Fig. 2

Myelination is delayed during postnatal brain development in the mdx mouse model of DMD. a Breeding strategy to generate litters with mdx males and heterozygous mdx/+ females (controls), b dystrophin isoform expression in oligodendrocytes and mdx mice, c western blot analysis of dystrophin protein content in lysates obtained from mdx and control cerebral cortices at postnatal day 8 (p8), p14, p21, 6 weeks, and 2 months. Comparable levels of Dp71 are found in both mdx and control lysates, while Dp427 is absent from mdx lysates. Cortical lysates from wildtype male and female mice (B6, Black 6) reveals that Dp427 and Dp71 levels are similar in males and females. Representative western blots are shown, including those for p115 as a loading control, d MBP immunohistochemistry of mdx and control coronal floating brain sections. Tiled confocal microscopy images reveal less MBP immunoreactivity in mdx cerebral cortices at postnatal day 21 (p21) but not at 2 months, e quantification of mean MBP densitometries from western blots comparing protein lysates from cerebral cortices of control and mdx mice at p14, p21, 6wks and 2 months. In addition, cortical lysates from wildtype mice (B6, Black 6) were analyzed to ensure that MBP levels did not differ by gender. Immunoblots to detect β-actin were used as loading controls. MBP levels in mdx cerebral cortices were decreased at p14, p21, and 6 weeks but were normal by 2 months (*p < 0.05), f representative western blots of cortical lysates from postnatal day (p14) and 2 month old (2 mos) mdx and control mice