%0 Online Multimedia %A Lajevardi, Aryan %A Paluzzi, Jean-Paul V. %D 2020 %T Video_1_Receptor Characterization and Functional Activity of Pyrokinins on the Hindgut in the Adult Mosquito, Aedes aegypti.MOV %U https://frontiersin.figshare.com/articles/media/Video_1_Receptor_Characterization_and_Functional_Activity_of_Pyrokinins_on_the_Hindgut_in_the_Adult_Mosquito_Aedes_aegypti_MOV/12349862 %R 10.3389/fphys.2020.00490.s002 %2 https://frontiersin.figshare.com/ndownloader/files/22761815 %K pyrokinin %K G protein-coupled receptor %K heterologous receptor functional assay %K hindgut %K motility %K scanning ion-selective electrode technique %K insect %K disease vector %X

Pyrokinins are structurally related insect neuropeptides, characterized by their myotropic, pheromonotropic and melanotropic roles in some insects, but their function is unclear in blood-feeding arthropods. In the present study, we functionally characterized the pyrokinin-1 and pyrokinin-2 receptors (PK1-R and PK2-R, respectively), in the yellow fever mosquito, Aedes aegypti, using a heterologous cell system to characterize their selective and dose-responsive activation by members of two distinct pyrokinin subfamilies. We also assessed transcript-level expression of these receptors in adult organs and found the highest level of PK1-R transcript in the posterior hindgut (rectum) while PK2-R expression was enriched in the anterior hindgut (ileum) as well as in reproductive organs, suggesting these to be prominent target sites for their peptidergic ligands. In support of this, PRXa-like immunoreactivity (where X = V or L) was localized to innervation along the hindgut. Indeed, we identified a myoinhibitory role for a PK2 on the ileum where PK2-R transcript was enriched. However, although we found that PK1 did not influence myoactivity or Na+ transport in isolated recta, the PRXa-like immunolocalization terminating in close association to the rectal pads and the significant enrichment of PK1-R transcript in the rectum suggests this organ could be a target of PK1 signaling and may regulate the excretory system in this important disease vector species.

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