Acts upstream of or within DNA replication and inner cell mass cell proliferation. Located in cytoplasm and nucleus. Is expressed in several structures, including alimentary system; brain; genitourinary system; respiratory system; and sensory organ. Human ortholog(s) of this gene implicated in immunodeficiency 55. Orthologous to human GINS1 (GINS complex subunit 1). [provided by Alliance of Genome Resources, Apr 2022]