Structures and Dynamics of ß-Rich Oligomers of ATTR (105-115) Assembly.

Transthyretin (TTR) is a tetrameric homologous protein that can dissociate into monomers. Misfolding and aggregation of TTR can lead to amyloid transthyretin amyloidosis (ATTR), which can cause many diseases (e.g., senile systemic amyloidosis, familial amyloid cardiomyopathy, and familial amyloid polyneuropathy). Despite growing evidence indicating that small oligomers play a critical role in regulating cytotoxicity, the structures of these oligomeric intermediates and their conformational transformations are still unclear, impeding our understanding of neurodegenerative mechanisms and the development of therapeutics targeting early aggregation species. The TTR monomer protein consists of various fragments prone to self-aggregation, including the residue 105-115 sequence. Therefore, our study investigated the assembly progress of ATTR (105-115) peptides using all-atom molecular dynamics simulations. The findings indicate that the probability of ß-sheet content increases with increasing numbers of peptides. Additionally, interactions between hydrophobic residues L110 and L111 are crucial for the formation of a ß-rich oligomer formation. These ß-rich oligomers may adopt ß-barrel conformations, potentially toxic oligomer species. Free-energy analysis reveals that ß-barrel conformations serve as intermediates for these ß-rich oligomers. Our insights into the structural ensemble dynamics of ATTR (105-115) contribute to understanding the physical mechanisms underlying the ß-barrel oligomers of ATTR. These findings may shed light on the pathological role of ATTR in neurodegenerative diseases and offer potential therapeutic targets.

AI-based Virtual Screening of Traditional Chinese Medicine and the Discovery of Novel Inhibitors of TCTP.

BACKGROUND: Translationally controlled tumour protein (TCTP) is associated with tumor diseases, such as breast cancer, and its inhibitor can reduce the growth of tumor cells. Unfortunately, there is currently no effective medication available for treating TCTP-related breast cancer. OBJECTIVE: The objective of this study was to explore the inhibitor candidates among natural compounds for the treatment of breast cancer related to TCTP protein. METHODS: To explore the potential inhibitors of TCTP, we first screened out four potential inhibitors in the Traditional Chinese Medicine (TCM) for cancer based on AI virtual screening using the docking method, and then revealed the interaction mechanism of TCTP and four candidate inhibitors from TCM with molecular docking and molecular dynamics (MD) methods. RESULTS: Based on the conformational characteristics and the MD properties of the four leading compounds, we designed the new skeleton molecules with the AI method using MolAICal software. Our MD simulations have revealed that different small molecules bind to different sites of TCTP, but the flexible regions and the signaling pathways are almost the same, and the VDW and hydrophobic interactions are crucial in the interactions between TCTP and ligands. CONCLUSION: We have proposed the candidate inhibitor of TCTP. Our study has provided a potential new method for exploring inhibitors from Traditional Chinese Medicine (TCM).

Propofol decreases cisplatin resistance of non-small cell lung cancer by inducing GPX4-mediated ferroptosis through the miR-744-5p/miR-615-3p axis.

Non-small cell lung cancer (NSCLC) is associated with high morbidity and mortality. Propofol functions as a tumor-inhibitor drug by regulating microRNAs (miRNAs). The primary objective of this study is to explore the functional mechanism of propofol in cisplatin (Cis) resistance of NSCLC cells by regulating the miR-744-5p/miR-615-3p axis. Cis-resistant NSCLC cell lines were cultured and chemotherapy-resistance (CR) to Cis of NSCLC cells to Cis was confirmed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method, flow cytometry, and colony formation assay. Ferroptosis was evaluated by measurement of iron content, ferroptosis-related proteins (GPX4/ ACSL4/SLC7A11) and lipid peroxidation (SOD/GSH/MDA) through Western blot analysis and assay kits. After the dual-luciferase reporter assay to testify gene interactions, the functional rescue experiments and nude mouse tumor formation assay were performed. Based on results, propofol reduced IC50 value and CR of NSCLC cells to Cis and induced ferroptosis. Propofol upregulated miR-744-5p/miR-615-3p to inhibit GPX4 transcription. Upregulation of GPX4 or downregulation of miR-744-5p/miR-615-3p attenuated the inhibitory effect of propofol on CR to Cis. In vivo, propofol inhibited tumor growth and CR to Cis by upregulating miR-744-5p/miR-615-3p and inhibiting GPX4 to induce ferroptosis. In summary, propofol inhibited GPX4-mediated ferroptosis and reduces CR of NSCLC cells to Cis through the miR-744-5p/miR-615-3p axis. SIGNIFICANCE: To study the effect of propofol on chemoresistance of non-small cell lung cancer (NSCLC), and to provide a new theoretical basis for the treatment of NSCLC.

