• 제목/요약/키워드: Gene flow

검색결과 540건 처리시간 0.026초

Spatial Genetic Structure of Allozyme Polymorphisms within a Small Population of Abies nephrolepis in Mt. Ohdae, South Korea

  • Lee, Seok-Woo;Yang, Byeong-Hoon;Lee, Kab Yeon;Song, Jeong Ho;Hur, Seong Doo;Lee, Jung Joo
    • 한국산림과학회지
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    • 제97권2호
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    • pp.144-151
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    • 2008
  • Using 8 isozyme polymorphic loci as gene markers, we studied the spatial distribution of genotypes in a naturally regenerated uneven-aged Eastern Siberian Fir (Abies nephrolepis Max.) stand (1ha, $100{\times}100m$) on Mt. Ohdae in northeastern South Korea. Gregorius' distograms and Moran's I correlograms revealed no evidence of significant genetic structure at three spatial classes of 5 m, 10 m, and 20 m. Extensive gene flow, due to the long distance dispersal of pollen and seeds in A. nephrolepis, may account for the lack of fine-scale spatial structure. Alternatives would be overlapping seed shadows caused by high densities of A. nephrolepis adult trees (160 trees/ha) and/or intraspecific competition resulting in extensive thinning within maternal half-sib groups.

Allozyme Diversity and Population Genetic Structure in Korean Endemic Plant Species : II. Hosta yingeri (Liliaceae)

  • Chung, Myong Gi
    • Journal of Plant Biology
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    • 제37권2호
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    • pp.141-149
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    • 1994
  • Levels of genetic diversity, population genetic structure, and gene flow in Hosta yingeri, a herbaceous perennial endemic to Taehuksan, Sohuksan, and Hong Islands, were investigated. Starch gel electrophoresis was conducted on leaves for 101 plants collected from three populations. Although the distribution of thespecies is restricted in the islands, it maintains high levels of genetic variatin; 64% of polymorphic loci in at least one population (Ps), the mean number of alleles per locus (Ap) of 1.92, and the mean effective number of alleles per locus (Aep) of 1.52. Overall, mean genetic diversity (Hep=0.250) was substantially higher than mean estimate for species with very similarlife history traits (0.102). Large populaton size, the persistence of multiple generations within populations, high fecundity, predominantly outcrossing breeding system, large size of pollinator visitation areas may be explanatory factors contributing the higher level of genetic diversity maintained within populations. Analysis of fixation indices showed an overall slight excess of heterozygotes (mean FIS=-0.066) relative to Hardy-Weinberg expectations, which may in part be due to the near self-incompatible breeding system in the species. Significant differences in allele frequencies among populaitns were found for 14 out of 16 polymorphic loci (P<0.05). Slightly more than 80% of the total variation in the species was common to all populations (GST=0.198). As expected, indirect estimate of the number of migrants per generation (Nm=0.45, calculated from mean GST) and nine private alleles found in the three populations indicate that gene movement among three isolated island populations was low.

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길경탕(桔梗湯)이 인체(人體) 폐세포(肺細胞)에 미치는 영향(影響)에 관(關)한 분자생물학적(分子生物學的) 연구(硏究) (Molecular Biological Study of The Effects of Gilgyung-Tang(GGT) on Cellular Proliferation and Viability of Normal Human Lung Fibriblast Cell)

  • 이형구
    • 대한한의학회지
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    • 제20권2호
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    • pp.88-97
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    • 1999
  • To characterize the effects of Gilgyung-Tang(GGT) on cellular proliferation and viability of normal lung fibroblast cells, we examined the cell cycle progression and cell cycle-related gene expression in T3891 using a flow cytometry and a quantitative RT-PCR analysis. 1. The significant surpression effect of cellular proliferations of GGT was observed in proportion to a certain concentration and time. 2. GGT was identified to induce apoptotic death of damaged cells by treatment with a DNA-damage agent and etoposide, while it stimulated the recovery of cellular viability of normal cells. 3 The significant reductions of mRNA expression of PCAN, c-Fos treated by GGT were observed. 4. The significant inductions of mRNA expression of p53, CDKN1. Gadd45 treated by GGT were observed. 5. The apoptosis caused by the reduction of Bcl-2 genes was significant and the Bax genes were increased. but the amount of Fas genes were not changed. These results strongly suggest that GGT triggers arrest of the cell cycle at G1 phase, and thus causes an inhibition of cellular proliferation of human normal lung cells through the transcriptional up-regulation of cell cycle inhibitory genes and down-regulation of induction of cell cycle stimulating genes respectably.

