Regular articleAATEX 2(4):177-181
Palatal primordia of day-12.5 mouse fetuses were cultivated in a chemically-defined medium by a suspension culture technique, and their growth and differentiation in vitro were compared with those of the fetal palates in vivo at the corresponding gestational stages. The maxillary explants cultivated in vitro for up to 72 hours did not grow in size and remained almost in the same size as those in day-12.5 fetuses. However, the palatal shelves elevated and grew faster towards the midline until 24 hours in culture as compared with in vivo development. In day-14.5 fetal palates in vivo, the opposing palatal shelves have contacted with each other in about 80% of cases and 73% of the palates have begun to fuse, while the corresponding rates in vitro were 19% and 6%, respectively, suggesting that in vitro palatogenesis is delayed by 48 hours in culture. At 72 hours of culture, the rate of completely closed palates was 89% against the 10% closure rate for day-15.5 fetuses in vivo. Although the comparison showed that the in vitro development of the fetal mouse palate is somewhat slower than that in vivo, the process of palate fusion in vitro was found to simulate the in vivo palatogenetic process, and suspension organ culture appears superior to the conventional static organ culture. Suspension organ culture of fetal mouse palates should be useful in the study of normal and abnormal palatogenetic processes.
Key words: palatogenesis, mouse fetus, secondary palate, in vitro, in vivo.