Chromosomal territory segmentation in apoptotic cells
| Authors | |
|---|---|
| Year of publication | 2003 |
| Type | Article in Periodical |
| Magazine / Source | Cellular and Molecular Life Sciences |
| MU Faculty or unit | |
| Citation | |
| Field | Morphological specializations and cytology |
| Keywords | Chromosomal territory; Nuclear architecture; Apoptosis; DNA fragmentation |
| Description | The nuclear architecture of selected chromosomes in apoptotic nuclei of human leukemic cells K-562 and HL-60 was investigated in the presented paper. Etoposide and prolonged confluence were used for the induction of apoptosis. DAPI- as well as TUNEL- labelling of apoptotic nuclear bodies was combined with visualisation of chromosomal territories by the FISH technique. Simultaneous vital staining by Annexin V, PI and Hoechst 33342 was applied in order to distinguish apoptotic, necrotic and intact cell fraction of tested population. Our FISH analyses revealed that the 3D- structure of apoptotic nuclei as well as the 3D- structure of apoptotic bodies is preserved in formaldehyde fixed cells. High molecular weight DNA fragmentation was determined in apoptotic K-562 cells in contrast to oligonucleosomal cleavage observed in apoptotic HL-60 cells. In K-562 population, chromosomal territories were located separately either in one apoptotic body or to undergo disassembly into chromosomal segments dispersed into single and/or several apoptotic bodies. The apoptotic disorganisation of chromosomal territories was irregular, leading mainly to chromosomal segments of different sizes and, consequently, chromosomal disassembly was not observed at specific sites. Enhanced segmentation was also detected at selected centromeric regions. Sequential staining of the same apoptotic nuclei by the FISH and TUNEL techniques revealed that chromosomal territory segmentation precedes the formation of nuclear apoptotic bodies. |
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