Germination of Leafy Spurge (Euphorbia esula) Seeds under Constant and Alternating Temperature
Ontology highlight
ABSTRACT:
ORGANISM(S): Euphorbia esula
SUBMITTER: Michael Foley
PROVIDER: E-GEOD-18533 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Publications
Initial changes in the transcriptome of Euphorbia esula seeds induced to germinate with a combination of constant and diurnal alternating temperatures.
Foley Michael E ME Anderson James V JV Chao Wun S WS Doğramaci Münevver M Horvath David P DP
Plant molecular biology 20091115 1-2
We investigated transcriptome changes in Euphorbia esula (leafy spurge) seeds with a focus on the effect of constant and diurnal fluctuating temperature on dormancy and germination. Leafy spurge seeds do not germinate when incubated for 21 days at 20 degrees C constant temperatures, but nearly 30% germinate after 21 days under fluctuating temperatures 20:30 degrees C (16:8 h). Incubation at 20 degrees C for 21 days followed by 20:30 degrees C resulted in approximately 63% germination in about 10 ...[more]
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Project description:Persistence of the invasive perennial weed leafy spurge is mainly attributed to seasonal production of underground adventitious buds (UABs), which undergo well-defined phases of dormancy (para-, endo- and eco-dormancy). These well-defined phases of dormancy also allow UABs of leafy spurge to survive extreme seasonal variations, including dehydration-stress. Consequently, objectives of this study include understanding the effects of dehydration-stress on vegetative reproduction, flowering competence, and transcript profiles at different phases of bud dormancy. The vegetative growth potential of UABs was monitored by removing the aerial portion of dehydration-stressed plants and re-watering the root system. Further, microarray analysis was used to follow transcriptome profiles to identify critical defense- and signaling-pathways at different phases of dormancy in UABs. Surprisingly, only 3 days of dehydration-stress is required to break the endodormant phase in UABs. In leafy spurge, vernalization of endodormant UABs has previously been shown to induce flower competence, while breaking of endodormancy via dehydration-stress did not induce floral induction. Thus, these two environmental treatments open a unique approach to independently dissect molecular mechanisms involved in endodormancy maintenance and floral competence. Bioinformatics analysis of transcriptome data helped to identify models and overlapping pathways. During endodormancy break, LEC1, PHOTOSYSTEM I RC, and brassinosteroids were identified as ooverlapping hubs of up-regulated genes, and DREB1A, CBF2, GPA1, MYC2, BHLH, BZIP, and flavonoids were identified as overlapping hubs of down-regulated genes. Additionally, key genes involved in metabolic activity, chromatin modification, and cross-talk between growth regulators were identified as playing a role during endodormancy maintenance. Plant material, controlled environmental treatments, and vegetative growth: Three-month-old paradormant leafy spurge plants grown in a greenhouse were acclimated for one week, under growth chamber conditions, prior to being subjected to a ramp-down in temperature (27 °C → 10 °C) and photoperiod (16 h → 8 h light) for 12 weeks to induce endodormancy, as previously established (Doğramacı et al. 2010; Foley et al. 2009). Endodormancy status was confirmed by comparing vegetative growth rates of plants with and without a ramp-down treatment. To study the effects of dehydration-stress on vegetative growth from UABs, water was withheld from endodormant plants up to 21 days. After dehydration for 0, 1-, 3-, 7-, 14-, and 21-days, the aerial portion of the plants were decapitated at the soil surface and vegetative growth and floral competence of UABs were monitored under growth-conducive conditions by re-watering the root system. Vegetative shoot growth from six plants was recorded weekly for four weeks, and results of four replications were analyzed using SAS 9.2 (SAS Institute, Cary, NC, 2008) software as described by Doğramacı et al. (2010). Microarray analysis: At the end of each treatment, crown buds were collected, and RNA extraction, cDNA synthesis, fluorescent labeling, microarray hybridization using ~23K element arrays, and spot intensity analyses were performed as previously described by Doğramacı et al. (2010). Based on unexpected vegetative growth results obtained from this study, only microarray data obtained from 0-, 1-, and 3-day dehydration-stressed endodormant UABs, which were compared with microarray data for endodormant, and flowering competent ecodormant UABs from our previous study (Doğramacı et al. 2010; GSE19217), were used for bioinformatics analyses. However, to merge the datasets from these two separate experiments, T-tests were first performed on microarray data obtained from endodormant UABs from each experiment, and differentially-expressed genes (p<0.005) were removed from the dataset (~5% of the spots). After removing the outliers, the two endodormant transcriptome data sets were grouped together and used as the baseline control for further ANOVA, T-tests and other analyses. Array normalization, statistical analyses and clustering of the dataset and Venn diagram generation were done using GeneMaths XT 5.1 software as previously described by Doğramacı et al. (2010).
