What is the primary function of Pol α in eukaryotic DNA replication?

Pol α, or DNA polymerase alpha, plays a crucial role in eukaryotic DNA replication, particularly due to its primase activity. Its primary function involves synthesizing a short RNA primer, which is essential for the initiation of DNA synthesis. The ability of Pol α to synthesize these primers is vital because DNA polymerases can only add nucleotides to an existing 3' hydroxyl group, and the primer provides this necessary starting point.

After the primer is laid down, Pol α also has the capability to extend the newly synthesized strand by adding deoxyribonucleotides, bridging the gap until another polymerase, typically Pol δ or Pol ε, takes over to synthesize the leading or lagging strand in a more processive manner. This initial synthesis by Pol α ensures that the DNA replication process is initiated correctly at each replication fork.

Understanding the specific function of Pol α as a primase allows for a greater appreciation of its role in DNA replication, which is fundamental to cell division and the maintenance of genomic integrity.