Laurichesse Quentin, Moucaud Blandine, Laddada Lilia, Renaud Yoan, Jagla Krzysztof, Soler Cédric
GReD Institut - UMR CNRS 6293 / INSERM U1103 University of Clermont-Auvergne, Clermont-Ferrand, France.
Front Cell Dev Biol. 2021 Dec 16;9:747563. doi: 10.3389/fcell.2021.747563. eCollection 2021.
To ensure locomotion and body stability, the active role of muscle contractions relies on a stereotyped muscle pattern set in place during development. This muscle patterning requires a precise assembly of the muscle fibers with the skeleton via a specialized connective tissue, the tendon. Like in vertebrate limbs, leg muscles make connections with specific long tendons that extend through different segments. During the leg disc development, cell precursors of long tendons rearrange and collectively migrate to form a tube-shaped structure. A specific developmental program underlies this unique feature of tendon-like cells in the model. We provide for the first time a transcriptomic profile of leg tendon precursors through fluorescence-based cell sorting. From promising candidates, we identified the Krüppel-like factor Dar1 as a critical actor of leg tendon development. Specifically expressed in the leg tendon precursors, loss of disrupts actin-rich filopodia formation and tendon elongation. Our findings show that Dar1 acts downstream of Stripe and is required to set up the correct number of tendon progenitors.
为确保运动和身体稳定性，肌肉收缩的积极作用依赖于发育过程中建立的定型肌肉模式。这种肌肉模式形成需要肌肉纤维通过一种特殊的结缔组织——肌腱与骨骼精确组装。与脊椎动物的肢体一样，腿部肌肉与延伸穿过不同节段的特定长肌腱相连。在腿部盘状结构发育过程中，长肌腱的细胞前体重新排列并集体迁移以形成管状结构。该模型中肌腱样细胞的这一独特特征有特定的发育程序作为基础。我们首次通过基于荧光的细胞分选提供了腿部肌腱前体的转录组概况。从有前景的候选基因中，我们鉴定出Krüppel样因子Dar1是腿部肌腱发育的关键因子。Dar1在腿部肌腱前体中特异性表达，其缺失会破坏富含肌动蛋白的丝状伪足形成和肌腱伸长。我们的研究结果表明，Dar1在Stripe下游起作用，并且是建立正确数量的肌腱祖细胞所必需的。
