IUBio Biosequences .. Software .. Molbio soft .. Network News .. FTP

how to treat gaps in alignments for distance calculations?

Mackenzie, BAS basm101 at york.ac.uk
Wed Oct 30 11:33:53 EST 2002


Hello,

As I understand it at present there is no reliable way of taking gaps into
account in an
analysis. In the gap regions the alignment is more uncertain - for this
reason most
people choose to remove the gap regions from their dataset. You can do this
manually
in a program like BioEdit, or you can use PAUP and the exclude command to
specify
which columns you want to exclude from your dataset.

Hope that helps,

basm101
University of York

Tilman Lamparter wrote:

> How are gaps to be treated when aligned protein sequences are taken to
> obtain distance matrices? Should the regions be excised in all sequences?
> I use the Phylip protdist program with Jones-Taylor-Thornton model or
> Dayhoff PAM matrix. I always get different results when alignments with
> and without gaps are compared.
>
> --
> Tilman Lamparter
> Freie Universitaet Berlin, Pflanzenphysiologie
> Koenigin Luise Str. 12-16, D-14195 Berlin
> e-mail lamparte at zedat.fu-berlin.de
>
> ---

---




More information about the Mol-evol mailing list

Send comments to us at biosci-help [At] net.bio.net