scholarly journals Analysis of Genetic and Molecular Identity Among Field Isolates of the Rice Blast Fungus with an International Differential System, Rep-PCR, and DNA Sequencing

Plant Disease ◽  
2013 ◽  
Vol 97 (4) ◽  
pp. 491-495 ◽  
Author(s):  
Junjie Xing ◽  
Yulin Jia ◽  
James C. Correll ◽  
Fleet N. Lee ◽  
Richard Cartwright ◽  
...  
Keyword(s):  
Sequence Analysis ◽  
Dna Sequencing ◽  
Differential System ◽  
Repetitive Element ◽  
Chain Reaction ◽  
Specific Primers ◽  
Molecular Identity ◽  
Pcr Products ◽  
Polymerase Chain ◽  
Avr Gene

The Pi-ta gene deployed in southern U.S. rice germplasm is effective in preventing the infection by strains of Magnaporthe oryzae isolates that carry the avirulence (AVR) gene AVR-Pita1. In the present study, 169 isolates from rice (Oryza sativa) cultivars, with and without Pi-ta, were analyzed for their genetic identity using an international differential system, repetitive element-based polymerase chain reaction (Rep-PCR), and sequence analysis of PCR products of AVR-Pita1. These isolates belong to the races IA1, IB1, IB17, IC1, and IC17 of M. oryzae. These isolates were further classified into 15 distinct groups by Rep-PCR. There was a predominant group within each race. Pathogenicity assays on ‘Katy’ (Pi-ta) and ‘M202’ (pi-ta) rice determined that IC1 was virulent to Katy and M202; IB17, IC17, and most of IA1 and IB1 were avirulent to Katy and virulent to M202, suggesting that the Pi-ta gene in Katy is responsible for preventing infection by these isolates. Consistently, AVR-Pita1 was not amplified from 28 virulent isolates. One AVR-Pita1 allele was amplified by AVR-Pita1-specific primers in 78 avirulent isolates. Interestingly, different AVR-Pita1 alleles were found in each of the 12 avirulent isolates, as determined by DNA sequencing. Sequence analysis of 90 PCR products revealed 10 AVR-Pita1 haplotypes, 4 of which were new. In total, 12 amino acid changes were identified in the new variants when compared with the first described AVR-Pita sequence (AF207841). The finding of isolates with altered AVR-Pita1 from rice cultivars with and without Pi-ta suggests that these virulent isolates were adapted to the field environments in the southern United States. Further research will be needed to verify this prediction.

scholarly journals Characterization of clone-specific rearrangement T-cell receptor gamma- chain genes in lymphomas and leukemias by the polymerase chain reaction and DNA sequencing

Blood ◽  
1994 ◽  
Vol 84 (2) ◽  
pp. 574-581 ◽  
Author(s):  
M Kneba ◽  
I Bolz ◽  
B Linke ◽  
J Bertram ◽  
D Rothaupt ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Polymerase Chain Reaction ◽  
T Cell ◽  
Dna Sequencing ◽  
Cell Lines ◽  
Chain Reaction ◽  
Gamma Chain ◽  
Pcr Products ◽  
Polymerase Chain

The structures of rearranged gamma-chain T-cell antigen receptor (TCR) genes were analyzed in 5 cases of T-cell acute lymphoblastic leukemia (T-ALL), in 15 cases of peripheral T-cell non-Hodgkin's lymphoma (T- NHL), in 1 case with large granular CD8 lymphocytosis, 1 case with CD8 lymphocytosis after autologous bone marrow transplantation for Hodgkin's disease, and in 2 cases with nonneoplastic diseases. Rearranged V-J TCR gamma-gene segments were amplified by the polymerase chain reaction (PCR). Because most of the biopsy tissue or bone marrow samples contained significant amounts of admixed nonmalignant T-cells, direct DNA sequencing of the PCR products yielded mixed sequence data because of coamplification of clonal together with polyclonal TCR gamma V-N-J junctions. Reliable data could only be obtained by cloning the V gamma-J gamma PCR products and sequencing several (4 to 10) randomly chosen clones. In the polyclonal samples, all PCR-derived clones differed in their specific V-N-J junctions, as expected. In the two T- cell lines and in most of the T-cell malignancies, monoclonal PCR products could be identified by the demonstration of clonally restricted V-N-J junctions. In most cases, this information yielded the desired clone-specific sequence and showed a background population of polyclonal TCR gamma cells in each specimen, except for those that were obtained from the T-ALL samples, the cell lines, or the NHL samples with high tumor cell fraction. The results obtained by PCR-directed sequencing were confirmed by temperature-gradient gel electrophoresis (TGGE) that showed distinct DNA bands only with the PCR products containing predominant (ie, monoclonal) TCR gamma V-N-J junctions. By combined sequence and TGGE analysis, it was found that PCR/TGGE is able to distinguish between monoclonal and polyclonal TCR gamma-PCR products. This finding prompted us to complete the analysis of the TCR gamma locus in the samples by PCR/TGGE using primer mixes which covered all possible V gamma and J gamma recombinations. Monoclonality was shown with all mixes by PCR/TGGE in 21 of 24 (87%) of the lymphoproliferations. In summary, the present study shows that the combination of amplifying TCR gamma V-N-J junctions by PCR with the identification of clonal PCR products by TGGE and DNA sequencing is a reliable method for the characterization of clonal TCR gamma sequences.

