How does a fertilized egg give rise to an entire animal? How do billions of cells “know” how to work together to make complex tissues and organs? Where are stem cells found in animals and what makes cell a stem cell? How do stem cells replace cells that are lost in disease or through injury? How do animals give rise to eggs and sperm that give rise to the next generation? UCI scientists in the Developmental and Stem Cell Biology focus area study these and other fundamental questions in the fields of stem cells, embryonic development and regeneration. We study these questions in all major model organisms, including the fruit fly, zebrafish, frog, mouse and human, but also actively work in less traditional, emerging model systems. We use all the techniques of modern molecular biology such as CRISPR/Cas9-mediated gene editing, next generation sequencing, including single-cell sequencing and advanced microscopy, including light sheet and label-free imaging. Using unique strengths of UCI in Systems Biology, we also apply mathematics and computational modeling when looking for answers to the above questions. Ultimately our goal is to address some of biology’s most burning questions, not just because they are interesting but because the answers to these questions will help us solve some of the most pressing problems facing our species and our planet.