2011-04-05 | E-GEOD-28047 | biostudies-arrayexpress
Project description:Leafy spurge (Euphorbia esula) is an herbaceous perennial weed that produces vegetatively from an abundance of underground adventitious buds. The objectives of this study were to determine how mimicking natural seasonal conditions (photoperiod and temperature) under controlled environmental conditions affect dormancy and flowering competence; to determine molecular mechanisms associated with well-defined phases of seasonal dormancy transitions based on transcript profiles obtained by microarray analysis; and to link mechanisms regulating induction and release of endodormancy and flowering competence. Reduction in temperature (27 to 10°C) and photoperiod (16 to 8 h) over a three-month period induced a para- to endo-dormant transition in crown buds. An additional eleven weeks of prolonged cold (5-7°C) and short-photoperiod treatment resulted in accelerated shoot growth from crown buds, and 99% floral competence when plants were returned to growth promoting conditions. Exposure of paradormant plants to short-photoperiod and prolonged cold treatment alone had minimal affect growth potential or on flowering (~1%); whereas endodormant crown buds without prolonged cold treatment, had delayed shoot growth and approximately 2% flowering when returned to growth promoting conditions. Transcriptome analyses revealed that 373 and 260 genes were differentially expressed (p<0.005) during para- to endo-dormant and endo- to eco-dormant transitions, respectively. Transcripts from flower competent vs. non-flower competent crown buds identified 607 differentially expressed genes, and genes involved in cell cycle and DNA processing, oxidative stress, flower regulation, and proteolysis were over-represented. Further, sub-network analysis identified expression targets and binding partners associated with circadian clock, dehydration/cold signaling, phosphorylation cascades, and response to abscisic acid, ethylene, gibberellic acid, and jasmonic acid, suggesting these central regulators affect well-defined phases of dormancy. Potential genetic pathways associated with these dormancy transitions and flowering were used to develop a proposed conceptual model. Leafy spurge is an herbaceous perennial weed that undergoes vegetative reproduction from an abundance of underground adventitious buds which exhibit phases of para-, endo-, and eco-dormancy (defined by Lang et al. 1987) during summer, fall, and winter, respectively (Anderson et al. 2005). In this study a population of leafy spurge plants were propagated through random cuttings from the genetically uniform biotype 1984-ND001. Paradormant crown buds from three-month old greenhouse plants were collected after one week of acclimation under growth chamber conditions. Induction of endodormancy in crown buds was accomplished by subjecting greenhouse grown and growth chamber acclimated plants to a ramp down (RD) treatment consisting of a reduction in temperature of 1.42°C week-1 (27°C â 10°C) and a decreasing photoperiod of 40 min week-1 (16h â 8h light) for 12 weeks as previously established by Foley et al. (2009). These conditions mimic the average seasonal environmental conditions experienced in Fargo, ND (46°54â² N, 96°48â² W) during the transition from para- to endo-dormancy (Anderson et al. 2005). To induce a transition of crown buds from endo- to eco-dormancy, plants subjected to the RD treatment were given prolonged cold treatment for 11 weeks at 5-7°C, under constant 8 h:16 h day:night cycle; light fluencies were approximately 250 μmol m-2 s-1. To compare the effects of the prolonged cold with or without RD treatment on dormancy status and flowering competence in crown buds, greenhouse-grown and growth chamber acclimated plants were subjected directly to an extended cold treatment for 11 weeks at 5-7°C, as previously described, without a RD treatment. For microarray hybridizations, labeled cDNAs were prepared from 30 µg of total RNA using the Alexa Fluor cDNA labeling kit (Invitrogen, Carlsbad, CA, USA) according to manufacturer's protocols. Labeled cDNAs were hybridized to a custom made 