Table 1.

Cell-Cycle Parameters of Adult OPs in Different CNS Regions

P21		P60
Corpus Callosum
GF	99.8 ± 0.2	GF	99.2 ± 0.3
T	2.7 ± 0.2	T	9.5 ± 0.5
S	0.4 ± 0.1	S	0.8 ± 0.3
Cortex
GF	97.8 ± 1.7	GF	98 ± 2.0
T	18.6 ± 1.4	T	36.3 ± 2.1
S	1.1 ± 0.4	S	1.0 ± 0.8
Spinal White Matter
GF	98.1 ± 0.8	GF	99.2 ± 0.7
T	4.4 ± 0.3	T	14.9 ± 0.8
S	0.2 ± 0.4	S	1.1 ± 0.4
Spinal Grey Matter
GF	98.1 ± 1	GF	98.8 ± 1.2
T	8 ± 0.7	T	27.4 ± 1.9
S	0.1 ± 0.3	S	0.8 ± 0.7
Optic Nerve
GF	98.3 ± 0.7	GF	100 ± 0
T	7.6 ± 0.6	T	20 ± 1.7
S	0.6 ± 0.3	S	0.6 ± 0.4

A total of 0.2 mg/ml EdU was administered to P21 and P60 mice via their drinking water for up to 50 days. The proportion of Pdgfra⁺ OPs that became EdU⁺ was determined for various labeling periods (see Figures 1 and 2). From the cumulative labeling plots, we calculated the cell-cycle time (T, days), growth fraction (GF, %), and the duration of S phase (S, days) for OPs within the specified regions (Supplemental Experimental Procedures). Data are presented as mean ± SEM (n = 3 mice).