X染色体失活的区域控制可使大部分X连锁基因得以剂量补偿,这仍是一个有兴趣的研究课题。许多细胞学特征中与X-失活有关的区域性变异包括性染色质小体形成、细胞周期中S期DNA的晚复制和染色质用喹吖因染色的强度。这些观察导致了不同的假说,分别认为X失活中心的数量是单一的或是多个的。人类X长臂近端的某个区域被认为是原始的X失活中心。对于人类X染色体缺失与临床及细胞学特征相关联的分析,说明X失 The control of the inactivation of X chromosomes allows most of the X-linked genes to be dose compensated, which is still an interesting research topic. Regional variations associated with X-inactivation in many cytological features include the formation of sex chromatin bodies, the late replication of S-phase DNA in the cell cycle, and the intensity of chromatin staining with quinoxaline. These observations led to different hypotheses, respectively considering the number of X inactivation centers to be single or multiple. A region near the long arm of human X is considered to be the center of the original X inactivation. Analysis of the association between human X chromosome deletions and clinical and cytological features, demonstrating X loss