Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.27.1 (RNase)
 16,360 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Na+/Cl(-)-dependent glycine transporters are crucial for the termination of neurotransmission at glycinergic synapses. Two different glycine transporter genes, GlyT1 and GlyT2, have been described. Several isoforms differing in their 5' ends originate from the GlyT1 gene. We have determined the genomic structure of the murine GlyT1 gene to elucidate the genetic basis underlying the different isoforms. Analysis of cDNA 5'-ends revealed that the GlyT1a and 1b/1c mRNAs are transcribed from two different promoters. During murine embryonic development GlyT1 mRNAs were detectable by RNase protection assays as early as embryonic day E9 and reached maximal levels between E13 and E15. In situ hybridization revealed GlyT1 expression in the developing spinal cord mainly in the ventral part of the ventricular zone at E12. At later stages (E15) transcripts were also found in the lateral half of the basal and intermediate gray matter. In contrast, the second glycine transporter gene GlyT2 displayed a completely different expression pattern. At E11 it is expressed in the mantle zone, and at later stages throughout the ventral horns. In the adult rat brain and spinal cord, GlyT1 hybridization signals were found exclusively in glial cells. Our data indicate that GlyT1 is an early marker of neural development and encodes glia-specific transporter proteins.
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PMID:Gene structure and glial expression of the glycine transporter GlyT1 in embryonic and adult rodents. 789 Nov 86

We determined during photoreceptor development if there is a retina-specific hypomethylation of the mouse gene encoding interphotoreceptor retinoid-binding protein (IRBP) that is associated with its activation. Second, the role of IRBP gene and protein expression in development was assessed by determining if their expression occurs before that of opsin. Retina-specific hypomethylation of the IRBP promoter region started on Embryonic (E) Day 11, at the time of cone formation, increased from E12 to E14, at the time of rod formation, and reached a peak on Postnatal (P) Day 4, which was followed thereafter by a slow decrease. Starting on E11, IRBP and opsin mRNA levels were quantitated relative to that of the beta-actin gene with RNase protection analysis. beta-Actin and IRBP transcripts were readily detected on E11. beta-actin levels remained constant during embryonic and early postnatal stages and decreased slightly afterward. On the other hand, beginning on E13, when the rods are formed, the IRBP level markedly increased. In contrast, the opsin transcript first appeared later on P0 and then increased from P3 onward. After P6, the opsin and IRBP transcript levels became comparable and by P20 their levels reached constancy. The timing of the onset of protein expression for the IRBP and opsin genes was determined during the last proliferative cycle of the rod precursor cells before their differentiation. Mice at P2 or P3 were injected with bromodeoxyuridine (BrdU) and their retinal cells were dissociated and then double-labeled with antibodies against BrdU and either IRBP or opsin. Cells positive for both IRBP and BrdU were always observed as soon as 2 hr after injection but it took at least 40 hr before they became positive for both opsin and BrdU. Taken together, these results indicate that IRBP gene activation is associated with hypomethylation during the last mitosis before photoreceptor cell differentiation.
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PMID:Timing of interphotoreceptor retinoid-binding protein (IRBP) gene expression and hypomethylation in developing mouse retina. 831 88

We have examined the expression of the vav protooncogene during mouse embryogenesis using RNase protection assays, in situ hybridization, and immunocytochemical analysis. vav gene transcripts were first detected in E11.5 embryos in the blood-forming islands and megakaryocytes of the fetal liver. During diversification of hematopoietic activity in the embryo, vav gene expression became down-regulated in the liver and activated in thymus and spleen. In newborn animals, vav expression was also confined to hematopoietic tissues, with the exception of the ameloblastic cell layer at the latest stages of tooth morphogenesis. In the adult, vav transcripts were found in spleen, thymus, lymph nodes, and bone marrow, but not in liver. In spleen, vav transcripts were concentrated in the white pulp areas, whereas in the red pulp, the vav transcripts appeared to be primarily localized in the megakaryocytes. In thymus, vav expression was found to be more abundant in the cortical areas than in the medulla. In agreement with these observations, purified thymic lymphocytes showed heterogeneous immunoreactivity against the Vav protein, whereas splenic lymphocytes and bone marrow-derived cells displayed rather uniform levels of expression. These observations suggest that the vav protooncogene plays an important role in the signal transduction pathways that regulate the development and maintenance of the hematopoietic system.
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PMID:Developmental expression of the vav protooncogene. 849 92

