Fig. 3.

Analysis of gene nitrogen content of three parasites that occupy the same host niche but utilise different metabolic strategies. a The average mRNA nitrogen content per codon for 227 single copy genes present in each species. b The average nitrogen content per double-stranded codon (dsDNA) for the same genes. The y-axis is the probability density function (PDF) for the distributions. Yellow indicates an animal parasite that obtains energy from carbohydrate catabolism (medium nitrogen availability, M _N). Orange indicates an animal parasite that obtains energy from amino acid and/or amino sugar catabolism (high nitrogen availability, H _N). Pink indicates an animal parasite that obtains energy by exporting ammonia from the cell