View Single Post
Old 10-02-2013, 05:58 PM   #2
Senior Member
Location: Sydney

Join Date: Feb 2011
Posts: 149

Originally Posted by StephaniePi83 View Post
Dear all,
I'm analyzing small RNA seq data.
I have the genomic coordinates of some elements (called cluster) on the genome.
I have to make some graph, representing the density of small RNA mapping to these cluster using a windows size of 250nt and step size of 25 nt ( i have to do this because it has already been done in a paper).
I'm not sure to well understand :
does it mean that i have to created a BED file called windows.bed for 250nt windows across the element of interest and that each windows overlap by 25 nt.
For example :

chr1 0 250
chr1 225 475
and i create a 2nd bed file of sequence reads called reads.bed

And i can use coverageBed from Bedtools to calculate for each window in windows.bed the number of reads in reads.bed that overlap the window.

Do i well understand the notion of window size / step size ?

Thanks in advance for your help,

and then, i can use Bedtools

For example, it means you count the number of small RNA that mapped to pos 0-250, then 25-275, then 50-300 and so on, and you plot the total number of mapped smallRNA in these 250nt bins.
Kennels is offline   Reply With Quote