Fernández V, Zavala A, Musto H
Cátedra de Inmunología, Facultad de Química, Montevideo, Uruguay.
Parasitology. 2001 Aug;123(Pt 2):203-9. doi: 10.1017/s0031182001008150.
We analysed the intragenomic variation in codon usage in Echinococcus spp. by correspondence analysis. This approach detected a trend among genes which was correlated with expression levels. Among the (presumed) highly expressed sequences we found an increased usage of a subset of codons, almost all of them G- or C- ending. Since an increase in these bases at the synonymous sites is against the mutational bias (these genomes are slightly A+-T- rich), we conclude that codon usage in Echinococcus is the result of an equilibrium between compositional pressure and selection, the latter acting at the level of translation, mainly on highly expressed genes. This is the first report where translational selection for codon usage is detected among Platyhelminthes.
我们通过对应分析研究了棘球绦虫属物种密码子使用的基因组内变异。该方法检测到基因间的一种趋势，这种趋势与表达水平相关。在（假定的）高表达序列中，我们发现一组密码子的使用增加，几乎所有这些密码子都以G或C结尾。由于同义位点上这些碱基的增加与突变偏好相悖（这些基因组略富含A + -T -），我们得出结论，棘球绦虫的密码子使用是组成压力和选择之间平衡的结果，后者在翻译水平起作用，主要作用于高表达基因。这是首次在扁形动物中检测到密码子使用的翻译选择的报告。
