Measurements of Body Movement in Chick Embryos During Early Stages

In this study, we investigate developmental patterns of body movements that may play roles in normal embryonic growth using direct recordings of chick embryos during the early stages of development (72–125 h of incubation). In three individuals, embryonic body movements occurred intermittently and irregularly after 72-h incubation, and frequencies and sizes of movements increased with embryonic growth. Additionally, patterns of the body movements became periodic at 85 h in all individuals, and cyclic periods of body movements were then shortened and periodicities of movements gradually disappeared with embryonic development. If cyclic body movements are a common requirement during normal chick embryo growth, continuous monitoring of body movements could be used to predict abnormal embryonic growth. Future studies are required to investigate distinctive body movements and developmental patterns during embryonic growth in disease models and under various environmental conditions, such as under hypoxia.