The role of CRISPLD2 in mediating FGF8 signaling during craniofacial development

描述（申请人提供）：面部畸形是最常见的出生缺陷之一，这些缺陷会对患者的健康和心理健康产生深远的影响。然而，导致这些结构缺陷的潜在机制尚不清楚。我们知道，多种颅面畸形是由发育过程中成纤维细胞生长因子（FGFs）对正常信号的干扰引起的。FGF信号控制发育面部细胞的活动，但FGF信号是如何做到这一点的，在很大程度上是未知的。为了更好地理解FGF信号控制颅面发育的机制，初步研究已经确定了一个基因CRISPLD2，其表达受FGF信号的影响，其破坏与唇腭裂畸形有关。进一步的研究表明，该基因的表达会影响细胞的运动，在早期面部图案形成过程中，它在面部组织中表达，而改变的基因表达水平会导致鸡和斑马鱼胚胎中面部形状的改变。因此，本项目验证了这样一个假设，即作为面部形态发生过程中FGF信号传导的下游效应者，CRISPLD2影响细胞行为，包括面部间质和/或外胚层的增殖、迁移和/或极化，这些细胞行为在发育组织中共同决定了面部的大体形态。研究人员提出了一项为期两年的重点研究CRISPLD2对细胞和形态学的影响，利用小鸡模型系统快速获得结果。在第一个目标中，将研究CRISPLD2表达改变对体外神经嵴细胞行为的影响。对于第二个目标，改变CRISPLD2表达在鸡胚胎中的影响将通过量化细胞行为并将其与相同标本中的颅面形状相关联来评估。这种方法将把CRISPLD2的基因表达水平与细胞活性和颅面形状的产生联系起来。这项工作的结果将提供重要的见解

DESCRIPTION (provided by applicant): Facial malformations are among the most common birth defects, and these can impact patients' health and psychological well-being profoundly. However, the underlying mechanisms causing these structural defects are poorly understood. We know that a variety of craniofacial malformations are caused by disruptions to normal signaling by fibroblast growth factors (FGFs) during development. FGF signaling controls the activity of cells in the developing face, but how FGF signaling does this is largely unknown. To better understand the mechanisms by which FGF signaling controls craniofacial development, preliminary studies have identified a gene, CRISPLD2, whose expression is affected by FGF signaling and whose disruption is associated with cleft lip/palate malformations. It has been further shown that expression of this gene affects cell motility, that it is expressed in the tissus of the face during early facial patterning, and that altered gene expression levels cause altered facial shapes in chick and zebrafish embryos. Therefore, this project tests the hypothesis that, as a downstream effector of FGF signaling during facial morphogenesis, CRISPLD2 affects cell behaviors, including proliferation, migration, and/or polarization of the facial mesenchyme and/or ectoderm, which in developing tissues together determine the gross morphology of the face. A focused, two-year investigation is proposed to investigate the cellular and morphological effects of CRISPLD2, utilizing the chick model system for rapid results. For the first Aim, the effects of altered CRISPLD2 expression on neural crest cell behaviors in vitro will be examined. For the second Aim, the effects of altered CRISPLD2 expression in chick embryos will be evaluated by quantifying cell behaviors and correlating them to craniofacial shape in the same specimens. This approach will link gene expression levels of CRISPLD2 with cellular activity and the generation of craniofacial shape. The results of this work will provide important insights into how FGF signaling controls facial development and will identify specific mechanisms causing cleft lip/palate and other types of structural malformations of the face.