Here, we observed that the local myocardial cells and the clotted blood cells undergo cellular remodeling via cytoplasmic exocytosis and nuclear reorganization in zebrafish hearts after resection of the ventricular apex. The reconstruction of a blood supply system and myocardial recovery from inflamamtory reactions in the infract zone remains a challenge in cardiac regeneration after myocardial infarction. The expression of the BMP-regulated V-P meso- dermal marker eve1 was enhanced by BMP, yet markers of other V-P mesodermal derivatives (e.g., cdh17 kidney) were relatively unaffected, suggesting a specific role in hemogenesis ( Together, these data suggest that mid-to late gastrulation is a critical window for BMP-induced specification of hemato- poietic tissue, and that the role of BMP in blood formation from V-P mesoderm is conserved in fish and mice. Consistent with our hypothesis, bmp2b induction at midgastrulation strongly expanded the pos- terior blood islands, as assayed by expression of the blood markers gata1 and pu.1 ( Figure 3, iib and 3iic Figure S3 Davidson and Zon, 2004). a transgenic zebrafish line that expresses bmp2b under a heat shock-inducible promoter, we showed that BMP activation at midgastrulation (75% epiboly 8 hr post-fertilization ) induced only mild ventralization (V2 reduced, but present head structures, notochord, and somites Figure 3, iia, and Figure S2B) compared to embryos induced at the onset of gastrulation (50% epiboly 5.5 hpf), which were completely ventralized (V5 absent head, noto- chord, and somites Figure 3, iiia).
0 kommentar(er)
