A γ-glutamyl transpeptidase of Aphidius ervi venom induces apoptosis in the ovaries of host aphids

Falabella, Patrizia; Riviello, Lea; Caccialupi, Pasqua; Rossodivita, Tiziana; Valente, Maria Teresa; Stradis, Maria Luisa De; Tranfaglia, A.; Varricchio, Paola; Gigliotti, Silvia; Graziani, Franco; Malva, C.; Pennacchio, Francesco

doi:10.1016/j.ibmb.2007.02.005

Cited by 91 publications

(91 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…We also found reductions in the number and irregularities in the morphology of teratocytes deposited in H. defensa infected aphids suggesting a possible interaction. Polyploid teratocytes are believed to be involved in redirecting resources from aphid to wasp development [28,29]. Fewer, or defective, teratocytes may prevent the creation of an environment suitable for wasp development.…”

Section: Discussionmentioning

confidence: 99%

“…Endoparasitoid wasps such as A. ervi typically employ both maternal and embryonic factors to counter host defenses and create an environment suitable for wasp development [26]. During oviposition, for example, female A. ervi wasps inject a γ-glutamyl transpeptidase-containing venom, which targets and degenerates pea aphid ovarioles, leading to a reduction in aphid fecundity and presumably enhancing resource availability for developing wasps [27,28]. Also, fast-growing polyploid cells called teratocytes dissociate from the serosal membrane surrounding the wasp embryo and circulate within the aphid hemocoel during larval development [29].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Parasitic wasp responses to symbiont-based defense in aphids

et al. 2012

View full text Add to dashboard Cite

Background Recent findings indicate that several insect lineages receive protection against particular natural enemies through infection with heritable symbionts, but little is yet known about whether enemies are able to discriminate and respond to symbiont-based defense. The pea aphid, Acyrthosiphon pisum , receives protection against the parasitic wasp, Aphidius ervi , when infected with the bacterial symbiont Hamiltonella defensa and its associated bacteriophage APSE ( Acyrthosiphon pisum s econdary e ndosymbiont). Internally developing parasitoid wasps, such as A. ervi , use maternal and embryonic factors to create an environment suitable for developing wasps. If more than one parasitoid egg is deposited into a single aphid host (superparasitism), then additional complements of these factors may contribute to the successful development of the single parasitoid that emerges. Results We performed experiments to determine if superparasitism is a tactic allowing wasps to overcome symbiont-mediated defense. We found that the deposition of two eggs into symbiont-protected aphids significantly increased rates of successful parasitism relative to singly parasitized aphids. We then conducted behavioral assays to determine whether A. ervi selectively superparasitizes H. defensa -infected aphids. In choice tests, we found that A. ervi tends to deposit a single egg in uninfected aphids, but two or more eggs in H. defensa -infected aphids, indicating that oviposition choices may be largely determined by infection status. Finally, we identified differences in the quantity of the trans-β-farnesene, the major component of aphid alarm pheromone, between H. defensa -infected and uninfected aphids, which may form the basis for discrimination. Conclusions Here we show that the parasitic wasp A. ervi discriminates among symbiont-infected and uninfected aphids, and changes its oviposition behavior in a way that increases the likelihood of overcoming symbiont-based defense. More generally, our results indicate that natural enemies are not passive victims of defensive symbionts, and that an evolutionary arms race between A. pisum and the parasitoid A. ervi may be mediated by a bacterial symbiosis.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Parasitic wasp responses to symbiont-based defense in aphids

et al. 2012

View full text Add to dashboard Cite

show abstract

“…Ae-ENO is produced by cells deriving from the dissociation of the embryonic membrane, which play, along with the venom, an important role in the host regulation and nutritional exploitation of the host aphid A. pisum (Falabella et al, 2000(Falabella et al, , 2005(Falabella et al, , 2007Digilio et al, 2000;Pennacchio and Strand, 2006). In particular, the teratocytes intensely interact with host ovaries, which, as a consequence, show disruption signs (Falabella et al, 2000;Tremblay and Iaccarino, 1971), associated with the presence of an impressive number of intense round spots, stemming from the teratocytes surface (Tremblay and Iaccarino, 1971).…”

Section: Discussionmentioning

confidence: 99%

“…This endophagous braconid wasp severely impairs host reproduction, by the action of a gamma glutamyl transpeptidase contained in the venom, which triggers apoptosis in the germarial cells of the ovarioles (Digilio et al, 2000;Falabella et al, 2007). The resulting castration effect is complemented by teratocytes, which mediate the disruption of host embryos already formed, further reinforcing the enhancement of the nutritional suitability of the host microenvironment (Tremblay and Iaccarino, 1971;Falabella et al, 2000).…”

Section: Introductionmentioning

confidence: 99%

Aphidius ervi teratocytes release an extracellular enolase

Falabella¹,

Riviello²,

Stradis³

et al. 2009

Insect Biochemistry and Molecular Biology

Self Cite

View full text Add to dashboard Cite

“…Wasp venom causes degeneration of the early embryos of the viviparous host aphid, thus redirecting host nutritional resources to the parasitoid. It was shown recently that two A. ervi venom proteins (of 18 and 36 kDa) trigger apoptosis of the germarial cells and ovariole sheath of the host aphid (Falabella et al, 2007). Teratocytes, which are giant cells that are freed from the parasitoid embryo at larval eclosion, subsequently act in this interaction as independent collectors of host haemolymph resources and abundantly release nutrients that hence become available to the growing parasitoid larva.…”

Section: Introductionmentioning

confidence: 99%