Several characteristic morphological and functional differences distinguish arteries from veins. It was thought that hemodynamic forces shaped these differences; however, increasing evidence suggests that morphogenetic programs play a central role in blood vessel differentiation. @entity1884 ( @entity1884 ) is a @entity455 characterized by the inappropriate fusion of arterioles with venules. The genes implicated in this disease, @entity20356 and @entity31973 , may be involved in defining the fundamental boundaries between arteries and veins. We previously showed that @entity19 lacking @entity20356 lost structural, molecular, and functional distinctions between arteries and veins. Here, we report that @entity19 lacking @entity31973 develop @entity455 and fail to confine intraembryonic hematopoiesis to arteries. In contrast to @entity20356 mutants, @entity31973 mutants do not show profound vessel dilation or downregulation of arterial @entity33592 . Finally, our data indicate that a failure in cardiac cushion formation observed in both strains may be secondary to the peripheral vasculature defect. The phenotypic similarities, yet reduced severity, implicates @entity31973 as an accessory coreceptor that specifically modulates @entity20356 signaling. We propose that @entity31973 and @entity20356 are necessary for the maintenance of distinct arterial-venous vascular beds and that attenuation of the @entity20356 signaling pathway is the precipitating event in the etiology of @entity1884 .

@entity455 in XXXX lacking @entity31973 , a vascular-specific TGFbeta coreceptor.

@entity455 :: ('MESH:D014652', 'Disease') :: ['vascular dysplasia', 'arterial-venous malformations'] @entity31973 :: ('13805(Tax:10090)', 'Gene') :: ['endoglin'] @entity19 :: ('10090', 'Species') :: ['mice'] @entity1884 :: ('MESH:D013683', 'Disease') :: ['HHT', 'Hereditary hemorrhagic telangiectasia'] @entity33592 :: ('13642(Tax:10090)', 'Gene') :: ['ephrinB2'] @entity20356 :: ('11482(Tax:10090)', 'Gene') :: ['ALK1', 'Alk1']
@entity19 :: (10090,Species) :: ['mice']
