• 제목/요약/키워드: genetic effect

검색결과 1,749건 처리시간 0.029초

Allozyme Variation and Population Genetic Structure of an Invasive Plant, Ageratina altissima(White Snakeroot), in Seoul

  • Chun, Young-Jin;Lee, Hyun-Woo;Lee, Eun-Ju
    • Animal cells and systems
    • /
    • 제5권4호
    • /
    • pp.309-312
    • /
    • 2001
  • Allozyme studies have been widely used to estimate genetic variation and to describe genetic structure in natural populations. In many cases, the genetic diversity of recently established populations is generally lower than that of central populations. In addition, the genetic composition of an invasive species is influenced by its History of introduction as well as its ecological characters. Ageratina altissima (L.) R. King & H. Robinson (white snakeroot) is a perennial herb native to the eastern United States and Canada, and is currently receiving much attention for its rapid invasion of the Korean forests. Starch gel electrophoresis was used to assess the genetic variability at 11 putative loci in seven introduced populations of A. altissima in Seoul. Populations of A. altissima maintained lower levels of allozyme diversity (expected heterozygosity = 0.063) than those reported for other taxa with similar ecological traits. The degree of differentiation observed among A. altissima populations was considerably low. It is suggested that the populations were recently established from only a few founders via dispersal by human activities, resulting in the loss of genetic variation.

  • PDF

Effect of Proportion of Recorded Cows Inseminated by Young A. I. Bulls on Genetic Improvement in Japanese Holstein Population

  • Terawaki, Y.;Shimizu, H.;Fukui, Y.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제11권4호
    • /
    • pp.410-415
    • /
    • 1998
  • The effects of the proprotion of cows inseminated by young A. I. bulls on genetic improvement in the Japanese Holstein population were examined using a simulation technique. The proportion of recorded cows inseminated by young A. I. bulls was assumed to be from 10% to 100% of the total number of recorded cows. The expected total genetic improvement was estimated for all cows and recorded and non recorded cows. The effects of the above were remarkable in the schemes that proven sires were used to produce recorded and non recorded cows for a limited time. Also the increase in the rates for -the expected total genetic improvement was larger when the proportion of recorded cows that were inseminated by young A. I. bulls was about 10% to 40%. When the expected total genetic improvement was estimated for the entire population, we found that the highest values were in a range of about 40 to 60% recorded cows that were inseminated by young A. I. bulls. On the other hand, the expected total genetic improvement that was only estimated in recorded cows dramatically decreased for more than 40% of the recorded cows. The results of this study showed that the optimal proportion of recorded cows inseminated with young A. I. bulls should be about 30% in the Japanese Holstein population.

Type 1 diabetes genetic susceptibility markers and their functional implications

  • Park, Yongsoo
    • Journal of Genetic Medicine
    • /
    • 제11권1호
    • /
    • pp.1-10
    • /
    • 2014
  • Type 1 diabetes (T1D) is a chronic autoimmune disease characterized by selective destruction of pancreatic ${\beta}$-cells resulting in insulin deficiency. The genetic determinants of T1D susceptibility have been linked to several loci, in particular to the human leukocyte antigen (HLA) region, which accounts for 50% of the genetic risk of developing T1D. Multiple genes in the HLA region, which are in strong linkage disequilibrium, are thought to be involved. Another important locus, with a smaller effect on genetic predisposition to T1D, is the insulin gene. The advent of numerous single nucleotide polymorphism markers and genome screening has enabled the identification of dozens of new T1D susceptibility loci. Some of them appear to predispose to T1D independently of the HLA and may be important in families with T1D who lack strong HLA susceptibility. Other loci may interact with each other to cause susceptibility. The autoimmune response against ${\beta}$-cells can also be triggered by environmental factors in the presence of a predisposing genetic background. Deciphering the environmental and genetic factors involved should help to understand the origin of T1D and aid in the design of individualized prevention programs.

