Structural variation among human beta-tubulin genes.
Structural variation among human beta-tubulin genes.
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人类β-微管蛋白基因的结构变异。
DOI：
10.1073/pnas.78.8.4877
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发表时间：
1981
影响因子：
11.1
通讯作者：
Wefald,FC
中科院分区：
文献类型：
--
作者：
Cowan,NJ;Wilde,CD;Chow,LT;Wefald,FC
鸡 β-微管蛋白 cDNA 探针已用于筛选两个独立生成的人类基因组文库。在人类基因组 Southern 印迹实验中可检测到的 13 个 EcoRI 片段中，有 7 个片段的大小与从重组噬菌体中分离的 EcoRI 片段相对应。确定每个克隆片段内β-微管蛋白特异性区域的位置和转录方向。一个克隆 (5 beta) 含有 6.8 kbp 的 β-微管蛋白特异性区域，其中包括三个插入序列以及许多反向重复结构。其余的克隆含有 β-微管蛋白特异性序列，其长度接近或在两种情况下远小于 1.9 kbp。由于成熟的人类 β-微管蛋白 mRNA 长度约为 1.9 kbp，因此这些短 DNA 区域本身无法编码功能性 β-微管蛋白 mRNA。使用源自鸡 cDNA 克隆的 3' 和 5' 特异性探针进行分析表明，在一个截短的微管蛋白样序列中存在这两个末端区域。第二个短微管蛋白特异性区域未能与 3' 特异性探针杂交。因此，这些短序列很可能是假基因的例子，这些假基因是由于生产功能性人 β-微管蛋白 mRNA 所必需的部分 DNA 的丢失而产生的。
A chicken beta-tubulin cDNA probe has been used to screen two independently generated human genomic libraries. Of 13 EcoRI fragments detectable in a human genomic Southern blot experiment, 7 correspond in size to EcoRI fragments isolated from recombinant bacteriophage. The location of beta-tubulin-specific regions and the direction of transcription were determined within each cloned fragment. One clone (5 beta) contained a beta-tubulin-specific region of 6.8 kilobase pairs (kbp) that included three intervening sequences as well as a number of inverted repeat structures. The remaining clones contained beta-tubulin-specific sequences that were close to or, in two cases, substantially less than 1.9 kbp long. Because mature human beta-tubulin mRNA is approximately 1.9 kbp long, these short DNA regions cannot on their own encode a functional beta-tubulin mRNA. Analysis using 3'- and 5'-specific probes derived from the chicken cDNA clone showed the presence of both of these end regions within one truncated tubulin-like sequence. A second short tubulin-specific region failed to hybridize with a 3'-specific probe. These short sequences are therefore likely to be examples of pseudogenes that have arisen by loss of a portion of DNA essential to the production of functional human beta-tubulin mRNA.