Why All These Maps?

Evolution of mapping methods over time:

• older mapping technologies - lower resolution (e.g., cytogenetic, genetic linkage)
• newer mapping technologies - higher resolution (e.g., rh, YAC maps)
• sequence map - final goal - highest resolution, definitive map

Also maps produced by different groups or using different methods often show:

• different types of map objects, for example:
• cytogenetic maps shows location of genes
• genetic maps show the location of genes and/or markers such as microsatellites
• STS maps show the location of sequence tagged sites. An STS is a short stretches of sequence that is unique in the genome, and therefore can be used as a landmark for mapping
• sequence maps show the location of every base pair in a chromosome


• different subsets of map objects, for example:
• RH map A might show the map location of markers 1, 2, 3, 4, 5
• RH map B might show the map location of markers 1, 4, 5, 6, 7, 8, 9


• sequence maps show the placement (alignment) of many types of map objects to the chromosome sequence, such as:
• genes
• STSs
• SNPs (variation)