Genetic diversity and molecular characterization of puroindoline genes ( Pina-D1 and Pinb-D1 ) in bread wheat landraces from Andalusia (Southern Spain)

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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Molecular characterization of bread wheat mutants lacking the entire cluster of chromosome 6A controlled gliadin components

Journal of Cereal Science ◽

10.1016/s0733-5210(09)80133-1 ◽

1991 ◽

Vol 14 (2) ◽

pp. 125-129 ◽

Cited By ~ 10

Author(s):

R. D'Ovidio ◽

D. Lafiandra ◽

O.A. Tanzarella ◽

O.D. Anderson ◽

F.C. Greene

Keyword(s):

Molecular Characterization ◽

Bread Wheat

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Temporal diversity changes among 198 Nordic bread wheat landraces and cultivars detected by retrotransposon-based S-SAP analysis

Plant Genetic Resources ◽

10.1017/s1479262108983544 ◽

2008 ◽

Vol 6 (02) ◽

pp. 113-125 ◽

Cited By ~ 11

Author(s):

Shu-Chin Hysing ◽

Torbjörn Säll ◽

Hilde Nybom ◽

Erland Liljeroth ◽

Arnulf Merker ◽

...

Keyword(s):

Genetic Diversity ◽

Bread Wheat ◽

Growth Habit ◽

Gene Diversity ◽

Pedigree Information ◽

Principal Coordinates Analysis ◽

Subsequent Increase ◽

Principal Coordinates ◽

Frequent Exchange ◽

Wheat Landraces

The sequence-specific amplified polymorphism (S-SAP) method was used to genotype 198 Nordic bread wheat landraces and cultivars from the 19th to the 21st centuries. It was shown that theSukkula-9900-LARD retrotransposon primer was highly suitable for resolving closely related wheat materials. Cluster analysis was generally consistent with pedigree information and revealed a clear separation for growth habit but not for countries. A principal coordinates analysis (PCoA) showed a separation into different time periods (before 1910, 1910–1969 and 1970–2003). These results are consistent with the breeding history and pedigree information, indicating that little hybridization has occurred between winter and spring wheat, in contrast to frequent exchange of germplasm between the Nordic countries. Estimates of gene diversity, the PCoA results, and changes in band frequencies across time indicate that plant breeding has led to substantial genetic shifts in Nordic wheat. Diversity was reduced through selections from landraces during the early 20th century, followed by a period of relatively lower genetic diversity, and a subsequent increase and net gains in diversity from the late 1960s onwards through the use of exotic germplasm. Thus, an anticipated loss of overall genetic diversity was found to be negligible, although allele losses have occurred at specific loci.

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