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Construction, and In Vitro and In Vivo Analyses of Tetravalent Immunoadhesins

  • Cho, Hoonsik;Chung, Yong-Hoon
    • Journal of Microbiology and Biotechnology
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    • 제22권8호
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    • pp.1066-1076
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    • 2012
  • Previous observations demonstrated that various immunosuppressive agents and their combination therapies can increase allograft survival rates. However, these treatments may have serious side effects and cannot substantially improve or prolong graft survival in acute graft-versus-host disease (GVHD). To improve the therapeutic potency of divalent immunoadhesins, we have constructed and produced several tetravalent forms of immunoadhesins comprising each of cytotoxic T-lymphocyte-associated antigen-4 (CTLA4), CD2, and lymphocyte activation gene-3 (LAG3). Flow cytometric and T cell proliferation analyses displayed that tetravalent immunoadhesins have a higher binding affinity and more potent efficacy than divalent immunoadhesins. Although all tetravalent immunoadhesins possess better efficacies, tetravalent forms of CTLA4-Ig and LAG3-Ig revealed higher inhibitory effects on T cell proliferation than tetravalent forms of TNFR2-Ig and CD2-Ig. In vitro mixed lymphocytes reaction (MLR) showed that combined treatment with tetravalent CTLA4-Ig and tetravalent LAG3-Ig was highly effective for inhibiting T cell proliferation in both human and murine allogeneic stimulation. In addition, both single tetravalent-form and combination treatments can prevent the lethality of murine acute GVHD. The results of this study demonstrated that co-blockade of the major histocompatibility complex class (MHC)II:T cell receptor (TCR) and CD28:B7 pathways by using tetravalent human LAG3-Ig and CTLA4-Ig synergistically prevented murine acute GVHD.

Abundance and expression of denitrifying genes (narG, nirS, norB, and nosZ) in sediments of wastewater stabilizing constructed wetlands

  • Chon, Kyongmi;Cho, Jaeweon
    • Environmental Engineering Research
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    • 제20권1호
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    • pp.51-57
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    • 2015
  • As expected, the expression of denitrifying genes in a Typha wetland (relatively stagnant compared to other ponds), showing higher nitrogen removal efficiency in summer, was affected by temperature. The abundance and gene transcripts of nitrate reductase (narG), nitrite reductase (nirS), nitric oxide reductase (norB), and nitrous oxide reductase (nosZ) genes in seasonal sediment samples taken from the Acorus and Typha ponds of free surface flow constructed wetlands were investigated using quantitative polymerase chain reaction (Q-PCR) and quantitative reverse transcription PCR (Q-RT-PCR). Denitrifying gene copy numbers ($10^5-10^8$ genes $g^{-1}$ sediment) were found to be higher than transcript numbers-($10^3-10^7$ transcripts $g^{-1}$ sediment) of the Acorus and Typha ponds, in both seasons. Transcript numbers of the four functional genes were significantly higher for Typha sediments, in the warm than in the cold season, potentially indicating greater bacterial activity, during the relatively warm season than the cold season. In contrast, copy numbers and expression of denitrifying genes of Acorus did not provide a strong correlation between the different seasons.

Genetic Analysis of Asian Chum Salmon Populations Based on Microsatellite DNA Variation

  • Yoon, Moon-Geun;Abe, Syuiti;Jin, Deuk-Hee
    • Fisheries and Aquatic Sciences
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    • 제10권4호
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    • pp.186-190
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    • 2007
  • We examined the genetic variability of Asian chum salmon (Oncorhynchus keta) populations using nuclear microsatellite (ms) DNA analysis with four polymorphic loci (OKM4, OKM5, OKM7, and OKM8) in 397 individuals from nine populations, including one in Korea, seven in Japan, and one in Russia. The msDNA gene diversity was highest in the Japanese populations, suggesting greater genetic variation in the populations in Japan than in populations in Korea and Russia. The pairwise $F_{ST}$ estimates based on our msDNA data showed that the Korean population was genetically different from the Japanese and Russian populations, and there were higher $F_{ST}$ estimates between Hokkaido and Honshu populations than between other population pairs. A neighbor-joining tree showed that the Korean population was distinct from two other clusters, representing the populations in Honshu and the populations in Hokkaido and Russia. These results suggest that the observed population genetic patterns of Asian chum salmon might be influenced by low or restricted gene flow.

