FIGURE 1.

Changes of oocyte components during oocyte maturation and embryogenesis. In vivo and in vitro mammalian oocyte growth/maturation and embryonic development depicting corresponding stages of follicular development, oocyte maturation, and embryonic development. The changes of oocyte components prior to MZT are described, and the processes discussed in this review is shown in red letters. During the reorganization and specialization, oocyte components changes its localization and characteristics drastically (indicated by color gradation), and large amounts of oocyte components are actively degraded prior to ZGA. GV, germinal vesicle; GVBD, germinal vesicle breakdown; ICSI, intracytoplasmic sperm injection; IVF, in vitro fertilization; IVG, in vitro growth; IVM, in vitro maturation; MII, oocyte stops in metaphase of the second meiosis; MZT, maternal‐zygotic transition; PN, pronuclear; ZGA, zygotic gene activation