23K element microarray that contained 19,808 unigenes from a leafy spurge EST database (Anderson et al. 2007) and an additional 4,129 unigenes from a cassava EST database (Lokko et al. 2007). Comparison of gene expression between samples was accomplished using a rolling circle dye swap hybridization scheme (Churchill 2002) to provide every biological replicate with technical replicates. In our microarray analyses experiment, each of the four biological replicates included four technical replicates using two different dyes, resulting in a total of 16 technical replicates for each treatment. Microarray hybridization was visualized using a GenePix 4000B scanner and probe intensities and background were quantified using GenePix 6.0 software (Molecular Devices, Sunnyvale, California, USA). A quality control value of â1â was assigned to all probes that had intensity values greater than 2 times the standard deviation over average of the negative control and empty probe intensities (after deletion of 1% of the most intense negative/empty probe values). Hybridization intensities were log2 transformed, and arrays were centered and normalized against each other.
2010-05-19 | E-GEOD-19217 | biostudies-arrayexpress
Project description:Leafy spurge is a model for studying well-defined phases of dormancy in underground adventitious buds (UABs) of herbaceous perennial weeds, which is a primary factor allowing many invasive perennial weeds to escape conventional control measures. A 12-week ramp down in both temperature (27M-BM-0C M-bM-^FM-^R 10M-BM-0C) and photoperiod (16 h M-bM-^FM-^R 8 h light) is required to induce a transition from para- to endo-dormancy in UABs of leafy spurge. To evaluate the effects of photoperiod and temperature on molecular networks associated with this transition, we compared global transcriptome data-sets obtained from UABs of leafy spurge exposed to a ramp down in both temperature and photoperiod (RDtp) vs. a ramp down in temperature (RDt) alone. Analysis of transcriptome data-sets indicated that numerous genes associated with circadian clock, photoperiodism, flowering, and hormone responses (CCA1, COP1, HY5, MAF3, MAX2) were preferentially expressed during the transition from para- to endo-dormancy. Gene-set enrichment analyses highlighted metabolic pathways associated with ethylene, auxin, flavonoids, and carbohydrate metabolism; whereas, sub-network enrichment analyses identified hubs (CCA1, CO, FRI, mir172A, EINs, DREBs) of gene networks associated with carbohydrate metabolism, circadian clock, flowering, and stress and hormone responses during the transition to endodormancy. These results helped refine existing models for the transition to endodormancy in UABs of leafy spurge, which strengthened the roles of circadian clock associated genes, DREBs, COP1-HY5, carbohydrate metabolism, and involvement of hormones (ABA, ethylene, and strigolactones). Further, we propose that the RDtp treatment ultimately leads to a chain effect, responsive to photoperiod and temperature signaling, to synchronize molecular processes associated with the transition from para- to endo-dormancy. Plant material, environmental treatments, and vegetative growth Leafy spurge plants were propagated from the uniform biotype (1984-ND001) and maintained in a greenhouse as described by Anderson and Davis (2004). Prior to the start of each experiment, plants were acclimated in a Conviron growth chamber (Model PGR15) for one week at 27M-BM-0C, 16:8 h light:dark photoperiod. Each experiment was replicated four times, and each replicate contained 30 plants. Six plants from each replicate were used to determine vegetative growth rate, and crown buds from the remaining 24 plants were collected for transcriptome studies. All samples were collected between 11:00 and 13:00 a.m. to avoid diurnal variation. We previously established conditions for induction and release of dormancy phases under controlled environments (DoM-DM-^_ramacM-DM-1 et al. 2010; Foley et al. 2009). To induce endodormancy, paradormant plants were subjected to a ramp-down in temperature (27M-BM-0C M-bM-^FM-^R 10M-BM-0C) and photoperiod (16 h