Plasminogen Activator Inhibitor-1 (PAI-1) gene 4G/5G alleles frequency distribution in the Lebanese population.

Science.gov (United States)

Shammaa, Dina M R; Sabbagh, Amira S; Taher, Ali T; Zaatari, Ghazi S; Mahfouz, Rami A R

2008-09-01

Plasminogen activator inhibitor-1 (PAI-1) is an inhibitor of fibrinolysis. Increased plasma PAI-1 levels play an essential role in the pathogenesis of cardiovascular risk and other diseases associated with thrombosis. The 4G/5G polymorphism of the PAI-1 promoter region has been extensively studied in different populations. We studied 160 healthy unrelated Lebanese individuals using a reverse hybridization PCR assay to detect the 5G/5G, 4G/5G and, 4G/4G genotypes of the PAI-1 gene and the frequencies of the 4G and 5G alleles. We found that 4G/5G genotype was the most prevalent (45.6%) followed by 5G/5G (36.9%) and 4G/4G (17.5%). The frequencies of the 4G and 5G alleles were calculated to be 0.403 and 0.597, respectively. Compared to other ethnic communities, the Lebanese population was found to harbour a relatively high prevalence of the rare 4G allele. This, in turn, may predispose this population to develop cardiovascular diseases and other thrombotic clinical conditions. This study aids to enhance our understanding of the genetic features of the Lebanese population.

Genotype and allelic frequencies of CYP2E1*5B polymorphism in the southwest population of Iran

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Fatemeh Zanganeh

2014-10-01

Full Text Available Background: Cytochrome P450 2E1 (CYP2E1 is a main enzyme which plays a major role in activating and detoxifying many xenobiotics, carcinogens and drugs. Available studies suggest that CYP2E1 single nucleotide polymorphisms (SNPs are involved in the risk of developing certain cancers after exposure to carcinogens. The purpose of the present study was to assess genotype and allele frequencies of polymorphic CYP2E1*5B in the Iranian population. Material and Methods: This study was performed on 200 healthy individuals (female: 100, male: 100 in medical laboratories of Ahvaz during 2011. The CYP2E1 *5B (rs3813867 G-1293C assessment was carried out using PCR-RFLP method. The data were analyzed with ĸ2 and hardy-Weinberg Equation statistically methods. Results: The frequency of *1A/*1A (c1/c1, *1A/*5B (c1/c2 and *5B/*5B (c2/c2 genotypes was computed 97, 3 and 0 percent, respectively. The frequency of *1A (c1 and *5B (c2 alleles was computed 98.5 and 1.5 percent, respectively. No statistically significant difference was between two genders (p>0.05. Conclusion: The genotype distribution and allele frequencies of CYP2E1*5B polymorphism were similar to Turkish and some of the European populations. However, there are significant interethnic differences when the Iranian population is compared with the Eastern Asian, American and some of the European populations. The allelic distribution of this polymorphism did not vary with gender.

Allele and Genotype Distributions of DNA Repair Gene Polymorphisms in South Indian Healthy Population

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Katiboina Srinivasa Rao

2014-01-01

Full Text Available Various DNA repair pathways protect the structural and chemical integrity of the human genome from environmental and endogenous threats. Polymorphisms of genes encoding the proteins involved in DNA repair have been found to be associated with cancer risk and chemotherapeutic response. In this study, we aim to establish the normative frequencies of DNA repair genes in South Indian healthy population and compare with HapMap populations. Genotyping was done on 128 healthy volunteers from South India, and the allele and genotype distributions were established. The minor allele frequency of Xeroderma pigmentosum group A ( XPA G23A, Excision repair cross-complementing 2 ( ERCC2 /Xeroderma pigmentosum group D ( XPD Lys751Gln, Xeroderma pigmentosum group G ( XPG His46His, XPG Asp1104His, and X-ray repair cross-complementing group 1 ( XRCC1 Arg399Gln polymorphisms were 49.2%, 36.3%, 48.0%, 23.0%, and 34.0% respectively. Ethnic variations were observed in the frequency distribution of these polymorphisms between the South Indians and other HapMap populations. The present work forms the groundwork for cancer association studies and biomarker identification for treatment response and prognosis.

Determination of allele frequencies in nine short tandem repeat loci ...

African Journals Online (AJOL)

SERVER

2008-04-17

Apr 17, 2008 ... the normal cellular process of replication of DNA molecules. ... probability of a certain genetic variant (alleles) occuring in ... have preservatives that hinder spoilage and are easily packaged .... Allele distribution at Nine STR.

Frequency distribution of ABO and Rh (D) blood group alleles in ...

African Journals Online (AJOL)

Kassahun Tesfaye

2014-09-22

Sep 22, 2014 ... Rh (D). Abstract Background: Frequency distribution of blood groups is important as it is used in mod- ern medicine ... sion practice. The need for ... The study design was approved by the Research Ethics Com- mittee, College ...

Allele frequency analysis of Chinese chestnut ( Castanea mollissima ...

African Journals Online (AJOL)

The aim of this study was to establish a method for allele frequency detection in bulk samples. The abundance of polymerase chain reaction (PCR) products in bulk leaf samples was detected using fluorescent labeled Simple sequence repeat (SSR) primers and an Applied biosystems (AB) automatic DNA analyzer.

A genomic study on distribution of human leukocyte antigen (HLA-A and HLA-B alleles in Lak population of Iran

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Farhad Shahsavar

2017-03-01

Full Text Available Anthropological studies based on the highly polymorphic gene, human leukocyte antigen (HLA, provide useful information for bone marrow donor registry, forensic medicine, disease association studies, as well as infertility treatment, designing peptide vaccines against tumors, and infectious or autoimmune diseases. The aim of this study was to determine HLA-A and HLA-B allele frequencies in 100 unrelated Lak/lᴂk/individuals from Lorestan province of Iran. Finally, we compared the results with that previously described in Iranian population. Commercial HLA-Type kits from BAG (Lich, Germany company were used for determination of the HLA-A and HLA-B allele frequencies in genomic DNA, based on polymerase chain reaction with sequence specific primer (PCR-SSP assay. The differences between the populations in distribution of HLA-A and HLA-B alleles were estimated by chi-squared test with Yate's correction. The most frequent HLA-A alleles were *24 (20%, *02 (18%, *03 (12% and *11 (10%, and the most frequent HLA-B alleles were *35 (24%, *51 (16%, *18 (6% and *38 (6% in Lak population. HLA-A*66 (1%, *74(1% and HLA-B*48 (1%, *55(1% were the least observed frequencies in Lak population. Our results based on HLA-A and HLA-B allele frequencies showed that Lak population possesses the previously reported general features of Iranians but still with unique.

Phenotypic and allelic distribution of the ABO and Rhesus (D) blood groups in the Cameroonian population.

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Ndoula, S T; Noubiap, J J N; Nansseu, J R N; Wonkam, A

2014-06-01

Data on blood group phenotypes are important for blood transfusion programs, for disease association and population genetics studies. This study aimed at reporting the phenotypic and allelic distribution of ABO and Rhesus (Rh) groups in various ethnolinguistic groups in the Cameroonians. We obtained ABO and Rhesus blood groups and self-identified ethnicity from 14,546 Cameroonian students. Ethnicity was classified in seven major ethnolinguistic groups: Afro-Asiatic, Nilo-Saharan, Niger-Kordofanian/West Atlantic, Niger-Kordofanian/Adamawa-Ubangui, Niger-Kordofanian/Benue-Congo/Bantu/Grassfield, Niger-Kordofanian/Benue-Congo/Bantu/Mbam and Niger-Kordofanian/Benue-Congo/Bantu/Equatorial. ABO allelic frequencies were determined using the Bernstein method. Differences in phenotypic distribution of blood groups were assessed using the chi-square test; a P value blood groups O, A, B and AB were 48.62%, 25.07%, 21.86% and 4.45%, respectively. Rhesus-positive was 96.32%. The allelic frequencies of O, A and B genes were 0.6978, 0.1605 and 0.1416, respectively. Phenotypic frequencies of the blood groups in the general study population and in the different ethnolinguistic groups were in agreement with Hardy-Weinberg equilibrium expectations (P > 0.05). The frequencies of O, A, and B blood phenotypes were significantly lower, respectively, in the Nilo-Saharan group (P = 0.009), the Niger-Kordofanian/Benue-Congo/Bantu groups (P = 0.021) and the Niger-Kordofanian/West-Atlantic group. AB blood group was most frequent in the Niger-Kordofanian/Adamawa-Ubangui group (P = 0.024). Our study provides the first data on ethnic distribution of ABO and Rhesus blood groups in the Cameroonian population and suggests that its general profile is similar to those of several sub-Saharan African populations. We found some significant differences in phenotypic distribution amongst major ethnolinguistic groups. These data may be important for blood donor recruitment policy and blood transfusion

Lower Frequency of HLA-DRB1 Type 1 Diabetes Risk Alleles in Pediatric Patients with MODY.

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Urrutia, Inés; Martínez, Rosa; López-Euba, Tamara; Velayos, Teresa; Martínez de LaPiscina, Idoia; Bilbao, José Ramón; Rica, Itxaso; Castaño, Luis

2017-01-01

The aim of this study was to determine the frequency of susceptible HLA-DRB1 alleles for type 1 diabetes in a cohort of pediatric patients with a confirmed genetic diagnosis of MODY. 160 families with a proband diagnosed with type 1 diabetes and 74 families with a molecular diagnosis of MODY (61 GCK-MODY and 13 HNF1A-MODY) were categorized at high definition for HLA-DRB1 locus. According to the presence or absence of the susceptible HLA-DRB1 alleles for type 1 diabetes, we considered three different HLA-DRB1 genotypes: 0 risk alleles (no DR3 no DR4); 1 risk allele (DR3 or DR4); 2 risk alleles (DR3 and/or DR4). Compared with type 1 diabetes, patients with MODY carried higher frequency of 0 risk alleles, OR 22.7 (95% CI: 10.7-48.6) and lower frequency of 1 or 2 risk alleles, OR 0.53 (95% CI: 0.29-0.96) and OR 0.06 (95% CI: 0.02-0.18), respectively. The frequency of HLA-DRB1 risk alleles for type 1 diabetes is significantly lower in patients with MODY. In children and adolescents with diabetes, the presence of 2 risk alleles (DR3 and/or DR4) reduces the probability of MODY diagnosis, whereas the lack of risk alleles increases it. Therefore, we might consider that HLA-DRB1 provides additional information for the selection of patients with high probability of monogenic diabetes.

Lower Frequency of HLA-DRB1 Type 1 Diabetes Risk Alleles in Pediatric Patients with MODY.

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Inés Urrutia

Full Text Available The aim of this study was to determine the frequency of susceptible HLA-DRB1 alleles for type 1 diabetes in a cohort of pediatric patients with a confirmed genetic diagnosis of MODY.160 families with a proband diagnosed with type 1 diabetes and 74 families with a molecular diagnosis of MODY (61 GCK-MODY and 13 HNF1A-MODY were categorized at high definition for HLA-DRB1 locus. According to the presence or absence of the susceptible HLA-DRB1 alleles for type 1 diabetes, we considered three different HLA-DRB1 genotypes: 0 risk alleles (no DR3 no DR4; 1 risk allele (DR3 or DR4; 2 risk alleles (DR3 and/or DR4.Compared with type 1 diabetes, patients with MODY carried higher frequency of 0 risk alleles, OR 22.7 (95% CI: 10.7-48.6 and lower frequency of 1 or 2 risk alleles, OR 0.53 (95% CI: 0.29-0.96 and OR 0.06 (95% CI: 0.02-0.18, respectively.The frequency of HLA-DRB1 risk alleles for type 1 diabetes is significantly lower in patients with MODY. In children and adolescents with diabetes, the presence of 2 risk alleles (DR3 and/or DR4 reduces the probability of MODY diagnosis, whereas the lack of risk alleles increases it. Therefore, we might consider that HLA-DRB1 provides additional information for the selection of patients with high probability of monogenic diabetes.

Genome Wide Allele Frequency Fingerprints (GWAFFs) of populations via genotyping by sequencing

DEFF Research Database (Denmark)

Byrne, Stephen; Czaban, Adrian; Studer, Bruno

2013-01-01

-wide scale would be very powerful, examples include the breeding of outbreeding species, varietal protection in outbreeding species, monitoring changes in population allele frequencies. This motivated us to test the potential to use GBS to evaluate allele frequencies within populations. Perennial ryegrass...... these fingerprints can be used to distinguish between plant populations. Even at current costs and throughput, using sequencing to directly evaluate populations on a genome-wide scale is viable. GWAFFs should find many applications, from varietal development in outbreeding species right through to playing a role...... in protecting plant breeders’ rights....

Mutation Rate Variation is a Primary Determinant of the Distribution of Allele Frequencies in Humans.

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Arbel Harpak

2016-12-01

Full Text Available The site frequency spectrum (SFS has long been used to study demographic history and natural selection. Here, we extend this summary by examining the SFS conditional on the alleles found at the same site in other species. We refer to this extension as the "phylogenetically-conditioned SFS" or cSFS. Using recent large-sample data from the Exome Aggregation Consortium (ExAC, combined with primate genome sequences, we find that human variants that occurred independently in closely related primate lineages are at higher frequencies in humans than variants with parallel substitutions in more distant primates. We show that this effect is largely due to sites with elevated mutation rates causing significant departures from the widely-used infinite sites mutation model. Our analysis also suggests substantial variation in mutation rates even among mutations involving the same nucleotide changes. In summary, we show that variable mutation rates are key determinants of the SFS in humans.

Estimation of allele frequency and association mapping using next-generation sequencing data

DEFF Research Database (Denmark)

Kim, Su Yeon; Lohmueller, Kirk E; Albrechtsen, Anders

2011-01-01

Estimation of allele frequency is of fundamental importance in population genetic analyses and in association mapping. In most studies using next-generation sequencing, a cost effective approach is to use medium or low-coverage data (e.g., frequency estimation...

Population estimators or progeny tests: what is the best method to assess null allele frequencies at SSR loci?

NARCIS (Netherlands)

Oddou-Muratorio, S.; Vendramin, G.G.; Buiteveld, J.; Fady, B.

2009-01-01

Nuclear SSRs are notorious for having relatively high frequencies of null alleles, i.e. alleles that fail to amplify and are thus recessive and undetected in heterozygotes. In this paper, we compare two kinds of approaches for estimating null allele frequencies at seven nuclear microsatellite

Comparison of allele frequencies of Plasmodium falciparum merozoite antigens in malaria infections sampled in different years in a Kenyan population.

Science.gov (United States)

Ochola-Oyier, Lynette Isabella; Okombo, John; Wagatua, Njoroge; Ochieng, Jacob; Tetteh, Kevin K; Fegan, Greg; Bejon, Philip; Marsh, Kevin

2016-05-06

Plasmodium falciparum merozoite antigens elicit antibody responses in malaria-endemic populations, some of which are clinically protective, which is one of the reasons why merozoite antigens are the focus of malaria vaccine development efforts. Polymorphisms in several merozoite antigen-encoding genes are thought to arise as a result of selection by the human immune system. The allele frequency distribution of 15 merozoite antigens over a two-year period, 2007 and 2008, was examined in parasites obtained from children with uncomplicated malaria. In the same population, allele frequency changes pre- and post-anti-malarial treatment were also examined. Any gene which showed a significant shift in allele frequencies was also assessed longitudinally in asymptomatic and complicated malaria infections. Fluctuating allele frequencies were identified in codons 147 and 148 of reticulocyte-binding homologue (Rh) 5, with a shift from HD to YH haplotypes over the two-year period in uncomplicated malaria infections. However, in both the asymptomatic and complicated malaria infections YH was the dominant and stable haplotype over the two-year and ten-year periods, respectively. A logistic regression analysis of all three malaria infection populations between 2007 and 2009 revealed, that the chance of being infected with the HD haplotype decreased with time from 2007 to 2009 and increased in the uncomplicated and asymptomatic infections. Rh5 codons 147 and 148 showed heterogeneity at both an individual and population level and may be under some degree of immune selection.

Could FIV zoonosis responsible of the breakdown of the pathocenosis which has reduced the European CCR5-Delta32 allele frequencies?

Science.gov (United States)

Faure, Eric

2008-01-01

Background In Europe, the north-south downhill cline frequency of the chemokine receptor CCR5 allele with a 32-bp deletion (CCR5-Δ32) raises interesting questions for evolutionary biologists. We had suggested first that, in the past, the European colonizers, principally Romans, might have been instrumental of a progressively decrease of the frequencies southwards. Indeed, statistical analyses suggested strong negative correlations between the allele frequency and historical parameters including the colonization dates by Mediterranean civilisations. The gene flows from colonizers to native populations were extremely low but colonizers are responsible of the spread of several diseases suggesting that the dissemination of parasites in naive populations could have induced a breakdown rupture of the fragile pathocenosis changing the balance among diseases. The new equilibrium state has been reached through a negative selection of the null allele. Results Most of the human diseases are zoonoses and cat might have been instrumental in the decrease of the allele frequency, because its diffusion through Europe was a gradual process, due principally to Romans; and that several cat zoonoses could be transmitted to man. The possible implication of a feline lentivirus (FIV) which does not use CCR5 as co-receptor is discussed. This virus can infect primate cells in vitro and induces clinical signs in macaque. Moreover, most of the historical regions with null or low frequency of CCR5-Δ32 allele coincide with historical range of the wild felid species which harbor species-specific FIVs. Conclusion We proposed the hypothesis that the actual European CCR5 allelic frequencies are the result of a negative selection due to a disease spreading. A cat zoonosis, could be the most plausible hypothesis. Future studies could provide if CCR5 can play an antimicrobial role in FIV pathogenesis. Moreover, studies of ancient DNA could provide more evidences regarding the implications of

HLA class II variation in the Gila River Indian Community of Arizona: alleles, haplotypes, and a high frequency epitope at the HLA-DR locus.

Science.gov (United States)

Williams, R C; McAuley, J E

1992-01-01

A genetic distribution for the HLA class II loci is described for 349 "full-blooded" Pima and Tohono O'odham Indians (Pimans) in the Gila River Indian Community. A high frequency epitope in the *DRw52 family was defined by reactions with 31 alloantisera, which we have designated *DR3X6. It segregates as a codominant allele at HLA-DR with alleles *DR2, *DR4, and *DRw8, and has the highest frequency yet reported for an HLA-DR specificity, 0.735. It forms a common haplotype with *DRw52 and *DQw3 that is a valuable marker for genetic admixture and anthropological studies. Phenotype and allele frequencies, and haplotype frequencies for two and three loci, are presented. Variation at these loci is highly restricted, the mean heterozygosity for HLA-DR and HLA-DQ being 0.361. The Pimans represent a contemporary model for the Paleo-Indians who first entered North America 20,000 to 40,000 years ago.

Correlation of geographic distributions of haptoglobin alleles with prevalence of multiple sclerosis (MS) - a narrative literature review.

Science.gov (United States)

Bamm, Vladimir V; Geist, Arielle M; Harauz, George

2017-02-01

We have proposed that the myelin damage observed in multiple sclerosis (MS) may be partly mediated through the long-term release and degradation of extracellular hemoglobin (Hb) and the products of its oxidative degradation [Cellular and Molecular Life Sciences, 71, 1789-1798, 2014]. The protein haptoglobin (Hpt) binds extracellular Hb as a first line of defense, and can serve as a vascular antioxidant. Humans have two different Hpt alleles: Hpt1 and Hpt2, giving either homozygous Hpt1-1 or Hpt2-2 phenotypes, or a heterozygous Hpt1-2 phenotype. We questioned whether those geographic regions with higher frequency of the Hpt2 allele (conversely, lower frequency of Hpt1 allele) would correlate with an increased incidence of MS, because different Hpt phenotypes will have variable anti-oxidative potentials in protecting myelin from damage inflicted by extracellular Hb and its degradation products. To test this hypothesis, we undertook a systematic analysis of the literature on reported geographic distributions of Hpt alleles to compare them with data reported in the World Health Organization Atlas of worldwide MS prevalence. We found the frequency of the Hpt1 allele to be low in European and North American countries with a high prevalence of MS, consistent with our hypothesis. However, this correlation was not observed in China and India, countries with the lowest Hpt1 frequencies, yet low reported prevalence of MS. Nevertheless, this work shows the need for continued refinement of geographic patterns of MS prevalence, including data on ethnic or racial origin, and for new clinical studies to probe the observed correlation and evaluate Hpt phenotype as a predictor of disease variability and progression, severity, and/or comorbidity with cardiovascular disorders.

Frequency of null allele of Human Leukocyte Antigen-G (HLA-G locus in subjects to recurrent miscarriage

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Nazila Alizadeh

2016-07-01

Full Text Available Background: Human leukocyte antigen-G (HLA-G is a non-classical class I molecule highly expressed by extravillous cytotrophoblast cells. Due to a single base pair deletion, its function can be compensated by other isoforms. Investigating the frequency of null allele in Recurrent Miscarriage (RM subjects could be useful in understanding the relationship between frequency of this allele and RM in a given population. Objective: This study aimed to determine the frequency of HLA-G*0105N null allele and its potential association with down-regulation of HLA-G in subjects with RM. Materials and Methods: Western blotting was used to assess the level of HLA-G protein expression. For investigating the frequency of HLA-G*0105N null allele in RM subjects, PCR-RFLP method was used. Exon 3 of HLA-G gene was amplified by polymerase chain reaction (PCR. Subsequently, PpuM-1 enzyme was employed to digest the PCR products and fragments were analyzed using gel electrophoresis. Results: Digestion using restriction enzyme showed the presence of heterozygous HLA-G*0105N null allele in 10% of the test population. Western blotting results confirmed the decrease in expression of HLA-G in the placental tissue of subjects with RM compared to subjects who could give normal birth. Conclusion: The frequency of heterozygous HLA-G*0105N null allele was high to some extent in subjects with RM. The mutation rate in subjects suggested that there is a significant association between RM and frequency of mutations in this allele.

Frequency of null allele of Human Leukocyte Antigen-G (HLA-G) locus in subjects to recurrent miscarriage

Science.gov (United States)

Alizadeh, Nazila; Mosaferi, Elnaz; Farzadi, Laya; Majidi, Jafar; Monfaredan, Amir; Yousefi, Bahman; Baradaran, Behzad

2016-01-01

Background: Human leukocyte antigen-G (HLA-G) is a non-classical class I molecule highly expressed by extravillous cytotrophoblast cells. Due to a single base pair deletion, its function can be compensated by other isoforms. Investigating the frequency of null allele in Recurrent Miscarriage (RM) subjects could be useful in understanding the relationship between frequency of this allele and RM in a given population. Objective: This study aimed to determine the frequency of HLA-G*0105N null allele and its potential association with down-regulation of HLA-G in subjects with RM. Materials and Methods: Western blotting was used to assess the level of HLA-G protein expression. For investigating the frequency of HLA-G*0105N null allele in RM subjects, PCR-RFLP method was used. Exon 3 of HLA-G gene was amplified by polymerase chain reaction (PCR). Subsequently, PpuM-1 enzyme was employed to digest the PCR products and fragments were analyzed using gel electrophoresis. Results: Digestion using restriction enzyme showed the presence of heterozygous HLA-G*0105N null allele in 10% of the test population. Western blotting results confirmed the decrease in expression of HLA-G in the placental tissue of subjects with RM compared to subjects who could give normal birth. Conclusion: The frequency of heterozygous HLA-G*0105N null allele was high to some extent in subjects with RM. The mutation rate in subjects suggested that there is a significant association between RM and frequency of mutations in this allele. PMID:27525330

SNP calling, genotype calling, and sample allele frequency estimation from new-generation sequencing data

DEFF Research Database (Denmark)

Nielsen, Rasmus; Korneliussen, Thorfinn Sand; Albrechtsen, Anders

2012-01-01

We present a statistical framework for estimation and application of sample allele frequency spectra from New-Generation Sequencing (NGS) data. In this method, we first estimate the allele frequency spectrum using maximum likelihood. In contrast to previous methods, the likelihood function is cal...... be extended to various other cases including cases with deviations from Hardy-Weinberg equilibrium. We evaluate the statistical properties of the methods using simulations and by application to a real data set....

A Theoretical Framework for Association Studies in F2 Family Pools Using Allele Frequencies from Genotyping-By-Sequencing

DEFF Research Database (Denmark)

Janss, Luc L; Ashraf, Bilal H; Greve-Pedersen, Morten

a sequencing approach to obtain Single Nucleotide Polymorphisms (SNPs) frequencies is considered here. In this work we develop the theoretical framework to perform association studies using allele frequencies from such F2 family pools. We show that expected allele frequencies in the F2 families will have...

Frequency of Cry1F resistance alleles in Spodoptera frugiperda (Lepidoptera: Noctuidae) in Brazil.

Science.gov (United States)

Farias, Juliano R; Andow, David A; Horikoshi, Renato J; Bernardi, Daniel; Ribeiro, Rebeca da S; Nascimento, Antonio Rb do; Santos, Antonio C Dos; Omoto, Celso

2016-12-01

The frequency of resistance alleles is a major factor influencing the rate of resistance evolution. Here, we adapted the F 2 screen procedure for Spodoptera frugiperda (J. E. Smith) with a discriminating concentration assay, and extended associated statistical methods to estimate the frequency of resistance to Cry1F protein in S. frugiperda in Brazil when resistance was not rare. We show that F 2 screen is efficient even when the resistance frequency is 0.250. It was possible to screen 517 isoparental lines from 12 populations sampled in five states of Brazil during the first half of 2012. Western Bahia had the highest allele frequency of Cry1F resistance, 0.192, with a 95% confidence interval (CI) between 0.163 and 0.220. All other states had a similar and lower frequency varying from 0.042 in Paraná to 0.080 in Mato Grosso do Sul. The high frequency in western Bahia may be related to year-round availability of maize, the high population density of S. frugiperda, the lack of refuges and the high adoption rate of Cry1F maize. Cry1F resistance alleles were not rare and occurred at frequencies that have already compromised the useful life of TC1507 maize in western Bahia. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Allele frequencies of AVPR1A and MAOA in the Afrikaner population

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J. Christoff Erasmus

2015-07-01

Full Text Available The Afrikaner population was founded mainly by European immigrants that arrived in South Africa from 1652. However, female slaves from Asia and Africa and local KhoeSan women may have contributed as much as 7% to this population’s genes. We quantified variation at two tandem repeats to see if this historical founder effect and/or admixture could be detected. The two loci were chosen because they are in the promoters of genes of neurotransmitters that are known to be correlated with social behaviour. Specifically, arginine vasopressin receptor 1A’s (AVPR1A RS3 locus has been shown to correlate with age of sexual onset and happiness in monogamous relationships while the tandem repeat in the promoter of the monoamine oxidase A (MAOA gene correlates with reactive aggression. The Afrikaner population contained more AVPR1A RS3 alleles than other Caucasoid populations, potentially reflecting a history of admixture. Even though Afrikaners have one of the lowest recorded non-paternity rates in the world, the population did not differ at AVPR1A RS3 locus form other European populations, suggesting a non-genetic explanation, presumably religion, for the low non-paternity rate. By comparing population allele-frequency spectra it was found that different studies have confused AVPR1A RS3 alleles and we make some suggestions to rectify these mistakes in future studies. While MAOA allele frequencies differed between racial groups, the Afrikaner population showed no evidence of admixture. In fact, Afrikaners had more 4-repeat alleles than other populations of European origin, not fewer. The 4-repeat allele may have been selected for during colonisation.

Cytochrome P450 2D6 variants in a Caucasian population: Allele frequencies and phenotypic consequences

Energy Technology Data Exchange (ETDEWEB)

Sachse, C.; Brockmoeller, J.; Bauer, S.; Roots, I. [Humboldt Univ., Berlin (Germany)

1997-02-01

Cytochrome P450 2D6 (CYP2D6) metabolizes many important drugs. CYP2D6 activity ranges from complete deficiency to ultrafast metabolism, depending on at least 16 different known alleles. Their frequencies were determined in 589 unrelated German volunteers and correlated with enzyme activity measured by phenotyping with dextromethorphan or debrisoquine. For genotyping, nested PCR-RFLP tests from a PCR amplificate of the entire CYP2D6 gene were developed. The frequency of the CYP2D6*1 allele coding for extensive metabolizer (EM) phenotype was .364. The alleles coding for slightly (CYP2D6*2) or moderately (*9 and *10) reduced activity (intermediate metabolizer phenotype [IM]) showed frequencies of .324, .018, and .015, respectively. By use of novel PCR tests for discrimination, CYP2D6 gene duplication alleles were found with frequencies of.005 (*1 x 2), .013 (* 2 x 2), and .001 (*4 x 2). Frequencies of alleles with complete deficiency (poor metabolizer phenotype [PM]) were .207 (*4), .020 (*3 and *5), .009 (*6), and .001 (*7, *15, and *16). The defective CYP2D6 alleles *8, *11, *12, *13, and *14 were not found. All 41 PMs (7.0%) in this sample were explained by five mutations detected by four PCR-RFLP tests, which may suffice, together with the gene duplication test, for clinical prediction of CYP2D6 capacity. Three novel variants of known CYP2D6 alleles were discovered: *1C (T{sub 1957}C), *2B (additional C{sub 2558}T), and *4E (additional C{sub 2938}T). Analysis of variance showed significant differences in enzymatic activity measured by the dextromethorphan metabolic ratio (MR) between carriers of EN/PM (mean MR = .006) and IM/PM (mean MR = .014) alleles and between carriers of one (mean MR = .009) and two (mean MR = .003) functional alleles. The results of this study provide a solid basis for prediction of CYP2D6 capacity, as required in drug research and routine drug treatment. 35 refs., 4 figs., 5 tabs.

Beta2-adrenergic receptor allele frequencies in the Quechua, a high altitude native population.

Science.gov (United States)

Rupert, J L; Monsalve, M V; Devine, D V; Hochachka, P W

2000-03-01

The beta2-adrenergic receptor is involved in the control of numerous physiological processes and, as the primary catecholamine receptor in the lungs, is of particular importance in the regulation of pulmonary function. There are several polymorphic loci in the beta2-adrenergic receptor gene that have alleles that alter receptor function, including two (A/G46, G/C79) that increase agonist sensitivity. As such a phenotype may increase vaso and bronchial dilation, thereby facilitating air and blood flow through the lungs, we hypothesized that selection may have favoured these alleles in high altitude populations as part of an adaptive strategy to deal with the hypoxic conditions characteristic of such environments. We tested this hypothesis by determining the allele frequencies for these two polymorphisms, as well one additional missense mutation (C/T491) and two silent mutations (G/A252 and C/A523) in 63 Quechua speaking natives from communities located between 3200 and 4200 m on the Peruvian altiplano. These frequencies were compared with those of two lowland populations, one native American (Na-Dene from the west coast of Canada) and one Caucasian of Western European descent. The Quechua manifest many of the pulmonary characteristics of high altitude populations and differences in allele frequencies between the Quechua and lowlanders could be indicative of a selective advantage conferred by certain genotypes in high altitude environments. Allele frequencies varied between populations at some loci and patterns of linkage disequilibrium differed between the old-world and new-world samples; however, as these populations are not closely related, significant variation would be expected due to stochastic effects alone. Neither of the alleles associated with increased receptor sensitivity (A46, G79) was significantly over-represented in the Quechua compared with either lowland group. The Quechua were monomorphic for the C allele at base 79. This variant has been

Microsatellite D21D210 (GT-12) allele frequencies in sporadic Alzheimer's disease

International Nuclear Information System (INIS)

Lannfelt, L.; Lilius, L.; Viitanen, M.; Winblad, B.; Basun, H.; Houlden, H.; Rossor, M.; Hardy, J.

1995-01-01

Four disease-causing mutations have so far been described in the amyloid precursor protein gene on chromosome 21 in familial early-onset Alzheimer's disease. Linkage analysis with a fourteen-allele microsatellite at D21S210 named GT-12 has proven useful in the elucidation of amyloid presursor protein gene involvement in Alzheimer's disease families, as it is closely linked to the gene. Most cases of Alzheimer's disease are thought to be sporadic and not familial. However, evidence from earlier studies suggests an important genetic contribution also in sporadic cases, where gene-environment interaction may contribute to the disease. We have determined frequencies of the GT-12 alleles in 78 Swedish and 49 British sporadic Alzheimer's disease cases and 104 healthy elderly control subjects, to investigate if the disease associates with a particular genotype in GT-12. However, no differences in allele frequencies were observed between any of the groups. (au) (26 refs.)

Estimation of 2N(e)s from temporal allele frequency data

DEFF Research Database (Denmark)

Bollback, Jonathan Paul; York, Thomas L.; Nielsen, Rasmus

2008-01-01

We develop a new method for estimating effective population sizes, Ne, and selection coefficients, s, from time-series data of allele frequencies sampled from a single diallelic locus. The method is based on calculating transition probabilities, using a numerical solution of the diffusion process...

Frequency of alleles and haplotypes of the human leukocyte antigen system in Bauru, São Paulo, Brazil

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Luana de Cassia Salvadori

2014-04-01

Full Text Available Background: HLA allele identification is used in bone marrow transplant programs as HLA compatibility between the donor and recipient may prevent graft rejection. Objective: This study aimed to estimate the frequency of alleles and haplotypes of the HLA system in the region of Bauru and compare these with the frequencies found in other regions of the country. Methods: HLA-A*, HLA-B*, and HLA-DRB1* allele frequencies and haplotypes were analyzed in a sample of 3542 volunteer donors at the National Registry of Voluntary Bone Marrow Donors (REDOME in Bauru. HLA low resolution typing was performed using reverse line blot with the Dynal Reli(tm SSO-HLA Typing Kit and automated Dynal AutoReli(tm48 device (Invitrogen, USA. Results: Twenty, 36, and 13 HLA-A*, HLA-B*, and HLA-DRB1* allele groups, respectively, were identified. The most common alleles for each locus were HLA-A*02, HLA-B*35, and HLA-DRB1*07. The most frequent haplotype was A*01-B*08-DRB1*03. Allele and haplotype frequencies were compared to other regions in Brazil and the similarities and differences among populations are shown. Conclusion: The knowledge of the immunogenic profile of a population contributes to the comprehension of the historical and anthropological aspects of different regions. Moreover, this helps to find suitable donors quickly, thereby shortening waiting lists for transplants and thus increasing survival rates among recipients.

Allele frequencies of ten short tandem repeats loci in the central ...

Indian Academy of Sciences (India)

2009-04-03

Apr 3, 2009 ... c Indian Academy of Sciences. RESEARCH NOTE. Allele frequencies of ten short tandem ... Statistical parameters of forensic importance, the power of discrimination (PD), observed and expected ... rameters indicated the usefulness of the loci in forensic per- sonal identification and paternity testing among ...

Worldwide Distribution of Cytochrome P450 Alleles: A Meta-analysis of Population-scale Sequencing Projects.

Science.gov (United States)

Zhou, Y; Ingelman-Sundberg, M; Lauschke, V M

2017-10-01

Genetic polymorphisms in cytochrome P450 (CYP) genes can result in altered metabolic activity toward a plethora of clinically important medications. Thus, single nucleotide variants and copy number variations in CYP genes are major determinants of drug pharmacokinetics and toxicity and constitute pharmacogenetic biomarkers for drug dosing, efficacy, and safety. Strikingly, the distribution of CYP alleles differs considerably between populations with important implications for personalized drug therapy and healthcare programs. To provide a global distribution map of CYP alleles with clinical importance, we integrated whole-genome and exome sequencing data from 56,945 unrelated individuals of five major human populations. By combining this dataset with population-specific linkage information, we derive the frequencies of 176 CYP haplotypes, providing an extensive resource for major genetic determinants of drug metabolism. Furthermore, we aggregated this dataset into spectra of predicted functional variability in the respective populations and discuss the implications for population-adjusted pharmacological treatment strategies. © 2017 The Authors Clinical Pharmacology & Therapeutics published by Wiley Periodicals, Inc. on behalf of American Society for Clinical Pharmacology and Therapeutics.

Low frequency of the scrapile resistance-associated allele and presence of lysine-171 allele of the prion protein gene in Italian Biellese ovine breed

NARCIS (Netherlands)

Acutis, P.L.; Sbaiz, L.; Verburg, F.J.; Riina, M.V.; Ru, G.; Moda, G.; Caramelli, M.; Bossers, A.

2004-01-01

Frequencies of polymorphisms at codons 136, 154 and 171 of the prion protein (PrP) gene were studied in 1207 pure-bred and cross-bred Italian Biellese rams, a small ovine breed of about 65 000 head in Italy. Aside from the five most common alleles (VRQ, ARQ, ARR, AHQ and ARH), the rare ARK allele

Frequency distribution of ABO and Rh (D) blood group alleles in Silte Zone, Ethiopia

OpenAIRE

Kassahun Tesfaye; Yohannes Petros; Mebeaselassie Andargie

2015-01-01

Background: Frequency distribution of blood groups is important as it is used in modern medicine, genetic research, anthropology, and tracing ancestral relations of humans. The ABO and Rh blood groups are the most important blood groups despite the long list of several other blood groups discovered so far. Aim of the study: To study and document the frequency of ABO and Rh (D) blood groups in three ethnic groups of Silte Zone, Ethiopia. Subjects and methods: ABO and Rh (D) typing was ca...

[High frequency of ancestral allele of the TJP1 polymorphism rs2291166 in Mexican population, conformational effect and applications in surgery and medicine].

Science.gov (United States)

Ramirez-Garcia, Sergio Alberto; Flores-Alvarado, Luis Javier; Topete-González, Luz Rosalba; Charles-Niño, Claudia; Mazariegos-Rubi, Manuel; Dávalos-Rodríguez, Nory Omayra

2016-01-01

TJP1 gene encodes a ZO-1 protein that is required for the recruitment of occludins and claudins in tight junction, and is involved in cell polarisation. It has different variations, the frequency of which has been studied in different populations. In Mexico there are no studies of this gene. These are required because their polymorphisms can be used in studies associated with medicine and surgery. Therefore, the aim of this study was to estimate the frequency of alleles and genotypes of rs2291166 gene polymorphism TJP1 in Mexico Mestizos population, and to estimate the conformational effect of an amino acid change. A total of 473 individuals were included. The rs2291166 polymorphism was identified PASA PCR-7% PAGE, and stained with silver nitrate. The conformational effect of amino acid change was performed in silico, and was carried out with servers ProtPraram Tool and Search Database with Fasta. The most frequent allele in the two populations is the ancestral allele (T). A genotype distribution similar to other populations was found. The polymorphism is in Hardy-Weinberg, p>0.05. Changing aspartate to alanine produced a conformational change. The study reveals a high frequency of the ancestral allele at rs2291166 polymorphism in the Mexican population. Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.

The allelic distribution of -308 Tumor Necrosis Factor-alpha gene polymorphism in South African women with cervical cancer and control women

International Nuclear Information System (INIS)

Govan, Vandana A; Constant, Debbie; Hoffman, Margaret; Williamson, Anna-Lise

2006-01-01

Cervical cancer is due to infection with specific high-risk types of human papillomavirus (HPV). Although the incidence of genital HPV infection in various population groups is high, most of these regress without intervention. Investigating genetic host factors and cellular immune responses, particularly cytokines, could help to understand the association between genital HPV infection and carcinogenesis. The tumor necrosis factor alpha (TNF-α) cytokine plays an important role in all stages of cervical cancer and has the ability to induce the regression of human tumors. Therefore the aim of the study was to investigate the allelic distribution of -308 TNF-α gene polymorphism in South African women with cervical cancer compared to control women. Included in our study were women with histologically proven cancer of the cervix (n = 244) and hospital-based controls (n = 228). All patients and controls were from mixed race and black population groups in South Africa. The detection of a bi-allelic -308 (A/G) polymorphism in the promoter region of TNF-α was investigated using the amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) technique. The distributions of the allelic frequencies were stratified in both patients and controls into two South African ethnic population groups. In this study we observed no association between the distribution of -308 TNF-α polymorphism and the risk of developing cervical cancer even after combining the data from the two ethnic populations (X 2 = 2.26). In addition, using the chi-squared test we found no significant association between the known risk factors for cervical cancer and the allele distribution of -308 TNF-α. However, the frequency of the rare high-producing allele -308A of TNF-α was significantly lower in the South African population when compared to Caucasians and Chinese population groups. We demonstrated no association between -308 TNF-α polymorphism and the risk of cervical cancer among two

Detection of MPLW515L/K mutations and determination of allele frequencies with a single-tube PCR assay.

Science.gov (United States)

Takei, Hiraku; Morishita, Soji; Araki, Marito; Edahiro, Yoko; Sunami, Yoshitaka; Hironaka, Yumi; Noda, Naohiro; Sekiguchi, Yuji; Tsuneda, Satoshi; Ohsaka, Akimichi; Komatsu, Norio

2014-01-01

A gain-of-function mutation in the myeloproliferative leukemia virus (MPL) gene, which encodes the thrombopoietin receptor, has been identified in patients with essential thrombocythemia and primary myelofibrosis, subgroups of classic myeloproliferative neoplasms (MPNs). The presence of MPL gene mutations is a critical diagnostic criterion for these diseases. Here, we developed a rapid, simple, and cost-effective method of detecting two major MPL mutations, MPLW515L/K, in a single PCR assay; we termed this method DARMS (dual amplification refractory mutation system)-PCR. DARMS-PCR is designed to produce three different PCR products corresponding to MPLW515L, MPLW515K, and all MPL alleles. The amplicons are later detected and quantified using a capillary sequencer to determine the relative frequencies of the mutant and wild-type alleles. Applying DARMS-PCR to human specimens, we successfully identified MPL mutations in MPN patients, with the exception of patients bearing mutant allele frequencies below the detection limit (5%) of this method. The MPL mutant allele frequencies determined using DARMS-PCR correlated strongly with the values determined using deep sequencing. Thus, we demonstrated the potential of DARMS-PCR to detect MPL mutations and determine the allele frequencies in a timely and cost-effective manner.

Detection of MPLW515L/K mutations and determination of allele frequencies with a single-tube PCR assay.

Directory of Open Access Journals (Sweden)

Hiraku Takei

Full Text Available A gain-of-function mutation in the myeloproliferative leukemia virus (MPL gene, which encodes the thrombopoietin receptor, has been identified in patients with essential thrombocythemia and primary myelofibrosis, subgroups of classic myeloproliferative neoplasms (MPNs. The presence of MPL gene mutations is a critical diagnostic criterion for these diseases. Here, we developed a rapid, simple, and cost-effective method of detecting two major MPL mutations, MPLW515L/K, in a single PCR assay; we termed this method DARMS (dual amplification refractory mutation system-PCR. DARMS-PCR is designed to produce three different PCR products corresponding to MPLW515L, MPLW515K, and all MPL alleles. The amplicons are later detected and quantified using a capillary sequencer to determine the relative frequencies of the mutant and wild-type alleles. Applying DARMS-PCR to human specimens, we successfully identified MPL mutations in MPN patients, with the exception of patients bearing mutant allele frequencies below the detection limit (5% of this method. The MPL mutant allele frequencies determined using DARMS-PCR correlated strongly with the values determined using deep sequencing. Thus, we demonstrated the potential of DARMS-PCR to detect MPL mutations and determine the allele frequencies in a timely and cost-effective manner.

Microsatellite D21D210 (GT-12) allele frequencies in sporadic Alzheimer`s disease

Energy Technology Data Exchange (ETDEWEB)

Lannfelt, L; Lilius, L; Viitanen, M; Winblad, B; Basun, H [Huddinge Hospital, Karolinska Institute, Dept. of Geriatric Medicine, (Sweden); Houlden, H; Rossor, M [St. Mary` s Hospital, Dept. of Neurology, Medical School, London (United Kingdom); Hardy, J [University of South Florida, Suncoast Alzheimer` s Disease Research Labs, Department of Psychiatry, Tampa (United States)

1995-02-01

Four disease-causing mutations have so far been described in the amyloid precursor protein gene on chromosome 21 in familial early-onset Alzheimer`s disease. Linkage analysis with a fourteen-allele microsatellite at D21S210 named GT-12 has proven useful in the elucidation of amyloid presursor protein gene involvement in Alzheimer`s disease families, as it is closely linked to the gene. Most cases of Alzheimer`s disease are thought to be sporadic and not familial. However, evidence from earlier studies suggests an important genetic contribution also in sporadic cases, where gene-environment interaction may contribute to the disease. We have determined frequencies of the GT-12 alleles in 78 Swedish and 49 British sporadic Alzheimer`s disease cases and 104 healthy elderly control subjects, to investigate if the disease associates with a particular genotype in GT-12. However, no differences in allele frequencies were observed between any of the groups. (au) (26 refs.).

Type 2 diabetes risk alleles demonstrate extreme directional differentiation among human populations, compared to other diseases.

Directory of Open Access Journals (Sweden)

Rong Chen

Full Text Available Many disease-susceptible SNPs exhibit significant disparity in ancestral and derived allele frequencies across worldwide populations. While previous studies have examined population differentiation of alleles at specific SNPs, global ethnic patterns of ensembles of disease risk alleles across human diseases are unexamined. To examine these patterns, we manually curated ethnic disease association data from 5,065 papers on human genetic studies representing 1,495 diseases, recording the precise risk alleles and their measured population frequencies and estimated effect sizes. We systematically compared the population frequencies of cross-ethnic risk alleles for each disease across 1,397 individuals from 11 HapMap populations, 1,064 individuals from 53 HGDP populations, and 49 individuals with whole-genome sequences from 10 populations. Type 2 diabetes (T2D demonstrated extreme directional differentiation of risk allele frequencies across human populations, compared with null distributions of European-frequency matched control genomic alleles and risk alleles for other diseases. Most T2D risk alleles share a consistent pattern of decreasing frequencies along human migration into East Asia. Furthermore, we show that these patterns contribute to disparities in predicted genetic risk across 1,397 HapMap individuals, T2D genetic risk being consistently higher for individuals in the African populations and lower in the Asian populations, irrespective of the ethnicity considered in the initial discovery of risk alleles. We observed a similar pattern in the distribution of T2D Genetic Risk Scores, which are associated with an increased risk of developing diabetes in the Diabetes Prevention Program cohort, for the same individuals. This disparity may be attributable to the promotion of energy storage and usage appropriate to environments and inconsistent energy intake. Our results indicate that the differential frequencies of T2D risk alleles may

Frequency of the CCRD32 allele in Brazilians: a study in colorectal cancer and in HTLV-I infection

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Pereira Rinaldo W.

2000-01-01

Full Text Available The identification of a 32-bp deletion in the cc-chemokine receptor-5 gene (CCR5delta32 allele that renders homozygous individuals highly resistant to HIV infection has prompted worldwide investigations of the frequency of the CCR5delta32 allele in regional populations. It is important to ascertain if CCR5delta32 is a factor to be considered in the overall epidemiology of HIV in individual populations. With this in mind we determined the CCR5delta32 allele frequency in a large sample (907 individuals of the southeastern Brazilian urban population, stratified as follows: 322 healthy unrelated individuals, 354 unselected colorectal cancer patients, and 229 blood donors. The three groups displayed essentially identical allelic frequencies of CCR5delta32 and pairwise comparisons did not show significant differences. Thus, our results can be pooled to provide a reliable estimate of the CCR5delta32 allele frequency in the southeastern Brazil of 0.053 ± 0.005. The blood donors comprised 50 HTLV-I serologically negative individuals, 115 non-symptomatic individuals HTLV-I positive by ELISA but with indeterminate Western blot results, 49 healthy blood donors HTLV-I positive both at ELISA and Western blot and 15 patients with clinical spinal cord disease (HAM. A suggestive trend was observed, with the CCR5delta32 frequencies decreasing progressively in these four categories. However, when we applied Fischer's exact test no significant differences emerged. We believe that further studies in larger cohorts should be performed to ascertain whether the CCR5delta32 allele influences the chance of becoming infected or developing clinical symptoms of HTLV-I infection.

Association between the CCR5 32-bp deletion allele and late onset of schizophrenia

DEFF Research Database (Denmark)

Rasmussen, H.B.; Timm, S.; Wang, A.G.

2006-01-01

OBJECTIVE: The 32-bp deletion allele in chemokine receptor CCR5 has been associated with several immune-mediated diseases and might be implicated in schizophrenia as well. METHOD: The authors genotyped DNA samples from 268 schizophrenia patients and 323 healthy subjects. Age at first admission...... to a psychiatric hospital department served as a measure of disease onset. RESULTS: Patients and comparison subjects differed marginally in their genotype distribution, with a slightly higher frequency of the deletion allele seen in the patients. The authors found the deletion allele to be associated with higher......-onset schizophrenia) and healthy subjects differed significantly. This was reflected in an increased frequency of the deletion allele in the patient subgroup. Patients with ages at first admission below and above 40 years significantly differed in distribution of genotypes and alleles, with an overrepresentation...

Identification of internal variation in the pseudoautosomal VNTR DXYS17, with nonrandom distribution of the alleles on the X and the Y chromosomes

Energy Technology Data Exchange (ETDEWEB)

Decorte, R.; Wu, R.; Marynen, P.; Cassiman, J.J.

1994-03-01

The PCR technique was used to analyze the DXYS17 locus in the pseudoautosomal region of the X and the Y chromosomes. Analysis on an automated DNA sequencer allowed for sensitive and highly accurate typing of 16 different alleles with a size between 480 and 1,100 bp. Two DXYS17 alleles migrated with the same size on agarose or denaturing polyacrylamide gels but with different mobilities on nondenaturing polyacrylamide gels. Sequence analysis showed that, while an identical number of repeats were present in both alleles, differences in the composition of the units were observed. The origin of these differences was found in the 28- and 33-bp units, which only had a specific repeat pattern at the 5' and 3' ends of the region. The genotype distribution for DXYS17 in a Caucasian population did not deviate from the values expected under Hardy-Weinberg equilibrium. However, the frequency of one allele and one genotype was significantly different between males and females. Segregation analysis showed that this difference was the result of a nonrandom distribution of certain alleles on the sex chromosomes in males. 31 refs., 4 figs., 2 tabs.

Confidence intervals for population allele frequencies: the general case of sampling from a finite diploid population of any size.

Science.gov (United States)

Fung, Tak; Keenan, Kevin

2014-01-01

The estimation of population allele frequencies using sample data forms a central component of studies in population genetics. These estimates can be used to test hypotheses on the evolutionary processes governing changes in genetic variation among populations. However, existing studies frequently do not account for sampling uncertainty in these estimates, thus compromising their utility. Incorporation of this uncertainty has been hindered by the lack of a method for constructing confidence intervals containing the population allele frequencies, for the general case of sampling from a finite diploid population of any size. In this study, we address this important knowledge gap by presenting a rigorous mathematical method to construct such confidence intervals. For a range of scenarios, the method is used to demonstrate that for a particular allele, in order to obtain accurate estimates within 0.05 of the population allele frequency with high probability (> or = 95%), a sample size of > 30 is often required. This analysis is augmented by an application of the method to empirical sample allele frequency data for two populations of the checkerspot butterfly (Melitaea cinxia L.), occupying meadows in Finland. For each population, the method is used to derive > or = 98.3% confidence intervals for the population frequencies of three alleles. These intervals are then used to construct two joint > or = 95% confidence regions, one for the set of three frequencies for each population. These regions are then used to derive a > or = 95%% confidence interval for Jost's D, a measure of genetic differentiation between the two populations. Overall, the results demonstrate the practical utility of the method with respect to informing sampling design and accounting for sampling uncertainty in studies of population genetics, important for scientific hypothesis-testing and also for risk-based natural resource management.

Confidence intervals for population allele frequencies: the general case of sampling from a finite diploid population of any size.

Directory of Open Access Journals (Sweden)

Tak Fung

Full Text Available The estimation of population allele frequencies using sample data forms a central component of studies in population genetics. These estimates can be used to test hypotheses on the evolutionary processes governing changes in genetic variation among populations. However, existing studies frequently do not account for sampling uncertainty in these estimates, thus compromising their utility. Incorporation of this uncertainty has been hindered by the lack of a method for constructing confidence intervals containing the population allele frequencies, for the general case of sampling from a finite diploid population of any size. In this study, we address this important knowledge gap by presenting a rigorous mathematical method to construct such confidence intervals. For a range of scenarios, the method is used to demonstrate that for a particular allele, in order to obtain accurate estimates within 0.05 of the population allele frequency with high probability (> or = 95%, a sample size of > 30 is often required. This analysis is augmented by an application of the method to empirical sample allele frequency data for two populations of the checkerspot butterfly (Melitaea cinxia L., occupying meadows in Finland. For each population, the method is used to derive > or = 98.3% confidence intervals for the population frequencies of three alleles. These intervals are then used to construct two joint > or = 95% confidence regions, one for the set of three frequencies for each population. These regions are then used to derive a > or = 95%% confidence interval for Jost's D, a measure of genetic differentiation between the two populations. Overall, the results demonstrate the practical utility of the method with respect to informing sampling design and accounting for sampling uncertainty in studies of population genetics, important for scientific hypothesis-testing and also for risk-based natural resource management.

Changes in allelic frequency over time in European bread wheat (Triticum aestivum L.) varieties revealed using DArT and SSR markers

DEFF Research Database (Denmark)

Orabi, Jihad; Jahoor, Ahmed; Backes, Gunter Martin

2014-01-01

A collection of 189 bread wheat landraces and cultivars, primarily of European origin, released between 1886 and 2009, was analyzed using two DNA marker systems. A set of 76 SSR markers and ~7,000 DArT markers distributed across the wheat genome were employed in these analyses. All of the SSR...... markers were found to be polymorphic, whereas only 2,532 of the ~7,000 DArT markers were polymorphic. A Mantel test between the genetic distances calculated based on the SSR and DArT data showed a strong positive correlation between the two marker types, with a Pearson's value (r) of 0.66. We assessed...... the genetic diversity and allelic frequencies among the accessions based on spring- versus winter-wheat type as well as between landraces and cultivars. We also analyzed the changes in genetic diversity and allelic frequencies in these samples over time. We observed separation based on both vernalization type...

Association studies using family pools of outcrossing crops based on allele-frequency estimates from DNA sequencing

DEFF Research Database (Denmark)

Ashraf, Bilal; Jensen, Just; Asp, Torben

2014-01-01

effect from F2-family pools was verified and it was shown that the underestimation of the allele effect is correctly described. The optimal design for an association study when sequencing budget would be fixed is obtained using large sample size and lower sequence depth, and using higher SNP density......F2 families are frequently used in breeding of outcrossing species, for instance to obtain trait measurements on plots. We propose to perform association studies by obtaining a matching “family genotype” from sequencing a pooled sample of the family, and to directly use allele frequencies computed...... (resulting in higher LD with causative mutations) and lower sequencing depth. Therefore, association studies using genotyping by sequencing are optimal and use low sequencing depth per sample. The developed framework for association studies using allele frequencies from sequencing can be modified for other...

Frequency Specific Effects of ApoE ε4 Allele on Resting-State Networks in Nondemented Elders

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Ying Liang

2017-01-01

Full Text Available We applied resting-state functional magnetic resonance imaging (fMRI to examine the Apolipoprotein E (ApoE ε4 allele effects on functional connectivity of the default mode network (DMN and the salience network (SN. Considering the frequency specific effects of functional connectivity, we decomposed the brain network time courses into two bands: 0.01–0.027 Hz and 0.027–0.08 Hz. All scans were acquired by the Alzheimer’s Disease Neuroscience Initiative (ADNI. Thirty-two nondemented subjects were divided into two groups based on the presence (n=16 or absence (n=16 of the ApoE ε4 allele. We explored the frequency specific effects of ApoE ε4 allele on the default mode network (DMN and the salience network (SN functional connectivity. Compared to ε4 noncarriers, the DMN functional connectivity of ε4 carriers was significantly decreased while the SN functional connectivity of ε4 carriers was significantly increased. Many functional connectivities showed significant differences at the lower frequency band of 0.01–0.027 Hz or the higher frequency band of 0.027–0.08 Hz instead of the typical range of 0.01–0.08 Hz. The results indicated a frequency dependent effect of resting-state signals when investigating RSNs functional connectivity.

Prion protein genotype survey confirms low frequency of scrapie-resistant K222 allele in British goat herds.

Science.gov (United States)

Goldmann, W; Marier, E; Stewart, P; Konold, T; Street, S; Langeveld, J; Windl, O; Ortiz-Pelaez, A

2016-02-13

Scrapie in goats is a transmissible, fatal prion disease, which is endemic in the British goat population. The recent success in defining caprine PRNP gene variants that provide resistance to experimental and natural classical scrapie has prompted the authors to conduct a survey of PRNP genotypes in 10 goat breeds and 52 herds to find goats with the resistant K222 allele. They report here the frequencies in 1236 tested animals of the resistance-associated K222 and several other alleles by breed and herd. Eight animals were found to be heterozygous QK222 goats (0.64 per cent genotype frequency, 95 per cent CI 0.28 to 1.27 per cent) but no homozygous KK222 goats were detected. The K222 allele was found in Saanen, Toggenburg and Anglo-Nubian goats. The fact that only a few goats with the K222 allele have been identified does not preclude the possibility to design and implement successful breeding programmes at national level. British Veterinary Association.

Distribution of Human Leukocyte Antigen alleles in Systemic Lupus Erythematosus patients with Angiotensin Converting Enzyme Insertion/Deletion Polymorphism

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Nageen Hussain

2013-02-01

Full Text Available Systemic Lupus Erythematosus is one of the classic examples of autoimmune diseases among human beings and is a rare disease in Pakistani population. Clinically it is a quite diverse and complicated autoimmune disease in a sense that it involves multiple organs of the body and mimics with other diseases as well. This study focused on the distribution of HLA alleles in SLE patients with ACE I/D Polymorphism. A total of 122 individuals were enrolled in this study, 61 were the SLE patients who fulfilled revised ACR criteria and 61 were the healthy controls. Mean age of SLE patients at diagnosis was 30.35 ± 1.687 years (12-68 years. ACE gene I/D polymorphism was performed by nested PCR and DNA based HLA typing technique was used. ACE gene I/D polymorphism of Intron16 was studied and found to be involved in the activity of SLE. There is high frequency of HLA-A*01, HLA-B*40, HLA-DRB1*01 alleles in SLE patients with ACE DD genotype. The distribution of HLA-A, -B, -DRB1 alleles was analyzed in SLE patients with various disease phenotypes. HLA-A*01 and HLA-B*40 was the most common allele found in SLE patients with the involvement of skin. HLA-A*01, -A*03, HLA-B*13 and -B*46 were common in SLE patients with arthritis while HLA-A*26 and -A*69 were commonly found in Lupus nephritis cases. SLE patients involving both skin and kidney had an allele HLA-DRB1*01 common in them.

Beta-fibrinogen allele frequencies in Peruvian Quechua, a high-altitude native population.

Science.gov (United States)

Rupert, J L; Devine, D V; Monsalve, M V; Hochachka, P W

1999-06-01

Elevated hematocrits, which are found in many high-altitude populations, increase the oxygen-carrying capacity of blood and may represent an adaptation to hypoxic environments. However, as high hematocrit increases blood viscosity, which in turn is associated with hypertension and heart disease, it may be advantageous for high-altitude populations to limit other factors that contribute to increased blood viscosity. One such factor is the plasma concentration of the coagulation protein fibrinogen. Several common polymorphisms in the beta-fibrinogen gene have been identified that affect fibrinogen concentrations. We determined the allele frequencies of three of these polymorphisms (G/A-455(HaeIII), C/T-148(HindIII), and G/A+448(MnlI)) in sample groups drawn from three populations: Quechua-speaking natives living at over 3,200 m in the Peruvian Andes, North American natives (Na-Dene) from coastal British Columbia, and Caucasian North Americans. The frequencies of the alleles previously shown to be associated with increased fibrinogen levels were so low in the Quechuas that their presence could be accounted for solely by genetic admixture with Caucasians. Frequencies in the Na-Dene, a Native American group unrelated to the Quechua, were not significantly different from those in Caucasians.

CYP2D6 and CYP2C19 in Papua New Guinea: High frequency of previously uncharacterized CYP2D6 alleles and heterozygote excess.

Science.gov (United States)

von Ahsen, Nicolas; Tzvetkov, Mladen; Karunajeewa, Harin A; Gomorrai, Servina; Ura, Alice; Brockmöller, Jürgen; Davis, Timothy M E; Mueller, Ivo; Ilett, Kenneth F; Oellerich, Michael

2010-08-18

A high frequency of previously unknown CYP2D6 alleles have been reported in Oceania populations. Genetic and functional properties of these alleles remain unknown. We performed analyses of the genetic variability of CYP2D6 and CYP2C19 genes using AmpliChip genotyping in cohorts from two distinct Papua New Guinea (PNG) populations (Kunjingini, n=88; Alexishafen, n=84) focussing on the genetic characterisation of PNG-specific alleles by re-sequencing. Previously unknown CYP2D6 alleles have population frequencies of 24% (Kunjingini) and 12% (Alexishafen). An allele similar to CYP2D6*1, but carrying the 1661G>C substitution, was the second most frequent CYP2D6 allele (20% Kunjingini and 10% Alexishafen population frequency). Sequencing suggests the CYP2D6* 1661G>C allele originated from a cross-over between CYP2D6*1 and *2 and thus is predicted to confer fully active CYP2D6 enzyme. Two additional predicted full activity alleles [1661G>C;4180G>C] and 31G>A were found in the Kunjingini cohort (frequencies 3 c/c and 1%, respectively) and a novel predicted reduced activity allele [100C>T;1039C>T] was found in the Alexishafen cohort (frequency 2%). A high frequency of ultra-rapid (15%) and notably low frequencies of intermediate and poor CYP2D6 metabolizers (exogamy and recent introduction of alleles by migration that are yet to reach HWE in relatively isolated populations. The CYP2D6*1661 allele common in Oceania may be regarded as functionally equivalent to the full activity CYP2D6*1 allele.

On the testing of Hardy-Weinberg proportions and equality of allele frequencies in males and females at biallelic genetic markers.

Science.gov (United States)

Graffelman, Jan; Weir, Bruce S

2018-02-01

Standard statistical tests for equality of allele frequencies in males and females and tests for Hardy-Weinberg equilibrium are tightly linked by their assumptions. Tests for equality of allele frequencies assume Hardy-Weinberg equilibrium, whereas the usual chi-square or exact test for Hardy-Weinberg equilibrium assume equality of allele frequencies in the sexes. In this paper, we propose ways to break this interdependence in assumptions of the two tests by proposing an omnibus exact test that can test both hypotheses jointly, as well as a likelihood ratio approach that permits these phenomena to be tested both jointly and separately. The tests are illustrated with data from the 1000 Genomes project. © 2017 The Authors Genetic Epidemiology Published by Wiley Periodicals, Inc.

