Penicillium Marneffei Gene Cloning And Gene Function In D1ha Preliminary Study

Penicillium marneffei is a thermally dimorphic opportunistic human pathogen with a saprophytic filamentous hyphal form at 25°C and a pathogenic unicellular yeast form at 37°C. Despite its medical importance and its unusual thermal dimorphic character, a large part of P.marneffei still remains unknown and relative molecular researches have been limited due to the lack of genomic information and effective genetic tools. We cloned a 3936 gene dlhA highly conserved to the histidine kinase gene drk1, which has the globe regulation in morphogenesis, cell wall composition, sporulation and expression of virulence factors in Blastomyces dermatitidis. One RNAi expression cassette was designed with inverted repeats of coding sequence of the targeted gene separated by a segment of gus~ gene. Constructs were transferred by Agrobacterium -mediated transformation and under the control of promoter xylP, RNAi can be regulated in a controllable and reversible manner. dlhA-silenced transformants exhibited severe morphological defects and incapability of conidiogenesis compared with their parent strains. These evidences imply that dlhA plays a role regulating the expression of downstream effectors, which are necessary exploring the propable mechanisms of correct polarized growth, dimorphic switch, and further research for drug design.