From blastocyst to placenta

The morphology of implantation in the baboon

Allen C. Enders, Katherine C. Lantz, Pamela E. Peterson, Andrew G Hendrickx

Research output: Contribution to journalArticle

50 Citations (Scopus)

Abstract

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.

Original languageEnglish (US)
Pages (from-to)561-573
Number of pages13
JournalHuman Reproduction Update
Volume3
Issue number6
DOIs
StatePublished - Nov 1997

Fingerprint

Papio
Trophoblasts
Blastocyst
Placenta
Mothers
Ovulation
Uterus
Plastic Embedding
Morula
Placentation
Zona Pellucida
Polyribosomes
Arterioles
Aldehydes
Primates
Electron Microscopy
Mitochondria
Epithelium
Pregnancy
Skin

Keywords

  • Blastocyst
  • Endometrium
  • Human
  • Implantation
  • Primate
  • Trophoblast

ASJC Scopus subject areas

  • Obstetrics and Gynecology
  • Reproductive Medicine

Cite this

Enders, A. C., Lantz, K. C., Peterson, P. E., & Hendrickx, A. G. (1997). From blastocyst to placenta: The morphology of implantation in the baboon. Human Reproduction Update, 3(6), 561-573. https://doi.org/10.1093/humupd/3.6.561

From blastocyst to placenta : The morphology of implantation in the baboon. / Enders, Allen C.; Lantz, Katherine C.; Peterson, Pamela E.; Hendrickx, Andrew G.

In: Human Reproduction Update, Vol. 3, No. 6, 11.1997, p. 561-573.

Research output: Contribution to journalArticle

Enders, AC, Lantz, KC, Peterson, PE & Hendrickx, AG 1997, 'From blastocyst to placenta: The morphology of implantation in the baboon', Human Reproduction Update, vol. 3, no. 6, pp. 561-573. https://doi.org/10.1093/humupd/3.6.561
Enders, Allen C. ; Lantz, Katherine C. ; Peterson, Pamela E. ; Hendrickx, Andrew G. / From blastocyst to placenta : The morphology of implantation in the baboon. In: Human Reproduction Update. 1997 ; Vol. 3, No. 6. pp. 561-573.
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