CONTROL OF EARLY EYE DEVELOPMENT BY BMP'S

通过 BMP 控制早期眼睛发育

• 批准号: 6627149
• 负责人: YASUHIDE FURUTA
• 金额: $ 24.13万
• 依托单位: UNIVERSITY OF TX MD ANDERSON CAN CTR
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-01-01 至 2004-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6627149
• 关键词: bone morphogenetic proteins; early embryonic stage; embryogenesis; eye; fibroblast growth factor; genetic manipulation; genetically modified animals; growth factor receptors; in situ hybridization; laboratory mouse; optic disk; protein structure function; transfection

The long term goal of this proposal is to define the roles of Bone Morphogenetic Proteins (BMPs), members of the TGF- superfamily of secreted signaling molecules, during mammalian eye development. BMPs have been implicated in many aspects of embryonic inductive tissue interactions. In particular, we have recently shown that one family member, Bmp4, plays an essential role during lens induction in the mouse embryo. In recent studies, chromosomal deletions in humans at 14q22- q23, where the BMP4 gene is mapped, have been linked with dominant anopthalmia and pituitary hypoplasia. Moreover, it has been shown that another family member, Bmp7, is required for normal eye development in the mouse. However, the molecular mechanisms by which BMPs regulate specific processes in vertebrate eye development are poorly understood. Here, we propose genetic and experimental embryological approaches to address this question, focusing on the roles of Bmp4 and a type-I Bmp receptor, Alk3. We will test the following three hypotheses; (1) that Bmp4 function is required, not only during lens induction, but also during subsequent steps in eye formation, (2) that Bmp4 and another signaling factor, Fgf15, directly mediate the lens inductive signal of the optic vesicle, (3) and that Bmp signaling is required independently in both the lens ectoderm and the retinal neuroectoderm during early eye development. Our strategy utilizes an embryonic eye explant culture technique we have established. We will treat both mutant and wildtype embryonic eye tissues with exogenous Bmp4 and/or Fgf15 proteins to explore their functions in eye formation. Furthermore, we will generate mouse embryos that lack Alk3 receptor function specifically in the developing eye using the Cre-loxP system for conditional gene disruption. The original homozygous AIk3 mutation causes pre-gastrulation embryonic lethality, and therefore the eye specific gene disruption is crucial for studying function of this gene during embryonic eye development. The embryos generated by this technique will provide mutant eye tissues which will be used for recombination organ cultures to study tissue-type specific functions of BMP signaling. These studies will contribute significantly to our understanding of the fundamental roles of secreted signaling molecules in mammalian eye development. Moreover, the results will shed light on the possibility that abnormal regulation of intercellular signaling contributes to congenital eye defects and associated postnatal eye dysfunctions in humans.

该提案的长期目标是确定骨形态发生蛋白 (BMP)（分泌信号分子 TGF-超家族的成员）在哺乳动物眼睛发育过程中的作用。 BMP 与胚胎诱导组织相互作用的许多方面有关。 特别是，我们最近表明，一个家族成员 Bmp4 在小鼠胚胎晶状体诱导过程中发挥着重要作用。在最近的研究中，人类 14q22-q23（BMP4 基因所在位置）的染色体缺失与显性无眼症和垂体发育不全有关。 此外，研究表明，另一个家族成员 Bmp7 是小鼠眼睛正常发育所必需的。 然而，人们对 BMP 调节脊椎动物眼睛发育特定过程的分子机制知之甚少。在这里，我们提出了遗传和实验胚胎学方法来解决这个问题，重点关注 Bmp4 和 I 型 Bmp 受体 Alk3 的作用。我们将检验以下三个假设； (1) 不仅在晶状体诱导过程中，而且在眼睛形成的后续步骤中都需要 Bmp4 功能，(2) Bmp4 和另一种信号因子 Fgf15 直接介导视泡的晶状体诱导信号，(3) 在早期眼睛发育过程中，晶状体外胚层和视网膜神经外胚层都独立需要 Bmp 信号传导。我们的策略利用我们已经建立的胚胎眼外植体培养技术。我们将用外源 Bmp4 和/或 Fgf15 蛋白处理突变型和野生型胚胎眼组织，以探索它们在眼睛形成中的功能。此外，我们将使用 Cre-loxP 系统进行条件基因破坏，生成缺乏 Alk3 受体功能的小鼠胚胎，特别是在发育中的眼睛中。原始纯合 AIk3 突变会导致原肠胚形成前胚胎致死，因此眼睛特异性基因破坏对于研究该基因在胚胎眼睛发育过程中的功能至关重要。通过该技术产生的胚胎将提供突变的眼组织，该组织将用于重组器官培养，以研究 BMP 信号传导的组织类型特异性功能。这些研究将极大地有助于我们了解分泌信号分子在哺乳动物眼睛发育中的基本作用。此外，这些结果将揭示细胞间信号传导异常调节可能导致人类先天性眼部缺陷和相关的出生后眼部功能障碍的可能性。