Identification and expression characteristics of putative chemosensory proteins in the peach fruit borer Carposina sasakii Matsumura (Lepidoptera: Carposinidae)

Chemosensory proteins (CSPs) are important for insect chemoreception, which bind, solubilize and transport hydrophobic chemical molecules from external environment to dendrite membrane of chemosensory neurons. Moreover, CSPs are also involved in non-sensory physiological activities. The peach fruit borers Carposina sasakii Matsumura (Lepidoptera: Carposinidae) seriously damage fruit trees and their chemoreception mainly occurs in the adult stage. We identified 10 putative CSPs (CsasCSP1 similar to CsasCSP10) from head transcriptomes of C. sasakii adult males and females, all of which are classic CSPs that have 4 conserved cysteines with a spacing pattern C-1-X-6-C-2-X17-18-C-3-X-2-C-4. Their phylogenetic characteristics were also described. An analysis using fluorescence quantitative PCR showed CsasCSP2 has the highest level of expression in the heads, so it is more likely to be involved in C. sasakii chemoreception than the other C. sasakii CSPs. CsasCSP1, CsasCSP3, CsasCSP4, CsasCSP6, CsasCSP7 and CsasCSP8 are expressed dominantly in the wings; CsasCSP5 and CsasCSP10 have the highest expression level in the thoraxes; CsasCSP9 is dominantly and equally expressed in the thoraxes and abdomens. This study contributes to understanding physiological functions of C. sasakii CSPs and chemosensory mechanism at C. sasakii molecular level.

Automated summary

Chemosensory proteins are crucial for insect chemoreception, particularly in the peach fruit borer Carposina sasakii where different CSPs are expressed in males and females in varying body parts. The study sheds light on the physiological functions of CSPs in C. sasakii and the molecular mechanisms involved in chemoreception.