Related Experiment Videos
Human preimplantation development in vivo: ultrastructural observations
1Laboratorio de Embriologia y Microscopia Electrónica, Facultad de Medicina, Universidad de Chile, Santiago.
Annals of the Academy of Medicine, Singapore
|July 1, 1992
Summary
This study compared ultrastructure changes in early human embryos (2- to 16-cell stages). Key organelle transformations, including mitochondria and nucleoli, were observed during preimplantation development.
Area of Science:
- Developmental Biology
- Cell Biology
- Reproductive Medicine
Background:
- Understanding human preimplantation embryo development is crucial for reproductive technologies.
- In vivo embryo development provides a baseline for assessing in vitro fertilization (IVF) outcomes.
Purpose of the Study:
- To compare the ultrastructure of human embryos at 2, 4, 7, and 16-cell stages.
- To identify significant ultrastructural changes in key organelles during early development.
- To provide a reference for evaluating in vitro-developed human embryos.
Main Methods:
- Transmission electron microscopy (TEM) was used.
- Ultrastructural analysis of human embryos developed in vivo at specific cleavage stages (2, 4, 7, 16 cells).
Main Results:
- Mitochondria changed from round and dense to oval with altered cristae orientation.
- Ribosome and polyribosome levels fluctuated, decreasing by the 7-cell stage and increasing by the 16-cell stage.
- Nuclear envelope blebbing decreased, and nucleoli matured progressively from the 2-cell to 16-cell stage.
Conclusions:
- Significant ultrastructural changes occur in mitochondria, ribosomes, nuclear envelope, and nucleoli during human preimplantation development.
- These findings offer insights into organelle ontogenesis and cell differentiation.
- The study provides a valuable comparative standard for assessing human embryos developed in vitro.