Project description:Mice were acclimatized for 2 weeks and randomly assigned to treatment and control groups (five per group). Animals were given a single dose of 250, 50, 5 and 0.5 mg/kg isoproterenol by oral gavage alongside 0.9% saline (vehicle control group)and sacrificed after eight hours. Total mouse liver RNA was isolated and used for the microarry analysis on custom oligonucleotide DNA microarray, the HC ToxArray V1.2.<br><br>
Project description:An oligonucleotide microarray, the HC ToxArrayTM was used to study the gene expression changes induced by lead acetate in mouse liver.
Project description:In this study, we employ high-density oligonucleotide microarrays to characterize the MutaMouse FE1 cell line at various stages of cell growth, in primary MutaMouse lung epithelial cell cultures, and in whole lung. Global transcriptional analysis and real-time RT-PCR was applied to (1) further define the cellular origin of the FE1 cell line and its responses under different culture conditions (media and substratum), (2) provide insight into the transcriptional differences in cellular processes between FE1 cultures compared to whole lung tissues, more specifically in toxicological response, and (3) preliminarily examine FE1 culture response to exposure of benzo(a)pyrene compared to whole animals. Total RNA samples from 3 cell culture types (50% FE1, %100 FE1, and Primary lung) or MutaMouse lung were labeled with Cyanine 5-CTP, and universal reference total RNA (Stratagene, CA, USA) was labeled with Cyanine 3-CTP (Perkin Elmer Life Sciences, Woodbridge, ON, Canada) using Agilent linear Amplification kits (Agilent Tech. Inc. Mississauga, ON, Canada) following the manufacturer's instruction. Briefly, double-stranded cDNA was synthesized using MMLV-RT with T7 promoter primer, starting with 5 ug total RNA. Cyanine-labeled cRNA targets were in vitro transcribed using T7 RNA polymerase. The synthesized cRNA was precipitated by LiCl and fragmented at 60 degrees C for 30 min with fragmentation solution. Cy5- sample cRNA and Cy3- reference cRNA were hybridized to Agilent mouse development microarrays (containing ~20,000 unique 60 mer oligonucleotides; Agilent Tech. Inc. Mississauga, ON, Canada) at 60 degrees C overnight with Agilent hybridization solution and washed according to manufacturer's instruction. Arrays were scanned on a VersArray ChipReader (BioRad Laboratories Ltd., Waterloo, Ontario, Canada), and data were acquired with ImaGene 5.5 (BioDiscovery, Inc. CA, USA). Present calls were determined as signals that were greater than the mean plus three times the standard deviation of the average of the negative control spots.
Project description:The use of custom-made focused microarrays has become a popular alternative, allowing the study of genes relevant to a specific hypothesis. To address the limitations of commercial arrays in toxicogenomics investigations, we have developed a custom mouse oligonucleotide microarray, the HC ToxArrayTM, which, by virtue of including genes that respond to a variety of chemical and physical stressors, is more relevant for toxicological studies. Furthermore, we have incorporated an extensive series of controls useful for both quality control and normalization of small focused arrays. Validation of the EC series for normalization was achieved by determining the gene expression profile in liver samples following treatment with the hepatotoxin phenobarbital. Technical variability experiments were also carried out by two different technicians using two hybridization methods (automated and manual) and compared. In this study, we demonstrate that dilution of oligonucleotides on the microarray itself provides an innovative approach allowing the full dynamic range of the scanner to be covered with a single gene spike-in. The dilution series can be used in a composite normalization to improve detection of differential gene expression and provide quality control measures.
Project description:Biological comparison of gene expression profiles of adult male whole MutaMouse lung with its immortalized 100% confluent epithelial lung cell line counterpart. White, P.A.,et al. 2003. Development and characterization of an epithelial cell line from MutaMouse lung. Environ Mol Mutagen 42,3 pgs 166-184
Project description:Cross-platform target gene screening in colorectal cancer (CRC): we have compared 25 tumoural CRC biopsies against their normal counterpart in 30 hybridizations with a home-made cDNA array (CNIO oncochip) and 16 hybridisations with a custom oligoarray (Agilent Technologies).
Project description:Pregnant dams were treated with 0.1% or 0.04% 6-propyl-2-thiouracil (PTU) in drinking water continuously from day 13 post conception until weaning to produce hypothyroid pups. livers were collected from vehicle and 0.1% PTU treated pups at post-natal day (PND) 15 and mRNA from these was subjected to microarray analysis using Agilent high-density oligonucleotide chips.
Project description:The aim of this study was to identify alarm (fast) and acclimation phase (delayed) changes in the gene expression pattern in leaves of maize (CM 109 genotype) subjected to moderate chilling for 28 hours.
Project description:Mating is a complex process that causes many behavioral and physiological changes, but the factors triggering these changes and the underlying molecular processes are not well characterized. Honey bee queens provide a convenient system for dissecting these factors (e.g., physical manipulation, insemination volume, insemination substance) via instrumental insemination. We examined the effects of carbon dioxide (CO2), a commonly used anesthetic in instrumental insemination that causes changes similar to those observed after mating, and physical manipulation, which presumably mimics the act of copulation, on the brain transcriptional changes in honey bee queens. We found significant gene overlap between our study and previous mating studies in honey bee queens and Drosophila. This suggests that molecular pathways regulating the mating process are conserved across different mating regimes of honey bees as well as across insect orders.