Topic
Ectoderm formation
About: Ectoderm formation is a research topic. Over the lifetime, 22 publications have been published within this topic receiving 1249 citations.
Papers
TL;DR: It is demonstrated that LIF selectively inhibits the formation of primitive ectoderm, while permitting the differentiation of primitive endoderm in a precise manner, suggesting a specific role for LIF in preimplantation mouse development.
Abstract: Among its many activities, leukemia inhibitory factor (LIF) can maintain embryonic stem cell monolayers in a pluripotent undifferentiated state. Presuming that this might reflect its physiologic role during embryogenesis, we have examined LIF expression in the embryonic environment by RNase protection assays and have determined its in vitro effect on differentiating embryonic stem cell embryoid bodies. Of all adult tissues analyzed, LIF transcripts appear only in the uterus, where their level fluctuates with the estrous cycle, peaking after ovulation. LIF expression continues in the uteri of pregnant and pseudopregnant females, with a relative peak when blastocysts are normally present. As for its effects on in vitro differentiation, we have found that LIF blocks embryoid body differentiation only partially, yet in a precise manner. Using molecular markers to follow the differentiation of defined cell types, we demonstrate that LIF selectively inhibits the formation of primitive ectoderm, while permitting the differentiation of primitive endoderm. These results suggest a specific role for LIF in preimplantation mouse development.
261 citations
TL;DR: The results suggest that SpTcf/Lef functions by interacting with β-catenin to specify cell fates along the sea urchin animal-vegetal axis.
Abstract: Members of the Tcf/Lef family interact with β-catenin to activate programs of gene expression during development. Recently β-catenin was shown to be essential for establishing cell fate along the animal-vegetal axis of the sea urchin embryo. To examine the role of Tcf/Lef in sea urchins we cloned a Strongylocentrotus purpuratus Tcf/Lef homolog. Expression of SpTcf/Lef was maximal when β-catenin became localized to nuclei of vegetal blastomeres, consistent with its acting in combination with β-catenin to specify vegetal cell fates. Expression of a dominant-negative SpTcf/Lef inhibited primary and secondary mesenchyma, endoderm, and aboral ectoderm formation in a manner similar to that observed when nuclear accumulation of β-catenin was prevented. Our results suggest that SpTcf/Lef functions by interacting with β-catenin to specify cell fates along the sea urchin animal-vegetal axis.
66 citations
TL;DR: It is suggested that SpOtx mediates some of beta-catenin's functions in endoderm and aboral ectoderm formation as well as downstream of or parallel to nuclear beta-Catenin in sea urchin embryogenesis.
51 citations
TL;DR: This work shows that the forkhead protein FoxI1e is required at the blastula stage for normal formation of both the central nervous system and epidermis, the two early derivatives of the ectoderm, and plays a role in the embryo in the poorly understood process of differential adhesion, which limits cell mixing as primary germ layers become specified.
Abstract: The segregation of the vertebrate embryo into three primary germ layers is
one of the earliest developmental decisions. In Xenopus , where the
process is best understood, the endoderm is specified by a vegetally localized
transcription factor, VegT, which releases nodal signals that specify the
adjacent marginal zone of the blastula to become mesoderm. However, little is
known about how the ectoderm becomes specified. In this paper, we show that
the forkhead protein FoxI1e (also known as Xema) is required at the blastula
stage for normal formation of both the central nervous system and epidermis,
the two early derivatives of the ectoderm. In addition, FoxI1e is required to
maintain the regional identity of the animal cells of the blastula, the cells
that are precursors of ectodermal structures. In its absence, they lose
contact with the animal cap, mix with cells of other germ layers and
differentiate according to their new positions. Because FoxI1e is
initially expressed in the animal region of the embryo and is rapidly
downregulated in the neural plate, its role in neural and epidermal gene
expression must precede the division of the ectoderm into neural and
epidermal. The work also shows that FoxI1e plays a role in the embryo in the
poorly understood process of differential adhesion, which limits cell mixing
as primary germ layers become specified.
47 citations
TL;DR: The data suggest a novel mechanism by which a ceramide-induced, apicolateral polarity complex with PKCζ/λ regulates primitive ectoderm cell polarity and morphogenesis.
46 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2019 | 2 |
| 2018 | 1 |
| 2015 | 2 |
| 2012 | 1 |
| 2011 | 1 |
| 2010 | 3 |