Allelic structure and distribution of 103 STR loci in a Southern ...

Indian Academy of Sciences (India)

Unknown

compared with a standard t test at 5% level of significance. The allele frequency .... 72 50. 70 28. 0.150. 0.223. 0.100. 0.142. 0.147. 0.360. 0.168. 13. D13S171. D13S170 ..... structure of LD within this region in BEH population, more markers ...

The allele frequency of two single nucleotide polymorphisms in the von Hippel-Lindau (VHL) tumor suppressor gene in the Taiwanese population.

Science.gov (United States)

Wang, Wen-Chung; Chen, Hui-Ju; Shu, Wei-Pang; Tsai, Yi-Chang; Lai, Yen-Chein

2011-10-01

The von Hippel-Lindau (VHL) tumor suppressor gene located on chromosome 3p25-26 is implicated in VHL disease. Two informative single nucleotide polymorphisms are at positions 19 and 1149 on the nucleotide sequence from Gene Bank NM_000551. In this study we examined the allele frequencies at these two loci in the Taiwanese population and compared the results to those from European ethnic populations. The allele frequency was examined in 616 healthy individuals including 301 university students and 315 neonates. Both A/G polymorphisms were investigated using restriction fragment length polymorphism analysis created by restriction enzymes, BsaJ I and Acc I. Among these subjects, the allele frequencies at 19 SNP and 1149 SNP for variant G were 0.130 and 0.133, respectively. And these results were significant differences from those of the Caucasian populations. In addition, 90% of the tested subjects had identical genotypes at these two loci suggesting the existence of nonrandom association of alleles. We found that the G allele frequency at these two loci in the Taiwanese population is much lower than that in people from Western countries. This phenomenon may be attributed to ethnic effects. Copyright © 2011. Published by Elsevier B.V.

Assessment of the myostatin Q204X allele using an allelic discrimination assay

OpenAIRE

Sifuentes-Rincón,Ana M.; Puentes-Montiel,Herlinda E.; Moreno-Medina,Víctor R.; Rosa-Reyna,Xóchitl F. de la

2006-01-01

An allelic discrimination assay was designed and used to determine the genotypic and allelic frequencies of the myostatin (MSTN) gene Q204X allele from two Mexican Full-French herds. The assay is a simple high throughput genotyping method that could be applied to investigate the effect of the Q204X allele on the Charolais breed.

The geographic spread of the CCR5 Delta32 HIV-resistance allele.

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John Novembre

2005-11-01

Full Text Available The Delta32 mutation at the CCR5 locus is a well-studied example of natural selection acting in humans. The mutation is found principally in Europe and western Asia, with higher frequencies generally in the north. Homozygous carriers of the Delta32 mutation are resistant to HIV-1 infection because the mutation prevents functional expression of the CCR5 chemokine receptor normally used by HIV-1 to enter CD4+ T cells. HIV has emerged only recently, but population genetic data strongly suggest Delta32 has been under intense selection for much of its evolutionary history. To understand how selection and dispersal have interacted during the history of the Delta32 allele, we implemented a spatially explicit model of the spread of Delta32. The model includes the effects of sampling, which we show can give rise to local peaks in observed allele frequencies. In addition, we show that with modest gradients in selection intensity, the origin of the Delta32 allele may be relatively far from the current areas of highest allele frequency. The geographic distribution of the Delta32 allele is consistent with previous reports of a strong selective advantage (>10% for Delta32 carriers and of dispersal over relatively long distances (>100 km/generation. When selection is assumed to be uniform across Europe and western Asia, we find support for a northern European origin and long-range dispersal consistent with the Viking-mediated dispersal of Delta32 proposed by G. Lucotte and G. Mercier. However, when we allow for gradients in selection intensity, we estimate the origin to be outside of northern Europe and selection intensities to be strongest in the northwest. Our results describe the evolutionary history of the Delta32 allele and establish a general methodology for studying the geographic distribution of selected alleles.

Worldwide distribution of the MYH9 kidney disease susceptibility alleles and haplotypes: evidence of historical selection in Africa.

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Taras K Oleksyk

2010-07-01

Full Text Available MYH9 was recently identified as renal susceptibility gene (OR 3-8, p or = 60% than in European Americans (< 4%, revealing a genetic basis for a major health disparity. The population distributions of MYH9 risk alleles and the E-1 risk haplotype and the demographic and selective forces acting on the MYH9 region are not well explored. We reconstructed MYH9 haplotypes from 4 tagging single nucleotide polymorphisms (SNPs spanning introns 12-23 using available data from HapMap Phase II, and by genotyping 938 DNAs from the Human Genome Diversity Panel (HGDP. The E-1 risk haplotype followed a cline, being most frequent within sub-Saharan African populations (range 50-80%, less frequent in populations from the Middle East (9-27% and Europe (0-9%, and rare or absent in Asia, the Americas, and Oceania. The fixation indexes (F(ST for pairwise comparisons between the risk haplotypes for continental populations were calculated for MYH9 haplotypes; F(ST ranged from 0.27-0.40 for Africa compared to other continental populations, possibly due to selection. Uniquely in Africa, the Yoruba population showed high frequency extended haplotype length around the core risk allele (C compared to the alternative allele (T at the same locus (rs4821481, iHs = 2.67, as well as high population differentiation (F(ST(CEU vs. YRI = 0.51 in HapMap Phase II data, also observable only in the Yoruba population from HGDP (F(ST = 0.49, pointing to an instance of recent selection in the genomic region. The population-specific divergence in MYH9 risk allele frequencies among the world's populations may prove important in risk assessment and public health policies to mitigate the burden of kidney disease in vulnerable populations.

A strategy to discover genes that carry multi-allelic or mono-allelic risk for common diseases: A cohort allelic sums test (CAST)

International Nuclear Information System (INIS)

Morgenthaler, Stephan; Thilly, William G.

2007-01-01

A method is described to discover if a gene carries one or more allelic mutations that confer risk for any specified common disease. The method does not depend upon genetic linkage of risk-conferring mutations to high frequency genetic markers such as single nucleotide polymorphisms. Instead, the sums of allelic mutation frequencies in case and control cohorts are determined and a statistical test is applied to discover if the difference in these sums is greater than would be expected by chance. A statistical model is presented that defines the ability of such tests to detect significant gene-disease relationships as a function of case and control cohort sizes and key confounding variables: zygosity and genicity, environmental risk factors, errors in diagnosis, limits to mutant detection, linkage of neutral and risk-conferring mutations, ethnic diversity in the general population and the expectation that among all exonic mutants in the human genome greater than 90% will be neutral with regard to any effect on disease risk. Means to test the null hypothesis for, and determine the statistical power of, each test are provided. For this 'cohort allelic sums test' or 'CAST', the statistical model and test are provided as an Excel (TM) program, CASTAT (C) at http://epidemiology.mit.edu. Based on genetics, technology and statistics, a strategy of enumerating the mutant alleles carried in the exons and splice sites of the estimated ∼25,000 human genes in case cohort samples of 10,000 persons for each of 100 common diseases is proposed and evaluated: A wide range of possible conditions of multi-allelic or mono-allelic and monogenic, multigenic or polygenic (including epistatic) risk are found to be detectable using the statistical criteria of 1 or 10 ''false positive'' gene associations per 25,000 gene-disease pair-wise trials and a statistical power of >0.8. Using estimates of the distribution of both neutral and gene-inactivating nondeleterious mutations in humans and

The frequency of allelic lethals and complementation maps in natural populations of drosophila melanogaster from Mexico

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Salceda Victor M.

2004-01-01

Full Text Available Departing from a previous study on the genetic loads affecting the second chromosome of Drosophila melanogaster in four natural populations, 171 lethal chromosomes were recovered and maintained as a balanced stocks in the condition Cy L / 1 (l=lethal; of those lethais 24 correspond to population A, 50 to populations B and C and 47 to population D. later on an intra-population allelism test for the four populations was performed for each one. A total of 3807 inter lethal crosses were done yielding a total of i 10 allelic combinations, from them the respective percentage of allelism for each population was calculated and they are as follow: 3.98 % for population A, 1.80 % for population B, 3.67 % for population C and 2.96 % for population D. the observed values for the frequency of allelism in these populations are not significantly different from those reported by other authors in similar studies in natural and/or experimental populations. Beside these values the frequency for singles, doubles, triplets and even quadruplets present in each population were determined, they shown the presence of various complementation maps due to the clustering of few different lethals: also a large complementation map formed by a large cluster involving the presence of 26 different lethals found in population D all of them combined constituting a single unit was found.

Genetic variation of the angiotensin-converting enzyme gene: increased frequency of the insertion allele in Koreans.

Science.gov (United States)

Hong, S H; Kang, B Y; Park, W H; Kim, J Q; Lee, C C

1997-01-01

In view of the clinical importance of angiotensin-converting enzyme (ACE) as a major marker for cardiovascular diseases, we investigated insertion/deletion (I/D) polymorphism of the ACE gene in Koreans. Genotype frequencies were examined by polymerase chain reaction in 171 patients with coronary artery disease (CAD) and 120 healthy subjects. Allele frequencies of ACE polymorphism in Koreans were not significantly different between patient and control groups. In addition, association between ACE genotypes and the number of stenosed coronary arteries was not detected. ACE genotypes in the CAD group were not associated with body mass index and plasma lipid levels. Thus, our results suggest that, at least in Koreans, I/D polymorphism of the gene is unlikely to be a useful marker for CAD subjects. However, the I allele frequency of Koreans (0.58) was higher than that of Caucasian populations (0.47) but lower than that of Samoan (0.91) and Yanomami (0.85) populations. Here, we discuss the clinical and ethnic importance of ACE polymorphism.

Allele Frequency Data for 17 Short Tandem Repeats in a Czech Population Sample

Czech Academy of Sciences Publication Activity Database

Šimková, H.; Faltus, Václav; Marván, Richard; Pexa, T.; Stenzl, V.; Brouček, J.; Hořínek, A.; Mazura, Ivan; Zvárová, Jana

2009-01-01

Roč. 4, č. 1 (2009), e15-e17 ISSN 1872-4973 R&D Projects: GA MŠk(CZ) 1M06014 Institutional research plan: CEZ:AV0Z10300504 Keywords : short tandem repeat (STR) * allelic frequency * PowerPlex 16 System * AmpflSTR Identifiler * population genetics * Czech Republic Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.421, year: 2009

ABO and Rh (D group distribution and gene frequency; the first multicentric study in India

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Amit Agrawal

2014-01-01

Full Text Available Background and Objectives: The study was undertaken with the objective to provide data on the ABO and Rh(D blood group distribution and gene frequency across India. Materials and Methods: A total of 10,000 healthy blood donors donating in blood banks situated in five different geographical regions of the country (North, South, East and Center were included in the study. ABO and Rh (D grouping was performed on all these samples. Data on the frequency of ABO and Rh(D blood groups was reported in simple numbers and percentages. Results: The study showed that O was the most common blood group (37.12% in the country closely followed by B at 32.26%, followed by A at 22.88% while AB was the least prevalent group at 7.74%. 94.61% of the donor population was Rh positive and the rest were Rh negative. Regional variations were observed in the distribution. Using the maximum likelihood method, the frequencies of the I A , I B and I O alleles were calculated and tested according to the Hardy Weinberg law of Equilibrium. The calculated gene frequencies are 0.1653 for I A (p, 0.2254 for I B (q and 0.6093 for I O (r. In Indian Population, O (r records the highest value followed by B (q and A (p; O > B > A. Conclusion: The study provides information about the relative distribution of various alleles in the Indian population both on a pan-India basis as well as region-wise. This vital information may be helpful in planning for future health challenges, particularly planning with regards to blood transfusion services.

Ancient DNA Investigation of a Medieval German Cemetery Confirms Long-Term Stability of CCR5-Δ32 Allele Frequencies in Central Europe.

Science.gov (United States)

Bouwman, Abigail; Shved, Natallia; Akgül, Gülfirde; Rühli, Frank; Warinner, Christina

2017-04-01

The CCR5-Δ32 mutation present in European populations is among the most prominently debated cases of recent positive selection in humans. This allele, a 32-bp deletion that renders the T-cell CCR5 receptor nonfunctional, has important epidemiological and public health significance, as homozygous carriers are resistant to several HIV strains. However, although the function of this allele in preventing HIV infection is now well described, its human evolutionary origin is poorly understood. Initial attempts to determine the emergence of the CCR5-Δ32 allele pointed to selection during the 14th-century Black Death pandemic; however, subsequent analyses suggest that the allele rose in frequency more than 5,000 years ago, possibly through drift. Recently, three studies have identified populations predating the 14th century CE that are positive for the CCR5-Δ32 allele, supporting the claim for a more ancient origin. However, these studies also suggest poorly understood regional differences in the recent evolutionary history of the CCR5-Δ32 allele. Here a new hydrolysis-probe-based real-time PCR assay was designed to ascertain CCR5 allele frequency in 53 individuals from a 10th- to 12th-century CE church and convent complex in central Germany that predates outbreaks of the Black Death pandemic. High-confidence genotypes were obtained for 32 individuals, and results show that CCR5-Δ32 allele frequency has remained unchanged in this region of Central Europe over the last millennium, suggesting that there has been no strong positive selective pressure over this time period and confirming a more ancient origin for the allele.

High frequency of NAT2 slow acetylator alleles in the Malay population of Indonesia: an awareness to the anti-tuberculosis drug induced liver injury and cancer

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Retno W. Susilowati

2017-05-01

Full Text Available Background: Arylamine N-acetyltransferase 2 (NAT2 polymorphism was previously reported to have association with the risk of drug toxicities and the development of various diseases. Previous research on the Indonesian population, especially Javanese and Sundanese, showed that there were 33% NAT2 slow acetylator phenotype. The aim of this study was to map the NAT2 variation in the Malay ethnic to gain a deeper insight into NAT2 haplotypic composition in this ethnic.Methods: 50 healthy samples from the Indonesian Malay ethnic were obtained. They were interviewed about their ethnic backgrounds for the last three generations. DNA was extracted from peripheral blood and NAT2 genotyping was done using the PCR direct Sequencing. Data were compiled according to the genotype and allele frequencies estimated from the observed numbers of each specific allele. Haplotype reconstruction was performed using PHASE v2.1.1 software.Results: We found 7 haplotypes consisting of 6 SNPs and 14 NAT2 genotype variations in Indonesian Malay population. The most frequent allele was NAT2*6A (38% which was classified as a slow acetylator allele. According to bimodal distribution, the predicted phenotype of the Malay population was composed of 62% rapid acetylator and 38% slow acetylator. According to trimodal distribution, the predicted phenotypes for rapid, intermediate and slow acetylators were 10%, 52% and 38% respectively.Conclusion: Our result indicates the presence of the allelic distribution and revealed the most frequent acetylator status and phenotype for the Indonesian Malay population. The result of this study will be helpful for future epidemiological or clinical studies and for understanding the genetic basis of acetylation polymorphism in Indonesia.

The SCA1 (Spinocerebellar ataxia type 1 and MJD (Machado-Joseph disease CAG repeats in normal individuals: segregation analysis and allele frequencies

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Cláudia Emília Vieira Wiezel

2003-01-01

Full Text Available Spinocerebellar ataxia type 1 (SCA1 and Machado-Joseph disease (MJD/SCA3 are autosomal dominant neurodegenerative diseases caused by expansions of a CAG trinucleotide repeat in the SCA1 and MJD genes. These expanded sequences are unstable upon transmission, leading to an intergeneration increase in the number of repeats (dynamic mutation. The transmission of the CAG repeat was studied in normal mother-father-child trios, referred for paternity testing (SCA1, n = 367; MJD, n = 879. No segregation distortion was detected. The CAG allele frequencies were determined in 330 unrelated individuals (fathers from couples tested for paternity. The allele frequency distributions did not differ from those previously reported for European populations. The estimated values for the statistic parameters indicating diversity at the SCA1 locus did not differ much from those reported previously for other STRs in the Brazilian population, while those for the MJD locus were close to or higher than the maximum values of previous reports. This shows that SCA1 and MJD are highly informative loci for applications in genetic and population studies and for forensic analysis.

Allelic Diversity and Geographical Distribution of the Gene Encoding Plasmodium falciparum Merozoite Surface Protein-3 in Thailand.

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Sawaswong, Vorthon; Simpalipan, Phumin; Siripoon, Napaporn; Harnyuttanakorn, Pongchai; Pattaradilokrat, Sittiporn

2015-04-01

Merozoite surface proteins (MSPs) of malaria parasites play critical roles during the erythrocyte invasion and so are potential candidates for malaria vaccine development. However, because MSPs are often under strong immune selection, they can exhibit extensive genetic diversity. The gene encoding the merozoite surface protein-3 (MSP-3) of Plasmodium falciparum displays 2 allelic types, K1 and 3D7. In Thailand, the allelic frequency of the P. falciparum msp-3 gene was evaluated in a single P. falciparum population in Tak at the Thailand and Myanmar border. However, no study has yet looked at the extent of genetic diversity of the msp-3 gene in P. falciparum populations in other localities. Here, we genotyped the msp-3 alleles of 63 P. falciparum samples collected from 5 geographical populations along the borders of Thailand with 3 neighboring countries (Myanmar, Laos, and Cambodia). Our study indicated that the K1 and 3D7 alleles coexisted, but at different proportions in different Thai P. falciparum populations. K1 was more prevalent in populations at the Thailand-Myanmar and Thailand-Cambodia borders, whilst 3D7 was more prevalent at the Thailand-Laos border. Global analysis of the msp-3 allele frequencies revealed that proportions of K1 and 3D7 alleles of msp-3 also varied in different continents, suggesting the divergence of malaria parasite populations. In conclusion, the variation in the msp-3 allelic patterns of P. falciparum in Thailand provides fundamental knowledge for inferring the P. falciparum population structure and for the best design of msp-3 based malaria vaccines.

Analysis of the CCR5 gene coding region diversity in five South American populations reveals two new non-synonymous alleles in Amerindians and high CCR5*D32 frequency in Euro-Brazilians

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Angelica B.W. Boldt

2009-01-01

Full Text Available The CC chemokine receptor 5 (CCR5 molecule is an important co-receptor for HIV. The effect of the CCR5*D32 allele in susceptibility to HIV infection and AIDS disease is well known. Other alleles than CCR5*D32 have not been analysed before, neither in Amerindians nor in the majority of the populations all over the world. We investigated the distribution of the CCR5 coding region alleles in South Brazil and noticed a high CCR5*D32 frequency in the Euro-Brazilian population of the Paraná State (9.3%, which is the highest thus far reported for Latin America. The D32 frequency is even higher among the Euro-Brazilian Mennonites (14.2%. This allele is uncommon in Afro-Brazilians (2.0%, rare in the Guarani Amerindians (0.4% and absent in the Kaingang Amerindians and the Oriental-Brazilians. R223Q is common in the Oriental-Brazilians (7.7% and R60S in the Afro-Brazilians (5.0%. A29S and L55Q present an impaired response to b-chemokines and occurred in Afro- and Euro-Brazilians with cumulative frequencies of 4.4% and 2.7%, respectively. Two new non-synonymous alleles were found in Amerindians: C323F (g.3729G > T in Guarani (1.4% and Y68C (g.2964A > G in Kaingang (10.3%. The functional characteristics of these alleles should be defined and considered in epidemiological investigations about HIV-1 infection and AIDS incidence in Amerindian populations.

Frequencies distribution of dihydrofolate reductase and dihydropteroate synthetase mutant alleles associated with sulfadoxine-pyrimethamine resistance in Plasmodium falciparum population from Hadhramout Governorate, Yemen.

Science.gov (United States)

Bamaga, Omar A A; Mahdy, Mohammed A K; Lim, Yvonne A L

2015-12-22

Malaria in Yemen is mainly caused by Plasmodium falciparum and 25% of the population is at high risk. Sulfadoxine-pyrimethamine (SP) had been used as monotherapy against P. falciparum. Emergence of chloroquine resistance led to the shift in anti-malarial treatment policy in Yemen to artemisinin-based combination therapy, that is artesunate (AS) plus SP as first-line therapy for uncomplicated malaria and artemether-lumefantrine as second-line treatment. This study aimed to screen mutations in the dihydrofolate reductase (dhfr) and dihydropteroate synthetase (dhps) genes associated with SP resistance among P. falciparum population in Hadhramout governorate, Yemen. Genomic DNA was extracted from dried blood spots of 137 P. falciparum isolates collected from a community-based study. DNA was amplified using nested polymerase chain reaction (PCR) and subsequently sequenced for Pfdhfr and Pfdhps genes. Sequences were analysed for mutations in Pfdhfr gene codons 51, 59, 108, and 164 and in Pfdhps gene codons 436, 437, and 540. A total of 128 and 114 P. falciparum isolates were successfully sequenced for Pfdhfr and Pfdhps genes, respectively. Each Pfdhfr mutant allele (I51 and N108) in P. falciparum population had a frequency of 84%. Pfdhfr R59 mutant allele was detected in one isolate. Mutation at codon 437 (G437) in the Pfdhps gene was detected in 44.7% of falciparum malaria isolates. Frequencies of Pfdhfr double mutant genotype (I51C59N108I164) and Pfdhfr/Pfdhps triple mutant genotype (I51C59N108I164-S436G437K540) were 82.8 and 39.3%, respectively. One isolate harboured Pfdhfr triple mutant genotype (I51, R59, N108, I164) and Pfdhfr/Pfdhps quadruple mutant genotype (I51R59N108I164-S436G437K540). High frequencies of Pfdhfr and Pfdhps mutant alleles and genotypes in P. falciparum population in Hadhramout, Yemen, highlight the risk of developing resistance for SP, the partner drug of AS, which subsequently will expose the parasite to AS monotherapy increasing then the

Frequencies of two CYP2C19 defective alleles (CYP2C19*2, and *3 among Iranian population in Mazandaran Province

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Naghi Shahabi-Majd

2013-02-01

Conclusion: The result of the present study showed that the two inactive alleles of CYP2C19 accounted for 9.0% of CYP2C19 alleles in our sample versus 8.8 - 40.1% reported in other populations. The frequencies of the studied alleles resulted significant differences between our sample and African and Eastern Asian populations.

Determination of frequencies of alleles, associated with the pseudodeficiency of lysosomal hydrolases, in population of Ukraine

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N. V. Olkhovych

2016-10-01

Full Text Available The pseudodeficiency of lysosomal hydrolases described as a significant reduction in enzyme activi­ty in vitro in clinically healthy individuals, can lead to diagnostic errors in the process of biochemical analysis of lysosomal storage disease in case of its combination with pathology of another origin. Pseudodeficiency is mostly caused by some non-pathogenic changes in the corresponding gene. These changes lead to the in vitro lability of the enzyme molecule, whereas in vivo the enzyme retains its functional activity. To assess the prevalence of the most common lysosomal hydrolases pseudodeficiency alleles in Ukraine, we have determined the frequency of alleles c.1055A>G and c.* 96A>G in the ARSA gene, substitutions c.739C>T (R247W and c.745C>T (R249W in the HEXA gene, c.1726G>A (G576S and c.2065G>A (E689K in the GAA gene, c.937G>T (D313Y in the GLA1 gene and c.898G>A (A300T in the IDUA gene in a group of 117 healthy individuals from different regions of the country and 14 heterozygous carriers of pathogenic mutations in the HEXA gene (parents of children with confirmed diagnosis of Tay-Sachs disease. The total frequency of haplotypes, associated with arylsulfatase A pseudodeficiency, in healthy people in Ukraine (c.1055G/c.*96G and c.1055G/c.*96A haplotypes was 10.3%. The frequency of c.739C>T (R247W allele, associated with hexo­saminidase A pseudodeficiency, among Tay-Sachs carriers from Ukraine was 7.1%. The total frequency of α-glucosidase pseudodeficiency haplotypes in healthy individuals in Ukraine (c.1726A/c.2065A and c.1726G/c.2065A haplotypes was 2.6%. No person among examined individuals with the substitution c.937G>T (D313Y in the GLA1 gene and c.898G>A (A300T in the IDUA gene was found. The differential diagnostics of lysosomal storage diseases requires obligatory determination of the presence of the pseudodeficiency alleles, particularly the ones with high incidence in the total population. Ignoring phenomenon of

Determination of frequencies of alleles, associated with the pseudodeficiency of lysosomal hydrolases, in population of Ukraine.

Science.gov (United States)

Olkhovych, N V; Gorovenko, N G

2016-01-01

The pseudodeficiency of lysosomal hydrolases described as a significant reduction in enzyme activi­ty in vitro in clinically healthy individuals, can lead to diagnostic errors in the process of biochemical analysis of lysosomal storage disease in case of its combination with pathology of another origin. Pseudodeficiency is mostly caused by some non-pathogenic changes in the corresponding gene. These changes lead to the in vitro lability of the enzyme molecule, whereas in vivo the enzyme retains its functional activity. To assess the prevalence of the most common lysosomal hydrolases pseudodeficiency alleles in Ukraine, we have determined the frequency of alleles c.1055A>G and c.* 96A>G in the ARSA gene, substitutions c.739C>T (R247W) and c.745C>T (R249W) in the HEXA gene, c.1726G>A (G576S) and c.2065G>A (E689K) in the GAA gene, c.937G>T (D313Y) in the GLA1 gene and c.898G>A (A300T) in the IDUA gene in a group of 117 healthy individuals from different regions of the country and 14 heterozygous carriers of pathogenic mutations in the HEXA gene (parents of children with confirmed diagnosis of Tay-Sachs disease). The total frequency of haplotypes, associated with arylsulfatase A pseudodeficiency, in healthy people in Ukraine (c.1055G/c.*96G and c.1055G/c.*96A haplotypes) was 10.3%. The frequency of c.739C>T (R247W) allele, associated with hexo­saminidase A pseudodeficiency, among Tay-Sachs carriers from Ukraine was 7.1%. The total frequency of α-glucosidase pseudodeficiency haplotypes in healthy individuals in Ukraine (c.1726A/c.2065A and c.1726G/c.2065A haplotypes) was 2.6%. No person among examined individuals with the substitution c.937G>T (D313Y) in the GLA1 gene and c.898G>A (A300T) in the IDUA gene was found. The differential diagnostics of lysosomal storage diseases requires obligatory determination of the presence of the pseudodeficiency alleles, particularly the ones with high incidence in the total population. Ignoring phenomenon of pseudodeficiency may

Efficient simulation and likelihood methods for non-neutral multi-allele models.

Science.gov (United States)

Joyce, Paul; Genz, Alan; Buzbas, Erkan Ozge

2012-06-01

Throughout the 1980s, Simon Tavaré made numerous significant contributions to population genetics theory. As genetic data, in particular DNA sequence, became more readily available, a need to connect population-genetic models to data became the central issue. The seminal work of Griffiths and Tavaré (1994a , 1994b , 1994c) was among the first to develop a likelihood method to estimate the population-genetic parameters using full DNA sequences. Now, we are in the genomics era where methods need to scale-up to handle massive data sets, and Tavaré has led the way to new approaches. However, performing statistical inference under non-neutral models has proved elusive. In tribute to Simon Tavaré, we present an article in spirit of his work that provides a computationally tractable method for simulating and analyzing data under a class of non-neutral population-genetic models. Computational methods for approximating likelihood functions and generating samples under a class of allele-frequency based non-neutral parent-independent mutation models were proposed by Donnelly, Nordborg, and Joyce (DNJ) (Donnelly et al., 2001). DNJ (2001) simulated samples of allele frequencies from non-neutral models using neutral models as auxiliary distribution in a rejection algorithm. However, patterns of allele frequencies produced by neutral models are dissimilar to patterns of allele frequencies produced by non-neutral models, making the rejection method inefficient. For example, in some cases the methods in DNJ (2001) require 10(9) rejections before a sample from the non-neutral model is accepted. Our method simulates samples directly from the distribution of non-neutral models, making simulation methods a practical tool to study the behavior of the likelihood and to perform inference on the strength of selection.

The immunogenetics of multiple sclerosis. The frequency of HLA-alleles class 1 and 2 is lower in Southern Brazil than in the European population.

Science.gov (United States)

Werneck, Lineu Cesar; Lorenzoni, Paulo José; Arndt, Raquel Cristina; Kay, Cláudia Suemi Kamoi; Scola, Rosana Herminia

2016-08-01

To study the HLA of class 1and 2 in a multiple sclerosis (MS) population to verify the susceptibility for the disease in the Southern Brazil. We analyzed patients with MS and controls, by direct sequencing of the genes related to HLA DRB1, DQB1, DPB1, A, B and C alleles with high resolution techniques. We found a lower frequency of all HLA alleles class 1 and 2 in MS and controls comparing to the European population. Several alleles had statistical correlation, but after Bonferroni correction, the only allele with significance was the HLA-DQB1*02:03, which has a positive association with MS. Our data have different frequency of HLA-alleles than the previous published papers in the Southeast Brazil and European population, possible due to several ethnic backgrounds.

Predominance of N-acetyl transferase 2 slow acetylator alleles in ...

African Journals Online (AJOL)

Student

The human N-acetyltransferase II (NAT2) gene may vary between individuals resulting in variability in the incidence of adverse drug reactions. We set out in this adhoc analysis to determine the distribution of allele frequencies of NAT2 gene variants among children less than ten years treated with artemisinin-based.

Allele Frequency - JSNP | LSDB Archive [Life Science Database Archive metadata

Lifescience Database Archive (English)

Full Text Available nd 39 SNPs are assayed in three (POP_*) and two (RIKEN_japanese_*) panels, respectively. Derived from Flat f... assay (JBIC-allele and RIKEN_japanese_*), TaqMan assay (RIKEN-allele) or direct sequencing / allelic discri...unteers under informed consent RIKEN_japanese_normal_weight - 711 unrelated japanese normal weight volunteer...s ( body mass index RIKEN_japanese_obese - 796 unrelated japanese obese patients

[Geographic variability of Adh-F allele frequency in populations of Drosophila melanogaster].

Science.gov (United States)

Bubliĭ, O A; Imasheva, A G

1997-07-01

Variation of Adh-F allele frequency in seven regions of North and South America, Eurasia, Africa, and Australia was analyzed on the basis of published data. In six regions, regression of Adh-F frequency on latitude was positive; in four regions, slopes of the regression curves were identical. Regression on the average lowest temperature of the coldest month was negative in six regions. No definite trends in regression on the highest temperature of the hottest month and on rainfall in the most humid month and the driest months were found. Geographic differentiation of populations was independent of climatic parameters. Examination of variation in various climatic zones revealed that tropical populations were distinctly different from those from other climatic zones. No climatic differentiation of fixation index FST was detected. These results indicate that Adh polymorphism is maintained by natural selection.

Allelic frequencies and association with carcass traits of six genes in local subpopulations of Japanese Black cattle.

Science.gov (United States)

Nishimaki, Takahiro; Ibi, Takayuki; Siqintuya; Kobayashi, Naohiko; Matsuhashi, Tamako; Akiyama, Takayuki; Yoshida, Emi; Imai, Kazumi; Matsui, Mayu; Uemura, Keiichi; Eto, Hisayoshi; Watanabe, Naoto; Fujita, Tatsuo; Saito, Yosuke; Komatsu, Tomohiko; Hoshiba, Hiroshi; Mannen, Hideyuki; Sasazaki, Shinji; Kunieda, Tetsuo

2016-04-01

Marker-assisted selection (MAS) is expected to accelerate the genetic improvement of Japanese Black cattle. However, verification of the effects of the genes for MAS in different subpopulations is required prior to the application of MAS. In this study, we investigated the allelic frequencies and genotypic effects for carcass traits of six genes, which can be used in MAS, in eight local subpopulations. These genes are SCD, FASN and SREBP1, which are associated with the fatty acid composition of meat, and NCAPG, MC1R and F11, which are associated with carcass weight, coat color and blood coagulation abnormality, respectively. The frequencies of desirable alleles of SCD and FASN were relatively high and that of NCAPG was relatively low, and NCAPG was significantly associated with several carcass traits, including carcass weight. The proportions of genotypic variance explained by NCAPG to phenotypic variance were 4.83 for carcass weight. We thus confirmed that NCAPG is a useful marker for selection of carcass traits in these subpopulations. In addition, we found that the desirable alleles of six genes showed no negative effects on carcass traits. Therefore, selection using these genes to improve target traits should not have negative impacts on carcass traits. © 2015 Japanese Society of Animal Science.

Geographic differences in allele frequencies of susceptibility SNPs for cardiovascular disease

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Kullo Iftikhar J

2011-04-01

Full Text Available Abstract Background We hypothesized that the frequencies of risk alleles of SNPs mediating susceptibility to cardiovascular diseases differ among populations of varying geographic origin and that population-specific selection has operated on some of these variants. Methods From the database of genome-wide association studies (GWAS, we selected 36 cardiovascular phenotypes including coronary heart disease, hypertension, and stroke, as well as related quantitative traits (eg, body mass index and plasma lipid levels. We identified 292 SNPs in 270 genes associated with a disease or trait at P -8. As part of the Human Genome-Diversity Project (HGDP, 158 (54.1% of these SNPs have been genotyped in 938 individuals belonging to 52 populations from seven geographic areas. A measure of population differentiation, FST, was calculated to quantify differences in risk allele frequencies (RAFs among populations and geographic areas. Results Large differences in RAFs were noted in populations of Africa, East Asia, America and Oceania, when compared with other geographic regions. The mean global FST (0.1042 for 158 SNPs among the populations was not significantly higher than the mean global FST of 158 autosomal SNPs randomly sampled from the HGDP database. Significantly higher global FST (P FST of 2036 putatively neutral SNPs. For four of these SNPs, additional evidence of selection was noted based on the integrated Haplotype Score. Conclusion Large differences in RAFs for a set of common SNPs that influence risk of cardiovascular disease were noted between the major world populations. Pairwise comparisons revealed RAF differences for at least eight SNPs that might be due to population-specific selection or demographic factors. These findings are relevant to a better understanding of geographic variation in the prevalence of cardiovascular disease.

HLA-A, HLA-B, and HLA-DRB1 Allele and Haplotype Frequencies in Renal Transplant Candidates in a Population in Southern Brazil.

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Saito, Patrícia Keiko; Yamakawa, Roger Haruki; Noguti, Erika Noda; Bedendo, Gustavo Borelli; Júnior, Waldir Veríssimo da Silva; Yamada, Sérgio Seiji; Borelli, Sueli Donizete

2016-05-01

Very few studies have examined the diversity of human leukocyte antigens (HLA) in the Brazilian renal transplant candidates. The frequencies of the HLA-A, HLA-B, and HLA-DRB1 alleles, haplotypes and phenotypes were studied in 522 patients with chronic renal failure, renal transplant candidates, registered at the Transplant Centers in north/northwestern Paraná State, southern Brazil. Patients were classified according to the ethnic group (319 whites [Caucasians], 134 mestizos [mixed race descendants of Europeans, Africans, and Amerindians; browns or "pardos"] and 69 blacks). The HLA typing was performed by the polymerase chain reaction sequence-specific oligonucleotide method (PCR-SSO), combined with Luminex technology. In the analysis of the total samples, 20 HLA-A, 32 HLA-B, and 13 HLA-DRB1 allele groups were identified. The most frequent allele groups for each HLA locus were HLA-A*02 (25.4%), HLA-B*44 (10.9%), and HLA-DRB1*13 (13.9%). The most frequent haplotypes were HLA-A*01-B*08-DRB1*03 (2.3%), A*02-B*44-DRB1*07 (1.2%), and A*03-B*07-DRB1*11 (1.0%). Significant differences (P < 0.05) were observed in the HLA-A*68, B*08, and B*58 allele frequencies among ethnic groups. This study provides the first data on the HLA-A, HLA-B, and HLA-DRB1 allele, phenotype and haplotype frequencies of renal transplant candidates in a population in southern Brazil. © 2015 Wiley Periodicals, Inc.

Gene Frequency and Heritability of Rh Blood Group Gene in 44 Human Populations

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Supriyo CHAKRABORTY

2010-09-01

Full Text Available The frequency of RhD and Rhd alleles of Rh blood group gene was estimated in 44 human populations distributed all over the world from the RhD phenotypic data. The average frequency of RhD and Rhd allele over these populations was 0.70 and 0.30, respectively. Higher frequency of RhD allele than the expected estimate (0.50 in all the populations, under Hardy-Weinberg equilibrium condition assuming equal frequency of both alleles in the initial population, indicated inbreeding at RhD/d locus as well as natural selection for RhD allele. Very high heritability estimate (84.04% of Rh allele frequency revealed that this trait was under weak selection pressure and resulted in greater genetic variation in existing populations. It is consistent with Fishers fundamental theorem of natural selection. The results from the present study suggest that inbreeding at RhD/d locus and some other factors (possibly mutation, migration and genetic drift other than natural selection alone played major roles in changing the Rh allele frequency in these populations.

The allele-frequency spectrum in a decoupled Moran model with mutation, drift, and directional selection, assuming small mutation rates.

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Vogl, Claus; Clemente, Florian

2012-05-01

We analyze a decoupled Moran model with haploid population size N, a biallelic locus under mutation and drift with scaled forward and backward mutation rates θ(1)=μ(1)N and θ(0)=μ(0)N, and directional selection with scaled strength γ=sN. With small scaled mutation rates θ(0) and θ(1), which is appropriate for single nucleotide polymorphism data in highly recombining regions, we derive a simple approximate equilibrium distribution for polymorphic alleles with a constant of proportionality. We also put forth an even simpler model, where all mutations originate from monomorphic states. Using this model we derive the sojourn times, conditional on the ancestral and fixed allele, and under equilibrium the distributions of fixed and polymorphic alleles and fixation rates. Furthermore, we also derive the distribution of small samples in the diffusion limit and provide convenient recurrence relations for calculating this distribution. This enables us to give formulas analogous to the Ewens-Watterson estimator of θ for biased mutation rates and selection. We apply this theory to a polymorphism dataset of fourfold degenerate sites in Drosophila melanogaster. Copyright © 2012 Elsevier Inc. All rights reserved.

Impact of population structure, effective bottleneck time, and allele frequency on linkage disequilibrium maps.

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Zhang, Weihua; Collins, Andrew; Gibson, Jane; Tapper, William J; Hunt, Sarah; Deloukas, Panos; Bentley, David R; Morton, Newton E

2004-12-28

Genetic maps in linkage disequilibrium (LD) units play the same role for association mapping as maps in centimorgans provide at much lower resolution for linkage mapping. Association mapping of genes determining disease susceptibility and other phenotypes is based on the theory of LD, here applied to relations with three phenomena. To test the theory, markers at high density along a 10-Mb continuous segment of chromosome 20q were studied in African-American, Asian, and Caucasian samples. Population structure, whether created by pooling samples from divergent populations or by the mating pattern in a mixed population, is accurately bioassayed from genotype frequencies. The effective bottleneck time for Eurasians is substantially less than for migration out of Africa, reflecting later bottlenecks. The classical dependence of allele frequency on mutation age does not hold for the generally shorter time span of inbreeding and LD. Limitation of the classical theory to mutation age justifies the assumption of constant time in a LD map, except for alleles that were rare at the effective bottleneck time or have arisen since. This assumption is derived from the Malecot model and verified in all samples. Tested measures of relative efficiency, support intervals, and localization error determine the operating characteristics of LD maps that are applicable to every sexually reproducing species, with implications for association mapping, high-resolution linkage maps, evolutionary inference, and identification of recombinogenic sequences.

Positive selection of deleterious alleles through interaction with a sex-ratio suppressor gene in African Buffalo: a plausible new mechanism for a high frequency anomaly.

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Pim van Hooft

Full Text Available Although generally rare, deleterious alleles can become common through genetic drift, hitchhiking or reductions in selective constraints. Here we present a possible new mechanism that explains the attainment of high frequencies of deleterious alleles in the African buffalo (Syncerus caffer population of Kruger National Park, through positive selection of these alleles that is ultimately driven by a sex-ratio suppressor. We have previously shown that one in four Kruger buffalo has a Y-chromosome profile that, despite being associated with low body condition, appears to impart a relative reproductive advantage, and which is stably maintained through a sex-ratio suppressor. Apparently, this sex-ratio suppressor prevents fertility reduction that generally accompanies sex-ratio distortion. We hypothesize that this body-condition-associated reproductive advantage increases the fitness of alleles that negatively affect male body condition, causing genome-wide positive selection of these alleles. To investigate this we genotyped 459 buffalo using 17 autosomal microsatellites. By correlating heterozygosity with body condition (heterozygosity-fitness correlations, we found that most microsatellites were associated with one of two gene types: one with elevated frequencies of deleterious alleles that have a negative effect on body condition, irrespective of sex; the other with elevated frequencies of sexually antagonistic alleles that are negative for male body condition but positive for female body condition. Positive selection and a direct association with a Y-chromosomal sex-ratio suppressor are indicated, respectively, by allele clines and by relatively high numbers of homozygous deleterious alleles among sex-ratio suppressor carriers. This study, which employs novel statistical techniques to analyse heterozygosity-fitness correlations, is the first to demonstrate the abundance of sexually-antagonistic genes in a natural mammal population. It also has

HLA-A, -B, -DRB1 allele and haplotype frequencies of 920 cord blood units from Central Chile.

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Schäfer, Christian; Sauter, Jürgen; Riethmüller, Tobias; Kashi, Zahra Mehdizadeh; Schmidt, Alexander H; Barriga, Francisco J

2016-08-01

We present human leukocyte antigen (HLA) haplotype and allele/antigenic group frequencies derived from a data set of 920 umbilical cord blood units collected in Central Chile. HLA-A and -B genotypes were typed using sequence specific oligonucleotide probe methods while HLA-DRB1 genotypes were obtained from sequencing-based typing. The most frequent haplotype is A*29~B*44~DRB1*07:01 with an estimated frequency of 2.1%. Copyright © 2016 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

Positive Selection of Deleterious Alleles through Interaction with a Sex-Ratio Suppressor Gene in African Buffalo: A Plausible New Mechanism for a High Frequency Anomaly

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Hooft, van W.F.; Greyling, B.J.; Getz, W.M.; Helden, P.D.; Zwaan, B.J.; Bastos, A.D.S.

2015-01-01

Although generally rare, deleterious alleles can become common through genetic drift, hitchhiking or reductions in selective constraints. Here we present a possible new mechanism that explains the attainment of high frequencies of deleterious alleles in the African buffalo (Syncerus caffer)

Positive Selection of Deleterious Alleles through Interaction with a Sex-Ratio Suppressor Gene in African Buffalo: A Plausible New Mechanism for a High Frequency Anomaly

NARCIS (Netherlands)

Hooft, van W.F.; Greyling, B.J.; Getz, W.M.; Helden, van P.D.; Zwaan, B.J.; Bastos, A.D.S.

2014-01-01

Although generally rare, deleterious alleles can become common through genetic drift, hitchhiking or reductions in selective constraints. Here we present a possible new mechanism that explains the attainment of high frequencies of deleterious alleles in the African buffalo (Syncerus caffer)

BRAF Gene Copy Number and Mutant Allele Frequency Correlate with Time to Progression in Metastatic Melanoma Patients Treated with MAPK Inhibitors.

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Stagni, Camilla; Zamuner, Carolina; Elefanti, Lisa; Zanin, Tiziana; Bianco, Paola Del; Sommariva, Antonio; Fabozzi, Alessio; Pigozzo, Jacopo; Mocellin, Simone; Montesco, Maria Cristina; Chiarion-Sileni, Vanna; De Nicolo, Arcangela; Menin, Chiara

2018-06-01

Metastatic melanoma is characterized by complex genomic alterations, including a high rate of mutations in driver genes and widespread deletions and amplifications encompassing various chromosome regions. Among them, chromosome 7 is frequently gained in BRAF -mutant melanoma, inducing a mutant allele-specific imbalance. Although BRAF amplification is a known mechanism of acquired resistance to therapy with MAPK inhibitors, it is still unclear if BRAF copy-number variation and BRAF mutant allele imbalance at baseline can be associated with response to treatment. In this study, we used a multimodal approach to assess BRAF copy number and mutant allele frequency in pretreatment melanoma samples from 46 patients who received MAPK inhibitor-based therapy, and we analyzed the association with progression-free survival. We found that 65% patients displayed BRAF gains, often supported by chromosome 7 polysomy. In addition, we observed that 64% patients had a balanced BRAF -mutant/wild-type allele ratio, whereas 14% and 23% patients had low and high BRAF mutant allele frequency, respectively. Notably, a significantly higher risk of progression was observed in patients with a diploid BRAF status versus those with BRAF gains [HR, 2.86; 95% confidence interval (CI), 1.29-6.35; P = 0.01] and in patients with low percentage versus those with a balanced BRAF mutant allele percentage (HR, 4.54; 95% CI, 1.33-15.53; P = 0.016). Our data suggest that quantitative analysis of the BRAF gene could be useful to select the melanoma patients who are most likely to benefit from therapy with MAPK inhibitors. Mol Cancer Ther; 17(6); 1332-40. ©2018 AACR . ©2018 American Association for Cancer Research.

Allelic Frequencies of 20 Visible Phenotype Variants in the Korean Population

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Ji Eun Lim

2013-06-01

Full Text Available The prediction of externally visible characteristics from DNA has been studied for forensic genetics over the last few years. Externally visible characteristics include hair, skin, and eye color, height, and facial morphology, which have high heritability. Recent studies using genome-wide association analysis have identified genes and variations that correlate with human visible phenotypes and developed phenotype prediction programs. However, most prediction models were constructed and validated based on genotype and phenotype information on Europeans. Therefore, we need to validate prediction models in diverse ethnic populations. In this study, we selected potentially useful variations for forensic science that are associated with hair and eye color, iris pattern, and facial morphology, based on previous studies, and analyzed their frequencies in 1,920 Koreans. Among 20 single nucleotide polymorphisms (SNPs, 10 SNPs were polymorphic, 6 SNPs were very rare (minor allele frequency < 0.005, and 4 SNPs were monomorphic in the Korean population. Even though the usability of these SNPs should be verified by an association study in Koreans, this study provides 10 potential SNP markers for forensic science for externally visible characteristics in the Korean population.

HLA Dr beta 1 alleles in Pakistani patients with rheumatoid arthritis

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Naqi, N.; Ahmed, T.A.; Bashir, M.M.

2011-01-01

Objective: To determine frequencies of HLA DR beta 1 alleles in rheumatoid arthritis in Pakistani patients. Study Design: Cross sectional / analytical study. Place and Duration of Study: Department of Immunology, Armed Forces Institute of Pathology, Rawalpindi in collaboration with Rheumatology departments of Military Hospital, Rawalpindi and Fauji Foundation Hospital, Rawalpindi, from January 2009 to January 2010. Methodology: HLA DR beta 1 genotyping of one hundred Pakistani patients, diagnosed as having RA as per American College of Rheumatology revised criteria 1987, was done. HLA DR beta 1 genotyping was carried out at allele group level (DR beta 1*01-DR beta 1*16) by sequence specific primers in RA patients. Comparison of HLA DR beta 1 allele frequencies between patients and control groups was made using Pearson's chi-square test to find possible association of HLA DR?1 alleles with RA in Pakistani rheumatoid patients. Results: HLA DR beta 1*04 was expressed with significantly increased frequency in patients with rheumatoid arthritis (p <0.05). HLA DR?1*11 was expressed statistically significantly more in control group as compared to rheumatoid patients indicating a possible protective effect. There was no statistically significant difference observed in frequencies of HLA DR beta 1 allele *01, DR beta 1 allele *03, DR beta 1 allele *07, DR beta 1 allele *08, DR beta 1 allele *09, DR beta 1 allele *10, DR beta 1 allele *12, DR beta 1 allele *13, DR beta 1 allele *14, DR?1 allele *15 and DR beta 1 allele *16 between patients and control groups. Conclusion: The identification of susceptible HLA DR beta 1 alleles in Pakistani RA patients may help physicians to make early decisions regarding initiation of early intensive therapy with disease modifying anti rheumatic medicines and biological agents decreasing disability in RA patients. (author)

Real-time PCR genotyping assay for canine progressive rod-cone degeneration and mutant allele frequency in Toy Poodles, Chihuahuas and Miniature Dachshunds in Japan.

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Kohyama, Moeko; Tada, Naomi; Mitsui, Hiroko; Tomioka, Hitomi; Tsutsui, Toshihiko; Yabuki, Akira; Rahman, Mohammad Mahbubur; Kushida, Kazuya; Mizukami, Keijiro; Yamato, Osamu

2016-03-01

Canine progressive rod-cone degeneration (PRCD) is a middle- to late-onset, autosomal recessive, inherited retinal disorder caused by a substitution (c.5G>A) in the canine PRCD gene that has been identified in 29 or more purebred dogs. In the present study, a TaqMan probe-based real-time PCR assay was developed and evaluated for rapid genotyping and large-scale screening of the mutation. Furthermore, a genotyping survey was carried out in a population of the three most popular breeds in Japan (Toy Poodles, Chihuahuas and Miniature Dachshunds) to determine the current mutant allele frequency. The assay separated all the genotypes of canine PRCD rapidly, indicating its suitability for large-scale surveys. The results of the survey showed that the mutant allele frequency in Toy Poodles was high enough (approximately 0.09) to allow the establishment of measures for the prevention and control of this disorder in breeding kennels. The mutant allele was detected in Chihuahuas for the first time, but the frequency was lower (approximately 0.02) than that in Toy Poodles. The mutant allele was not detected in Miniature Dachshunds. This assay will allow the selective breeding of dogs from the two most popular breeds (Toy Poodle and Chihuahua) in Japan and effective prevention or control of the disorder.

Distribution of the CCR5delta32 allele (gene variant CCR5) in Rondônia, Western Amazonian region, Brazil

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de Farias, Josileide Duarte; Santos, Marlene Guimarães; de França, Andonai Krauze; Delani, Daniel; Tada, Mauro Shugiro; Casseb, Almeida Andrade; Simões, Aguinaldo Luiz; Engracia, Vera

2012-01-01

Since around 1723, on the occasion of its initial colonization by Europeans, Rondonia has received successive waves of immigrants. This has been further swelled by individuals from northeastern Brazil, who began entering at the beginning of the twentieth century. The ethnic composition varies across the state according to the various sites of settlement of each wave of immigrants. We analyzed the frequency of the CCR5Δ32 allele of the CCR5 chemokine receptor, which is considered a Caucasian marker, in five sample sets from the population. Four were collected in Porto Velho, the state capital and the site of several waves of migration. Of these, two, from the Hospital de Base were comprised of HB Mothers and HB Newborns presenting allele frequencies of 3.5% and 3.1%, respectively, a third from the peri-urban neighborhoods of Candelária/Bate-Estaca (1.8%), whereas a fourth, from the Research Center on Tropical Medicine/CEPEM (0.6%), was composed of malaria patients under treament. The fifth sample (3.4%) came from the inland Quilombola village of Pedras Negras. Two homozygous individuals (CCR5Δ32/CCR5Δ32) were detected among the HB Mother samples. The frequency of this allele was heterogeneous and higher where the European inflow was more pronounced. The presence of the allele in Pedras Negras revealed European miscegenation in a community largely comprising Quilombolas. PMID:22481870

Human Leukocyte Antigen-A, B, C, DRB1, and DQB1 Allele and Haplotype Frequencies in a Subset of 237 Donors in the South African Bone Marrow Registry

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Mqondisi Tshabalala

2018-01-01

Full Text Available Human leukocyte antigen- (HLA- A, HLA-B, HLA-C, HLA-DRB1, and HLA-DQB1 allele and haplotype frequencies were studied in a subset of 237 volunteer bone marrow donors registered at the South African Bone Marrow Registry (SABMR. Hapl-o-Mat software was used to compute allele and haplotype frequencies from individuals typed at various resolutions, with some alleles in multiple allele code (MAC format. Four hundred and thirty-eight HLA-A, 235 HLA-B, 234 HLA-DRB1, 41 HLA-DQB1, and 29 HLA-C alleles are reported. The most frequent alleles were A∗02:02g (0.096, B∗07:02g (0.082, C∗07:02g (0.180, DQB1∗06:02 (0.157, and DRB1∗15:01 (0.072. The most common haplotype was A∗03:01g~B∗07:02g~C∗07:02g~DQB1∗06:02~DRB1∗15:01 (0.067, which has also been reported in other populations. Deviations from Hardy-Weinberg equilibrium were observed in A, B, and DRB1 loci, with C~DQB1 being the only locus pair in linkage disequilibrium. This study describes allele and haplotype frequencies from a subset of donors registered at SABMR, the only active bone marrow donor registry in Africa. Although the sample size was small, our results form a key resource for future population studies, disease association studies, and donor recruitment strategies.

High allele frequency of CYP2C9*3 (rs1057910) in a Negrito's subtribe population in Malaysia; Aboriginal people of Jahai.

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Rosdi, Rasmaizatul Akma; Mohd Yusoff, Narazah; Ismail, Rusli; Soo Choon, Tan; Saleem, Mohamed; Musa, Nurfadhlina; Yusoff, Surini

2016-09-01

CYP2C9 gene polymorphisms modulate inter-individual variations in the human body's responses to various endogenous and exogenous drug substrates. To date, little is known about the CYP2C9 gene polymorphisms among the aboriginal populations of the world, including those in Malaysia. To characterise and compare the CYP2C9 polymorphisms (CYP2C9*2, CYP2C9*3, CYP2C9*4 and CYP2C9*5) between one of Malaysia's aboriginal populations, Jahai, with the national major ethnic, Malay. To also compare the allele frequencies from these two populations with available data of other aboriginal populations around the world. The extracted DNA of 155 Jahais and 183 Malays was genotyped for CYP2C9 polymorphisms using a nested multiplex allele-specific polymerase chain reaction technique. The results were confirmed by DNA direct sequencing. Genotyping results revealed that CYP2C9*2, CYP2C9*4 and CYP2C9*5 were absent in Jahais, while only the latter two were absent in Malays. The CYP2C9*3 allelic frequency in Jahais was 36.2%, making them the most frequent carriers of the allele thus far reported in any ethnic group from Southeast Asia. The high frequency of CYP2C9*3 and the absence of CYP2C9*2 in Jahais suggest that genetic drift may be occurring in this ethnic group. This is the first study to determine the CYP2C9 polymorphisms in an aboriginal population in Malaysia.

Identification of the Rare, Four Repeat Allele of IL-4 Intron-3 VNTR Polymorphism in Indian Populations.

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Verma, Henu Kumar; Jha, Aditya Nath; Khodiar, Prafulla Kumar; Patra, Pradeep Kumar; Bhaskar, Lakkakula Venkata Kameswara Subrahmanya

2016-06-01

Cytokines are cell signaling molecules which upon release by cells facilitate the recruitment of immune-modulatory cells towards the sites of inflammation. Genetic variations in cytokine genes are shown to regulate their production and affect the risk of infectious as well as autoimmune diseases. Intron-3 of interleukin-4 gene (IL-4) harbors 70-bp variable number of tandem repeats (VNTR) that may alter the expression level of IL-4 gene. To determine the distribution of IL-4 70-bp VNTR polymorphism in seven genetically heterogeneous populations of Chhattisgarh, India and their comparison with the finding of other Indian and world populations. A total of 371 healthy unrelated individuals from 5 caste and 2 tribal populations were included in the present study. The IL-4 70-bp VNTR genotyping was carried out using PCR and electrophoresis. Overall, 3 alleles of IL-4 70-bp VNTR (a2, a3 and a4) were detected. The results demonstrated the variability of the IL-4 70-bp VNTR polymorphism in Chhattisgarh populations. Allele a3 was the most common allele at the 70-bp VNTR locus in all populations followed by a2 allele. This study reports the presence four repeat allele a4 at a low frequency in the majority of the Chhattisgarh populations studied. Further, the frequency of the minor allele (a2) in Chhattisgarh populations showed similarity with the frequencies of European populations but not with the East Asian populations where the a2 allele is a major allele. Our study provides a baseline for future research into the role of the IL-4 locus in diseases linked to inflammation in Indian populations.

Comparison of allele frequency for HLA-DR and HLA-DQ between patients with ECC and caries-free children

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Bagherian A

2008-03-01

Full Text Available Background: Early childhood caries (ECC is one of the most common diseases of childhood. The etiology of ECC is multifactorial and both genetic and environmental factors play important roles in the pathogenesis of the disease. Genetic variations in the hosts may contribute to changes in the risk for dental caries. Genetic factors such as human leukocyte antigen (HLA have recently been suggested as a predisposing factor. Aim: The aim of this study was to look for an association between HLA-DRB1 and HLA-DQB1 with ECC for developing new strategies for the diagnosis as well as the prevention of the disease. Design: In this study, we extracted the genomic DNAs from whole blood samples of 44 patients with ECC and 35 caries-free children by the salting-out method. We amplified the genomic DNA by PCR-SSP and then HLA-typing was performed for all alleles. Results: The results revealed a significant increase in the frequency of HLA-DRB1FNx0104 in the patient group (P = 0.019. The odds ratio for this allele was detected to be 10. The frequency of HLA-DQB1 alleles was not significantly different between the two groups. Conclusion: The above results suggest that HLA-DRB1FNx0104 is associated with the susceptibility to ECC. Thus HLA-DRB1FNx0104 detection as a molecular marker for early diagnosis of ECC may be recommended.

The allele frequency of two single nucleotide polymorphisms in the von Hippel-Lindau (VHL tumor suppressor gene in the Taiwanese population

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Wen-Chung Wang

2011-10-01

Conclusion: We found that the G allele frequency at these two loci in the Taiwanese population is much lower than that in people from Western countries. This phenomenon may be attributed to ethnic effects.

Human minisatellite alleles detectable only after PCR amplification.

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Armour, J A; Crosier, M; Jeffreys, A J

1992-01-01

We present evidence that a proportion of alleles at two human minisatellite loci is undetected by standard Southern blot hybridization. In each case the missing allele(s) can be identified after PCR amplification and correspond to tandem arrays too short to detect by hybridization. At one locus, there is only one undetected allele (population frequency 0.3), which contains just three repeat units. At the second locus, there are at least five undetected alleles (total population frequency 0.9) containing 60-120 repeats; they are not detected because these tandem repeats give very poor signals when used as a probe in standard Southern blot hybridization, and also cross-hybridize with other sequences in the genome. Under these circumstances only signals from the longest tandemly repeated alleles are detectable above the nonspecific background. The structures of these loci have been compared in human and primate DNA, and at one locus the short human allele containing three repeat units is shown to be an intermediate state in the expansion of a monomeric precursor allele in primates to high copy number in the longer human arrays. We discuss the implications of such loci for studies of human populations, minisatellite isolation by cloning, and the evolution of highly variable tandem arrays.

An informational view of accession rarity and allele specificity in germplasm banks for management and conservation.

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Reyes-Valdés, M Humberto; Burgueño, Juan; Singh, Sukhwinder; Martínez, Octavio; Sansaloni, Carolina Paola

2018-01-01

Germplasm banks are growing in their importance, number of accessions and amount of characterization data, with a large emphasis on molecular genetic markers. In this work, we offer an integrated view of accessions and marker data in an information theory framework. The basis of this development is the mutual information between accessions and allele frequencies for molecular marker loci, which can be decomposed in allele specificities, as well as in rarity and divergence of accessions. In this way, formulas are provided to calculate the specificity of the different marker alleles with reference to their distribution across accessions, accession rarity, defined as the weighted average of the specificity of its alleles, and divergence, defined by the Kullback-Leibler formula. Albeit being different measures, it is demonstrated that average rarity and divergence are equal for any collection. These parameters can contribute to the knowledge of the structure of a germplasm collection and to make decisions about the preservation of rare variants. The concepts herein developed served as the basis for a strategy for core subset selection called HCore, implemented in a publicly available R script. As a proof of concept, the mathematical view and tools developed in this research were applied to a large collection of Mexican wheat accessions, widely characterized by SNP markers. The most specific alleles were found to be private of a single accession, and the distribution of this parameter had its highest frequencies at low levels of specificity. Accession rarity and divergence had largely symmetrical distributions, and had a positive, albeit non-strictly linear relationship. Comparison of the HCore approach for core subset selection, with three state-of-the-art methods, showed it to be superior for average divergence and rarity, mean genetic distance and diversity. The proposed approach can be used for knowledge extraction and decision making in germplasm collections of

Identification and distribution of three serologically undetected alleles of HLA-DR by oligonucleotide x DNA typing analysis

International Nuclear Information System (INIS)

Tiercy, J.M.; Gorski, J.; Jeannet, M.; Mach, B.

