Expression Differences (expression + difference)

Distribution by Scientific Domains

Kinds of Expression Differences

  • gene expression difference


  • Selected Abstracts


    Impact of Sex: Determination of Alcohol Neuroadaptation and Reinforcement

    ALCOHOLISM, Issue 2 2006
    Kristine M. Wiren
    This article represents the proceedings of a symposium at the Research Society on Alcoholism meeting in Santa Barbara, California. The organizers/chairs were Kristine M. Wiren and Deborah A. Finn. Following a brief introduction by Deborah Finn, the presentations were (1) The Importance of Gender in Determining Expression Differences in Mouse Lines Selected for Chronic Ethanol Withdrawal Severity, by Kristine M. Wiren and Joel G. Hashimoto; (2) Sex Differences in Ethanol Withdrawal Involve GABAergic and Stress Systems, by Paul E. Alele and Leslie L. Devaud; (3) The Influence of Sex on Ethanol Consumption and Reward in C57BL/6 Mice, by Kimber L. Price and Lawrence D. Middaugh; and (4) Sex Differences in Alcohol Self-administration in Cynomolgus Monkeys, by Kathleen A. Grant. [source]


    Global Gene Expression Differences Associated with Changes in Glycolytic Flux and Growth Rate in Escherichia coli during the Fermentation of Glucose and Xylose

    BIOTECHNOLOGY PROGRESS, Issue 1 2002
    Ramon Gonzalez
    The simplicity of the fermentation process (anaerobic with pH, temperature, and agitation control) in ethanologenic Escherichia coli KO11 and LY01 makes this an attractive system to investigate the utility of gene arrays for biotechnology applications. By using this system, gene expression, glycolytic flux, and growth rate have been compared in glucose-grown and xylose-grown cells. Although the initial metabolic steps differ, ethanol yields from both sugars were essentially identical on a weight basis, and little carbon was diverted to biosynthesis. Expression of only 27 genes changed by more than 2-fold in both strains. These included induction of xylose-specific operons ( xylE, xylFGHR, and xylAB) regulated by XylR and the cyclic AMP,CRP system and repression of Mlc-regulated genes encoding glucose uptake ( ptsHIcrr, ptsG) and mannose uptake ( manXYZ) during growth on xylose. However, expression of genes encoding central carbon metabolism and biosynthesis differed by less than 2-fold. Simple statistical methods were used to investigate these more subtle changes. The reproducibility (coefficient of variation of 12%) of expression measurements (mRNA as cDNA) was found to be similar to that typically observed for in vitro measurements of enzyme activities. Using Studentapos;s t test, many smaller but significant sugar-dependent changes were identified ( p < 0.05 in both strains). A total of 276 genes were more highly expressed during growth on xylose; 307 genes were more highly expressed with glucose. Slower growth (lower ATP yield) on xylose was accompanied by decreased expression of 62 genes concerned with the biosynthesis of small molecules (amino acids, nucleotides, cofactors, and lipids), transcription, and translation; 5 such genes were expressed at a higher level. In xylose-grown cells, 90 genes associated with the transport, catabolism, and regulation of pathways for alternative carbon sources were expressed at higher levels than in glucose-grown cells, consistent with a relaxation of control by the cyclic AMP,CRP regulatory system. Changes in expression of genes encoding the Embden,Meyerhof,Parnas (EMP) pathway were in excellent agreement with calculated changes in flux for individual metabolites. Flux through all but one step, pyruvate kinase, was predicted to be higher during glucose fermentation. Expression levels (glucose/xylose) were higher in glucose-grown cells for all EMP genes except the isoenzymes encoding pyruvate kinase ( pykA and pykF). Expression of both isoenzymes was generally higher during xylose fermentation but statistically higher in both strains only for pykF encoding the isoenzyme activated by fructose-6-phosphate, a key metabolite connecting pentose metabolism to the EMP pathway. The coordinated changes in expression of genes encoding the EMP pathway suggest the presence of a common regulatory system and that flux control within the EMP pathway may be broadly distributed. In contrast, expression levels for genes encoding the Pentose,Phosphate pathway did not differ significantly between glucose-grown and xylose-grown cells. [source]


    Varying ratios of wavelengths in dual wavelength LED photomodulation alters gene expression profiles in human skin fibroblasts

