Schistosoma mansoni: patterns of codon usage and bias.

Codon usage and bias has been examined in 20 genes of Schistosoma mansoni. Significant heterogeneity was detected in the patterns of codon usage and bias among genes by metric multidimensional scaling and three general indicators of bias (GC3S, Nc and B). In keeping with observations on sporozoan parasites, codon usage bias was observed to be dependent on the overall base composition of the genes analysed, which in turn was reflected in the types of codons that were over or under-represented in the sequences.