αTubulin 67C and Ncd Are Essential for Establishing a Cortical Microtubular Network and Formation of the Bicoid mRNA Gradient in Drosophila.
Author
Summary, in English
The Bicoid (Bcd) protein gradient in Drosophila serves as a paradigm for gradient formation in textbooks. To explain the generation of the gradient, the ARTS model, which is based on the observation of a bcd mRNA gradient, proposes that the bcd mRNA, localized at the anterior pole at fertilization, migrates along microtubules (MTs) at the cortex to the posterior to form a bcd mRNA gradient which is translated to form a protein gradient. To fulfil the criteria of the ARTS model, an early cortical MT network is thus a prerequisite. We report hitherto undiscovered MT activities in the early embryo important for bcd mRNA transport: (i) an early and omnidirectional MT network exclusively at the anterior cortex of early nuclear cycle embryos showing activity during metaphase and anaphase only, (ii) long MTs up to 50 µm extending into the yolk at blastoderm stage to enable basal-apical transport. The cortical MT network is not anchored to the actin cytoskeleton. The posterior transport of the mRNA via the cortical MT network critically depends on maternally-expressed αTubulin67C and the minus-end motor Ncd. In either mutant, cortical transport of the bcd mRNA does not take place and the mRNA migrates along another yet undisclosed interior MT network, instead. Our data strongly corroborate the ARTS model and explain the occurrence of the bcd mRNA gradient.
Department/s
- Invertebrate Developmental Biology, Stefan Baumgartner's group
Publishing year
2014
Language
English
Publication/Series
PLoS ONE
Volume
9
Issue
11
Full text
- Available as PDF - 26 MB
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Links
Document type
Journal article
Publisher
Public Library of Science (PLoS)
Topic
- Developmental Biology
Status
Published
Project
- Formation of the bicoid gradient in Drosophila
Research group
- Invertebrate Developmental Biology, Stefan Baumgartner's group
ISBN/ISSN/Other
- ISSN: 1932-6203