Project description:PURPOSE: To provide a detailed gene expression profile of the normal postnatal mouse cornea. METHODS: Serial analysis of gene expression (SAGE) was performed on postnatal day (PN)9 and adult mouse (6 week) total corneas. The expression of selected genes was analyzed by in situ hybridization. RESULTS: A total of 64,272 PN9 and 62,206 adult tags were sequenced. Mouse corneal transcriptomes are composed of at least 19,544 and 18,509 unique mRNAs, respectively. One third of the unique tags were expressed at both stages, whereas a third was identified exclusively in PN9 or adult corneas. Three hundred thirty-four PN9 and 339 adult tags were enriched more than fivefold over other published nonocular libraries. Abundant transcripts were associated with metabolic functions, redox activities, and barrier integrity. Three members of the Ly-6/uPAR family whose functions are unknown in the cornea constitute more than 1% of the total mRNA. Aquaporin 5, epithelial membrane protein and glutathione-S-transferase (GST) omega-1, and GST alpha-4 mRNAs were preferentially expressed in distinct corneal epithelial layers, providing new markers for stratification. More than 200 tags were differentially expressed, of which 25 mediate transcription. CONCLUSIONS: In addition to providing a detailed profile of expressed genes in the PN9 and mature mouse cornea, the present SAGE data demonstrate dynamic changes in gene expression after eye opening and provide new probes for exploring corneal epithelial cell stratification, development, and function and for exploring the intricate relationship between programmed and environmentally induced gene expression in the cornea. Keywords: other
Project description:We collected whole genome testis expression data from hybrid zone mice. We integrated GWAS mapping of testis expression traits and low testis weight to gain insight into the genetic basis of hybrid male sterility. Gene expression was measured in whole testis from males aged 62-86 days. Samples include 190 first generation lab-bred male offspring of wild-caught mice from the Mus musculus musculus - M. m. domesticus hybrid zone.
Project description:To characterize the genetic basis of hybrid male sterility in detail, we used a systems genetics approach, integrating mapping of gene expression traits with sterility phenotypes and QTL. We measured genome-wide testis expression in 305 male F2s from a cross between wild-derived inbred strains of M. musculus musculus and M. m. domesticus. We identified several thousand cis- and trans-acting QTL contributing to expression variation (eQTL). Many trans eQTL cluster into eleven ‘hotspots,’ seven of which co-localize with QTL for sterility phenotypes identified in the cross. The number and clustering of trans eQTL - but not cis eQTL - were substantially lower when mapping was restricted to a ‘fertile’ subset of mice, providing evidence that trans eQTL hotspots are related to sterility. Functional annotation of transcripts with eQTL provides insights into the biological processes disrupted by sterility loci and guides prioritization of candidate genes. Using a conditional mapping approach, we identified eQTL dependent on interactions between loci, revealing a complex system of epistasis. Our results illuminate established patterns, including the role of the X chromosome in hybrid sterility. Gene expression was measured in whole testis in males aged 70(±5) days. Samples include 294 WSB/EiJ x PWD/PhJ F2s, 11 PWD/PhJ x WSB/EiJ F2s, 8 WSB/EiJ, 8 PWD/PhJ, 6 PWD/PhJ x WSB/EiJ F1s and 4 WSB/EiJ x PWD/PhJ F1s.
Project description:osteocyte is the mechanosensor in bone, taking up pivotal position in mediating the mechano-induced bone remodeling. Dimagnetic levitation has been used to stimulating a reduced gravity environment for studing the effects of changed gravity to different organisms.we constructed a superconducting magnet based platform with a large gradient high magnetic field(LG-HMF),which can provide three apparent gravity levels (μ-g,1-g and 2-g). osteocytes are sensetive to gravitational changes, our aim is to explore what responses do osteocytes exists under different gravitational environments in gene level, together with filtering the up- and down-regulated genes. mouse osteocyte-like cell line MLO-Y4 were cultured under three different apparent gravity levels (μ-g,1-g and 2-g) and normal gravity environment (control) for 48 hours, after which total RNA was extracted . And then RNA samples hybridized on affymetrix microarrays to obtain the whole genome expression profiles. the aim that we selected 48 hours as the cell culture time was to make a comparison with our previous researches of osteocytes.
