The Relationship of DNA Methylation within C4/CYP21 Locus and Adrenal-Specific Gene Expression

• Main Authors: Tien-Tzu Chang, 張恬慈
• Other Authors: Shwu-Fen Chang
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/83433648970616169779

碩士 === 臺北醫學大學 === 細胞及分子生物研究所 === 91 === Steroid 21-hydroxylase mediates biosynthesis of glucocorticoids and mineralcorticoids. Enzymatic deficiency of steroid 21-hydroxylase is associated with congenital adrenal hyperplasia. There are two copies of human steroid 21 hydroxylase genes, the active CYP21 gene and pseudogene CYP21P and these two genes exhibit approximately 98% homology. These duplicated genes are located within the C4/CYP21 locus. Now, more and more pairs of duplicated genes which specifically express in the adrenal gland have been found within this locus. DNA methylation is thought to be one of the facts that can regulate tissue specific expression. We therefore used sodium bisulfite modification to analyze the methylation status of predicted CpG islands in the C4/CYP21 locus and compared the methylation status of these CpG islands of genome from adrenal H295 and non-adrenal HepG2 cells. The results showd that the CpG sequence within -13873/-13813 bp、 -13316/-13230 bp、 -12223 /-12138 bp、 -11461 bp /-11350bp、 -8450/-8332 bp and -3574/-3473 bp upstream of CYP21P gene are all methylated and there were no differences between genomes of H295 and HepG2 cells. In addition, within -12561/-12516bp、 -11075 bp /-11015 bp and -4176/-4113 bp upstream of CYP21P gene are all methylated and there were no difference between H295 and HepG2 cells so the sequence in these regions may not influence the adrenal-specific expression of CYP21 gene.