BMP inhibition by DAN in Hensen's node is a critical step for the establishment of left-right asymmetry in the chick embryo.

During left-right (L-R) axis formation, Nodal is expressed in the node and has a central role in the transfer of L-R information in the vertebrate embryo. Bone morphogenetic protein (BMP) signaling also has an important role for maintenance of gene expression around the node. Several members of the Cerberus/Dan family act on L-R patterning by regulating activity of the transforming growth factor-β (TGF-β) family.

Interplay between the tumor suppressor p53 and TGF beta signaling shapes embryonic body axes in Xenopus.

The transcription factor p53 has been shown to mediate cellular responses to diverse stresses such as DNA damage. However, the function of p53 in cellular differentiation in response to growth factor stimulations has remained obscure. We present evidence that p53 regulates cellular differentiation by modulating signaling of the TGF beta family of growth factors during early Xenopus embryogenesis.

Primary stages in photosignal transduction leading to step-up photophobic response in the unicellular eukaryote Blepharisma japonicum.

In order to elucidate the primary stage in the blepharismin phototransduction pathway, changes in the molecular structure of light-exposed blepharismins and oxyblepharismins, were examined. When exposed to light, blepharismins (pink form) were converted into oxyblepharismins (blue form) or dissociated into stentorins/p-hydroxybenzaldehyde with an O2-requiring process, whereas light-exposed oxyblepharismins were not dissociated into stentorins/p-hydroxybenzaldehyde. Since both blepharismins and oxyblepharismins can activate the phototransduction chain leading to the step-up photophobic response presumably through the same pathway, dissociation of p-hydroxybenzaldehyde may not be involved in signal transduction.

Analyses of structure of photoreceptor organelle and blepharismin-associated protein in unicellular eukaryote Blepharisma.

In the ciliated protozoan Blepharisma, step-up photophobic response is believed to be mediated by a novel type of photosensory pigment known as "blepharismins" (BL) that are contained in the pigment granules located just beneath the plasma membrane. We examined the ultrastructure of the pigment granules by freeze-fracture and thin-section electron microscopy and proposed a schematic diagram showing the granules' three-dimensional inner membranous structure. Some of the BL are suggested to be associated with 200 kDa membrane protein.