Fig. 9. Quantitation of PLP genomic in situ hybridization combined with Myt1 immunostaining. The PLP gene and Myt1 domains were scored as co-localized when there was pixel overlap in the red and green channels (see Fig. 8). Myt1 nuclear domains were found associated with the PLP gene in approximately 50% of the cells analyzed (pre-oligodendrocyte progenitors (preOP, n=50), progenitors (OPs, n=101), and oligodendrocytes (oligos, n=100). The IRBP gene, which is not expressed in oligodendrocyte progenitors, was also found associated with Myt1 nuclear domains in approximately 50% of the progenitor cells analyzed (n=50). No statistical difference was found between any of the groups using the chi-square statistical test. Error bars=standard error of the proportion.