A spectraplakin is enriched on the fusome and organizes microtubules during oocyte specification in Drosophila
A spectraplakin is enriched on the fusome and organizes microtubules during oocyte specification in Drosophila
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DOI：
10.1016/j.cub.2003.12.056
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发表时间：
2004-01-20
期刊：
影响因子：
9.2
通讯作者：
Brown, NH
中科院分区：
文献类型：
--
作者：
Röper, K;Brown, NH
背景：在果蝇卵子发生过程中，一个被称为丝状体的膜性细胞器在决定卵母细胞的命运和极性方面起着关键作用，最终导致动物主体轴的建立。熔合体是微管驱动的卵母细胞命运标记对卵母细胞的限制所必需的，但熔合体组织微管的机制尚不清楚。Spetraplains是一种巨大的细胞骨架连接蛋白，每个基因产生多种异构体。枪击是果蝇中唯一的幽灵。缺少Shot导致的表型不同于Fusome的其他组分，而类似于缺少与微管相互作用的下游组分：动力蛋白/动力肌动蛋白复合体相关的平等蛋白和BicaudaID。在16细胞包囊中，微管与纺锤体的结合以及随后的卵母细胞的规范都需要Shot。中心小体进入卵母细胞的浓缩也需要Shot，这一过程被认为是独立于微管的，因为它仍然在微管解聚药物存在的情况下发生。这表明，Shot可以保护一些微管免于解聚，这些微管对于这一过程是足够的。结论：Sort提供了减数分裂包囊中融合体和微管之间缺失的环节，这对卵母细胞的建立是必不可少的。Shot与梭形体相联系，是微管组织所必需的。我们建议它通过微管结合Gas2结构域直接完成这一功能。
Background: During Drosophila oogenesis a membranous organelle called the fusome has a key function in the establishment of oocyte fate and polarity, ultimately leading to the establishment of the major body axes of the animal. The fusome is necessary for the microtubule-driven restriction of markers of oocyte fate to the oocyte, but the mechanism by which the fusome organizes the microtubules is not known.Results: We have identified the spectraplakin Short stop (Shot) as a new component of the fusome. Spectraplakins are giant cytoskeletal linker proteins, with multiple isoforms produced from each gene. Shot is the sole spectraplakin in Drosophila. The phenotype caused by the absence of Shot is not similar to that of other components of the fusome but instead is similar to the absence of the downstream components that interact with microtubules: the dynein/dynactin-complex-associated proteins Egalitarian and BicaudaID. Shot is required for the association of microtubules with the fusome and the subsequent specification of the oocyte in 16-cell cysts. Shot is also required for the concentration of centrosomes into the oocyte, a process thought to be independent of microtubules because it still occurs in the presence of microtubule depolymerizing drugs. This suggests that Shot may protect some microtubules from depolymerization and that these microtubules are sufficient for this process.Conclusions: Shot provides the missing link between the fusome and microtubules within meiotic cysts, which is essential for the establishment of the oocyte. Shot associates with the fusome and is required for microtubule organization. We suggest that it does this directly, via its microtubule binding GAS2 domain.