Feschotte Cédric, Wessler Susan R
Department of Botany and Genetics, University of Georgia, Athens, GA 30602, USA.
Proc Natl Acad Sci U S A. 2002 Jan 8;99(1):280-5. doi: 10.1073/pnas.022626699. Epub 2001 Dec 26.
Complete and partial sequences of mariner-like elements (MLEs) have been reported for hundreds of species of animals, but only two have been identified in plants. On the basis of these two plant MLEs and several related sequences identified by database searches, plant-specific degenerate primers were derived and used to amplify a conserved region of MLE transposase genes from a variety of plant genomes. Positive products were obtained for 6 dicots and 31 monocots of 54 plant species tested. Phylogenetic analysis of 68 distinct MLE transposase sequences from 25 grass species is consistent with vertical transmission and rapid diversification of multiple lineages of transposases. Surprisingly, the evolution of MLEs in grasses was accompanied by repeated and independent acquisition of introns in a localized region of the transposase gene.
数百种动物的类水手元件(MLEs)的完整和部分序列已被报道,但在植物中仅鉴定出两种。基于这两种植物MLEs以及通过数据库搜索鉴定出的几个相关序列,设计了植物特异性简并引物,并用于从多种植物基因组中扩增MLE转座酶基因的保守区域。在所测试的54种植物中,6种双子叶植物和31种单子叶植物获得了阳性产物。对来自25种草种的68个不同的MLE转座酶序列进行系统发育分析,结果与转座酶多个谱系的垂直传递和快速多样化一致。令人惊讶的是,草中MLEs的进化伴随着转座酶基因局部区域内含子的反复和独立获得。