Lymphocyte trajectories are associated with prognosis in critically ill patients: A convenient way to monitor immune status.

Background: Immunosuppression is a risk factor for poor prognosis of critically ill patients, but current monitoring of the immune status in clinical practice is still inadequate. Absolute lymphocyte count (ALC) is not only a convenient biomarker for immune status monitoring but is also suitable for clinical application. In this study, we aimed to explore different trajectories of ALC, and evaluate their relationship with prognosis in critically ill patients. Methods: We retrospectively enrolled 10,619 critically ill patients admitted to a general intensive care unit (ICU) with 56 beds from February 2016 to May 2020. Dynamic ALC was defined as continuous ALC from before ICU admission to 5 days after ICU admission. Initial ALC was defined as the minimum ALC within 48 h after ICU admission. Group-based trajectory modeling (GBTM) was used to group critically ill patients according to dynamic ALC. Multivariate cox regression model was used to determine the independent association of trajectory endotypes with death and persistent inflammation, immunosuppression, catabolism syndrome (PICS). Results: A total of 2022 critically ill patients were unsupervisedly divided into four endotypes based on dynamic ALC, including persistent lymphopenia endotype (n = 1,211; 58.5%), slowly rising endotype (n = 443; 22.6%), rapidly decreasing endotype (n = 281; 14.5%) and normal fluctuation endotype (n = 87; 4.4%). Among the four trajectory endotypes, the persistent lymphopenia endotype had the highest incidence of PICS (24.9%), hospital mortality (14.5%) and 28-day mortality (10.8%). In multivariate cox regression model, persistent lymphopenia was associated with increased risk of 28-day mortality (HR: 1.54; 95% CI: 1.06-2.23), hospital mortality (HR: 1.66; 95% CI: 1.20-2.29) and PICS (HR: 1.79; 95% CI: 1.09-2.94), respectively. Sensitivity analysis further confirmed that the ALC trajectory model of non-infected patients and non-elderly patients can accurately distinguished 91 and 90% of critically ill patients into the same endotypes as the original model, respectively. Conclusion: The ALC trajectory model is helpful for grouping critically ill patients, and early persistent lymphopenia is associated with poor prognosis. Notably, persistent lymphopenia may be a robust signal of immunosuppression in critically ill patients.

Microbiota Comparison of Amur ide (Leuciscus waleckii) Intestine and Waters at Alkaline Water and Freshwater as the Living Environment.

The intestinal microbiota of marine animals was influenced by the water and environment in which they live. The Amur ide (Leuciscus waleckii) adapts to extremely high alkalinity and is an ideal material for aquacultural studies of alkaline adaptation. In this study, we screened intestinal indicator flora and functional redundancy of intestinal colonies in alkaline-water species (AW) and freshwater species (FW) of Amur ide (L. waleckii) in these different aquatic environments. The available vs. community composition correlations were then predicted by contrasting each other with the flora contained in environmental water samples. Here, five microbial species and six genera were identified owing to the classifiable sequence. The intestinal microbiota that existed in AW and FW had approximately 1/3 of the operational taxonomic units in the respective living water environments, meaning gut microbes in the aqueous habitats will have an influential association with gut microbes in AW and FW. Compared to the bacterial composition of the FW intestine and that present in freshwater, Moraxella osloensis, Psychrobacter maritimus, and Psychrobacter faecalis were significantly enriched in the intestine of AW and alkaline water samples. In the FW intestine and freshwater samples, however, Cryptomonas curvata and Polynucleobacter asymbioticus were highly improved, which can be summarized as Enterobacter sp., the predominant population in the AW gut, while Aeromonas and Ralstonia being primarily present in FW intestines. Photosynthetic bacteria were most significant in both water samples. The results indicated that the intestinal microbiota composition, abundance, and diversity of AW and FW were quite different. In contrast, the microbial composition of the additional alkaline water and freshwater environments showed slight differences. This study expects to enhance our understanding of the alkalinity tolerance of L. waleckii, which will be provided for the breeding of fish living in alkaline water, and push the development of alkaline water resources with increased efficiency.

