Semaphorin3a1 regulates angioblast migration and vascular development in XXXX embryos.

@entity24798 @entity3392 @entity72900
Semaphorins are a large family of secreted and cell surface molecules that guide neural growth cones to their targets during development. Some semaphorins are expressed in cells and tissues beyond the nervous system suggesting the possibility that they function in the development of non-neural tissues as well. In the trunk of @entity3392 embryos endothelial precursors (angioblasts) are located ventral and lateral to the somites. The angioblasts migrate medially and dorsally along the medial surface of the somites to form the dorsal aorta just ventral to the notochord. Here we show that in @entity3392 @entity72900 is involved in angioblast migration in vivo. Expression of @entity72900 in somites and neuropilin 1, which encodes for a component of the Sema3a receptor, in angioblasts suggested that @entity72900 regulates the pathway of the dorsally migrating angioblasts. Antisense knockdown of @entity72900 inhibited the formation of the dorsal aorta. Induced ubiquitous expression of @entity72900 in @entity24798 :(gfp) @entity72900 (myc) transgenic embryos inhibited migration of angioblasts ventral and lateral to the somites and retarded development of the dorsal aorta, resulting in severely reduced blood circulation. Furthermore, analysis of cells that express angioblast markers following induced expression of @entity72900 or in a mutant that changes the expression of @entity72900 in the somites confirmed these results. These data implicate @entity72900 , a guidance factor for neural growth cones, in the development of the vascular system.
