Before July 2004, DDBJ/EMBL/GenBank had assigned an accession number for each of sequences separated by unsequenced regions, and treated the entries of the sequences as SEGMENT entries.
However, as a result of the change of our annotation policy for such sequences, from July, 2004 we began to accept one sequence in which unsequenced regions are indicated as strings of "n"s. In the case that the length of an unsequenced region can be estimated, "n"s of the estimated length are inserted. In the case that the length of an unsequenced region is unknown, 100 "n"s are inserted.
At the same time, we are amending all of the SEGMENT entries submitted before July 2004 to combine them into a single entry in accordance with the above rules. Accession numbers of combined SEGMENT entries will be displayed as secondary accession numbers in a single entry. As for already published SEGMENT entries, we will re-release them after the amendment.
We appreciate your understanding and cooperation.
If you have any questions and concerns about this matter, please send e-mail to us at email@example.com.
* If you wish to submit your sequence with unsequenced regions of unknown length via SAKURA, please select "multi-exons with unknown gaps" in "Categories" at"Hold-date information" page, and submit only sequenced regions. One sequence with strings of 100 "n"s in the unsequenced regions will be sent to DDBJ.