within-family variance, which leads to the intriguing situation that

Genetic diversity in different populations of sloths assessed by DNA fingerprinting

Directory of Open Access Journals (Sweden)

MORAES N.

2002-01-01

Full Text Available In this study we analyzed a population of Bradypus torquatus with individuals originally distributed in different localities of Bahia, and two populations of B. variegatus with individuals from Bahia and São Paulo States. Using the DNA fingerprinting method, we assessed the genetic variability within and between populations. Analysis of the DNA profiles revealed genetic similarity indices ranging from 0.34 ± 0.07 to 0.87 ± 0.04. Similar low levels of genetic variability were found only in isolated mammalian populations or among related individuals. This study presents the first analyses of genetic diversity in sloth populations.

The Impact of Genetic and Non-Genetic Factors on Warfarin Dose Prediction in MENA Region: A Systematic Review.

Science.gov (United States)

Bader, Loulia Akram; Elewa, Hazem

2016-01-01

Warfarin is the most commonly used oral anticoagulant for the treatment and prevention of thromboembolic disorders. Pharmacogenomics studies have shown that variants in CYP2C9 and VKORC1 genes are strongly and consistently associated with warfarin dose variability. Although different populations from the Middle East and North Africa (MENA) region may share the same ancestry, it is still unclear how they compare in the genetic and non-genetic factors affecting their warfarin dosing. To explore the prevalence of CYP2C9 and VKORC1 variants in MENA, and the effect of these variants along with other non-genetic factors in predicting warfarin dose. In this systematic review, we included observational cross sectional and cohort studies that enrolled patients on stable warfarin dose and had the genetics and non-genetics factors associated with mean warfarin dose as the primary outcome. We searched PubMed, Medline, Scopus, PharmGKB, PHGKB, Google scholar and reference lists of relevant reviews. We identified 17 studies in eight different populations: Iranian, Israeli, Egyptian, Lebanese, Omani, Kuwaiti, Sudanese and Turkish. Most common genetic variant in all populations was the VKORC1 (-1639G>A), with a minor allele frequency ranging from 30% in Egyptians and up to 52% and 56% in Lebanese and Iranian, respectively. Variants in the CYP2C9 were less common, with the highest MAF for CYP2C9*2 among Iranians (27%). Variants in the VKORC1 and CYP2C9 were the most significant predictors of warfarin dose in all populations. Along with other genetic and non-genetic factors, they explained up to 63% of the dose variability in Omani and Israeli patients. Variants of VKORC1 and CYP2C9 are the strongest predictors of warfarin dose variability among the different populations from MENA. Although many of those populations share the same ancestry and are similar in their warfarin dose predictors, a population specific dosing algorithm is needed for the prospective estimation of warfarin

Low genetic variability in a mountain rodent, the Tatra vole

Czech Academy of Sciences Publication Activity Database

Rudá, M.; Žiak, D.; Kocian, Ľ.; Martínková, Natália

2010-01-01

Roč. 281, č. 2 (2010), s. 118-124 ISSN 0952-8369 Institutional research plan: CEZ:AV0Z60930519 Keywords : Tatra vole * population genetics * effective population size * multiple paternity * microsatellites Subject RIV: EH - Ecology, Behaviour Impact factor: 1.787, year: 2010

Genetic variance for uniformity of harvest weight in Nile tilapia (Oreochromis niloticus)

NARCIS (Netherlands)

Khaw, H.L.; Ponzoni, R.W.; Yee, H.Y.; Aziz, M.A.; Mulder, H.A.; Marjanovic, J.; Bijma, P.

2016-01-01

Competition for resources is common in aquaculture, which inflates the variability of fish body weight. Selective breeding is one of the effective approaches that may enable a reduction of size variability (or increase in uniformity) for body weight by genetic means. The genetic variance of

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.

Uniform selection as a primary force reducing population genetic differentiation of cavitation resistance across a species range.

