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Temporal Expression (temporal + expression)
Terms modified by Temporal Expression Selected AbstractsTemporal expression of growth factors and matrix molecules in healing tendon lesionsJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 1 2005Linda A. Dahlgren Abstract Overuse tendon injuries are common among elite and recreational athletes. Tendon healing may be enhanced at the cellular level through the use of exogenous growth factors; however, little is known about the endogenous expression of growth factors in healing tendon. This study describes the temporal expression of insulin-like growth factor-I (IGF-I), transforming growth factor-,1 (TGF-,1), and collagen types I and III in healing tendon lesions. Collagenase-induced lesions were created in the tensile region of the flexor digitorum superficialis tendon of both forelimbs of 14 horses. Tendons were harvested from euthanatized horses 1, 2, 4, 8 or 24 weeks following injury. Gene expression was evaluated using Northern blot analysis (collagen types I and III), real time PCR (IGF-I and TGF-,1), and in situ hybridization. Protein content was assayed by dye-binding assay (collagen types I and III), radioimmunoassay (IGF-I), ELISA (TGF-,1), and immunohistochemistry. Samples were also processed for differential collagen typing. DNA and glycosaminoglycan content, and routine H&E staining. Microscopically, lesions progressed from an amorphous, acellular lesion soon after injury to scar tissue filled with collagen fibers and mature fibroblasts organized along lines of tension. Early lesions were characterized by immediate increases in expression of growth factors and collagen. Message levels for TGF-,1 peaked early in the wound healing process (1 week), while IGF-I peaked later (4 weeks), as the regenerative phase of healing was progressing. In the first 2 weeks after lesion induction, tissue levels of IGF-I protein actually decreased approximately 40% compared to normal tendon. By 4 weeks, these levels had exceeded those of normal tendon and remained elevated through 8 weeks. Message expression for collagen types I and III increased by 1 week following injury and remained elevated throughout the course of the study. Collagen type I represented the major type of collagen in healing tendon at all time points of the study. Based on these results, IGF-I, administered exogenously during the first 2 weeks following injury, may provide a therapeutic advantage by bolstering low endogenous tissue levels and enhancing the metabolic response of individual tendon fibroblasts. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. [source] Induction of alpha-caveolin-1 (,CAV1) expression in bovine granulosa cells in response to an ovulatory dose of human chorionic gonadotropinMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 11 2006Mame Nahé Diouf Abstract Caveolins are implicated in endocytosis, cholesterol trafficking and signal transduction. A cDNA fragment corresponding to caveolin-1 (CAV1) was identified in a mRNA profiling expression study in bovine granulosa cells (GC) following human chorionic gonadotropin (hCG)-induced ovulation. Thus, we have characterized CAV1 cDNA and studied its spatio-temporal expression pattern in bovine ovarian follicles. The full-length bovine ,CAV1 cDNA was cloned and encodes a putative 22 kDa protein. Expression of ,CAV1 was studied in bovine GC obtained from follicles at different developmental stages: small follicles (SF: 2,4 mm), dominant follicles (DF), ovulatory follicles (OF: 24 hr post-hCG), and corpus luteum (CL). Semiquantitative RT-PCR analysis showed a 6.5-fold increase in ,CAV1 mRNA in GC of OF versus DF (P,<,0.0001), whereas CAV2 mRNA was increased by only twofold (P,<,0.0007). Temporal expression of ,CAV1 mRNA from OF recovered at 0, 6, 12, 18, and 24 hr after hCG injection showed an 8.5-fold increase of ,CAV1 mRNA after 24 hr compared to 0 hr (P,<,0.0018) whereas no significant variation was detected for CAV2. Immunoblot demonstrated an initial increase in ,CAV1 protein level 12 hr post-hCG, reaching a maximum at 24 hr. Immunohistochemical localization of CAV1 was observed in GC of OF isolated 18 and 24 hr after hCG injection, whereas no signal was detected in GC of DF and SF. The induction of ,CAV1 in GC of OF suggests that ,CAV1 likely contributes to control