An open source software for graphical sperm movement analysis

GUIDOBALDI, HA; CUBILLA, MC; GIOJALAS, LC

Holderness

Congreso; Gordon Research Conference: Fertilization & development; 2017

Gordon Research Congference

The motion analysis has been used from long time ago to determine kinetic parameters of spermatozoa. From the analyses of trajectories made by hand to the automated systems like CASA, kinetic determinations have been and are important for sperm evaluation not only for scientific, but also, for infertile diagnosis purposes. However, usually these methods report average parameters, either individually (e.g., the average speed of a cell) or at the population level (e.g., the average speed of the semen sample). But, sometimes is interesting and necessary, to analyze the behavior of sperm along its trajectory, by permanently evaluating changes in kinetic parameters or its orientation. Such is the case of the studies of sperm chemotaxis in mammals. Where only a small population of sperm re-orientates its movement and where most of the cells tends to swimstraight or in large circles, without a visible change during its chemotactic orientation. These characteristics, have always hindered the analysis of chemotaxis by videomicroscopy in mammals. Hence, its evaluation has been based on complex mathematical analysis, some of them, requiring thousands of cells to obtain a significative response. Thus, the methodological complexity of the chemotaxis analysis, has been perhaps one the most important obstacles in the progress of the study and characterization of chemotaxis in mammals, which has been relegated to some few research groups. Recently, by using ImageJ, an open access image analysis platform, we have developed a software that allows us to analyze and evaluate graphically the kinetic parameters along the whole trajectory. Thus, we could associate variations in sperm orientation during chemotaxis with changes in the pattern of movement and/or changes in sperm velocity, allowing a simpler and more intuitive analysis of the cellular behavior. As example of its application, this software has been recently employed to characterize a novel mechanism of sperm chemorepulsion induced by zinc and synthetic progesterone receptor ligands (Guidobaldi et al, 2017, Hum Reprod) and here we show its fundamentals and some practical applications.