Electrophorectic karyotype of the pathogenic fungus Penicillium marneffei /

Abstract

An electrophoretic karyotype of Penicillium marneffei, an emergmg AIDS-associated pathogen, was derived usmg contoured-clamped homogeneous electric field (CHEF) gel electrophoresis. Five chromosomesized DNA fragments were clearly resolved in two different strains of P. marneffei. Chromosomal length polymorphisms were evident among the three largest molecules. Based upon these electrophoretic separation patterns, individual chromosomes were estimated to range in size from 2.2 to ~ 6..1 Mbp with a total genome size of 19.6 to > 20.6 Mbp. However, Southern blot analysis using a telomeric probe suggests that P. marneffei may possess at least six chromosomes. Further hybridization analysis also localized P. marneffei genes for chitin synthase, chitinase, malate synthase, isocitrate lyase, isocitrate dehydrogenase, actin, and 28S rDNA, to specific chromosomes. These analyses confirmed the existence of multiple chitin synthase and chitinase gene homologues in P. marneffei. The collective results of this study provide foundations for facilitating both the genetic characterization of P. marneffei and the molecular epidemilogical study of penicilliosis due to this fungus.