Differentially expressed genes associated with tryptophan-dependent pigment synthesis in Malassezia furfur--a comparison with the recently published genome of Malassezia globosa.

Malassezia (M.) furfur, a commensal organism found on the human skin, produces a wide range of pigments and fluorochromes when cultured with tryptophan as a sole nitrogen source. Some compounds of this pigment metabolism may provide an explanation for clinical characteristics of pityriasis versicolor (PV), a frequent skin disease in humans characterised by long-lasting pigmentary changes. Malassezia globosa is currently regarded as the causative agent of PV, but tryptophan-dependent pigment production has not yet been demonstrated in this species. In a previous study, we identified M. furfur genes that were differentially expressed 3 and 5 h, respectively, after induction of tryptophan-dependent pigment production. The recent publication of the genome of M. globosa prompted us to check the M. furfur sequences for homologues in M. globosa. The 3-h pool contained 79 sequences and the 5-h pool contained 91 sequences. A translated vs. translated BLAST search resulted in 62 sequences (78%) of the 3-h pool and 61 sequences (67%) of the 5-h pool showing similarity to a sequence from M. globosa. It appears that M. globosa possesses homologues to most of the genes that are differentially expressed during pigment production in M. furfur.