Upon fertilization, eggs shift their cell cycle from the meiotic to the mitotic pattern for embryogenesis. The information on chromosome formation has been accumulated by various experiments using inhibitors to affect formation and behavior of chromosomes in the cycle of cell proliferation. Based on experimental results on meiosis and early stages of development of the teleostOryzias latipes, we discuss the roles of the activities of histone H1 kinase, microtubule-associated protein kinase, DNA polymerase, DNA topoisomerase, and other cytoplasmic factors that play a crucial role in formation and separation of chromosomes.
