Objective Chitinases are essential for chitin metabolism and the growth and development of insects. This study systematically identified the chitinase gene family members in the red fire ant (Solenopsis invicta), analyzed their molecular characteristics and expression patterns, and explored their potential functions during development. The findings provide a theoretical basis and genetic resources for novel green control strategies targeting chitin metabolism.

Method Based on the whole genome data of S. invicta, members of the chitinase gene family were identified. Bioinformatics analysis were performed to characterize the physicochemical properties, chromosomal localization, and phylogenetic relationships of their encoded proteins. The expression patterns of these genes across different developmental stages (egg, larva, pupa, and adult) and in various tissues were further examined using RT-qPCR.

Result A total of six chitinase genes were identified in S. invicta, including five SiCht genes and one SiIDGF gene. The corresponding encoded proteins exhibited lengths ranging from 444 to 3 050 amino acids, most of which were predicted to be stable and acidic in nature. These genes were distributed across five chromosomes, with SiCht6-1 and SiCht6-2 both located on chromosome 6. Collinearity analysis suggested that the chitinase gene family is evolutionarily conserved, and phylogenetic analysis grouped them into seven distinct clades. Expression profiling revealed that SiCht1, SiCht2, and SiCht7 were predominantly expressed at high levels during eggs, larvae, and pupae stages, whereas SiIDGF3 displayed the highest expression in adults. Tissue-specific expression analysis further demonstrated that SiCht7 and SiIDGF3 were significantly enriched in the epidermis, suggesting their potential key roles in cuticular development and remodeling.

Conclusion This study successfully identified six members of the chitinase gene family in S. invicta, which exhibit diverse molecular features and evolutionary conservation. Expression patterns suggest that SiCht genes are involved in molting and growth-related processes of S. invicta, with SiCht7 and SiIDGF3 emerging as potential key targets for cuticle remodeling. These findings provide insights into the molecular mechanisms contributing to the invasiveness of S. invicta and provide a theoretical basis for the development of environmentally friendly control strategies, such as RNAi or chitinase inhibitors targeting chitin metabolism.