Hidden hotspots of amphibian biodiversity in China.

Identifying and protecting hotspots of endemism and species richness is crucial for mitigating the global biodiversity crisis. However, our understanding of spatial diversity patterns is far from complete, which severely limits our ability to conserve biodiversity hotspots. Here, we report a comprehensive analysis of amphibian species diversity in China, one of the most species-rich countries on Earth. Our study combines 20 y of field surveys with new molecular analyses of 521 described species and also identifies 100 potential cryptic species. We identify 10 hotspots of amphibian diversity in China, each with exceptional species richness and endemism and with exceptional phylogenetic diversity and phylogenetic endemism (based on a new time-calibrated, species-level phylogeny for Chinese amphibians). These 10 hotspots encompass 59.6% of China's described amphibian species, 49.0% of cryptic species, and 55.6% of species endemic to China. Only four of these 10 hotspots correspond to previously recognized biodiversity hotspots. The six new hotspots include the Nanling Mountains and other mountain ranges in South China. Among the 186 species in the six new hotspots, only 9.7% are well covered by protected areas and most (88.2%) are exposed to high human impacts. Five of the six new hotspots are under very high human pressure and are in urgent need of protection. We also find that patterns of richness in cryptic species are significantly related to those in described species but are not identical.

Comparing the gut microbiota of Sichuan golden monkeys across multiple captive and wild settings: roles of anthropogenic activities and host factors.

BACKGROUND: Captivity and artificial food provision are common conservation strategies for the endangered golden snub-nosed monkey (Rhinopithecus roxellana). Anthropogenic activities have been reported to impact the fitness of R. roxellana by altering their gut microbiota, a crucial indicator of animal health. Nevertheless, the degree of divergence in gut microbiota between different anthropogenically-disturbed (AD) R. roxellana and their counterparts in the wild has yet to be elucidated. Here, we conducted a comparative analysis of the gut microbiota across nine populations of R. roxellana spanning China, which included seven captive populations, one wild population, and another wild population subject to artificial food provision. RESULTS: Both captivity and food provision significantly altered the gut microbiota. AD populations exhibited common variations, such as increased Bacteroidetes and decreased Firmicutes (e.g., Ruminococcus), Actinobacteria (e.g., Parvibacter), Verrucomicrobia (e.g., Akkermansia), and Tenericutes. Additionally, a reduced Firmicutes/Bacteroidetes ratiosuggested diminished capacity for complex carbohydrate degradation in captive individuals. The results of microbial functional prediction suggested that AD populations displayed heightened microbial genes linked to vitamin and amino acid metabolism, alongside decreased genes associated antibiotics biosynthesis (e.g., penicillin, cephalosporin, macrolides, and clavulanic acid) and secondary metabolite degradation (e.g., naphthalene and atrazine). These microbial alterations implied potential disparities in the health status between AD and wild individuals. AD populations exhibited varying degrees of microbial changes compared to the wild group, implying that the extent of these variations might serve as a metric for assessing the health status of AD populations. Furthermore, utilizing the individual information of captive individuals, we identified associations between variations in the gut microbiota of R. roxellana and host age, as well as pedigree. Older individuals exhibited higher microbial diversity, while a closer genetic relatedness reflected a more similar gut microbiota. CONCLUSIONS: Our aim was to assess how anthropogenic activities and host factors influence the gut microbiota of R. roxellana. Anthropogenic activities led to consistent changes in gut microbial diversity and function, while host age and genetic relatedness contributed to interindividual variations in the gut microbiota. These findings may contribute to the establishment of health assessment standards and the optimization of breeding conditions for captive R. roxellana populations.

diseaseGPS: auxiliary diagnostic system for genetic disorders based on genotype and phenotype.

