“These results suggest that immunity is stronger at night, consistent with the hypothesis that circadian proteins upregulate restorative functions such as specific immune responses during sleep, when animals are not engaged in metabolically costly activities,” Stanford researcher Mimi Shirasu-Hiza said in a news release issued by the conference organisers.
Circadian rhythm paces the human body as well as the fruit fly, running internal clock’s time for eating and rest every day.
The researchers noted that previous experiments with flies found that bacterial infection threw off the insects’ circadian rhythm, and not having this internal clock working properly made them highly susceptible to infection. In this experiment, the researchers infected the flies with two different bacteria at different times of day or night. Those infected at night were more likely to survive than those infected during the day.
The News, 19th December 2008-12-19