• Title/Summary/Keyword: hardy-weinberg

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Gregor Mendel and the Seven Genes (2)

  • Tateno, Yoshio
    • Interdisciplinary Bio Central
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    • v.5 no.4
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    • pp.8.1-8.3
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    • 2013
  • Unlike the traditional view, it is not mysterious about how G. Mendel chose the seven characters of the pea, Pisum sativum, that he studied. He first chose the pea that met three conditions he set up and repeated experiments for two years. Apparently, he knew that those characters were controlled by countable elements. Then, he derived the prediction on the basis of his idea about the elements, and selected the seven characters that satisfied the prediction. He knew "no prediction no science". In population genetics the Hardy-Weinberg principle is well known and cited in many papers and books. However, Mendel already derived the same principle in his paper, because he was acquainted also with physics and mathematics. Actually, the principle was trivial when they derived, but not at all when Mendel did. It is also well known that Mendel's laws were forgotten and rediscovered at the term of the 19th century. That may not be true either. His laws were internationally well known before the rediscovery. In fact, the 1881-year version of the Encyclopedia Britannica contains his laws.

Simulation study on the estimation of multinomial proportions

  • Kim, Dae-Hak
    • Journal of the Korean Data and Information Science Society
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    • v.23 no.2
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    • pp.411-417
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    • 2012
  • In this paper, we consider the estimation of multinomial proportions. Multinomial distribution is the most important multivaritate distribution. Estimation of multinomial parameters for multinomial distribution is widely applicable to many practical research areas including genetics. We investigated the properties of several frequency substitution estimates and derived the maximum likelihood estimate of multinomial proportions of Hardy Weinberg proportions. Phenotype and genotype frequencies of allele are used to the estimation of multinomial proportions. These estimates are then analyzed via numerical data. Small sample Monte Carlo simulation is conducted to compare considered estimates of multinomial proportions.

Effects of CSN1S2 Genotypes on Economic Traits in Chinese Dairy Goats

  • Yue, X.P.;Fang, Q.;Zhang, X.;Mao, C.C.;Lan, X.Y.;Chen, H.;Lei, Chuzhao
    • Asian-Australasian Journal of Animal Sciences
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    • v.26 no.7
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    • pp.911-915
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    • 2013
  • The aim of this study was to investigate allele frequencies at the CSN1S2 locus in two Chinese dairy goat breeds and the effects of its variation on dairy goat economic traits. Seven hundred and eight goats from Xinong Saanen (XS, n = 268) and Guanzhong (GZ, N = 440) breeds were selected. The milk samples of 268 XS goats were collected during the middle of lactation, body size parameters (708 goats) and daily milk yield (202 goats) were registered. The RFLP (restriction fragment length polymorphism) and SSCP (single strand conformation polymorphism) were used to detect the polymorphisms in CSN1S2. The Hardy-Weinberg (HW) equilibrium and the associations between body size, milk yield and composition and the genotypes were calculated. The results revealed that only A and F CSN1S2 alleles were found in the two Chinese dairy goat breeds. Allelic frequencies of A and F were 0.795, 0.205 and 0.739, 0.261 in Xinong Saanen and Guanzhong population respectively. Xinong Saanen breed was in Hardy-Weinberg equilibrium, while Guanzhong breed deviated from Hardy-Weinberg equilibrium (p<0.05). The association of polymorphism with economic traits indicated that the goats with FF genotype have higher milk fat and total solid concentration than those with AA and AF genotypes (p<0.05).

Study on Genetic Diversity of Six Duck Populations with Microsatellite DNA

  • Wu, Yan;Liu, Xiao-Lin;Hou, Shui-Sheng;Huang, Wei
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.6
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    • pp.776-783
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    • 2008
  • In this study, we investigated the genetic diversity and phylogenetic relationship of six duck populations by employing the genetic polymorphisms of 20 microsatellites. The parameters used in this study included number of alleles, average effective numbers of alleles (E) and average rates of heterozygosity of each population. The results showed that all the microsatellite loci were highly polymorphic except that the locus AJ515896 in Muscovy duck was 0. The average PIC (0.762), average h (0.7843) and average E (5.261) of the six duck populations were all high, indicating that the gene polymorphisms and genetic diversity were high. The test of Hardy-Weinberg equilibrium showed that the six populations in this study were all in Hardy-Weinberg disequilibrium. The F-statistic analysis results showed the range of FST was from 0.0205 (AJ515895) to 0.2558 (AJ515896). The mean FST was 0.0936. Phylogenetic study revealed that Peking duck (Z1 and Z4), Shaoxing duck, Cherry Valley duck and Aobaixing duck were clustered in one group, while the Muscovy duck was clustered in one group alone. The phylogenetic relationships among different populations were in accordance with their breeding history and distribution. Our data suggested that the 20 microsatellite loci were effective markers for analysis of genetic relationships among duck populations.

Genetic Relationships among Australian and Mongolian Fleece-bearing Goats

  • Bolormaa, S.;Ruvinsky, A.;Walkden-Brown, S.;van der Werf, J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.11
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    • pp.1535-1543
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    • 2008
  • Microsatellites (MS) are useful for quantifying genetic variation within and between populations and for describing the evolutionary relationships of closely related populations. The main objectives of this work were to estimate genetic parameters, measure genetic distances and reconstruct phylogenetic relationships between Australian Angora/Angora_Aus/ and Cashmere/Cashmere_Aus/ populations and three Mongolian Cashmere goat (Bayandelger/BD/, Zavkhan Buural/ZB/, and Gobi Gurvan Saikhan/GGS/) populations based on variation at fourteen MS loci. The level and pattern of observed and expected heterozygosity and polymorphic information content of the fourteen loci studied across the populations were quite similar and high. Except for SRCRSP07, all studied microsatellites were in Hardy-Weinberg Equilibrium (p<0.001). Moderate genetic variation (7.5%) was found between the five goat populations with 92.5% of total genetic variation attributable to diversity existing between the individuals within each population. The greatest Nei's genetic distances were found between the Angora and four Cashmere populations (0.201-0.276) and the lowest distances were between the Mongolian Cashmere goat populations (0.026-0.031). Compared with other Cashmere goat populations, the GGS (crossbred with Russian Don Goats) population had the smallest pairwise genetic distance from the Australian Angora population (0.192). According to a three-factorial correspondence analysis (CA), the three different Mongolian Cashmere populations could hardly be distinguished from each other.

