• 제목/요약/키워드: Different Populations

검색결과 1,246건 처리시간 0.027초

Human CD8+ T-Cell Populations That Express Natural Killer Receptors

  • June-Young Koh;Dong-Uk Kim;Bae-Hyeon Moon;Eui-Cheol Shin
    • IMMUNE NETWORK
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    • 제23권1호
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    • pp.8.1-8.13
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    • 2023
  • CD8+ T cells are activated by TCRs that recognize specific cognate Ags, while NK-cell activation is regulated by a balance between signals from germline-encoded activating and inhibitory NK receptors. Through these different processes of Ag recognition, CD8+ T cells and NK cells play distinct roles as adaptive and innate immune cells, respectively. However, some human CD8+ T cells have been found to express activating or inhibitory NK receptors. CD8+ T-cell populations expressing NK receptors straddle the innate-adaptive boundary with their innate-like features. Recent breakthrough technical advances in multi-omics analysis have enabled elucidation of the unique immunologic characteristics of these populations. However, studies have not yet fully clarified the heterogeneity and immunological characteristics of each CD8+ T-cell population expressing NK receptors. Here we aimed to review the current knowledge of various CD8+ T-cell populations expressing NK receptors, and to pave the way for delineating the landscape and identifying the various roles of these T-cell populations.

Morphological Variations in Tetrapleura tetraptera Taub. (Fabaceae) Fruits and Seed Traits from Lowland Rainforest Zones of Nigeria: A Keystone Non Timber Forest Tree Species in the Tropics

  • Aishat Adeola Olaniyi;Samuel Olalekan Olajuyigbe;Musbau Bayo Olaniyi
    • Journal of Forest and Environmental Science
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    • 제40권2호
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    • pp.111-117
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    • 2024
  • An evaluation was carried out on variability in morphology of fruits and seeds (number and weight) of Tetrapleura tetraptera (Schumach. and Thonn.) Taub. from different populations across its distribution range in Nigeria. Bulk fruit samples were collected and examined for variations in morphological characters. Differences in morphological character of fruits and seeds among the populations were determined using analysis of variance at 5% level of probability. The relationships among morphological characters were determined using Pearson correlation coefficient (r). Significant variations (p<0.05) existed among T. tetraptera populations for all the evaluated characters: fruit length, fruit width, number of seeds per fruit and seed weight. A positive significant strong correlation (r=0.96) was found between seed weight and number of seeds per fruit, while no correlation existed between fruit length, width and number of seeds. Seed weight was positively correlated with minimum altitude (r=0.97) and maximum altitude (r=0.99) of seed populations. Number of seeds was also significantly correlated with maximum altitude (r=0.965). There was no significant correlation between geo-climatic variables and fruit dimensions (length and width). Observed variations in morphological traits within and across populations of T. tetraptera may be used as proxy to estimate genetic diversity and selection of superior trees for improved productivity.

Electron-Morphometric Classification of the Native Honeybees from Korea. Part II. Discriminant Analysis for Different Populations Based on the Total Characters (한국산 재래꿀벌의 전자계량형태학적 분류. II. 전 47형질에 대한 각 지역개체군간 판정분석)

  • 권용정;허은엽
    • Korean journal of applied entomology
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    • 제32권1호
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    • pp.30-41
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    • 1993
  • In the present investigation, some multivariate discriminant analyses were done for each population of the native honeybee workers (Apis cerana), which were selected for 15 different localities in spring and 16 in summer form Korea. when the comparison of both seasons for different populations and regardless of seasons were conducted, all the classification results revealed that the differences were significantly prominent. And the length of fore tibia(FTL) was the best contributed character among the 47 morphometric characters used in the analysis.

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Distribution of Length Variation of the mtDNA 9-bp Motif in the Intergenic COII/tRNAX$^{Lys}$ Region in East Asian Populations

  • Han Jun Jin;Jeon Won Choi;Dong Jik Shin;Jung Min Kim;Wook Kim
    • Animal cells and systems
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    • 제3권4호
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    • pp.393-397
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    • 1999
  • Length variations in human mitochondrial DNA (mtDNA) offer useful markers in the study of female aspects of human population history. One such length variation is a 9-bp deletion in the small noncoding segment located between the COII and Iysine tRNA genes (COII/tRNA/$^{Lys}$ intergenic region) which usually contain two tandemly arranged copies of a 9-bp sequence (ccccctcta) in human mtDNA. The mtDNA 9-bp deletion and polymorphic variants of expanded 9-bp repeat motif in the intergenic COII/tRNA$^{Lys}$ region have been found at varying frequencies among different human ethnic groups. We have examined the length variation of the mtDNA COII/tRNA$^{Lys}$ intergenic region from a total of 813 individuals in east Asian populations. The occurrence of the 9-bp deletion was found to be relatively homogeneous in northeast Asian populations (Chinese, 14.2%; Japanese, 14.3%: Koreans, 15.5%), with the exception of Mongolians (5.1%). In contrast, Indonesians (25.0%) and Vietnamese (23.2%) of the southeast Asian populations appeared to have relatively high frequencies of the 9-bp deletion. We identified the existence of a new expanded 9-bp repeat motif which likely resulted from a slipped mispairing insertion of six more cytosines in the intergenic COII$^{Lys}$ region. It was present at low frequencies in the Korean (2/349) and Japanese populations (2/147). Based on the results of this study, the Korean population may reflect a close genetic affinity with the Japanese and Chinese populations than the others surveyed east Asian populations.

