Identification of sister chromatids by DNA template strand sequences.
Identification of sister chromatids by DNA template strand sequences.
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一般认为姐妹染色单体在遗传和功能上是相同的，向子细胞的分离是一个随机过程。然而，姐妹染色单体之间的功能差异在酵母中调节子细胞的命运，姐妹染色单体的分离在大肠杆菌中不是随机的2。分化的姐妹染色单体，加上非随机分离，被认为在多细胞生物的发育过程中调节细胞命运。这一假设尚未得到验证，因为可靠地区分姐妹染色单体的分子特征并不明显。本研究使用CO-FISH（染色体定向荧光原位杂交）技术在小鼠中期染色体的姐妹染色单体中鉴定亲本“Watson”和“Crick”DNA模板链，该技术具有对着丝粒和端粒重复序列特异性的单向探针。所有的染色体都表现出统一的方向，短臂的5 '端与富含t的主要卫星重复序列在同一条链上。利用重复DNA的不变取向来区分姐妹染色单体，并直接研究不同细胞类型的有丝分裂分离模式。尽管姐妹染色单体在培养的肺成纤维细胞和胚胎干细胞的子细胞之间似乎是随机分布的，但在结肠隐窝上皮细胞亚群中，包括结肠干细胞外位置的细胞中，观察到显著（p<0.01）的非随机姐妹染色单体分离。我们的研究结果表明，DNA模板序列可以用来区分姐妹染色单体，并跟踪它们在体内的有丝分裂分离。
It is generally assumed that sister chromatids are genetically and functionally identical and that segregation to daughter cells is a random process. However, functional differences between sister chromatids regulate daughter cell fate in yeast and sister chromatid segregation is not random in Escherichia coli2. Differentiated sister chromatids, coupled with non-random segregation, have been proposed to regulate cell fate during the development of multicellular organisms. This hypothesis has not been tested because molecular features to reliably distinguish between sister chromatids are not obvious. Here we show that parental “Watson” and “Crick” DNA template strands can be identified in sister chromatids of murine metaphase chromosomes using CO-FISH (Chromosome Orientation Fluorescence in situ Hybridization) with unidirectional probes specific for centromeric and telomeric repeats. All chromosomes were found to exhibit a uniform orientation with the 5′ end of the short arm on the same strand as T-rich major satellite repeats. The invariable orientation of repetitive DNA was used to differentially label sister chromatids and directly study mitotic segregation patterns in different cell types. Whereas sister chromatids appeared to be randomly distributed between daughter cells in cultured lung fibroblasts and embryonic stem cells, significant (p<0.01) non-random sister chromatid segregation was observed in a subset of colon crypt epithelial cells including cells outside positions reported for colon stem cells. Our results establish that DNA template sequences can be used to distinguish sister chromatids and follow their mitotic segregation in vivo.
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DOI：
10.1073/pnas.74.5.2041
发表时间：
1977-01-01
影响因子：
11.1
作者：
SCHNEIDER, EL;STERNBERG, H;TICE, RR
通讯作者：
TICE, RR
影响因子：
3.3
作者：
Kita, K;Wittmann, T;Waterman-Storer, CM
通讯作者：
Waterman-Storer, CM
影响因子：
14.9
作者：
HORZ, W;ALTENBURGER, W
通讯作者：
ALTENBURGER, W
影响因子：
2.5
作者：
RUDERT, F;BRONNER, S;DOLLE, P
通讯作者：
DOLLE, P
影响因子：
7.8
作者：
Jansen, Lars E. T.;Black, Ben E.;Foltz, Daniel R.;Cleveland, Don W.
通讯作者：
Cleveland, Don W.