Molecular characterization and gene expression of apolipophorin III from the ghost moth, Thitarodes pui (Lepidoptera, Hepialidae)

摘要: Apolipophorin III (apoLp-III) functions in lipid transport and immune activation insects. We cloned a cDNA encoding putative apoLp-III from larvae of Thitarodes pui, host species Ophiocordyceps sinensis, with great economic importance the Tibetan Plateau. Excluding signal peptide first 20 amino acid residues, 171-residue mature has calculated molecular mass 18,606 Da. T. pui shares little sequence homologies (<36%) other apoLp-IIIs. Phylogenetic analysis reveals that belongs to distinct, early diverging lineage lepidopteran Homology modeling shows bundle five amphipathic α-helices, including short helix 3′. was constitutively expressed larval fat body at lower levels than pupal adult body. Significant induction expression, associated strongest nodulation response, observed both sixth eighth instar challenged Beauveria bassiana conidia 1 hr after inoculation, compared saline-injected controls. The inoculation experiment as well previous field studies revealed relative susceptibility entomopathogenic fungus. ApoLp-III transcripts infected instars were found be induced highest 2- 14.7-fold, respectively, during 12 hr. In late-stage infection, susceptible showed decrease expression followed by production B. hyphal bodies, whereas longer lasting increase expression. These results suggest might contribute response against fungal pathogens. © 2011 Wiley Periodicals, Inc.