• Title/Summary/Keyword: Population Genetics

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Microsatellite Sequences of Mammals and Their Applications in Genome Analysis in Pigs - A Review

  • Behl, Rahul;Sheoran, Neelam;Behl, Jyotsna;Tantia, M.S.;Vijh, R.K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.15 no.12
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    • pp.1822-1830
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    • 2002
  • The microsatellites are the short tandem repeats of 1 to 6 bp long monomer sequences that are repeated several times. These short tandem repeats are considered to be generated by the slipped strand mispairing. Based on the unique capability of alternating purine-pyrimidine residues to form Z-DNA, the possible role of the microsatellites in gene regulation has been proposed. The microsatellites are highly polymorphic, follow Mendelian inheritance and are evenly distributed throughout the genomes of eukaryotes. They are easy to isolate and the polymerase chain reaction based typing of the alleles can be readily automated. These properties make them the preferred markers for comparison of the genetic structure of the closely related breeds/populations; very high-resolution genetic mapping and parentage testing etc. The microsatellites have rapidly replaced the restriction fragment length polymorphism (RFLP) and the random amplified polymorphic DNA (RAPD) in most applications in the population genetics studies in most species, including the various farm animals viz. cattle, buffalo, goat, sheep and pigs etc. More and more reports are now available describing the use of microsatellites in pigs ranging from measurement of genetic variation between breeds/populations, developing high resolution genetic maps to identifying and mapping genes of biological and economic importance.

High Frequency of Codon 12 but not Codon 13 and 61 K-ras Gene Mutations in Invasive Ductal Carcinoma of Breast in a South Indian Population

  • Sushma, C;Prasad, Shiva;Devi, Rudrama;Murthy, Sudha;Rao, TS;Naidu, CK
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.8
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    • pp.3505-3508
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    • 2015
  • Background: Ras genes are thought to play an important role in human cancer since they have been found to be activated frequently in several types of tumors including breast cancer, where the overall incidence of K-RAS oncogene activation is 0-10%. Evaluation of K-RAS gene not only for mutational frequency but also for mutation types in this downstream signaling gene pathway is necessary to determine the mechanisms of action. The present study was conducted to test the hypothesis that K-RAS activation is involved in breast cancer risk of south Indian population. Materials and Methods: A total of 70 paired pathologically confirmed tumor and non-tumor tissues from the same breast cancer patients were analysed for most common K-RAS mutations of codon 12,13 and 61 by polymerase chain reaction followed by restriction digestion and direct nucleotide sequencing method. Results: We found that a high rate of homozygous and heterozygous mutations of codon 12, but not codon 13 and 61, may influence the invasive ductal carcinoma of breast risk in this study. Conclusions: Our study indicated that only codon 12 may be involved in initiating breast carcinogenesis in India.

Population Learning with Coercive Isomorphism in the Korean Business Groups: A Comparison between the Samsung and Hyunda Group (한국 기업진단의 강제적 동질성(isomorphism)을 수반한 모집단학습: 삼성그룹과 현대그룹의 비교)

  • 이홍
    • Journal of the Korean Operations Research and Management Science Society
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    • v.17 no.1
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    • pp.87-87
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    • 1992
  • The Purpose of the current study is to understand population learning with coercive isomorphism in the Korean Business Groups. Can we observe isomorphic phenomena by coercive isomorphism? Why do these happen? What mechanisms are embedded in the coercive isomorphism. To answer these questions this study focused on the two Korea's largest Chaeblos the Samsung and Hyundai. An empirical study to compared daily routines used in these two Chaeboles and contents analysis on the founders' characteristics were performed. Three major mechanisms were suggested as main processes to impact the formation of the coercive isomorpism in the two Korean Chaebols. Research implications were discussed at the end of study.

Mutations in GJB2 as Major Causes of Autosomal Recessive Non-Syndromic Hearing Loss: First Report of c.299-300delAT Mutation in Kurdish Population of Iran

