Genome-wide identification and transcriptome-based expression pattern of chemosensory genes in two wild silkmoths, Antheraea pernyi and Antheraea yamamai

Antheraea pernyi Guérin-Méneville and Antheraea yamamai Guérin-Méneville are two closely related wild silkmoths belonging to the family Saturniidae with highly edible and silk-producing value. In this study, we characterised candidate chemosensory genes from the genomes of the two silkmoths. In A. pernyi, 38 odorant-binding proteins (OBPs), 21 chemosensory proteins (CSPs), 3 sensory neuron membrane proteins (SNMPs), 28 ionotropic receptors (IRs), 54 odorant receptors (ORs) and 53 gustatory receptors (GRs) were identified. In A. yamamai, 36 OBPs, 21 CSPs, 3 SNMPs, 30 IRs, 50 ORs and 54 GRs were identified. Phylogenetic analysis showed that the OBP, OR and GR genes were significantly expanded or contracted in the two silkmoths when compared to lepidopteran model Bombyx mori L., while the CSP genes were only expanded. The SNMP and IR genes were greatly conserved in the two silkmoths and B. mori. Most OBP, CSP, SNMP, IR and OR genes had the expression in the antennal transcriptome, but most GR genes showed no expression. This is the first study to characterise chemosensory genes of Saturniidae species in the genome and antennal transcriptome.