%\VignetteIndexEntry{oneChannelGUI microarray gene-level data analysis overview} %\VignetteDepends{} %\VignetteKeywords{one channel microarray,extended Affymetrix GUI, limma, quality control, data filtering, time course, alternative splicing} %\VignettePackage{oneChannelGUI} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \documentclass[12pt]{article} \usepackage{times} \usepackage{hyperref} \textwidth=6.2in \textheight=8.5in \oddsidemargin=0.2in \evensidemargin=0.2in \headheight=0in \headsep=0in \begin{document} \title{oneChannelGUI Package Vignette} \author{Raffaele A Calogero, Francesca Cordero, Remo Sanges} \date{May 12 2011} \maketitle \section{Introduction} This package is an add-on of affylmGUI for \textit{mouse-click} based QC, statistical analysis and data mining for one channel microarray data. It is designed for Bioconductor beginners having limited or no experience in interacting with Bioconductor line commands. OneChannelGUI is a set of functions extending the affylmGUI capabilities, rearranging and extending affylmGUI menus. This package performs, in a graphical environment, the analysis pipe-line shown in figure \ref{fig:fig1}, green box. \begin{figure}[htbp] \begin{center} \includegraphics{fig1} \caption{\label{fig:fig1}Microarray analysis pipe-line.} \end{center} \end{figure} This vignette gives a general overview of the graphical interfaces available in oneChannelGUI for microarray gene-level analysis. \begin{Schunk} \begin{Sinput} N.B: All the oneChannelGUI graphical outputs are visualized in the R main window, to reduce RAM consumption, which is a critical issue when Affymetrix array data or large set of data are loaded. Furthermore, exon data generated with APT tools produce, in the working directory, a certain amount of temporary files and directories. A cleanup function is under development. At the present time, user can manually remove, from the working folder, any file starting with target, elevels, glevels, e.g. target51f81aeb, elevels3e9f6b76, and folders starting with out and outMidas, e.g. out17fb164, outMidas4a31ac4, without affecting the results stored in oneChannelGUI. \end{Sinput} \end{Schunk} \section{Installation} For the complete functionality of oneChannelGUI some external softwares and data need to be installed. Please refer to the \textit{install vignette} of oneChannelGUI package. \section{Main graphical window} oneChannelGUI inherits the core functionalities of affylmGUI and its main GUI. In oneChannelGUI some extra topics are available in the main affylmGUI info left frame, e.g. maSigPro results, Normalized Exon data, APT DABG, APT MiDAS, Splice Index, etc. Furthermore, four different menus are automatically exchanged depending on the type of array loaded: \begin{enumerate} \item .CEL IVT Affymetrix arrays. \item .CEL exon 1.0 ST arrays uploaded in oneChannelGUI by Affymetrix APT tools or gene/exon data exported from Affymetrix Expression Console. \item .CEL Gene 1.0 ST arrays uploaded in oneChannelGUI by Affymetrix APT tools. \item GEO/flat tab delimited expression data file. \item ILLUMINA output from BeadStudio software version 1, 2, 3 and GenomeStudio. \end{enumerate} Each item in the menus is simply a graphical implementation of a function of a specific Bioconductor library , e.g. ssize: sample size and statistical power estimation. To get more information on those libraries please refer to their specific vignettes, accessible from the \textit{Help menu}. \section{File} This menu allows the loading of .CEL IVT Affymetrix arrays as well as exon arrays, GEO Matrix Series files, tab delimited files containing only expression data and ILLUMINA data produced by BeadStudio and GenomeStudio. In this menu, fig. \ref{fig:fignew1}, are given the main functionalities to handle a microarray analysis project. \begin{figure}[htbp] \begin{center} \includegraphics{fignew1} \caption{\label{fig:fignew1} File menu.} \end{center} \end{figure} \subsection{New} The item \textit{New}, fig. \ref{fig:fignew1}, allow to load various types of array data, using the sub menu shown in fig. \ref{fig:fignew2}, \begin{figure}[htbp] \begin{center} \includegraphics{fignew2} \caption{\label{fig:fignew2} New: array type selection menu.} \end{center} \end{figure} \subsubsection{Target file structure} To load arrays oneChannelGUI uses the information available in a file describing the experimental structure of the data set. This file is called \textit{target file} and it is a tab delimited file with a fixed header structure also used by affylmGUI, fig. \ref{fig:fig3}. \begin{figure}[htbp] \begin{center} \includegraphics{fig3} \caption{\label{fig:fig3} Target file structure.} \end{center} \end{figure} \begin{Schunk} \begin{Sinput} IMPORTANT: TARGET FILE MUST NOT CONTAIN CHARACTERS LIKE ;,:_-|\!?+*^()[]{} \end{Sinput} \end{Schunk} \subsubsection{Loading Affy .CEL files} This sub menu, fig. \ref{fig:fignew2}, is enterily inherited by affylmGUI and allows to load .CEL files, if a Bioconductor cdf file is available. User will be asked to select the working folder, i.e. the one in which are present the .CEL files and the target file. \subsubsection{Loading EXON/GENE ARRAYS} This sub menu, fig. \ref{fig:fignew2}, allows to load exon/gene 1.0 ST arrays starting from .CEL, taking advantage of Affymetrix APT tools (\url{http://www.affymetrix.com/support/developer/powertools/index.affx}), or flat tab delimited files containing gene/exon level expression data exported from Affymetrix Expression Console (EC, \url{http://www.affymetrix.com/support/technical/software_downloads.affx}). If APT tool option is not used (it works only for Exon 1.0 ST data exported from EC), a sub-menu allows to select, for tab delimited data, the organism and the subset of exon data to be evaluated, fig. \ref{fig:fignew3} \begin{Schunk} \begin{Sinput} IMPORTANT: TO USE APT TOOLS THE DOWNLOAD OF GENE/EXON LIBRARY FILES IS REQUIRED. THIS CAN BE DONE WITH THE FUNCTION oneChannelGUI: Set library folder and install Affy gene/Exon library files LOCATED IN THE GENERAL TOOLS MENU \end{Sinput} \end{Schunk} \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew3} } \caption{\label{fig:fignew3} Sub menu to define the organism and the subset of exon data that will be loaded.} \end{center} \end{figure} Subsequently, the user will select: \begin{enumerate} \item a working directory, a target file, \item the flat tab delimited files containing respectively gene-level and exon-level data. \end{enumerate} If instead, APT tool option is selected, user will select: \begin{enumerate} \item the organism and the subset of exon arrays to be evaluated, fig. \ref{fig:fignew3}, \item a working directory, \item a target file, \item the type of probe set summary to be applied to gene/exon level data, fig. \ref{fig:fignew4}. \end{enumerate} \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew4} } \caption{\label{fig:fignew4} Sub menu to define the type of probe set summary to be applied.