Histology, physiology, and glucose and lipid metabolism of Lateolabrax maculatus under low temperature stress.

Spotted sea bass (Lateolabrax maculatus) is a popular and important commercial fish throughout the world, but it is unknown whether introducing domesticated fish to locations that experience cold weather might alter physiological performance. In this study, we evaluated the behavior, fatty acid content, histological analysis of liver and gills, liver enzymatic activity in carbohydrate and lipid metabolism, and gene expression in liver related to carbohydrate and lipid metabolism of spotted sea bass acclimatized at 22 °C (control), 16 °C, 10 °C, 8 °C, and 4 °C for 24 h, and 8 °C for 4 days. When L. maculatus was exposed to acute cold stress for 24 h, the gill showed curling, lamellar disorganization, lamellar epithelium hyperplasia, and formed aneurysms inside of the secondary lamellae. Long term stress over four days resulted in severe lamellar epithelium hyperplasia and curling. Continued extreme cold exposure (4 °C) in L. maculatus caused liver HK, PK levels and LDH activities to achieve a peak value at 0 h, and decreased over time. These indicated that glucose metabolism might play critical roles in the initial time of stress. Results of carbohydrate and lipid metabolism showed that lipids appear to play roles in prolonged cold stress. The constitutive transcriptional levels of six genes related to glucose (G6Pase) and lipid metabolism (PPAR-α, PPAR-γ) and mTOR signal pathway (eif4ebp1, eif4ebp2, mlst8) genes increased significantly in most groups during cold stress.

HMGB1-Mediated Neutrophil Extracellular Trap Formation Exacerbates Intestinal Ischemia/Reperfusion-Induced Acute Lung Injury.

Influx of activated neutrophils into the lungs is the histopathologic hallmark of acute lung injury (ALI) after intestinal ischemia/reperfusion (I/R). Neutrophils can release DNA and granular proteins to form cytotoxic neutrophil extracellular traps (NETs), which promotes bystander tissue injury. However, whether NETs are responsible for the remote ALI after intestinal I/R and the mechanisms underlying the dissemination of harmful gut-derived mediators to the lungs are unknown. In the C57BL/6J mouse intestinal I/R model, DNase I-mediated degradation and protein arginine deiminase 4 (PAD4) inhibitor-mediated inhibition of NET treatments reduced NET formation, tissue inflammation, and pathological injury in the lung. High-mobility group protein B1 (HMGB1) blocking prevented NET formation and protected against tissue inflammation, as well as reduced cell apoptosis and improved survival rate. Moreover, recombinant human HMGB1 administration further drives NETs and concurrent tissue toxic injury, which in turn can be reversed by neutrophil deletion via anti-Ly6G Ab i.p. injection. Furthermore, global MyD88 deficiency regulated NET formation and alleviated the development of ALI induced by intestinal I/R. Thus, HMGB1 released from necroptotic enterocytes caused ALI after intestinal I/R by inducing NET formation. Targeting NETosis and the HMGB1 pathway might extend effective therapeutic strategies to minimize intestinal I/R-induced ALI.

HCP5 contributes to cisplatin resistance in gastric cancer through miR-128/HMGA2 axis.

The long non-coding RNA HLA complex P5 (HCP5) is extensively related to cancer chemoresistance, while its function in gastric cancer (GC) has not been well elucidated yet. Here, the role and mechanism of HCP5 in regulating the chemoresistance of GC to cisplatin (DDP) was investigated. Our results revealed that HCP5 was increased in GC patients and indicated a poor prognosis. HCP5 knockdown weakens DDP resistance and reduced apoptosis of GC cells. miR-128 was decreased in GC patients and sponged by HCP5. HMGA2 was targeted by miR-128 and was increased in GC patients. HCP5 aggravated the resistance of GC cells to DDP in vitro by elevating HMGA2 expression via sponging miR-128. HCP5 silencing inhibited GC cells growth, resistance to DDP, and Ki-67 expression in vivo. In summary, HCP5 contributed to DDP resistance in GC cells through miR-128/HMGA2 axis, providing a promising therapeutic target for GC chemoresistance.

