• 제목/요약/키워드: virus variation

검색결과 124건 처리시간 0.024초

Genetic variation of BIV isolates characterized by PCR using degenerate primers

  • Kwon, Oh-Sik;Sninsky, John J.
    • Journal of Microbiology
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    • 제33권3호
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    • pp.252-259
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    • 1995
  • The PCR was employed to detect and characterize the bovine immunodeficiency-like virus (BIV), which is a newly recognized member of the I entivirinae of the retroviruses. Degenerate primers representing the conserved regions in the pol genes of the Lentivirinae, were used to detect proviral DNA obtained from the bovine embryonic spleen cell cultures infected with BIV. The PCR amplified DNA fragment was molecularly cloned and sequenced. The BIV DNA fragment contained a sequence identical to that reported by Garvey et al. (Garvey et al., 1990. Virology, 175, 391-409). With the degenerate primers, peripheral blood mononuclear cells (PBMCs) of sick cattle and cells cultured with BIV were tested to determine genetic variation of BIV pol conserved sequence. We found the sequence heterogeneity within cultures and most variations occurred at the third base of codons that would not lead to amino acid substitutions. Another change was GAG (Glu) to AAG (Lys) within the BIV isolates. Interestingly, the altered sequence is also found in other lentiviruses such as HIV-2, SIV mac, CAEV and EIAV.

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Insights into the Usage of Nucleobase Triplets and Codon Context Pattern in Five Influenza A Virus Subtypes

  • Deka, Himangshu;Chakraborty, Supriyo
    • Journal of Microbiology and Biotechnology
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    • 제26권11호
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    • pp.1972-1982
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    • 2016
  • Influenza A virus is a single-stranded RNA virus with a genome of negative polarity. Owing to the antigenic diversity and cross concrete shift, an immense number of novel strains have developed astronomically over the years. The present work deals with the codon utilization partialness among five different influenza A viruses isolated from human hosts. All the subtypes showed the homogeneous pattern of nucleotide utilization with a little variation in their utilization frequencies. A lower bias in codon utilization was observed in all the subtypes as reflected by higher magnitudes of an efficacious number of codons. Dinucleotide analysis showed very low CpG utilization and a high predilection of A/T-ending codons. The H5N1 subtype showed noticeable deviation from the rest. Codon pair context analysis showed remarkable depletion of NNC-GNN and NNT-ANN contexts. The findings alluded towards GC-compositional partialness playing a vital role, which is reflected in the consequential positive correlation between the GC contents at different codon positions. Untangling the codon utilization profile would significantly contribute to identifying novel drug targets that will pacify the search for antivirals against this virus.

Quantitative Trait Loci Affecting Rous Sarcoma Virus Induced Tumor Regression Trait in F2 Intercross Chickens

  • Uemoto, Y.;Saburi, J.;Sato, S.;Odawara, S.;Ohtake, T.;Yamamoto, R.;Miyata, T.;Suzuki, K.;Yamashita, H.;Irina, C.;Plastow, G.;Mitsuhashi, T.;Kobayashi, E.
    • Asian-Australasian Journal of Animal Sciences
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    • 제22권10호
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    • pp.1359-1365
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    • 2009
  • We performed a genome-wide linkage and quantitative trait locus (QTL) analysis to confirm the existence of QTL affecting Rous Sarcoma Virus (RSV) induced tumor regression, and to estimate their effects on phenotypic variance in an F2 resource population. The F2 population comprised 158 chickens obtained by crossing tumor regressive White Leghorn (WL) and tumor progressive Rhode Island Red (RIR) lines was measured for tumor formation after RSV inoculation. Forty-three tumor progressive and 28 tumor regressive chickens were then used for genome-wide linkage and QTL analysis using a total of 186 microsatellite markers. Microsatellite markers were mapped on 20 autosomal chromosomes. A significant QTL was detected with marker LEI0258 located within the MHC B region on chromosome 16. This QTL had the highest F ratio (9.8) and accounted for 20.1% of the phenotypic variation. Suggestive QTL were also detected on chromosomes 4, 7 and 10. The QTL on chromosome 4 were detected at the 1% chromosome-wide level explaining 17.5% of the phenotypic variation, and the QTLs on chromosome 7 and 10 were detected at the 5% chromosome-wide level and explained 11.1% and 10.5% of the phenotypic variation, respectively. These results indicate that the QTLs in the non-MHC regions play a significant role in RSV-induced tumor regression. The present study constitutes one of the first preliminary reports in domestic chickens for QTLs affecting RSV-induced tumor regression outside the MHC region.

