Wild type (WT) refers to the phenotype of the typical form of a species as it occurs in nature. Originally, the wild type was conceptualized as a product of the standard "normal" allele at a locus, in contrast to that produced by a non-standard, "mutant" allele. ... In general, however, the most prevalent allele – i.e., the one with the highest gene frequency – is the one deemed as wild type.