A high throughput method for egg size measurement in Drosophila

Area of Science:

• Evolutionary biology
• Insect genetics
• Trait evolution

Background:

• Life-history traits, such as egg size, are crucial fitness proxies in insects like Drosophila.
• Egg size variation is ecologically significant and genetically influenced, but manual measurement limits its use in large-scale studies.
• Existing methods for egg size measurement are low-throughput, hindering evolutionary and population genetics research.

Purpose of the Study:

• To establish an accurate, high-throughput method for measuring Drosophila egg size.
• To enable rapid sorting of viable eggs based on size for subsequent analyses.
• To provide a protocol applicable to diverse organisms within a specific size range.

Main Methods:

• Development and validation of a large particle flow cytometry (LPFC) protocol for insect egg size measurement.
• Comparison of LPFC measurements against manual measurements to assess accuracy.
• Assessment of egg survival rates after LPFC sorting.

Main Results:

• LPFC provides accurate egg size estimates, highly correlated with manual measurements.
• The method achieves high throughput (214 eggs/min) and rapid sorting (70 eggs/min).
• LPFC sorting does not compromise egg viability, making it suitable for downstream applications.

Conclusions:

• Large particle flow cytometry offers a powerful, efficient solution for measuring and sorting insect eggs by size.
• This technique significantly advances the study of egg size in evolutionary biology and population genetics.
• The protocol is adaptable for various organisms (10–1500 µm) and downstream molecular analyses.