title: Strain-specific modifier genes governing craniofacial phenotypes.
abstract: BACKGROUND
  The presence of strain-specific modifier genes is known to modulate the phenotype and pathophysiology of mice harboring genetically engineered mutations. Thus, identification of genetic modifier genes is requisite to understanding control of phenotypic expression. c-Ski is a transcriptional regulator. Ski(-/-) mice on a C57BL6J (B6) background exhibit facial clefting, while Ski(-/-) mice on a 129P3 (129) background present with exencephaly.
  
  
  METHODS
  In the present study, oligonucleotide-based gene expression profiling was used to identify potential strain-specific modifier gene candidates present in wild type mice of B6 and 129 genetic backgrounds. Changes in gene expression were verified by TaqMan quantitative real-time PCR.
  
  
  RESULTS
  Steady-state levels of 89 genes demonstrated a significantly higher level of expression, and those of 68 genes demonstrated a significantly lower level of expression in the developing neural tubes from embryonic day (E) 8.5, B6 embryos when compared to expression levels in neural tubes derived from E 8.5, 129 embryos.
  
  
  CONCLUSIONS
  Based on the results from the current comparative microarray study, and taking into consideration a number of relevant published reports, several potential strain-specific gene candidates, likely to modify the craniofacial phenotypes in various knockout mouse models have been identified.
authors.affiliation: University of Louisville Birth Defects Center, Department of Molecular, Cellular and Craniofacial Biology, ULSD, University of Louisville, Louisville, Kentucky 40292, USA.
authors.forename: Partha
authors.initials: P
authors.lastname: Mukhopadhyay
authors.forename: Guy
authors.initials: G
authors.lastname: Brock
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; D015820:Cadherins; D002971:Cleft Lip / Q000235:genetics* / Q000473:pathology; D002972:Cleft Palate / Q000235:genetics* / Q000473:pathology; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D060045:Genes, Modifier; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009436:Neural Tube Defects / Q000235:genetics* / Q000473:pathology; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D011518:Proto-Oncogene Proteins / Q000235:genetics* / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D013045:Species Specificity
chemical_list: C454220:CELSR1 cadherin, human; D015820:Cadherins; D011518:Proto-Oncogene Proteins