A research group led by Professor Kazuhiro Yagida of Kyoto Prefectural University of Medicine focused on the relationship between the two biological clocks (segmental clock and biological clock) that appear during fetal development, and in the first half of the development, "the biological clock is suppressed. It was revealed that "is necessary for the development of a normal fetal body."
Most living organisms on the earth have a biological clock that gives biological functions a biological rhythm with a cycle of about 24 hours.However, in mammals, the biological clock is strongly suppressed during its development, and it is not seen in fetuses such as mice until just before birth, but the reason is unknown.In order to clarify the mystery of this mammal's "development of a body clock that is too slow", the research group focused on the relationship with the "somitogenesis" phenomenon that occurs when there is no body clock, and studied using mice. Was done.
Somitogenesis is essential for the normal development of vertebrates, and the mechanism that controls this is the "segment clock".Unlike the body clock, the segmental clock keeps a rhythm of about 2 hours in the case of a mouse.Studies have revealed that the clock gene (Per1) that constitutes the biological clock is genomically adjacent to the gene (Hes7) that plays a major role in the segmental clock, suggesting a relationship between the biological clock and the segmental clock. ..
Therefore, the research group forcibly expressed the key factor CLOCK / BMAL1 of the biological clock during the somitogenic phase using an embryonic organoid (artificial pseudo-embryo) that artificially reproduced the somitogenic phase that forms the foetation.As a result, it was found that it interfered with the segmental clock, disrupted the rhythm control of the 2-hour cycle, and inhibited somitogenesis.
As a result, it is said that the start of the development of the biological clock after the end of the organogenesis phase in the developmental process is extremely important for the normal developmental process.In the future, it is expected that the understanding of the effects of the fetal body clock life rhythm on the foetation will progress.
Paper information:[PNAS] Circadian key components CLOCK / BMAL1 interfere with segmentation clock in mouse embryonic organoids