Within- and transgenerational effects of thermal variability on critical thermal limits and fitness in fruit-fly

BOHER, FRANCISCA; REZENDE, ENRICO; CAVIERES, GRISEL; ALRUIZ, JOSÉ M.; BOZINOVIC, FRANCISCO; CLAVIJO-BAQUET, SABRINA; RIVERA-REBELLA, CARLA

Ottawa

Congreso; 10th International Congress of Comparative Physiology and Biochemistry; 2019

IACPB

Global warming, thermal variability, and frequency of extreme environmental events have increased with a high impact on biodiversity, which is expected to be particularly challenging for ectotherms due to their lack of internal regulation. Experimental studies have shown that these organisms may react to thermal environment with physiological modifications that have an impact on fitness. Phenotypic changes in early ontogeny have long-term implications and may persist over generations. We studied ontogenetic and transgenerational effects of thermal variability on critical thermal limits (CTmin, CTmax) and demographic parameters (R0, Tg) in the fruit-fly Drosophila melanogaster. Adults were captured in Central Chile and maintained under controlled conditions (24°C and LD = 12:12). After three generations, flies were assigned to thermal treatments in climatic chambers, 28 ± 0°C (moderate mean, no variance), and 28 ± 4°C (moderate mean, high variance). The results revealed that variability of thermal conditions during ontogeny improved heat tolerances, but with an adverse effect on demographic parameters. Values of R0 and Tg decreased with the increased thermal variability and population density. Also, in variable thermal environments, when offspring grew up in the same environment as the one experienced by the parents, the demographic parameters were positively impacted.