Geenidupilkkaat

Geenidupilkkaat are genetic sequences that exist in multiple copies within a genome as a result of gene duplication events. They can be exact copies or diverged copies that have accumulated mutations over time. In many genomes, gene duplicates contribute to the expansion of gene families and provide raw material for evolutionary innovation.

They arise through several mechanisms, including unequal crossing over during meiosis, replication slippage, retroposition, and whole-genome duplications. Some duplicates remain functional, others become pseudogenes if they lose function. Duplicates can be arranged in clusters or dispersed, and their regulatory elements may differ, leading to varied expression patterns.

The fate of a gene duplicate is influenced by selective pressures and genomic context. Duplicates can undergo subfunctionalization, where each copy preserves a subset of the original function, or neofunctionalization, where one copy acquires a new function. Over time this drives gene-family expansion and genetic novelty, contributing to organismal complexity and adaptability.

Researchers study gene duplicates with genome sequencing and comparative genomics. Short- and long-read sequencing help resolve highly similar regions; copy-number variation analysis identifies dosage changes; synteny and phylogenetic analyses distinguish paralogs from orthologs and reveal historical duplication events.

In humans and other organisms, gene duplications contribute to biological diversity and disease susceptibility. Dosage-sensitive duplications can cause disorders, while other duplicates support adaptation and specialized tissues. Databases of segmental duplications and paralogous gene families summarize known instances of Geenidupilkkaat.