Bentolila Stéphane, Elliott Leah E, Hanson Maureen R
Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853, USA.
Genetics. 2008 Mar;178(3):1693-708. doi: 10.1534/genetics.107.073585. Epub 2007 Jun 11.
We have analyzed the mitochondrial editing behavior of two Arabidopsis thaliana accessions, Landsberg erecta (Ler) and Columbia (Col). A survey of 362 C-to-U editing sites in 33 mitochondrial genes was conducted on RNA extracted from rosette leaves. We detected 67 new editing events in A. thaliana rosette leaves that had not been observed in a prior study of mitochondrial editing in suspension cultures. Furthermore, 37 of the 441 C-to-U editing events reported in A. thaliana suspension cultures were not observed in rosette leaves. Forty editing sites that are polymorphic in extent of editing were detected between Col and Ler. Silent editing sites, which do not change the encoded amino acid, were found in a large excess compared to nonsilent sites among the editing events that differed between accessions and between tissue types. Dominance relationships were assessed for 15 of the most polymorphic sites by evaluating the editing values of the reciprocal hybrids. Dominance is more common in nonsilent sites than in silent sites, while additivity was observed only in silent sites. A maternal effect was detected for 8 sites. QTL mapping with recombinant inbred lines detected 12 major QTL for 11 of the 13 editing traits analyzed, demonstrating that efficiency of editing of individual mitochondrial C targets is generally governed by a major factor.
我们分析了拟南芥两个生态型，即直立型兰茨贝格（Ler）和哥伦比亚（Col）的线粒体编辑行为。对从莲座叶中提取的RNA进行了33个线粒体基因中362个C-to-U编辑位点的调查。我们在拟南芥莲座叶中检测到67个新的编辑事件，这些事件在先前悬浮培养物中线粒体编辑的研究中未被观察到。此外，在拟南芥悬浮培养物中报道的441个C-to-U编辑事件中，有37个在莲座叶中未被观察到。在Col和Ler之间检测到40个编辑程度多态的位点。在不同生态型和不同组织类型之间存在差异的编辑事件中，与非沉默位点相比，发现大量不改变编码氨基酸的沉默编辑位点。通过评估正反交杂种的编辑值，对15个最具多态性的位点评估了显性关系。显性在非沉默位点比在沉默位点更常见，而加性仅在沉默位点中观察到。在8个位点检测到母体效应。利用重组自交系进行的QTL定位，对分析的13个编辑性状中的11个检测到12个主要QTL，表明单个线粒体C靶点的编辑效率通常受一个主要因素控制。
