蓝氏贾第虫核小体的初步研究

A Preliminary Study on Nucleosome in the Most Primitive Eukaryote—Giardia lamblia

最原始的真核生物蓝氏贾第虫虽已有五种组蛋白 ,但以微球菌核酸酶水解却得不到规则的DNA片段。鉴于贾第虫的特殊进化地位 ,探讨其是否具有核小体结构 ,对于研究核小体的起源和进化具有重要的意义。采用改进的染色质铺展技术制备核小体并进行透射电镜观察。结果表明蓝氏贾第虫已有了直径约 1 0nm的核小体结构。作者认为核小体的形成可追溯到真核生物形成的初期甚至更早 ,核小体的完善则在真核生物形成之后。

Although five kinds of histone exist in the most primitive Eukaryote_Giardia lamblia,no regular DNA fragments are observed.In virtue of the special status of this species in evolution,it is very important to find out whether it has nucleosome in order to clarify the origin and evolution of nucleosome.Nucleosomes of G.lamblia were prepared with a modified technique of chromatin dispersion and observed with transmission electronmicroscopy.It is shown that is concluded that the formation of nucleosome might be in the early age of the origin of eukaryotic cell,while the perfect structure of nucleosome may be formed after the origin of eukaryotic cell.