• Title/Summary/Keyword: Population differentiation

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Clinicopathological Factors and Gastric Cancer Prognosis in the Iranian Population: a Meta-analysis

  • Somi, Mohammad Hossein;Ghojazadeh, Morteza;Bagheri, Masood;Tahamtani, Taraneh
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권3호
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    • pp.853-857
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    • 2015
  • Background: Gastric cancer is the most common cancer in the Iranian population. The aim of this study was to determine the effect of clinicopathological factors on prognosis by meta-analysis. Materials and Methods: A literature search was conducted using MEDLINE, EMBASE and Cochrane library and extensive literature search using the Persian databases until February 2011. Prospective follow up studies with multivariate analysis of overall survival of the patients with gastric cancer were included in this review. The data were analyzed by CMA.2. Publication bias are checked by funnel plot and data are shown as Forest plots. Results: From a total of 63 articles, 14 retrospective studies which examined 5 prognostic factors and involving 10,500 patients were included. Tumor size (>35mm) was the main significant factor predicting an unfavorable prognosis for the patients with gastric cancer (RR=1.829, p<0.001) followed by presence of distant metastases (RR=1.607, p<0.001), poor differentiation (RR=1.408, p<0.001) and male sex (RR=1.194, p<0.001). Lymph node metastases (RR=1.058, p=0.698) and moderate differentiation (RR=0.836, p=0.043) were not statistically significant as prognostic factors. Conclusions: This meta-analysis suggests that tumor size>35mm, poor differentiation, presence of distant metastasis and male gender are strongly associated with a poor prognosis in Iranian patients with gastric cancer.

Genetic Variation in the Asian Shore Crab Hemigrapsus sanguineus in Korean Coastal Waters as Inferred from Mitochondrial DNA Sequences

  • Hong, Sung-Eic;Kim, Jin-Koo;Yu, Jeong-Nam;Kim, Keun-Yong;Lee, Chung-Il;Hong, Kwan-Eui;Park, Kie-Young;Yoon, Moon-Geun
    • Fisheries and Aquatic Sciences
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    • 제15권1호
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    • pp.49-56
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    • 2012
  • Genetic variation in the Asian shore crab Hemigrapsus sanguineus was determined from partial mitochondrial DNA (mtDNA) sequences of the cytochrome b (Cytb) gene. Samples included 143 crabs from six localities along three coastlines in South Korea. A nucleotide sequence analysis revealed 38 variable sites in a 470-bp sequence, which defined 37 haplotypes. The haplotypes were not associated geographically and had a shallow genealogy. Pairwise $F_{ST}$ tests and a two-dimensional scaling analysis revealed no significant genetic differentiation among most of the populations. The low pairwise comparison values, but significant genetic differentiation of a northeastern population from all other populations, might have been influenced by a restriction in gene flow caused by hydrographic conditions such as ocean boundaries. The high haplotype diversity, low nucleotide diversity, and time since H. sanguineus expansion in Korean coastal waters indicate rapid population growth and a recent, sudden expansion in the Late Pleistocene.

Population Genetic Structure and Marker - Trait Associations in a Collection of Traditional Rice (Oryza sativa L.) from Northern Vietnam

  • Ngoc Ha Luong;Le-Hung Linh;Kyu-Chan Shim;Cheryl Adeva;Hyun-Sook Lee;Sang-Nag Ahn
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2022년도 춘계학술대회
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    • pp.110-110
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    • 2022
  • Rice is the world's most important food crop and a major source of nutrition for about two thirds of populations. Northern Vietnam is one of the most important centers of genetic diversity for cultivated rice. In this study, we determined the genetic diversity and population structure of 79 rice landraces collected from northern Vietnam and 19 rice accessions collected from different countries. In total, 98 rice accessions could be differentiated into japonica and indica with moderate genetic diversity and a polymorphism information content of 0.382. We also detected subspecies-specific markers to classify rice (Oryza sativa L.) into indica and japonica. Additionally, we detected five marker-trait associations and rare alleles that can be applied in future breeding programs. Most interestingly, analysis of molecular variance (AMOVA) found genetic differentiation was related to geographical regions with an overall PhiPT (analog of fixation index FST) value of 0.130. More emphasis was given to provide signatures and infer explanations about the role of geographical isolation and environmental heterogeneity in genetic differentiation among regions in landraces from northern Vietnam. Our results suggest that rice landraces in northern Vietnam have a dynamic genetic system that can create different levels of genetic differentiation among regions, but also maintain a balanced genetic diversity between regions.

