Vaĭsertreĭger I S R, Podgornaia O I, Enukashvili N I
Tsitologiia. 2007;49(1):62-9.
It is believed that satellite DNA is compact and transcriptionally inert during interphase. We determined localization, range of compactization and methylation state of the centromeric and pericentromeric satellite DNA using the method of fluorescence hybridization in situ (FISH) combined with the antibody immunostaining against the methylated DNA. We investigated the tissue cells (the cells of placenta and lymphocytes), primary (MRC5 fibroblasts) and malignant (A431) cell cultures. Centromeric satellite DNA was condensed and stained with antibodies against 5-methylcytosine in all the cases. Pericentromeric satellite 3 of the chromosome 1 was condensed in lymphocytes, placenta cells and young culture of fibroblasts. The unwrapping of satellite 3 of the chromosome 1 has been observed in the senescent MRC5 fibroblasts and in the malignant cell line A431. The compact areas of pericentromeric satellites were stained with antibodies against the methylated DNA, white the decondensed areas were'nt stained. Thus, we observed pericentromeric satellite 3 decondensation in senescent fibroblasts culture MRC5 and in cell line A431. The decondensation was accompanied by the partial demethylation of the satellite DNA, which is believed to belong to constitutive heterochromatin.
人们认为，卫星DNA在间期是紧密的且转录无活性。我们使用荧光原位杂交（FISH）方法结合针对甲基化DNA的抗体免疫染色，确定了着丝粒和着丝粒周围卫星DNA的定位、压缩范围和甲基化状态。我们研究了组织细胞（胎盘细胞和淋巴细胞）、原代（MRC5成纤维细胞）和恶性（A431）细胞培养物。在所有情况下，着丝粒卫星DNA都浓缩并用抗5-甲基胞嘧啶抗体染色。1号染色体的着丝粒周围卫星3在淋巴细胞、胎盘细胞和成纤维细胞的年轻培养物中浓缩。在衰老的MRC5成纤维细胞和恶性细胞系A431中观察到1号染色体卫星3的解压缩。着丝粒周围卫星的紧密区域用抗甲基化DNA抗体染色，而解压缩区域未染色。因此，我们在衰老的MRC5成纤维细胞培养物和A431细胞系中观察到着丝粒周围卫星3的解压缩。这种解压缩伴随着卫星DNA的部分去甲基化，卫星DNA被认为属于组成型异染色质。
