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Sample GSM242877 Query DataSets for GSM242877
Status Public on Nov 11, 2008
Title L1 vs L2_4H
Sample type RNA
 
Channel 1
Source name L2 of a SAM. L2 is a corpus, which will become internal part the matured plant.
Organism Zea mays
Characteristics Inbred line: B73
Developmental stage: 14-day old seedlings
Sample name: L2_4
Growth protocol Maize (Zea mays inbred line B73) kernels were planted ~2 cm deep in plastic pots (8.5 cm x 8.5 cm wide at the top and 7.5 cm deep) filled with SB 300 Universal (Sun Gro Horticulture). Pots were placed in an environmental control room (PGW-40, Percival Scientific). The light intensity at the growth medium surface was kept between 760 to 810 mol/m2s as measured with a quantum meter (Model QMSW, Apogee Instruments). Temperature and light cycles were set at 25C with 15-hour light conditions and at 20C with 9-hour dark conditions. Pots were watered with a solution containing 0.7 mM calcium nitrate. Tissue blocks including SAMs (3 mm x 2 mm x 1 mm) were harvested from 14-day-old seedlings and processed to prepare paraffin sections. This protocol is also available at our project web site:
http://maize-meristems.plantgenomics.iastate.edu/resources/protocols/
Extracted molecule total RNA
Extraction protocol PicoPure RNA Isolation Kit (Arcturus/Molecular Devices) was used to extract total RNA from LCM-collected L1 and L2 cells of maize SAMs according to the manual. The RNA samples were treated with RNase-free DNase I (Stratagene) on column using the DNase Incubation Buffer provided with PALM RNA ExtractionKit (P.A.L.M. Microlaser Technologies) according to the manual of PicoPure RNA Isolation Kit. Approximately 1 ng of Dnase I-treated total RNA from each sample was then amplified with RiboAmp HS RNA Amplification Kit (Arcturus/Molecular Devices).
Label Cy3
Label protocol Five to ten micrograms of amplified RNA (within each replication the same amount of amplified RNA was used for both L1 and L2) was labeled with Cy3 or Cy5 according to Nakazono et al. (2003, Plant Cell 15: 583-596) with slight modifications. Details of fluorescent target synthesis are available at our project website (http://maize-meristems.plantgenomics.iastate.edu/resources/protocols/). To remove dye-specific effects in the statistical analyses, Cy dyes were swapped between the RNA samples with odd and even numbers of the replications.
 
Channel 2
Source name L1 of a shoot apical meristem (SAM). L1 is a single cell layered tunica, which will become epidermal cell layers of the matured plant.
Organism Zea mays
Characteristics Inbred line: B73
Developmental stage: Vegetative SAMs from 14-day old seedlings
Sample name: L1_4
Growth protocol Maize (Zea mays inbred line B73) kernels were planted ~2 cm deep in plastic pots (8.5 cm x 8.5 cm wide at the top and 7.5 cm deep) filled with SB 300 Universal (Sun Gro Horticulture). Pots were placed in an environmental control room (PGW-40, Percival Scientific). The light intensity at the growth medium surface was kept between 760 to 810 mol/m2s as measured with a quantum meter (Model QMSW, Apogee Instruments). Temperature and light cycles were set at 25C with 15-hour light conditions and at 20C with 9-hour dark conditions. Pots were watered with a solution containing 0.7 mM calcium nitrate. Tissue blocks including SAMs (3 mm x 2 mm x 1 mm) were harvested from 14-day-old seedlings and processed to prepare paraffin sections. This protocol is also available at our project web site:
http://maize-meristems.plantgenomics.iastate.edu/resources/protocols/
Extracted molecule total RNA
Extraction protocol PicoPure RNA Isolation Kit (Arcturus/Molecular Devices) was used to extract total RNA from LCM-collected L1 and L2 cells of maize SAMs according to the manual. The RNA samples were treated with RNase-free DNase I (Stratagene) on column using the DNase Incubation Buffer provided with PALM RNA ExtractionKit (P.A.L.M. Microlaser Technologies) according to the manual of PicoPure RNA Isolation Kit. Approximately 1 ng of Dnase I-treated total RNA from each sample was then amplified with RiboAmp HS RNA Amplification Kit (Arcturus/Molecular Devices).
Label Cy5
Label protocol Five to ten micrograms of amplified RNA (within each replication the same amount of amplified RNA was used for both L1 and L2) was labeled with Cy3 or Cy5 according to Nakazono et al. (2003, Plant Cell 15: 583-596) with slight modifications. Details of fluorescent target synthesis are available at our project website (http://maize-meristems.plantgenomics.iastate.edu/resources/protocols/). To remove dye-specific effects in the statistical analyses, Cy dyes were swapped between the RNA samples with odd and even numbers of the replications.
 
