A ROLE FOR REVERSE TRANSCRIPTS IN GENE CONVERSION
A ROLE FOR REVERSE TRANSCRIPTS IN GENE CONVERSION
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DOI：
10.1038/361170a0
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发表时间：
1993-01-14
期刊：
影响因子：
64.8
通讯作者：
STRATHERN, JN
中科院分区：
文献类型：
--
作者：
DERR, LK;STRATHERN, JN
可扩散反转录与其同源染色体等位基因之间的重组被认为是从DNA中精确去除内含子和分散重复序列的基因转化的机制1，2。我们已经报道了RNA介导的重组发生在酿酒酵母3中。这种重组需要逆转录转座子Ty的表达，并导致质粒携带的标记基因的内含子丢失和假基因的形成。由于假基因嵌入到Ty序列中，染色体插入可能由Ty整合酶或与内源Ty序列的同源重组所介导。染色体重组体的结构以及质粒和染色体重组可以有不同的要求这一事实，要求直接证明RNA介导的染色体等位基因的基因转换。在这里，我们报告了第一次，据我们所知，反向转录本和它的染色体同源物之间的重组，并描述了一种专门检测这一新的重组途径的方法。
RECOMBINATION between a diffusible reverse transcript and its homologous chromosomal allele has been proposed as a mechanism for the precise removal of introns from DNA and gene conversion of dispersed repeated sequences1,2. We have reported that RNA-mediated recombination occurs in the yeast Saccharomyces cerevisiae3. This recombination requires expression of the retro-transposon Ty, and results in intron loss from a plasmid-borne marker gene and the formation of pseudogenes. Because the pseudogenes are embedded in Ty sequences, chromosomal insertion could have been mediated by Ty integrase or by homologous recombination with endogenous Ty sequences. The structure of the chromosomal recombinants and the fact that plasmid and chromosomal recombination can have different requirements demanded a direct demonstration of RNA-mediated gene conversion of a chromosomal allele. Here we report the first demonstration, to our knowledge, of recombination between a reverse transcript and its chromosomal homologue and describe an assay that specifically detects this novel recombination pathway.