Alejo Rodriguez-Fraticelli received his PhD from the Universidad Autonoma de Madrid in 2014, working with Miguel Alonso and Fernando Martin-Belmonte on epithelial morphogenesis. In 2015, Alejo moved to Harvard University to train as a postdoc with Fernando Camargo in hematopoietic development and lineage tracing. During this time, Alejo began a long-lasting collaboration with Caleb Weinreb and Allon Klein at Harvard Medical School, characterizing blood stem cells using single-cell profiling. In 2021, Alejo was recruited as a junior group leader at IRB Barcelona, expanding the Programme of Aging and Metabolism. During his career, Alejo received major grants and awards, including the LSRF Research Fellowship, the ASH Scholar Award, the LLS Special Fellowship, the NHLBI K99 Award, the Cris Excellence Award, and the ERC Starting Grant. Since 2023, Alejo is ICREA Research Professor.
Hematopoiesis has long been modeled as a stepwise hierarchical process, where all blood arises from a group of rare multipotent stem cells. In recent years, we have made major contributions that have challenged this paradigm, revealing an extensive heterogeneity among individual stem cells and their differentiation trajectories. To study heterogeneity, our lab develops advanced genetic tools that allow the simultaneous recording of progeny and state for thousands of single cells at a time. Using these methods, termed single-cell lineage tracing, we have uncovered distinct gene regulatory states linked with heritable fates during regeneration. More recently, we have been focused on how these differences in fate behaviors arise during development and how they influence cellular responses to leukemic mutations and aging. We propose that mapping cellular phylogenetics will lead to a revolution in understanding and treating disease.