Camargo M, Wang N
Hum Genet. 1980;55(1):81-5. doi: 10.1007/BF00329131.
Barr body staining procedures were applied directly to the chamber slide cultures of female amniotic cells. WI38 fibroblasts, normal female kidney cells, and a human breast carcinoma cell line, Elco. A high frequency of Barr bodies was found in all the normal female control cells; however, no Barr bodies were observed in the Elco cells. By trypsin G-banding analysis, two normal X chromosomes were identified in all Elco cells. The late DNA replication pattern of the cell line was then studied with the terminal BrdU pulse method. Both X chromosomes in the Elco cell line were found to be euchromatic with a characteristic R-banding pattern; no late-replicating X chromosome was observed. The absence of both a Barr body and a late-replicating heterocyclic X chromosome provides strong cytogenetic evidence that an inactivated X chromosome is absent in the human breast carcinoma cells bearing two X chromosomes.
巴氏小体染色程序直接应用于女性羊膜细胞的腔室玻片培养物。WI38成纤维细胞、正常女性肾细胞和一种人乳腺癌细胞系Elco。在所有正常女性对照细胞中发现了高频的巴氏小体；然而，在Elco细胞中未观察到巴氏小体。通过胰蛋白酶G显带分析，在所有Elco细胞中鉴定出两条正常的X染色体。然后用末端BrdU脉冲法研究该细胞系的晚期DNA复制模式。发现Elco细胞系中的两条X染色体均为常染色质，具有特征性的R显带模式；未观察到晚期复制的X染色体。既没有巴氏小体也没有晚期复制的异染色质X染色体，这提供了强有力的细胞遗传学证据，表明携带两条X染色体的人乳腺癌细胞中不存在失活的X染色体。