the increase in membrane signaling that occurs at the time of ovulation and luteinization. Mol. Reprod. Dev. 73: 1353,1360, 2006. © 2006 Wiley-Liss, Inc. [source] Cell type,specific expression of adenomatous polyposis coli in lung development, injury, and repairDEVELOPMENTAL DYNAMICS, Issue 8 2010Aimin Li Abstract Adenomatous polyposis coli (Apc) is critical for Wnt signaling and cell migration. The current study examined Apc expression during lung development, injury, and repair. Apc was first detectable in smooth muscle layers in early lung morphogenesis, and was highly expressed in ciliated and neuroendocrine cells in the advanced stages. No Apc immunoreactivity was detected in Clara or basal cells, which function as stem/progenitor cell in adult lung. In ciliated cells, Apc is associated mainly with apical cytoplasmic domain. In response to naphthalene-induced injury, Apcpositive cells underwent squamous metaplasia, accompanied by changes in Apc subcellular distribution. In conclusion, both spatial and temporal expression of Apc is dynamically regulated during lung development and injury repair. Differential expression of Apc in progenitor vs. nonprogenitor cells suggests a functional role in cell-type specification. Subcellular localization changes of Apc in response to naphthalene injury suggest a role in cell shape and cell migration. Developmental Dynamics 239:2288,2297, 2010. © 2010 Wiley-Liss, Inc. [source] Protein phosphatase 1, is required for murine lung growth and morphogenesisDEVELOPMENTAL DYNAMICS, Issue 4 2004Kadija-Kathy Hormi-Carver Abstract Protein phosphatase 1 (PP1) plays important roles in cell cycle control and apoptosis, two processes that impinge on morphogenesis and differentiation. Following the precedent set by other molecules regulating the cell cycle and apoptosis, we hypothesized that PP1 may have context-specific roles in development. Therefore, we have studied the spatial and temporal expression of PP1, during murine lung development and determined the consequences of loss of PP1, function on branching morphogenesis. By using an immunohistochemical approach, we show here that PP1, was expressed throughout the epithelium and mesenchyme upon the emergence of the lung primordium on embryonic day 10, with immunostaining exclusively extranuclear. During the late pseudoglandular stage, PP1, was predominantly expressed in the distal lung epithelium, whereas the mesenchyme contained very little or no PP1, protein. Peri- and postnatally, PP1, immunostaining was mostly nuclear in apparently differentiated cells, as judged by colocalization with well-known markers for lung differentiation. Exposure of fetal lung explants to antisense oligodeoxynucleotides against PP1,, resulted in decreased overall size of the cultured lung, a defect in forming new airways, lack of expression of surfactant protein C, and histologic signs of poor differentiation. These data suggest that PP1, is required for branching morphogenesis and differentiation. Developmental Dynamics 229:791,801, 2004. © 2004 Wiley-Liss, Inc. [source] Zebrafish E-cadherin: Expression during early embryogenesis and regulation during brain developmentDEVELOPMENTAL DYNAMICS, Issue 2 2001Sherry G. Babb Abstract Zebrafish E-cadherin (cdh1) cell adhesion molecule cDNAs were cloned. We investigated spatial and temporal expression of cdh1 during early embryogenesis. Expression was observed in blastomeres, the anterior mesoderm during gastrulation, and developing epithelial structures. In the developing nervous system, cdh1 was detected at the pharyngula stage (24 hpf) in the midbrain-hindbrain boundary (MHB). Developmental regulation of MHB formation involves wnt1 and pax2.1. wnt1 expression preceded cdh1 expression during MHB formation, and cdh1 expression in the MHB was dependent on normal development of this structure. © 2001 Wiley-Liss, Inc. [source] Identification of alternative promoter usage for the matrix Gla protein geneFEBS JOURNAL, Issue 6 2005Evidence for differential expression during early development in Xenopus laevis Recent cloning of the Xenopus laevis (Xl) matrix Gla protein (MGP) gene indicated the presence of a conserved overall structure for this gene between mammals and amphibians but identified an additional 5,-exon, not detected in mammals, flanked by a functional, calcium-sensitive promoter, 3042 bp distant