Dear Chunjiang,

Here is a previously answered question about calculating the conservation score 
in a region:

https://lists.soe.ucsc.edu/pipermail/genome/2010-November/024065.html

In this case you don't need to be concerned about how to calculate the reverse 
strand coordinates. My colleague answered this in one of your earlier questions:

> To answer your second question, strand has no meaning in these phyloP 
> tables. A conserved base prediction is simply a prediction of a conserved 
> base; it is the same base in forward or reverse strand. 

I hope that this helps to clarify things for you.

Vanessa Kirkup Swing
UCSC Genome Bioinformatics Group

----- Original Message -----
From: "chunjiang he" <[email protected]>
To: "Vanessa Kirkup Swing" <[email protected]>
Cc: [email protected]
Sent: Thursday, March 24, 2011 9:11:08 AM
Subject: Re: [Genome] a question about phylop conservation



Dear Dr. Swing, 

Thanks for your guide. As your answer, I am still a little confused about how 
to caculate the conservation score in a multiple bases region when I only have 
the 1-base step scores. 
I see there is 'span' parameter but I dont know how to use that from the table 
files. 

fixedStep chrom=chr1 start=10918 step=1 
0.064 
0.056 
0.064 

I can't find the answer from 
http://genome.ucsc.edu/cgi-bin/hgTrackUi?db=hg19&g=cons46way 

Another, I see chromsize is used to caculate the reverse strand coordinates. So 
how I can get the chromsize for each chromosome. 

Thanks again, 

Best, 
Chunjiang 


On Wed, Mar 9, 2011 at 12:14 PM, Vanessa Kirkup Swing < [email protected] > 
wrote: 


Dear Chunjiang, 

See the answers below: 


So should I treat the 0.064 as the conservation score of the base 10918? 

Yes, the coordinates for wiggle tracks are specified as 1-relative. For a 
chromosome of length N, the first position is 1 and the last position is N. 
Only positions specified have data. Here is more information on wiggle tracks: 
http://genome.ucsc.edu/goldenPath/help/wiggle.html 



If I want to get the conservation score from base 10918 to 10920, could I 
average the three scores "0.064,0.056,0.064" or by some other method? 

Please read the description page for this track and the papers that are 
referenced: 

http://genome.ucsc.edu/cgi-bin/hgTrackUi?db=hg19&g=cons46way 



And also, If I have a part of genome sequence located in: 

"chr1/- 1617197 1617281 " 

How could I get the conservation score of this part as it is on the reverse 
strand? 

If these coordinates are from the Genome Browser and not from a table they are 
1-based. If they are from a table, they are 0-based. This will help explain our 
coordinate system: 

http://genome.ucsc.edu/FAQ/FAQtracks.html#tracks1 

Here is information on how we calculate the reverse strand: 

http://genomewiki.ucsc.edu/index.php/Coordinate_Transforms 


Hope this helps! Please contact the mailing list if you have further questions. 

Vanessa Kirkup Swing 
UCSC Genome Bioinformatics Group 






----- Original Message ----- 
From: "chunjiang he" < [email protected] > 
To: "Katrina Learned" < [email protected] > 
Cc: [email protected] 
Sent: Tuesday, March 8, 2011 3:29:38 PM 
Subject: Re: [Genome] a question about phylop conservation 

Thanks so much Katrina, 

So as you say, I get the file "chr1.phyloP46way.placental.wigFix" and open 
it. And I see the file like this 
"fixedStep chrom=chr1 start=10918 step=1 
0.064 
0.056 
0.064 
... 
" . 

So should I treat the 0.064 as the conservation score of the base 10918? 
If I want to get the conservation score from base 10918 to 10920, could I 
average the three scores "0.064,0.056,0.064" or by some other method? 

And also, If I have a part of genome sequence located in: 

"chr1/- 1617197 1617281 " 

How could I get the conservation score of this part as it is on the reverse 
strand? 

Thanks again, 

Chunjiang 


On Tue, Mar 8, 2011 at 2:57 PM, Katrina Learned < [email protected] >wrote: 

> Hi Chunjiang, 
> 
> The score of each base isn't actually in the table. The best place to 
> obtain the score information is from the files in the following directory: 
> 
> http://hgdownload.cse.ucsc.edu/goldenPath/hg19/phyloP46way/placentalMammals/ 
> For downloading large or multiple files, please see our recommended methods 
> in the readme.txt file: 
> http://hgdownload.cse.ucsc.edu/goldenPath/hg19/phyloP46way/README.txt 
> 
> This directory contains the original ascii files that we translated (via 
> wigEncode) into the wiggle track data. These files are the best source for 
> the actual values at each base since the wigEncode procedure introduces its 
> own reduction in precision, as explained: 
> http://genomewiki.ucsc.edu/index.php/Wiggle 
> 
> To answer your second question, strand has no meaning in these phyloP 
> tables. A conserved base prediction is simply a prediction of a conserved 
> base; it is the same base in forward or reverse strand. 
> 
> I hope this information is helpful. Please don't hesitate to contact the 
> mail list again if you have any further questions. 
> 
> Katrina Learned 
> UCSC Genome Bioinformatics Group 
> 
> chunjiang he wrote, On 3/4/2011 12:06 PM: 
> 
>> Dear Mr/Ms, 
>> 
>> I want to ask which score can be used to represent conservation in 
>> phyloP46wayPlacental. 
>> I check it has a title like this: 
>> *chrom* 
>> *chromStart* 
>> *chromEnd* 
>> *lowerLimit* 
>> *dataRange* 
>> *validCount* 
>> *sumData* 
>> *sumSquares* 
>> But I am not sure which column is the most important one i should use. 
>> I see it is different to the paper they published. 
>> 
>> Another, I want to ask if the positive strand and negative strand in one 
>> chromosome have the same genomic coordinates. 
>> So here, the genomic coordinates are fit for both +/- strand? 
>> 
>> Thanks very much. 
>> 
>> Chunjiang 
>> _______________________________________________ 
>> Genome maillist - [email protected] 
>> https://lists.soe.ucsc.edu/mailman/listinfo/genome 
>> 
> 
_______________________________________________ 
Genome maillist - [email protected] 
https://lists.soe.ucsc.edu/mailman/listinfo/genome 

_______________________________________________
Genome maillist  -  [email protected]
https://lists.soe.ucsc.edu/mailman/listinfo/genome

Reply via email to