Harnessing transcriptomics to understand insect response to environmental alterations: recent advances and emerging applications

Insects constitute the largest and most diverse group of animals on earth, occupying nearly every habitat and playing fundamental roles in natural and agricultural ecosystems. The ability to decode their complex biology is therefore critical for both conserving beneficial species and controlling harmful insect pests. However, alterations in environmental conditions due to climate change, pollution, habitat degradation, and pesticide exposure are significantly affecting insect populations worldwide. Transcriptomics has emerged as a powerful approach providing a comprehensive understanding of gene activity and expression. The field has progressed from early exploration of RNA molecules to advanced analysis of gene expression, enabling precise insights into molecular mechanisms that regulate insect development, reproduction, adaptation, and various behaviours. By profiling specific tissues, organs, sex, and species, the RNA transcript with altered expression can be identified and targeted. Beyond fundamental biology, transcriptomics has also proven valuable in assessing the molecular responses of insects towards environmental abiotic stresses including temperature fluctuations, drought, and chemicals. The review provides insights into transcriptome studies that showed how various regulatory networks are associated with stress tolerance, detoxification, defence, behaviour, and environmental adaptations in insects. Furthermore, single-cell transcriptomics offers more potentiality and can be used to analyse the gene expression and heterogeneity at the level of individual cells. The integration of transcriptomics with other techniques like RNAi, CRISPR Cas 9, proteomics, and metabolomics will significantly enhance the functional studies of genes that elucidates the complex regulatory networks in insects. The current review discusses all these techniques that offer a new advancement in the field of entomology and can potentially transform traditional pest management practices into a more targeted, eco-friendly, and effective way at the molecular and behavioural level.