International Review of Cytology presents current advances and comprehensive reviews in cell biology, both plant and animal. Articles address structure and control of gene expression, nucleocytoplasmic interactions, control of cell development and differentiation, and cell transformation and growth. Authored by some of the foremost scientists in the field, each volume provides up-to-date information and directions for future research. This volume brings together current information on the localization and roles of RNAs in cell-lineage determination and subsequent patterning in embryonic development. Guest co-editor Lawrence Etkin is one of the leading researchers in molecular genetics of Xenopus. Key Features * A number of important concepts are discussed, including: * How polarity is established during oogenesis * How germ cell determinants become organized in the establishment of the germ cell lineage * Different strategies used by organisms to establish the germ cell lineage * Similarities and differences between the mechanisms used in embryonic patterning * The mechanisms and machinery by which molecules such as RNA become asymmetrically segregated * The use of similar signaling pathways in patterning of the dorsal-ventral and right-left asymmetries, embryonic germ layers, limb, and nervous system * The link between fundamental biological processes such as RNA translation and localization in the regulation of axis specification.