from the ATG initiation codon. DNA sequence analysis identified a second TATA-like DNA motif located at the 3, end of intron 1 and adjacent to the ATG-containing second exon. This putative proximal promoter was found to direct transcription of the luciferase reporter gene in the X. laevis A6 cell line, a result confirmed by subsequent deletion mutant analysis. RT-PCR analysis of XlMGP gene expression during early development identified a different temporal expression of the two transcripts, strongly suggesting differential promoter activation under the control of either maternally inherited or developmentally induced regulatory factors. Our results provide further evidence of the usefulness of nonmammalian model systems to elucidate the complex regulation of MGP gene transcription and raise the possibility that a similar mechanism of regulation may also exist in mammals. [source] Genetic and epigenetic mechanisms in the early development of the vascular systemJOURNAL OF ANATOMY, Issue 2 2006Domenico Ribatti Abstract The cardiovascular system plays a critical role in vertebrate development and homeostasis. Vascular development is a highly organized sequence of events that requires the correct spatial and temporal expression of specific sets of genes leading to the development of a primary vascular network. There have been intensive efforts to determine the molecular mechanisms regulating vascular growth and development, and much of the rationale for this has stemmed from the increasing clinical importance and therapeutic potential of modulating vascular formation during various disease states. [source] Spatial and Temporal Ontogenies of Glutathione Peroxidase and Glutathione Disulfide Reductase During Development of the Prenatal RatJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 4 2001Hyungsuk Choe Abstract Spatial and temporal expression and regulation of the antioxidant enzymes, glutathione peroxidase (GSH-Px), glutathione disulfide reductase (GSSG-Rd) may be important in determining cell-specific susceptibility to embryotoxicants. Creation of tissue-specific ontogenies for antioxidant enzyme activities during development is an important first step in understanding regulatory relationships. Early organogenesis-stage embryos were grouped according to the somite number (GD 9,13), and fetuses were evaluated by gestational day (GD 14,21). GSH-Px activities in the visceral yolk sac (VYS) increased on consecutive days from GD 9 to GD 13, representing a 5.7-fold increase during this period of development. GSH-Px activities in VYS decreased after GD 13, ultimately constituting a 37% decrease at GD 21. Head, heart, and trunk specific activities generally increased from GD 9 to GD 13 albeit not to the same magnitude as detected in the VYS. GSSG-Rd activities showed substantial increases in the VYS from GD 9 to GD 13, 6.3-fold and decreased thereafter to 50% by GD 21. The greatest changes in enzyme activities were noted in the period between GD 10 and GD 11, where the embryo establishes an active cardiovascular system and begins to convert to aerobic metabolism. Generally, from GD 14,21, embryonic organ GSH-Px and GSSG-Rd activities either remained constant or increased as gestation progressed. These studies suggest the importance of the VYS in dealing with ROS and protecting the embryo. Furthermore, understanding the consequences of lower antioxidant activities during organogenesis may help to pinpoint periods of teratogenic susceptibility to xenobiotics and increased oxygen. © 2001 John Wiley & Sons, Inc. J Biochem Mol Toxicol 15:197,206, 2001 [source] Alterations in the temporal expression and function of cadherin-7 inhibit cell migration and condensation during chondrogenesis of chick limb mesenchymal cells in vitroJOURNAL OF CELLULAR PHYSIOLOGY, Issue 1 2009Dongkyun Kim Endochondral bone formation requires a complex interplay among immature mesenchymal progenitor cells to form the cartilaginous anlagen, which involves migration, aggregation and condensation. Even though condensation of chondrogenic progenitors is an essential step in this process, its mechanism(s) has not been well studied. Here, we show that cadherin-7 plays a central role in cellular condensation by modulating cell motility and migration. In this study, many mesenchymal cells failed to migrate, and precartilage condensation was inhibited, after knockdown of endogenous cadherin-7 levels. Exposure of mesenchymal cells to SB203580 (a specific inhibitor of p38MAPK), LiCl (an inhibitor of GSK-3,) or overexpression of ,-catenin resulted in inhibition of cadherin-7 levels and, subsequently, suppression of cell migration. Collectively, our results suggest that cadherin-7 controls cell migration in chick limb bud mesenchymal cells, and that p38MAPK and GSK signals are responsible for regulating cadherin-7-mediated cell migration. J. Cell. Physiol. 