hi Alicia,
In your previous email, you didn't mention that you had used software
for estimating isoform specific counts, so I pasted a link to Simon's
answer concerning isoform counts. If one can assign reads to isoforms
with high confidence then it would be fine to do testing with DESeq2.
However, this is typically a difficult task which involves uncertainty
in estimation and DESeq2 does not take into account any uncertainty in
these estimated counts. If you have 10 reads in the count matrix,
DESeq2 will take this to mean 10 reads were unambiguously assigned to
this feature. Through estimation steps, this could be 10 reads plus or
minus 10 reads. So the quality of the results will depend on the
quality of the input.
Mike
On Fri, May 9, 2014 at 11:11 AM, Alicia R. P?rez-Porro
<alicia.r.perezporro at="" gmail.com=""> wrote:
> Hi Mike,
>
> Thanks for your answer. I read the explanation from Simon and am
still a
> little bit confuse, reading the edgeR manual I found this: "edgeR
can be
> applied to di fferential expression at the gene, exon, transcript or
tag
> level. In fact, read counts can be summarized by any genomic
feature. edgeR
> analyses at the exon level are easily extended to detect di
fferential
> splicing or isoform-specifi c dif ferential expression".
>
> So, my initial idea was to treat each isoform like a gene because
for the
> approach that I am attempting right now I am not interested in
differences
> in expression of isoforms belonging to the same gene. I did my de
novo with
> Trinity, alignment using Bowtie and estimation of abundance with
RSEM. I
> created a matrix with the RSEM counts (isoforms results) and I was
planning
> on using it as input for my next step.
>
> I understand that even I want to treat each isoform as a gene to do
it with
> DESeq or DESeq2 is not a good idea. I really don't know about edgeR
and am
> also considering EBseq.
>
> Suggestions? Thoughts?
>
> Thank you in advance.
> Alicia
>
>
>
> --
> Alicia R. P?rez-Porro
> PhD candidate
>
> Giribet lab
> Department of Organismic and Evolutionary Biology
> MCZ labs
> Harvard University
> 26 Oxford St, Cambridge MA 02138
> phone: +1 617-496-5308
> fax: +1 617-495-5667
> www.oeb.harvard.edu/faculty/giribet/
>
> Department of Marine Ecology
> Center for Advanced Studies of Blanes (CEAB-CSIC)
> C/Acc?s Cala St. Francesc 14
> 17300 Blanes, Girona, SPAIN
> phone: +34 972 336 101
> fax: +34 972 337 806
> www.ceab.csic.es
>
>
> On Fri, May 9, 2014 at 8:07 AM, Michael Love <michaelisaiahlove at="" gmail.com="">
> wrote:
>>
>> hi Alicia,
>>
>> DESeq2 is intended for gene-level analysis. here is some
explanation from
>> Simon on the list as to why doing a count-based analysis at the
>> transcript/isoform level is problematic:
>>
>>
https://stat.ethz.ch/pipermail/bioconductor/2012-February/043410.html
>>
>> if you are interested in looking for differential exon usage, you
can
>> instead consider using the DEXSeq package:
>>
>> publication
>> http://www.ncbi.nlm.nih.gov/pubmed/22722343
>>
>> software:
>> http://bioconductor.org/packages/release/bioc/html/DEXSeq.html
>>
>> Mike
>>
>>
>>
>> On Thu, May 8, 2014 at 7:26 PM, Alicia R. P?rez-Porro
>> <alicia.r.perezporro at="" gmail.com=""> wrote:
>>>
>>> Dear Bioconductor users,
>>>
>>> I am working with differential expression at the transcript
(isoform)
>>> level. I have 6 different conditions (2 replicates/condition).
>>>
>>> I want to know if I can use DESeq2 for that or if the package can
only be
>>> used at the gene level.