 
Hybridization protocol Microarray slides were prehybridized in 5X SSC (1X SSC is 0.15 M NaCl and 0.015 M sodium citrate), 0.1% SDS, and 0.1 mg/ml bovine serum albumin at 42oC for 45 min, then rinsed with autoclaved, Millipore water, dipped in isopropanol, and dried by centrifugation. Each target was resuspended in 30 l hybridization solution (5X SSC, 0.1% SDS, 0.2 g/l of yeast tRNA, 0.2 g/l of polyadenylic acid, 25% super-pure (99.5%) formamide (Fisher Scientific). Targets hybridized to the same slide were mixed, heated at 95oC for 3 min, collected by centrifugation, applied to a prehybridized microarray slide and covered with a 24 x 60 mm LiferSlip (Erie Scientific Company). Ten microliters of 3X SSC were added to each of the two slots of the hybridization chamber (TeleChem). The array was then sealed, submerged in a 42oC water bath and incubated for 12 to 18 h. Subsequently, each array was washed in 1X SSC and 0.2% SDS for two minutes, 0.1X SSC and 0.2% SDS for two minutes, and 0.1X SSC for two minutes, followed by a quick rinse in autoclaved, Millipore water. Arrays were then dried via centrifugation. This protocol is also available at our project web site:
http://maize-meristems.plantgenomics.iastate.edu/resources/protocols/
Scan protocol Fluorescence of Cy3 and Cy5 on slides was detected at 10-micron resolution with a ScanArray 5000 (Packard). The following setting was used as initial laser power and PMT gain, respectively: 82 and 63 for Cy3 and 77 and 58 for Cy5. These values were slightly adjusted depending on slides to have enough signals for the lowest scans and to have approximately the same amounts of signals between the two channels for the majority of the spots. For each successive scan, laser power and PMT gain were increased by two to three units and three to four units, respectively. Each slide was scanned seven times. Subsequently, three scans for each slide (“low/L”, “medium/M” and “high/H”) were selected for statistical analyses. In details “L” means Low laser power and PMT, “M” means Medium laser power and PMT and “H” means High laser power and PMT.
Description RNA was isolated from LCM-collected L1 and L2 cells that were derived from five to ten SAMs to generate one biological replication. PicoPure RNA Isolation Kit (Arcturus/Molecular Devices) was used for RNA isolation as per manufacturer’s instruction. In total, six biological replications were used for each microarray platform (see below). Approximately 1 ng of total RNA from each of the L1 and L2 RNA samples was used as starting material for RNA amplification. RiboAmp HS RNA Amplification Kit (Arcturus/Molecular Devices) was used as per manufacturer’s instruction. Each RNA sample yielded 30 to 90 g of amplified RNA (aRNA). Five to ten micrograms of each aRNA sample (the same amount of aRNA was used within each replication) were indirectly labeled with Cy dye and hybridized to the GPL2557, GPL2572, and GPL3538 sample platforms.
Data processing Spots were removed for bad PCR and empty on the microarrays. All data were background corrected and then an R implementation of the lowess normalization method (Dudoit and Fridlyand, 2002, Genome Biol: 3 RESEARCH0036) was used to normalize the two channels for each combination of slide and scan intensity. The data were centered around 0 for each slide. Subsequently, the data from each scan was used to conduct a mixed linear model analysis separately for each of 44,654 spots using a strategy similar to that of Wolfinger et al. (2001, J Comput Biol 8: 625-637). Following the statistical analysis, an additional 6,608 spots were removed from the data set because of concerns regarding the quality of the associated DNA sequences; 384 control spots that contained exogenous DNA were also removed. As a result, this study reports the gene expression patterns of 37,662 “informative” spots.
 
