title: Functional redundancy of the Notch gene family during mouse embryogenesis: analysis of Notch gene expression in Notch3-deficient mice.
abstract: The Notch3 gene, a member of the Notch gene family, is expressed in a wide variety of tissues during development. We generated and analyzed Notch3-deficient mice to assess the in vivo role of the Notch3 gene. Consistent with previous observation of Krebs et al. [Characterization of Notch3-deficient mice: normal embryonic development and absence of genetic interactions with a Notch1 mutation, Genesis 37 (3) (2003) 139-143], the Notch3-/- mice were viable, fertile, and developed normally despite abundant expression of Notch3 in various embryonic tissues. We examined the details of Notch1, 2, and 4 expressions in the Notch3-/- embryos compared with those in wild-type embryos. As a result, we found that a deficiency in Notch3 did not affect the expression of Notch1, 2, and 4, and that either Notch1 or Notch2, or sometimes both, was always expressed in all Notch3-expressing tissues examined. These results support the idea that other Notch genes functionally compensate for Notch3 during embryonic development. We also surveyed the adult tissues of Notch3-/- mice and found significantly fewer thymocytes in 10-week-old mice. Therefore, the thymus might be a target tissue affected by Notch3 deficiency.
authors.affiliation: Laboratory of Molecular Embryology, Department of Bioscience, Kitasato University School of Science, 1-15-1, Kitasato, Sagamihara, Kanagawa 228-8555, Japan.
authors.forename: Takeo
authors.initials: T
authors.lastname: Kitamoto
authors.forename: Keikichi
authors.initials: K
authors.lastname: Takahashi
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Takimoto
authors.forename: Kazuma
authors.initials: K
authors.lastname: Tomizuka
authors.forename: Michiko
authors.initials: M
authors.lastname: Hayasaka
authors.forename: Takeshi
authors.initials: T
authors.lastname: Tabira
authors.forename: Kazunori
authors.initials: K
authors.lastname: Hanaoka
mesh_terms: D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D018507:Gene Expression Regulation, Developmental; D051379:Mice; D018345:Mice, Knockout; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000502:physiology*; D000071656:Receptor, Notch3; D000074562:Receptor, Notch4; D011956:Receptors, Cell Surface / Q000235:genetics / Q000502:physiology*; D051880:Receptors, Notch; D013950:Thymus Gland / Q000196:embryology / Q000378:metabolism
chemical_list: D017931:DNA Primers; C499373:Notch3 protein, mouse; D011518:Proto-Oncogene Proteins; D000071656:Receptor, Notch3; D000074562:Receptor, Notch4; D011956:Receptors, Cell Surface; D051880:Receptors, Notch; C073572:Notch4 protein, mouse