Genetic Hierarchy Underlying Photoreceptor Regeneration

在大多数脊椎动物中，成年视网膜无法再生失去的神经元，这导致视力丧失。 相反，斑马鱼视网膜具有再生任何种类的视网膜神经元的能力， 由于各种侮辱。例如，持续的强光会导致视杆细胞和视锥细胞死亡。 光感受器再生起源于M？ller神经胶质细胞重新进入细胞周期并分裂产生 神经元祖细胞，其继续增殖，然后分化成再生的神经元。的 人类视网膜也有M？ller胶质细胞，但不能再生任何视网膜细胞。我们有兴趣 识别调节光损伤斑马鱼感光器视网膜再生的过程 视网膜。在这个提议中，我们将研究产生和维持神经元的分子机制。 在再生过程中处于未分化和增殖状态的祖细胞群体，这将识别 在受损的哺乳动物视网膜中诱导完全再生反应的方法。这可以提供一个 使患有遗传性失明（如色素性视网膜炎）的人恢复视力的策略 或黄斑变性。 我们将探讨Pax6a、Pax6b和Olig2蛋白在神经细胞增殖过程中的作用。 光损伤的斑马鱼视网膜中的祖细胞。我们将使用我们开发的一种技术， 反义吗啉代进入再生视网膜。这种技术给了我们强大的能力， 在光损伤的视网膜再生过程中阻止特定蛋白质的翻译。我们将测试 假设Pax6b蛋白是神经元祖细胞增殖启动所必需的，但不是 所需的后续表达的祖细胞转录因子，并最终，感光细胞 细胞视蛋白（S. A. 1）。然后我们将确定Pax6a是否是神经细胞持续增殖所必需的。 祖细胞和olig2基因的转录（S. A. 2）。最后，我们将确定是否还需要Olig2 对于神经元祖细胞的持续增殖，并且如果在Olig2不存在的情况下， 祖细胞过早分化成光感受器，损害了M？ller神经胶质细胞（S. A. 3）。

In most vertebrates, the adult retina is unable to regenerate lost neurons, which results in loss of vision. In contrast, the zebrafish retina possesses the ability to regenerate any class of retinal neurons that are lost due to a variety of insults. For example, constant intense light causes rod and cone photoreceptor death. Photoreceptor regeneration originates from the M¿ller glia that reenter the cell cycle and divide to produce neuronal progenitors, which continue to proliferate and then differentiate into the regenerated neurons. The human retina also possesses M¿ller glia, but fails to regenerate any retinal cell class. We are interested in identifying the processes that regulate retinal regeneration of photoreceptors in the light-damaged zebrafish retina. In this proposal, we will investigate the molecular mechanisms that generate and maintain the neuronal progenitor cell population in an undifferentiated and proliferating state during regeneration, which will identify approaches to induce a full regeneration response in the damaged mammalian retina. This could provide a strategy to restore vision to individuals who suffer from genetic forms of blindness, such as retinitis pigmentosa or macular degeneration. We will explore the roles of the Pax6a, Pax6b, and Olig2 proteins during proliferation of neuronal progenitors in the light-damaged zebrafish retina. We will use a technique that we developed to electroporate antisense morpholinos into the regenerating retina. This technique gives us the powerful ability to conditionally block the translation of specific proteins during regeneration of the light-damaged retina. We will test the hypothesis that the Pax6b protein is required for the initiation of neuronal progenitor cell proliferation, but is not required for the subsequent expression of progenitor cell transcription factors, and ultimately, photoreceptor cell opsins (S. A. 1). We will then determine if Pax6a is required for the continued proliferation of the neuronal progenitors and the transcription of the olig2 gene (S. A. 2). Finally, we will determine if Olig2 is also required for the continued proliferation of the neuronal progenitor cells and, if, in the absence of Olig2, the neuronal progenitors prematurely differentiate into photoreceptors at the expense of M¿ller glial cells (S. A. 3).