Front Cover; Advances in Genetics, Volume 37; Copyright Page; Contents; Chapter 1. Polytene Chromosomes, Heterochromatin, and Position Effect Variegation; I. General Remarks; II. Morphology of the Heterochromatic Regions of the Chromosomes in Dividing Cells; III. Repetitive Sequences; IV. Genetic Content of Heterochromatic Regions of Mitotic Chromosomes; V. Diminution of Chromatin and Chromosomes; VI. Centromeric Heterochromatin in Polytene Chromosomes; VII. Intercalary Heterochromatin; VIII. Telomeric Heterochromatin; IX. The B Chromosomes

X. Heterochromatin of Chromosomes Restricted to Germline CellsXI. Changes in Expression of Genes Dependent on Their Position in the Genome; XII. Genetic Inactivation under Position Effect Variegation; XIII. Modification of Gene Expression under Position Effect; XIV. Time of Genetic Inactivation in Development; XV. Unusual Cases of Position Effect; XVI. Molecular and Cytogenetic Aspects of Position Effect Variegation; XVII. Current Concepts of the Mechanism of Position Effect Variegation; XVIII. Heterochromatization of Chromosome Regions and Regulation of Gene Activity; References; Index