Sperm head attaches to the secondary oocyte
精子的细胞核细胞质进入卵子 生殖细胞和受精 Sperm head attaches to the secondary oocyte
Oocyte completes the second meioticdivision,the nucleus of matureovum is named the female pronucleus:sperm head enlarges to form the malepronucleus
卵子完成第二次减数分裂 雄性原核、雌性原核形成 生殖细胞和受精 Oocyte completes the second meiotic division, the nucleus of mature ovum is named the female pronucleus; sperm head enlarges to form the male pronucleus
Male and femalepronuclei fuse
两原核融合 生殖细胞和受精 Male and female pronuclei fuse
ZygoteFormation of zygote
受精卵（合子）形成 生殖细胞和受精 Formation of zygote
Phase1PenetrationofPhase2corona radiataRecognitionandPenetration ofzona pellucid00Acrosome3SpermnucleusPlasmamembrane2Membrane fusionand entryPhase3