Disruption of Drosophila Rad50 causes pupal lethality, the accumulation of DNA double-strand breaks and the induction of apoptosis in third instar larvae
Disruption of Drosophila Rad50 causes pupal lethality, the accumulation of DNA double-strand breaks and the induction of apoptosis in third instar larvae
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DOI：
10.1016/j.dnarep.2004.02.001
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发表时间：
2004-06-03
期刊：
影响因子：
3.8
通讯作者：
Pastink, A
中科院分区：
文献类型：
--
作者：
Gorski, MM;Romeijn, RJ;Pastink, A
Rad 50/Mre 11/Nbs 1蛋白复合物在DNA代谢中具有关键作用，特别是在通过同源重组（HR）的双链断裂（DSB）修复中。为了阐明Rad 50蛋白复合物在多细胞真核生物中DSB修复中的作用，我们通过P-元件介导的诱变产生了Rad 50缺陷型果蝇株。Rad 50的破坏导致发育迟缓和蛹致死。为了探讨蛹死亡的机制，对三龄幼虫的脑和翅成虫盘进行了更详细的研究。从Rad 50突变幼虫翅成虫盘显示了3.5倍增加自发凋亡细胞的诱导相比，他们的杂合子兄弟姐妹。这一发现与磷酸化组蛋白H2 Av水平的增加相关，表明DSB在Rad 50突变体幼虫中的积累。在Rad 50缺陷幼虫的大脑中检测到后期桥的频率增加了45倍，这与Rad 50在端粒维持和/或DNA复制中的作用一致。DSB的诱导和染色体分离的缺陷与果蝇Rad 50在修复复制过程中出现的DSB中的作用一致。(C)2004 Elsevier B. V.保留所有权利。
The Rad50/Mre 11/Nbs 1 protein complex has a crucial role in DNA metabolism, in particular in double-strand break (DSB) repair through homologous recombination (HR). To elucidate the role of the Rad50 protein complex in DSB repair in a multicellular eukaryote, we generated a Rad50 deficient Drosophila strain by P-element mediated mutagenesis. Disruption of Rad50 causes retarded development and pupal lethality. To investigate the mechanism of pupal death, brains and wing imaginal discs from third instar larvae were studied in more detail. Wing imaginal discs from Rad50 mutant larvae displayed a 3.5-fold increase in the induction of spontaneous apoptotic cells in comparison to their heterozygous siblings. This finding correlates with increased levels of phosphorylated histone H2Av, indicating an accumulation of DSBs in Rad50 mutant larvae. A 45-fold increase in the frequency of anaphase bridges was detected in the brains of Rad50 deficient larvae, consistent with a role for Rad50 in telomere maintenance and/or replication of DNA. The induction of DSBs and defects in chromosome segregation are in agreement with a role of Drosophila Rad50 in repairing the DSBs that arise during replication. (C) 2004 Elsevier B.V. All rights reserved.