1988-01-01

Recent progress in the molecular biology of human major histocompatibility complex class II genes (HLA-DP, -DQ, -DR) have shown that the genetic complexity and allelic polymorphism are greater than expected. In the case of HLA-DR, three DR β-chain loci have been identified and linked, two of which (DR βI and DR βIII, now assigned names HLA-DR1B and HLA-DR3B) are functional. The authors have shown that the HLA micropolymorphism detected at the DNA sequence level can easily be analyzed by hybridization with allele-specific oligonucleotides (HLA oligotyping). In the case of the HLA DRw52 supertypic specificity, which includes the DR3, DR5, DRw6, and DRw8 haplotypes, three alleles, referred to as DRw52a, DRw52b, and DRw52c, have recently been identified at the HLA-DR3B locus by DNA sequencing. Hybridization with locus- and allele-specific oligonucleotide probes (designated 52a, 52b, and 52c) has been performed on DNA from normal individuals forming a panel of 82 haplotypes to establish the distribution of these three alleles. Individuals of the DR3 haplotype had either the DRw52a or DRw52b allele, and individuals of extended haplotype HLA-A1,B8,DR3 had only the DRw52a allele. DR5 individuals all had the DRw52b allele, while individuals of DRw6 haplotype had the DRw52a, -52b, or -52c allele. None of these three alleles are found in DRw8 individuals. Analysis of this micropolymorphism, undetectable by common typing procedures, is therefore now operational for more accurate HLA matching for transplantation and for improving correlations between HLA and disease susceptibility

Tracking human migrations by the analysis of the distribution of HLA alleles, lineages and haplotypes in closed and open populations

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Vina, Marcelo A. Fernandez; Hollenbach, Jill A.; Lyke, Kirsten E.; Sztein, Marcelo B.; Maiers, Martin; Klitz, William; Cano, Pedro; Mack, Steven; Single, Richard; Brautbar, Chaim; Israel, Shosahna; Raimondi, Eduardo; Khoriaty, Evelyne; Inati, Adlette; Andreani, Marco; Testi, Manuela; Moraes, Maria Elisa; Thomson, Glenys; Stastny, Peter; Cao, Kai

2012-01-01

The human leucocyte antigen (HLA) system shows extensive variation in the number and function of loci and the number of alleles present at any one locus. Allele distribution has been analysed in many populations through the course of several decades, and the implementation of molecular typing has significantly increased the level of diversity revealing that many serotypes have multiple functional variants. While the degree of diversity in many populations is equivalent and may result from functional polymorphism(s) in peptide presentation, homogeneous and heterogeneous populations present contrasting numbers of alleles and lineages at the loci with high-density expression products. In spite of these differences, the homozygosity levels are comparable in almost all of them. The balanced distribution of HLA alleles is consistent with overdominant selection. The genetic distances between outbred populations correlate with their geographical locations; the formal genetic distance measurements are larger than expected between inbred populations in the same region. The latter present many unique alleles grouped in a few lineages consistent with limited founder polymorphism in which any novel allele may have been positively selected to enlarge the communal peptide-binding repertoire of a given population. On the other hand, it has been observed that some alleles are found in multiple populations with distinctive haplotypic associations suggesting that convergent evolution events may have taken place as well. It appears that the HLA system has been under strong selection, probably owing to its fundamental role in varying immune responses. Therefore, allelic diversity in HLA should be analysed in conjunction with other genetic markers to accurately track the migrations of modern humans. PMID:22312049

Distribution of a pseudodeficiency allele among Tay-Sachs carriers

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Tomczak, J.; Grebner, E.E. (Thomas Jefferson Univ., Philadelphia, PA (United States)); Boogen, C. (Univ. of Essen Medical School (Germany))

1993-08-01

Recently Triggs-Raine et al. (1992) identified a new mutation in the gene coding for the [alpha]-subunit of [beta]-hexosaminidase A (hex A), the enzyme whose deficiency causes Tay-Sachs disease. This mutation, a C[sub 739]-to-T transition in exon 7, results in an altered enzyme that is active (albeit at reduced levels) in cells but that has essentially no activity in serum. This so-called pseudodeficient allele was first detected in compound heterozygotes who also carried a Tay-Sachs disease allele and therefore had no detectable hex A in their serum but who were in good health. Carriers of this apparently benign mutation are generally indistinguishable from carriers of a lethal mutation by means of routine enzyme-based screening tests, because the product of the pseudodeficient allele is not detectable in serum and has decreased activity in cells. This suggests that some individuals who have been classified as Tay-Sachs carriers are actually carriers of the pseudodeficient allele and are not at risk to have a child affected with Tay-Sachs disease. The pseudodeficient allele may also be responsible for some inconclusive diagnoses, where leukocyte values fall below the normal range but are still above the carrier range. The fact that there are now two mutant alleles (the psuedodeficient and the adult) that are indistinguishable from the lethal infantile mutations by means of enzyme assay yet that are phenotypically very different and that together may account for as much as 12% of enzyme-defined carriers on the basis of the data here suggests that DNA analysis should be part of a comprehensive screening program. It will be particularly useful to identify the mutations in couples at risk, before they undergo prenatal diagnosis. DNA analysis will also resolve some inconclusive diagnoses.

Frequency of the GPR7 Tyr135Phe allelic variant in lean and obese subjects.

Science.gov (United States)

Pelosini, C; Maffei, M; Ceccarini, G; Marchi, M; Marsili, A; Galli, G; Scartabelli, G; Tamberi, A; Latrofa, F; Fierabracci, P; Vitti, P; Pinchera, A; Santini, F

2013-10-01

GPR7, the endogenous coupled receptor for neuropeptide B and neuropeptide W, is expressed in several regions of the central nervous system, which are involved in the regulation of feeding behavior. GPR7 affects the regulation of energy balance through a mechanism independent of leptin and melanocortin pathways. Aim of this study was to investigate whether GPR7 gene mutations can be detected in human subjects and, in that event, if they are differently distributed among lean and obese subjects. The coding region of GPR7 were sequenced in 150 obese patients and 100 normal-weight unrelated controls. Functional studies of the allelic variants were performed. One genetic GPR7 variant was found (Tyr135Phe - rs33977775) in obese subjects (13.3%) and lean control (25%). Functional studies did not reveal significant differences between the wild type and the Tyr135Phe allelic variants in their NPW-mediated capacity to inhibit forskolin-induced cAMP production. Screening of GPR7 gene mutations among lean and obese subjects revealed a Tyr135Phe allelic variant that was fairly common in the study population. As indicated by in vitro and in silico studies, this variant is unlikely to cause a functional derangement of the receptor.

Allele Workbench: transcriptome pipeline and interactive graphics for allele-specific expression.

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Carol A Soderlund

Full Text Available Sequencing the transcriptome can answer various questions such as determining the transcripts expressed in a given species for a specific tissue or condition, evaluating differential expression, discovering variants, and evaluating allele-specific expression. Differential expression evaluates the expression differences between different strains, tissues, and conditions. Allele-specific expression evaluates expression differences between parental alleles. Both differential expression and allele-specific expression have been studied for heterosis (hybrid vigor, where the hybrid has improved performance over the parents for one or more traits. The Allele Workbench software was developed for a heterosis study that evaluated allele-specific expression for a mouse F1 hybrid using libraries from multiple tissues with biological replicates. This software has been made into a distributable package, which includes a pipeline, a Java interface to build the database, and a Java interface for query and display of the results. The required input is a reference genome, annotation file, and one or more RNA-Seq libraries with optional replicates. It evaluates allelic imbalance at the SNP and transcript level and flags transcripts with significant opposite directional allele-specific expression. The Java interface allows the user to view data from libraries, replicates, genes, transcripts, exons, and variants, including queries on allele imbalance for selected libraries. To determine the impact of allele-specific SNPs on protein folding, variants are annotated with their effect (e.g., missense, and the parental protein sequences may be exported for protein folding analysis. The Allele Workbench processing results in transcript files and read counts that can be used as input to the previously published Transcriptome Computational Workbench, which has a new algorithm for determining a trimmed set of gene ontology terms. The software with demo files is available

Power laws for heavy-tailed distributions: modeling allele and haplotype diversity for the national marrow donor program.

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Noa Slater

2015-04-01

Full Text Available Measures of allele and haplotype diversity, which are fundamental properties in population genetics, often follow heavy tailed distributions. These measures are of particular interest in the field of hematopoietic stem cell transplant (HSCT. Donor/Recipient suitability for HSCT is determined by Human Leukocyte Antigen (HLA similarity. Match predictions rely upon a precise description of HLA diversity, yet classical estimates are inaccurate given the heavy-tailed nature of the distribution. This directly affects HSCT matching and diversity measures in broader fields such as species richness. We, therefore, have developed a power-law based estimator to measure allele and haplotype diversity that accommodates heavy tails using the concepts of regular variation and occupancy distributions. Application of our estimator to 6.59 million donors in the Be The Match Registry revealed that haplotypes follow a heavy tail distribution across all ethnicities: for example, 44.65% of the European American haplotypes are represented by only 1 individual. Indeed, our discovery rate of all U.S. European American haplotypes is estimated at 23.45% based upon sampling 3.97% of the population, leaving a large number of unobserved haplotypes. Population coverage, however, is much higher at 99.4% given that 90% of European Americans carry one of the 4.5% most frequent haplotypes. Alleles were found to be less diverse suggesting the current registry represents most alleles in the population. Thus, for HSCT registries, haplotype discovery will remain high with continued recruitment to a very deep level of sampling, but population coverage will not. Finally, we compared the convergence of our power-law versus classical diversity estimators such as Capture recapture, Chao, ACE and Jackknife methods. When fit to the haplotype data, our estimator displayed favorable properties in terms of convergence (with respect to sampling depth and accuracy (with respect to diversity

HLA-A AND HLA-B ALLELES ASSOCIATED IN PSORIASIS PATIENTS FROM MUMBAI, WESTERN INDIA

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Umapathy, Shankarkumar; Pawar, Aruna; Mitra, R; Khuperkar, D; Devaraj, J P; Ghosh, K; Khopkar, U

2011-01-01

Background: Psoriasis, a common autoimmune disorder characterized by T cell-mediated keratinocyte hyperproliferation, is known to be associated with the presence of certain specific Human Leukocyte Antigen (HLA) alleles. Aim: To evaluate distribution of HLA-A and HLA-B alleles and hence identify the susceptible allele of psoriasis from patients in Western India. Materials and Methods: The study design included 84 psoriasis patients and 291 normal individuals as controls from same geographical region. HLA-A and HLA-B typing was done using Serology typing. Standard statistical analysis was followed to identify the odds ratio (OR), allele frequencies, and significant P value using Graphpad software. Results: The study revealed significant increase in frequencies of HLA-A2 (OR-3.976, P<0.0001), B8 (OR-5.647, P<0.0001), B17 (OR-5.452, P<0.0001), and B44 (OR-50.460, P<0.0001), when compared with controls. Furthermore, the frequencies of HLA-A28 (OR-0.074, P=0.0024), B5 (OR-0.059, P<0.0001), B12 (OR-0.051, P=0.0002), and B15 (OR-0.237, P=0.0230) were significantly decreased in psoriasis patients. Conclusion: This study shows the strong association of HLA-A2, B8, and B17 antigens with psoriasis conferring susceptibility to psoriasis patients from Western India, while the antigens HLA-A28, B5, and B12 show strong negative association with the disease. PMID:22121262

Life satisfaction in the new country: a multilevel longitudinal analysis of effects of culture and 5-HTT allele frequency distribution in country of origin.

Science.gov (United States)

Kashima, Emiko S; Kent, Stephen; Kashima, Yoshihisa

2015-01-01

Life satisfaction of migrants to Australia from 17 countries, assessed at 4-5 months, 16-17 months and 3½ years after arrival, was analyzed with a longitudinal, multilevel analysis. The results indicated that migrants were more satisfied, if the national average life satisfaction was higher in their country of origin, after adjustment for individual-level income, age, and sex and a linear temporal trend. Simultaneously, the migrants were also happier if people in their country of origin had a higher frequency of 5-HTT long allele, a genotype known to be associated with resilience under life stresses. These two relationships were independent, suggesting that both culture and gene matter in international transitions. © The Author (2014). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Allele frequencies of human platelet antigens in Banjar, Bugis, Champa, Jawa and Kelantan Malays in Peninsular Malaysia.

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Wan Syafawati, W U; Norhalifah, H K; Zefarina, Z; Zafarina, Z; Panneerchelvam, S; Norazmi, M N; Chambers, G K; Edinur, H A

2015-10-01

The major aims of this study are to characterise and compile allelic data of human platelet antigen (HPA)-1 to -6 and -15 systems in five Malay sub-ethnic groups in Peninsular Malaysia. HPAs are polymorphic glycoproteins expressed on the surface of platelet membranes and are genetically differentiated across ethnogeographically unrelated populations. Blood samples were obtained with informed consent from 192 volunteers: Banjar (n = 30), Bugis (n = 37), Champa (n = 51), Jawa (n = 39) and Kelantan (n = 35). Genotyping was done using polymerase chain reaction-sequence specific primer method. In general, frequencies of HPAs in the Malay sub-ethnic groups are more similar to those in Asian populations compared with other more distinct populations such as Indians, Australian Aborigines and Europeans. This study provides the first HPA datasets for the selected Malay sub-ethnic groups. Subsequent analyses including previously reported HPA data of Malays, Chinese and Indians revealed details of the genetic relationships and ancestry of various sub-populations in Peninsular Malaysia. Furthermore, the comprehensive HPA allele frequency information from Peninsular Malaysia provided in this report has potential applications for future study of diseases, estimating risks associated with HPA alloimmunization and for developing an efficient HPA-typed donor recruitment strategy. © 2015 British Blood Transfusion Society.

Recurrent frequency-size distribution of characteristic events

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S. G. Abaimov

2009-04-01

Full Text Available Statistical frequency-size (frequency-magnitude properties of earthquake occurrence play an important role in seismic hazard assessments. The behavior of earthquakes is represented by two different statistics: interoccurrent behavior in a region and recurrent behavior at a given point on a fault (or at a given fault. The interoccurrent frequency-size behavior has been investigated by many authors and generally obeys the power-law Gutenberg-Richter distribution to a good approximation. It is expected that the recurrent frequency-size behavior should obey different statistics. However, this problem has received little attention because historic earthquake sequences do not contain enough events to reconstruct the necessary statistics. To overcome this lack of data, this paper investigates the recurrent frequency-size behavior for several problems. First, the sequences of creep events on a creeping section of the San Andreas fault are investigated. The applicability of the Brownian passage-time, lognormal, and Weibull distributions to the recurrent frequency-size statistics of slip events is tested and the Weibull distribution is found to be the best-fit distribution. To verify this result the behaviors of numerical slider-block and sand-pile models are investigated and the Weibull distribution is confirmed as the applicable distribution for these models as well. Exponents β of the best-fit Weibull distributions for the observed creep event sequences and for the slider-block model are found to have similar values ranging from 1.6 to 2.2 with the corresponding aperiodicities C_V of the applied distribution ranging from 0.47 to 0.64. We also note similarities between recurrent time-interval statistics and recurrent frequency-size statistics.

Analysis of HLA-A, HLA-B, HLA-DRB1 allelic, genotypic, and haplotypic frequencies in colombian population

OpenAIRE

Yazmin Rocío Árias-Murillo; Miguel Ángel Castro-Jiménez; María Fernanda Ríos-Espinosa; Juan Javier López-Rivera; Sandra Johanna Echeverry-Coral; Oscar Martínez-Nieto

2010-01-01

Introduction: The high polymorphism of the HLA system allows its typification to be used as valuable tool in establishing association to various illnesses, immune and genetic profiles; it also provides a guide to identifying compatibility among donors and receptors of organs transplants. Objective: To establish HLA-A, HLA-B, and HLA.DRB1 allele, genotype and haplotype frequencies among patients treated at Clinica Colsanitas SA. Methods: 561 patients coming from different regions in Col...

Frequency of interleukin 28B rs12979860 C>T variants in Filipino patients chronically infected with hepatitis B virus.

Science.gov (United States)

Baclig, Michael O; Reyes, Karen G; Mapua, Cynthia A; Gopez-Cervantes, Juliet; Natividad, Filipinas F

2015-03-01

Hepatitis B virus (HBV) is one of the most prevalent viral infections worldwide. Nearly 400 million individuals are chronic carriers of HBV. The aim of the present study was to determine the frequency of human interleukin 28B (IL28B) variants among treatment naive Filipino patients clinically diagnosed with chronic hepatitis B (CHB), and to compare the IL28B frequency distribution with various ethnic populations. Fifty-seven CHB patients and 43 normal controls were enrolled in this study. Real-time PCR was performed using the TaqMan genotyping assay for IL28B rs12979860. The allelic frequencies among normal controls were 0.94 and 0.06 for the IL28B rs12979860 C and T alleles, respectively. Eighty-eight percent were identified as homozygous for the IL28B C/C genotype and 12% were identified as heterozygous for the IL28B C/T genotype. Among CHB patients, the allelic frequencies were 0.90 for the IL28B C allele and 0.10 for the IL28B T allele. No IL28B T/T genotype was observed between the two groups. No significant difference in the distribution of IL28B genotypes was observed between normal controls and CHB patients. Allelic frequencies of IL28B among Filipinos were similar with other Asian populations but significantly different from Caucasians. The frequency of rs12979860 C>T variants among Filipino CHB patients has not yet been reported. These data provided new insight into the geographical frequency distribution of IL28B variants. Further studies are needed to determine the possible association between IL28B variants and response to pegylated-interferon-α plus ribavirin combination therapy among Filipino patients chronically infected with HBV.

Stochastic modelling of shifts in allele frequencies reveals a strongly polygynous mating system in the re-introduced Asiatic wild ass.

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Renan, Sharon; Greenbaum, Gili; Shahar, Naama; Templeton, Alan R; Bouskila, Amos; Bar-David, Shirli

2015-04-01

Small populations are prone to loss of genetic variation and hence to a reduction in their evolutionary potential. Therefore, studying the mating system of small populations and its potential effects on genetic drift and genetic diversity is of high importance for their viability assessments. The traditional method for studying genetic mating systems is paternity analysis. Yet, as small populations are often rare and elusive, the genetic data required for paternity analysis are frequently unavailable. The endangered Asiatic wild ass (Equus hemionus), like all equids, displays a behaviourally polygynous mating system; however, the level of polygyny has never been measured genetically in wild equids. Combining noninvasive genetic data with stochastic modelling of shifts in allele frequencies, we developed an alternative approach to paternity analysis for studying the genetic mating system of the re-introduced Asiatic wild ass in the Negev Desert, Israel. We compared the shifts in allele frequencies (as a measure of genetic drift) that have occurred in the wild ass population since re-introduction onset to simulated scenarios under different proportions of mating males. We revealed a strongly polygynous mating system in which less than 25% of all males participate in the mating process each generation. This strongly polygynous mating system and its potential effect on the re-introduced population's genetic diversity could have significant consequences for the long-term persistence of the population in the Negev. The stochastic modelling approach and the use of allele-frequency shifts can be further applied to systems that are affected by genetic drift and for which genetic data are limited. © 2015 John Wiley & Sons Ltd.

Inferring Allele Frequency Trajectories from Ancient DNA Indicates That Selection on a Chicken Gene Coincided with Changes in Medieval Husbandry Practices.

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Loog, Liisa; Thomas, Mark G; Barnett, Ross; Allen, Richard; Sykes, Naomi; Paxinos, Ptolemaios D; Lebrasseur, Ophélie; Dobney, Keith; Peters, Joris; Manica, Andrea; Larson, Greger; Eriksson, Anders

2017-08-01

Ancient DNA provides an opportunity to infer the drivers of natural selection by linking allele frequency changes to temporal shifts in environment or cultural practices. However, analyses have often been hampered by uneven sampling and uncertainties in sample dating, as well as being confounded by demographic processes. Here, we present a Bayesian statistical framework for quantifying the timing and strength of selection using ancient DNA that explicitly addresses these challenges. We applied this method to time series data for two loci: TSHR and BCDO2, both hypothesised to have undergone strong and recent selection in domestic chickens. The derived variant in TSHR, associated with reduced aggression to conspecifics and faster onset of egg laying, shows strong selection beginning around 1,100 years ago, coincident with archaeological evidence for intensified chicken production and documented changes in egg and chicken consumption. To our knowledge, this is the first example of preindustrial domesticate trait selection in response to a historically attested cultural shift in food preference. For BCDO2, we find support for selection, but demonstrate that the recent rise in allele frequency could also have been driven by gene flow from imported Asian chickens during more recent breed formations. Our findings highlight that traits found ubiquitously in modern domestic species may not necessarily have originated during the early stages of domestication. In addition, our results demonstrate the importance of precise estimation of allele frequency trajectories through time for understanding the drivers of selection. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Distribution of photoperiod-insensitive allele Ppd-A1a and its effect on heading time in Japanese wheat cultivars.

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Seki, Masako; Chono, Makiko; Nishimura, Tsutomu; Sato, Mikako; Yoshimura, Yasuhiro; Matsunaka, Hitoshi; Fujita, Masaya; Oda, Shunsuke; Kubo, Katashi; Kiribuchi-Otobe, Chikako; Kojima, Hisayo; Nishida, Hidetaka; Kato, Kenji

2013-09-01

The Ppd-A1 genotype of 240 Japanese wheat cultivars and 40 foreign cultivars was determined using a PCR-based method. Among Japanese cultivars, only 12 cultivars, all of which were Hokkaido winter wheat, carried the Ppd-A1a allele, while this allele was not found in Hokkaido spring wheat cultivars or Tohoku-Kyushu cultivars. Cultivars with a photoperiod-insensitive allele headed 6.9-9.8 days earlier in Kanto and 2.5 days earlier in Hokkaido than photoperiod-sensitive cultivars. The lower effect of photoperiod-insensitive alleles observed in Hokkaido could be due to the longer day-length at the spike formation stage compared with that in Kanto. Pedigree analysis showed that 'Purple Straw' and 'Tohoku 118' were donors of Ppd-A1a and Ppd-D1a in Hokkaido wheat cultivars, respectively. Wheat cultivars recently developed in Hokkaido carry photoperiod-insensitive alleles at a high frequency. For efficient utilization of Ppd-1 alleles in the Hokkaido wheat-breeding program, the effect of Ppd-1 on growth pattern and grain yield should be investigated. Ppd-A1a may be useful as a unique gene source for fine tuning the heading time in the Tohoku-Kyushu region since the effect of Ppd-A1a on photoperiod insensitivity appears to differ from the effect of Ppd-B1a and Ppd-D1a.

k-Casein, b-lactoglobulin and growth hormone allele frequencies and genetic distances in Nelore, Gyr, Guzerá, Caracu, Charolais, Canchim and Santa Gertrudis cattle

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Paola Augusta Kemenes

1999-12-01

Full Text Available The genotypes for k-casein (k-CN, b-lactoglobulin (b-LG and growth hormone (GH were determined by polymerase chain reaction (PCR and restriction enzyme digestion in seven breeds of cattle (Nelore, Gyr, Guzerá, Caracu, Charolais, Canchim and Santa Gertrudis. k-Casein had two alleles with the A allele occurring at a higher frequency in Bos indicus breeds (0.93, 0.92 and 0.91% for Gyr, Guzerá and Nelore, respectively. The b-lactoglobulin locus had two alleles in all of the breeds. European breeds had a higher frequency of the b-LG A allele than Zebu breeds. The GH locus had two alleles (L and V in Bos taurus and was monomorphic (L allele only in all of the Bos indicus breeds evaluated. The highest frequency for the V allele was observed in Charolais cattle. The markers used revealed a considerable similarity among breeds, with two main groups being discernible. One group consisted of Zebu and Santa Gertrudis breeds and the other consisted of European and Canchim breeds.Os genótipos de k-caseína (k-CN, b-lactoglobulina (b-LG e hormônio de crescimento foram determinados por reação em cadeia de polimerase (PCR e digestão com enzima de restrição em sete raças de bovinos (Nelore, Gir, Guzerá, Caracu, Charolesa, Canchim and Santa Gertrudis. A k-caseína apresentou dois alelos e as freqüências mais elevadas para o alelo A foram observadas em Bos indicus (0,93, 0,92 e 0,91% para as raças Gir, Guzerá e Nelore, respectivamente. A b-lactoglobulina apresentou dois alelos em todas as raças estudadas, sendo a freqüência do alelo A mais elevada nas raças européias. O loco de hormônio de crescimento apresentou dois alelos em Bos taurus e foi monomórfico (alelo L em todas as raças zebuínas. A maior freqüência para o alelo V foi observado na raça Charolesa. Os marcadores investigados revelaram alta similaridade entre as raças, com a formação de dois grupos principais: um composto de raças zebuínas e a raça Santa Gertrudis e outro

Relative frequencies of DRB1*11 alleles and their DRB3 associations in five major population groups in a United States bone marrow registry.

Science.gov (United States)

Tang, T F; Huang, A Y; Pappas, A; Slack, R; Ng, J; Hartzman, R J; Hurley, C K

2000-08-01

One hundred sixty-one individuals from each of five US population groups, Caucasians (CAU), African Americans (AFA), Asians/Pacific Islanders (API), Hispanics (HIS), and Native Americans (NAT), were randomly selected from a volunteer bone marrow registry database consisting of 14,452 HLA-DRB1*11 positive individuals. This sampling provided at least an 80% probability of detecting a rare allele that occurred at 1% in the DRB1*11 positive population. Samples were typed for DRB1*11 alleles by polymerase chain reaction-sequence specific oligonucleotide probe typing (PCR-SSOP). A total of 10 DRB1*11 alleles out of 27 possible alleles were detected. The distribution and diversity of DRB1*11 alleles varied among populations although DRB1*1101 was the predominant DRB1*11 allele in all populations. Caucasians were the least diversified; only four common alleles (DRB1*1101-*1104) were observed. As well as the four common alleles, other groups also carried one or two other less frequent alleles including DRB1*1105 (API), *1106 (API), *1110 (AFA), *1114 (HIS), *1115 (NAT), and *1117 (AFA). A subset (418) of these individuals were also typed for DRB3 alleles. Most (97.6%) showed a strong association of DRB1*11 with DRB3*0202.

Selection on alleles affecting human longevity and late-life disease: the example of apolipoprotein E.

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Fotios Drenos

2010-04-01

Full Text Available It is often claimed that genes affecting health in old age, such as cardiovascular and Alzheimer diseases, are beyond the reach of natural selection. We show in a simulation study based on known genetic (apolipoprotein E and non-genetic risk factors (gender, diet, smoking, alcohol, exercise that, because there is a statistical distribution of ages at which these genes exert their influence on morbidity and mortality, the effects of selection are in fact non-negligible. A gradual increase with each generation of the epsilon2 and epsilon3 alleles of the gene at the expense of the epsilon4 allele was predicted from the model. The epsilon2 allele frequency was found to increase slightly more rapidly than that for epsilon3, although there was no statistically significant difference between the two. Our result may explain the recent evolutionary history of the epsilon 2, 3 and 4 alleles of the apolipoprotein E gene and has wider relevance for genes affecting human longevity.

Polymorphism of κ-Casein in Italian Goat Breeds: A New ACRS-PCR Designed DNA Test for Discrimination of A and B Alleles

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Vlatka Cubric-Curik

2002-01-01

Full Text Available The objective of this study was to develop a DNA test for rapid characterisation of goat κ-casein (κ-CN A and B variants and to study this polymorphism in Italian goat breeds. Genetic polymorphism of κ-CN gene was, in addition to isoelectric focusing, analysed according to a new technique designated as amplification created restriction site. Two alleles that differ in one nucleotide mutation (G Ø A in exon 4 were characterised. The 167-bp PCR product surrounding the nucleotide mutation was amplified from genomic DNA and the PCR product was digested with MaeIII. After digestion the A allele gives three fragments of 77, 65 and 25 bp in comparison with the B allele which gives two fragments of 90 and 77 bp. The analysis of allele frequency distribution at κ-CN locus, based on 401 individual samples, revealed significant differences among three goat breeds from the north of Italy (Nera di Verzasca, Frontalasca and Alpine with frequency of κ-CN B allele around 0.3, versus two goat breeds from the south of Italy (Maltese and Sarda with frequency of κ-CN B allele around 0.5. While two goat breeds (Maltese and Nera di Verzasca did not show significant deviations from the Hardy-Weinberg equilibrium, a highly significant excess of heterozygote genotype (AB was observed in Alpine, Frontalasca and Sarda goats. Here the developed DNA method and observed relatively high frequency of κ-CN B allele give a prerequisite for the assessment of research related to the simultaneous estimation of the effects of composite αs1/κ-CN genotypes on milk production and cheese-making properties.

Linkage disequilibrium in the insulin gene region: Size variation at the 5{prime} flanking polymorphism and bimodality among {open_quotes}Class I{close_quotes} alleles

Energy Technology Data Exchange (ETDEWEB)

McGinnis, R.E.; Spielman, R.S. [Univ. of Pennsylvania School of Medicine, Philadelphia, PA (United States)

1994-09-01

The 5{prime} flanking polymorphism (5{prime}FP), a hypervariable region at the 5{prime} end of the insulin gene, has {open_quotes}class 1{close_quotes} alleles (650-900 bp long) that are in positive linkage disequilibrium with insulin-dependent diabetes mellitus (IDDM). The authors report that precise sizing of the 5{prime}FP yields a bimodal frequency distribution of class 1 allele lengths. Class 1 alleles belonging to the lower component (650-750 bp) of the bimodal distribution were somewhat more highly associated with IDDM than were alleles from the upper component (760-900 bp), but the difference was not statistically significant. They also examined 5{prime}FP length variation in relation to allelic variation at nearby polymorphisms. At biallelic RFLPs on both sides of the 5{prime}FP, they found that one allele exhibits near-total association with the upper component of the 5FP class 1 distribution. Such associations represent a little-known but potentially wide-spread form of linkage disequilibrium. In this type of disequilibrium, a flanking allele has near-complete association with a single mode of VNTR alleles whose lengths represent consecutive numbers of tandem repeats (CNTR). Such extreme disequilibrium between a CNTR mode and flanking alleles may originate and persist because length mutations at some VNTR loci usually add or delete only one or two repeat units. 22 refs., 5 figs., 6 tabs.

Linkage of familial Alzheimer disease to chromosome 14 in two large early-onset pedigrees: effects of marker allele frequencies on lod scores.

Science.gov (United States)

Nechiporuk, A; Fain, P; Kort, E; Nee, L E; Frommelt, E; Polinsky, R J; Korenberg, J R; Pulst, S M

1993-05-01

Alzheimer disease (AD) is a devastating neurodegenerative disease leading to global dementia. In addition to sporadic forms of AD, familial forms (FAD) have been recognized. Mutations in the amyloid precursor protein (APP) gene on chromosome (CHR) 21 have been shown to cause early-onset AD in a small number of pedigrees. Recently, linkage to markers on CHR 14 has been established in several early-onset FAD pedigrees. We now report lod scores for CHR 14 markers in two large early-onset FAD pedigrees. Pairwise linkage analysis suggested that in these pedigrees the mutation is tightly linked to the loci D14S43 and D14S53. However, assumptions regarding marker allele frequencies had a major and often unpredictable effect on calculated lod scores. Therefore, caution needs to be exercised when single pedigrees are analyzed with marker allele frequencies determined from the literature or from a pool of spouses.

Short alleles revealed by PCR demonstrate no heterozygote deficiency at minisatellite loci D1S7, D7S21, and D12S11

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Alonso, S.; Castro, A.; Fernandez-Fernandez, I.; Pancorbo, M.M. de [Universidad del Pais Vasco, Vizcaya (Spain)

1997-02-01

Short VNTR alleles that go undetected after conventional Southern blot hybridization may constitute an alternative explanation for the heterozygosity deficiency observed at some minisatellite loci. To examine this hypothesis, we have employed a screening procedure based on PCR amplification of those individuals classified as homozygotes in our databases for the loci D1S7, D7S21, and D12S11. The results obtained indicate that the frequency of these short alleles is related to the heterozygosity deficiency observed. For the most polymorphic locus, D1S7, {approximately}60% of those individuals previously classified as homozygotes were in fact heterozygotes for a short allele. After the inclusion of these new alleles, the agreement between observed and expected heterozygosity, along with other statistical tests employed, provide additional evidence for lack of population substructuring. Comparisons of allele frequency distributions reveal greater differences between racial groups than between closely related populations. 45 refs., 3 figs., 6 tabs.

Inheritance of Cry1F resistance, cross-resistance and frequency of resistant alleles in Spodoptera frugiperda (Lepidoptera: Noctuidae).

Science.gov (United States)

Vélez, A M; Spencer, T A; Alves, A P; Moellenbeck, D; Meagher, R L; Chirakkal, H; Siegfried, B D

2013-12-01

Transgenic maize, Zea maize L., expressing the Cry1F protein from Bacillus thuringiensis has been registered for Spodoptera frugiperda (J. E. Smith) control since 2003. Unexpected damage to Cry1F maize was reported in 2006 in Puerto Rico and Cry1F resistance in S. frugiperda was documented. The inheritance of Cry1F resistance was characterized in a S. frugiperda resistant strain originating from Puerto Rico, which displayed >289-fold resistance to purified Cry1F. Concentration-response bioassays of reciprocal crosses of resistant and susceptible parental populations indicated that resistance is recessive and autosomal. Bioassays of the backcross of the F1 generation crossed with the resistant parental strain suggest that a single locus is responsible for resistance. In addition, cross-resistance to Cry1Aa, Cry1Ab, Cry1Ac, Cry1Ba, Cry2Aa and Vip3Aa was assessed in the Cry1F-resistant strain. There was no significant cross-resistance to Cry1Aa, Cry1Ba and Cry2Aa, although only limited effects were observed in the susceptible strain. Vip3Aa was highly effective against susceptible and resistant insects indicating no cross-resistance with Cry1F. In contrast, low levels of cross-resistance were observed for both Cry1Ab and Cry1Ac. Because the resistance is recessive and conferred by a single locus, an F1 screening assay was used to measure the frequency of Cry1F-resistant alleles from populations of Florida and Texas in 2010 and 2011. A total frequency of resistant alleles of 0.13 and 0.02 was found for Florida and Texas populations, respectively, indicating resistant alleles could be found in US populations, although there have been no reports of reduced efficacy of Cry1F-expressing plants.

Polymorphism of the cytochrome P450 CYP2D6 gene in a European population: characterization of 48 mutations and 53 alleles, their frequencies and evolution.

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Marez, D; Legrand, M; Sabbagh, N; Lo Guidice, J M; Spire, C; Lafitte, J J; Meyer, U A; Broly, F

1997-06-01

The polymorphic cytochrome P450 CYP2D6 is involved in the metabolism of various drugs of wide therapeutic use and is a presumed susceptibility factor for certain environmentally-induced diseases. Our aim was to define the mutations and alleles of the CYP2D6 gene and to evaluate their frequencies in the European population. Using polymerase chain reaction-single strand conformation polymorphism analysis, 672 unrelated subjects were screened for mutations in the 9 exons of the gene and their exon-intron boundaries. A total of 48 point mutations were identified, of which 29 were novel. Mutations 1749 G-->C, 2938 C-->T and 4268 G-->C represented 52.6%, 34.3% and 52.9% of the mutations in the total population, respectively. Of the eight detrimental mutations detected, the 1934 G-->A, the 1795 Tdel and the 2637 Adel accounted for 65.8%, 6.2% and 4.8% respectively, within the poor metabolizer subgroup. Fifty-three different alleles were characterized from the mutation pattern and by allele-specific sequencing. They are derived from three major alleles, namely the wild-type CYP2D6*1A, the functional CYP2D6*2 and the null CYP2D6*4A. Five allelic variants (CYP2D6*1A, *2, *2B, *4A and *5) account for about 87% of all alleles, while the remaining alleles occur with a frequency of 0.1%-2.7%. These data provide a solid basis for future epidemiological, clinical as well as interethnic studies of the CYP2D6 polymorphism and highlight that the described single strand conformation polymorphism method can be successfully used in designing such studies.

Type I error rates of rare single nucleotide variants are inflated in tests of association with non-normally distributed traits using simple linear regression methods.

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Schwantes-An, Tae-Hwi; Sung, Heejong; Sabourin, Jeremy A; Justice, Cristina M; Sorant, Alexa J M; Wilson, Alexander F

2016-01-01

In this study, the effects of (a) the minor allele frequency of the single nucleotide variant (SNV), (b) the degree of departure from normality of the trait, and (c) the position of the SNVs on type I error rates were investigated in the Genetic Analysis Workshop (GAW) 19 whole exome sequence data. To test the distribution of the type I error rate, 5 simulated traits were considered: standard normal and gamma distributed traits; 2 transformed versions of the gamma trait (log 10 and rank-based inverse normal transformations); and trait Q1 provided by GAW 19. Each trait was tested with 313,340 SNVs. Tests of association were performed with simple linear regression and average type I error rates were determined for minor allele frequency classes. Rare SNVs (minor allele frequency < 0.05) showed inflated type I error rates for non-normally distributed traits that increased as the minor allele frequency decreased. The inflation of average type I error rates increased as the significance threshold decreased. Normally distributed traits did not show inflated type I error rates with respect to the minor allele frequency for rare SNVs. There was no consistent effect of transformation on the uniformity of the distribution of the location of SNVs with a type I error.

Allelic variance among ABO blood group genotypes in a population from the western region of Saudi Arabia.

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Mohamed, Abdularahman B O; Hindawi, Salwa Ibrahim; Al-Harthi, Sameer; Alam, Qamre; Alam, Mohammad Zubair; Haque, Absarul; Ahmad, Waseem; Damanhouri, Ghazi A

2016-12-01

Characterization of the ABO blood group at the phenotype and genotype levels is clinically essential for transfusion, forensics, and population studies. This study elucidated ABO phenotypes and genotypes, and performed an evaluation of their distribution in individuals from the western region of Saudi Arabia. One-hundred and seven samples underwent standard serological techniques for ABO blood group phenotype analysis. ABO alleles and genotypes were identified using multiplex polymerase chain reaction, and electrophoretic analysis was performed to evaluate the highly polymorphic ABO locus. A phenotype distribution of 37.4%, 30.8%, 24.3%, and 7.5% was found for blood groups O, A, B, and AB respectively in our study cohort. Genotype analysis identified 10 genotype combinations with the O01/O02 and A102/O02 genotypes being the most frequent with frequencies of 33.6% and 14.95%, respectively. Common genotypes such as A101/A101 , A101/A102 , A101/B101 , B101/B101 , and O01/O01 were not detected. Similarly, the rare genotypes, cis-AB01/O02 , cis-AB01/O01 , and cis-AB01/A102 were not found in our cohort. The most frequently observed allele was O02 (35.98%) followed by the A102 allele (17.76%). Furthermore, our findings are discussed in reference to ABO allele and genotype frequencies found in other ethnic groups. The study has a significant implication on the management of blood bank and transfusion services in Saudi Arabian patients.

On positivity of time-frequency distributions.

NARCIS (Netherlands)

Janssen, A.J.E.M.; Claasen, T.A.C.M.

1985-01-01

Consideration is given to the problem of how to regard the fundamental impossibility with time-frequency energy distributions of Cohen's class always to be nonnegative and, at the same time, to have correct marginal distributions. It is shown that the Wigner distribution is the only member of a

Associations of HLA-A, HLA-B and HLA-C Alleles Frequency with Prevalence of Herpes Simplex Virus Infections and Diseases Across Global Populations: Implication for the Development of an Universal CD8+ T-Cell Epitope-Based Vaccine

Science.gov (United States)

Samandary, Sarah; Kridane-Miledi, Hédia; Sandoval, Jacqueline S.; Choudhury, Zareen; Langa-Vives, Francina; Spencer, Doran; Chentoufi, Aziz A.; Lemonnier, François A.; BenMohamed, Lbachir

2014-01-01

A significant portion of the world’s population is infected with herpes simplex virus type 1 and/or type 2 (HSV-1 and/or HSV-2), that cause a wide range of diseases including genital herpes, oro-facial herpes, and the potentially blinding ocular herpes. While the global prevalence and distribution of HSV-1 and HSV-2 infections cannot be exactly established, the general trends indicate that: (i) HSV-1 infections are much more prevalent globally than HSV-2; (ii) Over half billion people worldwide are infected with HSV-2; (iii) the sub-Saharan African populations account for a disproportionate burden of genital herpes infections and diseases; (iv) the dramatic differences in the prevalence of herpes infections between regions of the world appear to be associated with differences in the frequencies of human leukocyte antigen (HLA) alleles. The present report: (i) analyzes the prevalence of HSV-1 and HSV-2 infections across various regions of the world; (ii) analyzes potential associations of common HLA-A, HLA-B and HLA-C alleles with the prevalence of HSV-1 and HSV-2 infections in the Caucasoid, Oriental, Hispanic and Black major populations; and (iii) discusses how our recently developed HLA-A, HLA-B, and HLA-C transgenic/H-2 class I null mice will help validate HLA/herpes prevalence associations. Overall, high prevalence of herpes infection and disease appears to be associated with high frequency of HLA-A*24, HLA-B*27, HLA-B*53 and HLA-B*58 alleles. In contrast, low prevalence of herpes infection and disease appears to be associated with high frequency of HLA-B*44 allele. The finding will aid in developing a T-cell epitope-based universal herpes vaccine and immunotherapy. PMID:24798939

Deleterious alleles in the human genome are on average younger than neutral alleles of the same frequency

NARCIS (Netherlands)

Kiezun, Adam; Pulit, Sara L.; Francioli, Laurent C.; van Dijk, Freerk; Swertz, Morris; Boomsma, Dorret I.; van Duijn, Cornelia M.; Slagboom, P. Eline; van Ommen, G. J. B.; Wijmenga, Cisca; de Bakker, Paul I. W.; Sunyaev, Shamil R.

Large-scale population sequencing studies provide a complete picture of human genetic variation within the studied populations. A key challenge is to identify, among the myriad alleles, those variants that have an effect on molecular function, phenotypes, and reproductive fitness. Most non-neutral

Correcting length-frequency distributions for imperfect detection

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Breton, André R.; Hawkins, John A.; Winkelman, Dana L.

2013-01-01

Sampling gear selects for specific sizes of fish, which may bias length-frequency distributions that are commonly used to assess population size structure, recruitment patterns, growth, and survival. To properly correct for sampling biases caused by gear and other sources, length-frequency distributions need to be corrected for imperfect detection. We describe a method for adjusting length-frequency distributions when capture and recapture probabilities are a function of fish length, temporal variation, and capture history. The method is applied to a study involving the removal of Smallmouth Bass Micropterus dolomieu by boat electrofishing from a 38.6-km reach on the Yampa River, Colorado. Smallmouth Bass longer than 100 mm were marked and released alive from 2005 to 2010 on one or more electrofishing passes and removed on all other passes from the population. Using the Huggins mark–recapture model, we detected a significant effect of fish total length, previous capture history (behavior), year, pass, year×behavior, and year×pass on capture and recapture probabilities. We demonstrate how to partition the Huggins estimate of abundance into length frequencies to correct for these effects. Uncorrected length frequencies of fish removed from Little Yampa Canyon were negatively biased in every year by as much as 88% relative to mark–recapture estimates for the smallest length-class in our analysis (100–110 mm). Bias declined but remained high even for adult length-classes (≥200 mm). The pattern of bias across length-classes was variable across years. The percentage of unadjusted counts that were below the lower 95% confidence interval from our adjusted length-frequency estimates were 95, 89, 84, 78, 81, and 92% from 2005 to 2010, respectively. Length-frequency distributions are widely used in fisheries science and management. Our simple method for correcting length-frequency estimates for imperfect detection could be widely applied when mark–recapture data

Mutation intolerant genes and targets of FMRP are enriched for nonsynonymous alleles in schizophrenia.

Science.gov (United States)

Leonenko, Ganna; Richards, Alexander L; Walters, James T; Pocklington, Andrew; Chambert, Kimberly; Al Eissa, Mariam M; Sharp, Sally I; O'Brien, Niamh L; Curtis, David; Bass, Nicholas J; McQuillin, Andrew; Hultman, Christina; Moran, Jennifer L; McCarroll, Steven A; Sklar, Pamela; Neale, Benjamin M; Holmans, Peter A; Owen, Michael J; Sullivan, Patrick F; O'Donovan, Michael C

2017-10-01

Risk of schizophrenia is conferred by alleles occurring across the full spectrum of frequencies from common SNPs of weak effect through to ultra rare alleles, some of which may be moderately to highly penetrant. Previous studies have suggested that some of the risk of schizophrenia is attributable to uncommon alleles represented on Illumina exome arrays. Here, we present the largest study of exomic variation in schizophrenia to date, using samples from the United Kingdom and Sweden (10,011 schizophrenia cases and 13,791 controls). Single variants, genes, and gene sets were analyzed for association with schizophrenia. No single variant or gene reached genome-wide significance. Among candidate gene sets, we found significant enrichment for rare alleles (minor allele frequency [MAF] schizophrenia by excluding a role for uncommon exomic variants (0.01 ≤ MAF ≥ 0.001) that confer a relatively large effect (odds ratio [OR] > 4). We also show risk alleles within this frequency range exist, but confer smaller effects and should be identified by larger studies. © 2017 Wiley Periodicals, Inc.

Rapid genotyping assays for the 4-base pair deletion of canine MDR1/ABCB1 gene and low frequency of the mutant allele in Border Collie dogs.

Science.gov (United States)

Mizukami, Keijiro; Chang, Hye-Sook; Yabuki, Akira; Kawamichi, Takuji; Hossain, Mohammad A; Rahman, Mohammad M; Uddin, Mohammad M; Yamato, Osamu

2012-01-01

P-glycoprotein, encoded by the MDR1 or ABCB1 gene, is an integral component of the blood-brain barrier as an efflux pump for xenobiotics crucial in limiting drug uptake into the central nervous system. Dogs homozygous for a 4-base pair deletion of the canine MDR1 gene show altered expression or function of P-glycoprotein, resulting in neurotoxicosis after administration of the substrate drugs. In the present study, the usefulness of microchip electrophoresis for genotyping assays detecting this deletion mutation was evaluated. Mutagenically separated polymerase chain reaction (MS-PCR) and real-time PCR assays were newly developed and evaluated. Furthermore, a genotyping survey was carried out in a population of Border Collies dogs in Japan to determine the allele frequency in this breed. Microchip electrophoresis showed advantages in detection sensitivity and time saving over other modes of electrophoresis. The MS-PCR assay clearly discriminated all genotypes. Real-time PCR assay was most suitable for a large-scale survey due to its high throughput and rapidity. The genotyping survey demonstrated that the carrier and mutant allele frequencies were 0.49% and 0.25%, respectively, suggesting that the mutant allele frequency in Border Collies is markedly low compared to that in the susceptible dog breeds such as rough and smooth Collies.

Positivity of time-frequency distribution functions

NARCIS (Netherlands)

Janssen, A.J.E.M.

1988-01-01

This paper deals with the question how various 'natural' conditions posed on time-frequency distribution functions prevent them to be nonnegative everywhere for all signals. The attention is restricted mainly to distribution functions that involve the signal bilinearly. This paper summarizes and

Diversity Outbred Mice at 21: Maintaining Allelic Variation in the Face of Selection

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Elissa J. Chesler

2016-12-01

Full Text Available Multi-parent populations (MPPs capture and maintain the genetic diversity from multiple inbred founder strains to provide a resource for high-resolution genetic mapping through the accumulation of recombination events over many generations. Breeding designs that maintain a large effective population size with randomized assignment of breeders at each generation can minimize the impact of selection, inbreeding, and genetic drift on allele frequencies. Small deviations from expected allele frequencies will have little effect on the power and precision of genetic analysis, but a major distortion could result in reduced power and loss of important functional alleles. We detected strong transmission ratio distortion in the Diversity Outbred (DO mouse population on chromosome 2, caused by meiotic drive favoring transmission of the WSB/EiJ allele at the R2d2 locus. The distorted region harbors thousands of polymorphisms derived from the seven non-WSB founder strains and many of these would be lost if the sweep was allowed to continue. To ensure the utility of the DO population to study genetic variation on chromosome 2, we performed an artificial selection against WSB/EiJ alleles at the R2d2 locus. Here, we report that we have purged the WSB/EiJ allele from the drive locus while preserving WSB/EiJ alleles in the flanking regions. We observed minimal disruption to allele frequencies across the rest of the autosomal genome. However, there was a shift in haplotype frequencies of the mitochondrial genome and an increase in the rate of an unusual sex chromosome aneuploidy. The DO population has been restored to genome-wide utility for genetic analysis, but our experience underscores that vigilant monitoring of similar genetic resource populations is needed to ensure their long-term utility.

Frequencies and ethnic distribution of ABO and Rh(D) blood groups in Mauritania: results of first nationwide study.

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Hamed, C T; Bollahi, M A; Abdelhamid, I; Med Mahmoud, M A; Ba, B; Ghaber, S; Habti, N; Houmeida, A

2012-04-01

There is no data available on the ABO/Rh(D) frequencies in the Mauritanian population. We retrospectively analysed records of a 5-year database that contained ABO/Rh phenotype and ethnic origin of 10 116 volunteers giving blood at the national blood transfusion centre to derive the frequencies of ABO/Rh(D) groups in the Mauritanian population. The two race categories in the country and their sub-ethnic groups: the Moors (whites and black) and the black Africans (Pulhars, Soninkes and Wolof) were included in this study. Globally, group O had the highest frequency (49.10%) followed by A (28.28%), B (18.56%) and AB (4.05%). This order more common in North African populations was found in four of the five ethnic groups composing our population. Allele frequencies were, respectively, 70.20%, 17.74% and 12.04% giving the same order of O > A > B. We observed no significant variation in these frequencies between the different ethnic groups. Rhesus study showed that with a percentage of 94.23% Rh(D) positive is by far the most prevalent, while Rh(D) negative is present only in 5.77% of the total population. This frequency distribution supports the mixed-race composition of the Mauritanian population. © 2011 Blackwell Publishing Ltd.

Angiotensin-converting enzyme (ACE) alleles in the Quechua, a high altitude South American native population.

Science.gov (United States)

Rupert, J L; Devine, D V; Monsalve, M V; Hochachka, P W

1999-01-01

Recently it was reported that an allelic variant of the gene encoding angiotensin-converting enzyme (ACE) was significantly over-represented in a cohort of elite British mountaineers. It was proposed that this may be evidence for a specific genetic factor influencing the human capacity for physical performance. The implication that this allele could enhance performance at high altitude prompted us to determine its frequency in Quechua speaking natives living at altitudes greater than 3000m on the Andean Altiplano in South America. We found that the frequency of the putative performance allele in the Quechuas, although significantly higher than in Caucasians, was not different from lowland Native American populations. This observation suggests that, although the higher frequency of the 'performance allele' may have facilitated the migration of the ancestral Quechua to the highlands, the ACE insertion allele has not been subsequently selected for in this high altitude population.

Tri-allelic SNP markers enable analysis of mixed and degraded DNA samples.

Science.gov (United States)

Westen, Antoinette A; Matai, Anuska S; Laros, Jeroen F J; Meiland, Hugo C; Jasper, Mandy; de Leeuw, Wiljo J F; de Knijff, Peter; Sijen, Titia

2009-09-01

For the analysis of degraded DNA in disaster victim identification (DVI) and criminal investigations, single nucleotide polymorphisms (SNPs) have been recognized as promising markers mainly because they can be analyzed in short sized amplicons. Most SNPs are bi-allelic and are thereby ineffective to detect mixtures, which may lead to incorrect genotyping. We developed an algorithm to find non-binary (i.e. tri-allelic or tetra-allelic) SNPs in the NCBI dbSNP database. We selected 31 potential tri-allelic SNPs with a minor allele frequency of at least 10%. The tri-allelic nature was confirmed for 15 SNPs residing on 14 different chromosomes. Multiplex SNaPshot assays were developed, and the allele frequencies of 16 SNPs were determined among 153 Dutch and 111 Netherlands Antilles reference samples. Using these multiplex SNP assays, the presence of a mixture of two DNA samples in a ratio up to 1:8 could be recognized reliably. Furthermore, we compared the genotyping efficiency of the tri-allelic SNP markers and short tandem repeat (STR) markers by analyzing artificially degraded DNA and DNA from 30 approximately 500-year-old bone and molar samples. In both types of degraded DNA samples, the larger sized STR amplicons failed to amplify whereas the tri-allelic SNP markers still provided valuable information. In conclusion, tri-allelic SNP markers are suited for the analysis of degraded DNA and enable the detection of a second DNA source in a sample.

Polymorphism discovery and allele frequency estimation using high-throughput DNA sequencing of target-enriched pooled DNA samples

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Mullen Michael P

2012-01-01

Full Text Available Abstract Background The central role of the somatotrophic axis in animal post-natal growth, development and fertility is well established. Therefore, the identification of genetic variants affecting quantitative traits within this axis is an attractive goal. However, large sample numbers are a pre-requisite for the identification of genetic variants underlying complex traits and although technologies are improving rapidly, high-throughput sequencing of large numbers of complete individual genomes remains prohibitively expensive. Therefore using a pooled DNA approach coupled with target enrichment and high-throughput sequencing, the aim of this study was to identify polymorphisms and estimate allele frequency differences across 83 candidate genes of the somatotrophic axis, in 150 Holstein-Friesian dairy bulls divided into two groups divergent for genetic merit for fertility. Results In total, 4,135 SNPs and 893 indels were identified during the resequencing of the 83 candidate genes. Nineteen percent (n = 952 of variants were located within 5' and 3' UTRs. Seventy-two percent (n = 3,612 were intronic and 9% (n = 464 were exonic, including 65 indels and 236 SNPs resulting in non-synonymous substitutions (NSS. Significant (P ® MassARRAY. No significant differences (P > 0.1 were observed between the two methods for any of the 43 SNPs across both pools (i.e., 86 tests in total. Conclusions The results of the current study support previous findings of the use of DNA sample pooling and high-throughput sequencing as a viable strategy for polymorphism discovery and allele frequency estimation. Using this approach we have characterised the genetic variation within genes of the somatotrophic axis and related pathways, central to mammalian post-natal growth and development and subsequent lactogenesis and fertility. We have identified a large number of variants segregating at significantly different frequencies between cattle groups divergent for calving

Human leukocyte antigen class II susceptibility conferring alleles among non-insulin dependent diabetes mellitus patients

International Nuclear Information System (INIS)

Tipu, H.N.; Ahmed, T.A.; Bashir, M.M.

2010-01-01

To determine the frequency of Human Leukocyte Antigen (HLA) class II susceptibility conferring alleles among type 2 Diabetes mellitus patients, in comparison with healthy controls. Cross-sectional comparative study. Patients with non-insulin dependent Diabetes mellitus meeting World Health Organization criteria were studied. These were compared with age and gender matched healthy control subjects. For each subject (patients as well as controls), DNA was extracted from ethylene diamine tetra-acetate sample and HLA class II DRB1 typing was carried out at allele group level (DRB1*01-DRB1*16) by sequence specific primers. Human leukocyte antigen DRB1 type was determined by agarose gel electrophoresis and results were recorded. Frequencies were determined as number of an allele divided by total number of alleles per group; p-value was computed using Pearson's chi-square test. Among the 100 patients, there were 63 males and 37 females with 68 controls. A total of 13 different HLA DRB1 alleles were detected, with DRB1*15 being the commonest in both the groups. The allele DRB1*13 had statistically significant higher frequency in patient group as compared to controls (p 0.005). HLA DRB1*13 was found with a significantly increased frequency in non-insulin dependent Diabetes mellitus. (author)

Frequency of the MDR1 mutant allele associated with multidrug sensitivity in dogs from Brazil

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Monobe MM

2015-04-01

Full Text Available Marina M Monobe,1 João P Araujo Junior,2 Kari V Lunsford,3 Rodrigo C Silva,4 Camilo Bulla41Department of Veterinary Clinics, School of Veterinary Medicine and Animal Science, 2Department of Microbiology and Immunology, Biosciences Institute, Sao Paulo State University (UNESP, Botucatu, Brazil; 3Department of Clinical Sciences and Animal Health Center, 4Department of Pathobiology and Population Medicine, College of Veterinary Medicine, Mississippi State University, Mississippi, MS, USAAbstract: To date, a 4-bp deletion in the MDR1 gene has been detected in more than ten dog breeds, as well as in mixed breed dogs, in several countries, however information regarding this mutation in dogs from Brazil is lacking. For this reason, 103 Collies, 77 Border Collies, 76 Shetland Sheepdogs, 20 Old English Sheepdogs, 55 German Shepherds, 16 Australian Shepherds, and 53 Whippets from Brazil were screened for the presence of the mutation. The heterozygous mutated genotype, MDR1 (+/−, frequency found for Collies, Australian Shepherd, and Shetland Sheepdog was 50.5% (95% CI =41.1%–59.9%, 31.3% (95% CI =8.6%–53.2%, and 15.8% (95% CI =7.7%–23.9%, respectively. Homozygous mutated genotype, MDR1 (−/−, was detected only in Collies 35.9%. The MDR1 allele mutant frequency found for Collies, Australian Shepherd, and Shetland Sheepdog was 61.2% (95% CI =54.8%–67.5%, 15.6% (95% CI =3.1%–28.2%, and 7.9% (95% CI =3.7%–12.1%, respectively. Additionally, even free of the mutant allele, the maximum mutant prevalence (MMP in that population, with 95% CI, was 3.8%, 5.2%, 5.4%, and 13.8% for Border Collies, German Shepherds, Whippets, and Old English Sheepdogs, respectively. In this way, this information is important, not only for MDR1 genotype-based breeding programs and international exchange of breeding animals of predisposed breeds, but also for modification of drug therapy for breeds at risk.Keywords: P-glycoprotein, MDR1 mutation, ivermectin, dog, drug

HLA-Cw Allele Frequency in Definite Meniere’s Disease Compared to Probable Meniere’s Disease and Healthy Controls in an Iranian Sample

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Sasan Dabiri

2016-05-01

Full Text Available Introduction Several lines of evidence support the contribution of autoimmune mechanisms in the pathogenesis of Meniere’s disease. The aim of this study was determining the association between HLA-Cw Alleles in patients with definite Meniere’s disease and patients with probable Meniere’s disease and a control group.  Materials and Methods: HLA-Cw genotyping was performed in 23 patients with definite Meniere’s disease, 24 with probable Meniere’s disease, and 91 healthy normal subjects, using sequence specific primers polymerase chain reaction technique. The statistical analysis was performed using stata 8 software.  Results: There was a significant association between HLA-Cw*04 and HLA-Cw*16 in both definite and probable Meniere’s disease compared to normal healthy controls. We observed a significant difference in HLA-Cw*12 frequencies between patients with definite Meniere’s disease compared to patients with probable Meniere’s disease (P=0.04. The frequency of HLA-Cw*18 is significantly higher in healthy controls (P=0.002.  Conclusion: Our findings support the rule of HLA-Cw Alleles in both definite and probable Meniere’s disease. In addition, differences in HLA-Cw*12 frequency in definite and probable Meniere’s disease in our study’s population might indicate distinct immune and inflammatory mechanisms involved in each condition.

Correlation between carboxylesterase alleles and insecticide resistance in Culex pipiens complex from China

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Liu Yangyang

2011-12-01

Full Text Available Abstract Background In China, large amounts of chemical insecticides are applied in fields or indoors every year, directly or indirectly bringing selection pressure on vector mosquitoes. Culex pipiens complex has evolved to be resistant to all types of chemical insecticides, especially organophosphates, through carboxylesterases. Six resistant carboxylesterase alleles (Ester were recorded previously and sometimes co-existed in one field population, representing a complex situation for the evolution of Ester genes. Results In order to explore the evolutionary scenario, we analyzed the data from an historical record in 2003 and a recent investigation on five Culex pipiens pallens populations sampled from north China in 2010. Insecticide bioassays showed that these five populations had high resistance to pyrethroids, medium resistance to organophosphates, and low resistance to carbamates. Six types of Ester alleles, EsterB1, Ester2, Ester8, Ester9, EsterB10, and Ester11 were identified, and the overall pattern of their frequencies in geographic distribution was consistent with the report seven years prior to this study. Statistical correlation analysis indicated that Ester8 and Ester9 positively correlated with resistance to four insecticides, and EsterB10 to one insecticide. The occurrences of these three alleles were positively correlated, while the occurrence of EsterB1 was negatively correlated with Ester8, indicating an allelic competition. Conclusion Our analysis suggests that one insecticide can select multiple Ester alleles and one Ester allele can work on multiple insecticides. The evolutionary scenario of carboxylesterases under insecticide selection is possibly "one to many".

HLA-DRB1 alleles in four Amerindian populations from Argentina and Paraguay

Science.gov (United States)

2009-01-01

The major histocompatibility complex (MHC) is one of the biological systems of major polymorphisms. The study of HLA class II variability has allowed the identification of several alleles that are characteristic to Amerindian populations, and it is an excellent tool to define the relations and biological affinities among them. In this work, we analyzed the allelic distribution of the HLA-DRB1 class II locus in four Amerindian populations: Mapuche (n = 34) and Tehuelche (n = 23) from the Patagonian region of Argentina, and Wichi SV (n = 24) and Lengua (n = 17) from the Argentinean and Paraguayan Chaco regions, respectively. In all of these groups, relatively high frequencies of Amerindian HLA-DRB1 alleles were observed (DRB1*0403, DRB1*0407, DRB1*0411, DRB1*0417, DRB1*0802, DRB1*0901, DRB1*1402, DRB1*1406 and DRB1*1602). However, we also detected the presence of non-Amerindian variants in Mapuche (35%) and Tehuelche (22%). We compared our data with those obtained in six indigenous groups of the Argentinean Chaco region and in a sample from Buenos Aires City. The genetic distance dendrogram showed a clear-cut division between the Patagonian and Chaco populations, which formed two different clusters. In spite of their linguistic differences, it can be inferred that the biological affinities observed are in concordance with the geographic distributions and interethnic relations established among the groups studied. PMID:21637670

HLA-DRB1 allele association with rheumatoid arthritis susceptibility and severity in Syria.

Science.gov (United States)

Mourad, Jamil; Monem, Fawza

2013-02-01

Rheumatoid arthritis (RA) is a complex multifactorial chronic disease. The importance of human leukocyte antigen as a major genetic risk factor for RA was studied worldwide. Although it is widely distributed in different Syrian areas, studies of human leukocyte antigen (HLA) alleles' role are absent. The aim of our study was to determine the association of HLA-DRB1 alleles with the susceptibility and severity of RA in Syria. Eighty-six RA patients and 200 healthy controls from Syria were genotyped using polymerase chain reaction with sequence-specific primer (PCR-SSP). Anti-CCP antibodies were measured by ELISA. Rheumatoid factor (RF), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and disease activity score 28 (DAS-28) values were obtained from patients' medical records. DAS-28 was used to assess the clinical severity of the patients. The HLA-DRB1*01, *04, and *10 frequencies showed a strong association with the disease susceptibility (OR = 2.29, 95% CI = 1.11-4.75, P = 0.022; OR = 3.16, 95% CI = 2.0 -4.8, P < 0.0001; OR = 2.43, 95% CI = 1.07-5.51, P = 0.029 respectively), while the frequencies of HLA-DRB1*11, and *13 were significantly lower in RA patients than in controls (OR = 0.49, 95% CI = 0.3-0.8, P = 0.004; OR = 0.32, 95% CI = 0.15-0.69, P = 0.002, respectively). The other HLA-DRB1 alleles showed no significant difference. The frequency of anti-CCP antibodies was higher in shared epitope (SE) positive patients compared with SE-negative patients (OR = 5.5, 95% CI = 2-15.1, P = 0.00054). DAS-28 of RA patients didn't show significant difference between the SE negative and the SE positive groups. Our results indicate that HLA-DRB1*01, *04, and *10 alleles are related with RA, while HLA-DRB1*11 and *13 protect against RA in the Syrian population.

A population frequency analysis of the FABP2 gene polymorphism

African Journals Online (AJOL)

salah

DNA was extracted from blood samples for genotype analysis. A PCR-RFLP ... Thr54 genotype. The frequencies of the allele Ala54 and the allele Thr54 of the .... Table 2: Genotype percentages and allele frequencies of FABP2 polymorphism in various ethnic groups. Study Group (n). Genotype %. Allele frequency. P. (vs.

