Chaudhari N, Craig S P
Proc Natl Acad Sci U S A. 1979 Dec;76(12):6101-5. doi: 10.1073/pnas.76.12.6101.
In keeping with earlier reports, we have found that reassociated long repeat DNA from sea urchins is thermostable, indicating the absence of evolutionarily diverged families of repeated sequences. However, we found that when fragments of radiolabeled long repeat DNA were denatured and reassociated with intact long repeat driver DNA, then sheared to 350 basepairs and assayed for thermal stability, the level of mismatch found in the duplexes varied inversely with the length of the starting fragments. This effect was shown to be due directly to the physical size of the molecules involved in reassociation. These results are consistent with, and support a model for, long repeat DNA in which short units of repetition are arranged in precise arrays. The significance of this arrangement of sequence units within long repeat DNA is discussed.
与早期报告一致，我们发现海胆重新结合的长重复DNA是热稳定的，这表明不存在进化上分化的重复序列家族。然而，我们发现，当放射性标记的长重复DNA片段变性并与完整的长重复驱动DNA重新结合，然后剪切成350个碱基对并检测其热稳定性时，双链体中发现的错配水平与起始片段的长度成反比。这种效应被证明直接归因于参与重新结合的分子的物理大小。这些结果与长重复DNA的一种模型一致，并支持该模型，在该模型中，短重复单元以精确的阵列排列。本文讨论了长重复DNA中这种序列单元排列的意义。
