The "DNA fingerprint" at right shows typical results of PCR reactions from plant DNA. In each pair of adjacent lanes in this gel image, DNA from barley cultivars Proctor (left lane) and Nudinka (right lane) was amplified. (The results using six different primer sets are shown, for a total of 12 lanes.) DNA differences (polymorphisms) between Proctor and Nudinka, marked with numbers, appear as presence or absence of bands on the gel. For example, the band labeled 1 for primer combination E37/M32 is present in cultivar Proctor (left) but absent in cultivar Nudinka (right). This band represents a genetic locus at which the DNA sequence is different between the two cultivars. Between bands 1 and 2 is an unmarked band that is shared in common between Proctor and Nudinka. This band represents a different chromosomal locus that is identical between the two cultivars.
This DNA fingerprint was produced as part of the Barley Genome Mapping project. For more information, see the GrainGenes Web site.Since each band (marker) represents a distinct genetic locus, it is possible to place each marker on a genetic map by scoring the presence or absence of bands in offspring from a cross between two different parents.
previous page
next page