The occurrence of the filarial nematode Dirofilaria repens in canine hosts from Maio Island, Cape Verde

2016 ◽  
Vol 91 (1) ◽  
pp. 87-90 ◽  
Author(s):  
R. Marcos ◽  
C. Pereira ◽  
J.P. Maia ◽  
M. Santos ◽  
C. Luzzago ◽  
...  
Keyword(s):  
Dirofilaria Immitis ◽  
Parasite Species ◽  
Cape Verde ◽  
Control Measures ◽  
Chain Reaction ◽  
Species Identity ◽  
Specific Primers ◽  
Pcr Products ◽  
Males And Females ◽  
Polymerase Chain

AbstractThe prevalence of canine Dirofilaria infection in Maio Island (Cape Verde) was analysed by serology, morphological and molecular identification of the parasite species. Blood and sera were collected from 150 dogs and 80 cats aged over 6 months from various localities of the island. DNA was extracted from blood and samples were screened by polymerase chain reaction (PCR) using microfilaria-specific primers. No Dirofilaria immitis was found in dogs while D. repens microfilariae were found in 5.3% of dogs and 6% were positive by PCR. The species identity was confirmed by sequencing of PCR products, which showed almost 100% homology with D. repens European sequences published in GenBank. No difference in Dirofilaria infection was observed between males and females or in dogs with different weights. However, older dogs and those from the western part of Maio Island were more frequently infected. No Dirofilaria was found in cats. This study represents the first evidence of D. repens in Cape Verde (West Africa) and highlights the need for implementing control measures and for a better surveillance of dirofilariosis in Africa.

scholarly journals Survey of mutations in prolificacy genes in Santa Ines and Morada Nova sheep

2017 ◽  
Vol 69 (4) ◽  
pp. 1047-1053
Author(s):  
G.M.L. Holanda ◽  
J.C. Oliveira ◽  
D.M.F. Silva ◽  
S.S.N. Rocha ◽  
V. Pandolfi ◽  
...  
Keyword(s):  
Restriction Site ◽  
Fragment Length Polymorphism ◽  
Nucleotide Sequencing ◽  
Chain Reaction ◽  
Specific Primers ◽  
Pcr Rflp ◽  
Pcr Products ◽  
Polymerase Chain ◽  
Santa Inês ◽  
Restriction Fragment Length

ABSTRACT Polymorphisms in the BMP-15 gene related to Galway (FecXG) and Inverdale (FecXI) and in the BMPR-1B gene known as Booroola (FecB) mutations were investigated using the Polymerase Chain Reaction - Restriction Fragment Length Polymorphism (PCR-RFLP) method, on sheep from the breeds Santa Inês (n= 574) and Morada Nova (n=282). DNA was extracted and amplified through PCR with specific primers that introduced a restriction site in association with the mutation. The PCR products were submitted to endonucleases. The experiment found no FecXG and FecXI mutations. Six samples of animals with multiple offspring/birth history presented polymorphism for FecB similar to control samples, but this pattern was not confirmed by nucleotide sequencing. Although the absence of these mutations in the studied breeds, other factors related to prolificacy should be investigated to explain the inherent prolificity mechanisms.

scholarly journals Characterization of clone-specific rearrangement T-cell receptor gamma- chain genes in lymphomas and leukemias by the polymerase chain reaction and DNA sequencing

