The nuclear receptor Unfulfilled is needed for natural daily rhythms in fruit fly brain clock cells

The nuclear receptor gene unfulfilled (unf) is required for the function of the small ventral lateral neurons (s-LNvs) in Drosophila.

• s-LNvs are identified as the main pacemaker neurons that synchronize circadian rhythms.
• unf is rhythmically expressed in s-LNvs and is necessary for maintaining free-running locomotor rhythms.
• Flies with mutations in unf display behavior that is arrhythmic, indicating its role in circadian control.
• Knockdown of unf during development leads to a permanent loss of rhythm-generating ability in adult s-LNvs.
• Depletion of UNF from adult s-LNvs reduces rhythmicity only under constant darkness, suggesting a context-dependent role.
• The study indicates that UNF is essential for the coordination of molecular and behavioral rhythms across the circadian circuit.

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