title: Downregulation of msh-like 2 (msx2) and neurotrophic tyrosine kinase receptor type 2 (ntrk2) in the developmental gut of KIT mutant mice.
abstract: In the gastrointestinal tract, interstitial cells of Cajal (ICC) are the regulatory cells of gut movement. W/W mutant mice that have receptor tyrosine kinase KIT mutation lack ICC along the myenteric plexus layer of small intestine. The development and maintenance of the ICC phenotype have been related to KIT, but the other genes involved in ICC development during embryogenesis are not clear. Our aim was to identify ICC-specific genes in the embryonic stage. We examined genes that are expressed less in ICC-deficient W/W mice than in wild type (WT) at embryonic day 14 (E14) in order to clarify the genes associated with the ICC development using subtractive hybridization and microarray. Among them, we identified msh-like 2 (msx2) and neurotrophic tyrosine kinase receptor type 2 (ntrk2). Using real-time PCR, msx2 and ntrk2 were found to be expressed at significantly lower levels in W/W than in WT during embryogenesis. Msx2 immunoreactivity was high in the WT small intestine. These data suggest that the gene expressions of ntrk2 and msx2 were significantly suppressed in KIT mutant mouse embryo and neonate and that these genes are likely to regulate ICC development.
authors.affiliation: Division of Anatomy and Neuroscience, Department of Morphological and Physiological Sciences, University of Fukui Faculty of Medical Sciences, Eiheiji-cho, Matsuoka-Shimoaizuki 23-3, Fukui 910-1193, Japan.
authors.forename: Satomi
authors.initials: S
authors.lastname: Horiguchi
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Horiguchi
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Nojyo
authors.forename: Satoshi
authors.initials: S
authors.lastname: Iino
mesh_terms: D000818:Animals; D015536:Down-Regulation; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000235:genetics*; D056885:Interstitial Cells of Cajal / Q000502:physiology*; D007421:Intestine, Small / Q000166:cytology / Q000196:embryology* / Q000502:physiology; D008562:Membrane Glycoproteins / Q000235:genetics*; D051379:Mice; D008817:Mice, Mutant Strains; D011505:Protein-Tyrosine Kinases / Q000235:genetics*; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics; D020813:Receptor, trkB
chemical_list: D018398:Homeodomain Proteins; D008562:Membrane Glycoproteins; D011505:Protein-Tyrosine Kinases; D019009:Proto-Oncogene Proteins c-kit; C084119:MSX2 protein; C064371:Ntrk2 protein, mouse; D020813:Receptor, trkB