Tooth and scale morphogenesis in shark: an alternative process to the mammalian enamel knot system.
Tooth and scale morphogenesis in shark: an alternative process to the mammalian enamel knot system.
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DOI：
10.1186/s12862-015-0557-0
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发表时间：
2015-12-24
影响因子：
3.4
通讯作者：
Borday-Birraux V
中科院分区：
文献类型：
--
作者：
Debiais-Thibaud M;Chiori R;Enault S;Oulion S;Germon I;Martinand-Mari C;Casane D;Borday-Birraux V
参与牙齿形态发生的基因调控网络已经在哺乳动物中得到了非常好的描述，并且其建模允许预测可能导致牙齿形状进化的调控途径的变化。然而，很少有人知道以外的哺乳动物，以了解如何这种监管框架也可能占牙齿形状的进化在有颚类的水平。在这项工作中，我们描述了表达模式和增殖/凋亡检测，以揭示同源的调节途径在猫鲨Scyliorhinus canicula。由于其相似的结构和发育特征，基因表达模式描述了猫鲨的牙齿和鳞片芽的四个发育阶段。这些基因表达模式与小鼠牙齿发育不同，并且在猫鲨的牙齿和鳞片发育之间也观察到差异。然而，一个类似的嵌套表达的Shh和Fgf表明类似的信号参与所有结构的形态发生，虽然细胞凋亡检测不支持严格等同的釉结系统在鲨鱼。在基因表达模式的拓扑结构，包括BMP信号通路的相似性，表明小鼠磨牙发育更类似于鳞芽发育的猫鲨。这些结果支持了这样一个事实，即没有釉质结，在哺乳动物的牙齿，可以描述在鲨鱼牙齿或鳞片的形态发生。然而，同源信号通路参与生长和形态发生，其各自的表达模式存在差异。我们推测，在这种拓扑结构的表达变化也是一个基板的牙齿形状的演变，特别是在调节生长轴和对称性的发展结构。本文的在线版本（doi：10.1186/s12862-015-0557-0）包含补充材料，可供授权用户使用。
The gene regulatory network involved in tooth morphogenesis has been extremely well described in mammals and its modeling has allowed predictions of variations in regulatory pathway that may have led to evolution of tooth shapes. However, very little is known outside of mammals to understand how this regulatory framework may also account for tooth shape evolution at the level of gnathostomes. In this work, we describe expression patterns and proliferation/apoptosis assays to uncover homologous regulatory pathways in the catshark Scyliorhinus canicula. Because of their similar structural and developmental features, gene expression patterns were described over the four developmental stages of both tooth and scale buds in the catshark. These gene expression patterns differ from mouse tooth development, and discrepancies are also observed between tooth and scale development within the catshark. However, a similar nested expression of Shh and Fgf suggests similar signaling involved in morphogenesis of all structures, although apoptosis assays do not support a strictly equivalent enamel knot system in sharks. Similarities in the topology of gene expression pattern, including Bmp signaling pathway, suggest that mouse molar development is more similar to scale bud development in the catshark. These results support the fact that no enamel knot, as described in mammalian teeth, can be described in the morphogenesis of shark teeth or scales. However, homologous signaling pathways are involved in growth and morphogenesis with variations in their respective expression patterns. We speculate that variations in this topology of expression are also a substrate for tooth shape evolution, notably in regulating the growth axis and symmetry of the developing structure. The online version of this article (doi:10.1186/s12862-015-0557-0) contains supplementary material, which is available to authorized users.