The bending rigidity of mitotic chromosomes
The bending rigidity of mitotic chromosomes
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DOI：
10.1091/mbc.01-08-0401
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发表时间：
2002-06-01
影响因子：
3.3
通讯作者：
Marko, JF
中科院分区：
文献类型：
--
作者：
Poirier, MG;Eroglu, S;Marko, JF
通过观察有丝分裂染色体的自发热弯曲波动，测量了培养的绿色新月藻和非洲爪哇上皮细胞有丝分裂染色体的弯曲刚性。当与拉伸弹性的同时测量相结合时，这些测量限制了高阶有丝分裂染色体结构的模型。我们测量了类似于10(-22)N()的B的弯曲刚性。M(2)，与10(-23)N(.)M(2)，用于从细胞中提取非洲爪哇染色体。通过观察中期停滞细胞的弯曲波动，在体内测量了纽特染色体的类似弯曲刚性。在每次弯曲刚性测量之后，在该范围内测量相同染色体的拉伸(杨氏)模数。10(2)~10(3)pA。对于每条染色体，B和Y的值与简单弹性杆的预期值一致，B近似于YR4，其中R是染色体的横截面半径。我们的测量排除了染色体拉伸和弯曲弹性主要是由于中央核心区僵硬而表明内部结构的可能性，而内部结构在整个染色体横截面上的连接性基本上是均匀的。
The bending rigidities of mitotic chromosomes isolated from cultured N. viridescens (newt) and Xenopus epithelial cells were measured by observing their spontaneous thermal bending fluctuations. When combined with simultaneous measurement of stretching elasticity, these measurements constrain models for higher order mitotic chromosome structure. We measured bending rigidities of B similar to10(-22) N (.) m(2) for newt and similar to10(-23) N (.) m(2) for Xenopus chromosomes extracted from cells. A similar bending rigidity was measured for newt chromosomes in vivo by observing bending fluctuations in metaphase-arrested cells. Following each bending rigidity measurement, a stretching (Young's) modulus of the same chromosome was measured in the range. of 10(2) to 10(3) Pa for newt and Xenopus chromosomes. For each chromosome, these values of B and Y are consistent with those expected for a simple elastic rod, B approximate to YR4, where R is the chromosome cross-section radius. Our measurements rule out the possibility that chromosome stretching and bending elasticity are principally due to a stiff central core region and are instead indicative of an internal structure, which is essentially homogeneous in its connectivity across the chromosome cross-section.