Jack bean urease impairs oogenesis in the Chagas disease vector Rhodnius prolixus

Area of Science:

• Plant biochemistry
• Insect physiology
• Toxicology

Background:

• Jack Bean Urease (JBU) from Canavalia ensiformis has known insecticidal properties.
• Its full entomotoxic potential, particularly on insect reproduction, is not well understood.

Purpose of the Study:

• To investigate the effects of JBU on the reproduction of Rhodnius prolixus, a vector of Chagas disease.
• To elucidate the mechanisms underlying JBU-induced reproductive impairment.

Main Methods:

• Injection of sublethal JBU doses into vitellogenic Rhodnius prolixus females.
• Microscopy (apoptosis, autophagy, necrosis) and qPCR analysis of ovarian and fat body tissues.
• ELISA assays for vitellogenin and lipophorin levels; in vivo imaging of fluorescently labeled JBU.

Main Results:

• JBU significantly reduced oviposition and delayed ovarian development, causing follicular degeneration.
• Ovarian tissues showed signs of cell death; fat bodies exhibited necrosis and altered lipid metabolism.
• JBU impaired vitellogenin uptake and lipid transfer to oocytes, accumulating lipids in the fat body.

Conclusions:

• JBU-induced reproductive impairment in insects is partly mediated by disruptions in lipid metabolism.
• JBU interferes with the fat body-ovary axis, affecting vitellogenin and lipophorin dynamics.
• These findings highlight JBU's potential impact on insect population dynamics and its entomotoxic effects.