Cell migration that orients the dorsoventral axis is coordinated with anteroposterior patterning mediated by Hedgehog signaling in the early spider embryo
Cell migration that orients the dorsoventral axis is coordinated with anteroposterior patterning mediated by Hedgehog signaling in the early spider embryo
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DOI：
10.1242/dev.045625
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发表时间：
2010-04-15
期刊：
影响因子：
4.6
通讯作者：
Oda, Hiroki
中科院分区：
文献类型：
--
作者：
Akiyama-Oda, Yasuko;Oda, Hiroki
蜘蛛Achaearanea tepidariorum的早期胚胎正在成为同时研究细胞迁移和图案形成的模型。在径向对称的胚盘中心内化的细胞簇表达进化上保守的背侧信号Decapentaplegic。该细胞团从胚盘中心沿着上皮基底侧迁移至胚盘边缘。这种细胞迁移被认为是确定背腹轴方向的破坏性事件。在这项研究中，敲低补丁同源物，At-ptc，编码一个假定的负调节刺猬（Hh）信号，防止启动的破坏性细胞迁移。敲除平滑的同源物，At-smo，表明Hh信号转导失活也逮捕了细胞在胚芽盘中心，而中度失活导致零星的失败，细胞迁移终止在胚芽盘边缘。hh转录本表达模式表明，生殖盘的边缘和外部是Hh配体的来源。图案化事件的分析表明，在胚芽盘，短程Hh信号促进前规格和远程Hh信号抑制尾规格。此外，Hh信号的负调控At-PTC似乎需要从胚盘中心的尾部规格的渐进去阻遏。At-ptc和At-smo敲低引起的细胞迁移缺陷与生殖盘上皮的图案缺陷相关。我们建议，在Achaearanea的背腹轴方向至关重要的细胞迁移是协调与Hh信号介导的前后图案。
The early embryo of the spider Achaearanea tepidariorum is emerging as a model for the simultaneous study of cell migration and pattern formation. A cell cluster internalized at the center of the radially symmetric germ disc expresses the evolutionarily conserved dorsal signal Decapentaplegic. This cell cluster migrates away from the germ disc center along the basal side of the epithelium to the germ disc rim. This cell migration is thought to be the symmetry-breaking event that establishes the orientation of the dorsoventral axis. In this study, knockdown of a patched homolog, At-ptc, that encodes a putative negative regulator of Hedgehog (Hh) signaling, prevented initiation of the symmetry-breaking cell migration. Knockdown of a smoothened homolog, At-smo, showed that Hh signaling inactivation also arrested the cells at the germ disc center, whereas moderate inactivation resulted in sporadic failure of cell migration termination at the germ disc rim. hh transcript expression patterns indicated that the rim and outside of the germ disc were the source of the Hh ligand. Analyses of patterning events suggested that in the germ disc, short-range Hh signal promotes anterior specification and long-range Hh signal represses caudal specification. Moreover, negative regulation of Hh signaling by At-ptc appears to be required for progressive derepression of caudal specification from the germ disc center. Cell migration defects caused by At-ptc and At-smo knockdown correlated with patterning defects in the germ disc epithelium. We propose that the cell migration crucial for dorsoventral axis orientation in Achaearanea is coordinated with anteroposterior patterning mediated by Hh signaling.