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Tissue-specific Expression Patterns (tissue-specific + expression_pattern)
Selected AbstractsAndrogen receptor gene expression in the developing and adult zebrafish brainDEVELOPMENTAL DYNAMICS, Issue 10 2008Daniel A. Gorelick Abstract Androgens play a central role in the regulation of male sexual differentiation and behavior in many vertebrates, including zebrafish. Their signaling is mediated by activation of the androgen receptor. A single androgen receptor (ar) gene was recently identified in zebrafish, which encodes a protein that binds androgens in vitro. However, the tissue-specific expression pattern of this receptor in vivo has not been described. Using whole-mount RNA in situ hybridization, we characterized expression of the ar gene in developing zebrafish and in the adult brain. In embryos, transcripts were found in the presumptive pronephros and in olfactory placodes. By 3,5 days postfertilization, ar transcripts were also detected in the pineal organ anlage and the retina. In the adult brain, ar was expressed in discrete regions of the telencephalon, in the preoptic area, and throughout the periventricular hypothalamus, regions previously implicated in the regulation of sexually dimorphic behaviors in mammals. Developmental Dynamics 237:2987,2995, 2008. © 2008 Wiley-Liss, Inc. [source] Dlk1 expression marks developing endothelium and sites of branching morphogenesis in the mouse embryo and placentaDEVELOPMENTAL DYNAMICS, Issue 4 2006Aleksey Yevtodiyenko Abstract The protein product of the Delta-like 1 (Dlk1) gene belongs to the Delta-Notch family of signaling molecules, proteins involved in cell fate determination in many tissues during development. The DLK1 protein is believed to function as a growth factor, maintaining the proliferative state of undifferentiated cells, and is usually down-regulated as immature cells differentiate. The expression pattern of the DLK1 protein has been described in certain human tissues; however, Dlk1 expression is not well understood in the mouse, the most tractable mammalian genetic model system. To better understand the role of Dlk1 in embryonic development, the tissue-specific expression pattern of Dlk1 mRNA during mouse embryogenesis was analyzed by in situ hybridization. In embryonic day 12.5 (e12.5) embryos, high levels of Dlk1 were found in the developing pituitary, pancreas, lung, adrenal, and many mesodermally derived tissues. Strikingly, Dlk1 expression also marks the growing branches of organs that develop through the process of branching morphogenesis. At e16.5, Dlk1 expression is down-regulated in most tissues but remains in the pituitary, the adrenal gland, and in skeletal muscle. In the placenta, expression of Dlk1 is detected in endothelial cells lining the fetal blood vessels of the labyrinth. This pattern is distinct from that seen in the human placenta and suggests a role for Dlk1 in regulating maternal,fetal interactions. Developmental Dynamics 235:1115,1123, 2006. © 2006 Wiley-Liss, Inc. [source] The protein family of glucose transport facilitators: It's not only about glucose after allIUBMB LIFE, Issue 5 2010Robert Augustin Abstract The protein family of facilitative glucose transporters comprises 14 isoforms that share common structural features such as 12 transmembrane domains, N- and C-termini facing the cytoplasm of the cell, and a N-glycosylation side either within the first or fifth extracellular loop. Based on their sequence homology, three classes can be distinguished: class I includes GLUT1-4 and GLUT14, class II the "odd transporters" GLUT5, 7, 9, 11, and class III the "even transporters" GLUT6, 8, 10, 12 and the proton driven myoinositol transporter HMIT (or GLUT13). With the cloning and characterization of the more recent class II and III isoforms, it became apparent that despite their structural similarities, the different isoforms not only show a distinct tissue-specific expression pattern but also show distinct characteristics such as alternative splicing, specific (sub)cellular localization, and affinities for a spectrum of substrates. This review summarizes the current understanding of the physiological role for the various transport facilitators based on human genetically inherited disorders or single-nucleotide polymorphisms and knockout mice models. The emphasis of the review will be on the potential functional role of the more recent isoforms. © 2010 IUBMB IUBMB Life, 62(5): 315,333, 2010 [source] Differential Expression Patterns of Runx2 Isoforms in Cranial Suture MorphogenesisJOURNAL OF