Resequencing and SNP discovery of Amur ide (Leuciscus waleckii) provides insights into local adaptations to extreme environments.

Amur ide (Leuciscus waleckii), a Cyprinid species, is broadly distributed in Northeast Asia. Different from its freshwater counterparts, the population in Lake Dali Nor has a strong alkalinity tolerance and can adapt to extremely alkali-saline water with bicarbonate over 50 mmol/L. To uncover the genetic basis of its alkaline adaptation, three populations, including one alkali form from Lake Dali Nor (DL), one freshwater form from its adjacent sister Lake Ganggeng Nor (GG), and one freshwater form from its historical origin, namely, the Songhua River (SH), were analyzed using genome resequencing technology. A total of 679.82 Gb clean data and 38,091,163 high-quality single-nucleotide polymorphism (SNP) loci were detected in the three populations. Nucleotide diversity and population structure analysis revealed that the DL and GG populations have lower nucleotide diversities and different genetic structures than those of the SH population. Selective sweeping showed 21 genes involved in osmoregulatory regulation (DLG1, VIPR1, AKT1, and GNAI1), inflammation and immune responses (DLG1, BRINP1, CTSL, TRAF6, AKT1, STAT3, GNAI1, SEC22b, and PSME4b), and cardiorespiratory development (TRAF6, PSME4b, STAT3, AKT1, and COL9A1) to be associated with alkaline adaption of the DL population. Interestingly, selective pressure (CodeML, MEME, and FEL) methods identified two functional codon sites of VIPR1 to be under positive selection in the DL population. The subsequent 3D protein modeling confirmed that these selected sites will incur changes in protein structure and function in the DL population. In brief, this study provides molecular evidence of population divergence and alkaline adaptation, which will be very useful for revealing the genetic basis of alkaline adaptation in Amur ide.

High environmental temperature and low pH stress alter the gill phenotypic plasticity of Hoven's carp Leptobarbus hoevenii.

Climate warming and low pH environment are known to negatively impact all levels of aquatic organism from cellular to organism and population levels. For ammonotelic freshwater species, any abiotic factor fluctuation will cause disturbance to the fish, specifically at the gills which act as a multifunctional organ to support all biological processes. Therefore, this study was designed to investigate the effect of temperature (28 vs. 32°C) and pH (7.0 vs. 5.0) stress on the gill plasticity of Hoven's carp after 20 days of continuous exposure. The results demonstrated that high temperature and low pH caused severe changes on the primary and secondary lamellae as well as the cells within lamellae. An increasing trend of the proportion available for gas exchange was noticed at high temperature in both pH exposures, which resulted from a reduction of the primary lamellae width with elongated and thinner secondary lamellae compared to fishes at ambient temperature. Following exposure to high temperature and acidic pH, Hoven's carp experienced gill modifications including aneurysm, oedema, hypertrophy, curling of secondary lamellae, epithelial lifting, hyperplasia and lamellae fusion. These modifications are indicators of the coping mechanism of Hoven's carp to the changing environment in order to survive.

P-Selectin-Based Dual-Model Nanoprobe Used for the Specific and Rapid Visualization of Early Detection toward Severe Acute Pancreatitis in Vivo.

