PCR-based analysis of the intergenic spacers of the Nor loci on the A genomes of Triticum diploids and polyploids

Genome ◽  
1999 ◽  
Vol 42 (1) ◽  
pp. 116-128 ◽  
Author(s):  
Robert Sallares ◽  
Terence A Brown
Keyword(s):  
Sequence Data ◽  
Random Noise ◽  
Intergenic Spacer ◽  
Population Variation ◽  
Chain Reactions ◽  
Intergenic Spacers ◽  
Polymerase Chain Reactions ◽  
Dna Sequence Data ◽  
Polymerase Chain ◽  
Ribosomal Dnas

We present DNA sequence data showing population variation in the intergenic spacer (IGS) regions of the ribosomal DNAs (rDNAs) on the A genomes of 27 diploid and polyploid wheats. PCRs (polymerase chain reactions) specific for the Am genome gave products with five populations of Triticum monococcum but did not give products with AABB or AABBDD wheats. PCRs specific to the Au genome of T. urartu gave products with all the AABB and AABBDD polyploids that were tested, but not with T. monococcum. AAGG tetraploids gave products only with the Au-specific primers, but the AAAAGG hexaploid T. zhukovskyi gave products with both the Au and Am primers. Phylogenetic analysis showed a substantial degree of IGS divergence for both the Am and Au genomes in diploids and polyploids compared with other genomes of Triticum and Aegilops. The rate of evolution of the IGS is much greater than previously reported for the internal transcribed region of the rDNAs but the view that the IGS only gives random noise is rejected, the IGS sequences presented here reflecting the general evolutionary trends affecting the wheat genome as a whole.Key words: wheat, ribosomal DNA, intergenic spacer, polymerase chain reaction.

Quantitative Detection of Aflatoxin and Species Identification of Aspergillus section Flavi Isolates from Peanuts using Molecular Approaches

2020 ◽  
Author(s):  
I. Lavkor
Keyword(s):  
Sequence Data ◽  
Aflatoxin Production ◽  
Quantitative Detection ◽  
Aflatoxin Biosynthesis ◽  
Chain Reactions ◽  
Polymerase Chain Reactions ◽  
Dna Sequence Data ◽  
Aspergillus Section Flavi ◽  
Molecular Approaches ◽  
Aspergillus Section

Totally, 50 Aspergillus section Flavi were identified isolates having aflatoxin biosynthesis genes on peanut by molecular method and aflatoxin production. Primer pair (IGS-F/R) recognized the aflatoxin biosynthesis gene (aflJ-aflR) targeting the intergenic region (IGS) on DNA was amplified by polymerase chain reactions (PCR). The PCR product were restricted by BglII enzyme within Restriction Fragment Length Polymorphism (RFLP) and obtained from 33 (66%) Aspergillus flavus was cleaved into three band sizes of 362, 210 and 102 bp. However, BglII enzyme generated two band sizes of 363 and 311 bp for 17 (34%) Aspergillus parasiticus. An investigation examined DNA sequence data to characterize these isolates and describe the species. Phylogenetic analysis showed that A. flavus and A. parasiticus have been identified in different groups. All the A. flavus and A. parasiticus isolates produced aflatoxins. The present study provides a new method on molecular characterization of A. section Flavi in Turkey.

scholarly journals Investigation of Lethal Concurrent Outbreak of Chlamydiosis and Pigeon Circovirus in a Zoo

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1654
Author(s):  
Wei-Tao Chen ◽  
Chin-Ann Teng ◽  
Cheng-Hsin Shih ◽  
Wei-Hsiang Huang ◽  
Yi-Fan Jiang ◽  
...  
Keyword(s):  
Disease Outbreaks ◽  
Chlamydia Psittaci ◽  
Bursa Of Fabricius ◽  
Chain Reactions ◽  
Renal Epithelium ◽  
Polymerase Chain Reactions ◽  
Transmission Electron ◽  
Intracytoplasmic Inclusion Bodies ◽  
Polymerase Chain ◽  
Streptopelia Orientalis

During the spring, an outbreak of sudden death involving 58 birds occurred in a zoo. Histopathological examinations revealed variable numbers of intracytoplasmic basophilic microorganisms in the macrophages, hepatocytes, and renal epithelium of most birds, along with occasional botryoid intracytoplasmic inclusion bodies within histiocytes in the bursa of Fabricius. Based on the results of histopathological examinations, immunohistochemical staining, transmission electron microscopy, and polymerase chain reactions, genotype B Chlamydia psittaci infection concurrent with pigeon circovirus (PiCV) was diagnosed. A retrospective survey, including two years before the outbreak and the outbreak year, of C. psittaci and PiCV infections of dead birds in the aviaries, revealed that the outbreak was an independent episode. The findings of this study indicate that concurrent infection with C. psittaci and PiCV might lead to lethal outbreaks of chlamydiosis, particularly Streptopelia orientalis. In addition, persistently monitoring both pathogens and identifying potential PiCV carriers or transmitters might also help prevent lethal disease outbreaks.

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