Summary: By using pulsed-field gel electrophoresis, we have separated the entire chromosome bands and examined the electrophoretic karyotypes of 27 strains of . The electrophoretic karyotype varied widely among these strains. Their chromosomal DNAs were resolved into 7-12 bands ranging in size from 0·42 to 3·0 Mb. Most of the separated chromosomal bands were assigned by eight cloned DNA probes. These results suggest that the haploid number of chromosomes is eight. Each of the probes hybridized specifically to one or two bands of similar size in most strains. With the exception of the MGL1 probe, when two bands were detected by one probe, the size of one of them was very conserved whilst the other was of fairly variable size. The sizes of the chromosome bands assigned by the MGL1 probe were much more variable. As is considered to be a diploid organism, it is inferred that the karyotype polymorphism between strains is mainly derived from wide size heterogeneity in one of the homologous chromosomes. Furthermore, we have confirmed species-specific and strain-specific variation in medically important species ( and ). Electrophoretic karyotype analysis is thus useful for species assignation. The TUB2 probe, encoding beta-tubulin, hybridized to the chromosomal DNA of all the species examined, but four probes exhibited cross-species hybridization with only. The karyotype of seems to be within the range of the intraspecies variation observed in .


Article metrics loading...

Loading full text...

Full text loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error