Relative DNA Methylation and Demethylation Efficiencies during Postnatal Liver Development Regulate Hepatitis B Virus Biosynthesis.

Hepatitis B virus (HBV) transcription and replication increase progressively throughout postnatal liver development with maximal viral biosynthesis occurring at around 4 weeks of age in the HBV transgenic mouse model of chronic infection. Increasing viral biosynthesis is associated with a corresponding progressive loss of DNA methylation. The loss of DNA methylation is associated with increasing levels of 5-hydroxymethylcytosine (5hmC) residues which correlate with increased liver-enriched pioneer transcription factor Forkhead box protein A (FoxA) RNA levels, a rapid decline in postnatal liver DNA methyltransferase (Dnmt) transcripts, and a very modest reduction in ten-eleven translocation (Tet) methylcytosine dioxygenase expression.

PCR effects of melting temperature adjustment of individual primers in degenerate primer pools.

Deep sequencing of small subunit ribosomal RNA (SSU rRNA) gene amplicons continues to be the most common approach for characterization of complex microbial communities. PCR amplifications of conserved regions of SSU rRNA genes often employ degenerate pools of primers to enable targeting of a broad spectrum of organisms. One little noticed feature of such degenerate primer sets is the potential for a wide range of melting temperatures between the primer variants.

Making and Sequencing Heavily Multiplexed, High-Throughput 16S Ribosomal RNA Gene Amplicon Libraries Using a Flexible, Two-Stage PCR Protocol.

Deep sequencing of polymerase chain reaction (PCR)-amplified small subunit (16S or 18S) ribosomal RNA (rRNA) genes fragments is commonly employed to characterize the composition and structure of microbial communities. Preparing genomic DNA for sequencing of such gene fragments on Illumina sequencers can be performed in a straightforward, two-stage PCR method, described herein. The protocol described allows for up to 384 samples to be sequenced simultaneously, and provides great flexibility in choice of primers.