Identification of Endogenous Genes for Normalizing Titer Variation of Citrus Tristeza Virus in Aphids at Different Post-acquisition Feeding Times

  • Wang, Hongsu;Chen, Qi;Liu, Luqin;Zhou, Yan;Wang, Huanhuan;Li, Zhongan;Liu, Jinxiang
    • The Plant Pathology Journal
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    • 제38권4호
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    • pp.287-295
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    • 2022
  • Citrus tristeza virus (CTV) is efficiently transmitted in a semi-persistent manner by the brown citrus aphid (Toxoptera citricida (Kirkaldy)). Currently, the most sensitive method for detecting plant viruses in insect vectors is reverse-transcription quantitative polymerase chain reaction (RT-qPCR). In this study, the elongation factor-1 alpha (EF-1α) gene and acidic p0 ribosomal protein (RPAP0) gene were confirmed to be suitable reference genes for RT-qPCR normalization in viruliferous T. citricida aphids using the geNorm, NormFinder, and BestKeeper tools. Then the relative CTV titer in aphids (T. citricida) at different post-acquisition feeding times on healthy plants was quantified by RT-qPCR using EF-1α and RPAP0 as reference genes. The relative CTV titer retained in the aphids gradually decreased with increasing feeding time. During the first 0.5 h of feeding time on healthy plants, the remaining CTV titer in aphids showed about 80% rapid loss for the highly transmissible isolate CT11A and 40% loss for the poorly transmissible isolate CTLJ. The relative CTV titer in aphids during more than 12 h post-acquisition times for CT11A was significantly lower than at the other feeding times, which is similar to the trend found for CTLJ. To our knowledge, this is the first report about the relative titer variation of CTV remaining in T. citricida at different post-acquisition feeding times on healthy plants.

한국에서 분리된 Ustilago maydis 바이러스의 유전자의 변이와 독소의 특이성 (Genomic Variation and Toxin Specificity of Ustilago maydis Virus Isolated in Korea)

  • Hee, Hwang-Seon;Yie, Se won
    • 미생물학회지
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    • 제31권3호
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    • pp.184-188
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    • 1993
  • Novel Ustilagomaydis strains, designated as SH1 to 14 containing new types of ds RNA segments, are identified from corn smut in Korea. Among 14 isolates, 7 isolates appear to posses virus particles and the other isolates may contain dsRNA as a plasmid form. The pattern of dsRNA is highly diverse form a typical P-type containing one or more of H, M, and L dsRNAs to the one containing one or move M dsRNAs. It is likely that the strains containing H dsRNA posses virus particles which were confirmed by sucrose density gradient followed with different range of specificity and the activity of the strain (SH14) is stronger than A4 toxin. The sensitivity of 14 isolates is also very diverse and two strains (SH10, SH11) appear tobe universal sensitve strains against 5 tested toxin samples.

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닭 전염성 기관지염 바이러스 한국분리주의 분자생물학적, 역학적 특성 (Molecular and Epidemiological Characteristics of Infectious Bronchitis Virus Isolated in Korea)

  • 송창선;이윤정
    • 한국가금학회지
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    • 제27권2호
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    • pp.91-98
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    • 2000
  • Phylogenetic tree constructed from the nucleotide sequences of the S1 gene showed that the 15 Korean strains of infectious bronchitis virus(IBV) examined were classified into 2 genetically distinct groups, except one respiratory strain, RB86, which was clustered with Massachusetts group. All the 5 respiratory strains belonged to Korean group I and the rest 9 nephropathogenic strains belonged to Korean group II according to the analysis, based on S1 gene sequences. Like previous classifications corresponded with the geographic origin, Korean stains were discriminated from geographically distinct reference strains of IBV. The nephropathogenic strains within Korean group IIsharing 96% homology were continuously isolated since 1990, and seemed to be genetically stable. Whereas the respiratory strains within Korean group Ⅰ sharing 88% homology were sporadically isolate since 1986m and seemed to be genetically unstable. Because we found putative accumulated point mutation as well as recombination events in Korean group Ⅰ, we discussed why genetic variations have often occurred in respiratory strains rather than nephropathognic strains.

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Calcium in Infectious Hematopoietic Necrosis Virus (IHNV) Infected Fish Cell Lines (Calcium in Infectious Hematopoietic Necrosis Virus (IHNV) Infected Fish Cell Lines)

