Evidence for Vip3Aa1 expression in transgenic (BbV28) and wild-type (BbW) B. bassiana strains. (a) RT-PCR detection of vip3Aa1 transcription in BbV28 and BbW (negative control). (b) Western blot analysis with a polyclonal antibody against Vip3Aa1. Lanes 1 and 3, protein extracts from BbW mycelia and conidia, respectively; lanes 2 and 4, protein extracts from BbV28 mycelia and conidia, respectively; lanes 5 and 6, lysates of E. coli cells expressing His6-tagged Vip3Aa1 (positive control) and of cells vectoring an empty plasmid, respectively; lane M, molecular size marker. (c) Immunogold localization of Vip3Aa1 expressed in aerial conidia of BbV28. (1) BbW integrated only with empty plasmid pAN52-Bar (blank control); (2) BbW (negative control); (3) BbV28 expressing Vip3Aa1. Note that dense 10-nm colloidal gold particles (expressing Vip3Aa1) labeled with the polyclonal antibody and a goat anti-rabbit IgG antibody were present only in the conidial cytoplasm of BbV28.