Biology subjects

Hu, P.

Publications and source records attributed to Hu, P..

4 recordsLinked to original sources

bioRxiv2017

Acute and chronic toxicity assessment of benzylpenicillin G residue in cooked meat

The current level of penicillin use and its persisting residues in livestock is potentially concerning; the toxicity of penicillin residues in heat-treated animal food products (HAFP) is yet to be elucidated. In this study, the acute and chronic toxicity of benzylpenicillin G (BPG) residues in HAFP was investigated in a mouse model. The calculated LD50 of BPG heated to cooking temperature (BPHCT) was 933.04 mg kg-1 [b.w.] intraperitoneally corresponding to 3.75 times lower than its prototype. Mice fed on the experimental diet containing heat-treated beef with high BPG levels for 6 months displayed a reduction in body weight and altered serum values indicating for liver and renal function. Further, the organ ratios of intestinal and spleen were increased. Histopathological changes were observed in the liver, lung and parenchyma testis tissue. BPHCT residue induced sperm aberration and micronucleated polychromatic erythrocytes formation. Present results indicate that prolonged exposure of BPHCT at higher levels of residue might have an impact on public health. Importantly the toxic concentrations of BPHCT are relatively high compared with levels that would result from the degradation of antibiotic residues in meat from animals that have received a therapeutic dose of BPG.

pharmacology and toxicology↗

bioRxiv2017

sNucDrop-Seq: Dissecting cell-type composition and neuronal activity state in mammalian brains by massively parallel single-nucleus RNA-Seq

Massively parallel single-cell RNA sequencing can precisely resolve cellular diversity in a high-throughput manner at low cost, but unbiased isolation of intact single cells from complex tissues, such as adult mammalian brains, is challenging. Here, we integrate sucrose-gradient assisted nuclear purification with droplet microfluidics to develop a highly scalable single-nucleus RNA-Seq approach (sNucDrop-Seq), which is free of enzymatic dissociation and nucleus sorting. By profiling ~11,000 nuclei isolated from adult mouse cerebral cortex, we demonstrate that sNucDrop-Seq not only accurately reveals neuronal and non-neuronal subtype composition with high sensitivity, but also enables analysis of long non-coding RNAs and transient states such as neuronal activity-dependent transcription at single-cell resolution in vivo.

genomics↗

bioRxiv2017

NLR1-V, a CC-NBS-LRR encoding gene, is a potential candidate gene of the wheat powdery mildew resistance gene Pm21

Wheat powdery mildew caused by Blumeria graminisb f. sp. tritici is one of the most destructive diseases all over the world. Pm21, transferred from the wild Haynaldia villosa to wheat, confers broad spectrum resistance throughout the whole stage, and this gene has been widely used in wheat production for more than 20 years. Cloning the candidate gene of Pm21 is the prerequisite for elucidating the resistance mechanism, and is a valuable attempt to clone the target genes from the evolutionarily distant wild species. In this study, an innovative approach, which combined cytogenetic stocks development, mutagenesis, RenSeq and PacBio, was tried successfully to clone an NBS-LRR type gene NLR1-V from the Pm21 locus. Firstly, a powdery mildew resistant cryptic alien introgression line HP33 involved very small 6VS segment was developed, and 6 independent susceptible mutants of T6VS {middle dot} 6AL was identified. Then, the transcriptome of H. villosa was obtained by NGS and the full-length NBS-LRR gene database was constructed by RenSeq-PacBio. In the following study, two expressed NLR genes were located to the Pm21 locus using the HP33 as the mapping material, and only NLR1-V showed polymorphism between the wild T6VS {middle dot} 6AL and its six mutants. The functional analysis indicated that silencing of NLR1-V could compromise the resistance of T6VS {middle dot} 6AL completely, and could also decrease the resistance of T6VS {middle dot} 6DL dramatically. Moreover, NLR1-V could recover the resistance of the susceptible mutant and increase the resistance in the susceptible wheat. The study implied that NLR1-V, a CC-NBS-LRR encoding gene, is a potential candidate gene of the powdery mildew resistance gene Pm21.

plant biology↗

bioRxiv2016

Metabolic and spatio-taxonomic response of uncultivated seafloor bacteria following the Deepwater Horizon oil spill

The release of 700 million liters of oil into the Gulf of Mexico over a few months in 2010 produced dramatic changes in the microbial ecology of the water and sediment. Previous 4 studies have examined the phylogeny and function of these changes, but until now a 5 fundamental examination of the extant hydrocarbon metabolisms that supported these 6 changes had not been performed. Here, we reconstructed the genomes of 57 widespread 7 uncultivated bacteria from post spill sediments, and recovered their gene expression 8 pattern across the seafloor. These genomes comprised a common collection of bacteria 9 that were highly enriched in heavily affected sediments around the wellhead. While rare in distal sediments, some members were still detectable at sites up to 60 km away. Many of these genomes exhibited phylogenetic clustering indicative of common trait selection by the environment, and within half we identified 264 genes associated with hydrocarbon degradation. Observed alkane degradation ability was near ubiquitous among candidate hydrocarbon degraders, while just 3 harbored elaborate gene inventories for the degradation of alkanes and (poly)aromatic hydrocarbons. Differential gene expression profiles revealed a spill-promoted microbial sulfur cycle alongside gene up-regulation associated with polyaromatic hydrocarbon degradation. Gene expression associated with alkane degradation was widespread, although active alkane degrader identities changed along the pollution gradient. The resulting analysis suggests a broad metabolic capacity to respond to oil exists across a large array of usually rare bacteria.

microbiology↗