Homeobox protein Siamois

Gene: Siamois

Organism: xenopuus laevis  (African clawed frog)

Essential for Wnt/beta-catenin-mediated formation of the Spemann organizer and for induction of the organizer precursor, the Nieuwkoop center. Acts as a transcriptional activator, cooperating with TGFbeta signals to induce a program of organizer-specific gene expression and to generate an organizer with both head- and trunk-inducing activity. Activates the head organizer gene cer1 by acting synergistically with otx2 and mix-A/mix.1 through the 5'-TAATCT-3' element of the cer1 promoter. Also binds as a complex with lhx1/lim1 and mix-A/mix.1 to the 3x 5'-TAAT-3' element of the cer1 promoter. Required for subsequent dorsoventral axis formation in the embryo, dorsalizing ventral mesoderm and cooperating with t/bra to induce dorsal mesoderm. Also involved in neural induction, inducing the cement gland and neural tissue in overlying ectoderm. Later in development, has the second function of indirectly repressing ventral genes, probably by activating the expression of a transcriptional repressor.

Homeobox protein goosecoid

Gene: GSC

Organism: Homo sapiens (Human)

Regulates chordin (CHRD). May play a role in spatial programing within discrete embryonic fields or lineage compartments during organogenesis. In concert with NKX3-2, plays a role in defining the structural components of the middle ear; required for the development of the entire tympanic ring by similarity. Probably involved in the regulatory networks that define neural crest cell fate specification and determine mesoderm cell lineages in mammals.

A mutation in the GSC gene causes short stature, auditory canal atresia, mandibular hypoplasia, and skeletal abnormalities (SAMS). Mutations in the Gsc gene can lead to specific phenotypes resulting from the second expression of the Gsc gene during organogenesis. Mice knock-out models of the gene express defects in the tongue, nasal cavity, nasal pits, inner ear, and external auditory meatus.

Chordin-like protein 1

Gene: CHRDL1

Organism: Homo sapiens (Human)

Antagonizes the function of BMP4 by binding to it and preventing its interaction with receptors. Alters the fate commitment of neural stem cells from gliogenesis to neurogenesis. Contributes to neuronal differentiation of neural stem cells in the brain by preventing the adoption of a glial fate. May play a crucial role in dorsoventral axis formation. May play a role in embryonic bone formation by similarity. May also play an important role in regulating retinal angiogenesis through modulation of BMP4 actions in endothelial cells. Plays a role during anterior segment eye development.

https://www.wikigenes.org/e/gene/e/12667.html

http://www.sciencedirect.com/science/article/pii/S0960982298000098