Comparative transcriptomic analysis of functional and metabolic changes in mass-reared and wild Anastrepha ludens Loew (Diptera: Tephritidae).

Abstract

Introduction: Mass rearing for the Sterile Insect Technique (SIT) may induce transcriptomic changes that influence post-release performance. We compared head transcriptomes of two mass-reared Anastrepha ludens strains, Bisexual and Tap-7, with wild individuals associated with their preferred natural host, sweet orange.

Methods: RNA-seq data were analyzed to assess transcriptomic differentiation, differential gene expression, Gene Ontology (GO) enrichment, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, and chemosensory gene expression profiles among the three groups.

Results: Principal component analysis clearly separated the mass-reared strains from wild host-associated individuals. More than 1,300 differentially expressed genes were identified per strain, with gene repression predominating and enrichment of functions related to translation, cellular energy metabolism, RNA processing, and metabolic regulation. Both mass-reared strains shared signatures of metabolic adjustment but also displayed strain-specific patterns. The Bisexual strain showed signatures associated with stress response, immunity, and mitochondrial quality control, whereas Tap-7 showed enrichment of pathways related to calcium regulation, secretion, detoxification, and folate metabolism. Both strains also exhibited reorganization of chemosensory gene expression, including conservation of receptors and co-receptors such as Ir25a, Ir68b, Ir85a, Or74a, and SNMP1, together with convergent downregulation of odorant-binding proteins, particularly Obp56a-like and members of the Obp99 clade.

Discussion: These results indicate that mass-reared A. ludens strains exhibit a distinct head transcriptomic state relative to wild host-associated flies. The shared and strain-specific expression patterns suggest that mass rearing may be associated with metabolic and sensory changes relevant to post-release performance. The identified sensory and metabolic markers provide candidates for future behavioral, electrophysiological, and physiological evaluation of fruit fly strains used in SIT programs.