Cell adhesive affinity does not dictate primitive endoderm segregation and positioning during murine embryoid body formation

Robert Moore, Kathy Q. Cai, Diogo O. Escudero, Xiangxi Xu

28 Scopus citations

Abstract

The classical cell sorting experiments undertaken by Townes and Holtfreter described the intrinsic propensity of dissociated embryonic cells to self-organize and reconcile into their original embryonic germ layers with characteristic histotypic positioning. Steinberg presented the differential adhesion hypothesis to explain these patterning phenomena. Here, we have reappraised these issues by implementing embryoid bodies to model the patterning of epiblast and primitive endoderm layers. We have used combinations of embryonic stem (ES) cells and their derivatives differentiated by retinoic acid treatment to model epiblast and endodermcells, and wild-type or E-cadherin null cells to represent strongly orweakly adherent cells, respectively. One cell type was fluorescently labeled and reconstituted with another heterotypically to generate chimeric embryoid bodies, and cell sorting was tracked by time-lapse videomicroscopy and confirmed by immunostaining. When undifferentiated wild-type and E-cadherin null ES cellswere mixed, the resulting cell aggregates consisted of a core of wild-type cells surrounded by loosely associated E-cadherin null cells, consistent with the differential adhesion hypothesis. However, when mixed with undifferentiated ES cells, the differentiated primitive endoderm-like cells sorted to the surface to form a primitive endoderm layer irrespective of cell-adhesive strength, contradicting the differential adhesion hypothesis. We propose that the primitive endoderm cells reach the surface by random movement, and subsequently the cells generate an apical/basal polarity that prevents reentry. Thus, the ability to generate epithelial polarity, rather than adhesive affinity, determines the surface positioning of the primitive endoderm cells.

Original languageEnglish
Pages (from-to)579-589
Number of pages11
JournalGenesis
Volume47
Issue number9
DOIs
StatePublished - Sep 1 2009

    Fingerprint

Keywords

  • Cell adhesion
  • Cell segregation
  • Cell sorting
  • Embryos
  • Endoderm
  • Epithelial polarity
  • Germinal layers
  • Morphogenesis

ASJC Scopus subject areas

  • Endocrinology
  • Cell Biology
  • Genetics

Cite this