Temporal transcriptomic profiling of the ant-feeding assassin bug Acanthaspis cincticrus reveals a biased expression of genes associated with predation in nymphs

Abstract

Acanthaspis cincticrus (Stal) is an assassin bug with a specialized camouflaging behavior to ambush ants in the nymphal stages. In this study, we comprehensively sequenced all the life stages of A. cincticrus, including the eggs, five nymph instars, female and male adults using Illumina HiSeq technology. We obtained 176 million clean sequence reads. The assembled 84,055 unigenes were annotated and classified functionally based on protein databases. Among the unigenes, 29.03% were annotated by one or more databases, suggesting their well-conserved functions. Comparison of the gene expression profiles in the egg, nymph and adult stages revealed certain bias. Functional enrichment analysis of significantly differentially expressed genes (SDEGs) showed positive correlation with specific physiological processes within each stage, including venom, aggression, olfactory recognition as well as growth and development. Relative expression of ten SDEGs involved in predation process was validated using quantitative real-time PCR (qRT-PCR).