} \end{center} \end{figure} Concerning probe set summary options, fig. \ref{fig:fignew4}, PLIER/RMA model-based algorithms are available. Probe set summary calculation and uploading will take few minutes depending on the number of .CEL to be loaded and the PC in use. Ones probe set summary has been calculated, using APT tool, it is also possibile to calculate DABG p-values, fig. \ref{fig:fignew5}. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew5} } \caption{\label{fig:fignew5} Selecting DABG p-value calculation.} \end{center} \end{figure} DABG p-values represent \textit{data above background}, it is a p-value similar to that used to derive presence/absence calls in MAS 5.0. DABG p-values could be useful to remove low intensity signals which could produce mis-leading results when alternative splicing events are evaluated using the Splice Index, where signal intensity information is not considered. The progress of the probe set summary calculation is shown in the main R window. \begin{Schunk} \begin{Sinput} Gene level probe sets summary started Read 6 cel files from: target3d92750 Opening bgp file: HuEx-1_0-st-v2.r2.antigenomic.bgp Opening clf file: HuEx-1_0-st-v2.r2.clf Opening pgf file: HuEx-1_0-st-v2.r2.pgf Expecting 1 iteration. Doing iteration: 1 Opening clf file: HuEx-1_0-st-v2.r2.clf Opening pgf file: HuEx-1_0-st-v2.r2.pgf Loading 22011 probesets and 908532 probes. Reading 6 cel files......Done. Processing Probesets......................Done. Cleaning up. Done. Run took approximately: 9.56 minutes. Gene level probe sets summary ended Gene level probe sets summary ended Exon level probe sets summary started Exon level probe sets summary started Read 6 cel files from: target3d92750 Opening bgp file: HuEx-1_0-st-v2.r2.antigenomic.bgp Opening clf file: HuEx-1_0-st-v2.r2.clf Opening pgf file: HuEx-1_0-st-v2.r2.pgf Expecting 1 iteration. Doing iteration: 1 Opening clf file: HuEx-1_0-st-v2.r2.clf Opening pgf file: HuEx-1_0-st-v2.r2.pgf Loading 287329 probesets and 1111849 probes. Reading 6 cel files......Done. Processing Probesets......................Done. Cleaning up. Done. Run took approximately: 6.41 minutes. Exon level probe sets summary ended Exon level probe sets summary ended DABG calculation started Read 6 cel files from: target3d92750 Opening bgp file: HuEx-1_0-st-v2.r2.antigenomic.bgp Opening clf file: HuEx-1_0-st-v2.r2.clf Opening pgf file: HuEx-1_0-st-v2.r2.pgf Expecting 1 iteration. Doing iteration: 1 Opening clf file: HuEx-1_0-st-v2.r2.clf Opening pgf file: HuEx-1_0-st-v2.r2.pgf Loading 22011 probesets and 908532 probes. Reading 6 cel files......Done. Processing Probesets......................Done. Cleaning up. Done. Run took approximately: 3.55 minutes. DABG calculation ended \end{Sinput} \end{Schunk} \subsubsection{Loading GENE ARRAYS} This sub menu, fig. \ref{fig:fignew2}, allows to load gene 1.0 ST arrays starting from .CEL, taking advantage of Affymetrix APT tools (\url{http://www.affymetrix.com/support/developer/powertools/index.affx}). Subsequently, the user will select: \begin{enumerate} \item the organism and the subset of exon arrays to be evaluated, fig. \ref{fig:fignew73}, \item a working directory, \item a target file, \item the type of probe set summary to be applied to gene/exon level data, fig. \ref{fig:fignew74}. \end{enumerate} \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew73} } \caption{\label{fig:fignew73} Sub menu to define the organism and the subset of data that will be loaded.} \end{center} \end{figure} \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew74} } \caption{\label{fig:fignew74} Sub menu to define the type of probe set summary to be applied.} \end{center} \end{figure} Probe set summary calculation and uploading will take few minutes depending on the number of .CEL to be loaded and the PC in use. \subsubsection{Loading ILLUMINA BeadStudio} This sub menu, fig. \ref{fig:fignew2}, allows user to load expression data starting form the output of BeadStudio software. The interface allows to load outputs generated by BeadStudio version 1, 2 and 3. The Bioconductor annotation libraries for illumina arrays are associated to the loaded data. Since output of BeadStudio is not log2 transformed, a popup menu will allow the data modification. Furthermore, if BeadStudio data were not normalized, user could apply various normalization procedures available in the Menu Probe set summary. It is possible to load also data from beadstudio v3. Files should be tab delimited and contain at least Average signal intensity for PROBE LEVEL this is needed to use the annotation library available in Bioconductor. Here are described the steps to generate an export file from BeadStudio v3 compatible with onechannelGUI, figs. \ref{fig:fignew80}, \ref{fig:fignew81}, \ref{fig:fignew82}. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew80} } \caption{\label{fig:fignew80} After having generated an analysis in BeadStudio v3 enter in the analysis menu and select reports.} \end{center} \end{figure} \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew81} } \caption{\label{fig:fignew81} select the name of the final report and press OK.} \end{center} \end{figure} \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew82} } \caption{\label{fig:fignew82} Select sample probe profile, select ProbeID, the array slots you want to export and AVG \textunderscore signal column and all annotation data. Subsequently edit the file with excel and exchange the column ProbeID with the column PROBE\_ID present in the annotation section. Delete all columns unless PROBE\_ID and expression data} \end{center} \end{figure} \begin{Schunk} \begin{Sinput} An example of genome studio exported dataset before probeid_report_from_genomestudio.txt and after probeid_report_from_genomestudio_ready_foroneChanneGUI.txt the editing is available at http://sourceforge.net/projects/ochguiextras/files/illumina_array_reformat_examples/ \end{Sinput} \end{Schunk} In general tools menu us present the function GenomeStudio reformat that reformat the genome studio output in a format suitable for oneChannelGUI. \subsubsection{Loading GEO Matrix Series files} This sub menu, fig. \ref{fig:fignew2}, allows to load GEO Matrix Series files. To load a GEO Matrix Series file it is only necessary to locate in a specific folder a target file and the Matrix Series file downloaded from GEO database. \begin{Schunk} \begin{Sinput} NB: In the target file the FileName column must contain exactly the same names present in the header below the row !series_matrix_table_begin in the Matrix Series file. Instead Target column could be derived by the row !Sample_description in the Matrix Series file. \end{Sinput} \end{Schunk} \subsubsection{Creating a Target file from GEO matrix series file} To make easier to user the creation of target file for GEO matrix series files. This function, fig. \ref{fig:fignew1} opens the GEO matrix file of interest and creates a data