Department of Molecular Medicine and Pathology, University of Auckland, Auckland 1142, New Zealand.
Department of Developmental Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA.
Nat Commun. 2016 Jul 13;7:12197. doi: 10.1038/ncomms12197.
Despite the fundamental importance of patterning along the dorsal-ventral (DV) and anterior-posterior (AP) axes during embryogenesis, uncertainty exists in the orientation of these axes for the mesoderm. Here we examine the origin and formation of the zebrafish kidney, a ventrolateral mesoderm derivative, and show that AP patterning of the non-axial mesoderm occurs across the classic gastrula stage DV axis while DV patterning aligns along the animal-vegetal pole. We find that BMP signalling acts early to establish broad anterior and posterior territories in the non-axial mesoderm while retinoic acid (RA) functions later, but also across the classic DV axis. Our data support a model in which RA on the dorsal side of the embryo induces anterior kidney fates while posterior kidney progenitors are protected ventrally by the RA-catabolizing enzyme Cyp26a1. This work clarifies our understanding of vertebrate axis orientation and establishes a new paradigm for how the kidney and other mesodermal derivatives arise during embryogenesis.
尽管在胚胎发生过程中沿背腹（DV）和前后（AP）轴进行模式形成具有重要意义，但中胚层的这些轴的方向仍存在不确定性。在这里，我们研究了斑马鱼肾脏的起源和形成，这是一个侧腹中胚层衍生物，并表明非轴向中胚层的 AP 模式形成发生在经典原肠胚阶段的 DV 轴上，而 DV 模式形成则沿着动物-植物极排列。我们发现 BMP 信号在早期作用于非轴向中胚层以建立广泛的前后区域，而视黄酸（RA）在后期也作用于经典的 DV 轴。我们的数据支持这样一种模型，即胚胎背侧的 RA 诱导前肾命运，而 RA 代谢酶 Cyp26a1 在腹侧保护后肾祖细胞。这项工作阐明了我们对脊椎动物轴定向的理解，并为肾脏和其他中胚层衍生物在胚胎发生过程中是如何产生的建立了一个新的范例。
