[Interphase cytogenetic studies of human X chromosome]

The chromosome in situ hybridization with human X chromosome alpha satellite DNA probe (pBamX7) on human lymphocyte metaphases and interphase nuclei was performed for interphase cytogenetic studies. The individuals with numerical or structural abnormalities of X chromosome were studied. The results showed that the probe hybridized specifically to the centromeric region (p11----q11) of X chromosome. The number of silver grain clusters in interphase nuclei was correlated with that of X chromosome. Most of the clusters located near the nuclear membrane where inactive X chromatins (Barr-bodies) were usually found. The method of ascertaining the number of X chromosomes by in situ hybridization was much more reliable than that by counting the number of Barr-bodies. The modified R-banding technique was introduced and the significance of this work was also discussed.