From blastocyst to placenta: the morphology of implantation in the baboon
From blastocyst to placenta: the morphology of implantation in the baboon
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DOI：
10.1093/humupd/3.6.561
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发表时间：
1997-11-01
影响因子：
13.3
通讯作者：
Hendrickx, AG
中科院分区：
文献类型：
--
作者：
Enders, AC;Lantz, KC;Hendrickx, AG
狒狒的着床和胎盘形成与其他灵长类动物有许多共同的形态学特征，也有一些特殊的区别。利用性皮肤的消肿作为排卵时间的方法的能力和子宫腔可以冲洗的容易程度已经被用来检查该物种囊胚分化和着床的形态学方面。通过排卵后6-8天非手术冲洗子宫获得植入前囊胚，并从妊娠第10-16天取出的子宫中切除植入部位。通过醛固定和塑料包埋制备所有组织用于电子显微镜检查。滋养层从致密桑椹胚期到扩张囊胚期的成熟包括多聚核糖体数量的增加，线粒体构象的变化，以及有效的内吞装置的发育。在内细胞团下方形成内胚层，然后失去透明细胞，壁内胚层细胞延伸到内细胞团之外。无调囊胚具有邻近内细胞团的合胞滋养层区域，并且它们可能代表早期植入的粘附阶段。在早期植入后阶段，滋养层取代子宫上皮并且合胞体滋养层的过程侵入扩张的浅表母体血管，在随后的陷窝期，随着陷窝的扩大，发育中的孕体迅速升高到子宫表面以上。细胞滋养层迅速进入母体血管，小动脉被迁移的细胞滋养层部分或完全闭塞。抢先体验控制母体血流显然允许滋养层腔隙表面扩张，而不是更广泛的子宫内膜浸润。
Implantation and placentation in the baboon share many morphological features with other primates, as well as having some specific distinctions, The ability to use deturgescence of the sex skin as a method of timing ovulation and the ease with which the uterine lumen can be flushed have been used to examine morphological aspects of blastocyst differentiation and implantation in this species. Preimplantation blastocysts were obtained by non-surgical flushing of the uterus 6-8 days after ovulation, and implantation sites were excised from uteri removed on days 10-16 of gestation, All tissues were prepared for electron microscopy by aldehyde fixation and plastic embedding, Maturation of trophoblast from the compacted morula stage to the expanded blastocyst stage includes increase in numbers of polyribosomes, changes in conformation of mitochondria, and development of an effective endocytic apparatus, An endodermal layer forms beneath the inner cell mass prior to loss of the zona pellucida, and parietal endodermal cells extend beyond the inner cell mass, Atonal blastocysts have regions of syncytial trophoblast adjacent to the inner cell mass, and they may represent adhesion stages of early implantation, In early postimplantation stages, trophoblast replaces the uterine epithelium and processes of syncytial trophoblast invade dilated superficial maternal vessels, In subsequent lacunar stages there is rapid elevation of the developing conceptus above the uterine surface as the lacunae enlarge. Cytotrophoblast rapidly enters maternal vessels, and arterioles are partially or completely occluded by migrating cytotrophoblast, The early access to controlled maternal blood flow apparently allows trophoblastic lacunae to expand superficially as opposed to more extensive endometrial invasion.