The Sequence Revision History tool allows you to see the various gi numbers, version numbers, and update dates for sequences that appeared in a specific GenBank record.

E.g., search for U46667 in the tool to see the old and current identifiers of the nucleotide sequence in that record.

Note that the original gi number for the nucleotide sequence, 2734632, does not have a corresponding version number. This is true because it was removed from the database (and replaced by 3172140) before the new accession.verion system was implemented in Feb. 1999. At that time, each sequence in the GenBank/EMBL/DDBJ database received a version number of 1, even if they had been updated in the past.

In addition, if a GenBank record contains an updated sequence, the Comment field will contain a cross-reference to the gi number of the earlier sequence. (E.g., see U46667 in Entrez.) If you follow the link for that earlier gi number, Entrez will display that version of the GenBank record. Similarly, the Comment field of the older version will have a warning that the sequence has been updated, and will contain a cross-reference to the newer version.

More details about sequence identification numbers (GI and accession.version).

Back to sample record.