Allele Age Under Non-Classical Assumptions is Clarified by an Exact Computational Markov Chain Approach.

Science.gov (United States)

De Sanctis, Bianca; Krukov, Ivan; de Koning, A P Jason

2017-09-19

Determination of the age of an allele based on its population frequency is a well-studied problem in population genetics, for which a variety of approximations have been proposed. We present a new result that, surprisingly, allows the expectation and variance of allele age to be computed exactly (within machine precision) for any finite absorbing Markov chain model in a matter of seconds. This approach makes none of the classical assumptions (e.g., weak selection, reversibility, infinite sites), exploits modern sparse linear algebra techniques, integrates over all sample paths, and is rapidly computable for Wright-Fisher populations up to N e  = 100,000. With this approach, we study the joint effect of recurrent mutation, dominance, and selection, and demonstrate new examples of "selective strolls" where the classical symmetry of allele age with respect to selection is violated by weakly selected alleles that are older than neutral alleles at the same frequency. We also show evidence for a strong age imbalance, where rare deleterious alleles are expected to be substantially older than advantageous alleles observed at the same frequency when population-scaled mutation rates are large. These results highlight the under-appreciated utility of computational methods for the direct analysis of Markov chain models in population genetics.

Entropy-based derivation of generalized distributions for hydrometeorological frequency analysis

Science.gov (United States)

Chen, Lu; Singh, Vijay P.

2018-02-01

Frequency analysis of hydrometeorological and hydrological extremes is needed for the design of hydraulic and civil infrastructure facilities as well as water resources management. A multitude of distributions have been employed for frequency analysis of these extremes. However, no single distribution has been accepted as a global standard. Employing the entropy theory, this study derived five generalized distributions for frequency analysis that used different kinds of information encoded as constraints. These distributions were the generalized gamma (GG), the generalized beta distribution of the second kind (GB2), and the Halphen type A distribution (Hal-A), Halphen type B distribution (Hal-B) and Halphen type inverse B distribution (Hal-IB), among which the GG and GB2 distribution were previously derived by Papalexiou and Koutsoyiannis (2012) and the Halphen family was first derived using entropy theory in this paper. The entropy theory allowed to estimate parameters of the distributions in terms of the constraints used for their derivation. The distributions were tested using extreme daily and hourly rainfall data. Results show that the root mean square error (RMSE) values were very small, which indicated that the five generalized distributions fitted the extreme rainfall data well. Among them, according to the Akaike information criterion (AIC) values, generally the GB2 and Halphen family gave a better fit. Therefore, those general distributions are one of the best choices for frequency analysis. The entropy-based derivation led to a new way for frequency analysis of hydrometeorological extremes.

Optimizing Power–Frequency Droop Characteristics of Distributed Energy Resources

Energy Technology Data Exchange (ETDEWEB)

Guggilam, Swaroop S.; Zhao, Changhong; Dall Anese, Emiliano; Chen, Yu Christine; Dhople, Sairaj V.

2018-05-01

This paper outlines a procedure to design power-frequency droop slopes for distributed energy resources (DERs) installed in distribution networks to optimally participate in primary frequency response. In particular, the droop slopes are engineered such that DERs respond in proportion to their power ratings and they are not unfairly penalized in power provisioning based on their location in the distribution network. The main contribution of our approach is that a guaranteed level of frequency regulation can be guaranteed at the feeder head, while ensuring that the outputs of individual DERs conform to some well-defined notion of fairness. The approach we adopt leverages an optimization-based perspective and suitable linearizations of the power-flow equations to embed notions of fairness and information regarding the physics of the power flows within the distribution network into the droop slopes. Time-domain simulations from a differential algebraic equation model of the 39-bus New England test-case system augmented with three instances of the IEEE 37-node distribution-network with frequency-sensitive DERs are provided to validate our approach.

Global Earthquake Hazard Frequency and Distribution

Data.gov (United States)

National Aeronautics and Space Administration — Global Earthquake Hazard Frequency and Distribution is a 2.5 minute grid utilizing Advanced National Seismic System (ANSS) Earthquake Catalog data of actual...

Modeling coverage gaps in haplotype frequencies via Bayesian inference to improve stem cell donor selection.

Science.gov (United States)

Louzoun, Yoram; Alter, Idan; Gragert, Loren; Albrecht, Mark; Maiers, Martin

2018-05-01

Regardless of sampling depth, accurate genotype imputation is limited in regions of high polymorphism which often have a heavy-tailed haplotype frequency distribution. Many rare haplotypes are thus unobserved. Statistical methods to improve imputation by extending reference haplotype distributions using linkage disequilibrium patterns that relate allele and haplotype frequencies have not yet been explored. In the field of unrelated stem cell transplantation, imputation of highly polymorphic human leukocyte antigen (HLA) genes has an important application in identifying the best-matched stem cell donor when searching large registries totaling over 28,000,000 donors worldwide. Despite these large registry sizes, a significant proportion of searched patients present novel HLA haplotypes. Supporting this observation, HLA population genetic models have indicated that many extant HLA haplotypes remain unobserved. The absent haplotypes are a significant cause of error in haplotype matching. We have applied a Bayesian inference methodology for extending haplotype frequency distributions, using a model where new haplotypes are created by recombination of observed alleles. Applications of this joint probability model offer significant improvement in frequency distribution estimates over the best existing alternative methods, as we illustrate using five-locus HLA frequency data from the National Marrow Donor Program registry. Transplant matching algorithms and disease association studies involving phasing and imputation of rare variants may benefit from this statistical inference framework.

Novel rapid genotyping assays for neuronal ceroid lipofuscinosis in Border Collie dogs and high frequency of the mutant allele in Japan.

Science.gov (United States)

Mizukami, Keijiro; Chang, Hye-Sook; Yabuki, Akira; Kawamichi, Takuji; Kawahara, Natsuko; Hayashi, Daisuke; Hossain, Mohammad A; Rahman, Mohammad M; Uddin, Mohammad M; Yamato, Osamu

2011-11-01

Neuronal ceroid lipofuscinosis (NCL) constitutes a group of recessively inherited lysosomal storage diseases that primarily affect neuronal cells. Such diseases share certain clinical and pathologic features in human beings and animals. Neuronal ceroid lipofuscinosis in Border Collie dogs was first detected in Australia in the 1980s, and the pathogenic mutation was shown to be a nonsense mutation (c.619C>T) in exon 4 in canine CLN5 gene. In the present study, novel rapid genotyping assays including polymerase chain reaction (PCR)-restriction fragment length polymorphism, PCR primer-induced restriction analysis, mutagenically separated PCR, and real-time PCR with TaqMan minor groove binder probes, were developed. The utility of microchip electrophoresis was also evaluated. Furthermore, a genotyping survey was carried out in a population of Border Collies in Japan using these assays to determine the current allele frequency in Japan, providing information to control and prevent this disease in the next stage. All assays developed in the current study are available to discriminate these genotypes, and microchip electrophoresis showed a timesaving advantage over agarose gel electrophoresis. Of all assays, real-time PCR was the most suitable for large-scale examination because of its high throughput. The genotyping survey demonstrated that the carrier frequency was 8.1%. This finding suggested that the mutant allele frequency of NCL in Border Collies is high enough in Japan that measures to control and prevent the disease would be warranted. The genotyping assays developed in the present study could contribute to the prevention of NCL in Border Collies.

Global Drought Hazard Frequency and Distribution

Data.gov (United States)

National Aeronautics and Space Administration — Global Drought Hazard Frequency and Distribution is a 2.5 minute grid based upon the International Research Institute for Climate Prediction's (IRI) Weighted Anomaly...

Allele frequencies of 18 autosomal STR loci in the Uyghur population living in Kashgar Prefecture, Northwest China.

Science.gov (United States)

Zhang, Jian; Li, Zhenghui; Mo, Xiaoting; Ma, Wenhua; Zhang, Hantao; Lin, Ziqing; Ye, Jian

2018-03-10

There is currently no large population data-based data set in Kashgar Prefecture Uyghur. The allele frequencies of 18 autosomal short tandem repeat (STR) loci included in the DNATyper™ 19 kit were evaluated in 2600 Uyghur individuals living in Kashgar Prefecture, Northwest China. The values of combined power of discrimination (CPD) and combined probability of exclusion (CPE) of all 18 autosomal STR loci were 0.99999999999999999998235 and 0.99999998670, respectively. Phylogenetic analyses revealed that the Uyghur population has a closer relationship with the Xinjiang-Kazakh, Inner Mongolia-Mongolian, and other three Uyghur populations. In addition, our results are consistent with the hypothesis that Uyghur population is an admixture of Eastern Asian and European populations.

The frequency characteristics of medium voltage distribution system impedances

Directory of Open Access Journals (Sweden)

Liviu Emil Petrean

2009-10-01

Full Text Available In this paper we present the frequency characteristics of impedances involved in the electrical equivalent circuit of a large medium voltage distribution system. These impedances influence harmonics distortions propagation occurring due to the nonsinusoidal loads. We analyse the case of a 10 kV large urban distribution system which supplies industrial, commercial and residential customers. The influence of various parameters of the distribution network on the frequency characteristics are presented, in order to assess the interaction of harmonic distortion and distribution system network.

TRPV6 alleles do not influence prostate cancer progression

International Nuclear Information System (INIS)

Kessler, Thorsten; Wissenbach, Ulrich; Grobholz, Rainer; Flockerzi, Veit

2009-01-01

The transient receptor potential, subfamily V, member 6 (TRPV6) is a Ca 2+ selective cation channel. Several studies have shown that TRPV6 transcripts are expressed in locally advanced prostatic adenocarcinoma, metastatic and androgen-insensitive prostatic lesions but are undetectable in healthy prostate tissue and benign prostatic hyperplasia. Two allelic variants of the human trpv6 gene have been identified which are transcribed into two independent mRNAs, TRPV6a and TRPV6b. We now asked, whether the trpv6a allele is correlated with the onset of prostate cancer, with the Gleason score and the tumour stage. Genomic DNA of prostate cancer patients and control individuals was isolated from resections of prostatic adenocarcinomas and salivary fluid respectively. Genotyping of SNPs of the TRPV6 gene was performed by restriction length polymorphism or by sequencing analysis. RNA used for RT-PCR was isolated from prostate tissue. Data sets were analyzed by Chi-Square test. We first characterized in detail the five polymorphisms present in the protein coding exons of the trpv6 gene and show that these polymorphisms are coupled and are underlying the TRPV6a and the TRPV6b variants. Next we analysed the frequencies of the two TRPV6 alleles using genomic DNA from saliva samples of 169 healthy individuals. The homozygous TRPV6b genotype predominated with 86%, whereas no homozygous TRPV6a carriers could be identified. The International HapMap Project identified a similar frequency for an Utah based population whereas in an African population the a-genotype prevailed. The incidence of prostate cancer is several times higher in African populations than in non-African and we then investigated the TRPV6a/b frequencies in 141 samples of prostatic adenocarcinoma. The TRPV6b allele was found in 87% of the samples without correlation with Gleason score and tumour stage. Our results show that the frequencies of trpv6 alleles in healthy control individuals and prostate cancer patients

TRPV6 alleles do not influence prostate cancer progression.

Science.gov (United States)

Kessler, Thorsten; Wissenbach, Ulrich; Grobholz, Rainer; Flockerzi, Veit

2009-10-26

The transient receptor potential, subfamily V, member 6 (TRPV6) is a Ca(2+) selective cation channel. Several studies have shown that TRPV6 transcripts are expressed in locally advanced prostatic adenocarcinoma, metastatic and androgen-insensitive prostatic lesions but are undetectable in healthy prostate tissue and benign prostatic hyperplasia. Two allelic variants of the human trpv6 gene have been identified which are transcribed into two independent mRNAs, TRPV6a and TRPV6b. We now asked, whether the trpv6a allele is correlated with the onset of prostate cancer, with the Gleason score and the tumour stage. Genomic DNA of prostate cancer patients and control individuals was isolated from resections of prostatic adenocarcinomas and salivary fluid respectively. Genotyping of SNPs of the TRPV6 gene was performed by restriction length polymorphism or by sequencing analysis. RNA used for RT-PCR was isolated from prostate tissue. Data sets were analyzed by Chi-Square test. We first characterized in detail the five polymorphisms present in the protein coding exons of the trpv6 gene and show that these polymorphisms are coupled and are underlying the TRPV6a and the TRPV6b variants. Next we analysed the frequencies of the two TRPV6 alleles using genomic DNA from saliva samples of 169 healthy individuals. The homozygous TRPV6b genotype predominated with 86%, whereas no homozygous TRPV6a carriers could be identified. The International HapMap Project identified a similar frequency for an Utah based population whereas in an African population the a-genotype prevailed. The incidence of prostate cancer is several times higher in African populations than in non-African and we then investigated the TRPV6a/b frequencies in 141 samples of prostatic adenocarcinoma. The TRPV6b allele was found in 87% of the samples without correlation with Gleason score and tumour stage. Our results show that the frequencies of trpv6 alleles in healthy control individuals and prostate cancer patients

TRPV6 alleles do not influence prostate cancer progression

Directory of Open Access Journals (Sweden)

Flockerzi Veit

2009-10-01

Full Text Available Abstract Background The transient receptor potential, subfamily V, member 6 (TRPV6 is a Ca2+ selective cation channel. Several studies have shown that TRPV6 transcripts are expressed in locally advanced prostatic adenocarcinoma, metastatic and androgen-insensitive prostatic lesions but are undetectable in healthy prostate tissue and benign prostatic hyperplasia. Two allelic variants of the human trpv6 gene have been identified which are transcribed into two independent mRNAs, TRPV6a and TRPV6b. We now asked, whether the trpv6a allele is correlated with the onset of prostate cancer, with the Gleason score and the tumour stage. Methods Genomic DNA of prostate cancer patients and control individuals was isolated from resections of prostatic adenocarcinomas and salivary fluid respectively. Genotyping of SNPs of the TRPV6 gene was performed by restriction length polymorphism or by sequencing analysis. RNA used for RT-PCR was isolated from prostate tissue. Data sets were analyzed by Chi-Square test. Results We first characterized in detail the five polymorphisms present in the protein coding exons of the trpv6 gene and show that these polymorphisms are coupled and are underlying the TRPV6a and the TRPV6b variants. Next we analysed the frequencies of the two TRPV6 alleles using genomic DNA from saliva samples of 169 healthy individuals. The homozygous TRPV6b genotype predominated with 86%, whereas no homozygous TRPV6a carriers could be identified. The International HapMap Project identified a similar frequency for an Utah based population whereas in an African population the a-genotype prevailed. The incidence of prostate cancer is several times higher in African populations than in non-African and we then investigated the TRPV6a/b frequencies in 141 samples of prostatic adenocarcinoma. The TRPV6b allele was found in 87% of the samples without correlation with Gleason score and tumour stage. Conclusion Our results show that the frequencies of trpv6

Seasonally adjusted birth frequencies follow the Poisson distribution.

Science.gov (United States)

Barra, Mathias; Lindstrøm, Jonas C; Adams, Samantha S; Augestad, Liv A

2015-12-15

Variations in birth frequencies have an impact on activity planning in maternity wards. Previous studies of this phenomenon have commonly included elective births. A Danish study of spontaneous births found that birth frequencies were well modelled by a Poisson process. Somewhat unexpectedly, there were also weekly variations in the frequency of spontaneous births. Another study claimed that birth frequencies follow the Benford distribution. Our objective was to test these results. We analysed 50,017 spontaneous births at Akershus University Hospital in the period 1999-2014. To investigate the Poisson distribution of these births, we plotted their variance over a sliding average. We specified various Poisson regression models, with the number of births on a given day as the outcome variable. The explanatory variables included various combinations of years, months, days of the week and the digit sum of the date. The relationship between the variance and the average fits well with an underlying Poisson process. A Benford distribution was disproved by a goodness-of-fit test (p Poisson process when monthly and day-of-the-week variation is included. The frequency is highest in summer towards June and July, Friday and Tuesday stand out as particularly busy days, and the activity level is at its lowest during weekends.

ACTN3 allele frequency in humans covaries with global latitudinal gradient.

Directory of Open Access Journals (Sweden)

Scott M Friedlander

Full Text Available A premature stop codon in ACTN3 resulting in α-actinin-3 deficiency (the ACTN3 577XX genotype is common in humans and reduces strength, muscle mass, and fast-twitch fiber diameter, but increases the metabolic efficiency of skeletal muscle. Linkage disequilibrium data suggest that the ACTN3 R577X allele has undergone positive selection during human evolution. The allele has been hypothesized to be adaptive in environments with scarce resources where efficient muscle metabolism would be selected. Here we test this hypothesis by using recently developed comparative methods that account for evolutionary relatedness and gene flow among populations. We find evidence that the ACTN3 577XX genotype evolved in association with the global latitudinal gradient. Our results suggest that environmental variables related to latitudinal variation, such as species richness and mean annual temperature, may have influenced the adaptive evolution of ACTN3 577XX during recent human history.

Allele frequency present within the DYS635, DYS437, DYS448 ...

African Journals Online (AJOL)

Ejiro

2015-03-11

Mar 11, 2015 ... institute and courts of law. Key words: Allele ... individual identification and relatedness testing polymor- phic (Yamamoto et al. ... haplogroup an individual matches, STR analysis typically provides a person haplotype. Most tests on the Y chromosome examine between 12 and 67 STR markers. (Jobling et al.

Association between diabetes type 1 and DQB1 alleles in a case-control study conducted in Montevideo, Uruguay.

Science.gov (United States)

Mimbacas, Adriana; Pérez-Bravo, Francisco; Hidalgo, Pedro C; Javiel, Gerardo; Pisciottano, Carmen; Grignola, Rosario; Jorge, Ana María; Gallino, Juan Pablo; Gasagoite, Jackeline; Cardoso, Horacio

2003-03-31

We studied HLA DQB1 allele frequencies and the relative risk (RR) of various genotypes in 72 type 1 diabetic patients and 40 control individuals in Uruguay. This is a tri-racial (Caucasian, Black and Indo-American) mixed population. The products of the polymerase chain reaction amplifications were hybridized with oligonucleotides by allele-specific oligonucleotide reverse or dot blot methods. Significant differences between these two groups were observed only for allele DQB1*0302 (35%, RR = 7.34, P<0.001). The frequency of the alleles carrying a non-aspartic acid residue at position 57 was significantly higher in the diabetic patients (85 vs 53%, P<0.001). In contrast, the frequency of Asp alleles was negatively associated with type 1 diabetes (RR = 0.20, P<0.001). The genotype DQB1*0302/DQB1*0201 (33%, RR = 5.41, P<0.05) was positively associated with this disease. The genotype frequencies associated with type 1 diabetes in our population were significantly different from what is known for Caucasian and Black populations as well as compared with another admixed population, from Chile.

Frequency distributions from birth, death, and creation processes.

Science.gov (United States)

Bartley, David L; Ogden, Trevor; Song, Ruiguang

2002-01-01

The time-dependent frequency distribution of groups of individuals versus group size was investigated within a continuum approximation, assuming a simplified individual growth, death and creation model. The analogy of the system to a physical fluid exhibiting both convection and diffusion was exploited in obtaining various solutions to the distribution equation. A general solution was approximated through the application of a Green's function. More specific exact solutions were also found to be useful. The solutions were continually checked against the continuum approximation through extensive simulation of the discrete system. Over limited ranges of group size, the frequency distributions were shown to closely exhibit a power-law dependence on group size, as found in many realizations of this type of system, ranging from colonies of mutated bacteria to the distribution of surnames in a given population. As an example, the modeled distributions were successfully fit to the distribution of surnames in several countries by adjusting the parameters specifying growth, death and creation rates.

Genetic variation among the Mapuche Indians from the Patagonian region of Argentina: mitochondrial DNA sequence variation and allele frequencies of several nuclear genes.

Science.gov (United States)

Ginther, C; Corach, D; Penacino, G A; Rey, J A; Carnese, F R; Hutz, M H; Anderson, A; Just, J; Salzano, F M; King, M C

1993-01-01

DNA samples from 60 Mapuche Indians, representing 39 maternal lineages, were genetically characterized for (1) nucleotide sequences of the mtDNA control region; (2) presence or absence of a nine base duplication in mtDNA region V; (3) HLA loci DRB1 and DQA1; (4) variation at three nuclear genes with short tandem repeats; and (5) variation at the polymorphic marker D2S44. The genetic profile of the Mapuche population was compared to other Amerinds and to worldwide populations. Two highly polymorphic portions of the mtDNA control region, comprising 650 nucleotides, were amplified by the polymerase chain reaction (PCR) and directly sequenced. The 39 maternal lineages were defined by two or three generation families identified by the Mapuches. These 39 lineages included 19 different mtDNA sequences that could be grouped into four classes. The same classes of sequences appear in other Amerinds from North, Central, and South American populations separated by thousands of miles, suggesting that the origin of the mtDNA patterns predates the migration to the Americas. The mtDNA sequence similarity between Amerind populations suggests that the migration throughout the Americas occurred rapidly relative to the mtDNA mutation rate. HLA DRB1 alleles 1602 and 1402 were frequent among the Mapuches. These alleles also occur at high frequency among other Amerinds in North and South America, but not among Spanish, Chinese or African-American populations. The high frequency of these alleles throughout the Americas, and their specificity to the Americas, supports the hypothesis that Mapuches and other Amerind groups are closely related.(ABSTRACT TRUNCATED AT 250 WORDS)

Distribution of HIV-1 resistance-conferring polymorphic alleles SDF ...

Indian Academy of Sciences (India)

Polymorphic allelic variants of chemokine receptors CCR2 and CCR5, as well as of stromal-derived factor-1 SDF-1, the ligand for the chemokine receptor CXCR4, are known to have protective effects against HIV-1 infection and to be involved with delay in disease progression. We have studied the DNA polymorphisms at ...

The link between some alleles on human leukocyte antigen system and autism in children.

Science.gov (United States)

Mostafa, Gehan A; Shehab, Abeer A; Al-Ayadhi, Laila Y

2013-02-15

The reason behind the initiation of autoimmunity to brain in some patients with autism is not well understood. There is an association between some autoimmune disorders and specific alleles of human leukocyte antigen (HLA) system. Thus, we examined the frequency of some HLA-DRB1 alleles in 100 autistic children and 100 healthy matched-children by differential hybridization with sequence-specific oligonucleotide probes. The risk of association between acquisition or absence of these alleles and autism and also a history of autoimmune diseases in autistic relatives was studied. Autistic children had significantly higher frequency of HLA-DRB1*11 allele than controls (P<0.001). In contrast, autistic children had significantly lower frequency of HLA-DRB1*03 allele than controls (P<0.001). Acquisition of HLA-DRB1*011 and absence of HLA-DRB1*3 had significant risk for association with autism (odds ratio: 3.21 and 0.17, respectively; 95% CI: 1.65-6.31 and 0.06-0.45, respectively). HLA-DRB1*11 had a significant risk for association with a family history of autoimmunity in autistic children (odds ratio: 5.67; 95% CI: 2.07-16.3). In conclusions, the link of some HLA alleles to autism and to family history of autoimmunity indicates the possible contributing role of these alleles to autoimmunity in some autistic children. Despite a relatively small sample size, we are the first to report a probable protective association of HLA-DRB1*03 allele with autism. It warrants a replication study of a larger sample to validate the HLA-DRB1 genetic association with autism. This is important to determine whether therapeutic modulations of the immune function are legitimate avenues for novel therapy in selected cases of autism. Copyright © 2012 Elsevier B.V. All rights reserved.

Reducing Bias of Allele Frequency Estimates by Modeling SNP Genotype Data with Informative Missingness

Directory of Open Access Journals (Sweden)

Wan-Yu eLin

2012-06-01

Full Text Available The presence of missing single-nucleotide polymorphism (SNP genotypes is common in genetic data. For studies with low-density SNPs, the most commonly used approach to deal with genotype missingness is to simply remove the observations with missing genotypes from the analyses. This naïve method is straightforward but is appropriate only when the missingness is random. However, a given assay often has a different capability in genotyping heterozygotes and homozygotes, causing the phenomenon of ‘differential dropout’ in the sense that the missing rates of heterozygotes and homozygotes are different. In practice, differential dropout among genotypes exists in even carefully designed studies, such as the data from the HapMap project and the Wellcome Trust Case Control Consortium. In this study, we propose a statistical method to model the differential dropout among different genotypes. Compared with the naïve method, our method provides more accurate allele frequency estimates when the differential dropout is present. To demonstrate its practical use, we further apply our method to the HapMap data and a scleroderma data set.

Time-Frequency Distribution of Music based on Sparse Wavelet Packet Representations

DEFF Research Database (Denmark)

Endelt, Line Ørtoft

We introduce a new method for generating time-frequency distributions, which is particularly useful for the analysis of music signals. The method presented here is based on $\\ell1$ sparse representations of music signals in a redundant wavelet packet dictionary. The representations are found using...... the minimization methods basis pursuit and best orthogonal basis. Visualizations of the time-frequency distribution are constructed based on a simplified energy distribution in the wavelet packet decomposition. The time-frequency distributions emphasizes structured musical content, including non-stationary content...

Damage Detection Based on Cross-Term Extraction from Bilinear Time-Frequency Distributions

Directory of Open Access Journals (Sweden)

Ma Yuchao

2014-01-01

Full Text Available Abundant damage information is implicated in the bilinear time-frequency distribution of structural dynamic signals, which could provide effective support for structural damage identification. Signal time-frequency analysis methods are reviewed, and the characters of linear time-frequency distribution and bilinear time-frequency distribution typically represented by the Wigner-Ville distribution are compared. The existence of the cross-term and its application in structural damage detection are demonstrated. A method of extracting the dominant term is proposed, which combines the short-time Fourier spectrum and Wigner-Ville distribution; then two-dimensional time-frequency transformation matrix is constructed and the complete cross-term is extracted finally. The distribution character of which could be applied to the structural damage identification. Through theoretical analysis, model experiment and numerical simulation of the girder structure, the change rate of cross-term amplitude is validated to identify the damage location and degree. The effectiveness of the cross-term of bilinear time-frequency distribution for damage detection is confirmed and the analytical method of damage identification used in structural engineering is available.

A WIDE DISTRIBUTION OF A NEW VRN-B1c ALLELE OF WHEAT TRITICUM AESTIVUM L. IN RUSSIA, UKRAINE AND ADJACENT REGIONS: A LINK WITH THE HEADING TIME AND ADAPTIVE POTENTIAL

Directory of Open Access Journals (Sweden)

Shcherban A.

2012-08-01

Full Text Available The adaptation of common wheat (T. aestivum L. to diverse environmental conditions is greatly under the control of genes involved in determination of vernalization response (Vrn-1 genes. It was found that the variation in common wheat heading time is affected not only by combination of Vrn-1 homoeoalleles but also by multiple alleles at a separate Vrn-1 locus. Previously, we described the Vrn-B1c allele from T.aestivum cv. 'Saratovskaya 29' and found significant differences in the structure of the first (1st intron of this allele when compared to another highly abundant Vrn-B1a allele, specifically, the deletion of 0.8 kb coupled with the duplication of 0.4 kb. We suggested that the changes in the intron 1 of Vrn-B1c allele caused earlier ear emergence in the near-isogenic line and cultivars, carrying this allele. In this study we investigate the distribution of the Vrn-B1c allele in a wide set of spring wheat cultivars from Russia, Ukraine and adjacent regions. The analysis revealed that 40% of Russian and 53% of Ukranian spring wheat cultivars contain the Vrn-B1c allele. The high distribution of the Vrn-B1c allele can be explained by a frequent using of 'Saratovskaya 29' in the breeding process inside the studied area. From the other hand, the predominance of the Vrn-B1c allele among cultivars cultivated in West Siberia and Kazakhstan may be due to the selective advantage of this allele for the region where there is a high risk of early fall frosts.

CYP3A4 allelic variants with amino acid substitutions in exons 7 and 12: evidence for an allelic variant with altered catalytic activity.

Science.gov (United States)

Sata, F; Sapone, A; Elizondo, G; Stocker, P; Miller, V P; Zheng, W; Raunio, H; Crespi, C L; Gonzalez, F J

2000-01-01

To determine the existence of mutant and variant CgammaP3A4 alleles in three racial groups and to assess functions of the variant alleles by complementary deoxyribonucleic acid (cDNA) expression. A bacterial artificial chromosome that contains the complete CgammaP3A4 gene was isolated and the exons and surrounding introns were directly sequenced to develop primers to polymerase chain reaction (PCR) amplify and sequence the gene from lymphocyte DNA. DNA samples from Chinese, black, and white subjects were screened. Mutating the affected amino acid in the wild-type cDNA and expressing the variant enzyme with use of the baculovirus system was used to functionally evaluate the variant allele having a missense mutation. To investigate the existence of mutant and variant CgammaP3A4 alleles in humans, all 13 exons and the 5'-flanking region of the human CgammaP3A4 gene in three racial groups were sequenced and four alleles were identified. An A-->G point mutation in the 5'-flanking region of the human CgammaP3A4 gene, designated CgammaP3A4*1B, was found in the three different racial groups. The frequency of this allele in a white population was 4.2%, whereas it was 66.7% in black subjects. The CgammaP3A4*1B allele was not found in Chinese subjects. A second variant allele, designated CgammaP3A4*2, having a Ser222Pro change, was found at a frequency of 2.7% in the white population and was absent in the black subjects and Chinese subjects analyzed. Baculovirus-directed cDNA expression revealed that the CYP3A4*2 P450 had a lower intrinsic clearance for the CYP3A4 substrate nifedipine compared with the wild-type enzyme but was not significantly different from the wild-type enzyme for testosterone 6beta-hydroxylation. Another rare allele, designated CgammaP3A4*3, was found in a single Chinese subject who had a Met445Thr change in the conserved heme-binding region of the P450. These are the first examples of potential function polymorphisms resulting from missense mutations in

Frequency of distribution of leptin receptor gene polymorphism in obstructive sleep apnea patients.

Science.gov (United States)

Popko, K; Gorska, E; Wasik, M; Stoklosa, A; Pływaczewski, R; Winiarska, M; Gorecka, D; Sliwinski, P; Demkow, U

2007-11-01

Leptin is an adipocyte-derived hormone regulating energy homeostasis and body weight. Leptin concentration is increased in patients with the obstructive sleep apnea syndrome (OSAS). Leptin receptor (LEPR) is a single transmembrane protein belonging to the superfamily of cytokine receptors related by a structure to the hemopoietin receptor family. The aim of the present study was to evaluate the frequency of distribution of leptin receptor gene polymorphism GLN223ARG in OSAS patients compared with healthy controls. The examined group included 179 subjects: 102 OSAS patients (74 men and 28 women) and 77 non-apneic controls (39 men and 38 women). Genomic DNA was isolated with the use of a column method and genotyping of DNA sequence variation was carried out by restriction enzyme analysis of PCR-amplified DNA. The results revealed a significant correlation between the polymorphism of LEPR and OSAS. Carriers of Arg allele in homozygotic genotype Arg/Arg and heterozygotic genotype Gln/Arg were more often obese and developed OSAS than the group of carriers of homozygotic Gln/Gln genotype. This tendency was observed in the whole examined population and in the group of obese women. We also found the highest levels of total cholesterol, LDL, HDL, and triglycerides in the group of homozygotic Arg/Arg genotype carriers, lower in heterozygotic Gln/Arg genotype carriers, and the lowest in the group of persons carring homozygotic Gln/Gln genotype. The presence of Arg allel seems linked to a higher risk of obesity and higher lipid levels in OSAS patients. OSAS may have a strong genetic basis due to the effects from a variety of genes including those for leptin receptor.

Genetic frequencies related to severe or profound sensorineural hearing loss in Inner Mongolia Autonomous Region

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Yongzhi Liu

Full Text Available Abstract The aim was to study the frequencies of common deafness-related mutations and their contribution to hearing loss in different regions of Inner Mongolia. A total of 738 deaf children were recruited from five different ethnic groups of Inner Mongolia, including Han Chinese (n=486, Mongolian (n=216, Manchurian (n=24, Hui (n=6 and Daur (n=6. Nine common mutations in four genes (GJB2, SLC26A4, GJB3 and mitochondrial MT-RNR1 gene were detected by allele-specific PCR and universal array. At least one mutated allele was detected in 282 patients. Pathogenic mutations were detected in 168 patients: 114 were homozygotes and 54 were compound heterozygotes. The 114 patients were carriers of only one mutated allele. The frequency of GJB2 variants in Han Chinese (21.0% was higher than that in Mongolians (16.7%, but not significantly different. On the other hand, the frequency of SLC26A4 variants in Han Chinese (14.8% was lower than that in Mongolians (19.4%, but also not significantly different. The frequency of patients with pathogenic mutations was different in Ulanqab (21.4%, Xilingol (40.0%, Chifeng (40.0%, Hulunbeier (30.0%, Hohhot (26.3%, and in Baotou (0%. In conclusion, the frequency of mutated alleles in deafness-related genes did not differ between Han Chinese and Mongolians. However, differences in the distribution of common deafness-related mutations were found among the investigated areas of Inner Mongolia.

Allelic frequencies of two microsatellite loci in four populations of brown trout (Salmo trutta)

OpenAIRE

EDIT VARDHAMI; ANILA HODA; ADIOLA BIBA; MANUELA GUALTIERI; MASSIMO MECATTI; AGIM REXHEPI

2014-01-01

Two microsatellite loci, Str60Inra and Ssa197, were PCR amplified on 30 individuals for each populations of brown trout (Salmo trutta). A total of 120 individuals were selected from rivers of the Florence province (Italy), Valbona and Cen (Albania), Lepenci (Kosovo). There were identified 32 different alleles for Str60Inra and 41 for the locus Ssa197. Mean number of alleles ranged from 9 (Cen) to 20.5 (Florence). The mean observed and expected heterosygosities values were 0.329 and 0.755, res...

Association of apolipoprotein E allele {epsilon}4 with late-onset sporadic Alzheimer`s disease

Energy Technology Data Exchange (ETDEWEB)

Lucotte, G.; David, F.; Berriche, S. [Regional Center of Neurogenetics, Reims (France)] [and others

1994-09-15

Apolipoprotein E, type {epsilon}4 allele (ApoE {epsilon}4), is associated with late-onset sporadic Alzheimer`s disease (AD) in French patients. The association is highly significant (0.45 AD versus 0.12 controls for {epsilon}4 allele frequencies). These data support the involvement of ApoE {epsilon}4 allele as a very important risk factor for the clinical expression of AD. 22 refs., 1 fig., 3 tabs.

The Adaptive Change of HLA-DRB1 Allele Frequencies Caused by Natural Selection in a Mongolian Population That Migrated to the South of China.

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Hao Sun

Full Text Available Pathogen-driven balancing selection determines the richness of human leukocyte antigen (HLA alleles. Changes in the pathogen spectrum may cause corresponding changes in HLA loci. Approximately 700 years ago, a Mongolian population moved from the north of China to the Yunnan region in the south of China. The pathogen spectrum in the south of China differs from that in the north. In this study, changes in the HLA genes in the Yunnan Mongolian population, as well as the underlying mechanism, were investigated. A sequence-based typing method (SBT was used to genotype HLA-DRB1 in 470 individuals from two Mongolian populations and another five ethnic groups. Meanwhile, 10 autosomal short tandem repeats (STRs were genotyped to assess the influence of genetic background on HLA-DRB1 frequencies. The frequencies of certain alleles changed significantly in the Mongolian population that migrated to Yunnan. For example, DRB1*12:02:01 increased from 6.1% to 35.4%. STR analysis excluded the possibility of a recent bottleneck and indicated that 50% of the genetic consistency between northern and southern Mongolians; Tajima's D value for HLA-DRB1 exon2 and dN/dS analysis showed that the HLA-DRB1 genes in both Mongolian populations were under balancing selection. However, the sites under natural selection changed. We proposed that the dramatically change of HLA frequencies in southern Mongolian was caused by a combination of inter-population gene flow and natural selection. Certain diseases specific to the south of China, such as malaria, may be the driving force behind the enhanced DRB1*12:02:01 frequency.

Peripheral subnuclear positioning suppresses Tcrb recombination and segregates Tcrb alleles from RAG2.

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Chan, Elizabeth A W; Teng, Grace; Corbett, Elizabeth; Choudhury, Kingshuk Roy; Bassing, Craig H; Schatz, David G; Krangel, Michael S

2013-11-26

Allelic exclusion requires that the two alleles at antigen-receptor loci attempt to recombine variable (V), diversity (D), and joining (J) gene segments [V(D)J recombination] asynchronously in nuclei of developing lymphocytes. It previously was shown that T-cell receptor β (Tcrb) alleles frequently and stochastically associate with the nuclear lamina and pericentromeric heterochromatin in CD4(-)CD8(-) thymocytes. Moreover, rearranged alleles were underrepresented at these locations. Here we used 3D immunofluorescence in situ hybridization to identify recently rearranged Tcrb alleles based on the accumulation of the DNA-repair protein 53BP1. We found that Tcrb alleles recombine asynchronously in double-negative thymocytes and that V(D)J recombination is suppressed on peripheral as compared with central Tcrb alleles. Moreover, the recombination events that did take place at the nuclear periphery preferentially occurred on Tcrb alleles that were partially dissociated from the nuclear lamina. To understand better the mechanism by which V(D)J recombination is suppressed at the nuclear periphery, we evaluated the subnuclear distribution of recombination-activating gene 2 (RAG2) protein. We found that RAG2 abundance was reduced at the nuclear periphery. Moreover, RAG2 was distributed differently from RNA polymerase II and histone H3K4 trimethylation. Our data suggest that the nuclear periphery suppresses V(D)J recombination, at least in part, by segregating Tcrb alleles from RAG proteins.

Similarity of Symbol Frequency Distributions with Heavy Tails

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Martin Gerlach

2016-04-01

Full Text Available Quantifying the similarity between symbolic sequences is a traditional problem in information theory which requires comparing the frequencies of symbols in different sequences. In numerous modern applications, ranging from DNA over music to texts, the distribution of symbol frequencies is characterized by heavy-tailed distributions (e.g., Zipf’s law. The large number of low-frequency symbols in these distributions poses major difficulties to the estimation of the similarity between sequences; e.g., they hinder an accurate finite-size estimation of entropies. Here, we show analytically how the systematic (bias and statistical (fluctuations errors in these estimations depend on the sample size N and on the exponent γ of the heavy-tailed distribution. Our results are valid for the Shannon entropy (α=1, its corresponding similarity measures (e.g., the Jensen-Shanon divergence, and also for measures based on the generalized entropy of order α. For small α’s, including α=1, the errors decay slower than the 1/N decay observed in short-tailed distributions. For α larger than a critical value α^{*}=1+1/γ≤2, the 1/N decay is recovered. We show the practical significance of our results by quantifying the evolution of the English language over the last two centuries using a complete α spectrum of measures. We find that frequent words change more slowly than less frequent words and that α=2 provides the most robust measure to quantify language change.

CYP2C9 polymorphism in patients with epilepsy: genotypic frequency analyzes andphenytoin adverse reactions correlation

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Carlos Alexandre Twardowschy

2011-04-01

Full Text Available OBJECTIVE: CYP2C9 is a major enzyme in human drug metabolism and the polymorphism observed in the corresponding gene may affect therapeutic outcome during treatment. The distribution of variant CYP2C9 alleles and prevalence of phenytoin adverse reactions were hereby investigated in a population of patients diagnosed with epilepsy. METHOD: Allele-specific PCR analysis was carried out in order to determine frequencies of the two most common variant alleles, CYP2C9*2 and CYP2C9*3 in genomic DNA isolated from 100 epileptic patients. We also analyzed the frequency of phenytoin adverse reactions among those different genotypes groups. The data was presented as mean±standard deviation. RESULTS: The mean age at enrollment was 39.6±10.3 years (range, 17-72 years and duration of epilepsy was 26.5±11.9 years (range 3-48 years. The mean age at epilepsy onset was 13.1±12.4 years (range, 1 month-62 years. Frequencies of CYP2C9*1 (84%, CYP2C9*2 (9% and CYP2C9*3 (7% were similar to other published reports. Phenytoin adverse reactions were usually mild and occurred in 15% patients, without correlation with the CYP2C9 polymorphism (p=0.34. CONCLUSION: Our findings indicate an overall similar distribution of the CYP2C9 alleles in a population of patients diagnosed with epilepsy in the South of Brazil, compared to other samples. This sample of phenytoin users showed no drug related adverse reactions and CYP2C9 allele type correlation. The role of CYP2C9 polymorphism influence on phenytoin adverse reaction remains to be determined since some literature evidence and our data found negative results.

The Impact of Collisions on the Ability to Detect Rare Mutant Alleles Using Barcode-Type Next-Generation Sequencing Techniques

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Jenna VanLiere Canzoniero

2017-07-01

Full Text Available Barcoding techniques are used to reduce error from next-generation sequencing, with applications ranging from understanding tumor subclone populations to detecting circulating tumor DNA. Collisions occur when more than one sample molecule is tagged by the same unique identifier (UID and can result in failure to detect very-low-frequency mutations and error in estimating mutation frequency. Here, we created computer models of barcoding technique, with and without amplification bias introduced by the UID, and analyzed the effect of collisions for a range of mutant allele frequencies (1e−6 to 0.2, number of sample molecules (10 000 to 1e7, and number of UIDs (4 10 -4 14 . Inability to detect rare mutant alleles occurred in 0% to 100% of simulations, depending on collisions and number of mutant molecules. Collisions also introduced error in estimating mutant allele frequency resulting in underestimation of minor allele frequency. Incorporating an understanding of the effect of collisions into experimental design can allow for optimization of the number of sample molecules and number of UIDs to minimize the negative impact on rare mutant detection and mutant frequency estimation.

Simple method of generating and distributing frequency-entangled qudits

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Jin, Rui-Bo; Shimizu, Ryosuke; Fujiwara, Mikio; Takeoka, Masahiro; Wakabayashi, Ryota; Yamashita, Taro; Miki, Shigehito; Terai, Hirotaka; Gerrits, Thomas; Sasaki, Masahide

2016-11-01

High-dimensional, frequency-entangled photonic quantum bits (qudits for d-dimension) are promising resources for quantum information processing in an optical fiber network and can also be used to improve channel capacity and security for quantum communication. However, up to now, it is still challenging to prepare high-dimensional frequency-entangled qudits in experiments, due to technical limitations. Here we propose and experimentally implement a novel method for a simple generation of frequency-entangled qudts with d\\gt 10 without the use of any spectral filters or cavities. The generated state is distributed over 15 km in total length. This scheme combines the technique of spectral engineering of biphotons generated by spontaneous parametric down-conversion and the technique of spectrally resolved Hong-Ou-Mandel interference. Our frequency-entangled qudits will enable quantum cryptographic experiments with enhanced performances. This distribution of distinct entangled frequency modes may also be useful for improved metrology, quantum remote synchronization, as well as for fundamental test of stronger violation of local realism.

Genotypic and allelic variability in CYP19A1 among populations of African and European ancestry.

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Athena Starlard-Davenport

Full Text Available CYP19A1 facilitates the bioconversion of estrogens from androgens. CYP19A1 intron single nucleotide polymorphisms (SNPs may alter mRNA splicing, resulting in altered CYP19A1 activity, and potentially influencing disease susceptibility. Genetic studies of CYP19A1 SNPs have been well documented in populations of European ancestry; however, studies in populations of African ancestry are limited. In the present study, ten 'candidate' intronic SNPs in CYP19A1 from 125 African Americans (AA and 277 European Americans (EA were genotyped and their frequencies compared. Allele frequencies were also compared with HapMap and ASW 1000 Genomes populations. We observed significant differences in the minor allele frequencies between AA and EA in six of the ten SNPs including rs10459592 (p<0.0001, rs12908960 (p<0.0001, rs1902584 (p = 0.016, rs2470144 (p<0.0001, rs1961177 (p<0.0001, and rs6493497 (p = 0.003. While there were no significant differences in allele frequencies between EA and CEU in the HapMap population, a 1.2- to 19-fold difference in allele frequency for rs10459592 (p = 0.004, rs12908960 (p = 0.0006, rs1902584 (p<0.0001, rs2470144 (p = 0.0006, rs1961177 (p<0.0001, and rs6493497 (p = 0.0092 was observed between AA and the Yoruba (YRI population. Linkage disequilibrium (LD blocks and haplotype clusters that is unique to the EA population but not AA was also observed. In summary, we demonstrate that differences in the allele frequencies of CYP19A1 intron SNPs are not consistent between populations of African and European ancestry. Thus, investigations into whether CYP19A1 intron SNPs contribute to variations in cancer incidence, outcomes and pharmacological response seen in populations of different ancestry may prove beneficial.

MICA diversity and linkage disequilibrium with HLA-B alleles in renal-transplant candidates in southern Brazil.

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Yamakawa, Roger Haruki; Saito, Patrícia Keiko; Gelmini, Geórgia Fernanda; da Silva, José Samuel; Bicalho, Maria da Graça; Borelli, Sueli Donizete

2017-01-01

The major histocompatibility complex (MHC) class I chain-related gene A (MICA) is located centromerically to the human leukocyte antigen (HLA)-B. The short distance between these loci in the MHC indicates the presence of linkage disequilibrium (LD). Similarly to the HLA, the MICA is highly polymorphic, and this polymorphism has not been well documented in different populations. In this study, we estimated the allelic frequencies of MICA and the linkage disequilibrium with HLA-B alleles in 346 renal-transplant candidates in southern Brazil. MICA and HLA were typed using the polymerase chain reaction-sequence-specific primer method (PCR-SSO), combined with the Luminex technology. A total of 19 MICA allele groups were identified. The most frequent allele groups were MICA*008 (21.6%), MICA*002 (17.0%) and MICA*004 (14.8%). The most common haplotypes were MICA*009-B*51 (7.8%), MICA*004-B*44 (6.06%) and MICA*002-B*35 (5.63%). As expected from the proximity of the MICA and HLA-B loci, most haplotypes showed strong LD. Renal patients and healthy subjects in the same region of Brazil showed statistically significant differences in their MICA polymorphisms. The MICA*027 allele group was more frequent in renal patients (Pc = 0.018, OR: 3.421, 95% CI: 1.516-7.722), while the MICA*019 allele group was more frequent in healthy subjects (Pc = 0.001, OR: 0.027, 95% CI: 0.002-0.469). This study provided information on the distribution of MICA polymorphisms and linkage disequilibrium with HLA-B alleles in Brazilian renal-transplant candidates. This information should help to determine the mechanisms of susceptibility to different diseases in patients with chronic kidney disease, and to elucidate the mechanisms involved in allograft rejection associated with MICA polymorphisms in a Brazilian population.

Inference of population splits and mixtures from genome-wide allele frequency data.

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Joseph K Pickrell

Full Text Available Many aspects of the historical relationships between populations in a species are reflected in genetic data. Inferring these relationships from genetic data, however, remains a challenging task. In this paper, we present a statistical model for inferring the patterns of population splits and mixtures in multiple populations. In our model, the sampled populations in a species are related to their common ancestor through a graph of ancestral populations. Using genome-wide allele frequency data and a Gaussian approximation to genetic drift, we infer the structure of this graph. We applied this method to a set of 55 human populations and a set of 82 dog breeds and wild canids. In both species, we show that a simple bifurcating tree does not fully describe the data; in contrast, we infer many migration events. While some of the migration events that we find have been detected previously, many have not. For example, in the human data, we infer that Cambodians trace approximately 16% of their ancestry to a population ancestral to other extant East Asian populations. In the dog data, we infer that both the boxer and basenji trace a considerable fraction of their ancestry (9% and 25%, respectively to wolves subsequent to domestication and that East Asian toy breeds (the Shih Tzu and the Pekingese result from admixture between modern toy breeds and "ancient" Asian breeds. Software implementing the model described here, called TreeMix, is available at http://treemix.googlecode.com.

High-specificity detection of rare alleles with Paired-End Low Error Sequencing (PELE-Seq).

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Preston, Jessica L; Royall, Ariel E; Randel, Melissa A; Sikkink, Kristin L; Phillips, Patrick C; Johnson, Eric A

2016-06-14

Polymorphic loci exist throughout the genomes of a population and provide the raw genetic material needed for a species to adapt to changes in the environment. The minor allele frequencies of rare Single Nucleotide Polymorphisms (SNPs) within a population have been difficult to track with Next-Generation Sequencing (NGS), due to the high error rate of standard methods such as Illumina sequencing. We have developed a wet-lab protocol and variant-calling method that identifies both sequencing and PCR errors, called Paired-End Low Error Sequencing (PELE-Seq). To test the specificity and sensitivity of the PELE-Seq method, we sequenced control E. coli DNA libraries containing known rare alleles present at frequencies ranging from 0.2-0.4 % of the total reads. PELE-Seq had higher specificity and sensitivity than standard libraries. We then used PELE-Seq to characterize rare alleles in a Caenorhabditis remanei nematode worm population before and after laboratory adaptation, and found that minor and rare alleles can undergo large changes in frequency during lab-adaptation. We have developed a method of rare allele detection that mitigates both sequencing and PCR errors, called PELE-Seq. PELE-Seq was evaluated using control E. coli populations and was then used to compare a wild C. remanei population to a lab-adapted population. The PELE-Seq method is ideal for investigating the dynamics of rare alleles in a broad range of reduced-representation sequencing methods, including targeted amplicon sequencing, RAD-Seq, ddRAD, and GBS. PELE-Seq is also well-suited for whole genome sequencing of mitochondria and viruses, and for high-throughput rare mutation screens.

Multimer Formation Explains Allelic Suppression of PRDM9 Recombination Hotspots.

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Baker, Christopher L; Petkova, Pavlina; Walker, Michael; Flachs, Petr; Mihola, Ondrej; Trachtulec, Zdenek; Petkov, Petko M; Paigen, Kenneth

2015-09-01

Genetic recombination during meiosis functions to increase genetic diversity, promotes elimination of deleterious alleles, and helps assure proper segregation of chromatids. Mammalian recombination events are concentrated at specialized sites, termed hotspots, whose locations are determined by PRDM9, a zinc finger DNA-binding histone methyltransferase. Prdm9 is highly polymorphic with most alleles activating their own set of hotspots. In populations exhibiting high frequencies of heterozygosity, questions remain about the influences different alleles have in heterozygous individuals where the two variant forms of PRDM9 typically do not activate equivalent populations of hotspots. We now find that, in addition to activating its own hotspots, the presence of one Prdm9 allele can modify the activity of hotspots activated by the other allele. PRDM9 function is also dosage sensitive; Prdm9+/- heterozygous null mice have reduced numbers and less active hotspots and increased numbers of aberrant germ cells. In mice carrying two Prdm9 alleles, there is allelic competition; the stronger Prdm9 allele can partially or entirely suppress chromatin modification and recombination at hotspots of the weaker allele. In cell cultures, PRDM9 protein variants form functional heteromeric complexes which can bind hotspots sequences. When a heteromeric complex binds at a hotspot of one PRDM9 variant, the other PRDM9 variant, which would otherwise not bind, can still methylate hotspot nucleosomes. We propose that in heterozygous individuals the underlying molecular mechanism of allelic suppression results from formation of PRDM9 heteromers, where the DNA binding activity of one protein variant dominantly directs recombination initiation towards its own hotspots, effectively titrating down recombination by the other protein variant. In natural populations with many heterozygous individuals, allelic competition will influence the recombination landscape.

A study of the association of childhood asthma with HLA alleles in the population of Siliguri, West Bengal, India.

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Lama, M; Chatterjee, M; Chaudhuri, T K

2014-09-01

Asthma is a heterogeneous disease for which a strong genetic basis is firmly established. It is a complex disorder influenced by gene-environment interaction. Human leukocyte antigen (HLA) genes have been shown to be consistently associated with asthma and its related phenotypes in various populations. The aim of this study was to determine the frequency of the selected HLA classes I and II allelic groups in asthmatic and control groups. HLA typing was performed using polymerase chain reaction-sequence-specific typing (PCR-SSP) method. The allele frequency was estimated by direct counting. Frequency of each HLA allelic group was compared between asthmatic group and control group using χ(2) test. P-value was corrected by multiplying with the number of the allelic groups studied. Odds ratio (OR) and its corresponding 95% confidence interval (CI) for each allelic group were calculated using graphpad instat 3.10. The results of this study showed a significantly higher frequency of HLA-DRB1*03 in asthmatics than in controls (11.43% vs 3.64%, OR = 3.78, 95% CI = 1.61-8.85, P = 0.0025, Pcorr  population. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

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

DEFF Research Database (Denmark)

Li, Yingrui; Vinckenbosch, Nicolas; Tian, Geng

2010-01-01

data, we derived the allele frequency spectrum of cSNPs with a minor allele frequency greater than 0.02. We identified a 1.8-fold excess of deleterious, non-syonomyous cSNPs over synonymous cSNPs in the low-frequency range (minor allele frequencies between 2% and 5%). This excess was more pronounced...

The frequency-independent control method for distributed generation systems

DEFF Research Database (Denmark)

Naderi, Siamak; Pouresmaeil, Edris; Gao, Wenzhong David

2012-01-01

In this paper a novel frequency-independent control method suitable for distributed generation (DG) is presented. This strategy is derived based on the . abc/. αβ transformation and . abc/. dq transformation of the ac system variables. The active and reactive currents injected by the DG are contr......In this paper a novel frequency-independent control method suitable for distributed generation (DG) is presented. This strategy is derived based on the . abc/. αβ transformation and . abc/. dq transformation of the ac system variables. The active and reactive currents injected by the DG...

Extent and distribution of linkage disequilibrium in the Old Order Amish.

Science.gov (United States)

Van Hout, Cristopher V; Levin, Albert M; Rampersaud, Evadnie; Shen, Haiqing; O'Connell, Jeffrey R; Mitchell, Braxton D; Shuldiner, Alan R; Douglas, Julie A

2010-02-01

Knowledge of the extent and distribution of linkage disequilibrium (LD) is critical to the design and interpretation of gene mapping studies. Because the demographic history of each population varies and is often not accurately known, it is necessary to empirically evaluate LD on a population-specific basis. Here we present the first genome-wide survey of LD in the Old Order Amish (OOA) of Lancaster County Pennsylvania, a closed population derived from a modest number of founders. Specifically, we present a comparison of LD between OOA individuals and US Utah participants in the International HapMap project (abbreviated CEU) using a high-density single nucleotide polymorphism (SNP) map. Overall, the allele (and haplotype) frequency distributions and LD profiles were remarkably similar between these two populations. For example, the median absolute allele frequency difference for autosomal SNPs was 0.05, with an inter-quartile range of 0.02-0.09, and for autosomal SNPs 10-20 kb apart with common alleles (minor allele frequency > or =0.05), the LD measure r(2) was at least 0.8 for 15 and 14% of SNP pairs in the OOA and CEU, respectively. Moreover, tag SNPs selected from the HapMap CEU sample captured a substantial portion of the common variation in the OOA ( approximately 88%) at r(2) > or =0.8. These results suggest that the OOA and CEU may share similar LD profiles for other common but untyped SNPs. Thus, in the context of the common variant-common disease hypothesis, genetic variants discovered in gene mapping studies in the OOA may generalize to other populations. 2009 Wiley-Liss, Inc.

Rapid detection of the CYP2A6*12 hybrid allele by Pyrosequencing® technology

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Gallagher Margaret L

2009-08-01

Full Text Available Abstract Background Identification of CYP2A6 alleles associated with reduced enzyme activity is important in the study of inter-individual differences in drug metabolism. CYP2A6*12 is a hybrid allele that results from unequal crossover between CYP2A6 and CYP2A7 genes. The 5' regulatory region and exons 1–2 are derived from CYP2A7, and exons 3–9 are derived from CYP2A6. Conventional methods for detection of CYP2A6*12 consist of two-step PCR protocols that are laborious and unsuitable for high-throughput genotyping. We developed a rapid and accurate method to detect the CYP2A6*12 allele by Pyrosequencing technology. Methods A single set of PCR primers was designed to specifically amplify both the CYP2A6*1 wild-type allele and the CYP2A6*12 hybrid allele. An internal Pyrosequencing primer was used to generate allele-specific sequence information, which detected homozygous wild-type, heterozygous hybrid, and homozygous hybrid alleles. We first validated the assay on 104 DNA samples that were also genotyped by conventional two-step PCR and by cycle sequencing. CYP2A6*12 allele frequencies were then determined using the Pyrosequencing assay on 181 multi-ethnic DNA samples from subjects of African American, European Caucasian, Pacific Rim, and Hispanic descent. Finally, we streamlined the Pyrosequencing assay by integrating liquid handling robotics into the workflow. Results Pyrosequencing results demonstrated 100% concordance with conventional two-step PCR and cycle sequencing methods. Allele frequency data showed slightly higher prevalence of the CYP2A6*12 allele in European Caucasians and Hispanics. Conclusion This Pyrosequencing assay proved to be a simple, rapid, and accurate alternative to conventional methods, which can be easily adapted to the needs of higher-throughput studies.

Different HLA-DRB1 allele distributions in distinct clinical subgroups of sarcoidosis patients

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Nisell Magnus

2010-02-01

Full Text Available Abstract Background A strong genetic influence by the MHC class II region has been reported in sarcoidosis, however in many studies with different results. This may possibly be caused by actual differences between distinct ethnic groups, too small sample sizes, or because of lack of accurate clinical subgrouping. Subjects and methods In this study we HLA typed a large patient population (n = 754 recruited from one single centre. Patients were sub-grouped into those with Löfgren's syndrome (LS (n = 302 and those without (non-Löfgren's (n = 452, and the majority of them were clinically classified into those with recovery within two years (resolving and those with signs of disease for more than two years (non-resolving. PCR was used for determination of HLA-DRB1 alleles. Swedish healthy blood donors (n = 1366 served as controls. Results There was a dramatic difference in the distribution of HLA alleles in LS compared to non-LS patients (p = 4 × 10-36. Most notably, DRB1*01, DRB1*03 and DRB1*14, clearly differed in LS and non-LS patients. In relation to disease course, DRB1*07, DRB1*14 and DRB1*15 generally associated with, while DRB1*01 and DRB1*03 protected against, a non-resolving disease. Interestingly, the clinical influence of DRB1*03 (good prognosis dominated over that of DRB1*15 (bad prognosis. Conclusions We found several significant differences between LS and non-LS patients and we therefore suggest that genetic association studies in sarcoidosis should include a careful clinical characterisation and sub-grouping of patients, in order to reveal true genetic associations. This may be particularly accurate to do in the heterogeneous non-LS group of patients.

The characterization and geographical distribution of the genes responsible for vernalization requirement in Chinese bread wheat.

Science.gov (United States)

Sun, Qing-Ming; Zhou, Rong-Hua; Gao, Li-Feng; Zhao, Guang-Yao; Jia, Ji-Zeng

2009-04-01

The frequency and distribution of the major vernalization requirement genes and their effects on growth habits were studied. Of the 551 bread wheat genotypes tested, seven allelic combinations of the three Vrn-1 genes were found to be responsible for the spring habit, three for the facultative habit and one for the winter habit. The three Vrn-1 genes behaved additively with the dominant allele of Vrn-A1 exerting the strongest effect. The allele combinations of the facultative genotypes and the discovery of spring genotypes with "winter" allele of Vrn-1 implied the presence of as yet unidentified alleles/genes for vernalization response. The dominant alleles of the three Vrn-1 genes were found in all ten ecological regions where wheat is cultivated in China, with Vrn-D1 as the most common allele in nine and Vrn-A1 in one. The combination of vrn-A1vrn-B1Vrn-D1 was the predominant genotype in seven of the regions. Compared with landraces, improved varieties contain a higher proportion of the spring type. This was attributed by a higher frequency of the dominant Vrn-A1 and Vrn-B1 alleles in the latter. Correlations between Vrn-1 allelic constitutions and heading date, spike length, plant type as well as cold tolerance were established.

Allelic state at the microsatellite locus Xgwm261 marking the dwarfing gene Rht8 in Egyptian bread wheat (Triticum aestivum L. genotypes released from 1947 to 2004

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Salem Khaled F.M.

2015-01-01

Full Text Available Rht8 is widely used in dry environments such as Mediterranean regions where it increases plant adaptability. Variation at the Gatersleben wheat microsatellite Xgwm261 locus, whose 192-bp allele closely linked to the dwarfing gene Rht8, on chromosome 2D within 0.6 cM, was used to screen thirty Egyptian bread wheat genotypes released from (1947-2004 to assess the variation at this locus. There were three microsatellite allelic variants based on size. Screening of this wheat collection showed that the three alleles Xgwm261-165, Xgwm261-174 and Xgwm261-192 bp were the most frequent. The highest allele frequency was observed for a Xgwm261-165 bp fragment (65.52% followed by a Xgwm261-174 bp fragment (24.14%. However, the allele frequency of a Xgwm261-192 bp fragment among these wheat genotypes was 10.34%. The percentage distribution of dwarfing alleles for the microsatellite locus Xgwm261 in the Egyptian wheat breeding programs was 30, 20, 20 and 30% for the wheat breeding program Giza, Sakha, Gemmiza and Sids, respectively. PIC for Xgwm261 was 0.527. Genetic heritage of Egyptian genotypes at the microsatellite locus Xgwm261 is consequence of new parental components usage, carriers short plant and early maturity attributes and consequent selection progeny with these traits in breeding programs. The present study will be helpful in characterization Egyptian wheat genotypes, as well as in accurate selection of parents for wheat breeding program in Egypt.

Human Leukocyte Antigen Class II Alleles (DQB1 and DRB1 as Predictors for Response to Interferon Therapy in HCV Genotype 4

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Olfat Shaker

2013-01-01

Full Text Available Human leukocyte antigens class II play an important role in immune response against HCV. We investigated whether HLA class II alleles influence susceptibility to HCV infection and response to interferon therapy. HLA-DRB1 and -DQB1 loci were genotyped using PCR-SSO Luminex technology. According to our regimen, 41 (66% of patients achieved sustained virological response to combined treatment of IFN and ribavirin. Frequencies of DQB1*0313 allele and DRB1*04-DRB1*11, DQB1*0204-DQB1*0313, DQB1*0309-DQB1*0313, and DQB1*0313-DQB1*0319 haplotypes were significantly more frequent in nonresponders than in responders. In contrast, DQB1*02, DQB1*06, DRB1*13, and DRB1*15 alleles were significantly more frequent in responders than in nonresponders. Similarly, DRB1*1301, DRB1*1361, and DRB1*1369 alleles and DRB1*1301-DRB1*1328, DRB1*1301-DRB1*1361, DRB1*1301-DRB1*1369, DRB1*1328-DRB1*1361, and DRB1*1328-DRB1*1369 haplotypes were significantly found only in responders. Some alleles and linkages showed significantly different distributions between patient and healthy groups. These alleles may be used as predictors for response to treatment or to susceptibility to HCV infection in the Egyptian population.

