Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Myelin has pronounced effects upon the morphology, function, and growth of axons in the mammalian CNS. Consequently, oligodendrocyte development and myelination have been investigated using a wide variety of histological, immunocytochemical, ultrastructural, and biochemical techniques. While many of the spatial and temporal features of myelin appearance have been characterized, for any one species only limited regions of the CNS have been investigated. To address this limitation, we have derived transgenic mice in which the bacterial Lac Z gene is regulated by promoter elements of the myelin basic protein gene. When differentiating oligodendrocytes begin to elaborate recognizable myelin, they initiate expression of the MBP-Lac Z transgene and accumulate readily detectable levels of beta-galactosidase. Here, we exploit the sensitivity, resolution, and ease of beta-galactosidase histochemical assays to characterize the temporal and spatial patterns of CNS myelination in the mouse. Many features of the myelination program revealed by this approach were predicted by the immunocytochemical and ultrastructural data derived from other species. Nonetheless, previously undocumented patterns were also encountered. beta-Galactosidase was expressed first by oligodendrocytes in the ventral spinal cord, 1 d prior to birth. There, myelination proceeded in a strictly rostral-caudal direction, whereas in the dorsal cord, myelination initiated in the cervical enlargement and proceeded in both rostral and caudal directions. In the cerebellum, deep regions myelinated first, and in the optic nerve, myelination initiated at the retinal end. In contrast, the lateral olfactory tracts, pons, and optic chiasm initiated myelination along their entire course.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Myelin acquisition in the central nervous system of the mouse revealed by an MBP-Lac Z transgene. 128 97

We developed a sensitive two-site enzyme immunoassay (EIA) system for acidic fibroblast growth factor (aFGF), using a polyclonal antibody raised in rats. This assay is based on the sandwiching of the antigen between anti-aFGF antibody immunoglobulin G (IgG) coated on plates and biotinylated anti-aFGF antibody IgG; the detection of biotinylated IgG was performed by enzyme reaction of streptavidin-conjugated beta-D-galactosidase (beta-D-galactoside hydrolase; EC 3.2.1.23). Our system was specific for aFGF, because basic fibroblast growth factor, which shares a 55% homology of amino acid sequence with aFGF, hardly cross-reacted at all. The sensitivity of this system (0.2 ng/ml) enabled us to quantify endogenous immunoreactive aFGF in the CNS. Using this two-site EIA system, we examined the levels of aFGF in various regions of rat brain and their developmental changes. At the early stage of neonatal development, i.e., 2 days after birth, all brain regions registered low aFGF levels (less than 10 ng/g tissue). However, at the young adult stage (21- to 49-day-old animals), an extremely high level of aFGF (75-90 ng/g tissue) was found in the ponsmedulla; relatively high levels (30-40 ng/g tissue) were found in the diencephalon and mesencephalon; and comparatively low aFGF levels (5-15 ng/g tissue) were found in various other brain regions such as the frontal cortex, piriform cortex, hippocampus, olfactory bulb, cerebellum, and striatum. This marked change in the regional distribution of aFGF in the rat brain during postnatal development from 2 to 21 days after birth suggests that this factor plays a significant role in the brain during this period.
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PMID:Developmental changes in distribution of acidic fibroblast growth factor in rat brain evaluated by a sensitive two-site enzyme immunoassay. 170 23

Prostaglandin (PG) D2 bound specifically to a particulate fraction rich in the synaptic membrane of rat brain. The binding was dependent on time and temperature, equilibrium being reached after 5 min at 37 degrees C. The specific binding constituted about 70% of the total binding at 37 degrees C, and 55% at 0 degrees C. The maximal binding was obtained in the presence of 100 mM sodium ion and at pH 8. The equilibrium dissociation constant and the maximal concentration of binding sites as determined by Scatchard analysis were 28 +/- 7 nM and 0.45 pmol/mg of protein (n = 3), respectively. Hill coefficient was 1.15, indicating a single entity of binding sites and no cooperativity. The binding sites were highly specific for PGD2; the Ki values for PGD1 and PGF2 alpha were 523 and 693 nM, respectively. Other PGs including 13,14-dihydro-15-keto-PGD2, an inactive metabolite of PGD2, had 150- to 1000-fold lower affinities than PGD2. The binding was inhibited by boiling or treatment with proteases, phospholipases, or beta-galactosidase. The specific activity of PGD2 binding was highest in the pituitary gland, followed by the hypothalamus and the olfactory bulb od the rat brain, this pattern being almost parallel to that of the cytosolic NADP-linked PGD2 dehydrogenase activity. The results suggest that PGD2 plays a significant role in these regions of the rat brain.
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PMID:Specific binding of prostaglandin D2 to rat brain synaptic membrane. Occurrence, properties, and distribution. 629 97

