Genome-Wide Identification, Evolution, and Female-Biased Expression Analysis of Odorant Receptors in Tuta absoluta (Lepidoptera: Gelechiidae)

The tomato leafminer, (Lepidoptera: Gelechiidae), is a highly destructive invasive pest targeting Solanaceae crops. Its olfactory system plays a crucial role in host location, mate finding, and other behavioral activities. However, there is a notable gap in the literature regarding the characterization of its chemosensory genes. In this study, we conducted a genome-wide identification of 58 odorant receptors (ORs) of The identified ORs exhibit coding sequence (CDS) lengths ranging from 1062 bp to 1419 bp, encoding proteins of 354 to 473 amino acids. Gene structure analysis showed that the majority of these ORs consist of five, seven, eight, or nine exons, collectively representing 67% of the total ORs identified. Through chromosomal mapping, we identified several tandemly duplicate genes, including , , , , , , , , , and . The phylogenetic analysis indicated that six were clustered within the lepidopteran sex pheromone receptor clade, while an expansion clade containing ten resulted from tandem duplication events. Additionally, five were classified into a specific OR clade in . Furthermore, through RNA-Seq and RT-qPCR analyses, we identified five ( , , , , and ) exhibiting female-antennae-biased expression. Our study provides a valuable foundation to further investigations into the molecular and ecological functions of , particularly in relation to oviposition behavior. These findings provide foundational data for the future exploration of the functions of female-biased expression OR genes in , thereby facilitating the further development of eco-friendly attract-and-kill techniques for the prevention and control of .