# Evaluating the potential toxicity of ampicillin using Drosophila melanogaster as a model organism

## TL;DR

This study shows that ampicillin affects fruit flies' lifespan, fertility, and gene expression across generations, with sex-specific differences in immune and epigenetic responses.

## Contribution

The novelty lies in revealing trans-generational and sex-specific effects of ampicillin on Drosophila physiology and gene regulation.

## Key findings

- AMP stress reduces lifespan and fertility of Drosophila melanogaster, peaking in F3 and F4 generations in rescue flies.
- Low-dose AMP exposure alters epigenetic and apoptotic gene expression in a sex-specific manner.
- Reproductive cell viability declines, with stronger effects in females.

## Abstract

Antibiotic resistance is an indispensable threat facing in the present era. However, the studies on long term and trans-generational effects of using drugs or antibiotics on living organisms are scarce. Emphasizing the necessity to address such problems, this study investigated the potential effects of antibiotic, ampicillin (AMP) stress on the physiology of Drosophila melanogaster across multiple generations with mechanistic details. We evaluated the larval feeding behavior, fertility, cell viability in ovary and testis, longevity, expression of methylation-related genes (dDnmt2 and dMBD2/3), and antimicrobial peptide production. Larvae exposed to AMP exhibited increased mouth hook movement, indicating altered behaviour. AMP stress significantly reduced fertility across generations, with eclosion counts decreasing notably in F3 and F4 generations compared to controls. Moreover, AMP-treated flies showed decreased cell viability in ovary and testis, leading to impaired reproductive function. AMP exposure shortened the mean lifespan of flies and upregulated the expression of apoptosis-related gene p53 in females. However, there was no significant difference in p53 expression in males. Additionally, AMP stress caused a significant decrease in Drosomycin expression in treated males, while no significant changes were observed in Drosocin and Metchnikowin. In treated females, Drosocin and Drosomycin expression increased significantly, whereas the increase in Metchnikowin was not significant. The study also revealed downregulation of methylation-related genes (dDnmt2 and dMBD2/3) in AMP-treated female flies which was normalised in the rescue flies suggesting disrupted epigenetic mechanisms. Overall, the findings highlighted the importance of evaluating the trans-generational impacts of AMP stress on Drosophila physiology and gene expression, particularly in reproductive function and epigenetic regulation. The study of the impact of widely used antibiotic, AMP on model organism, Drosophila (model organism known for its genetic similarity to human), will help in predicting potential impacts on higher organisms and human. The finding would ultimately promote proper use of antibiotics and use of alternative medicine.

•AMP stress reduces lifespan and fertility of Drosophila melanogaster, peaking in F3 and F4 generations in rescue flies.•Low-dose AMP exposure alters epigenetic and apoptotic gene expression in a sex-specific manner.•AMP effects persist across generations but normalize in rescue flies over time.•Reproductive cell viability declines, with stronger effects in females.•Immune response gene expression upregulated in female and downregulated in males under AMP stress.

AMP stress reduces lifespan and fertility of Drosophila melanogaster, peaking in F3 and F4 generations in rescue flies.

Low-dose AMP exposure alters epigenetic and apoptotic gene expression in a sex-specific manner.

AMP effects persist across generations but normalize in rescue flies over time.

Reproductive cell viability declines, with stronger effects in females.

Immune response gene expression upregulated in female and downregulated in males under AMP stress.