Schema for Gap - Gap Locations
  Database: rn6    Primary Table: gap    Row Count: 145,732   Data last updated: 2014-07-08
Format description: Gaps in golden path
On download server: MariaDB table dump directory
fieldexampleSQL type info description
bin 585smallint(6) range Indexing field to speed chromosome range queries.
chrom chr1varchar(255) values Reference sequence chromosome or scaffold
chromStart 1035int(10) unsigned range start position in chromosome
chromEnd 1060int(10) unsigned range end position in chromosome
ix 2int(11) range index count of this fragment (obsolete/useless)
n Nchar(1) values 'N' for gaps of known size, 'U' for gaps of unknown size
size 25int(10) unsigned range size of gap
type scaffoldvarchar(255) values scaffold, contig, clone, fragment, etc.
bridge yesvarchar(255) values yes, no, mrna, bacEndPair, etc.

Sample Rows

Note: all start coordinates in our database are 0-based, not 1-based. See explanation here.

Gap (gap) Track Description


This track shows the gaps in the Jul. 2014 rat genome assembly.

Genome assembly procedures are covered in the NCBI assembly documentation.
NCBI also provides specific information about this assembly.

The definition of the gaps in this assembly is from the AGP file delivered with the sequence. The NCBI document AGP Specification describes the format of the AGP file.

Gaps are represented as black boxes in this track. If the relative order and orientation of the contigs on either side of the gap is supported by read pair data, it is a bridged gap and a white line is drawn through the black box representing the gap.

This assembly contains the following principal types of gaps:

  • contig - gaps between contigs in scaffolds (count: 440; all of size 10,000 bases)
  • scaffold - gaps between scaffolds in chromosome assemblies (count: 70,224; size range: 10 - 200,000 bases)