How mutant mice will help select Mars missionaries
Posted: January 30, 2016
Human population-based and experimental studies show that disrupting the body clock is not good for your health and maybe your survival. Normally the internal body clock runs very close to 24 hours which allows alignment with the natural light/dark cycle. If your body clock is abnormal you could be in trouble.
Scientists at the University of Manchester used a mutant mouse genetic model that has a shorter body clock period than normal. They have a short-period mutation in the enzyme casein kinase 1ε (tau mutation), which speeds up the body clock cycles. These mice were compared with normal mice in a semi-natural environment measuring daily activity, survival and reproduction. Survival was reduced in the mutant mice, revealing strong selection against mice-types with shorter body clock periods. Over the course of 14 mo, the number of the mutant sub-type dropped from 50% of the total mouse population at start to 20%. Therefore mice with near 24-h rhythms survived longer and reproduced more than mice with rhythms shortened by the mutation. Apart from the potential crucial significance for humans subjected to body-clock deviations under abnormal work and lighting schedules, it would deep impact on such extreme circadian-challenging activities such as Mars missions.