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Open Access Publications from the University of California

Scholarly Works (3 results)

  • Article
  • Peer Reviewed
UC San Francisco Previously Published Works (2020)
Bilateral symmetry is the predominant body plan in the animal kingdom. Cells on the left and right sides remain compartmentalized on their ipsilateral side throughout life, but with occasional variation, as evidenced by gynandromorphs and human disorders. How this evolutionarily conserved body plan is programmed remains a fundamental yet unanswered question. Here, we show that germ-layer patterning in avian gastrulation is ipsilateral despite cells undergoing highly invasive mesenchymal transformation and cell migration. Contralateral invasion is suppressed by extracellular matrix (ECM) and programmed cell death (PCD) along the embryonic midline. Ipsilateral gastrulation was lost by midline ECM and PCD inhibition but restored with exogenously induced PCD. Our data support ipsilaterality as an integral component of bilaterality and highlight a positive functional role of PCD in development.
    Cover page: Programmed cell death along the midline axis patterns ipsilaterality in gastrulation
    • Thesis
    • Peer Reviewed
    UC San Francisco Electronic Theses and Dissertations (2017)

    Bilaterality, is the predominant body plan in the animal kingdom. Cells either from the left or right side, rarely cross the body midline plane throughout life, as evidenced by naturally occurring bilateral gynandromorphs. However, it has been a longstanding mystery how this evolutionary conserved ipsilaterality is achieved in bilaterians, including humans. Using the chick embryo as a model, we show that extracellular matrix (ECM) and caspase-3-dependent programmed cell death (PCD) localize to the primitive streak (PS) midline. Both, faithfully direct ipsilateral ingression through the inhibition of contralateral cellular invasion. PS midline PCD is dependent on ECM accumulation. Suppression of these components results in contralateral cellular invasion. Remarkably, induced PCD alone, without ECM, is sufficient to rescue ipsilateral gastrulation. Our findings reveal that PCD actively patterns ipsilaterality, a hitherto unknown role for this basic developmental process.

      Cover page: Programmed cell death at the midline patterns ipsilateral gastrulation in the amniote
      • Article
      • Peer Reviewed
      UC San Francisco Previously Published Works (2013)
      The proepicardium is a transient extracardiac embryonic tissue that gives rise to the epicardium and a number of coronary vascular cell lineages. This important extracardiac tissue develops through multiple steps of inductive events, from specification of multiple cell lineages to morphogenesis. This article will review our current understanding of inductive events involved in patterning of the proepicardium precursor field, specification of cell types within the proepicardium, and their extension and attachment to the heart.
        Cover page: Induction of the Proepicardium
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