Using Map Position Fields on MGI Query Forms
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This help document describes how to use the Map Position fields on an MGI Query Form. Depending on the query form, some or all of the following fields are available:

Chromosome(s) | Genome Coordinates | Marker Range | cM Position
Chromosome(s) Select one or more items from the chromosome selection list.
Genome Coordinates
  • Make a selection on the Chromosome(s) list if available, otherwise, prepend the chromosome number followed by a colon (e.g. 19: or chr19:). Use MT for the Mitochondrial Chromosome.
  • Click the other down arrow and select either bp (base pairs) or Mbp (mega base pairs) as the unit of measurement. (The default is base pairs.)
  • Enter the coordinate(s):
To search for...Type or paste in the box... Examples: (be sure to select the proper unit: Mbp or bp)
BetweenCoordinates indicating the area that includes the marker of interest, separated by a hyphen (-) or 2 periods (..). 125618206-125622026
< =A single coordinate less than or equal to that of a mapped gene or marker. 1-125618205
> =A single coordinate greater than or equal to a mapped gene or marker. 125622026-999999999
Note: The build number appearing on the query form is that of the NCBI assembly sequence loaded in the MGI database. This may or may not be the number of the most current build at NCBI.
Marker Range Enter the exact marker or gene symbol in the boxes on either side of the word and. The query is inclusive; markers are returned if at least one base pair (bp) overlaps the range you specify.  
  • Define both a start marker and an end marker.
  • Use only markers on the same chromosome (e.g., Hoxd1 and Pax6). (You do not have to select a chromosome.)
  • Use only markers that have coordinates.
  • Use only the current symbol for each marker.
cM Position Centimorgan (cM) positions for genes and markers in MGI are based on linear interpolation using the standard genetic map described in Cox et al. (2009). (PMID). Markers without genome coordinates cannot be assigned specific cM locations and are designated as syntenic.
  1. Select a chromosome from the Chromosome(s) list.
  2. Specify a region BETWEEN two points (on this chromosome) by entering beginning and ending values, separated by a hyphen (e.g. 50-75).