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We give one plot for each chromosome that shows the data from the
resource
of FISH-mapped BAC clones (NCBI Clone
Registry) placed on the working draft. These plots are at a fixed
scale, so you will need to scroll right to cover the larger
chromosomes. Another set of plots covers the genome in fixed scale
50mb windows, and a third set of plots covers the genome in 10mb
windows.
The position along the working draft sequence for the chromosome is
plotted along the horizontal axis. Each cytogenetic band is allocated
a height on the vertical axis, using the standard fractional lengths
of the bands. A horizonal line is drawn across the plot at the height
corresponding to the start position of each major band. The predicted
location of every sub-band is shown by a light blue horizontal line
segment that is located at the height corresponding to the midpoint of
that sub-band, and positioned so that it begins at the horizontal
coordinate predicted to be the beginning of the sub-band in the
working draft sequence, and ends at the horizontal coordinate
predicted to be the end of that sub-band in the working draft
sequence. These predictions are calculated by a dynamic programming
method described in "A
Dynamic Programming Method to Locate Cytogenetic Bands on the Working
Draft Sequence," and will be described more fully elsewhere.
Each FISH-mapped clone is displayed as a point with error bars. The
position of the point along the working draft sequence is determined
using information about the clone, including STSs and BAC ends. The
vertical position of the point is the midpoint in the range of
possible bands predicted for the clone by FISH. The error bars
indicate the range of uncertainty for the band location for the
clone. The point is color-coded according to the lab that FISH-mapped
the clone; see the key in upper right corner of the plot. Some clone
markers are FISH-mapped to different chromosomes entirely. These are
shown at the bottom of the display.
Caveats:
- The cytogenetic band assignments by FISH have limited
accuracy, for more details see
"Integration of cytogenetic landmarks
into the draft sequence of the human genome," by the BAC
Resource Consortium, Nature, Vol. 409.
- The predictions of band positions by dynamic programming are
subject to errors due to inaccuracies in the FISH data. They
also rely weakly on approximations of the band sizes given by standard
fractional band lengths, these can be very inaccurate and can
vary between individuals, especially in the centromeric and
telomeric regions.
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