    LASERS IN SURGERY AND MEDICINE, Issue 6 2010
    D.H. McDaniel MD
    Abstract Background and Objective LED photomodulation has been shown to profoundly influence cellular behavior. A variety of parameters with LED photomodulation can alter cellular response in vitro. The effects of one visible and one infrared wavelength were evaluated to determine the optimal ratio to produce a net increase in dermal collagen by altering the ratio of total energy output of each wavelength. The ratio between the two wavelengths (590 and 870,nm) was shifted in 25% increments. Study Design/Materials and Methods Human skin fibroblasts in culture were exposed to a 590/870,nm LED array with total combined energy density fixed at 4.0,mW/cm.. The ratio of 590/870,nm tested parameters were: 100/0%, 75/25%, 50/50%, 25/75%, and 0/100%. These ratios were delivered using pulsed duty cycle of exposure (250,milliseconds "on" time/100,milliseconds "off" time/100,pulses) for a total energy fluence of 0.1,J/cm.. Gene expression was examined using commercially available extra cellular matrix and adhesion molecule RT PCR Arrays (SA Biosciences, Fredrick, MD) at 24,hours post-exposure. Results Different expression profiles were noticed for each of the ratios studied. Overall, there was an average (in an 80 gene array) of 6% expression difference in up or downregulation between the arrays. The greatest increase in collagen I and decrease in collagenase (MMP-1) was observed with 75/25% ratio of 590/870,nm. The addition of increasing proportions of IR wavelengths causes alteration in gene expression profile. The ratios of the wavelengths caused variation in magnitude of expression. Conclusions Cell metabolism and gene expression can be altered by simultaneous exposure to multiple wavelengths of low energy light. Varying the ratios of specific wavelength intensity in both visible and near infrared light therapy can strongly influence resulting fibroblast gene expression patterns. Lasers Surg. Med. 42:540,545, 2010. © 2010 Wiley,Liss, Inc. [source]


    Association of a single nucleotide polymorphism in ribosomal protein L27a gene with marbling in Japanese Black beef cattle

    ANIMAL SCIENCE JOURNAL, Issue 6 2009
    Takahisa YAMADA
    ABSTRACT Marbling, defined by the amount and distribution of intramuscular fat, is an economically important trait of beef cattle in Japan. The c2-11#2 expressed sequence tag (EST) has been previously shown to possess expression difference in musculus longissimus muscle between low-marbled and high-marbled steer groups, and to be located within genomic region of a quantitative trait locus for marbling. Thus, the ribosomal protein L27a (RPL27A) gene containing the c2-11#2 EST sequence was considered as a positional candidate for the gene responsible for marbling. In the present study, a single nucleotide polymorphism (SNP) in the promoter region of the RPL27A, referred to as g.3109537C>T, was detected between the 2 steer groups. The SNP was associated with the predicted breeding value for beef marbling standard number by the analyses using Japanese Black beef cattle population. The effect of genotypes of the SNP on the predicted breeding value for subcutaneous fat thickness was not statistically significant. These findings suggest that the RPL27A SNP may be useful for effective marker-assisted selection to increase the levels of marbling in Japanese Black beef cattle. [source]


    Microarray analysis yields candidate markers for rotation resistance in the western corn rootworm beetle, Diabrotica virgifera virgifera

    EVOLUTIONARY APPLICATIONS (ELECTRONIC), Issue 1 2010
    Lisa M. Knolhoff
    Abstract As pest species may evolve resistance to chemical controls, they may also evolve resistance to cultural control methods. Yearly rotation of corn (Zea mays) with another crop interrupts the life cycle of the western corn rootworm beetle (Diabrotica virgifera virgifera, Coleoptera: Chrysomelidae), but behavioral resistance to crop rotation is now a major problem in the Midwest of the USA. Resistant adult females exhibit reduced fidelity to corn as a host and lay their eggs in the soil of both corn and soybean (Glycine max) fields. Behavioral assays suggest that the adaptation is related to increased locomotor activity, but finding molecular markers has been difficult. We used microarray analysis to search for gene expression differences between resistant and wild-type beetles. Candidates validated with real-time polymerase chain reaction exhibit predicted patterns from the microarray in independent samples across time and space. Many genes more highly expressed in the rotation-resistant females have no matches to known proteins, and most genes that were more lowly expressed are involved in antimicrobial defense. [source]


