• Title/Summary/Keyword: Homozygosity

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A Study on Genetic Nature of Korean Local Corn Lines (한국 재래종 옥수수의 유전적 특성)

  • ;Bong-Ho Chae
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.28 no.4
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    • pp.473-480
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    • 1983
  • To obtain basic information on the Korean local com lines a total of 57 lines were selected from 1,000 Korean local collection at Chungnam National University, and classified by principal component analysis, and genetic nature was investigated. There were a great variation in mean values of plant characters of the lines. The mean values of plant characters except for density of kernels varied with types of crossing. All characters except for tasselling dates were reduced in magnitude when selfed, while those characters were increased when topcrossed. The inbreeding depression varied with plant characters and lines. The characters such as yield, kernel weight per ear, ear weight and plant height showed great degree of inbreeding depression. Group I showed high inbreeding depression in such characters as 100 kernel weight, leaf number, plant height and days to tasselling, while group II showed high inbreeding depression in other plant characters. Heterosis of plant characters varied also with lines. The ear weight, kernel weight per ear, yield, 100 kernel weight, and plant height were some of the plant characters showing high heterosis. Group II showed high values of heterosis in such characters as ear length, ear diameter, ear weight, kernel weight per ear, 100 kernel weight and leaf length, while group I was high in heterosis in other plant characters. The degree of homozygosity was highest in ear weight (79.1%) and lowest in ear number per plant (-2.1%). Group II showed higher degree of homozygosity than group I. Correlation coefficients between characters of sibbed and topcrossed lines were positive for all characters. Highly significant correlation coefficients between sibbed and topcrossed lines were obtained especially for characters such as ear number per plant, plant height, leaf length and yield per plot.

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Identification of a Novel Rb-regulated Gene Associated with the Cell Cycle

  • Sung, Young Hoon;Kim, Hye Jin;Lee, Han-Woong
    • Molecules and Cells
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    • v.24 no.3
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    • pp.409-415
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    • 2007
  • The retinoblastoma (Rb) gene is one of the most important genes in cell cycle regulation and tumorigenesis. Homozygosity for a germ-line Rb mutation results in embryonic lethality and evokes developmental defects associated with inappropriate S-phase entry and high levels of apoptosis. Although Rb has been extensively studied, more target genes need to be identified and characterized to unravel the precise mechanism of Rb function. In order to identify Rb-regulated genes, we analyzed the gene expression profile of Rb-deficient mouse embryo fibroblasts (MEFs), and identified an unknown gene, RbEST47, that is transcriptionally upregulated in Rb-deficient MEFs. This gene is conserved from fruitfly to human. It is expressed in brain, lung, kidney, and testis, and is located on mouse chromosome 2. This region is syntenic to human chromosome 9q34.3, which frequently exhibits loss of heterozygosity in neoplastic diseases. RbEST47 was considerably down-regulated in immortalized cells, and showed cell cycle-dependent expression, suggesting important roles in S and/or G2.

Genetic Diversity of Ascaris in China Assessed Using Simple Sequence Repeat Markers

  • Zhou, Chunhua;Jian, Shaoqing;Peng, Weidong;Li, Min
    • Parasites, Hosts and Diseases
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    • v.56 no.2
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    • pp.175-181
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    • 2018
  • The giant roundworm Ascaris infects pigs and people worldwide and causes serious diseases. The taxonomic relationship between Ascaris suum and Ascaris lumbricoides is still unclear. The purpose of the present study was to investigate the genetic diversity and population genetic structure of 258 Ascaris specimens from humans and pigs from 6 sympatric regions in Ascaris-endemic regions of China using existing simple sequence repeat data. The microsatellite markers showed a high level of allelic richness and genetic diversity in the samples. Each of the populations demonstrated excess homozygosity (Ho0). According to a genetic differentiation index (Fst=0.0593), there was a high-level of gene flow in the Ascaris populations. A hierarchical analysis on molecular variance revealed remarkably high levels of variation within the populations. Moreover, a population structure analysis indicated that Ascaris populations fell into 3 main genetic clusters, interpreted as A. suum, A. lumbricoides, and a hybrid of the species. We speculated that humans can be infected with A. lumbricoides, A. suum, and the hybrid, but pigs were mainly infected with A. suum. This study provided new information on the genetic diversity and population structure of Ascaris from human and pigs in China, which can be used for designing Ascaris control strategies. It can also be beneficial to understand the introgression of host affiliation.