Transgenic mice containing the human angiotensinogen (HAGT) gene were utilized to determine the developmental regulation of HAGT expression. RNase protection assay on total RNA obtained from whole transgenic fetuses revealed that HAGT expression was first detected at embryonic day 8.5 (E8.5) and was abundant from E9.5 onward. The earliest expression of the HAGT transgene appeared to precede the earliest expression of the endogenous mouse AGT gene by 1-2 days. Northern blot analysis revealed moderate levels of HAGT mRNA in liver and kidney and low levels of HAGT mRNA in heart and brain from E16.5 (day 16.5 of gestation) onward. HAGT mRNA in liver, although abundant during late gestation and in 2-wk-old and adult mice, decreased transiently around birth. In situ hybridization performed on sections from whole fetuses revealed that HAGT mRNA was restricted to the developing liver and heart between E9.5 and E11.5 but became more widespread to include the developing aorta, brain, subcutaneous tissues, and vertebra at E13.5. In situ hybridization analysis on fetal kidneys from late gestation, newborn, and 2-wk-old mice demonstrated a progressive restriction of HAGT mRNA to developing cortical proximal tubular cells. These data illustrate the developmental tissue-specific regulation of HAGT expression and demonstrate that sequences present in the transgene can confer an appropriate developmental expression profile.
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PMID:Developmental expression of human angiotensinogen in transgenic mice. 961 31

Recent genetic analysis of the Drosophila dachshund (dac) gene has established that dac encodes a novel nuclear protein that is involved in both eye and leg development. In the Drosophila eye, dac expression appears to be controlled by the product of the eyeless/Pax6 gene. In order to analyze the Pax6 pathway in vertebrates we have isolated and characterized the cDNA and genomic clones corresponding to the human and mouse homologues of Drosophila dac. A full-length human cDNA encoding dachshund (DACH) encodes the 706 amino acids protein with predicted molecular weight of 73 kDa. A 109 amino acid domain located at the N-terminus of the DACH showed significant sequence and secondary structure homologies to the ski/sno oncogene products. Northern blot analysis found human DACH predominantly in adult kidney, heart, and placenta, with less expression detected in the brain, lung, skeletal muscle and pancreas. A panel of human cell lines was studied and most notably a large proportion of neuroblastomas expressed DACH mRNA. Mouse Dach encodes a protein of 751 amino acids with predicted molecular weight of 78 kDa that is 95% identical to the human DACH. RNase protection analysis showed the highest Dach mRNA expression in the adult mouse kidney and lung, whereas lower expression was detected in the brain and testis. RT/PCR analysis readily detected Dach mRNA in the adult mouse cornea and retina. Dach mRNA expression in the mouse E11.5 embryo was observed primarily in the fore and hind limbs, as well as in the somites.
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PMID:Molecular cloning and expression of the human and mouse homologues of the Drosophila dachshund gene. 1050 10

