• Title/Summary/Keyword: Linkage disequilibria

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Distributions of HLA Microsatellite Markers and the Linkage Disequilibria between HLA and Microsatellites in Koreans (한국인에서 HLA 유전자 부위 내 Microsatellite 표지자의 분포와 HLA 대립유전자의 유전적 연관성)

  • Jang, Jung-Pil;Choi, Eun-Jeong;Yoon, Ho-Yeul;Choi, Hee-Baeg;Kim, Hee-Je;Cho, Byung-Sik;Min, Woo-Sung;Lee, Jong-Wook;Kim, Chun-Choo;Kim, Tai-Gyu
    • IMMUNE NETWORK
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    • v.7 no.3
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    • pp.149-157
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    • 2007
  • Background: The microsatellites within human leukocyte antigen (HLA) region show considerable polymorphism and strong linkage disequilibrium (LD) with HLA alleles. These microsatellites have been used for genetic analysis including disease mapping to understand susceptibility to autoimmune and infectious diseases. Also, use of microsatellites has recently been proposed as an approach for identifying non-HLA markers within the HLA region that could function as transplantation determinants and for the selection of potential donors for transplantation. Methods: To analyse the frequency of five microsatellites in the Korean population, genotyping for polymorphisms at five microsatellites markers (BAT2, MIB, DQCAR, D6S105 and TNFd) within HLA region was performed on 143 healthy Korean controls. Results: The most frequent genotype shown in healthy Korean controls were BAT2 8 (153 bp, 42.7%), MIB 1 (326 bp, 40.6%), DQCAR 3 (188 bp, 38.5%), D6S105 7 (126 bp, 58.0%) and TNFd 3 (128 bp, 58.0%). And common two-loci haplotypes were found as MIB 1-HLA-B*62 (HF: 10.6%), MIB 6-HLA-B*44 (HF: 7.8%), DQCAR 3-HLA-DRB1*13 (HF: 8.5%), TNFd 5-HLA-B*62 (HF: 7.8%) and D6S105 7-HLA-A*02 (HF: 16.2%). Conclusion: These data might provide useful information on the microsatellites markers with HLA region in Korean population and be helpful in further defining the clinical impact of these microsatellites.

Potential of the Quantitative Trait Loci Mapping Using Crossbred Population

  • Yang, Shulin;Zhu, Zhengmao;Li, Kui
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.12
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    • pp.1675-1683
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    • 2005
  • In the process of crossbreeding, the linkage disequilibria between the quantitative trait loci (QTL) and their linked markers were reduced gradually with increasing generations. To study the potential of QTL mapping using the crossbred population, we presented a mixed effect model that treated the mean allelic value of the different founder populations as the fixed effect and the allelic deviation from the population mean as random effect. It was assumed that there were fifty QTLs having effect on the trait variation, the population mean and variance were divided to each QTL in founder generation in our model. Only the additive effect was considered in this model for simulation. Six schemes (S1-S6) of crossbreeding were studied. The selection index was used to evaluate the synthetic breeding value of two traits of the individual in the scheme of S2, S4 and S6, and the individuals with high selection index were chosen as the parents of the next generation. Random selection was used in the scheme of S1, S3 and S5. In this study, we premised a QTL explained 40% of the genetic variance was located in a region of 20 cM by the linkage analysis previously. The log likelihood ratio (log LR) was calculated to determine the presence of a QTL at the particular chromosomal position in each of the generations from the fourth to twentieth. The profiles of log LR and the number of the highest log LR located in the region of 5, 10 and 20 cM were compared between different generations and schemes. The profiles and the correct number reduced gradually with the generations increasing in the schemes of S2, S4 and S6, but both of them increased in the schemes of S1, S3 and S5. From the results, we concluded that the crossbreeding population undergoing random selection was suitable for improving the resolution of QTL mapping. Even experiencing index selection, there was still enough variation existing within the crossbred population before the fourteenth generation that could be used to refine the location of QTL in the chromosome region.

초파리 집단내 역위빈도의 계절적 변동에 관한 연구

  • Lee, Tae-Hun;Gwon, Guk-Il;Im, Nak-Ryong
    • The Korean Journal of Zoology
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    • v.31 no.4
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    • pp.327-333
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    • 1988
  • 계절에 따른 초파리 집단내 역위다형 현상의 변동상을 알기 위하여 전주근교의 과수원에서 1983년 1월부터 11월까지 격월로 여섯번 채집한 집단 표본을 분석하였다. 총 1071마리에서 얻은 15개형의 역위는 모두 편동원체역위(paracentric inversion)였으며, 이 중 7개형은 세계형91위(cosmopolitan inversion)였고, 나머지 8개형은 지역형역위(endemic inversion)였다. 개체당 역위의 평균 보유수는 0.639이고 역위를 보유한 개체의 빈도는 0.465였다. 7개의 세계형역위에 대한 표본집단을 분석한 결과 격월 집단간에서 유의한 차이를 보이는 반면 1월과 1 1월 표본간에서는 그 성황이 오히려 비숫해짐으로서 집단내 총역위빈도는 주기적으로 변동하고 있음이 암시된다. 역위와 환경변수와의 다중상관분석에서는 기온, 습도, 강수량이 역위빈도에 유의한 영향을 미치는 것으로 나타났고 역위 중 In(2L)t가 상기한 환경변수 모두에 대하여 유의한 상관관계를 보인 반면, In(3R)C와 In(3R)P는 어느 것과도 상관성을 보이지 않았다. 염색체내 그리고 염색체간의 연관 또는 조합의 검정결과 연관불평형혈상을 1월, 5월, 그리고 7월 표본의 제3염색체에서, 그리고 비균일조합은 1월과 7월 표본에서 역시 제3염색체에서만 산출 되었다. Seasonal changes of inversion frequencies in Chonju 0. melanogaster populations were studied. A total of 1071 males were collected six times with ho months intewal from January through November in 1983. to analyse diploid sets of chromosomes carried by males, each male was mated to several virgin females homoBvgous for cytologically standard sequence in all chromo-somes. From each mating, more than seven FL larvae were selected in random and tested to find chromosomal aberrations. In the present study, 15 different inversions were found and identified to be paracentric only In both second and third chromosomes; seven were cosmopolitan and the rest eight endemic types. The average frequency of inversions was 0.465 and the mean number of inversions carried by a single male was 0.639. The linkage disequilibria were detected between the leK and right arms of third chromosomes from the samples of January, May and Julv, Whereas nonrandom associations appeared also in the third chromosomes only in January and Julv samples. In multiple regression analysis among frequencies of inversions and environ-mental variables it appeared that mean temperature, relative humidity and total precipitation for a month skipped over 30 days before collected affect to change to frequencies of particular inver-sions. With respect to the behavior of inversions in the present samples, it is suggested, with the Friedman's analysis of variance by ranks of inversion frequency orders, that the frequencies of inversions change cyclically year to year.

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