To gain a better understanding of the progression of progenitor cells in the odontoblast lineage, we have examined and characterized the expression of a series of GFP reporters during odontoblast differentiation. However, previously reported GFP reporters (pOBCol2.3-GFP, pOBCol3.6-GFP, and DMP1-GFP), similar to the endogenous proteins, are also expressed by bone-forming cells, which made it difficult to delineate the two cell types in various in vivo and in vitro studies. To overcome these difficulties we generated DSPP-Cerulean/DMP1-Cherry transgenic mice using a bacterial recombination strategy with the mouse BAC clone RP24-258g7. We have analyzed the temporal and spatial expression of both transgenes in tooth and bone in vivo and in vitro. This transgenic animal enabled us to visualize the interactions between odontoblasts and surrounding tissues including dental pulp, ameloblasts and cementoblasts. Our studies showed that DMP1-Cherry, similar to Dmp1, was expressed in functional and fully differentiated odontoblasts as well as osteoblasts, osteocytes and cementoblasts. Expression of DSPP-Cerulean transgene was limited to functional and fully differentiated odontoblasts and correlated with the expression of Dspp. This transgenic animal can help in the identification and isolation of odontoblasts at later stages of differentiation and help in better understanding of developmental disorders in dentin and odontoblasts.

• Klíčová slova
• Odontoblasts, bone, dentin matrix protein 1, dentin sialophosphoprotein, fluorescent protein reporters,
• MeSH
• buněčná diferenciace MeSH
• extracelulární matrix - proteiny genetika   MeSH
• fluorescenční barviva MeSH
• fosfoproteiny genetika   MeSH
• myši transgenní MeSH
• myši MeSH
• odontoblasty cytologie   MeSH
• reportérové geny * MeSH
• sialoglykoproteiny genetika   MeSH
• transgeny MeSH
• zelené fluorescenční proteiny genetika   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• dentin sialophosphoprotein MeSH Prohlížeč
• Dmp1 protein, mouse MeSH Prohlížeč
• extracelulární matrix - proteiny MeSH
• fluorescenční barviva MeSH
• fosfoproteiny MeSH
• sialoglykoproteiny MeSH
• zelené fluorescenční proteiny MeSH

The Wnt pathway plays a crucial role in self-renewal and differentiation of cells in the adult gut. In the present study, we revealed the functional consequences of inhibition of canonical Wnt signaling in the intestinal epithelium. The study was based on generation of a novel transgenic mouse strain enabling inducible expression of an N-terminally truncated variant of nuclear Wnt effector T cell factor 4 (TCF4). The TCF4 variant acting as a dominant negative (dn) version of wild-type (wt) TCF4 protein decreased transcription of β-catenin-TCF4-responsive genes. Interestingly, suppression of Wnt/β-catenin signaling affected asymmetric division of intestinal stem cells (ISCs) rather than proliferation. ISCs expressing the transgene underwent several rounds of division but lost their clonogenic potential and migrated out of the crypt. Expression profiling of crypt cells revealed that besides ISC-specific markers, the dnTCF4 production downregulated expression levels of epithelial genes produced in other crypt cells including markers of Paneth cells. Additionally, in Apc conditional knockout mice, dnTCF activation efficiently suppressed growth of Apc-deficient tumors. In summary, the generated mouse strain represents a convenient tool to study cell-autonomous inhibition of β-catenin-Tcf-mediated transcription.

• Klíčová slova
• Cre/loxP, TCF/LEF transcription factors, Wnt pathway, gene targeting, gut, β-catenin,
• MeSH
• beta-katenin metabolismus   MeSH
• buněčná diferenciace MeSH
• buněčné dělení MeSH
• genetická transkripce MeSH
• kmenové buňky cytologie   metabolismus   MeSH
• myši transgenní MeSH
• myši MeSH
• proliferace buněk MeSH
• signální dráha Wnt * MeSH
• střevní sliznice cytologie   metabolismus   MeSH
• tenké střevo cytologie   metabolismus   MeSH
• transkripční faktor 4 MeSH
• transkripční faktory BHLH-Zip chemie   genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• beta-katenin MeSH
• Tcf4 protein, mouse MeSH Prohlížeč
• transkripční faktor 4 MeSH
• transkripční faktory BHLH-Zip MeSH

HIC1 (hypermethylated in cancer 1) is a tumor suppressor gene located on chromosome 17p13.3, a region frequently hypermethylated or deleted in human neoplasias. In mouse, Hic1 is essential for embryonic development and exerts an antitumor role in adult animals. Since Hic1-deficient mice die perinatally, we generated a conditional Hic1 null allele by flanking the Hic1-coding region by loxP sites. When crossed to animals expressing Cre recombinase in a cell-specific manner, the Hic1 conditional mice will provide new insights into the function of Hic1 in developing and mature tissues. Additionally, we used gene targeting to replace sequence-encoding amino acids 186-893 of Hic1 by citrine fluorescent protein cDNA. We demonstrate that the distribution of Hic1-citrine fusion polypeptide corresponds to the expression pattern of wild-type Hic1. Consequently, Hic1-citrine "reporter" mice can be used to monitor the activity of the Hic1 locus using citrine fluorescence.

