Exon shuffling

Exon shuffling is a molecular mechanism for the creation of new genes. It involves the rearrangement of exons, or coding sequences, within a gene or between different genes. This process can lead to the evolution of new proteins with novel functions. Exon shuffling is considered a significant driver of evolution and genetic diversity.

Mechanisms of Exon Shuffling

Exon shuffling can occur through several mechanisms, including recombination, transposition, and retrotransposition. These processes can result in the duplication, deletion, or rearrangement of exons.

Recombination

Recombination is a process where genetic material is exchanged between different DNA molecules. During exon shuffling, recombination can occur between homologous sequences flanking exons, leading to the rearrangement of exons within a gene or between different genes.

Transposition

Transposition involves the movement of DNA sequences within the genome. Transposons, or "jumping genes," can facilitate exon shuffling by inserting themselves into new genomic locations, carrying exons with them.

Retrotransposition

Retrotransposition is a process where RNA is reverse-transcribed into DNA and inserted back into the genome. This mechanism can capture exons and insert them into new locations, contributing to exon shuffling.

Role in Evolution

Exon shuffling plays a crucial role in the evolution of new proteins. By rearranging exons, organisms can create proteins with new combinations of functional domains, leading to novel functions and adaptations. This process is a key factor in the diversification of protein functions across different species.

Examples of Exon Shuffling

Exon shuffling has been observed in various genes across different organisms. For example, the immunoglobulin genes in vertebrates have evolved through exon shuffling, allowing for the generation of a diverse array of antibodies.

Related pages

• Gene duplication
• Alternative splicing
• Protein domain