The liver is an essential organ that produces several serum proteins, stores vital nutrients, and detoxifies many carcinogenic and xenobiotic compounds. Various growth factors positively regulate liver growth, but only a few negative regulators are known. Among the latter are the transforming growth factor beta (TGF-beta) superfamily members TGF-beta1 and activin A. To study the function of novel activin family members, we have cloned and generated mice deficient in the activin betaC and betaE genes. Expression analyses demonstrated that these novel genes are liver specific in adult mice. Here, we show by RNase protection that activin betaC transcripts are present in the liver beginning at embryonic day 11.5 (E11.5) whereas activin betaE expression is detected starting from E17.5. Gene targeting in embryonic stem cells was used to generate mice with null mutations in either the individual activin betaC and betaE genes or both genes. In contrast to the structurally related activin betaA and betaB subunits, which are necessary for embryonic development and pituitary follicle-stimulating hormone homeostasis, mice deficient in activin betaC and betaE were viable, survived to adulthood, and demonstrated no reproductive abnormalities. Although activin betaC and betaE mRNAs are abundantly expressed in the liver of wild-type mice, the single and double mutants did not show any defects in liver development and function. Furthermore, in the homozygous mutant mice, liver regeneration after >70% partial hepatectomy was comparable to that in wild-type mice. Our results suggest that activin betaC and betaE are not essential for either embryonic development or liver function.
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PMID:Activin betaC and betaE genes are not essential for mouse liver growth, differentiation, and regeneration. 1091 94

gamma-Aminobutyric acid type B receptors (GABA(B)Rs) mediate both slow inhibitory synaptic activity in the adult nervous system and motility signals for migrating embryonic cortical cells. Previous papers have described the expression of GABA(B)Rs in the adult brain, but the expression and functional significance of these gene products in the embryo are largely unknown. Here we examine GABA(B)R expression from rat embryonic day 10 (E10) to E18 compared with adult and ask whether embryonic cortical neurons contain functional GABA(B)R. GABA(B)R1 transcript levels greatly exceed GABA(B)R2 levels in the developing neural tube at E11, and olfactory bulb and striatum at E17 but equalize in most regions of adult nervous tissue, except for the glomerular and granule cell layers of the main olfactory bulb and the striatum. Consistent with expression differences, the binding affinity of GABA for GABA(B)Rs is significantly lower in adult striatum compared with cerebellum. Multiple lines of evidence from in situ hybridization, RNase protection, and real-time PCR demonstrate that GABA(B)R1a, GABA(B)R1b, GABA(B)R1h (a subunit subtype, lacking a sushi domain, that we have identified in embryonic rat brain), GABA(B)R2, and GABA(B)L transcript levels are not coordinately regulated. Despite the functional requirement for a heterodimer of GABA(B)R subunits, the expression of each subunit mRNA is under independent control during embryonic development, and, by E18, GABA(B)Rs are negatively coupled to adenylyl cyclase in neocortical neurons. The presence of embryonic GABA(B)R transcripts and protein and functional receptor coupling indicates potentially important roles for GABA(B)Rs in modulation of synaptic transmission in the developing embryonic nervous system.
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PMID:Differential expression of gamma-aminobutyric acid type B receptor subunit mRNAs in the developing nervous system and receptor coupling to adenylyl cyclase in embryonic neurons. 1506 15

Whole mount in situ hybridization is a very informative approach for defining gene expression patterns in embryos. The in situ hybridization procedures are lengthy and technically demanding with multiple important steps that collectively contribute to the quality of the final result. This protocol describes in detail several key quality control steps for optimizing probe labeling and performance. Overall, our protocol provides a detailed description of the critical steps necessary to reproducibly obtain high quality results. First, we describe the generation of digoxygenin (DIG) labeled RNA probes via in vitro transcription of DNA templates generated by PCR. We describe three critical quality control assays to determine the amount, integrity and specific activity of the DIG-labeled probes. These steps are important for generating a probe of sufficient sensitivity to detect endogenous mRNAs in a whole mouse embryo. In addition, we describe methods for the fixation and storage of E8.5-E11.5 day old mouse embryos for in situ hybridization. Then, we describe detailed methods for limited proteinase K digestion of the rehydrated embryos followed by the details of the hybridization conditions, post-hybridization washes and RNase treatment to remove non-specific probe hybridization. An AP-conjugated antibody is used to visualize the labeled probe and reveal the expression pattern of the endogenous transcript. Representative results are shown from successful experiments and typical suboptimal experiments.
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PMID:Whole mount in situ hybridization of E8.5 to E11.5 mouse embryos. 2200 71