Max Planck Institute for Developmental Biology, Spemannstrasse 35, 72076 Tübingen, Germany.
Curr Biol. 2009 Oct 13;19(19):1642-7. doi: 10.1016/j.cub.2009.07.065. Epub 2009 Sep 3.
The genetic basis of morphological variation both within and between species has been a lasting question in evolutionary biology and one of considerable recent debate. It is thought that changes in postembryonic development leading to variations in adult form often serve as a basis for selection . Thus, we investigated the genetic basis of the development of adult structures in the zebrafish via a forward genetic approach and asked whether the genes and mechanisms found could be predictive of changes in other species. Here we describe the spiegeldanio (spd) zebrafish mutation, which leads to reduced scale formation in the adult. The affected gene is fibroblast growth factor receptor 1 (fgfr1), which is known to have an essential embryonic function in vertebrate development. We find that the zebrafish has two paralogs encoding Fgfr1 and show that they function redundantly during embryogenesis. However, only one paralog is required for formation of scales during juvenile development. Furthermore, we identify loss-of-function alleles changing the coding sequence of Fgfr1a1 that have been independently selected twice during the domestication of the carp (Cyprinus carpio). These findings provide evidence for the role for gene duplication in providing the raw material for generation of morphological diversity.
形态变异的遗传基础在物种内和物种间一直是进化生物学中的一个持久问题，也是最近相当有争议的问题之一。人们认为，导致成年形态变化的胚胎后发育变化常常是选择的基础。因此，我们通过正向遗传学方法研究了斑马鱼成年结构发育的遗传基础，并询问所发现的基因和机制是否可以预测其他物种的变化。在这里，我们描述了 spd 斑马鱼突变，该突变导致成年鱼鳞片形成减少。受影响的基因是成纤维细胞生长因子受体 1（fgfr1），它在脊椎动物发育中具有重要的胚胎功能。我们发现，斑马鱼有两个编码 Fgfr1 的旁系同源基因，并且它们在胚胎发生过程中具有冗余功能。然而，在幼年发育过程中仅需要一个旁系同源基因来形成鳞片。此外，我们还鉴定了改变 Fgfr1a1 编码序列的失活等位基因，这些等位基因在鲤鱼（Cyprinus carpio）的驯化过程中已经独立地被选择了两次。这些发现为基因复制在提供生成形态多样性的原材料方面的作用提供了证据。
