Total CpG genome count

Question

[Baylie_321]

Hiya, I'm trying to get a total count of all CpGs present in a non-model organism genome. I have used bam2nuc in bismark to count dinucleotides - am I correct in thinking the count of CGs will be the total CpG count of the genome?

Best wishes,

Rebekh

[cpad0112]

If you want to count only CGs from fasta (nt) in R:

library (Biostrings)
data(yeastSEQCHR1)
yeast1 <- DNAString(yeastSEQCHR1)
dinucleotideFrequency(yeast1)['CG']
 CG 
7089

in python:

s = 'ATATTGCGAAAGAACGTAATTTTATCGAAAAATCGATGTcgcgcg'
print(s.upper().count("CG"))

7

[maxime.policarpo]

Couldn't you also count GCs nucleotides as it will be a CpG on the reverse strand ?

[Baylie_321]

I was meaning more is the programme suitable for this

[Devon Ryan]

A GC is a GC on the other strand, not a CpG.

[lakhujanivijay]

A: How to find out total # of CpGs sites from a fasta file?

[Baylie_321]

Cheers :) I'll give the C program a go!

[lakhujanivijay]

Hello rebekah_321,

Don't forget to follow up on your threads.

If an answer was helpful, you should upvote it; if the answer resolved your question, you should mark it as accepted. You can accept more than one if they work.

[cpad0112]

Refer to Emboss programs : http://emboss.sourceforge.net/apps/cvs/emboss/apps/newcpgreport.html, http://emboss.sourceforge.net/apps/cvs/emboss/apps/cpgreport.html and http://emboss.sourceforge.net/apps/cvs/emboss/apps/newcpgseek.html

[Baylie_321]

I tried emboss - but doesn't it just report CpG islands?

[Baylie_321]

Yes I have used emboss to predict CpG islands - now I want all CpGs not just islands

[Baylie_321]

Yes I have used emboss to predict CpG islands - now I want all CpGs not just islands