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Jean-Baptiste Lamy

Full Text Available BACKGROUND: Cavitation resistance to water stress-induced embolism determines plant survival during drought. This adaptive trait has been described as highly variable in a wide range of tree species, but little is known about the extent of genetic and phenotypic variability within species. This information is essential to our understanding of the evolutionary forces that have shaped this trait, and for evaluation of its inclusion in breeding programs. METHODOLOGY: We assessed cavitation resistance (P(50, growth and carbon isotope composition in six Pinus pinaster populations in a provenance and progeny trial. We estimated the heritability of cavitation resistance and compared the distribution of neutral markers (F(ST and quantitative genetic differentiation (Q(ST, for retrospective identification of the evolutionary forces acting on these traits. RESULTS/DISCUSSION: In contrast to growth and carbon isotope composition, no population differentiation was found for cavitation resistance. Heritability was higher than for the other traits, with a low additive genetic variance (h(2 (ns = 0.43±0.18, CV(A = 4.4%. Q(ST was significantly lower than F(ST, indicating uniform selection for P(50, rather than genetic drift. Putative mechanisms underlying Q(ST

Genetic divergence and association among polygenic characters in gossypium hirsutum L

International Nuclear Information System (INIS)

BiBi, M.; Khan, N.U.; Mohammad, F.; Gul, R.

2011-01-01

Development of promising cotton populations with improved agronomic performance is primary objective of the cotton breeders. Genetic potential and variability in 8 X 8 F/sub 1/diallel hybrids versus their parental lines, traits correlation and heritability estimates were studied in Gossypium hirsutum L., during 2008-09 at Khyber Pakhtunkhwa Agricultural University, Peshawar, Pakistan. Highly significant variations were observed among the parental cultivars and their F/sub 1/ hybrids for all traits. Results indicated that F/sub 1/ hybrids CIM-506 X CIM-554, CIM-473 X CIM-554, CIM-446 X CIM-554 and CIM-446 X CIM-496 (its reciprocal) produced significantly higher seed cotton yield, bolls per sympodia, boll weight and seeds per boll. Most of the F/sub 1/ populations involving CIM-554 as maternal plant also revealed early maturity. Yield related traits revealed significant positive correlations with seed cotton yield. Heritability (broad sense) was high in magnitude for all traits. Results revealed that traits with high heritability and wide range of genetic variability in breeding material can work as a base population, and their significant contribution towards high yield can help in early segregating generations. (author)

Demographic variability and heterogeneity among individuals within and among clonal bacteria strains

DEFF Research Database (Denmark)

Jouvet, Lionel; Rodriguez-Rojas, Alexandro; Steiner, Ulrich

2018-01-01

to accurately decompose the drivers of heterogeneity among individuals as genetically fixed or selectively neutral. Rather than working on wild populations we present here data from a simple bacterial system in the lab, Escherichia coli. Our system, based on cutting-edge microfluidic techniques, provides high...... control over the genotype and the environment. It therefore allows to unambiguously decompose and quantify fixed genetic variability and dynamic stochastic variability among individuals. We show that within clonal individual variability (dynamic heterogeneity) in lifespan and lifetime reproduction...

Journal of Genetics | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Genetics; Volume 92; Issue 2. Molecular markers unravel intraspecific and interspecific genetic variability in Plantago ovata and some of its wild allies. Shivanjali Kotwal Manoj K. Dhar Balbir Kour Kuldeep Raj Sanjana Kaul. Research Note Volume 92 Issue 2 August 2013 pp 293-298 ...

Genetic and nutrition development of indigenous chicken in Africa

DEFF Research Database (Denmark)

Khobondo, J O; Muasya, T K; Miyumo, S

2015-01-01

This review gives insights into genetic and feeding regime development for indigenous chicken genetic resources. We highlight and combine confirming evidence of genetic diversity and variability using morphological and molecular techniques. We further discuss previous past and current genetic...... requirement for indigenous chicken and report nutritive contents of various local feedstuffs under various production systems. Various conservation strategies for sustainable utilization are hereby reviewed...

