GLOSSARY: Gene Mapping

Gene Mapping refers to the determination of the relative positions of genes on a DNA molecule (chromosome or plasmid) and of the distance, in linkage units or physical units, between them. When a genome is first investigated, this map is nonexistent. The map improves with the scientific progress and is perfect when the genomic DNA sequencing of the species has been completed. Two different ways of mapping are distinguished. Genetic mapping uses classical genetic techniques to determine sequence features within a genome. Using modern molecular biology techniques for the same purpose is usually referred to as physical mapping.