frame with the following columns, Name, FileName, using the informations written in GEO file: \begin{Schunk} \begin{Sinput} Name: !Sample_title FileName: ID_REF Target: !Sample_source_name_ch1 \end{Sinput} \end{Schunk} The data frame is the written in the working directory This target can be further edited and used to load the GEO matrix series file in oneChannelGUI. \begin{Schunk} \begin{Sinput} N.B. Editing of the target file is frequently neded to correctly organize the Target column, to fullfil the user analysis needs. The Target file could contain a subset of the array data present in the series matrix file. oneChannelGUI will load only the columns of the GEO matrix series file present in the Target file. \end{Sinput} \end{Schunk} \subsubsection{Combining GEO matrix series file} In large GEO experiments, e.g. GSE2109, the experiment is splitted in mutiple Matrix Series Files. The function \textit{Combining GEO matrix series file} ,\ref{fig:fignew1}, allows to combine the splitted Matrix series Files in a unique ExpressionSet to be used in oneChannelGUI. The user need to prepare a target file for each of the pieces of the experiment to be combined. The function will ask the user the number of GEO matrix series files to be combined and subsequently for each of them will ask for the Target file name and for the corresponding GEO matrix series file to be loaded. \subsubsection{Loading Tab delimited files} This sub menu, fig. \ref{fig:fignew2}, allows to load tab delimited file containing expression data only. Also in this case the target and the expression file are the only two files needed to load these data in oneChannelGUI. In the target file the FileName column should contain exactly the same names present in the header of the tab delimited matrix file. Example of targets are available at \url{http://www.bioinformatica.unito.it/bioinformatics/DAGEL.II/}. Actually a specialized module to load \textit{processed-data} derived from ArrayExpress database \url{http://www.ebi.ac.uk/arrayexpress/} is not available. However, \textit{processed-data}, reorganized in a flat tab delimited file containing only expression values, can be loaded on oneChannelGUI. \subsection{Open, Save, Save as} A project can be saved using the functions \textit{Save as} fig. \ref{fig:fignew1}. A microarray project can also be uploaded again in oneChannelGUI with the function \textit{open}. \subsection{Exporting normalized expression values} This function, fig. \ref{fig:fignew1}, allows to export, as tab delimited files expression data, loaded in oneChannelGUI. This function is also located in \textit{filtering menu} and in the \textit{exon menu}. If exon arrays are loaded in oneChannelGUI it is possible to extract not only the gene level expression data available but also exon level expression data and any other data generated during exon array analysis: Splice Index, MiDAS p-values, RP alternative splicing data. \subsection{Info about the loaded data set} This function, fig. \ref{fig:fignew1}, gives information about the set of data loaded in oneChannelGUI and on the corresponding annotation library, if available. \subsection{Attaching annotation lib info} If a Bioconductor library is available this is attached to the data loaded in oneChannelGUI and it will appear in the output of \textit{Info about the loaded data set}. Using \textit{Attaching annotation lib info} function, after loading expression data as a tab delimited file, it is possible to attach the Bioconductor annotation library associated to it. In case gene-level Affymetrix Whole transcriptome data are loaded as tab delimited file HuEx for human, MoEx for mouse and RaEx for rat annotation need to be attached. This is needed to allow the attachment of annotation information to the data set. \subsubsection{Probe set annotation} The Bioconductor annotation library for IVT Affymetrix arrays or GEO Matrix Series file are directly attached. Concerning Exon 1.0 ST arrays, gene level annotation information are actually embedded in oneChannelGUI, and a stand alone function is provided to use gene-level annotation externaly to oneChannelGUI. For exon arrays annotation is available at the gene level for the core subset of Hs/Mm/Rn. Info about the available Affymetrix annotation release can be found in the main R window as part of the oneChannelGUI release major changes. For EXON 1.0 ST arrays, it is possible to link GeneBank accession numbers and EG to the gene-level probe sets using the function \textit{Attaching ACC to Probe set IDs}, present in the Biological Interpretation menu. This function also allows to link EGs to glevel probe sets of a tab delimited fine that has in the first column the probe set ids. It is also possible to extract exon-level Probe Selection Region sequences associated to a specific gene-level probeset using the function \textit{Extracting exon-level PSR sequences associated to one gene-level probeset} in the Biological Interpretation menu. \section{RNA target} The first item in the menu, fig. \ref{fig:fignew6}, is inherited from affylmGUI and allows the visualization of the experimental structure described by the target file used to load the expression data. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew6} } \caption{\label{fig:fignew6} RNA target menu.} \end{center} \end{figure} The second item, fig. \ref{fig:fignew6}, \textit{maSigPro create/view edesign} reorganizes the target file to extract all the information needed to analyse a time course experiment using maSigPro. For time course experiments a specific target file is needed, fig. \ref{fig:fig4}. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fig4} } \caption{\label{fig:fig4} Target file for time course analysis.} \end{center} \end{figure} Each row of the column named Target, in the target file, describes the array on the basis of the experimental design. Each element needed for the construction of design fro time course is separated from the others by an underscore. The first three elements of the row are fixed and represent \texttt{Time Replicate Control}, all separated by an underscore: \begin{Schunk} \begin{Sinput} Time_Replicate_Control \end{Sinput} \end{Schunk} All the other elements refer to various experimental conditions. Considering two different conditions to be evaluated each row is made of 5 elements: \begin{Schunk} \begin{Sinput} Time_Replicate_Control_cond1_cond2 all separated by an underscore. \end{Sinput} \end{Schunk} Having an experiment made of 9 arrays, with two time points, 0h and 24h, in triplicate, and two different experimental conditions to be evaluated, the target file will look like: \begin{Schunk} \begin{Sinput} Name FileName Target mC1 M1.CEL 0_1_1_0_0 mC2 M4.CEL 0_1_1_0_0 mC3 M7.CEL 0_1_1_0_0 mE1 M3.CEL 24_2_0_1_0 mE2 M6.CEL 24_2_0_1_0 mE3 M9.CEL 24_2_0_1_0 mI1 M2.CEL 24_3_0_0_1 mI2 M5.CEL 24_3_0_0_1 mI3 M8.CEL 24_3_0_0_1 \end{Sinput} \end{Schunk} The third item, fig. \ref{fig:fignew6}, instead