Functional characterization of Aquaporin-like genes in the human bed bug Cimex lectularius

Abstract

The bed bug Cimex lectularius is a blood-feeding re-emerging annoyance pest insect that has the ability to transmit Trypanosoma cruzi under experimental laboratory conditions. Aquaporins (AQPs) are water channel proteins that are essential in biological organisms. C. lectularius are constantly exposed to water-related stress, suggesting that AQPs may offer novel control avenues. We identified and cloned four AQPs from C. lectularius, assessed tissue and lifestage-specific expression, and characterized biochemical functions in vitro and in vivo. We identified an efficient water-specific AQP (ClAQP1), two aquaglyceroporins (ClGlp1 and ClGlp2) and a homolog of Drosophila melanogaster big brain (ClBib). ClGlp1 was only functional when co-expressed with the water-specific AQP. Simultaneous RNAi gene silencing of ClAQP1 and ClGlp1 significantly reduced water and urea excretion post blood feeding. The Bib homologue was enriched in embryos, exclusively expressed in ovaries, and when silenced, dramatically increased bug fecundity. Our data demonstrate that AQPs have critical roles in excretion, water homeostasis and reproduction in C. lectularius, and could be potential targets for control in this notorious pest.

RNA interference‐mediated functional characterization of aquaporin genes in Tribolium castaneum

“…The redundancy of water channel functions of some aquaporins we observed here has also been noted in insects such as Ae. aegypti (Drake et al, 2010(Drake et al, , 2015, tsetse flies (Benoit et al, 2014) and Cimex lectularius (Tsujimoto et al, 2017), and in humans (Ikeguchi, 2009), in which multiple aquaporins act together in the same tissue. These results indicate that combination of several aquaporins facilitates water transport.…”

“…Insect Drips (Kaufmann et al, 2005;Raza et al, 2016;Shakesby et al, 2009;Tzin et al, 2015;Van Ekert et al, 2016), Prips (Kikawada et al, 2008;Herraiz et al, 2011;Tzin et al, 2015;Van Ekert et al, 2016) and Eglps (Van Ekert et al, 2016) have been confirmed to be involved in water permeability. Moreover, using in vivo RNA interference (RNAi; knockdown) techniques, inhibitory or modified effects have been documented in plant sap-sucking and blood-feeding insect species (Cohen, 2013;Jing et al, 2016;Van Ekert et al, 2016;Tsujimoto et al, 2017).…”

Insecticidal Activity of Doxycycline against the Common Bedbug

“…That is, the drugs can increase water excretion and electrolyte retention simultaneously. Intriguingly, bedbugs harbor several aquaporin-like genes, and RNA interference silencing of these genes reduces the insects' ability to excrete water following a blood meal (30). Perhaps doxycycline ingestion leads to a dysregulation of aquaporin activity that ultimately results in fluid leakage into the hemocoele, as we observed.…”

Enhancing RNAi Efficiency to Decipher the Functional Response of Potential Genes in Bemisia tabaci AsiaII-1 (Gennadius) Through dsRNA Feeding Assays

“…The quantitative fluid loss estimated through humidity analyzer revealed that the knockdown of dsAQP and dsCAL led to excretion of 123 and 86 nl/min per whitefly compared to 203.15 nl/min per whitefly in dsGFP control whiteflies [Figures 4(7-8)]. Earlier studies with knockdown of AQP in Cimex lectularius also observed in 50% reduction in water excretion (Tsujimoto et al, 2017). The knockdown of AQP and CAL in Phenacoccus solenopsis also witnessed reduction in fluid loss compared to GFP control (Singh et al, 2019).…”