>>>
>>> Thanks,
>>> Alicia
>>>
>>>
>>> --
>>> Alicia R. P?rez-Porro
>>> PhD candidate
>>>
>>> Giribet lab
>>> Department of Organismic and Evolutionary Biology
>>> MCZ labs
>>> Harvard University
>>> 26 Oxford St, Cambridge MA 02138
>>> phone: +1 617-496-5308
>>> fax: +1 617-495-5667
>>> www.oeb.harvard.edu/faculty/giribet/
>>>
>>> Department of Marine Ecology
>>> Center for Advanced Studies of Blanes (CEAB-CSIC)
>>> C/Acc?s Cala St. Francesc 14
>>> 17300 Blanes, Girona, SPAIN
>>> phone: +34 972 336 101
>>> fax: +34 972 337 806
>>> www.ceab.csic.es
>>>
>>> [[alternative HTML version deleted]]
>>>
>>>
>>> _______________________________________________
>>> Bioconductor mailing list
>>> Bioconductor at r-project.org
>>> https://stat.ethz.ch/mailman/listinfo/bioconductor
>>> Search the archives:
>>> http://news.gmane.org/gmane.science.biology.informatics.conductor
>>
>>
>
Hi Alicia,
Here is my two cents. I think RSEM isoform counts contain ?multi-
isoform? reads, i.e. reads mapped to multiple isoforms, but from a
single gene, so I don?t think DESeq2 would demonstrate it?s power in
terms of accuracy in your case. If your purpose is only to obtain an
?inspiration of biology? from your data, why not simply use the fold
change of your isoform expression and to check out what?s the most
changed ones? Yes, you probably need some kind of normalization to
leverage the library sizes.
Cheers,
Yuan
On May 9, 2014, at 2:08 PM, Alicia R. P?rez-Porro <alicia.r.perezporro at="" gmail.com=""> wrote:
> Hi everyone,
>
> Yes, sorry Mike, I forgot to mention that I calculated my isoform
counts
> estimation with RSEM.
>
> Thomas, I am aware about the pipeline using RSEM+(edgeR or DESeq) to
do DE
> analysis inside Trinity. I tried and I didn't like just because is
not a
> good option to use with my data. I have non standard data and the
pipeline
> is too hands off so works nicely if you have more standard data.
>
> Mainly what I want is to do pair-wise comparisons between my 5
different
> conditions (5 different moments along the life cycle of my animal)
to
> generate a list of the most DEG, blast them to see what they are,
> potentially get the GO:terms associated to them and have an overview
of
> what is happening along the life cycle. My intention in the future
is
> probably continue with analysis in differential exon expression
(DEXseq)
> and/or differential isoform expression. And I am also considering
> time-scale differential expression analysis. But like I said I'm
planning
> on doing that in the future because right now I am interested just
in an
> overview of what is going on in the life cycle of my animal. That's
why I
> was thinking about treating the isoforms as genes.
>
> Does that make sense to you, guys?
>
> Thanks again,
> Alicia
>
>
>
> --
> Alicia R. P?rez-Porro
> PhD candidate
>
> Giribet lab
> Department of Organismic and Evolutionary Biology
> MCZ labs
> Harvard University
> 26 Oxford St, Cambridge MA 02138
> phone: +1 617-496-5308
> fax: +1 617-495-5667
> www.oeb.harvard.edu/faculty/giribet/
>
> Department of Marine Ecology
> Center for Advanced Studies of Blanes (CEAB-CSIC)
> C/Acc?s Cala St. Francesc 14
> 17300 Blanes, Girona, SPAIN
> phone: +34 972 336 101
> fax: +34 972 337 806
> www.ceab.csic.es
>
>
> On Fri, May 9, 2014 at 1:45 PM, Michael Love <michaelisaiahlove at="" gmail.com="">wrote:
>
>> hi Alicia,
>>
>> In your previous email, you didn't mention that you had used
software
>> for estimating isoform specific counts, so I pasted a link to
Simon's
>> answer concerning isoform counts. If one can assign reads to
isoforms
>> with high confidence then it would be fine to do testing with
DESeq2.
>> However, this is typically a difficult task which involves
uncertainty
>> in estimation and DESeq2 does not take into account any uncertainty
in
>> these estimated counts. If you have 10 reads in the count matrix,
>> DESeq2 will take this to mean 10 reads were unambiguously assigned
to
>> this feature. Through estimation steps, this could be 10 reads plus
or
>> minus 10 reads. So the quality of the results will depend on the
>> quality of the input.
>>
>> Mike
>>
>> On Fri, May 9, 2014 at 11:11 AM, Alicia R. P?rez-Porro
>> <alicia.r.perezporro at="" gmail.com=""> wrote:
>>> Hi Mike,
>>>
>>> Thanks for your answer. I read the explanation from Simon and am
still a
>>> little bit confuse, reading the edgeR manual I found this: "edgeR
can be
>>> applied to di fferential expression at the gene, exon, transcript
or tag
>>> level. In fact, read counts can be summarized by any genomic
feature.
>> edgeR
>>> analyses at the exon level are easily extended to detect di
fferential
>>> splicing or isoform-specifi c dif ferential expression".
>>>
>>> So, my initial idea was to treat each isoform like a gene because
for the
>>> approach that I am attempting right now I am not interested in
>> differences
>>> in expression of isoforms belonging to the same gene. I did my de
novo
>> with
>>> Trinity, alignment using Bowtie and estimation of abundance with
RSEM. I
>>> created a matrix with the RSEM counts (isoforms results) and I was
>> planning
>>> on using it as input for my next step.
