Questions about Clock

Short answers, pulled from the story.

When was the CLOCK gene identified and by whom?

Joseph Takahashi and his team at Northwestern University identified the CLOCK gene in 1997 through a forward mutagenesis screen. They treated mice with N-ethyl-N-nitrosourea to induce random mutations across the genome.

What is the function of the CLOCK protein in circadian rhythms?

The CLOCK protein acts as a transcription factor within the circadian pacemaker system. In mammals, BMAL1 dimerizes with CLOCK to activate per and cryptochrome transcription while exhibiting histone acetyl transferase activity enhanced by dimerization.

How old are the oldest known clock genes found in cyanobacteria?

The kaiA/B/C gene clusters remain the oldest known clock genes present in cyanobacteria. Cryptochromes are thought to be descendants of kaiC resulting from genome duplication predating the Cambrian explosion.

Which human allele correlates with evening preference and sleep disorders?

In humans, the 3111C allele correlates with evening preference based on scored questionnaire responses. This polymorphism affects mRNA stability and could disrupt normal circadian patterns leading to insomnia or sleep disorders.

Do null mutant mice lacking Clock completely show normal circadian rhythms?

Null mutant mice lacking Clock completely show normal circatory rhythms challenging previous assumptions about necessity. Neuronal PAS domain containing protein 2 can substitute for CLOCK in these animals.

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