Identifying severe acute pancreatitis (SAP) as soon as possible is critical for achieving optimal outcomes and saving lives. In this study, a novel P-selectin-targeted, NIR fluorescent dye (Cy 5.5)-labeled dual-modal nanoprobe based on diethylenetriaminepentaacetic chelates (Gd-DTPA-Cy5.5-PsLmAb) was constructed for the bimodal imaging of SAP at the early stage. Gd-DTPA-Cy5.5-PsLmAb was prepared, and its structure was characterized by Fourier transform infrared spectroscopy, UV-vis spectroscopy, and fluorescence spectroscopy, and its stability was evaluated. Biocompatibility was evaluated by the hemolysis and cytotoxicity assays. The enzyme-linked immunosorbent assay was used to detect and evaluate the expression of P-selectin in the peripheral blood of 11 patients with acute pancreatitis (AP) and 5 healthy volunteers. The bimodal imaging ability of Gd-DTPA-Cy5.5-PsLmAb nanoprobes was evaluated via near-infrared fluorescence (NIRF) and magnetic resonance imaging (MRI) in AP animal models in vivo. Gd-DTPA-Cy5.5-PsLmAb showed low toxicity to human embryonic kidney cells (293T cells) and good blood compatibility. The P-selectin levels of humans and rats in the mild acute pancreatitis (MAP)/SAP stage were significantly higher than those in the control group and reached the highest level at the SAP stage. Furthermore, Gd-DTPA-Cy5.5-PsLmAb nanoprobes showed clear NIRF imaging of mouse pancreas at the MAP stage and SAP stage by a fluorescence signal at 6.09 × 108 and 1.95 × 109, respectively. Meanwhile, Gd-DTPA-Cy5.5-PsLmAb nanoprobes also successfully showed the T1-weighted MR signal of rat pancreas at the MAP stage, but Gd-DTPA seldom showed any signal increase at the MAP stage; Gd-DTPA-Cy5.5-PsLmAb and Gd-DTPA could show an increasing MR signal of rat pancreas at the SAP stage. Gd-DTPA-Cy5.5-PsLmAb proved to offer a stronger signal than Gd-DTPA.Our findings indicate that Gd-DTPA-Cy5.5-PsLmAb is an effective and specific MR/NIRF dual nanoprobe for bimodal imaging, providing a promising diagnostic approach for early SAP in clinic.

Is neuron-specific enolase useful for diagnosing malignant pleural effusions? evidence from a validation study and meta-analysis.

BACKGROUND: Neuron-Specific enolase (NSE) has been used as a typical tumor marker and shows a potential to diagnose malignant pleural effusion (MPE). The ability of NSE in diagnosing MPE has been investigated in many studies, but with inconsistent conclusions. This study sought to investigate the diagnostic accuracy of NSE for MPE through a clinical study and together with a meta-analysis. METHODS: Pleural effusion samples from 136 patients with MPE and 102 patients with benign pleural effusion (BPE) were collected, and NSE levels were measured by electrochemiluminescence immunoassay. Receiver operating characteristic (ROC) curve analysis was performed to assess the ability of NSE to differentiate MPE from BPE. Literature search was conducted to identify suitable publications, data were extracted and diagnostic indexes including sensitivity, specificity, positive/negative likelihood ratio (PLR/NLR), and diagnostic odds ratio (DOR) were pooled. Summary ROC curve was generated to determine the overall diagnostic accuracy of NSE for MPE. RESULTS: Levels of NSE were significantly increased in pleural effusion from patients with MPE than that from BPE (18.53 ± 27.30 vs. 6.41 ± 6.95 ng/ml, p < 0.001). With a cut-off value of 8.92 ng/ml, pleural NSE had a sensitivity of 59.56% and a specificity of 83.33% in diagnosing MPE. A total of 14 studies with 1896 subjects were included for meta-analysis. The diagnostic parameters of NSE were listed as follows: sensitivity, 0.53 (95% CI: 0.38-0.67); specificity, 0.85 (95% CI: 0.75-0.91); PLR, 3.54 (95% CI: 2.33-5.39); NLR, 0.56 (95% CI: 0.42-0.73); and DOR, 6.39 (95% CI: 3.72-10.96). The area under the summary ROC curve was 0.78. CONCLUSIONS: The role of pleural NSE measurement in diagnosing MPE is limited and with a low sensitivity. The clinical utility of NSE assay should be combined with the results of other tumor markers examination and the detail clinical information of patient. Further studies are needed to confirm the role of NSE in diagnosing MPE.

Diagnostic value of tumor markers for lung adenocarcinoma-associated malignant pleural effusion: a validation study and meta-analysis.

