The codon adaptation index (CAI) of mitochondrial genes in species in the clade Saccharomycotina.

The grey and black bars denote the post and pre-WGD fungi species, respectively. The average CAI values of the mitochondrial genes with P3E (A) and without P3E (B) were shown. The student t-test was used to compare CAI values between pre- and post-WGD fungi species.