DEVELOPMENT OF HEAD NERVES, BLOOD VESSELS, BONES, MUSCLE

描述（改编自研究者摘要）：本研究的目标 研究的目的是表征细胞相互作用的基础位置， 感觉和运动神经元及其靶点的特化 鸟类头部的发育。 重点将放在研究 三叉神经-颌复合体 细胞运动和谱系的研究 由于实验性改变导致细胞行为的变化， 前体与其环境之间的空间关系将 执行。 第一个目标将定义导致 三叉神经运动神经之间的特定连接的形成， 下巴肌肉神经母细胞和成肌细胞的谱系追踪将是 执行。实验策略包括使用逆转录病毒标记， 注射荧光染料示踪剂，手术移植 菱形节（运动神经元前体）和体节（肌肉 鹌鹑和鸡胚之间的差异。 第二个目标是 三叉神经感觉神经元来源于神经嵴和 基板细胞，并测试的假设，后者是依赖 在与前者接触的空间图案。这将是测试 通过手术操作的前兆，其次是详细的分析， 移植物和宿主的中央和外周突起 衍生的三叉神经感觉轴突使用特异性抗体鹌鹑或 小鸡轴突第三个目标将研究开发的两个特征， 颅面骨骼肌的起源，初级和次级 肌细胞和肌细胞变性。 拟议的研究将确定 禽类的初级和次级肌细胞是否具有共同的或单独的 胚胎起源发育中的头部肌肉中的大多数初级肌细胞 在鸡胚中在12-15天之间退化。 计划进行研究 研究神经支配与心肌细胞变性的关系 在颅面肌肉发育过程中 改变的可能性 神经支配模式与肌细胞变性有关， 研究了 最终的目的是研究单个神经嵴的命运 研究神经嵴细胞使用的策略， 在头部产生多样性的表型。 克隆 神经嵴细胞的分析将在体内用逆转录病毒 标记。 这些研究有望确定神经源性和 生肌细胞在形成功能性整合之前移动和相互作用 发育中的头部组织。

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.