refers to the reorganization of a target file containing the information related to clinical parameters to be used for classification pourposes. In this case each clinical parameter is separated from the others by an underscore as in the case of the time course. The absence of a parameter \texttt{NEEDS} to be indicated in the Target file by NA. Having an experiment made of 9 arrays with 4 different experimental/clinical parameters the target file will look like: \begin{Schunk} \begin{Sinput} Name FileName Target mC1 M1.CEL 0_1_pos_0_NA mC2 M4.CEL 0_1_pos_0_yes mC3 M7.CEL 0_1_neg_0_no mE1 M3.CEL 24_2_neg_1_NA mE2 M6.CEL 24_2_NA_1_yes mE3 M9.CEL 24_2_neg_1_yes mI1 M2.CEL 12_3_0_pos_yes mI2 M5.CEL 12_3_0_pos_no mI3 M8.CEL 12_3_0_pos_no \end{Sinput} \end{Schunk} Once the target file is reorganized by \textit{create/view classification parameters} function, the user will be requested to selected an external file containing the description of the experimental/clinical parameters. In this file, the description of each parameter is separated from the others by a carriage return. \begin{Schunk} \begin{Sinput} Drug treatment time Tumor grade IHC ER Metastasis within 5 years Positive lymphonode \end{Sinput} \end{Schunk} This information will be used to selected a specific clinical parameter for classification analysis. \section{QC} The functions available in this menu are specific of the type of microarray data set loaded \subsection{QC for IVT arrays loaded starting from .CEL files} This menu, fig. \ref{fig:fignew7}, inherits all affylmGUI probe/probe set level quality controls, please refer to affylmGUI for their usage. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew7} } \caption{\label{fig:fignew7} QC for IVT arrays.} \end{center} \end{figure} Furthermore, after probe set summary is calculated, samples similarities can be visualized using the \textit{Sample QC: PCA/HCL} function, producing a 2D PCA plot and a hierachical clustering of the samples, fig. \ref{fig:fignew8}. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew8} } \caption{\label{fig:fignew8} Sample QC: PCA/HCL output for IVT arrays. First panel on the left side contains the information content described by each of the PCs. Panel in the middle PC2 vesus PC1 plot. Last panel on the right HCL.} \end{center} \end{figure} If exon data are loaded the function \textit{Gene/Exon PCA/HCL} results could be visualized both at gene or exon level. Furthermore, the function \textit{Gene/Exon Intensity Histogram} will show the density plot of the normalized intensities both at gene and at exon level. \subsection{QC for GEO/flat tab delimited files} Ones probe set expression data derived by GEO Matrix Series file or an expression tab delimited file \textit{Sample QC: PCA/HCL} function is available as QC. There is also the function \textit{Box plot of normalized data} which show the array distribution as box plot \ref{fig:fignew72}. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew72} } \caption{\label{fig:fignew72} Box plot of normalized data.} \end{center} \end{figure} \subsection{QC for exon arrays} In the case of exon array the QC menu is slighly different, as shown in fig. \ref{fig:fignew9} \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew9} } \caption{\label{fig:fignew9} QC menu for exon arrays.} \end{center} \end{figure} Two functions are available: \begin{description} \item[Sample QC: PCA/HCL] This function will produce a PCA/HCL for both gene/exon level data. \item[Gene/Exon intensity histogram] This function will produce a density histogram for gene or exon expression levels. \item[Controls raw intensity histogram] This function will produce a box plot for exon, positive controls, and introns, negative controls, for housekeeping genes. Probe level data are directly extracted from CEL files using APT tools. \end{description} It useful, as quality control, to check intensities before normalization. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew75} } \caption{\label{fig:fignew75} A set of Illumina arrays before and after data normalization.} \end{center} \end{figure} As it can be seen in fig. \ref{fig:fignew75} normalization masks the fact that a sub set of arrays, i.e. those with a very narrow boxplot \ref{fig:fignew75}A, had something wrong in hybridization. This problem is completely masked in the normalized data \ref{fig:fignew75}B. For this reason \textit{Controls raw intensity histogram} was written for exon array data since probe sets data are directly uploaded as normalized in oneChannelGUI, via APT tools. This function produce a box plot for exon, positive controls, and introns, negative controls, for housekeeping genes. This box plot gives an idea of signals both at high and low intensity range. \section{Study design} This menu allows to investigate the statistical quality of a microarray study, fig. \ref{fig:fignew10}. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew10} } \caption{\label{fig:fignew10} Study design menu.} \end{center} \end{figure} This menu gives access to two functions, which are graphical implementations of the sizepower Bioconductor library. These functions allow user to determine how many samples are needed to achieve a specified power for a test of whether a gene is differentially expressed or, in reverse, to determine the power of a given sample size. \section{Probe set summary} This menu inherits the affylmGUI probe set summary methods for IVT arrays. Furthermore, the \textit{expresso} function, which allows the integration of different methods for background correction, normalization, probe specific correction, and summary value computation, is added. This menu is also available for GEO and tab delimited expression data files and it allows to perform the following normalization procedures if a data set without normalization is loaded: \begin{enumerate} \item Cyclic LOESS. \item QUANTILE. \item QSPLINE. \end{enumerate} \section{Filtering} A central problem in microarray data analysis is the high dimensionality of gene expression space, which prohibits a comprehensive statistical analysis without focusing on particular aspects of the joint distribution of the gene expression levels. Possible strategies are to perform data-driven nonspecific filtering of genes (von Heydebreck, 2004) before the actual statistical analysis or to filter, making use of biologically relevant a priori knowledge. This menu allows user to apply a variety of filtering procedures, fig. \ref{fig:fignew11} \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew11} } \caption{\label{fig:fignew11} Filtering menu for GEO/Affy IVT arrays.} \end{center} \end{figure} \subsection{Filtering by IQR} The IQR filter will select only those probe sets characterized by a relative large signal distribution. The way the IQR filter is shown in fig. \ref{fig:fignew12} \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew12} } \caption{\label{fig:fignew12} IQR filtering: The distributions of the various probe sets beloging to a data set are shown in red, if they are wide and they are retained by the filter, and in blue, if they are narrow and they are discarded by the filter.