Fig. 1

Comparison of protein lengths between one-to-one orthologs. a One-to-one orthologous genes between C. elegans and P. pacificus have highly similar protein lengths (Pearson’s r = 0.83). b Size distributions of one-to-one orthologs show a peak at around 300 amino acids. c P. pacificus genes with more than two-fold length difference were considered for manual curation. d The P. pacificus one-to-one ortholog (PPA0494) of C. elegans lev-8, is more than twice as long as LEV-8. BLAST analysis showed that the N-terminal region has similarity to another C. elegans gene (Y37B6BL.37) suggesting that it represents an artificial gene fusion. e Manual inspection of the PPA0494 in the genome browser shows that there are two assembled RNA-seq transcripts (red) that cover most of the original gene model and further support that PPA0494 is an artificially fused gene model