The three genes are a tcdA-like gene (7710 bp), predicted to code for a 284-kDa protein; a tcdB-like gene (4272 bp), predicted
to code for a 158-kDa protein; and a tccC3-like gene (2916 bp), predicted to encode a 107-kDa protein. All three predicted proteins contain conserved domains that are characteristic of their respective Tc proteins. By RT-PCR, all three tc-like genes were found to be expressed in this bacterium. Through genome walking and the use of PCR to join contigs Birinapant in vitro surrounding these three genes, a genomic island (87 712 bp, named tc-GIvp) was found on chromosome II localized next to the tRNA Gly. The GC content of this island, which is not found in other Vibrio species, is 40%. The tc-GIvp is characterized to have 60 ORFs encoding regulatory or virulence factors. These include a type 6 secretion protein VgrG, EAL domain-containing proteins, fimbriae subunits and assembly proteins, invasin-like proteins, peptidoglycan-binding proteins, and Tc proteins. The tc-GIvp also contains 21 transposase genes, suggesting that it was acquired through horizontal transfer from other organisms. “
“Xanthomonas oryzae pathovar oryzae (Xoo) and X. oryzae pv. oryzicola (Xoc) cause bacterial diseases in rice: leaf
blight and leaf streak, respectively. Although both the Asian and the African strains of Xoo induce similar symptoms, they are genetically Vemurafenib order different, with the African Xoo strains being more closely related to the Asian Xoc. To identify Gefitinib mw the sequences responsible for differences between African and Asian Xoo strains and
their relatedness to Xoc strains, a suppression-subtractive hybridization (SSH) procedure was performed, using the African Xoo MAI1 strain as a tester and the Philippine Xoo PXO86 strain and Xoc BLS256 strain as drivers. A nonredundant set of 134 sequences from MAI1 was generated. Several DNA fragments isolated by SSH were similar to genes of unknown function, hypothetical proteins, genes related to the type III secretion system, and other pathogenicity-related genes. The specificity of various fragments was validated by Southern blot analysis. SSH sequences were compared with several xanthomonad genomes. In silico analysis revealed SSH sequences as specific to strain MAI1, revealing their potential as specific markers for further epidemiological and diagnostic studies. SSH proved to be a useful method for rapidly identifying specific genes among closely related X. oryzae strains. Two major pathogens of rice –Xanthomonas oryzae pv. oryzae (Xoo) and X. oryzae pv. oryzicola (Xoc) – cause bacterial leaf blight and bacterial leaf streak, respectively (Leyns et al., 1984). Leaf blight has become a disease of major significance throughout Asia. Annual losses of 20–80% in severe epidemics have been reported (Mew, 1987).