Marín I, Fontdevila A
Departamento de Genética y Microbiología, Universidad Autónoma de Barcelona, Spain.
Mol Gen Genet. 1995 Aug 30;248(4):423-33. doi: 10.1007/BF02191642.
The cloning and characterization of Gandalf, a new DNA-transposing mobile element obtained from the Drosophila koepferae (repleta group) genome is described. A fragment of Gandalf was found in a middle repetitive clone that shows variable chromosomal localization. Restriction, Southern blot, PCR and sequencing analyses have shown that most Gandalf copies are about 1 kb long, are flanked by 12 bp inverted terminal repeats and contain subterminal repetitive regions on both sides of the element. As with other elements of the DNA-transposing type (known as the 'Ac family'), the Gandalf element generates 8 bp direct duplications at the insertion point. Coding region analysis has shown that the longer open reading frame found in Gandalf copies could encode part of a protein. However, whether or not the 1 kb copies of the element are actually the active transposons remains to be elucidated. Gandalf shows a very low copy number in D. buzzatii, a sibling species of D. koepferae. An attempt to induce interspecific hybrid dysgenesis in hybrids of these two species has been unsuccessful.
本文描述了从果蝇科佩费拉（repleta组）基因组中获得的一种新的DNA转座移动元件甘道夫（Gandalf）的克隆与特征分析。在一个中间重复克隆中发现了甘道夫的一个片段，该片段显示出可变的染色体定位。限制性内切酶分析、Southern印迹分析、PCR和测序分析表明，大多数甘道夫拷贝约1 kb长，两侧有12 bp的反向末端重复序列，元件两侧还含有亚末端重复区域。与其他DNA转座类型的元件（称为“Ac家族”）一样，甘道夫元件在插入点产生8 bp的直接重复序列。编码区分析表明，在甘道夫拷贝中发现的较长开放阅读框可能编码一种蛋白质的一部分。然而，该元件的1 kb拷贝是否实际上是活跃的转座子仍有待阐明。甘道夫在科佩费拉果蝇的近缘种布扎蒂果蝇中的拷贝数非常低。在这两个物种的杂交种中诱导种间杂种不育的尝试未成功。
