Transcriptomic analysis to elucidate the effects of high stocking density on grass carp (Ctenopharyngodon idella).

BACKGROUND: Grass carp (Ctenopharyngodon idella) is one of the most widely cultivated fishes in China. High stocking density can reportedly affect fish growth and immunity. Herein we performed PacBio long-read single-molecule real-time (SMRT) sequencing and Illumina RNA sequencing to evaluate the effects of high stocking density on grass carp transcriptome. RESULTS: SMRT sequencing led to the identification of 33,773 genes (14,946 known and 18,827 new genes). From the structure analysis, 8,009 genes were detected with alternative splicing events, 10,219 genes showed alternative polyadenylation sites and 15,521 long noncoding RNAs. Further, 1,235, 962, and 213 differentially expressed genes (DEGs) were identified in the intestine, muscle, and brain tissues, respectively. We performed functional enrichment analyses of DEGs, and they were identified to be significantly enriched in nutrient metabolism and immune function. The expression levels of several genes encoding apolipoproteins and activities of enzymes involved in carbohydrate enzymolysis were found to be upregulated in the high stocking density group, indicating that lipid metabolism and carbohydrate decomposition were accelerated. Besides, four isoforms of grass carp major histocompatibility complex class II antigen alpha and beta chains in the aforementioned three tissue was showed at least a 4-fold decrease. CONCLUSIONS: The results suggesting that fish farmed at high stocking densities face issues associated with the metabolism and immune system. To conclude, our results emphasize the importance of maintaining reasonable density in grass carp aquaculture.

Self-management of Diabetes for Empty Nest Older Adults: A Randomized Controlled Trial.

BACKGROUND: Despite much evidence showing the effectiveness of structured self-management education for diabetes, poor glycemic control remains a challenge among empty nest older adults. OBJECTIVE: We explored the effect of a health education intervention based on the PRECEDE-PROCEED model on the self-management of empty nest older adults with type 2 diabetes in Lanzhou, China. METHODS: We conducted a 2-armed, randomized controlled trial using a multistage sampling method. A total of 100 patients were randomly assigned to receive either community nurse-led diabetes education based on the PRECEDE-PROCEED model or general community diabetes education. Self-management scores and blood glucose were compared at baseline and at 3 and 6 months after the intervention. RESULTS: Analyses were conducted on the 98 patients completing follow-up. In the experimental group, diabetes self-management knowledge (t = 7.578, P < .001), self-management attitude (t = 9.155, P < .001), self-management behavior (t = 7.809, P < .001), and overall self-management scores (t = 7.626, P < .001) improved, with hemoglobin A1c (t = -2.825, P = .006), fasting plasma glucose (t = -3.100, P = .003), 2-hour postprandial blood glucose (t = -3.812, P < .001), and diastolic blood pressure (t = -2.104, P = .038) decreasing compared with the control group at 6 months postintervention. CONCLUSIONS: This study demonstrated that education based on the PRECEDE-PROCEED model was more effective than general health education in improving diabetes self-management and glycemic control among empty nest older adults.

Cryoprotectants protect medaka (Oryzias latipes) embryos from chilling injury.

