[Genome] tfbsConsSites.txt in hg17 and hg18

[Takeshi Nagashima]

Dear Sir/Madam,

I am using TFBS data. I have one question about this data.

I downloaded tfbsConsSites.txt.gz of hg17 and hg18 from ftp site (on Mar
22, 2007). I noticed that there is big difference between hg17 and hg18
in terms of file size and line number (= the number of TFBS). When I
count the number of lines in tfbsConsSites.txt, the file from hg18
database contains 3212789 lines, although the file from hg17 contains
695221 lines. When I extract TFBS for specific transcription factor
(e.g. estrogen receptor : V$ER_Q6) from tfbsConsSites.txt, 1040 and
11969 sites were found for hg17 and hg18, respectively (this was also
confirmed by using Table Browser).
Dose anyone explain where these differences come from?

Best regards,
Takeshi Nagashima

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Takeshi Nagashima (nagasima at gsc.riken.jp)
Cellular Systems Biology Team
Computational and Experiment Systems Biology Group
Genomic Sciences Center (GSC), RIKEN
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