Project description:Comparision of Mus musculus Control and Treated samples. Overall design: Low RNA Input Fluorescent Linear Amplification Kit (Agilent, Santa Clara, CA) was used for labeling. Briefly, both first and second strand cDNA were synthesized by incubating 500ng of total RNA with 1.2ul of oligo dT-T7 Promoter Primer in nuclease-free water at 65 ◦C for 10 min followed by incubation with 4.0ul of 5× First strand buffer, 2ul of 0.1M DTT, 1 ul of 10mM dNTP mix, 1ul of 200 U/ul MMLV-RT, and 0.5ul of 40U/ul RNaseOUT, at 40 ◦C for 2 hour. Immediately following cDNA synthesis, the reaction mixture was incubated with 2.4 ul of 10 mM Cyanine-3-CTP or 2.4 ul of 10 mM Cyanine-5-CTP (Perkin-Elmer, Boston, MA), 20ul of 4X Transcription buffer, 8 ul of NTP mixture, 6 ul of 0.1M DTT, 0.5 ul of RNaseOUT, 0.6ul of Inorganic pyrophosphatase, 0.8 ul of T7 RNA polymerase, and 15.3ul of nuclease-free water at 40 ◦C for 2 hour. Qiagen’s RNeasy mini spin columns were used for purifying amplified aRNA samples. The quantity and specific activity of cRNA was determined by using NanoDrop ND-1000 UV-VIS Spectrophotometer version3.2.1. Samples with specific activity >8 were used for hybridization. 825ng of each Cyanine 3 or Cyanine 5 labeled cRNA in a volume of 41.8ul were combined with 11ul of 10x Blocking agent and 2.2ul of 25x Fragmentation buffer (Agilent), and incubated at 60deg C for 30 minutes in dark. The fragmented cRNA were mixed with 55ul of 2x Hybridization Buffer (Agilent). About 110ul of the resulting mixture was applied to the Microarray and hybridized at 65degC for 17 hours in an Agilent Microarray Hybridization Chamber (SureHyb: G2534A) with Hybridization Oven. After hybridization, slides were washed with Agilent Gene expression Wash Buffer I for 1 minute at room temperature followed by a 1 min wash with Agilent Gene expression Wash Buffer II for 37C. Slides were finally rinsed with Acetonitrile for cleaning up and drying. Microarrays were scanned on an Agilent scanner (G2565AA) at 100% laser power, 30% PMT.Data extraction was carried out with Agilent Feature Extraction software (version 9.1), and normalization was done using linear per array algorithm according to the manufacturer’s protocol. The data was analysed by GeneSpring GX . The differential expression was considered if the Log 2 mean of at least -1 for the down regulated genes and +1 for the upregulated genes. We considered only the genes that were reproducible from all replicates.
Project description:Analysis of gene expression profiles is an attractive method for discovering how animals respond to environmental challenges in nature. Compared to low altitudes, high altitudes are characterized by reduced partial pressures of oxygen (hypoxia) and cooler ambient temperatures To better understand how mammals cope with high altitudes, we trapped wild house mice (Mus musculus domesticus) from 3 populations in La Paz, Bolivia (3000 - 3600 m) and 3 populations in Lima, Peru (0 – 200 m). Affymetrix GeneChip® Mouse Genome 430 2.0 Arrays were use to measure mRNA abundance in the livers of these mice. Eighteen male house mice were trapped from three different locations (3 mice per location)at high alttiude (La Paz, Bolivia, 3600 m) and from three locations at low altiditude (Lima, Peru, 100 m). Total mRNA was extracted from the livers and used for hybridization of Affymetrix GeneChip Mouse expression set 420.
Project description:High altitude environments are characterized by the unique and unavoidable stress of chronic hypoxia. While much is known about gene expression responses to acute or in vitro hypoxia, less is known about the gene expression profiles of animals exposed to systemic chronic hypoxia, such as that experienced at high elevations. Here we simulated the hypoxic environment of two high altitude elevations,and a third chamber recieved ambient Reno air. Mice were housed in the hypoxic chambers for 32 days. We used microarrays to characterize the differential gene expression in the livers of mice housed in hypoxic environment of 4500 m versus 3000 and 1400 m. We used this data to draw hypotheses related to novel physiological responses to chronic systemic hypoxia Overall design: Mice were housed one of three chambers; the first received ambient Reno air (1400 m) and the other two received air mixed with nitrogen such that one chamber simulated the hypoxic environment of 3000 m and the third chamber simulated hypoxic environment of 4500 m. Twelve mice were housed in each chamber for 32 days. Liver were extracted, and RNA from livers of 4 mice were pooled such that each treatment was represented by 3 pooled samples. Eight of the nine arrays were used for data analysis; one array was excluded as several Affymetrix quality control metrics indicated data quality that was not reliable.