RUI: Role of Mechanical Forces Axial Torsion and Flexure in Chick Embryos

发育中的小鸡胚胎经历了一系列复杂的形状变化，称为形态发生。虽然形态发生的遗传和分子方面的研究很好，但很少注意到力学方面。特别是，在胚胎发育过程中，巨大的形状变化背后的驱动力知之甚少。该项目考虑了两个经常被忽视，但在胚胎早期发育过程中发生的至关重要的形状变化：(1)身体弯曲，使最初笔直的胚胎身体轴弯曲；(2)身体扭转，使其旋转。屈曲和扭转对于心脏等重要器官的正常发育是必要的。驱动屈曲和扭转的力目前还不知道，理解它们是这个项目的目标。这项研究将培养众多本科生在各方面的研究能力。科学推广，特别是对代表性不足的少数民族的推广，是这个项目的另一个关键方面。它包括与联合学院的正式合作？美国的“科学与技术入门计划”（Science and Technology Entry Program），该计划将7-12年级未被充分代表的少数族裔和经济状况不佳的学生引入STEM领域。采用实验和计算相结合的方法来确定驱动屈曲和扭转的力。以鸡胚为实验模型。光学显微镜和光学相干断层扫描将用于定性和定量表征所考虑的发育阶段的弯曲和扭转。原子力显微镜将用于探测发生弯曲和扭转的区域的机械环境。化学和生物力学扰动将用于进一步研究这些过程。有限元方法将用于开发计算模型，该模型将通过比较实验和模型预测的全局和局部形状变化来验证。验证模型将用于假设检验，以确定驱动屈曲和扭转的力。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The developing chick embryo undergoes a series of complex shape changes called morphogenesis. Although the genetic and molecular aspects of morphogenesis are well-studied, scant attention is paid to the mechanical aspects. In particular, the driving forces behind the dramatic shape changes during embryo development are poorly understood. This project considers two often-overlooked, but critically important shape changes that occur during early embryo development: (1) body flexion, which curves the initially straight embryonic body axis and (2) body torsion, which rotates it. Flexion and torsion are necessary for proper development of important organs such as the heart. The forces driving flexion and torsion are not currently known and understanding them is the goal of this project. This research will train numerous undergraduate students in all aspects of research. Science outreach, particularly to under-represented minorities, is another critical aspect of this project. It includes a formal collaboration with Union College?s Science and Technology Entry Program, which introduces underrepresented minority and economically disadvantaged students in grades 7-12 to STEM fields. A combined experimental and computational approach is used to determine the forces driving flexion and torsion. The chick embryo is used as the experimental model. Light microscopy and optical coherence tomography will be used to qualitatively and quantitatively characterize flexion and torsion in the developmental stages under consideration. Atomic force microscopy will be used to probe the mechanical environment of the regions undergoing flexion and torsion. And chemical and biomechanical perturbations will be used to study these processes further. The finite element method will be used to develop the computational model which will be validated by comparing experimental and model-predicted global and local shape changes. The validated model will be used for hypothesis testing to determine the forces driving flexion and torsion.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.