Iurov Iu B, Mitkevich S P, Aleksandrov I A
Genetika. 1988 Feb;24(2):356-65.
Cloned alpha-satellite DNA sequences were used to evaluate the specificity and possible variability of repetitive DNA in constitutive heterochromatin of human chromosomes. Five probes of high specificity to individual chromosomes (chromosomes 3, 11, 17, 18 and X) were hybridized in situ to metaphase chromosomes of different individuals. The stable position of alpha-satellite DNA sequences in definite heterochromatic regions of particular chromosomes was found. Therefore, the chromosome-specific alpha-satellite DNA sequences may be used as molecular markers for heterochromatic regions of certain human chromosomes. The significant interindividual differences in relative copy number of alpha-satellite DNA have been detected. The homologous chromosomes of many individuals were characterized by cytologically visible heteromorphisms, as shown by intensity of hybridization with chromosome-specific alpha-satellite DNA sequences. A special analysis of hybridization between homologues with morphological differences gives evidence for a high resolution power of in situ hybridization technique for evaluation of chromosome heteromorphisms. The approaches for detection of heteromorphisms in cases without morphological differences between homologues are discussed. The results obtained indicate that constitutive heterochromatin of human chromosomes is variable for amount of alpha-satellite DNA sequences. In situ hybridization of cloned satellite DNA sequences may be used as novel general approach to analysis of chromosome heteromorphisms in man.
克隆的α-卫星DNA序列被用于评估人类染色体组成型异染色质中重复DNA的特异性和可能的变异性。五个对单个染色体（3号、11号、17号、18号和X染色体）具有高特异性的探针与不同个体的中期染色体进行原位杂交。发现α-卫星DNA序列在特定染色体的特定异染色质区域中的稳定位置。因此，染色体特异性α-卫星DNA序列可作为某些人类染色体异染色质区域的分子标记。已检测到α-卫星DNA相对拷贝数的显著个体间差异。许多个体的同源染色体具有细胞学可见的异态性，这通过与染色体特异性α-卫星DNA序列的杂交强度得以显示。对具有形态差异的同源染色体之间杂交的特殊分析为原位杂交技术评估染色体异态性的高分辨率能力提供了证据。讨论了在同源染色体之间无形态差异的情况下检测异态性的方法。所获得的结果表明，人类染色体的组成型异染色质在α-卫星DNA序列数量上是可变的。克隆卫星DNA序列的原位杂交可作为分析人类染色体异态性的一种新的通用方法。
