Cotesia vestalis teratocytes express a diversity of genes and exhibit novel immune functions in parasitism

Abstract

Some endoparasitoid wasps lay eggs that produce cells called teratocytes. In this study, we sequenced and analyzed the transcriptome of teratocytes from the solitary endoparasitoid Cotesia vestalis (Braconidae), which parasitizes larval stage Plutella xylostella (Plutellidae). Results identified many teratocyte transcripts with potential functions in affecting host immune defenses, growth or metabolism. Characterization of teratocyte-secreted venom-like protein 8 (TSVP-8) indicated it inhibits melanization of host hemolymph in vitro, while two predicted anti-microbial peptides (CvT-def 1 and 3) inhibited the growth of bacteria. Results also showed the parasitized hosts lacking teratocytes experienced higher mortality after immune challenge by pathogens than hosts with teratocytes. Taken together, these findings indicate that C. vestalis teratocytes secrete products that alter host immune functions while also producing anti-microbial peptides with functions that help protect the host from infection by other organisms.

Performance of the newly identified endoparasitoid Cotesia icipe Fernandez‐Triana & Fiaboe on Spodoptera littoralis (Boisduval)

“…Solitary (Gao et al., ) and gregarious species (Vos & Vet, ) are found in the genus Cotesia , but C. icipe has consistently proven to be a solitary koinobiont endoparasitoid. The results of this study showed that although the parasitoid was observed to oviposit more than once in a host larva, when parasitized larvae were singly isolated in vials, each yielded only one parasitoid cocoon, suggesting the solitary nature of C. icipe .…”

Biocontrol characteristics of the fruit fly pupal parasitoid Trichopria drosophilae (Hymenoptera: Diapriidae) emerging from different hosts

“…Parasitic wasps constitute a major class of natural enemies of many agriculture pests and have tremendous value as biocontrol agents. Most known parasitoid wasp species attack the egg, larval or pupal stages of their hosts and they carry virulence and some other parasitic factors to modify hosts’ physiology and immunity, to change hosts’ metabolism, to destruct hosts’ endocrine and reproductive structures, and finally kill the hosts for their own development 5 – 8 . Many parasitoids are reported to attack various Drosophilidae species, and the majority of them are larval parasitoids, such as Leptopilina heterotoma , L. boulardi and Asobara tabida 9 , 10 .…”

Differential responses of Helicoverpa armigera C‐type immunlectin genes to the endoparasitoid Campoletis chlorideae

“…Parasitoids have evolved immunosuppressive factors, such as polydnaviruses, venom components, and/or teratocyte, that reduce expression of the host CTL genes. These endoparasitoid factors manipulate many aspects of their hosts in ways that favor parasitoid development (Fang et al., ; Gao et al., ; Wu et al., ).…”