Dictyostelium Discoideum: A Developmental System

Dictyostelium Discoideum: A Developmental System presents D. discoideum as a model eukaryotic system to study a variety of developmental problems. The book describes the life cycle of the organism D. discoideum which exists in nature as a soil amoeba in forest detritus. The nuclei of D. discoideum contain DNA, RNA, and proteins which have properties similar to those of histones present in calf thymus nuclei. The unique sequences of the genome of the organism code for the gene products synthesize during its growth and development. One approach in genetic analyses to understanding the developmental processes of the organism is to isolate a large number of morphological mutants. The isolation process will indicate the number of variations that are open to the developing system, and will point to causal connections between stages. The text also explains that the number of cells which differentiate into stalk cells is the result of timing and mechanics of the process of culmination. Ashworth (1971) suggests that cells in pseudoplasmodia of D. discoideum adjust their positions in relation to the chemical structure of the sheath itself. A model shows how cells communicate their response to the sheath in an axial fashion. The book can prove beneficial for biochemists, micro-biologists, cellular researchers, and investigators involved in the study of cellular biology.

Table of Contents:
PrefaceChapter 1 The Life Cycle An Overview Related SpeciesChapter 2 Amoeboid Stage Growth Conditions Amoeboid Movement in D. Discoideum Feeding UltrastructureChapter 3 The Genome Karyotype Nuclear Composition Mitochondrial DNA Repetitive Sequences Unique SequencesChapter 4 Genetics of Dictyostelium Genetic Approaches Mutational Genetics Parasexuality Sexuality Stock MaintenanceChapter 5 Aggregation Stage Chemotaxis Periodic Movement Cohesion of Developing CellsChapter 6 Pseudoplasmodial Stage Integration Polarity of Migration Phototaxis Thermotaxis Cell Sorting in PseudoplasmodiaChapter 7 Culmination Stage Stalk Formation Spore Formation Avoidance Reaction Germination Inhibitor Germination Mutational Analysis of CulminationChapter 8 Macromolecular Aspects of Development Decrease in Dry Weight and Oxygen Consumption Protein Content RNA Content Polysaccharide Content DNA Content Axenically Grown Cells RNA Metabolism Structure of Nuclear and Cytoplasmic RNA Transcriptional ChangesChapter 9 Enzymatic Aspects of Development Enzymes of the Growth Phase Enzymes of Growth and Development Enzymes of Development Marker Enzymes of Development Enzyme Synthesis Enzyme Degradation Stage-Specific Enzymes Mutational Analysis of Stage-Specific EnzymesChapter 10 Changes in Metabolites during Development Cells Grown on Bacteria Axenically Grown CellsChapter 11 The Relation of Biochemical Differentiations to Morphogenesis Aggregation Pseudoplasmodium Formation Culmination Glycogen Metabolism Substrate Concentrations Metabolic Modeling Genetic AnalysisChapter 12 Modifications of Development Submerged Cultures Cell Density Overhead Light Dissociation Mechanical Barriers Effect of Nutrients Phenocopies of Aggregateless Mutants Phenocopies of Fruitless Mutants Phenocopies of Culmination Mutants Growth Conditions Genetic Modifications SynergyChapter 13 Tissue Proportioning Size Invariance Mechanical Analysis Differentiations of Prespore and Prestalk Cells Cell Sorting and Determination Regulation of Tissue Proportions Positional Information Cell Contact Model Diffusional Barrier Model Structural ModelBibliographySubject Index