Comparison of cloned mouse alpha- and beta-globin genes: conservation of intervening sequence locations and extragenic homology.
Comparison of cloned mouse alpha- and beta-globin genes: conservation of intervening sequence locations and extragenic homology.
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克隆小鼠α-珠蛋白基因和β-珠蛋白基因的比较：间插序列位置和基因外同源性的保守性。
DOI：
10.1073/pnas.75.12.6187
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发表时间：
1978
影响因子：
11.1
通讯作者：
P. Leder
中科院分区：
文献类型：
--
作者：
A. Leder;H. Miller;D. Hamer;J. Seidman;B. Norman;M. Sullivan;P. Leder
我们已经克隆并鉴定了含有α-珠蛋白基因的小鼠DNA的9.7-内切酶EcoRI片段。该基因编码在至少三个不连续的DNA片段中，被两个小的插入序列中断，这些插入序列在电子显微镜中可以被视为R环结构。该基因的大小及其小的插入序列与已知的α-珠蛋白mRNA前体的大小非常吻合，这表明这些插入序列与β-珠蛋白的插入序列一样，是转录的。部分序列分析表明，较大的间插序列中断α-珠蛋白基因在一个网站完全对应的中断较大的间插序列在β-珠蛋白的主要和次要基因。这一观察结果表明，这些序列存在于5亿多年前，当α-和β-珠蛋白基因在早期脊椎动物进化中分化时。此外，虽然α和β基因编码在不同的染色体上，但当通过异源双链结构的可视化直接比较它们的序列时，仅识别出一个150至200碱基对的同源片段。这些同源序列位于两个基因的3 '侧翼片段上，每个基因约1.5个内切酶。
We have cloned and characterized a 9.7-kilobase EcoRI fragment of mouse DNA that contains an alpha-globin gene. The gene is encoded in at least three discontinous segments of DNA interrupted by two small intervening sequences that can be visualized as R-loop structures in the electron miscroscope. The size of the gene and its small intervening sequences fits well with the known size of the alpha-globin mRNA precursor, suggesting that these intervening sequences, like those of beta-globin, are transcribed. Partial sequence analysis indicates that the larger intervening sequence interrupts the alpha-globin gene at a site exactly corresponding to that interrupted by the larger intervening sequences in both the beta-globin major and minor genes. This observation suggests that these sequences were present when the alpha- and beta-globin genes diverged in early vertebrate evolution, more than 500 million years ago. Furthermore, though alpha and betamaj genes are encoded on different chromosomes, when their sequences are compared directly by visualization of heteroduplex structures, only one 150- to 200-base-pair segment of homology is recognized. These homologous sequences are located on the 3'-flanking segments of both genes, about 1.5 kilobases from each.