Hippocampus Illumina (Oct06) Rank Database modify this page

    Summary:

INITIAL DATA SET (TEST PURPOSE ONLY): The October 2006 INIA LXS Hippocampus data set provides estimates of mRNA expression in the adult hippocampus of 77 genetically diverse strains of mice including 75 LXS recombinant inbred strains and the two parental strains ILS/Ibg and ISS/Ibg (Institute of Behavioral Genetics).

The hippocampus is an important and intriguing part of the forebrain that is crucial in memory formation and retrieval, and that is often affected in epilepsy, Alzheimer's disease, and schizophrenia. Unlike most other parts of the brain, the hippocampus contains a remarkable population of stems cells that continue to generate neurons and glial cells even in adult mammals (Kempermann, 2005). This genetic analysis of transcript expression in the hippocampus (dentate gyrus, CA1-CA3) is a joint effort of 14 investigators that is supported by numerous agencies described in the acknowledgments section. Samples were processed using a total of 240 samples and 40 Illumina mouse-6 oligomer microarray slides. Twenty-seven mouse-6 slides and a total of 157 samples passed stringent quality control and error checking. We should note that this was our first experience using the Illumina Sentrix Mouse-6 v 1.0 platform and the initial set of 13 slides were of little use and are not included in this data set. This particular data set was processed using a simple Rank protocol developed in house at UTHSC. Values were log2 transformed and the current data range from 6 to 16.5.

In this initial data set, 859 probes have LRS values greater than 50.

    About the strains used to generate this set of data:

The LXS genetic reference panel of recombinant inbred strains consists of just over 77 strains. All of these strains have been inbred from more than 23 generation (F23). All of these strains have been genotyped at 13,377 SNPs.

These strains are available from Drs. Beth Bennett and Tom Johnson at the Institute of Behavioral Genetics, in Boulder Colorado.

    About the animals and tissue used to generate this set of data:

All animals were raised at the IBG in Boulder Colorado by Bennett and colleagues in an SPF facility. No cases were MHV positive. Mice were killed by cervical dislocation. Whole brain dissections were performed at the IBG by Bennett and colleagues and shipped in RNAlater to UTHSC. Most hippocampal dissections (bilateral) were performed by Zhiping Jia. Cerebella, olfactory bulbs, and brain stem were also removed and stored at -80 deg C. Hippocampal samples are very close to complete (see Lu et al., 2001) but probably include variable amounts of fimbria.

A pool of dissected tissue from four hippocampi and two naive adults of the same strain, sex, and age was collected in one session and used to generate cRNA samples. All RNA samples were extracted at UTHSC by Zhiping Jia.

All animals used in this study were between 53 and 90 days of age (average of 72 days; see Table 1 below).

Sample Processing: Samples were processed by Lu Lu and colleagues in the Illumina Core at UTHSC between July 25 and Oct 19, 2006. All processing steps were performed by Feng Jiao. In brief, RNA purity was evaluated using the 260/280 nm absorbance ratio, and values had to be greater than 1.83. The majority of samples were 1.9 to 2.1. RNA integrity was assessed using the Agilent Bioanalyzer 2100. The standard Eberwine T7 polymerase method was used to catalyze the synthesis of cDNA template from polyA-tailed RNA using the Ambion/Illumina (http://www.ambion.com/catalog/CatNum.php?AMIL1791) TotalPrep RNA amplication kit (Cat#IL1791). The biotin labeled cRNA was then evaluated using both the 260/280 ratio (values of 2.0 or 2.1 are acceptable) using a NanoDrop ND-1000 (http://www.nanodrop.com/nd-1000-overview.html). Those samples that passed QC steps (1-3% failed and new RNA samples had to be acquired and processed) were immediately used on the mouse-6 slide. The slides were hybridized and washed following standard Illumina protocols.

Replication and Sample Balance: We obtained a male sample pool and female sample pool from each strain. While all strains were orginally represented by matched male and female samples, one strain LXS34 consists of a single male sample.

Experimental Design and Batch Structure: This data set consists arrays processed in 12 groups over a three month period (July 2006 to Oct 2006). Most groups consisted of 12 samples. All arrays in this data set were processed using a single protocol by a single operator, Feng Yiao.

    Data Table 1:

This table lists all arrays by order of processing (Run), Sample ID, Strain, Sex, Age, number of animals in each sample pool (Pool), F generation number when less than 30 (GenN, and the Source of animals. SampleID is the ID number of the pooled RNA sample with a H1 through H3 suffix to indicate the actual hippocampal RNA aliquot used to prepare cRNA. Grp is the sequential group processing number (1 - 6).
index tube ID strain age sex batch ID pool sizel RMA outlier scale factor back ground average present absent marginal AFFX-b-ActinMur (3'/5') AFFX-GapdhMur (3'/5') source
1R2028H2129S1/SvImJ66F530.14.36264.490.4970.4840.0192.781.13JAX
205R2199H1WSB/EiJ58M530.043.17154.950.4750.5050.021.320.81JAX

    Downloading all data:

All data links (right-most column above) will be made active as sooon as the global analysis of these data has been accepted for publication. Please see text on Data Sharing Policies, and Conditions and Limitations, and Contacts. Following publication, download a summary text file or Excel file of data. Contact Lu Lu regarding data access probelms.

    About the array platform:

Illumina Sentrix Mouse6 Bead Array Platform: The Mouse6 array consists of ....

Position data for the 50-mer Illumina Mouse-6 array was downloaded from Sanger at http://www.sanger.ac.uk/Users/avc/Illumina/Mouse-6_V1.gff.gz

    About data processing:

This data set uses a simple rank order method in which mean expression of all probes are computed across all good arrays. The means are then ranked. This ranked list of probe mean values is used as a lookup table to assign values to ranked data from the individual arrays. This produces a set of array data that have precisely the same range and distribution of values per array. This is an extreme form of normalizing.

Sex of the samples was validated using sex-specific probe sets such as Xist (probe scl00213742.1_141-S) and Ddx3y (scl0013129.1_159-S).

    Data source acknowledgment:

Data were generated with funds to Lu Lu, Beth Bennett, Mike Miles, Melloni Cook from INIA.

  • Lu Lu, M.D.
    Grant Support: NIH U01AA13499, U24AA13513 (Lu Lu, PI)

    •     About this text file:

    Data uploaded by Hongqiang Li, Oct 30, 2006. This text file originally generated by LL and RWW on November 29, 2006. Updated by LL, Dec 1, 2006.