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Morphogens are secreted signalling molecules that act in a graded manner to control the pattern of cellular differentiation in developing tissues. An example is Sonic hedgehog (Shh), which acts in several developing vertebrate tissues, including the central nervous system, to provide positional information during embryonic patterning. Here we address how(More)
Secreted signals, known as morphogens, provide the positional information that organizes gene expression and cellular differentiation in many developing tissues. In the vertebrate neural tube, Sonic Hedgehog (Shh) acts as a morphogen to control the pattern of neuronal subtype specification. Using an in vivo reporter of Shh signaling, mouse genetics, and(More)
The neural fate is generally considered to be the intrinsic direction of embryonic stem (ES) cell differentiation. However, little is known about the intracellular mechanism that leads undifferentiated cells to adopt the neural fate in the absence of extrinsic inductive signals. Here we show that the zinc-finger nuclear protein Zfp521 is essential and(More)
We report directed differentiaion of retinal precursors in vitro from mouse ES cells. Six3+ rostral brain progenitors are generated by culturing ES cells under serum-free suspension conditions (SFEB culture) in the presence of Wnt and Nodal antagonists (Dkk1 and LeftyA), and subsequently steered to differentiate into Rx+ cells (16%) by treatment with(More)
A relatively small number of signals are responsible for the variety and pattern of cell types generated in developing embryos. In part this is achieved by exploiting differences in the concentration or duration of signaling to increase cellular diversity. In addition, however, changes in cellular competence-temporal shifts in the response of cells to a(More)
We here report essential roles of the Bmp-binding protein crossveinless 2 (Cv2; Bmper) in mouse organogenesis. In the null Cv2 mutant mouse, gastrulation occurs normally, but a number of defects are found in Cv2-expressing tissues such as the skeleton. Cartilage differentiation by Bmp4 treatment is reduced in cultured Cv2(-/-) fibroblasts. Moreover, the(More)
The secreted ligand Sonic Hedgehog (Shh) organizes the pattern of cellular differentiation in the ventral neural tube. For the five neuronal subtypes, increasing levels and durations of Shh signaling direct progenitors to progressively more ventral identities. Here we demonstrate that this mode of action is not applicable to the generation of the most(More)
We have isolated a novel secreted dorsalizing factor of the neural tube, Xenopus Tiarin, which belongs to the olfactomedin-related family. Tiarin expression starts at the late gastrula stage in the nonneural ectoderm adjacent to the anterior neural plate. Overexpression of Tiarin in the embryo causes expansion of dorsal neural markers and suppression of(More)
In Xenopus, an asymmetric distribution of Wnt activity that follows cortical rotation in the fertilized egg leads to the dorsal-ventral (DV) axis establishment. However, how a clear DV polarity develops from the initial difference in Wnt activity still remains elusive. We report here that the Teashirt-class Zn-finger factor XTsh3 plays an essential role in(More)
During gastrulation of the amphibian embryo, specification of the three germ layers, endo-, ecto-, and mesoderm, is regulated by maternal and zygotic mechanisms. Although it is known that mesoderm specification requires the cooperation between TGF-beta signaling and p53 activity and requires maternal factors, essential zygotic factors have been elusive.(More)