Genetic Diversity of Xanthomonas campestris pv. vitians, the Causal Agent of Bacterial Leafspot of Lettuce

Bacterial leafspot of lettuce (BLS), caused by Xanthomonas campes-tris pv. vitians, has become more prevalent in many lettuce-growing areas of the world over the past decade. To gain insight into the nature of these outbreaks, the genetic variation in X. campestris pv. vitians strains from different geographical locations was examined. All strains were first tested for pathogenicity on lettuce plants, and then genetic diversity was assessed using (i) gas-chromatographic analysis of bacterial fatty acids, (ii) polymerase chain reaction analysis of repetitive DNA sequences (rep-PCR), (iii) DNA sequence analysis of the internal transcribed spacer region 1 (ITS1) of the ribosomal RNA, (iv) restriction fragment length polymorphism (RFLP) analysis of total genomic DNA with a repetitive DNA probe, and (v) detection and partial characterization of plasmid DNA. Fatty acid analysis identified all pathogenic strains as X. campestris, but did not consistently identify all the strains as X. campestris pv. vitians. The rep-PCR fingerprints and ITS1 sequences of all pathogenic X. campestris pv. vitians strains examined were identical, and distinct from those of the other X. campestris pathovars. Thus, these characteristics did not reveal genetic diversity among X. campestris pv. vitians strains, but did allow for differentiation of X. campestris pathovars. Genetic diversity among X. campestris pv. vitians strains was revealed by RFLP analysis with a repetitive DNA probe and by characterization of plasmid DNA. This diversity was greatest among strains from different geographical regions, although diversity among strains from the same location also was detected. The results of this study suggest that these X. campestris pv. vitians strains are not clonal, but comprise a relatively homogeneous group.

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Characterization of repetitive DNA sequences carrying 5S rDNA of the triploid ginbuna (Japanese silver crucian carp, Carassius auratus langsdorfi).

Genes & Genetic Systems ◽

10.1266/ggs.73.9 ◽

1998 ◽

Vol 73 (1) ◽

pp. 9-20 ◽

Cited By ~ 27

Author(s):

Masaru Murakami ◽

Hideo Fujitani

Keyword(s):

Repetitive Dna ◽

Dna Sequences ◽

Carassius Auratus ◽

Crucian Carp ◽

5S Rdna ◽

Repetitive Dna Sequences ◽

Silver Crucian Carp ◽

Crucian Carp Carassius Auratus

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Wheat specific repetitive DNA sequences ? construction and characterization of four different genomic clones

Theoretical and Applied Genetics ◽

10.1007/bf00266993 ◽

1986 ◽

Vol 72 (2) ◽

pp. 207-210 ◽

Cited By ~ 47

Author(s):

M. Metzlaff ◽

W. Troebner ◽

F. Baldauf ◽

R. Schlegel ◽

J. Cullum

Keyword(s):

Repetitive Dna ◽

Dna Sequences ◽

Repetitive Dna Sequences ◽

Genomic Clones

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Molecular Characterization of Pathogenicity Locus (PaLoc) and tcdC Genetic Diversity Among tcdA+B+ Clostridioides Difficile Clinical Isolates in Tehran, Iran

10.21203/rs.3.rs-56651/v1 ◽

2020 ◽

Author(s):

Mansoor Kodori ◽

Zohreh Ghalavand ◽

Abbas Yadegar ◽

Gita Eslami ◽

Masoumeh Azimirad ◽

...

