Nuclear behavior during branch formation in a centrifugedAdiantum protonema and the nuclear polarity |
| |
Authors: | Masamitsu Wada |
| |
Institution: | (1) Biology Department, Faculty of Science, Tokyo Metropolitan University, 192-03 Tokyo, Japan |
| |
Abstract: | A new branch was induced on the side wall of fern protonema by cell centrifugation and subsequent polarized red light irradiation
after the induction of cell division under white light. Nuclear behavior during the branch formation was analyzed.
Immediately after cell division, the two daughter nuclei moved away from the division site in both red and dark conditions.
Under continuous irradiation with polarized red light, cell swelling occurred as an early step of branching near the cell
dividing wall, even though the nucleus was localized far from the branching site at the beginning of the swelling. After a
new branch started to grow, the nucleus returned to the branching site and moved into the new branch from its basipetal end.
When a protonema incubated in the dark was centrifuged again acropetally or basipetally just before the irradiation of polarized
red light, the rate of apical growth or branch formation was increased, respectively. Moreover, growth of a branched protonema
was altered from its former apex or from the branch again by dislocating the nucleus acropetally or basipetally by centrifugation,
respectively. These facts suggest that the nucleus has no polarity physiologically, i.e. head and tail, namely either end
of the spindle-shaped nucleus can be the nuclear front in a tip-growing protonema. |
| |
Keywords: | Adiantum Branching Centrifugation Nuclear behavior Polarity (nucleus) Protonema (fern) |
本文献已被 SpringerLink 等数据库收录! |
|