Galleria mellonella is a destructive pest of honeybee colonies, its strong tolerance to temperature extremes and ultraviolet radiation facilitates its wide distribution and infestation. Small heat shock proteins (sHsps) play critical roles in insect development and in adaptive responses to environmental stresses. In this study, the molecular characteristics and expression patterns of the small heat shock protein gene GmsHsp12.2 were investigated in G. mellonella. Based on a previously generated transcriptome dataset, the full-length coding sequence (CDS) of GmsHsp12.2 was cloned using polymerase chain reaction (PCR) and subsequently analyzed using bioinformatics approaches. Phylogenetic relationships were inferred using MEGA-X software. Quantitative real-time PCR (RT-qPCR) was employed to examine the expression profiles of GmsHsp12.2 across different developmental stages, in various tissues, and under environmental stress conditions, including high temperature, low temperature, and ultraviolet-A (UV-A) exposure. The obtained CDS was 504 bp in length and encoded a protein of 167 amino acids containing the conserved α-crystallin domain characteristic of the sHsp family. The results revealed that GmsHsp12.2 expression was highest in fourth-instar larvae and Malpighian tubules. Moreover, the gene was significantly upregulated in response to high temperature (36 °C), low temperature (4 °C), and UV-A stress, with peak expression occurring at 90, 120, and 60 min, respectively. These findings indicated that GmsHsp12.2 is a stress-responsive gene and may function as a molecular chaperone involved in thermal and ultraviolet stress adaptation during the development of G. mellonella. This study provides a molecular basis for understanding stress adaptation mechanisms in this economically important pest and supports the development of novel pest management strategies targeting stress-related genes.
Liu et al. (Tue,) studied this question.