Blood ◽  
1994 ◽  
Vol 84 (2) ◽  
pp. 574-581 ◽  
Author(s):  
M Kneba ◽  
I Bolz ◽  
B Linke ◽  
J Bertram ◽  
D Rothaupt ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Polymerase Chain Reaction ◽  
T Cell ◽  
Dna Sequencing ◽  
Cell Lines ◽  
Chain Reaction ◽  
Gamma Chain ◽  
Pcr Products ◽  
Polymerase Chain

Abstract The structures of rearranged gamma-chain T-cell antigen receptor (TCR) genes were analyzed in 5 cases of T-cell acute lymphoblastic leukemia (T-ALL), in 15 cases of peripheral T-cell non-Hodgkin's lymphoma (T- NHL), in 1 case with large granular CD8 lymphocytosis, 1 case with CD8 lymphocytosis after autologous bone marrow transplantation for Hodgkin's disease, and in 2 cases with nonneoplastic diseases. Rearranged V-J TCR gamma-gene segments were amplified by the polymerase chain reaction (PCR). Because most of the biopsy tissue or bone marrow samples contained significant amounts of admixed nonmalignant T-cells, direct DNA sequencing of the PCR products yielded mixed sequence data because of coamplification of clonal together with polyclonal TCR gamma V-N-J junctions. Reliable data could only be obtained by cloning the V gamma-J gamma PCR products and sequencing several (4 to 10) randomly chosen clones. In the polyclonal samples, all PCR-derived clones differed in their specific V-N-J junctions, as expected. In the two T- cell lines and in most of the T-cell malignancies, monoclonal PCR products could be identified by the demonstration of clonally restricted V-N-J junctions. In most cases, this information yielded the desired clone-specific sequence and showed a background population of polyclonal TCR gamma cells in each specimen, except for those that were obtained from the T-ALL samples, the cell lines, or the NHL samples with high tumor cell fraction. The results obtained by PCR-directed sequencing were confirmed by temperature-gradient gel electrophoresis (TGGE) that showed distinct DNA bands only with the PCR products containing predominant (ie, monoclonal) TCR gamma V-N-J junctions. By combined sequence and TGGE analysis, it was found that PCR/TGGE is able to distinguish between monoclonal and polyclonal TCR gamma-PCR products. This finding prompted us to complete the analysis of the TCR gamma locus in the samples by PCR/TGGE using primer mixes which covered all possible V gamma and J gamma recombinations. Monoclonality was shown with all mixes by PCR/TGGE in 21 of 24 (87%) of the lymphoproliferations. In summary, the present study shows that the combination of amplifying TCR gamma V-N-J junctions by PCR with the identification of clonal PCR products by TGGE and DNA sequencing is a reliable method for the characterization of clonal TCR gamma sequences.

scholarly journals A Comparative Study of 5S rDNA Non-Transcribed Spacers in Elaeagnaceae Species

Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 4
Author(s):  
Oleg S. Alexandrov ◽  
Olga V. Razumova ◽  
Gennady I. Karlov
Keyword(s):  
Polymerase Chain Reaction ◽  
Molecular Markers ◽  
Dna Markers ◽  
5S Rdna ◽  
Chain Reaction ◽  
Closely Related Species ◽  
Pcr Products ◽  
Polymerase Chain ◽  
Species Specific ◽  
Shepherdia Canadensis

5S rDNA is organized as a cluster of tandemly repeated monomers that consist of the conservative 120 bp coding part and non-transcribed spacers (NTSs) with different lengths and sequences among different species. The polymorphism in the 5S rDNA NTSs of closely related species is interesting for phylogenetic and evolutional investigations, as well as for the development of molecular markers. In this study, the 5S rDNA NTSs were amplified with universal 5S1/5S2 primers in some species of the Elaeagnaceae Adans. family. The polymerase chain reaction (PCR) products of five Elaeagnus species had similar lengths near 310 bp and were different from Shepherdia canadensis (L.) Nutt. and Sh. argentea (Pusch.) Nutt. samples (260 bp and 215 bp, respectively). The PCR products were cloned and sequenced. An analysis of the sequences revealed that intraspecific levels of NTS identity are high (approximately 95–96%) and similar in the Elaeagnus L. species. In Sh. argentea, this level was slightly lower due to the differences in the poly-T region. Moreover, the intergeneric and intervarietal NTS identity levels were studied and compared. Significant differences between species (except E. multiflora Thunb. and E. umbellata Thunb.) and genera were found. Herein, a range of the NTS features is discussed. This study is another step in the investigation of the molecular evolution of Elaeagnaceae and may be useful for the development of species-specific DNA markers in this family.

