Gene Activity in Early Development, Second Edition is devoted to gene activity in early development, considering the estimates of RNA and protein synthesis rates, complexities, and amounts. A quantitative treatment of some of the key classes of macromolecules in early embryos and oocytes is also offered.
This edition is organized into eight chapters and begins with an overview of the variable gene activity theory of cell differentiation, emphasizing the transcription level regulation as the fundamental process underlying differentiation and development. The following chapters explore the genome regulation of embryogenesis, differential embryo cell function, and transcription and protein synthesis in early embryos. The reader is also introduced to direct measurements regarding the DNA sequences transcribed during early development and localization of morphogenetic determinants in egg cytoplasm. The book concludes with a discussion of the structure of lampbrush chromosomes and the synthesis of heterogeneous nuclear and messenger RNAs during oogenesis.
This book will prove useful to students as well as established researchers interested in developmental genetics.

Contenu

Preface
1 Introduction: The Variable Gene Activity Theory of Cell Differentiation
Early Evidence for the Informational Equivalence of Differentiated Cell Genomes
Transdifferentiation
DNA Constancy and Nuclear Transplantation
DNA Sequence Complements of Differentiated Cells Appear Identical
Gene Amplification Cannot Explain Differentiation
Direct Evidence for the Variable Gene Activity Theory of Cell Differentiation
Only Minor Fractions of DNA Sequence Are Transcribed in Any Given Differentiated Cell Type
Diverse Sets of Sequences Are Transcribed in Each Differentiated Cell Type
Differentiated Cell Nuclei Contain Inactive (Nontranscribed) DNA
Cytological Manifestations of Variable Genomic Activity
Measurements of Specific Messenger RNA Accumulation
Transcription Level Gene Regulation in Animal Cells
Levels of Control
DNA Sequence Organization and Transcription Level Regulation
2 The Onset of Genome Control in Embryogenesis
The First Species Hybrid Experiments and Their Conceptual Background
Nineteenth Century Species Hybrid Experiments
Origins of the Chromosome Theory of Cellular Inheritance
Evidence for Delayed Onset of Embryo Genome Control from Echinoderm Species Hybrid Studies
Morphogenesis in Echinoderm Species Hybrids
Biosynthetic Processes in Echinoderm Species Hybrids
Embryo Genome Control in the Development of Species Hybrids in Chordates
Amphibian Hybrids
Teleost and Ascidian Hybrids
Interpretation of the Species Hybrid Experiments
Development in Physically Enucleated Embryos
"Chemical Enucleation": Development of Actinomycin-Treated Embryos
Actinomycin Effects on Echinoderm Embryos
Actinomycin Effects on Chordate Embryos
Effects of Actinomycin and Other Treatments on Early Morphogenesis
Delayed Morphogenetic Response to Experimental Treatments
Interpretation of Morphogenetic Effects
3 First Indices of Differential Embryo Cell Function
Qualitative Changes in Patterns of Protein Synthesis Correlated with Developmental Stage
Changes in Protein Synthesis Pattern Studied by High Resolution Gel Electrophoresis
The Double Label Method
Are Changes in Protein Synthesis Pattern in Early Embryos Post-transcriptional?
