第二节早期胚胎发育、迁糁和附植 早期胚胎的发育 Development of Early embryos 妊娠识别 Maternal Recognition of Pregnancy 胚胎附植(着床) Implantation of Embryos 早期胚胎的迁移 Migration of Early Embryos
第二节 早期胚胎发育、迁移和附植 一、早期胚胎的发育 Development of Early Embryos 二、妊娠识别 Maternal Recognition of Pregnancy 三、胚胎附植（着床） Implantation of Embryos 早期胚胎的迁移 Migration of Early Embryos
早期胚胎的发育 )卵裂( Cleavage) 原核胚 2细胞胚胎 8细胞胚胎 (1 day-cow) 3 days-cow (14-16-0w) (3-4 days-sow
一、早期胚胎的发育 (一)卵裂 (Cleavage)
FIGURE 21 Scanning electron micrograph of uncompacted (left)and com their behavior. They suddenly huddle together, maximizing their con pacted (right)8-cell mouse em tact with the other blastomeres and forming a compact ball of cells bryo.(Photographs courtesy of C. Ziomek (Figure 21). This tightly packed arrangement is stabilized by tight junc tions that form between the outside cells of the ball, sealing off the inside of the sphere(Figure 22). The cells within the sphere form gap
Cleavage Cle ge Cleavage plane I C savage plane I p:aneⅡ plane IIA Cleavage p laneⅢB (A)ECHINODERM (Sea urchin) (B)MAMMAL (Rabbit)