|Budget Amount *help
¥2,100,000 (Direct Cost : ¥2,100,000)
Fiscal Year 1996 : ¥700,000 (Direct Cost : ¥700,000)
Fiscal Year 1995 : ¥1,400,000 (Direct Cost : ¥1,400,000)
Nuclear division in Boergesenia forbesii is very unique in the respect that the nuclear membrane is not fragmented throughout mitosis different from open-spindles in animals and higher plants. In this study, we observed the mitosis in B.forbesii under immunofluorescence microscopy using anti-beta tubulin, anti-centrin and anti-gamma tubulin antibodies. In interphase, microtubules (MTs) radiated around nuclei. One or two pairs of centrioles existed aroud the interphase nucleus. Toward mitosis, perinuclear MTs disappeared and, instead of them, MTs radiated from centrioles. These MT foci separated and migrated to both poles. Simultaneously, tublin molecules started to enter into the nucleus from prophase, and these tubulin molecules formed spindle MTs from poles to chromosomes and from pole to pole, and finally interzonal spindle fibers. Centrin molecules always localized around centrioles through the cell cycle of B.forbesii. On the contrary, gamma-tubulin could not detected around centrioles in interphase. Gamma-tubulin characteristically localized around centrioles from early prophase to early anaphase in mitosis, and they could not be observed around centrioles in late anaphase and telophase. Moreover, gamma-tubulin did not localize in the interzonal spindle fibers. This means that both ends of the interzonal spindle fibers are +end of MTs, not like centrosome.