• Korean Journal of Radiology
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• 제24권2호
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• pp.166-167
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• 2023

• The Plant Pathology Journal
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• 제25권3호
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• pp.236-240
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• 2009

Tylenchulus semipenetrans, citrus nematode is an important phytopathogenic nematode and responsible for serious damage on citrus. However, little information is available about genetic variability of T. semipenetrans among different populations with variation of conventional diagnostic characteristics. In this study, we compared the morphometric and genetic characteristics among different populations. The mature female of T. semipenetrans collected in this study had thicker cuticle than those in the previous studies. In comparative sequence analysis of T. semipenetrans populations obtained from Jeju in Korea, we observed genetic variations within clones generated from single individuals. To determine whether variability among copies of nuclear ribosomal DNA sequences exists in the genome of T. semipenetrans, PCR-RFLP technique from individuals of Korean isolates with MseI and MspI restriction enzymes was used to prove experimentally that all populations have intra-specific variations. Restriction enzyme digestion created several fragments on 3.0% agarose gel corresponding to several haplotypes in all populations, though some populations displayed fragment deletion. The total length of fragments was larger than before digestion, indicating sequence heterogeneity within the genome of T. semipenetrans.

• BMB Reports
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• 제54권10호
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• pp.505-515
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• 2021

Human pluripotent stem cells (hPSCs) include human embryonic stem cells (hESCs) derived from blastocysts and human induced pluripotent stem cells (hiPSCs) generated from somatic cell reprogramming. Due to their self-renewal ability and pluripotent differentiation potential, hPSCs serve as an excellent experimental platform for human development, disease modeling, drug screening, and cell therapy. Traditionally, hPSCs were considered to form a homogenous population. However, recent advances in single cell technologies revealed a high degree of variability between individual cells within a hPSC population. Different types of heterogeneity can arise by genetic and epigenetic abnormalities associated with long-term in vitro culture and somatic cell reprogramming. These variations initially appear in a rare population of cells. However, some cancer-related variations can confer growth advantages to the affected cells and alter cellular phenotypes, which raises significant concerns in hPSC applications. In contrast, other types of heterogeneity are related to intrinsic features of hPSCs such as asynchronous cell cycle and spatial asymmetry in cell adhesion. A growing body of evidence suggests that hPSCs exploit the intrinsic heterogeneity to produce multiple lineages during differentiation. This idea offers a new concept of pluripotency with single cell heterogeneity as an integral element. Collectively, single cell heterogeneity is Janus-faced in hPSC function and application. Harmful heterogeneity has to be minimized by improving culture conditions and screening methods. However, other heterogeneity that is integral for pluripotency can be utilized to control hPSC proliferation and differentiation.

• The Korean Journal of Ecology
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• 제24권6호
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• pp.353-357
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• 2001

Differential response of genotypes to temporal environmental heterogeneity may contribute to the long-term persistence of these genotypes within a population. In this experiment, we experimentally tested whether groups by season interactions for germination and seedling growth can explain genetic variability within the population. To determine whether seeds collected during the four seasons respond differentially to temperature treatments, two-way ANOVA was performed. This study indicates that seasonal environments have large effects on demography. Groups within populations respond differentially to seasonal environments by influencing population growth that may in turn influence community composition. Most importantly, the study showed that temporal heterogeneity in the environment might functions as a mechanism that maintains within-population genetic diversity.

