Figure 5. HERV-W env sequence analyses in healthy brain specimens.
(A) (i) Ethidium-stained agarose gel of amplicons after second PCR step from fetal (F) and adult (A) brain samples. (ii) Relative clonal frequency of transcriptionally active HERV-W env sequences in fetal and adult brain samples showing encoding loci to be 7q21.2 and other sites. Diversity relative to ERVWE1 is displayed in parenthesis. (B) Chromosomal loci distribution of transcriptionally active HERV-W env sequences in fetal and adult brain samples. (C) Heatmap of gene expression was generated from RNA tags obtained by deep sequencing analysis by selecting a set of host genes relevant to neuroinflammation and associated with HERV-W env abundance in the sample. Over-expressed genes are shown in red and under-expressed in blue. (D) Host genes with expression profiles highly correlated with HERV-W env tag abundance (r2≥0.75) were analyzed using DAVID tools (http://david.abcc.ncifcrf.gov/) for enriched gene ontology (GO) terms. Genes related to transcriptional activity and regulations were strongly associated with HERV-W env expression. (ND = none detected).