Kinesin I-dependent cortical exclusion restricts pole plasm to the oocyte posterior.
Microtubules and the plus-end-directed microtubule motor Kinesin I are required for the selective accumulation of oskar mRNA at the posterior cortex of the Drosophila melanogaster oocyte, which is essential to posterior patterning and pole plasm assembly. We present evidence that microtubule minus ends associate with the entire cortex, and that Kinesin and microtubules are not required for oskar mRNA association with the posterior pole, but prevent ectopic localization of this transcript and the pole plasm proteins Oskar and Vasa to other cortical regions. Cortical binding of oskar mRNA seems to be dependent on the actin cytoskeleton. We conclude that most of the actin-rich oocyte cortex can support pole plasm assembly, and propose that Kinesin restricts pole plasm formation to the posterior by moving oskar mRNA away from microtubule-rich lateral and anterior cortical regions.
Cha
Byeong-Jik
BJ
Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA.
Serbus
Laura R
LR
Koppetsch
Birgit S
BS
Theurkauf
William E
WE
D000818:Animals; D016764:Cell Polarity; D029721:Drosophila Proteins / Q000235:genetics; D004331:Drosophila melanogaster / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D005260:Female; D017404:In Situ Hybridization, Fluorescence; D016547:Kinesins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism; D008954:Models, Biological; D020409:Molecular Motor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D009865:Oocytes / Q000378:metabolism* / Q000648:ultrastructure; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
D029721:Drosophila Proteins; D020409:Molecular Motor Proteins; D012333:RNA, Messenger; C091675:osk protein, Drosophila; D016547:Kinesins