Ugarković D L, Plohl M, Lucijanić-Justić V, Borstnik B
Department of Organic Chemistry and Biochemistry, Ruder Bosković Institute, Zagreb, Croatia.
Biochimie. 1992 Dec;74(12):1075-82. doi: 10.1016/0300-9084(92)90005-y.
Very abundant and homogenous satellite DNA has been found in the flour beetle Palorus ratzeburgii, representing 40% of its genome. Sequencing of 14 randomly cloned satellite monomers revealed a conserved monomer length of 142 bp and an average A+T content of 68%. Sequence variation analysis showed that base substitutions, appearing with a frequency of 2.3%, are predominant differences among satellite monomers. The satellite sequence is unique without significant direct repeats and with only two potentially stable inverted repeats. After electrophoresis of satellite monomers on native polyacrylamide gel retarded mobilities characteristic for curved DNA molecules are observed. The curvature profiles and DNA helix axis trajectory are calculated on the basis of three different algorithms. These calculations predict that P ratzeburgii satellite DNA forms a left-handed solenoid superstructure. Comparison of described features with other satellite DNAs reveals some striking similarities with satellite DNA from related species Tenebrio molitor, which belongs to the same family of Tenebrionidae. Both satellites are very abundant and homogenous with the same, highly conserved monomer length, although there is no homology at the nucleotide level. Their monomers, as well as multimers, exhibit very similar retarded electrophoretic mobilities. The calculated curvature profiles predict two bend centers in monomers of each satellite, resulting in a model of left-handed solenoid superstructures of similar appearance.
在赤拟谷盗（Palorus ratzeburgii）中发现了非常丰富且均匀的卫星DNA，占其基因组的40%。对14个随机克隆的卫星单体进行测序，结果显示保守的单体长度为142 bp，平均A+T含量为68%。序列变异分析表明，碱基替换出现的频率为2.3%，是卫星单体之间的主要差异。该卫星序列是独特的，没有明显的直接重复序列，只有两个潜在稳定的反向重复序列。在天然聚丙烯酰胺凝胶上对卫星单体进行电泳后，观察到了弯曲DNA分子特有的迁移率延迟现象。基于三种不同算法计算了曲率轮廓和DNA螺旋轴轨迹。这些计算预测赤拟谷盗卫星DNA形成左手螺线管超结构。将所描述的特征与其他卫星DNA进行比较，发现与相关物种黄粉虫（Tenebrio molitor）的卫星DNA有一些显著的相似之处，黄粉虫属于拟步甲科同一科。两种卫星都非常丰富且均匀，单体长度相同且高度保守，尽管在核苷酸水平上没有同源性。它们的单体以及多聚体表现出非常相似的迁移率延迟现象。计算出的曲率轮廓预测每个卫星的单体中有两个弯曲中心，从而得出外观相似的左手螺线管超结构模型。