    Interpretation of knockout experiments: the congenic footprint

    GENES, BRAIN AND BEHAVIOR, Issue 3 2007
    L. C. Schalkwyk
    In gene targeting experiments, the importance of genetic background is now widely appreciated, and knockout alleles are routinely backcrossed onto a standard inbred background. This produces a congenic strain with a substantial segment of embryonic stem (ES)-cell-derived chromosome still flanking the knockout allele, a phenomenon often neglected in knockout studies. In cholecystokynin 2 (Cckbr) knockout mice backcrossed with C57BL/6, we have found a clear ,congenic footprint' of expression differences in at least 10 genes across 40 Mb sequence flanking the Cckbr locus, each of which is potentially responsible for aspects of the ,knockout' phenotype. The expression differences are overwhelmingly in the knockout-low direction, which may point to a general phenomenon of background dependence. This finding emphasizes the need for caution in using gene knockouts to attribute phenotypic effects to genes. This is especially the case when the gene is of unknown function or the phenotype is unexpected, and is a particular concern for large-scale knockout and phenotypic screening programmes. However, the impact of genetic background should not be simply viewed as a potential confound, but as a unique opportunity to study the broader responses of a system to a specific (genetic) perturbation. [source]


    Genome-wide gene expression differences in Crohn's disease and ulcerative colitis from endoscopic pinch biopsies: Insights into distinctive pathogenesis

    INFLAMMATORY BOWEL DISEASES, Issue 7 2007
    Feng Wu PhD
    Abstract Background: Ulcerative colitis (UC) and Crohn's disease (CD) are inflammatory bowel diseases (IBD) with variable, overlapping clinical features and complex pathophysiologies. Methods: To identify pathogenic processes underlying these disease subtypes, we used single endoscopic pinch biopsies to elucidate patterns of gene expression in active and inactive areas of UC and CD and compared these to infectious colitis and healthy control samples. Results: Unsupervised classification of a total of 36 samples yielded promising separation between the affected IBD, unaffected IBD, non-IBD colitis, and normal control samples, suggesting each sample type had a distinctive gene expression pattern. Genes differentially expressed in the CD samples compared to in the controls were related to IFN,-inducible TH1 processes (IFITM1, IFITM3, STAT1, and STAT3) and antigen presentation (TAP1, PSME2, PSMB8). The most noticeable change in the UC samples was reduced expression of genes regulating biosynthesis, metabolism, and electrolyte transport (HNF4G, KLF5, AQP8, ATP2B1, and SLC16A). Twenty-five percent of genes down-regulated in the UC samples were also down-regulated in the infectious colitis samples. Unaffected biopsy samples of IBD patients also registered differences expression of genes compared to in the normal controls. Of these differentially expressed genes, only 2 were up-regulated, PSKH1, a regulator of mRNA processing, and PPID, a suppressor of apoptosis. Conclusions: The study shows that the gene expression patterns of IBD, CD in particular, are quite different from those of infectious colitis, highlighting distinctive expression of genes and pathways in UC and CD. (Inflamm Bowel Dis 2007) [source]


    Gene expression associated with changes in cold tolerance levels of the Antarctic springtail, Cryptopygus antarcticus

    INSECT MOLECULAR BIOLOGY, Issue 1 2010
    G. Burns
    Abstract The ability of the Antarctic microarthropod Cryptopygus antarcticus (Collembola, Isotomidae) to survive low temperatures has been well studied at the physiological level, with recent investigations indicating the importance of the moulting process in conferring this ability. This study investigated gene expression in groups of C. antarcticus that have distinct differences in their ability to survive low temperatures. A microarray containing c. 5400 C. antarcticus expressed sequence tags was used to investigate gene expression differences between groups of animals with different supercooling points (SCP), and to low temperatures close to their SCP. By demonstrating the involvement of moult-related genes in the differential survival of two groups of C. antarcticus with distinct SCP profiles, the results of this investigation add support to the suggestion that moulting plays a role in conferring cold tolerance in C. antarcticus. [source]


    Maternal embryonic leucine zipper kinase transcript abundance correlates with malignancy grade in human astrocytomas

