Upload
keagan
View
43
Download
0
Tags:
Embed Size (px)
DESCRIPTION
Asymmetric Division in Muscle Stem Cells. Christian Elabd, Ph.D. Joey Pham, B.A. Muscle System. - The muscle system is a model for quiescence (resting) and activity - Satellite cells, or muscle stem cells, can regenerate repeatedly - PowerPoint PPT Presentation
Citation preview
Asymmetric Division in Muscle Stem Cells
Christian Elabd, Ph.D.Joey Pham, B.A.
- The muscle system is a model for quiescence (resting) and activity
- Satellite cells, or muscle stem cells, can regenerate repeatedly
- Satellite cells give rise to myoblasts (mostly), and fibroblasts, adipocytes, chondrocytes.
intactmuscle
intactmuscle
injuredmuscle
regeneratedmuscle
Histology 2 weeks after injury Hematoxylin and eosin cross section
satellitecells
myonuclei
myofiber
Pictures from MJ Conboy, UC Berkeley
Muscle System
Muscle Regeneration
Resting muscle Fiber
Quiescent Muscle
Stem Cell
1) ActivationMyotrauma
2) Proliferation
3) Regeneration
Fusion to repair damaged muscle fibers
Fusion to produce new muscle fibers
Multi-nucleationSelf
RenewalReturn to resting state
Symmetry Asymmetry
Stem
Stem
Diff
Stem
Stem
Asymmetric Division = Segregation of DNA, RNA or Proteins in one daughter cell
self renewal differentiation
Symmetric versus Asymmetric Division
Satellite
Satellite Satellite=
=
Myoblast
Satellite Dividing Satellite
Option 1
Option 2
=Option 3
Myoblast Myoblast
+
+
+
Symmetric versus Asymmetric Division
in the Context of Muscle
Hoechst Sca-1Desmin Merge
Differentiated cells are Desmin positive. Non-differentiated cells are Sca-1 positive.
Conboy MJ et al. PLoS Biol. 2007 Jul;5(7):e182
Asymmetric Division in the Context of Muscle
Summary of Asymmetric DivisionHoechst
Sca-1
Desmin
Merge
While most cells in the body divide strictly symmetrically, stem cells have the ability to divide asymmetrically as well.
In the context of muscle regeneration, asymmetric division may allow for muscle regeneration without exhausting the pool of satellite cells (or muscle stem cells).
Understanding the mechanism of asymmetric division is essential to advancing the control of stem cell self-renewal versus differentiation. Such control is necessary for the use of stem cells in regenerative medicine.