摘要
A cDNA encoding a protein is composed of coding region and nontranslated region (NTR). There are two parts of NTR. i.e. 5’ NTR or 3’ NTR, upstream or downstream the coding region respectively. According to neutral theory of molecular evolution, the following expectations might be true at cDNA level: (i)evolutionary rate of NTR is higher than that of coding region; (ii) synonymous substitutions in coding region evolution are more than missense substitutions; (iii) transition substitutions are more than
