Parisa Najari Hanjani - Golestan University of Medical Sciences, Gorgan, Iran.
Masoud Golalipour - Cellular and Molecular Research center, Golestan university of Medical science, Gorgan, Iran

Background: Circadian clocks are autonomous intracellular oscillators that synchronize metabolic and physiological processes with the external signals. So, misalignment of environmental and endogenous circadian rhythms leads to disruption of biological activities in living organisms. Noncoding transcripts including antisense RNAs are an important component of the molecular clocks. Commonly, the antisense transcripts are involved in the regulation of gene expression. PER۲AS and CRY۱AS are the only known Natural Antisense Transcripts (NAT) among the core clock genes, which overlap with the PER۲ and CRY۱ genes, respectively. In this study, we hypothesized that PER۲AS and CRY۱AS like the other clock genes, exhibit the oscillatory behavior in a ۲۴-hour period and affect the expression of PER۲ and CRY۱. Methods: First, the A۵۴۹ cell line was cultured under standard conditions. After horse serum shock, RNA extraction and cDNA synthesis was performed; then the expression fluctuations of PER۲AS, CRY۱AS, PER۲, and CRY۱ were measured with Real-time PCR.  Results: Our result showed that PER۲AS and CRY۱AS had similar oscillation patterns with their sense strand during ۲۴-hour period. Conclusions: Therefore, we suggested that PER۲AS and CRY۱AS transcripts probably by preventing the interaction of miRNAs with PER۲ and CRY۱ mRNAs, influence the expression of them, positively.

CRY۱, CRY۱AS, Natural Antisense Transcripts, PER۲, PER۲AS.