• 제목/요약/키워드: direct sequencing

검색결과 307건 처리시간 0.026초

Necrotrophic Fungus Pyrenophora tritici-repentis Triggers Expression of Multiple Resistance Components in Resistant and Susceptible Wheat Cultivars

  • Andersen, Ethan J.;Nepal, Madhav P.;Ali, Shaukat
    • The Plant Pathology Journal
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    • 제37권2호
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    • pp.99-114
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    • 2021
  • Tan spot of wheat, caused by Pyrenophora tritici-repentis (Ptr), results in a yield loss through chlorosis and necrosis of healthy leaf tissue. The major objective of this study was to compare gene expression in resistant and susceptible wheat cultivars after infection with Ptr ToxA-producing race 2 and direct infiltration with Ptr ToxA proteins. Greenhouse experiments included exposure of the wheat cultivars to pathogen inoculum or direct infiltration of leaf tissue with Ptr-ToxA protein isolate. Samples from the experiments were subjected to RNA sequencing. Results showed that ToxA RNA sequences were first detected in samples collected eight hours after treatments indicating that upon Ptr contact with wheat tissue, Ptr started expressing ToxA. The resistant wheat cultivar, in response to Ptr inoculum, expressed genes associated with plant resistance responses that were not expressed in the susceptible cultivar; genes of interest included five chitinases, eight transporters, five pathogen-detecting receptors, and multiple classes of signaling factors. Resistant and susceptible wheat cultivars therefore differed in their response in the expression of genes that encode chitinases, transporters, wall-associated kinases, permeases, and wound-induced proteins, among others. Plants exposed to Ptr inoculum expressed transcription factors, kinases, receptors, and peroxidases, which are not expressed as highly in the control samples or samples infiltrated with ToxA. Several of the differentially expressed genes between cultivars were found in the Ptr resistance QTLs on chromosomes 1A, 2D, 3B, and 5A. Future studies should elucidate the specific roles these genes play in the wheat response to Ptr.

Analysis of Expressed Sequence Tags of the Firefly, Pyrocoelia rufa

  • Lee, Kwang-Sik;Bae, Jin-Sik;Goo, Tae-Won;Kim, Sam-Eun;Kim, Jong-Gill;Sohn, Hung-Dae;Jin, Byung-Rae
    • International Journal of Industrial Entomology and Biomaterials
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    • 제1권2호
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    • pp.165-169
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    • 2000
  • We have constructed cDNA library from the larvae whole body of the firefly, Pyrocoelia rufa. Single direct partial sequencing of anonymous cDNA clones was performed to obtain genetic information on the firefly, P. rufa, of which genetic information is currently not available. This expressed sequence tags (EST) analysis of the 54 clones (54%) showed significant homology to the known genes registered in GenBank. Of these clones, twenty-four were related to the known insect genes, but these clones were not matched to previously identified firefly genes. Putative functional categories of these clones showed that the next abundant genes were associated with energy metabolism.

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Functional Metagenomics using Stable Isotope Probing: a Review

  • Vo, Nguyen Xuan Que;Kang, Ho-Jeong;Park, Joon-Hong
    • Environmental Engineering Research
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    • 제12권5호
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    • pp.231-237
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    • 2007
  • The microbial eco-physiology has been the vital key of microbial ecological research. Unfortunately, available methods for direct identity of microorganisms and for the investigation of their activity in complicated community dynamics are limited. In this study, metagenomics was considered as a promising functional genomics tool for improving our understanding of microbial eco-physiology. Its potential applications and challenges were also reviewed. Because of tremendous diversity in microbial populations in environment, sequence analysis for whole metagenomic libraries from environmental samples seems to be unrealistic to most of environmental engineering researchers. When a target function is of interest, however, sequence analysis for whole metagenomic libraries would not be necessary. For this case, nucleic acids of active populations of interest can be selectively gained using another cutting-edge functional genomic tool, SIP (stable isotope probing) technique. If functional genomes isolated by SIP can be transferred into metagenomic library, sequence analysis for such selected functional genomes would be feasible because the reduced size of clone library may become adequate for sequencing analysis. Herein, integration of metagenomics with SIP was suggested as a novel functional genomics approach to study microbial eco-physiology in environment.

