UNEQUAL CELL-DIVISION AND CHROMATIN DIFFERENTIATION IN POLLEN GRAIN CELLS .1. CENTRIFUGAL, COLD AND CAFFEINE TREATMENTS
UNEQUAL CELL-DIVISION AND CHROMATIN DIFFERENTIATION IN POLLEN GRAIN CELLS .1. CENTRIFUGAL, COLD AND CAFFEINE TREATMENTS
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DOI：
10.1007/bf02488324
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发表时间：
1987-06-01
期刊：
影响因子：
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通讯作者：
NIITSU, T
中科院分区：
文献类型：
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作者：
TERASAKA, O;NIITSU, T
正常发育的松树花粉粒受到离心力、低温和咖啡因溶液的影响。前两种处理诱导的子代细胞分裂方向异常，体积异常，染色质弥散。无论分裂方向如何，在不等分裂产生的两个子细胞中，较大的子细胞含有强分散的染色质，较小的子细胞含有弱分散的染色质。在近等分裂产生的两个子细胞中，染色质以相似的程度强烈分散，而通过中途不等分裂，大细胞中染色质强烈分散，小细胞中染色质中等分散。咖啡因诱导的双核细胞染色质分散程度一致。结果表明，在天然花粉粒中，异染色质构型的发生是细胞分裂不均匀所必需的，但分裂轴并不直接起作用，在小孢子和胚性细胞分裂过程中，经过离心法和低温处理后，受影响的子细胞按照一定的分裂轴和染色质分散分裂，而不是表现出发育异常。
Pinus pollen grains, normally developing, were subjected to centrifugal force, low temperature and caffeine solution. In the former two treatment, daughter cells with some abnormal directions of division, abnormal volume and chromatin dispersion were induced in pollen grains treated. Regardless of the direction of division, of the two daughter cells produced by the unequal division, the larger one contained strongly dispersed chromatin and the smaller one weakly dispersed chromatin. In the two daughter cells produced by approximately equal division, the chromatin was dispersed strongly to a similar degree, and by halfway unequal division, chromatin in the larger cell was dispersed strongly and in the smaller one intermediately. Chromatin in bi-nucleate cells induced by caffeine treatment was dispersed strongly to an identical degree. It is suggested that for the occurrence of heteronomous chromatin configuration in natural pollen grains the unequal cell division was indispensable, although the axis of division didn''t directly contribute. After both the treatments of centrifugation and low temperature during microspore and embryonal cell divisions, the affected daughter cells divided in terms of the certain fixed axis of division and chromatin dispersion, instead of exhibiting abnormal development.