High impact information on bmp4

• These zebrafish morphants show Rac hyperactivation and progress faster through epiboly, leading to tailbud-stage embryos that have a narrow axis and an enlarged tailbud with expanded bmp4 and shh expression [1].
• A constitutively active Alk8-TGFbeta-receptor can ectopically induce bmp2b and bmp4 and rescues the dorsalization of MZspg [2].
• By contrast, when FGF signaling is inhibited, beta-catenin did not induce goosecoid and chordin, repress bmp4 expression or induce a dorsal axis [3].
• Overexpression of scl, but not bmp4 or gata1, can lead to partial rescue of embryonic blood cells in bls [4].
• In addition, gene expression analysis under these experimental conditions suggests that msxA and msxD expression in the ray and interray epidermis is controlled by the ray blastema and that bmp4 could be a candidate signal involved in these inductions [5].

Biological context of bmp4

• Based on their predicted amino acid sequences, these two clones were designated as zbmp-2 and zbmp-4 [6].
• Together, these results indicate that the 7.5-kb BMP4 promoter/proximal upstream region specifically contains regulatory elements for BMP4 expression in the heart, while regulatory elements for other endogenous BMP4-expressing tissues may reside in more distal regions and/or in introns [7].

Anatomical context of bmp4

• Similar to the amphibian embryo, the key patterning functions of the fish dorsal organizer (i.e., dorsalization of mesoderm, ectoderm, and coordination of gastrulation movements) are performed by secreted molecules that antagonize the ventralizing activity of the swil (zbmp-2) and zbmp-4 gene products expressed on the ventral side of the embryo [8].
• Whole-mount in situ hybridization analysis revealed that in gastrula embryo, both genes were localized in the ventral part of the embryo, consistent with the proposed function of Xenopus BMP-4 in ventral mesoderm specification. zbmp-4 expression, however, was also seen in the embryonic shield, the most dorsal mesodermal structure [6].
• A graded response to BMP-4 spatially coordinates patterning of the mesoderm and ectoderm in the zebrafish [9].
• Consistent with their locations prior to formation of the neural tube, elevated BMP-4 increased the number of dorsal spinal cord neurons whilst sonic hedgehog and islet1 expression in the ventral spinal cord were reduced [9].

References