scholarly journals Refractory pemphigus vulgaris associated with herpes infection: case report and review

2011 ◽  
Vol 53 (2) ◽  
pp. 113-117 ◽  
Author(s):  
Maria Luiza Figueiredo Braga Brandão ◽  
Nurimar C. Fernandes ◽  
Danielle Pereira De Oliveira Batista ◽  
Norma Santos
Keyword(s):  
Sequence Analysis ◽  
Pemphigus Vulgaris ◽  
Chain Reaction ◽  
Upper Eyelid ◽  
Triggering Factor ◽  
Polymerase Chain ◽  
Genetic And Environmental Factors ◽  
The Right ◽  
Hsv 1

BACKGROUND: Pemphigus vulgaris (PV) is an autoimmune disease characterized by blistering of the skin and mucosa, which develops due to the interaction between predisposing genetic and environmental factors. Infections caused by members of the Herpesviridae family have been suggested as a possible triggering factor for PV. OBJECTIVE AND METHODS: In this report, we investigate the presence of herpesviruses in refractory lesions on the right upper eyelid. The lesion has persisted despite the treatment with corticosteroids. Polymerase chain reaction (PCR) and DNA sequence analysis have been used to detect the DNA of HSV 1/2, VZV, EBV, CMV, HHV-6, HHV-7, and HHV-8. RESULTS: The sample collected from the right upper eyelid has tested positive for HSV 1/2. Sequence analysis has confirmed the PCR results and allowed the identification of the HSV strain as belonging to type 1. After treatment with acyclovir, the lesion of the right upper eyelid has cleared and not relapsed. CONCLUSION: When patients present PV lesions which are refractory to corticosteroid therapy, herpetic infection should be considered.

Variation in bacterial endosymbionts associated with the date palm hopper,Ommatissus lybicuspopulations

2017 ◽  
Vol 108 (2) ◽  
pp. 271-281 ◽  
Author(s):  
S. Karimi ◽  
H. Izadi ◽  
M. Askari Seyahooei ◽  
A. Bagheri ◽  
P. Khodaygan
Keyword(s):  
Date Palm ◽  
Multiple Infections ◽  
Infection Frequency ◽  
Pcr Assay ◽  
Specific Primers ◽  
Consensus Sequences ◽  
Pcr Products ◽  
Bacterial Endosymbionts ◽  
Different Populations ◽  
Polymerase Chain

AbstractThe date palm hopper,Ommatissus lybicus, is a key pest of the date palm, which is expected to be comprised of many allopatric populations. The current study was carried out to determine bacterial endosymbiont diversity in the different populations of this pest. Ten date palm hopper populations were collected from the main date palm growing regions in Iran and an additional four samples from Pakistan, Oman, Egypt and Tunisia for detection of primary and secondary endosymbionts using polymerase chain reaction (PCR) assay with their specific primers. The PCR products were directly sequenced and edited using SeqMan software. The consensus sequences were subjected to a BLAST similarity search. The results revealed the presence of ‘CandidatusSulcia muelleri’ (primary endosymbiont) andWolbachia,ArsenophonusandEnterobacter(secondary endosymbionts) in all populations. This assay failed to detect ‘CandidatusNasuia deltocephalinicola’ andSerratiain these populations. ‘Ca. S. muelleri’ exhibited a 100% infection frequency in populations andWolbachia,ArsenophonusandEnterobacterdemonstrated 100, 93.04 and 97.39% infection frequencies, respectively. The infection rate ofArsenophonusandEnterobacterranged from 75 to 100% and 62.5 to 100%, respectively, in different populations of the insect. The results demonstrated multiple infections by ‘Ca. Sulcia muelleri’,Wolbachia,ArsenophonusandEnterobacterin the populations and may suggest significant roles for these endosymbionts on date palm hopper population fitness. This study provides an insight to endosymbiont variation in the date palm hopper populations; however, further investigation is needed to examine how these endosymbionts may affect host fitness.

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