Regulation of Cell Polarity and RNA Localization in Vertebrate Oocytes - International Review of Cell and Molecular Biology - page 125

CHAPTER FOUR

Regulation of Cell Polarity
and RNA Localization in
Vertebrate Oocytes

Douglas W. Houston 1
Department of Biology, University of Iowa, Iowa City, Iowa, USA
1

Corresponding author: e-mail address: [e-mail]

Contents
1. Introduction 128

2. Xenopus Oocytes and Oogenesis 130

2.1 The cytoskeletal organization of the stage VI Xenopus oocyte 131

2.2 Cell polarity signaling mechanisms in the oocyte 135

2.3 Generation of definitive animal - vegetal polarity 138

2.4 Molecular regulation of animal - vegetal polarity 140

3. Pathways and Mechanisms of RNA Localization 143

3.1 Late pathway RNAs 145

3.2 Early pathway RNAs 152

3.3 Intermediate/dual-pathway RNAs 154

3.4 RNA localization in other amphibians 154

3.5 Localized mRNAs in zebrafish oocytes 156

3.6 RNA localization mechanisms in zebrafish 157

3.7 mRNA localization in mammalian oocytes and embryos 158

4. Functions of Localized RNAs 160

4.1 Germ layer induction and patterning 161

4.2 Primordial germ cell specification 162

4.3 Axis formation 164

4.4 Oogenesis/oocyte maturation 167

4.5 Structural roles for localized RNAs 167

5. Concluding Remarks 169

Acknowledgments 171

References 172

Abstract
It has long been appreciated that the inheritance of maternal cytoplasmic determinants
from different regions of the egg can lead to differential specification of blastomeres
during cleavage. Localized RNAs are important determinants of cell fate in eggs and
embryos but are also recognized as fundamental regulators of cell structure and