Developmental Biology

How the richly varied cell-types in the human body arise from one embryonic cell is a biological marvel and mystery. We have mapped how human pluripotent stem cells develop into over thirty different human cell-types. This roadmap allowed us to efficiently and rapidly generate human liver, bone, heart and blood vessel progenitors in a Petri dish from pluripotent stem cells. Each of these tissue precursors could regenerate their cognate tissue upon injection into respective mouse models, with relevance to regenerative medicine.

The FUNR Lab, lead by Flora Rutaganira uses choanoflagellates—the closest living single-celled relatives to animals—to study the origin of animal cell communication. We apply chemical, genetic, and cell biological tools to probe choanoflagellate cell-cell communication. We hope that our research has implications for understanding not only animal cell signaling, but also the origin of multicellularity in animals.

The Martinez lab studies RNA regulatory mechanisms that control gene expression. We focus on mRNA processing, RNA modifications and their roles in development and disease.

Although the genomes of many organisms have now been sequenced, we still know relatively little about the specific DNA sequence changes that underlie important traits and diseases. My laboratory has developed an innovative combination of genetic and genomic approaches to identify the detailed molecular mechanisms that control key vertebrate traits. We use genetic crosses in mice, stickleback fish, and pluripotent stem cells to identify key chromosome regions controlling phenotypic traits.

We study the genetic and molecular mechanisms that regulate proliferation and differentiation in adult stem cell lineages, using the Drosophila male germ line as a model.  Our current work is focused on the switch from mitosis to meiosis and how the new gene expression program for cell type specific terminal differentiation is turned on.  One emerging surprise is the potential role of alternative processing of nascent mRNAs in setting up the dramatic change in cell state

Protein self-assembly in evolution, disease, and development; Systems biology of aging;  Mutational robustness in cancer and pathogens; Quantitative analysis of evolving genotype-to-phenotoype maps. Epigenetic control of interspecies interactions.