M-bM-^FM-^R 8 h light), i.e., RDtp, for 12 weeks (Fig. 1, Exp-1). To distinguish the individual effects of temperature and photoperiod on molecular networks involved in endodormancy induction (see Fig. 1, Exp-2), we compared three-month old paradormant plants subjected to a ramp-down in temperature (27M-BM-0C M-bM-^FM-^R 10M-BM-0C) under constant photoperiod (16 h light) for 12 weeks (i.e., RDt) to RDtp plants. Additionally, a set of paradormant plants were kept under constant temperature and light (27M-BM-0C, 16 h light) as a control. At the end of each treatment, the aerial portion of the plant was decapitated to determine the dormancy status of the crown buds by their vegetative growth rate in the greenhouse, as described by Foley et al. (2009). New vegetative shoot growth was recorded weekly; results were analyzed using the generalized linear mixed model (PROC GLIMMIX) procedure of SAS 9.2, and 95% confidence intervals for treatment by week means were generated. Transcriptome analyses At the end of each treatment, crown buds were collected from intact plants to study transcriptome profiles and were stored at -80M-BM-0C. RNA extraction, cDNA synthesis and fluorescent labeling, microarray hybridization using ~23K element arrays, and spot intensity analyses were performed as previously described (DoM-DM-^_ramacM-DM-1 et al. 2010). Transcriptome data obtained from Exp-1 and -2 (Fig. 1) was used for various bioinformatics analysis. GeneMaths XT 2.1 software was used to normalize the arrays, to conduct statistical analyses, and to generate Venn diagrams as previously described by DoM-DM-^_ramacM-DM-1 et al. (2010). Expression data for both Exp-1 and -2 are deposited at Gene Expression Omnibus (http://www.ncbi.nlm.nih.gov/geo/) as GEO dataset query GSE19217 and GSE??, respectively. The entire data set was further analyzed using Ariadne Pathway Studio 7 Software-Resnet Plant Version 2.1 (Ariadne Genomics Inc., Rockville, MD, USA) to obtain Gene Set Enrichment Analysis (GSEA) and Sub Network Enrichment Analysis (SNEA). GSEA is used to determine if predefined sets of genes are over-represented (P<0.05) between treatments; focusing on gene sets based on AraCyc metabolic pathways http://pmn.plantcyc.org/ARA/class-instances?object=Pathways, and gene ontology (GO) (http://www.geneontology.org/). SNEA algorithm was used to identify the networks by highlighting over-represented ontologies based on published gene regulation hierarchies, protein:protein interactions, or protein modification targets. Furthermore, these networks were visualized using the Union Selected Pathway function of the software for expression targets, binding partners, protein modification targets, and also custom advanced function to generate sub-networks as neighbors of proteins based on expression, regulation, molecular transport, protein modification, promoter binding, molecular synthesis, chemical reaction, and direct regulation.
2012-12-31 | E-GEOD-37477 | biostudies-arrayexpress
Project description:Ten populations were evolved for 6,000 generations. Five had strong selection for sporulation, imposed partially by their cultivation in sporulation-inducing medium, while the other five populations had relaxed selection for sporulation, by cultivating them in sporulation-repressing medium. Batch cultures were diluted 1:100 daily for approximately 892 days. In the five populations with relaxed selection for sporulation, sporulation ability was eventually lost. Keywords: comparative genome hybridization and transcriptome divergence Genomic DNA from all ten populations, and ancestors, was isolated, labeled and hybridized to microarrays. Only one hybridization was performed for each experimental population, with evolved and ancestral DNA hybridized to the slide. RNA hybridizations were done by chosing one strain that was evolved in sporulation-repressing medium and one strain that was evolved in sporulation-inducing medium. Two biological replicates were performed, as well as a dye swap for each biological replicate. Evolved and ancestral strains were grown in identical medium and RNA was isolated at the onset of stationary phase.