Replication-deficient adenoviruses have been used successfully to transfer foreign DNA into postmitotic cells. This article demonstrates that it is possible to transfer the Escherichia coli lacZ gene in vivo into the central nervous system structures of rats after nasal instillation of replication-defective adenoviral vector AdRSV beta gal. Mitral cells from the olfactory bulb, neurons from the anterior olfactory nucleus, locus coeruleus and area postrema expressed beta-galactosidase for at least 12 days. No cytopathic effect was observed in the CNS structures studied at the viral titer used (1-3 x 10(9) plaque-forming units (p.f.u.)). This method could be useful for the gene therapy of diseases affecting different CNS structures.
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PMID:Gene delivery into the central nervous system by nasal instillation in rats. 758 17

Tissue plasminogen activator (t-PA) is a secreted serine protease implicated in multiple aspects of development. In the adult rat brain, transcription of t-PA is an immediate-early response in the hippocampus following treatments that induce neuronal plasticity. To study the sequence elements that govern transcription of this gene, in situ analysis was used to define t-PA's temporal and spatial expression pattern in midgestation embryos. Transgenic mice were then generated carrying t-PA 5' flanking sequences linked to the E. coli lacZ gene. Constructs containing 4 kb of the flanking sequences (4.0TAMGAL) confer beta-galactosidase activity mostly to the same tissues that exhibit high levels of t-PA mRNA by in situ analysis. In 4.0TAMGAL embryos from embryonic day 8.5 (E8.5) to 13.5 (E13.5), the majority of expression observed is localized to neural ectoderm-derived tissues. beta-galactosidase activity is first detected in restricted neuromeres in the midbrain and diencephalon, at E8.5 and E9.5 respectively. At E10.5, transgene expression is observed in neural crest-derived cranial nerves and dorsal root ganglia, but not placode-derived cranial nerves. From E10.5 to E13.5, beta-galactosidase activity is observed in postmitotic neurons of the midbrain, spinal cord, neural retina and the developing olfactory system. beta-galactosidase activity is also detected in areas undergoing tissue remodeling such as the pinna of the ear, whisker follicles and the limbs. In adult mice, lacZ is expressed in the hippocampus and this expression was found to be enhanced upon seizure in the giant pyramidal neurons of CA3. These results reinforce the concept that t-PA plays a role in neurogenesis and morphogenesis, and identifies the promoter region that directs its transcriptional regulation both in development and in the CNS.
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PMID:The mouse tissue plasminogen activator gene 5' flanking region directs appropriate expression in development and a seizure-enhanced response in the CNS. 772 May 60

Replication-incompetent retroviral vectors that encode the heritable marker enzyme, beta-galactosidase, were used to study the lineage relationships of cells in the olfactory epithelium of unmanipulated animals and in the olfactory epithelium as it reconstitutes after lesion. Virally-marked cells are categorized as to type based on their position in the epithelium and on expression of NCAM (limited to neurons) and the carbohydrate moiety recognized by Griffonia lectin (limited to the dark/horizontal basal cells and the microvillar class of supporting cells). Direct injections of the vectors into the olfactory epithelium of otherwise intact animals produce clusters of beta-galactosidase-labeled cells when assessed 6-10 days after infection; these clusters are composed of neurons and NCAM-negative/lectin-negative light/globose basal cells exclusively. In contrast, clusters of virally-marked cells after MeBr-induced lesion of the epithelium frequently contain both neurons and supporting cells, as well as both types of basal cells. Other clusters contain supporting cells and/or Bowman's gland/duct cells. It is likely that the clusters of marked cells are derived from a single founder cell, i.e. the cells are clonal and lineally related, since the clusters are widely dispersed. Furthermore, infusion of mixtures of viruses that can be distinguished on the basis of the type and subcellular localization of the marker enzyme that is expressed produce clusters that are homogenous with respect to enzyme type, providing strong evidence in favor of the notion that the clusters are clonal in nature. Thus, the founders of the clones that contain neurons, supporting cells and basal cells are pluripotent in their capacity for differentiation. It is unlikely that the pluripotent cells are found in Bowman's gland/duct, since we have yet to observe a clone that contains neurons and cells in Bowman's gland/duct. Hence, the pluripotent stem cells are to be found in the basal cell compartment of the epithelium. However, the exact nature of these stem cells remains unknown and a subject for future investigation.
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PMID:Retroviral lineage studies of the rat olfactory epithelium. 773 46