  • Azadegan-Dehkordi, Fatemeh;Bahrami, Tayyebe;Shirzad, Maryam;Karbasi, Gelareh;Yazdanpanahi, Nasrin;Farrokhi, Effat;Koohiyan, Mahbobeh;Tabatabaiefar, Mohammad Amin;Hashemzadeh-Chaleshtori, Morteza
    • Journal of Audiology & Otology
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    • v.23 no.1
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    • pp.20-26
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    • 2019
  • Background and Objectives: Autosomal recessive non-syndromic hearing loss (ARNSHL) with genetic origin is common (1/2000 births). ARNSHL can be associated with mutations in gap junction protein beta 2 (GJB2). To this end, this cohort investigation aimed to find the contribution of GJB2 gene mutations with the genotype-phenotype correlations in 45 ARNSHL cases in the Kurdish population. Subjects and Methods: Genomic DNA was extracted from a total of 45 ARNSHL families. The linkage analysis with 3 short tandem repeat markers linked to GJB2 was performed on 45 ARNSHL families. Only 9 of these families were linked to the DFNB1 locus. All the 45 families who took part were sequenced for confirmation linkage analysis (to perform a large project). Results: A total of three different mutations were determined. Two of which [c.35delG and c.-23+1G>A (IVS1+1G>A)] were previously reported but (c.299-300delAT) mutation was novel in the Kurdish population. The homozygous pathogenic mutations of GJB2 gene was observed in nine out of the 45 families (20%), also heterozygous genotype (c.35delG/N)+(c.-23+1G>A/c.-23+1G>A) were observed in 4/45 families (8.8%). The degree of hearing loss (HL) in patients with other mutations was less severe than patients with c.35delG homozygous mutation (p<0.001). Conclusions: Our data suggest that GJB2 mutations constitute 20% of the etiology of ARNSHL in Iran; moreover, the c.35delG mutation is the most common HL cause in the Kurdish population. Therefore, these mutations should be included in the molecular testing of HL in this population.

Mutations in GJB2 as Major Causes of Autosomal Recessive Non-Syndromic Hearing Loss: First Report of c.299-300delAT Mutation in Kurdish Population of Iran

  • Azadegan-Dehkordi, Fatemeh;Bahrami, Tayyebe;Shirzad, Maryam;Karbasi, Gelareh;Yazdanpanahi, Nasrin;Farrokhi, Effat;Koohiyan, Mahbobeh;Tabatabaiefar, Mohammad Amin;Hashemzadeh-Chaleshtori, Morteza
    • Korean Journal of Audiology
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    • v.23 no.1
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    • pp.20-26
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    • 2019
  • Background and Objectives: Autosomal recessive non-syndromic hearing loss (ARNSHL) with genetic origin is common (1/2000 births). ARNSHL can be associated with mutations in gap junction protein beta 2 (GJB2). To this end, this cohort investigation aimed to find the contribution of GJB2 gene mutations with the genotype-phenotype correlations in 45 ARNSHL cases in the Kurdish population. Subjects and Methods: Genomic DNA was extracted from a total of 45 ARNSHL families. The linkage analysis with 3 short tandem repeat markers linked to GJB2 was performed on 45 ARNSHL families. Only 9 of these families were linked to the DFNB1 locus. All the 45 families who took part were sequenced for confirmation linkage analysis (to perform a large project). Results: A total of three different mutations were determined. Two of which [c.35delG and c.-23+1G>A (IVS1+1G>A)] were previously reported but (c.299-300delAT) mutation was novel in the Kurdish population. The homozygous pathogenic mutations of GJB2 gene was observed in nine out of the 45 families (20%), also heterozygous genotype (c.35delG/N)+(c.-23+1G>A/c.-23+1G>A) were observed in 4/45 families (8.8%). The degree of hearing loss (HL) in patients with other mutations was less severe than patients with c.35delG homozygous mutation (p<0.001). Conclusions: Our data suggest that GJB2 mutations constitute 20% of the etiology of ARNSHL in Iran; moreover, the c.35delG mutation is the most common HL cause in the Kurdish population. Therefore, these mutations should be included in the molecular testing of HL in this population.

ON THE MARTINGALE EXTENSION OF LIMITING DIFFUSION IN POPULATION GENETICS

  • Choi, Won
    • Korean Journal of Mathematics
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    • v.22 no.1
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    • pp.29-36
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    • 2014
  • The limiting diffusion of special diploid model can be defined as a discrete generator for the rescaled Markov chain. Choi([2]) defined the operator of projection $S_t$ on limiting diffusion and new measure $dQ=S_tdP$. and showed the martingale property on this operator and measure. Let $P_{\rho}$ be the unique solution of the martingale problem for $\mathcal{L}_0$ starting at ${\rho}$ and ${\pi}_1,{\pi}_2,{\cdots},{\pi}_n$ the projection of $E^n$ on $x_1,x_2,{\cdots},x_n$. In this note we define $$dQ_{\rho}=S_tdP_{\rho}$$ and show that $Q_{\rho}$ solves the martingale problem for $\mathcal{L}_{\pi}$ starting at ${\rho}$.

