Published online by Cambridge University Press: 21 May 2001
A 909 bp region containing a genomic clone encoding for hydrophobin (ssgA) from the entomopathogenic fungus Metarhizium anisopliae has been sequenced and the regulatory motifs analysed against those recognized in other fungi. The genomic clone was also compared with the open reading frame of the hydrophobin ssgA (starvation stress gene) cDNA sequence. The genomic clone contained a 291 bp coding sequence with one intron of 64 nucleotides. From this sequence primers were established that could be used to amplify the hydrophobin. Restriction fragment polymorphism analysis of hydrophobin amplified by the polymerase chain reaction from 80 isolates of M. anisopliae showed no variability. Analysis of the potential regulatory elements 313 bp upstream from the transcriptional start site revealed typical TATAA and CCAAT boxes. CT or GC motifs were not found. Upstream regulatory elements were also found with sequence homologies to the AREA, CREA, CRE (cAMP response element) and BRLA regions of Aspergillus nidulans as well as the CYS3 and AmyB regions of Aspergillus oryzae. The promoter regions of other fungal hydrophobins were also assessed for the presence of regulatory elements. Upstream regulatory elements are also present for the gene encoding a cuticle-degrading protease (Pr1) from M. anisopliae. We suggest that nutrient levels and cAMP mediation of thigmotropic signals in the entomopathogenic fungus, M. anisopliae, co-ordinate the regulation of the gene products required for morphological development and secretion of ‘penetration’ enzymes.