## Description

This track depicts gaps in the assembly. These gaps — with the exception of intractable heterochromatic gaps — will be closed during the finishing process.

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 known, 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:

- Fragment - gaps between the contigs of a supercontig. (In this context, a contig is a set of overlapping sequence reads.) These are represented by varying numbers of Ns in the assembly if the gap size is known, 600 if ? and 8000 if ?.
- Clone - gaps between clones in the same supercontig. These are represented by 10,000 Ns for all chromosomes except chrUn (concatenation of unplaced contigs), where gaps of 2,000 Ns are used.
- Contig - gaps between supercontigs. These are represented by 10,000 Ns in the assembly.
- Centromere - gaps from centromeres (1,500,000 Ns for chromosomes 1-8 and Z; 500,000 Ns for chromosomes 9-13, 17, and 26).