2010-06-30 | E-GEOD-4469 | biostudies-arrayexpress
Project description:We conducted a genome-wide survey of genes in Ae. aegypti females that are transcriptionally responsive upon challenge with dengue virus (serotype-2). The array was designed with 60-mer oligos specific to 16,092 gene transcripts of gene build AaegL1.1 (www. vectorbase.org). The hybridizations were performed at NimbleGen. We provided total RNA purified from the infected and control samples to NimbleGen. To identify dengue-specific transcription response (DTR) genes of MS and MR females upon infection with DENV2-JAM1409, a total of 15 independent samples (12 test samples and 3 control samples) were used for array hybridizations. These consisted of four DENV2 infected samples (MS-3hr, MR-3hr, MS-18hr and MR-18hr, post-infection, respectively) and a control sample that consisted of RNA isolated at the same time points following uninfected blood meals and pooled across strains and time of sampling. Three independent biological replicates were prepared for each of the above five samples were used for hybridizations. The Ae. aegypti genes responsive to dengue infection were identified in MOYO-S (MS) and MOYO-R (MR) females, upon challenging them with DENV serotype-2, by a genome-wide transcriptome analysis carried out using the NimbleGen oligonucleotide microarray format. We profiled gene expressions of Aedes aegypti mosquitoes, strain MOYO-S (MS, susceptible to dengue virus) and MOYO-R (MR, refractory to dengue virus) at 3 hr and 18 hr after infection with dengue virus (seroptype-2). The test samples were prepared in parallel to the control samples. The control samples were derived from females fed with normal blood that was not mixed with dengue (mock infection). The test samples were prepared from females that were fed with blood mixed with dengue virus (infectious meal). A total of 12 test samples were prepared that represented three biological replicates of dengue infected MS females at 3hr and 18 post-infection times; and MR females at 3hr and 18hr post-infection times. The test samples were compared to a common uninfected control that was prepared by pooling equal amount RNA of the individual control of both strains and both post-infection time points (MS at 3hr, MS at 18 hr, MR at 3hr and MR at 18hr). The control-pool strategy ensured us to identify genes that were responsive in response to dengue infection but not due to genetic differences between the two strains or developmental changes between the two post-infection time points. A total of 3 control pools were used in our array expression studies. Control-1 was prepared from RNA isolated from individual controls set up along with each of the test samples (MS at 3hr, MS at 18 hr, MR at 3hr and MR at 18hr) for the first biological replication. Similarly, control-2 was prepared from individual controls set up along with each of the test samples (MS at 3hr, MS at 18 hr, MR at 3hr and MR at 18hr) for the second biological replication. And control-3 was prepared from individual controls set up along with each of the test samples (MS at 3hr, MS at 18 hr, MR at 3hr and MR at 18hr) for the third biological replication. Thus, the three control pools represented three biological replicates corresponding to the three biological replicates of the test samples.
2011-09-29 | E-GEOD-16563 | biostudies-arrayexpress
Project description:To identify gene expression biomarkers associated with asbestos-related lung adenocarcinoma, we analyzed primary tumour gene expression for a total of 36 primary lung adenocarcinomas on 22,323 element microarrays, comparing 12 patients with lung asbestos body counts above levels associated with urban dwelling (ARLC-AC: asbestos-related lung cancer-adenocarcinoma) with 24 patients with no asbestos bodies (NARLC-AC: non-asbestos related lung cancer-adenocarcinoma). To identify gene expression biomarkers associated with asbestos-related lung tumorigenicity, we performed gene expression array analysis on tumours of 36 patients with primary lung adenocarcinoma, comparing twelve patients with lung asbestos body counts above levels associated with urban dwelling (ARLC-AC: asbestos-related lung cancer-adenocarcinoma) with twenty-four patients with no asbestos bodies (NARLC-AC: non-asbestos related lung cancer-adenocarcinoma). Synthesis of the labelled first strand cDNA was conducted using Amersham CyScribe Post-Labelling kit with starting material of 20 ug of total RNA. The amino-allyl labeled dNTP mix was added to the reaction to generate amino-allyl labelled second strand cDNA. Following the hydrolysis reaction, single-stranded cDNA probes were purified using Amersham GFX columns. Dye coupling reactions were performed by mixing the cDNA samples with Amersham Cy3 (reference) or Cy5 (tumour) and incubating in the dark. The reactions were purified with Amersham GFX columns to remove the unincorporated/quenched dyes. After the purification samples were combined for hybridization, the labeled cDNAs were co-hybridized to 22K oligo microarrays. Slides were scanned on GMS418 confocal scanner (Agilent). Genes differentially expressed between ARLC-AC and NARLC-AC were identified on fold change and P-value, and then prioritised using gene ontology.
