Abstract
Structural investigation and morphometry of meiotic chromosomes by scanning electron microscopy (in comparison to light microscopy) of all stages of condensation of meiosis I + II show remarkable differences during chromosome condensation in mitosis and meiosis I of rye (Secale cereale) with respect to initiation, mode and degree of condensation. Mitotic chromosomes condense in a linear fashion, shorten in length and increase moderately in diameter. In contrast, in meiosis I, condensation of chromosomes in length and diameter is a sigmoidal process with a retardation in zygotene and pachytene and an acceleration from diplotene to diakinesis. The basic structural components of mitotic chromosomes of rye are ``parallel fibers{''} and ``chromomeres{''} which become highly compacted in metaphase. Although chromosome architecture in early prophase of meiosis seems similar to mitosis in principle, there is no equivalent stage during transition to metaphase I when chromosomes condense to a much higher degree and show a characteristic ``smooth{''} surface. No indication was found for helical winding of chromosomes either in mitosis or in meiosis. Based on measurements, we propose a mechanism for chromosome dynamics in mitosis and meiosis, which involves three individual processes: (i) aggregation of chromatin subdomains into a chromosome filament, (ii) condensation in length, which involves a progressive increase in diameter and (iii) separation of chromatids. Copyright (C) 2003 S. Karger AG, Basel.
| Item Type: | Journal article |
|---|---|
| Form of publication: | Publisher's Version |
| Faculties: | Medicine |
| Subjects: | 600 Technology > 610 Medicine and health |
| URN: | urn:nbn:de:bvb:19-epub-16948-6 |
| ISSN: | 1424-8581 |
| Alliance/National Licence: | This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. |
| Language: | English |
| Item ID: | 16948 |
| Date Deposited: | 29. Aug 2013 10:17 |
| Last Modified: | 04. Nov 2020 12:58 |

