Both the extracellular matrix and parathyroid hormone-related peptide (PTHrP) have been implicated in the differentiation and migration of extra-embryonic endodermal cells in the pre-implantation mammalian blastocyst. In order to define the individual roles and interactions between these factors in endodermal differentiation, we have used embryoid bodies derived from Lamc1(-/-) embryonic stem c...

The formation of the proamniotic cavity in the mammalian embryo is the earliest of many instances throughout development in which programmed cell death and the formation of epithelia play fundamental roles (Coucouvanis, E., and G.R. Martin. 1995. Cell. 83:279-287). To determine the role of the basement membrane (BM) in cavitation, we use embryoid bodies derived from mouse embryonic stem cells i...

Antibody perturbation experiments suggested that migration, terminal differentiation and fusion of myoblasts are dependent on beta1 integrin expression. In addition, several studies have postulated that beta1 integrins have a role in the formation of sarcomeres. In the present report we have analysed skeletal myogenesis in wild-type/beta1-null chimeric mice and beta1-null embryoid bodies. Trunk...

Evidence exists that cells of mesenchymal origin show a differentiation plasticity that depends on their differentiation state. We used in vitro differentiation of embryonic stem cells through embryoid bodies as a model to analyze chondrogenic and osteogenic differentiation because embryonic stem cells recapitulate early embryonic developmental phases during in vitro differentiation. Here, we s...

Hsp47 is a molecular chaperone that specifically recognizes procollagen in the endoplasmic reticulum. Hsp47-null mouse embryos produce immature type I collagen and form discontinuous basement membranes. We established Hsp47 / embryonic stem cell lines and examined formation of basement membrane and production of type IV collagen in embryoid bodies, a model for postimplantation egg-cylinder stag...

Embryonic stem cell studies have generated great interest, due to their ability to form a wide variety of matured cells. However, there remains a poor understanding of mechanisms regulating the cell state of embryonic stem cells (ESCs) and of the genes they express during early differentiation. Gene expression analysis may be a valuable tool to elucidate either the molecular pathways involved i...

Mouse embryonic stem (ES) cells in culture can differentiate into late stages of many lineage-committed precursor cells. Under appropriate organ-culture conditions, ES cells differentiate into lymphoidlike cells at a stage equivalent to lymphoid cells found in fetal liver. These hematopoietic precursors are located in cup-shaped structures found in some embryoid bodies; we called such embryoid ...