Genetic aspects of pathological gambling: a complex disorder with shared genetic vulnerabilities.

Science.gov (United States)

Lobo, Daniela S S; Kennedy, James L

2009-09-01

To summarize and discuss findings from genetic studies conducted on pathological gambling (PG). Searches were conducted on PubMed and PsychInfo databases using the keywords: 'gambling and genes', 'gambling and family' and 'gambling and genetics', yielding 18 original research articles investigating the genetics of PG. Twin studies using the Vietnam Era Twin Registry have found that: (i) the heritability of PG is estimated to be 50-60%; (ii) PG and subclinical PG are a continuum of the same disorder; (iii) PG shares genetic vulnerability factors with antisocial behaviours, alcohol dependence and major depressive disorder; (iv) genetic factors underlie the association between exposure to traumatic life-events and PG. Molecular genetic investigations on PG are at an early stage and published studies have reported associations with genes involved in the brain's reward and impulse control systems. Despite the paucity of studies in this area, published studies have provided considerable evidence of the influence of genetic factors on PG and its complex interaction with other psychiatric disorders and environmental factors. The next step would be to investigate the association and interaction of these variables in larger molecular genetic studies with subphenotypes that underlie PG. Results from family and genetic investigations corroborate further the importance of understanding the biological underpinnings of PG in the development of more specific treatment and prevention strategies.

Genomic patterns in Acropora cervicornis show extensive population structure and variable genetic diversity.

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Drury, Crawford; Schopmeyer, Stephanie; Goergen, Elizabeth; Bartels, Erich; Nedimyer, Ken; Johnson, Meaghan; Maxwell, Kerry; Galvan, Victor; Manfrino, Carrie; Lirman, Diego

2017-08-01

Threatened Caribbean coral communities can benefit from high-resolution genetic data used to inform management and conservation action. We use Genotyping by Sequencing (GBS) to investigate genetic patterns in the threatened coral, Acropora cervicornis , across the Florida Reef Tract (FRT) and the western Caribbean. Results show extensive population structure at regional scales and resolve previously unknown structure within the FRT. Different regions also exhibit up to threefold differences in genetic diversity (He), suggesting targeted management based on the goals and resources of each population is needed. Patterns of genetic diversity have a strong spatial component, and our results show Broward and the Lower Keys are among the most diverse populations in Florida. The genetic diversity of Caribbean staghorn coral is concentrated within populations and within individual reefs (AMOVA), highlighting the complex mosaic of population structure. This variance structure is similar over regional and local scales, which suggests that in situ nurseries are adequately capturing natural patterns of diversity, representing a resource that can replicate the average diversity of wild assemblages, serving to increase intraspecific diversity and potentially leading to improved biodiversity and ecosystem function. Results presented here can be translated into specific goals for the recovery of A. cervicornis , including active focus on low diversity areas, protection of high diversity and connectivity, and practical thresholds for responsible restoration.

[Clinical and genetic aspects of albinism].

Science.gov (United States)

Arveiler, Benoit; Lasseaux, Eulalie; Morice-Picard, Fanny

Albinism is a genetic disease affecting 1/17,000 person worldwide. It constitutes the second cause of congenital loss of visual acuity after optic atrophy. Albinism is heterogeneous both at the clinical and genetic levels. It is characterized by ocular development anomalies and by a variable degree of hypopigmentation. Clinically, three forms of the disease are described: oculocutaneous, ocular and syndromic (Hermansky-Pudlak syndrome, Chediak-Higashi syndrome). Nineteen genes involved in the different types of albinism have been described so far. The broad phenotypic variability between the different forms but also within a particular form renders the establishment of phenotype-genotype correlations impossible. A genetic test exploring all 19 genes is necessary to establish the diagnosis and to distinguish between syndromic and non-syndromic forms. We present the creation of an albinism-dedicated Day Hospital at the University Hospital of Bordeaux. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Variabilidad genética de poblaciones en cautiverio de Crocodylus moreletii (Crocodylia: Crocodylidae mediante el uso de marcadores microsatelitales Genetic variability in captive populations of Crocodylus moreletii (Crocodylia: Crocodylidae using microsatellites markers

