Kaufmann, B. P., Gay, H., McDonald, M.R. (1960) Organizational patterns within chromosomes. Int Rev Cytol, 9. pp. 77-127. ISSN 0074-7696 (Print)0074-7696 (Linking)
Abstract
This chapter discusses the structure of chromosome. The condensed chromosomes of somatic and meiotic mitoses are characterized by helically disposed chromonemata. When seen in end view-both in living material and in fixed preparations, the chromosome appears as a ring with its constituent chromonemata surrounding a central core. In fixed and stained preparations, the chromonemata reveal a high degree of basophilia, except in the zones of lesser stainability that mark the positions of primary and secondary constrictions. The primary constriction indicates the location of the centromere. Secondary constrictions are often detectable, such as those that separate terminal satellites from the body of the chromosome. Chromosomes of higher plants and animals—and probably the chromosomes of microorganisms—are multistranded. In the terminology of Darlington, they are polynemic. A chromosome in a given type of cell generally maintains a constant number of strands, apart from the variability imposed by their recurrent doubling and halving in chromosomal replication and distribution during the mitotic cycles. Further, polynemic and polytenic chromosomes are assumedly composed of genetically equivalent subsidiary strands. Within the limits of its stability, the chromosome is subject to changes in the patterns of association of its constituent materials during somatic and meiotic mitoses and in the course of differentiation. A consideration of these changes recommends a measure of caution in attempting to designate any one component as the essential structure or functional material. Deoxyribonucleic acid has often been selected to fill this role, largely on the basis of studies of cells that function in the transfer of “genetic information” from one individual to another.
| Item Type: | Paper |
|---|---|
| Uncontrolled Keywords: | *Chromosomes Humans |
| Subjects: | bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > chromosomes, structure and function |
| CSHL Authors: | |
| Communities: | The Carnegie Institution Department of Genetics |
| Depositing User: | Matt Covey |
| Date: | 1960 |
| Date Deposited: | 22 Jan 2018 16:34 |
| Last Modified: | 22 Jan 2018 16:34 |
| Related URLs: | |
| URI: | https://repository.cshl.edu/id/eprint/35970 |
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