Hello,

RefSeq sequences are independently aligned using BLAT and the 
coordinates are based on complete chromosomes. The genomic 
version/source is noted on the gateway page for each assembly. Some 
differences in alignment position are known and expected for this track, 
but most should be the same or very similar for the same version of an 
assembly and query RefSeq.

The UCSC Browser uses a different method of storing coordinates than 
NCBI. This may be the source of the discrepancy. Please read the 
documentation below and if you still have some questions, send a few 
examples (database, refseqID, NCBI coordinates as you interpret them, 
UCSC coordinates as you interpret them) for review and feedback.

The main table for the RefSeq Genes track is called refGene and is in 
genePred format
http://genome.ucsc.edu/FAQ/FAQformat#format9

Description of UCSC Browser coordinate system
http://genomewiki.ucsc.edu/index.php/Coordinate_Transforms

Jennifer Jackson
UCSC Genome Bioinformatics Group



Kwan, Phoenix wrote:
> Hi,
>
> I have found that most of the locations for the NM transcripts in the RefGene 
> file do not match with what are in NCBI.  Are the positions in the RefGene 
> file genomic locations relative to the full length of a chromosome?  Or 
> something else?
>
> Thank you very much for your time,
> Phoenix Kwan
>
> _______________________________________________
> 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