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Ricardo Serna-Lagunes

2012-03-01

Full Text Available Crocodylus moreletii representa un emblema para los ecosistemas tropicales de México pero actualmente está amenazada por extinción. Sorprendentemente, hay una falta de información de su constitución genética, que debe ser evaluada para un manejo apropiado ex situ y para toma de decisiones en la liberación de cocodrilos a su hábitat natural. El objetivo del estudio fue caracterizar y comparar la variabilidad genética de cuatro grupos poblacionales de C. moreletii (dos silvestres y dos nacidas ex situ. Mediante PCR se amplificaron siete loci de microsatélites polimórficos, sin embargo se encontró déficit de heterocigotos en las poblaciones (promedio H O=0.02 mermado por la presencia de alelos nulos. El AMOVA indicó que la mayor proporción de variabilidad genética se encuentra dentro de las poblaciones y una limitada diferenciación genética entre poblaciones (promedio F ST =0.03, probablemente debida al alto índice de endogamia (promedio F IS=0.97. Al comparar la variabilidad genética inter e intra especies de cocodrilianos, encontramos que en C. moreletii está muy por debajo de los reportados. Se concluye que la limitada variabilidad genética de las poblaciones nacidas ex situ probablemente se debe al efecto fundador derivado de la estructura social de sus progenitores, y de las poblaciones silvestres, por el efecto cuello de botella, inferido por el limitado tamaño efectivo de población que presentó históricamente en su distribución natural.Genetic variability in captive populations of Crocodylus moreletii (Crocodylia: Crocodylidae using microsatellites markers. Crocodylus moreletii, an extinction threatened species, represents an emblem for tropical ecosystems in Mexico. Surprisingly, there is a lack of information about their genetic constitution, which should be evaluated for a proper management ex situ and for making decisions on the release of crocodiles into natural habitats. The aim of this study was to

Genetic divergence of physiological-quality traits of seeds in a population of peppers.

Science.gov (United States)

Pessoa, A M S; Barroso, P A; do Rêgo, E R; Medeiros, G D A; Bruno, R L A; do Rêgo, M M

2015-10-16

Brazil has a great diversity of Capsicum peppers that can be used in breeding programs. The objective of this study was to evaluate genetic variation in traits related to the physiological quality of seeds of Capsicum annuum L. in a segregating F2 population and its parents. A total of 250 seeds produced by selfing in the F1 generation resulting from crosses between UFPB 77.3 and UFPB 76 were used, with 100 seeds of both parents used as additional controls, totaling 252 genotypes. The seeds were germinated in gerboxes containing substrate blotting paper moistened with distilled water. Germination and the following vigor tests were evaluated: first count, germination velocity index, and root and shoot lengths. Data were subjected to analysis of variance, and means were compared by Scott and Knott's method at 1% probability. Tocher's clustering based on Mahalanobis distance and canonical variable analysis with graphic dispersion of genotypes were performed, and genetic parameters were estimated. All variables were found to be significant by the F test (P ≤ 0.01) and showed high heritability and a CVg/CVe ratio higher than 1.0, indicating genetic differences among genotypes. Parents (genotypes 1 and 2) formed distinct groups in all clustering methods. Genotypes 3, 104, 153, and 232 were found to be the most divergent according to Tocher's clustering method, and this was mainly due to early germination, which was observed on day 14, and would therefore be selected. Understanding the phenotypic variability among these 252 genotypes will serve as a basis for continuing the breeding program within this family.

