Koike M, Matsuda Y, Mimori T, Harada Y N, Shiomi N, Shiomi T
Genome Research Group, National Institute of Radiological Sciences, Chiba, Japan.
Genomics. 1996 Nov 15;38(1):38-44. doi: 10.1006/geno.1996.0589.
The Ku p70 and Ku p80/XRCC5 genes are involved in DNA double-strand break repair and V(D)J recombination, and their gene products are the components of the DNA-dependent protein kinase. We have determined the chromosomal locations of the mouse Ku p70 and Ku p80/XRCC5 genes by both in situ hybridization and molecular linkage analysis: the Ku p70 gene was localized to mouse chromosome 15 and rat chromosome 7, and the Ku p80/XRCC5 gene was localized to mouse chromosome 1 and rat chromosome 9. Both genes were mapped to a region of conserved linkage homology among three species, i.e., the mouse, rat, and human. Molecular linkage analysis using interspecific backcross mice revealed that the murine Ku p70 locus was localized 0.7 cM terminal to D15Mit1 and that the murine Ku p80/XRCC5 locus was 0.7 cM proximal to D1Mit46. To determine the size and tissue transcription specificity of the mouse Ku p70 and Ku p80/XRCC5 mRNA, Northern blot analysis was carried out with six mouse tissues. Each tissue expressed one species of the Ku p70 gene transcript with 2.4 kb and one species of the Ku p80/XRCC5 gene transcript with 2.6 kb. In the latter case, however, the brain showed two sizes of transcript, 2.6 and 2.9 kb.
Ku p70和Ku p80/XRCC5基因参与DNA双链断裂修复和V(D)J重组，其基因产物是DNA依赖性蛋白激酶的组成部分。我们通过原位杂交和分子连锁分析确定了小鼠Ku p70和Ku p80/XRCC5基因的染色体定位：Ku p70基因定位于小鼠15号染色体和大鼠7号染色体，Ku p80/XRCC5基因定位于小鼠1号染色体和大鼠9号染色体。这两个基因都被定位到小鼠、大鼠和人类这三个物种间保守的连锁同源区域。利用种间回交小鼠进行的分子连锁分析表明，小鼠Ku p70基因座位于D15Mit1末端0.7 cM处，小鼠Ku p80/XRCC5基因座位于D1Mit46近端0.7 cM处。为了确定小鼠Ku p70和Ku p80/XRCC5 mRNA的大小和组织转录特异性，我们用六种小鼠组织进行了Northern印迹分析。每种组织都表达一种2.4 kb的Ku p70基因转录本和一种2.6 kb的Ku p80/XRCC5基因转录本。然而，在后一种情况下，大脑显示出两种大小的转录本，分别为2.6 kb和2.9 kb。
