käänteiskopioituminen

Käänteiskopioituminen, often translated as reverse transcription, is a biological process where an RNA molecule is used as a template to synthesize a complementary DNA (cDNA) molecule. This process is primarily carried out by enzymes called reverse transcriptases, which are found in retroviruses, telomeres, and eukaryotes.

In retroviruses, such as HIV, reverse transcriptase is essential for their replication cycle. Upon entering a host cell, the retroviral RNA genome is converted into DNA. This DNA then integrates into the host cell's genome, allowing the virus to hijack the cell's machinery to produce more viral RNA and proteins.

Reverse transcriptase also plays a role in maintaining the ends of eukaryotic chromosomes, known as telomeres. Telomerase, a specialized reverse transcriptase, uses an RNA template to extend the telomeres, preventing their shortening during DNA replication. This process is crucial for cellular aging and preventing genomic instability.

Beyond its biological roles, reverse transcription is a fundamental technique in molecular biology. Researchers use it to generate cDNA from RNA, enabling studies of gene expression, RNA sequencing, and the creation of complementary DNA libraries. This technique has been instrumental in advancing our understanding of genetics and developing diagnostic and therapeutic tools.