BONE AND MINERAL RESEARCH, Issue 5 2001Mi-Hyun Park Abstract Runx2 (previously known as Cbfa1/Pebp2,A/AML3), a key transcription factor in osteoblast differentiation, has at least two different isoforms using alternative promoters, which suggests that the isoforms might be expressed differentially. Haploinsufficiency of the Runx2 gene is associated with cleidocranial dysplasia (CCD), the main phenotype of which is inadequate development of calvaria. In spite of the biological relevance, Runx2 gene expression patterns in developing calvaria has not been explored previously, and toward this aim we developed three probes: pRunx2, which comprises the common coding sequence of Runx2 and hybridizes with all isoforms; pPebp2,A, which specifically hybridizes with the isoform transcribed with the proximal promoter; and pOsf2, which hybridizes with the isoform transcribed with the distal promoter. These probes were hybridized with tissue sections of mouse calvaria taken at various time points in development. Runx2 expression was localized to the critical area of cranial suture closure, being found in parietal bones, osteogenic fronts, and sutural mesenchyme. Pebp2,A and Osf2 showed tissue-specific expression patterns. The sites of Pebp2,A expression were almost identical to that of pRunx2 hybridization but expression was most intense in the sutural mesenchyme, where undifferentiated mesenchymal cells reside. The Osf2 isoform was strongly expressed in the osteogenic fronts, as well as in developing parietal bones, where osteopontin (OP) and osteocalcin (OC) also were expressed. However, in contrast to Pebp2,A, Osf2 expression did not occur in sutural mesenchyme. Pebp2,A also was expressed prominently in primordial cartilage that is found under the sutural mesenchyme and is not destined to be mineralized. Thus, Osf2 isoforms contribute to events later in osteoblast differentiation whereas the Pebp2,A isoform participates in a wide variety of cellular activities ranging from early stages of osteoblast differentiation to the final differentiation of osteoblasts. [source] A rice promoter containing both novel positive and negative cis -elements for regulation of green tissue-specific gene expression in transgenic plantsPLANT BIOTECHNOLOGY JOURNAL, Issue 5 2007Meng Cai Summary The tissue-specific expression of transgenes is essential in plant breeding programmes to avoid the fitness costs caused by constitutive expression of a target gene. However, knowledge on the molecular mechanisms of tissue-specific gene expression and practicable tissue-specific promoters is limited. In this study, we identified the cis -acting elements of a tissue-specific promoter from rice, PD54O, and tested the application of original and modified PD54O and its cis -elements in the regulation of gene expression. PD54O is a green tissue-specific promoter. Five novel tissue-specific cis -elements (LPSE1, LPSE2, LPSRE1, LPSRE2, PSE1) were characterized from PD54O. LPSE1 activated gene expression in leaf and young panicle. LPSRE2 suppressed gene expression in leaf, root, young panicle and stem, and PSE1 suppressed gene expression in young panicle and stem. LPSRE1 and LPSE2 had dual roles in the regulation of tissue-specific gene expression; both functioned as activators in leaf, but LPSRE1 acted as a repressor in stem and LPSE2 as a repressor in young panicle and root. Transgenic rice plants carrying cry1Ac encoding Bacillus thuringiensis endotoxin, regulated by PD54O, were resistant to leaf-folders, with no Cry1Ac protein found in endosperm or embryo. A reporter gene regulated by a series of truncated PD54O showed various tissue-specific expression patterns. Different fragments of PD54O fused with the constitutive cauliflower mosaic virus 35S promoter suppressed 35S -regulated gene expression in various tissues. PD54O, truncated PD54O and the tissue-specific cis -elements provide useful tools for the regulation of tissue-specific gene expression in rice breeding programmes. [source] Wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) multiple inositol polyphosphate phosphatases (MINPPs) are phytases expressed during grain filling and germination,PLANT BIOTECHNOLOGY JOURNAL, Issue 2 2007Giuseppe Dionisio Summary At present, little is known about the phytases of plant seeds in spite of the fact that this group of enzymes is the primary determinant for the utilization of the major phosphate storage compound in seeds, phytic acid. We report the cloning and characterization of complementary DNAs (cDNAs) encoding one of the groups of enzymes with phytase activity, the multiple