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Genetic Variation of Coreoleuciscus splendidus Populations from Four Major Rivers in Korea as Assessed by RAPD PCR (RAPD PCR에 의한 4대강 쉬리 Coreoleuciscus splendidus 개체군들의 유전변이 분석)

  • Song, Ha-Yoon;Bang, In-Chul
    • Korean Journal of Ichthyology
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    • 제21권2호
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    • pp.129-133
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    • 2009
  • Random Amplified Polymorphic DNA (RAPD) analysis was used to investigate the genetic variations of Coreoleuciscus splendidus within and among the West Korea Subdistrict populations (in Han and Geum Rivers) and the South Korea Subdistrict populations (in Seomjin and Nakdong Rivers). Twelve random primers were employed to generate RAPD markers. All primers were produced to identify specific RAPD markers between the West and South Korea Subdistrict populations. Analyses of genetic similarity and distance among the West and South Korea Subdistrict populations of C. splendidus also revealed similar results, with low genetic similarity (0.49~0.53) and high distance value (0.63~0.71). UPGMA dendrogram based on genetic distance was also similar in results. Therefore, the West Korea Subdistrict populations and the South Korea Subdistrict populations vary in genetic structure, and C. splendidus in the South Korea Subdistrict may represent a different species.

Genetic Differences and Variation in Two Purple Washington Clam (Saxidomus purpuratus) Populations from South and North Korea

  • Yoon, Jong-Man;Park, Su-Young
    • The Korean Journal of Malacology
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    • 제22권2호
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    • pp.97-108
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    • 2006
  • Genomic DNA samples isolated from geographical purple Washington clam (Saxidomus purpuratus) were obtained from two different regions in Korean Peninsula: Gunsan (Gunsan population; GSP), and Haeju (Haeju population; HJP), a collection area in the vicinity of the West Sea. The seven arbitrarily primers, OPA-07, OPA-09, OPA-18, OPA-20, OPC-03, OPC-06 and OPC-09 were shown to generate the total loci, loci observed per primer, shared loci by each population, specific, and polymorphic loci which could be clearly scored. We also generated the unique shared loci to each population and shared loci by the two populations in purple Washington clam. The size of the DNA fragments also varied wildly, from 50 to 2,400 bp. Here, 304 total loci were identified in the GSP purple Washington clam population, and 282 in the HJP: 91 polymorphic loci (29.9%) in the GSP and 47 (16.7) in the HJP. 198 shared loci, with an average of 28.3 per primer, were observed in the GSP population. The decamer primer OPA-07 generated the shared loci by the two populations, approximately 1,000 bp, between the two Saxidomus populations. The oligonucleotide primer OPC-03 also generated the shared loci by the two populations, approximately 500 bp and 1,000 bp, in GSP population from Gunsan and HJP population from Haeju. The other primer, OPC-06 generated the shared loci by two Gomphina populations (approximately 400 bp). The dendrogram, generated by seven reliable primers, indicates three genetic clusters. The dendrogram obtained by the seven primers indicates three genetic clusters: cluster 1 (GUNSAN 01-GUNSAN 02), cluster 2 (GUNSAN 03-GUNSAN 11), and cluster 3 (HAEJU 12-HAEJU 22). The genetic distance between the two geographical populations ranged from 0.043 to 0.506. Especially, the longest genetic distance displaying significant molecular differences, 0.506, was found to exist between individuals GUNSAN no. 11 of Gunsan and HAEJU no. 17 of Haeju.

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Microsatellite Markers for Non-Invasive Examination of Individual Identity, Genetic Variation, and Population Differentiation in Two Populations of Korean Long-Tailed Goral (Naemorhedus caudatus)

  • Kim, Baek-Jun
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • 제3권4호
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    • pp.191-198
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    • 2022
  • Natural habitats of the Korean long-tailed goral (Naemorhedus caudatus) have been fragmented by anthropogenic activities in South Korea in the last decades. Here, the individual identity, genetic variation, and population differentiation of the endangered species were examined via the multiple-tube approach using a non-invasive genotyping method. The average number of alleles was 3.16 alleles/locus for the total population. The Yanggu population (1.66) showed relatively lower average number of alleles than the Inje population (3.67). Of the total 19 alleles, only seven (36.8%) alleles were shared by the two populations. Using five polymorphic out of six loci, four and six different goral individuals from the captive Yanggu (n=24) and the wild Inje (n=28) population were identified, respectively. The allele distribution was not identical between the two populations (Fisher's exact test: P<0.01). A considerably low migration rate was detected between the two populations (no. of migrants after correction for size=0.294). Additionally, the F statistics results indicated significant population differentiation between them, however, quite low (FST=0.327, P<0.01). The posterior probabilities indicated that the two populations originated from a single panmictic population (P=0.959) and the assignment test results designated all individuals to both populations with nearly equal likelihood. These could be resulted from moderate population differentiation between the populations. No significant evidence supported recent population bottleneck in the total Korean goral population. This study could provide us with useful population genetic information for conservation and management of the endangered species.

