Finding old archived entries

Sequence Version Archive

In the section 'How sequence is assembled', we saw that sequence entries are subject to change, for instance when a sequence changes from being partially to fully assembled, or when annotation is added/changed for a sequence. The EMBL-Bank database, which contains the assembled sequences in ENA, only displays the most recent version of a sequence and its annotation. However, older versions of EMBL-Bank entries can still be accessed through the ENA Sequence Version Archive (SVA) (Figure 30) (5).

ENA Sequence Version Archive search for finding old versions of EMBL-Bank entries

 Figure 30. ENA Sequence Version Archive search for finding old versions of EMBL-Bank entries.

Notes

[A] Accession Number or Sequence Version lets you search using an EMBL-Bank accession number (for example BN000065) or a sequence version (for example BN000065.2, which is version 2 of entry BN000065).

[B] Snapshot enables you to see a specific EMBL-Bank entry (which you  must enter in [A]) as it looked on a particular date.

SVA results - querying an accession number

If you search on an EMBL-Bank accession number in the SVA, then you will get a list of all the version changes for that EMBL-Bank entry and the date they became public (Figure 31). You can select to view and/or save any of these versions. You can also cross-compare different versions to see exactly what has changed.

SVA search results displaying a list of all the versions of EMBL-Bank entry BN000065

Figure 31. SVA search results displaying a list of all the versions of EMBL-Bank entry BN000065.

Notes

[A] View allows you to see a snapshot of the EMBL-Bank entry at the date listed.

[B] Check two or more versions and click [C] Compare Selected to see a comparison of the selected versions of the entry, with all the differences highlighted.

[D] You can save old versions of an entry in EMBL or Fasta formats.

 

 

 

SVA results - comparing different versions of an entry

If you select to compare two or more versions of an EMBL-Bank entry, the SVA will display the full entry with everything that has been removed or inserted highlighted, so you can quickly see what changes have occurred (Figure 32).

SVA search results showing a comparision of two versions of EMBL-Bank entry BN000065

Figure 32. SVA search results showing a comparision of two versions of EMBL-Bank entry BN000065 (14-NOV-2006 and 05-OCT-2004), where the lines inserted or removed are highlighted.

Notes

[A] SVA search, where two different versions of entry BN000065 have been selected (red arrows).

[B] SVA results showing which lines have been added to the entry highlighted in green [C], and lines that have been removed from the entry highlighted in orange [D].