Question

genetics- please explain in paragraph

Why is cDNA of such practical importance to molecular biolog

Answer 1

Complementary DNA (cDNA) is DNA synthesized from a single-stranded RNA (e.g., messenger RNA or microRNA)  template in a reaction by enzyme reverse transcriptase.

It is used to clone eukaryotic genes in prokaryotes.Eg: to express a specific protein in a cell that does not normally express that protein, transfer of the cDNA would codes for the protein to the recipient cell. It is also produced naturally by retroviruses and then integrated into the host's genome, where it creates a provirus.

It is also often used in gene cloning or as gene probes or in the creation of a cDNA library.

Another application may include expressing the new genetic material as a protein in the recipient cell, the cDNA will be added to the recipient (rather than the entire gene), because the DNA for an entire gene may include DNA that does not code for the protein or that interrupts the coding sequence of the protein (e.g., introns). Partial sequences of cDNAs are often obtained as expressed sequence tags (EST).

With amplification of DNA sequences via polymerase chain reaction (PCR). Once amplified, the sequence can be cut at each end with nucleases and inserted into one of many small circular DNA sequences known as expression vectors. Such vectors allow for self-replication, inside the cells, and potentially integration in the host DNA. They typically also contain a strong promoter to drive transcription of the target cDNA into mRNA, which is then translated into protein.

Hence, it is fast becoming a strong tool to produce vaccines and desired cells.