DEVELOPMENT OF HEAD NERVES, BLOOD VESSELS, BONES, MUSCLE

描述(改编自调查者摘要)：目标 研究的目的是描述细胞相互作用的位置 感觉神经元和运动神经元及其靶点的规范 鸟头的发育。重点将放在对 三叉神经-颌骨复合体。对细胞运动和谱系的研究也是如此 由于实验改变导致的细胞行为的改变 前兆与其环境之间的空间关系将是 已执行。第一个目标将定义导致 三叉神经运动神经与神经的特异性联系的形成 下巴肌肉。神经母细胞和成肌细胞的谱系追踪将是 已执行。实验策略包括使用逆转录病毒标记物， 注射荧光示踪剂，外科移植 菱形核(运动神经元前体)和团粒(肌肉 前体)在鹌鹑胚胎和雏鸡胚胎之间。第二个目标集中在 三叉神经脊神经和三叉神经感觉神经元规范 胎盘细胞，并检验了后者依赖的假设 在与前者联系以进行空间图案设计时。这将进行测试 通过手术操作前体，然后进行详细的分析 移植物和宿主的中枢和外周投射- 用特异性抗体获得三叉神经感觉轴突 小鸡的轴突。第三个目标将考察发展的两个特征 头面部骨骼肌的原发和继发 肌细胞和肌细胞变性。拟议的研究将确定 禽类初级和次级肌细胞是共有的还是分开的 胚胎起源。发育中的头部肌肉中的大多数原代肌细胞 雏鸡胚胎在12-15天之间退化。研究正在计划中 研究神经支配与心肌细胞变性的关系 在头面部肌肉发育过程中。改变的可能性 在神经支配模式上与心肌细胞退行性变有关 学习。最终目的是考察单个神经波峰的命运。 祖细胞研究神经脊细胞使用的策略 产生在头部发现的多样性的表型。克隆性 对神经脊细胞的分析将在体内进行，并携带逆转录病毒 记号笔。这些研究预计将定义神经源性和 肌源性细胞在形成功能整合之前移动和相互作用 发育中头部的组织。

DESCRIPTION (adapted from the Investigator's abstract): The goal of this research is to characterize the cell interactions underlying positional specification of sensory and motor neurons and their targets during development of the avian head. Emphasis will be on studies of the trigeminal- jaw complex. Studies of cell movements and lineages as well as changes in cell behavior resulting from experimental alteration in the spatial relations between precursors and their environment will be performed. The first aim will define interactions leading to the formation of specific connections between trigeminal motor nerves and jaw muscles. Lineage tracing of neuroblasts and myoblasts will be performed. Experimental strategies involve use of retroviral markers, injection of fluorochrome tracers, and surgical transplantation of rhombomeres (motor neuron precursors) and somitomeres (muscle precursors) between quail and chick embryos. The second aim focuses on specification of trigeminal sensory neurons derived from neural crest and placodal cells, and tests the hypothesis that the latter are dependent upon contact with the former for spatial patterning.This will be tested by surgical manipulation of precursors, followed by a detailed analysis of the central and peripheral projections of both graft- and host- derived trigeminal sensory axons using antibodies specific to quail or chick axons. The third aim will examine two features of developing craniofacial skeletal muscles, the origins of primary and secondary myocytes and myocyte degeneration. The proposed studies will determine whether avian primary and secondary myocytes have common or separate embryonic origins. Most primary myocytes in developing head muscles degenerate between days 12-15 in the chick embryo. Studies are planned to study the relationships between innervation and myocyte degeneration during craniofacial muscle development. The possibility that changes in innervation patterns are related to myocyte degeneration will be studied. The final aim examines the fate of single neural crest progenitors to study the strategies used by neural crest cells to generate the diversity of phenotypes found in the head. Clonal analyses of neural crest cells will be performed in vivo with retroviral markers. These investigations are expected to define how neurogenic and myogenic cells move and interact before forming functionally integrated tissues in the developing head.