【摘要】 采用原子力显微镜术(AtomicForceMicroscopy,AFM)首次观察到了近自然状态下多头绒泡菌(Physarumpolycephalum)中期染色体的整体结构和表面细微结构.染色体整体结构成像显示其边缘轮廓清晰圆滑,具有明显的着丝点;染色体表面高分辨率成像发现,中期染色体是由约230nm的染色质纤维经螺旋且在底部回转180°形成,同时表面有3个层次有序折叠的染色质纤维同时存在,它们分别是:30～40nm,60～70nm,90～100nm.由高度图和侧向力成像图都可推测它们是螺旋结构.这些结果进一步证实了中期染色体包装的高度有序性,多层次结构是由螺旋方式形成,同时表明AFM是在近自然状态下研究生物大分子结构的强有力工具.更多还原

【Abstract】 The whole structures and the surface details of a native metaphase chromosome of Physarum polycephalum were firstly observed and imaged by atomic force microscopy.The imaging picture showed that the chromosome has clear and slick edge and apparent centromere.Furthermore imaging revealed that it is also observed from a chromosome was established by folding of a macro-helix fiber about 230 nm rotating 180° at its end.Three levels of chromatin fibers on the surface of metaphase chromosomes were observed,they are 30~40 nm,60~70 nm,90~110 nm,respectively.They were inferred helical structures from height imaging and friction imaging.The results confirm that the packages of mataphase chromosomes are highly order and the chromosome structures at near native state as well.更多还原