2010-05-28 | E-GEOD-20875 | biostudies-arrayexpress
Project description:The data in this series forms the basis for the analysis presented in the above named paper. In this study, we used cDNA microarrays to ask if changes in gene expression are observed in response to a dietary shift in Drosophila melanogaster, a dietary generalist. Methods: Flies used in this study were derived from a multifemale collection at Iraklion, Crete, Greece, in August 2002 and reared in the laboratory for several generations. Three replicates were performed. At the start of each replicate, we collected 300 newly eclosed adults, separated them by sex, and stored them at low density in shell vials with standard cornmeal media for 3 days. Sexually mature males and females were placed together and allowed to mate. Mated females were allowed to oviposit overnight in chambers containing cornmeal medium filled Petri dishes (http://flyfood.arl.arizona.edu/cornmeal.php3). Hatching first instar larvae were reared for 36 hours on cornmeal medium in Petri dishes and then transferred to one of two conditions: 1) a control Petri dish consisting of cornmeal medium, or 2) an experimental Petri dish containing pure mashed banana. After 24 hours, larvae were plucked from these dishes, washed, transferred to microcentrifuge tubes in groups of 20, and flash frozen in liquid nitrogen. All samples were stored at -80C until RNA extraction. RNA was extracted from each tube using a Qiagen RNeasy kit (Qiagen, Inc., standard protocol). We used cDNA microarrays printed by the Genetic Analysis and Technology Core Custom Microarray Facility at the University of Arizona to assess expression levels. Printing material was amplified from BDGP Unigene library v1.0 containing 6K ESTs. Products were purified using Millipore Multiscreen filtration plates and re-suspended in 50%DMSO solution. Each product was printed in triplicate on Corning GAPSII aminosilane slides using a Virtek Chipwriter PRO microarray spotter. Between 10-15 micrograms of RNA were used for each reaction. RNA was reverse transcribed and labeled with one of two fluorescent dyes, Cy3 or Cy5 (details of protocol at http://gatc.arl.arizona.edu/Services/Microarray/aminoallyllabelling.html). Hybridization was completed on a Genomic Solutions Gentac automated hybridization station. Labeled material was allowed to hybridize to the array for 16 hours at 60°C. Wash conditions were: 1) low stringency wash twice at 50°C for 40seconds (1X SSC/ 0.2% SDS), 2) medium stringency wash twice at 42°C for 40 seconds ( 0.1X SSC/ 0.2% SDS), 3) high stringency wash twice at 42°C for 40 seconds (0.1X SSC). Hybridized arrays were scanned using the Applied Precision ArrayworxE slide scanner. We performed three independent hybridizations and three dye flips for a total of six arrays (2 treatments x 2 dyes x 3 replications = 12 samples, for 6 arrays). Each replicate consisted of an independent biological sample isolated on separate days. Identification of series: There are 18 series in this experiment. The second number in each series record represents the slide number (there were six slides used in this experiment). The third number in each series record represents the set on a given slide. For instance, for series record 331_2_1, these data correspond to slide 2, set 1. Each slide has 3 series numbers assoicated with it, representing set 1,2, or 3 on the slide. Each slide was paired with another in a "dye flip" experiment; thus, slides 2 and 3 were paired, slides 25 and 28 were paired, and slides 29 and 30 were paired. Keywords = dietary shifts Keywords = ecological genomics
2010-06-09 | E-GEOD-2687 | biostudies-arrayexpress
