Yamada Yoichi, Shirakawa Tomoyo, Taylor Todd D, Okamura Kohji, Soejima Hidenobu, Uchiyama Michiko, Iwasaka Tsuyoshi, Mukai Tsunehiro, Muramoto Ken-Ichiro, Sakaki Yoshiyuki, Ito Takashi
Department of Information and Systems Engineering, Faculty of Engineering, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
DNA Seq. 2006 Aug;17(4):300-6. doi: 10.1080/10425170600886128.
It was generally believed that autosomal CpG islands (CGIs) escape methylation. However, our comprehensive analysis of allelic methylation status of 149 CGIs on human chromosome 21q revealed that a sizable fraction of them are methylated on both alleles even in normal blood cells. Here, we performed a similar analysis of 656 CGIs on chromosome 11q, which is gene-rich in contrast with 21q. The results indicate that 11q contains less methylated CGIs, especially those with tandem repeats and those in the coding or 3'-untranslated regions (UTRs), than 21q. Thus, methylation status of CGIs may substantially differ from one chromosome to another.
人们普遍认为常染色体CpG岛（CGIs）不会发生甲基化。然而，我们对人类21号染色体上149个CGIs的等位基因甲基化状态进行的全面分析表明，即使在正常血细胞中，其中相当一部分在两个等位基因上都发生了甲基化。在这里，我们对11号染色体上的656个CGIs进行了类似分析，与21号染色体相比，11号染色体富含基因。结果表明，与21号染色体相比，11号染色体上甲基化的CGIs较少，尤其是那些具有串联重复的CGIs以及编码区或3'非翻译区（UTRs）中的CGIs。因此，CGIs的甲基化状态可能在不同染色体之间存在显著差异。
