FunNet.R-package {FunNet} | R Documentation |
FunNet is an integrative tool for analyzing gene co-expression networks built from microarray expression data. The analytic model implemented in this library involves two abstraction layers: transcriptional and functional (biological roles). A functional profiling technique using Gene Ontology & KEGG annotations is applied to extract a list of relevant biological themes from microarray expression profiling data. Afterwards multiple-instance representations are built to relate significant themes to their transcriptional instances (i.e. the two layers of the model). An adapted non-linear dynamical system model is used to quantify the proximity of relevant genomic themes based on the similarity of the expression profiles of their gene instances. Eventually an unsupervised multiple-instance clustering procedure, relying on the two abstraction layers, is used to identify the structure of the co-expression network composed from modules of functionally related transcripts. Functional and transcriptional maps of the co-expression network are provided separately together with detailed information on the network centrality of related transcripts and genomic themes.
Together with the FunNet algorithm this package provides also:
1. GO and KEGG annotations automatically extracted from their respective web resources and updated on a regular
basis
2. The routine for the automated extraction and update of the functional annotations from their respective
web resources. The use of this routine is simple: annotations(date.annot = "")
. Under common
circumstances these routine will provide up-to-date annotations, stored into environmental variables,
directly formatted for FunNet's use. Some errors may be seen when using this routine related to a
lack of availability of the GO annotations for the current month. In case of extraction errors,
explained most usually by a delay in updating GO web servers, the release date can be expressly
indicated (see annotations
).
3. Four test data sets (see examples below and the dedicated man pages). Two of these datasets are related to
adipose tissue expression profiling in obese subjects at baseline and after a bariatric surgery.
The other two are yeast datasets related to the cell cycle and DNA repairing processes induced by
irradiation.
The format of the data should be respected in order to perform a successful analysis. The only transcript
identification system acceptable for FunNet analysis is EntrezGene GeneID's. The transcript
expression data should be organized in dataframes within one row for each transcript. The
first column contains the transcript identifiers for each transcript and the rest of them
the expression level of that transcript in each of the available microarray samples.
See the provided test data for more details.
The results of the FunNet analysis of transcript expression data are stored as HTML, tab separated text or R data files in a "Results" subfolder of the working folder. For each type of available biological annotations and for each list of transcript expression data to be analyzed (one or two), FunNet provides a ranked list with the significantly enriched annotating categories, as well as network structures as text files designed to be imported in Cytoscape for graphical analysis. Detailed findings on the terminological composition and transcript enrichment significance of the resulting functional clusters, as well as various network centrality measures are equally provided.
Corneliu Henegar corneliu@henegar.info
1. Prifti E, Zucker JD, Clement K, Henegar C. FunNet: an integrative tool for exploring transcriptional interactions. Bioinformatics. 2008 Nov 15;24(22):2636-8.
2. Henegar C, Tordjman J, Achard V, Lacasa D, Cremer I, Guerre-Millo M, Poitou C, Basdevant A, Stich V, Viguerie N, Langin D, Bedossa P, Zucker J-D, Clement K. Adipose tissue transcriptomic signature highlights the pathologic relevance of extracellular matrix in human obesity. Genome Biology 2008, 9(1):R14.
3. Henegar C, Clement K, and Zucker JD (2006). Unsupervised multiple-instance learning for functional profiling of genomic data. Lecture Notes in Computer Science: ECML 2006. Springer Berlin / Heidelberg, 4212/2006 : 186-197.
4. Henegar C, Cancello R, Rome S, Vidal H, Clement K, Zucker JD. Clustering biological annotations and gene expression data to identify putatively co-regulated biological processes. J Bioinform Comput Biol. 2006 Aug;4(4):833-52.
5. Cancello R, Henegar C, Viguerie N, Taleb S, Poitou C, Rouault C, Coupaye M, Pelloux V, Hugol D, Bouillot JL, Bouloumie A, Barbatelli G, Cinti S, Svensson PA, Barsh GS, Zucker JD, Basdevant A, Langin D, Clement K. Reduction of macrophage infiltration and chemoattractant gene expression changes in white adipose tissue of morbidly obese subjects after surgery-induced weight loss. Diabetes 2005; 54(8):2277-86.
6. Zhang B, Horvath S. A general framework for weighted gene co-expression network analysis. Stat Appl Genet Mol Biol 4 (2005) Article17.
7. FunNet websites: http://corneliu.henegar.info/FunNet.htm, http://www.funnet.ws, http://www.funnet.info
## Not run: ## most common use data(obese) FunNet(org="HS", two.lists=TRUE, up.frame=up.frame, down.frame=down.frame, genes.frame=NULL, restrict=TRUE, ref.list=ref.list, logged=TRUE, discriminant=TRUE, go.bp=TRUE, go.cc=TRUE, go.mf=TRUE, kegg=TRUE, annot.method="specificity", annot.details=TRUE, direct=FALSE, enriched=TRUE, fdr=NA, build.annot.net=TRUE, coexp.matrix=NULL, coexp.method="spearman", estimate.th=FALSE, hard.th=0.8, soft.th=NA, topological = FALSE, keep.sign=FALSE, level=1, annot.clust.method="umilds", annot.prox.measure="dynamical", test.recovery=FALSE, test.robust=FALSE, replace.annot=NA, build.gene.net=TRUE, gene.clust.method="hclust", gene.net.details=TRUE, gene.clusters=NA, alpha=0.05, RV=0.90, sigma=NA, keep.rdata=FALSE, zip=TRUE) ## the following example forces the use of a previous GO release (e.g. October 2007) for updating annotations annotations(date.annot = "200710") ## End(Not run)