Neurophysiological defects and neuronal gene deregulation in drosophila mir-124 mutants Journal Article


Authors: Sun, K.; Westholm, J. O.; Tsurudome, K.; Hagen, J. W.; Lu, Y.; Kohwi, M.; Betel, D.; Gao, F. B.; Haghighi, A. P.; Doe, C. Q.; Lai, E. C.
Article Title: Neurophysiological defects and neuronal gene deregulation in drosophila mir-124 mutants
Abstract: miR-124 is conserved in sequence and neuronal expression across the animal kingdom and is predicted to have hundreds of mRNA targets. Diverse defects in neural development and function were reported from miR-124 antisense studies in vertebrates, but a nematode knockout of mir-124 surprisingly lacked detectable phenotypes. To provide genetic insight from Drosophila, we deleted its single mir-124 locus and found that it is dispensable for gross aspects of neural specification and differentiation. On the other hand, we detected a variety of mutant phenotypes that were rescuable by a mir-124 genomic transgene, including short lifespan, increased dendrite variation, impaired larval locomotion, and aberrant synaptic release at the NMJ. These phenotypes reflect extensive requirements of miR-124 even under optimal culture conditions. Comparison of the transcriptomes of cells from wild-type and mir-124 mutant animals, purified on the basis of mir-124 promoter activity, revealed broad upregulation of direct miR-124 targets. However, in contrast to the proposed mutual exclusion model for miR-124 function, its functional targets were relatively highly expressed in miR-124-expressing cells and were not enriched in genes annotated with epidermal expression. A notable aspect of the direct miR-124 network was coordinate targeting of five positive components in the retrograde BMP signaling pathway, whose activation in neurons increases synaptic release at the NMJ, similar to mir-124 mutants. Derepression of the direct miR-124 target network also had many secondary effects, including over-activity of other post-transcriptional repressors and a net incomplete transition from a neuroblast to a neuronal gene expression signature. Altogether, these studies demonstrate complex consequences of miR-124 loss on neural gene expression and neurophysiology. © 2012 Sun et al.
Keywords: signal transduction; controlled study; unclassified drug; promoter region; gene deletion; genetics; mutation; nonhuman; animal cell; phenotype; animal; animals; microrna; gene expression; epidermis; bone morphogenetic protein; gene locus; drosophila; gene function; genetic transcription; cell differentiation; pathology; wild type; physiology; animalia; vertebrata; gene expression regulation; gene expression regulation, developmental; sensory receptor cells; gene repression; transgene; gene inactivation; upregulation; drosophila melanogaster; genetic disorder; micrornas; nervous system development; neurogenesis; nerve cell; transcriptome; neuroblast; locomotion; mutant; lifespan; larva; dendrite; sensory receptor; synapses; neurophysiology; synapse; genetic regulation; gene knockout techniques; neuromuscular synapse; neuromuscular junction; microrna 124
Journal Title: PLoS Genetics
Volume: 8
Issue: 2
ISSN: 1553-7390
Publisher: Public Library of Science  
Date Published: 2012-02-01
Start Page: e1002515
Language: English
DOI: 10.1371/journal.pgen.1002515
PROVIDER: scopus
PMCID: PMC3276548
PUBMED: 22347817
DOI/URL:
Notes: --- - "Export Date: 1 May 2012" - "Source: Scopus"
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MSK Authors
  1. Eric C Lai
    159 Lai
  2. Joshua W Hagen
    7 Hagen
  3. Kailiang Sun
    6 Sun