Table 3.

Axon deficiencies in B6.Unc5c^−/− phrenic nerves

Genotype	Left nerve (axons)	Right nerve (axons)
+/+	88.2 ± 5.6 (n = 5)	83.0 ± 6.9 (n = 9)
+/−	82.2 ± 10.8 (n = 5)	86.3 ± 10.5 (n = 4)
−/− #1	7	22
−/− #2	ND	67
−/− #3	63	0
−/− #4	9	16
−/− #5	12	ND

Right and left phrenic nerves from E18.5 embryos were plastic embedded and cross sectioned. Axons, as distinguished by their round, pale profiles containing cytoskeletal filaments, were counted in toluidine blue-stained sections or in thin sections by transmission electron microscopy. ND, Not determined.