Genomduplikációk

Genomduplikációk, also known as whole-genome duplication (WGD) or polyploidization, refer to the process where an organism's entire genome is copied, resulting in a cell or organism with multiple sets of chromosomes. This phenomenon can occur in various organisms, including plants, fungi, and animals. In plants, WGD is a common evolutionary event and has played a significant role in the diversification and adaptation of many plant species, leading to novel traits and increased genetic variation. For example, many crops like wheat, cotton, and potatoes are polyploids. In animals, WGD is rarer but has been observed in certain lineages, such as some fish and amphibians.

The mechanisms of WGD can vary. It can happen during meiosis, the cell division process that produces gametes (sperm and egg cells), leading to the formation of diploid gametes that, upon fertilization, result in a polyploid offspring. Alternatively, it can occur during mitosis, the process of cell division for growth and repair, leading to polyploid somatic cells. The consequences of WGD can be diverse. Initially, the duplicated genome can lead to gene dosage effects, where having more copies of genes alters their expression levels. Over time, these duplicated genes can diverge through mutations, potentially acquiring new functions or becoming pseudogenes. WGD can provide a raw material for evolutionary innovation and adaptation, but it can also lead to genomic instability and developmental challenges.