A graphical method of comparing the nucleotide sequences or amino acid sequences along sections of two polymeric molecules that may or may not be homologous. For example, a comparison could be made of the exons from a gene known for two different animal species (A and B). A dot plot diagram is generated with the A gene on the vertical axis and the B gene on the horizontal axis. Dots are placed within this rectangular array at every place where sequences from the two species match. The technique allows all pairs to be compared simultaneously, and regions of sequence similarity are seen as a series of dots. If there is no homology, the dots form a random pattern. If the dots form a diagonal line, the exons of the two genes have similar sequences and are arrayed in the same order.
Subjects: Genetics and Genomics.