• BMB Reports
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• 제37권4호
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• pp.493-502
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• 2004

The genetic diversity and species-diagnostic markers in the introduced apple snail, Pomacea canaliculata and in the native Thai apple snails; Pila ampullacea, P. angelica, P. pesmei, and P. polita, were investigated by restriction analysis of COI and are reported for the first time. Twenty-one composite haplotypes showing non-overlapping distributions among species were found. Genetic heterogeneity analysis indicated significant differences between species (P < 0.0001) and within P. pesmei (P < 0.0001) and P. angelica (P < 0.0004). No such heterogeneity was observed in Pomacea canaliculata (P > 0.0036 as modified by the Bonferroni procedure), P. ampullacea (P = 0.0824-1.000) and P. polita (P = 1.0000). A neighbor-joining tree based on genetic distance between pairs of composite haplotypes differentiated all species and indicated that P. angelica and P. pesmei are closely related phylogenetically. In addition, the 16S rDNA of these species was cloned and sequenced. A species-specific PCR for P. canaliculata was successfully developed with a sensitivity of detection of approximately 50 pg of the target DNA template. The amplification of genomic DNA (50 pg and 25 ng) isolated from the fertilized eggs, and juveniles (1, 7, and 15 d after hatching) of Pomacea canaliculata was also successful, and suggested that Pomacea canaliculata and Pila species can be discriminated from the early stages of development.

• Journal of Genetic Medicine
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• 제19권2호
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• pp.85-93
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• 2022

Purpose: Cornelia de Lange syndrome (CdLS) is a rare genetically heterogeneous disorder caused by genetic variants of the cohesin complex. However, the diverse genetic etiologies and their phenotypic correlations in Korean patients with CdLS are still largely unknown. Hence, this study aimed to clarify the clinical characteristics and genetic background of Korean patients with CdLS. Materials and Methods: The medical records of 15 unrelated patients (3 males and 12 females) genetically confirmed to have CdLS were retrospectively reviewed. All individuals were diagnosed with CdLS using target gene analysis, whole-exome sequencing, and/or chromosomal microarray analysis. The clinical score (CS) was calculated to assess disease severity. Results: The median age at diagnosis was 1.7 (range, 0.0-11.8) years, and median follow-up duration was 3.8 (range, 0.4-11.7) years. Eight (53.3%) patients showed classic phenotypes of CdLS, two (13.3%) showed non-classic phenotypes, and five (33.3%) had other phenotypes sharing limited signs of CdLS. Fifteen causative variants were identified: NIPBL in five (33.3%, including 3 males), SMC1A in three (20.0%), SMC3 in three (20.0%), and HDAC8 in four (26.7%) patients. The CS was significantly higher in the NIPBL group than in the non-NIPBL group (14.2±1.3 vs. 8.7±2.9, P<0.001). Conclusion: We identified the clinical and genetic heterogeneity of CdLS in Korean patients. Patients with variants of NIPBL had a more distinctive phenotype than those carrying variants of other cohesin complex genes (SMC1A, SMC3, and HDAC8). However, further studies are warranted to understand the pathogenesis of CdLS as a cohesinopathy and its genotype-phenotype correlations.

• Asian Pacific Journal of Cancer Prevention
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• 제16권11호
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• pp.4525-4530
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• 2015

Background: The MTHFR C677T polymorphism is a genetic alteration affecting an enzyme involved in folate metabolism, but its relationship to host susceptibility to prostate cancer remains uncertain. The aim of this study was to investigate the association between MTHFR C677T polymorphism and prostate cancer by performing a meta-analysis. Materials and Methods: Pubmed and Web of Science databases were searched for case-control studies investigating the association between MTHFR C677T polymorphism and prostate cancer. Odds ratios (OR) and 95% confidence intervals (95%CI) were used to assess any link. Results: A total of 22 independent studies were identified, including 10,832 cases and 11,993 controls. Meta-analysis showed that there was no obvious association between MTHFR C677T polymorphism and risk of prostate cancer under all five genetic models. There was also no obvious association between MTHFR C677T polymorphism and risk of prostate cancer in the subgroup analyses of Caucasians. In contrast, MTHFR C677T polymorphism was associated with increased risk for prostate cancer in Asians with the allele model (C vs G: OR=1.299, 95 %CI =1.121-1.506, P=0.001, $P_{heterogeneity}=0.120$, $I^2=45%$), additive genetic model (CC vs TT: OR =1.925, 95 % CI= 1.340-2.265, P=0.00, $P_{heterogeneity}=0.587$, $I^2=0.00%$), recessive model (CC vs TT+TC: OR= 1.708, 95 % CI=1.233-2.367, P=0.001, $P_{heterogeneity}=0.716$, $I^2=0.00%$), and heterozygote genetic model (CT vs TT: OR=2.193, 95 % CI =1.510-3.186, P=0.000, $P_{heterogeneity}=0.462$, $I^2=0.00%$). Conclusions: These results suggest that the MTHFR C677T polymorphism does not contribute to the risk of prostate cancer from currently available evidence in populations overall and Caucasians. However, the meta analysis indicates that it may play a role in prostate cancer development in Asians.