BACKGROUND: Pleural effusion is one of the most common complications of lung adenocarcinoma and is diagnostically challenging. This study aimed to investigate the diagnostic performance of carcinoembryonic antigen (CEA), cytokeratin fragment (CYFRA) 21-1, and cancer antigen (CA) 19-9 for lung adenocarcinoma-associated malignant pleural effusion (MPE) through a validation study and meta-analysis. METHODS: Pleural effusion samples were collected from 81 lung adenocarcinoma-associated MPEs and 96 benign pleural effusions. CEA, CYFRA 21-1, and CA19-9 were measured by electrochemiluminescence immunoassay. The capacity of tumor markers was assessed with receiver operating characteristic curve analyses and the area under the curve (AUC) was calculated. Standard methods for meta-analysis of diagnostic studies were used to summarize the diagnostic performance of CEA, CYFRA 21-1, and CA19-9 for lung adenocarcinoma-associated MPE. RESULTS: The pleural levels of CEA, CYFRA 21-1, and CA19-9 were significantly increased in lung adenocarcinoma-associated MPE compared to benign pleural effusion. The cut-off points for CEA, CYFRA 21-1, and CA19-9 were optimally set at 4.55 ng/ml, 43.10 µg/ml, and 12.89 U/ml, and corresponding AUCs were 0.93, 0.85, and 0.81, respectively. The combination of CEA, CYFRA 21-1, and CA19-9 increased the sensitivity to 95.06%, with an AUC of 0.95. Eight studies were included in this meta-analysis. CEA showed the best diagnostic performance with pooled sensitivity, specificity, positive/negative likelihood ratio, and diagnostic odds ratio of 0.75, 0.96, 16.01, 0.23, and 81.49, respectively. The AUC was 0.93. CONCLUSIONS: CEA, CYFRA 21-1, and CA19-9 play a role in the diagnosis of lung adenocarcinoma-associated MPE. The combination of these tumor markers increases the diagnostic accuracy.

Transcriptome Analysis to Identify Cold-Responsive Genes in Amur Carp (Cyprinus carpio haematopterus).

The adaptation of fish to low temperatures is the result of long-term evolution. Amur carp (Cyprinus carpio haematopterus) survives low temperatures (0-4°C) for six months per year. Therefore, we chose this fish as a model organism to study the mechanisms of cold-adaptive responses using high-throughput sequencing technology. This system provided an excellent model for exploring the relationship between evolutionary genomic changes and environmental adaptations. The Amur carp transcriptome was sequenced using the Illumina platform and was assembled into 163,121 cDNA contigs, with an average read length of 594 bp and an N50 length of 913 bp. A total of 162,339 coding sequences (CDSs) were identified and of 32,730 unique CDSs were annotated. Gene Ontology (GO), EuKaryotic Orthologous Groups (KOG) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to classify all CDSs into different functional categories. A large number of cold-responsive genes were detected in different tissues at different temperatures. A total of 9,427 microsatellites were identified and classified, with 1952 identifying in cold-responsive genes. Based on GO enrichment analysis of the cold-induced genes, "protein localization" and "protein transport" were the most highly represented biological processes. "Circadian rhythm," "protein processing in endoplasmic reticulum," "endocytosis," "insulin signaling pathway," and "lysosome" were the most highly enriched pathways for the genes induced by cold stress. Our data greatly contribute to the common carp (C. carpio) transcriptome resource, and the identification of cold-responsive genes in different tissues at different temperatures will aid in deciphering the genetic basis of ecological and environmental adaptations in this species. Based on our results, the Amur carp has evolved special strategies to survive low temperatures, and these strategies include the system-wide or tissue-specific induction of gene expression during their six-month overwintering period.

Transcriptome and expression profiling analysis of Leuciscus waleckii: an exploration of the alkali-adapted mechanisms of a freshwater teleost.

The strategies by which freshwater teleosts maintain acid-base homeostasis under alkaline stress are attractive and have been explored for a long time. In this study, a cyprinid fish that tolerates extremely alkaline environments (pH 9.6), Leuciscus waleckii, was used as a model to explore the molecular mechanisms of acid-base regulation. Using a lab-controlled alkaline challenge test and 454 sequencing, the transcriptomes of their gills and kidney were profiled and compared. mRNA profiling produced 1 826 022 reads, generated 30 606 contigs with an average length of 1022 bp, of which 19 196 were annotated successfully. Comparative analysis of the expression profiles between alkaline and freshwater L. waleckii habitats revealed approximately 4647 and 7184 genes that were differentially expressed (p < 0.05) in gills and kidney, respectively, of which 2398 and 5127 had more than twofold changes in expression. Gene ontology analysis and KEGG enrichment analysis were conducted. Comprehensive analysis found that genes involved in ion transportation, ammonia transportation, and arachidonic acid metabolism pathways changed dramatically and played important roles in acid-base homeostasis in fish under alkaline stress. These results support the existing hypotheses about candidate genes involved in acid-base regulation under alkaline stress and prompt several new hypotheses. The large transcriptome dataset collected in this study is a useful resource for the exploration of homeostasis modulation in other fish species.

