First published online February 8, 2008
Development 135, 503e (2008)
© The Company of Biologists Limited
ES cells: a pluripotent mix
Pluripotent embryonic stem (ES) cells are derived from the inner cell mass
(ICM) and epiblast of mammalian embryos. Given their origin, do ES cell
cultures contain cells at a single developmental stage or mixtures of cells at
slightly different stages? On p.
909, Toyooka and colleagues report that these cultures actually
contain subpopulations of cells that correspond to ICM, epiblast and primitive
ectoderm (PrE). The ICM expresses Oct3/4 (a transcription factor that
maintains pluripotency) and Rex1 (a marker of pluripotency); the PrE expresses
only Oct3/4. By using ES cell lines in which genes for fluorescent proteins
have been inserted into the Rex1 and Oct3/4 gene loci, the
researchers identified subpopulations of
Rex1+/Oct3/4+ (ICM-like) cells and
Rex1-/Oct3/4+ (PrE-like) cells in
undifferentiated ES cell cultures. These subpopulations can interconvert in
vitro, they report, but have different differentiation potencies in vitro and
in vivo. Given these results, the researchers suggest that their gene knock-in
approach could help to identify the factor(s) that turn ICM into PrE.

CiteULike
Complore
Connotea
Del.icio.us
Digg
Reddit
Technorati
Twitter What's this?
Related articles in Development:
- Identification and characterization of subpopulations in undifferentiated ES cell culture
- Yayoi Toyooka, Daisuke Shimosato, Kazuhiro Murakami, Kadue Takahashi, and Hitoshi Niwa
Development 2008 135: 909-918.
[Abstract]
[Full Text]