Regulation of Aquaporin Prip Expression and Its Physiological Function in (Coleoptera: Bostrichidae).

Prip () cDNA was cloned (GenBank accession no. OK318454), and the encoded 276-amino-acid protein indicated the typical aquaporin structure, including six transmembrane regions and two NPA motifs. The developmental and tissue profiles of transcription were determined. was highly transcribed in female adults, followed by larvae, pupae, and male adults. The transcriptional expression levels of were significantly high in the ovary and hindgut (including cryptonephridial systems) compared with the foregut, testis, midgut, and Malpighian tubules. Knockdown of in female adults did not decrease fecundity, but significantly decreased the hatching rate of eggs laid by the females. The results suggest that functions in embryonic development, not in egg formation. In addition, the transcriptional expression level of was lower in the spinosad-resistant strain than in the susceptible one, and the resistant strain produced fewer progeny than the susceptible strain did. These studies support the functional role of in female reproduction. The absence of significant mortality reduction in the exposed to spinosad after RNAi suggests that other aquaporins that were not knocked down may exist for the excretion of metabolized pesticides.