Zmojdzian Monika, de Joussineau Svetlana, Da Ponte Jean Philippe, Jagla Krzysztof
GReD - INSERM U1103, CNRS UMR6293, University of Clermont Auvergne, 63000 Clermont-Ferrand, France
GReD - INSERM U1103, CNRS UMR6293, University of Clermont Auvergne, 63000 Clermont-Ferrand, France.
Development. 2018 Jan 17;145(2):dev158717. doi: 10.1242/dev.158717.
The heart, composed of discrete subsets of cardioblasts and pericardial cells, undergoes Hox-triggered anterior-posterior morphogenesis, leading to a functional subdivision into heart proper and aorta, with its most anterior part forming a funnel-shaped cardiac outflow. Cardioblasts differentiate into Tin-positive 'working myocytes' and Svp-expressing ostial cells. However, developmental fates and functions of heart-associated pericardial cells remain elusive. Here, we show that the pericardial cells that express the transcription factor Even Skipped adopt distinct fates along the anterior-posterior axis. Among them, the most anterior Antp-Ubx-AbdAnegative cells form a novel cardiac outflow component we call the outflow hanging structure, whereas the Antp-expressing cells differentiate into wing heart precursors. Interestingly, gene expression in the Even Skipped-positive cells not only underlies their antero-posterior diversification, but also influences heart morphogenesis in a non-cell-autonomous way. In brief, we identify a new cardiac outflow component derived from a subset of Even Skipped-expressing cells that stabilises the anterior heart tip, and demonstrate non-cell-autonomous effects of Hox gene expression in the Even Skipped-positive cells on heart morphogenesis.
心脏由成心肌细胞和心包细胞的离散亚群组成，经历由Hox触发的前后形态发生，导致功能性地细分为心脏本体和主动脉，其最前部形成漏斗状的心脏流出道。成心肌细胞分化为Tin阳性的“工作心肌细胞”和表达Svp的开口细胞。然而，与心脏相关的心包细胞的发育命运和功能仍然不清楚。在这里，我们表明表达转录因子Even Skipped的心包细胞沿前后轴采用不同的命运。其中，最前部的Antp-Ubx-AbdA阴性细胞形成一种新的心脏流出道成分，我们称之为流出悬挂结构，而表达Antp的细胞分化为翼状心脏前体。有趣的是，Even Skipped阳性细胞中的基因表达不仅是其前后分化的基础，还以非细胞自主的方式影响心脏形态发生。简而言之，我们鉴定出一种源自表达Even Skipped的细胞亚群的新的心脏流出道成分，它稳定了心脏尖端前部，并证明了Even Skipped阳性细胞中Hox基因表达对心脏形态发生的非细胞自主作用。