>>>
>>> I understand that even I want to treat each isoform as a gene to
do it
>> with
>>> DESeq or DESeq2 is not a good idea. I really don't know about
edgeR and
>> am
>>> also considering EBseq.
>>>
>>> Suggestions? Thoughts?
>>>
>>> Thank you in advance.
>>> Alicia
>>>
>>>
>>>
>>> --
>>> Alicia R. P?rez-Porro
>>> PhD candidate
>>>
>>> Giribet lab
>>> Department of Organismic and Evolutionary Biology
>>> MCZ labs
>>> Harvard University
>>> 26 Oxford St, Cambridge MA 02138
>>> phone: +1 617-496-5308
>>> fax: +1 617-495-5667
>>> www.oeb.harvard.edu/faculty/giribet/
>>>
>>> Department of Marine Ecology
>>> Center for Advanced Studies of Blanes (CEAB-CSIC)
>>> C/Acc?s Cala St. Francesc 14
>>> 17300 Blanes, Girona, SPAIN
>>> phone: +34 972 336 101
>>> fax: +34 972 337 806
>>> www.ceab.csic.es
>>>
>>>
>>> On Fri, May 9, 2014 at 8:07 AM, Michael Love <
>> michaelisaiahlove at gmail.com>
>>> wrote:
>>>>
>>>> hi Alicia,
>>>>
>>>> DESeq2 is intended for gene-level analysis. here is some
explanation
>> from
>>>> Simon on the list as to why doing a count-based analysis at the
>>>> transcript/isoform level is problematic:
>>>>
>>>>
https://stat.ethz.ch/pipermail/bioconductor/2012-February/043410.html
>>>>
>>>> if you are interested in looking for differential exon usage, you
can
>>>> instead consider using the DEXSeq package:
>>>>
>>>> publication
>>>> http://www.ncbi.nlm.nih.gov/pubmed/22722343
>>>>
>>>> software:
>>>> http://bioconductor.org/packages/release/bioc/html/DEXSeq.html
>>>>
>>>> Mike
>>>>
>>>>
>>>>
>>>> On Thu, May 8, 2014 at 7:26 PM, Alicia R. P?rez-Porro
>>>> <alicia.r.perezporro at="" gmail.com=""> wrote:
>>>>>
>>>>> Dear Bioconductor users,
>>>>>
>>>>> I am working with differential expression at the transcript
(isoform)
>>>>> level. I have 6 different conditions (2 replicates/condition).
>>>>>
>>>>> I want to know if I can use DESeq2 for that or if the package
can only
>> be
>>>>> used at the gene level.
>>>>>
>>>>> Thanks,
>>>>> Alicia
>>>>>
>>>>>
>>>>> --
>>>>> Alicia R. P?rez-Porro
>>>>> PhD candidate
>>>>>
>>>>> Giribet lab
>>>>> Department of Organismic and Evolutionary Biology
>>>>> MCZ labs
>>>>> Harvard University
>>>>> 26 Oxford St, Cambridge MA 02138
>>>>> phone: +1 617-496-5308
>>>>> fax: +1 617-495-5667
>>>>> www.oeb.harvard.edu/faculty/giribet/
>>>>>
>>>>> Department of Marine Ecology
>>>>> Center for Advanced Studies of Blanes (CEAB-CSIC)
>>>>> C/Acc?s Cala St. Francesc 14
>>>>> 17300 Blanes, Girona, SPAIN
>>>>> phone: +34 972 336 101
>>>>> fax: +34 972 337 806
>>>>> www.ceab.csic.es
>>>>>
>>>>> [[alternative HTML version deleted]]
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> Bioconductor mailing list
>>>>> Bioconductor at r-project.org
>>>>> https://stat.ethz.ch/mailman/listinfo/bioconductor
>>>>> Search the archives:
>>>>>
http://news.gmane.org/gmane.science.biology.informatics.conductor
>>>>
>>>>
>>>
>>
>
> [[alternative HTML version deleted]]
>
> _______________________________________________
> Bioconductor mailing list
> Bioconductor at r-project.org
> https://stat.ethz.ch/mailman/listinfo/bioconductor
> Search the archives:
http://news.gmane.org/gmane.science.biology.informatics.conductor
If you assembled your transcriptome, you might be aware that the
Trinity site
has some protocols for this that are based on RSEM and edgeR:
http://trinityrnaseq.sourceforge.net/analysis/diff_expression_analysis
.html
Whether this is the best possible way of addressing this need is a
different
question.
