Fig. 2.

Classification of HD proteins. A phylogenetic tree of the HD sequences in Sup. Fig. S1 was created using neighbor joining in Clustal X (Larkin et al. 2007). Classification of the HDs is marked on the right. Genes belonging to genomic clusters are marked in different colors in italics. The three PRD class families with HDs are indicated. Due to the limited number of sequences, the tree should only be taken as simple guide to illustrate how similar or divergent HD sequences are when compared to each other. Hence, not all genes within a class fall within the same clade