Doctor of Philosophy, University of California Berkeley (2010)
Bachelor of Arts, University of Chicago, Biology (2004)
Julie Baker, Postdoctoral Faculty Sponsor
I am interested in understanding the development and evolution of the placenta, a mammalian specific organ crucial for fetal well-being. A key feature of the placenta are polyploid trophoblast cells that invade and remodel the mother’s uterus in order to promote blood flow and nutrient delivery to the fetus. In rodents, these cells are called trophoblast giant cells (TGCs) and have up to 1,000N DNA content due to endoreplication. As recent work has shown that TGC endoreplication is essential for fetal health, my research uses mouse knock-outs and genomics to elucidate the function of endopolyploidy. In addition, I am studying human trophoblast cells, as defects in these cells have drastic consequences for both fetal and maternal health, including preeclampsia and preterm birth, yet very little is understood about the molecular mechanisms behind these diseases.
Discovery of lineage-specific somatic copy number variation (CNV) in mammals has led to debate over whether CNVs are mutations that propagate disease or whether they are a normal, and even essential, aspect of cell biology. We show that 1,000 N polyploid trophoblast giant cells (TGCs) of the mouse placenta contain 47 regions, totaling 138 Megabases, where genomic copies are underrepresented (UR). UR domains originate from a subset of late-replicating heterochromatic regions containing gene deserts and genes involved in cell adhesion and neurogenesis. While lineage-specific CNVs have been identified in mammalian cells, classically in the immune system where V(D)J recombination occurs, we demonstrate that CNVs form during gestation in the placenta by an underreplication mechanism, not by recombination nor deletion. Our results reveal that large scale CNVs are a normal feature of the mammalian placental genome, which are regulated systematically during embryogenesis and are propagated by a mechanism of underreplication.
View details for DOI 10.1371/journal.pgen.1004290
View details for PubMedID 24785991