In adults, CDT-1 is present in germ cell nuclei and is enriched in oocyte nuclei. In early embryos, CDT-1 is localized to chromosomes in mitotic cells during anaphase and early telophase. CDT-1 nuclear staining is not present in S phase, which directly follows mitosis in the early embryo. Anti-CDT-1 staining in embryos is abolished by
cdt-1 RNAi, indicating the validity of the staining pattern. Newly hatched larvae lack detectable CDT-1 expression. However, CDT-1 levels are transiently increased in the nuclei of blast cells before their mitotic divisions.