Microtubule Polarity Predicts Direction of Egg Chamber Rotation in Drosophila
Microtubule Polarity Predicts Direction of Egg Chamber Rotation in Drosophila
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DOI：
10.1016/j.cub.2013.06.014
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发表时间：
2013-08
期刊：
影响因子：
9.2
通讯作者：
Ivana Viktorinová;Christian Dahmann
中科院分区：
文献类型：
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作者：
Ivana Viktorinová;Christian Dahmann
全组织旋转最近被认为是一种广泛的形态发生过程，对组织伸长很重要[1-4]。在果蝇体内，卵室的伸长涉及卵泡上皮沿前后轴的整体旋转[5]。单独的卵室以顺时针或逆时针方向旋转；然而，如何打破卵室的对称性以允许旋转仍是未知的。在这里，我们发现在卵泡细胞的基底部，微管优先垂直于卵室的前后轴排列。微管解聚停止卵室旋转和卵室伸长。微管的优先排列和卵室的旋转依赖于非典型的钙粘蛋白Fat2，平面极化的Fat2定位依赖于完整的微管。此外，通过使用EB1：：GFP跟踪体内微管+端的生长，我们发现微管在卵泡上皮平面上高度极化。微管的极化先于卵室开始旋转，并预测旋转的方向。我们的数据表明，Fat2定位和微管极性之间存在反馈放大机制，参与破坏对称性和引导卵室旋转。
Whole-tissue rotations have recently been recognized as a widespread morphogenetic process important for tissue elongation [1–4]. InDrosophilaovaries, elongation of the egg chamber involves a global rotation of the follicle epithelium along the anterior-posterior axis [5]. Individual egg chambers rotate either in a clockwise or counterclockwise direction; however, how the symmetry of egg chambers is broken to allow rotation remains unknown. Here we show that at the basal side of follicle cells, microtubules are preferentially aligned perpendicular to the anterior-posterior axis of the egg chamber. Microtubule depolymerization stalls egg chamber rotation and egg chamber elongation. The preferential alignment of microtubules and egg chamber rotation depend on the atypical cadherin Fat2 and the planar polarized Fat2 localization depends on intact microtubules. Moreover, by tracking microtubule plus-end growth in vivo using EB1::GFP, we find that microtubules are highly polarized in the plane of the follicle epithelium. Polarization of microtubules precedes the onset of egg chamber rotation and predicts the direction of rotation. Our data suggest a feedback amplification mechanism between Fat2 localization and microtubule polarity involved in breaking symmetry and directing egg chamber rotation.