Enables DNA-directed DNA polymerase activity. Involved in DNA replication, synthesis of RNA primer. Acts upstream of or within DNA replication. Located in nucleus. Part of alpha DNA polymerase:primase complex. Human ortholog(s) of this gene implicated in Van Esch-O'Driscoll syndrome and X-linked reticulate pigmentary disorder. Orthologous to human POLA1 (DNA polymerase alpha 1, catalytic subunit). [provided by Alliance of Genome Resources, Apr 2022]