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

Modern genetic biocontrol techniques for insect pest management, when
compared to chemical insecticide spraying, offer high species specificity
and reduced environmental impact. However, some of these methods require
the environmental release of genetically modified insects. Because
organisms exposed to different environments often show variability in
phenotype and gene expression, it is likely that genetically modified
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
treatment exposure influenced the probability of larval hatching and the
transcript abundance of the transgenic system. Our findings revealed that
(1) transgene performance distinctly responds to temperature and
nutrition, (2) thermal stress has a greater impact when embryos, rather
than parents, are exposed, and (3) extreme nutritional conditions can
markedly reduce the penetrance of transgenic lethality. Although changes
in transgene transcript abundance were observed, they did not fully
explain the phenotypic variation, suggesting that factors downstream of
transcription likely drive variation in transgenic lethality.