MicroRNAs are essential for development and function of inner ear hair cells in vertebrates.
MicroRNAs (miRNAs) inhibit the translation of target mRNAs and affect, directly or indirectly, the expression of a large portion of the protein-coding genes. This study focuses on miRNAs that are expressed in the mouse cochlea and vestibule, the 2 inner ear compartments. A conditional knock-out mouse for Dicer1 demonstrated that miRNAs are crucial for postnatal survival of functional hair cells of the inner ear. We identified miRNAs that have a role in the vertebrate developing inner ear by combining miRNA transcriptome analysis, spatial and temporal expression patterns, and bioinformatics. Microarrays revealed similar miRNA profiles in newborn-mouse whole cochleae and vestibules, but different temporal and spatial expression patterns of six miRNAs (miR-15a, miR-18a, miR-30b, miR-99a, miR-182, and miR-199a) may reflect their roles. Two of these miRNAs, miR-15a-1 and miR-18a, were also shown to be crucial for zebrafish inner ear development and morphogenesis. To suggest putative target mRNAs whose translation may be inhibited by selected miRNAs, we combined bioinformatics-based predictions and mRNA expression data. Finally, we present indirect evidence that Slc12a2, Cldn12, and Bdnf mRNAs may be targets for miR-15a. Our data support the hypothesis that inner ear tissue differentiation and maintenance are regulated and controlled by conserved sets of cell-specific miRNAs in both mouse and zebrafish.
Friedman
Lilach M
LM
Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
Dror
Amiel A
AA
Mor
Eyal
E
Tenne
Tamar
T
Toren
Ginat
G
Satoh
Takunori
T
Biesemeier
Deborah J
DJ
Shomron
Noam
N
Fekete
Donna M
DM
Hornstein
Eran
E
Avraham
Karen B
KB
D000818:Animals; D003051:Cochlea / Q000196:embryology* / Q000502:physiology; D019295:Computational Biology / Q000379:methods; D020869:Gene Expression Profiling; D006199:Hair Cells, Auditory, Inner / Q000502:physiology*; D006720:Homozygote; D051379:Mice; D018345:Mice, Knockout; D035683:MicroRNAs / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D017354:Point Mutation; D014714:Vertebrates; D014722:Vestibule, Labyrinth / Q000196:embryology* / Q000502:physiology; D015027:Zebrafish
D035683:MicroRNAs