} \end{center} \end{figure} In oneChannelGUI it is possible to select three filtering values: \begin{enumerate} \item IQR 0.1, weak filter, i.e. only the estreme unchanging probe sets are removed. \item IQR 0.25, intermediate filter. \item IQR 0.5, strong filter, i.e. the majority of the unchanged probe sets are removed. \end{enumerate} This filtering procedure can be applied to any kind of loaded arrays. However, it seems not to be very effective when it is used to gene level expression data calculated with iterPlier. \subsection{Filtering by intensity} For IVT/GEO/tab delimited expression data files it is also possibile to apply a filtering procedure based on intensity signals, the graphical interface to do it is shown in fig. \ref{fig:fignew13}. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew13} } \caption{\label{fig:fignew13} Intensity fitering: This filter will retain a probe set only if a certain fraction of the samples are characterized by an intensity value over a certain user defined threshold.} \end{center} \end{figure} This filtering approach is quite useful to remove probe sets having very low intensity values. \subsection{Filtering by list of probe sets/EG ids} It is also possible to filter expression data using a text file containing a list of probe set ids separated by carriage return. If the data set is associated to a Bioconductor annotation library the filtering procedure can be also done using a text file containing a list of Entrez gene identifiers separated by carriage return. \subsection{Recovering unfiltered data} It is possible to recover the data before the last filtering using the \textit{Recovering unfiltered data} function. \section{Modelling statistics} This menu allows to perform limma differential expression analysis as well as time course analysis using the maSigPro package, fig. \ref{fig:fignew14}. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew14} } \caption{\label{fig:fignew14} Modelling statistics} \end{center} \end{figure} \subsection{limma} The affylmGUI interface to limma is fully inherited, see limma and affylmGUI vignettes for usage. The function \textit{raw p-value distribution} is implemented to evaluate if the BH/BY type I error correction methods could be used. To apply BH correction two conditions should be satisfied: \begin{enumerate} \item The gene expressions are independent from each other. \item The raw distribution of p-values should be uniform in the non significant range. \end{enumerate} Instead if BY correction is used it is sufficient only the second one, fig. \ref{fig:fignew15}. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew15} } \caption{\label{fig:fignew15} Output of \textit{raw p-value distribution}: The raw distribution of p-values is uniform in the non significant range.} \end{center} \end{figure} The affylmGUI function \textit{Table of genes ranked in order of differential expression} is a modified version of the original found in affylmGUI to allow users to check with MA/Volcano plots the set of differentially expressed probe sets before saving the table, fig. \ref{fig:fignew16}. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew16} } \caption{\label{fig:fignew16} MA and Volcano plots for differentially expressed probe sets, red dots, detected by limma method.} \end{center} \end{figure} The limma analysis, implemented in affylmGUI, does not allow the inclusion in the model of batch effect. A new function \textit{Two groups Linear Model with batch effect}, in the Modelling menu, integrates in linear model batch effect. This functionality is only available for two sample groups. For this analysis the different origins of the samples are inserted in the Target column of the target file as shown below in the Rank Product section. \subsection{Venn diagrams between probe set list} This function is modified with respect to the original one presents in affylmGUI to allow Venn diagrams using lists of probe sets, saved in text files where each id is separed by the others by carriage return, derived by any of the available statistical methods implemented in oneChannelGUI. Furthermore, if a Bioconductor annotation library is linked to the loaded data set, Venn diagrams can be generated using the Entrez Gene ids associated to the probe sets, removing probe sets retundancy. \subsection{Time course analysis} Time course analysis can be performed on oneChannelGUI using maSigPro package, fig. \ref{fig:fignew14}. maSigPro is a R package for the analysis of single and multiseries time course microarray experiments. maSigPro follows a two steps regression strategy to find genes with significant temporal expression changes and significant differences between experimental groups. To handle the batch effect the target file should be organized as the target file used in the RankProduct section. The first step, to run maSigPro analysis, is to reorganize the target file using the function \textit{create an edesign for maSigPro}, see also target file paragraph for time course experiment requirements. Using the function \textit{Execute maSigPro} user will select the parameters needed for maSigPro, fig. \ref{fig:fignew17}. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew17} } \caption{\label{fig:fignew17} maSipPro parameters setup.} \end{center} \end{figure} \subsubsection{Lever of FDR control: Q parameter} The first step is to compute a regression fit for each gene. The p-value associated to the F-Statistic of the model are computed and they are subsequently used to select significant genes. maSigPro corrects this p-value for multiple comparisons by applying false discovery rate (FDR) procedures. The level of FDR control is given by the function parameter Q, fig. \ref{fig:fignew17}. \subsubsection{P-value cut off: alfa} maSigPro applies, as second step, a variable selection procedure to find significant variables for each gene. This will ultimatelly be used to find which are the profile differences between experimental groups. At each regression step the p-value of each variable is computed and variables get in/out the model when this p-value is lower or higher than the given cut-off value alfa, fig. \ref{fig:fignew17}. \subsubsection{R-squared threshold of the regression model} The last step in maSigPro analysis is to generate a lists of significant genes. As filtering maSigPro uses the R-squared of the regression model, fig. \ref{fig:fignew17}. maSigPro calculation steps can be followed on the main R window. The end of the maSigPro analysis will be given by a popup message, fig. \ref{fig:fignew18}. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew18} } \caption{\label{fig:fignew18} End of maSigPro calculation.