No more than 14: the end of the amphioxus Hox cluster.
No more than 14: the end of the amphioxus Hox cluster.
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DOI：
10.7150/ijbs.1.19
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发表时间：
2005
影响因子：
9.2
通讯作者：
Garcia-Fernàndez J
中科院分区：
文献类型：
--
作者：
Minguillón C;Gardenyes J;Serra E;Castro LF;Hill-Force A;Holland PW;Amemiya CT;Garcia-Fernàndez J
Hox 基因簇一直是一代发育和进化生物学家的关键范例。自 20 世纪 80 年代中期发现以来，Hox 基因的鉴定、基因组组织、表达、共线性和调控已成为任何新模式生物研究的直接目标，并且后生动物基因组计划始终参考特定 Hox 簇的结构。自 20 世纪 90 年代初以来，人们一直认为脊椎动物的 Hox 簇由 13 个旁系同源类群组成。尽管如此，我们发现在典型的头索动物文昌鱼（佛罗里达文昌鱼）中，Hox簇含有第14个Hox基因，最近，在腔棘鱼和角鲨中发现了第14个Hox旁系同源群体，这表明文昌鱼簇预期在一些脊椎动物谱系中发现Hox 14。鉴于文昌鱼在脊椎动物进化中占据的关键地位，我们认为确定其Hox基因簇的界限非常有意义，即解决文昌鱼簇中是否存在更多Hox基因（例如Hox 15）。使用两种策略，我们在这里报告了单个文昌鱼 Hox 簇的 Hox 基因内容的完成和表征，该簇包含从 Hox1 到 Evx 的 650 kb。我们的数据对脊索动物的原始 Hox 基因簇具有重要意义：单个文昌鱼 Hox 基因簇的原型性质使得在任何脊索动物谱系中都不太可能发现其他旁系同源群体。我们建议14号结束。
The Hox gene cluster has been a key paradigm for a generation of developmental and evolutionary biologists. Since its discovery in the mid-1980's, the identification, genomic organization, expression, colinearity, and regulation of Hox genes have been immediate targets for study in any new model organism, and metazoan genome projects always refer to the structure of the particular Hox cluster(s). Since the early 1990's, it has been dogma that vertebrate Hox clusters are composed of thirteen paralogous groups. Nonetheless, we showed that in the otherwise prototypical cephalochordate amphioxus (Branchiostoma floridae), the Hox cluster contains a fourteenth Hox gene, and very recently, a 14th Hox paralogous group has been found in the coelacanth and the horn shark, suggesting that the amphioxus cluster was anticipating the finding of Hox 14 in some vertebrate lineages. In view of the pivotal place that amphioxus occupies in vertebrate evolution, we thought it of considerable interest to establish the limits of its Hox gene cluster, namely resolution of whether more Hox genes are present in the amphioxus cluster (e.g., Hox 15). Using two strategies, here we report the completion and characterization of the Hox gene content of the single amphioxus Hox cluster, which encompasses 650 kb from Hox1 to Evx. Our data have important implications for the primordial Hox gene cluster of chordates: the prototypical nature of the single amphioxus Hox cluster makes it unlikely that additional paralogous groups will be found in any chordate lineage. We suggest that 14 is the end.