From Stress Exposure to Survival: Gene Expression Modules Under Heat–Desiccation Extremes in Insects

Insects increasingly experience climatic extremes as coupled stressors rather than isolated challenges, with high temperatures frequently co-occurring with low humidity to create compound heat–desiccation events. These hot–dry episodes threaten survival by simultaneously destabilizing proteostasis, elevating oxidative stress, and accelerating water loss, thereby compressing thermal safety margins and amplifying failure risk during and after exposure. This study synthesizes current evidence that insect stress transcriptomes are organized into coordinated gene-expression modules—rather than scattered, independent responses—and that the timing, magnitude, and integration of these modules can predict resilience, collapse, and recovery capacity. This study emphasizes a conserved “core” program centered on molecular chaperones (including HSP families), redox buffering, and damage-control pathways, which is repeatedly recruited under both heat and severe dehydration. Layered onto this core are stressor- and lineage-specific modules that govern water balance and osmotic stability, including cuticular barrier remodeling, transport and excretory regulation, osmolyte metabolism (notably trehalose pathways in extreme tolerance), and protective proteins. It further examines regulatory architectures that tune these modules—stress-activated signaling networks, transcription factors, and epigenetic or chromatin-linked mechanisms that may shape acclimation and short-term stress “memory,” while noting that strong evidence for durable, generalizable epigenetic memory remains uneven across insect taxa. Finally, it highlights emerging priorities for the field: field-realistic thermal–humidity trajectories, life-stage- and tissue-resolved sampling, multi-omics integration, and causal perturbation pipelines that move from signatures to mechanisms. Together, a modular framework clarifies why similar transcriptional activation can yield divergent outcomes across species and populations and provides a practical basis for biomarker discovery, conservation physiology, and climate-aware pest management.

کلیدواژه ها:

Gene Regulatory Networks ، Modular Response ، Heat–Desiccation Stress ، Proteostasis ، Stress Memory