Figure 1.

Nonradioactive in situ hybridization for the detection of Ret and GFRα1 mRNAs in developing and postnatal murine DRGs at the indicated stages. Ret was highly expressed during development, at birth, and in the adult (Ad). GFRα1 was expressed in a diffuse pattern at E13, but was up-regulated at E16 and remained relatively high at birth. Only a subpopulation of neurons expressed ret and/or GFRα1 in the adult. Thus, both GDNF receptors were present throughout the ages studied in this work, albeit in varying patterns and levels. (Bars = 100 μm.)