What are the three main DNA polymerases involved in eukaryotic DNA replication?

The three main DNA polymerases involved in eukaryotic DNA replication are DNA polymerase alpha (Pol α), DNA polymerase delta (Pol δ), and DNA polymerase epsilon (Pol ε).

Pol α plays a crucial role in initiating DNA synthesis. It has a primase activity, meaning it adds RNA primers to the template DNA, which provides a starting point for DNA synthesis. Once the primer is laid down, Pol α also begins synthesizing the new DNA strand but does not have a high processivity, which is why it quickly hands off the newly synthesized strand to another polymerase.

Pol δ is primarily responsible for synthesizing the lagging strand during DNA replication. It exhibits high processivity and can carry out extended synthesis on the DNA strands after the primer is added by Pol α. Pol δ also has proofreading capabilities, which allows it to correct mistakes that may occur during replication.

Pol ε is mainly involved in synthesizing the leading strand. Like Pol δ, it also possesses proofreading activity, ensuring fidelity during DNA replication. Studies have demonstrated that Pol ε is particularly important in maintaining genome stability due to its role in the continuous synthesis of the leading strand.

Together, these three polymerases work efficiently and cohesively to ensure accurate and complete duplication