221: 161,170, 2009. © 2009 Wiley-Liss, Inc [source] Poster Sessions AP01: Gene Expression and RegulationJOURNAL OF NEUROCHEMISTRY, Issue 2001J. M. Calandria The formation of Cortico-Thalamic projections requires the precise spatial and temporal expression of proteins that are involved in the different stages of synaptogenesis. We reasoned that the underlying molecular mechanism of this process is the differential expression of genes that code for stage specific proteins. Our research objective was to identify the differential expressed mRNAs during the main stages of synapses formation, which starts at embryonic day 12 (E12) and finishes on the first postnatal days in the rat. We approach this problem using Differential Display technique on three distinct ages of rat cerebral cortex that were: E13, E18 and postnatal day 0 (P0). We found 80 differential bands using 54 random primers and 18 of them were cloned and sequenced. The sequence analysis showed among others, a cDNA fragment highly homologous with the human A Kinase Anchoring Protein 450/350 also called CG-NAP. We found that this cDNA fragment homologous to AKAP was up regulated at E15 when cortical cells are undergoing active axogenesis. The expression pattern of this cDNA was confirmed by Real Time PCR. Our findings suggest a possible function for AKAP 450 in the regulation of the state of phosphorylation of centrosomal components during the initial stages of synapses formation during the establishment of Cortico-Thalamic connection. [source] Temporal expression of growth factors and matrix molecules in healing tendon lesionsJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 1 2005Linda A. Dahlgren Abstract Overuse tendon injuries are common among elite and recreational athletes. Tendon healing may be enhanced at the cellular level through the use of exogenous growth factors; however, little is known about the endogenous expression of growth factors in healing tendon. This study describes the temporal expression of insulin-like growth factor-I (IGF-I), transforming growth factor-,1 (TGF-,1), and collagen types I and III in healing tendon lesions. Collagenase-induced lesions were created in the tensile region of the flexor digitorum superficialis tendon of both forelimbs of 14 horses. Tendons were harvested from euthanatized horses 1, 2, 4, 8 or 24 weeks following injury. Gene expression was evaluated using Northern blot analysis (collagen types I and III), real time PCR (IGF-I and TGF-,1), and in situ hybridization. Protein content was assayed by dye-binding assay (collagen types I and III), radioimmunoassay (IGF-I), ELISA (TGF-,1), and immunohistochemistry. Samples were also processed for differential collagen typing. DNA and glycosaminoglycan content, and routine H&E staining. Microscopically, lesions progressed from an amorphous, acellular lesion soon after injury to scar tissue filled with collagen fibers and mature fibroblasts organized along lines of tension. Early lesions were characterized by immediate increases in expression of growth factors and collagen. Message levels for TGF-,1 peaked early in the wound healing process (1 week), while IGF-I peaked later (4 weeks), as the regenerative phase of healing was progressing. In the first 2 weeks after lesion induction, tissue levels of IGF-I protein actually decreased approximately 40% compared to normal tendon. By 4 weeks, these levels had exceeded those of normal tendon and remained elevated through 8 weeks. Message expression for collagen types I and III increased by 1 week following injury and remained elevated throughout the course of the study. Collagen type I represented the major type of collagen in healing tendon at all time points of the study. Based on these results, IGF-I, administered exogenously during the first 2 weeks following injury, may provide a therapeutic advantage by bolstering low endogenous tissue levels and enhancing the metabolic response of individual tendon fibroblasts. