• 제목/요약/키워드: population genetics

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Genetic variation of the endangered species Halenia coreana (Gentianaceae)

  • YUN, Narae;OH, Sang-Hun
    • Korean Journal of Plant Taxonomy
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    • v.52 no.1
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    • pp.45-53
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    • 2022
  • Halenia coreana is an endangered, endemic species that is distributed in only a few locations in Korea, such as Mts. Hwaaksan and Daeamsan. It has been recently segregated from H. corniculata, broadly distributed in cold temperate regions that include northern Japan, the Russian Far East, northeastern China, Mongolia, and eastern Europe, where population sizes are usually large. To examine the genetic diversity of H. coreana and evaluate the level of genetic differentiation of the species compared with that of H. corniculata, we surveyed 183 candidate simple sequence repeats (SSR) motif markers for H. coreana and H. corniculata from sequence data of amplified fragments of a specific length in the genome. A total of 17 genomic-SSR markers were selected to examine the levels of genetic diversity and differentiation using 17 samples of H. coreana and 60 samples of three populations of H. corniculata. The results here suggest that the genetic diversity of H. coreana is very low with a high frequency of inbreeding within its population. We found that H. coreana is genetically differentiated from H. corniculata, supporting the recognition of the geographically isolated H. coreana as a distinct species.

Genetic Contribution of Indigenous Yakutian Cattle to Two Hybrid Populations, Revealed by Microsatellite Variation

  • Li, M.H.;Nogovitsina, E.;Ivanova, Z.;Erhardt, G.;Vilkki, J.;Popov, R.;Ammosov, I.;Kiselyova, T.;Kantanen, J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.5
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    • pp.613-619
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    • 2005
  • Indigenous Yakutian cattle' adaptation to the hardest subarctic conditions makes them a valuable genetic resource for cattle breeding in the Siberian area. Since early last century, crossbreeding between native Yakutian cattle and imported Simmental and Kholmogory breeds has been widely adopted. In this study, variations at 22 polymorphic microsatellite loci in 5 populations of Yakutian, Kholmogory, Simmental, Yakutian-Kholmogory and Yakutian-Simmental cattle were analysed to estimate the genetic contribution of Yakutian cattle to the two hybrid populations. Three statistical approaches were used: the weighted least-squares (WLS) method which considers all allele frequencies; a recently developed implementation of a Markov chain Monte Carlo (MCMC) method called likelihood-based estimation of admixture (LEA); and a model-based Bayesian admixture analysis method (STRUCTURE). At population-level admixture analyses, the estimate based on the LEA was consistent with that obtained by the WLS method. Both methods showed that the genetic contribution of the indigenous Yakutian cattle in Yakutian-Kholmogory was small (9.6% by the LEA and 14.2% by the WLS method). In the Yakutian-Simmental population, the genetic contribution of the indigenous Yakutian cattle was considerably higher (62.8% by the LEA and 56.9% by the WLS method). Individual-level admixture analyses using STRUCTURE proved to be more informative than the multidimensional scaling analysis (MDSA) based on individual-based genetic distances. Of the 9 Yakutian-Simmental animals studied, 8 showed admixed origin, whereas of the 14 studied Yakutian-Kholmogory animals only 2 showed Yakutian ancestry (>5%). The mean posterior distributions of individual admixture coefficient (q) varied greatly among the samples in both hybrid populations. This study revealed a minor existing contribution of the Yakutian cattle in the Yakutian-Kholmogory hybrid population, but in the Yakutian-Simmental hybrid population, a major genetic contribution of the Yakutian cattle was seen. The results reflect the different crossbreeding patterns used in the development of the two hybrid populations. Additionally, molecular evidence for differences among individual admixture proportions was seen in both hybrid populations, resulting from the stochastic process in crossing over generations.

Genetic Background of Congenital Hearing Loss (선천성 난청의 유전적 배경)

  • Oh, Seung-Ha;Song, Jae-Jin
    • Journal of Genetic Medicine
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    • v.6 no.1
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    • pp.8-24
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    • 2009
  • Understanding the genetic background of hearing loss is important since almost 50% of the cases of profound hearing loss are caused by genetic factors. Until now, more than 150 causative genes have been identified. In this review, classification of genetic hearing loss (syndromic versus non-syndromic, recessive versus dominant, X-linked and mitochondrial), pitfalls in elucidating causative genes, anatomy of the inner ear, introduction of the most common syndromic hearing loss, introduction of the most common non-syndromic hearing loss-causing genes, mitochondrial and multifactorial hearing losses were discussed. Moreover, clinical approaches to the patients with hereditary hearing loss and genetic counseling were also explained briefly. Finally, future directions of the hereditary hearing loss research in Korean population were presented.

