Investigating the role of female-specific odorant receptors in the detection of host plant odors in Manduca sexta

Insects exhibit high sensitivity and specificity in detecting a diverse array of volatile organic compounds (VOCs) in their environment, primarily through chemosensory receptors, which include odorant receptors (ORs), gustatory receptors (GRs), and ionotropic receptors. In insects, the detection of hosts or mates is predominantly mediated by olfactory receptors. Insect ORs are heteromeric complexes consisting of transmembrane proteins with seven transmembrane domains, comprising an odor-specific odorant receptor and the odorant receptor co-receptor. The tobacco hornworm Manduca sexta, is a lepidopteran insect organism extensively used in the field of insect olfaction. Whole genome sequencing has identified the major chemosensory receptor gene families and current research focuses on the functional analysis of these receptors to determine their role in host detection behavior. Plant volatiles play an important role in mediating interactions between plants and insects, including serving as cues for nectar feeding and oviposition. We are investigating the function of Manduca ORs, which are specifically expressed in the female antennae which might be involved in the detection of host-plant odors, potentially playing a crucial role in floral visitation and oviposition behavior. To investigate the role of these receptors, we generated mutant lines using CRISPR/Cas9 and checking their effects on host odor detection and oviposition and checking odor-tuning profile by heterologusly expressing these receptors in drosophila OSN. Further, we are generating transgenic Manduca lines to ectopically express re-engineered ORs and will use these genetically engineered female antennae on a bio-inspired microcomputing platform for the detection of chemicals related to human health and diseases.