Systematic differences in protein stability underlie species-specific developmental tempo.

Protein stability differences across species underlie the slower developmental tempo in humans compared to mice, with human proteins degrading more slowly.

• Why it matters: Understanding the mechanisms behind species-specific developmental rates is crucial for insights into developmental biology and evolutionary differences, yet the role of protein stability remains unclear.
• What they did: The study used SILAC-based proteomic analysis of approximately 5,000 proteins in human and mouse iPSM cells, revealing a widespread trend of slower protein degradation in human cells, independent of localization or pathways.
• The result: Modulating protein stability affected the segmentation clock and differentiation timing, indicating that systematic differences in protein degradation link metabolism to developmental pace across species.