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.