基于山谷特征的重叠蛋白质点分离算法

An Algorithm for Separating Overlapped Protein Spots Based on Valley Characteristics

针对二维凝胶电泳(2-DE)图像蛋白质点重叠和堆聚问题,本文提出了一种基于山谷特征的重叠蛋白质点自动分离算法。首先,采用内外标记分水岭法进行粗检测,提取目标区域的初始轮廓;然后,采用中轴变换和分层剪枝算法提取目标区域主骨架,确定蛋白质点重叠方向;最后,在重叠方向各法平面上,采用分层扫描三维目标区域的方法,提取山谷特征,并利用验证模型构造分离线。结果表明:通过对两组真实扫描凝胶图像进行检测实验,重叠蛋白质点的正确分离率分别为78.95%和85.71%,明显高于现有方法,可用于工程实际。

To separate the overlapped protein spots in two-dimensional gel electrophoresis （2-DE） images, we pro- posed an auto separating algorithm based on valley characteristics. Firstly, the marker-controlled watershed algo- rithm was used to detect the initial outlines of the object regions. Secondly, medial axis transform and hierarchical branch pruning method were applied to the main skeletons of the object regions, and each main skeleton was fitted in- to line segments to describe the overlap directions. Then, the 3-dimensional model of the object region was scanned on the normal planes of the line segments to find the valley locations. And finally, a validation model was adopted to construct separation lines. The experiments on 2 real scanned 2-DE images showed that the true overlap separate （TOSs） were 78.95 % and 85.71%, respectively. The results indicated that the proposed algorithm was better than the existing algorithms and could be used in engineering practice.