Arabidopsis DNA Methylation Mutants

理查兹技术 具有DNA甲基化（ddm）降低的拟南芥突变体被分离并较早地表征。ddml突变体虽然具有野生型水平的甲基转移酶，但仅具有野生型甲基胞嘧啶的约30%。此外，已经发现，如果这些突变体连续自交，则会出现进行性异常。一个这样的异常是减少植物大小和顶端优势（球）。球状突变是稳定的，它被定位在一个不同于ddml突变的基因组位点。在该项目的任期内，DDM1基因将被分离和表征。此外，将通过基于图位的克隆方法分离BAL基因座，并在分子水平上进行表征。ddm 2突变体的表型、遗传、生化和分子分析也将继续进行。 已经观察到，存在不能用孟德尔遗传学解释的描述的遗传现象，并且暗示性证据涉及DNA甲基化。它一直难以文件的原因和影响，但从这项工作所产生的信息应该提供更多的洞察力到基本的遗传机制。

9604972 Richards Technical Mutants of Arabidopsis thaliana which have a decrease in DNA methylation (ddm) were isolated and characterized earlier. The ddml mutant has only about 30% of the wild type methylcytosine although it has wild type levels of methyl transferase. Moreover, it has been found that if these mutants are continuously selfed, progressive abnormalities appear. One such abnormality was reduced plant size and apical dominance (ball). The ball mutation, which is stable, has been mapped to a genome site different than the ddml mutation. During the tenure of this project, the DDMl gene will be isolated and characterized. Additionally, the BAL locus will be isolated by a map-based cloning approach and characterized at a molecular level. The phenotypic, genetic, biochemical and molecular analysis of ddm2 mutants will also continue. Non-technical It has been observed that there are described genetic phenomena which cannot be explained by Mendelian genetics and suggestive evidence implicates DNA methylation. It has been difficult to document cause and effect but the information resulting from this work should provide greater insiqht into basic qenetic mechanisms.