Department of Physics, Lehigh University, Bethlehem, Pennsylvania 18015, USA.
Cytoskeleton (Hoboken). 2010 Nov;67(11):693-705. doi: 10.1002/cm.20481.
We use open active contours to quantify cytoskeletal structures imaged by fluorescence microscopy in two and three dimensions. We developed an interactive software tool for segmentation, tracking, and visualization of individual fibers. Open active contours are parametric curves that deform to minimize the sum of an external energy derived from the image and an internal bending and stretching energy. The external energy generates (i) forces that attract the contour toward the central bright line of a filament in the image, and (ii) forces that stretch the active contour toward the ends of bright ridges. Images of simulated semiflexible polymers with known bending and torsional rigidity are analyzed to validate the method. We apply our methods to quantify the conformations and dynamics of actin in two examples: actin filaments imaged by TIRF microscopy in vitro, and actin cables in fission yeast imaged by spinning disk confocal microscopy.
我们使用开放式主动轮廓线来量化荧光显微镜成像的二维和三维细胞骨架结构。我们开发了一个用于分割、跟踪和可视化单个纤维的交互式软件工具。开放式主动轮廓线是参数曲线，它们会变形以最小化来自图像的外部能量和内部弯曲和拉伸能量的总和。外部能量会产生（i）将轮廓吸引到图像中纤维中央亮线的力，以及（ii）将主动轮廓拉伸到亮脊末端的力。分析具有已知弯曲和扭转刚度的模拟半柔性聚合物的图像以验证该方法。我们将我们的方法应用于两个示例中肌动蛋白构象和动力学的定量分析：体外使用 TIRF 显微镜成像的肌动蛋白丝，以及使用旋转盘共聚焦显微镜成像的裂变酵母中的肌动蛋白电缆。
