Kanno Chihiro, Sun-Sik Kang, Sakamoto Kentaro Q, Yanagawa Yojiro, Katagiri Seiji, Nagano Masashi
Laboratory of Clinical Veterinary Medicine for Large Animal, Division of Veterinary Medicine, School of Veterinary Medicine, Kitasato University, Towada, Japan.
Hanwoo Research Institute, National Institute of Animal Science of Korea, Pyeongchang, Korea.
Anim Sci J. 2022 Jan-Dec;93(1):e13796. doi: 10.1111/asj.13796.
The authors investigated the relationship between frame rates and subpopulation structure of bovine sperm divided by their motility analyzed by a computer-assisted sperm analysis (CASA). Kinematic parameters of bovine sperm incubated in Brackett & Oliphant medium with and without calcium ionophore for 0, 1, 5, 10, 15, 20, 25, and 30 min were evaluated by a CASA at 150 frames per second (fps) and analyzed structure of sperm motility subpopulation by cluster analysis. Then, we converted CASA data at 150 fps to 75, 50, and 30 fps and evaluated the structures of sperm motility subpopulation at different fps in each sperm by a discriminant analysis. As the results, the structure of sperm motility subpopulation was affected by frame rate. Sperm were divided into six clusters at 150, 75, and 50 fps; on the other hand, there were five clusters at 30 fps. Straight-line velocity was similar at all frame rates. However, as the frame rate became higher, curvilinear velocity and beat cross frequency of sperm head increased significantly, whereas lateral sperm head displacement decreased significantly. In conclusion, higher frame rate at 150 fps is recommended to capture the trajectory of sperm accurately by CASA in the present study.
作者研究了帧率与通过计算机辅助精子分析（CASA）按运动性划分的牛精子亚群结构之间的关系。在含有和不含有钙离子载体的Brackett&Oliphant培养基中孵育0、1、5、10、15、20、25和30分钟的牛精子的运动学参数，通过CASA以每秒150帧（fps）进行评估，并通过聚类分析分析精子运动亚群的结构。然后，我们将150 fps的CASA数据转换为75、50和30 fps，并通过判别分析评估每个精子在不同帧率下的精子运动亚群结构。结果表明，精子运动亚群的结构受帧率影响。在150、75和50 fps时，精子被分为六类；另一方面，在30 fps时有五类。所有帧率下的直线速度相似。然而，随着帧率升高，精子头部的曲线速度和鞭打交叉频率显著增加，而精子头部的横向位移显著降低。总之，在本研究中，建议使用150 fps的较高帧率通过CASA准确捕捉精子轨迹。
