Heat map of gene expression levels of UniRef50 clusters. Gene expression levels of the 5% most highly expressed UniRef50 clusters passing a variance filtering of 0.3 (total 160) are shown. I to IX indicate nine clusters that were identified using hierarchical clustering of normalized, log2-transformed read counts (+1). The right panels shows annotations of the UniRef50 cluster sequences based on the presence of Pfam domains (Additional file 7). Bold indicates domains that were found among 25 expanded Pfam domains identified in the genome of M. haptotylum. Ao(Mh) denotes A. oligospora and M. hapla; Ao(Hs), A. oligospora and H. schachtii; Ad(Mh), A. dactyloides and M. hapla; Ad(Hs), A. dactyloides and H. schachtii; and Mc(Hs), M. cionopagum and H. schachtii.