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anna freni sterrantino
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@anna-freni-sterrantino-2847
Last seen 10.2 years ago
Hi Chanchal ,
as long you have only a list on entrezID, there is not much to do, oh
well:
Of course you can get gene sets ,information related to the gene set
structure, description etc
it should be fine, with GSEABase.
But to perform a Gene Set Enrichment Analysis, ( in a more general
framework)
you'll need a statistic ( usually a t-stat) at gene level
and then you will use that to compute a statistic for gene set level.
As long as I understood from your email you only know the order
of gene's fold change, this kind of information is not enough, for
this latter type of analysis.
Hope it helps
Best regards
Anna
----- Messaggio originale -----
Da: Chanchal Kumar <chanchal@biochem.mpg.de>
A: bioconductor@stat.math.ethz.ch
Inviato: Venerdì 25 luglio 2008, 1:14:20
Oggetto: [BioC] How to carry out Gene Set Enrichment Analysis(GSEA) on
an ordered list of Entrezgene ids?
Dear All,
I have a set of Entrez ids which have been ordered as per fold
change
expression from a control experiment. I am now interested in carrying
out gene set enrichment analysis using Bioconductor GSEABase package.
I
don't have any other statistics for these genes. Is it possible to
carry
out GSEA on a vector of Entrezids which is ordered by say fold change?
I
attach an example vector and would like to carry out GSEA on this test
set to get an idea of how this might work.
library(annotate)
library(hgu95av2.db)
set.seed(12345)
set1 <- unique(getEG(sample(ls(hgu95av2GO), 100), "hgu95av2"))
set1<-na.omit(set1) # as I get NAs in the vector before
For GSEA I assume that element set1[1] has highest fold change and
set1[length(set1)] has the lowest fold change. Any help in this regard
will be appreciated. Thanks in advance!
----------------------------------------------------------------------
--
---------------
> sessionInfo()
R version 2.7.0 (2008-04-22)
i386-pc-mingw32
locale:
LC_COLLATE=German_Germany.1252;LC_CTYPE=German_Germany.1252;LC_MONETAR
Y=
German_Germany.1252;LC_NUMERIC=C;LC_TIME=German_Germany.1252
attached base packages:
[1] tools stats graphics grDevices utils datasets
methods
[8] base
other attached packages:
[1] annotate_1.18.0 xtable_1.5-2 hgu95av2.db_2.2.0
[4] AnnotationDbi_1.2.1 RSQLite_0.6-8 DBI_0.2-4
[7] Biobase_2.0.1
loaded via a namespace (and not attached):
[1] splines_2.7.0
----------------------------------------------------------------------
--
---------------
Best Regards,
Chanchal
===============================
Chanchal Kumar, Ph.D. Candidate
Dept. of Proteomics and Signal Transduction
Max Planck Institute of Biochemistry
Am Klopferspitz 18
82152 D-Martinsried (near Munich)
Germany
e-mail: chanchal@biochem.mpg.de
Phone: (Office) +49 (0) 89 8578 2296
Fax:(Office) +49 (0) 89 8578 2219
http://www.biochem.mpg.de/mann/
===============================
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Anna Freni Sterrantino
Ph.D Student
Department of Statistics
University of Bologna, Italy
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