Abstract
In terms of the LD50 values for alcohols, third-instar wild-type larvae of Drosophila melanogaster had a greater tolerance to ethanol, n-propanol and n-butanol than alcohol dehydrogenase (ADH)-deficient larvae. The tolerances of the two strains to methanol were similar. Methanol, ethanol, n-propanol and n-butanol all induced higher ADH activity in wild-type larvae. Ethanol, n-propanol, methanol and n-butanol slowed the growth for ADH-deficient larvae, whereas only methanol had this effect on wild-type larvae. The proportion of wild-type pupae to eclose was increased by n-butanol, n-propanol and ethanol. Cytometric methods to measure the densities of storage bodies--glycogen rosettes, protein bodies and lipid droplets--in fat body cells indicated that all of the test alcohols exerted some negative influence on the accumulation of at least one type of storage body. Analyses of total protein, glycogen and acylglycerols indicated that ethanol and n-butanol were associated with an accumulation of acylglycerols in both wild-type and ADH-deficient larvae; whereas, the other test alcohols resulted in low glycogen and protein concentrations in both test strains. The short-chain primary alcohols may in part be toxic to larvae because of disruptions in metabolism that lead to reductions in one or more kinds of storage bodies in the larval fat body.
