As a proof of principle, Klein, Megason and colleagues used the CRISPR/Cas9 gene editing system to create zebrafish with a mutant form of chordin
, a gene involved in determining the back-to-front orientation of a developing embryo.
BMP antagonists such as Gremlin1, Gremlin2, and Chordin
are secreted by the ISEMFs and smooth muscle cells at the human colonic crypt bottom to repress BMP signalling, while BMP ligands are expressed in the upper colonic crypt to drive differentiation .
Based on the number of ring cysteine domains, they are classified as: (a) 8-ring cysteine proteins, members of DAN (7,8); (b) 9-ring cysteine proteins, twisted gastrulation (tgs) (9,10); and (c) 10-ring cysteine proteins, Chordin
(Chd) and Noggin (Nog) (11-14).
4E) probably through the action of Chordin
, which is an antagonist for Admp and Bmp2/4 and is expressed in the dorsal region of the epidermis.
Total RNA of the somites was extracted and RT-PCR carried out with specific primers of cerberus, chordin
, FGF8, follistatin and noggin.
There are many types of extracellular BMP antagonists, such as noggin, chordin
, cerberus, and follistatin [36, 37].
The ectopic expression of shh or bmp2b in the blastema induced excess bone deposition and altered the patterning of the regenerate; and the forced expression of the Bmp antagonist Chordin
disrupted fin growth and osteoblast differentiation (Smith et al, 2006).
Vertebrates develop a corresponding dorsal-ventral gradient with bone morphogentic protein (BMP, homologous to DPP) and chordin
(homologous to SOG).
Differential regulation of the bone morphogenic protein antagonist chordin
in human normal and osteoarthritic chondrocytes.
Genomic organisation of the human chordin
gene and mutation screening of candidate Cornelia de Lange syndrome genes.
More recent studies have shown that genes such as noggin, follistatin, chordin
, cerberus, and xnr3 may be involved in neural induction.
2, 1994 Cell, De Robertis and his colleagues reported isolating a gene called chordin