The genetic code is the recipe for life, and provides the instructions for how to make proteins, generally using just 20 amino acids. But certain groups of microbes have an expanded genetic code, in ...

Knowledge of the frequencies of synonymous triplets in protein-coding and non-coding DNA stretches can be used in gene finding. These frequencies depend on the GC content of the genome or parts of it.

In the human genome, the fraction of synonymous codons changes monotonically with the GC content of coding sequences: with increasing the GC content the codons that are richer in GC within their ...