Analysis of Microsatellite DNA Polymorphisms in Five China Native Cattle Breeds and Application to Population Genetics Studies

  • Jin, Hai-Guo;Zhao, Yu-Min;Zhou, Guo-li
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.12
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    • pp.1696-1700
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    • 2005
  • Five China native cattle breeds have been characterized by using 10 microsatellite DNA markers. The studied populations can be divided into five groups: Luxi cattle, Nanyang cattle, Jinnan cattle, Qinchuan cattle and Yanbian cattle. Allele frequencies were calculated and used for the characterization of the breeds and the study of their genetic relationships. Heterozygosity, polymorphism information content, the effective number of alleles was calculated. Nei' standard genetic distance (1978) was calculated and used for a neighbor-joining tree construction. NJ tree showed that Luxi cattle, Nanyang cattle, Jinnan cattle and Qinchuan cattle are closely related, whereas Yanbian cattle are clearly distinct from other four populations. The genetic relationship of five breeds corresponds to their history and geographic origins. This work analyzes the recent origin of these populations and contributes to the knowledge and genetic characterization of China native breeds.

Combined Genome Mapping of RFLP-AFLP-SSR in Pepper

  • Lee, Je Min;Kim, Byung-Dong
    • Genomics & Informatics
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    • v.1 no.2
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    • pp.108-112
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    • 2003
  • We have constructed a molecular linkage map of pepper (Capsicum spp.) in an interspecific $F_2$ population of 107 plants with 320 RFLP, 136 AFLP, and 46 SSR markers. The resulting linkage map consists of 15 linkage groups covering 1,720 cM with an average map distance of 3.7 cM between framework markers. Most RFLP markers ($80\%$) were pepper-derived clones and these markers were evenly distributed all over the genome. Genes for defense and biosynthesis of carotenoids and capsaicinoids were mapped on this linkage map. By using 30 primer combinations, AFLP markers were generated in the $F_2$ population. For development of SSR markers in Capsicum, microsatellites were isolated from two small-insert genomic libraries and the GenBank database. This combined map provides a starting point for high-resolution QTL analysis, gene isolation, and molecular breeding.

Comparison of the estimated breeding value and accuracy by imputation reference Beadchip platform and scaling factor of the genomic relationship matrix in Hanwoo cattle

  • Soo Hyun, Lee;Chang Gwon, Dang;Mina, Park;Seung Soo, Lee;Young Chang, Lee;Jae Gu, Lee;Hyuk Kee, Chang;Ho Baek, Yoon;Chung-il, Cho;Sang Hong, Lee;Tae Jeong, Choi
    • Korean Journal of Agricultural Science
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    • v.49 no.3
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    • pp.431-440
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    • 2022
  • Hanwoo cattle are a unique and historical breed in Korea that have been genetically improved and maintained by the national evaluation and selection system. The aim of this study was to provide information that can help improve the accuracy of the estimated breeding values in Hanwoo cattle by showing the difference between the imputation reference chip platforms of genomic data and the scaling factor of the genetic relationship matrix (GRM). In this study, nine sets of data were compared that consisted of 3 reference platforms each with 3 different scaling factors (-0.5, 0 and 0.5). The evaluation was performed using MTG2.0 with nine different GRMs for the same number of genotyped animals, pedigree, and phenotype data. A five multi-trait model was used for the evaluation in this study which is the same model used in the national evaluation system. Our results show that the Hanwoo custom v1 platform is the best option for all traits, providing a mean accuracy improvement by 0.1 - 0.3%. In the case of the scaling factor, regardless of the imputation chip platform, a setting of -1 resulted in a better accuracy increased by 0.5 to 1.6% compared to the other scaling factors. In conclusion, this study revealed that Hanwoo custom v1 used as the imputation reference chip platform and a scaling factor of -0.5 can improve the accuracy of the estimated breeding value in the Hanwoo population. This information could help to improve the current evaluation system.

Analysis of genetic divergence according to each mitochondrial DNA region of Haliotis discus hannai (북방전복 (Haliotis discus hannai) 의 mitochondrial DNA 영역별 유전적 변이성 분석)

  • Park, Choul-Ji;Nam, Won Sick;Lee, Jeong-Ho;Noh, Jae Koo;Kim, Hyun Chul;Park, Jong Won;Hwang, In Jun;Kim, Sung Yeon
    • The Korean Journal of Malacology
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    • v.29 no.4
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    • pp.335-341
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    • 2013
  • The seven mitochondrial DNA regions (ND2, ND5, ND4, ND4L, ND6, ND1 and 12SrRNA) of Haliotis discus hannai were examined to estimate the availability as a genetic marker for the study of population genetic. The region with the highest genetic variation was ND4 (Haplotype diversity = 1.0000, Nucleotide diversity = 0.0108). On the other hand, ND2 and ND1 regions have significantly appeared genetic divergence between clusters (divergence of 90% and 87%). Also, pairwise $F_{ST}$ between clusters within ND2 and ND1 regions showed high values; 0.4061 (P = 0.0000), 0.4805 (P = 0.0000) respectively. Therefore we can infer that it is the most efficient and accurate way to analyze the region of ND4 with the highest variation in addition to the regions of ND2 and ND1, which formed clusters with high bootstrap value, for study of population genetic structure in this species.