Genduplikation

GenDuplikation is the genetic process by which segments of DNA are copied within an organism’s genome, producing additional copies of genes or other genomic regions. It encompasses several forms, including tandem duplications (copies placed adjacent to the original), segmental duplications (copies separated by other sequences), and whole-genome duplications (polyploidy), which raise the number of chromosome sets. Duplications provide genetic redundancy and serve as raw material for evolutionary innovation.

Several mechanisms can generate duplications. Unequal crossing over during meiosis can create one chromosome with extra copies and another with deletions. Replication errors, such as fork stalling and template switching, can duplicate segments. Non-allelic homologous recombination can misalign similar sequences, leading to duplications. Retrotransposition can create duplicated genes, sometimes via reverse transcription of RNA transcripts.

The consequences of GenDuplikation are diverse. Redundant gene copies can accumulate mutations, leading to neofunctionalization (new functions) or subfunctionalization (partitioning of ancestral functions). Duplication can affect gene dosage, with positive or negative fitness effects depending on context. In plants and some animals, duplications and polyploidy are major drivers of diversification and complexity. In humans, segmental duplications contribute to copy-number variations linked with disease risk as well as beneficial traits.

Detecting GenDuplikation relies on genome sequencing, comparative genomics, and analyses of read depth and paralogous gene families to identify duplicated regions and estimate their origins and ages. As a fundamental force in genome evolution, GenDuplikation shapes gene content, organization, and function across lineages.