What is the role of reverse transcriptase in genetic engineering?

Reverse transcriptase is used in genetic engineering to synthesise complementary DNA (cDNA) from an RNA template.

In more detail, reverse transcriptase is an enzyme that plays a crucial role in the process of genetic engineering. It is primarily used to convert RNA into DNA, a process that is contrary to the usual flow of genetic information in cells, which is from DNA to RNA. This reverse transcription process is essential in the creation of complementary DNA (cDNA), which is a form of DNA that is synthesised from a messenger RNA (mRNA) template.

The cDNA produced by reverse transcriptase is a vital tool in genetic engineering. It is often used in the cloning of eukaryotic genes in prokaryotes. For instance, when scientists want to study a specific protein, they can use reverse transcriptase to create cDNA from the mRNA of that protein. This cDNA can then be inserted into a plasmid and introduced into a bacterium for protein production. This is a common method used in the production of human insulin, growth hormones, and other therapeutic proteins.

Moreover, reverse transcriptase is also used in the technique of reverse transcription polymerase chain reaction (RT-PCR). This technique is used to amplify specific RNA targets. It involves the synthesis of cDNA from the RNA target using reverse transcriptase. The cDNA then serves as a template for the amplification of the target gene. RT-PCR is widely used in research, for example, in the detection and quantification of RNA levels in cells and tissues, and in the diagnosis of viral infections, such as HIV and COVID-19, where the viral RNA is reverse-transcribed to DNA for detection.

In summary, reverse transcriptase is a key enzyme in genetic engineering, enabling the synthesis of cDNA from RNA, which is crucial for gene cloning and the amplification of specific RNA targets.