title: Developmental microRNA expression profiling of murine embryonic orofacial tissue.
abstract: BACKGROUND
  Orofacial development is a multifaceted process involving precise, spatio-temporal expression of a panoply of genes. MicroRNAs (miRNAs), the largest family of noncoding RNAs involved in gene silencing, represent critical regulators of cell and tissue differentiation. MicroRNA gene expression profiling is an effective means of acquiring novel and valuable information regarding the expression and regulation of genes, under the control of miRNA, involved in mammalian orofacial development.
  
  
  METHODS
  To identify differentially expressed miRNAs during mammalian orofacial ontogenesis, miRNA expression profiles from gestation day (GD) -12, -13 and -14 murine orofacial tissue were compared utilizing miRXplore microarrays from Miltenyi Biotech. Quantitative real-time PCR was utilized for validation of gene expression changes. Cluster analysis of the microarray data was conducted with the clValid R package and the UPGMA clustering method. Functional relationships between selected miRNAs were investigated using Ingenuity Pathway Analysis.
  
  
  RESULTS
  Expression of over 26% of the 588 murine miRNA genes examined was detected in murine orofacial tissues from GD-12-GD-14. Among these expressed genes, several clusters were seen to be developmentally regulated. Differential expression of miRNAs within such clusters wereshown to target genes encoding proteins involved in cell proliferation, cell adhesion, differentiation, apoptosis and epithelial-mesenchymal transformation, all processes critical for normal orofacial development.
  
  
  CONCLUSIONS
  Using miRNA microarray technology, unique gene expression signatures of hundreds of miRNAs in embryonic orofacial tissue were defined. Gene targeting and functional analysis revealed that the expression of numerous protein-encoding genes, crucial to normal orofacial ontogeny, may be regulated by specific miRNAs.
authors.affiliation: University of Louisville Birth Defects Center, Department of Molecular Cellular and Craniofacial Biology, ULSD, University of Louisville, Kentucky, USA.
authors.forename: Partha
authors.initials: P
authors.lastname: Mukhopadhyay
authors.forename: Guy
authors.initials: G
authors.lastname: Brock
authors.forename: Vasyl
authors.initials: V
authors.lastname: Pihur
authors.forename: Cynthia
authors.initials: C
authors.lastname: Webb
authors.forename: M Michele
authors.initials: MM
authors.lastname: Pisano
authors.forename: Robert M
authors.initials: RM
authors.lastname: Greene
mesh_terms: D000818:Animals; D004622:Embryo, Mammalian / Q000378:metabolism*; D005145:Face / Q000196:embryology*; D005260:Female; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D035683:MicroRNAs / Q000378:metabolism*; D046228:Microarray Analysis; D009055:Mouth / Q000196:embryology*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D035683:MicroRNAs