Chill-Coma Tolerance, a Major Climatic Adaptation Among Drosophila Species

Abstract

Most drosophilid species can be classified either as temperate or tropical. Adults of species were submitted to a cold treatment (0ЊC) and then brought back to ambient temperature. They generally exhibited a chill coma and the time needed to recover was measured. We found in a set of 26 temperate species that recovery was rapid (average 1.8 min, range 0.15-4.9). In contrast, a long recovery time (average 56 min, range 24-120) was observed for 48 tropical species. A few species, like Drosophila melanogaster, are cosmopolitan and can proliferate under temperate and tropical climates. In 9 of 10 such species, slight genetic differences were found: a shorter recovery in temperate than in tropical populations. Comparing physiological data to phylogeny suggests that chill-coma tolerance has been a recurrent adaptation that is selected for in cold climates but tends to disappear under a permanently warm environment. This major climatic adaptation, evidenced in drosophilids, seems to occur in other insect groups also.

Altitudinal variation for stress resistance traits and thermal adaptation in adult Drosophila buzzatii from the New World

“…Chill‐coma recovery has been used by several authors and seems to be a trait causally related to cold adaptation both within and between species (Gibert et al. , 2001; Hallas et al.…”

“…, 2003a). For cold adaptation, an ecologically important trait for identifying adaptive variation among populations of small insects has been suggested to be chill‐coma recovery (Gibert et al. , 2001; Hoffmann et al.…”

“…, 2002). Temperate species and populations show faster recovery to chill induced coma than do tropical species and populations (Gibert et al. , 2001; Hoffmann et al.…”

Thermal preference in Drosophila

“…Given the important effects of rearing and acclimation temperatures on other aspects of Drosophila thermal physiology (see, e.g. David et al, 1983; Gibert et al, 2000, 2001; Petavy et al, 2001), future work on the effects of these on T p may prove fruitful.…”

Molecular characterizations of DNA methyltransferase 3 and its roles in temperature tolerance in the whitefly, Bemisia tabaci Mediterranean

“…We measured the interval between when the tube was placed in the water bath and when the whitefly lost control of its body and fell to the bottom of the tube. To test cold resistance, we measured the time to recovery following a chill coma induced by cold shock (Gibert et al ., ; Ma et al ., ). One adult, confined as described above, was exposed to a temperature of −5 °C in a refrigeration bath circulator (K6‐cc‐NR, Huber Kältemaschinenbau GmbH) for 10 min, and the recovery time was measured at 26 °C.…”