I got a list of kegg gene ID for fruitfly. Now I want to get these sequences. I think mapping these KEGG gene ID to flybase gene ID and then extracting the sequences from flybase is a good way to do the job. I am sure there is a map between kegg gene id and flybase gene id (see below), however, I do not know where it is. Give me a hint? Thanks!
The CG identifiers are not Kegg gene ids but the FlyBase Computed Gene IDs. The CG id nomeclature was inherited from Celera/Berkeley and then gene model names were rationalized into the FlyBase paradigm, where all object types are given a FBxx id, where FB=FlyBase and xx=object type (in this case, gene name).
To get a mapping between CGids <-> FBgns, use biomart, with this query.
If you have KEGG gene IDs, and you want to get the sequences, why not simply download the sequences from KEGG and save yourself the painful and error-prone mapping exercise?
You are accessing the FlyBase database directly, right?
CG10219 and CG10320 are synonyms in FlyBase, which you can use to get the FlyBase gene ID as follows:
SELECT DISTINCT
f.uniquename
FROM
feature f,
synonym s,
feature_synonym fs
WHERE
s.name = 'CG10219'
AND
s.synonym_id = fs.synonym_id
AND
f.feature_id = fs.feature_id
AND
f.organism_id = 1;;
Some explanation:
You need DISTINCT because there are several mappings in feature_synonym that match the same synonym_id and feature_id, but differ in pub_id (otherwise it will just return the FlyBase ID a couple of times)
You need to match organism_id because otherwise you get non-dmel results too
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updated 5.1 years ago by
Ram
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written 13.6 years ago by
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No. I am trying to download a batch of sequences from the website of FlyBase. The batch download accepts IDs like CG.However, a CG-like ID ofen corresponds to more than one FBgn ID and only one of them is what I want. Thus, it is inconvenient to use the batch download on the website. Any other method? Thanks.
Thanks, Casey. The query you provided is right what I want.