Thomas
On Fri, May 09, 2014 at 04:38:54PM +0000, Alicia R. P?rez-Porro wrote:
> Hi Xiayu,
>
> I don't think that I can use Cufflink, I don't have a reference
genome, I
> created my own reference transcriptome.
>
> Best,
> Alicia
>
>
>
> --
> Alicia R. P?rez-Porro
> PhD candidate
>
> Giribet lab
> Department of Organismic and Evolutionary Biology
> MCZ labs
> Harvard University
> 26 Oxford St, Cambridge MA 02138
> phone: +1 617-496-5308
> fax: +1 617-495-5667
> www.oeb.harvard.edu/faculty/giribet/
>
> Department of Marine Ecology
> Center for Advanced Studies of Blanes (CEAB-CSIC)
> C/Acc?s Cala St. Francesc 14
> 17300 Blanes, Girona, SPAIN
> phone: +34 972 336 101
> fax: +34 972 337 806
> www.ceab.csic.es
>
>
> On Fri, May 9, 2014 at 12:09 PM, Rao,Xiayu <xrao at="" mdanderson.org="">
wrote:
>
> > Hi, Alicia
> >
> > You may try cufflinks. After running cuffdiff, you will get
isoform.diff
> > and other files, in which you will find the isoform expression
level.
> > Correct me if I am wrong.
> >
> > Thanks,
> > Xiayu
> >
> >
> >
> > -----Original Message-----
> > From: bioconductor-bounces at r-project.org [mailto:
> > bioconductor-bounces at r-project.org] On Behalf Of Alicia R. P
?rez-Porro
> > Sent: Thursday, May 08, 2014 6:26 PM
> > To: bioconductor at r-project.org list
> > Subject: [BioC] DESeq2 transcript level
> >
> > Dear Bioconductor users,
> >
> > I am working with differential expression at the transcript
(isoform)
> > level. I have 6 different conditions (2 replicates/condition).
> >
> > I want to know if I can use DESeq2 for that or if the package can
only be
> > used at the gene level.
> >
> > Thanks,
> > Alicia
> >
> >
> > --
> > Alicia R. P??rez-Porro
> > PhD candidate
> >
> > Giribet lab
> > Department of Organismic and Evolutionary Biology MCZ labs Harvard
> > University
> > 26 Oxford St, Cambridge MA 02138
> > phone: +1 617-496-5308
> > fax: +1 617-495-5667
> > www.oeb.harvard.edu/faculty/giribet/
> >
> > Department of Marine Ecology
> > Center for Advanced Studies of Blanes (CEAB-CSIC) C/Acc??s Cala
St.
> > Francesc 14
> > 17300 Blanes, Girona, SPAIN
> > phone: +34 972 336 101
> > fax: +34 972 337 806
> > www.ceab.csic.es
> >
> > [[alternative HTML version deleted]]
> >
> >
>
> [[alternative HTML version deleted]]
>
> _______________________________________________
> Bioconductor mailing list
> Bioconductor at r-project.org
> https://stat.ethz.ch/mailman/listinfo/bioconductor
> Search the archives:
http://news.gmane.org/gmane.science.biology.informatics.conductor
Hi, Alicia
You may try cufflinks. After running cuffdiff, you will get
isoform.diff and other files, in which you will find the isoform
expression level. Correct me if I am wrong.
Thanks,
Xiayu
-----Original Message-----
From: bioconductor-bounces@r-project.org [mailto:bioconductor-
bounces@r-project.org] On Behalf Of Alicia R. P?rez-Porro
Sent: Thursday, May 08, 2014 6:26 PM
To: bioconductor at r-project.org list
Subject: [BioC] DESeq2 transcript level
Dear Bioconductor users,
I am working with differential expression at the transcript (isoform)
level. I have 6 different conditions (2 replicates/condition).
I want to know if I can use DESeq2 for that or if the package can only
be used at the gene level.
Thanks,
Alicia
--
Alicia R. P??rez-Porro
PhD candidate
Giribet lab
Department of Organismic and Evolutionary Biology MCZ labs Harvard
University
26 Oxford St, Cambridge MA 02138
phone: +1 617-496-5308
fax: +1 617-495-5667
www.oeb.harvard.edu/faculty/giribet/
Department of Marine Ecology
Center for Advanced Studies of Blanes (CEAB-CSIC) C/Acc??s Cala St.
Francesc 14
17300 Blanes, Girona, SPAIN
phone: +34 972 336 101
fax: +34 972 337 806
www.ceab.csic.es
[[alternative HTML version deleted]]