This study was conducted to investigate the effect of six cryoprotectants (dimethyl sulfoxide (DMSO), glycerol (Gly), methanol (MeOH), ethylene glycol (EG), 1,2-propylene glycol (PG) and N,N-dimethylformamide (DMF) on the survival of medaka (Oryzias lapites) embryos at low temperatures (0 and -5C). Firstly, the embryos at 8 to 16-cell stages were exposed to different concentrations (1 to 4 mol per L) of DMSO, Gly, MeOH, EG, PG and DMF for 40min at 26C. After removal of the cryoprotectants (CPAs), the embryo survivals were assessed by their development into live fries following 9 day of culture. The results showed that the higher concentration of the CPA, the lower survival of the embryos; and that the toxicity of the six CPAs to medaka embryos is in the order of PG < MeOH = DMSO < Gly < EG < DMF (P < 0.05). Secondly, based on the results obtained above, embryos at 8 to 16-cell stages or other stages were exposed to 2 mol per L of PG, MeOH or DMSO for up to 180 min at 0C and up to 80 min at -5C respectively. The 8 to 16-cell embryos treated with MeOH at low temperatures showed highest survival. Thirdly, when embryos at different stages were treated with 2 mol per L of MeOH at -5C for 60 min, 16-somite stage embryos showed highest survival, followed by 4-somite, neurula, 50 percent epiboly, blastula, 32-cell and 8 to 16-cell embryos. These results demonstrated that PG had the lowest toxicity to medaka embryos among the six permeable CPAs at 26C, whereas MeOH showed highest cryoprotective efficiency under chilling conditions and chilling injury decreased gradually with the development of medaka embryos.

The effects of exposure to microplastics on grass carp (Ctenopharyngodon idella) at the physiological, biochemical, and transcriptomic levels.

Microplastics (MPs) are pollutants that are widely distributed in the aquatic environment. Fish are directly exposed to water and are at risk of ingesting a large amount of MPs. In the present study, the grass carp were exposed to two concentrations of MPs (1000 and 100 µg/L) and fluorescence signals were detected in the liver digestion solution. Grass carp exposed to MPs for 21-days showed liver cytoplasmic vacuolation and inhibited growth. At the end of the exposure period, the fish treated with MPs exhibited inhibition of the antioxidant system and enhancement oxidative stress in comparison with the control group. The transcriptome analysis of grass carp was then performed to reveal the molecular mechanism of the response to MPs. In total, 1554 differentially expressed genes (DEGs) were identified. The results of GO and KEGG pathway analysis of the DEGs identified energy metabolism-related pathways and peroxisome proliferator-activated receptor (PPAR) signaling pathway. Taken together, the present study not only highlighted oxidative stress and metabolism disorders related to MP ingestion, but also determined the risk of MP exposure to teleost.

Bioaugmentation with Diaphorobacter polyhydroxybutyrativorans to enhance nitrate removal in a poly (3-hydroxybutyrate-co-3-hydroxyvalerate)-supported denitrification reactor.

A newly isolated and identified Diaphorobacter polyhydroxybutyrativorans strain (SL-205) was employed to enhance the denitrification performance of a laboratory-scale solid-phase denitrification (SPD) reactor using poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) as a carbon source, and dynamic variations in microbial communities in the reactor were investigated. Results indicated that bioaugmentation with strain SL-205 enabled rapid reactor startup and improved denitrification performance relative to the reactor inoculated with activated sludge. Illumina sequencing revealed that bioaugmentation also significantly increased Proteobacteria abundance along with increased influent nitrate loading. Additionally, two genera of PHBV-degrading denitrifers, Diaphorobacter and Acidovorax, exhibited higher abundance, and elevated expression of denitrification-associated genes (narG, nirK, and nirS) was observed following bioaugmentation relative to the control at influent nitrate loading ranging from 1.28 g N/(L·d) to 1.6 g N/(L·d).

Determination of the Role of Microcystis aeruginosa in Toxin Generation Based on Phosphoproteomic Profiles.

Microcystis aeruginosa is the most common species responsible for toxic cyanobacterial blooms and is considered a significant contributor to the production of cyanotoxins, particularly the potent liver toxins called microcystins. Numerous studies investigating Microcystis spp. blooms have revealed their deleterious effects in freshwater environments. However, the available knowledge regarding the global phosphoproteomics of M. aeruginosa and their regulatory roles in toxin generation is limited. In this study, we conducted comparative phosphoproteomic profiling of non-toxic and toxin-producing strains of M. aeruginosa. We identified 59 phosphorylation sites in 37 proteins in a non-toxic strain and 26 phosphorylation sites in 18 proteins in a toxin-producing strain. The analysis of protein phosphorylation abundances and functions in redox homeostasis, energy metabolism, light absorption and photosynthesis showed marked differences between the non-toxic and toxin-producing strains of M. aeruginosa, indicating that these processes are strongly related to toxin generation. Moreover, the protein-protein interaction results indicated that BJ0JVG8 can directly interact with the PemK-like toxin protein B0JQN8. Thus, the phosphorylation of B0JQN8 appears to be associated with the regulatory roles of toxins in physiological activity.

