Characterization and biochemical analyses of venom from the ectoparasitic waspNasonia vitripennis (Walker) (hymenoptera: Pteromalidae)

Abstract

During parasitism, the ectoparasitic wasp Nasonia vitripennis (Walker) (Hymenoptera: Pteromalidae) induces a developmental arrest in host pupae that is sustained until the fly is either consumed by developing larvae or the onset of death. Bioassays using fluids collected from the female reproductive system (calyx, alkaline gland, acid gland, and venom reservoir) indicated that the venom gland and venom reservoir are the sources of the arrestant and inducer(s) of death. Infrared spectroscopic analyses revealed that crude venom is acidic and composed of amines, peptides, and proteins, which apparently are not glycosylated. Reversed phase high performance liquid chromatography (HPLC) and sodium dodecyl polyacrylamide gel electrophoresis (SDS-PAGE) confirmed the proteinaceous nature of venom and that it is composed mostly of mid to high molecular weight proteins in the range of 13 to 200.5 kilodaltons (kDa). Ammonium sulfate precipitation and centrifugal size exclusion membranes were used to isolate venom proteins. SDS-PAGE protein profiles of the isolated venom fractions displaying biological activity suggest that multiple proteins contribute to arresting host development and eliciting death. Additionally, HPLC fractionation coupled with use of several internal standards implied that two of the low molecular weight proteins were apamin and histamine. However, in vitro assays using BTI-TN-5B1-4 cells contradict the presence of these agents. Abbreviations used: HPLC = high performance liquid chromatography; I.R. = infrared spectroscopy; kDa = kilodalton; LC 99 = lethal concentration to kill 100% of population; LD = light-dark; MWCO = molecular weight cutoff; SDS-PAGE = sodium dodecyl sulfate polyacrylamide gel electrophoresis; TFA = trifluoroacetic acid; VRE = venom reservoir equivalent.

Characterization of phenoloxidase activity in venom from the ectoparasitoid Nasonia vitripennis (Walker) (Hymenoptera: Pteromalidae)

“…In gel staining conWrmed the presence of two protein bands with PO activity in crude wasp venom: a high molecular weight protein with an estimated molecular weight (MW) of 160 kDa and a mid-range protein that was approximately 68 kDa (under diVerent electrophoretic conditions, this later protein had an estimated MW of 66 kDa; Rivers et al, 2006) (Fig. 4).…”

“…Of those parasitoid venoms that have been at least partially puriWed, multiple proteins have been implicated as necessary to manipulate or subdue the host (Digilio et al, 2000;Doury et al, 1997;Jones et al, 1992;Parkinson et al, 2002a). Indeed, recent (Rivers et al, 2006) biochemical analyses of venom from N. vitripennis suggest that four mid-to-high molecular weight proteins are necessary to induce developmental arrest in pharate adults of the Xesh Xy, Sarcophaga bullata Parker (Diptera: Sarcophagidae), and that multiple proteins are necessary to evoke Xy death. Our continued eVorts to characterize these venom proteins have uncovered that venom possess phenoloxidase (PO) activity, which has only been reported in one other species, the endoparasitoid Pimpla hypochondriacae (Parkinson and Weaver, 1999;Parkinson et al, 2001Parkinson et al, , 2003.…”

“…Adult females possess a well-developed venom system, which produces a complex, proteinaceous venom (Rivers et al, 2006) in the acid gland, and which is stored in active form within a single, cuticular-lined reservoir King, 1967, 1969). Venom inhibits host cellular immune responses (Rivers et al, 2002a), depresses respiratory metabolism (Rivers and Denlinger, 1994b), triggers increases in lipid levels within hemolymph and fat body (Rivers and Denlinger, 1995;Rivers et al, 1998), and ultimately induces death.…”

Molecular Pharmacology and Toxinology of Venom from Ants

“…Additionaly, two peptides with less than 10 kDa, as well as proteins with molecular weight ranging from 26-90 kDa were also found in the venom of Myrmecia pilosula [32]. The electrophoretic profile of wasps also shows variation in the protein molecular weight, ranging from 5 to 200kDa [33,34], whereas the venoms of bees was shown to range from 2 to108 kDa [35].…”

Insecticides and Parasitoids

“…Pupal ectoparasitoids also have to paralyze and fix the host to avoid consumption of food resource by growth of the host after parasitization with venom. On the other hands, Nasonia vitripennis as pupal endoparasitoid has non-paralysing venom that causes developmental arrest by 13 to 200.5 kDa proteins (Rivers et al, 2006), but venom shows PO (Phenol oxidase) activity and may induce apoptosis in host tissues (Abt & Rivers, 2007). Mellitobia wasp shows different mode of action in developmental arrest to different host species (Deyrup et al, 2006).…”