title: Cellular distribution of the fragile X mental retardation protein in the mouse brain.
abstract: The fragile X mental retardation protein (FMRP) plays an important role in normal brain development. Absence of FMRP results in abnormal neuronal morphologies in a selected manner throughout the brain, leading to intellectual deficits and sensory dysfunction in the fragile X syndrome (FXS). Despite FMRP importance for proper brain function, its overall expression pattern in the mammalian brain at the resolution of individual neuronal cell groups is not known. In this study we used FMR1 knockout and isogenic wildtype mice to systematically map the distribution of FMRP expression in the entire mouse brain. Using immunocytochemistry and cellular quantification analyses, we identified a large number of prominent cell groups expressing high levels of FMRP at the subcortical levels, in particular sensory and motor neurons in the brainstem and thalamus. In contrast, many cell groups in the midbrain and hypothalamus exhibit low FMRP levels. More important, we describe differential patterns of FMRP distribution in both cortical and subcortical brain regions. Almost all major brain areas contain high and low levels of FMRP cell groups adjacent to each other or between layers of the same cortical areas. These differential patterns indicate that FMRP expression appears to be specific to individual neuronal cell groups instead of being associated with all neurons in distinct brain regions, as previously considered. Taken together, these findings support the notion of FMRP differential neuronal regulation and strongly implicate the contribution of fundamental sensory and motor processing at subcortical levels to FXS pathology. J. Comp. Neurol. 525:818-849, 2017. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida, USA.
authors.forename: Diego A R
authors.initials: DA
authors.lastname: Zorio
authors.affiliation: Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida, USA.
authors.forename: Christine M
authors.initials: CM
authors.lastname: Jackson
authors.affiliation: Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida, USA.
authors.forename: Yong
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Virginia Merrill Bloedel Hearing Research Center, Department of Otolaryngology-Head and Neck Surgery, University of Washington School of Medicine, Seattle, Washington, USA.
authors.forename: Edwin W
authors.initials: EW
authors.lastname: Rubel
authors.affiliation: Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida, USA.|Program in Neuroscience, Florida State University, Tallahassee, Florida, USA.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000818:Animals; D015153:Blotting, Western; D001921:Brain / Q000378:metabolism*; D051860:Fragile X Messenger Ribonucleoprotein 1 / Q000096:biosynthesis*; D005600:Fragile X Syndrome / Q000378:metabolism; D020869:Gene Expression Profiling; D007150:Immunohistochemistry; D051379:Mice; D018345:Mice, Knockout; D059467:Transcriptome
chemical_list: D051860:Fragile X Messenger Ribonucleoprotein 1
keywords: RRID:AB_10805421; RRID:AB_1157880; RRID:AB_476743; cortical laminar heterogeneity; fragile X syndrome; sensory information processing; subcortical sensory systems; whole brain analyses