High impact information on LOC398045

• The expression of chordin starts in Spemann's organizer subsequent to that of goosecoid, and its induction by activin requires de novo protein synthesis [1].
• Xenopus chordin: a novel dorsalizing factor activated by organizer-specific homeobox genes [1].
• The chordin gene encodes a novel protein of 941 amino acids that has a signal sequence and four Cys-rich domains [1].
• Endoderm induction by the organizer-secreted factors chordin and noggin in Xenopus animal caps [2].
• Our findings indicate that GATA-1b can function in ectoderm to specifically regulate neural inducing mechanisms, apparently related to the expression of chordin, a neuralizing gene [3].

Biological context of LOC398045

• The results suggest that follistatin acts as an organizer factor in early amphibian embryogenesis by inhibiting BMP activities by a different mechanism from that used by chordin and noggin [4].
• We show that, in contrast to Spemann organiser genes such as goosecoid, chordin and noggin, Siamois gene expression is not induced following overexpression of mesoderm inducers in ectodermal (animal cap) cells [5].

Anatomical context of LOC398045

• This finding reveals an unexpected function for spadetail in midline mesoderm and in differential regulation of chordin expression during gastrulation [6].
• The present results suggest an additional function for beta-Catenin, the early activation of expression of secreted BMP antagonists, such as Chordin, in a preorganizer region in the dorsal side of the Xenopus blastula [7].
• When mesoderm involution was prevented in dorsal marginal-zone explants, the anterior neural tissue formed in ectoderm was derived from BCNE cells and had a complete requirement for Chd [8].
• Injection of noggin or chordin RNA into animal pole blastomeres effectively inhibited VBI development, while marginal zone injection had no effect [9].
• In contrast, XTcf4 has no repressive role but is required to activate expression of Xnr3 and chordin in organizer cells at the gastrula stage [10].

Associations of LOC398045 with chemical compounds

• In addition, although dorsal mesodermal cells from lithium- or Wnt-exposed embryos are specified properly, and produce normal levels of the anterior neural inducing molecules noggin and chordin, they show a greatly reduced capacity to induce anterior neural tissue in conjugated ectoderm [11].
• In a previous study, we demonstrated that FGFR1 activity within the organizer is required for the production of both the somitic muscle- and pronephros-patterning signals by the organizer and the expression of chordin, an organizer-specific secreted protein (Mitchell and Sheets [2001] Dev. Biol. 237:295-305) [12].

Enzymatic interactions of LOC398045

• Xlr conditioned media cleaves Chordin in vitro, indicating that this protease may regulate the availability of Chordin in vivo [13].

Regulatory relationships of LOC398045

• Conversely, earlier in development, chordin can induce an ectopic primitive streak much more effectively than noggin, while neither BMP antagonist can induce neural tissue from extraembryonic epiblast [14].

Other interactions of LOC398045

• Bmp4 knockdown was sufficient to rescue the ventralizing effects caused by loss of Chordin activity [15].
• Surprisingly, dorsal signaling molecules such as Chordin, Noggin, Xnr6 and Cerberus were not re-expressed in these embryos [15].
• In animal pole explants PV.1 counteracts the neuralizing effects of chordin and the DN-BR and restores them to their original epidermal fate [16].
• In contrast, the expression of Wnt-8 and the homeobox gene Vent-1 is suppressed by G2en, whilst the organiser-secreted BMP antagonist chordin becomes ectopically expressed [17].
• The ventral halves of axin-depleted embryos at the gastrula stage have dramatically increased levels of chordin expression, and severely decreased levels of Xwnt 8 mRNA expression, while BMP4 transcript levels are only slightly reduced [18].

Analytical, diagnostic and therapeutic context of LOC398045

• Microinjection of chordin mRNA induces twinned axes and can completely rescue axial development in ventralized embryos [1].

References