Book contents
- Frontmatter
- Dedication
- Contents
- List of Contributors
- Preface
- Section 1 Historical perspective
- Section 2 Life cycle
- Section 3 Developmental biology
- 8 Structural basis for oocyte–granulosa cell interactions
- 9 Differential gene expression mediated by oocyte–granulosa cell communication
- 10 Hormones and growth factors in the regulation of oocyte maturation
- 11 Getting into and out of oocyte maturation
- 12 Chromosome behavior and spindle formation in mammalian oocytes
- 13 Transcription, accumulation, storage, recruitment, and degradation of maternal mRNA in mammalian oocytes
- 14 Setting the stage for fertilization: transcriptome and maternal factors
- 15 Egg activation: initiation and decoding of Ca2+ signaling
- 16 In vitro growth and differentiation of oocytes
- 17 Metabolism of the follicle and oocyte in vivo and in vitro
- 18 Improving oocyte maturation in vitro
- Section 4 Imprinting and reprogramming
- Section 5 Pathology
- Section 6 Technology and clinical medicine
- Index
- References
14 - Setting the stage for fertilization: transcriptome and maternal factors
from Section 3 - Developmental biology
Published online by Cambridge University Press: 05 October 2013
- Frontmatter
- Dedication
- Contents
- List of Contributors
- Preface
- Section 1 Historical perspective
- Section 2 Life cycle
- Section 3 Developmental biology
- 8 Structural basis for oocyte–granulosa cell interactions
- 9 Differential gene expression mediated by oocyte–granulosa cell communication
- 10 Hormones and growth factors in the regulation of oocyte maturation
- 11 Getting into and out of oocyte maturation
- 12 Chromosome behavior and spindle formation in mammalian oocytes
- 13 Transcription, accumulation, storage, recruitment, and degradation of maternal mRNA in mammalian oocytes
- 14 Setting the stage for fertilization: transcriptome and maternal factors
- 15 Egg activation: initiation and decoding of Ca2+ signaling
- 16 In vitro growth and differentiation of oocytes
- 17 Metabolism of the follicle and oocyte in vivo and in vitro
- 18 Improving oocyte maturation in vitro
- Section 4 Imprinting and reprogramming
- Section 5 Pathology
- Section 6 Technology and clinical medicine
- Index
- References
Summary
Introduction
Toward the end of oocyte growth, an oocyte matures so that it can be fertilized by a sperm and develop into an early embryo. Oocyte maturation encompasses two main interrelated developmental programs, nuclear maturation and cytoplasmic maturation [1]. Nuclear maturation involves the progression from prophase I of meiosis to metaphase II and can be visualized microscopically as germinal vesicle breakdown (GVBD), spindle formation, chromosomal condensation/segregation, and polar body extrusion. Cytoplasmic maturation prepares the oocyte for activation and early development and is characterized structurally by the dramatic redistribution of endoplasmic reticulum (ER) and mitochondria from a relatively diffuse localization in germinal vesicle (GV) stage oocytes to a much more polarized distribution pattern in mature eggs. The targeting of mitochondria around the spindle apparatus is thought to provide energy, in the form of ATP, to drive processes such as chromosome segregation, while the targeting of the ER to distinct cortical clusters underneath the microvillar cortex is believed to be required for the generation of repetitive Ca2+ transients that are necessary for activation of development [2, 3]. At the molecular level, cytoplasmic maturation involves the accumulation and processing of mRNA and proteins that are also required for successful activation and early development [4]. Microtubules (MTs) play a central role in orchestrating the events of nuclear maturation and are also thought to be important mediators of organelle redistribution during cytoplasmic maturation [5]. Once mature, the oocyte is then competent for fertilization. Sperm–egg interaction is a sequential process whereby sperm first passes through the cumulus cell extracellular matrix, binds to and penetrates the zona pellucida (ZP), and then binds to and fuses with the oocyte plasma membrane (oolemma) [6]. The molecular mechanisms behind each of these interactions are now coming to light, thus greatly increasing our understanding of the fertilization process in mammals. Due, in part, to the transcriptional arrest that occurs upon resumption of meiotic maturation and prior to activation of the embryonic genome (EGA), the embryo must rely on stores of maternal transcripts and proteins to provide the material necessary to make the oocyte-to-embryo transition (OET) [4]. These stored factors are encoded by maternal-effect genes (MEG), which can be defined as genes encoded by the maternal genome that are essential for early embryogenesis.
- Type
- Chapter
- Information
- Biology and Pathology of the OocyteRole in Fertility, Medicine and Nuclear Reprograming, pp. 164 - 176Publisher: Cambridge University PressPrint publication year: 2013