A pathway for mitotic chromosome formation

作者：Gibcus, Johan H.; Samejima, Kumiko; Goloborodko, Anton; Samejima, Itaru; Naumova, Natalia; Nuebler, Johannes; Kanemaki, Masato T.; Xie, Linfeng; Paulson, James R.; Earnshaw, William C.^*; Mirny, Leonid A.^*; Dekker, Job^*

来源：Science, 2018, 359(6376): 652-+.

DOI：10.1126/science.aao6135

• SISTER-CHROMATID RESOLUTION
• CONDENSIN-I
• METAPHASE CHROMOSOMES
• VERTEBRATE CELLS
• TOPOISOMERASE-II
• SCAFFOLD ATTACHMENT
• CHROMOKINESIN KIF4A
• MAMMALIAN-CELLS
• LOOP EXTRUSION
• HUMAN GENOME

Mitotic chromosomes fold as compact arrays of chromatin loops. To identify the pathway of mitotic chromosome formation, we combined imaging and Hi-C analysis of synchronous DT40 cell cultures with polymer simulations. Here we show that in prophase, the interphase organization is rapidly lost in a condensin-dependent manner, and arrays of consecutive 60-kilobase (kb) loops are formed. During prometaphase, similar to 80-kb inner loops are nested within similar to 400-kb outer loops. The loop array acquires a helical arrangement with consecutive loops emanating from a central "spiral staircase" condensin scaffold. The size of helical turns progressively increases to similar to 12 megabases during prometaphase. Acute depletion of condensin I or II shows that nested loops form by differential action of the two condensins, whereas condensin II is required for helical winding.

• 出版日期2018-2-9
• 单位河北医科大学