# Abiotic conditions can modify the penetrance of transgene-based lethality systems for insect population control

## TL;DR

Environmental factors like temperature and nutrition can affect how well genetic pest control systems work in insects.

## Contribution

The study shows that abiotic factors influence transgenic lethality in insects, with embryos being more sensitive than parents.

## Key findings

- Transgene performance is affected by temperature and nutrition.
- Embryos exposed to thermal stress show greater impact than parents.
- Extreme nutrition can reduce the effectiveness of transgenic lethality.

## Abstract

Modern genetic biocontrol techniques for insect pest management, when compared to chemical insecticide spraying, offer high species specificity and reduced environmental impact, and some of these methods require the environmental release of genetically modified (GM) insects. Because organisms exposed to different environments often show variability in phenotype and gene expression, it is likely that GM insects will also experience environmentally mediated variation, potentially compromising pest control efficiency. This study examines the impact of temperature and nutrition on the early embryonic Tet-off conditional lethality system in Drosophila melanogaster. By independently manipulating parental and offspring environments, we assessed how exposure to variable environments influenced the probability of larval hatching and the transcript abundance of the transgenic system. Our findings revealed that: (i) transgene performance distinctly responds to temperature and nutrition; (ii) thermal stress has a greater impact when embryos, rather than parents, are exposed; and (iii) extreme nutritional conditions can markedly reduce the penetrance of transgenic lethality. Although changes in transgene transcript abundance were observed across environments, these changes did not fully explain the phenotypic variation, suggesting that factors downstream of transcription probably drive variation in transgenic lethality.