DNA Polymorphism Analysis of the HLA-DRB1 Gene Using Polymerase Chain Reaction-Sequence Specific Primer (PCR-SSP) among Korean Subjects

  • Lee, Kyung-Ok;Park, Taek-Kyu;Park, Young-Suk;Oh, Moon-Ju;Kim, Yoon-Jung
    • BMB Reports
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    • v.29 no.1
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    • pp.45-51
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    • 1996
  • Most expressed HLA loci exhibit a remarkable degree of allelic polymorphism, which derives from sequence differences predominantly localized to discrete hypervariable regions of the amino-terminal domain of the molecule. In this study, the HLA-DRB1 genotypes were determined in eighteen control cell lines and 112 unrelated Koreans using the PCR-SSP (Polymerase Chain Reaction-Sequence Specific Primer) technique. 29 specific primer pairs in assigning the DRB1 gene were used. The results of control cells correlated well with the data which was previously reported. The heterozygosity and homozygosity of the DRB1 gene were 0.786 and 0.214, respectively. In a total of 41 different DRB1 alleles and 83 genotypes, the most frequent allele and genotype were DRB1*04 and DRB1*0901/1501, respectively. This study shows that the PCR-SSP technique is relatively simple, fast and a practical tool for the determination of the HLA-DRBI genotypes. Moreover, these results-allele and genotype frequency and heterozygosity of the HLA DRB1 gene-could be useful for database study before being applied to individual identification and transplantation immunity.

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GSTM1 and GSTT1 Allele Frequencies among Various Indian and non-Indian Ethnic Groups

  • Senthilkumar, K.P.;Thirumurugan, R.
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.12
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    • pp.6263-6267
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    • 2012
  • Background: Glutathione-S-transferase (GST) is an important phase II xenobiotic compound metabolizing enzyme family, involved in tolerance to a particular drug or susceptibility to a diseasec. This study focused the GSTM1 and T1 null allele frequency in the Gujarat population with a comparison across other Inter- and Intra-Indian ethnic groups to predict variation in the possible susceptible status. Methods: DNA was isolated by a salting out method and GSTM1 and T1 homozygous null genotypes were detected by multiplex polymerase chain reaction in 504 unrelated individuals. The genotype distribution of null alleles was compared with Indian and non Indian ethnics reported earlier in the literature using Fisher's test. Results: The frequencies of the homozygous null genotypes of GSTM1 and GSTT1 were 20% (95%CI 16.7-23.9) and 35.5% (95%CI 31.4-39.9) respectively. GSTM1 null frequency did not deviate from most other Indian ethnic groups but differed from the majority of those of non Indian ethnicity studied. The frequency of homozygous null type of GSTT1 was significantly higher and deviated from all Indian groups and a few of non Indian ethnicity. Conclusions: Gujarat ethnicity, possibly the most susceptible for GSTT1 dependent drug disposition and diseases regarding effects of pollution. Further, the results have implications for GSTT1 dependent drugs used for treatment, a serious problem which needs to be solved by physicians and clinical researchers.

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.

Isolation of Gamma-Induced Rice Mutants with Increased Tolerance to Salt by Anther Culture

  • Lee, In-Sok;Kim, Dong-Sub;Hyun, Do-Yoon;Lee, Sang-Jae;Song, Hi-Sup;Lim, Yong-Pyo;Lee, Young-Il
    • Journal of Plant Biotechnology
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    • v.5 no.1
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    • pp.51-57
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    • 2003
  • Doubled haploids have long been recognized as a valuable tool in plant breeding since it not only offers the quickest method of advancing heterozygous breeding lines to homozygosity, but also increased the selection efficiency over conventional procedures due to better discrimination between genotypes within any one generation. Salt tolerant mutants were obtained in rice the variety, 'Hawsungbyeo', through in vitro mutagenesis of in vitro cultured anther-derived calli. Various doses (30, 50, 70 and 90 Gy) of gamma ray were applied to investigate the effect of radiation on callus formation on medium containing 1% NaCl, green plant regeneration, frequency of selected doubled haploid mutants and of the salt tolerant screen. It was demonstrated that the dose of 30 and 50 Gy gamma rays had significant effects on callus formation, regeneration and selection of salt tolerance. No tolerant lines were obtained from non-mutagenized cultures. From gamma ray irradiated cultures, five tolerant lines ($M_2$generation) at germination stage and 13 tolerant lines ($M_3$genoration) at seedling stage were obtained. The frequency of salt tolerant mutants indicates that anther culture applied in connection with gamma rays is an effective way to improve salt tolerance.

