Description
This track depicts gaps in the assembly of chrUn, the "unordered chromosome"
for this browser. Gaps are represented as black boxes.
This assembly contains two types of gaps:
- contig - gaps between scaffolds. These gaps, represented by 1000
	Ns, are placeholders between scaffolds that were added as part of
	the construction of chrUn. Because the order and orientation
	between the scaffolds is unknown, contig gaps are considered to be
	unbridged.  There are 3,031 gaps of this type, for a total of
	3,031,000 bases.
- fragment - these gaps are merely locations of N's that are not in
	the contig gaps.  They are marked as bridged gaps, although there
	are 30 unusual cases were a scaffold sequence happens to
	begin or end with a single N and thus appears adjacent to
	the contig gaps.  There are 91,784 gaps of this type, for a total
	of 92,153,565 bases.