Ben-David Eyal, Burga Alejandro, Kruglyak Leonid
Department of Human Genetics, Department of Biological Chemistry, and Howard Hughes Medical Institute, University of California, Los Angeles, CA 90095, USA.
Science. 2017 Jun 9;356(6342):1051-1055. doi: 10.1126/science.aan0621. Epub 2017 May 11.
Selfish genetic elements spread in natural populations and have an important role in genome evolution. We discovered a selfish element causing embryonic lethality in crosses between wild strains of the nematode The element is made up of , a maternal-effect toxin that kills developing embryos, and , its zygotically expressed antidote. has long been considered essential for pharynx development on the basis of its mutant phenotype, but this phenotype arises from a loss of suppression of toxicity. Inactive copies of the element show high sequence divergence from active copies, and phylogenetic reconstruction suggests that they represent ancestral stages in the evolution of the element. Our results suggest that other essential genes identified by genetic screens may turn out to be components of selfish elements.
自私的遗传元件在自然种群中传播，并在基因组进化中发挥重要作用。我们发现了一种自私元件，它在秀丽隐杆线虫野生菌株的杂交中导致胚胎致死。该元件由一种母源效应毒素（可杀死发育中的胚胎）和一种合子表达的解毒剂组成。长期以来，基于其突变表型，一直认为该基因对咽发育至关重要，但这种表型是由于对毒性抑制作用的丧失而产生的。该元件的无活性拷贝与活性拷贝表现出高度的序列差异，系统发育重建表明它们代表了该元件进化的祖先阶段。我们的结果表明，通过遗传筛选鉴定出的其他必需基因可能原来是自私元件的组成部分。
