Orthologue

An orthologue is a gene in different species that evolved from a common ancestral gene. Orthologues generally retain the same function throughout evolution, reflecting their shared ancestry. Identifying orthologues is crucial in comparative genomics, as it allows researchers to transfer knowledge about gene function and regulation across species. This helps in understanding evolutionary relationships and the conservation of biological processes. Orthology differs from paralogy, which describes genes related by duplication within a genome.

Orthologue meaning with examples

• Researchers studying the human gene responsible for insulin production sought to find its orthologue in the mouse genome. They successfully identified a corresponding gene with high sequence similarity and a known function in glucose regulation, confirming its role as an orthologue. This finding enabled them to study insulin's function and potential therapeutic targets using the mouse model. The identification of the orthologue simplified study.
• When comparing the genomes of fruit flies and humans, scientists identified multiple orthologues of the genes responsible for eye development. Although the eyes of the two species are vastly different, these orthologues play a crucial role in the formation and function of the eyes. This highlights the remarkable conservation of fundamental developmental pathways. These orthologues help understand evolution and adaptation, proving the gene's importance.
• To understand the function of a specific gene involved in plant defense against pathogens, a biologist identified its orthologues in several other plant species. Through the comparison of these orthologues, they discovered conserved protein domains and regulatory elements, helping to predict the gene's function in related species. This helps identify commonalities, further accelerating understanding of the plants' processes by comparing genes.
• In drug development, researchers often study orthologues of human disease genes in model organisms like zebrafish or yeast. By analyzing these orthologues, they can test potential drug candidates and assess their efficacy and safety before moving to human clinical trials. The gene's study in the model gives a faster answer to potential drug development than direct human study.