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Distributions of the GSTM1 and GSTT1 Null Genotypes Worldwide are Characterized by Latitudinal Clines

  • Saitou, Marie;Ishida, Takafumi
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.1
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    • pp.355-361
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    • 2015
  • Background: Deletion types of genetic variants of glutathione S-transferase (GST) M1 and T1, the GSTM1 null and GSTT1 null which are risk factors for certain cancers, have been ubiquitously found in human populations but their worldwide distribution pattern is unclear. Materials and Methods: To perform a meta-analysis, a systematic search for the literature on GSTM1 and GSTT1 null genotypes was done to identify 63 reports for 81 human populations. Relationships between the GSTM1 and GSTT1 null genotype frequencies and the absolute latitude of 81 populations were tested by Spearman's rank correlation coefficient. Results: A significant positive correlation was detected between the GSTM1 null genotype frequency and the absolute latitude (r=0.28, p-value <0.05), whereas the GSTT1 null genotype frequency and absolute latitude showed a significant negative correlation (r= -0.41 p-value <0.01). There was no correlation between the frequencies of GSTM1 and GSTT1 null genotype in each population (r= -0.029, p-value=0.80). Conclusions: Latitudinal clines of the distribution of the GSTM1 and GSTT1 null genotypes may be attributed to the result of gene-environmental adaptation. No functional compensation between GSTM1 and GSTT1 was suggested by the lack of correlation between the null frequencies for GSTM1 and GSTT1.

Combined Germline Variations of Thrombophilic Genes Promote Genesis of Lung Cancer

  • Ozen, Filiz;Polat, Fikriye;Arslan, Sulhattin;Ozdemir, Ozturk
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.9
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    • pp.5449-5454
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    • 2013
  • Background: A large variety of familiar and non-familiar lung carcinomas (LC) are caused by long term exposure to chemical carcinogens that are present in tobacco smoke. We aimed to investigate the prevalence of 5 thrombophilic germ-line mutations in patients with lung carcinomas. Materials and Methods:A total of 52 LC patients and 212 healthy controls from same population were analyzed for FV Leiden, factor V H1299R (R2), PAI-1, MTHFR C677T, MTHFR A1298C, ACE I/D, and Apo E genes and compared. Results: Overall, heterozygous and/or homozygous point mutations in FV Leiden Apo E2, PAI-1 and MTHFR C677T genes were associated with LC in the current cohort. There was no meaningful association between LC and ACE I/D gene markers. Conclusions: The current results showed that LC is related to combined thrombophilic gene mutations and individuals with homozygosity of 4G in PAI-1 and MTHFR C677T genes and heterozygosity of FV Leiden, Apo E4 genes have a germ-line risk for LC tumorigenesis.

Recent advances in breeding and genetics for dairy goats

  • Gipson, Terry A.
    • Asian-Australasian Journal of Animal Sciences
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    • v.32 no.8_spc
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    • pp.1275-1283
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    • 2019
  • Goats (Capra hircus) were domesticated during the late Neolithic, approximately 10,500 years ago, and humans exerted minor selection pressure until fairly recently. Probably the largest genetic change occurring over the millennia happened via natural selection and random genetic drift, the latter causing genes to be fixed in small and isolated populations. Recent human-influenced genetic changes have occurred through biometrics and genomics. For the most part, biometrics has concentrated upon the refining of estimates of heritabilities and genetic correlations. Heritabilities are instrumental in the calculation of estimated breeding values and genetic correlations are necessary in the construction of selection indices that account for changes in multiple traits under selection at one time. Early genomic studies focused upon microsatellite markers, which are short tandem repeats of nucleic acids and which are detected using polymerase chain reaction primers flanking the microsatellite. Microsatellite markers have been very important in parentage verification, which can impact genetic progress. Additionally, microsatellite markers have been a useful tool in assessing genetic diversity between and among breeds, which is important in the conservation of minor breeds. Single nucleotide polymorphisms are a new genomic tool that have refined classical BLUP methodology (biometric) to provide more accurate genomic estimated breeding values, provided a large reference population is available.

Genetic diversity and relationship of Halla horse based on polymorphisms in microsatellites

  • Jung, Ji Su;Seong, Jiyeon;Lee, Gwang Hyeon;Kim, Yesong;An, Je Hyun;Yun, Ji Hye;Kong, Hong Sik
    • Journal of Animal Reproduction and Biotechnology
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    • v.36 no.2
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    • pp.76-81
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    • 2021
  • Halla horse is crossbreed between Jeju and Thoroughbred horses and is used for riding, racing and meat production. Thus, molecular genetic studies are needed to establish and preserve the industrially valuable Halla horses. This study aimed to analyses the genetic diversity and population structure through 12 microsatellite (MS) markers for Halla and putatively related 3 breeds (Jeju, Mongolian and Thoroughbred horses). On average, the number of alleles, observed heterozygosity (Hobs), expected heterozygosity (Hexp), and polymorphic information content (PIC) among all horses were 10, 0.767, 0.799, and 0.771, respectively. Neighbor-joining tree and STRUCTURE analysis showed that Halla horses were between Thoroughbred and Jeju horses, tend to more influenced by Thoroughbred horses. Therefore, these results could be considered for use as the basic genetic breed relationships resource among the horse breeds (Jeju, Mongolian, and Thoroughbred horses) related to the origins of the Halla horse.