} \end{center} \end{figure} N.B: Multiple test problem is also present in maSigPro analysis. Therefore, before running maSigPro, remember to perform some filter based on functional information or samples distribution. \subsubsection{View maSipPro results} The coefficients obtained in the second regression model will be useful to cluster together significant genes with similar expression patterns and to visualize results. Various visualization options are available: \begin{enumerate} \item Venn diagrams, fig. \ref{fig:fignew19} . \item Expression profiles saved in a pdf file, figs. \ref{fig:fignew20}, \ref{fig:fignew21}. \item Tab delimited files with the probe sets found differentially expressed in each of the experimental conditions. \end{enumerate} \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew19} } \caption{\label{fig:fignew19} maSigPro Venn diagrams output.} \end{center} \end{figure} \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew20} } \caption{\label{fig:fignew20} Selecting the experimental condition to be used to profiles plotting.} \end{center} \end{figure} \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew21} } \caption{\label{fig:fignew21} An example of profiles plotting.} \end{center} \end{figure} \section{Permutation statistics} The permutation statistics menu, fig. \ref{fig:fignew22}, allows to run two class unpaired SAM analysis implemented in the siggenes package and two class samples analysis using the rank product method implemented in RankProd package. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew22} } \caption{\label{fig:fignew22} Permutation statistics menu.} \end{center} \end{figure} \subsection{SAM analysis} The module recognizes if a two class unpaired analysis can be performed. Subsequently, a table with DELTA values and FDRs will be shown to the user. Furthermore, user need to select a delta threshold to continue the analysis, fig. \ref{fig:fignew23}. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew23} } \caption{\label{fig:fignew23} DELTA table and DELTA value selection module.} \end{center} \end{figure} Siggenes output for differentially expressed genes, given the selected DELTA value, will be shown in the main R window, fig. \ref{fig:fignew24}, togheter with a absolute log2(FC) selection module, fig. \ref{fig:fignew24}. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew24} } \caption{\label{fig:fignew24} SAM results given at specific user defined DELTA value and the absolute log2(fc) selection mask.} \end{center} \end{figure} The fold change filters allows the selection, within the SAM significant probe sets, of those grater than a user defined threshold. Subsequently, the differentially expressed genes will be shown, fig. \ref{fig:fignew25}, and the user will decide if they should be saved. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew25} } \caption{\label{fig:fignew25} Differentially expressed probe sets to be saved.} \end{center} \end{figure} \subsection{Rank product analysis} The RankProd module is a graphical interface to the RankProd package functions for the analysis of gene expression microarray data. RankProduct package allows the identification of differentially expressed genes using the so called rank product non-parametric method (Breitling et al., 2004, FEBS Letters 573:83) to identify up-regulated or down-regulated genes under one condition against another condition, e.g. two different treatments, two different tissue types, etc. The user needs only to define the pfp (percentage of false prediction) threshold and the number of permutations to be applied, fig. \ref{fig:fignew26}. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew26} } \caption{\label{fig:fignew26} RankProd selection parameters mask.} \end{center} \end{figure} At the end of the analysis the user will decide if he would like to save the differentially expressed probe sets in a tab delimited file. If a Bioconductor annotation library is available Entrez Gene identifier and Symbols will be added to the saved output. \subsubsection{Target structure} In a rank product analysis for data sets from different origin the structure of the Target column of the target file can contain also an integer describing the data origin. \begin{Schunk} \begin{Sinput} Name FileName Target mC1 M1.CEL 0_1 mC2 M4.CEL 0_1 mC3 M7.CEL 0_1 mE1 M3.CEL 0_2 mE2 M6.CEL 0_2 mE3 M9.CEL 1_1 mI1 M2.CEL 1_1 mI2 M5.CEL 1_2 mI3 M8.CEL 1_2 \end{Sinput} \end{Schunk} The oneChannelGUI module will select the RankProd method on the basis of the Target structure. \section{Classification} This module, fig. \ref{fig:fignew27}, provides a link to the pamr and pdmclass packages designed to carry out sample classification from gene expression data, respectively by the method of nearest shrunken centroids (Tibshirani, et al., 2002) and by penalized discriminant methods. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew27} } \caption{\label{fig:fignew27} Classification menu.} \end{center} \end{figure} \subsubsection{Create/view/reset classification parameters} The \textit{Create/view classification parameters} function reorganizes the Target columns separating the experimental/clinical parameters. The \textit{Reset classification parameters} function deletes the Targets reorganization and the association to the file containing the names of the parameters present in the Target column of the target file. \subsubsection{Create a training/test set} The first step of this module is the definition of the covariate to be used for the classification analysis. The user will be requested to select, from a table, listing the names clinical parameters, i.e. phenoData covariate names, one of them indicating its row number, fig. \ref{fig:fignew29}. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew29} } \caption{\label{fig:fignew29} Selecting the classification parameter.} \end{center} \end{figure} Subsequently, the user could decide to divide the data set in a training (2/3) and a test (1/3) set or use the full data set as training set. All arrays, which are not linked to any of clinical/experimental params, i.e. those marked as NA, will be discarded from the following analyses. The \textit{Create a training/test set} function then allows the access to PAMR/PDMCLASS classification tools and to a PCA visualization module, fig. \ref{fig:fignew28}. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew28} } \caption{\label{fig:fignew28} Classification methods selection mask.