Replikatsioonivigade

Replikatsioonivigade, also known as replication errors, are mistakes that occur during the process of DNA replication. DNA replication is the fundamental biological process by which a cell duplicates its DNA, ensuring that each daughter cell receives a complete set of genetic instructions. While this process is remarkably accurate, it is not entirely error-free.

These errors can arise from various sources. For instance, the DNA polymerase enzymes responsible for synthesizing new DNA strands can occasionally insert an incorrect nucleotide base. These incorrect insertions can be due to the chemical nature of the bases or external factors that damage the DNA. Spontaneous chemical changes in the DNA bases themselves can also lead to mispairing during replication.

Fortunately, cells possess sophisticated repair mechanisms to correct most replication errors. These proofreading and mismatch repair systems identify and remove incorrectly incorporated nucleotides, significantly reducing the overall mutation rate. However, if these repair systems fail or are overwhelmed, the replication error can persist and become a permanent change in the DNA sequence, known as a mutation.

The consequences of replication errors depend on where they occur in the genome. Errors in non-coding regions may have no observable effect. However, if an error occurs within a gene, it can alter the protein produced by that gene, potentially leading to a loss of function, a gain of function, or a completely new function. Such mutations can contribute to genetic diseases or play a role in evolution.