    INTERNATIONAL JOURNAL OF CANCER, Issue 4 2008
    Suely K.N. Marie
    Abstract We have performed cDNA microarray analyses to identify gene expression differences between highly invasive glioblastoma multiforme (GBM) and typically benign pilocytic astrocytomas (PA). Despite the significant clinical and pathological differences between the 2 tumor types, only 63 genes were found to exhibit 2-fold or greater overexpression in GBM as compared to PA. Forty percent of these genes are related to the regulation of the cell cycle and mitosis. QT-PCR validation of 6 overexpressed genes: MELK, AUKB, ASPM, PRC1, IL13RA2 and KIAA0101 confirmed at least a 5-fold increase in the average expression levels in GBM. Maternal embryonic leucine zipper kinase (MELK) exhibited the most statistically significant difference. A more detailed investigation of MELK expression was undertaken to study its oncogenic relevance. In the examination of more than 100 tumors of the central nervous system, we found progressively higher expression of MELK with astrocytoma grade and a noteworthy uniformity of high level expression in GBM. Similar level of overexpression was also observed in medulloblastoma. We found neither gene promoter hypomethylation nor amplification to be a factor in MELK expression, but were able to demonstrate that MELK knockdown in malignant astrocytoma cell lines caused a reduction in proliferation and anchorage-independent growth in in vitro assays. Our results indicate that GBM and PA differ by the expression of surprisingly few genes. Among them, MELK correlated with malignancy grade in astrocytomas and represents a therapeutic target for the management of the most frequent brain tumors in adult and children. © 2007 Wiley-Liss, Inc. [source]


    Reduction of appeasement-related affect as a concomitant of diazepam-induced aggression: evidence for a link between aggression and the expression of self-conscious emotions

    AGGRESSIVE BEHAVIOR, Issue 2 2009
    Patricia S. Wallace
    Abstract Aggressive responding following benzodiazepine ingestion has been recorded in both experimental and client populations, however, the mechanism responsible for this outcome is unclear. The goal of this study was to identify an affective concomitant linked to diazepam-induced aggression that might be responsible for this relationship. Thirty males (15 diazepam and 15 placebo) participated in the Taylor Aggression Paradigm while covertly being videotaped. The videotapes were analyzed using the Facial Action Coding System with the goal of identifying facial expression differences between the two groups. Relative to placebo participants, diazepam participants selected significantly higher shock settings for their opponents, consistent with past findings using this paradigm. Diazepam participants also engaged in significantly fewer appeasement expressions (associated with the self-conscious emotions) during the task, although there were no group differences for other emotion expressions or for movements in general. Aggr. Behav. 35:203,212, 2009. © 2008 Wiley-Liss, Inc. [source]


    Allele C-specific methylation of the 5-HT2A receptor gene: Evidence for correlation with its expression and expression of DNA methylase DNMT1

    JOURNAL OF NEUROSCIENCE RESEARCH, Issue 3 2006
    Oxana O. Polesskaya
    Abstract Differential DNA methylation has been suggested to contribute to differential activity of alleles C and T and thereby to genetic associations between the C/T(102) polymorphism in the 5-HT2A receptor gene (5HT2AR) and psychiatric disorders. We surveyed methylation in two CpG sites, which are specific to allele C. The majority of allele C-specific CpG sites were methylated in human temporal cortex and peripheral leukocytes and levels of methylation varied between individuals. Levels of methylation in the promoter correlated significantly with the expression of 5HT2AR. Methylation of allele C-specific CpG sites in the first exon correlated significantly with the expression of DNA methylase 1 (DNMT1) but not S-adenosylhomocysteine hydrolase (AHCY). These findings support the hypothesis that allele-specific DNA methylation is involved in regulation of 5HT2AR expression, influencing expression differences between alleles C and T. © 2005 Wiley-Liss, Inc. [source]


    Genome-wide expression analysis of intra- and extraarticular connective tissue

    JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 4 2009
    Richard V. Pearse II
    Abstract In comparison to extraarticular ligaments and tendons, the intraarticular ligaments such as the anterior and posterior cruciates exhibit different biochemical, biomechanical, and viscoelastic properties and most importantly, differential abilities to heal after surgical repair. Little is known about the underlying basis for these differences, in large measure due to the paucity of molecular markers distinguishing different classes of tendons and ligaments. To date, there has been no systematic analysis of gene expression differences between different types of connective tissues. We used Affymetrix expression arrays to analyze the differences in gene expression levels between the anterior cruciate, posterior cruciate, and medial collateral ligaments, the patellar and Achilles tendons and the synovium. We have identified five clusters of gene cohorts displaying similar expression patterns. These clusters group into three categories including: (1) genes that are strongly expressed in all connective tissues compared to the synovium control tissue; (2) genes that distinguish intraarticular connective tissues from extraarticular connective tissues; and (3) a group of genes expressed in common by the patellar tendon and the synovium. Our analysis identifies a new marker of tendons and ligaments (fibin2), demonstrates molecular diversity between subtypes of tendons and ligaments, and indicates that the primary molecular subdivision among dense regular connective tissues is intra- versus extraarticular rather than ligament versus tendon. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27: 427,434, 2009 [source]


