Abstract: The objective of this study is to localize G protein αq subunit of Helicoverpa assulta (HassGαq) in the male antennae for the further research about the role of HassGαq in olfactory signal transduction in H. assulta. Balb/c mice were immunized with HassGαq protein expressed in prokaryotic cells to produce antiserum. The prepared antiserum and the purchased anti-G_q/11α antiserum were used in Western blot after male antennal homogenate of Helicoverpa assulta was separated by SDS-PAGE. The results indicated that the prepared antiserum could react with HassGαq, and also the non-target proteins, suggesting that several transcripts of HassGαq or other G protein α subunits may be expressed in male antennae. In addition, anti-G_q/11α antiserum could detect HassGαq with high specificity. Accordingly, the expression sites of HassGαq in adult male antennae were examined by immunocytochemical method using anti-G_q/11α antiserum. The results revealed that HassGαq was associated with trichodic sensilla and basiconic sensilla as immunolabelling were typically observed inside and at the base of the two kinds of sensilla. It is so inferred that HassGαq may be involved in olfactory signal transduction in H. assulta.

Key words: Helicoverpa assulta, G protein αq subunit, antiserum, immunolocalization, olfactory signal transduction