Allelic exclusion - Once allele’s functional protein is generated, rearrangement at the other allele is shut down

TLS Online TPP Program

#Id: 8961

#Section 3: Genetics, Cellular and Molecular Biology

No matter how it is born, a new gene starts its life as a single copy in the population.

As with any new mutation, by far the most likely outcome is that it will be lost by random drift or selection over the next few generations

TLS Online TPP Program

#Id: 8962

#Section 3: Genetics, Cellular and Molecular Biology

Fate of duplicate gene 

TLS Online TPP Program

#Id: 8963

#Section 3: Genetics, Cellular and Molecular Biology

If the duplicate is redundant and does not provide a fitness benefit, it will be lost by deletion or the accumulation of loss of-function mutations.

A second fate is that a duplicate can simply retain its original function.

TLS Online TPP Program

#Id: 8964

#Section 3: Genetics, Cellular and Molecular Biology

A third fate that can befall a duplicated gene is neofunctionalization. Here the duplicate evolves a novel biological function. 

TLS Online TPP Program

#Id: 8960

#Section 3: Genetics, Cellular and Molecular Biology

Duplicate gene and its parental copy can subfunctionalize so that each carries out only some of the roles that the ancestral gene performed. 

Ex- a duplicate of the β-hemoglobin locus is expressed in the fetus. 

TLS Online TPP Program

#Id: 2243

#Section 3: Genetics, Cellular and Molecular Biology

The loci that encode hemoglobins are members of a gene family, which is a set of loci that arose by duplication.