Bruvo B, Plohl M, Ugarković D
Department of Molecular Genetics, Ruder Bosković Institute, Zagreb, Croatia.
Hereditas. 1995;123(1):69-75. doi: 10.1111/j.1601-5223.1995.00069.x.
The chromosomes of tenebrionid species Alphitobius diaperinus contain large blocks of pericentromerically located constitutive heterochromatin, as revealed by C-banding procedure. As previously reported, satellite DNA of this species is composed of two related monomeric units organized in three satellite subfamilies. In order to analyze the chromosomal location of the satellite DNA and the distribution of monomeric variants within it, and compare it with the distribution of monomer variants in Tenebrio molitor satellite DNA, the methods of in situ hybridization and restriction enzyme/nick translation were performed. Fluorescent in situ hybridization with the entire satellite DNA reveals the pericentromerically located signals on all chromosomes of the complement, coinciding with heterochromatic blocks. Results of fluorescent in situ hybridization with particular monomeric variants and of in situ restriction enzyme/nick translation show that monomeric variants are homogeneously dispersed within the entire satellite DNA. The spreading of satellite monomeric variants of the related species T. molitor within the pericentromeric heterochromatin of the entire complement, is demonstrated using the method of in situ restriction enzyme/nick translation. Although the complexity of organization of satellite DNAs is quite distinct in these two species, obtained results suggest similar efficiency of mechanisms of spreading and homogenization resulting in random chromosomal distribution of their satellite variants.
通过C带技术揭示，拟步甲科物种赤拟谷盗（Alphitobius diaperinus）的染色体含有位于着丝粒周围的大片组成型异染色质。如先前报道，该物种的卫星DNA由两个相关的单体单元组成，这些单体单元组成了三个卫星亚家族。为了分析卫星DNA的染色体定位及其内部单体变体的分布，并将其与黄粉虫（Tenebrio molitor）卫星DNA中单体变体的分布进行比较，采用了原位杂交和限制性内切酶/缺口平移方法。用整个卫星DNA进行荧光原位杂交，结果显示在整套染色体的所有染色体上，着丝粒周围均有信号，与异染色质块位置一致。用特定单体变体进行荧光原位杂交以及原位限制性内切酶/缺口平移的结果表明，单体变体均匀地分散在整个卫星DNA中。采用原位限制性内切酶/缺口平移方法，证实了相关物种黄粉虫的卫星单体变体在整套染色体着丝粒周围异染色质中的分布情况。尽管这两个物种卫星DNA的组织复杂性截然不同，但所得结果表明，它们的卫星变体在染色体上随机分布的扩散和均质化机制效率相似。