BLOOD PROTEIN POLYMORPHISMS OF NATIVE AND JUNGLE FOWLS IN INDONESIA

  • Hashiguchi, T.;Nishida, T.;Hayashi, Y.;Maeda, Y.;Mansjoer, S.S.
    • Asian-Australasian Journal of Animal Sciences
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    • 제6권1호
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    • pp.27-35
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    • 1993
  • In an attempt to reveal the interrelationship between fowls of jungle and native origin, their gene constitutions were compared using gene frequencies at the 16 loci controlling blood protein variations. Of the 16 loci analysed by electrophoresis, polymorphism was detected at following seven loci: Es-1, Amy-1, Akp-akp, Akp-2, Alb, Tf and 6-PGD. The other nine loci: Amy-3, Es-D, PGM, PHI, MDH, To, LDH, Hb-1 and Hb-2, were noted to be monomorphic. Genetic distance between pairs of native fowl and jungle fowls was estimated by a numerical taxonomic method. The Indonesian native fowl was genetically close to the Indonesian red jungle fowl, and the grey jungle fowl was genetically similar to the Ceylonese jungle fowl. It was also suggested that the green jungle fowl was genetically remote from the other jungle fowls and from the Indonesian native flow. The proportion of polymorphic loci (Ppoly), the expected average heterozygosity per individual $\bar{H}$, and the effective number of alleles per locus (Ne) were calculated to evaluate the genetic variabilities in the native and jungle fowls. The Indonesian native fowl exhibited slightly higher the proportion of polymorphic loci than the jungle fowls.

상기생(桑寄生)이 HepG2 cell의 세포분열 및 관련유전자 발현에 미치는 영향 (The Effects of Loranthus parasiticus Merr. on Cell Cycle and Expression of Related Genes in HepG2 Cell)

  • 류광열;김영철;우홍정;이장훈
    • 대한한방내과학회지
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    • 제26권1호
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    • pp.60-73
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    • 2005
  • Objectives : The aim of this study was to evaluate the effects of Loranthus parasiticus Merr. on cell cycle and expression of related genes in HepG2 cells. Methods : The MTT assay, cell counting assay, $[^3H]-Thymidine$ incorporation assay, flow cytometric analysis, quantitative RT-PCR and western blot assay were studied. Results : In the water extract of Loranthus parasiticus Merr., inhibition of cell proliferation and DNA synthesis in HepG2 cells was seen. These inhibitory effects were due to inhibition of G l-S transition in cell cycle. After treatment with the extract, expression of cyclin D1(G1 check point related gene) was inhibited particularly in dose-dependent and time-dependent manners. Conclusion : These results suggest that the inhibition of cell cycle progression by Loranthus parasiticus Merr. in HepG2 cell is due to suppression of cyclin D1(G1 check point related gene) mRNA expression and protein synthesis.

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Recent advances in genetic studies of stuttering

  • Kang, Changsoo
    • Journal of Genetic Medicine
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    • 제12권1호
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    • pp.19-24
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    • 2015
  • Speech and language are uniquely human-specific traits, which contributed to humans becoming the predominant species on earth. Disruptions in the human speech and language function may result in diverse disorders. These include stuttering, aphasia, articulation disorder, spasmodic dysphonia, verbal dyspraxia, dyslexia and specific language impairment. Among these disorders, stuttering is the most common speech disorder characterized by disruptions in the normal flow of speech. Twin, adoption, and family studies have suggested that genetic factors are involved in susceptibility to stuttering. For several decades, multiple genetic studies including linkage analysis were performed to connect causative gene to stuttering, and several genetic studies have revealed the association of specific gene mutation with stuttering. One notable genetic discovery came from the genetic studies in the consanguineous Pakistani families. These studies suggested that mutations in the lysosomal enzyme-targeting pathway genes (GNPTAB, GNPTG and NAPGA) are associated with non-syndromic persistent stuttering. Although these studies have revealed some clues in understanding the genetic causes of stuttering, only a small fraction of patients are affected by these genes. In this study, we summarize recent advances and future challenges in an effort to understand genetic causes underlying stuttering.

Comparison of Genetic Diversity and Population Structure of Kalopanax pictus (Araliaceae) and its Thornless Variant Using RAPD

  • Huh, Man-Kyu;Jung, Sang-Duk;Moon, Heung-Kyu;Kim, Sea-Hyun;Sung, Jung-Sook
    • 한국약용작물학회지
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    • 제13권2호
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    • pp.69-74
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    • 2005
  • Kalopanax pictus is a long-lived woody species mostly distributed in East Asia. K. pictus has been regarded as medically and ecologically important species in Korea. Thornless castor aralia variant, local name 'Cheongsong' is an endemic to Cheongsong province in Korea. Random amplified polymorphic DNA (RAPD) was used to investigate the genetic variation and structure of Korean populations of two species. A high level of genetic variation was found in six K. pictus populations. Twelve primers revealed 49 loci, of which 29 were polymorphic (59.2%). Nei's gene diversity for K.pictus and K. pictus variant were 0.119 and 0.098, respectively. Mean of genetic diversity in K. pictus was higher than average values for species with similar life history traits. The asexual and sexual reproduction, perennial habitat, and longevity are proposed as possible factors contributing to high genetic diversity. An indirect estimate of the number of migrants per generation (Nm=0.857) indicated that gene flow was not extensive among Korean populations of K.pictus. It is suggested that the isolation of geographical distance and reproductive isolation between K.pictus and K.pictus variant populations may have played roles in shaping the population structure of this species.