Anaya N, Roncero M I
Departamento de Genética, Facultad de Ciencias, Universidad de Córdoba, Spain.
Mol Gen Genet. 1995 Dec 20;249(6):637-47. doi: 10.1007/BF00418033.
A retrotransposon from the fungal plant pathogen Fusarium oxysporum f. sp. lycopersici has been isolated and characterized. The element, designated skippy (skp) is 7846 bp in length, flanked by identical long terminal repeats (LTR) of 429 bp showing structural features characteristic of retroviral and retrotransposon LTRs. Target-site duplications of 5 bp were found. Two long overlapping open reading frames (ORF) were identified. The first ORF, 2562 bp in length, shows homology to retroviral gag genes. The second ORF, 3888 bp in length, has homology to the protease, reverse transcriptase. RNase H and integrase domains of retroelement pol genes in that order. Sequence comparisons and the order of the predicted proteins from skippy indicate that the element is closely related to the gypsy family of LTR-retrotransposons. The element is present in similar copy numbers in the two races investigated, although RFLP analysis showed differences in banding patterns. The number of LTR sequences present in the genome is higher than the number of copies of complete elements, indicating excision by homologous recombination between LTR sequences.
已从植物真菌病原体尖孢镰刀菌番茄专化型中分离并鉴定出一种逆转座子。该元件命名为斯基皮（skp），长度为7846 bp，两侧是429 bp的相同长末端重复序列（LTR），显示出逆转录病毒和逆转座子LTR的结构特征。发现了5 bp的靶位点重复序列。鉴定出两个长的重叠开放阅读框（ORF）。第一个ORF长度为2562 bp，与逆转录病毒gag基因具有同源性。第二个ORF长度为3888 bp，依次与逆转座子pol基因的蛋白酶、逆转录酶、核糖核酸酶H和整合酶结构域具有同源性。斯基皮的序列比较和预测蛋白质的顺序表明，该元件与LTR逆转座子的吉普赛家族密切相关。在所研究的两个小种中，该元件的拷贝数相似，尽管RFLP分析显示条带模式存在差异。基因组中存在的LTR序列数量高于完整元件的拷贝数，表明通过LTR序列之间的同源重组进行了切除。