Noninvasive Testing for Colorectal Cancer Screening: Where Are We Now?

  • Jaeyoung Chun;Jie-Hyun Kim;Young Hoon Youn;Hyojin Park
    • Journal of Digestive Cancer Research
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    • v.11 no.2
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    • pp.85-92
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    • 2023
  • Colorectal cancer (CRC) is one of the most prevalent cancers and is the leading cause of cancer-related mortality worldwide. Based on the current screening guidelines by the American Cancer Society and Korean multi-society expert committee, CRC screening is recommended in asymptomatic adults starting at the age of 45 years. Fecal immunochemical test-based screening programs reduce the development of CRC and related mortality in the general population. However, this most popular CRC screening strategy demonstrates a crucial limitation due to modest diagnostic accuracy. Colonoscopy may be considered as an alternative primary method for CRC screening; however, its implementation can still be challenging due to concerns regarding invasiveness, low adherence, cost-effectiveness, and quality assurance. To overcome the limitations of current screening tests, innovative noninvasive tests for CRC screening have been developed with advances in molecular biology, genetics, epigenetics, and microbiomics for detecting CRC, which may enhance the approach to CRC screening and diagnosis in clinical practice in the near future. This review explores the emerging screening methods and discusses their potential for integration into current practice.

Radioiodine internal dose coefficients specific for Koreans

  • Tae-Eun Kwon;Yoonsun Chung;Choonsik Lee
    • Nuclear Engineering and Technology
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    • v.56 no.7
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    • pp.2732-2739
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    • 2024
  • This study developed internal dose coefficients for radioiodine, tailored to the Korean population, by incorporating the Korean biokinetic model along with the Korean S values. The observed differences in dose coefficients for Koreans compared to the International Commission on Radiological Protection (ICRP) reference values noticeably varied depending on physical half-lives of iodine isotopes. For longer-lived isotopes such as I-125 and I-129, significant differences in thyroid dose coefficients were observed, with ratios (Korean/ICRP) from 0.30 to 0.55, indicating that actual doses for Koreans can be considerably lower than those evaluated based on the ICRP data. However, for short-lived iodine isotopes, such as I-131, the thyroid dose coefficients were comparable to the ICRP reference values (ratio = 0.95-0.98). These comparable dose coefficients resulted from the lower thyroidal iodine uptake in the Korean model being almost entirely offset by the higher thyroid self-absorption S values in the Korean phantoms. Additionally, this study delves into the substantial differences in absorbed dose coefficients for non-thyroidal regions and effective dose coefficients, which arose not only from physiological/anatomical variability but also technical differences in phantom design. The use of Korean-specific dose coefficients is advisable particularly in scenarios predicting elevated doses, yielding a more precise and clinically relevant dose assessment.

P53 Polymorphism at Codon 72 is Associated with Keratocystic Odontogenic Tumors in the Thai Population

  • Yanatatsaneejit, Pattamawadee;Boonsrang, Ajaree;Mutirangura, Apiwat;Patel, Vyomesh;Kitkumthorn, Nakarin
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.5
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    • pp.1997-2001
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    • 2015
  • Objective: To clarify the association between the p53 polymorphism at codon 72 and susceptibility to the sporadic keratocystic odontogenic tumor (KCOT). Design: One hundred KCOTs and 160 match-group healthy controls were genotyped to ascertain the frequency of the p53 codon 72 polymorphism using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), confirmed by direct sequencing. Results: The frequencies of the Pro/Pro, Arg/Pro, and Arg/Arg genotypes were 23.8%, 49.4%, and 26.9%, respectively, in the controls, while the KCOT cohort demonstrated 43.0%, 39.0%, and 18.0%, respectively. Further analysis suggested that p53 Pro could be a KCOT-susceptible allele (OR (95%CI)=1.77 (1.22 to 2.59), p=0.0024), with a sex-adjusted OR (95%CI) of 1.71 (1.17-2.50), p=0.0046. Moreover, the results indicated that p53 codon 72 Pro homozygous was associated with a two-fold risk of developing KCOT (adjusted OR (95%CI) =2.17(1.23-3.84), p=0.0062). Conclusions: The C/C genotype of P53 gene codon 72 increases the risk of developing sporadic KCOT and may be a useful tool for screening and diagnostic purposes.