This includes all about complementation mapping.

1. Complementation Mapping
Molecular Genetics II
Presented by Muhammad Farooq
Collage Roll No. 870
University Roll No. 023821
6th Semester, BS Zoology

2. Introduction
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Complementation Mapping/Test is also know as cis-trans test.
Complementation Test was developed by American geneticist
Edward B. Lewis.
It is used to determine whether the mutation in two strains are
in different gene.
Complementation will not occur if the mutations are in same
gene means it will occur if mutations are in different gene.
It is used to determine whether different recessive mutations
affects the same gene or locus or whether they different
genes.

3. Cis-trans Test
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Cis-Heterozygote : Both the mutant alleles are located
in the same chromosome while the wildtype (normal)
are present in homologous chromosome.
Trans-Heterozygote : One muted allele is located on one
chromosome while the other one in other homologous
chromosome.

5. • Complementation will not occur if the mutations are in same gene
means it will occur if mutations are in different gene.

6. Example of a Simple
Complementation Test
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For a simple example of a complementation test,
suppose a geneticist is interested in studying two
strains of white-eyed flies of the species Drosophila
melanogaster, more commonly known as the
common fruit fly.
In this species, wild type flies have red eyes and eye
color is known to be related to two genes, A and B.

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Each one of these genes has two alleles, a
dominant one that codes for a working protein (A
and B respectively) and a recessive one that codes
for a malfunctioning protein (a and b respectively).
Since both proteins are necessary for the
synthesis of red pigmentation in the eyes, if a
given fly is homozygous for either a or b, it will
have white eyes.

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Knowing this, the geneticist may perform a
complementation test on two separately obtained strains
of pure-breeding white-eyed flies.
The test is performed by crossing two flies, one from each
strain. If the resulting progeny have red eyes, the two
strains are said to complement; if the progeny have white
eyes, they do not.