The octopamine receptor OAα1 influences oogenesis and reproductive performance in <i>Rhodnius prolixus</i>

by Luca Finetti, Ian Orchard, Angela B. Lange

The control of reproductive processes in Rhodnius prolixus involves a variety of neuroactive chemicals. Among these, several studies have suggested that the biogenic amine octopamine (OA), might play an active role in these processes. Here, we investigate the molecular profile of the R. prolixus α adrenergic-like OA receptor 1 (RpOAα1-R) and its role in egg production. Comparative molecular analyses confirm that the RpOAα1-R gene codes for a true OAα1 receptor. The RpOAα1-R transcript is highly expressed in tissues associated with egg production, and after a blood meal, which is the stimulus for full egg production in R. prolixus, the RpOAα1-R transcript is upregulated in the ovaries and spermatheca. After RNAi-mediated RpOAα1-R knockdown, an ovarian phenotype characterized by slow egg development is observed. Furthermore, an altered egg phenotype has been characterized with eggs that are deformed. Interestingly, there is no evidence of disruption in vitellogenin (Vg) synthesis by the fat body or uptake by the oocytes. On the other hand, RpOAα1-R downregulation is correlated with defective choriogenesis in the eggs. These results provide critical information concerning the role of OAα1-R in oogenesis in R. prolixus.