ACCLIMATION FOR DESICCATION RESISTANCE IN DROSOPHILA-MELANOGASTER AND THE ASSOCIATION BETWEEN ACCLIMATION RESPONSES AND GENETIC-VARIATION

Drosophila melanogaster females became more resistant to desiccation after prior exposure to a non-lethal desiccation stress. The response developed within 2 h of initial exposure to low humidity, and persisted more than 28 h after completion of the prior stress period. The acclimation response increased as the prior stress periods were increased upto 9 h after which the flies began to die. Prior exposure to a heat shock caused a smaller increase in desiccation resistance. The magnitude of the acclimation response depended on genetically-determined levels of desiccation resistance. Lines selected for resistance showed a markedly reduced acclimation response after exposure to non-lethal periods of desiccation and heat stress compared to unselected lines, suggesting that the acclimation response and genetic variation for desiccation resistance are partly based on the same mechanism. © 1990.