Blouin J L, Rahmani Z, Chettouh Z, Prieur M, Fermanian J, Poissonnier M, Leonard C, Nicole A, Mattei J F, Sinet P M
Unité de Recherches Associée, Centre National de la Recherche Scientifique, Laboratoire de Biochimie Génétique, Hôpital Necker-Enfants Malades, Paris, France.
Am J Hum Genet. 1990 Mar;46(3):518-26.
As an alternative to the methods of gene dosage based on either RFLP studies or Southern blots using specific and reference probes, we designed a "slot blot" method for the evaluation of the copy number of unique chromosome 21 sequences. Varying amounts of denatured DNA from a normal control, a trisomy 21 patient, and the subject to be analyzed were loaded on the same membrane. Successive hybridizations with reference probes and chromosome 21 probes were then carried out. Intensities of the signals on autoradiograms were quantified by densitometric scanning. Graphic and statistical analysis of the linear regressions between reference and chromosome 21 probe signals were performed, and the conclusion that the DNA from the studied subject had two or three copies for a given chromosome 21 sequence was assessed by statistical comparison of the slopes. As a test for the validation of this method, 10 coded blood DNAs from five normal controls and from five trisomy 21 patients were analyzed, by using two reference (COL1A1 and COL1A2) and two chromosome 21 (D21S11 and D21S17) probes. Among the 10 DNAs analyzed, it was possible to diagnose, with 100% accuracy, normal controls and trisomic 21 individuals. Application of this methodology to the mapping of partial chromosome 21 rearrangements is presented.
作为基于RFLP研究或使用特异性和参照探针的Southern印迹法的基因剂量方法的替代方法，我们设计了一种“狭缝印迹”法来评估21号染色体独特序列的拷贝数。将来自正常对照、21三体患者以及待分析对象的不同量变性DNA加载到同一张膜上。然后依次用参照探针和21号染色体探针进行杂交。通过光密度扫描对放射自显影片上信号的强度进行定量。对参照探针和21号染色体探针信号之间的线性回归进行图形和统计分析，并通过斜率的统计比较来评估所研究对象的DNA对于给定的21号染色体序列有两个或三个拷贝这一结论。作为该方法验证的一项测试，使用两个参照探针（COL1A1和COL1A2）以及两个21号染色体探针（D21S11和D21S17）对来自五个正常对照和五个21三体患者的10份编码血液DNA进行了分析。在所分析的10份DNA中，能够以100%的准确率诊断出正常对照和21三体个体。本文还介绍了该方法在部分21号染色体重排图谱绘制中的应用。