Asymptotic Time Averages and Frequency Distributions

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Muhammad El-Taha

2016-01-01

Full Text Available Consider an arbitrary nonnegative deterministic process (in a stochastic setting {X(t,  t≥0} is a fixed realization, i.e., sample-path of the underlying stochastic process with state space S=(-∞,∞. Using a sample-path approach, we give necessary and sufficient conditions for the long-run time average of a measurable function of process to be equal to the expectation taken with respect to the same measurable function of its long-run frequency distribution. The results are further extended to allow unrestricted parameter (time space. Examples are provided to show that our condition is not superfluous and that it is weaker than uniform integrability. The case of discrete-time processes is also considered. The relationship to previously known sufficient conditions, usually given in stochastic settings, will also be discussed. Our approach is applied to regenerative processes and an extension of a well-known result is given. For researchers interested in sample-path analysis, our results will give them the choice to work with the time average of a process or its frequency distribution function and go back and forth between the two under a mild condition.

Delimiting Allelic Imbalance of TYMS by Allele-Specific Analysis.

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Balboa-Beltrán, Emilia; Cruz, Raquel; Carracedo, Angel; Barros, Francisco

2015-07-01

Allelic imbalance of thymidylate synthase (TYMS) is attributed to polymorphisms in the 5'- and 3'-untranslated region (UTR). These polymorphisms have been related to the risk of suffering different cancers, for example leukemia, breast or gastric cancer, and response to different drugs, among which are methotrexate glutamates, stavudine, and specifically 5-fluorouracil (5-FU), as TYMS is its direct target. A vast literature has been published in relation to 5-FU, even suggesting the sole use of these polymorphisms to effectively manage 5-FU dosage. Estimates of the extent to which these polymorphisms influence in TYMS expression have in the past been based on functional analysis by luciferase assays and quantification of TYMS mRNA, but both these studies, as the association studies with cancer risk or with toxicity or response to 5-FU, are very contradictory. Regarding functional assays, the artificial genetic environment created in luciferase assay and the problems derived from quantitative polymerase chain reactions (qPCRs), for example the use of a reference gene, may have distorted the results. To avoid these sources of interference, we have analyzed the allelic imbalance of TYMS by allelic-specific analysis in peripheral blood mononuclear cells (PBMCs) from patients.Allelic imbalance in PBMCs, taken from 40 patients with suspected myeloproliferative haematological diseases, was determined by fluorescent fragment analysis (for the 3'-UTR polymorphism), Sanger sequencing and allelic-specific qPCR in multiplex (for the 5'-UTR polymorphisms).For neither the 3'- nor the 5'-UTR polymorphisms did the observed allelic imbalance exceed 1.5 fold. None of the TYMS polymorphisms is statistically associated with allelic imbalance.The results acquired allow us to deny the previously established assertion of an influence of 2 to 4 fold of the rs45445694 and rs2853542 polymorphisms in the expression of TYMS and narrow its allelic imbalance to 1.5 fold, in our population

Influences on flood frequency distributions in Irish river catchments

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S. Ahilan

2012-04-01

Full Text Available This study explores influences on flood frequency distributions in Irish rivers. A Generalised Extreme Value (GEV type I distribution is recommended in Ireland for estimating flood quantiles in a single site flood frequency analysis. This paper presents the findings of an investigation that identified the GEV statistical distributions that best fit the annual maximum (AM data series extracted from 172 gauging stations of 126 rivers in Ireland. Analysis of these data was undertaken to explore hydraulic and hydro-geological factors that influence flood frequency distributions. A hierarchical approach of increasing statistical power that used probability plots, moment and L-moment diagrams, the Hosking goodness of fit algorithm and a modified Anderson-Darling (A-D statistical test was followed to determine whether a type I, type II or type III distribution was valid. Results of the Hosking et al. method indicated that of the 143 stations with flow records exceeding 25 yr, data for 95 (67% was best represented by GEV type I distributions and a further 9 (6% and 39 (27% stations followed type II and type III distributions respectively. Type I, type II and type III distributions were determined for 83 (58%, 16 (11% and 34 (24% stations respectively using the modified A-D method (data from 10 stations was not represented by GEV family distributions. The influence of karst terrain on these flood frequency distributions was assessed by incorporating results on an Arc-GIS platform showing karst features and using Monte Carlo simulations to assess the significance of the number and clustering of the observed distributions. Floodplain effects were identified by using two-sample t-tests to identify statistical correlations between the distributions and catchment properties that are indicative of strong floodplain activity. The data reveals that type I distributions are spatially well represented throughout the country. While also well represented throughout

HLA-DRB1 alleles associated with polymyalgia rheumatica in northern Italy: correlation with disease severity

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Salvarani, C.; Boiardi, L.; Mantovani, V.; Ranzi, A.; Cantini, F.; Olivieri, I.; Bragliani, M.; Collina, E.; Macchioni, P.

1999-01-01

OBJECTIVE—To examine the association of HLA-DRB1 alleles with polymyalgia rheumatica (PMR) in a Mediterranean country and to explore the role of HLA-DRB1 genes in determining disease severity.
METHODS—A five year prospective follow up study of 92 consecutive PMR patients diagnosed by the secondary referral centre of rheumatology of Reggio Emilia, Italy was conducted. HLA-DRB1 alleles were determined in the 92 patients, in 29 DR4 positive rheumatoid arthritis (RA) patients, and in 148 controls from the same geographical area by polymerase chain reaction amplification and oligonucleotide hybridisation.
RESULTS—No significant differences were observed in the frequencies of HLA-DRB1 types and in the expression of HLA-DRB 70-74 shared motif between PMR and controls. The frequency of the patients with double dose of epitope was low and not significantly different in PMR and in controls. No significant differences in the distribution of HLA-DR4 subtypes were observed between DR4+ PMR, DR+ RA, and DR4+ controls. Results of the univariate analysis indicated that an erythrocyte sedimentation rate (ESR) at diagnosis > 72 mm 1st h, the presence of HLA-DR1, DR10, rheumatoid epitope, and the type of rheumatoid epitope were significant risk factors associated with relapse/recurrence. Cox proportional hazards modelling identified two variables that independently increased the risk of relapse/recurrence: ESR at diagnosis > 72 mm 1st h (RR=1.5) and type 2 (encoded by a non-DR4 allele) rheumatoid epitope (RR=2.7).
CONCLUSION—These data from a Mediterranean country showed no association of rheumatoid epitope with PMR in northern Italian patients. A high ESR at diagnosis and the presence of rheumatoid epitope encoded by a non-DR4 allele are independent valuable markers of disease severity.

 PMID:10225816

The Frequency of Cytochrome P450 2E1 Polymorphisms in Black South Africans

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Paul K. Chelule

2006-01-01

Full Text Available Polymorphisms in the promoter region of the Cytochrome P4502E1 (CYP2E1 gene reportedly modify the metabolic activity of CYP2E1 enzyme, and have been associated with increased susceptibility to squamous cell carcinoma (SCC of the oesophagus in high prevalence areas such as China. To assess the frequency of these polymorphisms in Black South Africans, a population with a high incidence of oesophageal SCC, this study examined genomic DNA from 331 subjects for restriction fragment length polymorphisms in the CYP2E1 (RsaI and PstI digestion. The frequency of the CYP2E1 c1/c1 and c1/c3 genotypes was 95% and 5% respectively. The frequency of the CYP2E1 allele distribution was found to be markedly different between Chinese and South African populations; hence it is important to place racial differences into consideration when proposing allelic variants as genetic markers for cancer.

Increased frequency of co-existing JAK2 exon-12 or MPL exon-10 mutations in patients with low JAK2(V617F) allelic burden.

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Nussenzveig, Roberto H; Pham, Ha T; Perkins, Sherrie L; Prchal, Josef T; Agarwal, Archana M; Salama, Mohamed E

2016-01-01

The frequency of co-existing JAK2(V617F)/MPL and JAK2(V617F)/JAK2 exon-12 mutations has not been previously investigated in MPNs. Poor survival was reported in primary myelofibrosis with low JAK2(V617F) allelic burden. However, mutational status of JAK2 exon-12 or MPL were not reported in these patients. This study developed a cost-effective multiplex high resolution melt assay that screens for mutations in JAK2 gene exons-12 and -14 ((V617F)) and MPL gene exon-10. Co-existing mutations with JAK2(V617F) were detected in 2.9% (6/208; two JAK2 exon-12 and four MPL exon-10) patient specimens with known JAK2(V617F) (allelic-burden range: 0.1-96.8%). Co-existing mutations were detected in specimens with MPL exon-10 mutation should be pursued.

Systematic Functional Interrogation of Rare Cancer Variants Identifies Oncogenic Alleles | Office of Cancer Genomics

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Cancer genome characterization efforts now provide an initial view of the somatic alterations in primary tumors. However, most point mutations occur at low frequency, and the function of these alleles remains undefined. We have developed a scalable systematic approach to interrogate the function of cancer-associated gene variants. We subjected 474 mutant alleles curated from 5,338 tumors to pooled in vivo tumor formation assays and gene expression profiling. We identified 12 transforming alleles, including two in genes (PIK3CB, POT1) that have not been shown to be tumorigenic.

Word frequencies: A comparison of Pareto type distributions

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Wiegand, Martin; Nadarajah, Saralees; Si, Yuancheng

2018-03-01

Mehri and Jamaati (2017) [18] used Zipf's law to model word frequencies in Holy Bible translations for one hundred live languages. We compare the fit of Zipf's law to a number of Pareto type distributions. The latter distributions are shown to provide the best fit, as judged by a number of comparative plots and error measures. The fit of Zipf's law appears generally poor.

Use of commercial vessels in survey augmentation: the size-frequency distribution

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Eric N. Powell

2006-09-01

Full Text Available The trend towards use of commercial vessels to enhance survey data requires assessment of the advantages and limitations of various options for their use. One application is to augment information on size-frequency distributions obtained in multispecies trawl surveys where stratum boundaries and sampling density are not optimal for all species. Analysis focused on ten recreationally and commercially important species: bluefish, butterfish, Loligo squid, weakfish, summer flounder, winter flounder, silver hake (whiting, black sea bass, striped bass, and scup (porgy. The commercial vessel took 59 tows in the sampled domain south of Long Island, New York and the survey vessel 18. Black sea bass, Loligo squid, and summer flounder demonstrated an onshore-offshore gradient such that smaller fish were caught disproportionately inshore and larger fish offshore. Butterfish, silver hake, and weakfish were characterized by a southwest-northeast gradient such that larger fish were caught disproportionately northeast of the southwestern-most sector. All sizes of scup, striped bass, and bluefish were caught predominately inshore. Winter flounder were caught predominately offshore. The commercial vessel was characterized by an increased frequency of large catches for most species. Consequently, patchiness was assayed to be higher by the commercial vessel in nearly all cases. The size-frequency distribution obtained by the survey vessel for six of the ten species, bluefish, butterfish, Loligo squid, summer flounder, weakfish, and silver hake, could not be obtained by chance from the size-frequency distribution obtained by the commercial vessel. The difference in sample density did not significantly influence the size-frequency distribution. Of the six species characterized by significant differences in size-frequency distribution between boats, all but one was patchy at the population level and all had one or more size classes so characterized. Although the

HFE gene C282Y, H63D and S65C mutations frequency in the Transylvania region, Romania.

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Trifa, Adrian P; Popp, Radu A; Militaru, Mariela S; Farcaş, Marius F; Crişan, Tania O; Gana, Ionuţ; Cucuianu, Andrei; Pop, Ioan V

2012-06-01

HFE-associated haemochromatosis is one of the most frequent autosomal recessive disorders in the Caucasian population. Although most of the cases are homozygous individuals for the C282Y mutation, another two mutations, H63D and S65C, have been reported to be associated with milder forms of the disease. This study was a first attempt to evaluate the distribution of these HFE gene mutations in the Transylvania region. Two-hundred and twenty-five healthy, unrelated volunteers originating from the Transylvania region, Romania, were screened for the HFE gene C282Y, H63D and S65C mutations, using molecular genetics assays (Polymerase Chain Reaction-Restriction Fragments Length Polymorphism). For the C282Y mutation, 7 heterozygotes (3.1%) were found, but no homozygous individual. In the case of the H63D mutation, 40 heterozygotes (17.8%) and 4 homozygotes (1.75%) for the mutant allele were evidenced. We found a compound heterozygous genotype (C282Y/H63D) in one individual (0.45%). Thus, the allele frequencies of the C282Y and H63D were 1.75% and 10.9%, respectively. Three individuals (1.3%) were found to harbour the S65C mutation in a heterozygous state, but none in a homozygous state: the allele frequency of the mutant allele was 0.75%. The distribution of the HFE gene C282Y, H63D and S65C mutations found in our group matches the tendencies observed in other European countries: a decreasing gradient from Northern to Southern Europe for the C282Y mutation; high frequency for the H63D mutation, and low frequency for the S65C mutation in most of the countries.

Fast Grid Frequency Support from Distributed Inverter-Based Resources

Energy Technology Data Exchange (ETDEWEB)

Hoke, Anderson F [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2018-05-04

This presentation summarizes power hardware-in-the-loop testing performed to evaluate the ability of distributed inverter-coupled generation to support grid frequency on the fastest time scales. The research found that distributed PV inverters and other DERs can effectively support the grid on sub-second time scales.

A rare FANCA gene variation as a breast cancer susceptibility allele in an Iranian population.

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Abbasi, Sakineh; Rasouli, Mina

2017-06-01

Fanconi Anemia (FA) is an autosomal recessive syndrome characterized by congenital abnormalities, progressive bone marrow failure and Fanconi anemia complementation group A (FANCA) is also a potential breast and ovarian cancer susceptibility gene. A novel allele with tandem duplication of 13 base pair sequence in promoter region was identified. To investigate whether the 13 base pair sequence of tandem duplication in promoter region of the FANCA gene is of high penetrance in patients with breast cancer and to determine if the presence of the duplicated allele was associated with an altered risk of breast cancer, the present study screened DNA in blood samples from 304 breast cancer patients and 295 normal individuals as controls. The duplication allele had a frequency of 35.4 and 21.2% in patients with breast cancer and normal controls, respectively. There was a significant increase in the frequency of the duplication allele in patients with familial breast cancer compared with controls (45.1%, P=0.001). Furthermore, the estimated risk of breast cancer in individuals with a homozygote [odds ratio (OR), 4.093; 95% confidence intervals (CI), 1.957‑8.561] or heterozygote duplicated genotype (OR, 3.315; 95% CI, 1.996‑5.506) was higher compared with the corresponding normal homozygote genotype. In conclusion, the present study indicated that the higher the frequency of the duplicated allele, the higher the risk of breast cancer. To the best of our knowledge, the present study is the first to report FANCA gene duplication in patients with breast cancer.

An approximate stationary solution for multi-allele neutral diffusion with low mutation rates.

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Burden, Conrad J; Tang, Yurong

2016-12-01

We address the problem of determining the stationary distribution of the multi-allelic, neutral-evolution Wright-Fisher model in the diffusion limit. A full solution to this problem for an arbitrary K×K mutation rate matrix involves solving for the stationary solution of a forward Kolmogorov equation over a (K-1)-dimensional simplex, and remains intractable. In most practical situations mutations rates are slow on the scale of the diffusion limit and the solution is heavily concentrated on the corners and edges of the simplex. In this paper we present a practical approximate solution for slow mutation rates in the form of a set of line densities along the edges of the simplex. The method of solution relies on parameterising the general non-reversible rate matrix as the sum of a reversible part and a set of (K-1)(K-2)/2 independent terms corresponding to fluxes of probability along closed paths around faces of the simplex. The solution is potentially a first step in estimating non-reversible evolutionary rate matrices from observed allele frequency spectra. Copyright © 2016 Elsevier Inc. All rights reserved.

HLA alleles and haplotypes in Burmese (Myanmarese) and Karen in Thailand.

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Kongmaroeng, C; Romphruk, A; Puapairoj, C; Leelayuwat, C; Kulski, J K; Inoko, H; Dunn, D S; Romphruk, A V

2015-09-01

This is the first report on human leukocyte antigen (HLA) allele and haplotype frequencies at three class I loci and two class II loci in unrelated healthy individuals from two ethnic groups, 170 Burmese and 200 Karen, originally from Burma (Myanmar), but sampled while residing in Thailand. Overall, the HLA allele and haplotype frequencies detected by polymerase chain reaction sequence-specific primer (PCR-SSP) at five loci (A, B, C, DRB1 and DRQB1) at low resolution showed distinct differences between the Burmese and Karen. In Burmese, five HLA-B*15 haplotypes with different HLA-A and HLA-DR/DQ combinations were detected with three of these not previously reported in other Asian populations. The data are important in the fields of anthropology, transplantation and disease-association studies. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

SCREENING LOW FREQUENCY SNPS FROM GENOME WIDE ASSOCIATION STUDY REVEALS A NEW RISK ALLELE FOR PROGRESSION TO AIDS

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Le Clerc, Sigrid; Coulonges, Cédric; Delaneau, Olivier; Van Manen, Danielle; Herbeck, Joshua T.; Limou, Sophie; An, Ping; Martinson, Jeremy J.; Spadoni, Jean-Louis; Therwath, Amu; Veldink, Jan H.; van den Berg, Leonard H.; Taing, Lieng; Labib, Taoufik; Mellak, Safa; Montes, Matthieu; Delfraissy, Jean-François; Schächter, François; Winkler, Cheryl; Froguel, Philippe; Mullins, James I.; Schuitemaker, Hanneke; Zagury, Jean-François

2011-01-01

Background Seven genome-wide association studies (GWAS) have been published in AIDS and only associations in the HLA region on chromosome 6 and CXCR6 have passed genome-wide significance. Methods We reanalyzed the data from three previously published GWAS, targeting specifically low frequency SNPs (minor allele frequency (MAF)<5%). Two groups composed of 365 slow progressors (SP) and 147 rapid progressors (RP) from Europe and the US were compared with a control group of 1394 seronegative individuals using Eigenstrat corrections. Results Of the 8584 SNPs with MAF<5% in cases and controls (Bonferroni threshold=5.8×10−6), four SNPs showed statistical evidence of association with the SP phenotype. The best result was for HCP5 rs2395029 (p=8.54×10−15, OR=3.41) in the HLA locus, in partial linkage disequilibrium with two additional chromosome 6 associations in C6orf48 (p=3.03×10−10, OR=2.9) and NOTCH4 (9.08×10−07, OR=2.32). The fourth association corresponded to rs2072255 located in RICH2 (p=3.30×10−06, OR=0.43) in chromosome 17. Using HCP5 rs2395029 as a covariate, the C6orf48 and NOTCH4 signals disappeared, but the RICH2 signal still remained significant. Conclusion Besides the already known chromosome 6 associations, the analysis of low frequency SNPs brought up a new association in the RICH2 gene. Interestingly, RICH2 interacts with BST-2 known to be a major restriction factor for HIV-1 infection. Our study has thus identified a new candidate gene for AIDS molecular etiology and confirms the interest of singling out low frequency SNPs in order to exploit GWAS data. PMID:21107268

Distribution function of frequency of stellar flares in the Orion association

International Nuclear Information System (INIS)

Parsamyan, Eh.S.

1980-01-01

Using the chronology of discoveries of new flares and the chronology of confirmation i.e. the time distribution of second flares (Ambartsumian's method), the distribution function of frequency of flares on stars in the Orion association is obtained. A number of stars having different frequencies is also found. It is shown that flare stars with high flare frequency (ν -1 13sup(m). The quantities of flare stars in aggregates determined by two independent methods show that the number of flare stars in Orion association is about 1.5 times greater than in the Pleiades cluster [ru

Eigenmode frequency distribution of rapidly rotating neutron stars

International Nuclear Information System (INIS)

Boutloukos, Stratos; Nollert, Hans-Peter

2007-01-01

We use perturbation theory and the relativistic Cowling approximation to numerically compute characteristic oscillation modes of rapidly rotating relativistic stars which consist of a perfect fluid obeying a polytropic equation of state. We present a code that allows the computation of modes of arbitrary order. We focus here on the overall distribution of frequencies. As expected, we find an infinite pressure mode spectrum extending to infinite frequency. In addition we obtain an infinite number of inertial mode solutions confined to a finite, well-defined frequency range which depends on the compactness and the rotation frequency of the star. For nonaxisymmetric modes we observe how this range is shifted with respect to the axisymmetric ones, moving towards negative frequencies and thus making all m>2 modes unstable. We discuss whether our results indicate that the star's spectrum must have a continuous part, as opposed to simply containing an infinite number of discrete modes

Lack of association between TaqI A1 Allele of dopamine D2 receptor gene and alcohol-use disorders in Atayal natives of Taiwan

Energy Technology Data Exchange (ETDEWEB)

Chia-Hsiang Chen [Cheng Hsin Rehabilitation and Medical Center, Taipei (Taiwan, Province of China); Shih-Hsiang Chien; Hai-Gwo Hwu [National Taiwan Univ., Taipei (Taiwan, Province of China)

1996-09-20

Association studies between the A1 allele of the dopamine D2 receptor (DRD2) gene TaqI A polymorphism and alcoholism remain controversial. A recent study from Japan demonstrated that the A1 allele is associated with severe alcoholism in the Japanese population. We were interested in knowing if this association also exists in the Atayals of Taiwan, who were found to have a higher prevalence of alcohol-use disorders than the Han Chinese in Taiwan. Genotype and allele frequencies were determined in alcohol-abusing, alcohol-dependent, and nonalcoholic control Atayal natives in Taiwan. A1 allele frequencies in alcohol-dependent, alcohol-abusing, and normal control Atayals were 0.39, 0.42, and 0.39, respectively. No difference in A1 allele frequency was found among these three groups. Our data do not support the hypothesis that the A1 allele of the TaqI A polymorphism of the DRD2 gene increases susceptibility to alcohol-use disorders in the Atayals of Taiwan. 18 refs., 1 tab.

Frequency distributions: from the sun to the earth

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N. B. Crosby

2011-11-01

Full Text Available The space environment is forever changing on all spatial and temporal scales. Energy releases are observed in numerous dynamic phenomena (e.g. solar flares, coronal mass ejections, solar energetic particle events where measurements provide signatures of the dynamics. Parameters (e.g. peak count rate, total energy released, etc. describing these phenomena are found to have frequency size distributions that follow power-law behavior. Natural phenomena on Earth, such as earthquakes and landslides, display similar power-law behavior. This suggests an underlying universality in nature and poses the question of whether the distribution of energy is the same for all these phenomena. Frequency distributions provide constraints for models that aim to simulate the physics and statistics observed in the individual phenomenon. The concept of self-organized criticality (SOC, also known as the "avalanche concept", was introduced by Bak et al. (1987, 1988, to characterize the behavior of dissipative systems that contain a large number of elements interacting over a short range. The systems evolve to a critical state in which a minor event starts a chain reaction that can affect any number of elements in the system. It is found that frequency distributions of the output parameters from the chain reaction taken over a period of time can be represented by power-laws. During the last decades SOC has been debated from all angles. New SOC models, as well as non-SOC models have been proposed to explain the power-law behavior that is observed. Furthermore, since Bak's pioneering work in 1987, people have searched for signatures of SOC everywhere. This paper will review how SOC behavior has become one way of interpreting the power-law behavior observed in natural occurring phenomenon in the Sun down to the Earth.

HLA Class II Alleles Susceptibility Markers of Type 1 Diabetes Fail to Specify Phenotypes of Ketosis-Prone Diabetes in Adult Tunisian Patients

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Lilia Laadhar

2011-01-01

Full Text Available We aimed to characterize the different subgroups of ketosis-prone diabetes (KPD in a sample of Tunisian patients using the Aβ scheme based on the presence or absence of β-cell autoantibodies (A+ or A− and β-cell functional reserve (β+ or β− and we investigated whether HLA class II alleles could contribute to distinct KPD phenotypes. We enrolled 43 adult patients with a first episode of ketosis. For all patients we evaluated clinical parameters, β-cell autoimmunity, β-cell function and HLA class II alleles. Frequency distribution of the 4 subgroups was 23.3% A+β−, 23.3% A−β−, 11.6% A+β+ and 41.9% A−β+. Patients from the group A+β− were significantly younger than those from the group A−β− (P=.002. HLA susceptibility markers were significantly more frequent in patients with autoantibodies (P=.003. These patients also had resistance alleles but they were more frequent in A+β+ than A+β− patients (P=.04. Insulin requirement was not associated to the presence or the absence of HLA susceptibility markers. HLA class II alleles associated with susceptibility to autoimmune diabetes have not allowed us to further define Tunisian KPD groups. However, high prevalence of HLA resistance alleles in our patients may reflect a particular genetic background of Tunisian KPD population.

Type 2 diabetes mellitus: distribution of genetic markers in Kazakh population.

Science.gov (United States)

Sikhayeva, Nurgul; Talzhanov, Yerkebulan; Iskakova, Aisha; Dzharmukhanov, Jarkyn; Nugmanova, Raushan; Zholdybaeva, Elena; Ramanculov, Erlan

2018-01-01

Ethnic differences exist in the frequencies of genetic variations that contribute to the risk of common disease. This study aimed to analyse the distribution of several genes, previously associated with susceptibility to type 2 diabetes and obesity-related phenotypes, in a Kazakh population. A total of 966 individuals belonging to the Kazakh ethnicity were recruited from an outpatient clinic. We genotyped 41 common single nucleotide polymorphisms (SNPs) previously associated with type 2 diabetes in other ethnic groups and 31 of these were in Hardy-Weinberg equilibrium. The obtained allele frequencies were further compared to publicly available data from other ethnic populations. Allele frequencies for other (compared) populations were pooled from the haplotype map (HapMap) database. Principal component analysis (PCA), cluster analysis, and multidimensional scaling (MDS) were used for the analysis of genetic relationship between the populations. Comparative analysis of allele frequencies of the studied SNPs showed significant differentiation among the studied populations. The Kazakh population was grouped with Asian populations according to the cluster analysis and with the Caucasian populations according to PCA. According to MDS, results of the current study show that the Kazakh population holds an intermediate position between Caucasian and Asian populations. A high percentage of population differentiation was observed between Kazakh and world populations. The Kazakh population was clustered with Caucasian populations, and this result may indicate a significant Caucasian component in the Kazakh gene pool.

Inosine triphosphatase allele frequency and association with ribavirin-induced anaemia in Brazilian patients receiving antiviral therapy for chronic hepatitis C

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Nathália Delvaux

2015-08-01

Full Text Available Inosine triphosphatase (ITPA single nucleotide polymorphisms (SNPs are strongly associated with protection against ribavirin (RBV-induced anaemia in European, American and Asian patients; however, there is a paucity of data for Brazilian patients. The aim of this study was to evaluate the ITPA SNP (rs7270101/rs1127354 frequency in healthy and hepatitis C virus (HCV-infected patients from Brazil and the association with the development of severe anaemia during antiviral therapy. ITPA SNPs were determined in 200 HCV infected patients and 100 healthy individuals by sequencing. Biochemical parameters and haemoglobin (Hb levels were analysed in 97 patients who underwent antiviral therapy. A combination of AArs7270101+CCrs1127354 (100% ITPase activity was observed in 236/300 individuals. Anaemia was observed in 87.5% and 86.2% of treated patients with AA (rs7270101 and CC genotypes (rs1127354, respectively. Men with AA (rs7270101 showed a considerable reduction in Hb at week 12 compared to those with AC/CC (p = 0.1475. In women, there was no influence of genotype (p = 0.5295. For rs1127354, men with the CC genotype also showed a sudden reduction in Hb compared to those with AC. Allelic distribution of rs7270101 and rs1127354 shows high rates of the genotypes AA and CC, respectively, suggesting that the study population had a great propensity for developing RBV-induced anaemia. A progressive Hb reduction during treatment was observed; however, this reduction was greater in men at week 12 than in women.

[Distribution of three polymorphisms of the TSLP gen in African-descendent population from San Basilio de Palenque, Colombia].

Science.gov (United States)

Fang, Luis; Martínez, Beatriz; Marrugo, Javier

2013-01-01

Thymic stromal lymphopoietin (TSLP) has been linked as a susceptibility gene for the development of allergic diseases. It is known that the population of Cartagena is a triethnic mix, in which the component of African ancestry was significantly associated with risk of asthma and high total serum IgE levels. This component comes from African slaves brought into the continent and settled in "palenques", one of them is San Basilio de Palenque, in the Colombian Caribbean Coast. To analyze the distribution of single nucleotide polymorphisms (SNP) rs1837253, rs17551370 and rs2289276 located in TSLP gene, in the African-descendent population of San Basilio de Palenque. By real time-PCR and probes TaqMan SNP Genotyping™, we genotyped three polymorphisms in 80 individuals of African-descent aged 5 to 18 years of age. The frequency of the rs1837253 allele T was 41.9%, for the allele A, 14.3% for rs17551370, and 22.5% for the allele T of rs2289276. The rs17551370 and rs2289276 distribution remained in Hardy- Weinberg genetic equilibrium. The allele frequency of each SNP did not show statistically significant differences with those reported for other African and African-descendent populations. The three polymorphisms in the TSLP were present in the sample population of San Basilio de Palenque and its distribution is similar to that reported for African populations and African ancestry in America.

The effect of subdivision on variation at multi-allelic loci under balancing selection

DEFF Research Database (Denmark)

Schierup, M H; Vekemans, X; Charlesworth, D

2000-01-01

Simulations are used to investigate the expected pattern of variation at loci under different forms of multi-allelic balancing selection in a finite island model of a subdivided population. The objective is to evaluate the effect of restricted migration among demes on the distribution of polymorp......Simulations are used to investigate the expected pattern of variation at loci under different forms of multi-allelic balancing selection in a finite island model of a subdivided population. The objective is to evaluate the effect of restricted migration among demes on the distribution...

Detection of ancestry informative HLA alleles confirms the admixed origins of Japanese population.

Science.gov (United States)

Nakaoka, Hirofumi; Mitsunaga, Shigeki; Hosomichi, Kazuyoshi; Shyh-Yuh, Liou; Sawamoto, Taiji; Fujiwara, Tsutomu; Tsutsui, Naohisa; Suematsu, Koji; Shinagawa, Akira; Inoko, Hidetoshi; Inoue, Ituro

2013-01-01

The polymorphisms in the human leukocyte antigen (HLA) region are powerful tool for studying human evolutionary processes. We investigated genetic structure of Japanese by using five-locus HLA genotypes (HLA-A, -B, -C, -DRB1, and -DPB1) of 2,005 individuals from 10 regions of Japan. We found a significant level of population substructure in Japanese; particularly the differentiation between Okinawa Island and mainland Japanese. By using a plot of the principal component scores, we identified ancestry informative alleles associated with the underlying population substructure. We examined extent of linkage disequilibrium (LD) between pairs of HLA alleles on the haplotypes that were differentiated among regions. The LDs were strong and weak for pairs of HLA alleles characterized by low and high frequencies in Okinawa Island, respectively. The five-locus haplotypes whose alleles exhibit strong LD were unique to Japanese and South Korean, suggesting that these haplotypes had been recently derived from the Korean Peninsula. The alleles characterized by high frequency in Japanese compared to South Korean formed segmented three-locus haplotype that was commonly found in Aleuts, Eskimos, and North- and Meso-Americans but not observed in Korean and Chinese. The serologically equivalent haplotype was found in Orchid Island in Taiwan, Mongol, Siberia, and Arctic regions. It suggests that early Japanese who existed prior to the migration wave from the Korean Peninsula shared ancestry with northern Asian who moved to the New World via the Bering Strait land bridge. These results may support the admixture model for peopling of Japanese Archipelago.

Functional PMS2 hybrid alleles containing a pseudogene-specific missense variant trace back to a single ancient intrachromosomal recombination event.

Science.gov (United States)

Ganster, Christina; Wernstedt, Annekatrin; Kehrer-Sawatzki, Hildegard; Messiaen, Ludwine; Schmidt, Konrad; Rahner, Nils; Heinimann, Karl; Fonatsch, Christa; Zschocke, Johannes; Wimmer, Katharina

2010-05-01

Sequence exchange between PMS2 and its pseudogene PMS2CL, embedded in an inverted duplication on chromosome 7p22, has been reported to be an ongoing process that leads to functional PMS2 hybrid alleles containing PMS2- and PMS2CL-specific sequence variants at the 5'-and the 3'-end, respectively. The frequency of PMS2 hybrid alleles, their biological significance, and the mechanisms underlying their formation are largely unknown. Here we show that overall hybrid alleles account for one-third of 384 PMS2 alleles analyzed in individuals of different ethnic backgrounds. Depending on the population, 14-60% of hybrid alleles carry PMS2CL-specific sequences in exons 13-15, the remainder only in exon 15. We show that exons 13-15 hybrid alleles, named H1 hybrid alleles, constitute different haplotypes but trace back to a single ancient intrachromosomal recombination event with crossover. Taking advantage of an ancestral sequence variant specific for all H1 alleles we developed a simple gDNA-based polymerase chain reaction (PCR) assay that can be used to identify H1-allele carriers with high sensitivity and specificity (100 and 99%, respectively). Because H1 hybrid alleles harbor missense variant p.N775S of so far unknown functional significance, we assessed the H1-carrier frequency in 164 colorectal cancer patients. So far, we found no indication that the variant plays a major role with regard to cancer susceptibility. (c) 2010 Wiley-Liss, Inc.

Distribution of HLA-A, -B and -DRB1 genes and haplotypes in the Tujia population living in the Wufeng Region of Hubei Province, China.

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Li Zhang

Full Text Available BACKGROUND: The distribution of HLA alleles and haplotypes varies widely between different ethnic populations and geographic areas. Before any genetic marker can be used in a disease-associated study it is therefore essential to investigate allelic frequencies and establish a genetic database. METHODOLOGY/PRINCIPAL FINDINGS: This is the first report of HLA typing in the Tujia group using the Luminex HLA-SSO method HLA-A, -B and -DRB1 allelic distributions were determined in 124 unrelated healthy Tujia individuals, and haplotypic frequencies and linkage disequilibrium parameters were estimated using the maximum-likelihood method. In total 10 alleles were detected at the HLA-A locus, 21 alleles at the HLA-B locus and 14 alleles at the HLA-DRB1 locus. The most frequently observed alleles in the HLA-I group were HLA-A*02 (35.48%, A*11 (28.23%, A*24 (15.73%; HLA-B*40 (25.00%, B*46 (16.13%, and B*15 (15.73%. Among HLA-DRB1 alleles, high frequencies of HLA-DRB1*09 (25.81% were observed, followed by HLA-DRB1*15 (12.9%, and DRB1*12 (10.89%. The two-locus haplotypes at the highest frequency were A*02-B*46A (8.47%, followed by A*11-B*40 (7.66%, A*02-B*40 (8.87%, A*11-B*15 (6.45%, A*02-B*15 (6.05%, B*40-DRB1*09 (9.27% and B*46-DRB1*09 (6.45%. The most common three-locus haplotypes found in the Tujia population were A*02-B*46-DRB1*09 (4.84% and A*02-B*40-DRB1*09 (4.03%. Fourteen two-loci haplotypes had significant linkage disequilibrium. Construction of a neighbor-joining phylogenetic tree and principal component analysis using the allelic frequencies at HLA-A was performed to compare the Tujia group and twelve other previously reported populations. The Tujia population in the Wufeng of Hubei Province had the closest genetic relationship with the central Han population, and then to the Shui, the Miao, the southern Han and the northern Han ethnic groups. CONCLUSIONS/SIGNIFICANCE: These results will become a valuable source of data for tracing population

Development of optical fiber frequency and time distribution systems

Science.gov (United States)

Lutes, G.

1982-01-01

The development of ultra stable optical fiber distribution systems for the dissemination of frequency and timing references is reported. The ultimate design goals for these systems are a frequency stability of 10 to the -17 power for tau or = 100 sec and time stability of + or - 0.1 ns for 1 year and operation over distances or = 30 km. A prototype system is reviewed and progress is discussed.

Beneficial role of D allele in controlling ACE levels: a study among Brahmins of north India.

Science.gov (United States)

Kumari, Shobha; Sharma, Nidhi; Thakur, Sunil; Mondal, Prakash R; Saraswathy, Kallur N

2016-06-01

India being a country with vast diversity is expected to have different dietary and life style patterns which in turn may lead to population-specific environmental risk factors. Further, the interaction of these risk factors with the genetic makeup of population makes it either susceptible or resistant to cardiovascular disease. One such candidate gene is angiotensin converting enzyme (ACE) for various cardiovascular mechanisms. ACE is the key enzyme of the renin angiotensin aldosterone system pathway which maintains homeostasis blood pressure in the body and any variation in the levels is reported to be associated with various complex diseases. The DD genotype is found to increase ACE levels, which is associated with cardiovascular diseases and decrease in ACE levels are associated with kidney diseases. The aim of this study was to understand the distribution of ACE I/D polymorphism and ACE levels among Brahmins of National Capital Region (NCR) north India, with respect to age and sex ratio distribution. In this study, 136 subjects of which 50 males and 86 females, who were unrelated up to first cousin, aged 25 to70 years were studied. ACE gene was found to be polymorphic with high frequency of heterozygote (ID) followed by II and DD genotypes. The studied population was found to be in Hardy-Weinberg equilibrium with respect to ACE I/D polymorphism (P = 0.55). I allele frequency was found to be higher (0.560) than the D allele (0.44). The median level of ACE was found to be 65.96 ng/mL (48.12-86.24) which is towards lower side of the normal range. ACE levels were found to be increased among individual having either of the homozygotes that is II or DD and higher frequency of heterozygote (ID) is indicative of advantage in the population by maintaining lower ACE levels. The limitation of the present study is low sample size, however, the merit is that the subjects belonged to a Mendalian population with a common gene pool.

statistical tests for frequency distribution of mean gravity anomalies

African Journals Online (AJOL)

ES Obe

1980-03-01

Mar 1, 1980 ... STATISTICAL TESTS FOR FREQUENCY DISTRIBUTION OF MEAN. GRAVITY ANOMALIES. By ... approach. Kaula [1,2] discussed the method of applying statistical techniques in the ..... mathematical foundation of physical ...

Expression and loss of alleles in cultured mouse embryonic fibroblasts and stem cells carrying allelic fluorescent protein genes

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Stringer Saundra L

2006-10-01

Full Text Available Abstract Background Loss of heterozygosity (LOH contributes to many cancers, but the rate at which these events occur in normal cells of the body is not clear. LOH would be detectable in diverse cell types in the body if this event were to confer an obvious cellular phenotype. Mice that carry two different fluorescent protein genes as alleles of a locus would seem to be a useful tool for addressing this issue because LOH would change a cell's phenotype from dichromatic to monochromatic. In addition, LOH caused by mitotic crossing over might be discernable in tissues because this event produces a pair of neighboring monochromatic cells that are different colors. Results As a step in assessing the utility of this approach, we derived primary embryonic fibroblast populations and embryonic stem cell lines from mice that carried two different fluorescent protein genes as alleles at the chromosome 6 locus, ROSA26. Fluorescence activated cell sorting (FACS showed that the vast majority of cells in each line expressed the two marker proteins at similar levels, and that populations exhibited expression noise similar to that seen in bacteria and yeast. Cells with a monochromatic phenotype were present at frequencies on the order of 10-4 and appeared to be produced at a rate of approximately 10-5 variant cells per mitosis. 45 of 45 stably monochromatic ES cell clones exhibited loss of the expected allele at the ROSA26 locus. More than half of these clones retained heterozygosity at a locus between ROSA26 and the centromere. Other clones exhibited LOH near the centromere, but were disomic for chromosome 6. Conclusion Allelic fluorescent markers allowed LOH at the ROSA26 locus to be detected by FACS. LOH at this locus was usually not accompanied by LOH near the centromere, suggesting that mitotic recombination was the major cause of ROSA26 LOH. Dichromatic mouse embryonic cells provide a novel system for studying genetic/karyotypic stability and factors

Haplotype frequency distribution for 7 microsatellites in chromosome 8 and 11 in relation to the metabolic syndrome in four ethnic groups: Tehran Lipid and Glucose Study.

Science.gov (United States)

Daneshpour, Maryam Sadat; Hosseinzadeh, Nima; Zarkesh, Maryam; Azizi, Fereidoun

2012-03-01

Different variants of haplotype frequencies may lead to various frequencies of the same variants in individuals with drug resistance and disease susceptibility at the population level. In this study, the haplotype frequencies of 4 STR loci including the D8S1132, D8S1779, D8S514 and D8S1743, and 3 STR loci including D11S1304, D11S1998 and D11S934 were investigated in 563 individuals of four Iranian ethnic groups in the capital city of Iran, Tehran. One hundred thirty subjects had the metabolic syndrome. Haplotype frequencies of all markers were calculated. There were significant differences in the haplotype frequencies in short and long alleles between the metabolic affected subjects and controls. In addition, haplotype frequencies were significant in the four ethnic groups in both chromosomes 8 and 11. Our findings show a relation between the short allele of D8S1743 in all related haplotype frequencies of subjects with metabolic syndrome. These findings may require more studies of some candidate genes, including the lipoprotein lipase gene, in this chromosomal region. Copyright © 2011. Published by Elsevier B.V.

Molecular monitoring of resistant dhfr and dhps allelic haplotypes in ...

African Journals Online (AJOL)

Objective: The present study assesses the frequency of resistant dhfr and dhps alleles in Morogoro-Mvomero district in south eastern Tanzania and contrast their rate of change during 17 years of SP second line use against five years of SP first line use. Methodology: Cross sectional surveys of asymptomatic infections were ...

The Microcephalin Ancestral Allele in a Neanderthal Individual

Science.gov (United States)

Lari, Martina; Rizzi, Ermanno; Milani, Lucio; Corti, Giorgio; Balsamo, Carlotta; Vai, Stefania; Catalano, Giulio; Pilli, Elena; Longo, Laura; Condemi, Silvana; Giunti, Paolo; Hänni, Catherine; De Bellis, Gianluca; Orlando, Ludovic; Barbujani, Guido; Caramelli, David

2010-01-01

Background The high frequency (around 0.70 worlwide) and the relatively young age (between 14,000 and 62,000 years) of a derived group of haplotypes, haplogroup D, at the microcephalin (MCPH1) locus led to the proposal that haplogroup D originated in a human lineage that separated from modern humans >1 million years ago, evolved under strong positive selection, and passed into the human gene pool by an episode of admixture circa 37,000 years ago. The geographic distribution of haplogroup D, with marked differences between Africa and Eurasia, suggested that the archaic human form admixing with anatomically modern humans might have been Neanderthal. Methodology/Principal Findings Here we report the first PCR amplification and high- throughput sequencing of nuclear DNA at the microcephalin (MCPH1) locus from Neanderthal individual from Mezzena Rockshelter (Monti Lessini, Italy). We show that a well-preserved Neanderthal fossil dated at approximately 50,000 years B.P., was homozygous for the ancestral, non-D, allele. The high yield of Neanderthal mtDNA sequences of the studied specimen, the pattern of nucleotide misincorporation among sequences consistent with post-mortem DNA damage and an accurate control of the MCPH1 alleles in all personnel that manipulated the sample, make it extremely unlikely that this result might reflect modern DNA contamination. Conclusions/Significance The MCPH1 genotype of the Monti Lessini (MLS) Neanderthal does not prove that there was no interbreeding between anatomically archaic and modern humans in Europe, but certainly shows that speculations on a possible Neanderthal origin of what is now the most common MCPH1 haplogroup are not supported by empirical evidence from ancient DNA. PMID:20498832

The microcephalin ancestral allele in a Neanderthal individual.

Directory of Open Access Journals (Sweden)

Martina Lari

Full Text Available BACKGROUND: The high frequency (around 0.70 worldwide and the relatively young age (between 14,000 and 62,000 years of a derived group of haplotypes, haplogroup D, at the microcephalin (MCPH1 locus led to the proposal that haplogroup D originated in a human lineage that separated from modern humans >1 million years ago, evolved under strong positive selection, and passed into the human gene pool by an episode of admixture circa 37,000 years ago. The geographic distribution of haplogroup D, with marked differences between Africa and Eurasia, suggested that the archaic human form admixing with anatomically modern humans might have been Neanderthal. METHODOLOGY/PRINCIPAL FINDINGS: Here we report the first PCR amplification and high-throughput sequencing of nuclear DNA at the microcephalin (MCPH1 locus from Neanderthal individual from Mezzena Rockshelter (Monti Lessini, Italy. We show that a well-preserved Neanderthal fossil dated at approximately 50,000 years B.P., was homozygous for the ancestral, non-D, allele. The high yield of Neanderthal mtDNA sequences of the studied specimen, the pattern of nucleotide misincorporation among sequences consistent with post-mortem DNA damage and an accurate control of the MCPH1 alleles in all personnel that manipulated the sample, make it extremely unlikely that this result might reflect modern DNA contamination. CONCLUSIONS/SIGNIFICANCE: The MCPH1 genotype of the Monti Lessini (MLS Neanderthal does not prove that there was no interbreeding between anatomically archaic and modern humans in Europe, but certainly shows that speculations on a possible Neanderthal origin of what is now the most common MCPH1 haplogroup are not supported by empirical evidence from ancient DNA.

Allele coding in genomic evaluation

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Christensen Ole F

2011-06-01

Full Text Available Abstract Background Genomic data are used in animal breeding to assist genetic evaluation. Several models to estimate genomic breeding values have been studied. In general, two approaches have been used. One approach estimates the marker effects first and then, genomic breeding values are obtained by summing marker effects. In the second approach, genomic breeding values are estimated directly using an equivalent model with a genomic relationship matrix. Allele coding is the method chosen to assign values to the regression coefficients in the statistical model. A common allele coding is zero for the homozygous genotype of the first allele, one for the heterozygote, and two for the homozygous genotype for the other allele. Another common allele coding changes these regression coefficients by subtracting a value from each marker such that the mean of regression coefficients is zero within each marker. We call this centered allele coding. This study considered effects of different allele coding methods on inference. Both marker-based and equivalent models were considered, and restricted maximum likelihood and Bayesian methods were used in inference. Results Theoretical derivations showed that parameter estimates and estimated marker effects in marker-based models are the same irrespective of the allele coding, provided that the model has a fixed general mean. For the equivalent models, the same results hold, even though different allele coding methods lead to different genomic relationship matrices. Calculated genomic breeding values are independent of allele coding when the estimate of the general mean is included into the values. Reliabilities of estimated genomic breeding values calculated using elements of the inverse of the coefficient matrix depend on the allele coding because different allele coding methods imply different models. Finally, allele coding affects the mixing of Markov chain Monte Carlo algorithms, with the centered coding being

Secondary Frequency and Voltage Control of Islanded Microgrids via Distributed Averaging

DEFF Research Database (Denmark)

W. Simpson-Porco, John; Shafiee, Qobad; Dorfler, Florian

2015-01-01

actions. The frequency controller rapidly regulates the microgrid frequency to its nominal value while maintaining active power sharing among the distributed generators. Tuning of the voltage controller provides a simple and intuitive trade-off between the conflicting goals of voltage regulation...

Geostatistical analysis of allele presence patterns among American black bears in eastern North Carolina

Science.gov (United States)

Thompson, L.M.; Van Manen, F.T.; King, T.L.

2005-01-01

Highways are one of the leading causes of wildlife habitat fragmentation and may particularly affect wide-ranging species, such as American black bears (Ursus americanus). We initiated a research project in 2000 to determine potential effects of a 4-lane highway on black bear ecology in Washington County, North Carolina. The research design included a treatment area (highway construction) and a control area and a pre- and post-construction phase. We used data from the pre-construction phase to determine whether we could detect scale dependency or directionality among allele occurrence patterns using geostatistics. Detection of such patterns could provide a powerful tool to measure the effects of landscape fragmentation on gene flow. We sampled DNA from roots of black bear hair at 70 hair-sampling sites on each study area for 7 weeks during fall of 2000. We used microsatellite analysis based on 10 loci to determine unique multi-locus genotypes. We examined all alleles sampled at ???25 sites on each study area and mapped their presence or absence at each hair-sample site. We calculated semivariograms, which measure the strength of statistical correlation as a function of distance, and adjusted them for anisotropy to determine the maximum direction of spatial continuity. We then calculated the mean direction of spatial continuity for all examined alleles. The mean direction of allele frequency variation was 118.3?? (SE = 8.5) on the treatment area and 172.3?? (SE = 6.0) on the control area. Rayleigh's tests showed that these directions differed from random distributions (P = 0.028 and P < 0.001, respectively), indicating consistent directional patterns for the alleles we examined in each area. Despite the small spatial scale of our study (approximately 11,000 ha for each study area), we observed distinct and consistent patterns of allele occurrence, suggesting different directions of gene flow between the study areas. These directions seemed to coincide with the

Estimation of modal parameters using bilinear joint time frequency distributions

Science.gov (United States)

Roshan-Ghias, A.; Shamsollahi, M. B.; Mobed, M.; Behzad, M.

2007-07-01

In this paper, a new method is proposed for modal parameter estimation using time-frequency representations. Smoothed Pseudo Wigner-Ville distribution which is a member of the Cohen's class distributions is used to decouple vibration modes completely in order to study each mode separately. This distribution reduces cross-terms which are troublesome in Wigner-Ville distribution and retains the resolution as well. The method was applied to highly damped systems, and results were superior to those obtained via other conventional methods.

Automated analysis of high-throughput B-cell sequencing data reveals a high frequency of novel immunoglobulin V gene segment alleles.

Science.gov (United States)

Gadala-Maria, Daniel; Yaari, Gur; Uduman, Mohamed; Kleinstein, Steven H

2015-02-24

Individual variation in germline and expressed B-cell immunoglobulin (Ig) repertoires has been associated with aging, disease susceptibility, and differential response to infection and vaccination. Repertoire properties can now be studied at large-scale through next-generation sequencing of rearranged Ig genes. Accurate analysis of these repertoire-sequencing (Rep-Seq) data requires identifying the germline variable (V), diversity (D), and joining (J) gene segments used by each Ig sequence. Current V(D)J assignment methods work by aligning sequences to a database of known germline V(D)J segment alleles. However, existing databases are likely to be incomplete and novel polymorphisms are hard to differentiate from the frequent occurrence of somatic hypermutations in Ig sequences. Here we develop a Tool for Ig Genotype Elucidation via Rep-Seq (TIgGER). TIgGER analyzes mutation patterns in Rep-Seq data to identify novel V segment alleles, and also constructs a personalized germline database containing the specific set of alleles carried by a subject. This information is then used to improve the initial V segment assignments from existing tools, like IMGT/HighV-QUEST. The application of TIgGER to Rep-Seq data from seven subjects identified 11 novel V segment alleles, including at least one in every subject examined. These novel alleles constituted 13% of the total number of unique alleles in these subjects, and impacted 3% of V(D)J segment assignments. These results reinforce the highly polymorphic nature of human Ig V genes, and suggest that many novel alleles remain to be discovered. The integration of TIgGER into Rep-Seq processing pipelines will increase the accuracy of V segment assignments, thus improving B-cell repertoire analyses.

Preferential Allele Expression Analysis Identifies Shared Germline and Somatic Driver Genes in Advanced Ovarian Cancer

Science.gov (United States)

Halabi, Najeeb M.; Martinez, Alejandra; Al-Farsi, Halema; Mery, Eliane; Puydenus, Laurence; Pujol, Pascal; Khalak, Hanif G.; McLurcan, Cameron; Ferron, Gwenael; Querleu, Denis; Al-Azwani, Iman; Al-Dous, Eman; Mohamoud, Yasmin A.; Malek, Joel A.; Rafii, Arash

2016-01-01

Identifying genes where a variant allele is preferentially expressed in tumors could lead to a better understanding of cancer biology and optimization of targeted therapy. However, tumor sample heterogeneity complicates standard approaches for detecting preferential allele expression. We therefore developed a novel approach combining genome and transcriptome sequencing data from the same sample that corrects for sample heterogeneity and identifies significant preferentially expressed alleles. We applied this analysis to epithelial ovarian cancer samples consisting of matched primary ovary and peritoneum and lymph node metastasis. We find that preferentially expressed variant alleles include germline and somatic variants, are shared at a relatively high frequency between patients, and are in gene networks known to be involved in cancer processes. Analysis at a patient level identifies patient-specific preferentially expressed alleles in genes that are targets for known drugs. Analysis at a site level identifies patterns of site specific preferential allele expression with similar pathways being impacted in the primary and metastasis sites. We conclude that genes with preferentially expressed variant alleles can act as cancer drivers and that targeting those genes could lead to new therapeutic strategies. PMID:26735499

Low-frequency and common genetic variation in ischemic stroke: The METASTROKE collaboration.

Science.gov (United States)

Malik, Rainer; Traylor, Matthew; Pulit, Sara L; Bevan, Steve; Hopewell, Jemma C; Holliday, Elizabeth G; Zhao, Wei; Abrantes, Patricia; Amouyel, Philippe; Attia, John R; Battey, Thomas W K; Berger, Klaus; Boncoraglio, Giorgio B; Chauhan, Ganesh; Cheng, Yu-Ching; Chen, Wei-Min; Clarke, Robert; Cotlarciuc, Ioana; Debette, Stephanie; Falcone, Guido J; Ferro, Jose M; Gamble, Dale M; Ilinca, Andreea; Kittner, Steven J; Kourkoulis, Christina E; Lemmens, Robin; Levi, Christopher R; Lichtner, Peter; Lindgren, Arne; Liu, Jingmin; Meschia, James F; Mitchell, Braxton D; Oliveira, Sofia A; Pera, Joana; Reiner, Alex P; Rothwell, Peter M; Sharma, Pankaj; Slowik, Agnieszka; Sudlow, Cathie L M; Tatlisumak, Turgut; Thijs, Vincent; Vicente, Astrid M; Woo, Daniel; Seshadri, Sudha; Saleheen, Danish; Rosand, Jonathan; Markus, Hugh S; Worrall, Bradford B; Dichgans, Martin

2016-03-29

To investigate the influence of common and low-frequency genetic variants on the risk of ischemic stroke (all IS) and etiologic stroke subtypes. We meta-analyzed 12 individual genome-wide association studies comprising 10,307 cases and 19,326 controls imputed to the 1000 Genomes (1 KG) phase I reference panel. We selected variants showing the highest degree of association (p frequencies for all IS and stroke subtypes. We showed genome-wide significance for 4 loci: ABO for all IS, HDAC9 for large vessel disease (LVD), and both PITX2 and ZFHX3 for cardioembolic stroke (CE). We further refined the association peaks for ABO and PITX2. Analyzing different allele frequency bins, we showed significant enrichment in low-frequency variants (allele frequency frequency variants (allele frequency 10% and 30%) for CE (all p low-frequency and rare variants. Larger sample sizes are needed to identify the variants associated with all IS and stroke subtypes. © 2016 American Academy of Neurology.

Altered enzymatic activity and allele frequency of OMI/HTRA2 in Alzheimer's disease

Science.gov (United States)

Westerlund, Marie; Behbahani, Homira; Gellhaar, Sandra; Forsell, Charlotte; Belin, Andrea Carmine; Anvret, Anna; Zettergren, Anna; Nissbrandt, Hans; Lind, Charlotta; Sydow, Olof; Graff, Caroline; Olson, Lars; Ankarcrona, Maria; Galter, Dagmar

2011-01-01

The serine-protease OMI/HTRA2, required for several cellular processes, including mitochondrial function, autophagy, chaperone activity, and apoptosis, has been implicated in the pathogenesis of both Alzheimer's disease (AD) and Parkinson's disease (PD). Western blot quantification of OMI/HTRA2 in frontal cortex of patients with AD (n=10) and control subjects (n=10) in two separate materials indicated reduced processed (active, 35 kDa) OMI/HTRA2 levels, whereas unprocessed (50 kDa) enzyme levels were not significantly different between the groups. Interestingly, the specific protease activity of OMI/HTRA2 was found to be significantly increased in patients with AD (n=10) compared to matched control subjects (n=10) in frontal cortex in two separate materials. Comparison of OMI/HTRA2 mRNA levels in frontal cortex and hippocampus, two brain areas particularly affected by AD, indicated similar levels in patients with AD (n=10) and matched control subjects (n=10). In addition, we analyzed the occurrence of the OMI/HTRA2 variants A141S and G399S in Swedish case-control materials for AD and PD and found a weak association of A141S with AD, but not with PD. In conclusion, our genetic, histological, and biochemical findings give further support to an involvement of OMI/HTRA2 in the pathology of AD; however, further studies are needed to clarify the role of this gene in neurodegeneration.—Westerlund, M., Behbahani, H., Gellhaar, S., Forsell, C., Carmine Belin, A., Anvret, A., Zettergren, A., Nissbrandt, H., Lind, C., Sydow, O., Graff, C., Olson, L., Ankarcrona, M., Galter, D. Altered enzymatic activity and allele frequency of OMI/HTRA2 in Alzheimer's disease. PMID:21163861

Frequency distribution function of stellar flares in the Orion association

International Nuclear Information System (INIS)

Parsamian, E.S.

1981-01-01

The temporal distributions of flare stars in the Orion association and the numbers of stars with different flare frequencies are determined by means of Ambartsumian's (1978) method, which uses the chronology of discovery of 'first' flares and the chronology of confirmations, i.e., the temporal distributions of 'repeated' flares. It is shown that flare stars with high flare frequency (not greater than 1000 hours) in the Pleiades are basically stars of low luminosity with M(U) not less than 13m. Two independent methods of determining the number of flare stars in the aggregates confirm that there are about 1.5 times more flare stars in the Orion association than in the Pleiades

Distributed Optimization Design of Continuous-Time Multiagent Systems With Unknown-Frequency Disturbances.

Science.gov (United States)

Wang, Xinghu; Hong, Yiguang; Yi, Peng; Ji, Haibo; Kang, Yu

2017-05-24

In this paper, a distributed optimization problem is studied for continuous-time multiagent systems with unknown-frequency disturbances. A distributed gradient-based control is proposed for the agents to achieve the optimal consensus with estimating unknown frequencies and rejecting the bounded disturbance in the semi-global sense. Based on convex optimization analysis and adaptive internal model approach, the exact optimization solution can be obtained for the multiagent system disturbed by exogenous disturbances with uncertain parameters.

Distribution of HLA-A, -B, and -C Alleles and HLA/KIR Combinations in Han Population in China

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Yunsong Shen

2014-01-01

Full Text Available We investigated polymorphisms of the human leukocyte antigen (HLA class I (A, B, and C loci of a Han population (n, 239 from the Yunnan province, Southwest China, using high-resolution polymerase chain reaction-Luminex (PCR-Luminex typing. We combined the HLA data from this study with the KIR genotypes from a previous study of this Han population to analyze the combination of KIR/HLA ligands. A total of 27 HLA-A, 54 HLA-B, and 31 HLA-C alleles were found in this population. The frequencies of A*11:01, A*24:02, B*40:01, B*46:01, C*01:02, C*03:04, and C*07:02 were all > 10%. The following haplotypes were common, with frequencies > 5%: 1 A-B (A*02:07-B*46:01, 2 A-C (A*02:07-C*01:02, and A*11:01-C*07:02, 4 C-B (B*13:01-C*03:04, B*40:01-C*07:02, B*46:01-C*01:02 and B*58:01-C*03:02, and 1 A-C-B (A*02:07-C*01:02-B*46:01. Analysis of KIR3D and their ligands HLA-A3/A11 and HLA-Bw4 showed that the frequencies of 3DL2+-A3/A11+ and 3DL2+-A3/A11− were 0.527 and 0.473, and the frequencies of 3DL1+-Bw4+, 3DL1+-Bw4−, 3DL1−-Bw4+, and 3DL1−-Bw4− were 0.552, 0.397, 0.038, and 0.013, respectively. The results of KIR/HLA-C combination analysis showed that all individuals had at least one inhibitory or activating KIR/HLA-C pair, and one KIR/HLA-C pair was the most frequent (157/239, followed by two pairs (46/239, three pairs (33/239, and no pairs (3/239. Comparison of KIR gene and HLA gene and their pair frequency between Yunnan Han and the isolated Han (FYDH who also lived in Yunnan province showed no significant difference (P>0.05 in KIR frequencies, but significant differences (P0.05 between the two populations for KIR/HLA pairs.

The Analysis of A Frequent TMPRSS3 Allele Containing P.V116M and P.V291L in A Cis Configuration among Deaf Koreans

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Ah Reum Kim

2017-10-01

Full Text Available We performed targeted re-sequencing to identify the genetic etiology of early-onset postlingual deafness and encountered a frequent TMPRSS3 allele harboring two variants in a cis configuration. We aimed to evaluate the pathogenicity of the allele. Among 88 cochlear implantees with autosomal recessive non-syndromic hearing loss, subjects with GJB2 and SLC26A4 mutations were excluded. Thirty-one probands manifesting early-onset postlingual deafness were sorted. Through targeted re-sequencing, we detected two families with a TMPRSS3 mutant allele containing p.V116M and p.V291L in a cis configuration, p.[p.V116M; p.V291L]. A minor allele frequency was calculated and proteolytic activity was measured. A p.[p.V116M; p.V291L] allele demonstrated a significantly higher frequency compared to normal controls and merited attention due to its high frequency (4.84%, 3/62. The first family showed a novel deleterious splice site variant—c.783-1G>A—in a trans allele, while the other showed homozygosity. The progression to deafness was noted within the first decade, suggesting DFNB10. The proteolytic activity was significantly reduced, confirming the severe pathogenicity. This frequent mutant allele significantly contributes to early-onset postlingual deafness in Koreans. For clinical implication and proper auditory rehabilitation, it is important to pay attention to this allele with a severe pathogenic potential.

