The principles of genetic analysis that we have described for a single locus can be extended to the study of alleles at two loci simultaneously. Analysis of two loci in parallel is required for genetic mapping and can also reveal gene interactions. These techniques are very useful for both basic and applied research. Before discussing these techniques, we will first revisit Mendel’s classical experiments.
Thumbnail: Coat color in animals is an example of a trait that is controlled by more than one locus. (Flickr-Gossamer1013-CC:AND).