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. [source] The temporal expression and localization of extracellular matrix metalloproteinase inducer (EMMPRIN) during the development of perio-dontitis in an animal modelJOURNAL OF PERIODONTAL RESEARCH, Issue 4 2010L. Liu Liu L, Li C, Cai X, Xiang J, Cao Z, Dong W. The temporal expression and localization of extracellular matrix metalloproteinase inducer (EMMPRIN) during the development of periodontitis in an animal model. J Periodont Res 2010; 45: 541,549. © 2010 John Wiley & Sons A/S Background and Objective:, We previously demonstrated extracellular matrix metalloproteinase inducer (EMMPRIN) was associated with the matrix metalloproteinases production of human periodontitis. The aim of this study was to investigate the temporal expression and localization of EMMPRIN during ligature-induced periodontitis in rats. Material and Methods:, Periodontitis was inducd in rats by placing a thread around the cervix of the first mandibular molar. Animals were killed 3, 7, 11, 15 or 21 d after ligation. Mandibles were processed for paraffin sections and stained with hematoxylin and eosin or picrosirius red. The distance from the amelocemental junction to the alveolar crest (ACJ,AC) and the area fraction (Area%) of collagen fibers were measured. EMMPRIN was examined by immunohistochemistry and quantified by positive cell counting. Correlation analyses were then performed. Results:, Histologically, alveolar bone was gradually destroyed from day 3 to 11 and then stabilized. Collagen fibers were slightly dissociated on day 3 and extensively broken on day 7. They were reconstructed from day 11 to 21. EMMPRIN was localized predominantly in infiltrating cells and adjacent fibroblasts in interdental gingiva. The number of EMMPRIN-positive cells increased on day 3, peaked on day 7 and then gradually subsided from day 11 to 21. Statistically, there was a moderate positive correlation regarding the ACJ,AC distance (r = 0.552, p < 0.01) and a strong negative correlation with the Area% of collagen fibers (r = ,0.808, p < 0.01). In gingival epithelium, the immunoreactivity was extremely strong in basal layer cells and sulcular epithelial cells in health. It was greatly enhanced in the inflamed conditions on days 3 and 7. In the interradicular bone, EMMPRIN was localized in the osteoclasts on days 3 and 7, as well as in the osteoblasts from day 11 onwards. Conclusion:, The expression and localization of EMMPRIN are temporally varied during the development of periodontitis. In addition, the inflammation-dependent expression of EMMPRIN might be involved in alveolar bone resorption and collagen breakdown. [source] Embryotropic effect of insulin-like growth factor (IGF)-I and its receptor on development of porcine preimplantation embryos produced by in vitro fertilization and somatic cell nuclear transferMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 1 2005Sue Kim Abstract Insulin-like growth factor (IGF)-I is a receptor-mediated autocrine/paracrine growth/survival factor for mammalian embryo development. The present study investigated the temporal expression and regulation of porcine IGF-I receptor (IGF-IR) mRNA and the role of IGF-I on development of porcine in vitro fertilized (IVF) and somatic cell nuclear transfer (SCNT) embryos. As assessed by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR), the level of IGF-IR mRNA expression was high in unfertilized oocytes, 2-cell and 4-cell embryos and gradually decreased in 8-cell embryos, morulae, and blastocysts in both IVF and SCNT series. The IVF or SCNT embryos were cultured with 0, 1, 10, 50, or 100 ng/ml IGF-I for 168 hr. Supplementing with 50 ng/ml IGF-I increased blastocyst formation and the number of cells in inner cell masses (ICMs) in both IVF and SCNT embryos. In a second experiment, more blastocysts were obtained when IVF or SCNT embryos were cultured for the first 48 hr or for the entire 168 hr with 50 ng/ml IGF-I compared to culturing without IGF-I for 48 hr or with IGF-I for the last 120 hr or without IGF-I for the entire 168 hr. Treating IVF or SCNT embryos with 50 ng/ml IGF-I significantly up-regulated IGF-IR mRNA compared to untreated control embryos. In conclusion, the present study