High-throughput single-fly LC-MS/MS for quantitative profiling of biogenic amines in Drosophila

Area of Science:

• Neuroscience
• Analytical Chemistry
• Biochemistry

Background:

• Biogenic amines like octopamine, dopamine, and serotonin are crucial neuromodulators in Drosophila.
• Understanding their dynamic changes requires sensitive and reproducible quantification methods at the individual organism level.
• Existing methods often involve complex extraction and derivatization, limiting throughput and reproducibility.

Purpose of the Study:

• To develop a streamlined, quantitative liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for detecting multiple biogenic amines in single Drosophila.
• To establish a reproducible workflow applicable to various experimental conditions.
• To investigate neuromodulator dynamics in response to environmental and physiological challenges.

Main Methods:

• A minimal methanol extraction followed by direct injection LC-MS/MS analysis.
• Quantification of octopamine, dopamine, serotonin, and their precursors from individual flies.
• No derivatization or extensive purification steps were required.

Main Results:

• The method demonstrated high reproducibility and sensitivity for detecting multiple biogenic amines.
• Circadian rhythms showed a rise in octopamine at dusk.
• Cold stress induced acute increases in octopamine, dopamine, and serotonin.
• Starvation led to elevated levels of octopamine, serotonin, and tryptophan.

Conclusions:

• The developed single-fly LC-MS/MS method is efficient and robust for biogenic amine quantification.
• It enables the study of neuromodulator dynamics in response to specific biological conditions.
• This approach provides valuable insights into the neurochemical basis of behavior and physiology in individual organisms.