Gene duplication

Definition

Gene duplication is a process where a segment of DNA containing a gene is copied, resulting in two identical or similar copies of that gene within the genome. This mechanism plays a crucial role in evolution, allowing for genetic redundancy that can lead to the development of new functions or roles for the duplicated genes, thereby contributing to the robustness of biological networks.

5 Must Know Facts For Your Next Test

1. Gene duplication is a primary driver of evolutionary innovation, enabling organisms to adapt and evolve new traits over time.
2. Duplicated genes can acquire mutations that may lead to novel functions, which can enhance the adaptability and robustness of biological systems.
3. The fate of duplicated genes can vary: they may become nonfunctional (pseudogenes), retain their original function, or develop new functions (neofunctionalization).
4. Gene duplication events can occur through various mechanisms such as unequal crossing over during meiosis or through retrotransposition.
5. The increased genetic material resulting from gene duplication contributes to network robustness by providing alternative pathways and functions that can compensate for losses or failures in biological processes.

Review Questions

• How does gene duplication contribute to the robustness of biological networks?
  • Gene duplication enhances the robustness of biological networks by providing genetic redundancy. When a gene is duplicated, there are now two copies that can perform similar functions, which means if one copy is mutated or becomes nonfunctional, the other can often compensate for its loss. This redundancy helps maintain essential biological processes and contributes to the overall stability of the organism's genetic and metabolic networks.
• What are some potential evolutionary outcomes of gene duplication in terms of gene function?
  • Gene duplication can lead to several evolutionary outcomes regarding gene function. The duplicated genes may become paralogs that evolve distinct functions, a process known as neofunctionalization. Alternatively, both copies may retain their original function (conservation) or one copy may lose its function altogether, becoming a pseudogene. These outcomes increase genetic diversity within populations, allowing for adaptation and evolutionary innovation.
• Evaluate the significance of gene duplication in the context of evolutionary biology and its implications for understanding genetic diseases.
  • Gene duplication is significant in evolutionary biology as it serves as a key mechanism for generating genetic diversity and facilitating the evolution of new traits. By providing additional genetic material, it allows organisms to experiment with new functions without losing essential ones. In terms of genetic diseases, understanding how gene duplications can lead to variations in gene expression and function helps researchers identify potential causes of disorders. It highlights the complex relationship between genetic architecture and disease susceptibility, showing how duplications can sometimes confer advantages or lead to pathologies depending on their effects on phenotype.

Related terms

paralogs: Paralogs are genes that arise from gene duplication events and evolve new functions, often within the same organism.

orthologs: Orthologs are genes in different species that evolved from a common ancestral gene through speciation, often retaining similar functions.

genomic redundancy: Genomic redundancy refers to the presence of duplicate genes in an organism's genome, which can provide a buffer against mutations or loss of function.