Insertional Transposon Mutagenesis of Xanthomonas oryzae pv. oryzae KXO85 by Electroporation

  • Lee, Byoung-Moo;Park, Young-Jin;Park, Dong-Suk;Kang, Hee-Wan;Lee, Gil-Bok;Hahn, Jang-Ho
    • The Plant Pathology Journal
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    • 제20권3호
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    • pp.229-233
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    • 2004
  • The bacterial leaf blight, which is caused by Xantho-monas oryzae pv. oryzae, is the most damaging and intractable disease of rice. To identify the genes involved in the virulence mechanism of transposon TnS complex, which possesses a linearized transposon and transposase, was successfully introduced into X. oryzae pv. oryzae by electroporation. The transposon mutants were selected and confirm the presence of transposition in X. oryzae pv. oryzae by the PCR amplification of transposon fragments and the Southern hybridization using these mutants. Furthermore, transposon insertion sites in the mutant bacterial chromosome were deter-mined by direct genomic DNA sequencing using transposon-specific primers with ABI 3100 Genetic Analyzer. Efficiency of transposition was influenced mostly by the competence status of X. oryzae pv. oryzae cells and the conditions of electroporation. These results indicated that the insertion mutagenesis strategy could be applied to define function of uncharacterized genes in X. oryzae pv. oryzae.

BRAF Mutations in Iranian Patients with Papillary Thyroid Carcinoma

  • Ranjbari, Nastran;Almasi, Sara;Mohammadi-asl, Javad;Rahim, Fakher
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권4호
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    • pp.2521-2523
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    • 2013
  • Background: Papillary thyroid cancer or papillary thyroid carcinoma (PTC) is the most common thyroid cancer. The fact that it occasionally occurs in women aged 30-40 years old suggests that genetic alterations are involved its genesis. Recently, activator mutations in BRAF gene have been relatively frequently discovered. Materials and Methods: In this study, we tested 63 DNA samples from PTC patients to identify the V600E mutation frequency in the Ahvaz population. DNA was isolated from formalin fixed paraffin-embedded (FFPE) PTC tumor tissues. Genotyping was performed by PCR-RFLP and confirmed by direct DNA sequencing of a subset of PCR products. PCR-RFLP data were reported as genotype frequencies and percentages. Results: Forty nine out of 63 patients (77.8%) had a mutated heterozygote form while 14 (22.2%) showed normal genotype but none demonstrated a mutant homozygote genotype. The frequency of V600E mutation was significantly high in PTC patients. Conclusions: These findings support involvement of V600E mutations in PTC occurrence in Iran. Assessment of correlations between BRAF V600E mutations and papillary thyroid cancer progression needs to be performed.

맥주오염미생물의 동정과 specific PCR primer의한 신속한 검출 방법 (Characterization of beer-spoilage microorganism and its rapid detection by specific PCR primer)

  • 이택인;최신건
    • 산업기술연구
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    • 제28권A호
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    • pp.141-147
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    • 2008
  • Several contaminated bacteria such as Lactobacillus brevis and Pediococcus damnosus in beer production cause beer spoilage by producing off flavours and turbidity. Detection of these organisms is complicated by the strict anaerobic conditions and lengthy incubation times required for their cultivation, consequently there is a need for more rapid detection methods. Recently, two contaminated strains were isolated from vessel of beer production and identified as Lactobacillus species by API kit identificaton as well as 16S-23S ITS sequencing analyses. Two isolated strains were named as Lactobacillus sp. HLA1 and Lactobacillus HLB2, respectively. A polymerase chain reaction (PCR) method was developed for the rapid and specific detection of Lactobacillus sp.. Two sets of primer pairs (HLA1-F/HLA1-R and HLB2-F/HLB2-R) were designed for the amplification of a 1576 base pair (bp) fragment of the HLA1 16S-23S rRNA gene and 1888 bp fragement of the HLB2 16S-23S rRNA. Amplified PCR products were highly specific to detect corresponding bacteria when other contaminated strains were used as PCR templates. However, detection of both strains were limited when $100{\mu}{\ell}$ of cultured samples were mixed with $100m{\ell}$ of beer sample in arbitrary manner. The sensitivity of the assay still needs to be improved for direct detection of the small amounts of bacteria present in beer.