• 한국산림과학회지
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• 제94권4호통권161호
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• pp.209-213
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• 2005

희귀수종 들쭉나무(Vaccinium uliginosum L.)의 유전자원 보존을 위한 분자유전학적 정보를 제공하고자 한라산 및 설악산 정상부에 국소적으로 분포하고 있는 2개 집단을 대상으로 I-SSR 표지자 분석을 수행하였다. 증폭된 I-SSR 산물은 총 68개였고, 유전다양성은 한라산 집단이 0.539로 설악산 집단(0.401) 보다 높았으며, 동일한 표지자로 분석된 타 희귀수종에 비해 상대적으로 높은 유전적 다양성을 보였다. AMOVA 분석 결과 전체 유전변이 중 66.5%가 각 집단 내 개체 간에 공통적으로 존재하며, 33.5%는 집단간 유전적 차이에 기인하는 것으로 추정되어 분석된 두 집단 간에 매우 높은 유전적 분화가 관찰되었다. 지리적으로 격리된 이들 집단 간의 높은 유전적 이질성은 두 집단이 각각 별개의 조상집단으로부터 유래되었을 가능성과 빙하기 이후 급격한 환경변화와 지리적 격리 등으로 인해 각 집단이 유전적 부동과정을 거치며 유전적 이질성이 증가하였을 가능성 등에 의해 설명될 수 있을 것으로 생각된다.

• Asian-Australasian Journal of Animal Sciences
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• 제15권8호
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• pp.1222-1226
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• 2002

Estimates of genetic correlation between direct and maternal effects for weaning weight of beef cattle are often negative in field data. The biological existence of this genetic antagonism has been the point at issue. Some researchers perceived such negative estimate to be an artifact from poor modeling. Recent studies on sources affecting the genetic correlation estimates are reviewed in this article. They focus on heterogeneity of the correlation by sex, selection bias caused from selective reporting, selection bias caused from splitting data by sex, sire by year interaction variance, and sire misidentification and inbreeding depression as factors contributing sire by year interaction variance. A biological justification of the genetic antagonism is also discussed. It is proposed to include the direct-maternal genetic covariance in the analytical models.

• Asian-Australasian Journal of Animal Sciences
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• 제14권11호
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• pp.1520-1522
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• 2001

Relationship among Tibetan cashmere goats, Inner Mongolia cashmere goats and Liaoning cashmere goats was studied using the technique of random amplified polymorphic DNA (RAPD). One primer and four primer combinations were screened. With the five primers and primer combinations, DNA fragments were amplified from the three breeds. Each breed has 28 samples. According to their RAPD fingerprint maps, the Nei's (1972) standard genetic distance was: 0.0876 between Tibetan cashmere goats and Inner Mongolia cashmere goats, 0.1601 between Tibetan cashmere goats and Liaoning cashmere goats, 0.0803 between the Inner Mongolia cashmere goats and Liaoning cashmere goats. It coincides with their geographic location. The genetic heterogeneity of Tibetan cashmere goats, Inner Mongolia cashmere goats and Liaoning cashmere goats is 0.3266, 0.2622 and 0.2475 respectively. It is also consistent with their development history.