Plays a central role in centrosome maturation and mitotic spindle assembly during the first division of the zygote. Required for the centrosomal localization of air-1 and zyg-9. Probably not required in late embryogenesis and during larval development. Component of the centrosome. First expressed at two different foci in early postmeiotic one-cell stage embryos, prior to pronuclear migration but after the sperm-donated centriole duplication. These two foci greatly increase in size prior to and during mitosis. In metaphase, it is localized throughout centrosomes. In late anaphase or telophase, it surrounds a central core devoid of microtubules. Its localization is independent of microtubules and other centrosomal proteins (PubMed:12431374). Recruitment to the centrosome during prophase of the 1-cell embryo is regulated by the cye-1/cdk-2 complex (PubMed:17115027). Expressed throughout embryogenesis and during postembryonic meiotic divisions that produce sperm in males.