Keyword(s):

Genetic Diversity ◽

Molecular Characterization ◽

Disease Severity ◽

Genetic Variants ◽

Rflp Analysis ◽

Clostridioides Difficile ◽

Pcr Rflp ◽

The Common ◽

Healthcare Associated

Abstract Background: Clostridioides difficile is the main cause of healthcare-associated diarrhea worldwide. It is proposed that certain C. difficile toxinotypes with distinct pathogenicity locus (PaLoc) variants are associated with disease severity and outcomes. Additionally, few studies have described the common C. difficile toxinotypes, and also little is known about the tcdC variants in Iranian isolates. We characterized the toxinotypes and the tcdC genotypes from a collection of Iranian clinical C. difficile tcdA+B+ isolates with known ribotypes (RTs).Methods: Fifty C. difficile isolates with known RTs and carrying the tcdA and tcdB toxin genes were analyzed. Toxinotyping was carried out based on a PCR-RFLP analysis of a 19.6 kb region encompassing the PaLoc. Genetic diversity of the tcdC gene was determined by the sequencing of the gene.Results: Of the 50 C. difficile isolates investigated, five distinct toxinotypes were recognized. Toxinotypes 0 (33/50, 66%) and V (11/50, 22%) were the most frequently found. C. difficile isolates of the toxinotype 0 mostly belonged to RT 001 (12/33, 36.4%), whereas toxinotype V consisted of RT 126 (9/11, 81.8%). The tcdC sequencing showed six variants (35/50, 70%); tcdC-sc3 (24%), tcdC-A (22%), tcdC-sc9 (18%), tcdC-B (2%), tcdC-sc14 (2%), and tcdC-sc15 (2%). The remaining isolates were wild-types (15/50, 30%) in the tcdC gene.Conclusions: The present study demonstrates that the majority of clinical tcdA+B+ isolates of C. difficile frequently harbor tcdC genetic variants. We also found that the RT 001/ toxinotype 0 and the RT 126/ toxinotype V are the most common types among Iranian isolates. Further studies are needed to investigate the putative association of various tcdC genotypes with CDI severity and its recurrence.

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In vitro Rearrangement and Deletion of Plasmid DNA Sequences: The Isolation and Partial Characterization of a Novel F-Controlled Plasmid Cloning Vehicle

Plasmids ◽

10.1007/978-3-642-81064-0_49 ◽

1977 ◽

pp. 407-415

Author(s):

J. J. Manis ◽

B. C. Kline

Keyword(s):

Dna Sequences ◽

Plasmid Dna ◽

Partial Characterization

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Variation in highly repetitive DNA composition of heterochromatin in rye studied by fluorescence in situ hybridization

Genome ◽

10.1139/g95-142 ◽

1995 ◽

Vol 38 (6) ◽

pp. 1061-1069 ◽

Cited By ~ 42

Author(s):

A. Cuadrado ◽

N. Jouve ◽

C. Ceoloni

Keyword(s):

In Situ Hybridization ◽

Fluorescence In Situ Hybridization ◽

Repetitive Dna ◽

Dna Sequences ◽

5S Rdna ◽

Individual Identification ◽

Highly Repetitive Dna ◽

The Individual

The molecular characterization of heterochromatin in six lines of rye has been performed using fluorescence in situ hybridization (FISH). The highly repetitive rye DNA sequences pSc 119.2, pSc74, and pSc34, and the probes pTa71 and pSc794 containing the 25S–5.8S–18S rDNA (NOR) and the 5S rDNA multigene families, respectively, were used. This allowed the individual identification of all seven rye chromosomes and most chromosome arms in all lines. All varieties showed similar but not identical patterns. A standard in situ hybridization map was constructed following the nomenclature system recommended for C-bands. All FISH sites observed appeared to correspond well with C-band locations, but not all C-banding sites coincided with hybridization sites of the repetitive DNA probes used. Quantitative and qualitative differences between different varieties were found for in situ hybridization response at corresponding sites. Variation between plants and even between homologous chromosomes of the same plant was found in open-pollinated lines. In inbred lines, the in situ pattern of the homologues was practically identical and no variation between plants was detected. The observed quantitative and qualitative differences are consistent with a corresponding variation for C-bands detected both within and between cultivars.Key words: fluorescence in situ hybridization, repetitive DNA, rye, Secale cereale, polymorphism.

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