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Discussion:

From the first experiment, bFGF was shown to be influential in blood vessel formation. After embryos were exposed prematurely to the growth factor, a large number (in comparison with either the DMEM or VEGF blood vessel counts) of blood vessels formed. Insufficient data from the second experiment prevents any definite conclusions about the role of bFGF on blood vessel formation within the CAM membrane. However, the bFGF CAM membrane did exhibit more blood vessels than either of the DMEM segements. The bFGF membrane segment had a total of thirteen blood vessels, whereas the DMEM segments had seven and twelve blood vessels, respectively. In comparison to the bFGF blood vessel count (13), the average of the DMEM filter square blood vessels (7.5) was moderately lower.

The first experiment showed a strong correlation between the growth factor and increased blood vessel formation on the CAM membrane of chick embryos. bFGF, produced in the CAM membrane, is required for the process of vasculogenesis, during which time hemangioblasts are specified and blood vessels are created (Gilbert 2003). A greater concentration of bFGF may cause more blood vessels to appear during vasculogenesis. Within an area of high bFGF concentration, more mesoderm cells may be specified to form hemangioblasts, and more blood islands and vessels will be produced (Gilbert, 2003). In addition, the importance of these growth factors is demonstrated by mutant embryos that lack the proper receptors for bFGF (and also VEGF), which have a significantly lower chance of survival as vascular development will not occur properly.

References:

Brooks, P.C., Montgomery, A.M., and Cheresh, D.A. (1999) Methods Mol. Biol. 129:257-269.

Gilbert, Scott F.(2000) Developmental Biology, 6th, Sunderland: Sinauer Associates, Inc., MA.

Gilbert, Scott. 2003. Developmental Biology, 7th ed. Sinauer Associates, Inc., MA, pp. 501-505; 517.

© Cebra-Thomas, 2001
Last Modified: 1 April 2004

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