This track shows all gaps (any sequence of N's) in the 31 Dec 2019 Catharus ustulatus/GCF_009819885.1_bCatUst1.pri genome assembly. Not all gaps were annotated in the AGP file, this track includes all sequences of N's in the assembly.
Genome assembly procedures are covered in the NCBI
NCBI also provides specific information about this assembly.
Any sequence of N's in the assembly is marked as a gap in this track.
The standard gap track only shows the gaps as annotated in the AGP file:
The NCBI document AGP Specification describes the format of the AGP file.
Gaps are represented as black boxes in this track. There is no information in this track about order or orientation of the contigs on either side of the gap.
Gap count and coverage: gap count: 428 bases covered: 12,903,595