Zimek Alexander, Weber Klaus
Max Planck Institute for Biophysical Chemistry, Am Fassberg, D-37077 Goettingen, Germany.
Eur J Cell Biol. 2008 May;87(5):305-9. doi: 10.1016/j.ejcb.2008.01.003. Epub 2008 Mar 6.
We identified the single gene for nuclear lamin in the genome draft of the sea anemone Nematostella vectensis, a member of the cnidaria, a very old metazoan phylum. The gene consists of 10 exons and 9 introns. Strikingly all 9 intron positions are conserved in the human lamin B genes, which have only 1 (lamin B1) or 2 (lamin B2) additional introns. Using the information on neighboring genes we propose that the human lamin B1 gene on chromosome 5 is the true homolog of the Nematostella lamin gene, while the lamin B2 gene on chromosome 19 arose during vertebrate evolution. In marked contrast to this conservation of gene structure are the results in the rapidly evolving genomes of Drosophila and Caenorhabditis elegans. Here the lamin genes have much fewer introns and these occur often at novel positions. In the single nematode lamin gene and the Drosophila lamin Dmo gene no intron position coincides with an intron in the sea anemone lamin gene.
我们在海葵星状海葵（Nematostella vectensis）的基因组草图中鉴定出了核纤层蛋白的单一基因，星状海葵属于刺胞动物门，这是一个非常古老的后生动物门。该基因由10个外显子和9个内含子组成。令人惊讶的是，所有9个内含子位置在人类核纤层蛋白B基因中都是保守的，而人类核纤层蛋白B基因只有1个（核纤层蛋白B1）或2个（核纤层蛋白B2）额外的内含子。利用相邻基因的信息，我们提出5号染色体上的人类核纤层蛋白B1基因是星状海葵核纤层蛋白基因的真正同源物，而19号染色体上的核纤层蛋白B2基因是在脊椎动物进化过程中产生的。与这种基因结构的保守性形成鲜明对比的是果蝇和秀丽隐杆线虫快速进化的基因组中的结果。在这里，核纤层蛋白基因的内含子要少得多，而且这些内含子经常出现在新的位置。在单个线虫核纤层蛋白基因和果蝇核纤层蛋白Dmo基因中，没有一个内含子位置与海葵核纤层蛋白基因中的内含子位置重合。