• MeSH
• alely * MeSH
• delece genu MeSH
• DNA vazebné proteiny genetika   MeSH
• embryo savčí metabolismus   MeSH
• genový targeting MeSH
• integrasy genetika   metabolismus   MeSH
• myši transgenní MeSH
• myši MeSH
• reportérové geny MeSH
• transkripční faktory Krüppel-like genetika   MeSH
• transkripční faktory genetika   MeSH
• tumor supresorové geny * MeSH
• vývojová regulace genové exprese * MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• Cre recombinase MeSH Prohlížeč
• DNA vazebné proteiny MeSH
• Hic1 protein, mouse MeSH Prohlížeč
• integrasy MeSH
• transkripční faktory Krüppel-like MeSH
• transkripční faktory MeSH

Lens formation in mouse is critically dependent on proper development of the retinal neuroectoderm that is located close beneath the head surface ectoderm. Signaling from the prospective retina triggers lens-specific gene expression in the surface-ectoderm. Supression of canonical Wnt/beta-catenin signaling in the surface ectoderm is one of the prerequisites for lens development because, as we show here, ectopic Wnt activation in the retina and lens abrogates lens formation. Wnt inhibiton is mediated by signals coming from the retina but its exact mechanism is unknown. We show that Pax6 directly controls expression of several Wnt inhibitors such as Sfrp1, Sfrp2, and Dkk1 in the presumptive lens. In accordance, absence of Pax6 function leads to aberrant canonical Wnt activity in the presumptive lens that subsequently impairs lens development. Thus Pax6 is required for down-regulation of canonical Wnt signaling in the presumptive lens ectoderm.

• MeSH
• beta-katenin genetika   metabolismus   MeSH
• ektoderm metabolismus   MeSH
• embryo savčí metabolismus   MeSH
• homeodoménové proteiny genetika   metabolismus   MeSH
• morfogeneze genetika   MeSH
• myši transgenní MeSH
• myši MeSH
• oční čočka embryologie   metabolismus   MeSH
• oční proteiny genetika   metabolismus   MeSH
• proteiny Wnt metabolismus   MeSH
• represorové proteiny genetika   metabolismus   MeSH
• retina metabolismus   MeSH
• signální transdukce genetika   MeSH
• transkripční faktor PAX6 MeSH
• transkripční faktory paired box genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• beta-katenin MeSH
• homeodoménové proteiny MeSH
• oční proteiny MeSH
• Pax6 protein, mouse MeSH Prohlížeč
• proteiny Wnt MeSH
• represorové proteiny MeSH
• transkripční faktor PAX6 MeSH
• transkripční faktory paired box MeSH

beta-Catenin plays a key role in cadherin-mediated cell adhesion as well as in canonical Wnt signaling. To study the role of beta-catenin during eye development, we used conditional Cre/loxP system in mouse to inactivate beta-catenin in developing lens and retina. Inactivation of beta-catenin does not suppress lens fate, but instead results in abnormal morphogenesis of the lens. Using BAT-gal reporter mice, we show that beta-catenin-mediated Wnt signaling is notably absent from lens and neuroretina throughout eye development. The observed defect is therefore likely due to the cytoskeletal role of beta-catenin, and is accompanied by impaired epithelial cell adhesion. In contrast, inactivation of beta-catenin in the nasal ectoderm, an area with active Wnt signaling, results in formation of crystallin-positive ectopic lentoid bodies. These data suggest that, outside of the normal lens, beta-catenin functions as a coactivator of canonical Wnt signaling to suppress lens fate.

• MeSH
• beta-katenin genetika   fyziologie   MeSH
• buněčná adheze MeSH
• choristom vrozené   genetika   MeSH
• morfogeneze genetika   MeSH
• myši transgenní MeSH
• myši MeSH
• nemoci nosu vrozené   genetika   MeSH
• oči embryologie   MeSH
• oční čočka cytologie   embryologie   MeSH
• proteiny Wnt fyziologie   MeSH
• signální transdukce genetika   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• beta-katenin MeSH
• proteiny Wnt MeSH

Structure and developmental expression are described for amphioxus AmphiVent, a homolog of vertebrate Vent genes. In amphioxus, AmphiVent-expressing ventral mesoderm arises at midneurula by outgrowth from the paraxial mesoderm, but in vertebrates, Vent-expressing ventral mesoderm originates earlier, at the gastrula stage. In other embryonic tissues (nascent paraxial mesoderm, neural plate, endoderm, and tailbud), AmphiVent and its vertebrate homologs are expressed in similar spatiotemporal domains, indicating conservation of many Vent gene functions during chordate evolution. The ventral mesoderm evidently develops precociously in vertebrates because their relatively large embryos probably require an early and extensive deployment of the mesoderm-derived circulatory system. The vertebrate ventral mesoderm, in spite of its strikingly early advent, still resembles the nascent ventral mesoderm of amphioxus in expressing Vent homologs. This coincidence may indicate that Vent homologs in vertebrates and amphioxus play comparable roles in ventral mesoderm specification.

• MeSH
• crista neuralis metabolismus   MeSH
• DNA vazebné proteiny genetika   MeSH
• duplikace genu MeSH
• embryo nesavčí metabolismus   ultrastruktura   MeSH
• exprese genu MeSH
• fylogeneze MeSH
• homeoboxové geny MeSH
• homeodoménové proteiny chemie   klasifikace   genetika   fyziologie   MeSH
• hybridizace in situ MeSH
• mezoderm metabolismus   MeSH
• molekulární evoluce MeSH
• molekulární sekvence - údaje MeSH
• nižší strunatci embryologie   genetika   ultrastruktura   MeSH
• sekvence aminokyselin MeSH
• sekvence nukleotidů MeSH
• threonin chemie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Názvy látek
• DNA vazebné proteiny MeSH
• homeodoménové proteiny MeSH
• threonin MeSH
• Vent protein, Amphioxus MeSH Prohlížeč