Abe Gembu, Ide Hiroyuki, Tamura Koji
Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Aobayama, Aoba-ku, Sendai 980-8578, Japan.
Dev Biol. 2007 Apr 1;304(1):355-66. doi: 10.1016/j.ydbio.2006.12.040. Epub 2006 Dec 23.
Median fins, unpaired appendages in fish, are fundamental locomotory organs that are believed to have evolved before paired lateral appendages in vertebrates. However, the early process of median fin development remains largely unknown. We investigated the early development of the median fin fold, a rudiment of median fins, and report here the process in zebrafish embryos and the function of FGF signaling in the process. Using expressions of three genes, dlx5a, sp9 and fgf24, as markers of different phases of fold development, our findings suggest that the early process of median fin fold development can be divided into two steps, specification of the median fin fold territory and construction of the fold structure. Both loss-of-function and gain-of-function assays revealed that FGF signaling plays roles in each step, suggesting a common mechanism for the development of median appendages and paired lateral appendages.
中鳍是鱼类的不成对附肢，是基本的运动器官，被认为在脊椎动物的成对侧附肢之前就已经进化出来。然而，中鳍发育的早期过程在很大程度上仍然未知。我们研究了中鳍褶（中鳍的原基）的早期发育，并在此报告斑马鱼胚胎中的这一过程以及FGF信号在此过程中的作用。利用三个基因dlx5a、sp9和fgf24的表达作为褶发育不同阶段的标记，我们的研究结果表明，中鳍褶发育的早期过程可分为两个步骤，即中鳍褶区域的特化和褶结构的构建。功能丧失和功能获得实验均表明，FGF信号在每个步骤中都发挥作用，这表明中附肢和成对侧附肢的发育存在共同机制。