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GENETICAL STUDIES ON NATIVE CHICKENS IN INDONESIA

  • Yamamoto, Y.;Namikawa, T.;Okada, I.;Nishibori, M.;Mansjoer, S.S.;Martojo, H.
    • Asian-Australasian Journal of Animal Sciences
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    • 제9권4호
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    • pp.405-410
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    • 1996
  • Phylogenetic analyses were carried out using four Indonesian native chicken breeds; Kampung, Bangkok, Pelung and Kedu. Gene frequencies of four blood group (A, B, D and E) and eight electrophoretic loci (akp, Akp-2, Es-1, Amy-1, Alb, Tf, Pas and Pa-1) were examined. Geographical and breed specific trends in the gene frequencies were not found in the local population of Kampung breed or in four native breeds. The values of average heterozygosity were estimated as 0.35-0.45. Genetic distances among the local populations of Kampung breed and other native breeds were comparatively small. In a cluster analysis, the Bangkok breed and Kampung E population showed distance from another cluster. The coefficient of gene differentiation for local populations of Kampung breed was estimated as 0.099.

Genetic Similarity and Variation in the Cultivated and Wild Carassius carassius Estimated with Random Amplified Polymorphic DNAs

  • Yoon, Jong-Man;Kim, Tae-Sun
    • 한국발생생물학회:학술대회논문집
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    • 한국발생생물학회 2001년도 후기 제12차 학술대회 논문집
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    • pp.34-35
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    • 2001
  • RAPD analysis based on numerous markers have been used to investigate patterns of genetic differentiation ann and within two cultured and wild populations represented by the species crucian carp(Carassius carassius). From RAPD analysis using five primers, a total of 442 polymorphic bands were obtained in two populations and 273 were found to be specific to a wild population. According to RAPD-based estimates, average number of polymorphic bands in wild population was approximately 1.5 times as diverse as that in cultured. The average level of bandsharing values was $0.40 \pm 0.05$ in wild population, but was $0.69 \pm 0.08$ in cultured population, With reference to bandsharing values and banding patterns, wild population was considerably more diverse than cultured population. Knowledge of the genetic diversity of crucian carp should help in formulating more effective strategies for managing this aquacultural fish species.

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Feeder Independent Culture of Mouse Embryonic Stem Cells

  • Kim, Myoung Ok;Ryoo, Zae Young
    • Reproductive and Developmental Biology
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    • 제36권4호
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    • pp.291-294
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    • 2012
  • Embryonic stem cell classically cultured on feeder layer with FBS contained ES medium. Feeder-free mouse ES cell culture systems are essential to avoid the possible contamination of nonES cells. First we determined the difference between ES cell and MEF by Oct4 population. We demonstrate to culture and to induce differentiation on feeder free condition using a commercially available mouse ES cell lines.

Genetic Diversity and Population Structure of Peanut (Arachis hypogaea L.) Accessions from Five Different Origins

  • Zou, Kunyan;Kim, Ki-Seung;Lee, Daewoong;Jun, Tae-Hwan
    • 한국작물학회지
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    • 제65권4호
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    • pp.447-456
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    • 2020
  • Peanut is an allotetraploid derived from a single recent polyploidization. Polyploidization has been reported to have caused significant loss in genetic diversity during the domestication of cultivated peanuts. Single nucleotide polymorphism (SNP)-based markers such as cleaved amplified polymorphic sequences (CAPS) derived from next-generation sequencing (NGS) have been developed and widely applied for breeding and genetic research in peanuts. This study aimed to identify the genetic diversity and population structure using 30 CAPS markers and 96 peanut accessions from five different origins. High genetic dissimilarities were detected between the accessions from Korea and those from the other three South American origins generally regarded as the origin of peanuts, while the accessions from Brazil and Argentina presented the lowest genetic dissimilarity. Based on the results of the present study, accessions from Korea have unique genetic variation compared to those from other countries, while accessions from the other four origins are closely related. Our study identified the genetic differentiation in 96 peanut accessions from five different origins, and this study also showed the successful application of SNP information derived from re-sequencing based on NGS technology.