The Trox-2 Hox/ParaHox gene of Trichoplax (Placozoa) marks an epithelial boundary
The Trox-2 Hox/ParaHox gene of Trichoplax (Placozoa) marks an epithelial boundary
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DOI：
10.1007/s00427-004-0390-8
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发表时间：
2004-04-01
影响因子：
2.4
通讯作者：
Schierwater, B
中科院分区：
文献类型：
--
作者：
Jakob, W;Sagasser, S;Schierwater, B
Hox和ParaHox基因与刺胞动物和双侧刺胞动物的轴向模式有关，并且被认为起源于单个“ProtoHox”基因的串联复制，随后是所得基因簇的复制。目前还不清楚Hox/ParaHox基因在刺胞动物和双壁动物分化之前的祖先作用，或者假设的ProtoHox基因发挥了什么作用。在这里，我们描述了完整的编码区，空间表达和功能的Trox-2，单一的Hox/ParaHox型基因中确定的Trichoplax adhaerens（门Placozoa）和候选ProtoHox或ParaHox基因。Trox-2在Trichoplax外周周围的环中表达，在位于上下上皮细胞层的外缘之间的小细胞中。通过摄取吗啉代反义寡核苷酸或通过RNA干扰抑制Trox-2功能，导致生长和二分裂的完全停止。我们推测，Trox-2的功能可能是多潜能外周干细胞，有助于在Trichoplax的上皮边界分化的细胞中的一个迄今未被认识的人口。
Hox and ParaHox genes are implicated in axial patterning of cnidarians and bilaterians, and are thought to have originated by tandem duplication of a single "ProtoHox" gene followed by duplication of the resultant gene cluster. It is unclear what the ancestral role of Hox/ParaHox genes was before the divergence of Cnidaria and Bilateria, or what roles the postulated ProtoHox gene(s) played. Here we describe the full coding region, spatial expression and function of Trox-2, the single Hox/ParaHox-type gene identified in Trichoplax adhaerens (phylum Placozoa) and either a candidate ProtoHox or a ParaHox gene. Trox-2 is expressed in a ring around the periphery of Trichoplax, in small cells located between the outer margins of the upper and lower epithelial cell layers. Inhibition of Trox-2 function, either by uptake of morpholino antisense oligonucleotides or by RNA interference, causes complete cessation of growth and binary fission. We speculate that Trox-2 functions within a hitherto unrecognized population of possibly multipotential peripheral stem cells that contribute to differentiated cells at the epithelial boundary of Trichoplax.