} \end{center} \end{figure} It is also possible to evaluate how the classification performance can be associated to a single subset of probesets or if it is a general characteristic of the data set. Ideally we espect that only a small subset of probe sets should be able to discriminate between groups, if the full data set is able to discriminate in a way independent by the subset of probe sets considered for the classification it might be an indication of some bias that could not be necessarely associated to the biological event under investigation, eg. it could be due to some experimental bias. This functionality is provided if the \textit{Probability of classification given a random set of data} option is selected, see fig. \ref{fig:fignew28} Using this function user can select the size of the dandom set to be used for classification, e.g. 100 probesets, and the number of samples retrived form the total data set used to perform this analysis, eg. 1000. Subsequently the user will select a classification method, e.g. PAMR, and the function will calculate the frequence of correct classification of the random set size defined by the user. This funcitn is particularly useful if user is interested to evaluate the specificity of a specific transcription signature. \subsubsection{PAMR} If PAMR method is selected, 2-3 steps are performed and pop-up info messages allow to check the resulting plots. Initially the cross-validated misclassification error curves are calculated, fig. \ref{fig:fignew30}, and shown in the main R window. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew30} } \caption{\label{fig:fignew30} Cross-validated misclassification error curves} \end{center} \end{figure} Then, user defines a shrinking threshold and if the number of selected probe sets is below 50 the centroids will be plotted, fig. \ref{fig:fignew31}. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew31} } \caption{\label{fig:fignew31} Shrunken class centroids.} \end{center} \end{figure} Subsequently the classification performance of the selected sub group of probe sets will be shown as plot and as text in the R window , fig. \ref{fig:fignew32}. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew32} } \caption{\label{fig:fignew32} Cross-validated sample probabilities.} \end{center} \end{figure} Results are also available as numerica values in the R window: \begin{Schunk} \begin{Sinput} neg pos Class Error rate neg 23 5 0.1785714 pos 2 48 0.0400000 \end{Sinput} \end{Schunk} If the results are satisfying user can save the probe sets defined by this analysis, fig. \ref{fig:fignew33}. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew33} } \caption{\label{fig:fignew33} Probe sets to be use as classifier.} \end{center} \end{figure} Furthermore, if the test set was created it will be possible to check the ability of the selected sub set of genes to separate the classes under analysis using a hierarchical clustering, fig. \ref{fig:fignew34}. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew34} } \caption{\label{fig:fignew34} Testing the efficacy of the classifier on the test set by HCL.} \end{center} \end{figure} \subsubsection{PCA} The PCA visualization method offers the possibility to see how the data set can be grouped on the basis of the used clinical/experimental parameter under analysis, fig. \ref{fig:fignew35}. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew35} } \caption{\label{fig:fignew35} 1st and 2nd principal components space.} \end{center} \end{figure} \subsubsection{PDMCLASS} The PDMCLASS module allows the selection of different type of classification procedures, fig. \ref{fig:fignew36}. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew36} } \caption{\label{fig:fignew36} PDMCLASS methods selection mask.} \end{center} \end{figure} The analysis will produce a numerical output of the effecacy of the dataset as classifier: \begin{Schunk} \begin{Sinput} object neg pos neg 21 1 pos 22 74 attr(,"error") [1] 0.1949153 \end{Sinput} \end{Schunk} It is notable that this part of the analysis could take some minutes depending on the data set under analysis and the machine used for the analysis. Subsequently it will be possible to select the probe sets that have the gratest influence in differentiating sample classes. To do it, user will be requested to select the number of top ranked probe sets and the number of permutations to be used for the cross-validation. Probe set will be shown in a TK/TCL table with their probabilities to be able to discriminate between classes: \begin{Schunk} \begin{Sinput} pos vs neg 209604_s_at 1 202088_at 0.92 218807_at 0.8 211430_s_at 0.56 205081_at 0.48 213693_s_at 0.4 209138_x_at 0.44 200670_at 0.32 212099_at 0.44 208682_s_at 0.28 \end{Sinput} \end{Schunk} These results could be saved as a tab delimited file. \section{Biological Interpretation} This section gives a graphical interface to the GOstats package fig. \ref{fig:fignew38}. It also allows very basic meta-analysis using the metaArray package. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew38} } \caption{\label{fig:fignew38} Biological interpretation menu.} \end{center} \end{figure} \subsection{Identifying enriched GO terms and related issues} This function is also available for gene level exon array analysis. Specific annotation libraries are not available for exon arrays, yet. Therefore, to perform this analysis we use the annotation informations embedded in oneChannelGUI and link the accession ids available in this annotation to Entrez Gene ids using the humanLLMappings, mouseLLMapppings and ratLLMappings available in Bioconductor. The function \textit{oneChannelGUI: Identifying enriched GO terms} searches for the presence of enriched GO terms within a set of differentially expressed probe sets, given a certain probe set universe, i.e. the array data available in Normalized Affy Data. For more information about GO enrichment please refer to the GOstats vignette in the oneChannelGUI help menu. The user needs to select some parameters using a selection mask, fig. \ref{fig:fignew39}. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew39} } \caption{\label{fig:fignew39} GO terms enrichment parameters selection mask.} \end{center} \end{figure} Subsequently, the user will be requested to select a list of differentially expressed probe sets, saved in a txt file. The file should contain only a list of probe set separated by carriage return, without header: \begin{Schunk} \begin{Sinput} 1452968_at 1448228_at 1418028_at 1439113_at 1424338_at 1416503_at 1416371_at 1437165_a_at 1451047_at 1434005_at 1421916_at 1457012_at 1443823_s_at 1429379_at 1416168_at 1429974_at 1416121_at 1421917_at 1416405_at \end{Sinput} \end{Schunk} The analysis could require quite a lot of RAM and when it is finished a message summarizing the results pops up, fig. \ref{fig:fignew40}. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew40} } \caption{\label{fig:fignew40} GO enrichment results summary message.} \end{center} \end{figure} A table with the enriched GO terms will be then shown and it could be saved as tab delimited file, fig. \ref{fig:fignew41}. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew41} } \caption{\label{fig:fignew41} Enriched GO terms table.