The complementation test was developed by American geneticist Edward B. Lewis. If the combination of two genomes containing different recessive mutations yields a mutant phenotype, then there are three possibilities: Mutations occur in the same gene.

What is the complementation test in genetics?

Complementation test, also called cis-trans test, in genetics, test for determining whether two mutations associated with a specific phenotype represent two different forms of the same gene (alleles) or are variations of two different genes.

Why is a complementation test used?

In summary, the complementation test is used to assign mutant alleles to specific genetic loci. Mutant alleles of the same gene fail to complement one another, while alleles of different genes do complement each other.