碱基替换

结果：28例喉癌中有50%在p53基因的第7～8外显子有突变，其中4例行DNA序列分析表明均有碱基替换、插入或丢失；

Results : p53 gene mutation existed in 50 % cases of laryngeal cancer and DNA sequencing showed base substitution , insertion or deletion in 4 cases ;

结果显示，在猪PLIN1基因第2、4外显子分别发现一处碱基替换突变。

The results showed that one base substitution was found in the exon 2 and exon 4 , respectively .

检出的由单个碱基替换而导致的无义突变都发生在CpG岛，表现为C向T的转换。

All of four nonsense mutations resulted from C to T transitions at CpG sites .

radiodurans这些基因在DNA错配修复途径中的作用。我们利用来自分析escherichiacoli碱基替换的突变分析系统&rpoB/Rif~R突变分析系统，测定和分析了自发突变导致D。

To further understand the functions of these genes , the rpoB / Rif ~ R mutation analysis system for analyzing base substitutions in Escherichia coli was used to D.

结论：Fc受体γ链基因3′-UTR3804位点T/G单碱基替换的多态性现象在中国南方汉族人群中少见，该位点的基因多态现象与SLE发病无关。

Conclusion : The T / G polymorphism at position 3804 in 3 ′ - UTR of Fc receptor gene is rare in populations of southern China and this polymorphism has no relationship with SLE .

仅1例鼻咽癌为EB病毒LMP1WtXhoI/BamHIF，基因序列分析（LMP1第3外显子）发现也有7个碱基替换（其中5个为错义突变和2个为同义突变）。

In the NPC tissue ( 1 case only ) showing the prototype of Wt-XhoI / BamHI f , there were several base substitutions , including 5 missense mutations and 2 silent mutations present in LMP1 exon 3 , on DNA sequencing .

考虑碱基组成对碱基替换的影响后，转换对颠换的优势在四倍简并位点也存在，但不如线粒体DNA中显著。

Taking into account of the effects of base composition on base substitution , it was found that the transition-transversion bias was evident but not as pronounced as in mitochondrial DNA .

动物线粒体编码序列相邻碱基组成对核苷酸替换的影响

Influence of neighboring base composition on nucleotide substitutions in animal mitochondrial coding sequences

和活体标本的18Srdna序列相比，标本DNA的碱基缺失率为7%，碱基替换比例为11%。

Compared with live specimen , 80 % bases of 18S rDNA sequence are identical , 7 % are deleted , and 11 % are replaced in formalin-fixed specimen .