Solid-state NMR reveals differential carbohydrate utilization in diapausing Culex pipiens.

Area of Science:

• Entomology
• Biochemistry
• Metabolomics

Background:

• Culex pipiens mosquitoes transmit West Nile Virus and other flaviviruses.
• Diapause preparation in female Cx. pipiens involves increased carbohydrate feeding for energy storage (glycogen and lipids).

Purpose of the Study:

• To investigate the effects of different carbohydrate sources on glycogen and lipid biosynthesis in diapausing Cx. pipiens.
• To elucidate insect carbohydrate metabolism during diapause.

Main Methods:

• In vivo investigation using 13C solid-state Nuclear Magnetic Resonance (NMR) spectroscopy.
• Feeding diapausing and non-diapausing adult female Cx. pipiens with sucrose, D-[13C6]glucose, or a combination.

Main Results:

• Sucrose feeding led to increased glycogen accumulation with more branching, but less lipid synthesis.
• Exclusive glucose feeding resulted in accumulation of both glycogen and lipids, with longer aliphatic chains.
• When co-fed with sucrose, glucose was exclusively metabolized for triacylglyceride biosynthesis.

Conclusions:

• Carbohydrate metabolism differs between sucrose and glucose in diapausing mosquitoes.
• Findings offer novel insights into insect carbohydrate metabolism governing energy storage for diapause survival in adverse conditions.