SEQanswers

Go Back   SEQanswers > Bioinformatics > Bioinformatics



Similar Threads
Thread Thread Starter Forum Replies Last Post
How to call SNP using known SNP information nkwuji Bioinformatics 1 07-23-2013 09:16 PM
how to construct phylogenetic tree using SNPs tianyub836 Bioinformatics 10 05-21-2013 06:27 AM
CREST/perl module Tree::Interval flipwell Bioinformatics 2 08-15-2011 04:48 PM
Phylogeny nitinkumar Bioinformatics 0 07-19-2011 06:25 AM

Reply
 
Thread Tools
Old 01-13-2011, 07:27 AM   #1
Salmon
Junior Member
 
Location: az

Join Date: Jan 2009
Posts: 9
Default Why is ML/NJ phylogeny different from SNP tree?

Greetings.

I am working on a bacterial genome. We have determined the complete genome sequence of this genome and want to study the evolutionary relationship of my genome and its VERY CLOSE relatives (within the same species).

I need to construct a tree for these genomes.

First, I generated a tree based on the number of SNPS detected in conserved genomic region (~80% of whole genome).

I also constructed trees based on the conserved genomic sequence using ML and NJ methods. The two trees with ML and NJ have the same topology.

When I compared the ML/NJ trees with the SNP tree, it shows the different phylogenetic relationship of some genomes.

When I checked the published papers, it seems most studies like inferring trees using the number of SNPs, especially for the very closed genomes. I think the ML/NJ trees based on the sequence information should be much better than the number of SNPs.


We got two trees with different topologies. I couldn't get a reason for the difference. Does anybody have any comments? which tree should I use? how to explain the difference?


Many thanks,
Salmon
Salmon is offline   Reply With Quote
Old 01-17-2013, 10:55 AM   #2
mm.perrineau
Member
 
Location: New Jersey

Join Date: Sep 2012
Posts: 12
Default

Hi Salmon,

How do you make your SNPs tree?

Thank you

MM
mm.perrineau is offline   Reply With Quote
Old 01-21-2013, 09:38 PM   #3
A_Morozov
Member
 
Location: Russia, Irkutsk

Join Date: Feb 2011
Posts: 40
Default

Well, you use a bunch of methods and you get a bunch of different trees, that is usual. If you add, for instance, analysis of genomic rearrangements, you will get one more tree, some phenotypic traits will support yet another one and so on. So, pls do the following.
1) Give us some more details on analysis protocol, esp. on application of ML on 80% of genome (either I misunderstood you or it was incredibly computationally expensive) and on how exactly you built the SNP tree.
2) You don't mention whether you take into account horizontal gene transfer. If you do not, you surely must, because otherwise it may mislead your inference.
3) Consider using consensus tree or, better, consensus network for representing results, if everything else fails.
A_Morozov is offline   Reply With Quote
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off




All times are GMT -8. The time now is 02:07 PM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Single Sign On provided by vBSSO