DMBase: An Integrated Genetic Information Resource for Diabetes Mellitus

  • Lee, Sun-Young;Park, Young-Kyu;Kim, Jae-Heup;Kim, Young-Joo
    • Interdisciplinary Bio Central
    • /
    • 제3권2호
    • /
    • pp.6.1-6.3
    • /
    • 2011
  • Diabetes Mellitus (DM), often simply referred to as diabetes, has developed into a major health concern affecting more than 200 million people worldwide with approximately 4 million deaths per year attributed to the presence of the disease. Diabetes mellitus is categorized as Type 1 and Type 2, where Type 1 diabetes represents a lack of insulin production, and Type 2 diabetes is characterized by a relative lack of insulin receptor (i.e., decreased sensitivity to the effect of insulin) and cased by a complex interplay between genetic factors and environmental factors. Up to date, various studies on the pathology and mechanism in terms of genetic experiments have been conducted and approximately hundreds of genes were reported as diabetes mellitus associated genes. At this point, to support studies on the cause and mechanism of diabetes mellitus, an efficient database system to provide genetic variants related to diabetes mellitus is needed. DMBase is an integrated web-based genetic information resource for diabetes mellitus designed to service genomic variants, genes, and secondary information derived for diabetes mellitus genetics researchers. The current version of DMBase documents 754 genes with 3056 genetic variants and 66 pathways. It provides many effective search interfaces for retrieving diabetes mellitus and genetic information. A web interface for the DMBase is freely available at http://sysbio.kribb.re.kr/dmBase.

Estimates of Genetic Correlations between Production and Semen Traits in Boar

  • Oh, S.H.;See, M.T.;Long, T.E.;Galvin, J.M.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제19권2호
    • /
    • pp.160-164
    • /
    • 2006
  • Currently, boars selected for commercial use as AI sires are evaluated on grow-finish performance and carcass characteristics. If AI sires were also evaluated and selected on semen production, it may be possible to reduce the number of boars required to service sows, thereby improving the productivity and profitability of the boar stud. The objective of this study was to estimate genetic correlations between production and semen traits in the boar: average daily gain (ADG), backfat thickness (BF) and muscle depth (MD) as production traits, and total sperm cells (TSC), total concentration (TC), volume collected (SV), number of extended doses (ND), and acceptance rate of ejaculates (AR) as semen traits. Semen collection records and performance data for 843 boars and two generations of pedigree data were provided by Smithfield Premium Genetics. Backfat thickness and MD were measured by real-time ultrasound. Genetic parameters were estimated from five four-trait and one five-trait animal models using MTDFREML. Average heritability estimates were 0.39 for ADG, 0.32 for BF, 0.15 for MD, and repeatability estimates were 0.38 for SV, 0.37 for TSC, 0.09 for TC, 0.39 for ND, and 0.16 for AR. Semen traits showed a strong negative genetic correlation with MD and positive genetic correlation with BF. Genetic correlations between semen traits and ADG were low. Therefore, current AI boar selection practices may be having a detrimental effect on semen production.

EvoSNP-DB: A database of genetic diversity in East Asian populations

  • Kim, Young Uk;Kim, Young Jin;Lee, Jong-Young;Park, Kiejung
    • BMB Reports
    • /
    • 제46권8호
    • /
    • pp.416-421
    • /
    • 2013
  • Genome-wide association studies (GWAS) have become popular as an approach for the identification of large numbers of phenotype-associated variants. However, differences in genetic architecture and environmental factors mean that the effect of variants can vary across populations. Understanding population genetic diversity is valuable for the investigation of possible population specific and independent effects of variants. EvoSNP-DB aims to provide information regarding genetic diversity among East Asian populations, including Chinese, Japanese, and Korean. Non-redundant SNPs (1.6 million) were genotyped in 54 Korean trios (162 samples) and were compared with 4 million SNPs from HapMap phase II populations. EvoSNP-DB provides two user interfaces for data query and visualization, and integrates scores of genetic diversity (Fst and VarLD) at the level of SNPs, genes, and chromosome regions. EvoSNP-DB is a web-based application that allows users to navigate and visualize measurements of population genetic differences in an interactive manner, and is available online at [http://biomi.cdc.go.kr/EvoSNP/].