    Role of Potassium Channel Gene Kcnj10 in Ethanol Preference in C57bl/6J and DBA/2J Mice

    ALCOHOLISM, Issue 3 2009
    Shicong B. Zou
    Background:, Inwardly-rectifying potassium channel protein Kir4.1 is encoded by Kcnj10 which maps to a quantitative trait locus on chromosome 1 for the voluntary alcohol consumption phenotype in mice. Kcnj10 brain expression differences have been established between ethanol-preferring C57Bl/6J and ethanol-avoiding BALB/cJ mice, but its differential expression in other tissues and strains have largely been overlooked. A nonsynonymous single nucleotide polymorphism exists between C57Bl/6J and ethanol-avoiding DBA/2J mice which changes amino acid 262 from threonine (C57Bl/6J) to serine (DBA/2J). This Kcnj10 SNP and its expression may serve as valuable markers in predicting the ethanol preference phenotype in mice. Methods:, The evolutionary divergence of the Kir gene family was characterized using phylogenetic analysis involving the 16 mouse Kir channels. Kcnj10 expression differences in the brain, liver, lung, heart, spleen, kidney, testes, and muscle of male C57Bl/6J and DBA/2J mice at different developmental stages were examined using semiquantitative RT-PCR analysis. A SNP analysis was conducted to assess the association of Kcnj10 Thr262Ser SNP and the ethanol preference phenotype in F2 mice derived from the reciprocal crosses of the C57Bl/6J and DBA/2J strains. Results:, Evolutionary analysis supports gene duplication and genetic recombination as likely sources of diversity within the Kir gene family. Semiquantitative RT-PCR analysis revealed significantly higher Kcnj10 expression in the brain, spleen, and kidney of both strains when compared to other tissues from the same strain. There were no significant differences in tissue-specific mRNA levels between strains except in the testes. Genotype distributions of the Kcnj10 Thr262Ser SNP were different between low- and high-drinkers. A significant difference in the average ethanol preference level of each genotype was also observed. Conclusion:, Our results suggest a role for Kcnj10 in ethanol preference determination in mice. However, further experiments are needed to establish if this association is due to the nonsynonymous SNP or other additional factors associated with Kcnj10. [source]


    Identification of Candidate Genes for Alcohol Preference by Expression Profiling of Congenic Rat Strains

    ALCOHOLISM, Issue 7 2007
    Lucinda G. Carr
    Background: A highly significant quantitative trait locus (QTL) on chromosome 4 that influenced alcohol preference was identified by analyzing crosses between the iP and iNP rats. Congenic strains in which the iP chromosome 4 QTL interval was transferred to the iNP (NP.P) exhibited the expected increase in alcohol consumption compared with the iNP background strain. This study was undertaken to identify genes in the chromosome 4 QTL interval that might contribute to the differences in alcohol consumption between the alcohol-naïve congenic and background strains. Methods: RNA from 5 brain regions from each of 6 NP.P and 6 iNP rats was labeled and analyzed separately on an Affymetrix Rat Genome 230 2.0 microarray to look for both cis -regulated and trans -regulated genes. Expression levels were normalized using robust multi-chip average (RMA). Differential gene expression was validated using quantitative real-time polymerase chain reaction. Five individual brain regions (nucleus accumbens, frontal cortex, amygdala, hippocampus, and striatum) were analyzed to detect differential expression of genes within the introgressed QTL interval, as well as genes outside that region. To increase the power to detect differentially expressed genes, combined analyses (averaging data from the 5 discrete brain regions of each animal) were also carried out. Results: Analyses within individual brain regions that focused on genes within the QTL interval detected differential expression in all 5 brain regions; a total of 35 genes were detected in at least 1 region, ranging from 6 genes in the nucleus accumbens to 22 in the frontal cortex. Analysis of the whole genome detected very few differentially expressed genes outside the QTL. Combined analysis across brain regions was more powerful. Analysis focused on the genes within the QTL interval confirmed 19 of the genes detected in individual regions and detected 15 additional genes. Whole genome analysis detected 1 differentially expressed gene outside the interval. Conclusions: Cis -regulated candidate genes for alcohol consumption were identified using microarray profiling of gene expression differences in congenic animals carrying a QTL for alcohol preference. [source]


