Development of early somitic mouse embryos in static culture in vitro

We have compared the in vitro development of 8.5-day early somitic mouse embryos cultured in static organ cultures dishes in human cord serum or rat serum with the development of embryos of the same age cultured in rotating tubes or developing in vivo. The growth of embryos cultured in rat serum in organ culture dishes was comparable during the first 24 hours, with the growth achieved in rotating tubes and paralleled the embryonic growth in vivo. The morphogenesis of embryos in static organ culture was delayed in comparison with the normal embryogenesis in vivo, but was not statistically different from embryos developing in rotating tube cultures. Embryos cultured for 36 hours continued to grow but were almost all lagging in development behind the embryos developing in utero or in the rotating tubes. Our data show that 24-hour culture of somitic mouse embryos in rat serum may be used to evaluate the growth of explanted embryos, and to study the in vitro development and function of certain embryonic structures, such as somite number, yolk sac circulation, heart function, and development of allantois. Static culture is inadequate for the study or evaluation of neural fold closure, branchial arch formation, anterior limb bud formation, and axial turning of the explanted embryos. Embryo cultures in rat serum yield better results than do cultures in human cord serum.