Question

1. Describe evidence suggesting that inter-individual variation in the per gene might account for inter-individual variation in the nature of circadian rhythms expressed.

Answer 1

Ans: Circadian rhythms are endogenous oscillators that control 24 hours physiological and behavioral changes.

circadian rhythms have an effect on the body temperature, sleep,wakefullness,various hormonal changes which depends on several external/ environmental factors as well as genetic factors which regulates the expression of genes responsible for circadian rhythms.

External factors include exercise,medication etc.Most of the core clock genes are conserved across the various individuals but their are certain genes which differs from one individual to the other individual which brings  about variations in the expression of genes responsible for circadian rhythms.

The expression of genes occurs with respect to cell signalling which brings about the transcription and translation of desired genes based on the need of our body and external environment.

Within cells ,rhythmicity is maintained by transcriptional and post translational feedback loops involving a set of clock genes.

Recently,transcriptome wide analyses from animal tissues such as blood,brain,liver,kidney,skeletal muscle and heart revealed that many genes beyond the core clock genes undergo daily variations in expression levels .The engagement of these additional circadian genes likely reflects tissue specific functional needs.

Thus inter-individual variation in the per gene accounts for the inter-individual variation in the nature of circadian rhythms expressed.