Occan, a novel transposon in the Fot1 family, is ubiquitously found in several Magnaporthe grisea isolates.
We investigated a DNA fragment and its flanking region deleted in the spontaneous Pi-a virulent mutant of Magnaporthe grisea Ina168. A new transposon-like sequence was identified from a region adjacent to the deleted fragment and was named Occan. Occan contained a 2,259-bp ORF interrupted by one 63-bp intron and had both a TA dinucleotide and 77 bp of perfect inverted repeats at both termini, without direct repeats. These features indicated that Occan is a member of the Fot1 family. RT-PCR analysis confirmed the expression of the putative transposase and the presence of an intron. Southern analysis of pulse-field gel electrophoresis-separated chromosomes indicated that Occan was dispersed in all chromosomes of the rice pathogen, Ina168. Copy numbers of Occan were also preserved in a host-specific manner amongst M. grisea isolates. In particular, rice pathogens contained a large number of the element inserted into their genome. Phylogenetic analysis with other known members of the Fot1 family revealed that Occan was dissimilar to any other known elements and it is thus proposed that Occan be separated to a new subfamily.
Kito
Hideki
H
Laboratory of Applied Microbiology, Department of Molecular Bioscience, Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, 060-8589, Sapporo, Japan.
Takahashi
Yosuke
Y
Sato
Junko
J
Fukiya
Satoru
S
Sone
Teruo
T
Tomita
Fusao
F
D000595:Amino Acid Sequence; D001483:Base Sequence; D004251:DNA Transposable Elements; D020082:Magnaporthe / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D019105:Random Amplified Polymorphic DNA Technique; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D019895:Transposases / Q000235:genetics
D004251:DNA Transposable Elements; D019895:Transposases