Genome Physical Mapping UsingBACs

Abstract

A physical map of a region or the entirety of the genome of an organism is a representation of the genome providing information on the relative order and the arrangement of physically defined entities. For most physical maps, these entities are cloned genomic DNA fragments propagated in cosmids, bacteriophage P1, bacterial artificial chromosomes (BACs), P1‐derived artificial chromosomes (PACs), or yeast artificial chromosomes (YACs). The various cloning systems differ in the sizes of the cloned DNA fragments and the fidelity of DNA structure maintenance. Owing to its excellent properties, the BAC system is the premier system for this purpose. Several different, highly efficient procedures have been developed and applied successfully to identify overlaps between the DNA fragments represented in different clones. The procedures are based on different experimental techniques, including nucleic acid hybridization, DNA amplification through polymerase chain reaction (PCR), DNA restriction fragment analysis, and DNA sequencing. Applied separately or in combination, these procedures have been used successfully to generate extensive physical maps of human, animal, and plant genomes.