A physical map of a chromosome or a genome that shows the physical locations of genes and other DNA sequences of interest. Physical maps are used to help scientists identify and isolate genes by positional cloning. According to the ICSM (Intergovernmental Committee on Surveying and Mapping), there are five different types of maps: General Reference, Topographical, Thematic, Navigation Charts and Cadastral Maps and Plans.

1. PHYSICAL
MAPPING
Dr. Priya Trivedi
M.Sc.(BOTANY), M.Ed., Ph.D. (BOTANY)

5. A physical map gives the actual distances in number
of bases between genes on a chromosome.
As such, it describes the structural characteristics of
the chromosome itself.
The physical map is one in which chromosomes are
cut into large fragments, then copied (or cloned) many
millions of times. The copies are then analyzed with a
goal of finding segments that overlap.
Rearranging these overlapping segments reconstitutes
the chromosome.
Distance is expressed in Megabase pairs ( need not be
proportionate to recombination frequencies).

10. Restriction
Mapping

15. Fluorescence in situ
Hybridization (FISH)

22. Sequence tag sites or STSs

28. Chromosome
walking

29. Principle
Identification of fragments with overlapping
sequences may be a key to the reconstruction
or characterization of large chromosome
regions.
Using the conventional cloning techniques to
isolate fragments, one may be able to isolate
>100kb chromosome region per month.
In addition, pulsed field gel electrophoesis
may be used to isolated >100 kb DNA
fragments, which may be cloned.

37. THANK U