Variability in large-scale wind power generation: Variability in large-scale wind power generation

Energy Technology Data Exchange (ETDEWEB)

Kiviluoma, Juha [VTT Technical Research Centre of Finland, Espoo Finland; Holttinen, Hannele [VTT Technical Research Centre of Finland, Espoo Finland; Weir, David [Energy Department, Norwegian Water Resources and Energy Directorate, Oslo Norway; Scharff, Richard [KTH Royal Institute of Technology, Electric Power Systems, Stockholm Sweden; Söder, Lennart [Royal Institute of Technology, Electric Power Systems, Stockholm Sweden; Menemenlis, Nickie [Institut de recherche Hydro-Québec, Montreal Canada; Cutululis, Nicolaos A. [DTU, Wind Energy, Roskilde Denmark; Danti Lopez, Irene [Electricity Research Centre, University College Dublin, Dublin Ireland; Lannoye, Eamonn [Electric Power Research Institute, Palo Alto California USA; Estanqueiro, Ana [LNEG, Laboratorio Nacional de Energia e Geologia, UESEO, Lisbon Spain; Gomez-Lazaro, Emilio [Renewable Energy Research Institute and DIEEAC/EDII-AB, Castilla-La Mancha University, Albacete Spain; Zhang, Qin [State Grid Corporation of China, Beijing China; Bai, Jianhua [State Grid Energy Research Institute Beijing, Beijing China; Wan, Yih-Huei [National Renewable Energy Laboratory, Transmission and Grid Integration Group, Golden Colorado USA; Milligan, Michael [National Renewable Energy Laboratory, Transmission and Grid Integration Group, Golden Colorado USA

2015-10-25

The paper demonstrates the characteristics of wind power variability and net load variability in multiple power systems based on real data from multiple years. Demonstrated characteristics include probability distribution for different ramp durations, seasonal and diurnal variability and low net load events. The comparison shows regions with low variability (Sweden, Spain and Germany), medium variability (Portugal, Ireland, Finland and Denmark) and regions with higher variability (Quebec, Bonneville Power Administration and Electric Reliability Council of Texas in North America; Gansu, Jilin and Liaoning in China; and Norway and offshore wind power in Denmark). For regions with low variability, the maximum 1 h wind ramps are below 10% of nominal capacity, and for regions with high variability, they may be close to 30%. Wind power variability is mainly explained by the extent of geographical spread, but also higher capacity factor causes higher variability. It was also shown how wind power ramps are autocorrelated and dependent on the operating output level. When wind power was concentrated in smaller area, there were outliers with high changes in wind output, which were not present in large areas with well-dispersed wind power.

Cryptic Genetic Variation in Evolutionary Developmental Genetics

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Annalise B. Paaby

2016-06-01

Full Text Available Evolutionary developmental genetics has traditionally been conducted by two groups: Molecular evolutionists who emphasize divergence between species or higher taxa, and quantitative geneticists who study variation within species. Neither approach really comes to grips with the complexities of evolutionary transitions, particularly in light of the realization from genome-wide association studies that most complex traits fit an infinitesimal architecture, being influenced by thousands of loci. This paper discusses robustness, plasticity and lability, phenomena that we argue potentiate major evolutionary changes and provide a bridge between the conceptual treatments of macro- and micro-evolution. We offer cryptic genetic variation and conditional neutrality as mechanisms by which standing genetic variation can lead to developmental system drift and, sheltered within canalized processes, may facilitate developmental transitions and the evolution of novelty. Synthesis of the two dominant perspectives will require recognition that adaptation, divergence, drift and stability all depend on similar underlying quantitative genetic processes—processes that cannot be fully observed in continuously varying visible traits.

Merits and pitfalls of genetic testing in a hypertrophic cardiomyopathy clinic.

