Divergent strategies for adaptation to desiccation stress in two Drosophila species of immigrans group

Parkash, R; Aggarwal, DD; Ranga, P; Singh, D

HERO ID

1447497

Reference Type

Journal Article

Year

2012

Language

English

PMID

22407357

HERO ID 1447497
In Press No
Year 2012
Title Divergent strategies for adaptation to desiccation stress in two Drosophila species of immigrans group
Authors Parkash, R; Aggarwal, DD; Ranga, P; Singh, D
Journal Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology
Volume 182
Issue 6
Page Numbers 751-769
Abstract Water balance mechanisms have been investigated in desert Drosophila species of the subgenus Drosophila from North America, but changes in mesic species of subgenus Drosophila from other continents have received lesser attention. We found divergent strategies for coping with desiccation stress in two species of immigrans group--D. immigrans and D. nasuta. In contrast to clinal variation for body melanization in D. immigrans, cuticular lipid mass showed a positive cline in D. nasuta across a latitudinal transect (10°46'-31°43'N). Based on isofemale lines variability, body melanization showed positive correlation with desiccation resistance in D. immigrans but not in D. nasuta. The use of organic solvents has supported water proofing role of cuticular lipids in D. nasuta but not in D. immigrans. A comparative analysis of water budget of these two species showed that higher water content, reduced rate of water loss and greater dehydration tolerance confer higher desiccation resistance in D. immigrans while the reduced rate of water loss is the only possible mechanism to enhance desiccation tolerance in D. nasuta. We found that carbohydrates act as metabolic fuel during desiccation stress in both the species, whereas their rates of utilization differ significantly between these two species. Further, acclimation to dehydration stress improved desiccation resistance due to increase in the level of carbohydrates in D. immigrans but not in D. nasuta. Thus, populations of D. immigrans and D. nasuta have evolved different water balance mechanisms under shared environmental conditions. Multiple measures of desiccation resistance in D. immigrans but reduction in water loss in D. nasuta are consistent with their different levels of adaptive responses to wet and dry conditions on the Indian subcontinent.
Doi 10.1007/s00360-012-0655-x
Pmid 22407357
Wosid WOS:000306698400003
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English