Paré Adam C, Vichas Athea, Fincher Christopher T, Mirman Zachary, Farrell Dene L, Mainieri Avantika, Zallen Jennifer A
Howard Hughes Medical Institute and Developmental Biology Program, Sloan Kettering Institute, New York, New York 10065, USA.
Nature. 2014 Nov 27;515(7528):523-7. doi: 10.1038/nature13953. Epub 2014 Nov 2.
Elongation of the head-to-tail body axis by convergent extension is a conserved developmental process throughout metazoans. In Drosophila, patterns of transcription factor expression provide spatial cues that induce systematically oriented cell movements and promote tissue elongation. However, the mechanisms by which patterned transcriptional inputs control cell polarity and behaviour have long been elusive. We demonstrate that three Toll family receptors, Toll-2, Toll-6 and Toll-8, are expressed in overlapping transverse stripes along the anterior-posterior axis and act in combination to direct planar polarity and polarized cell rearrangements during convergent extension. Simultaneous disruption of all three receptors strongly reduces actomyosin-driven junctional remodelling and axis elongation, and an ectopic stripe of Toll receptor expression is sufficient to induce planar polarized actomyosin contractility. These results demonstrate that tissue-level patterns of Toll receptor expression provide spatial signals that link positional information from the anterior-posterior patterning system to the essential cell behaviours that drive convergent extension.
通过汇聚延伸实现头尾身体轴的延长是整个后生动物中保守的发育过程。在果蝇中,转录因子表达模式提供空间线索,诱导系统定向的细胞运动并促进组织延长。然而,模式化转录输入控制细胞极性和行为的机制长期以来一直难以捉摸。我们证明,三种Toll家族受体Toll-2、Toll-6和Toll-8沿前后轴以重叠的横向条纹形式表达,并共同作用以在汇聚延伸过程中指导平面极性和极化细胞重排。同时破坏所有三种受体会强烈减少肌动球蛋白驱动的连接重塑和轴延长,并且Toll受体表达的异位条纹足以诱导平面极化的肌动球蛋白收缩性。这些结果表明,Toll受体表达的组织水平模式提供空间信号,将来自前后模式系统的位置信息与驱动汇聚延伸的基本细胞行为联系起来。