Davis C A, Wyatt G R
Department of Biology, Queen's University, Kingston, Ontario, Canada.
Nucleic Acids Res. 1989 Jul 25;17(14):5579-86. doi: 10.1093/nar/17.14.5579.
The mealworm beetle, Tenebrio molitor, contains an unusually abundant and homogeneous satellite DNA which constitutes up to 60% of its genome. The satellite DNA is shown to be present in all of the chromosomes by in situ hybridization. 18 dimers of the repeat unit were cloned and sequenced. The consensus sequence is 142 nt long and lacks any internal repeat structure. Monomers of the sequence are very similar, showing on average a 2% divergence from the calculated consensus. Variant nucleotides are scattered randomly throughout the sequence although some variants are more common than others. Neighboring repeat units are no more alike than randomly chosen ones. The results suggest that some mechanism, perhaps gene conversion, is acting to maintain the homogeneity of the satellite DNA despite its abundance and distribution on all of the chromosomes.
黄粉虫（Tenebrio molitor）含有一种异常丰富且均匀的卫星DNA，其占基因组的比例高达60%。通过原位杂交表明，卫星DNA存在于所有染色体中。重复单元的18个二聚体被克隆并测序。共有序列长142个核苷酸，没有任何内部重复结构。该序列的单体非常相似，与计算出的共有序列平均有2%的差异。变异核苷酸随机分布在整个序列中，尽管有些变异比其他变异更常见。相邻的重复单元并不比随机选择的重复单元更相似。结果表明，尽管卫星DNA在所有染色体上都有丰富的含量和分布，但可能存在某种机制，也许是基因转换，在维持卫星DNA的同质性。
