These results suggest that they have diverged from a common origin. Thirty isolates of P. verrucosa and two isolates of P. americana possessed intron-F, G and H either individually or as a combination of these introns. Genotypes based on the combinations of presence or absence of introns, type and position of insertions were established to discriminate among the isolates surveyed. As a result, five genotypes; namely, F, FG, FH, FGH and N were identified, as shown in Table 1. Type-F

was isolated in all the countries where the strains used in the study. Intron distribution was found to have some correlation with geographic location, albeit the number of isolates used was small. For example, most of the Chinese isolates except for Yao-strain had only type-F. Isolates from South American ABT-888 datasheet continent had slight tendency to have an intron-H,

wherein they were either type-FH or FGH. Intron-G’s occurred as type-FG in the clinical isolates of Japan and China and as two type-FGH’s in soil isolates of Brazil. In addition, according to Selleck AR-13324 an interpretation from a different viewpoint, insight into possible correlation of geographic origin among introns from P. verrucosa strains have emerged from these insertion position results, namely, the spread of L798 among a large number of P. verrucosa isolates and the existence of L1921 and L2563 that coexist with the other intron insertions among the species and strains that have lost introns. L1921 positions are only seen in two clinical isolates from Japan

and China and two isolates from Brazilian soil. The L2563 position seems to be specific to the South American continent in six environmental isolates. The possible correlation tendencies shown in our results have also been reported in previous studies described below. For example, group 1 intron CgSSU was found in the SSU rDNA of deuteromycetes mycorrhizal fungus Cenococcum geophilum, and the intron-positive isolates occurred mainly in North America and Europe and negative Cell press isolates in Western, Midwestern and Southern North America [33]. In other studies on intron distribution from a single species, four different group 1 intron combinations within LSU rDNA from entomopathogenic hyphomycete Beauveria bassiana were divided into 13 genotypes to investigate distribution frequencies in the population and it was found that there was a tenuous correlation with geographic origin or insect host species [34]. Moreover, M. Márquez, et al. have found three intron insertion positions within LSU rDNA and established seven genotypes among 26 biocontrol isolates for entomopathogenic anamorphic Metarhizum anisopliae [35]. Meanwhile, we found that five isolates of P. americana had no introns, even though two isolates were detected as type-F. Intron-loss strains might have been lost from taxa possessing intron-F in the common ancestor of the species during its evolution [36]. Further, the lateral transfers appear to have been rare events in P.