First published online March 9, 2006
Development 133, 705e (2006)
© The Company of Biologists Limited
Knockout insights into mammalian PAR3
Epithelial cysts - cavities formed from monolayers of polarised epithelial
cells - serve as progenitors for many mammalian organs. However, what controls
cyst formation is poorly understood. Hirose et al. now report that the
polarity protein PAR3 is required for the formation of epicardial progenitor
(EPP) cell cysts in mice (see p.
1389). During
mammalian heart development, cysts made from EPP cells migrate to the
myocardium and envelop it in a layer of epicardial cells. The researchers show
that targeted disruption of the mouse Par3 gene causes midgestational
embryonic lethality with defective epicardial development. They report that
PAR3-deficient EPP cells form normal cell-cell junctions and basal domains but
do not establish apical cortical domains or form cell cysts. Because cell-cell
and cell-extracellular matrix interactions (which occur through basal domains)
provide the spatial cues for epithelial cell polarity, these results suggest
that PAR3 normally interprets these cues and, importantly, they provide the
first evidence for the involvement of PAR3 in epithelial polarity and tissue
organisation during mammalian development.
Related articles in Development:
- PAR3 is essential for cyst-mediated epicardial development by establishing apical cortical domains
- Tomonori Hirose, Mika Karasawa, Yoshinobu Sugitani, Masayoshi Fujisawa, Kazunori Akimoto, Shigeo Ohno, and Tetsuo Noda
Development 2006 133: 1389-1398.
[Abstract]
[Full Text]
