What is used in the ligation of cDNA to the DNA vector in cDNA cloning?

In cDNA cloning, the process typically involves the conversion of mRNA into complementary DNA (cDNA) using an enzyme known as reverse transcriptase. However, the question specifically asks about the ligation of cDNA to the DNA vector, which is a critical step in the cloning procedure.

During this ligation step, DNA ligase is used. This enzyme catalyzes the formation of phosphodiester bonds between the 3’ hydroxyl end of the cDNA and the 5’ phosphate end of the vector DNA. As a result, the cDNA becomes incorporated into the vector, allowing for the successful cloning of the cDNA insert into a plasmid or other vector suitable for transformation into host cells. DNA ligase is essential for ensuring that these two pieces of DNA are covalently linked, enabling the propagation of the cDNA in bacterial or other systems for further study or manipulation.

The other options serve different functions in molecular biology. Reverse transcriptase is crucial for synthesizing cDNA from mRNA but does not participate in the ligation process. RNA polymerase synthesizes RNA from a DNA template, which is not directly involved in the ligation of cDNA to the vector. Endonucleases are enzymes that cut DNA at