I am doing some data analysis about gene expression time series. When I plot mRNA produced by P. Furiosus cells irradiated by gamma radiation against the time of extraction, it seems that there is a negative correlation between them. Is it a good result from a biological point of view ?
$\gamma$-irradiation produces single- and double-strand DNA breaks, depending on the dosage, and activates DNA damage repair pathways like p53. During this time, the cell cycle arrests and most if not all mRNA production ceases. For sub-lethal doses of $\gamma$ rays, I would expect to see newly-produced mRNA levels drop off fairly quickly with time following the initial dose, then possibly begin to ramp up again later as the damage is repaired and the cell cycle arrest checkpoints released.