demonstrated that IGF-IR mRNA is expressed in porcine IVF and SCNT embryos, and that IGF-I improved the developmental competence of IVF and SCNT embryos through its specific receptors. Mol. Reprod. Dev. © 2005 Wiley-Liss, Inc. [source] Specific maternal transcripts in bovine oocytes and cleavaged embryos: Identification with novel DDRT-PCR methodsMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 3 2005Kyu-Chan Hwang Abstract We used annealing control primer (ACP)-based differential display reverse transcription polymerase chain reaction (DDRT-PCR) to isolate differentially expressed amplicons in bovine germinal vesicle (GV) stage oocytes, 8-cell stage embryos produced in vitro, and blastocyst stage embryos produced in vitro. Four expressed sequence tags (ESTs) of genes that were specifically and predominantly expressed in GV oocytes were cloned and sequenced. We have used a fluorescence monitored real-time quantitative PCR (qPCR) to quantify and analyzed the temporal expression of the target differentially expressed transcripts throughout the preimplantation stages from oocytes to blastocysts. The cloned genes or ESTs all exhibited significant sequence similarity with known bovine genes (98%,100%; DNCL1 and ZP2) or ESTs (81%,97%; FANK1 and GTL3) of other species. As revealed by real-time qRT-PCR, DNCL1, FANK1, GTL3, and ZP2 transcripts were observed in the GV stage oocytes and expression gradually decreased up to the 8-cell stage embryo and the transcripts were not detected in later stages. Similarly, upregulation was observed in GV stage mouse oocytes and metaphase II, suggesting that these four differentially expressed orthologous genes play important roles in early preimplantation, as maternally-derived transcripts. Mol. Reprod. Dev. © 2005 Wiley-Liss, Inc. [source] Ablation of Lung Epithelial Cells Deregulates FGF-10 Expression and Impairs Lung Branching MorphogenesisTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 1 2009Namjin Kim Abstract Epithelial-mesenchymal interactions are essential for tissue patterning during organogenesis. Distal lung epithelium and its adjacent mesenchyme comprise the epithelial-mesenchymal signaling unit that regulates lung branching morphogenesis. Tissue recombination experiments have demonstrated the importance of mesenchymal signals in inducing lung epithelial differentiation and branching, but the role of the epithelium in regulating mesenchymal signals has not been well characterized. Using transgenic mice, we ablated distal lung epithelial cells during lung development by inducing the expression of a constitutively active proapoptotic Bax protein under the surfactant protein C (SP-C) promoter. We found that epithelial cell ablation results in impaired lung branching morphogenesis, which progresses to emphysematous airspaces in the adults. Mesenchymal expression of fibroblast growth factor 10 (Fgf-10), whose strict spatial and temporal expression is critical for proper lung branching morphogenesis, is disrupted and loses its localized pattern. Interestingly, the expression of sonic hedgehog (Shh), an epithelial gene known to modulate Fgf-10 expression, is unchanged, indicating the existence of other distal epithelial signals that regulate mesenchymal Fgf-10expression. We propose that distal SP-C expressing lung epithelial cells provide essential signals for the downregulation of Fgf-10expression in the distal mesenchyme during lung development. 292:123,130, 2009. © 2008 Wiley-Liss, Inc. [source] Neurodevelopmental expression and localization of the cellular prion protein in the central nervous system of the mouseTHE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 11 2010Stefano Benvegnù Abstract Transmissible spongiform encephalopathies (TSEs) are neurodegenerative disorders caused by PrPSc, or prion, an abnormally folded form of the cellular prion protein (PrPC). The abundant expression of PrPC in the central nervous system (CNS) is a requirement for prion replication, yet despite years of intensive research the physiological function of PrPC still remains unclear. Several routes of investigation point out a potential role for PrPC in axon growth and neuronal development. Thus, we undertook a detailed analysis of the spatial and temporal expression of PrPC during mouse CNS development. Our findings show regional differences of the expression of PrP, with some specific white matter structures showing the earliest and highest expression of PrPC. Indeed, all these regions are part of the thalamolimbic neurocircuitry, suggesting a potential role of PrPC in the development and functioning of this specific brain system. J. Comp. Neurol. 