  • 김남식;허강준;이찬희
    • Journal of Microbiology
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    • 제34권3호
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    • pp.263-263
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    • 1996
  • Infection of fish cells with IHNV resulted in gradual increase in cytosolic free $Ca^{2+}$ concentration $([Ca^{2+}]_i)$ in CHSE, gradual decrease in $[Ca^{2+}]_i$ in FHM, and no significant change in RTG cells. The degree of $[Ca^{2+}]_i$ increase or decrease was dependent on the amount of infectious virus, and these $[Ca^{2+}]_i$ variations were maximal at 16 hours after virus infection (p. i.) in both cell lines. When the fish cells were infected with inactivated IHNV, evident variation in $[Ca^{2+}]_i$ was not observed. Thus, infectivity of IHNV appears to correlate with changes in $[Ca^{2+}]_i$ in virus-infected cells. These IHNV-induced $[Ca^{2+}]_i$ changes were partially blocked by cycloheximide, but not affected by cordycepin. It seems to be that virus-induced $Ca^{2+}$ variations were more related with protein synthesis than RNA synthesis. Various $Ca^{2+}$ related drugs were used in search for the mechanisms of the $[Ca^{2+}]_i$, changes following IHNV infection of CHSE cells. Decreasing extracellular $Ca^{2+}$ concentration or blocking $Ca^{2+}$ influx from extracellular media inhibited the IHNV-induced increase in $[Ca^{2+}]_i$, in CHSE cells. Similar results were obtained with intracellular $Ca^{2+}$ blockers. Thus it is suggested that both the extracellular and the intracellular $Ca^{2+}$ sources are important in IHNV-induced $[Ca^{2+}]_i$ increase in CHSE cells.

A Single Variation in the Influenza A Virus Genomic RNA Shows a Different Secondary Structure

  • Bae, Sung-Hun;Lee, Mi-Kyong;Park, Byong-Seok
    • 한국생물물리학회:학술대회논문집
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    • 한국생물물리학회 1999년도 학술발표회 진행표 및 논문초록
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    • pp.37-37
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    • 1999
  • The influenza A viruses which are the most severe and common among the influenza viruses have 8 segmented RNA genomes Each RNA segment has highly conserved 3' and 5' terminal sequence except a single U\longrightarrowC variation especially in the 4 position of the 3' terminal of the 3 segments encoding own RNA polymerase.(omitted)

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바이러스 외피단백질 유전자로 형질전환된 연초 식물체의 TMV 저항성 발현 및 유전자 안정성

  • 박성원;이기원;이청호;이영기;강신웅;최순용
    • 한국연초학회지
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    • 제21권1호
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    • pp.77-81
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    • 1999
  • Tobacco plants(Nicotiana tabacum cv. NC82) transformed with TMV CP cDNA were self-fertilized until 8th generation (R$_{8}$), and the transgenic plants from 6th to 8th generation were analized for their resistance to tobacco mosaic virus(TMV) and stability of the gene expression. The 6th generation of the plants(R$_{6}$) showed high resistance(81-91 %) to TMV at eight weeks after artificial inoculation with the virus. The transgenic cell line 601 was the most prominant in the expression of resistance. 98 % of the plants showed no symptom without any agronomic phynotepe variation when they were inoculated with the virus in a experimental field. However, 2% of the plants were revealed as delay type of symptom with mild mosaic on a few leaves. The viral resistance in greenhouse tests of the 7th generation (R$_{7}$) was 54-64%, and the number of delay type plants were increased than that of 6th generation plants. In the 8th generation, 81 % of the plants was complete resistant to the virus. The TMV CP cDNA of the transgenic plants of each generation was also confirmed by genomic PCR, and there was no systemic viral multiplication in the resistant plants. It suggests that the viral resistance and gene expression of the transgenic plants might be stable through the generations.ons.s.

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Knowledge, Attitudes and Beliefs about Cervical Cancer and Human Papilloma Virus Vaccination with Related Factors in Turkish University Students

  • Yilmazel, Gulay;Duman, Nuriye Buyukkayaci
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권8호
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    • pp.3699-3704
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    • 2014
  • Background: This study aimed to determine knowledge, attitudes and believes about cervical cancer and human papilloma virus (HPV) vaccination with related factors in Turkish university students. Materials and Methods: This descriptive and cross sectional study was conducted between June-July 2013 in Hitit University located in Corum, a rural area to the East of Ankara. The population consisted of 550 university students who were training in first and last year from Faculties of Economics, Theology and Health. We reached 463 volunteer students without selection. The study of data was collected with a 44 item questionaire covering socio-demographic features, knowledge, attitudes and beliefs about cervical cancer, HPV and vaccination. Also for this study ethic committee report was taken from Bozok University. Data were evaluated with the SPSS 17.0 programme using the Ki kare test with P<0.05 accepted as statistically significant. Results: It was seen that there was a statistically significant variation between classrooms and departments of students with knowledge about cervical cancer and human papilloma virus and vaccine (p<0.001; p<0.01; p<0.05). Also we found low attitudes to thinking about taking HPV vaccination of girls and their children in the future. Conclusions: In light of the study findings; it was concluded that knowledge levels, beliefs and attitudes of the university students about cervical cancer, HPV infection and HPV vaccination were low.