Different Development Timing of Daily Rhythm Proteins in the Brain's Master Clock and Hormone-Regulating Area in Mice

In the foetal suprachiasmatic nucleus (SCN), levels of clock proteins were significantly lower than adult levels except for BMAL1.

• The SCN functions as a master pacemaker that coordinates circadian rhythms in mammals.
• Clock proteins in the SCN undergo ontogenetic maturation, with the foetal stage showing lower levels compared to adults.
• By the infant stage, clock protein levels in the SCN reach those similar to adults.
• The pars tuberalis (PT) exhibits consistent clock protein levels across different ontogenetic stages, influenced by maternal melatonin.
• Maternal melatonin may play a crucial role in establishing circadian rhythms in the foetal PT, as the foetal pineal gland cannot produce melatonin yet.

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