The Role of Chromosomes in Development is a collection of papers that deals with structural patterns and functional organization of chromosomes. Some papers discuss chromosomal proteins, DNA replication sequences in higher animals, and the implications of localized DNA synthesis in polytene chromosomes. Several papers describe chromosomal RNA, nuclear RNA fractions, genetic control, and the regulation of developmental pathways. One paper concerns the "bithorax" series that controls the development of certain body segments of the fly in a polarized and coordinated manner reminiscent of the genes in the operons of microorganisms. The bithorax genes evidently exploit and amplify a gradient arising from an anteroposterior gradient during mitotic division rates. The bithorax genes produces a whole set of new substances that repress certain systems of cellular differentiation, letting other systems to emerge and develop. Another paper investigates the hypothesis of diploid subnuclei as the architectural subunit of the ciliate macronucleus, as well as the hypothesis of "allelic repression" as the basis for certain examples of subnuclear differentiation. The collection can prove beneficial for biochemists, micro-biologists, bio-physicists, cellular researchers, and academicians involved in the study of cellular biology.