[Spatiotemporal variation patterns of water quality of Taoranting Lake, Beijing of China].

By the methods of cluster analysis, discriminant analysis, and factor analysis, this paper studied the spatiotemporal variations of water quality of Taoranting Lake, a typical eutrophic urban landscape lake in Beijing, from March to November 2011. At temporal scale, the water quality of the Lake could be grouped into three periods which corresponded to the rainy season, normal season, and dry season in Beijing, respectively, reflecting an obvious temporal variation. At spatial scale, the water quality of the Lake at five sampling sites could be grouped into two groups, implying the different pollution degree. Water temperature, pH, transparency (SD), CODMn, total suspended solid (TSS) , and Chl-a content were the main factors affecting the temporal variation of the water quality, and the eutrophication of the water body was mainly controlled by the water temperature and Chl-a, total nitrogen, and total phosphorous contents. The effects of TSS and organic pollution should be also paid more attention.

OPS vitrification of mouse immature oocytes before or after meiosis: the effect on cumulus cells maintenance and subsequent development.

Cryopreservation can cause cumulus cell damage around the immature oocytes, which may result in poor subsequent development. To evaluate the effect of the meiosis stage on the cumulus cell cryoinjury and determine the suitable stage for cryopreservation in immature oocytes, mouse oocytes at germinal vesicle (GV) and germinal vesicle breakdown (GVBD) stages were vitrified using open pulled straw (OPS) method. Cumulus cells damage was scored immediately after thawing by double-fluorescent staining. The survival rate of the oocytes was evaluated and the subsequent development of oocytes was assessed through in vitro culture (IVC) and in vitro fertilization (IVF) separately. After vitrification, a higher proportion of cumulus cells of GV oocytes were damaged than those of GVBD and untreated control groups. The survival rate of vitrified GVBD oocytes (94.1%) was significantly higher (p < 0.05) than that of GV oocytes (85.4%). Oocytes vitrified at GVBD stage (55.7%) showed similar cleavage rate compared to those at GV stage (49.2%), but significantly higher (p < 0.05) blastocyst rate (40.9% vs. 27.4%). These results demonstrate that oocytes at GVBD stage remain better cumulus membrane integrity and developmental ability during vitrification than those at GV stage, indicating they are more suitable for immature oocytes cryopreservation in mice.

[Relationships between copepods and Eriocheir sinensis larvae in ecological breeding ponds].

The study on the relationships between two copepod species Eurytemor affinis and Sinocalanus tenellus and Chinese mitten crab Eriocheir sinensis larvae in the ecological breeding ponds of E. sinensis larvae in Liaohe Delta district of Panjing City, Liaoning Province showed that E. affinis and S. tenellus had significant effects on the survival rate of first stage zoae (Z1). The higher the density of the two copepod species, the lower the survival rate of Z, was (P < 0.01). Third stage zoae (Z3) could prey on the copepods nauplii, and the feeding amount was increased with the increasing density of the nauplii (P < 0.01). Fifth stage zoae (Z5) and megalopae could easily prey on E. affinis, but not on S. tenellus. The megalopae yield in the ecological breeding ponds was negatively correlated with the quantity of the copepods during early breeding stage of E. sinensis larvae, and there was a significant difference among the megalopae yields when different quantity of copepods existed (P < 0.01). Some measures for controlling and utilizing the copepods in ecological breeding ponds of E. sinensis larvae were put forward.