Ablation of de novo DNA methyltransferase Dnmt3a in the nervous system leads to neuromuscular defects and shortened lifespan

Authors

  • Suzanne Nguyen,

    1. Whitehead Institute for Biomedical Research, Cambridge, Massachusetts
    2. Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts
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  • Konstantinos Meletis,

    1. Whitehead Institute for Biomedical Research, Cambridge, Massachusetts
    Current affiliation:
    1. Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts
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  • Dongdong Fu,

    1. Whitehead Institute for Biomedical Research, Cambridge, Massachusetts
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  • Sonal Jhaveri,

    1. Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts
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  • Rudolf Jaenisch

    Corresponding author
    1. Whitehead Institute for Biomedical Research, Cambridge, Massachusetts
    2. Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts
    • Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, MA, 02142
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Abstract

DNA methylation is an epigenetic mechanism involved in gene regulation and implicated in the functioning of the nervous system. The de novo DNA methyltransferase Dnmt3a is expressed in neurons, but its specific role has not been clarified. Dnmt3a is activated around embryonic day 10.5 in mouse neuronal precursor cells and remains active in postmitotic neurons in the adult. We assessed the role of neuronal Dnmt3a by conditional gene targeting. Mice lacking functional Dnmt3a in the nervous system were born healthy, but degenerated in adulthood and died prematurely. Mutant mice were hypoactive, walked abnormally, and underperformed on tests of neuromuscular function and motor coordination. Loss of Dnmt3a also led to fewer motor neurons in the hypoglossal nucleus and more fragmented endplates in neuromuscular junctions of the diaphragm muscle. Our results implicate a role for Dnmt3a in the neuromuscular control of motor movement. Developmental Dynamics 236:1663–1676, 2007. © 2007 Wiley-Liss, Inc.

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