Yu C W, Chen H, Fowler M
Am J Med Genet. 1983 Mar;14(3):501-11. doi: 10.1002/ajmg.1320140314.
Using the thymidine pulse method, DNA replication kinetics were studied on cells derived from cartilage, gonad, lymphocytes, and skin of a live-born triploid (69,XXY) infant with typical clinical findings. Replication studies showed that 3% of the lymphocytes had one early and one late replicating X, and 97% of the lymphocytes, and cartilage, gonad, and skin cells had two early replicating X's. Asynchronous DNA replication between the two early replicating X's was observed in all tissues (range 25-40%). The predominant terminal replication sequence of X chromosomes from chondrocytes, gonad, and skin fibroblast differed from that of the lymphocytes. Thus, a tissue-specific DNA replication pattern of the early-replicating X chromosome may be present. In every tissue, the last band to complete DNA replication was Xq21. Polymorphisms of metaphase chromosomes of parents and the patient were studied by Q-banding. The possible origin of the extra haploid set of chromosomes is discussed.
采用胸苷脉冲法，对一名具有典型临床表现的活产三倍体（69,XXY）婴儿的软骨、性腺、淋巴细胞和皮肤来源的细胞进行了DNA复制动力学研究。复制研究表明，3%的淋巴细胞有一条早期复制和一条晚期复制的X染色体，97%的淋巴细胞以及软骨、性腺和皮肤细胞有两条早期复制的X染色体。在所有组织中均观察到两条早期复制的X染色体之间存在异步DNA复制（范围为25%-40%）。软骨细胞、性腺和皮肤成纤维细胞的X染色体的主要末端复制序列与淋巴细胞不同。因此，可能存在早期复制的X染色体的组织特异性DNA复制模式。在每个组织中，最后完成DNA复制的带是Xq21。通过Q带分析研究了父母和患者中期染色体的多态性。讨论了额外单倍体染色体组的可能来源。
