Oppenheimer D G, Haas N, Silflow C D, Snustad D P
Department of Genetics and Cell Biology, University of Minnesota, St. Paul 55108.
Gene. 1988;63(1):87-102. doi: 10.1016/0378-1119(88)90548-3.
The genome of Arabidopsis thaliana (L.) Heynh. was shown to contain a beta-tubulin gene family consisting of at least seven distinct genes and/or pseudogenes. Genomic clones of five different beta-tubulin genes and/or pseudogenes have been isolated and partially characterized. The complete nucleotide sequence of one A. thaliana beta-tubulin gene, designated beta 1, has been determined. A comparison of the predicted amino acid sequence of the A. thaliana beta 1-tubulin with the predicted sequences of beta-tubulins of animals and protists indicated that this plant beta-tubulin shows a high degree of homology with other beta-tubulins. However, the beta 1-tubulin contains a novel single amino acid insertion at position 41. The A. thaliana beta 1-tubulin gene is transcribed, as shown by RNA blot hybridization and S1 nuclease analyses. A 3'-noncoding gene-specific probe was used to examine the expression of the beta 1-tubulin gene in leaves, roots, and flowers by blot hybridization analyses of total RNA isolated from these tissues. The results showed that the transcript of the beta 1 gene accumulates predominantly in roots, with low levels of transcript in flowers, and barely detectable levels of transcript in leaves. A second genomic clone was shown to contain two essentially identical beta-tubulin coding sequences in direct tandem orientation and separated by 1 kb.
拟南芥（Arabidopsis thaliana (L.) Heynh.）的基因组被证明含有一个β-微管蛋白基因家族，该家族由至少七个不同的基因和/或假基因组成。五个不同的β-微管蛋白基因和/或假基因的基因组克隆已被分离并进行了部分特征分析。已确定了一个拟南芥β-微管蛋白基因（命名为β1）的完整核苷酸序列。将拟南芥β1-微管蛋白的预测氨基酸序列与动物和原生生物的β-微管蛋白预测序列进行比较，结果表明这种植物β-微管蛋白与其他β-微管蛋白具有高度同源性。然而，β1-微管蛋白在第41位含有一个新的单氨基酸插入。如RNA印迹杂交和S1核酸酶分析所示，拟南芥β1-微管蛋白基因是转录的。使用一个3'-非编码基因特异性探针，通过对从这些组织中分离的总RNA进行印迹杂交分析，来检测β1-微管蛋白基因在叶、根和花中的表达。结果表明，β1基因的转录本主要在根中积累，花中的转录本水平较低，而叶中的转录本水平几乎检测不到。第二个基因组克隆被证明含有两个基本相同的β-微管蛋白编码序列，它们以直接串联的方向排列，间隔1 kb。
