Figure 1. HP1 diversity in Drosophila genomes.

A. Phylogeny of 12 Drosophila species, which were each queried for HP1-like genes in this study [2], [42]. Scale bar refers to the approximate divergence time between these species [2], [42]. B. Schematics of proteins encoded by the various HP1 genes in Drosophila genomes are presented alongside the HP1 gene name. Highlighted in boxes are the canonical chromo (green) and shadow (blue) domains that typify HP1 genes. Note that in some instances, we were unable to confirm the exact gene model and therefore the lengths of the N-terminal tails (these are indicated with dashed lines). We also report the D. melanogaster cytolocation of the gene or if the gene is absent in D. melanogaster, the sytenic location in the D. melanogaster genome based on neighboring genes. The final column reports the species in which the gene is found. Genes shaded gray represent founding HP1 gene family members that were reported in the original D. melanogaster genome sequencing study [42]. “*” refers to an allele that harbors a premature stop codon but conserved C-terminal sequence (Table S1, Figure S4) and predicted CD and CSD domains, consistent with a polymorphic full length gene or an incorrect base call.