Weinreb A, Katzenberg D R, Gilmore G L, Birshtein B K
Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461.
Proc Natl Acad Sci U S A. 1988 Jan;85(2):529-33. doi: 10.1073/pnas.85.2.529.
Previous studies from this laboratory have provided evidence that the duplication of the IgG2a heavy chain constant region gene (C gamma 2a) in the murine myeloma cell line MPC-11 occurred via unequal sister chromatid exchange. We now report the determination of the DNA sequences of the germ-line regions in which this exchange has occurred. The two donor sequences have long regions of virtual identity. Furthermore, both chromatids contain stretches of T-C and T-G dinucleotides; the latter has the potential to form Z-DNA. Localization of the actual breakpoints via genomic Southern blot analysis suggests a novel mechanism for the recombination and strongly implicates the simple sequence in the process.
本实验室先前的研究已提供证据表明，鼠骨髓瘤细胞系MPC-11中IgG2a重链恒定区基因（Cγ2a）的复制是通过不等姐妹染色单体交换发生的。我们现在报告已发生这种交换的种系区域DNA序列的测定结果。这两个供体序列有很长的几乎完全相同的区域。此外，两条染色单体都含有T-C和T-G二核苷酸序列；后者有可能形成Z-DNA。通过基因组Southern印迹分析对实际断点进行定位，提示了一种新的重组机制，并有力地表明了该过程中的简单序列。
