沉默突变

对为什么叫做C3435T的沉默突变比对癌细胞存活没有作用的突变发生得更频繁，研究人员感到好奇。

Researchers wondered why the silent mutation , called C3435T , showed up much more frequently than expected for a change that doesn 't have an effect on the cancer cells'survival .

细胞可能可以弥补一次沉默突变，但对那些多重的极少使用的三联体密码子则不行。

The cell might be able to compensate for one silent mutation but not for multiple rarely used triplets .

全基因组cDNA克隆构建过程中引入的沉默突变（8453位核苷酸由C变为T）产生XbaI酶切位点作为遗传标记，在子代恢复病毒的基因组中稳定存在。

A silent nucleotide change was introduced into the cDNA clone to create a Xba I site ( C to T at 8453nt ) that is used as a genetic marker of this infectious clone . This genetic marker was retained in the genome of recovered progeny virus .

对在外显子2表现SSCP多态性的MSTN基因扩增片段进行了克隆测序，测序结果表明，MSTN基因发生了单碱基的突变：即G480→T，该突变未导致氨基酸的改变，属沉默突变。

The fragment with SSCP polymorphism in the second exon was cloned and sequenced , the sequencing results showed that there was a single nucleotide mutation , i. e G → T at 480 , this mutation did not change its encoding amino acid . 4 .

在经过验证的165个非沉默突变位点中经常出现碱基的转换和颠换。

Base transitions and base transversions were frequently found among 165 confirmed non-silenced mutations .

结果：28例标本中检测到29个突变（不包括2种沉默突变），包括15个缺失突变和14个错义突变。

Results : 29 mutations were found in 28 tumor tissues not including 2 types of silent mutation , in which included 15 deletion mutations and 14 missense mutations .