genesis
The goal of this study was to determine the presence of osteoprogenitor cells in the peripheral blood. Experiments were conducted with a parabiosis model in which osteoblast specific transgenic mice (Col2.3GFP or hOC‐GFP) were surgically joined with a transgenic mouse where herpes virus thymidine kinase gene is under the control of the collagen α1 promoter (Col2.3ΔTK). This method permits conditional...
Sall1 is expressed in the metanephric mesenchyme in the developing kidney, and mice deficient in Sall1 show kidney agenesis or dysgenesis. Sall1 is also expressed elsewhere, including in the limb buds, anus, heart, and central nervous system. Dominant‐negative mutations of Sall1 in mice and humans lead to developmental defects in these organs. Here, we generated a mouse line expressing tamoxifen‐inducible...
We have characterized a transgenic mouse line in which enhanced green fluorescent protein (EGFP) is expressed under the control of multimerized LEF‐1 responsive elements. In embryos, EGFP was detected in known sites of Wnt activation, including the primitive streak, mesoderm, neural tube, somites, heart, limb buds, mammary placodes, and whisker follicles. In vitro cultured transgenic embryonic fibroblasts...
The translational repressor Nanos is required in the germ line stem cells of the Drosophila ovary to maintain their capacity for self‐renewal. Following division of the stem cells, Nanos is inhibited in the daughters that differentiate into cysts and ultimately become mature oocytes. The control of Nanos activity is thus an important aspect of the switch from self‐renewal to differentiation. In this...
The T‐box transcription factor Tbx2 plays important roles in patterning and development, and has been implicated in cell‐cycle regulation and cancer. Conventional disruption of Tbx2 results in abnormalities of the heart, limbs, eye and other structures, and early fetal lethality. To gain insight into the role of Tbx2 in different tissues and at different stages of development, we have generated a...
Notch signaling is essential for embryonic vascular development in mammals and other vertebrates. Here we show that mouse embryos with conditional activation of the Notch1 gene in endothelial cells (Notch1 gain of function embryos) exhibit defects in vascular remodeling increased diameter of the dorsal aortae, and form arteriovenous malformations. Conversely, embryos with either constitutive or endothelial...
Transgenic mice are vital tools in both basic and applied research. Unfortunately, the transgenesis process as well as many other assisted reproductive techniques involving embryo transfer rely on vasectomized males to induce pseudopregnancy in surrogate mothers. Vasectomy is a surgical procedure associated with moderate pain and must be carried out under full anaesthesia by qualified personnel. Eliminating...
Proteolytical cleavage of the β‐amyloid precursor protein (APP) generates β‐amyloid, which is deposited in the brains of patients suffering from Alzheimer's disease (AD). Despite the well‐established key role of APP for AD pathogenesis, the physiological function of APP and its close homologues APLP1 and APLP2 remains poorly understood. Previously, we generated APP–/– mice that proved viable, whereas...
Brain‐derived neurotrophic factor (BDNF), a member of the neurotrophin family of neurotrophic factors, has important functions in the peripheral and central nervous system of vertebrates. We have generated bacterial artificial chromosome (BAC) transgenic mice harboring 207 kb of the rat BDNF (rBDNF) locus containing the gene, 13 kb of genomic sequences upstream of BDNF exon I, and 144 kb downstream...
Two main classes of proteins, Polycomb group (PcG) and Trithorax group (TrxG), play a key role in the regulation of homeotic genes. These proteins act in multimeric complexes to remodel chromatin. A third class of proteins named Enhancers of Trithorax and Polycomb (ETP) modulates the activity of TrxG and PcG, but their role remains largely unknown. We previously identified an HMGB‐like protein, DSP1...
Williams‐Beuren syndrome (WBS) is a neurodevelopmental disorder presenting with an elfin‐like face, supravalvular aortic stenosis, a specific cognitive‐behavioral profile, and infantile hypercalcemia. We encountered two WBS patients presenting with infantile spasms, which is extremely rare in WBS. Array comparative genomic hybridization (aCGH) and fluorescent in situ hybridization (FISH) analyses...
Cellular immortalization provides a way for expansion and subsequent molecular characterization of rare cell types. Ideally, immortalization can be achieved by the reversible expression of immortalizing proteins. Here, we describe the use of conditional immortalization based on a modified tetracycline‐regulated system for the expression of SV40 large T‐antigen in embryonic stem (ES) cells and mice...
Formation of polyploid organisms by fertilization of unreduced gametes in meiotic mutants is believed to be a common phenomenon in species evolution. However, not well understood is how species in nature generally exist as haploid and diploid organisms in a long evolutionary time while polyploidization must have repeatedly occurred via meiotic mutations. Here, we show that the ploidy increased for...
Transgenic mice are highly valuable tools for biological research as they allow cell type–specific expression of functionally instrumental genes. In this protocol, the generation of bacterial artificial chromosome (BAC) transgenic constructs is described. We give an overview of different transgenic inserts, such as fluorescent proteins (alone or in combination with Cre variants), diphtheria toxin...
Formation of polyploid organisms by fertilization of unreduced gametes in meiotic mutants is believed to be a common phenomenon in species evolution. However, not well understood is how species in nature generally exist as haploid and diploid organisms in a long evolutionary time while polyploidization must have repeatedly occurred via meiotic mutations. Here, we show that the ploidy increased for...
The four highly homologous members of the C‐terminal EH domain‐containing (EHD) protein family (EHD1‐4) regulate endocytic recycling. To delineate the role of EHD4 in normal physiology and development, mice with a conditional knockout of the Ehd4 gene were generated. PCR of genomic DNA and Western blotting of organ lysates from Ehd4−/− mice confirmed EHD4 deletion. Ehd4−/− mice were viable and born...
The c‐myb gene encodes two proteins, termed p75 and p89. Of these, the larger isoform is transcribed from an alternatively spliced message that contains an additional exon, exon 9A. Disruption of the c‐myb locus in mice results in embryonic lethality due to defective hematopoiesis and in the adult, tissue‐specific inactivation of c‐myb in hematopoietic tissues blocks differentiation along several...
To study the expression/function of Tbx10, a T‐box gene, Tbx10LacZ/+ mice were established by replacing the T‐box coding region with a LacZ gene. X‐gal staining showed that LacZ+ cells were localized to two‐cell populations in rhombomere 4 and rhombomere 6. No significant differences in the locations of LacZ+ cells were found between Tbx10LacZ/+ and Tbx10LacZ/LacZ mice, and the Tbx10LacZ/LacZ mice...