The Complete Mitochondrial Genome of Eurasian Minnow (Phoxinus cf. Phoxinus) from the Heilongjiang River, and Its Phylogenetic Implications

Over the past two decades, the genus Phoxinus has undergone extensive taxonomic revision and many new species or mitochondrial lineages have been found in Europe. However, Asian populations of Phoxinus spp. have received less attention and have rarely been compared with their European relatives. In this study, we deciphered the 16,789-nucleotide mitochondrial genome of Phoxinus cf. phoxinus from the Heilongjiang River (HLJ) and compared it with other known mitogenomes or partial mitochondrial DNA (mtDNA) sequences of Phoxinus spp. We discovered that all known mitochondrial genomes of Phoxinus had a typical mtDNA architecture across vertebrates, but their D-loop regions varied greatly in length. A repetitive motif of ~130 bp was identified in the D-loop regions of Phoxinus spp. The unusual repetitive structure was revealed at the beginning of D-loop regions of all known mitogenomes of Phoxinus spp. The length differences of the D-loop region were attributed mainly to the number of repetitive motifs and the inserted sequences among them. However, this repetitive structure was absent in the other Far East phoxinins. This is further evidence for the notion that Far Eastern phoxinins should be divided into two genera: Phoxinus and Rhynchocypris. All mtDNA sequences (including three mitogenomes) from South Korea represent the same genetic lineage, as there were only slight differences among them. The remaining six mtDNA sequences are highly divergent and represent different lineages of the genus, as supported by partial mtDNA sequences. The updated phylogeny of genus Phoxinus suggests that there are five distinct mtDNA lineages in Asia. The Asian lineages have diverged markedly from their European relatives and should not be included with the European minnow (P. phoxinus)

Heroin Inhibits HIV-Restriction miRNAs and Enhances HIV Infection of Macrophages

Although opioids have been extensively studied for their impact on the immune system, limited information is available about the specific actions of opioids on intracellular antiviral innate immunity against HIV infection. Thus, we investigated whether heroin, one of the most abused drugs, inhibits the expression of intracellular HIV restriction microRNA (miRNA) and facilitates HIV replication in macrophages. Heroin treatment of macrophages enhanced HIV replication, which was associated with the downregulation of several HIV restriction miRNAs. These heroin-mediated actions on the miRNAs and HIV could be antagonized by naltrexone, an opioid receptor antagonist. Furthermore, the in vitro negative impact of heroin on HIV-associated miRNAs was confirmed by the in vivo observation that heroin addicts had significantly lower levels of macrophage-derived HIV restriction miRNAs than those in the control subjects. These in vitro and in vivo findings indicate that heroin use compromises intracellular anti-HIV innate immunity, providing a favorable microenvironment for HIV survival in the target cells

Peach MYB7 activates transcription of the proanthocyanidin pathway gene encoding leucoanthocyanidin reductase, but not anthocyanidin reductase

Proanthocyanidins (PAs) are a group of natural phenolic compounds that have a great effect on both flavour and nutritious value of fruit. It has been shown that PA synthesis is regulated by R2R3-MYB transcription factors (TFs) via activation of PA-specific pathway genes encoding leucoanthocyanidin reductase (LAR) and anthocyanidin reductase (ANR). Here, we report the isolation and characterization of a MYB gene designated PpMYB7 in peach. The peach PpMYB7 represents a new group of R2R3-MYB genes regulating PA synthesis in plants. It is able to activate transcription of PpLAR1 but not PpANR, and has a broader selection of potential bHLH partners compared with PpMYBPA1. Transcription of PpMYB7 can be activated by the peach basic leucine-zipper 5 TF (PpbZIP5) via response to ABA. Our study suggests a transcriptional network regulating PA synthesis in peach, with the results aiding the understanding of the functional divergence between R2R3-MYB TFs in plants