FINDbase: A worldwide database for genetic variation allele frequencies updated

NARCIS (Netherlands)

M. Georgitsi (Marianthi); E. Viennas (Emmanouil); D.I. Antoniou (Dimitris I.); V. Gkantouna (Vassiliki); S. van Baal (Sjozef); E.F. Petricoin (Emanuel F.); K. Poulas (Konstantinos); G. Tzimas (Giannis); G.P. Patrinos (George)

2011-01-01

textabstractFrequency of INherited Disorders database (FIND base; http://www.findbase. org) records frequencies of causative genetic variations worldwide. Database records include the population and ethnic group or geographical region, the disorder name and the related gene, accompanied by links to

Identification of common bean alleles resistant to anthracnose using RAPD

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Ana L.M. Castanheira

1999-12-01

Full Text Available RAPD markers were identified close to common bean alleles responsible for resistance to the fungus Colletotrichum lindemuthianum and may be useful in selecting plants resistant to this pathogen. DNA from F2 plants of the crosses Carioca 300V x P45, Carioca 300V x Ouro and P24 x Ouro was amplified by RAPD. Line P45 has the Co.4 allele for resistance, and the Ouro cultivar has the Co.5 allele. The primer OPC08 amplified a DNA fragment of about 1059 bp linked to the Co.4 allele. The recombination frequency was 0.133 (SE = 0.039; 95% CI = 0.056-0.211. Using the primer OPF10 a DNA fragment of about 912 bp was amplified and found to be associated with the Co.5 allele. The recombination frequency was 0.115 (SE = 0.038; 95% CI = 0.041-0.189. A second marker (1122 pb amplified by the OPR03 primer was identified in the population P24 x Ouro. The recombination frequency for this marker was 0.363 (SE = 0.081; 95% CI = 0.205-0.522. Both these markers flanked the Co.5 allele. The markers identified in this study may be useful in identifying lines with the Co.4 and Co.5 alleles.Marcadores RAPD foram identificados próximos de alelos do feijão responsáveis pela resistência ao Colletotrichum lindemuthianum, visando auxiliar na seleção de plantas resistentes ao patógeno. Empregou-se o método dos bulks segregantes de DNA extraídos de plantas F2 dos seguintes cruzamentos: Carioca 300V x P45, Carioca 300V x Ouro e P24 x Ouro. A linhagem P45 é portadora do alelo Co.4 de resistência e o cultivar Ouro é portador do alelo Co.5, os quais foram marcados. Procedeu-se à reação RAPD dos bulks e foi identificado o iniciador OPC08 que amplificou um fragmento de DNA com cerca de 1059 pb, ligado ao alelo Co.4. A freqüência de recombinação foi de 0,133 (erro padrão 0,039 e o intervalo de confiança foi 0,056 e 0,211, com 95% de probabilidade. Em relação ao alelo Co.5 foi identificado um fragmento de DNA amplificado pelo iniciador OPF10 com cerca de 912 pb, na

Semiparametric Allelic Tests for Mapping Multiple Phenotypes: Binomial Regression and Mahalanobis Distance.

Science.gov (United States)

Majumdar, Arunabha; Witte, John S; Ghosh, Saurabh

2015-12-01

Binary phenotypes commonly arise due to multiple underlying quantitative precursors and genetic variants may impact multiple traits in a pleiotropic manner. Hence, simultaneously analyzing such correlated traits may be more powerful than analyzing individual traits. Various genotype-level methods, e.g., MultiPhen (O'Reilly et al. []), have been developed to identify genetic factors underlying a multivariate phenotype. For univariate phenotypes, the usefulness and applicability of allele-level tests have been investigated. The test of allele frequency difference among cases and controls is commonly used for mapping case-control association. However, allelic methods for multivariate association mapping have not been studied much. In this article, we explore two allelic tests of multivariate association: one using a Binomial regression model based on inverted regression of genotype on phenotype (Binomial regression-based Association of Multivariate Phenotypes [BAMP]), and the other employing the Mahalanobis distance between two sample means of the multivariate phenotype vector for two alleles at a single-nucleotide polymorphism (Distance-based Association of Multivariate Phenotypes [DAMP]). These methods can incorporate both discrete and continuous phenotypes. Some theoretical properties for BAMP are studied. Using simulations, the power of the methods for detecting multivariate association is compared with the genotype-level test MultiPhen's. The allelic tests yield marginally higher power than MultiPhen for multivariate phenotypes. For one/two binary traits under recessive mode of inheritance, allelic tests are found to be substantially more powerful. All three tests are applied to two different real data and the results offer some support for the simulation study. We propose a hybrid approach for testing multivariate association that implements MultiPhen when Hardy-Weinberg Equilibrium (HWE) is violated and BAMP otherwise, because the allelic approaches assume HWE

Some evidence for skewed mating type distribution in Iranian populations of Rhynchosporium commune, the cause of barley scald disease

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Arzanlou Mahdi

2016-07-01

Full Text Available Rhynchosporium commune (formerly known as Rhynchosporium secalis, the causal agent of scald disease on barley, is known to spread asexually by splash dispersed conidia. However, there are multiple lines of evidence for the possibility of a clandestine sexual cycle occurrence in this species including extensive genotypic diversity, equal distribution of mating type alleles across the world and expression of mating type genes. In the current study, the potential for the occurrence of a sexual cycle amongst the Iranian population of R. commune was assessed by analyzing distribution and frequency of the mating type alleles at both micro and macro-spatial scales. A total of 95 single-conidial R. commune isolates were obtained from different barley fields in Kurdistan province. Previously designed primers were applied in a multiplex PCR assay to study distribution and frequency of the mating type alleles within and between populations. Totally, 67 isolates were determined as MAT1-1 and the remaining 28 isolates as MAT1-2 throughout the sampling counties. The results obtained at a macro-spatial scale revealed that unlike Kamyaran county (both MAT1-1 and MAT1-2 at an equal ratio, an unequal distribution of mating type genes was dominant among R. commune isolates in both Mariwan and Dehgolan counties. Our findings support a predominantly asexual reproduction for Mariwan and Dehgolan counties and the possibility of sexual stage occurrence in Kamyarna county.

Advantage of using allele-specific copy numbers when testing for association in regions with common copy number variants.

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Gaëlle Marenne

Full Text Available Copy number variants (CNV can be called from SNP-arrays; however, few studies have attempted to combine both CNV and SNP calls to test for association with complex diseases. Even when SNPs are located within CNVs, two separate association analyses are necessary, to compare the distribution of bi-allelic genotypes in cases and controls (referred to as SNP-only strategy and the number of copies of a region (referred to as CNV-only strategy. However, when disease susceptibility is actually associated with allele specific copy-number states, the two strategies may not yield comparable results, raising a series of questions about the optimal analytical approach. We performed simulations of the performance of association testing under different scenarios that varied genotype frequencies and inheritance models. We show that the SNP-only strategy lacks power under most scenarios when the SNP is located within a CNV; frequently it is excluded from analysis as it does not pass quality control metrics either because of an increased rate of missing calls or a departure from fitness for Hardy-Weinberg proportion. The CNV-only strategy also lacks power because the association testing depends on the allele which copy number varies. The combined strategy performs well in most of the scenarios. Hence, we advocate the use of this combined strategy when testing for association with SNPs located within CNVs.

Inferring the flood frequency distribution for an ungauged basin using a spatially distributed rainfall-runoff model

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G. Moretti

2008-08-01

Full Text Available The estimation of the peak river flow for ungauged river sections is a topical issue in applied hydrology. Spatially distributed rainfall-runoff models can be a useful tool to this end, since they are potentially able to simulate the river flow at any location of the watershed drainage network. However, it is not fully clear to what extent these models can provide reliable simulations over a wide range of spatial scales. This issue is investigated here by applying a spatially distributed, continuous simulation rainfall-runoff model to infer the flood frequency distribution of the Riarbero River. This is an ungauged mountain creek located in northern Italy, whose drainage area is 17 km². The hydrological model is first calibrated by using a 1-year record of hourly meteorological data and river flows observed at the outlet of the 1294 km² wide Secchia River basin, of which the Riarbero is a tributary. The model is then validated by performing a 100-year long simulation of synthetic river flow data, which allowed us to compare the simulated and observed flood frequency distributions at the Secchia River outlet and the internal cross river section of Cavola Bridge, where the basin area is 337 km². Finally, another simulation of hourly river flows was performed by referring to the outlet of the Riarbero River, therefore allowing us to estimate the related flood frequency distribution. The results were validated by using estimates of peak river flow obtained by applying hydrological similarity principles and a regional method. The results show that the flood flow estimated through the application of the distributed model is consistent with the estimate provided by the regional procedure as well as the behaviors of the river banks. Conversely, the method based on hydrological similarity delivers an estimate that seems to be not as reliable. The analysis highlights interesting perspectives for the application of

Highly stable microwave carrier generation using a dual-frequency distributed feedback laser

NARCIS (Netherlands)

Khan, M.R.H.; Bernhardi, Edward; Marpaung, D.A.I.; Burla, M.; de Ridder, R.M.; Worhoff, Kerstin; Pollnau, Markus; Roeloffzen, C.G.H.

2012-01-01

Photonic generation of microwave carriers by using a dual-frequency distributed feedback waveguide laser in ytterbium-doped aluminum oxide is demonstrated. A highperformance optical frequency locked loop is implemented to stabilize the microwave carrier. This approach results in a microwave

The Influence of Orthographic Neighborhood Density and Word Frequency on Visual Word Recognition: Insights from RT Distributional Analyses

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Stephen Wee Hun eLim

2016-03-01

Full Text Available The effects of orthographic neighborhood density and word frequency in visual word recognition were investigated using distributional analyses of response latencies in visual lexical decision. Main effects of density and frequency were observed in mean latencies. Distributional analyses, in addition, revealed a density x frequency interaction: for low-frequency words, density effects were mediated predominantly by distributional shifting whereas for high-frequency words, density effects were absent except at the slower RTs, implicating distributional skewing. The present findings suggest that density effects in low-frequency words reflect processes involved in early lexical access, while the effects observed in high-frequency words reflect late postlexical checking processes.

Prevalence of Huntington's disease gene CAG trinucleotide repeat alleles in patients with bipolar disorder.

Science.gov (United States)

Ramos, Eliana Marisa; Gillis, Tammy; Mysore, Jayalakshmi S; Lee, Jong-Min; Alonso, Isabel; Gusella, James F; Smoller, Jordan W; Sklar, Pamela; MacDonald, Marcy E; Perlis, Roy H

2015-06-01

Huntington's disease is a neurodegenerative disorder characterized by motor, cognitive, and psychiatric symptoms that are caused by huntingtin gene (HTT) CAG trinucleotide repeat alleles of 36 or more units. A greater than expected prevalence of incompletely penetrant HTT CAG repeat alleles observed among individuals diagnosed with major depressive disorder raises the possibility that another mood disorder, bipolar disorder, could likewise be associated with Huntington's disease. We assessed the distribution of HTT CAG repeat alleles in a cohort of individuals with bipolar disorder. HTT CAG allele sizes from 2,229 Caucasian individuals diagnosed with DSM-IV bipolar disorder were compared to allele sizes in 1,828 control individuals from multiple cohorts. We found that HTT CAG repeat alleles > 35 units were observed in only one of 4,458 chromosomes from individuals with bipolar disorder, compared to three of 3,656 chromosomes from control subjects. These findings do not support an association between bipolar disorder and Huntington's disease. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Mannose-binding lectin variant alleles and HLA-DR4 alleles are associated with giant cell arteritis

DEFF Research Database (Denmark)

Jacobsen, Soren; Baslund, Bo; Madsen, Hans O.

2002-01-01

/GCA, MBL variant alleles were associated with signs of increased inflammatory activity and clinical signs of arteritic manifestations. This was not found for HLA-DR4 alleles. These findings indicate that HLA-DR4 and MBL are contributing to the pathophysiology of GCA at different levels in the disease...... alleles in controls, patients with PMR only, and patients with GCA was 37, 32, and 53% (p = 0.01), respectively. HLA-DRB1*04 was found in 47% of patients with PMR only and in 54% of patients with GCA, which differed significantly from the 35% found in controls (p = 0.01). HLA-DR4 alleles were...... not associated with any clinical phenotypes of PMR/GCA, whereas MBL variant alleles were associated with cranial arteritis, high erythrocyte sedimentation rate, and low B-hemoglobin. CONCLUSION: We found MBL variant alleles and HLA-DR4 alleles to be weak susceptibility markers for GCA. In patients with PMR...

Impact of QTL minor allele frequency on genomic evaluation using real genotype data and simulated phenotypes in Japanese Black cattle.

Science.gov (United States)

Uemoto, Yoshinobu; Sasaki, Shinji; Kojima, Takatoshi; Sugimoto, Yoshikazu; Watanabe, Toshio

2015-11-19

Genetic variance that is not captured by single nucleotide polymorphisms (SNPs) is due to imperfect linkage disequilibrium (LD) between SNPs and quantitative trait loci (QTLs), and the extent of LD between SNPs and QTLs depends on different minor allele frequencies (MAF) between them. To evaluate the impact of MAF of QTLs on genomic evaluation, we performed a simulation study using real cattle genotype data. In total, 1368 Japanese Black cattle and 592,034 SNPs (Illumina BovineHD BeadChip) were used. We simulated phenotypes using real genotypes under different scenarios, varying the MAF categories, QTL heritability, number of QTLs, and distribution of QTL effect. After generating true breeding values and phenotypes, QTL heritability was estimated and the prediction accuracy of genomic estimated breeding value (GEBV) was assessed under different SNP densities, prediction models, and population size by a reference-test validation design. The extent of LD between SNPs and QTLs in this population was higher in the QTLs with high MAF than in those with low MAF. The effect of MAF of QTLs depended on the genetic architecture, evaluation strategy, and population size in genomic evaluation. In genetic architecture, genomic evaluation was affected by the MAF of QTLs combined with the QTL heritability and the distribution of QTL effect. The number of QTL was not affected on genomic evaluation if the number of QTL was more than 50. In the evaluation strategy, we showed that different SNP densities and prediction models affect the heritability estimation and genomic prediction and that this depends on the MAF of QTLs. In addition, accurate QTL heritability and GEBV were obtained using denser SNP information and the prediction model accounted for the SNPs with low and high MAFs. In population size, a large sample size is needed to increase the accuracy of GEBV. The MAF of QTL had an impact on heritability estimation and prediction accuracy. Most genetic variance can be captured

Distribution of photoperiod-insensitive alleles Ppd-B1a and Ppd-D1a and their effect on heading time in Japanese wheat cultivars.

Science.gov (United States)

Seki, Masako; Chono, Makiko; Matsunaka, Hitoshi; Fujita, Masaya; Oda, Shunsuke; Kubo, Katashi; Kiribuchi-Otobe, Chikako; Kojima, Hisayo; Nishida, Hidetaka; Kato, Kenji

2011-12-01

The genotypes of photoperiod response genes Ppd-B1 and Ppd-D1 in Japanese wheat cultivars were determined by a PCR-based method, and heading times were compared among genotypes. Most of the Japanese wheat cultivars, except those from the Hokkaido region, carried the photoperiod-insensitive allele Ppd-D1a, and heading was accelerated 10.3 days compared with the Ppd-D1b genotype. Early cultivars with Ppd-D1a may have been selected to avoid damage from preharvest rain. In the Hokkaido region, Ppd-D1a frequency was lower and heading date was late regardless of Ppd-D1 genotype, suggesting another genetic mechanism for late heading in Hokkaido cultivars. In this study, only 11 cultivars proved to carry Ppd-B1a, and all of them carried another photoperiod-insensitive allele, Ppd-D1a. The Ppd-B1a/Ppd-D1a genotype headed 6.7 days earlier than the Ppd-B1b/Ppd-D1a genotype, indicating a significant effect of Ppd-B1a in the genetic background with Ppd-D1a. Early-maturity breeding in Japan is believed to be accelerated by the introduction of the Ppd-B1a allele into medium-heading cultivars carrying Ppd-D1a. Pedigree analysis showed that Ppd-B1a in three extra-early commercial cultivars was inherited from 'Shiroboro 21' by early-heading Chugoku lines bred at the Chugoku Agriculture Experimental Station.

Genotype frequencies of polymorphic MDR1 variants in the Kazakhstani population

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Samat Kozhakhmetov

2014-03-01

Full Text Available Introduction: Statins appear to be handled by an ATP-dependent membrane transporter and three SNPs (C1236T (rs1128503, G2677T (rs2032582, and C3435T (rs1045642, which capture the common genetic variation at this locus. Individuals, who carry the T allele at each SNP (i.e., the T-T-T haplotype, have higher systemic exposure to simvastatin. A triallelic thymine (T - guanine (G - adenine (A, which is  a point mutation at nucleotide 2677 in exon 22, leads to ABCB1 in a non-synonymous codons (GCT alanine, TCT serine, threonine ACT at position 893 in a cytoplasmic loop of ATP-dependent membrane transporters. Methods: Blood samples from healthy individuals were collected in the Republican Diagnostic Center, Astana, Kazakhstan. The research samples included 461 healthy people. Genomic DNA was extracted from peripheral blood using the ‘salting out’ procedure. For the MDR1 exon 21, 2677G˃T/A (Ala893Ser/Thr polymorphism was genotyped by PCR sequencing by the use of dye-terminator (ABI 3730xl sequencer. Results: The GG allele appeared in 23% of samples, the GA in 6.7%, the GT in 44%, the non-G heterozygote in 4.5%, and the non-G homozygote in 18%. These results are consistent with previously published data. Importantly, the frequency of 2677T alleles in our group was 15.4%. This represents the lowest frequency of this allele compared to published data in different populations. The frequency of the 2677T allele in Asians and Caucasians varies from 38 to 62%, and is 15% for African Americans. On the other hand, the 2677A allele frequency in the Japanese varies from 15 to 22%, and in Caucasians from 2% and 4%. The 2677A allele frequency has been found in 4.6% of samples. Conclusions: Our study further emphasizes differences between various Asian populations and the importance of repeating this genetic study  in different ethnic groups.

Gene frequencies of ABO and Rh blood groups in Nigeria: A review

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Abass Toba Anifowoshe

2017-07-01

Conclusion: The study provides information on the distribution/frequency of ABO/Rh(D blood group and their corresponding allelic proportion in a large Nigeria study. It also revealed how the Nigerian populations in the North, South, West and East vary with respect to genetic traits. This vital information will be important for population genetics and anthropology studies and may be helpful in planning for future health strategy and blueprint, particularly planning with regards to disease management and blood transfusion medicine.

A modified Janus cassette (Sweet Janus to improve allelic replacement efficiency by high-stringency negative selection in Streptococcus pneumoniae.

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Yuan Li

Full Text Available The Janus cassette permits marker-free allelic replacement or knockout in streptomycin-resistant Streptococcus pneumoniae (pneumococcus through sequential positive and negative selection. Spontaneous revertants of Janus can lead to high level of false-positives during negative selection, which necessitate a time-consuming post-selection screening process. We hypothesized that an additional counter-selectable marker in Janus would decrease the revertant frequency and reduce false-positives, since simultaneous reversion of both counter-selectable makers is much less likely. Here we report a modified cassette, Sweet Janus (SJ, in which the sacB gene from Bacillus subtilis conferring sucrose sensitivity is added to Janus. By using streptomycin and sucrose simultaneously as selective agents, the frequency of SJ double revertants was about 105-fold lower than the frequency of Janus revertants. Accordingly, the frequency of false-positives in the SJ-mediated negative selection was about 100-fold lower than what was seen for Janus. Thus, SJ enhances negative selection stringency and can accelerate allelic replacement in pneumococcus, especially when transformation frequency is low due to strain background or suboptimal transformation conditions. Results also suggested the sacB gene alone can function as a counter-selectable marker in the Gram-positive pneumococcus, which will have the advantage of not requiring a streptomycin-resistant strain for allelic replacement.

Linear time algorithms to construct populations fitting multiple constraint distributions at genomic scales.

Science.gov (United States)

Siragusa, Enrico; Haiminen, Niina; Utro, Filippo; Parida, Laxmi

2017-10-09

Computer simulations can be used to study population genetic methods, models and parameters, as well as to predict potential outcomes. For example, in plant populations, predicting the outcome of breeding operations can be studied using simulations. In-silico construction of populations with pre-specified characteristics is an important task in breeding optimization and other population genetic studies. We present two linear time Simulation using Best-fit Algorithms (SimBA) for two classes of problems where each co-fits two distributions: SimBA-LD fits linkage disequilibrium and minimum allele frequency distributions, while SimBA-hap fits founder-haplotype and polyploid allele dosage distributions. An incremental gap-filling version of previously introduced SimBA-LD is here demonstrated to accurately fit the target distributions, allowing efficient large scale simulations. SimBA-hap accuracy and efficiency is demonstrated by simulating tetraploid populations with varying numbers of founder haplotypes, we evaluate both a linear time greedy algoritm and an optimal solution based on mixed-integer programming. SimBA is available on http://researcher.watson.ibm.com/project/5669.

Global pharmacogenomics: distribution of CYP3A5 polymorphisms and phenotypes in the Brazilian population.

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Guilherme Suarez-Kurtz

Full Text Available The influence of self-reported "race/color", geographical origin and genetic ancestry on the distribution of three functional CYP3A5 polymorphisms, their imputed haplotypes and inferred phenotypes was examined in 909 healthy, adult Brazilians, self-identified as White, Brown or Black ("race/color" categories of the Brazilian census. The cohort was genotyped for CYP3A5*3 (rs776746, CYP3A5*6 (rs10264272 and CYP3A5*7 (rs41303343, CYP3A5 haplotypes were imputed and CYP3A5 metabolizer phenotypes were inferred according to the number of defective CYP3A5 alleles. Estimates of the individual proportions of Amerindian, African and European ancestry were available for the entire cohort. Multinomial log-linear regression models were applied to infer the statistical association between the distribution of CYP3A5 alleles, haplotypes and phenotypes (response variables, and self-reported Color, geographical region and ancestry (explanatory variables. We found that Color per se or in combination with geographical region associates significantly with the distribution of CYP3A5 variant alleles and CYP3A5 metabolizer phenotypes, whereas geographical region per se influences the frequency distribution of CYP3A5 variant alleles. The odds of having the default CYP3A5*3 allele and the poor metabolizer phenotype increases continuously with the increase of European ancestry and decrease of African ancestry. The opposite trend is observed in relation to CYP3A5*6, CYP3A5*7, the default CYP3A5*1 allele, and both the extensive and intermediate phenotypes. No significant effect of Amerindian ancestry on the distribution of CYP3A5 alleles or phenotypes was observed. In conclusion, this study strongly supports the notion that the intrinsic heterogeneity of the Brazilian population must be acknowledged in the design and interpretation of pharmacogenomic studies, and dealt with as a continuous variable, rather than proportioned in arbitrary categories that do not capture the

Ultra-stable long distance optical frequency distribution using the Internet fiber network.

Science.gov (United States)

Lopez, Olivier; Haboucha, Adil; Chanteau, Bruno; Chardonnet, Christian; Amy-Klein, Anne; Santarelli, Giorgio

2012-10-08

We report an optical link of 540 km for ultrastable frequency distribution over the Internet fiber network. The stable frequency optical signal is processed enabling uninterrupted propagation on both directions. The robustness and the performance of the link are enhanced by a cost effective fully automated optoelectronic station. This device is able to coherently regenerate the return optical signal with a heterodyne optical phase locking of a low noise laser diode. Moreover the incoming signal polarization variation are tracked and processed in order to maintain beat note amplitudes within the operation range. Stable fibered optical interferometer enables optical detection of the link round trip phase signal. The phase-noise compensated link shows a fractional frequency instability in 10 Hz bandwidth of 5 × 10(-15) at one second measurement time and 2 × 10(-19) at 30,000 s. This work is a significant step towards a sustainable wide area ultrastable optical frequency distribution and comparison network.

Oxide vapor distribution from a high-frequency sweep e-beam system

Science.gov (United States)

Chow, R.; Tassano, P. L.; Tsujimoto, N.

1995-03-01

Oxide vapor distributions have been determined as a function of operating parameters of a high frequency sweep e-beam source combined with a programmable sweep controller. We will show which parameters are significant, the parameters that yield the broadest oxide deposition distribution, and the procedure used to arrive at these conclusions. A design-of-experimental strategy was used with five operating parameters: evaporation rate, sweep speed, sweep pattern (pre-programmed), phase speed (azimuthal rotation of the pattern), profile (dwell time as a function of radial position). A design was chosen that would show which of the parameters and parameter pairs have a statistically significant effect on the vapor distribution. Witness flats were placed symmetrically across a 25 inches diameter platen. The stationary platen was centered 24 inches above the e-gun crucible. An oxide material was evaporated under 27 different conditions. Thickness measurements were made with a stylus profilometer. The information will enable users of the high frequency e-gun systems to optimally locate the source in a vacuum system and understand which parameters have a major effect on the vapor distribution.

Allele coding in genomic evaluation

DEFF Research Database (Denmark)

Standen, Ismo; Christensen, Ole Fredslund

2011-01-01

Genomic data are used in animal breeding to assist genetic evaluation. Several models to estimate genomic breeding values have been studied. In general, two approaches have been used. One approach estimates the marker effects first and then, genomic breeding values are obtained by summing marker...... effects. In the second approach, genomic breeding values are estimated directly using an equivalent model with a genomic relationship matrix. Allele coding is the method chosen to assign values to the regression coefficients in the statistical model. A common allele coding is zero for the homozygous...... genotype of the first allele, one for the heterozygote, and two for the homozygous genotype for the other allele. Another common allele coding changes these regression coefficients by subtracting a value from each marker such that the mean of regression coefficients is zero within each marker. We call...

Time-frequency representation of a highly nonstationary signal via the modified Wigner distribution

Science.gov (United States)

Zoladz, T. F.; Jones, J. H.; Jong, J.

1992-01-01

A new signal analysis technique called the modified Wigner distribution (MWD) is presented. The new signal processing tool has been very successful in determining time frequency representations of highly non-stationary multicomponent signals in both simulations and trials involving actual Space Shuttle Main Engine (SSME) high frequency data. The MWD departs from the classic Wigner distribution (WD) in that it effectively eliminates the cross coupling among positive frequency components in a multiple component signal. This attribute of the MWD, which prevents the generation of 'phantom' spectral peaks, will undoubtedly increase the utility of the WD for real world signal analysis applications which more often than not involve multicomponent signals.

Frequency and distribution of Notch mutations in tumor cell lines

International Nuclear Information System (INIS)

Mutvei, Anders Peter; Fredlund, Erik; Lendahl, Urban

2015-01-01

Deregulated Notch signaling is linked to a variety of tumors and it is therefore important to learn more about the frequency and distribution of Notch mutations in a tumor context. In this report, we use data from the recently developed Cancer Cell Line Encyclopedia to assess the frequency and distribution of Notch mutations in a large panel of cancer cell lines in silico. Our results show that the mutation frequency of Notch receptor and ligand genes is at par with that for established oncogenes and higher than for a set of house-keeping genes. Mutations were found across all four Notch receptor genes, but with notable differences between protein domains, mutations were for example more prevalent in the regions encoding the LNR and PEST domains in the Notch intracellular domain. Furthermore, an in silico estimation of functional impact showed that deleterious mutations cluster to the ligand-binding and the intracellular domains of NOTCH1. For most cell line groups, the mutation frequency of Notch genes is higher than in associated primary tumors. Our results shed new light on the spectrum of Notch mutations after in vitro culturing of tumor cells. The higher mutation frequency in tumor cell lines indicates that Notch mutations are associated with a growth advantage in vitro, and thus may be considered to be driver mutations in a tumor cell line context. The online version of this article (doi:10.1186/s12885-015-1278-x) contains supplementary material, which is available to authorized users

Blind Separation of Nonstationary Sources Based on Spatial Time-Frequency Distributions

Directory of Open Access Journals (Sweden)

Zhang Yimin

2006-01-01

Full Text Available Blind source separation (BSS based on spatial time-frequency distributions (STFDs provides improved performance over blind source separation methods based on second-order statistics, when dealing with signals that are localized in the time-frequency (t-f domain. In this paper, we propose the use of STFD matrices for both whitening and recovery of the mixing matrix, which are two stages commonly required in many BSS methods, to provide robust BSS performance to noise. In addition, a simple method is proposed to select the auto- and cross-term regions of time-frequency distribution (TFD. To further improve the BSS performance, t-f grouping techniques are introduced to reduce the number of signals under consideration, and to allow the receiver array to separate more sources than the number of array sensors, provided that the sources have disjoint t-f signatures. With the use of one or more techniques proposed in this paper, improved performance of blind separation of nonstationary signals can be achieved.

Daris, a low-frequency distributed aperture array for radio astronomy in space

NARCIS (Netherlands)

Boonstra, A.J.; Saks, N.; Bentum, Marinus Jan; van 't Klooster, K.; Falcke, H.

2010-01-01

DARIS (Distributed Aperture Array for Radio Astronomy in Space) is a radio astronomy space mission concept aimed at observing the low-frequency radio sky in the range 1-10 MHz. Because of the Earth's ionospheric disturbances and opaqueness, this frequency range can only be observed from space. The

Signatures of positive selection: from selective sweeps at individual loci to subtle allele frequency changes in polygenic adaptation.

Science.gov (United States)

Stephan, Wolfgang

2016-01-01

In the past 15 years, numerous methods have been developed to detect selective sweeps underlying adaptations. These methods are based on relatively simple population genetic models, including one or two loci at which positive directional selection occurs, and one or two marker loci at which the impact of selection on linked neutral variation is quantified. Information about the phenotype under selection is not included in these models (except for fitness). In contrast, in the quantitative genetic models of adaptation, selection acts on one or more phenotypic traits, such that a genotype-phenotype map is required to bridge the gap to population genetics theory. Here I describe the range of population genetic models from selective sweeps in a panmictic population of constant size to evolutionary traffic when simultaneous sweeps at multiple loci interfere, and I also consider the case of polygenic selection characterized by subtle allele frequency shifts at many loci. Furthermore, I present an overview of the statistical tests that have been proposed based on these population genetics models to detect evidence for positive selection in the genome. © 2015 John Wiley & Sons Ltd.

Estimating the probability of allelic drop-out of STR alleles in forensic genetics

DEFF Research Database (Denmark)

Tvedebrink, Torben; Eriksen, Poul Svante; Mogensen, Helle Smidt

2009-01-01

In crime cases with available DNA evidence, the amount of DNA is often sparse due to the setting of the crime. In such cases, allelic drop-out of one or more true alleles in STR typing is possible. We present a statistical model for estimating the per locus and overall probability of allelic drop......-out using the results of all STR loci in the case sample as reference. The methodology of logistic regression is appropriate for this analysis, and we demonstrate how to incorporate this in a forensic genetic framework....

HLA-DQA1 and HLA-DQB1 allele diversity and its extended haplotypes in Madeira Island (Portugal).

Science.gov (United States)

Spínola, H; Lemos, A; Couto, A R; Parreira, B; Soares, M; Dutra, I; Bruges-Armas, J; Brehm, A

2017-02-01

This study shows, for the first time, high-resolution allele frequencies of HLA-DQA1 loci in Madeira Island (Portugal) and allows us to better understand and refine present knowledge on DQB1 variation, with the identification of several alleles not previously reported in this population. Estimates on haplotype profile, involving HLA-A, HLA-B, HLA-DRB1, HLA-DQA1 and HLA-DQB1, are also reported. © 2016 John Wiley & Sons Ltd.

Frequency of single nucleotide polymorphisms of some immune response genes in a population sample from São Paulo, Brazil

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Léa Campos de Oliveira

2011-09-01

Full Text Available Objective: To present the frequency of single nucleotide polymorphismsof a few immune response genes in a population sample from SãoPaulo City (SP, Brazil. Methods: Data on allele frequencies ofknown polymorphisms of innate and acquired immunity genes werepresented, the majority with proven impact on gene function. Datawere gathered from a sample of healthy individuals, non-HLA identicalsiblings of bone marrow transplant recipients from the Hospital dasClínicas da Faculdade de Medicina da Universidade de São Paulo,obtained between 1998 and 2005. The number of samples variedfor each single nucleotide polymorphism analyzed by polymerasechain reaction followed by restriction enzyme cleavage. Results:Allele and genotype distribution of 41 different gene polymorphisms,mostly cytokines, but also including other immune response genes,were presented. Conclusion: We believe that the data presentedhere can be of great value for case-control studies, to define whichpolymorphisms are present in biologically relevant frequencies and toassess targets for therapeutic intervention in polygenic diseases witha component of immune and inflammatory responses.

Recombinational micro-evolution of functionally different metallothionein promoter alleles from Orchesella cincta

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van Straalen Nico M

2007-06-01

Full Text Available Abstract Background Metallothionein (mt transcription is elevated in heavy metal tolerant field populations of Orchesella cincta (Collembola. This suggests that natural selection acts on transcriptional regulation of mt in springtails at sites where cadmium (Cd levels in soil reach toxic values This study investigates the nature and the evolutionary origin of polymorphisms in the metallothionein promoter (pmt and their functional significance for mt expression. Results We sequenced approximately 1600 bp upstream the mt coding region by genome walking. Nine pmt alleles were discovered in NW-European populations. They differ in the number of some indels, consensus transcription factor binding sites and core promoter elements. Extensive recombination events between some of the alleles can be inferred from the alignment. A deviation from neutral expectations was detected in a cadmium tolerant population, pointing towards balancing selection on some promoter stretches. Luciferase constructs were made from the most abundant alleles, and responses to Cd, paraquat (oxidative stress inducer and moulting hormone were studied in cell lines. By using paraquat we were able to dissect the effect of oxidative stress from the Cd specific effect, and extensive differences in mt induction levels between these two stressors were observed. Conclusion The pmt alleles evolved by a number of recombination events, and exhibited differential inducibilities by Cd, paraquat and molting hormone. In a tolerant population from a metal contaminated site, promoter allele frequencies differed significantly from a reference site and nucleotide polymorphisms in some promoter stretches deviated from neutral expectations, revealing a signature of balancing selection. Our results suggest that the structural differences in the Orchesella cincta metallothionein promoter alleles contribute to the metallothionein -over-expresser phenotype in cadmium tolerant populations.

On the Frequency Distribution of Neutral Particles from Low-Energy Strong Interactions

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Federico Colecchia

2017-01-01

Full Text Available The rejection of the contamination, or background, from low-energy strong interactions at hadron collider experiments is a topic that has received significant attention in the field of particle physics. This article builds on a particle-level view of collision events, in line with recently proposed subtraction methods. While conventional techniques in the field usually concentrate on probability distributions, our study is, to our knowledge, the first attempt at estimating the frequency distribution of background particles across the kinematic space inside individual collision events. In fact, while the probability distribution can generally be estimated given a model of low-energy strong interactions, the corresponding frequency distribution inside a single event typically deviates from the average and cannot be predicted a priori. We present preliminary results in this direction and establish a connection between our technique and the particle weighting methods that have been the subject of recent investigation at the Large Hadron Collider.

Global phylogeography of the avian malaria pathogen Plasmodium relictum based on MSP1 allelic diversity

Science.gov (United States)

Hellgren, Olof; Atkinson, Carter T.; Bensch, Staffan; Albayrak, Tamer; Dimitrov, Dimitar; Ewen, John G.; Kim, Kyeong Soon; Lima, Marcos R.; Martin, Lynn; Palinauskas, Vaidas; Ricklefs, Robert; Sehgal, Ravinder N. M.; Gediminas, Valkiunas; Tsuda, Yoshio; Marzal, Alfonso

2015-01-01

Knowing the genetic variation that occurs in pathogen populations and how it is distributed across geographical areas is essential to understand parasite epidemiology, local patterns of virulence, and evolution of host-resistance. In addition, it is important to identify populations of pathogens that are evolutionarily independent and thus ‘free’ to adapt to hosts and environments. Here, we investigated genetic variation in the globally distributed, highly invasive avian malaria parasite Plasmodium relictum, which has several distinctive mitochondrial haplotyps (cyt b lineages, SGS1, GRW11 and GRW4). The phylogeography of P. relictum was accessed using the highly variable nuclear gene merozoite surface protein 1 (MSP1), a gene linked to the invasion biology of the parasite. We show that the lineage GRW4 is evolutionarily independent of GRW11 and SGS1 whereas GRW11 and SGS1 share MSP1 alleles and thus suggesting the presence of two distinct species (GRW4 versus SGS1 and GRW11). Further, there were significant differences in the global distribution of MSP1 alleles with differences between GRW4 alleles in the New and the Old World. For SGS1, a lineage formerly believed to have both tropical and temperate transmission, there were clear differences in MSP1 alleles transmitted in tropical Africa compared to the temperate regions of Europe and Asia. Further, we highlight the occurrence of multiple MSP1 alleles in GRW4 isolates from the Hawaiian Islands, where the parasite has contributed to declines and extinctions of endemic forest birds since it was introduced. This study stresses the importance of multiple independent loci for understanding patterns of transmission and evolutionary independence across avian malaria parasites.

Allelic diversity of S-RNase at the self-incompatibility locus in natural flowering cherry populations (Prunus lannesiana var. speciosa).

Science.gov (United States)

Kato, S; Mukai, Y

2004-03-01

In the Rosaceae family, which includes Prunus, gametophytic self-incompatibility (GSI) is controlled by a single multiallelic locus (S-locus), and the S-locus product expressed in the pistils is a glycoprotein with ribonuclease activity (S-RNase). Two populations of flowering cherry (Prunus lannesiana var. speciosa), located on Hachijo Island in Japan's Izu Islands, were sampled, and S-allele diversity was surveyed based on the sequence polymorphism of S-RNase. A total of seven S-alleles were cloned and sequenced. The S-RNases of flowering cherry showed high homology to those of Prunus cultivars (P. avium and P. dulcis). In the phylogenetic tree, the S-RNases of flowering cherry and other Prunus cultivars formed a distinct group, but they did not form species-specific subgroups. The nucleotide substitution pattern in S-RNases of flowering cherry showed no excess of nonsynonymous substitutions relative to synonymous substitutions. However, the S-RNases of flowering cherry had a higher Ka/Ks ratio than those of other Prunus cultivars, and a subtle heterogeneity in the nucleotide substitution rates was observed among the Prunus species. The S-genotype of each individual was determined by Southern blotting of restriction enzyme-digested genomic DNA, using cDNA for S-RNase as a probe. A total of 22 S-alleles were identified. All individuals examined were heterozygous, as expected under GSI. The allele frequencies were, contrary to the expectation under GSI, significantly unequal. The two populations studied showed a high degree of overlap, with 18 shared alleles. However, the allele frequencies differed considerably between the two populations.

Distribution of HLA-A,B alleles in 13 panels of blood donors in France.

Science.gov (United States)

Prevost, P; Busson, M; Marcelli-Barge, A

1984-05-01

In this study, we analysed 13 samples of the French population--4147 non-related individuals living in Bordeaux, Brest, Caen, Dijon, Limoges, Lyon, Marseille, Nancy, Paris, Poitiers, Rennes, Strasbourg and Toulouse--all of whom were typed for 10 alleles of the HLA-A locus and 16 alleles of the HLA-B locus. The results showed a strong heterogeneity (chi 2 = 675.13 for 324 df, p less than 10(5)). A diagram has been drawn up, showing the matrix of genetic distances obtained thanks to the B2 of Balkrishnan & Sanghvi (1968). This diagram enables us to envisage the hypothesis of 6 homogeneous clusters. A partition of chi 2 was used to test this 6 luster hypothesis: Paris and Caen (p = 0.98); Nancy, Strasbourg (p less than 5%); Rennes, Brest (p less than 1%); Dijon, Lyon, Marseille (p = 0.89); Limoges, Poitiers (p = 0.18); Toulouse, Bordeaux (p less than 10(-5)). The heterogeneity within these clusters represents only 1/43 of the total heterogeneity.

Frequencies of polymorphisms of the Rh, Kell, Kidd, Duffy and Diego systems of Santa Catarina, Southern Brazil

Directory of Open Access Journals (Sweden)

Daiane Cobianchi Costa

Full Text Available ABSTRACT BACKGROUND: Red blood cell genes are highly polymorphic with the distribution of alleles varying between different populations and ethnic groups. The objective of this study was to investigate gene polymorphisms of blood groups in the state of Santa Catarina, Southern Brazil. METHODS: Three hundred and seventy-three unrelated blood donors and 31 transfusion-dependent patients were evaluated to investigate polymorphisms of the Rh, Kell, Duffy, Kidd, and Diego blood group systems in a population from the state of Santa Catarina. The subjects, from seven regions that comprise the blood-banking network of the state, were assessed between August 2011 and March 2014. The genotypes of the Rh, Kell, Duffy, Kidd, and Diego systems were determined using the restriction fragment length polymorphism-polymerase chain reaction and allele-specific polymerase chain reaction techniques. RESULTS: The genotype frequencies in this study were significantly different when populations from different regions of Santa Catarina were compared. Furthermore, there were also significant differences in the genetic frequencies compared to other Brazilian states. The genotype frequencies of the Kell and Kidd blood groups are similar to European populations from Naples, Italy and Zurich, Switzerland. CONCLUSION: This article reports for the first time the frequency of polymorphisms of blood group systems in blood donors from Santa Catarina, Southern Brazil.

Real-time updating of the flood frequency distribution through data assimilation

Science.gov (United States)

Aguilar, Cristina; Montanari, Alberto; Polo, María-José

2017-07-01

We explore the memory properties of catchments for predicting the likelihood of floods based on observations of average flows in pre-flood seasons. Our approach assumes that flood formation is driven by the superimposition of short- and long-term perturbations. The former is given by the short-term meteorological forcing leading to infiltration and/or saturation excess, while the latter is originated by higher-than-usual storage in the catchment. To exploit the above sensitivity to long-term perturbations, a meta-Gaussian model and a data assimilation approach are implemented for updating the flood frequency distribution a season in advance. Accordingly, the peak flow in the flood season is predicted in probabilistic terms by exploiting its dependence on the average flow in the antecedent seasons. We focus on the Po River at Pontelagoscuro and the Danube River at Bratislava. We found that the shape of the flood frequency distribution is noticeably impacted by higher-than-usual flows occurring up to several months earlier. The proposed technique may allow one to reduce the uncertainty associated with the estimation of flood frequency.

Mutational jackpot events generate effective frequency-dependent selection in adapting populations

Science.gov (United States)

Hallatschek, Oskar

The site-frequency spectrum is one the most easily measurable quantities that characterize the genetic diversity of a population. While most neutral models predict that site frequency spectra should decay with increasing frequency, a high-frequency uptick has been reported in many populations. Anomalies in the high-frequency tail are particularly unsettling because the highest frequencies can be measured with greatest accuracy. Here, we show that an uptick in the spectrum of neutral mutations generally arises when mutant frequencies are dominated by rare jackpot events, mutational events with large descendant numbers. This leads to an effective pattern of frequency-dependent selection (or unstable internal equilibrium at one half frequency) that causes an accumulation of high-frequency polymorphic sites. We reproduce the known uptick occurring for recurrent hitchhiking (genetic draft) as well as rapid adaptation, and (in the future) generalize the shape of the high-frequency tail to other scenarios that are dominated by jackpot events, such as frequent range expansions. We also tackle (in the future) the inverse approach to use the high-frequency uptick for learning about the tail of the offspring number distribution. Positively selected alleles need to surpass, typically, an u NSF Career Award (PoLS), NIH NIGMS R01, Simons Foundation.

Inverter design for high frequency power distribution

Science.gov (United States)

King, R. J.

1985-01-01

A class of simple resonantly commutated inverters are investigated for use in a high power (100 KW - 1000 KW) high frequency (10 KHz - 20 KHz) AC power distribution system. The Mapham inverter is found to provide a unique combination of large thyristor turn-off angle and good utilization factor, much better than an alternate 'current-fed' inverter. The effects of loading the Mapham inverter entirely with rectifier loads are investigated by simulation and with an experimental 3 KW 20 KHz inverter. This inverter is found to be well suited to a power system with heavy rectifier loading.

Frequency distribution analysis of the long-lived beta-activity of air dust

International Nuclear Information System (INIS)

Bunzl, K.; Hoetzl, H.; Winkler, R.

1977-01-01

In order to compare the average annual beta activities of air dust a frequency distribution analysis of data has been carried out in order to select a representative quantity for the average value of the data group. It was found that the data to be analysed were consistent with a log-normal frequency distribution and therefore calculations were made of, as the representative average, the median of the beta activity of each year as the antilog of the arithmetric mean of the logarithms, log x, of the analytical values x. The 95% confidence limits were also obtained. The quantities thus calculated are summarized in tabular form. (U.K.)

Single-frequency thulium-doped distributed-feedback fibre laser

DEFF Research Database (Denmark)

Agger, Søren; Povlsen, Jørn Hedegaard; Varming, Poul

2004-01-01

We have successfully demonstrated a single-frequency distributed-feedback (DFB) thulium-doped silica fiber laser emitting at a wavelength of 1735 nm. The laser cavity is less than 5 cm long and is formed by intracore UV-written Bragg gratings with a phase shift. The laser is pumped at 790 nm from...... a Ti:sapphire laser and has a threshold pump power of 59 mW. The laser has a maximum output power of 1 mW in a singlefrequency, single-polarization radiation mode and is tunable over a few nanometers. To the best of the authors’ knowledge, this is the first report of a single-frequency DFB fiber laser...... that uses thulium as the amplifying medium. The lasing wavelength is the longest demonstrated with DFB fiber lasers and yet is among the shortest obtained for thulium-doped silica fiber lasers....

Maximum-likelihood methods for array processing based on time-frequency distributions

Science.gov (United States)

Zhang, Yimin; Mu, Weifeng; Amin, Moeness G.

1999-11-01

This paper proposes a novel time-frequency maximum likelihood (t-f ML) method for direction-of-arrival (DOA) estimation for non- stationary signals, and compares this method with conventional maximum likelihood DOA estimation techniques. Time-frequency distributions localize the signal power in the time-frequency domain, and as such enhance the effective SNR, leading to improved DOA estimation. The localization of signals with different t-f signatures permits the division of the time-frequency domain into smaller regions, each contains fewer signals than those incident on the array. The reduction of the number of signals within different time-frequency regions not only reduces the required number of sensors, but also decreases the computational load in multi- dimensional optimizations. Compared to the recently proposed time- frequency MUSIC (t-f MUSIC), the proposed t-f ML method can be applied in coherent environments, without the need to perform any type of preprocessing that is subject to both array geometry and array aperture.

CYP3A4*18: it is not rare allele in Japanese population.

Science.gov (United States)

Yamamoto, Takehito; Nagafuchi, Nobue; Ozeki, Takeshi; Kubota, Takahiro; Ishikawa, Hiroshi; Ogawa, Seishi; Yamada, Yasuhiko; Hirai, Hisamaru; Iga, Tatsuji

2003-01-01

We sequenced all 13 exons of the CYP3A4 gene derived from 48 Japanese subjects. One subject possess the 20070 T>C mutation in the exon 10 (result in leu293Pro substitution, namely CYP3A4(*)18), as heterozygote. Thus, we investigated the frequency of CYP3A4(*)18 in 118 Japanese population using polymerase chain reaction-restriction fragment length polymorphism with Msp I and determined that the frequency of the CYP3A4(*)18 allele was 1.3%.

Association of HLA-DRB1 alleles with susceptibility to mixed connective tissue disease in Polish patients.

Science.gov (United States)

Paradowska-Gorycka, A; Stypińska, B; Olesińska, M; Felis-Giemza, A; Mańczak, M; Czuszynska, Z; Zdrojewski, Z; Wojciechowicz, J; Jurkowska, M

2016-01-01

Mixed connective tissue disease (MCTD) is a systemic autoimmune disease, originally defined as a connective tissue inflammatory syndrome with overlapping features of systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), polymyositis/dermatomyositis (PM/DM) and systemic sclerosis (SSc), characterized by the presence of antibodies against components of the U1 small nuclear ribonucleoprotein (U1snRNP). The aim of the study was to assess the frequency of (high-resolution-typed) DRB1 alleles in a cohort of Polish patients with MCTD (n = 103). Identification of the variants potentially associated with risk and protection was carried out by comparison with the DKMS Polish Bone Marrow Donor Registry (41306 alleles). DRB1*15:01 (odds ratio (OR): 6.06; 95% confidence interval (CI) 4.55-8.06), DRB1*04 (OR: 3.69; 95% CI 2.69-5.01) and *09:01 (OR: 8.12; 95% CI 2.15-21.75) were identified as risk alleles for MCTD, while HLA-DRB1*07:01 allele was found to be protective (OR: 0.50; 95% CI 0.28-0.83). The carrier frequency of the DRB1*01 was higher in MCTD patients compared with controls, although the differences were not statistically significant. Our results confirm the modulating influence of HLA-DRB1 genotypes on development of connective tissue diseases such as MCTD. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The derived allele of ASPM is associated with lexical tone perception.

Directory of Open Access Journals (Sweden)

Patrick C M Wong

Full Text Available The ASPM and MCPH1 genes have been implicated in the adaptive evolution of the human brain [Mekel-Bobrov N. et al., 2005. Ongoing adaptive evolution of ASPM, a brain size determinant in homo sapiens. Science 309; Evans P.D. et al., 2005. Microcephalin, a gene regulating brain size, continues to evolve adaptively in humans. Science 309]. Curiously, experimental attempts have failed to connect the implicated SNPs in these genes with higher-level brain functions. These results stand in contrast with a population-level study linking the population frequency of their alleles with the tendency to use lexical tones in a language [Dediu D., Ladd D.R., 2007. Linguistic tone is related to the population frequency of the adaptive haplogroups of two brain size genes, ASPM and microcephalin. Proc. Natl. Acad. Sci. U.S.A. 104]. In the present study, we found a significant correlation between the load of the derived alleles of ASPM and tone perception in a group of European Americans who did not speak a tone language. Moreover, preliminary results showed a significant correlation between ASPM load and hemodynamic responses to lexical tones in the auditory cortex, and such correlation remained after phonemic awareness, auditory working memory, and non-verbal IQ were controlled. As in previous studies, no significant correlation between ASPM and cognitive measures were found. MCPH1 did not correlate with any measures. These results suggest that the association between the recently derived allele of ASPM is likely to be specific and is tied to higher level brain functions in the temporal cortex related to human communication.

Abnormal segregation of alleles in CEPH pedigree DNAs arising from allele loss in lymphoblastoid DNA.

Science.gov (United States)

Royle, N J; Armour, J A; Crosier, M; Jeffreys, A J

1993-01-01

Somatic events that result in the reduction to hemi- or homozygosity at all loci affected by the event have been identified in lymphoblastoid DNA from mothers of two CEPH families. Using suitably informative probes, the allele deficiencies were detected by the abnormal transmission of alleles from grandparents to grandchildren, with the apparent absence of the alleles from the parent. Undetected somatic deficiencies in family DNAs could result in misscoring of recombination events and consequently introduce errors into linkage analysis.

Impact of protection settings of the distributed generation frequency under 1MW in the national electric system

International Nuclear Information System (INIS)

Alpizar Chavarria, Oscar

2013-01-01

A literature review is conducted to understand the distributed generation, the reason for the introduction into modern power systems and other distributed generation technologies based on renewable energies that have been installed around the country. The frequency protections of distributed generation equipment under 1MW are studied according to international standards like IEEE-1547 and specifications of equipment manufacturers. The influence of the recommended international standards settings are investigated for systems of distributed generation, the performance in frequency that have presented under some frequency perturbation, as well as the influence that can have on the national and regional electrical system, with different amounts of technologies included in the national system. The recommended settings are evaluated through simulations in PSSE program in the context of the behavior of the frequency in the national electric system [es

Explaining Ethnic Variability of Transporter Substrate Pharmacokinetics in Healthy Asian and Caucasian Subjects with Allele Frequencies of OATP1B1 and BCRP: A Mechanistic Modeling Analysis.

Science.gov (United States)

Li, Rui; Barton, Hugh A

2018-04-01

Ethnic variability in the pharmacokinetics of organic anion transporting polypeptide (OATP) 1B1 substrates has been observed, but its basis is unclear. A previous study hypothesizes that, without applying an intrinsic ethnic variability in transporter activity, allele frequencies of transporters cannot explain observed ethnic variability in pharmacokinetics. However, this hypothesis contradicts the data collected from compounds that are OATP1B1 substrates but not breast cancer resistance protein (BCRP) substrates. The objective of this study is to evaluate a hypothesis that is physiologically reasonable and more consistent with clinical observations. We evaluated if allele frequencies of two transporters (OATP1B1 and BCRP) are key contributors to ethnic variability. In this hypothesis, the same genotype leads to the same activity independent of ethnicity, in contrast to the previous hypothesis of intrinsic ethnic variability in OATP1B1 activity. As a validation, we perform mechanistic pharmacokinetic modeling for SLCO1B1 (encoding OATP1B1) and ABCG2 (encoding BCRP) genotyped pharmacokinetic data from 18 clinical studies with healthy Caucasian and/or Asian subjects. Simulations based on the current hypothesis reasonably describe SLCO1B1 and ABCG2 genotyped pharmacokinetic time course data for five transporter substrates (atorvastatin, pitavastatin, pravastatin, repaglinide, and rosuvastatin) in Caucasian and Asian populations. This hypothesis covers the observations that can (e.g., ethnic differences in rosuvastatin pharmacokinetics) or cannot (e.g., lack of differences for pitavastatin pharmacokinetics) be explained by the previous hypothesis. It helps to characterize sources of ethnic variability and provides a foundation for predicting ethnic variability in transporter substrate pharmacokinetics.

Diploid male dynamics under different numbers of sexual alleles and male dispersal abilities.

Science.gov (United States)

Faria, Luiz R R; Soares, Elaine Della Giustina; Carmo, Eduardo do; Oliveira, Paulo Murilo Castro de

2016-09-01

Insects in the order Hymenoptera (bees, wasps and ants) present an haplodiploid system of sexual determination in which fertilized eggs become females and unfertilized eggs males. Under single locus complementary sex-determination (sl-CSD) system, the sex of a specimen depends on the alleles at a single locus: when diploid, an individual will be a female if heterozygous and male if homozygous. Significant diploid male (DM) production may drive a population to an extinction scenario called "diploid male vortex". We aimed at studying the dynamics of populations of a sl-CSD organism under several combinations of two parameters: male flight abilities and number of sexual alleles. In these simulations, we evaluated the frequency of DM and a genetic diversity measure over 10,000 generations. The number of sexual alleles varied from 10 to 100 and, at each generation, a male offspring might fly to another random site within a varying radius R. Two main results emerge from our simulations: (i) the number of DM depends more on male flight radius than on the number of alleles; (ii) in large geographic regions, the effect of males flight radius on the allelic diversity turns out much less pronounced than in small regions. In other words, small regions where inbreeding normally appears recover genetic diversity due to large flight radii. These results may be particularly relevant when considering the population dynamics of species with increasingly limited dispersal ability (e.g., forest-dependent species of euglossine bees in fragmented landscapes).

Colony size-frequency distribution of pocilloporid juvenile corals along a natural environmental gradient in the Red Sea

KAUST Repository

Lozano-Cortes, Diego

2015-10-29

Coral colony size-frequency distributions can be used to assess population responses to local environmental conditions and disturbances. In this study, we surveyed juvenile pocilloporids, herbivorous fish densities, and algal cover in the central and southern Saudi Arabian Red Sea. We sampled nine reefs with different disturbance histories along a north–south natural gradient of physicochemical conditions (higher salinity and wider temperature fluctuations in the north, and higher turbidity and productivity in the south). Since coral populations with negatively skewed size-frequency distributions have been associated with unfavorable environmental conditions, we expected to find more negative distributions in the southern Red Sea, where corals are potentially experiencing suboptimal conditions. Although juvenile coral and parrotfish densities differed significantly between the two regions, mean colony size and size-frequency distributions did not. Results suggest that pocilloporid colony size-frequency distribution may not be an accurate indicator of differences in biological or oceanographic conditions in the Red Sea.

Colony size-frequency distribution of pocilloporid juvenile corals along a natural environmental gradient in the Red Sea.

Science.gov (United States)

Lozano-Cortés, Diego F; Berumen, Michael L

2016-04-30

Coral colony size-frequency distributions can be used to assess population responses to local environmental conditions and disturbances. In this study, we surveyed juvenile pocilloporids, herbivorous fish densities, and algal cover in the central and southern Saudi Arabian Red Sea. We sampled nine reefs with different disturbance histories along a north-south natural gradient of physicochemical conditions (higher salinity and wider temperature fluctuations in the north, and higher turbidity and productivity in the south). Since coral populations with negatively skewed size-frequency distributions have been associated with unfavorable environmental conditions, we expected to find more negative distributions in the southern Red Sea, where corals are potentially experiencing suboptimal conditions. Although juvenile coral and parrotfish densities differed significantly between the two regions, mean colony size and size-frequency distributions did not. Results suggest that pocilloporid colony size-frequency distribution may not be an accurate indicator of differences in biological or oceanographic conditions in the Red Sea. Copyright © 2015 Elsevier Ltd. All rights reserved.

Enhanced Recovery Utilizing Variable Frequency Drives and a Distributed Power System

Energy Technology Data Exchange (ETDEWEB)

Randy Peden; Sanjiv Shah

2005-07-26

This report describes complete results of the project entitled ''Enhanced Recovery Utilizing Variable Frequency Drives and a Distributed Power System''. This demonstration project was initiated in July 2003 and completed in March 2005. The objective of the project was to develop an integrated power production/variable frequency drive system that could easily be deployed in the oil field that would increase production and decrease operating costs. This report describes all the activities occurred and documents results of the demonstration.

Spindle frequency activity in the sleep EEG: individual differences and topographic distribution.

Science.gov (United States)

Werth, E; Achermann, P; Dijk, D J; Borbély, A A

1997-11-01

The brain topography of EEG power spectra in the frequency range of sleep spindles was investigated in 34 sleep recordings from 20 healthy young men. Referential (F3-A2, C3-A2, P3-A2 and O1-A2) and bipolar derivations (F3-C3, C3-P3 and P3-O1) along the anteroposterior axis were used. Sleep spindles gave rise to a distinct peak in the EEG power spectrum. The distribution of the peak frequencies pooled over subjects and derivations showed a bimodal pattern with modes at 11.5 and 13.0 Hz, and a trough at 12.25 Hz. The large inter-subject variation in peak frequency (range: 1.25 Hz) contrasted with the small intra-subject variation between derivations, non-REM sleep episodes and different nights. In some individuals and/or some derivations, only a single spindle peak was present. The topographic distributions from referential and bipolar recordings showed differences. The power showed a declining trend over consecutive non-REM sleep episodes in the low range of spindle frequency activity and a rising trend in the high range. The functional and topographic heterogeneity of sleep spindles in conjunction with the intra-subject stability of their frequency are important characteristics for the analysis of sleep regulation on the basis of the EEG.

Spatially distributed patterns of oscillatory coupling between high-frequency amplitudes and low-frequency phases in human iEEG

NARCIS (Netherlands)

Maris, Eric; van Vugt, Marieke; Kahana, Michael

2011-01-01

Spatially distributed coherent oscillations provide temporal windows of excitability that allow for interactions between distinct neuronal groups. It has been hypothesized that this mechanism for neuronal communication is realized by bursts of high-frequency oscillations that are phase-coupled to a

QuASAR-MPRA: accurate allele-specific analysis for massively parallel reporter assays.

Science.gov (United States)

Kalita, Cynthia A; Moyerbrailean, Gregory A; Brown, Christopher; Wen, Xiaoquan; Luca, Francesca; Pique-Regi, Roger

2018-03-01

The majority of the human genome is composed of non-coding regions containing regulatory elements such as enhancers, which are crucial for controlling gene expression. Many variants associated with complex traits are in these regions, and may disrupt gene regulatory sequences. Consequently, it is important to not only identify true enhancers but also to test if a variant within an enhancer affects gene regulation. Recently, allele-specific analysis in high-throughput reporter assays, such as massively parallel reporter assays (MPRAs), have been used to functionally validate non-coding variants. However, we are still missing high-quality and robust data analysis tools for these datasets. We have further developed our method for allele-specific analysis QuASAR (quantitative allele-specific analysis of reads) to analyze allele-specific signals in barcoded read counts data from MPRA. Using this approach, we can take into account the uncertainty on the original plasmid proportions, over-dispersion, and sequencing errors. The provided allelic skew estimate and its standard error also simplifies meta-analysis of replicate experiments. Additionally, we show that a beta-binomial distribution better models the variability present in the allelic imbalance of these synthetic reporters and results in a test that is statistically well calibrated under the null. Applying this approach to the MPRA data, we found 602 SNPs with significant (false discovery rate 10%) allele-specific regulatory function in LCLs. We also show that we can combine MPRA with QuASAR estimates to validate existing experimental and computational annotations of regulatory variants. Our study shows that with appropriate data analysis tools, we can improve the power to detect allelic effects in high-throughput reporter assays. http://github.com/piquelab/QuASAR/tree/master/mpra. fluca@wayne.edu or rpique@wayne.edu. Supplementary data are available online at Bioinformatics. © The Author (2017). Published by

Genome-wide analysis of allele frequency change in sunflower crop-wild hybrid populations evolving under natural conditions

Science.gov (United States)

Hybridization is known to occur between cultivated and wild populations of numerous plant species. This represents a major mechanism by which a wild population’s genetic structure and evolutionary dynamics could be altered. Studying crop-derived alleles in wild populations is also relevant to assess...

Type 2 diabetes mellitus: distribution of genetic markers in Kazakh population

Directory of Open Access Journals (Sweden)

Sikhayeva N

2018-03-01

Full Text Available Nurgul Sikhayeva,1,2 Yerkebulan Talzhanov,1 Aisha Iskakova,1 Jarkyn Dzharmukhanov,1 Raushan Nugmanova,1 Elena Zholdybaeva,1 Erlan Ramanculov1–3 1National Scientific Laboratory of Biotechnology, National Center for Biotechnology, Astana, Kazakhstan; 2Faculty of Natural Sciences, L.N. Gumilyov Eurasian National University, Astana, Kazakhstan; 3School of Science and Technology, Nazarbayev University, Astana, Kazakhstan Background: Ethnic differences exist in the frequencies of genetic variations that contribute to the risk of common disease. This study aimed to analyse the distribution of several genes, previously associated with susceptibility to type 2 diabetes and obesity-related phenotypes, in a Kazakh population.Methods: A total of 966 individuals belonging to the Kazakh ethnicity were recruited from an outpatient clinic. We genotyped 41 common single nucleotide polymorphisms (SNPs previously associated with type 2 diabetes in other ethnic groups and 31 of these were in Hardy–Weinberg equilibrium. The obtained allele frequencies were further compared to publicly available data from other ethnic populations. Allele frequencies for other (compared populations were pooled from the haplotype map (HapMap database. Principal component analysis (PCA, cluster analysis, and multidimensional scaling (MDS were used for the analysis of genetic relationship between the populations.Results: Comparative analysis of allele frequencies of the studied SNPs showed significant differentiation among the studied populations. The Kazakh population was grouped with Asian populations according to the cluster analysis and with the Caucasian populations according to PCA. According to MDS, results of the current study show that the Kazakh population holds an intermediate position between Caucasian and Asian populations.Conclusion: A high percentage of population differentiation was observed between Kazakh and world populations. The Kazakh population was clustered

Application of Choi—Williams Reduced Interference Time Frequency Distribution to Machinery Diagnostics

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Howard A. Gaberson

1995-01-01

Full Text Available This article discusses time frequency analysis of machinery diagnostic vibration signals. The short time Fourier transform, the Wigner, and the Choi–Williams distributions are explained and illustrated with test cases. Examples of Choi—Williams analyses of machinery vibration signals are presented. The analyses detect discontinuities in the signals and their timing, amplitude and frequency modulation, and the presence of different components in a vibration signal.

