New developments in the study of environmental mutagens continue to evolve in this rapidly emerging field. In Volume 7 of Chemical Mutagens, we have focused on various new techniques for the detection of genetic damage in somatic cells and germ cells of mammals and the use of lower eukaryotic microorganisms to detect aneuploidy as well as other types of genetic damage. Attention has also been given to the role of in vitro metabolic activation as a mechanism for modifying the genetic effects of different environmental chemicals. In a chapter on compar­ ative mutagenesis, reaction kinetics and their relationship to the mu­ tagenic action of monofunctional alkylating agents in higher eukaryotic organisms are examined. In another chapter, the pharmacology and toxicology of nitrites and nitrates, which are in widespread distribution in the environment, are discussed in detail. The books in this series have provided a mechanism for the publication of many important new developments in the study of the genetic effects of environmental chemicals. This series was launched by Dr. Alexander Hollaender who, beginning in 1971, edited Volumes 1-4 and then coedited Volumes 5-7. The success of his lO-year effort with these volumes is another testimony to Dr. Hollaender's many contri­ butions to the field of environmental mutagenesis. As Dr.

1 Effects of Chemicals on Chromosome-Aberration Production in Male and Female Germ Cells.- 1. Introduction.- 2. Methods of Detecting Chromosome Aberrations Induced in Germ Cells.- 3. Male Germ Cells.- 4. Female Germ Cells.- 5. Interpretations and Conclusions.- 6. References.- 2 The Use of Immunological Techniques to Detect Cells of Rare Genotype.- 1. Introduction.- 2. Isolation of Antibodies Suitable for Detecting Mutants: Antibodies to Single and Multiple Amino Acid Differences in Proteins.- 3. Detection of Mutants with the Help of Antibodies.- 4. Conclusion.- 5. References.- 3 Metabolic Activation Systems in Vitro for Carcinogen/Mutagen Screening Tests.- 1. Introduction.- 2. Common Pathways for the Activation and Detoxification of Carcinogens/Mutagens.- 3. Subcellular Metabolic Activation Systems: Some General Remarks.- 4. Cellular Metabolic Activation Systems.- 5. Combination of in Vivo-in Vitro Screening Tests of Carcinogens/Mutagens: Recent Developments.- 6. Problems in the Extrapolation of Data Obtained in Vitro to the Intact Mammalian Organism.- 7. Conclusions.- 8. References.- 4 Microbial Metabolism of Environmental Chemicals to Mutagens and Carcinogens.- 1. Introduction.- 2. Definition of a Compound as a Promutagen.- 3. Chemicals That Can Be Activated to Environmental Mutagens and Carcinogens by Microorganisms.- 4. Role of the Intestinal Microflora in the Formation of Mutagens and Carcinogens.- 5. Short-Term Test Systems and the Role of Microorganisms in the Metabolism of Chemicals into Mutagens: Conclusions.- 6. Summary.- 7. References.- 5 Short-Term Tests for Chemicals That Promote Aneuploidy.- 1. Introduction.- 2. Test Systems.- 3. Discussion.- 4. References.- 6 Nitrates and Nitrites: Ingestion, Pharmacodynamics, and Toxicology.- 1. Introduction.- 2. MajorSources of Human Exposure.- 3. Flow in Humans.- 4. Suspected Health Consequences.- 5. Reduction of Exposure.- 6. Summary.- 7. References.- 7 The Relation between Reaction Kinetics and Mutagenic Action of Monofunctional Alkylating Agents in Higher Eukaryotic Systems: Interspecies Comparisons.- 1. Introduction.- 2. Mechanism of Action of Alkylating Agents.- 3. Reaction of Alkylating Agents with DNA and Proteins.- 4. Response to Alkylating Agents.- 5. Interspecies Comparisons.- 6. Conclusions.- 7. References.- 8 The Human Leukocyte Test System.- 1. Introduction.- 2. Some Early Events during Human Leukocyte Stimulation...- 3. DNA Synthesis, Mitosis, and the Diversity of the Culture System.- 4. Differences in Mutagen Sensitivity of Leukocyte Subpopulations?.- 5. Fate of Chromosomal Damage during Successive Cell Cycles.- 6. Selected Examples of in Vivo Investigations with Human Leukocytes.- 7. Appendix: Standard Protocol for Human Leukocyte Culture Preparation.- 8. References.- 9 The Activation of Chemicals into Mutagens by Green Plants.- 1. Introduction.- 2. Plant Activation of Promutagens.- 3. Deactivation of Mutagens by Plants.- 4. Response of Plant Genetic Assays to Known Mammalian Promutagens.- 5. Conclusion.- 6. References.- 10 Unscheduled DNA Synthesis in Mammalian Germ Cells-Its Potential Use in Mutagenicity Testing Gary A. Sega.- 1. Introduction.- 2. What Does the Occurrence of Unscheduled DNA Synthesis in Mouse Germ Cells Mean?.- 3. Procedures for Treating Animals with [3H]Thymidine and Chemical Mutagens.- 4. Detection of Unscheduled DNA Synthesis in the Germ Cells.- 5. Germ-Cell Stages That Undergo Unscheduled DNA Synthesis When Exposed to Mutagenic Agents.- 6. Comparison of the Sensitivity of the Test for Unscheduled DNA Synthesis with That of Other GeneticTests.- 7. Relationship between Genetic Effects and Unscheduled DNA Synthesis Induced by Mutagens.- 8. Development and Characterization of Mouse Stocks with Reduced Levels of Unscheduled DNA Synthesis in Their Germ Cells.- 9. Relevancy of the Test for Mammalian Germ-Cell Unscheduled DNA Synthesis Compared with That of Other Mutagenicity Tests.- 10. References.- 11 Aspergillus nidulans-An Organism for Detecting a Range of Genetic Damage.- 1. Introduction.- 2. Basic Biology.- 3. General Methodology.- 4. Assay Systems.- 5. Concluding Remarks.- 6. References.