Mitochondria structural reorganization during mouse embryonic stem cell derivation

Area of Science:

• Developmental Biology
• Cell Biology
• Stem Cell Research

Background:

• Mouse embryonic stem (ES) cells are crucial for developmental biology and transgenic research.
• The ultrastructural reorganization of inner cell mass (ICM) cells during in vitro culture is not well-described.

Purpose of the Study:

• To perform comparative morphological and morphometric analyses of ES cell lines during in vitro derivation.
• To detail the ultrastructural reorganization of ICM cells into ES cells.

Main Methods:

• Comparative morphological and morphometric analyses of three ES cell lines.
• Examination of blastocyst ICM cells and ES cells at different passages (0, 2, 4, and 15).
• Ultrastructural analysis focusing on cellular components, including mitochondria.

Main Results:

• At passage 0, cultures contained ES-like cells, fibroblast-like cells (trophoblast derivatives), and dying cells.
• ES-like cells at passage 0 exhibited autolysosomes and enlarged mitochondria with varied morphology.
• ES cell morphology and parameters stabilized by passage 4, showing reduced heterogeneity.

Conclusions:

• ICM cell structures destabilize during ES cell line derivation and subsequently reorganize into typical ES cell structures.
• Mitochondrial ultrastructure suggests functional changes occur during early ES cell formation from the ICM.