Quantification and Graphical Method for DNA Fingerprinting (유전자검사자료의 통계분석을 위한 수량화 및 그래프 방법)

  • 박미라
    • The Korean Journal of Applied Statistics
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    • v.15 no.1
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    • pp.85-105
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    • 2002
  • To explore the relationships among frequencies for sets of alleles, within or between loci, is one of the first analyses in population genetic study. The general question is whether the frequency of a set of alleles is the same as the product of each of the separate allele frequencies. For two alleles of a single locus, Hardy-Weinberg equilibrium is tested and for an allele from each of two loci, linkage disequilibrium is tested. However, it is more useful if we can quantify and graphically represent this information. In this study, we suggest graphical methods to find associations between alleles. We also analyze the STR data of Korean population as an illustration.

Association of Dopamine D4 Receptor(DRD4) Gene Polymorphism with Korean Schizophrenic Patients (정신분열병에서 도파민 D4 수용체(DRD4) 유전자의 다형성)

  • Lee, Hong Seock;Lee, Min Soo;Han, Deock-Jeong;Lee, Heon-Jeong
    • Korean Journal of Biological Psychiatry
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    • v.7 no.2
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    • pp.152-158
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    • 2000
  • Background : No association between schizophrenia and dopamine D4 receptor polymorphisms have been reported. Despite these results, it is premature to exclude the association. It has been suggested that the susceptibility to develop schizophrenia could result from variation at a number loci which may interact or coact with each other. Therefore, we investigated a possible association of combinations of exon III 48bp polymorphism[D4E3] and exon I 12bp polymorphism of the DRD4 gene [D4E1] with schizophrenia. Methods : 207 unrelated Korean schizophrenic patients and 191 healthy controls were recruited. DRD4 genotype was established using the polymerase chain reaction. Statistical analysis consisted of ${\chi}^2$ tests for Hardy-Weinberg proportions and genotypic and allelic frequencies in the patients and control groups. Results : There were no statistically significant differences in the each polymorphisms between schizophrenics and controls. And all genotype frequencies were within Hardy-Weinberg expectations. When the combinations of the polymorphism in schizophrenia and controls were compared, however, there were significant differences at $A1A2^*2/4$ in the distributions of the combinations of D4E1 and D4E3(p<0.01). Conclusions : These findings suggest that the certain combination of D4E1 and D4E3($A1A2^*2/4$) has the protective role to a susceptibility for schizophrenia.

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Bootstrap Confidence Intervals for a One Parameter Model using Multinomial Sampling

  • Jeong, Hyeong-Chul;Kim, Dae-Hak
    • Journal of the Korean Data and Information Science Society
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    • v.10 no.2
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    • pp.465-472
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    • 1999
  • We considered a bootstrap method for constructing confidenc intervals for a one parameter model using multinomial sampling. The convergence rates or the proposed bootstrap method are calculated for model-based maximum likelihood estimators(MLE) using multinomial sampling. Monte Carlo simulation was used to compare the performance of bootstrap methods with normal approximations in terms of the average coverage probability criterion.

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Hanwoo individual identification with DNA marker information

  • Lee, Jea-Young;Choi, Yu-Mi
    • Journal of the Korean Data and Information Science Society
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    • v.18 no.3
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    • pp.599-608
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    • 2007
  • This study was conducted to establish an individual identification system in Hanwoo cattle. Samples of 33 Hanwoo individuals from Korean elite sire families were used. Thirteen major microsatellite markers were selected from alleles amplified, their frequencies, H(Heterozygosity) and PIC(Polymorphism Information Content) with Hardy-Weinberg equilibrium. Next, in order to evaluate the power of the markers selected on the individual animal identification, MP(Match probability) and R(Relatedness coefficient) with the percentage of animal incorrectly identified were computed. Finally nine microsatellite markers were selected and discussed.

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Genetic Diversity and Population Structure of Pseudobagrus fulvidraco in the Nakdong River (낙동강에 분포하는 동자개 집단의 유전적 다양성과 집단구조)

  • Huh, Man-Kyu;Choi, Joo-Soo;Heo, Youn-Seong;Lee, Bok-Kyu
    • Journal of Life Science
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    • v.17 no.7 s.87
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    • pp.882-888
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    • 2007
  • Enzyme electrophoresis was used to estimate genetic diversity and population genetic structure of Pseudobagrus fulvidraco in Korea. Nine of the 14 loci (64.3%) showed detectable polymorphism. Genetic diversity at the population and species levels were 0.286 and 0.277, respectively. Analysis of fixation indices, calculated for all polymorphic loci in each population, showed a substantial deficit of hetero-zygotes relative to Hardy-Weinberg expectations. This deficit is expected that it is due to a limited effective number of individuals per population. The average $G_{ST}$ for polymorphic loci was 0.064, indicating that most (93.6%) of the genetic diversity occurred within populations. The indirect estimate of gene flow based on mean $G_{ST}$ was 3.67. Given limited gene flow is expected to diverge genetically due to drift and reduced populations. Most populations in our study experience annual, severe demo-graphic bottlenecks due to drought and floods.