AllelicImbalance: An R/ bioconductor package for detecting, managing, and visualizing allele expression imbalance data from RNA sequencing

DEFF Research Database (Denmark)

Gådin, Jesper R.; van't Hooft, Ferdinand M.; Eriksson, Per

2015-01-01

the possible biases. Results: We present AllelicImblance, a software program that is designed to detect, manage, and visualize allelic imbalances comprehensively. The purpose of this software is to allow users to pose genetic questions in any RNA sequencing experiment quickly, enhancing the general utility...... of RNA sequencing. The visualization features can reveal notable, non-trivial allelic imbalance behavior over specific regions, such as exons. Conclusions: The software provides a complete framework to perform allelic imbalance analyses of aligned RNA sequencing data, from detection to visualization...

Association between the DRD2 A1 allele and response to methadone and buprenorphine maintenance treatments.

Science.gov (United States)

Barratt, Daniel T; Coller, Janet K; Somogyi, Andrew A

2006-06-05

The TaqI A polymorphism (A(1)) of the dopamine D(2) receptor gene (DRD2), although not a specific predictor of opioid dependence, has been strongly associated with high levels of prior heroin use and poor treatment outcomes among methadone maintenance patients. The aims of this study were to confirm these findings via a retrospective analysis of A(1) allele frequency in methadone (n = 46) and buprenorphine (n = 25) patients, and non-opioid-dependent controls (n = 95). Subjects were genotyped at the DRD2 TaqI A locus using PCR amplification followed by TaqI restriction enzyme digestion and gel electrophoresis. For methadone and buprenorphine subjects, heroin use (prior to treatment), treatment outcomes, and withdrawal occurrence were determined from comprehensive case notes. No significant differences in A(1) allele frequency (%) were observed between: methadone (19.6%), buprenorphine (18.0%), and control (17.9%) groups (P > 0.7); successful and poor treatment outcome groups, methadone: 20.0% and 19.2%, respectively (P = 1.0); buprenorphine: 18.4% and 20.0%, respectively (P = 1.0). Also, there were no significant relationships between TaqI A genotype and prior heroin use (P = 0.47). However, among the successful methadone subjects, significantly fewer A(1) allele carriers experienced withdrawal than non-A(1) carriers (P = 0.04). In conclusion, the DRD2 genotype effects did not affect opioid maintenance treatment outcomes. This suggests the need for a further prospective investigation into the role of the DRD2 A(1) allele in heroin use and response to maintenance pharmacotherapies for opioid dependence.

Alpha-1 antitrypsin Pi*Z gene frequency and Pi*ZZ genotype numbers worldwide: an update.

Science.gov (United States)

Blanco, Ignacio; Bueno, Patricia; Diego, Isidro; Pérez-Holanda, Sergio; Casas-Maldonado, Francisco; Esquinas, Cristina; Miravitlles, Marc

2017-01-01

In alpha-1 antitrypsin deficiency (AATD), the Z allele is present in 98% of cases with severe disease, and knowledge of the frequency of this allele is essential from a public health perspective. However, there is a remarkable lack of epidemiological data on AATD worldwide, and many of the data currently used are outdated. Therefore, the objective of this study was to update the knowledge of the frequency of the Z allele to achieve accurate estimates of the prevalence and number of Pi*ZZ genotypes worldwide based on studies performed according to the following criteria: 1) samples representative of the general population, 2) AAT phenotyping characterized by adequate methods, and 3) measurements performed using a coefficient of variation calculated from the sample size and 95% confidence intervals. Studies fulfilling these criteria were used to develop maps with an inverse distance weighted (IDW)-interpolation method, providing numerical and graphical information of Pi*Z distribution worldwide. A total of 224 cohorts from 65 countries were included in the study. With the data provided by these cohorts, a total of 253,404 Pi*ZZ were estimated worldwide: 119,594 in Europe, 91,490 in America and Caribbean, 3,824 in Africa, 32,154 in Asia, 4,126 in Australia, and 2,216 in New Zealand. In addition, the IDW-interpolation maps predicted Pi*Z frequencies throughout the world even in some areas that lack real data. In conclusion, the inclusion of new well-designed studies and the exclusion of the low-quality ones have significantly improved the reliability of results, which may be useful to plan strategies for future research and diagnosis and to rationalize the therapeutic resources available.

Human hypervariable sequences in risk assessment: rare Ha-ras alleles in cancer patients

International Nuclear Information System (INIS)

Krontiris, T.G.; DiMartino, N.A.; Mitcheson, H.D.; Lonergan, J.A.; Begg, C.; Parkinson, D.R.

1987-01-01

A variable tandem repeat (VTR) is responsible for the hyperallelism one kilobase 3' to the human c-Ha-ras-1 (Ha-ras) gene. Thirty-two distinct restriction fragments, comprising 3 allelic classes by frequency of occurrence, have thus far been detected in a sample size of approximately 800 caucasians. Rare Ha-ras alleles, 21 in all, are almost exclusively confined to the genomes of cancer patients. From their data the authors have computed the relative cancer risk associated with possession of a rare Ha-ras allele to be 27. To understand the molecular basis for this phenomenon, they have begun to clone Ha-ras fragments from nontumor DNA of cancer patients. They report here the weak activation, as detected by transfection and transformation of NIH 3T3 mouse cells, of two Ha-ras genes which were obtained from lymphocyte DNA of a melanoma patient. They have mapped the regions that confer this transforming activity to the fragment containing the VTR in one Ha-ras clone and the fragment containing gene coding sequences in the other

Estimated allele substitution effects underlying genomic evaluation models depend on the scaling of allele counts

NARCIS (Netherlands)

Bouwman, Aniek C.; Hayes, Ben J.; Calus, Mario P.L.

2017-01-01

Background: Genomic evaluation is used to predict direct genomic values (DGV) for selection candidates in breeding programs, but also to estimate allele substitution effects (ASE) of single nucleotide polymorphisms (SNPs). Scaling of allele counts influences the estimated ASE, because scaling of

Apolipoprotein E epsilon 4 allele and outcomes of traumatic spinal cord injury in a Chinese Han population.

Science.gov (United States)

Sun, Chongyi; Ji, Guangrong; Liu, Qingpeng; Yao, Meng

2011-10-01

The association between apolipoprotein E (APOE) epsilon 4 (ε4) allele and outcomes of traumatic spinal cord injury (SCI) is still controversial and ambiguous. The objective of this study was to test the hypothesis that APOE polymorphisms are associated with outcomes after SCI in Chinese Han patients. APOE polymorphisms were determined in 100 patients with cervical SCI (C3-C8). The genotype frequency of this polymorphism was determined by using a polymerase chain reaction-restriction fragment length polymorphism assay. Patients with an APOE ε4 allele had significantly less motor recovery during rehabilitation than did patients without an APOE ε4 allele (mean 3.7 vs. 6.1; P = 0.04) and a longer rehabilitation length of stay (LOS) (mean 117.4 vs. 94.5; P = 0.02), but better sensory-pinprick recovery (mean 6.1 vs. 4.0; P = 0.03). There were no significant differences by APOE ε4 allele status in sensory-light touch recovery or acute LOS. This study suggests that the APOE ε4 allele is associated with outcomes after SCI and longer rehabilitation LOS in Chinese Han patients.

Always look on both sides: phylogenetic information conveyed by simple sequence repeat allele sequences.

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Stéphanie Barthe

Full Text Available Simple sequence repeat (SSR markers are widely used tools for inferences about genetic diversity, phylogeography and spatial genetic structure. Their applications assume that variation among alleles is essentially caused by an expansion or contraction of the number of repeats and that, accessorily, mutations in the target sequences follow the stepwise mutation model (SMM. Generally speaking, PCR amplicon sizes are used as direct indicators of the number of SSR repeats composing an allele with the data analysis either ignoring the extent of allele size differences or assuming that there is a direct correlation between differences in amplicon size and evolutionary distance. However, without precisely knowing the kind and distribution of polymorphism within an allele (SSR and the associated flanking region (FR sequences, it is hard to say what kind of evolutionary message is conveyed by such a synthetic descriptor of polymorphism as DNA amplicon size. In this study, we sequenced several SSR alleles in multiple populations of three divergent tree genera and disentangled the types of polymorphisms contained in each portion of the DNA amplicon containing an SSR. The patterns of diversity provided by amplicon size variation, SSR variation itself, insertions/deletions (indels, and single nucleotide polymorphisms (SNPs observed in the FRs were compared. Amplicon size variation largely reflected SSR repeat number. The amount of variation was as large in FRs as in the SSR itself. The former contributed significantly to the phylogenetic information and sometimes was the main source of differentiation among individuals and populations contained by FR and SSR regions of SSR markers. The presence of mutations occurring at different rates within a marker's sequence offers the opportunity to analyse evolutionary events occurring on various timescales, but at the same time calls for caution in the interpretation of SSR marker data when the distribution of within

Single Frequency Network Based Distributed Passive Radar Technology

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Wan Xian-rong

2015-01-01

Full Text Available The research and application of passive radar are heading from single transmitter-receiver pair to multiple transmitter-receiver pairs. As an important class of the illuminators of opportunity, most of modern digital broadcasting and television systems work on Single Frequency Network (SFN, which intrinsically determines that the passive radar based on such illuminators must be distributed and networked. In consideration of the remarkable working and processing mode of passive radar under SFN configuration, this paper proposes the concept of SFN-based Distributed Passive Radar (SDPR. The main characteristics and key problems of SDPR are first described. Then several potential solutions are discussed for part of the key technologies. The feasibility of SDPR is demonstrated by preliminary experimental results. Finally, the concept of four network convergence that includes the broadcast based passive radar network is conceived, and its application prospects are discussed.

Frequency distribution of the reduced unit cells of centred lattices from the Protein Data Bank.

Science.gov (United States)

Swaminathan, Kunchithapadam

2012-03-01

In crystallography, a centred conventional lattice unit cell has its corresponding reduced primitive unit cell. This study presents the frequency distribution of the reduced unit cells of all centred lattice entries of the Protein Data Bank (as of 23 August 2011) in four unit-cell-dimension-based groups and seven interaxial-angle-based subgroups. This frequency distribution is an added layer of support during space-group assignment in new crystals. In addition, some interesting patterns of distribution are discussed as well as how some reduced unit cells could be wrongly accepted as primitive lattices in a different crystal system.

Fully-distributed Load Frequency Control Strategy in an Islanded Microgrid Considering Plug-In Electric Vehicles

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Xiao Qi

2018-06-01

Full Text Available With large-scale integration of electric vehicles, this paper investigates the load frequency control problem in an islanded microgrid with plug-in electric vehicles (PEVs, which can be regarded as mobile battery energy storages to provide a valuable contribution to frequency regulation. A novel fully-distributed control strategy is proposed to achieve fast frequency regulation of islanded microgrids and effective coordination control of distributed energy sources. Firstly, distributed control based on an improved linear active disturbance rejection algorithm is realized through a multi-agent system, and it greatly enhances the anti-disturbance capability of the microgrid. Then, in order to guarantee the effectiveness of PEVs in frequency regulation, PEVs are controlled following the controllable power rate (CPR calculated from the consensus-based multi-agent system. Furthermore, the system control construction in this paper is well designed to avoid the negative effects caused by system communication time delay. Finally, numerical simulations under different disturbances are carried out to demonstrate the effectiveness of the proposed control strategy in comparison with other previous control strategies.

Electron energy distributions and excitation rates in high-frequency argon discharges

International Nuclear Information System (INIS)

Ferreira, C.M.; Loureiro, J.

1983-06-01

The electron energy distribution functions and rate coefficients for excitation and ionisation in argon under the action of an uniform high-frequency electric field were calculated by numerically solving the homogeneous Boltzmann equation. Analytic calculations in the limiting cases ω>>νsub(c) and ω<<νsub(c), where ω is the wave angular frequency and νsub(c) is the electron-neutral collision frequency for momentum transfer, are also presented and shown to be in very good agreement with the numerical computations. The results reported here are relevant for the modelling of high-frequency discharges in argon and, in particular, for improving recent theoretical descriptions of a plasma column sustained by surface microwaves. The properties of surface wave produced plasmas make them interesting as possible substitutes for other more conventional plasma sources for such important applications as plasma chemistry laser excitation, plasma etching spectroscopic sources etc...

Frequency distribution of Radium-226, Thorium-228 and Potassium-40 concentration in ploughed soils

International Nuclear Information System (INIS)

Drichko, V.F.; Krisyuk, B.E.; Travnikova, I.G.; Lisachenko, E.P.; Dubenskaya, M.A.

1977-01-01

The results of studying Ra-226, Th-228 and K-40 concentration distribution laws in podsol, chernozem and saline soils are considered. Radionuclide concentrations were determined by gamma-spectrometric method in the samples chosen from arable soil layer according to the generally accepted agrotechnical procedure. Measuring procedure is described. The results show that frequency distributions of radionuclide concentrations transform from asymmetric form in normal coordinates into symmetric form in logarithmic coordinates. The usage of the lognormal law to describe frequency concentration distributions is substantiated. The values of concentration distribution parameters are given. The analysis of the data obtained permits to establish that Ra-226 and Th-228 concentrations in soils distribute lognormally and K-40 concentrations - normally and lognormally. According to the degree of decreasing mean concentrations of Ra-226 and Th-228, soils lie in line: chernozems=chernozem salterns > podsols; and according to the degree of decreasing mean quadratic deviation - in line: podsols>chernozems=salterns. It is necessary to determine the value of mean quadratic deviation and distribution type for full characteristics of the studied soil radioactivity

A New Quantum Key Distribution Scheme Based on Frequency and Time Coding

International Nuclear Information System (INIS)

Chang-Hua, Zhu; Chang-Xing, Pei; Dong-Xiao, Quan; Jing-Liang, Gao; Nan, Chen; Yun-Hui, Yi

2010-01-01

A new scheme of quantum key distribution (QKD) using frequency and time coding is proposed, in which the security is based on the frequency-time uncertainty relation. In this scheme, the binary information sequence is encoded randomly on either the central frequency or the time delay of the optical pulse at the sender. The central frequency of the single photon pulse is set as ω 1 for bit 0 and set as ω 2 for bit 1 when frequency coding is selected. However, the single photon pulse is not delayed for bit 0 and is delayed in τ for 1 when time coding is selected. At the receiver, either the frequency or the time delay of the pulse is measured randomly, and the final key is obtained after basis comparison, data reconciliation and privacy amplification. With the proposed method, the effect of the noise in the fiber channel and environment on the QKD system can be reduced effectively

Breed distribution of the nt230(del4) MDR1 mutation in dogs.

Science.gov (United States)

Gramer, Irina; Leidolf, Regina; Döring, Barbara; Klintzsch, Stefanie; Krämer, Eva-Maria; Yalcin, Ebru; Petzinger, Ernst; Geyer, Joachim

2011-07-01

A 4-bp deletion mutation associated with multiple drug sensitivity exists in the canine multidrug resistance (MDR1) gene. This mutation has been detected in more than 10 purebred dog breeds as well as in mixed breed dogs. To evaluate the breed distribution of this mutation in Germany, 7378 dogs were screened, including 6999 purebred and 379 mixed breed dogs. The study included dog breeds that show close genetic relationship or share breeding history with one of the predisposed breeds but in which the occurrence of the MDR1 mutation has not been reported. The breeds comprised Bearded Collies, Anatolian Shepherd Dog, Greyhound, Belgian Tervuren, Kelpie, Borzoi, Australian Cattle Dog and the Irish Wolfhound. The MDR1 mutation was not detected is any of these breeds, although it was found as expected in the Collie, Longhaired Whippet, Shetland Sheepdog, Miniature Australian Shepherd, Australian Shepherd, Wäller, White Swiss Shepherd, Old English Sheepdog and Border Collie with varying allelic frequencies for the mutant MDR1 allele of 59%, 45%, 30%, 24%, 22%, 17%, 14%, 4% and 1%, respectively. Allelic frequencies of 8% and 2% were determined in herding breed mixes and unclassified mixed breeds, respectively. Because of its widespread breed distribution and occurrence in many mixed breed dogs, it is difficult for veterinarians and dog owners to recognise whether MDR1-related drug sensitivity is relevant for an individual animal. This study provides a comprehensive overview of all affected dog breeds and many dog breeds that are probably unaffected on the basis of ∼15,000 worldwide MDR1 genotyping data. Copyright © 2010 Elsevier Ltd. All rights reserved.

Variant allele frequency enrichment analysis in vitro reveals sonic hedgehog pathway to impede sustained temozolomide response in GBM.

Science.gov (United States)

Biswas, Nidhan K; Chandra, Vikas; Sarkar-Roy, Neeta; Das, Tapojyoti; Bhattacharya, Rabindra N; Tripathy, Laxmi N; Basu, Sunandan K; Kumar, Shantanu; Das, Subrata; Chatterjee, Ankita; Mukherjee, Ankur; Basu, Pryiadarshi; Maitra, Arindam; Chattopadhyay, Ansuman; Basu, Analabha; Dhara, Surajit

2015-01-21

Neoplastic cells of Glioblastoma multiforme (GBM) may or may not show sustained response to temozolomide (TMZ) chemotherapy. We hypothesize that TMZ chemotherapy response in GBM is predetermined in its neoplastic clones via a specific set of mutations that alter relevant pathways. We describe exome-wide enrichment of variant allele frequencies (VAFs) in neurospheres displaying contrasting phenotypes of sustained versus reversible TMZ-responses in vitro. Enrichment of VAFs was found on genes ST5, RP6KA1 and PRKDC in cells showing sustained TMZ-effect whereas on genes FREM2, AASDH and STK36, in cells showing reversible TMZ-effect. Ingenuity pathway analysis (IPA) revealed that these genes alter cell-cycle, G2/M-checkpoint-regulation and NHEJ pathways in sustained TMZ-effect cells whereas the lysine-II&V/phenylalanine degradation and sonic hedgehog (Hh) pathways in reversible TMZ-effect cells. Next, we validated the likely involvement of the Hh-pathway in TMZ-response on additional GBM neurospheres as well as on GBM patients, by extracting RNA-sequencing-based gene expression data from the TCGA-GBM database. Finally, we demonstrated TMZ-sensitization of a TMZ non-responder neurosphere in vitro by treating them with the FDA-approved pharmacological Hh-pathway inhibitor vismodegib. Altogether, our results indicate that the Hh-pathway impedes sustained TMZ-response in GBM and could be a potential therapeutic target to enhance TMZ-response in this malignancy.

Hitchhiking and Selective Sweeps of Plasmodium falciparum Sulfadoxine and Pyrimethamine Resistance Alleles in a Population from Central Africa▿ †

Science.gov (United States)

McCollum, Andrea M.; Basco, Leonardo K.; Tahar, Rachida; Udhayakumar, Venkatachalam; Escalante, Ananias A.

2008-01-01

Sulfadoxine-pyrimethamine (SP) resistance in Plasmodium falciparum is encoded by a number of mutations in the dihydrofolate reductase (dhfr) and dihydropteroate synthetase (dhps) genes. Here, we have characterized point mutations in dhfr and dhps and microsatellite loci around dhfr on chromosome 4 and dhps on chromosome 8 as well as neutral markers on chromosomes 2 and 3 in 332 samples from Yaoundé, Cameroon. The triple mutant dhfr haplotype that originated in Southeast Asia is the most predominant in this sample set, but we also find additional independent haplotypes at low frequency and an incipient process of genetic differentiation among alleles of Southeast Asian origin. As reported for other African populations, we find evidence of a selective sweep for resistant dhfr mutants in this Cameroonian population due to drug selection. Although we find evidence for a selective sweep in dhps mutants associated with SP resistance, the dynamics of dhps mutants appear different than those observed for dhfr mutants. Overall, our results yield support for the use of microsatellite markers to track resistant parasites; however, the detection of resistant dhfr alleles in low frequency, the evidence of divergence among dhfr alleles that share a common evolutionary origin, and the distinct dynamics of resistant dhps alleles emphasize the importance of comprehensive, population-based investigations to evaluate the effects of drug selection on parasite populations. PMID:18765692

Dominant hemimelia and En-1 on mouse chromosome 1 are not allelic.

Science.gov (United States)

Higgins, M; Hill, R E; West, J D

1992-08-01

Previous studies have shown that En-1, a homeobox-containing gene, maps close to or at the Dh locus in the mouse. Since homeobox-containing genes are key genes in the control of development the close proximity of En-1 to the developmentally significant gene Dh raised the possibility that the Dh mutation represented a mutant allele of En-1. A genetic analysis involving En-1, Dh, and other chromosome 1 markers (Emv-17, ln and Pep-3) shows that although Dh and En-1 are closely linked they are separable by recombination (4/563). The likely gene order and recombination frequencies of these loci are: ln (5.2 +/- 0.9) Emv-17 (1.1 +/- 0.4) Dh (0.7 +/- 0.4) En-1 (3.0 +/- 0.7) Pep-3. This shows that Dh is not a mutant allele of En-1.

A new method for studying population genetics of cyst nematodes based on Pool-Seq and genomewide allele frequency analysis.

Science.gov (United States)

Mimee, Benjamin; Duceppe, Marc-Olivier; Véronneau, Pierre-Yves; Lafond-Lapalme, Joël; Jean, Martine; Belzile, François; Bélair, Guy

2015-11-01

Cyst nematodes are important agricultural pests responsible for billions of dollars of losses each year. Plant resistance is the most effective management tool, but it requires a close monitoring of population genetics. Current technologies for pathotyping and genotyping cyst nematodes are time-consuming, expensive and imprecise. In this study, we capitalized on the reproduction mode of cyst nematodes to develop a simple population genetic analysis pipeline based on genotyping-by-sequencing and Pool-Seq. This method yielded thousands of SNPs and allowed us to study the relationships between populations of different origins or pathotypes. Validation of the method on well-characterized populations also demonstrated that it was a powerful and accurate tool for population genetics. The genomewide allele frequencies of 23 populations of golden nematode, from nine countries and representing the five known pathotypes, were compared. A clear separation of the pathotypes and fine genetic relationships between and among global populations were obtained using this method. In addition to being powerful, this tool has proven to be very time- and cost-efficient and could be applied to other cyst nematode species. © 2015 Her Majesty the Queen in Right of Canada Molecular Ecology Resources © 2015 John Wiley & Sons Ltd Reproduced with the permission of the Minister of Agriculture and Agri-food.

Efficiency of the estimators of multivariate distribution parameters from the one-dimensional observed frequencies

International Nuclear Information System (INIS)

Chernov, N.I.; Kurbatov, V.S.; Ososkov, G.A.

1988-01-01

Parameter estimation for multivariate probability distributions is studied in experiments where data are presented as one-dimensional hystograms. For this model a statistics defined as a quadratic form of the observed frequencies which has a limitig x 2 -distribution is proposed. The efficiency of the estimator minimizing the value of that statistics is proved whithin the class of all unibased estimates obtained via minimization of quadratic forms of observed frequencies. The elaborated method was applied to the physical problem of analysis of the secondary pion energy distribution in the isobar model of pion-nucleon interactions with the production of an additional pion. The numerical experiments showed that the accuracy of estimation is twice as much if comparing the conventional methods

EOMES-positive CD4+ T cells are increased in PTPN22 (1858T) risk allele carriers.

Science.gov (United States)

Chemin, Karine; Ramsköld, Daniel; Diaz-Gallo, Lina-Marcela; Herrath, Jessica; Houtman, Miranda; Tandre, Karolina; Rönnblom, Lars; Catrina, Anca; Malmström, Vivianne

2018-04-01

The presence of the PTPN22 risk allele (1858T) is associated with several autoimmune diseases including rheumatoid arthritis (RA). Despite a number of studies exploring the function of PTPN22 in T cells, the exact impact of the PTPN22 risk allele on T-cell function in humans is still unclear. In this study, using RNA sequencing, we show that, upon TCR-activation, naïve human CD4 + T cells homozygous for the PTPN22 risk allele overexpress a set of genes including CFLAR and 4-1BB, which are important for cytotoxic T-cell differentiation. Moreover, the protein expression of the T-box transcription factor Eomesodermin (EOMES) was increased in T cells from healthy donors homozygous for the PTPN22 risk allele and correlated with a decreased number of naïve CD4 + T cells. There was no difference in the frequency of other CD4 + T-cell subsets (Th1, Th17, Tfh, Treg). Finally, an accumulation of EOMES + CD4 + T cells was observed in synovial fluid of RA patients with a more pronounced production of Perforin-1 in PTPN22 risk allele carriers. Altogether, we propose a novel mechanism of action of PTPN22 risk allele through the generation of cytotoxic CD4 + T cells and identify EOMES + CD4 + T cells as a relevant T-cell subset in RA pathogenesis. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dependence of exponents on text length versus finite-size scaling for word-frequency distributions

Science.gov (United States)

Corral, Álvaro; Font-Clos, Francesc

2017-08-01

Some authors have recently argued that a finite-size scaling law for the text-length dependence of word-frequency distributions cannot be conceptually valid. Here we give solid quantitative evidence for the validity of this scaling law, using both careful statistical tests and analytical arguments based on the generalized central-limit theorem applied to the moments of the distribution (and obtaining a novel derivation of Heaps' law as a by-product). We also find that the picture of word-frequency distributions with power-law exponents that decrease with text length [X. Yan and P. Minnhagen, Physica A 444, 828 (2016), 10.1016/j.physa.2015.10.082] does not stand with rigorous statistical analysis. Instead, we show that the distributions are perfectly described by power-law tails with stable exponents, whose values are close to 2, in agreement with the classical Zipf's law. Some misconceptions about scaling are also clarified.

Distribution of genotypes C825T polymorphism G-protein β3-subunit gene in patients with hypertension depending on body mass index

Directory of Open Access Journals (Sweden)

Prystupa L.N.

2015-09-01

Full Text Available The aim of the study was to investigate the frequency of genotypes of C825T polymorphism G-protein β3-subunit gene (GNB3 in patients with arterial hypertension (AH, depending on body mass index (BMI. The study involved 155 patients with verified diagnosis of AH (study group and 50 healthy individuals (control group. The patients of the main group were divided into 3 groups according to BMI: I - 35 patients with normal body weight, II - 38 patients with overweight, III - 82 patients with obesity. We used general clinical, anthropometric, instrumental, molecular-genetic and statistical methods. Probability of differences in the frequency of alleles and genotypes was determined using χ² criteria. Pairwise comparison of groups was made using nonparametric Mann-Whitney test. The difference was considered statistically significant at p <0,05. Investigation of the distribution of genotypes C825T polymorphism GNB3 in patients with AH according to BMI showed statistically significant increase in the frequency of genotypes C / T and T / T and T allele in patients with overweight and obesity as compared with patients with normal body weight (χ² = 26 8; p <0.001. The risk of weight increase in AH patients with T allele carriers is 2,2 times higher than in C allele carriers. Association of C825T polymorphism of GNB3 with a tendency to obesity and overweight in patients with AH was proved.

Effect of APOE ε4 allele on survival and fertility in an adverse environment.

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Eric van Exel

Full Text Available The apolipoprotein-ε4 allele (APOE-ε4 is strongly associated with detrimental outcomes in affluent populations including atherosclerotic disease, Alzheimer's disease, and reduced lifespan. Despite these detrimental outcomes, population frequencies of APOE-ε4 are high. We hypothesize that the high frequency of APOE-ε4 was maintained because of beneficial effects during evolution when infectious pathogens were more prevalent and a major cause of mortality. We examined a rural Ghanaian population with a high pathogen exposure for selective advantages of APOE-ε4, to survival and or fertility.This rural Ghanaian population (n = 4311 has high levels of mortality from widespread infectious diseases which are the main cause of death. We examined whether APOE-ε4 was associated with survival (total follow-up time was 30,262 years and fertility after stratifying by exposure to high or low pathogen levels. Households drawing water from open wells and rivers were classified as exposed to high pathogen levels while low pathogen exposure was classified as those drawing water from borehole wells. We found a non-significant, but positive survival benefit, i.e. the hazard ratio per APOE-ε4 allele was 0.80 (95% confidence interval: 0.69 to 1.05, adjusted for sex, tribe, and socioeconomic status. Among women aged 40 years and older (n = 842, APOE-ε4 was not associated with the lifetime number of children. However, APOE-ε4 was associated with higher fertility in women exposed to high pathogen levels. Compared with women not carrying an APOE-ε4 allele, those carrying one APOE-ε4 allele had on average one more child and those carrying two APOE-ε4 alleles had 3.5 more children (p = 0.018.Contrary to affluent modern-day populations, APOE-ε4 did not carry a survival disadvantage in this rural Ghanaian population. Moreover, APOE-ε4 promotes fertility in highly infectious environments. Our findings suggest that APOE-ε4 may be considered as evolutionarily

Effect of APOE ε4 allele on survival and fertility in an adverse environment.

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van Exel, Eric; Koopman, Jacob J E; Bodegom, David van; Meij, Johannes J; Knijff, Peter de; Ziem, Juventus B; Finch, Caleb E; Westendorp, Rudi G J

2017-01-01

The apolipoprotein-ε4 allele (APOE-ε4) is strongly associated with detrimental outcomes in affluent populations including atherosclerotic disease, Alzheimer's disease, and reduced lifespan. Despite these detrimental outcomes, population frequencies of APOE-ε4 are high. We hypothesize that the high frequency of APOE-ε4 was maintained because of beneficial effects during evolution when infectious pathogens were more prevalent and a major cause of mortality. We examined a rural Ghanaian population with a high pathogen exposure for selective advantages of APOE-ε4, to survival and or fertility. This rural Ghanaian population (n = 4311) has high levels of mortality from widespread infectious diseases which are the main cause of death. We examined whether APOE-ε4 was associated with survival (total follow-up time was 30,262 years) and fertility after stratifying by exposure to high or low pathogen levels. Households drawing water from open wells and rivers were classified as exposed to high pathogen levels while low pathogen exposure was classified as those drawing water from borehole wells. We found a non-significant, but positive survival benefit, i.e. the hazard ratio per APOE-ε4 allele was 0.80 (95% confidence interval: 0.69 to 1.05), adjusted for sex, tribe, and socioeconomic status. Among women aged 40 years and older (n = 842), APOE-ε4 was not associated with the lifetime number of children. However, APOE-ε4 was associated with higher fertility in women exposed to high pathogen levels. Compared with women not carrying an APOE-ε4 allele, those carrying one APOE-ε4 allele had on average one more child and those carrying two APOE-ε4 alleles had 3.5 more children (p = 0.018). Contrary to affluent modern-day populations, APOE-ε4 did not carry a survival disadvantage in this rural Ghanaian population. Moreover, APOE-ε4 promotes fertility in highly infectious environments. Our findings suggest that APOE-ε4 may be considered as evolutionarily adaptive. Its

Coordinated control of distributed energy resources to support load frequency control

International Nuclear Information System (INIS)

Ravikumar Pandi, V.; Al-Hinai, A.; Feliachi, Ali

2015-01-01

Highlights: • We aims to maintain feeder power flow by the coordination of DER units. • The error in feeder flow with respect to scheduled value is used by the controller. • The particle swarm optimization is employed to minimize the error in feeder flow. • Implemented on a transmission system along with 37 bus distribution feeder. • The results of proposed feeder control is analyzed with no feeder control scheme. - Abstract: The control of generating resources to follow the unscheduled load changes is considered to be an essential process in the power system in order to maintain the frequency of power supply. This load frequency control (LFC) problem has been given more importance in the recent smart grid environment because of the impact from high penetration of distributed energy resources (DER) installed at the distribution level. The renewable sources are highly intermittent in nature, so it is required to coordinate and control the DER units to maintain the feeder power flow at substation bus bar which is seen by transmission system operator during the LFC process. This paper aims to identify the impact of distributed generation and its control method to reduce the deviation of feeder power flow from the scheduled value in real time operation. The error in feeder power flow with respect to scheduled value is utilized by the PI controller to estimate the change in power reference of all DER units. The power output of DER units are maintained to reference values by the individual PI controllers. The particle swarm optimization algorithm is employed to minimize the error in feeder power flow by optimally tuning the gain values of all PI controllers. The proposed method is examined on a small transmission system along with the feeder of IEEE 37 bus distribution system with balanced loading condition. The complete system along with DER units is implemented in the MATLAB based stability package named Power Analysis Toolbox (PAT) for performing time domain

Enhancement of allele discrimination by introduction of nucleotide mismatches into siRNA in allele-specific gene silencing by RNAi.

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Yusuke Ohnishi

Full Text Available Allele-specific gene silencing by RNA interference (RNAi is therapeutically useful for specifically inhibiting the expression of disease-associated alleles without suppressing the expression of corresponding wild-type alleles. To realize such allele-specific RNAi (ASP-RNAi, the design and assessment of small interfering RNA (siRNA duplexes conferring ASP-RNAi is vital; however, it is also difficult. In a previous study, we developed an assay system to assess ASP-RNAi with mutant and wild-type reporter alleles encoding the Photinus and Renilla luciferase genes. In line with experiments using the system, we realized that it is necessary and important to enhance allele discrimination between mutant and corresponding wild-type alleles. Here, we describe the improvement of ASP-RNAi against mutant alleles carrying single nucleotide variations by introducing base substitutions into siRNA sequences, where original variations are present in the central position. Artificially mismatched siRNAs or short-hairpin RNAs (shRNAs against mutant alleles of the human Prion Protein (PRNP gene, which appear to be associated with susceptibility to prion diseases, were examined using this assessment system. The data indicates that introduction of a one-base mismatch into the siRNAs and shRNAs was able to enhance discrimination between the mutant and wild-type alleles. Interestingly, the introduced mismatches that conferred marked improvement in ASP-RNAi, appeared to be largely present in the guide siRNA elements, corresponding to the 'seed region' of microRNAs. Due to the essential role of the 'seed region' of microRNAs in their association with target RNAs, it is conceivable that disruption of the base-pairing interactions in the corresponding seed region, as well as the central position (involved in cleavage of target RNAs, of guide siRNA elements could influence allele discrimination. In addition, we also suggest that nucleotide mismatches at the 3'-ends of sense

Frequency of the CHEK2 1100delC mutation among women with breast cancer: an international study.

Science.gov (United States)

Zhang, Shiyu; Phelan, Catherine M; Zhang, Phil; Rousseau, Francois; Ghadirian, Parviz; Robidoux, Andre; Foulkes, William; Hamel, Nancy; McCready, David; Trudeau, Maureen; Lynch, Henry; Horsman, Douglas; De Matsuda, Maria Lourdes Leon; Aziz, Zeba; Gomes, Magda; Costa, Mauricio Magalhaes; Liede, Alexander; Poll, Aletta; Sun, Ping; Narod, Steven A

2008-04-01

A founder allele in the CHEK2 gene (1100delC) has been associated with an elevated risk of breast cancer. This allele is responsible for the majority of CHEK2-associated breast cancers in women from northern European countries; however, within Europe, it seems to be rare in countries that are close to the Mediterranean. The frequency of the 1100delC allele has not been measured in non-White populations. We measured the frequency of the CHEK2 founder allele in 3,882 breast cancer patients and 8,609 controls from various countries. The allele was not seen among Asian patients (from Pakistan or the Philippines) and was present in 1 of 155 cases from Brazil. Among White women, the allele was present in 1.5% of 825 familial cases of breast cancer and in 0.7% of 1,106 patients with nonfamilial breast cancer. The allele was equally frequent in Jewish and non-Jewish patients. We estimate that the CHEK2 1100delC allele is associated with an odds ratio of 2.6 for breast cancer, which corresponds to a lifetime risk of approximately 24% in Ontario.

Maternal and fetal human leukocyte antigen class Ia and II alleles in severe preeclampsia and eclampsia

DEFF Research Database (Denmark)

Emmery, J.; Hachmon, R.; Pyo, C. W.

2016-01-01

and -DPB1) alleles and the risk of developing severe preeclampsia/eclampsia were investigated in a detailed and large-scale study. In total, 259 women diagnosed with severe preeclampsia or eclampsia and 260 matched control women with no preeclampsia, together with their neonates, were included in the study....... HLA genotyping for mothers and neonates was performed using next-generation sequencing. The HLA-DPB1*04:01:01G allele was significantly more frequent (Pc=0.044) among women diagnosed with severe preeclampsia/eclampsia compared with controls, and the DQA1*01:02:01G allele frequency was significantly...... lower (Pc=0.042) among newborns born by women with severe preeclampsia/eclampsia compared with controls. In mothers with severe preeclampsia/eclampsia, homozygosity was significantly more common compared with controls at the HLA-DPB1 locus (Pc=0.0028). Although the current large study shows some...

HLA-DR alleles among Pakistani patients of coeliac disease

International Nuclear Information System (INIS)

Saleem, N.; Ahmed, T.A.; Bashir, M.; Ali, S.; Iqbal, M.

2013-01-01

Objectives: To investigate whether certain DR alleles might also contribute to the genetic susceptibility among Coeliac disease patients in Pakistan. Methods: The case-control study was conducted at the Military Hospital, Rawalpindi, from October 2011 to January 2012, and analysed 25 children diagnosed to have coeliac disease as per the criteria set by the European Society of Paediatric Gastroenterology and Nutrition, which included histopathological alterations in duodenal biopsies, clinical response to gluten withdrawal, and presence of anti-endomyseal antibodies. Patients were compared with a group of 150 healthy subjects. Dioxyribonucleic acid was extracted from peripheral blood collected in ethylenediaminetetraacetic acid.K3. Human leukocyte antigen DRB1 typing was carried out on allele level (DRB1*01 - DRB1*16) using sequence specific primers. Human leukocyte antigen type was determined by agarose gel electrophoresis and results were recorded. Phenotype frequency of various alleles among the patient group and the control group was calculated by direct counting, and significance of their association was determined by Fisher Exact Test. Results: A total of 11 (44%) female paediatric coeliac patients in age range 1-9 (mean 7.2+-4.8 years) and 14 (56%) male paediatric patients in the age range 6-14 (mean 8.6+-5.1 years) were genotyped for HLA-DRB1 loci. A statistically significant positive association of the disease with HLA-DRB1*03 (n=23; 92% versus n=31; 21% in controls, p <0.01) was observed. Conclusion: HLA-DRB1*03 is associated with increased risk of developing coeliac disease. (author)

Analysis of a hundred-years series of magnetic activity indices. III. Is the frequency distribution logarithmo-normal

International Nuclear Information System (INIS)

Mayaud, P.N.

1976-01-01

Because of the various components of positive conservation existing in the series of aa indices, their frequency distribution is necessarily distorted with respect to any random distribution. However when one takes these various components into account, the observed distribution can be considered as being a logarithmo-normal distribution. This implies that the geomagnetic activity satisfies the conditions of the central limit theorem, according to which a phenomenon which presents such a distribution is due to independent causes whose effects are multiplicative. Furthermore, the distorsion of the frequency distribution caused by the 11-year and 90-year cycles corresponds to a pure attenuation effect; an interpretation by the solar 'coronal holes' is proposed [fr

Frequency Of C3435 Mdr1 And A6896g Cyp3a5 Single Nucleotide Polymorphism in an Iranian Population and Comparison with Other Ethnic Groups

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N. AZARPIRA

2006-11-01

Full Text Available Background:It is well recognized that different patients respond in different ways to medications. The inter-individual variations are greater than the intera- individual variations,a finding consistent with the notion that inheritance is a determinant of drug responses. The recent identification of genetic polymorphisms in drug-metabolizing enzymes and drug transporters led to the hypothesis that genetic factors may be implicated in this interindividual variation. Single nucleotide polymorphism in common metabolic pathway,cytochrome P450 and common transporter,multidrug resistance-1 gene are two important sites that might involve clinically significant genetic variations. Ethnicity greatly influences these genetic polymorphism distributions. Methods: We studied the inheritance patterns of polymorphisms for MDR1 and CYP3A5 genes in the Iranian population and compared its genotype and allele frequencies with 3 different ethnic groups: Caucasian (United Kingdom, Chinese and Japanese. Results: We found striking differences in the distribution of MDR allelic variants between Iranian,Japanese and Chinese (p<0.02 and similar between the Iranian and Caucasian population.(p=0.06.Almost 50% of Iranian and Caucasian individuals were homozygous carriers of the variant T allele compared with 32% of the Japanese and 43% of the Chinese (p<0.02.More than half of Iranian subjects have at least one T allele,with lower P-gp level in small intestine.We also noted dramatic differences in the CYP3A5 alleles and genotypes distribution between Iranian subjects with other compared populations.99% of Iranian individuals were homozygous carriers of the variant G allele compared with about 70% of the Chinese and Japanese and 19% of the Caucasian population. The G/G genotype has a very low level of active cytochrome P450 enzyme.Conclusion:Our results emphasize the role of ethnicity in interindividual variability of the pharmacokinetic and pharmacodynamic characteristics

Human Platelet Antigen Alleles in 998 Taiwanese Blood Donors Determined by Sequence-Specific Primer Polymerase Chain Reaction

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Shun-Chung Pai

2013-01-01

Full Text Available Polymorphism of human platelet antigens (HPAs leads to alloimmunizations and immune-mediated platelet disorders including fetal-neonatal alloimmune thrombocytopenia (FNAIT, posttransfusion purpura (PTP, and platelet transfusion refractoriness (PTR. HPA typing and knowledge of antigen frequency in a population are important in particular for the provision of HPA-matched blood components for patients with PTR. We have performed allele genotyping for HPA-1 through -6 and -15 among 998 platelet donors from 6 blood centers in Taiwan using sequence-specific primer polymerase chain reaction. The HPA allele frequency was 99.55, and 0.45% for HPA-1a and -1b; 96.49, and 3.51% for HPA-2a and -2b; 55.81, and 44.19% for HPA-3a and -3b; 99.75, and 0.25% for HPA-4a and -4b; 98.50, and 1.50% for HPA-5a and -5b; 97.75 and 2.25% for HPA-6a and -6b; 53.71 and 46.29% for HPA-15a and -15b. HPA-15b and HPA-3a, may be considered the most important, followed by HPA-2, -6, -1, -5, and -4 systems, as a cause of FNAIT, PTP, and PTR based on allele frequency. HPA-4b and HPA-5b role cannot be excluded based on their immunogenicity. A larger-scale study will now be conducted to confirm these hypotheses and to establish an apheresis donor database for the procurement of HPA-matched apheresis platelets for patients with PTR.

Low Frequency Electrostatic Waves in Weakly Inhomogeneous Magnetoplasma Modeled by Lorentzian (kappa) Distributions

National Research Council Canada - National Science Library

Basu, Bamandas

2008-01-01

... (to the ambient magnetic field) flow velocities associated with the current. In order to illustrate the distinguishing features of the kappa distributions, stability properties of the low frequency...

Allele frequencies in the VRN-A1, VRN-B1 and VRN-D1 vernalization response and PPD-B1 and PPD-D1 photoperiod sensitivity genes, and their effects on heading in a diverse set of wheat cultivars (Triticum aestivum L.).

Science.gov (United States)

Kiss, Tibor; Balla, Krisztina; Veisz, Ottó; Láng, László; Bedő, Zoltán; Griffiths, Simon; Isaac, Peter; Karsai, Ildikó

2014-01-01

Heading of cereals is determined by complex genetic and environmental factors in which genes responsible for vernalization and photoperiod sensitivity play a decisive role. Our aim was to use diagnostic molecular markers to determine the main allele types in VRN - A1 , VRN - B1 , VRN - D1 , PPD - B1 and PPD - D1 in a worldwide wheat collection of 683 genotypes and to investigate the effect of these alleles on heading in the field. The dominant VRN - A1 , VRN - B1 and VRN - D1 alleles were present at a low frequency. The PPD - D1a photoperiod-insensitive allele was carried by 57 % of the cultivars and was most frequent in Asian and European cultivars. The PPD - B1 photoperiod-insensitive allele was carried by 22 % of the genotypes from Asia, America and Europe. Nine versions of the PPD - B1 -insensitive allele were identified based on gene copy number and intercopy structure. The allele compositions in PPD - D1 , PPD - B1 and VRN - D1 significantly influenced heading and together explained 37.5 % of the phenotypic variance. The role of gene model increased to 39.1 % when PPD - B1 intercopy structure was taken into account instead of overall PPD - B1 type (sensitive vs. insensitive). As a single component, PPD - D1 had the most important role (28.0 % of the phenotypic variance), followed by PPD - B1 (12.3 % for PPD - B1 _overall, and 15.1 % for PPD - B1 _intercopy) and VRN - D1 (2.2 %). Significant gene interactions were identified between the marker alleles within PPD - B1 and between VRN - D1 and the two PPD1 genes. The earliest heading genotypes were those with the photoperiod-insensitive allele in PPD - D1 and PPD - B1 , and with the spring allele for VRN - D1 and the winter alleles for VRN - A1 and VRN - B1 . This combination could only be detected in genotypes from Southern Europe and Asia. Late-heading genotypes had the sensitivity alleles for both PPD1 genes, regardless of the allelic composition of the VRN1 genes. There was a 10-day difference in

A General Model of Negative Frequency Dependent Selection Explains Global Patterns of Human ABO Polymorphism.

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Fernando A Villanea

Full Text Available The ABO locus in humans is characterized by elevated heterozygosity and very similar allele frequencies among populations scattered across the globe. Using knowledge of ABO protein function, we generated a simple model of asymmetric negative frequency dependent selection and genetic drift to explain the maintenance of ABO polymorphism and its loss in human populations. In our models, regardless of the strength of selection, models with large effective population sizes result in ABO allele frequencies that closely match those observed in most continental populations. Populations must be moderately small to fall out of equilibrium and lose either the A or B allele (N(e ≤ 50 and much smaller (N(e ≤ 25 for the complete loss of diversity, which nearly always involved the fixation of the O allele. A pattern of low heterozygosity at the ABO locus where loss of polymorphism occurs in our model is consistent with small populations, such as Native American populations. This study provides a general evolutionary model to explain the observed global patterns of polymorphism at the ABO locus and the pattern of allele loss in small populations. Moreover, these results inform the range of population sizes associated with the recent human colonization of the Americas.

HLA alleles and haplotypes distribution in Dai population in Yunnan province, Southwest China.

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Shi, L; Yao, Y F; Shi, L; Matsushita, M; Yu, L; Lin, Q K; Tao, Y F; Oka, T; Chu, J Y; Tokunaga, K

2010-02-01

Human leukocyte antigen (HLA) analysis would be a useful tool to trace the origin of modern humans. In this study, we provided the first four digital HLA-A, -B, -C and -DRB1 allele and haplotype data in the Dai ethnic population, which is a unique and representative Kam-Tai-speaking ethnic minority living in the Yunnan province of Southwestern China. Our results showed that the Dai population has unique HLA characteristic that are most closely related to the Southeastern Asia group and similar to the Kam-Tai speaking populations in China and Thailand.

Frequency of Cry1F Non-Recessive Resistance Alleles in North Carolina Field Populations of Spodoptera frugiperda (Lepidoptera: Noctuidae).

Science.gov (United States)

Li, Guoping; Reisig, Dominic; Miao, Jin; Gould, Fred; Huang, Fangneng; Feng, Hongqiang

2016-01-01

Fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is a target species of transgenic corn (Zea mays L.) that expresses single and pyramided Bacillus thuringiensis (Bt) toxin. In 2014, S. frugiperda were collected from a light trap in North Carolina, and a total of 212 F1/F2 isofemale lines of S. frugiperda were screened for resistance to Bt and non-Bt corn. All of the 212 isolines were susceptible to corn tissue expressing Cry1A.105 + Cry2Ab, Cry1F + Cry1A.105 + Cry2Ab, and Cry1F + Cry1Ab + Vip3Aa20. Growth rate bioassays were performed to isolate non-recessive Bt resistance alleles. Seven individuals out of the 212 isofemale lines carried major non-recessive alleles conferring resistance to Cry1F. A pooled colony was created from the seven individuals. This colony was 151.21 times more resistant to Cry1F than a known-susceptible population and was also resistant to Cry1A.105, but was not resistant to Cry2Ab and Vip3Aa20. The results demonstrate that field populations of S. frugiperda collected from North Carolina are generally susceptible to Cry1F, but that some individuals carry resistant alleles. The data generated in this study can be used as baseline data for resistance monitoring.

Diminished levels of allelic losses by homologous recombination in radiation-hypersensitive cells

International Nuclear Information System (INIS)

Tatsumi, K.; Abe, M.; Hoki, Y.; Kubo, E.; Muto, M.; Araki, R.; Sato, K.

2003-01-01

Mitotic recombination (MR) due to somatic crossing-over is a predominant mechanism for allelic losses in mammalian cells either spontaneous or radiation-induced. A selectable mutation assay accompanying real-time detection PCR was developed to analyze the second step in loss-of-function mutations employing a human lympho-blastoid cell line derived from an obligate heterozygote of 2,8-dihydroxyadenine urolithiasis, adenine phosphoribosyltransferase (APRT) deficiency with a nonsense mutation at exon 3 of the gene. 68 % of spontaneously arising 2,6-diaminopurine resistance (DAP r ) mutant clones were associated with loss of heterozygosity (LOH), while 92 % of 2 Gy gamma-ray induced mutant clones were so associated. Investigation of gene dosage revealed that about one half of the spontaneously arising mutant clones and two-thirds of those induced by gamma-rays showed reduction to homozygosity of the constitutionally inactivated APRT allele. In an ataxia telangiectasia (AT) cell subline in which a new inactivation mutation had been introduced into one APRT allele by ICR-191, MR rarely occurred and exclusively deletions predominated in both spontaneous and X-ray induced DAP r mutants with LOH. A similar assay system was also developed with C3H mouse FM3A mammary tumor cells, SR-1, carrying a C .T transition at exon 5 of an APRT allele. In an XRCC7 (DNA-PKcs) deficient subline of SR-1, SX9 , spontaneous mutation frequencies for the Aprt locus (8AA r ) was 10 -3 , which was about 10 times higher than that in parental SR-1 cells. Mutation frequencies induced by X-rays comparably increased in a dose-dependent manner for the Aprt locus in both cell lines. Against our expectation, the lack of an NHEJ pathway of DNA double strand break repair resulted in a lower proportion (11.1 %) of MR with deletions (77.8 %) as the molecular cause for 8AA r mutations following X-irradiation, while virtually all of X-ray induced 8AA r mutant clones were MR in the control SR-1 cells. Factors

HLA-DRB1 shared epitope alleles in patients with rheumatoid arthritis: relation to autoantibodies and disease severity in a south Indian population.

Science.gov (United States)

Konda Mohan, Vasanth; Ganesan, Nalini; Gopalakrishnan, Rajasekhar; Venkatesan, Vettriselvi

2017-10-01

To investigate the presence of the 'shared epitope' (SE) in the HLA-DRB1 alleles in patients with RA and to ascertain the frequency of the HLA-DRB1 alleles with autoantibodies (anti-cyclic citrullinated peptide [anti-CCP] rheumatoid factor [RF]) and disease severity. A total of 200 RA patients and 200 apparently healthy subjects participated in the study. HLA-DRB1 were genotyped using polymerase chain reaction with sequence-specific primer (PCR-SSP). Anti-CCP and RF in serum were determined by in vitro quantitative enzyme-linked immunosorbent assay (ELISA) method. Erythrocyte sedimentation rate (ESR) was measured by Westergren method. Disease activity was assessed by using the disease activity score-28 (DAS-28). Chi-square test and Student's t-test were used in the statistical analysis. A significant increase in the frequency of HLA-DRB1*01, *04, *10 and *14 were identified in RA patients and showed a strong association with the disease susceptibility. While the frequencies of HLA-DRB1*03, *07, *11 and *13 were significantly lower in RA patients than in controls. The other HLA-DRB1 alleles *08, *09, *12, *15 and *16 showed no significant difference. The frequency of anti-CCP and RF antibodies did not showed significant difference in SE-positive patients compared with SE-negative patients. DAS-28 values of RA patients showed no significant difference between SE-positive and SE-negative groups. Our results indicate that HLA-DRB1*01, *04, *10 and *14 alleles are related with RA, while HLA-DRB1*03, *07, *11 and *13 protect against RA in our population. On the other hand, we failed to provide evidence for the association of the autoantibodies and DAS-28 with SE-positive RA patients. © 2016 Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd.

The Study of Morphological Traits and Identification of Self-incompatibility Alleles in Almond Cultivars and Genotypes

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Mousa Rasouli

2017-12-01

Full Text Available The evaluation of an almond collection using morphological variables and identification of self-incompatibility genotype  is useful for selecting pollinizers and for the design of crossing in almond breeding programs. In this study, important morphological traits and self-incompatibilities in 71 almond cultivars and genotypes were studied. Simple and multiplex specific PCR analyses were used in order to identify self-incompatibility alleles. Based on the results, cultivars and genotypes including ‘Dir Ras–e-Savojbolagh’, ‘D-124’, ‘D-99’, ‘Shahrood 12’, ‘Tuono’, ‘Nonpareil’, ‘Price’, ‘Mirpanj-e-Tehran’, ‘Pakotahe-e- Taleghan’, ‘V-13-34’, ‘V-16-8, ‘V-11-10’, ‘Zarghan 10’, ‘Uromiyeh 68’, ‘Barg dorosht-e-Hamedan’ and ‘Yazd 60’ were late flowering and had the highest quality of nut and kernel characters. The result of the PCR method using combined primers AS1II and AmyC5R showed amplification of ten self-incompatibility alleles (S1, S2, S3, S5, S6, S7, S8, S10, S12,and S unknown allele and three Sfalleles. Moreover, S1 had the highest frequencies in comparison with other known S-alleles. Also, unknown alleles with different sizes were detected and 58 new bands were found in some cultivars.

Engineering Inertial and Primary-Frequency Response for Distributed Energy Resources: Preprint

Energy Technology Data Exchange (ETDEWEB)

Dall-Anese, Emiliano [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Zhao, Changhong [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Guggilam, Swaroop [University of Minnesota; Dhople, Sairaj V [University of Minnesota; Chen, Yu C [University of British Columbia; Zhao, Changhong [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-12-19

We propose a framework to engineer synthetic-inertia and droop-control parameters for distributed energy resources (DERs) so that the system frequency in a network composed of DERs and synchronous generators conforms to prescribed transient and steady-state performance specifications. Our approach is grounded in a second-order lumped-parameter model that captures the dynamics of synchronous generators and frequency-responsive DERs endowed with inertial and droop control. A key feature of this reduced-order model is that its parameters can be related to those of the originating higher-order dynamical model. This allows one to systematically design the DER inertial and droop-control coefficients leveraging classical frequency-domain response characteristics of second-order systems. Time-domain simulations validate the accuracy of the model-reduction method and demonstrate how DER controllers can be designed to meet steady-state-regulation and transient-performance specifications.

Spatial distribution of cold-season lightning frequency in the coastal areas of the Sea of Japan

Science.gov (United States)

Tsurushima, Daiki; Sakaida, Kiyotaka; Honma, Noriyasu

2017-12-01

The coastal areas of the Sea of Japan are a well-known hotspot of winter lightning activity. This study distinguishes between three common types of winter lightning in that region (types A-C), based on their frequency distributions and the meteorological conditions under which they occur. Type A lightning occurs with high frequency in the Tohoku district. It is mainly caused by cold fronts that accompany cyclones passing north of the Japanese islands. Type B, which occurs most frequently in the coastal areas of the Hokuriku district, is mainly caused by topographically induced wind convergence and convective instability, both of which are associated with cyclones having multiple centers. Type C's lightning frequency distribution pattern is similar to that of type B, but its principal cause is a topographically induced wind convergence generated by cold air advection from the Siberian continent. Type A is most frequently observed from October to November, while types B and C tend to appear from November to January, consistent with seasonal changes in lightning frequency distribution in Japan's Tohoku and Hokuriku districts.

Ultra-high resolution HLA genotyping and allele discovery by highly multiplexed cDNA amplicon pyrosequencing

Directory of Open Access Journals (Sweden)

Lank Simon M

2012-08-01

Full Text Available Abstract Background High-resolution HLA genotyping is a critical diagnostic and research assay. Current methods rarely achieve unambiguous high-resolution typing without making population-specific frequency inferences due to a lack of locus coverage and difficulty in exon-phase matching. Achieving high-resolution typing is also becoming more challenging with traditional methods as the database of known HLA alleles increases. Results We designed a cDNA amplicon-based pyrosequencing method to capture 94% of the HLA class I open-reading-frame with only two amplicons per sample, and an analogous method for class II HLA genes, with a primary focus on sequencing the DRB loci. We present a novel Galaxy server-based analysis workflow for determining genotype. During assay validation, we performed two GS Junior sequencing runs to determine the accuracy of the HLA class I amplicons and DRB amplicon at different levels of multiplexing. When 116 amplicons were multiplexed, we unambiguously resolved 99%of class I alleles to four- or six-digit resolution, as well as 100% unambiguous DRB calls. The second experiment, with 271 multiplexed amplicons, missed some alleles, but generated high-resolution, concordant typing for 93% of class I alleles, and 96% for DRB1 alleles. In a third, preliminary experiment we attempted to sequence novel amplicons for other class II loci with mixed success. Conclusions The presented assay is higher-throughput and higher-resolution than existing HLA genotyping methods, and suitable for allele discovery or large cohort sampling. The validated class I and DRB primers successfully generated unambiguously high-resolution genotypes, while further work is needed to validate additional class II genotyping amplicons.

Geographical and Ethnic Distributions of the MTHFR C677T, A1298C and MTRR A66G Gene Polymorphisms in Chinese Populations: A Meta-Analysis.

Directory of Open Access Journals (Sweden)

Xingmin Wang

Full Text Available The geographical and ethnic distributions of the polymorphic methylenetetrahydrofolate reductase (MTHFR mutations (C677T and A1298C and methionine synthase reductase (MTRR mutation (A66G remain heterogeneous in China. The goal of this study was to estimate the pooled frequencies of the alleles and associated genotypes of these gene polymorphisms among healthy populations in Mainland China.We systematically reviewed published epidemiological studies on the distributions of 3 genetic variants in Chinese healthy populations living in Mainland China through a meta-analysis. The relevant electronic databases were searched. All of the raw data of the eligible citations were extracted. The frequency estimates were stratified by geography, ethnicity and sex.Sixty-six studies were identified with a total of 92277 study participants. The meta-analysis revealed that the frequencies of the MTHFR C677T, A1298C, and MTRR A66G gene polymorphisms varied significantly between different ethnic groups and along geographical gradients. The frequencies of the 677T allele and 677TT genotype increased along the southern-central-northern direction across Mainland China (all Pvalues≤0.001. The frequencies of the 1298C, 1298CC, 66G and 66GG genotypes decreased along the south-central-north direction across the country (all Pvalues≤0.001.Our meta-analysis strongly indicates significant geographical and ethnic variations in the frequencies of the C677T, A1298C, and A66G gene polymorphisms in the folate metabolism pathway among Chinese populations.

Finite Time Control for Fractional Order Nonlinear Hydroturbine Governing System via Frequency Distributed Model

Directory of Open Access Journals (Sweden)

Bin Wang

2016-01-01

Full Text Available This paper studies the application of frequency distributed model for finite time control of a fractional order nonlinear hydroturbine governing system (HGS. Firstly, the mathematical model of HGS with external random disturbances is introduced. Secondly, a novel terminal sliding surface is proposed and its stability to origin is proved based on the frequency distributed model and Lyapunov stability theory. Furthermore, based on finite time stability and sliding mode control theory, a robust control law to ensure the occurrence of the sliding motion in a finite time is designed for stabilization of the fractional order HGS. Finally, simulation results show the effectiveness and robustness of the proposed scheme.

Real-Time Analysis of an Active Distribution Network - Coordinated Frequency Control for Islanding Operation

DEFF Research Database (Denmark)

Cha, Seung-Tae

distribution networks makes it possible to operate the distribution networks independently which is called islanding operation. However, it is a challenge to ensure secure and reliable operation of the islanded system due to a num-ber of reasons, e.g. low inertia in the islanded system, intermittency of some...... of the DERs, etc. Particularly during islanding operation, with relatively few DG units, the frequency and voltage control of the islanded system is not straightforward. DG units, specially based on renewable energy sources (RESs), i.e. wind and solar, have an inter-mittent nature and intrinsic...... system (BESS) and two secondary frequency control scenarios with BESS and DG units. During the island-ing transition, the frequency is regulated by the fast-acting primary control of the BESS. The secondary control of the main management system (MMS) detects the status of the BESS and tries to return...

Allelic genealogies in sporophytic self-incompatibility systems in plants

DEFF Research Database (Denmark)

Schierup, Mikkel Heide; Vekemans, Xavier; Christiansen, Freddy Bugge

1998-01-01

, alleles act codominantly in both pollen and style, in the SSIdom model, alleles form a dominance hierarchy, and in SSIdomcod, alleles are codominant in the style and show a dominance hierarchy in the pollen. Coalescence times of alleles rarely differ more than threefold from those under gametophytic self...

Local time distribution of the SSC-associated HF-Doppler frequency shifts

International Nuclear Information System (INIS)

Kikuchi, T.; Sugiuchi, H.; Ishimine, T.

