Weise Anja, Othman Moneeb A K, Bhatt Samarth, Löhmer Sharon, Liehr Thomas
Jena University Hospital, Institute of Human Genetics, Friedrich Schiller University, Kollegiengasse 10, 07743, Jena, Germany.
Methods Mol Biol. 2015;1227:299-307. doi: 10.1007/978-1-4939-1652-8_16.
Copy number variations (CNVs) are structural variations of the human genome. These alterations result in variant copy numbers of certain stretches of DNA. In other words, some regions may be present in more or less copies than in a reference genome; however, these copy number changes do not have any impact on the phenotype. Also, CNVs may be extremely large and cytogenetically detectable or submicroscopic but still spanning several megabasepairs (Mb). In the recent years, array technology has identified especially the latter ones as so-called copy number variant (CNV) polymorphisms. These CNVs are detected in ~12 % of the human genome sequences and may comprise several hundred kilobasepairs. CNVs contribute significantly to the inter-individual differences in humans, and can range between 0.5 and 1.5 Mb amongst different genomes, well within the level of detection using cytogenetics techniques. Thus, they can be visualized by FISH using bacterial artificial chromosomes (BACs) as probes. Here we describe a method that enables discrimination of individual homologous chromosomes at the single cell level based on CNVs in the genome, called parental origin determination fluorescence in situ hybridization (POD-FISH). Possible fields of applications of this single cell-directed approach are in analyses of the parental origin of single chromosomes in inherited and acquired chromosomal aberrations.
拷贝数变异（CNVs）是人类基因组的结构变异。这些改变导致特定DNA片段的拷贝数发生变化。换句话说，某些区域的拷贝数可能比参考基因组中的多或少；然而，这些拷贝数变化对表型没有任何影响。此外，CNVs可能非常大，可通过细胞遗传学检测到，也可能是亚显微的，但仍跨越几个兆碱基对（Mb）。近年来，阵列技术已将后者鉴定为所谓的拷贝数变异（CNV）多态性。在约12%的人类基因组序列中检测到这些CNVs，其长度可能包含几百千碱基对。CNVs对人类个体间差异有显著贡献，不同基因组之间的CNVs长度在0.5至1.5 Mb之间，这完全在细胞遗传学技术的检测水平范围内。因此，可使用细菌人工染色体（BACs）作为探针，通过荧光原位杂交（FISH）对其进行可视化。在此，我们描述一种基于基因组中的CNVs在单细胞水平上区分单个同源染色体的方法，称为亲本来源确定荧光原位杂交（POD-FISH）。这种单细胞定向方法的可能应用领域包括分析遗传性和获得性染色体畸变中单个染色体的亲本来源。