} \end{center} \end{figure} In the main R window it will be possible to see a plot summarizing the GO terms relations existing between the enriched GO terms, fig. \ref{fig:fignew42}. Plotting results depends on the availability in your system of graphviz software and Rgraphviz package. Their installation can be quite critical for windows users, please contact the oneChannelGUI mantainer if you get problem in their installation or search over the Bioconductor mailing list. \begin{figure}[htbp] \begin{center} \includegraphics{fignew42.pdf} \caption{\label{fig:fignew42} Relations between enriched GO terms. Enriched GO terms, red, others, light blue.} \end{center} \end{figure} It is also possible to highlight parents of a specific GO term using the function \textit{Plotting parents of a GO term} In this case a dialog will be used to pass to the function the GO term, e.g. GO:0001525. Subsequently after selecting the GO class, i.e. BP, MF or CC, the results will be available in the main R window, fig. \ref{fig:fignew43}. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew43} } \caption{\label{fig:fignew43} Plotting GO term parents.} \end{center} \end{figure} It is also possible to annotate and save, in an html file, the subset of differentially expressed probe sets associated to a specific enriched GO term using the function \textit{oneChannelGUI: Extracting Affy IDs linked to an enriched GO term}. In the case exon arrays are used with \textit{oneChannelGUI: Extracting Affy IDs linked to an enriched GO term} function the output file is a tab delimited file with the available annotations instead of an HTML file. The user will be requested to select the GO term of interest, fig. \ref{fig:fignew42}, and subsequently to open the file list of differentially expressed probe sets used for the GO enrichment analysis. A pop-up message will indicate when the annotation table will be ready to be saved in an HTML file, fig. \ref{fig:fignew44}. The output for exon arrays will be instead a tab delimited file. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew44} } \caption{\label{fig:fignew44} Annotation file for a subset of differentially expressed probe sets linked to GO:0001525 BP enriched term.} \end{center} \end{figure} \subsection{meta-analysis} This menu gives also access to some meta-analysis tools, fig. \ref{fig:fignew48}. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew48} } \caption{\label{fig:fignew48} Biological Interpretation DEVEL version.} \end{center} \end{figure} It is possible to merge to the NormalizedAffyData up to 3 other data sets characterized by having the same ids and the same order of the NormalizedAffyData ids. To merge the data sets it is necessary a tab delimited file and a target for each data set. Integrative correlation (Parmignani et al. 2004), implemented in the metaArray package, can be accessed with the function \textit{Mining similarities/dissimilarities between merged data sets (IC)}. The function produces an histogram of the various comparisons and it saves, in tab delimited file, the IC values for the various comparisons. \section{General tools} This section allows the use of some functions which are not part of a specific Bioconductor package but could be of general use. The function \textit{oneChannelGUI: Update all Bioconductor libraries} allows to run a on-line update of all the Bioconductor libraries present in the system. This function is very useful to keep updated for bugs correction during the 6 months life of a Bioconductor release. The function \textit{oneChannelGUI: Extract a column from a tab delimited file} allows the extraction of any of the colums of a tab delimited file. This function is particularly useful to generate probeset ids list to be used for Venn diagram rapresentation. The function \textit{oneChannelGUI: Filtering a tab delimited file} allows to subset a tab delimited file given a list of values, e.g. values, symbols, probe sets, etc., present in a file where each value is separated from the others by carriage return. The tab delimited file subsetting is performed on the basis of the column, fig. \ref{fig:fignew47} yellow, sharing the same header of the list of values, fig. \ref{fig:fignew47}. \begin{figure}[htbp] \begin{center} \resizebox{100mm}{!}{ \includegraphics{fignew47} } \caption{\label{fig:fignew47} Sub setting a tab delimited file by a list of symbols.} \end{center} \end{figure} The function \textit{oneChannelGUI: Downloading Gene/Exon library files} allows to download all the library files needed to use APT tools for probe set summaries for Gene and Exon 1.0 ST arrays. The function \textit{oneChannelGUI: Set Affymetrix apt tools folder and download Reference Sequences} allows the user to define a folder where apt tools were installed and to download in the subdir blast of the apt dir the reference sequences from NCBI repository. Those file are compressed and have the gz extension. They can be unpacked manually by the user or via oneChannelGUI. This option is available at the end of the downloading but takes quite a long time. The function \textit{oneChannelGUI: deleteLocalData} will reset the folders defined by \textit{oneChannelGUI: Downloading Gene/Exon library files} and \textit{oneChannelGUI: Downloading Gene/Exon library files}. Data present in the two folders will not be deleted! The function \textit{oneChannelGUI: buildingLocalAnnotation} allows to update the internal oneChannelGUI gene/exon-level annotations quiering netaffx database using the affyCompatible library. Annotation files are saved in .rda format in the subdir data in located in the oneChannelGUI folder. Windows users need to drag those .rda files in the Rdata.zip file present in the data dir. A file called netaffxUpdates.txt in the etc subdir keept tracks of annotation file updating. The function \textit{oneChannelGUI: variantExons} allows to update the internal oneChannelGUI gene/exon-level annotations that links exon-level probesets to exons which are associated only to a subset of transcript isoforms. The table is generated integrating the exon-level annotation derived by the core subset of Affymetrix exon level annotation and a USCS table mapping the location of variant exons on the genome. The function \textit{Installing meV clustering software} will install the meV clustering tool. A java application very powerful for microarray data clustering. meV software can be started using the function \textit{Starting meV clustering software} in the Biological Interpretation menu. The function \textit{Install Bowtie and Picard tools} allows the istallation of bowtie and picard tools for primary mapping of short reads. The above mentione function also allow to download/build Bowtie miRNAs precursors and exons reference sequences for human, mouse, rat, bovine. The function \textit{Information on external software and data connected to oneChannelGUI} provides information on external software installed and connected to oneChannelGUI \section{Help} This menu allows to acces to the vignettes of the Bioconductor packages implemented in oneChannelGUI and to this oneChannelGUI vignette. \end{document}