Gene duplication is a phenomenon that occurs when a segment of DNA is duplicated, generating a new copy.

For many duplicated genes, one of the copies will eventually be inactivated as it's superfluous to our requirements. It is as if we have a backup gene in case the original copy stops functioning effectively.

However, in some cases, both copies of the duplicated gene remain active.

This creates a dilemma as the extra gene appears to be redundant, and evolution would generally eliminate any genes that do not provide a benefit to the organism.

The team, led by Michael Hiller from the Department of Biology, has demonstrated that, in many cases, both gene copies are actively transcribed, but not at the same time.

Their study, published in Nature Communications, is the first large-scale analysis of the expression patterns of duplicated genes and provides an explanation for why many of these genes are retained despite appearing to be redundant.

Hiller and his team used RNA sequencing data from several organisms to examine gene expression patterns in duplicated gene pairs.

They found that in many cases, one gene is expressed more strongly in certain tissues or developmental stages, while the other is expressed more strongly in different tissues or stages.

This suggests that even though the genes may have the same overall function, they have acquired specialized roles in different contexts.

This means that neither copy becomes superfluous.

The researchers also identified cases where one copy of the gene has evolved a new function altogether.

This can occur when the gene acquires a new regulatory region or experiences other mutations that change its behavior.

The team's findings provide an explanation for why a significant proportion of duplicated genes remain in the genome, despite their apparent redundancy.

Their work has important implications for understanding the evolution of gene expression and the development of new traits in organisms.