Genetic analysis of population differentiation and adaptation in Leuciscus waleckii.

Demographic events and natural selection both influence animal phenotypic and genetic variation; exploring the effects of demography and selection on population divergence is of great significance in evolutionary biology. To uncover the causes behind the patterns of genetic differentiation and adaptation among six populations of Leuciscus waleckii from Dali Basin (two populations, alkaline vs. freshwater) and Amur Basin (four populations, freshwater rivers vs. alkaline lake), a set of 21 unlinked polymorphic microsatellite markers and two mitochondrial DNA sequences (Cytb and D-loop) were applied to examine whether populations from different environments or habitats have distinct genetic differentiation and whether alkalinity is the major factor that caused population divergence. Bayesian analysis and principal component analysis as well as haplotype network analysis showed that these populations are primarily divided into two groups, which are congruent with geographic separation but not inconsistent with the habitat environment (alkalinity). Using three different approaches, outlier detection indicated that one locus, HLJYL017, may be under directional selection and involved in local adaptation processes. Overall, this study suggested that demographic events and selection of local environmental conditions including of alkalinity are jointly responsible for population divergence. These findings constitute an important step towards the understanding of the genetic basis of differentiation and adaptation, as well as towards the conservation of L. waleckii.

The complete mitochondrial genome of the crucian carp, Carassius carassius (Cypriniformes, Cyprinidae).

The complete mitochondrial genome of Carassius carassius was determined to be 16,597 bp long circular molecule with a typical gene arrangement of vertebrate mitochondrial DNA. Its control region contains two copies of unit (TTCYCAATATAA) at 3' ends, which has never been reported before for Carassius species. Phylogenetic trees based on 12 protein-coding genes on heavy strand confirmed that the complete mtDNA sequence of crucian carp was reported in this study for the first time.

[Correlation and path analyses of phenotypic traits and body mass of transgenic carp with growth hormone gene of salmon].

Thirty 2-year old transgenic carp individuals with growth hormone gene of salmon were randomly selected to study the affecting degree of their phenotypic traits on their body mass by the methods of correlation and path analyses, with 30 individuals of non-transgenic carp as the control, aimed to ascertain the main phenotypic parameters affecting the body mass of the transgenic and non-transgenic carps. The test phenotypic traits were total length, body length, body height, least height of caudal peduncle, length of caudal peduncle, length of head, snout length, eyes horizontal diameter, inter-orbital distance, and body depth. Correlation analysis showed that for both of the transgenic and non-transgenic carps, most of the test phenotypic parameters were significantly correlated to body mass (P<0.01). Path analysis indicated that for transgenic carp, its body length and body height were the main predictable factors affecting body mass, with the path coefficient being 0.572 and 0.415, respectively, while for non-transgenic carp, its body depth and tail length were the main predictable factors affecting body mass, with the path coefficient being 0.610 and 0.377, respectively.

[Screening cold-acclimation differential expression candidate genes in the brain of common carp (Cyprinus carpio)].

In this study, 26 candidate genes were quantified and normalized in the brain cDNA of common carp (Cyprinus carpio) at 23°C and 6°C using double-standard curve method of real-time quantitative PCR. The results showed that five candidates up-regulated in the samples at 6°C (P<0.01) and quantified 2.11, 13.9, 2.52, 7.38, and 1.83 times more than in the samples at 23°C, respectively. Gene function searching indicated that the protein products of these five candidates were elongation of very long chain fatty acids protein, Acyl-CoA desaturase, Transcription initiation factor IIB, Myo-inositol- 1-phosphate synthase, and Blood-brain barrier HT7 antigen individually. Moreover, seven down-regulated candidates were also identified in the same samples at 6°C (P>0.05), and their expression levels were decreased by 21.8%, 25.9%, 16.6%, 23.7%, 15.8%, 16.3%, and 42.5%, respectively, in comparison with the samples at 23°C. These seven down-regulated candidates mainly participated in the inhibition of glycolysis, improvement of cell apoptosis, and intervention of synapse remodeling based on the results of function searching. The five cold-induced genes identified in this study will be used as important elements for fish with cold sensitive through transgenic technology in future.