Marianne Bronner’s journey to becoming a developmental biologist began when her family fled Hungary to escape a repressive communist regime. They came to the United States with little more than the clothes on their backs and the hope for a better life. This decision allowed Bronner to pursue her dreams of becoming a scientist.

Now a developmental biologist, Bronner studies how early stem cells form nerves, facial bones, and pigment cells. Sometimes, things can go wrong during the development of these cells, causing birth defects or certain types of cancer. For her groundbreaking career research on neural crest stem cells, Bronner receives the 2025 Vilcek Prize in Biomedical Science.

Breaking Ground in Biology

Bronner’s scientific aspirations began early. When she was just 11 years old, she announced to her family that she wanted to be a physicist when she grew up. Surprisingly, in high school the future developmental biologist thought biology was boring. It wasn’t until grad school that she discovered her passion for biology, thanks to an inspiring teacher who introduced her to neural crest cells. She became fascinated by the fact that the early nervous system looks so homogeneous, yet forms so many different types of neurons. During that class, she had an epiphany and knew she wanted to dedicate her career to the field. 

Throughout her career, Bronner has continued to make innovative discoveries. She pioneered the use of novel lineage-tracing tools to analyze the developmental potential of neural crest cells in living vertebrate animals. More recently, she found that neural crest cells play a significant role in adult heart regeneration and repair. Bronner’s revolutionary study has opened the door for scientists to explore how these stem cells can be used for therapeutic purposes.

Advancing Equity in Science

Though Bronner has been leading in the field of biology for many years, it wasn’t always easy. When she first started at CalTech, the faculty was 90% male and a majority of the women who worked there weren’t mothers, as she is. By joining the faculty in biology, she alone doubled the number of women faculty with children in her division. 

Thankfully, things have changed. Women now make up around 30% of the faculty, in a family friendly environment. As an early pioneer in the space, Bronner advances equity by helping younger scientists develop their strengths and navigate their careers. “My efforts to foster equity and diversity boil down to trying to be a very supportive and helpful mentor to all of my trainees… By treating each person as an individual, I strive to help them become their best self,” she said.

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Marianne Bronner’s path from a young immigrant to a leading developmental biologist is a testament to her dedication and resilience. Her contributions to developmental biology, and her advocacy for equity, will no doubt continue to shape the future of science.