Biomedical Engineering Reference
In-Depth Information
enucleated
CFU-E
red blood cell
Gly-A
(glycophorin A)
differentiation path
BFU-E
immature
progenitor
CD71 (the Transferrin receptor)
FIGURE 6.15
Two-parameter definition of erythropoietic differentiation. Glycophorin A is found on erythroid
cells post the blast-forming unit-erythroid (BFU-E) stage, whereas transferrin (CD71) is expressed at the progenitor
stage (BFU-E and
colony-forming
unit-erythroid (CFU-E)). By measuring the two simultaneously using a flow
cytometer, this differentiation process can be traced as a U-shaped path on a bivariate dot plot.
From [16].
The transition rate from one stage to the next is proportional to the number of cells present
at that stage. This transition rate can clearly be a function of growth factor concentration
and a number of other variables.
B. Differentiation as a continuous process.
An alternative view is to consider the differentia-
tion process to be a continuous process. Once the commitment to differentiation has been
