With the passing of Gail R. Martin in February 2026, we have lost one of developmental biology's most influential conceptual architects, a scientist who reshaped how we think about signaling, pattern formation and genetic analysis in the mouse. Although she is widely recognized for isolating and naming embryonic stem cells, her deeper and perhaps more enduring legacy lies in transforming mouse developmental genetics into a discipline defined by spatial and temporal precision.
Mariani et al. (Mon,) studied this question.