Submission date Nov 14, 2007
Last update date Nov 15, 2007
Contact name Patrick S. Schnable
E-mail(s) schnable@iastate.edu
Phone 515-294-0975
Organization name Iowa State University
Street address 2035B Roy J Carver Co-Lab
City Ames
State/province IA
ZIP/Postal code 50011
Country USA
 
Platform ID GPL2557
Series (1)
GSE9610 A global analysis of gene expression in histological layers of the shoot apical meristem of maize

Data table header descriptions
ID_REF
VALUE Normalized log ratio value of background corrected and median centered intensities of red channel and green channel
Ch1_Signal Mean Pixel intensity averaged over the local signal region for green channel (Cy3)
Ch1_Background Mean Pixel intensity averaged over the local background region for green channel (Cy3)
Ch1_Signal Median Median pixel intensity computed over the local signal region for green channel (Cy3)
Ch1_Background Median Median pixel intensity computed over the local background region for green channel (Cy3)
Ch2_Signal Mean Pixel intensity averaged over the local signal region for red channel (Cy5)
Ch2_Background Mean Pixel intensity averaged over the local background region for red channel (Cy5)
Ch2_Signal Median Median pixel intensity computed over the local signal region for red channel (Cy5)
Ch2_Background Median Median pixel intensity computed over the local background region for red channel (Cy5)
Ch1_Norm Background corrected, normalized and median centered log value of green channel(Cy3)
Ch2_Norm Background corrected, normalized and median centered log value of red channel(Cy5)

Data table
ID_REF VALUE Ch1_Signal Mean Ch1_Background Mean Ch1_Signal Median Ch1_Background Median Ch2_Signal Mean Ch2_Background Mean Ch2_Signal Median Ch2_Background Median Ch1_Norm Ch2_Norm
1 -0.35006406 2818.9934 197.8527 2787 100 2798.3571 814.9895 2855 331 -0.18858682 -0.53865088
2 0.112877027 2998.0993 174.5205 2980 67 4338.6665 359.5487 4246 235 -0.12822691 -0.015349883
3 0.021659426 3825.3222 167.4646 3703 60.5 4980.2148 346.7206 4731 245 0.114062551 0.135721977
4 0.291056598 324.1555 177.412 336 73 695.7999 312.1739 639 222 -2.522523842 -2.231467244
5 -0.020883486 2070.7465 174.0688 1922.5 67.5 2833.6437 372.9171 2615.5 275 -0.487700103 -0.508583589
6 0.253144087 5195.2031 205.7619 5522 109 8105.8813 310.6819 8575 188 0.405707054 0.658851141
7 -0.224642005 691.0642 175.9199 580 65 944.6238 368.656 862 238 -1.609663485 -1.83430549
8 -0.367640733 1018.9606 181.8584 986 56.5 1196.7324 487.3596 1041.5 266 -1.185856261 -1.553496994
9 -0.040351984 8369.8671 209.9657 8130 111 9717.1259 425.6375 8178 239 0.884716324 0.84436434
10 0.501321007 1639.104 185.6228 1564 102 3624.8359 423.9187 3552 313.5 -0.752268404 -0.250947397
11 -0.026907031 5930.476 207.6676 5775 92 7194.6577 447.3313 6944.5 325.5 0.543657609 0.516750578
12 0.196520639 4119.582 209.5013 3652.5 84 6258.476 382.0473 5856 263 0.179314839 0.375835478
13 0.673852671 5900.1752 163.8153 6003.5 48 13957.4687 370.5 13266 243.5 0.540099757 1.213952428
14 0.082973912 1446.836 207.6223 1385 123.5 2227.6984 413.1951 1906.5 295 -0.887024106 -0.804050194
15 0.148721667 1992.3889 196.7945 1879.5 114 3085.5207 379.397 3009.5 247.5 -0.552867884 -0.404146217
16 0.032011028 5806.8618 192.0876 5603.5 78 7407.6284 380.0947 7456 261 0.524520526 0.556531554
17 0.151108986 3961.2673 158.368 4037 49.5 5791.1489 373.1095 5892 223.5 0.149434202 0.300543188
18 -0.516575567 3162.1481 180.0186 3086.5 81.5 2641.2075 366.0122 2530 284 -0.065739013 -0.58231458
19 -0.106683641 4941.0727 211.4174 5189 107 5554.3974 382.1201 5662 258 0.359187754 0.252504113
20 -0.125949115 8143.1411 203.037 8606.5 75 8741.6552 331.6315 9214 225 0.862358656 0.736409541

Total number of rows: 19200

Table truncated, full table size 1706 Kbytes.




Supplementary data files not provided
Processed data included within Sample table

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