Comprehensive Analysis of Human Endogenous Retrovirus Transcriptional Activity in Human Tissues with a Retrovirus-Specific Microarray

Global analysis of DNA methylation and transcription of human repetitive sequences.

“…59 In contrast, our repeat-specific microarray might serve as a very fast and reliable tool to obtain an overview of overall transcriptional activity of the whole repetitive compartment in a given cell type.…”

Non-conflict theories for the evolution of genomic imprinting

“…Intriguingly, transcription of human endogenous retroviruses is elevated in both reproductive tissues and the placenta (Seifarth et al, 2005), and, indeed, Haig (2012) has suggested that the latter may set up heightened selection for silencing in female germlines, which could explain the asymmetry. However, perhaps the greatest weakness of the genome defence argument is that it ignores the molecular details of piRNA pathways for control of retrotransposable elements, and siRNAs for control of viral transcription in the germline (Aravin et al, 2007).…”

Human Endogenous Retroviral Long Terminal Repeat Sequences as Cell Type-Specific Promoters in Retroviral Vectors

“…In addition, we and others have shown that isolated HERV LTRs maintain their promoter specificity in transient-transfection assays, suggesting that cell type specificity is mediated by the presence of transcription factor binding sites within the LTR and the availability of corresponding transcription factors in the cell and does not depend on additional cellular sequences located upstream or downstream of the LTR. For example, cloned HERV-H LTRs show a similar promoter activity in various human cell lines in transient-transfection assays as suggested by the endogenous transcription patterns of HERV-H proviruses in human tissues and cell lines (11,14,36,38). To further test this assumption and to investigate the effect of reintegration on the cell type specificity of HERV promoters, we cloned three LTR sequences from two different HERV families into a modified Moloney murine leukemia virus (MLV)-based retroviral vector (pLXSNEGFP), which contains the enhanced green fluorescent protein (EGFP) gene under the transcriptional control of the retroviral LTR and the neomycin resistance gene under the control of the simian virus 40 promoter (19).…”

“…Using a retrovirus-specific microarray, we have established a comprehensive HERV expression profile of 19 different human tissues (12,38,39). Some HERVs are ubiquitously expressed, whereas others are highly specific and transcriptionally active only in a few tissues.…”