小麦胚乳细胞内,细胞间胞质骨架分布格局的超微结构观察

以小麦（ＴｒｉｔｉｃｕｍａｅｓｔｉｖｕｍＬ．）幼嫩胚乳为材料,经ＴｒｉｔｏｎＸ１００抽提、ＤＧＤ（ｄｉｅｔｈｙｌｅｎｅｇｌｙｃｏｌｄｉｓｔｅａｒａｔｅ）渗透、包埋,制备去包埋剂超薄切片,对细胞内、细胞间胞质骨架的分布格局与特征进行了电镜观察。由所获图像可见,胞质骨架呈主要由微管、微丝组成的三维网络结构;特别值得注意的是,有不少５～７ｎｍ的微丝在多处从网络表层向胞壁界面方向突出,并时而可见其横贯分界壁连接相邻骨架网络而将相邻细胞骨架联成一体。胚乳组织中微丝的跨胞分布以两种形式存在,直径达１００～２００ｎｍ微丝束的跨越和单个微丝的分散贯穿,看来这与该组织中开放态胞间通道与正常胞间连丝同时并存相吻合。初步讨论了微丝参与正常胞间连丝结构的可能性。     

Oblique cell plate formation in tobacco BY-2 cells originates in double preprophase bands

Under specific experimental conditions, the formation of oblique cell plates was observed in tobacco BY-2 cells. Examination of this process, using an inverted microscope and immunofluorescence microscopy, revealed that the oblique cell plates were formed in cells that had double preprophase bands (PPBs). The formation of the oblique cell plates is discussed with a relationship to PPBs.     

Role of cytoskeletal elements in cytochalasin E-induced superoxide production by human polymorphonuclear leukocytes

The release of superoxide anions from human polymorphonuclear leukocytes induced by cytochalasin E was greatly enhanced by the pretreatment of the cells either with deuterium oxide or with concanavalin A. Colchicine, vinblastine and cyclic AMP inhibited the release. Cytochalasins A and B also suppressed the superoxide release. These observations suggest the involvement of microfilament-microtubule system in the production and release of superoxide anions induced by cytochalasin E.