inositol phosphate phosphatases (MINPPs). Four wheat cDNAs (TaPhyIIa1, TaPhyIIa2, TaPhyIIb and TaPhyIIc) and three barley cDNAs (HvPhyIIa1, HvPhyIIa2 and HvPhyIIb) were isolated. The open reading frames ranged from 1548 to 1554 bp and the level of homology between the barley and wheat proteins ranged from 90.5% to 91.9%. All cDNAs contained an N-terminal signal peptide encoding sequence, and a KDEL-like sequence, KTEL, was present at the C-terminal, indicating that the enzyme was targeted to and retained within the endoplasmic reticulum. Expression of TaPhyIIa2 and HvPhyIIb in Escherichia coli revealed that the MINPPs possessed a significant phytase activity with narrow substrate specificity for phytate. The pH and temperature optima for both enzymes were pH 4.5 and 65 °C, respectively, and the Km values for phytate were 246 and 334 µm for the wheat and barley recombinant enzymes, respectively. The enzymes were inhibited by several metal ions, in particular copper and zinc. The cDNAs showed significantly different temporal and tissue-specific expression patterns during seed development and germination. With the exception of TaPhyIIb, the cDNAs were present during late seed development and germination. We conclude that MINPPs constitute a significant part of the endogenous phytase potential of the developing and germinating barley and wheat seeds. [source] G, encoding gene family of the malaria vector mosquito Anopheles gambiae: Expression analysis and immunolocalization of AG,q and AG,o in female antennaeTHE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 4 2006Michael Rützler Abstract To initiate a comprehensive investigation of chemosensory signal transduction downstream of odorant receptors, we identified and characterized the complete set of genes that encode G-protein , subunits in the genome of the malaria vector mosquito An. gambiae. Data are provided on the tissue-specific expression patterns of 10 corresponding aga -transcripts in adult mosquitoes and pre-imago developmental stages. Specific immunoreactivity in chemosensory hairs of female antennae provides evidence in support of the participation of a subset of AG,q isoforms in olfactory signal transduction in this mosquito. In contrast, AG,o is localized along the flagellar axon bundle but is absent from chemosensory sensilla, which suggests that this G-protein , subunit does not participate in olfactory signal transduction. J. Comp. Neurol. 499:533,545, 2006. © 2006 Wiley-Liss, Inc. [source] MicroRNA-140 is expressed in differentiated human articular chondrocytes and modulates interleukin-1 responsesARTHRITIS & RHEUMATISM, Issue 9 2009Shigeru Miyaki Objective MicroRNA (miRNA) are a class of noncoding small RNAs that act as negative regulators of gene expression. MiRNA exhibit tissue-specific expression patterns, and changes in their expression may contribute to pathogenesis. The objectives of this study were to identify miRNA expressed in articular chondrocytes, to determine changes in osteoarthritic (OA) cartilage, and to address the function of miRNA-140 (miR-140). Methods To identify miRNA specifically expressed in chondrocytes, we performed gene expression profiling using miRNA microarrays and quantitative polymerase chain reaction with human articular chondrocytes compared with human mesenchymal stem cells (MSCs). The expression pattern of miR-140 was monitored during chondrogenic differentiation of human MSCs in pellet cultures and in human articular cartilage from normal and OA knee joints. We tested the effects of interleukin-1, (IL-1,) on miR-140 expression. Double-stranded miR-140 (ds,miR-140) was transfected into chondrocytes to analyze changes in the expression of genes associated with OA. Results Microarray analysis showed that miR-140 had the largest difference in expression between chondrocytes and MSCs. During chondrogenesis, miR-140 expression in MSC cultures increased in parallel with the expression of SOX9 and COL2A1. Normal human articular cartilage expressed miR-140, and this expression was significantly reduced in OA tissue. In vitro treatment of chondrocytes with IL-1, suppressed miR-140 expression. Transfection of chondrocytes with ds,miR-140 down-regulated IL-1,,induced ADAMTS5 expression and rescued the IL-1,,dependent repression of AGGRECAN gene expression. Conclusion This study shows that miR-140 has a chondrocyte differentiation,related expression pattern. The reduction in miR-140 expression in OA cartilage and in response to IL-1, may contribute to the abnormal gene expression pattern characteristic of OA. [source] | |||||||||||||