Characterization of chemosensory genes in the subterranean pest Gryllotalpa Orientalis based on genome assembly and transcriptome comparison

Abstract

Background: Chemosensory perception plays a vital role in insect survival and adaptability, driving essential behaviours such as navigation, mate identification, and food location. This sensory process is governed by diverse gene families, including odorant-binding proteins (OBPs), olfactory receptors (ORs), ionotropic receptors (IRs), chemosensory proteins (CSPs), gustatory receptors (GRs), and sensory neuron membrane proteins (SNMPs). The oriental mole cricket (Gryllotalpa orientalis Burmeister), an invasive pest with an underground, phyllophagous lifestyle, causes substantial crop damage. This study characterizes the chemosensory gene repertoire of G. orientalis based on de novo genome assembly and transcriptomic analysis. Results: We present a draft genome of G. orientalis at the scaffold level, spanning 2.94 Gb and comprising 10,497 scaffolds. This assembly encodes 19,155 protein-coding genes, including 158 chemosensory genes: 30 odorant receptors (ORs), 64 ionotropic receptors (IRs), ten gustatory receptors (GRs), 28 odorant-binding proteins (OBPs), 25 chemosensory proteins (CSPs), and a single sensory neuron membrane protein (SNMP). Expression analysis indicated that 71 chemosensory genes were actively expressed in the head, thorax, and legs, with ORs and OBPs showing higher expression in the head and legs. In contrast, GRs and IRs were predominantly expressed in the head. Conclusions: This study provides the first comprehensive identification of chemosensory gene families in the G. orientalis genome, characterized as a scaffold-level draft genome. These findings provide a basis for future functional studies and highlight the role of chemoreception in the subterranean environment.