细胞骨架和粘性多糖对坛紫菜壳孢子极性形成的影响

应用解聚微丝和微管细胞骨架的特异性药物,结合组织化学染色方法观察了坛紫菜壳孢子早期发育阶段中的细胞极性形成过程。观察结果表明,坛紫菜壳孢子从放散入水作变形运动到萌发成二细胞的孢子苗共有两次细胞极性形成过程:第一次发生在坛紫菜壳孢子作变形运动期间(形成前后轴);第二次发生在壳孢子拉长呈椭圆形的一细胞萌发体期间(形成细胞的上下轴)。在这两次细胞极性形成过程中,壳孢子外的粘性多糖,尤其是硫酸化的酸性粘多糖主要聚集在运动壳孢子的后缘和壳孢子萌发体的下方,说明粘性多糖有协同形成、稳定壳孢子细胞极性的作用。刚放散的壳孢子经高浓度的细胞骨架抑制剂处理后,壳孢子的正常运动被阻止,从而影响壳孢子的第一次细胞极性形成,导致壳孢子不能萌发。运动后的壳孢子经高浓度的抑制剂处理后,出现了假根形成和细胞分裂面不正常的畸形萌发体,它们的基部均没有粘性多糖的显色。

Cytoskeleton and mucilage involved in the cell polarization of conchospores in Pyropia haitanensis

The specific inhibitors of cytoskeleton and histochemical stain were used to investigate formation of cell polarization during the early development of conchospores in Pyropia haitanensis.Polarized conchospores were observed twice:Anterior-posterior axis is formed in migrating conchospores.After migration,conchospores adhere to the substratum and then apical-basal axis is established.Meanwhile,composition of mucilage around conchospores was studied,and acidic polysaccharides and sulfated polysaccharides were found at the rear end in migrating conchospores and basal portion of up-righted conchospores.These results indicate that mucilage is involved in formation and maintenance of the cell polarization in conchospores.Inhibitors of cytoskeleton prevented the released conchospores from germinating through disturbing the anterior-posterior axis formed in migrating conchospores.It was found that they also affected the establishment of apical-basal axis for abnormal germinations in the inhibitors-treated migrated conchospores.These results indicate that cytoskeleton and mucilage are involved constantly in twice cell polarization formation of conchospores in P.haitanensis.