Osawa S, Muto A, Jukes T H, Ohama T
Department of Biology, Nagoya University, Japan.
Proc Biol Sci. 1990 Jul 23;241(1300):19-28. doi: 10.1098/rspb.1990.0060.
The genetic code has been influenced by directional mutation pressure affecting the base composition of DNA, sometimes in the direction of increased GC content and at other times, in the direction of AT. Such pressure led to changes in species-specific usages of codons and tRNA anticodons, and also in amino acid assignments of codons in mitochondria and in several intact organisms. These code changes are probably recent evolutionary events. The genetic code is not 'frozen', but instead it is still evolving.
遗传密码受到影响DNA碱基组成的定向突变压力的影响，有时朝着GC含量增加的方向，有时朝着AT的方向。这种压力导致了密码子和tRNA反密码子在物种特异性使用上的变化，以及线粒体和一些完整生物体中密码子的氨基酸分配变化。这些密码变化可能是近期的进化事件。遗传密码并非“一成不变”，而是仍在进化。
