Comparative transcriptomics of the model entomopathogenic fungi Metarhizium anisopliae and M. acridum during infection on different insects

We used RNA-Seq to compare transcriptional responses of M. anisopliae and M. acridum to infection of the optically clear hind wings of adult locusts and cockroaches. It was calculated that >82% of predicted M. anisopliae genes and >88% of predicted M. acridum genes were expressed during pre-penetration growth. Germination and growth by M. anisopliae and M. acridum on either insect triggered high level expression of genes associated with translation and post-translational modifications. Between 6 to 10% of the genes that were highly expressed by M. anisopliae and M. acridum on host cuticles encoded cell wall proteins. Consistent with early host recognition events being key to establishing specificity, M. acridum but not M. anisopliae transcribed different Pth11-like GPCRs on locust and cockroach cuticles, thus differential activation of different signaling pathways. Overall design: Examination of gene differential expressions by two different Metarhizium speceis on two different insects cuticles