• Molecules and Cells
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• v.24 no.1
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• pp.148-151
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• 2007

Porcine endogenous retroviruses (PERVs) in the pig genome represent a potential risk of infection in pig-to-human transplantation and are transmitted vertically. The solitary long terminal repeat (LTR) elements of the PERVs affect the replication properties of the individual viruses via their repeat sequences and by encoding a set of specific transcription factors. We examined the promoter activities of solitary LTR elements belonging to the PERV-A and -B families of the Korean domestic pig (KDP) using luciferase reporters. Three of the LTR structures (of PERV-A5-KDP, PERV-A7-KDP, PERV-A8-KDP) had different promoter activities in human HCT116 cells and monkey Cos7 cells, and potential negatively and positively acting regions affecting transcription were identified by deletion analysis. These data suggest that specific sequences in the U3 region of a given LTR element can affect the activities of promoter or enhancer elements in the PERV.

• Molecules and Cells
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• v.28 no.2
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• pp.87-92
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• 2009

Human SIRT3 gene contains an intronic VNTR enhancer. A T > C transition occurring in the second repeat of each VNTR allele implies the presence/absence of a putative GATA binding motif. A partially overlapping AP-1 site, not affected by the transition, was also identified. Aims of the present study were: 1) to verify if GATA and AP-1 sites could bind GATA2 and c-Jun/c-Fos factors, respectively; 2) to investigate whether such sites modulate the enhancer activity of the SIRT3-VNTR alleles. DAPA assay proved that GATA2 and c-Jun/c-Fos factors are able to bind the corresponding sites. Moreover, co-transfection experiments showed that the over-expression of GATA2 and c-Jun/c-Fos factors boosts the VNTR enhancer activity in an allelic-specific way. Furthermore, we established that GATA2 and c-Jun/c-Fos act additively in modulating the SIRT3-VNTR enhancer function. Therefore, GATA2 and AP-1 are functional sites and the T > C transition of the second VNTR repeat affects their activity.

• Animal cells and systems
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• v.3 no.4
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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.

• Biomedical Science Letters
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• v.17 no.2
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• pp.151-155
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• 2011

Short tandem repeats (STRs) loci are the genetic markers used for forensic human identity test. With multiplex polymerase chain reaction (PCR) assays, STRs are examined and measured PCR product length relative to sequenced allelic ladders. In the repeat region and the flanking region of the commonly-used STR may have DNA sequence variation. A mismatch due to sequence variation in the DNA template may cause allele drop-out (i.e., a "null" or "silent" allele) when it falls within PCR primer binding sites. The STR markers were co-amplified in a single reaction by using commercial PowerPlex$^{(R)}$ 16 system and AmpFlSTR$^{(R)}$ Identifiler$^{(R)}$ PCR amplification kits. Separation of the PCR products and fluorescence detection were performed by ABI PRISM$^{(R)}$ 3100 Genetic Analyzer with capillary electrophoresis. The GeneMapper$^{TM}$ ID software were used for size calling and analysis of STR profiles. Here, this study described a forensic human identity test in which allelic drop-out occurred in the STR system D18S51. During the course of human identity test, two samples with a homozygous (16, 16 and 21, 21) genotype at D18S51 locus were discovered using the PowerPlex$^{(R)}$ 16 system. The loss of alleles was confirmed when the samples were amplified using AmpFlSTR$^{(R)}$ Identifiler$^{(R)}$ PCR amplification kit and resulted in a heterozygous (16, 20 and 20, 21) genotype at this locus each other. This discrepancy results suggest that appropriate measures should be taken for database comparisons and that allele should be further investigated by sequence analysis and be reported to the forensic community.

• Journal of The Korean Association For Science Education
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• v.22 no.3
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• pp.455-465
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• 2002

This study investigates students' preconceptions about measurement theory; repeating measurements. how to handle repeat measurements, measurement errors, and uncertainty. Thirty students in seventh grade participated in this study. Students' conceptions were elicited using observation and interview notes. Half of the students measured only two times. and none of them more than five times. After repeating measurements, seventy seven percent of them selected result according to their feelings, while only thirteen percent of them calculated the mean. Sixty percent of them regarded the main cause of measurement errors as their mistakes, not as the problems of environment or measuring instrument. Most students thought the main reason of various results by different persons or time period as human. Forty percent of them denied the uncertainty of measurement, while thirty three agreed, and most students thought the reason of uncertainty was due to human imperfection. This study showed more than half of the students did not know how to handle repeat measurements, and they regarded the cause of measurement errors as their mistakes. In addition, they thought the main reason of various measuring results and uncertainty as human.