First Morphological Indications of Differential Cell Function
Intercellular Junctions in Early Embryos
Other Early Cytodifferentiations
Appearance of Histospecific Proteins
Appearance of Histospecific Proteins before Organogenesis
Differentiation of Primary Mesenchyme Cells in the Sea Urchin
Conclusions
4 Quantitative Aspects of Protein Synthesis in Early Embryos: The Role of Maternal Components
Absolute Rates of Protein Synthesis
Free Amino Acid Pools in Sea Urchin Embryos
Absolute Rates of Protein Synthesis in Sea Urchin Embryos
Absolute Rates of Protein Synthesis in Amphibian Embryos
Maternal Ribosomal and Transfer RNA's
Translational Capacities of Mature Oocytes and Early Cleavage Stage Embryos
In Vitro Protein Synthesis on Embryo Ribosomes
Injection of Exogenous Messenger RNA into Oocytes
Direct Demonstration of Maternal Messenger RNA
Protein Synthesis in Enucleated Egg Cytoplasm
Isolation and Quantitation of Maternal Messenger RNA
Postribosomal Particles Containing Maternal Messenger RNA
Fertilization and the Utilization of Maternal Message in Sea Urchin Embryos
Increase in Polysomes following Fertilization
Mechanisms of Maternal Messenger RNA Mobilization
Changes in Protein Synthesis Rate during Early Development in Other Organisms
Variations in the Effect of Fertilization on Protein Synthesis Rate
Relative Protein Synthesis Rates in Mammalian Embryos and in Hydrated Artemia Embryos
Synthesis and Inheritance of Some Specific Embryonic Proteins
Nucleosomes and the Requirement for Histones during Early Development
Histone Gene Clusters in the Sea Urchin
Quantitative Aspects of Histone Synthesis during Sea Urchin Embryogenesis
Qualitative Alterations in Histone Synthesis during Early Development
Quantitative Aspects of Histone Synthesis in Xenopus
DNA Polymerases
RNA Polymerases
Microtubule Proteins
5 Transcription in Early Embryos
RNA Synthesis in Amphibian Embryos
Accumulation of Labeled RNA Species
RNA Synthesis and Turnover Kinetics for the Case of Constant Precursor Specific Activity
Synthesis Rates and Steady State Quantities of the Heterogeneous RNAs of Xenopus Embryos
Apparent Change in the Relative Rate of Nuclear RNA Synthesis at Blastula Stage
Ribosomal RNA Synthesis in Xenopus Embryos
Mitochondrial RNA Synthesis in Xenopus Embryos
Transcriptional Rates and Patterns in Sea Urchin Embryos
The Heterogeneous Nuclear RNA of Sea Urchin Embryos
Synthesis and Decay Kinetics of Heterogeneous Nuclear RNA in Sea Urchin Embryos
Synthesis and Decay Kinetics for a Case of Changing Precursor Specific Activity: Calculation of Messenger RNA Synthesis Rates
Classes of Messenger RNA in Sea Urchin Embryos
Mitochondrial RNA Synthesis in Sea Urchin Embryos
Synthesis of Ribosomal and Transfer RNA in Sea Urchin Embryos
Transcription in Mammalian Embryos
Ribosomal RNA Synthesis in Early Mammalian Embryos
Synthesis of Heterogeneous RNAs in Mammalian Embryos
Transfer RNA Synthesis and Messenger RNA Synthesis in Mammalian Embryos
RNA Synthesis in the Embryos of Other Species
Ribosomal RNA Synthesis in Various Embryos
Generalization and a Paradox Regarding Classes of Newly Synthesized Embryonic RNA
6 RNA Sequence Complexity and Structural Gene Transcription in Early Embryos
Sequence Complexity and the Quantitative Analysis of Renaturation Experiments
Definition of Sequence Complexity
Basic Relations between Renaturation Rate Constant and Sequence Complexity
Renaturation of Repetitive Sequences
Kinetics of Disappearance of Single Strand Nucleotides and RNA Hybridization in DNA Excess
RNA Excess Hybridization Kinetics
Sequence Complexity of Oocyte RNA
Single Copy Sequence Complexity of Oocyte RNA's
Complexity of Repetitive Sequence Transcripts in Oocyte RNA
Oocyte Repetitive Sequence Transcripts in Early Embryos
Repetitive and Nonrepetitive Sequence Transcripts in the Newly Synthesized RNAs of Early Embryos
Absence of Detectable Interspersed Repetitive Sequence Transcripts in Messenger RNA
Interspersed Repetitive Sequence Transcripts in Embryo Nuclear RNA
The Complexity of Embryo Nuclear RNA and Developmental Changes in the Pattern of Nuclear RNA Transcription
Complexity of Mammalian Embryo RNA
Complexity of Repetitive Sequences Tra…