Science.gov (United States)

Arad, Michael; Monserrat, Lorenzo; Haron-Khun, Shiraz; Seidman, Jonathan G; Seidman, Christine E; Arbustini, Eloisa; Glikson, Michael; Freimark, Dov

2014-11-01

Hypertrophic cardiomyopathy (HCM) is a familial disease with autosomal dominant inheritance and age-dependent penetrance, caused primarily by mutations of sarcomere genes. Because the clinical variability of HCM is related to its genetic heterogeneity, genetic studies may improve the diagnosis and prognostic evaluation in HCM. To analyze the impact of genetic diagnosis on the clinical management of HCM. Genetic studies were performed for either research or clinical reasons. Once the disease-causing mutation was identified, the management plan was reevaluated. Family members were invited to receive genetic counseling and encouraged to be tested for the mutation. Ten mutations in sarcomere protein genes were identified in 9 probands: 2 novel and 8 previously described. Advanced heart failure or sudden death in a young person prompted the genetic study in 8 of the 9 families. Of 98 relatives available for genotyping, only 53 (54%) agreed to be tested. The compliance was higher in families with sudden death and lower in what appeared to be sporadic HCM or elderly-onset disease. Among the healthy we identified 9 carriers and 19 non-carriers. In 6 individuals the test result resolved an uncertainty about "possible HCM." In several cases the genetic result was also used for family planning and played a role in decisions on cardioverter-defibrillator implantation. Recurrence of a same mutation in different families created an opportunity to apply the information from the literature for risk stratification of individual patients. We suggest that the clinical context determines the indication for genetic testing and interpretation of the results.

Pelvic incidence variation among individuals: functional influence versus genetic determinism.

Science.gov (United States)

Chen, Hong-Fang; Zhao, Chang-Qing

2018-03-20

Pelvic incidence has become one of the most important sagittal parameters in spinal surgery. Despite its great importance, pelvic incidence can vary from 33° to 85° in the normal population. The reasons for this great variability in pelvic incidence remain unexplored. The objective of this article is to present some possible interpretations for the great variability in pelvic incidence under both normal and pathological conditions and to further understand the determinants of pelvic incidence from the perspective of the functional requirements for bipedalism and genetic backgrounds via a literature review. We postulate that both pelvic incidence and pelvic morphology may be genetically predetermined, and a great variability in pelvic incidence may already exist even before birth. This great variability may also serve as a further reminder that the sagittal profile, bipedal locomotion mode, and genetic background of every individual are unique and specific, and clinicians should avoid making universally applying broad generalizations of pelvic incidence. Although PI is an important parameter and there are many theories behind its variability, we still do not have clear mechanistic answers.

Is the experience of thermal pain genetics dependent?

DEFF Research Database (Denmark)

Horjales-Araujo, Emilia; Dahl, Joergen B

2015-01-01

It is suggested that genetic variations explain a significant portion of the variability in pain perception; therefore, increased understanding of pain-related genetic influences may identify new targets for therapies and treatments. The relative contribution of the different genes to the varianc...

Is the Experience of Thermal Pain Genetics Dependent?

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Emilia Horjales-Araujo

2015-01-01

Full Text Available It is suggested that genetic variations explain a significant portion of the variability in pain perception; therefore, increased understanding of pain-related genetic influences may identify new targets for therapies and treatments. The relative contribution of the different genes to the variance in clinical and experimental pain responses remains unknown. It is suggested that the genetic contributions to pain perception vary across pain modalities. For example, it has been suggested that more than 60% of the variance in cold pressor responses can be explained by genetic factors; in comparison, only 26% of the variance in heat pain responses is explained by these variations. Thus, the selection of pain model might markedly influence the magnitude of the association between the pain phenotype and genetic variability. Thermal pain sensation is complex with multiple molecular and cellular mechanisms operating alone and in combination within the peripheral and central nervous system. It is thus highly probable that the thermal pain experience is affected by genetic variants in one or more of the pathways involved in the thermal pain signaling. This review aims to present and discuss some of the genetic variations that have previously been associated with different experimental thermal pain models.

Taking the Perfect Selfie: Investigating the Impact of Perspective on the Perception of Higher Cognitive Variables

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Tobias M. Schneider