I am pleased to announce our next Technical Workshop which will take place on Thursday, August 10 at 12PM. Dr. Vaibhav P. Pai of Tufts University will give a talk on his work regarding organ patterning. Pizza will be served.
Dr. Pai is a research associate at Tufts University in the Center for Regenerative and Developmental Biology. He completed his PhD at the University of Cincinnati in the Systems Biology and Physiology Program. His current work focuses on studying endogenous bioelectrical signals as patterning information conduits during embryogenesis.
Title: Endogenous Bioelectrical Controls of Organ Patterning: Opportunities for Synthetic Bioengineering
Abstract: Biophysical forces play important roles throughout embryogenesis, but the roles of spatial differences in cellular resting potentials during large-scale brain morphogenesis remain unknown. We implicate endogenous bioelectricity as an instructive factor during
brain patterning in Xenopus laevis. Early frog embryos exhibit a characteristic hyperpolarization of cells lining the neural tube; disruption of this spatial gradient of the transmembrane potential (Vmem) diminishes or eliminates the expression of early brain markers, and causes anatomical mispatterning of the brain, including absent or malformed regions. This effect is mediated by voltage-gated calcium signaling and gap-junctional communication. In addition to cell-autonomous effects, we found that hyperpolarization of transmembrane potential (Vmem) in ventral cells outside the brain induces upregulation of neural cell proliferation at long range. Misexpression of the constitutively active form of Notch, a suppressor of neural induction, impairs the normal hyperpolarization pattern and neural patterning; forced hyperpolarization by misexpression of specific ion channels rescues brain defects induced by activated Notch signaling. Strikingly, hyperpolarizing posterior or ventral cells induces the production of ectopic neural tissue considerably outside the neural field. The hyperpolarization signal also synergizes with canonical reprogramming factors (POU and HB4), directing undifferentiated cells toward neural fate in vivo. These data identify a new functional role for bioelectric signaling in brain patterning, reveal interactions between Vmem and key biochemical pathways (Notch and Ca2+ signaling) as the molecular mechanism by which spatial differences of Vmem regulate organogenesis of the vertebrate brain, and suggest voltage modulation as a tractable strategy for intervention in certain classes of birth defects and for synthetic bioengineering.
On behalf of the SBC Student Leadership Board, we hope to see you there!