    Developmental expression and biochemical properties of a ,-1,4-endoglucanase family in the soybean cyst nematode, Heterodera glycines

    MOLECULAR PLANT PATHOLOGY, Issue 2 2004
    Bingli Gao
    SUMMARY The soybean cyst nematode, Heterodera glycines, produces ,-1,4-endoglucanases (cellulases) that are secreted during infection of soybean. The gene structures of three, hg-eng-4, hg-eng-5 and hg-eng-6, of the six ,-1,4-endoglucanase genes, all family 5 glycosyl hydrolases previously identified from H. glycines, are presented here. Furthermore, we present the detailed expression analyses of ,-1,4-endoglucanase genes as well as the biochemical properties of four H. glycines endoglucanase enzymes. Two of the endoglucanases, HG-ENG-5 and HG-ENG-6, differed significantly in their amino acid sequence of the catalytic domains and their gene structure from that of the other four ,-1,4-endoglucanases. Quantitative real-time RT-PCR revealed distinct developmental expression differences among the hg-eng family members during the early stages of parasitism and relatively low expression levels in late parasitic stages, with the exception of the adult male stage for some eng genes. Recombinant HG-ENGs degraded carboxymethylcellulose and optimum enzyme activity ranged from pH 5.5 for HG-ENG-5 to pH 8 for HG-ENG-6. EDTA, Ca2+, Co2+, Mg2+ and Fe2+ did not affect enzyme activity of any ENG protein, whereas Zn2+, Cu2+ and Mn2+ inhibited enzyme activity from 23% to 73% in some cases. In tests with 12 different polysaccharide substrates, enzyme activity was restricted to ,-1,4 linkages with all ENG proteins tested. Only HG-ENG-5 and HG-ENG-6 had relatively high activity on xylan and slightly degraded microcrystalline cellulose. Together, these data reveal distinct differences in expression and biochemistry of cyst nematode parasitism genes and proteins, respectively, and cast light on the intricate interactions between a parasitic animal and its plant host. [source]


    Neuronal gene expression correlates of Parkinson's disease with dementia,

    MOVEMENT DISORDERS, Issue 11 2008
    Chelsea Stamper BS
    Abstract Dementia is a common disabling complication in patients with Parkinson's disease (PD). The underlying molecular causes of Parkinson's disease with dementia (PDD) are poorly understood. To identify candidate genes and molecular pathways involved in PDD, we have performed whole genome expression profiling of susceptible cortical neuronal populations. Results show significant differences in expression of 162 genes (P < 0.01) between PD patients who are cognitively normal (PD-CogNL) and controls. In contrast, there were 556 genes (P < 0.01) significantly altered in PDD compared to either healthy controls or to PD-CogNL cases. These results are consistent with increased cortical pathology in PDD relative to PD-CogNL and identify underlying molecular changes associated with the increased pathology of PDD. Lastly, we have identified expression differences in 69 genes in PD cortical neurons that occur before the onset of dementia and that are exacerbated upon the development of dementia, suggesting that they may be relevant presymptomatic contributors to the onset of dementia in PD. These results provide new insights into the cortical molecular changes associated with PDD and provide a highly useful reference database for researchers interested in PDD. © 2008 Movement Disorder Society [source]


    Mutational and expression analysis of CDK1, cyclinA2 and cyclinB1 in epilepsy-associated glioneuronal lesions

    NEUROPATHOLOGY & APPLIED NEUROBIOLOGY, Issue 2 2007
    V. Schick
    Gangliogliomas and focal cortical dysplasias (FCDs) constitute glioneuronal lesions, which are frequently encountered in biopsy specimens of patients with pharmacoresistant focal epilepsy and relate to impaired differentiation and migration of neural precursors. However, their molecular pathogenesis and relationship are still largely enigmatic. Recent data suggest several components of the insulin-pathway, including TSC1 and TSC2 mutated in tuberous sclerosis complex (TSC), to be altered in gangliogliomas and FCD with Taylor type balloon cells (FCDIIb). The proteins tuberin (TSC2) and hamartin (TSC1) constitute a tumour suppressor mechanism involved in cell-cycle control. Hamartin and/or tuberin were reported to colocalize and/or interact with CDK1, cyclinB1 and cyclinA2 that are critically involved in cell-size and cell-growth control. Here, we have carried out mutational and expression analyses of CDK1, cyclinB1 and cyclinA2 in gangliogliomas and FCDIIb. Mutational screening was performed by single-strand conformation polymorphism analysis in gangliogliomas (n = 20), FCDIIb (n = 35) and controls. CyclinB1 revealed a polymorphism (G to A, cDNA Position 966, GenBank: NM_031966) in exon 7 with similar frequencies in FCDIIb, gangliogliomas and control specimens (FCD n = 9/35; gangliogliomas n = 5/20; control n = 20/100). We used real-time reverse transcription polymerase chain reaction to determine expression levels of CDK1, cyclinB1 and cyclinA2 in 10 FCDIIb and nine gangliogliomas compared with unaffected adjacent control tissue of the same patients. We observed significantly lower expression of CDK1 and cyclinA2 in FCDIIb vs. controls whereas no significant expression differences were present for CDK1, cyclinB1 and cyclinA2 in gangliogliomas. Our data strongly argue against mutational events of CDK1, cyclinB1 and cyclinA2 to play a role in gangliogliomas or FCDIIb. However, a potential functional significance of lower expression for the cell-size and cell-cycle regulators CDK1 and cyclinA2 in FCDIIb composed of large dysplastic neurones and balloon cells needs to be further resolved. [source]


