Nature Genetics
27, 327 - 331 (2001)
doi:10.1038/85906
Deficiency of methyl-CpG binding protein-2 in CNS neurons results in a Rett-like phenotype in miceRichard Z. Chen1, Schahram Akbarian1, 3, Matthew Tudor1, 2
& Rudolf Jaenisch1, 21
The Whitehead Institute for Biomedical Research, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA. 2
Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA. 3
Department of Psychiatry, Massachusetts General Hospital, Boston, Massachusetts, USA.
Correspondence should be addressed to Rudolf Jaenisch jaenisch@wi.mit.edu
Mecp2 is an X-linked gene encoding a nuclear protein that binds specifically to methylated DNA (ref. 1) and functions as a general transcriptional repressor by associating with chromatin-remodeling complexes2,
3. Mecp2 is expressed at high levels in the postnatal brain1,
4, indicating that methylation-dependent regulation of gene expression may have a crucial role in the mammalian central nervous system. Consistent with this notion is the recent demonstration that MECP2 mutations cause Rett syndrome5,
6,
7,
8 (RTT, MIM 312750), a childhood neurological disorder that represents one of the most common causes of mental retardation in females9,
10,
11. Here we show that Mecp2-deficient mice exhibit phenotypes that resemble some of the symptoms of RTT patients. Mecp2-null mice were normal until 5 weeks of age, when they began to develop disease, leading to death between 6 and 12 weeks. Mutant brains showed substantial reduction in both weight and neuronal cell size, but no obvious structural defects or signs of neurodegeneration. Brain-specific deletion of Mecp2 at embryonic day (E) 12 resulted in a phenotype identical to that of the null mutation, indicating that the phenotype is caused by Mecp2 deficiency in the CNS rather than in peripheral tissues. Deletion of Mecp2 in postnatal CNS neurons led to a similar neuronal phenotype, although at a later age. Our results indicate that the role of Mecp2 is not restricted to the immature brain, but becomes critical in mature neurons. Mecp2 deficiency in these neurons is sufficient to cause neuronal dysfunction with symptomatic manifestation similar to Rett syndrome.
|
