title: Developmental gene expression profiling of mammalian, fetal orofacial tissue.
abstract: BACKGROUND
  The embryonic orofacial region is an excellent developmental paradigm that has revealed the centrality of numerous genes encoding proteins with diverse and important biological functions in embryonic growth and morphogenesis. DNA microarray technology presents an efficient means of acquiring novel and valuable information regarding the expression, regulation, and function of a panoply of genes involved in mammalian orofacial development.
  
  
  METHODS
  To identify differentially expressed genes during mammalian orofacial ontogenesis, the transcript profiles of GD-12, GD-13, and GD-14 murine orofacial tissue were compared utilizing GeneChip arrays from Affymetrix. Changes in gene expression were verified by TaqMan quantitative real-time PCR. Cluster analysis of the microarray data was done with the GeneCluster 2.0 Data Mining Tool and the GeneSpring software.
  
  
  RESULTS
  Expression of >50% of the approximately 12,000 genes and expressed sequence tags examined in this study was detected in GD-12, GD-13, and GD-14 murine orofacial tissues and the expression of several hundred genes was up- and downregulated in the developing orofacial tissue from GD-12 to GD-13, as well as from GD-13 to GD-14. Such differential gene expression represents changes in the expression of genes encoding growth factors and signaling molecules; transcription factors; and proteins involved in epithelial-mesenchymal interactions, extracellular matrix synthesis, cell adhesion, proliferation, differentiation, and apoptosis. Following cluster analysis of the microarray data, eight distinct patterns of gene expression during murine orofacial ontogenesis were selected for graphic presentation of gene expression patterns.
  
  
  CONCLUSIONS
  This gene expression profiling study identifies a number of potentially unique developmental participants and serves as a valuable aid in deciphering the complex molecular mechanisms crucial for mammalian orofacial development.
authors.affiliation: University of Louisville Birth Defects Center, Department of Molecular Cellular and Craniofacial Biology, University of Louisville School of Dentistry, Louisville, Kentucky, KY 40292, USA.
authors.forename: Partha
authors.initials: P
authors.lastname: Mukhopadhyay
authors.forename: Robert M
authors.initials: RM
authors.lastname: Greene
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Zacharias
authors.forename: Martin C
authors.initials: MC
authors.lastname: Weinrich
authors.forename: Saurabh
authors.initials: S
authors.lastname: Singh
authors.forename: William W
authors.initials: WW
authors.lastname: Young
authors.forename: M Michele
authors.initials: MM
authors.lastname: Pisano
mesh_terms: D000818:Animals; D016172:DNA Fingerprinting; D005145:Face / Q000196:embryology; D005260:Female; D047109:Fetal Development / Q000235:genetics*; D020869:Gene Expression Profiling / Q000379:methods*; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D023421:Models, Animal; D009055:Mouth / Q000196:embryology; D020411:Oligonucleotide Array Sequence Analysis; D016133:Polymerase Chain Reaction