Differential response to hormesis by laboratory evolved short-lived and long-lived cytoraces ofnasuta-albomicanscomplex ofDrosophila

Abstract

Mild stresses are known to retard progressive decline in survival with age. The process wherein mild stresses exhibit a beneficial role is termed hormesis. The two mild stresses which are gaining interest in the present scenario of aging research are repeated mild heat shock (RMHS) and histone deacetylase inhibitors (HDACi). Our interest was to know how the unique laboratory-evolved short-and long-lived cytoraces of nasuta-albomicans complex of Drosophila would respond to these stresses. Differential response by these cytoraces to RMHS and HDACi was observed. The lifespan of short-lived cytoraces, SL-1 and SL-2, extended more remarkably than other races in response to both RMHS and HDACi, whereas two of the long-lived cytoraces, LL-1 and LL-2, have not shown significant response to HDACi, even though they showed mild response to RMHS. The LL-3 and LL-4 cytoraces have not behaved similarly for all the three hormesis treatments as LL-1 and LL-2 cytoraces. These findings specify that there is a race-specific response developed in each system, and the reason we predict for such plasticity would be their genetic background. These cytoraces which evolved through hybridization have unique genome introgression and recombination, through which they might have acquired a race specific aging pathways, which in turn, played a crucial role in their differential response to stresses.