The number of OGDs predicted for each of the 40 universal single-copy gene families used in this study.

The gene families in bold are the 9 gene families analysed here in addition to the 31 previously analysed using a manual approach [14]. “Interactions” are the number of interactions with other gene families predicted for this gene family using the String 7 database [33] with a cut-off of 0.7. A significant negative correlation was found to exist between the number of Interactions predicted and the number of OGDs detected for each of the genes (see Figure S3). There was also a significant correlation between the number of OGDs detected and whether the gene coded for a ribosomal protein or not (Figure 4a).