Transcriptional analysis of teratocyte in Cotesia plutellae

The Diamondback moth, Plutella xylostella, is the most destructive insect pest of brassica crops throughout the world. Cotesia plutellae has been known as a natural enemy against P. xylostella via laying eggs into a larva. When the larva hatches from the egg, teratocytes also are released and expected to work as immune suppressor via secreting immune suppressive factors. In order to analyze the gene expression in teratocytes, total RNAs were isolated and genes expressed in the teratocyte were sequenced by Illumina HiSeq2000 RNASeq analysis. The information on RNA sequences was assembled by Trinity and contigs were annotated by Blast analysis. The levels of gene expression were calculated by FPKM. Approximately, 6.3 Gbs were obtained and 34,686 contigs were found and annotated. Forty two percent of contigs were homologous to previously reported genes and classified by gene ontologies: the highly abundant components are metabolic process, biological regulation and cellular process in biological function; binding, catalytic activity and transporter activity in molecular function; cell part, membrane part and organelle in cellular function, respectively. In addition, some teratocyte transcripts of C. plutellae related to host regulation such as immunosuppression and nutrition, Ankyrin repeat proteins, Serpin, protease, lipase, chitinase and scavenger receptor, are identified by proteomic analysis, suggesting that teratocyte are contributed to the immunosuppression.