果蝇双尾mRNA定位的体内分析揭示了一种新的微管依赖性轴规格途径。

In vivo analysis of Drosophila bicoid mRNA localization reveals a novel microtubule-dependent axis specification pathway.

作者信息

Cha B J, Koppetsch B S, Theurkauf W E

机构信息

Program in Molecular Medicine, University of Massachusetts Medical School, 373 Plantation Street, Worcester, MA 01605, USA.

出版信息

Cell. 2001 Jul 13;106(1):35-46. doi: 10.1016/s0092-8674(01)00419-6.

DOI:10.1016/s0092-8674(01)00419-6

PMID:11461700

Abstract

Drosophila bicoid mRNA is synthesized in the nurse cells and transported to the oocyte where microtubules and Exuperantia protein mediate localization to the anterior pole. Fluorescent bicoid mRNA injected into the oocyte displays nonpolar microtubule-dependent transport to the closest cortical surface, and the oocyte microtubule cytoskeleton lacks clear axial asymmetry. Nonetheless, bicoid mRNA injected into the nurse cell cytoplasm, withdrawn, and injected into a second oocyte shows microtubule-dependent transport to the anterior cortex. Nurse cells require microtubules and Exuperantia to support anterior transport of bicoid mRNA, and microtubules are required for bicoid mRNA-Exuperantia particle coassembly. We propose that microtubule-dependent Exuperantia-bicoid mRNA complex formation in the nurse cell cytoplasm allows anterior-specific transport on a grossly nonpolar oocyte microtubule network.

摘要

果蝇的双尾mRNA在滋养细胞中合成，并被运输到卵母细胞中，在那里微管和过剩蛋白介导其定位到前极。注射到卵母细胞中的荧光双尾mRNA显示出依赖微管的非极性运输至最近的皮质表面，并且卵母细胞的微管细胞骨架缺乏明显的轴向不对称性。尽管如此，注射到滋养细胞细胞质中的双尾mRNA，取出后再注射到第二个卵母细胞中，显示出依赖微管的运输至前皮质。滋养细胞需要微管和过剩蛋白来支持双尾mRNA的前向运输，并且微管是双尾mRNA-过剩蛋白颗粒共组装所必需的。我们提出，在滋养细胞细胞质中依赖微管的过剩蛋白-双尾mRNA复合物形成，使得在总体上非极性的卵母细胞微管网络上进行前向特异性运输。