A map that shows the linear order of identifiable landmarks on chromosomal DNA, such as restriction enzyme cutting sites, sequence tagged sites, ORFs, and others. The distances between landmarks are always determined by methods other than genetic recombination (e.g., nucleotide sequencing, overlapping deletions in polytene chromosomes, electron micrographs of heteroduplex DNAs, etc.). The lowest resolution physical map would show the pattern of horizontal bands on each stained chromosome; the highest resolution map would give the complete nucleotide sequences for all chromosomes in the genome. Cloning vectors that can carry large DNA inserts are very useful in constructing physical maps of chromosomes or whole genomes. Compare with genetic map, linkage map. See bacterial artificial chromosomes (BACs), cosmid, P1 artificial chromosomes (PACs), yeast artificial chromosomes (YACs).
Subjects: Genetics and Genomics.