Identification of novel genes expressed during mouse molar tooth development by microarray gene expression analysis

To identify genes heretofore undiscovered as critical players in the biogenesis of teeth, we have used microarray gene expression analysis of the developing mouse molar tooth (DMT) between 1 and 10 days postnatal to identify genes differentially expressed when compared to 16 control tissues (GEO accession # GSE1986). Of the top 100 genes exhibiting increased expression in the DMT, 29 were found to have been previously associated with tooth development. Differential expression of the remaining 71 genes not previously associated with tooth development was confirmed by qRT-PCR analysis. Further analysis of seven of the latter genes by mRNA in situ hybridization found that five were specific to the developing tooth in the craniofacial region (Rspo4, Papln, Amtn, Gja1, Maf). Of the remaining two, one was found to be more widely expressed (Sp7) and the other was found to be specific to the nasal serous gland, which is close to, but distinct from, the developing tooth (Vrm). Keywords: tooth development mRNA from molar teeth extracted from Swiss Webster mouse pups between 1 and 10 days post-natal was pooled, labeled, and hybridized in quadruplicate to Affymetrix Mouse Genome Expression 430 2.0 microarrays. This data was compared to that of 16 control tissues (GEO accession # GSE1986) to identify genes differentially expressed in the DMT mRNA.