Furthermore, P2Y10 could provide an intriguing connection between heterotrimeric G proteins and membrane-proximal BCR signaling events. Mutant macrophages also display reduced integrin-mediated adhesion, suggesting abnormal homing and recruitment to sites of inflammation. Interestingly, mutations in the c- fes locus also lead to defects in vascular integrity and a midgestation lethality due to hemorrhaging of some embryos. During early embryogenesis, vascular development parallels that of hematopoiesis. These events are modulated by VEGFs and angiopoietins.
Most cells undergo growth arrest or apoptosis in response to hypoxia.
However, certain cells, such as vascular endothelial cells and placental cytotrophoblasts, proliferate in response to low O 2 tension. We find that the normal expansion of embryonic hematopoietic progenitors is also regulated by a hypoxia-mediated signaling pathway. Future experiments will focus on the mechanisms regulating cellular growth or apoptosis during hypoxia and defining a role for ARNT2 in hematopoiesis and angiogenesis.