Pipiserpin, a Culex factor Xa inhibitor, affects female reproductive capacity and serves as a potential target for mosquito control

BACKGROUND Mosquito control is still the main prevention and control measure for numerous mosquito-borne diseases causing millions of deaths each year. New strategies for mosquito control are in demand. Proteases play an important role in mosquito physiology, therefore this study explored the inhibition of a serpin (serine protease inhibitor) in mosquitoes and its effect on reproductive capacity. RESULTS A factor Xa inhibitor homolog (named Pipiserpin) was amplified and identified in Culex pipiens pallens mosquitoes. We expressed a recombinant Pipiserpin protein in vitro against which a mouse antiserum was generated. We found that female mosquitoes expressed more Pipiserpin protein than male mosquitoes. After mating, female mosquitoes were fed with blood mixed with different amounts of antisera and results showed that consumption of Pipiserpin impeded ovary development and decreased eggs hatching rates compared to that of the pre-immune serum group. CONCLUSION We identified a Culex mosquito factor Xa inhibitor, Pipiserpin, which affects female reproductive potential. Our results suggest that Pipiserpin may be a novel target for mosquito population control. The conclusions from our study on Cx. pipiens pallens might serve as a reference for the development of control measures for other mosquitoes as well. (c) 2022 Society of Chemical Industry.