title: Targeted identification of short interspersed nuclear element families shows their widespread existence and extreme heterogeneity in plant genomes.
abstract: Short interspersed nuclear elements (SINEs) are non-long terminal repeat retrotransposons that are highly abundant, heterogeneous, and mostly not annotated in eukaryotic genomes. We developed a tool designated SINE-Finder for the targeted discovery of tRNA-derived SINEs. We analyzed sequence data of 16 plant genomes, including 13 angiosperms and three gymnosperms and identified 17,829 full-length and truncated SINEs falling into 31 families showing the widespread occurrence of SINEs in higher plants. The investigation focused on potato (Solanum tuberosum), resulting in the detection of seven different SolS SINE families consisting of 1489 full-length and 870 5' truncated copies. Consensus sequences of full-length members range in size from 106 to 244 bp depending on the SINE family. SolS SINEs populated related species and evolved separately, which led to some distinct subfamilies. Solanaceae SINEs are dispersed along chromosomes and distributed without clustering but with preferred integration into short A-rich motifs. They emerged more than 23 million years ago and were species specifically amplified during the radiation of potato, tomato (Solanum lycopersicum), and tobacco (Nicotiana tabacum). We show that tobacco TS retrotransposons are composite SINEs consisting of the 3' end of a long interspersed nuclear element integrated downstream of a nonhomologous SINE family followed by successfully colonization of the genome. We propose an evolutionary scenario for the formation of TS as a spontaneous event, which could be typical for the emergence of SINE families.
authors: Department of Biology, Dresden University of Technology, D-01062 Dresden, Germany. thomas.schmidt@tu-dresden.de
authors: Torsten
authors: T
authors: Wenke
authors: Thomas
authors: T
authors: Döbel
authors: Thomas Rosleff
authors: TR
authors: Sörensen
authors: Holger
authors: H
authors: Junghans
authors: Bernd
authors: B
authors: Weisshaar
authors: Thomas
authors: T
authors: Schmidt
mesh_terms: D001483:Base Sequence; D055028:Comparative Genomic Hybridization; D019295:Computational Biology; D016384:Consensus Sequence; D018744:DNA, Plant / Q000235:genetics; D057225:Data Mining; D019143:Evolution, Molecular; D018745:Genome, Plant; D017404:In Situ Hybridization, Fluorescence; D018551:Solanum lycopersicum / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D018626:Retroelements; D017422:Sequence Analysis, DNA; D020086:Short Interspersed Nucleotide Elements; D011198:Solanum tuberosum / Q000235:genetics; D014026:Nicotiana / Q000235:genetics
chemical_list: D018744:DNA, Plant; D018626:Retroelements