Tri-phasic expression of posterior Hox genes during development of pectoral fins in zebrafish:: Implications for the evolution of vertebrate paired appendages
Tri-phasic expression of posterior Hox genes during development of pectoral fins in zebrafish:: Implications for the evolution of vertebrate paired appendages
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DOI：
10.1016/j.ydbio.2008.06.032
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发表时间：
2008-10-01
影响因子：
2.7
通讯作者：
Ho, Robert K.
中科院分区：
文献类型：
--
作者：
Ahn, Daegwon;Ho, Robert K.
在四肢发育过程中，同源类群9-13的Hox基因在三个不同的阶段表达，在肢体骨骼的节段模式中起关键作用。在硬骨鱼中，它们的鳍骨骼有一个非常不同的组织，尚不清楚是否有类似的模式机制在起作用。为了确定Hox基因是否也在硬骨鱼配对鳍发育的几个不同阶段表达，我们重新分析了斑马鱼胸鳍发育过程中hox9-13基因的表达模式。我们发现，与四足动物的Hox基因类似，斑马鱼胸鳍中hoxa/d基因的表达发生在三个不同的阶段，其中最末端/第三阶段与鳍的最末端结构——鳍叶片的发育有关。与四足动物一样，斑马鱼胸鳍在远/第三阶段的hox基因表达依赖于sonic hedgehog信号（hoxa和hoxd基因）和远程增强子（hoxa基因）的存在，这表明在进化过程中，Hex基因三相表达的调控机制相对保持不变。我们的研究结果表明，尽管硬骨鱼的鳍在组织上更简单，但它的鳍确实有一个远端结构，可以被认为与四肢的自足区相当。(c) 2008爱思唯尔公司版权所有。
During development of the limbs, Hox genes belonging to the paralogous groups 9-13 are expressed in three distinct phases, which play key roles in the segmental patterning of limb skeletons. In teleost fishes, which have a very different organization in their fin skeletons, it is not clear whether a similar patterning mechanism is at work. To determine whether Hox genes are also expressed in several distinct phases during teleost paired fin development, we re-analyzed the expression patterns of hox9-13 genes during development of pectoral fins in zebrafish. We found that, similar to tetrapod Hox genes, expression of hoxa/d genes in zebrafish pectoral fins Occurs in three distinct phases, in which the most distal/third phase is correlated with the development of the most distal structure of the fin, the fin blade. Like in tetrapods, hox gene expression in zebrafish pectoral fins during the distal/third phase is dependent upon sonic hedgehog signaling (hoxa and hoxd genes) and the presence of a long-range enhancer (hoxa genes), which indicates that the regulatory mechanisms underlying tri-phasic expression of Hex genes have remained relatively unchanged during evolution. Our results suggest that, although simpler in organization, teleost fins do have a distal structure that might be considered comparable to the autopod region of limbs. (c) 2008 Elsevier Inc. All rights reserved.