Gadi I K, Ryder O A
Cytogenet Cell Genet. 1983;35(2):124-30. doi: 10.1159/000131853.
A (G + C)-rich satellite DNA component (p = 1.716 g/ml) has been fractionated from the total DNA of the Iranian subspecies of the Asiatic wild ass, Equus hemionus onager, by successive dactinomycin-CsCl and netropsin sulfate-CsCl isopycnic gradients. Complementary 3H-RNA (cRNA) transcribed from the satellite DNA hybridized predominantly to the centromeric and telomeric constitutive heterochromatic regions of onager chromosomes. These studies have suggested that satellite DNA's with similar sequences are present in the centromeric, as well as telomeric, heterochromatic regions of some onager chromosomes. The centromeric region of the fusion metacentric t(23;24) of the onager is deficient in sequences homologous to the onager 1.716 g/ml satellite DNA, indicating a loss of satellite DNA during fusion or an amplification of the satellite DNA in the centromeric regions of the acrocentric chromosomes 23 and 24 subsequent to fission. Sequences complementary to onager 1.716 g/ml satellite DNA show extensive hybridization to the constitutive heterochromatin of the feral donkey (E. asinus) karyotype, consistent with a view of conservation and amplification of similar or identical sequences in the two species.
一种富含（G + C）的卫星DNA组分（p = 1.716 g/ml）已通过连续的放线菌素 - CsCl和硫酸纺锤菌素 - CsCl等密度梯度从亚洲野驴伊朗亚种（Equus hemionus onager）的总DNA中分离出来。从卫星DNA转录的互补3H - RNA主要与野驴染色体的着丝粒和端粒组成型异染色质区域杂交。这些研究表明，一些野驴染色体的着丝粒以及端粒异染色质区域中存在具有相似序列的卫星DNA。野驴融合中着丝粒t(23;24)的着丝粒区域缺乏与野驴1.716 g/ml卫星DNA同源的序列，这表明在融合过程中卫星DNA丢失，或者在裂变后acrocentric染色体23和24的着丝粒区域中卫星DNA发生了扩增。与野驴1.716 g/ml卫星DNA互补的序列与野生驴（E. asinus）核型的组成型异染色质显示出广泛的杂交，这与两种物种中相似或相同序列的保守和扩增观点一致。