잣나무 클론 채종원에서 간벌 강도에 따른 개량효과와 유전다양성 (Genetic Gain and Diversity in a Clonal Seed Orchard of Pinus Koraiensis Under Various Thinning Intensities)

  • 오창영;한상억;김장수;강규석;이병실
    • 한국육종학회지
    • /
    • 제40권3호
    • /
    • pp.263-268
    • /
    • 2008
  • 잣나무 채종원의 유전간벌을 위하여 재적생장에 대한 개량 효과와 유효클론수를 이용한 유전다양성을 평가하였다. 유전 간벌은 클론의 일반조합능력으로 나타나는 육종가(breeding value), 암꽃과 수꽃 개화량을 이용한 종자생산 기여도, 클론별 ramet수 등를 이용한 클론별 변이를 기초로 하였다. 차대 검정 결과에 의하여 산출된 재적생장에 대한 클론별 일반조합능력(genetic value) 및 1991년부터 2003년까지 조사된 개화량 성적을 이용하여 잣나무 채종원(1981년 조성) 179클론에 대하여 간벌 강도에 따른 유전다양성 및 개량효과를 분석하였다. 이때 채종원 외부로부터의 화분오염율은 30%(gene migration = 15%)로 설정하였다. 그 결과 재적생장에 대한 개량효과는 간벌율이 10%에서 60%까지 높아짐에 따라서 점차 증가하였다. 하지만 이보다 더 높은 간벌 강도에서 현저한 개량효과 증가는 나타나지 않았다. 유효클론수는 간벌강도 10%에서 60% 사이에서는 40클론으로 나타났으며, 70% 간벌율 이상에서는 증가하거나 감소하는 변동을 나타냈다. 따라서 본 잣나무 채종원에 대해서는 50%에서 60% 수준의 간벌 강도가 적당한 것으로 판단된다.

Analysis of Tunnelling Rate Effect on Single Electron Transistor

  • Sheela, L.;Balamurugan, N.B.;Sudha, S.;Jasmine, J.
    • Journal of Electrical Engineering and Technology
    • /
    • 제9권5호
    • /
    • pp.1670-1676
    • /
    • 2014
  • This paper presents the modeling of Single Electron Transistor (SET) based on Physical model of a device and its equivalent circuit. The physical model is derived from Schrodinger equation. The wave function of the electrode is calculated using Hartree-Fock method and the quantum dot calculation is obtained from WKB approximation. The resulting wave functions are used to compute tunneling rates. From the tunneling rate the current is calculated. The equivalent circuit model discuss about the effect of capacitance on tunneling probability and free energy change. The parameters of equivalent circuit are extracted and optimized using genetic algorithm. The effect of tunneling probability, temperature variation effect on tunneling rate, coulomb blockade effect and current voltage characteristics are discussed.

AFLP 마커를 이용한 당단풍나무 집단의 유전다양성과 유전구조 (Genetic Diversity and Genetic Structure of Acer pseudosieboldianum Populations in South Korea Based on AFLP Markers)

  • 안지영;홍경낙;백승훈;이민우;임효인;이제완
    • 한국산림과학회지
    • /
    • 제105권4호
    • /
    • pp.414-421
    • /
    • 2016
  • 국내 당단풍나무 집단의 유전다양성, 유전분화 및 유연관계를 알아보기 위해 AFLP 분석을 실시하였다. 14개 당단풍나무 집단에 대한 7개 AFLP 프라이머 조합을 적용한 결과 유효대립유전자 수($A_e$)가 1.4개, 다형적 유전자좌 비율(%P)이 82.2%, Shannon의 다양성 지수(I)가 0.358, 이형접합도 기대치($H_e$)가 0.231이었고, 베이즈 방법으로 추론한 이형접합도 기대치(Hj)는 0.253으로 나타났다. 당단풍나무의 유전다양성은 단풍나무속 수종들과 비교했을 때 중간수준이었고, 생활사나 생태적 특성이 유사한 수종들에 비해 낮았다. 베이즈 방법으로 추정된 평균 $F_{IS}$값은 0.712로 나타나 자가수분이나 근연관계 개체 간 교배에 의한 동형접합체 증가가 유전다양성에 영향을 준 것으로 생각된다. AMOVA로 추정한 당단풍나무의 유전분화율(${\Phi}_{ST}$)은 0.107이었고, 베이즈 방법으로 추정한 유전분화율(${\Phi}^{II}$)은 0.110이었다. 당단풍나무는 생활사나 생태적 특성이 유사한 종들에 비해 유전분화가 적게 이루어진 것으로 나타났다. 유연 관계 분석에서 울릉도 집단은 내륙의 집단들과 유전적으로 가장 상이한 집단으로 나타났다. 울릉도 집단은 유전다양성이 가장 낮은 집단으로서, 내륙의 집단 일부가 이주하면서 생긴 창시자 효과와 유전적 부동에 의해 유전다양성 감소가 이루어졌고 내륙과의 지리적 격리로 인해 유전자 교류가 감소했기 때문으로 추정된다.