Beagle dogs parentage testing by using 22 ISAG microsatellite markers

  • Ji, Hye-jung;Kim, Eun-hee;Lee, Kyoung-kap;Kang, Tae-young;Lee, Joo-myoung;Shin, Hyoung-doo;Kim, Lyoung-hyo;Yun, Young-min
    • Korean Journal of Veterinary Research
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    • v.47 no.4
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    • pp.457-460
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    • 2007
  • The objective of the study was to establish routine parentage testing system in Beagle dogs using 22 ISAG (International Society for Animal Genetics) canine microsatellite markers (2005). Blood collections were obtained from a mother dog, 4 candidate father dogs and 3 offspring (n = 8). Genomic DNA samples were extracted from 8 Beagle dogs blood for PCR analysis. PCR products for the allele were analyzed by ABI 3130 DNA Sequencer and GeneScan (Ver 3.0) analysis and Genotyper (Ver. 2.1) software. The genetic relationship of mother and 3 offspring as well as one father dog among 4 candidate father dogs was confirmed by microsatellite allele analysis. The results of locus for amelogenin, which was designed for sexing, were matching with real gender among 8 Beagle dogs (female; 217/217 homozygosity, male; 179/217 heterozygosity). Twenty two ISAG microsatellite markers are useful the parentage test of Beagle dogs. In addition, amelogenin is an applicable marker to detecting real sex in dogs.

A novel mutation in GJC2 associated with hypomyelinating leukodystrophy type 2 disorder

  • Komachali, Sajad Rafiee;Sheikholeslami, Mozhgan;Salehi, Mansoor
    • Genomics & Informatics
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    • v.20 no.2
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    • pp.24.1-24.8
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    • 2022
  • Hypomyelinating leukodystrophy type 2 (HLD2), is an inherited genetic disease of the central nervous system caused by recessive mutations in the gap junction protein gamma 2 (GJC2/GJA12). HLD2 is characterized by nystagmus, developmental delay, motor impairments, ataxia, severe speech problem, and hypomyelination in the brain. The GJC2 sequence encodes connexin 47 protein (Cx47). Connexins are a group of membrane proteins that oligomerize to construct gap junctions protein. In the present study, a novel missense mutation gene c.760G>A (p.Val254Met) was identified in a patient with HLD2 by performing whole exome sequencing. Following the discovery of the new mutation in the proband, we used Sanger sequencing to analyze his affected sibling and parents. Sanger sequencing verified homozygosity of the mutation in the proband and his affected sibling. The autosomal recessive inheritance pattern was confirmed since Sanger sequencing revealed both healthy parents were heterozygous for the mutation. PolyPhen2, SIFT, PROVEAN, and CADD were used to evaluate the function prediction scores of detected mutations. Cx47 is essential for oligodendrocyte function, including adequate myelination and myelin maintenance in humans. Novel mutation p.Val254Met is located in the second extracellular domain of Cx47, both extracellular loops are highly conserved and probably induce intramolecular disulfide interactions. This novel mutation in the Cx47 gene causes oligodendrocyte dysfunction and HLD2 disorder.

Estimation of Genetic Variation in Holstein Young Bulls of Iran AI Station Using Molecular Markers

  • Rahimi, G.;Nejati-Javaremi, A.;Saneei, D.;Olek, K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.19 no.4
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    • pp.463-467
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    • 2006
  • Genetic profiles of Iranian Holstein young bulls at the national artificial insemination station were determined on the basis of individual genotypes at 13 ISAG's recommended microsatellites, the most useful markers of choice for parentage identification. In the present study a total of 119 individuals were genotyped at 13 microsatellite loci and for possible parent-offspring combinations. A high level of genetic variation was evident within the investigated individuals as assessed from various genetic diversity measures. The mean number of observed alleles per microsatellite marker was 9.15 and the number of effective alleles as usual was less than the observed values (4.03). The average observed and expected heterozygosity values were 0.612 and 0.898, respectively. The mean polymorphic information content (PIC) value (0.694) further reflected a high level of genetic variability. The average exclusion of probability (PE) of the 13 markers was 0.520, ranging from 0.389 to 0.788. The combined exclusion of probability was 0.999, when 13 microsatellite loci were used for analysis in the individual identification system. Inbreeding was calculated as the difference between observed and expected heterozygosity. Observed homozygosity was less than expected which reflects inbreeding of -3.7% indicating that there are genetic differences between bull-sires and bull-dams used to produce young bulls. The results obtained from this study demonstrate that the microsatellite DNA markers used in the present DNA typing are useful and sufficient for individual identification and parentage verification without accurate pedigree information.