MAJOR EMBRYONIC DEVELOPMENT VISUALIZATION METHODS REVIEW

Embryonic development is one of the most important stages in the formation of the animal organism, so its study never lost its relevance. However, today, the detailed process of embryo development remains behind the «screen» that nature created by itself, which in turn creates certain technical difficulties that can be coped with by various methods of visualization of the embryo that are presented in this article. These are not only relatively simple 2D techniques that permit to see the embryo in the plane, but also novel 3D techniques that permit observation of an embryo in its volumetric structure. Since invasive methods are associated with unfavourable consequences during observation of the embryo, which produce a negative effect on the obtained scientific data and can lead to their misinterpretation, recently, non-invasive methods are more often used that allow to preserve the integrity of the structures of the embryo and reduce the risk of developmental disorders that occur during the observation process. The time-lapse technology was an innovative discovery which permits to visualize real-time events during embryonic development. Time-lapse is a frame-by-frame shooting, which collects the obtained static images into one continuous video. Frame montage is carried out using special equipment. This system has found application in a large number of scientific experiments. High resolution of modern technical devices permits to observe the formation of embryonic structures, to make a real assessment of an embryo growth and development according to the established parameters, and to observe changes induced by different factors.