What do epistatic effects refer to in genetics?

Epistatic effects specifically involve the interactions between genes located at different loci. This concept is crucial in genetics because it highlights how the expression or action of one gene can influence or suppress the effects of another gene, even if they are not physically located on the same chromosome. This interaction can help explain complex traits that do not follow simple Mendelian inheritance patterns, as it involves multiple genes working together, which can lead to a variety of phenotypic outcomes.

Understanding epistasis is vital for genetics and breeding studies, particularly in understanding how traits are inherited and how certain phenotypes can be produced through the combined effects of multiple genes. This complexity is often seen in traits that are polygenic or involve multiple pathways, further illustrating why the interaction at different loci is as significant as those at the same locus.