REPEAT-INDUCED G-C TO A-T MUTATIONS IN NEUROSPORA
REPEAT-INDUCED G-C TO A-T MUTATIONS IN NEUROSPORA
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DOI：
10.1126/science.2544994
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发表时间：
1989-06-30
期刊：
影响因子：
56.9
通讯作者：
SELKER, EU
中科院分区：
文献类型：
--
作者：
CAMBARERI, EB;JENSEN, BC;SELKER, EU
在脉孢菌基因组中，重复序列在有性阶段被检测到并改变。重复基因的两个拷贝在高频率下都是失活的，无论它们是否连锁。限制性位点改变，并且受影响的序列通常变得高度甲基化。为了表征DNA的改变，在一个或多个性周期之前和之后分离重复序列。DNA测序和异源双链体分析表明，该过程（称为RIP）只产生G-C到A-T突变。变化主要发生在腺嘌呤位于变化的胞嘧啶的3“处的位点。一个在基因组远端复制的序列在一次杂交中丢失了大约10%的G-C对。一个紧密连锁的重复的相同序列，通过两次交叉失去了大约一半的G-L对。结果表明RIP过程的机制。
In the Neurospora genome duplicate sequences are detected and altered in the sexual phase. Both copies of duplicate genes are inactivated at high frequnecy, whether or not they are linked. Restriction sites change, and affected sequences typically become heavily methylated. To characterize the alterations of the DNA, duplicated sequences were isolated before and after one or more sexual cycles. DNA sequencing and heteroduplex analyses demonstrated that the process (termed RIP) produces exclusively G-C to A-T mutations. Changes occur principally at sites where adenine is 3'' of the changed cytosine. A sequence duplicated at a distant site in the genome lost approximately 10 percent of its G-C pairs in one passage through a cross. A closely linked duplication of the same sequence that was passed twice through a cross lost about half of its G-L pairs. The results suggest a mechanism for the RIP process.