The neotenic centriole of fruit fly resembles an early procentriole . This neotenic, atypical centriole, is known as the Proximal Centriole-Like. A nonfunctioning centriole lies adjacent to the kinetosome. At this point, the daughter centriole which takes on characteristics of a mother centriole. Centrins participate in calcium signaling and are required for centriole duplication. The sperm contributes a pronucleus and a centriole to the egg. The basal body differs from the mother centriole in at least 2 aspects. CP110 is another cyclin E/CDK2 substrate which involves in centriole duplication and centrosome separation. The specimen contributes with DNA/chromatin, a centriole, and perhaps also an oocyte-activating factor (OAF). Later the centriole is modified in the process of centrosome reduction. Thus, the basal body in such a cell is derived from the centriole. The sperm supplies the centriole that creates the centrosome and microtubule system of the zygote.