Characterization of a method for quantitating food consumption for mutation assays in Drosophila

Environ Mol Mutagen. 1991;18(1):14-21. doi: 10.1002/em.2850180104.

Abstract

Quantitation of food consumption is necessary when determining mutation responses to multiple chemical exposures in the sex-linked recessive lethal assay in Drosophila. One method proposed for quantitating food consumption by Drosophila is to measure the incorporation of 14C-leucine into the flies during the feeding period (Thompson and Reeder: Environmental Mutagenesis 10:357-365, 1987). Three sources of variation in the technique of Thompson and Reeder have been identified and characterized. First, the amount of food consumed by individual flies differed by almost 30% in a 24 hr feeding period. Second, the variability from vial to vial (each containing multiple flies) was around 15%. Finally, the amount of food consumed in identical feeding experiments performed over the course of 1 year varied nearly 2-fold. The use of chemical consumption values in place of exposure levels provided a better means of expressing the combined mutagenic response. In addition, the kinetics of food consumption over a 3 day feeding period for exposures to cyclophosphamide which produce lethality were compared to non-lethal exposures. Extensive characterization of lethality induced by exposures to cyclophosphamide demonstrate that the lethality is most likely due to starvation, not chemical toxicity.

MeSH terms

  • Administration, Oral
  • Animals
  • Carbon Radioisotopes
  • Cyclophosphamide / administration & dosage
  • Cyclophosphamide / metabolism*
  • Cyclophosphamide / pharmacology
  • Drosophila / genetics*
  • Drosophila / physiology
  • Ethylnitrosourea / administration & dosage
  • Ethylnitrosourea / metabolism*
  • Ethylnitrosourea / pharmacology
  • Feeding Behavior
  • Female
  • Genes, Lethal*
  • Genes, Recessive*
  • Leucine / metabolism
  • Mutagenicity Tests / methods*
  • Oogonia / drug effects*
  • Radioisotope Dilution Technique
  • Sucrose

Substances

  • Carbon Radioisotopes
  • Sucrose
  • Cyclophosphamide
  • Leucine
  • Ethylnitrosourea