Effects of aflatoxin B 1, aflatoxin B 2, aflatoxin G 1, and sterigmatocystin on viability, rates of development, and body length in two strains of Drosophila melanogaster (Diptera)

Abstract

Two wild-type laboratory populations of Drosophila melanogaster, Florida-9 (sensitive to aflatoxin (AF) B 1-induced toxicity) and Lausanne-S (resistant to AFB 1-induced toxicity) were tested to determine relative degress of sensitivity to growth from the egg stage on media containing 0.2, 0.6, 2.0, and 4.0 ppm AFB 1, AFG 1, AFB 2, or sterigmatocystin (ST). Data indicate that strain Florida-9 is quite sensitive to AFG 1 toxicity at both the egg-pupa and egg-adult stages of development while Lausanne-S is quite resistant to such toxic effects. For Lausanne-S, AFB 1 > AFG 1 in relative toxicity, while for Florida-9, AFG 1 > AFB 1. The latter is noteworthy since vertebrate studies consistently show that AFB 1 is a significantly stronger carcinogen and mutagen than AFG 1. Possible explanations are discussed. Neither strain tested displayed toxic responses to the presence of AFB 2 or ST in the culture media; however, the 4.0-ppm Lausanne-S treatment displayed a significantly lower adult mortality rate than the control, indicating that Lausanne-S flies may benefit from the presence of ST in the culture medium.