Effects of plant growth retardant daminozide (Alar) on neuromuscular co-ordination behavior in Drosophila melanogaster.

Daminozide (alar), a plant growth retardant, is used in different fruit orchard to make fruits attractive and reduce pre-harvest losses. Previously data demonstrated that acute daminozide exposure affected reproductive fitness and produced neurodegeneration in Drosophila melanogaster. The goal of this study was to determine whether continuous exposure to daminozide affects neuromuscular co-ordination in D. melanogaster as manifested in various behavioral responses. Fruit flies were exposed to 200 or 400 mg/L concentration of daminozide for two successive generations. Treated D. melanogaster were examined for the behaviors indicative of neuromuscular coordination and cognitive abilities, that include climbing, social interaction, adult grooming, migration, flight, male aggression, and adult courtship. Aberrant behavioral responses were noted among treated D. melanogaster of both sexes as evidenced by the following parameters: reduction in flight duration, abnormal social interaction, altered copulatory acts, and over-aggressiveness. Data suggest that daminozide produces impairment in neuromuscular coordination and cognitive ability in Drosophila, which was reflected as altered behavioral patterns. As Drosophila is considered as a reliable in vivo model utilized in toxicity testing, our findings may help us to anticipate and monitor potential daminozide-induced toxicity in animals and humans.

Genes regulating development and behavior exhibited altered expression in Drosophila melanogaster exposed to bisphenol A: use of real-time quantitative PCR (qRT-PCR) and droplet digital PCR (ddPCR) in genotoxicity study.

Toxicity of bisphenol A on morphological and life-history traits of model insect Drosophila melanogaster was reported in our previous work. In the present study, we have analyzed the adversity of bisphenol A on the reproductive behavior of adult and on the expression of selected genes in the larva and adult stage of fruit fly exposed to bisphenol A (0.007 g/2 ml. or 3.5 mg/ml), in addition to determination of LC50 value of bisphenol A in larva and pupal stage. We employed both the quantitative reverse transcriptase PCR and droplet digital PCR for analyzing the expression profile of seven genes namely, decapentaplegic, vestigial, wingless, foraging, insulin-like receptor, doublesex, and fruitless. We found bisphenol A has more adverse effects on male sexual behavior than females. Moreover, we observed significant downregulation of all the selected genes in treated larvae except, fruitless in male where it showed significant upregulation. On contrary among the treated adult flies, significant downregulation of all target genes in both sexes is evident, except, doublesex and fruitless in males which showed significant upregulation. We did not observe any deviation of male: female sex ratio from 1:1 under bisphenol A exposure. All these results suggest bisphenol A adversely affects the optimum functioning of genes which are involved in the regulation of metabolic pathways, behavioral pattern, stress response, endocrine homeostasis, neural functioning, and the development of the specific organ in Drosophila melanogaster. Our result not only provides a foundation to study further the bisphenol A toxicity on different pivotal genes in Drosophila but also suggests the use of the droplet digital PCR technology in toxicity measurement at the molecular level in eukaryotic model systems.

Exploration of teratogenic and genotoxic effects of fruit ripening retardant Alar (Daminozide) on model organism Drosophila melanogaster.

Alar (Daminozide) is a plant growth regulator which is widely used as a fruit preservative for apple and mango to prevent pre-harvest fruit drop, promote color development and to delay excessive ripening. The aim of the present work was to demonstrate the effect of Alar on several life history traits, adult morphology, Hsp70 protein expression and in vivo DNA damage in the brain of the model organism Drosophila melanogaster. We assessed the life history and morphological traits including fecundity, developmental time, pupation height, egg-to-adult viability and mean wing length, body length, arista length and sternopleural bristle number of the emerging flies. The results showed a significant delay in the developmental milestones, increase in body length, wing length, arista length, a decrease in fecundity, pupal height and variation in sternopleural bristle number in the treated flies in comparison to the controls. Overexpression of Hsp70 protein suggests alar induced subcellular molecular stress and comet assay validates genotoxicity in the form of DNA damage in the treated larvae. Mutation screening experiment revealed induction of X lined lethal mutation.