1985-01-01

The HF-Doppler frequency shift observed at the storm's sudden commencement is composed of a frequency increase (+) and decrease (-), and classified into four types, SCF(+ -), SCF(- +), SCF(+) and SCF(-). Since the latter two types are special cases of the former two types, two different kinds of electrical field exist in the F region and cause the ExB drift motion of plasma. HUANG (1976) interpreted the frequency increase of SCF(+ -) as due to the westward induction electric field proportional to delta H/ delta t and the succeeding frequency decrease due to the eastward conduction electric field which produces ionospheric currents responsible for the magnetic increase on the ground. In spite of his success in interpreting the SCF(+ -), some other interpretations are needed for the explanation of the whole set of SCF's, particularly SCF(- +). Local time distributions of the SCF's are derived from 41 SCF's which are observed on the HF standard signal (JJY) as received in Okinawa (path length =1600 km) and Kokubunji (60 km). It is shown that the SCF(+ -) appears mainly during the day, whereas the SCF(- +) is observed during the night. The results indicate that the preliminary frequency shift (+) of SCF(+ -) and (-) of SCF(- +) is caused by a westward electric field in the dayside hemisphere, while by an eastward electric field in the nightside hemisphere. The main frequency shift (-) of SCF(+ -) and (+) of SCF(- +) is caused by the reversed electric field. Consequently, the preliminary frequency shift is caused by the dusk-to-dawn electric field, while the main frequency shift by the dawn-to-dusk electric field

Local time distribution of the SSC-associated HF-Doppler frequency shifts

Science.gov (United States)

Kikuchi, T.; Sugiuchi, H.; Ishimine, T.

1985-01-01

The HF-Doppler frequency shift observed at the storm's sudden commencement is composed of a frequency increase (+) and decrease (-), and classified into four types, SCF(+ -), SCF(- +), SCF(+) and SCF(-). Since the latter two types are special cases of the former two types, two different kinds of electrical field exist in the F region and cause the ExB drift motion of plasma. HUANG (1976) interpreted the frequency increase of SCF(+ -) as due to the westward induction electric field proportional to delta H/ delta t and the succeeding frequency decrease due to the eastward conduction electric field which produces ionospheric currents responsible for the magnetic increase on the ground. In spite of his success in interpreting the SCF(+ -), some other interpretations are needed for the explanation of the whole set of SCF's, particularly SCF(- +). Local time distributions of the SCF's are derived from 41 SCF's which are observed on the HF standard signal (JJY) as received in Okinawa (path length =1600 km) and Kokubunji (60 km). It is shown that the SCF(+ -) appears mainly during the day, whereas the SCF(- +) is observed during the night. The results indicate that the preliminary frequency shift (+) of SCF(+ -) and (-) of SCF(- +) is caused by a westward electric field in the dayside hemisphere, while by an eastward electric field in the nightside hemisphere. The main frequency shift (-) of SCF(+ -) and (+) of SCF(- +) is caused by the reversed electric field. Consequently, the preliminary frequency shift is caused by the dusk-to-dawn electric field, while the main frequency shift by the dawn-to-dusk electric field.

Discovery, evaluation and distribution of haplotypes of the wheat Ppd-D1 gene.

Science.gov (United States)

Guo, Zhiai; Song, Yanxia; Zhou, Ronghua; Ren, Zhenglong; Jia, Jizeng

2010-02-01

Ppd-D1 is one of the most potent genes affecting the photoperiod response of wheat (Triticum aestivum). Only two alleles, insensitive Ppd-D1a and sensitive Ppd-D1b, were known previously, and these did not adequately explain the broad adaptation of wheat to photoperiod variation. In this study, five diagnostic molecular markers were employed to identify Ppd-D1 haplotypes in 492 wheat varieties from diverse geographic locations and 55 accessions of Aegilops tauschii, the D genome donor species of wheat. Six Ppd-D1 haplotypes, designated I-VI, were identified. Types II, V and VI were considered to be more ancient and types I, III and IV were considered to be derived from type II. The transcript abundances of the Ppd-D1 haplotypes showed continuous variation, being highest for haplotype I, lowest for haplotype III, and correlating negatively with varietal differences in heading time. These haplotypes also significantly affected other agronomic traits. The distribution frequency of Ppd-D1 haplotypes showed partial correlations with both latitudes and altitudes of wheat cultivation regions. The evolution, expression and distribution of Ppd-D1 haplotypes were consistent evidentially with each other. What was regarded as a pair of alleles in the past can now be considered a series of alleles leading to continuous variation.

Time–frequency analysis of nonstationary complex magneto-hydro-dynamics in fusion plasma signals using the Choi–Williams distribution

International Nuclear Information System (INIS)

Xu, L.Q.; Hu, L.Q.; Chen, K.Y.; Li, E.Z.

2013-01-01

Highlights: • Choi–Williams distribution yields excellent time–frequency resolution for discrete signal. • CWD method provides clear time–frequency pictures of EAST and HT-7 fast MHD events. • CWD method has advantages to wavelets transform scalogram and the short-time Fourier transform spectrogram. • We discuss about how to choose the windows and free parameter of CWD method. -- Abstract: The Choi–Williams distribution is applied to the time–frequency analysis of signals describing rapid magneto-hydro-dynamic (MHD) modes and events in tokamak plasmas. A comparison is made with Soft X-ray (SXR) signals as well as Mirnov signal that shows the advantages of the Choi–Williams distribution over both continuous wavelets transform scalogram and the short-time Fourier transform spectrogram. Examples of MHD activities in HT-7 and EAST tokamak are shown, namely the onset of coupling tearing modes, high frequency precursors of sawtooth, and low frequency MHD instabilities in edge localized mode (ELM) free in H mode discharge

Frequency of the allelic variant c.1150T > C in exon 10 of the fibroblast growth factor receptor 3 (FGFR3 gene is not increased in patients with pathogenic mutations and related chondrodysplasia phenotypes

Directory of Open Access Journals (Sweden)

Thatiane Yoshie Kanazawa

2014-12-01

Full Text Available Mutations in the FGFR3 gene cause the phenotypic spectrum of FGFR3 chondrodysplasias ranging from lethal forms to the milder phenotype seen in hypochondroplasia (Hch. The p.N540K mutation in the FGFR3 gene occurs in ~70% of individuals with Hch, and nearly 30% of individuals with the Hch phenotype have no mutations in the FGFR3, which suggests genetic heterogeneity. The identification of a severe case of Hch associated with the typical mutation c.1620C > A and the occurrence of a c.1150T > C change that resulted in a p.F384L in exon 10, together with the suspicion that this second change could be a modulator of the phenotype, prompted us to investigate this hypothesis in a cohort of patients. An analysis of 48 patients with FGFR3 chondrodysplasia phenotypes and 330 healthy (control individuals revealed no significant difference in the frequency of the C allele at the c.1150 position (p = 0.34. One patient carrying the combination `pathogenic mutation plus the allelic variant c.1150T > C' had a typical achondroplasia (Ach phenotype. In addition, three other patients with atypical phenotypes showed no association with the allelic variant. Together, these results do not support the hypothesis of a modulatory role for the c.1150T > C change in the FGFR3 gene.

Analysis of an "off-ladder" allele at the Penta D short tandem repeat locus.

Science.gov (United States)

Yang, Y L; Wang, J G; Wang, D X; Zhang, W Y; Liu, X J; Cao, J; Yang, S L

2015-11-25

Kinship testing of a father and his son from Guangxi, China, the location of the Zhuang minority people, was performed using the PowerPlex® 18D System with a short tandem repeat typing kit. The results indicated that both the father and his son had an off-ladder allele at the Penta D locus, with a genetic size larger than that of the maximal standard allelic ladder. To further identify this locus, monogenic amplification, gene cloning, and genetic sequencing were performed. Sequencing analysis demonstrated that the fragment size of the Penta D-OL locus was 469 bp and the core sequence was [AAAGA]21, also called Penta D-21. The rare Penta D-21 allele was found to be distributed among the Zhuang population from the Guangxi Zhuang Autonomous Region of China; therefore, this study improved the range of DNA data available for this locus and enhanced our ability for individual identification of gene loci.

ADH1B*2 allele is protective against alcoholism but not chronic liver disease in the Hungarian population.

Science.gov (United States)

Toth, Reka; Pocsai, Zsuzsa; Fiatal, Szilvia; Szeles, Gyorgy; Kardos, Laszlo; Petrovski, Beata; McKee, Martin; Adany, Roza

2010-05-01

Standardized death rates from chronic liver diseases (CLDs) in Hungary are much higher than the European Union average. Carrying the alcohol dehydrogenase 1B 48His allele (rs1229984 or ADH1B*2) could decrease the risk of alcoholism, but with persistent drinking may confer a greater risk of CLDs. The aim of this study was to assess the prevalence of this polymorphism in the Hungarian population and its association with alcohol consumption and with CLDs. A total of 278 cases with diagnosed CLDs and 752 controls without any alterations in liver function, all males aged 45-64, were screened for ADH1B Arg48His polymorphism. ADH1B*2 allele frequencies in controls and cases were 8.31% and 4.50%, respectively (chi(2) = 9.2; P = 0.01). Carrying the ADH1B*2 allele was associated with significantly lower odds ratio (OR) for drinking frequency (OR = 0.63; P = 0.003), the number of positive answers on CAGE (Cut-down, Annoyed, Guilt, Eye-opener) assessment (OR = 0.58; P = 0.005) and a positive CAGE status (OR = 0.55; P = 0.007). There was a significant association between ADH1B*2 and CLDs (OR = 0.50; P = 0.003), but it disappeared after adjusting for CAGE status and scores (OR = 0.67 P = 0.134; OR = 0.67 P = 0.148, respectively) and weakened after adjusting for drinking frequency (OR = 0.61; P = 0.045). Among heavy drinkers the presence of ADH1B*2 did not increase the risk of cirrhosis but there was a significant interaction between genotype and CAGE status (P = 0.003, P = 0.042), with ADH1B*2 conferring reduced risk of CLDs in CAGE negatives. In Hungarians, the ADH1B 48His allele reduces the risk of alcoholism, but not the risk of chronic liver disease among heavy drinkers.

A Maximum-Likelihood Method to Correct for Allelic Dropout in Microsatellite Data with No Replicate Genotypes

Science.gov (United States)

Wang, Chaolong; Schroeder, Kari B.; Rosenberg, Noah A.

2012-01-01

Allelic dropout is a commonly observed source of missing data in microsatellite genotypes, in which one or both allelic copies at a locus fail to be amplified by the polymerase chain reaction. Especially for samples with poor DNA quality, this problem causes a downward bias in estimates of observed heterozygosity and an upward bias in estimates of inbreeding, owing to mistaken classifications of heterozygotes as homozygotes when one of the two copies drops out. One general approach for avoiding allelic dropout involves repeated genotyping of homozygous loci to minimize the effects of experimental error. Existing computational alternatives often require replicate genotyping as well. These approaches, however, are costly and are suitable only when enough DNA is available for repeated genotyping. In this study, we propose a maximum-likelihood approach together with an expectation-maximization algorithm to jointly estimate allelic dropout rates and allele frequencies when only one set of nonreplicated genotypes is available. Our method considers estimates of allelic dropout caused by both sample-specific factors and locus-specific factors, and it allows for deviation from Hardy–Weinberg equilibrium owing to inbreeding. Using the estimated parameters, we correct the bias in the estimation of observed heterozygosity through the use of multiple imputations of alleles in cases where dropout might have occurred. With simulated data, we show that our method can (1) effectively reproduce patterns of missing data and heterozygosity observed in real data; (2) correctly estimate model parameters, including sample-specific dropout rates, locus-specific dropout rates, and the inbreeding coefficient; and (3) successfully correct the downward bias in estimating the observed heterozygosity. We find that our method is fairly robust to violations of model assumptions caused by population structure and by genotyping errors from sources other than allelic dropout. Because the data sets

The Gaussian atmospheric transport model and its sensitivity to the joint frequency distribution and parametric variability.

Science.gov (United States)

Hamby, D M

2002-01-01

Reconstructed meteorological data are often used in some form of long-term wind trajectory models for estimating the historical impacts of atmospheric emissions. Meteorological data for the straight-line Gaussian plume model are put into a joint frequency distribution, a three-dimensional array describing atmospheric wind direction, speed, and stability. Methods using the Gaussian model and joint frequency distribution inputs provide reasonable estimates of downwind concentration and have been shown to be accurate to within a factor of four. We have used multiple joint frequency distributions and probabilistic techniques to assess the Gaussian plume model and determine concentration-estimate uncertainty and model sensitivity. We examine the straight-line Gaussian model while calculating both sector-averaged and annual-averaged relative concentrations at various downwind distances. The sector-average concentration model was found to be most sensitive to wind speed, followed by horizontal dispersion (sigmaZ), the importance of which increases as stability increases. The Gaussian model is not sensitive to stack height uncertainty. Precision of the frequency data appears to be most important to meteorological inputs when calculations are made for near-field receptors, increasing as stack height increases.

Prevalence of high-risk alleles in the LOXL1 gene and its association with pseudoexfoliation syndrome and exfoliation glaucoma in a Latin American population.

Science.gov (United States)

Jaimes, Martha; Rivera-Parra, David; Miranda-Duarte, Antonio; Valdés, Gerardo; Zenteno, Juan Carlos

2012-03-01

Pseudoexfoliation syndrome (XFS) is a major risk factor for exfoliation glaucoma (XFG). A significant association exists between XFG and several SNPs in the lysyl oxidase-like 1 (LOXL1) gene. The purpose of this study was to report the results of the first association study between LOXL1 polymorphisms and XFS and/or XFG in a Latin American population. Genotypes of three high-risk SNPs of LOXL1 (rs1048661, rs3825942, and rs2165241) were analyzed by direct sequencing. A case-control study was conducted with 102 unrelated XFS/XFG Mexican patients (42 XFS/60 XFG) as well as 97 control subjects. Allele frequencies, Hardy-Weinberg equilibrium, and haplotype association analysis were assessed with the Haplo View software. The T allele of the intronic SNP rs2165241 was more frequent in XFS/XFG patients than in controls (OR [95% CI] = 2.41 [1.59-3.64]; p = 0.00001). The G allele of rs3825942 was found in a higher frequency in XFS/XFG than in controls (100% vs 95% respectively, p = 0.0019). No significant association between XFS and the rs1048661 (R141L) SNP was observed. The TGT haplotype was observed in a higher frequency in patients than in controls (p = 0.025), and produced the highest risk in our study (OR [95% CI] = 3.20 [1.09-9.39]; p = 0.025). This is the first study associating LOXL1 gene polymorphism and XFS/XFG in Latin America. LOXL1 variants are associated with an elevated risk for XFS/XFG in the Mexican population. A higher risk was conferred by the T allele of the intronic rs2165241 SNP rather than by the worldwide "high-risk" G allele of rs3825942.

VNTR alleles associated with the {alpha}-globin locus are haplotype and population related

Energy Technology Data Exchange (ETDEWEB)

Martinson, J.J.; Clegg, J.B.; Boyce, A.J. [Univ. of Oxford (United Kingdom)

1994-09-01

The human {alpha}-globin complex contains several polymorphic restriction-enzyme sites (i.e., RFLPs) linked to form haplotypes and is flanked by two hypervariable VNTR loci, the 5{prime} hypervariable region (HVR) and the more highly polymorphic 3{prime}HVR. Using a combination of RFLP analysis and PCR, the authors have characterized the 5{prime}HVR and 3{prime}HVR alleles associated with the {alpha}-globin haplotypes of 133 chromosomes, and they here show that specific {alpha}-globin haplotypes are each associated with discrete subsets of the alleles observed at these two VNTR loci. This statistically highly significant association is observed over a region spanning {approximately} 100 kb. With the exception of closely related haplotypes, different haplotypes do not share identically sized 3{prime}HVR alleles. Earlier studies have shown that {alpha}-globin haplotype distributions differ between populations; the current findings also reveal extensive population substructure in the repertoire of {alpha}-globin VNTRs. If similar features are characteristic of other VNTR loci, this will have important implications for forensic and anthropological studies. 42 refs., 5 figs., 5 tabs.

Distribution of HIV-1 resistance-conferring polymorphic alleles SDF ...

Indian Academy of Sciences (India)

Unknown

involved with delay in disease progression. ... proteins in 525 healthy individuals without any history of HIV-1 infection from 11 diverse populations of ... in three populations (Yamani, Pathan and Kamma), all in low frequencies (i.e. 1% to 3%).

Distribution of the PKU mutation 165T in Spain and Latin America

Energy Technology Data Exchange (ETDEWEB)

Perez, B.; deLucca, M.; Desviat, L.R. [UAM-CSIC, Madrid (Spain)] [and others

1994-09-01

The 165T mutation is the second most common mutation in the Spanish PKU patients. In order to provide some additional data about the origin of this mutation, we have analyzed 452 PKU alleles from all regions of Spain. The mutation was found in 9% of alleles. We have found a South-North gradient with a highest frequency in the South and the lowest in the North. In the North-West regions (which has the greatest Celtic influence in Spain) the frequency was 7%. The chromosomes bearing this mutation contained the 8 repeat VNTR allele, as has been described in other populations. In view of these results, we suggest an origin other than Celtic for this mutation. On the other hand, we have analyzed 406 PKU alleles from five Latin American countries, 158 from Brazil, 170 from Chile, 56 from Argentina, 14 from Mexico and 8 from Venezuela. Unlike the results of the IVS10 mutation, 165T is present in Latin America with a low frequency. The results show that this mutation is rare in Chile (1%) and is absent in the chromosomes analyzed from Argentina, Mexico and Venezuela. Only in Brazil has this mutation been found in 5% of the alleles. Up to now, Spain is the only Mediterranean country where this mutation is present with a relatively high frequency. This mutation has been detected in the Portuguese patients and would also have migrated to Brazil.

Assigning breed origin to alleles in crossbred animals.

Science.gov (United States)

Vandenplas, Jérémie; Calus, Mario P L; Sevillano, Claudia A; Windig, Jack J; Bastiaansen, John W M

2016-08-22

For some species, animal production systems are based on the use of crossbreeding to take advantage of the increased performance of crossbred compared to purebred animals. Effects of single nucleotide polymorphisms (SNPs) may differ between purebred and crossbred animals for several reasons: (1) differences in linkage disequilibrium between SNP alleles and a quantitative trait locus; (2) differences in genetic backgrounds (e.g., dominance and epistatic interactions); and (3) differences in environmental conditions, which result in genotype-by-environment interactions. Thus, SNP effects may be breed-specific, which has led to the development of genomic evaluations for crossbred performance that take such effects into account. However, to estimate breed-specific effects, it is necessary to know breed origin of alleles in crossbred animals. Therefore, our aim was to develop an approach for assigning breed origin to alleles of crossbred animals (termed BOA) without information on pedigree and to study its accuracy by considering various factors, including distance between breeds. The BOA approach consists of: (1) phasing genotypes of purebred and crossbred animals; (2) assigning breed origin to phased haplotypes; and (3) assigning breed origin to alleles of crossbred animals based on a library of assigned haplotypes, the breed composition of crossbred animals, and their SNP genotypes. The accuracy of allele assignments was determined for simulated datasets that include crosses between closely-related, distantly-related and unrelated breeds. Across these scenarios, the percentage of alleles of a crossbred animal that were correctly assigned to their breed origin was greater than 90 %, and increased with increasing distance between breeds, while the percentage of incorrectly assigned alleles was always less than 2 %. For the remaining alleles, i.e. 0 to 10 % of all alleles of a crossbred animal, breed origin could not be assigned. The BOA approach accurately assigns

Recommendations of the DNA Commission of the International Society for Forensic Genetics (ISFG) on quality control of autosomal Short Tandem Repeat allele frequency databasing (STRidER)

DEFF Research Database (Denmark)

Bodner, Martin; Bastisch, Ingo; Butler, John M.

2016-01-01

for mitochondrial mtDNA, and YHRD for Y-chromosomal loci) that centralized quality control and data curation is essential to minimize error. The concepts employed for quality control involve software-aided likelihood-of-genotype, phylogenetic, and population genetic checks that allow the researchers to compare...... on the previously established ENFSI DNA WG STRbASE and applies standard concepts established for haploid and autosomal markers as well as novel tools to reduce error and increase the quality of autosomal STR data. The platform constitutes a significant improvement and innovation for the scientific community....... There is currently no agreed procedure of performing quality control of STR allele frequency databases, and the reliability and accuracy of the data are largely based on the responsibility of the individual contributing research groups. It has been demonstrated with databases of haploid markers (EMPOP...

Spectral Energy Distribution and Radio Halo of NGC 253 at Low Radio Frequencies

Energy Technology Data Exchange (ETDEWEB)

Kapińska, A. D.; Staveley-Smith, L.; Meurer, G. R.; For, B.-Q. [International Centre for Radio Astronomy Research (ICRAR), University of Western Australia, 35 Stirling Hwy, WA 6009 (Australia); Crocker, R. [Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611 (Australia); Bhandari, S.; Callingham, J. R.; Gaensler, B. M.; Hancock, P. J.; Lenc, E. [ARC Centre of Excellence for All-Sky Astrophysics (CAASTRO), Sydney NSW (Australia); Hurley-Walker, N.; Seymour, N. [International Centre for Radio Astronomy Research (ICRAR), Curtin University, Bentley, WA 6102 (Australia); Offringa, A. R. [Netherlands Institute for Radio Astronomy (ASTRON), P.O. Box 2, 7990 AA Dwingeloo (Netherlands); Hanish, D. J. [Spitzer Science Center, California Institute of Technology, MC 220-6, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Ekers, R. D.; Bell, M. E. [CSIRO Astronomy and Space Science (CASS), P.O. Box 76, Epping, NSW 1710 (Australia); Dwarakanath, K. S. [Raman Research Institute, Bangalore 560080 (India); Hindson, L. [Centre of Astrophysics Research, University of Hertfordshire, College Lane, Hatfield AL10 9AB (United Kingdom); Johnston-Hollitt, M. [School of Chemical and Physical Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6140 (New Zealand); McKinley, B., E-mail: anna.kapinska@uwa.edu.au [School of Physics, The University of Melbourne, Parkville, VIC 3010 (Australia); and others

2017-03-20

We present new radio continuum observations of NGC 253 from the Murchison Widefield Array at frequencies between 76 and 227 MHz. We model the broadband radio spectral energy distribution for the total flux density of NGC 253 between 76 MHz and 11 GHz. The spectrum is best described as a sum of a central starburst and extended emission. The central component, corresponding to the inner 500 pc of the starburst region of the galaxy, is best modeled as an internally free–free absorbed synchrotron plasma, with a turnover frequency around 230 MHz. The extended emission component of the spectrum of NGC 253 is best described as a synchrotron emission flattening at low radio frequencies. We find that 34% of the extended emission (outside the central starburst region) at 1 GHz becomes partially absorbed at low radio frequencies. Most of this flattening occurs in the western region of the southeast halo, and may be indicative of synchrotron self-absorption of shock-reaccelerated electrons or an intrinsic low-energy cutoff of the electron distribution. Furthermore, we detect the large-scale synchrotron radio halo of NGC 253 in our radio images. At 154–231 MHz the halo displays the well known X-shaped/horn-like structure, and extends out to ∼8 kpc in the z -direction (from the major axis).

Detection of MPL mutations by a novel allele-specific PCR-based strategy.

Science.gov (United States)

Furtado, Larissa V; Weigelin, Helmut C; Elenitoba-Johnson, Kojo S J; Betz, Bryan L

2013-11-01

MPL mutation testing is recommended in patients with suspected primary myelofibrosis or essential thrombocythemia who lack the JAK2 V617F mutation. MPL mutations can occur at allelic levels below 15%, which may escape detection by commonly used mutation screening methods such as Sanger sequencing. We developed a novel multiplexed allele-specific PCR assay capable of detecting most recurrent MPL exon 10 mutations associated with primary myelofibrosis and essential thrombocythemia (W515L, W515K, W515A, and S505N) down to a sensitivity of 2.5% mutant allele. Test results were reviewed from 15 reference cases and 1380 consecutive specimens referred to our laboratory for testing. Assay performance was compared to Sanger sequencing across a series of 58 specimens with MPL mutations. Positive cases consisted of 45 with W515L, 6 with S505N, 5 with W515K, 1 with W515A, and 1 with both W515L and S505N. Seven cases had mutations below 5% that were undetected by Sanger sequencing. Ten additional cases had mutation levels between 5% and 15% that were not consistently detected by sequencing. All results were easily interpreted in the allele-specific test. This assay offers a sensitive and reliable solution for MPL mutation testing. Sanger sequencing appears insufficiently sensitive for robust MPL mutation detection. Our data also suggest the relative frequency of S505N mutations may be underestimated, highlighting the necessity for inclusion of this mutation in MPL test platforms. Copyright © 2013 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

Microsatellite polymorphism within pfcrt provides evidence of continuing evolution of chloroquine-resistant alleles in Papua New Guinea

Directory of Open Access Journals (Sweden)

Sharma Yagya D

2007-03-01

Full Text Available Abstract Background Polymorphism in the pfcrt gene underlies Plasmodium falciparum chloroquine resistance (CQR, as sensitive strains consistently carry lysine (K, while CQR strains carry threonine (T at the codon 76. Previous studies have shown that microsatellite (MS haplotype variation can be used to study the evolution of CQR polymorphism and to characterize intra- and inter-population dispersal of CQR in Papua New Guinea (PNG. Methods Here, following identification of new polymorphic MS in introns 2 and 3 within the pfcrt gene (msint2 and msint3, respectively, locus-by-locus and haplotype heterozygosity (H analyses were performed to determine the distribution of this intronic polymorphism among pfcrt chloroquine-sensitive and CQR alleles. Results For MS flanking the pfcrt CQR allele, H ranged from 0.07 (B5M77, -18 kb to 0.094 (9B12, +2 kb suggesting that CQ selection pressure was responsible for strong homogenisation of this gene locus. In a survey of 206 pfcrt-SVMNT allele-containing field samples from malaria-endemic regions of PNG, H for msint2 was 0.201. This observation suggests that pfcrt msint2 exhibits a higher level of diversity than what is expected from the analyses of pfcrt flanking MS. Further analyses showed that one of the three haplotypes present in the early 1980's samples has become the predominant haplotype (frequency = 0.901 in CQR parasite populations collected after 1995 from three PNG sites, when CQR had spread throughout malaria-endemic regions of PNG. Apparent localized diversification of pfcrt haplotypes at each site was also observed among samples collected after 1995, where minor CQR-associated haplotypes were found to be unique to each site. Conclusion In this study, a higher level of diversity at MS loci within the pfcrt gene was observed when compared with the level of diversity at pfcrt flanking MS. While pfcrt (K76T and its immediate flanking region indicate homogenisation in PNG CQR parasite populations

ALEA: a toolbox for allele-specific epigenomics analysis.

Science.gov (United States)

Younesy, Hamid; Möller, Torsten; Heravi-Moussavi, Alireza; Cheng, Jeffrey B; Costello, Joseph F; Lorincz, Matthew C; Karimi, Mohammad M; Jones, Steven J M

2014-04-15

The assessment of expression and epigenomic status using sequencing based methods provides an unprecedented opportunity to identify and correlate allelic differences with epigenomic status. We present ALEA, a computational toolbox for allele-specific epigenomics analysis, which incorporates allelic variation data within existing resources, allowing for the identification of significant associations between epigenetic modifications and specific allelic variants in human and mouse cells. ALEA provides a customizable pipeline of command line tools for allele-specific analysis of next-generation sequencing data (ChIP-seq, RNA-seq, etc.) that takes the raw sequencing data and produces separate allelic tracks ready to be viewed on genome browsers. The pipeline has been validated using human and hybrid mouse ChIP-seq and RNA-seq data. The package, test data and usage instructions are available online at http://www.bcgsc.ca/platform/bioinfo/software/alea CONTACT: : mkarimi1@interchange.ubc.ca or sjones@bcgsc.ca Supplementary information: Supplementary data are available at Bioinformatics online. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Database for the ampC alleles in Acinetobacter baumannii.

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Nabil Karah

Full Text Available Acinetobacter baumannii is a troublesome opportunistic pathogen with a high capacity for clonal dissemination. We announce the establishment of a database for the ampC locus in A. baumannii, in which novel ampC alleles are differentiated based on the occurrence of ≥ 1 nucleotide change, regardless of whether it is silent or missense. The database is openly accessible at the pubmlst platform for A. baumannii (http://pubmlst.org/abaumannii/. Forty-eight distinctive alleles of the ampC locus have so far been identified and deposited in the database. Isolates from clonal complex 1 (CC1, according to the Pasteur multilocus sequence typing scheme, had a variety of the ampC locus alleles, including alleles 1, 3, 4, 5, 6, 7, 8, 13, 14, 17, and 18. On the other hand, isolates from CC2 had the ampC alleles 2, 3, 19, 20, 21, 22, 23, 24, 26, 27, 28, and 46. Allele 3 was characteristic for sequence types ST3 or ST32. The ampC alleles 10, 16, and 25 were characteristic for CC10, ST16, and CC25, respectively. Our study points out that novel gene databases, in which alleles are numbered based on differences in their nucleotide identities, should replace traditional records that use amino acid substitutions to define new alleles.

Natural Selection and Origin of a Melanistic Allele in North American Gray Wolves.

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Schweizer, Rena M; Durvasula, Arun; Smith, Joel; Vohr, Samuel H; Stahler, Daniel R; Galaverni, Marco; Thalmann, Olaf; Smith, Douglas W; Randi, Ettore; Ostrander, Elaine A; Green, Richard E; Lohmueller, Kirk E; Novembre, John; Wayne, Robert K

2018-05-01

Pigmentation is often used to understand how natural selection affects genetic variation in wild populations since it can have a simple genetic basis, and can affect a variety of fitness-related traits (e.g., camouflage, thermoregulation, and sexual display). In gray wolves, the K locus, a β-defensin gene, causes black coat color via a dominantly inherited KB allele. The allele is derived from dog-wolf hybridization and is at high frequency in North American wolf populations. We designed a DNA capture array to probe the geographic origin, age, and number of introgression events of the KB allele in a panel of 331 wolves and 20 dogs. We found low diversity in KB, but not ancestral ky, wolf haplotypes consistent with a selective sweep of the black haplotype across North America. Further, North American wolf KB haplotypes are monophyletic, suggesting that a single adaptive introgression from dogs to wolves most likely occurred in the Northwest Territories or Yukon. We use a new analytical approach to date the origin of the KB allele in Yukon wolves to between 1,598 and 7,248 years ago, suggesting that introgression with early Native American dogs was the source. Using population genetic simulations, we show that the K locus is undergoing natural selection in four wolf populations. We find evidence for balancing selection, specifically in Yellowstone wolves, which could be a result of selection for enhanced immunity in response to distemper. With these data, we demonstrate how the spread of an adaptive variant may have occurred across a species' geographic range.

A FEMTOSECOND-LEVEL FIBER-OPTICS TIMING DISTRIBUTION SYSTEM USING FREQUENCY-OFFSET INTERFEROMETRY

International Nuclear Information System (INIS)

Staples, J.W.; Byrd, J.; Doolittle, L.; Huang, G.; Wilcox, R.

2008-01-01

An optical fiber-based frequency and timing distribution system based on the principle of heterodyne interferometry has been in development at LBNL for several years. The fiber drift corrector has evolved from an RF-based to an optical-based system, from mechanical correctors (piezo and optical trombone) to fully electronic, and the electronics from analog to fully digital, all using inexpensive off-the-shelf commodity fiber components. Short-term optical phase jitter and long-term phase drift are both in the femtosecond range over distribution paths of 2 km or more

Correlation Between HLA-A, B and DRB1 Alleles and Severe Fever with Thrombocytopenia Syndrome.

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Shu-Jun Ding

2016-10-01

Full Text Available Severe fever with thrombocytopenia syndrome (SFTS is an emerging hemorrhagic fever caused by a tick-borne bunyavirus (SFTSV in East Asian countries. The role of human leukocyte antigen (HLA in resistance and susceptibility to SFTSV is not known. We investigated the correlation of HLA locus A, B and DRB1 alleles with the occurrence of SFTS.A total of 84 confirmed SFTS patients (patient group and 501 unrelated non-SFTS patients (healthy individuals as control group from Shandong Province were genotyped by PCR-sequence specific oligonucleotide probe (PCR-SSOP for HLA-A, B and DRB1 loci.Allele frequency was calculated and compared using χ2 test or the Fisher's exact test. A corrected P value was calculated with a bonferronis correction. Odds Ratio (OR and 95% confidence intervals (CI were calculated by Woolf's method.A total of 11 HLA-A, 23 HLA-B and 12 HLA-DRB1 alleles were identified in the patient group, whereas 15 HLA-A, 30 HLA-B and 13 HLA-DRB1 alleles were detected in the control group. The frequencies of A*30 and B*13 in the SFTS patient group were lower than that in the control group (P = 0.0341 and 0.0085, Pc = 0.5115 and 0.252. The ORs of A*30 and B*13 in the SFTS patient group were 0.54 and 0.49, respectively. The frequency of two-locus haplotype A*30-B*13 was lower in the patient group than in the control group(5.59% versus 12.27%, P = 0.037,OR = 0.41, 95%CI = 0.18-0.96 without significance(Pc>0.05. A*30-B*13-DRB1*07 and A*02-B*15-DRB1*04 had strong associations with SFTS resistance and susceptibility respectively (Pc = 0.0412 and 0.0001,OR = 0.43 and 5.07.The host HLA class I polymorphism might play an important role with the occurrence of SFTS. Negative associations were observed with HLA-A*30, HLA-B*13 and Haplotype A*30-B*13, although the associations were not statistically significant. A*30-B*13-DRB1*07 had negative correlation with the occurrence of SFTS; in contrast, haplotype A*02-B*15-DRB1*04 was positively correlated with SFTS.

The CFTR Met 470 allele is associated with lower birth rates in fertile men from a population isolate.

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Gülüm Kosova

2010-06-01

Full Text Available Although little is known about the role of the cystic fibrosis transmembrane regulator (CFTR gene in reproductive physiology, numerous variants in this gene have been implicated in etiology of male infertility due to congenital bilateral absence of the vas deferens (CBAVD. Here, we studied the fertility effects of three CBAVD-associated CFTR polymorphisms, the (TGm and polyT repeat polymorphisms in intron 8 and Met470Val in exon 10, in healthy men of European descent. Homozygosity for the Met470 allele was associated with lower birth rates, defined as the number of births per year of marriage (P = 0.0029. The Met470Val locus explained 4.36% of the phenotypic variance in birth rate, and men homozygous for the Met470 allele had 0.56 fewer children on average compared to Val470 carrier men. The derived Val470 allele occurs at high frequencies in non-African populations (allele frequency = 0.51 in HapMap CEU, whereas it is very rare in African population (Fst = 0.43 between HapMap CEU and YRI. In addition, haplotypes bearing Val470 show a lack of genetic diversity and are thus longer than haplotypes bearing Met470 (measured by an integrated haplotype score [iHS] of -1.93 in HapMap CEU. The fraction of SNPs in the HapMap Phase2 data set with more extreme Fst and iHS measures is 0.003, consistent with a selective sweep outside of Africa. The fertility advantage conferred by Val470 relative to Met470 may provide a selective mechanism for these population genetic observations.

Frequency and distribution analysis of chromosomal translocations induced by x-ray in human lymphocytes

International Nuclear Information System (INIS)

Lopez Hidalgo, Juana Ines

2000-01-01

The characteristic of ionizing radiation suggests that induced chromosomal damage in the form of translocations would appear to be randomly distributed. However, the outcome of tests performed in vitro and in vivo (irradiated individuals) are contradictories. The most translocation-related chromosomes, as far as some studies reveal on one hand, appear to be less involved in accordance with others. These data, together with those related to molecular mechanisms involved in translocations production suggest that in G 0 -irradiated cells, the frequency and distribution of this kind of chromosomal rearrangement, does not take place at random. They seem to be affected by in-nucleus chromosome distribution, by each chromosome's DNA length and functional features, by the efficiency of DNA repair mechanisms, and by inter individual differences. The objective of this study was to establish the frequency pattern of each human chromosome involved in radio-induced translocations, as well as to analyze the importance the chromosome length, the activity of DNA polymerase- dependant repair mechanisms, and inter individual differences within the scope of such distribution. To achieve the goals, peripheral blood lymphocytes from healthy donors were irradiated in presence and absence of 2'-3' dideoxithimidine (ddThd), a Β - DNA polymerase inhibitor, which takes part in the base repair mechanism (B E R). The results showed that: The presence of ddThd during the irradiation increase the basal frequency of radioinduced translocations in 60 %. This result suggests that ddThd repair synthesis inhibition can be in itself a valid methodology for radiation-induced bases damage assessment, damage which if not BER-repaired may result in translocation-leading double strand breaks. A statistically significant correlation between translocation frequency and chromosome length, in terms of percentage of genome, has been noticed both in (basal) irradiation and in irradiation with ddThd inhibitor

Extensive diversity in the allelic frequency of Plasmodium falciparum merozoite surface proteins and glutamate-rich protein in rural and urban settings of southwestern Nigeria.

Science.gov (United States)

Funwei, Roland I; Thomas, Bolaji N; Falade, Catherine O; Ojurongbe, Olusola

2018-01-02

Nigeria carries a high burden of malaria which makes continuous surveillance for current information on genetic diversity imperative. In this study, the merozoite surface proteins (msp-1, msp-2) and glutamate-rich protein (glurp) of Plasmodium falciparum collected from two communities representing rural and urban settings in Ibadan, southwestern Nigeria were analysed. A total of 511 febrile children, aged 3-59 months, whose parents/guardians provided informed consent, were recruited into the study. Capillary blood was obtained for malaria rapid diagnostic test, thick blood smears for parasite count and blood spots on filter paper for molecular analysis. Three-hundred and nine samples were successfully genotyped for msp-1, msp-2 and glurp genes. The allelic distribution of the three genes was not significantly different in the rural and urban communities. R033 and 3D7 were the most prevalent alleles in both rural and urban communities for msp-1 and msp-2, respectively. Eleven of glurp RII region genotypes, coded I-XII, with sizes ranging from 500 to 1100 base pairs were detected in the rural setting. Genotype XI (1000-1050 bp) had the highest prevalence of 41.5 and 38.5% in rural and urban settings, respectively. Overall, 82.1 and 70.0% of samples had multiclonal infection with msp-1 gene resulting in a mean multiplicity of infection (MOI) of 2.8 and 2.6 for rural and urban samples, respectively. Msp-1 and msp-2 genes displayed higher levels of diversity and higher MOI rates than the glurp gene. Significant genetic diversity was observed between rural and urban parasite populations in Ibadan, southwestern Nigeria. The results of this study show that malaria transmission intensity in these regions is still high. No significant difference was observed between rural and urban settings, except for a completely different msp-1 allele, compared to previous reports, thereby confirming the changing face of malaria transmission in these communities. This study provides

A two-component generalized extreme value distribution for precipitation frequency analysis

Czech Academy of Sciences Publication Activity Database

Rulfová, Zuzana; Buishand, A.; Roth, M.; Kyselý, Jan

2016-01-01

Roč. 534, March (2016), s. 659-668 ISSN 0022-1694 R&D Projects: GA ČR(CZ) GA14-18675S Institutional support: RVO:68378289 Keywords : precipitation extremes * two-component extreme value distribution * regional frequency analysis * convective precipitation * stratiform precipitation * Central Europe Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 3.483, year: 2016 http://www.sciencedirect.com/science/article/pii/S0022169416000500

Frequency of inhibitors of daphnid trypsin in the widely distributed cyanobacterial genus Planktothrix

DEFF Research Database (Denmark)

Rohrlack, T.; Christoffersen, K.; Friberg-Jensen, U.

2005-01-01

on the frequency of such compounds in the widely distributed cyanobacterial genus Planktothrix. Of the 89 Planktothrix strains analysed, about 70% produced inhibitors of daphnid trypsin. The strains tested positive represented three common Planktothrix species and were isolated from diverse localities...

Quantitative Single-letter Sequencing: a method for simultaneously monitoring numerous known allelic variants in single DNA samples

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Duborjal Hervé

2008-02-01

Full Text Available Abstract Background Pathogens such as fungi, bacteria and especially viruses, are highly variable even within an individual host, intensifying the difficulty of distinguishing and accurately quantifying numerous allelic variants co-existing in a single nucleic acid sample. The majority of currently available techniques are based on real-time PCR or primer extension and often require multiplexing adjustments that impose a practical limitation of the number of alleles that can be monitored simultaneously at a single locus. Results Here, we describe a novel method that allows the simultaneous quantification of numerous allelic variants in a single reaction tube and without multiplexing. Quantitative Single-letter Sequencing (QSS begins with a single PCR amplification step using a pair of primers flanking the polymorphic region of interest. Next, PCR products are submitted to single-letter sequencing with a fluorescently-labelled primer located upstream of the polymorphic region. The resulting monochromatic electropherogram shows numerous specific diagnostic peaks, attributable to specific variants, signifying their presence/absence in the DNA sample. Moreover, peak fluorescence can be quantified and used to estimate the frequency of the corresponding variant in the DNA population. Using engineered allelic markers in the genome of Cauliflower mosaic virus, we reliably monitored six different viral genotypes in DNA extracted from infected plants. Evaluation of the intrinsic variance of this method, as applied to both artificial plasmid DNA mixes and viral genome populations, demonstrates that QSS is a robust and reliable method of detection and quantification for variants with a relative frequency of between 0.05 and 1. Conclusion This simple method is easily transferable to many other biological systems and questions, including those involving high throughput analysis, and can be performed in any laboratory since it does not require specialized

High frequency of the CCR5delta32 variant among individuals from an admixed Brazilian population with sickle cell anemia

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J.A.B. Chies

2003-01-01

Full Text Available Homozygous sickle cell disease (SCD has a wide spectrum of clinical manifestations. In Brazil, the main cause of death of individuals with SCD is recurrent infection. The CCR5delta32 allele, which confers relative resistance to macrophage-tropic HIV virus infection, probably has reached its frequency and world distribution due to other pathogens that target macrophage in European populations. In the present investigation a relatively higher prevalence (5.1% of the CCR5delta32 allele was identified, by PCR amplification using specific primers, in 79 SCD patients when compared to healthy controls (1.3% with the same ethnic background (Afro-Brazilians. Based on a hypothesis that considers SCD as a chronic inflammatory condition, and since the CCR5 chemokine receptor is involved in directing a Th1-type immune response, we suggest that a Th1/Th2 balance can influence the morbidity of SCD. If the presence of the null CCR5delta32 allele results in a reduction of the chronic inflammation state present in SCD patients, this could lead to differential survival of SCD individuals who are carriers of the CCR5delta32 allele. This differential survival could be due to the development of less severe infections and consequently reduced or less severe vaso-occlusive crises.

Features of the use of time-frequency distributions for controlling the mixture-producing aggregate

Science.gov (United States)

Fedosenkov, D. B.; Simikova, A. A.; Fedosenkov, B. A.

2018-05-01

The paper submits and argues the information on filtering properties of the mixing unit as a part of the mixture-producing aggregate. Relevant theoretical data concerning a channel transfer function of the mixing unit and multidimensional material flow signals are adduced here. Note that ordinary one-dimensional material flow signals are defined in terms of time-frequency distributions of Cohen’s class representations operating with Gabor wavelet functions. Two time-frequencies signal representations are written about in the paper to show how one can solve controlling problems as applied to mixture-producing systems: they are the so-called Rihaczek and Wigner-Ville distributions. In particular, the latter illustrates low-pass filtering properties that are practically available in any of low-pass elements of a physical system.

Development of a distributed polarization-OTDR to measure two vibrations with the same frequency

Science.gov (United States)

Pan, Yun; Wang, Feng; Wang, Xiangchuan; Zhang, Mingjiang; Zhou, Ling; Sun, Zhenqing; Zhang, Xuping

2015-08-01

A polarization optical time-domain reflectometer (POTDR) can distributedly measure the vibration of fiber by detecting the vibration induced polarization variation only with a polarization analyzer. It has great potential in the monitoring of the border intrusion, structural healthy, anti-stealing of pipeline and so on, because of its simple configuration, fast response speed and distributed measuring ability. However, it is difficult to distinguish two vibrations with the same frequency for POTDR because the signal induced by the first vibration would bury the other vibration induced signal. This paper proposes a simple method to resolve this problem in POTDR by analyzing the phase of the vibration induced signal. The effectiveness of this method in distinguishing two vibrations with the same frequency for POTDR is proved by simulation.

Haplotype block structure study of the CFTR gene. Most variants are associated with the M470 allele in several European populations.

Science.gov (United States)

Pompei, Fiorenza; Ciminelli, Bianca Maria; Bombieri, Cristina; Ciccacci, Cinzia; Koudova, Monika; Giorgi, Silvia; Belpinati, Francesca; Begnini, Angela; Cerny, Milos; Des Georges, Marie; Claustres, Mireille; Ferec, Claude; Macek, Milan; Modiano, Guido; Pignatti, Pier Franco

2006-01-01

An average of about 1700 CFTR (cystic fibrosis transmembrane conductance regulator) alleles from normal individuals from different European populations were extensively screened for DNA sequence variation. A total of 80 variants were observed: 61 coding SNSs (results already published), 13 noncoding SNSs, three STRs, two short deletions, and one nucleotide insertion. Eight DNA variants were classified as non-CF causing due to their high frequency of occurrence. Through this survey the CFTR has become the most exhaustively studied gene for its coding sequence variability and, though to a lesser extent, for its noncoding sequence variability as well. Interestingly, most variation was associated with the M470 allele, while the V470 allele showed an 'extended haplotype homozygosity' (EHH). These findings make us suggest a role for selection acting either on the M470V itself or through an hitchhiking mechanism involving a second site. The possible ancient origin of the V allele in an 'out of Africa' time frame is discussed.

Association Study of Klotho Gene Polymorphism With Calcium Oxalate Stones in The Uyghur Population of Xinjiang, China.

Science.gov (United States)

Ali, Abdusamat; Tursun, Halmurat; Talat, Alim; Abla, Akpar; Muhtar, Erpan; Zhang, Tao; Mahmut, Murat

2017-01-18

The aim of the present study was to investigate the correlation between Klotho gene polymorphisms andcalcium oxalate stones in Xinjiang Uyghur people. We compared 128 patients with calcium oxalate stones (case group) and 94 healthypeople (control group), detected the genotype and allele distributions of single-nucleotide polymorphisms (SNPs)of the Klotho gene (rs3752472, rs650439, and rs1207568) by reverse transcription polymerase chain reaction. The distributions of the genotype and allele frequencies of the SNPs were consistent with the Hardy-Weinberg equilibrium in the two groups. There were statistically significant differences between the genotype andallele distributions of rs3752472 between the case and control groups; the allele frequencies in the case/controlgroups were C = 240 (93.7%)/151 (80.3%) and T = 16 (6.3%)/37 (19.7%). There was no statistically significantdifference in the genotype distribution of rs650439 between the case and control groups, but there was a differencein the allele distribution; the allele frequencies in the case/control groups were A = 202 (78.9%)/143 (57.2%) andT = 54 (21.1%)/107 (42.8%). There were no statistically significant differences in genotype and allele distributionsbetween the case and control groups of rs1207568; the allele frequencies in the case/control groups were C = 194(71.3%)/145 (77.1%) and T = 78 (28.7%)/43 (22.9%). In rs3752472, the risk for patients with the C and A allelesincreased by 3.675 and 2.799 times, respectively. The rs3752472 and rs650439 SNPs are related to the risk of calcium oxalate stones in Xinjiang Uyghurpeople, and might be one of the risk factors.

Procedures for identifying S-allele genotypes of Brassica.

Science.gov (United States)

Wallace, D H

1979-11-01

Procedures are described for efficient selection of: (1) homozygous and heterozygous S-allele genotypes; (2) homozygous inbreds with the strong self- and sib-incompatibility required for effective seed production of single-cross F1 hybrids; (3) heterozygous genotypes with the high self- and sib-incompatibility required for effective seed production of 3- and 4-way hybrids.From reciprocal crosses between two first generation inbred (I1) plants there are three potential results: both crosses are incompatible; one is incompatible and the other compatible; and both are compatible. Incompatibility of both crosses is useful information only when combined with data from other reciprocal crosses. Each compatible cross, depending on whether its reciprocal is incompatible or compatible, dictates alternative reasoning and additional reciprocal crosses for efficiently and simultaneously identifying: (A) the S-allele genotype of all individual I1 plants, and (B) the expressions of dominance or codominance in pollen and stigma (sexual organs) of an S-allele heterozygous genotype. Reciprocal crosses provide the only efficient means of identifying S-allele genotypes and also the sexual-organ x S-allele-interaction types.Fluorescent microscope assay of pollen tube penetration into the style facilitates quantitation within 24-48 hours of incompatibility and compatibility of the reciprocal crosses. A procedure for quantitating the reciprocal difference is described that maximizes informational content of the data about interactions between S alleles in pollen and stigma of the S-allele-heterozygous genotype.Use of the non-inbred Io generation parent as a 'known' heterozygous S-allele genotype in crosses with its first generation selfed (I1) progeny usually reduces at least 7 fold the effort required for achieving objectives 1, 2, and 3, compared to the method of making reciprocal crosses only among I1 plants.Identifying the heterozygous and both homozygous S-allele genotypes during

Allele specific expression and methylation in the bumblebee, Bombus terrestris

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Zoë Lonsdale

2017-09-01

Full Text Available The social hymenoptera are emerging as models for epigenetics. DNA methylation, the addition of a methyl group, is a common epigenetic marker. In mammals and flowering plants methylation affects allele specific expression. There is contradictory evidence for the role of methylation on allele specific expression in social insects. The aim of this paper is to investigate allele specific expression and monoallelic methylation in the bumblebee, Bombus terrestris. We found nineteen genes that were both monoallelically methylated and monoallelically expressed in a single bee. Fourteen of these genes express the hypermethylated allele, while the other five express the hypomethylated allele. We also searched for allele specific expression in twenty-nine published RNA-seq libraries. We found 555 loci with allele-specific expression. We discuss our results with reference to the functional role of methylation in gene expression in insects and in the as yet unquantified role of genetic cis effects in insect allele specific methylation and expression.

Balancing selection and heterogeneity across the classical human leukocyte antigen loci: a meta-analytic review of 497 population studies.

Science.gov (United States)

Solberg, Owen D; Mack, Steven J; Lancaster, Alex K; Single, Richard M; Tsai, Yingssu; Sanchez-Mazas, Alicia; Thomson, Glenys

2008-07-01

This paper presents a meta-analysis of high-resolution human leukocyte antigen (HLA) allele frequency data describing 497 population samples. Most of the datasets were compiled from studies published in eight journals from 1990 to 2007; additional datasets came from the International Histocompatibility Workshops and from the AlleleFrequencies.net database. In all, these data represent approximately 66,800 individuals from throughout the world, providing an opportunity to observe trends that may not have been evident at the time the data were originally analyzed, especially with regard to the relative importance of balancing selection among the HLA loci. Population genetic measures of allele frequency distributions were summarized across populations by locus and geographic region. A role for balancing selection maintaining much of HLA variation was confirmed. Further, the breadth of this meta-analysis allowed the ranking of the HLA loci, with DQA1 and HLA-C showing the strongest balancing selection and DPB1 being compatible with neutrality. Comparisons of the allelic spectra reported by studies since 1990 indicate that most of the HLA alleles identified since 2000 are very-low-frequency alleles. The literature-based allele-count data, as well as maps summarizing the geographic distributions for each allele, are available online.

Distortion of maternal-fetal angiotensin II type 1 receptor allele transmission in pre-eclampsia.

Science.gov (United States)

Morgan, L; Crawshaw, S; Baker, P N; Brookfield, J F; Broughton Pipkin, F; Kalsheker, N

1998-01-01

OBJECTIVE: To investigate the fetal angiotensin II type 1 receptor genotype in pre-eclampsia. DESIGN: Case-control study. POPULATION: Forty-one maternal-fetal pairs from pre-eclamptic pregnancies and 80 maternal-fetal pairs from normotensive pregnancies. METHODS: Maternal and fetal DNA was genotyped at three diallelic polymorphisms, at nucleotides 573, 1062, and 1166, in the coding exon of the angiotensin II type 1 receptor gene, and at a dinucleotide repeat polymorphism in its 3' flanking region. RESULTS: Allele and genotype frequencies at the four polymorphic regions investigated did not differ between pre-eclamptic and normotensive groups, in either fetal or maternal samples. Mothers heterozygous for the dinucleotide repeat allele designated A4 transmitted this allele to the fetus in 15 of 18 informative pre-eclamptic pregnancies and in eight of 26 normotensive pregnancies. This was greater than the expected probability in pre-eclamptic pregnancies (p=0.04) and less than expected in normotensive pregnancies (p<0.005). The 573T variant, which is in partial linkage disequilibrium with the A4 allele, showed a similar distortion of maternal-fetal transmission. CONCLUSION: Angiotensin II type 1 receptor gene expression in the fetus may contribute to the aetiology of pre-eclampsia. It is unclear whether susceptibility is conferred by the fetal genotype acting alone, or by allele sharing by mother and fetus. Possible mechanisms for the effect of the angiotensin II type 1 receptor gene are suggested by the association of the 573T variant with low levels of surface receptor expression on platelets. If receptor expression is similarly genetically determined in the placenta, responsiveness to angiotensin II may be affected, with the potential to influence placentation or placental prostaglandin secretion. PMID:9719367

Body size diversity and frequency distributions of Neotropical cichlid fishes (Cichliformes: Cichlidae: Cichlinae.

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Sarah E Steele

Full Text Available Body size is an important correlate of life history, ecology and distribution of species. Despite this, very little is known about body size evolution in fishes, particularly freshwater fishes of the Neotropics where species and body size diversity are relatively high. Phylogenetic history and body size data were used to explore body size frequency distributions in Neotropical cichlids, a broadly distributed and ecologically diverse group of fishes that is highly representative of body size diversity in Neotropical freshwater fishes. We test for divergence, phylogenetic autocorrelation and among-clade partitioning of body size space. Neotropical cichlids show low phylogenetic autocorrelation and divergence within and among taxonomic levels. Three distinct regions of body size space were identified from body size frequency distributions at various taxonomic levels corresponding to subclades of the most diverse tribe, Geophagini. These regions suggest that lineages may be evolving towards particular size optima that may be tied to specific ecological roles. The diversification of Geophagini appears to constrain the evolution of body size among other Neotropical cichlid lineages; non-Geophagini clades show lower species-richness in body size regions shared with Geophagini. Neotropical cichlid genera show less divergence and extreme body size than expected within and among tribes. Body size divergence among species may instead be present or linked to ecology at the community assembly scale.

Vehicle-to-Grid Systems for Frequency Regulation in an Islanded Danish Distribution Network

DEFF Research Database (Denmark)

Pillai, Jayakrishnan Radhakrishna; Bak-Jensen, Birgitte

2010-01-01

vehicles could provide power system ancillary services in the form of power balancing reserves to support the large-scale integration of variable renewable energy sources like wind power. This paper investigates the dynamic frequency response of an islanded Danish distribution system operation with large...

Drop-out probabilities of IrisPlex SNP alleles

DEFF Research Database (Denmark)

Andersen, Jeppe Dyrberg; Tvedebrink, Torben; Mogensen, Helle Smidt

2013-01-01

In certain crime cases, information about a perpetrator's phenotype, including eye colour, may be a valuable tool if no DNA profile of any suspect or individual in the DNA database matches the DNA profile found at the crime scene. Often, the available DNA material is sparse and allelic drop-out...... of true alleles is possible. As part of the validation of the IrisPlex assay in our ISO17025 accredited, forensic genetic laboratory, we estimated the probability of drop-out of specific SNP alleles using 29 and 30 PCR cycles and 25, 50 and 100 Single Base Extension (SBE) cycles. We observed no drop-out...... when the amount of DNA was greater than 125 pg for 29 cycles of PCR and greater than 62 pg for 30 cycles of PCR. With the use of a logistic regression model, we estimated the allele specific probability of drop-out in heterozygote systems based on the signal strength of the observed allele...

Common breast cancer risk alleles and risk assessment

DEFF Research Database (Denmark)

Näslund-Koch, C; Nordestgaard, B G; Bojesen, S E

2017-01-01

general population were followed in Danish health registries for up to 21 years after blood sampling. After genotyping 72 breast cancer risk loci, each with 0-2 alleles, the sum for each individual was calculated. We used the simple allele sum instead of the conventional polygenic risk score......, as it is likely more sensitive in detecting associations with risks of other endpoints than breast cancer. RESULTS: Breast cancer incidence in the 19,010 women was increased across allele sum quintiles (log-rank trend test; p=1*10(-12)), but not incidence of other cancers (p=0.41). Age- and study-adjusted hazard...... ratio for the 5(th) vs. 1(st) allele sum quintile was 1.82(95% confidence interval;1.53-2.18). Corresponding hazard ratios per allele were 1.04(1.03-1.05) and 1.05(1.02-1.08) for breast cancer incidence and mortality, similar across risk factors. In 50-year old women, the starting age for screening...

Ultraviolet-induced reversion of cyc1 alleles in radiation-sensitive strains of yeast. III. rev 3 mutant strains

International Nuclear Information System (INIS)

Lawrence, C.W.; Crhistensen, R.B.

1979-01-01

The role of rev3 gene function in uv-induced mutagenesis in the yeast Saccharomyces cerevisiae has been examined by determining the reversion of 12 well-defined cyc1 mutations in diploid strains homozygous for the rev3-1 or rev3-3 allale. The 12 cyc1 alleles include one ochre, one amber, four initiation, two proline missense, and four frameshift mutations. We find that the rev3 mutations reduce the frequency of UV-induced reversion of all of the cyc1 alleles, though different classes of alleles respond to a different extent. These results imply that the rev3 gene function is required for the production of a wide variety of mutational events, though probably not all, and show that each of the three rev loci have different mutational phenotypes. Such diverse phenotypes are not predicted by the unitary model for bacterial mutagenes, suggesting that this is at best an incomplete description of eukaryotic mutagenesis

Ultra-stable long distance optical frequency distribution using the Internet fiber network and application to high-precision molecular spectroscopy

International Nuclear Information System (INIS)

Lopez, O; Chanteau, B; Bercy, A; Argence, B; Darquié, B; Chardonnet, C; Amy-Klein, A; Nicolodi, D; Zhang, W; Abgrall, M; Haboucha, A; Kanj, A; Rovera, D; Achkar, J; Pottie, P-E; Coq, Y Le; Santarelli, G

2013-01-01

We report an optical link of 540 km for ultrastable frequency distribution over the Internet fiber network. The phase-noise compensated link shows a fractional frequency instability in full bandwidth of 3×10 −14 at one second measurement time and 2×10 −18 at 30 000 s. This work is a significant step towards a sustainable wide area ultrastable optical frequency distribution and comparison network. Time transfer was demonstrated simultaneously on the same link and led to an absolute time accuracy (250 ps) and long-term timing stability (20 ps) which outperform the conventional satellite transfer methods by one order of magnitude. Current development addresses the question of multiple users distribution in the same metropolitan area. We demonstrate on-line extraction and first results show frequency stability at the same level as with conventional link. We also report an application to coherent frequency transfer to the mid-infrared. We demonstrate the frequency stabilisation of a mid-infrared laser to the near-infrared frequency reference transferred through the optical link. Fractional stability better than 4×10 −14 at 1 s averaging time was obtained, opening the way to ultrahigh resolution spectroscopy of molecular rovibrational transitions

Evidence of an association between the Arg72 allele of the peptide YY and increased risk of type 2 diabetes

DEFF Research Database (Denmark)

Torekov, Signe S; Larsen, Lesli H; Glümer, Charlotte

2005-01-01

We tested the hypothesis that variants in the gene encoding the prepropeptide YY (PYY) associate with type 2 diabetes and/or obesity. Mutation analyses of DNA from 84 patients with obesity and familial type 2 diabetes identified two polymorphisms, IVS3 + 68C>T and Arg72Thr, and one rare variant......, +151C>A of PYY. The common allele of the Arg72Thr variant associated with type 2 diabetes with an allele frequency of the Arg allele of 0.667 (95% CI 0.658-0.677) among 4,639 glucose-tolerant subjects and 0.692 (0.674-0.710) among 1,326 patients with type 2 diabetes (P = 0.005, odds ratio 1.19 [95% CI...... tolerance test (OGTT) (P = 0.03), an increased area under the curve for the post-OGTT plasma glucose level (P = 0.03), and a lower insulinogenic index (P = 0.01). In conclusion, the common Arg allele of the PYY Arg72Thr variant modestly associates with type 2 diabetes and with type 2 diabetes...

Frequency of the Hemochromatosis Gene (HFE Variants in a Jordanian Arab Population and in Diabetics from the Same Region

Directory of Open Access Journals (Sweden)

Asem Alkhateeb

2009-01-01

Full Text Available Hereditary HFE-linked hemochromatosis is a frequent recessive disorder among individuals of northern European ancestry. The clinical characteristic of this disease is the gradual accumulation of iron in internal organs, which ultimately may lead to organ damage and death. Three allelic variants of HFE gene have been correlated with hereditary hemochromatosis: C282Y is significantly associated with hereditary hemochromatosis in populations of Celtic origin, H63D and S65C are associated with milder form of iron overload. In this study we performed mutation analysis to identify allele frequency of the three variants of HFE gene in Jordanian Arab population, to assess deviations of these frequencies from those detected elsewhere, and to determine if there is an increased frequency of these variants in a diabetic population (Type 2 diabetes from the same area. DNA was extracted from blood samples of 440 individuals attending King Abdullah University Hospital for ambulatory services. We used polymerase chain reaction (PCR to amplify exons 2 and 4 of the HFE gene then restriction fragment length polymorphism (RFLP method to detect the variants. There were neither homozygous nor heterozygous for C282Y variant. For the H63D variant, 0.68% were homozygous and 21.1% were heterozygous. For the S65C variant, there were no homozygous and 0.23% were heterozygous. Allelic frequencies were, 0%, 11.25%, and 0.11% for C282Y, H63D, and S65C, respectively. Our samples were subdivided into two categories of type 2 diabetic (89 cases and controls (blood donors, 204 cases and compared with regard to the H63D variant. Both groups did not have homozygous H63D variant. H63D heterozygous in diabetics were 23.60% and in blood donor controls 22.55%. Allelic frequency of the mutant H63D allele was 11.80% in diabetics and 11.27% for the blood donor controls. This is the first study to show the frequency of the three hemochromatosis gene variants in Jordan with the interesting

Quantitative threefold allele-specific PCR (QuanTAS-PCR) for highly sensitive JAK2 V617F mutant allele detection

International Nuclear Information System (INIS)

Zapparoli, Giada V; Jorissen, Robert N; Hewitt, Chelsee A; McBean, Michelle; Westerman, David A; Dobrovic, Alexander