Table 1.

Frequency of neural crest-derived (β-gal expressing, bluo-gal+) Schwann cells, endoneurial fibroblasts, and perineurial cells by electron microscopic examination of bluo-gal-stained sciatic nerves from P11 Wnt1-Cre⁺loxpRosa⁺ pups

		Total cells examined	Bluo-gal+ by electron microscopy
Myelinating Schwann cells	With nuclei visible	321	95.3%
	Only processes visible	2832	61.4%
Non-myelinating Schwann cells	With nuclei visible	135	87.4%
	Only processes visible	567	68.3%
Endoneurial fibroblasts		219	86.3%
Perineurial cells		180	3.3%

The data represent sections derived from five mice in three independent experiments. Sciatic nerves from five littermate control mice (Wnt1-Cre⁻loxpRosa⁺ were also examined in detail by electron microscopy to determine whether there was any background bluo-gal staining. In these control sections, 117 non-myelinating Schwann cells, 693 myelinating Schwann cells, 46 fibroblasts and 73 perineurial cells were examined, but none exhibited detectable bluo-gal staining.