Stefanie Weber1, Susan Jung2, Walter Doerfler1,3. 1. Institute of Clinical & Molecular Virology, University Erlangen-Nürnberg Medical School, 91054 Erlangen, Germany. 2. Pediatric Research Center, University Erlangen-Nürnberg, 91052 Erlangen, Germany. 3. Institute of Genetics, University of Cologne, 50674 Cologne, Germany.
Abstract
AIM: DNA methylation and transcriptional profiles were determined in the regulatory sequences of the human endogenous retroviral (HERV-K, -W, -E) and LINE-1.2 elements and were compared between non-transgenomic and plasmid-transgenomic cells. METHODS: DNA methylation profiles in the HERV (K, W, E) and LINE sequences were determined by bisulfite genomic sequencing. The transcription of these genome segments was assessed by quantitative real-time PCR. RESULTS: In HERV-K, HERV-W and LINE-1.2 the levels of DNA methylation ranged between 75 and 98%, while in HERV-E they were around 60%. Nevertheless, the HERV and LINE-1.2 sequences were actively transcribed. No differences were found in comparisons of HERV and LINE-1.2 CpG methylation and transcription patterns between non-transgenomic and plasmid-transgenomic HCT116 cells. CONCLUSION: The insertion of a 5.6 kbp plasmid into the HCT116 genome had no effect on the HERV and LINE-1.2 methylation and transcription profiles, although other parts of the HCT116 genome had shown marked changes. These repetitive sequences are transcribed, probably because the large number of HERV and LINE-1.2 elements harbor copies with non- or hypo-methylated long terminal repeat sequences.
AIM: DNA methylation and transcriptional profiles were determined in the regulatory sequences of the human endogenous retroviral (HERV-K, -W, -E) and LINE-1.2 elements and were compared between non-transgenomic and plasmid-transgenomic cells. METHODS: DNA methylation profiles in the HERV (K, W, E) and LINE sequences were determined by bisulfite genomic sequencing. The transcription of these genome segments was assessed by quantitative real-time PCR. RESULTS: In HERV-K, HERV-W and LINE-1.2 the levels of DNA methylation ranged between 75 and 98%, while in HERV-E they were around 60%. Nevertheless, the HERV and LINE-1.2 sequences were actively transcribed. No differences were found in comparisons of HERV and LINE-1.2 CpG methylation and transcription patterns between non-transgenomic and plasmid-transgenomic HCT116 cells. CONCLUSION: The insertion of a 5.6 kbp plasmid into the HCT116 genome had no effect on the HERV and LINE-1.2 methylation and transcription profiles, although other parts of the HCT116 genome had shown marked changes. These repetitive sequences are transcribed, probably because the large number of HERV and LINE-1.2 elements harbor copies with non- or hypo-methylated long terminal repeat sequences.
Entities:
Keywords:
CpG methylation in HERV and LINE-1.2 DNA; bisulfite genomic sequencing; comparisons of methylation and transcription between non-transgenomic and transgenomic cells; human cell line HCT116; human endogenous retroviral (HERV-K,-W,-E) and LINE-1.2 sequences; plasmid-transgenomic HCT116 cells; quantitative real-time PCR
Authors: Vera R Lezhnyova; Ekaterina V Martynova; Timur I Khaiboullin; Richard A Urbanowicz; Svetlana F Khaiboullina; Albert A Rizvanov Journal: Biology (Basel) Date: 2020-12-11