Project description:Lung cancer remains the leading cause of cancer death worldwide. Overall 5-year survival is about 10-15% and despite curative intent surgery, treatment failure is primarily due to recurrent disease. Conventional prognostic markers are unable to determine which patients with completely resected disease within each stage group are likely to relapse. To identify a gene signature associated with recurrent squamous cell carcinoma (SCC) of lung, we analyzed primary tumour gene expression for a total of fifty-one SCCs (stage I-III) on 22,323 element microarrays, comparing expression profiles for individuals who remained disease-free for a minimum of 36 months with those from individuals whose disease recurred within 18 months of complete resection. Cox proportional hazards modeling with leave-one-out cross-validation identified a 70-gene capable of predicting the likelihood of tumor recurrence and a 79-gene signature predictive for overall survival. These two signatures were pooled to generate a 111-gene classifier which achieved an overall predictive accuracy for disease recurrence of 72% (77% sensitivity, 67% specificity) in an independent set of fifty-eight stage I-III SCCs. This classifier also predicted differences in survival (log-rank P=0.0008, hazard ratio (HR), 3.8 [95% confidence interval, 1.6-8.7]), and was superior to conventional prognostic markers such as TNM stage or N stage in predicting patient outcome. Genome-wide profiling has revealed a distinct gene expression profile for recurrent lung SCC which may be clinically useful as a prognostic tool. Expression profiling using 22K element microarrays of 51 primary lung squamous cell carcinomas.
2010-07-01 | E-GEOD-5123 | biostudies-arrayexpress
Project description:Mycorrhizal fungi colonize orchid seed and induce the germination. This so-called symbiotic germination is a critical developmental process in the lifecycle of all orchids. However, the molecular changes taking place during the orchid seed symbiotic germination still remains largely unknown. To better understand the molecular mechanism of orchid seed germination, we performed comparative transcriptomic and proteomic analysis on Chinese traditional medicinal orchid plants, Dendrobium officinale to explore protein expression change at the different developmental stages between asymbiotic and symbiotic germination and identify the key proteins regulated symbiotic germination of orchid seeds. iTRAQ analysis from 8 samples identified 2256 plant proteins, of which, 308 proteins were differentially expressed across three developmental stages within asymbiotic or symbiotic accession and 229 proteins are differentially expressed in the symbiotic germination compared to asymbiotic germination. 32 proteins are co-upregulated in both proteomic and transcriptomic level for symbiotic germination compared to asymbiotic germination. Our results revealed that symbiotic germination of D. officinale seeds probably shares the common signal pathway with asymbiotic germination during the early germination stage.
2017-05-12 | PXD006102 | Pride
Project description:Vertebrates have two cohesin complexes that consist of Smc1, Smc3, Rad21/Scc1 and either SA1 or SA2, but their functional specificity is unclear. Mouse embryos lacking SA1 show developmental delay and die before birth. Comparison of the genome wide distribution of cohesin in wild-type and SA1-null cells reveals that SA1 is largely responsible for cohesin accumulation at promoters and at sites bound by the insulator protein CTCF. As a consequence, ablation of SA1 alters transcription of genes involved in biological processes related to Cornelia de Lange syndrome (CdLS), a genetic disorder linked to dysfunction of cohesin. We show that the presence of cohesin-SA1 at the promoter of myc and of protocadherin genes positively regulates their expression, a task that cannot be assumed by cohesin-SA2. Cohesin binding pattern along some gene clusters is also affected by the lack of SA1, leading to dysregulation of the genes within. We hypothesize that impaired cohesin-SA1 function in gene expression underlies the molecular etiology of CdLS. Examination of genome wide distribution of cohesin subunits in wildtype and SA1-null cells
2012-03-15 | E-GEOD-32319 | biostudies-arrayexpress