Laser microirradiation of kinetochores in mitotic PtK2 cells |
| |
Authors: | Sari L Brenner Lih-Huei Liaw Michael W Berns |
| |
Institution: | (1) Development and Cell Biology, University of California, 92717 Irvine, California |
| |
Abstract: | Irradiation of the kinetochore region of PtK2 chromosomes by laser light of 532 nm was used to study the function of the kinetochore region in chromosome movement and
to create artificial micronuclei in cells. When the sister kinetochores of a chromosome were irradiated at prometaphase, the
affected chromosome detached from the spindle and exhibited no further directed movements for the duration of mitosis. The
chromatids of the chromosome remained attached to one another until anaphase, at which point they separated. No poleward movement
of the chromatids was observed, and at telophase they passively moved to one of the daughter cells and were enclosed in a
micronucleus. The daughter cell containing the micronucleus was then isolated by micromanipulation and followed through subsequent
mitoses. At the next mitosis, two chromosomes, each with two chromatids, condensed in the micronucleus. These chromosomes
did not attach to the spindle and showed chromatid separation, but no poleward movements at anaphase. They were again enclosed
in micronuclei at telophase. The third generation mitosis was similar to the second.
Occasionally, both the irradiation-produced and naturally occurring micronuclei exhibited no chromosome condensation at mitosis.
Feulgenstained monolayers of PtK2 cells with naturally occurring micronuclei showed that some micronuclei stain positive for DNA and others do not. This finding
raises questions about the fate of chromosomes in a micronucleus. |
| |
Keywords: | Laser microirradiation of kinetochores in PtK2 cells microirradiation laser of kinetochores in PtK2 cells mitosis and laser microirradiation of kinetochores kinetochores of PtK2 cells spindles of mitotic PtK2 cells chromosomes of mitotic PtK2 cells chromatid separation in PtK2 cells micronucleus formation in laser-irradiated PtK2 cells |
本文献已被 SpringerLink 等数据库收录! |
|