Transcriptome profile analysis of the accompanying migratory parasitic wasp Aenasius bambawalei (= Aenasius arizonensis girault) (Hymenoptera: Encyrtidae): Genes related to fertilization involved at different stage of ovary development

Age-related declines in fertilization success have been reported for a wide range of species. The fertilization of parasitic wasps is closely related to egg production and sperm storage. Aenasius bambawalei (Hymenoptera: Encyridae) is a key parasitic wasp of the important invasive mealybug Phenacoccus solenopsis (Hemiptera: Pseudococcidae). The female offspring ratio of this parasitic wasp was declined with parental age in mass rearing under laboratory conditions. To investigate the molecular mechanisms involved in the reproduction of A. bambawalei, an extensive analysis of the impact of age on transcriptome profile of mated ovaries of this wasp was performed by comparing the gene expression profiles of various maternal ages: the early stage (ES), the intermediate stage (IS), and the advanced stage (AS). In total, 358 differentially expressed genes were identified, with 17.60% (63 genes) of the changes associated with greater expression in fertilization. Moreover, the expression of serine protease 47 precursor, serine protease inhibitor 3/4, glucose dehydrogenase, fatty acyl-CoA reductase 1-like, major royal jelly, and acyl-CoA delta (11) desaturase-like was detected by real-time fluorescence quantitative (RT-qPCR). The results showed that fertilization related genes exhibited a stage-specific pattern. Egg production and sperm storage genes in A. bambawalei were significantly modified in the transcriptome, providing a starting point for the genetic dissection of fertilization.