ASSESSING CALIBRATION ROBUSTNESS FOR INTACT FRUIT

  • Guthrie, John A.;Walsh, Kerry B.
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 한국근적외분광분석학회 2001년도 NIR-2001
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    • pp.1154-1154
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    • 2001
  • Near infra-red (NIR) spectroscopy has been used for the non-invasive assessment of intact fruit for eating quality attributes such as total soluble solids (TSS) content. However, little information is available in the literature with respect to the robustness of such calibration models validated against independent populations (however, see Peiris et al. 1998 and Guthrie et al. 1998). Many studies report ‘prediction’ statistics in which the calibration and prediction sets are subsets of the same population (e. g. a three year calibration validated against a set from the same population, Peiris et al. 1998; calibration and validation subsets of the same initial population, Guthrie and Walsh 1997 and McGlone and Kawano 1998). In this study, a calibration was developed across 84 melon fruit (R$^2$= 0.86$^{\circ}$Brix, SECV = 0.38$^{\circ}$Brix), which predicted well on fruit excluded from the calibration set but taken from the same population (n = 24, SEP = 0.38$^{\circ}$Brix with 0.1$^{\circ}$Brix bias), relative to an independent group (same variety and farm but different harvest date) (n = 24, SEP= 0.66$^{\circ}$ Brix with 0.1$^{\circ}$Brix bias). Prediction on a different variety, different growing district and time was worse (n = 24, SEP = 1.2$^{\circ}$Brix with 0.9$^{\circ}$Brix bias). Using an ‘in-line’ unit based on a silicon diode array spectrometer, as described in Walsh et al. (2000), we collected spectra from fruit populations covering different varieties, growing districts and time. The calibration procedure was optimized in terms of spectral window, derivative function and scatter correction. Performance of a calibration across new populations of fruit (different varieties, growing districts and harvest date) is reported. Various calibration sample selection techniques (primarily based on Mahalanobis distances), were trialled to structure the calibration population to improve robustness of prediction on independent sets. Optimization of calibration population structure (using the ISI protocols of neighbourhood and global distances) resulted in the elimination of over 50% of the initial data set. The use of the ISI Local Calibration routine was also investigated.

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Gene Flow of Oriental Fruit Moth, Grapholita molesta, Populations Analyzed by RAPD Molecular Markers (RAPD 분자지표를 이용한 복숭아순나방(Grapholita molesta)의 집단 유전적 변동 분석)

  • Son, Ye-Rim;Kim, Yong-Gyun
    • Korean journal of applied entomology
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    • 제47권1호
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    • pp.37-44
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    • 2008
  • Oriental fruit moth, Grapholita molesta, is a serious pest on apples. To control this pest in an environmentally friendly method, mating disruption strategy using sex pheromone has been developed. Area-wide application of mating disruption has been needed to be effective, with little understanding on how much size of apple cultivating area should be treated in one time application of the mating disruption technique. On this matter, we needed to determine a minimal mating active zone of G. molesta that should be applied with mating disrupters to be effective. Molecular markers to discriminate a specific population should be developed to trace population migration for reproductive behaviors. Here we developed two effective molecular markers using random amplified polymorphic DNA (RAPD) technique. Different field populations of G. molesta, based on locations and seasons, were analyzed with these markers. In a specific location, G. molesta populations varied in genetic composition with different seasons. Different local populations showed differential variation according to their relative distances among apple orchards. In overall, genetic variation among different populations became lessen with progression of seasons.

Growth Characteristics of Cutting Culms Sectioned at Different Positions from Three Reed Populations (세 갈대 개체군의 절단 부위별 삽목 생장 특성)

  • Hong, Mun-Gi;Kim, Jae Geun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • 제15권1호
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    • pp.53-62
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    • 2012
  • Culm cutting is very effective and convenient method for asexual propagation and even much less destructive than the other ways such as excavation of rhizomes. Despite that culm cutting is such a useful method, only few investigations for raising its efficiency have been carried out. We tried to examine the effect of different geographical populations and cutting sections on the shoot emergence, biomass production and its allocation in terms of cutting efficiency. Culms were sampled from three environmentally distinct wetlands : riparian marsh, salt marsh and montane fen and then they were cut separately into four sections from the bottom to the top part. Both factors of different population and section affected the shoot emergence together. Middle parts on the culm always showed more shoot emergence irrespective of different population. On the other hand, first section from salt marsh and fourth section from the montane fen did not exhibit any shoot emergence. Significant difference in increase of shoot emergence between different sections during investigation period was confirmed only from salt marsh population. Not only different population but also appropriate cutting section should be considered together for better efficiency in cutting of reed culms.