Streit Adrian, Wang Jianbin, Kang Yuanyuan, Davis Richard E
Department Evolutionary Biology, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany.
Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO, United States.
Curr Opin Microbiol. 2016 Aug;32:120-127. doi: 10.1016/j.mib.2016.05.012. Epub 2016 Jun 14.
Maintenance of genome integrity is essential. However, programmed DNA elimination removes specific DNA sequences from the genome during development. DNA elimination occurs in unicellular ciliates and diverse metazoa ranging from nematodes to vertebrates. Two distinct groups of nematodes use DNA elimination to silence germline-expressed genes in the soma (ascarids) or for sex determination (Strongyloides spp.). Data suggest that DNA elimination likely evolved independently in these nematodes. Recent studies indicate that differential CENP-A deposition within chromosomes defines which sequences are retained and lost during Ascaris DNA elimination. Additional studies are needed to determine the distribution, functions, and mechanisms of DNA elimination in nematodes.
维持基因组完整性至关重要。然而，程序性DNA消除在发育过程中会从基因组中去除特定的DNA序列。DNA消除发生在单细胞纤毛虫以及从线虫到脊椎动物等多种后生动物中。两类不同的线虫利用DNA消除来沉默体细胞中生殖系表达的基因（蛔虫）或用于性别决定（类圆线虫属）。数据表明，DNA消除可能在这些线虫中独立进化。最近的研究表明，染色体中CENP-A的差异沉积决定了蛔虫DNA消除过程中哪些序列被保留和哪些序列丢失。还需要进一步研究来确定线虫中DNA消除的分布、功能和机制。
