Butler M G, Joseph G M, Dev V G
Am J Med Genet. 1987 Mar;26(3):565-8. doi: 10.1002/ajmg.1320260309.
To evaluate the suggested nonrandom folding of Xq13-q21 (center of Barr body condensation) of the inactivated X chromosomes, metaphases from nine subjects with or without X chromosome abnormalities (eight females and one male) were investigated with RBG-staining. A significant increase (p less than .05) in the number of arm folds (Xq13-q21) of the late-replicating X chromosome, particularly in early to mid-metaphase, was observed in four of eight females. Therefore, the stage of chromosome contraction was an important factor with more folds observed at the centromeres and in longer chromosomes in early metaphase compared with mid- to late metaphase. X chromosome folds were present in cells of subjects treated with or without bromodeoxyuridine. While our study agrees with the relationship of Xq13-q21 fold with the X-inactivation center, the correlation of extended chromosomes and folding limits this method as a sole indicator of X-inactivation in routine mid-metaphase, but is useful in the analysis of early metaphase chromosomes.
为评估失活X染色体Xq13 - q21（巴氏小体浓缩中心）的非随机折叠情况，对9名有或无X染色体异常的受试者（8名女性和1名男性）的中期染色体进行了RBG染色研究。在8名女性中的4名中观察到，晚期复制X染色体的臂折叠（Xq13 - q21）数量显著增加（p小于0.05），尤其是在早中期。因此，染色体收缩阶段是一个重要因素，与中晚期相比，在早中期着丝粒和较长染色体上观察到更多的折叠。无论是否用溴脱氧尿苷处理过的受试者细胞中都存在X染色体折叠。虽然我们的研究认同Xq13 - q21折叠与X失活中心的关系，但延长染色体与折叠的相关性限制了该方法作为常规中期X失活的唯一指标，不过它在早中期染色体分析中很有用。
