ACTIN MICROFILAMENT ORGANIZATION DURING POLLEN DEVELOPMENT OF BRASSICA-NAPUS CV TOPAS
ACTIN MICROFILAMENT ORGANIZATION DURING POLLEN DEVELOPMENT OF BRASSICA-NAPUS CV TOPAS
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DOI：
10.1007/bf01276814
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发表时间：
1994-01-01
期刊：
影响因子：
2.9
通讯作者：
NEWCOMB, W
中科院分区：
文献类型：
--
作者：
GERVAIS, C;SIMMONDS, DH;NEWCOMB, W
研究了甘蓝型油菜花粉发育过程中肌动蛋白微丝(MFS)的组成。托帕斯。用三种技术制备细胞，并在荧光显微镜下用罗丹明标记的鬼臼糖苷标记MFS和Hoechst 33258标记DNA。除了开花前的三细胞花粉外，微丝存在于花粉发育的所有阶段。单细胞小孢子含有从核膜表面辐射到细胞质的微孢子。在有丝分裂过程中，MFS形成一个部分围绕有丝分裂器的网络，并延伸到细胞质中。在胞质分裂过程中，胞质和膜质相关的MFS都存在。在双细胞小孢子的营养细胞中出现核伴生的、胞质的和随机定向的皮质MFS。营养细胞中的皮质微纤维排列成平行的微纤维束(MFBs)，横向排列在沟槽上。MFBs在小孢子伸长之前消失。在开花时，微丝被限制在营养细胞棱槽附近的皮层区域。用细胞松弛素D干扰微丝分裂功能的结果是：(1)单细胞小孢子无着丝点核移位；(2)有丝分裂细胞纺锤体移位；(3)双细胞小孢子对称生长而不是伸长；(4)成熟花粉粒中花粉管萌发受到抑制。这说明在小孢子有丝分裂过程中，MFS在单细胞小孢子内锚定细胞核和纺锤体，在小孢子形状确定和花粉管萌发中起着重要作用。
The organization of actin microfilaments (MFs) was studied during pollen development of Brassica napus cv. Topas. Cells were prepared using three techniques and double labelled for fluorescence microscopy with rhodamine-labelled phalloidin for MFs and Hoechst 33258 for DNA. Microfilaments are present at all stages of pollen development with the exception of tricellular pollen just prior to anthesis. Unicellular microspores contain MFs which radiate from the surface of the nuclear envelope into the cytoplasm. During mitosis MFs form a network partially surrounding the mitotic apparatus and extend into the cytoplasm. Both cytoplasmic and phragmoplast-associated MFs are present during cytokinesis. Nuclear associated-, cytoplasmic, and randomly oriented cortical MFs appear in the vegetative cell of the bicellular microspore. Cortical MFs in the vegetative cell organize into parallel MF bundles (MFBs) aligned transverse to the furrows. The MFBs disappear prior to microspore elongation. At anthesis MFs are restricted to the cortical areas subjacent to the furrows of the vegetative cell. The use of cytochalasin D to disrupt MF function resulted in: (1) displacement of the acentric nucleus in the unicellular microspore; (2) displacement of the spindle apparatus in the mitotic cell; (3) symmetrical growth of the bicellular microspore rather than elongation and (4) inhibition of pollen tube germination in the mature pollen grain. This suggests that MFs play an important role in anchoring the nucleus in the unicellular microspore as well as the spindle apparatus during microspore mitosis, in microspore shape determination and in pollen tube germination.