    Expression of the AtSUC1 gene in the female gametophyte, and ecotype-specific expression differences in male reproductive organs

    PLANT BIOLOGY, Issue 2010
    A. Feuerstein
    Abstract Based on analyses in Arabidopsis thaliana ecotype C24, the AtSUC1 protein was previously characterised as a male gametophyte-specific H+/sucrose symporter. Later, expression analyses in ecotype Columbia-0 (Col-0) identified AtSUC1 expression also in trichomes (not detected in trichome-less C24 plants) and roots, suggesting ecotype-specific differences in AtSUC1 expression. Here, we present data on additional ecotype-specific differences in AtSUC1 expression in other tissues. Using different AtSUC1 promoter,reporter gene lines, we performed comparative analyses of AtSUC1 expression in floral tissues of C24 and Col-0 plants, and using an AtSUC1 -specific antiserum, we performed immunohistochemical analyses on tissue sections from C24, Col-0, Landsberg erecta (Ler) and Wassilewskaija (Ws) ecotypes. We show that AtSUC1 expression occurs in the funicular epidermis of C24, Ler and Ws, but not in Col-0. In contrast, we observed high levels of AtSUC1 protein in pollen grains of Col-0, lower levels in pollen of C24 and Ler, and no AtSUC1 protein in Ws pollen. Moreover, our reporter gene analyses identified a previously undetected expression of AtSUC1 in the female gametophyte, and revealed that AtSUC1 expression in the funicular epidermis is absent from unpollinated siliques and is induced upon successful pollination. The impact of these findings on the potential physiological role of AtSUC1 is discussed. [source]


    Identification of breast cancer biomarkers in transgenic mouse models: A proteomics approach

    PROTEOMICS - CLINICAL APPLICATIONS, Issue 6-7 2010
    Wendy Rodenburg
    Abstract Purpose: Transgenic mouse models for cancer circumvent many challenges that hamper human studies aimed at biomarker discovery. Lower biological variances among mice combined with controllable factors such as food uptake and health status may enable the detection of more subtle protein expression differences. This is envisioned to result in the identification of biomarkers better discriminating cancer cases from controls. Experimental design: The current study used two innovative mouse models for breast-cancer to identify new serum biomarkers. Multi-analyte profiling technique was used to analyze 70 proteins in individual serum samples of non-tumor and mammary tumor-bearing Tg.NK (MMTV/c-neu) mice. Results: A small set of proteins fully differentiated tumor samples from controls. These comprised osteopontin, interleukin-18, cystatin C and CD40 antigen. Comparison of protein expression in another breast-cancer mouse model, the humanized p53.R270H mice, showed common discriminatory expression of osteopontin. However, other biomarkers showed distinct expression in the two different breast-cancer models, indicating that different mammary tumor sub-types with respect to molecular and estrogen receptor status reveal divergent serum biomarker sets. Conclusions and clinical relevance: The current study supports the concept that serum proteins can discriminate mammary tumor cases from controls, and yielded interesting biomarkers that need further testing and validation in human studies. [source]


    Metastases and multiple myeloma generate distinct transcriptional footprints in osteocytes in vivo,

