WormSizer: high-throughput analysis of nematode size and shape

Area of Science:

• Developmental Biology
• Genetics
• Image Analysis

Background:

• Nematode growth, size, and morphology are influenced by genotype and environment.
• Existing methods for nematode volume estimation have limitations in accuracy and robustness to shape/opacity variations.

Purpose of the Study:

• To develop a high-throughput software application, WormSizer, for computing nematode size and shape from brightfield images.
• To provide a robust and extensible tool for quantitative analysis of nematode phenotypes.

Main Methods:

• WormSizer software was developed as a plugin for Fiji/ImageJ, assuming only radial symmetry for robust volume estimation.
• Technical performance was evaluated, and the software was used to analyze Caenorhabditis elegans mutants across developmental time series.
• A power analysis was conducted using the collected data to guide experimental design.

Main Results:

• WormSizer accurately quantifies phenotypes of known mutants (Dumpy, Long, Small, daf-2), confirming their size and shape characteristics.
• The software can distinguish between dauer larvae and normal larvae.
• WormSizer is effective even with mutants exhibiting behavioral phenotypes (Uncoordinated, Roller).

Conclusions:

• WormSizer offers a robust, accurate, and extensible solution for high-throughput analysis of nematode size and shape.
• The software confirms and extends existing knowledge of C. elegans mutant phenotypes.
• WormSizer facilitates quantitative phenotyping and aids in experimental design through power analysis.