Satou Yutaka, Imai Kaoru S, Satoh Nori
Department of Zoology, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
Dev Genes Evol. 2002 Oct;212(9):432-8. doi: 10.1007/s00427-002-0266-8. Epub 2002 Sep 5.
In vertebrates, a number of fibroblast growth factors (FGFs) have been shown to play important roles in developing embryos and adult organisms. However, the molecular relationships of the vertebrate FGFs are not yet completely understood, partly due to the divergence of their amino acid sequences. To solve this problem, we have identified six FGF genes in a basal chordate, the ascidian Ciona intestinalis. A phylogenetic analysis confidently assigned two of them to vertebrate FGF8/17/18 and FGF11/12/13/14, respectively. Based on the presence of the conserved domains within or outside of the FGF domains, we speculate that three of the other genes are orthologous to vertebrate FGF3/7/10/22, FGF4/5/6 and FGF9/16/20, respectively, although we cannot assign the sixth member to any of the vertebrate FGFs. A survey of the raw whole genome shotgun sequences of C. intestinalis demonstrated the presence of no FGF genes other than the six genes in the genome. The identification of these six FGF genes in the basal chordate gave us an insight into the diversification of specific subfamilies of vertebrate FGFs.
在脊椎动物中，多种成纤维细胞生长因子（FGFs）已被证明在胚胎发育和成年生物体中发挥重要作用。然而，脊椎动物FGFs的分子关系尚未完全明确，部分原因在于其氨基酸序列的差异。为解决这一问题，我们在一种基础脊索动物——海鞘（Ciona intestinalis）中鉴定出了六个FGF基因。系统发育分析明确地将其中两个基因分别归为脊椎动物的FGF8/17/18和FGF11/12/13/14。基于FGF结构域内部或外部保守结构域的存在情况，我们推测另外三个基因分别与脊椎动物的FGF3/7/10/22、FGF4/5/6和FGF9/16/20直系同源，尽管我们无法将第六个成员归为任何一种脊椎动物FGF。对海鞘原始全基因组鸟枪法测序序列的调查表明，基因组中除这六个基因外不存在其他FGF基因。在基础脊索动物中鉴定出这六个FGF基因，使我们对脊椎动物FGFs特定亚家族的多样化有了深入了解。
