Wnt Signaling Specifies Anteroposterior Progenitor Zone Identity in the Drosophila Visual Center
Wnt Signaling Specifies Anteroposterior Progenitor Zone Identity in the Drosophila Visual Center
复制标题
Wnt 信号传导指定果蝇视觉中心的前后祖区身份
DOI：
10.1523/jneurosci.0864-16.2016
复制
发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Makoto Sato
中科院分区：
文献类型：
--
作者：
Takumi Suzuki;Olena Trush;Tetsuo Yasugi;Rie Takayama;Makoto Sato
在大脑发育过程中，不同类型的神经元群从不同的祖细胞库中产生，以产生足以建立功能性神经元回路的神经元多样性。然而，指定每个祖细胞库身份的分子机制仍然不清楚。在这里，我们表明 Wnt 信号对于果蝇视觉中心后祖细胞池的身份规范至关重要。在髓质（视觉中心最大的组成部分）中，不同类型的神经元由两个祖细胞库产生：外增殖中心 (OPC) 和神经胶质前体细胞 (GPC；也称为 OPC 尖端)。我们发现，当 GPC 中的 Wnt 信号传导受到抑制时，OPC 型神经元是由 GPC 产生的，但会消耗 GPC 型神经元。相比之下，当 OPC 中 Wnt 信号传导被异位激活时，GPC 型神经元就会被异位诱导。这些结果表明 Wnt 信号传导对于祖细胞库身份的规范是必要且充分的。我们还发现，在 OPC 中暂时表达的 Homothorax (Hth) 通过抑制 Wnt 信号在 GPC 中异位诱导，并且 Hth 的异位诱导表型复制了 GPC 中 Wnt 信号的抑制。因此，Wnt 信号传导通过抑制 Hth 表达来规范位于髓质后方的祖细胞池，从而参与果蝇视觉中心的区域化。意义陈述 大脑由不同来源的相当多样化的神经元组成。在哺乳动物大脑中，兴奋性和抑制性神经元分别源自背侧端脑和腹侧端脑。多个祖细胞库也有助于果蝇大脑中神经元的多样性。然而，目前尚不清楚这些祖细胞库之间的差异是如何建立的。在这里，我们表明 Wnt 信号传导（一种进化上保守的信号传导）参与了建立这些祖细胞库之间差异的过程。由于受 Wnt 配体控制的 β-连环蛋白信号传导指定发育中的哺乳动物丘脑中的祖细胞池身份，因此 Wnt 信号传导介导的祖细胞池身份指定可能在昆虫和哺乳动物大脑中保守。
During brain development, various types of neuronal populations are produced from different progenitor pools to produce neuronal diversity that is sufficient to establish functional neuronal circuits. However, the molecular mechanisms that specify the identity of each progenitor pool remain obscure. Here, we show that Wnt signaling is essential for the specification of the identity of posterior progenitor pools in the Drosophila visual center. In the medulla, the largest component of the visual center, different types of neurons are produced from two progenitor pools: the outer proliferation center (OPC) and glial precursor cells (GPCs; also known as tips of the OPC). We found that OPC-type neurons are produced from the GPCs at the expense of GPC-type neurons when Wnt signaling is suppressed in the GPCs. In contrast, GPC-type neurons are ectopically induced when Wnt signaling is ectopically activated in the OPC. These results suggest that Wnt signaling is necessary and sufficient for the specification of the progenitor pool identity. We also found that Homothorax (Hth), which is temporally expressed in the OPC, is ectopically induced in the GPCs by suppression of Wnt signaling and that ectopic induction of Hth phenocopies the suppression of Wnt signaling in the GPCs. Thus, Wnt signaling is involved in regionalization of the fly visual center through the specification of the progenitor pool located posterior to the medulla by suppressing Hth expression. SIGNIFICANCE STATEMENT Brain consists of considerably diverse neurons of different origins. In mammalian brain, excitatory and inhibitory neurons derive from the dorsal and ventral telencephalon, respectively. Multiple progenitor pools also contribute to the neuronal diversity in fly brain. However, it has been unclear how differences between these progenitor pools are established. Here, we show that Wnt signaling, an evolutionarily conserved signaling, is involved in the process that establishes the differences between these progenitor pools. Because β-catenin signaling, which is under the control of Wnt ligands, specifies progenitor pool identity in the developing mammalian thalamus, Wnt signaling-mediated specification of progenitor pool identity may be conserved in insect and mammalian brains.
影响因子：
56.9
作者：
Anderson, SA;Eisenstat, DD;Rubenstein, JLR
通讯作者：
Rubenstein, JLR
影响因子：
4.6
作者：
K. Ito;W. Awano;Kazumi Suzuki;Y. Hiromi;D. Yamamoto
通讯作者：
K. Ito;W. Awano;Kazumi Suzuki;Y. Hiromi;D. Yamamoto