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Developmental expression of FMRP in the astrocyte lineage: Implications for fragile X syndrome
Author(s) -
Pacey Laura K. K.,
Doering Laurie C.
Publication year - 2007
Publication title -
glia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.954
H-Index - 164
eISSN - 1098-1136
pISSN - 0894-1491
DOI - 10.1002/glia.20573
Subject(s) - biology , neurosphere , astrocyte , fragile x syndrome , progenitor cell , oligodendrocyte , embryonic stem cell , neural stem cell , fmr1 , neurogenesis , microbiology and biotechnology , ependymal cell , neuroscience , central nervous system , stem cell , adult stem cell , fragile x , genetics , myelin , gene
One of the most common causes of mental retardation in humans, Fragile X syndrome, results from the absence of FMRP, the protein product of the FMR1 gene. In the nervous system, expression of FMRP has been thought to be confined mainly to neurons as little research has examined FMRP expression in non‐neuronal lineages. We present evidence that, in addition to neuronal expression, FMRP is expressed in developing CNS glial cells in vitro and in vivo . The neurosphere assay was used to establish cultures of stem and progenitor cells from the brains of wildtype and FMRP knockout (B6.129.FMR1/FvBn) mouse pups. When the neurospheres were differentiated in vitro , ∼50% of the FMRP positive cells also expressed GFAP. Immunocytochemical studies of the embryonic and postnatal mouse brain revealed coexpression of FMRP and GFAP in the developing hippocampus. Prominent coexpression was also observed in ependymal cells surrounding the third ventricle and astrocytes of the glia limitans. No double‐labeled cells were evident in the brains of young adult mice. Cells coexpressing FMRP and the oligodendrocyte precursor marker NG2 were also identified in the hippocampus and corpus callosum of the early postnatal brain. Our results suggest that FMRP is expressed in cells of non‐neuronal lineage(s) during development. This represents potential involvement of glial cells in the neural development of fragile X syndrome. © 2007 Wiley‐Liss, Inc.