A spatially discrete region of the anterior part of the postnatal telencephalic subventricular zone, referred to as the SVZa generates vast numbers of lineally-related neurons destined for the olfactory bulb (Luskin, 1993). The cells originating in the SVZa migrate to the olfactory bulb along a highly restricted pathway which is in a direction orthogonal to the orientation of radial glial fibers. In this study we analysed the number, distribution, orientation and rate of migration of SVZa-derived cells as they approach the olfactory bulb. In order to track the SVZa-derived cells, a retroviral lineage tracer, encoding the reporter gene E. coli beta-galactosidase (lacZ) was injected precisely into the rat SVZa at postnatal day 1 (P1). The lacZ-positive cells were visualized 1, 2 and 3 days later by X-Gal histochemistry in cryostat sections. As the number of SVZa-derived cells in the pathway increased with survival time, their distribution changed systematically. The distribution pattern of lacZ-positive cells by 2 and 3 days postinjection suggested that some of the progeny of infected progenitor cells were undergoing neurogenesis as they proceeded to the olfactory bulb; a large percentage of the lacZ-positive cells were substantially displaced from the SVZa injection site. To investigate whether lacZ-positive cells migrate in a directed fashion, their orientation preference was scored. For the majority of lacZ-positive cells (> 94%), their leading process was directed toward the olfactory bulb, possibly reflecting a response to migratory cues present along the pathway. The estimated average rate of cell migration to the olfactory bulb was 23 mu m/h, which is approximately twice the speed of radially directed neuronal migration from the telencephalic ventricular zone to the cortical plate (O'Rourke et al., 1992). Collectively, these results suggest that SVZa-derived interneurons en route to the olfactory bulb may employ a novel mode of tangential migration.
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PMID:Rate and pattern of migration of lineally-related olfactory bulb interneurons generated postnatally in the subventricular zone of the rat. 773 48

The olfactory sensilla on the antenna of adult Drosophila melanogaster develop during the first 36 hr after pupariation, from their anlagen in the cephalic disc. We have used tissue-specific beta-galactosidase expression in the enhancer trap strain A101.IF3 and the monoclonal antibody 22C10 as sensory cell markers, as well as the lineage tracer 5-bromo-2'-deoxyuridine (BrdU), to describe this process. The development of an olfactory sensillum begins with the selection of a "founder cell" (FC). These cells are distinct in that they possess large apically located nuclei revealed by beta-galactosidase expression in A101.IF3. In the following 6 hr, a few cells neighboring the FC also start expressing beta-galactosidase and together comprise a group. Cells of this group, denoted a "presensillum-cluster" (PSC), undergo at least one round of replication and give rise to all of the cells of a sensillum. A subset of the cells within each PSC and, later, all the sensory neurons are recognized by MAb22C10. The antennae of the mutant lozenge3 (lz3) lack all basiconic and some trichoid sensilla. The mutation apparently affects early steps in sensillum development and many of the FCs fail to form. Those that are present, however, proceed to form mature olfactory sensilla. Therefore, we conclude that the selection of an FC is the first step in olfactory sense organ development. Our study reveals novel aspects of sensory development in Drosophila.
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PMID:Cellular events during development of the olfactory sense organs in Drosophila melanogaster. 787 69

MT-III, a brain-specific member of the metallothionein gene family, binds zinc and may facilitate the storage of zinc in neurons. The distribution of MT-III mRNA within the adult brain was determined by solution and in situ hybridization and compared to that of MT-I mRNA. MT-III mRNA is particularly abundant within the cerebral cortex, hippocampus, amygdala, and nuclei at base of the cerebellum. Transgenic mice generated using 11.5 kb of the mouse MT-III 5' flanking region fused to the E. coli lacZ gene express beta-galactosidase in many of the same regions identified by in situ hybridization. MT-III mRNA was present in readily identifiable neurons within the olfactory bulb, hippocampus, and cerebellum, and beta-galactosidase activity was localized to neurons throughout the brain, but not to glia, as determined by costaining with X-Gal and neural- and glia-specific antibodies. There is marked correspondence between the neurons that are rich in MT-III mRNA and those neurons that store zinc in their terminal vesicles. MT-III is found complexed with zinc in vivo and its expression in cultured cells leads to the intracellular accumulation of zinc and enhanced histochemical detection of zinc. These results are discussed in light of the possibility that MT-III may participate in the utilization of zinc as a neuromodulator.
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PMID:Metallothionein III is expressed in neurons that sequester zinc in synaptic vesicles. 793 47

The propagation of pseudorabies virus (PrV) in the mouse nervous system was studied after intranasal inoculation of a PrV mutant expressing beta-galactosidase after insertion of the Escherichia coli Lac-Z gene into the gene encoding the nonstructural, nonessential glycoprotein gG. This allowed rapid detection of infected cells by a single step reaction with the substrate X-gal. The gG-beta-gal+ mutant behaved like the wild-type Kaplan strain of origin. The incubation period was very short and the animals did not survive more than 52 hr after inoculation. In the nasal cavity, the virus infected almost exclusively the respiratory epithelium. The virus propagated to the nervous system via three neuronal pathways: (i) the trigeminal route, with primary infection in the trigeminal ganglion followed by anterograde transneuronal transfer to the spinal trigeminal nucleus; (ii) the sympathetic route, with a first cycle of replication in the superior cervical ganglion and retrograde transneuronal transfer to sympathetic preganglionic neurons in the intermediolateral nucleus in the spinal cord; and (iii) the parasympathetic route, with primary infection in the pterygopalatine ganglion, followed by retrograde transneuronal transfer and replication in the superior salivatory nucleus. In contrast, the olfactory system was rarely found infected, probably because of the short survival of the animals.
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PMID:Propagation of pseudorabies virus in the nervous system of the mouse after intranasal inoculation. 794 29


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