    THE JOURNAL OF PATHOLOGY, Issue 5 2008
    S Eisenberger
    Abstract Osteocytes are the most abundant bone cells, playing important roles in tissue maintenance. Little is known of how they react in vivo to cancer stress. Here we present a comparative study of the effect of a bone-residing tumour (myeloma) and metastases of bone-remote cancers on osteocytes. While no differences in morphology of the bone are seen, the changes in the transcriptome of osteocytes are specifically related to the tumour stress present. Screening ,22 000 genes in osteocytes prepared from cryosections of native bone using laser-supported microdissection, we observed ,1400 and ,1800 gene expression differences between osteocytes dissected from normal bone compared with those associated with metastases and multiple myeloma, respectively. The genes up-regulated due to the stress exerted by metastases were repressed by multiple myeloma and vice versa, indicating stress-specific footprints in the transcriptome of osteocytes. Functionally, the stressors seem to impose selective pressures on signalling pathways such as that of TGF,, a major player in bone biology. Our data show for the first time that the transcriptome of osteocytes in vivo becomes strongly affected by cancer stress, generating gene expression footprints which, in contrast to comparable morphological changes, appear to relate to the nature of cancer and might thus become helpful in distinguishing different bone diseases. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [source]


    Novel SNP in 5, flanking region of EDG1 associated with marbling in Japanese Black beef cattle

    ANIMAL SCIENCE JOURNAL, Issue 4 2009
    Takahisa YAMADA
    ABSTRACT Marbling, defined by the amount and distribution of intramuscular fat, is an economically important trait of beef cattle in Japan. The endothelial differentiation, sphingolipid G-protein-coupled receptor, 1 (EDG1) gene has been considered as a positional functional candidate for the gene responsible for marbling. We have recently reported that 2 single nucleotide polymorphisms (SNPs), c.-312A>G in the 5, untranslated region (UTR) and c.*446G>A in the 3, UTR in EDG1 were associated with marbling in Japanese Black beef cattle, but this was not functional and a causal mutation for marbling. In the present study, we detected 2 novel SNPs, referred to as g.1475435G>A and g.1471620G>T, in the 5, flanking region of the EDG1 between low-marbled and high-marbled steer groups, which were previously shown to have EDG1 expression differences in musculus longissimus muscle. The g.1475435G>A SNP seemed not to segregate in Japanese Black beef cattle. The g.1471620G>T SNP was associated with the predicted breeding value for beef marbling standard number by the analyses using Japanese Black beef cattle population. Based on these findings, we hypothesized that the g.1471620G>T SNP might have an impact on EDG1 expression and also marbling. [source]


    Effects of intrauterine undernutrition on the expression of CYP3A23/3A1, PXR, CAR and HNF4, in neonate rats

    BIOPHARMACEUTICS AND DRUG DISPOSITION, Issue 9 2008
    Shaoqing Ni
    Abstract Cytochrome P-450 3A (CYP3A) together with its nuclear receptors plays a critical role in drug metabolism. The present study investigated the effects of undernutrition in utero on hepatic mRNA and protein expression of the enzyme CYP3A23/3A1 and nuclear receptors including pregnane X receptor (PXR; NR1I2), constitutive androstane receptor (CAR; NR1I3) and nuclear factor-4alpha (HNF4,; HNF4A) in neonatal rats. At gestational day 2, pregnant rats were randomly divided into two groups: nourished (fed ad libitum) and undernourished (50% of nourished group). The pups delivered by nourished rats were designated as the normal-birth-weight group (NBW, n=15) and those delivered by undernourished rats were designated as the low-birth-weight group (LBW, n=15). Hepatic mRNA expression was detected by quantitative real-time PCR and the corresponding protein expression was examined by immunohistochemistry (IHC). Compared with NBW pups, LBW pups tended to have lower mRNA expression levels of CYP3A23/3A1, PXR and CAR but higher levels of HNF4,. Only the CAR mRNA expression differences were significant (p<0.05). mRNA expression of CYP3A23/3A1 correlated with that of HNF4, in both the LBW(r=0.808, p=0.007) and NBW (r=0.452, p=0.012) groups. CYP3A23/3A1 and CAR protein expression differed between the two groups (CYP3A23/3A1, ,2=7.87, p=0.005; CAR, ,2=12.069, p=0.001). In conclusion, these findings suggest that undernutrition may influence the mRNA expression of CAR and protein expression of both CYP3A23/3A1 and CAR in neonatal rats. Since CYP3A23/3A1 and CAR are critically involved in drug metabolism, these results may have clinical implications for optimal medication in LBW children. Copyright © 2008 John Wiley & Sons, Ltd. [source]