Period 2: A Regulator of Multiple Tissue-Specific Circadian Functions

Area of Science:

• Chronobiology
• Genetics
• Zebrafish models

Background:

• Zebrafish possess light-sensitive peripheral clocks, making them ideal for studying light's effect on circadian rhythms.
• The per2 clock gene is thought to be vital for transmitting light signals to the central circadian clock mechanism.

Purpose of the Study:

• To investigate the specific role of the per2 gene in zebrafish circadian clock function.
• To determine the impact of per2 gene disruption on circadian clock gene expression, clock-controlled genes, and larval behavior.

Main Methods:

• Generation of a loss-of-function per2 gene mutation in zebrafish.
• Analysis of rhythmic expression of circadian clock genes and clock-controlled genes.
• Assessment of behavioral rhythms in intact zebrafish larvae.
• Investigation of the per2 gene's effect on in vivo cell cycle regulation.

Main Results:

• The per2 gene exhibits a tissue-specific role in maintaining rhythmic gene expression.
• Disruption of the per2 gene affects rhythmic expression of clock genes and clock-controlled genes.
• Loss of per2 function impacts rhythmic behavior in zebrafish larvae and circadian cell cycle regulation.

Conclusions:

• The per2 gene is essential for the light input pathway to the circadian clock in zebrafish.
• Per2 acts as a circadian regulator of tissue-specific physiological functions in zebrafish.