Contact Behavior of Developing Cells

拟议研究的总体目标是了解正常组织细胞和癌细胞如何在生物体内侵入性移动-作为单个细胞，细胞簇，细胞流和细胞片。由于现在有大量的证据表明，正常组织细胞和癌细胞在体外和体内利用相同的机制进行侵入性运动，任何对其中一种运动方式的理解的增加都将有助于理解另一种的运动。本研究的重点是细胞运动的机制，特别是在定向细胞运动过程中，细胞如何相互接触以及与它们移动的各种基质接触，上皮中紧密连接的细胞如何移动重排，以及它们的运动如何协调，以及细胞如何响应可能的外源信号并定向移动。更具体地说，研究将涉及细胞表面的突出活动，特别是在前缘，收缩性，细胞质结构和程序性内吞作用作为形态发生机制，含有肌动蛋白的微丝的组织与细胞质收缩性和原肠胚形成期间的张力有关，微管的存在和方向与外胚轴期间皮质细胞质的扩散运动有关，原肠原管表面细胞的侵入与外胚层和下胚层的形成有关，在定向形态发生细胞运动过程中，细胞之间的接触抑制和其他协调相互作用的作用，以及收缩诱导的突出活动在促进细胞在特定方向上运动的持久性方面的可能作用。将采用的主要技术有：细胞培养、高分辨率差干涉对比和相对比光学、共聚焦显微摄影、体内和体外运动细胞的慢速视频拍摄、高分辨率显微摄影、显微手术和移植和删除实验的微操作、用cytochalazin D抑制细胞收缩性、用nocodazole解聚微管并用紫杉醇固定微管、用抗微管蛋白荧光抗体染色微管、微注射荧光标记跟踪运动细胞，透射和扫描电子显微镜-所有与细胞运动有关。在分析每个问题时，将尽可能多地运用这些技术。

Trinkaus 9723054 The overall objective of the proposed research is to understand how normal tissue cells and cancer cells move invasively within organisms - as individual cells, cell clusters, cell streams and as cell sheets. Since there is now abundant evidence that normal tissue cells and cancer cells utilize the same mechanisms for their invasive movements, both in vitro and in viva, any increase in understanding how one moves will aid in understanding the movement of the other. The emphasis in this research is on the mechanism of cell motility, particularly during directional cell movements, how cells make contacts with each other and with various substrata over which they move, how tightly-joined cells in epithelia move to rearrange, and how their movements are coordinated, and how cells respond to possible exogenous signals and move directionally. More specifically, the investigations will be concerned with protrusive activity of the cell surface, particularly at the leading edge, contractility, cytoplasmic structure and programmed endocytosis as morphogenetic mechanisms, the organization of actin-containing microfilaments as related to cytoplasmic contractilitv, and tension during gastrulation, presence and orientation of microtubules as related to the spreading movements of cortical cytoplasm during epibolv, the ingression of cells at the surface of the gastrula as related to the formation of the epiblast and hypoblast, the role of contact inhibition and other coordinated interactions between and among cells during directional morphogenetic cell movements, and the possible role of retraction induced protrusive activity in the promotion of the persistence of cell movements in a particular direction. The principal techniques that will be utilized are: cell culture, high resolution differential interference contrast and phase contrast optics, confocal micrography, time-lapse video filming of moving cells in vivo and in vitro, high resolution photomicrography, microsurgery and micr omanipulation for transplantation and deletion experiments, inhibiting cell contractility with cytochalazin D and depolymerizing microtubules with nocodazole and immobilizing them with taxol, staining microtubules with fluorescent antibodies against tubulin, microinjecting fluorescent labels to follow moving cells, transmission and scanning electron microscopy - all in relation to cell motility. As many of these techniques as apply will be brought to bear in the analysis of each problem.