Courtesy of Dr. Susan Bryant, Univ. of Calif., Irvine
| It appears that 2 extra Apical Ectodermal Ridges (A.E.R.s) were grafted onto a regenerating newt limb. Each A.E.R. sends out growth factors such as FGF-2, FGF-4 and FGF-8 that causes the underlying mesodermal cells in the Progress Zone to proliferate and expand outward in three different directions. Courtesy of Dr. Susan Bryant, Univ. of Calif., Irvine |