| Summary: | 碩士 === 國立陽明大學 === 微生物及免疫學研究所 === 94 === The transcript AK092558 is a human-specific low copy repeat gene. It contains 4 nearly identical sequences with up to 98.9% nucleotide identity that map to the subtelomeric regions of chromosome 16, 9, 7 and 3. I studied the connection between epigenetic modifications and the expression patterns of the transcript AK092558, and then proceeded to the next step of investigating the chromatin structures in subtelomeric regions. Through RT-PCR with specific pairs of primer, I observed that the AK092558 mRNA was transcribed from chromosome 3 only in MCF10F cells but not in the breast tumor cell line MCF7. This mRNA was also founding in U937 cells and various human fetal tissues, whereas the homologous transcripts from chromosome 16, 7 and 3 were found in various human adult tissues and resting blood cells. There were no differences in expression patterns of AK092558 between normal and tumor cells in commercial lung, ovary, and colon normal/tumor pair cDNA panels. In order to study of regulation of expression of this gene in chromosome 3, I carried out bisulfite genomic sequencing of 5’ end regulatory region of AK092558 to study the methylation status of CpG dinucleotides in MCF10F and MCF7 cells. In both cell lines, the 35 CpG dinucleotides were methylated except the region spanning across exon 1 in MCF10F cells. This unmethylated region around exon 1 might play a role in gene regulation. Finally, I identified several MNase sensitivity regions in MCF10F cells but not in MCF7 cells. This differential methylation and chromatin organization between the two cell lines correlated with the differential expression pattern.
|
|---|