• Journal of KSNVE
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• v.10 no.1
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• pp.160-167
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• 2000

This paper addresses issues encountered in using the ISO and national standard codes to assess the hazards of whole-body vibration and repeat shocks. Their assessment methods are given in ISO 2631-1 (1974, 1985, 1997) and BS 6841 (1987) that are now available to us. Two standard codes can yield unfortunately different assessment results even for a single measured vibration signal. Possible reasons for such different results are pointed out and, furthermore, related questions that should be re-examined in the future are raised in this paper.

• IMMUNE NETWORK
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• v.2 no.3
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• pp.150-157
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• 2002

Background: Although Tat plays a role as a potent transactivator in the viral gene expression from the Human Immunodeficiency Virus type 1 long terminal repeat (HIV-1 LTR), it does not function efficiently in rodent cells implying the absence of a human specific factor essential for Tat-medicated transactivation in rodent cells. In previous experiments, we demonstrated that one of chimeric forms of TAR (transacting responsive element) of HIV-1 LTR compensated the restriction in rodent cells. Methods: To characterize the nature of the compensation, we tested the effects of several upstream binding factors of HIV-1 LTR by simple substitution, and also examined the role of the configuration of the upstream binding factor(s) indirectly by constructing spacing mutants that contained insertions between Sp1 and TATA box on Tat-mediated transactivation. Results: Human Sp1 had no effect whereas its associated factors displayed differential effects in human and rodent cells. In addition, none of the spacing mutants tested overcame the restriction in rodent cells. Rather, when the secondary structure of the chimeric HIV-1 TAR construct was destroyed, the compensation in rodent cells was disappeared. Interestingly, the proper interaction between Sp1 and TATA box binding proteins, which is essential for Tat-dependent transcription, was dispensable in rodent cells. Conclusion: This result suggests that the human-specific Tat cofactor acts to allow Tat to interact effectively in a ribonucleoprotein complex that includes Tat, cellular factors, and TAR RNA, rather than be associated with the HIV-1 LTR upstream DNA binding factors.

• Journal of Life Science
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• v.11 no.5
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• pp.400-404
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• 2001

A new human endogenous retroviral family (HERV-S) has recently been identified from human X chromosome. It is 6.7 kb in length and has a typical retroviral structure with LTR-gag-pol-env-LTR. Using the PCR and sequencing approach, we investigated LTR elements of the HERV-S family from a human genomic DNA. Four LTR elements (HSL-1, HSL-5, HSL-10, HSL-11) were identified and have a high degree of sequence similarity(96-99%) with that of the HERV-S. Phylogenetic analysis from the HERV-S family indicated that the LTR elements were mainly divided into 2- groups through evolutionary divergence in the primate evolution. Further investigation of the HERV-S LTR elements in primates may cast light on the integration timing into the primate genome and understanding of human evolution.

• Molecules and Cells
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• v.22 no.3
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• pp.360-363
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• 2006

Human endogenous retroviruses (HERVs) contribute to various kinds of genomic instability via rearrangement and retrotransposition events. In the present study the formation of a new human-specific solo-LTR belonging to the HERV-H family (AP001667; chromosome 21q21) was detected by a comparative analysis of human chromosome 21 and chimpanzee chromosome 22. The solo-LTR was formed as a result of an equal homologous recombination excision event. Several evolutionary processes have occurred at this locus during primate evolution, indicating that mammalian-wide interspersed repeat (MIR) and full-length HERV-H elements integrated into hominoid genomes after the divergence of Old World monkeys and hominoids, and that the solo-LTR element was created by recombination excision of the HERV-H only in the human genome.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.11a
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• pp.168-168
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• 2005