Isolation and characterization of a cold-tolerant heterotrophic nitrification-aerobic denitrification bacterium and evaluation of its nitrogen-removal efficiency.

With a view toward addressing the poor efficiency with which nitrogen is removed from wastewater below 10 °C, in this study, we isolated a novel cold-tolerant heterotrophic nitrification-aerobic denitrification (HN-AD) bacterium from a wetland and characterized its nitrogen removal performance and nitrogen metabolic pathway. On the basis of 16S rRNA gene sequencing, this strain was identified as a species of Janthinobacterium, designated J1-1. At 8 °C, strain J1-1 showed excellent removal efficiencies of 89.18% and 68.18% for single-source NH4+-N and NO3--N, respectively, and removal efficiencies of 96.23% and 79.64% for NH4+-N and NO3--N, respectively, when supplied with mixed-source nitrogen. Whole-genome sequence analysis and successful amplification of the amoA, napA, and nirK functional genes related to nitrogen metabolism provided further evidence in support of the HN-AD capacity of strain J1-1. The deduced HN-AD metabolic pathway of the strain was NH4+-N→NH2OH→NO2--N→NO3--N→NO2--N→NO→N2O. In addition, assessments of NH4+-N removal under different conditions revealed the following conditions to be optimal for efficient removal: a temperature of 20 °C, pH of 7, shaking speed of 150 rpm, sodium succinate as a carbon source, and a C/N mass ratio of 16. Given its efficient nitrogen removal capacity at 8 °C, the J1-1 strain characterized in this study has considerable application potential in the treatment of low-temperature wastewater.

Magnetic bead-based separation of sperm from buccal epithelial cells using a monoclonal antibody against MOSPD3.

Forensic DNA analysis of sexual assault evidence requires unambiguous differentiation of DNA profiles in mixed samples. To investigate the feasibility of magnetic bead-based separation of sperm from cell mixtures using a monoclonal antibody against MOSPD3 (motile sperm domain-containing protein 3), 30 cell samples were prepared by mixing 10(4) female buccal epithelial cells with sperm cells of varying densities (10(3), 10(4), or 10(5) cells/mL). Western blot and immunofluorescence assays showed that MOSPD3 was detectable on the membrane of sperm cells, but not in buccal epithelial cells. After biotinylated MOSPD3 antibody was incubated successively with the prepared cell mixtures and avidin-coated magnetic beads, microscopic observation revealed that each sperm cell was bound by two or more magnetic beads, in the head, neck, mid-piece, or flagellum. A full single-source short tandem repeat profile could be obtained in 80% of mixed samples containing 10(3) sperm cells/mL and in all samples containing ≥10(4) sperm cells/mL. For dried vaginal swab specimens, the rate of successful detection was 100% in both flocked and cotton swabs preserved for 1 day, 87.5% in flocked swabs and 40% in cotton swabs preserved for 3 days, and 40% in flocked swabs and 16.67% in cotton swabs preserved for 10 days. Our findings suggest that immunomagnetic bead-based separation is potentially a promising alternative to conventional methods for isolating sperm cells from mixed forensic samples.

Genetic variants influencing lipid levels and risk of dyslipidemia in Chinese population.

Recently, several human genetic and genomewide association studies (GWAS) have discovered many genetic loci that are associated with the concentration of the blood lipids. To confirm the reported loci in Chinese population, we conducted a crosssection study to analyse the association of 25 reported SNPs, genotyped by the ABI SNaPshot method, with the blood levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglycerides (TG) in 1900 individuals by multivariate analysis. Logistic regression was applied to assess the association of the genetic loci with the risk of different types of dyslipidemia. Our study has convincingly identified that 12 of 25 studied SNPs were strongly associated with one or more blood lipid parameters (TC, LDL, HDL and TG). Among the 12 associated SNPs, 10 significantly influence the risk of one or more types of dyslipidemia.We firstly found four SNPs (rs12654264 in HMGCR; rs2479409 in PCSK9; rs16996148 in CILP2, PBX4; rs4420638 in APOE-C1-C4-C2) robustly and independently associate with four types of dyslipidemia (MHL, mixed hyperlipidemia; IHTC, isolated hypercholesterolemia; ILH, isolated low HDL-C; IHTG, isolated hypertriglyceridemia). Our results suggest that genetic susceptibility is different on the same candidate locus for the different populations. Meanwhile, most of the reported genetic variants strongly influence one or more plasma lipid levels and the risk of dyslipidemia in Chinese population.

A novel deleterious mutation in the COMP gene that causes pseudoachondroplasia.

Pseudoachondroplasia (PSACH) is a rare and severe genetic disease; therefore, an accurate molecular diagnosis is essential for appropriate disease treatment and family planning. Currently, the diagnosis of PSACH is based mainly on family history, physical examination and radiographic evaluation. Genetic studies of patients with PSACH in Chinese populations have been very limited. With the application of next-generation sequencing (NGS), a comprehensive molecular diagnosis of PSACH is now possible. The purpose of this study was to perform comprehensive NGS-based molecular diagnoses for patients with PSACH in China. We investigated the molecular genetics of one suspected PSACH family in this study. The DNA sample from the proband was sequenced using a custom capture panel that included 249 bone disease genes. Variant calls were filtered and annotated using an in-house automated pipeline. Then, we confirmed the variants by Sanger sequencing in three family members. After co-segregation analysis, the variant, c.1160_1162del of the COMP gene, was identified as a novel mutation responsible for this spontaneous form of PSACH.