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Absence of P53 Gene Mutations in Exons 5 - 7 Among Breast Cancer Patients of Bengalee Hindu Caste Females, West Bengal, India

  • Roy, Abhishikta Ghosh;Sarkar, B.N.;Roy, Rakesh;Rao, V.R.;Bandyopadhyay, A.R.
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권9호
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    • pp.4477-4479
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    • 2012
  • Background: The high incidence and relatively good prognosis of breast cancer has made it the most prevalent cancer in the world today. A large number of distinct mutations and polymorphisms in the p53 gene have been reported worldwide, but there is no report regarding the role of this inherited susceptibility gene in breast cancer risk among the Bengalee Hindu Caste females of West Bengal, India. Aim of the Study: We investigated the distribution and the nature of p53 gene mutations and polymorphisms in exons 5-7 in a cohort of 110 Bengalee Hindu breast cancer patients and 127 age, sex and caste matched controls by direct sequencing. Results: We did not observe any mutations and polymorphisms in our studied individuals. Conclusion: We therefore conclude that mutations in exons 5-7 of p53 gene are rare causes of breast cancer among Bengalee Hindu caste females, and therefore of little help for genetic counseling and diagnostic purposes.

Cloning, Sequencing and Characterization of Mitochondrial Control Region of the Domestic Silkwom, Bombyx mori

  • Lee, Jin-Sung;Kim, Ki-Hwan;Hoe, Hyang-Sook;Park, Jae-Heung;Kang, Seok-Woo;Lee, Sang-Han;Hwang, Jae-Sam
    • International Journal of Industrial Entomology and Biomaterials
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    • 제2권1호
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    • pp.87-89
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    • 2001
  • The nucleotide sequence of the domestic silkworm (Bombyx mori) mitochondrial (mt) control region and its flanking genes was determined from PCR clones. The control region of the silkworm mt genome was located between the small ribosomal RNA gene and transfer RN $A^{Met}$. This 499 bp control region hale 95.4% A+T content. Extensive comparative analysis studies performed with similar control region of other insect genomes could not reveal a highly conserved region containing conserved motifs of animal mito-chondrial genome. The remarkable feature that found in this control region was the presence of tandem motifs containing nine repetitive sequences. The potential usefulness of this motif sequences for Bombyx species or their taxonomically related species is enhanced by its unique localization in the maternally inheritance mitochondrial molecule.e.

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Painless Jaundice Caused by Clonorchis sinensis Infection: A Case Report

  • Hao, Yuhua;Bao, Wanguo;Jin, Meishan;Li, Yuxiang;Wang, Feng
    • Parasites, Hosts and Diseases
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    • 제54권3호
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    • pp.323-327
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    • 2016
  • A man with only yellowing of the skin and eye sclera was diagnosed with clonorchiasis, which rarely manifested jaundice as the initial symptom. However, because of a lack of evidence for a diagnostic gold standard, the time until definitive diagnosis was more than a week. The diagnostic process relied on inquiring about the patient's history, including the place of residence, dietary habits, and symptoms, as well as on serological findings, an imaging examination, and pathological findings. MRCP and CT results showed mild dilatation of intrahepatic ducts and increased periductal echogenicity. The eggs were ultimately found in stool by water sedimentation method after the negative report through direct smear. DNA sequencing of PCR production of the eggs demonstrated 98-100% homology with ITS2 of Clonorchis sinensis. After anti-parasite medical treatment, the patient's symptoms were gradually relieved. Throughout the diagnostic procedure, besides routine examinations, the sedimentation method or concentration method could be used as a sensitive way for both light and heavy C. sinensis infection in the definite diagnosis.

Site-Directed Mutagenesis of Two Cysteines (155, 202) in Catechol 1,2-dioxygenase $I_1$ of Acinetobacter lwoffii K24

  • Kim, Seung-Il;Kim, Soo-Jung;Leem, Sun-Hee;Oh, Kye-Heon;Kim, Soo-Hyun;Park, Young-Mok
    • BMB Reports
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    • 제34권2호
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    • pp.172-175
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    • 2001
  • Catechol 1,2-dioxygenase $I_1$ ($CDI_1$) is the first enzyme of the $\beta$-ketoadipate pathway in Acinetobacter lowffii K24. $CDI_1$ has two cysteines (155, 202) and its enzyme activity is inhibited by the cysteine inhibitor, $AgNO_3$. Two mutants, $CDI_1$ C155V and $CDI_1$ C202V, were obtained by site-directed mutagenesis. The two mutants were overexpressed and the mutated amino acid residues (Cys$\rightarrow$Val) were characterized by peptide mapping and amino acid sequencing. Interestingly, $CDI_1$ C155V was inhibited by $AgNO_3$, whereas $CDI_1$ C202V was not inhibited. This suggests that $Cys^{202}$ is the sole inhibition site by $AgNO_3$ and is close to the active site of the enzyme. However, the results of the biochemical assay of mutated $CDI_1s$ suggest that the two cysteines are not directly involved in the activity of the catechol 1,2-dioxygenase of $CDI_1$.

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