Insect host-parasitoid systems are examples of complex interactions. Parasitoids have fit to their respective hosts by developingseveral strategies ensuring the success of parasitism, providing physiological alterations and overcoming the immune response of their host. A key role in host regulation and immune suppression is played by maternal factors introduced by the female wasps into the host during egg deposition together with embryonic factor. Teratocytes are specialized cells deriving from the dissociation of the membrane surrounding the parasitoid embryo (serosa), released in the host haemocoel when the parasitoid egg hatches. To date, only a putative chitinase has been identified in Toxoneuron nigriceps (Hymenoptera:Braconidae) teratocytes. A de novo T. nigriceps teratocytes transcriptome has been generated by high-throughput RNA sequencing (RNA-Seq). Data assembly resulted in 24,569 contigs which were annotated by BLASTx algorithm against the nr database and functionally analysed byBlast2GO software. The distribution of the species associated with top BLAST hitsshowed that a high proportion of genes in the T. nigriceps teratocyte transcriptome was most similar to genes belonging to different parasitoid wasp species, in particular to Microplitis demolitor. Putative antimicrobial peptides (AMPs) were identified and will be produced and functionally characterized. In add, ovalbumin-related X-like proteins, serpin proteins, chitinases and Rho GAP proteins, potentially involved in host immunosuppression, were identified. These preliminary results led us to hypothesize that teratocytes are not only responsible for host immunosuppression but at the same time could prevent host infection by pathogen intruders, supporting the immunosuppressed host through the production of parasitoid-derived AMPs.
Toxoneuron nigriceps (Hymenoptera:Braconidae) teratocytes: generation and analysis of a comprehensive transcriptome for the identification of antimicrobial peptides
Rosanna Salvia;Andrea Scala;Carmen Scieuzo;Marisa Nardiello;Donatella Farina;Patrizia Falabella
2018-01-01
Abstract
Insect host-parasitoid systems are examples of complex interactions. Parasitoids have fit to their respective hosts by developingseveral strategies ensuring the success of parasitism, providing physiological alterations and overcoming the immune response of their host. A key role in host regulation and immune suppression is played by maternal factors introduced by the female wasps into the host during egg deposition together with embryonic factor. Teratocytes are specialized cells deriving from the dissociation of the membrane surrounding the parasitoid embryo (serosa), released in the host haemocoel when the parasitoid egg hatches. To date, only a putative chitinase has been identified in Toxoneuron nigriceps (Hymenoptera:Braconidae) teratocytes. A de novo T. nigriceps teratocytes transcriptome has been generated by high-throughput RNA sequencing (RNA-Seq). Data assembly resulted in 24,569 contigs which were annotated by BLASTx algorithm against the nr database and functionally analysed byBlast2GO software. The distribution of the species associated with top BLAST hitsshowed that a high proportion of genes in the T. nigriceps teratocyte transcriptome was most similar to genes belonging to different parasitoid wasp species, in particular to Microplitis demolitor. Putative antimicrobial peptides (AMPs) were identified and will be produced and functionally characterized. In add, ovalbumin-related X-like proteins, serpin proteins, chitinases and Rho GAP proteins, potentially involved in host immunosuppression, were identified. These preliminary results led us to hypothesize that teratocytes are not only responsible for host immunosuppression but at the same time could prevent host infection by pathogen intruders, supporting the immunosuppressed host through the production of parasitoid-derived AMPs.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
