Outline of parvovirus B19 genome structure and organization.

<p>Top, ORF distribution within B19V internal coding region and related coding sequences. Center, functional map of B19V genome and distribution of regulatory signals: grey boxes, inverted terminal regions; P₆, promoter region; pAp1, pAp2, pAd: proximal and distal cleavage-polyadenylation sites; D1, A1-1/2, D2, A2-1/2, donor and alternative acceptor sites for introns 1 and 2, respectively. Below, a simplified map of B19V transcripts. Bottom, position of primers used in the PCR array (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0148547#pone.0148547.t001" target="_blank">Table 1</a>).