518:1879,1891, 2010. © 2010 Wiley-Liss, Inc. [source] Neurodevelopmental expression and localization of the cellular prion protein in the central nervous system of the mouseTHE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 11 2010Stefano Benvegnù Abstract Transmissible spongiform encephalopathies (TSEs) are neurodegenerative disorders caused by PrPSc, or prion, an abnormally folded form of the cellular prion protein (PrPC). The abundant expression of PrPC in the central nervous system (CNS) is a requirement for prion replication, yet despite years of intensive research the physiological function of PrPC still remains unclear. Several routes of investigation point out a potential role for PrPC in axon growth and neuronal development. Thus, we undertook a detailed analysis of the spatial and temporal expression of PrPC during mouse CNS development. Our findings show regional differences of the expression of PrP, with some specific white matter structures showing the earliest and highest expression of PrPC. Indeed, all these regions are part of the thalamolimbic neurocircuitry, suggesting a potential role of PrPC in the development and functioning of this specific brain system. J. Comp. Neurol. 518:1879,1891, 2010. © 2010 Wiley-Liss, Inc. [source] Molecular characterization of a novel patched-related protein in Apis mellifera and Drosophila melanogasterARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 3 2008Luis Pastenes Abstract The molecular identification and characterization of the patched-related (ptr) gene and protein in Apis mellifera and Drosophila melanogaster are reported. Ptr proteins are closely related in predicted topology and domain organization to the protein encoded by the Drosophila segment polarity gene patched. Ptrs have 12 potential transmembrane domains arranged in two sets of 1+5 membrane-spanning segments containing a conserved sterol-sensing domain (SSD) and functional GxxxD and PPXY motifs. Phylogenetic analysis showed that Ptrs belong to a previously uncharacterized class of insect proteins that share a high level of sequence identity. Analysis using quantitative real-time polymerase chain reaction (qPCR) indicates that ptr gene is preferentially expressed during embryo stages of A. mellifera development; interestingly, this pattern of temporal expression was also observed for the D. melanogaster homologue, suggesting that these proteins might be involved in embryo morphogenesis. To understand Ptr function at the molecular level, we investigated the subcellular distribution of DmPtr. We have shown by biochemical analysis that DmPtr protein is tightly associated with membranes. Consistently, Ptr immunoreactivity appears to be localized at the sites of membrane furrow formation during cellularization of D. melanogaster embryos. These studies indicated that Ptrs belong to a previously uncharacterized class of insect transmembrane proteins that share a high level of sequence identity. Our analysis of ptr gene expression and protein localization suggest that Ptr might fulfil a developmental role by participating in processes that require growth and stabilization of plasma membrane. Arch. Insect Biochem. Physiol. 68:156,170, 2008. © 2008 Wiley-Liss, Inc. [source] Overexpression, purification and preliminary X-ray diffraction analysis of the controller protein C.Csp231I from Citrobacter sp.ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 9 2009RFL23 Restriction,modification controller proteins play an essential role in regulating the temporal expression of restriction,modification genes. The controller protein C.Csp231I represents a new class of controller proteins. The gene was sublconed to allow overexpression in Escherichia coli. The protein was purified to homogeneity and crystallized using the hanging-drop vapour-diffusion method. The crystals diffracted to 2.0,Å resolution and belonged to space group P21. An electrophoretic mobility-shift assay provided evidence of strong binding of C.Csp231I to a sequence located upstream of the csp231IC start codon. [source] | |||||||||||||||||||||||||