How do we become a complex, integrated multicellular organism from a single cell?
While developmental biologists have long researched this fundamental question, Stanford University biologist and HHMI investigator Dominique Bergmann’s recent work on the plant Arabidopsis thaliana has uncovered surprising answers.
In a new study, published April 5 in Developmental Cell, led by Dominique Bergmann and postdoctoral scholar Camila Lopez-Anido, researchers used single-cell RNA sequencing technologies to track genetic activity in nearly 20,000 cells as they formed the surface and inner parts of an Arabidopsis leaf. Through this highly detailed technique, the researchers captured transient and rare cell states and found a surprising abundance of ambiguity in how cells traversed various identities, particularly early on within the stem cell population.
“All the cells are coordinated, and yet they’re all individuals with their own genetic programs,” said Bergmann, who is the Shirley R. and Leonard W. Ely, Jr. Professor in the School of Humanities and Sciences and senior author of the study. “And so we’re really working to appreciate that balance between seeing what’s new and special and unique about each one while also recognizing how they are working together.”
While many scientists in this field focus on fruit flies and roundworms, some aspects of biological development will only be understood by studying other organisms – such as the plant Arabidopsis thaliana, which is the Bergmann lab’s specialty.
“As we think about flexibility and resilience in the face of a changing world, we want to learn more about how organisms can manage to build functional bodies when they are under stress or exposed to extreme environments,” said Lopez-Anido, who is lead author of the study. “This requires research with organisms that have flexible and tunable lifestyles, such as the plants we study.”
As part of a family of artists, Lopez-Anido also embraced a uniquely artistic perspective to interpret and share this research. Within the paper itself, she used a pointillism-inspired analysis software to elegantly organize and visualize her massive dataset. Additionally, her sister, artist Virginia Lopez-Anido, created artwork inspired by Camila’s research, which will be featured on the cover of Developmental Cell.
Bergmann credits Lopez-Anido and this work with inspiring several avenues of research, including reconsidering what it means to be a stem cell, reframing events that define final differentiation stages and reevaluating what it means to be born as a cell on the top versus bottom of a leaf.