Seminar Poster

Speaker:
Professor Dawn DW Cornelison
Professor, Biological Sciences & Medical Microbiology and Immunology
Investigator, Christopher S. Bond Life Sciences Center
University of Missouri
Columbia, USA

About the Speaker:
Professor Dawn Cornelison is a professor in biological sciences. Professor Cornelison and her group study development, regeneration and disease in mammalian skeletal muscle, with a focus on extracellular signalling pathways that modify muscle stem cell (satellite cell) activity. The signalling molecules controlling satellite cell activation, proliferation, migration, differentiation, and self-renewal are produced by muscle fibres, muscle fibroblasts, inflammatory immune cells, and the satellite cells themselves, and are dynamically expressed in space and time. Their “big picture question” is how satellite cells integrate and respond to extracellular signals in order to rapidly, efficiently, and repeatedly respond to muscle damage or disease. The team studies satellite cells from wildtype and disease models of mouse, dog, and human in vitro and in vivo using timelapse microscopy, immunohistochemistry, gene expression assays, flow cytometry and molecular tools.

Abstract:
The conversion of proliferating skeletal muscle precursors (myoblasts) to terminally-differentiated myocytes is a critical step in skeletal muscle development and repair. One level of control for this process is cell density: since skeletal muscle fibers are generated by the fusion of differentiated myocytes, it has been observed that commitment to differentiation is inhibited by low density and augmented by high density (named the 'community effect' by John Gurdon.) Professor Cornelison and her team recently showed that EphA7, a juxtacrine signalling receptor, is expressed on myocytes during embryonic and fetal myogenesis and on nascent myofibers during muscle regeneration in vivo. EphA7-/- mice are smaller from birth and have fewer myofibers with smaller diameters, fewer myonuclei, and fewer muscle precursor cells than WT mice; EphA7-/- cells also show delayed differentiation in vitro and in vivo. The team proposes a model in which EphA7 expression on differentiated myocytes promotes commitment of adjacent myoblasts to terminal differentiation.

CME Accreditation:
* One CME point for attendance pending for approval by the Medical Council of Hong Kong (MCHK).

All are welcome.
For enquiries, please contact Mr. Jonathan Lee at 3763 6005.