Regulatory subunit for cdc7 which activates its kinase activity thereby playing a central role in DNA replication and cell proliferation. Not required during the initiation of DNA replication in egg and during early embryonic development but is required later and throughout development. The complex cdc7-dbf4a phosphorylates mcm2 subunit. Forms a complex with cdc7. Present throughout development. During the cell cycle progression, levels in egg extracts do not change. Appears during the first 12 hours of development, and they further increases significantly between 12 and 24 hours. Not present in oocytes I-VI but it is detected at maturation. The level of protein remains constant from mature oocytes to stage 8.5 embryos but increases after mid-blastula (at protein level). Phosphorylated.