Intracellular buffering enables developmental robustness after genome doubling in C. elegans embryos

Area of Science:

• Developmental Biology
• Genetics
• Cell Biology

Background:

• Whole-organism polyploidy is common in nature.
• Mechanisms of embryogenesis adaptation to genome doubling are not well understood.

Purpose of the Study:

• To systematically compare embryogenesis in de novo-induced tetraploid and diploid C. elegans.
• To investigate how cells scale intracellular components in response to genome duplication.

Main Methods:

• Single-cell analysis integrating live imaging, lineage tracing, and phenotypic quantification.
• Transcriptomic profiling of tetraploid and diploid embryos.
• Comparative analysis of cell proliferation, lineage patterns, fate specification, and morphogenesis.

Main Results:

• Tetraploid embryos exhibit elevated transcript levels, slower proliferation, and altered cell architecture but develop with high fidelity, mirroring diploid embryos in cell number, lineage, fate, and morphogenesis.
• Transcriptional output scales proportionally with cell volume, maintaining stable transcript concentrations, with specific gene set divergences indicating regulatory layers.
• Sublinear volume increase relative to genome content in tetraploids correlates with delayed proliferation, suggesting DNA-to-volume ratio constraints.

Conclusions:

• Intracellular scaling strategies, particularly the proportional increase of transcriptional output with cell volume, are crucial for accurate embryogenesis following genome doubling.
• C. elegans tetraploid embryos demonstrate remarkable developmental robustness despite altered cellular parameters.
• The study highlights potential physical or regulatory constraints on cell volume expansion in polyploid systems.