SUMMARY: The next-generation sequencing brought opportunities for the diagnosis of genetic disorders due to its high-throughput capabilities. However, the majority of existing methods were limited to only sequencing candidate variants, and the process of linking these variants to a diagnosis of genetic disorders still required medical professionals to consult databases. Therefore, we introduce diseaseGPS, an integrated platform for the diagnosis of genetic disorders that combines both phenotype and genotype data for analysis. It offers not only a user-friendly GUI web application for those without a programming background but also scripts that can be executed in batch mode for bioinformatics professionals. The genetic and phenotypic data are integrated using the ACMG-Bayes method and a novel phenotypic similarity method, to prioritize the results of genetic disorders. diseaseGPS was evaluated on 6085 cases from Deciphering Developmental Disorders project and 187 cases from Shanghai Children's hospital. The results demonstrated that diseaseGPS performed better than other commonly used methods. AVAILABILITY AND IMPLEMENTATION: diseaseGPS is available to freely accessed at https://diseasegps.sjtu.edu.cn with source code at https://github.com/BioHuangDY/diseaseGPS.

What frog gill resorption brings: loss of function, cell death, and metabolic reorganization.

BACKGROUND: Anuran metamorphosis, which is driven by thyroid hormone (TH)-mediated processes, orchestrates intricate morphological and functional transformations for the transition from aquatic tadpoles to terrestrial life, providing a valuable model for studying organ functionalization, remodeling, and regression. Larva-specific organ regression is one of the most striking phenomena observed during the anuran metamorphic climax. While previous studies extensively analyzed the regression mechanisms of the tail, the molecular processes governing gill resorption remain elusive. RESULTS: We employed Microhyla fissipes as a model, and utilized a comprehensive approach involving histological analysis, transmission electron microscopy, and transcriptomics to unravel gill development and resorption. The pro-metamorphic stages revealed highly developed gill structures, emphasizing their crucial role as the primary respiratory organ for tadpoles. The transcriptomic analysis highlighted the upregulation of genes associated with enhanced respiratory efficiency, such as hemoglobin and mucins. However, as metamorphosis progressed, gill filaments underwent shrinkage, decreases in blood vessel density, and structural changes that signified a decline in respiratory function. The molecular mechanisms driving gill resorption involved the TH pathway-in particular, the upregulation of thyroid hormone receptor (TR) ß, genes associated with the tumor necrosis factor pathway and matrix metalloproteinases. Two distinct pathways orchestrate gill resorption, involving apoptosis directly induced by TH and cell death through the degradation of the extracellular matrix. In addition, metabolic reorganization during metamorphosis is a complex process, with tadpoles adapting their feeding behavior and mobilizing energy storage organs. The gills, which were previously overlooked, have been unveiled as potential energy storage organs that undergo metabolic reorganization. The transcriptomic analysis revealed dynamic changes in metabolism-related genes, indicating decreased protein synthesis and energy production and enhanced substrate transport and metabolism during metamorphic climax. CONCLUSION: This study sheds light on the structural, molecular, and metabolic dynamics during gill development and resorption in M. fissipes. The findings deepen our understanding of the intricate mechanisms governing organ regression and underscore the pivotal role of the gills in facilitating the transition from aquatic to terrestrial habitats.

Additive partitioning of multispecies distributional aggregation of local assemblages.

The distribution of species is not random in space. At the finest-resolution spatial scale, that is, field sampling locations, distributional aggregation level of different species would be determined by various factors, for example spatial autocorrelation or environmental filtering. However, few studies have quantitatively measured the importance of these factors. In this study, inspired by the statistical properties of a Markov transition model, we propose a novel additive framework to partition local multispecies distributional aggregation levels for sequential sampling-derived field biodiversity data. The framework partitions the spatial distributional aggregation of different species into two independent components: regional abundance variability and the local spatial inertia effect. Empirical studies from field amphibian surveys through line-transect sampling in southwestern China (Minya Konka) and central-southern Vietnam showed that local spatial inertia was always the dominant mechanism structuring the local occurrence and distributional aggregation of amphibians in the two regions with a latitudinal gradient from 1200 to nearly 4000 m. However, regional abundance variability is still nonnegligible in highly diverse tropical regions (i.e. Vietnam) where the altitude is not higher than 2000 m. In summary, we propose a novel framework that shows that the multispecies distributional aggregation level can be structured by two additive components. The two partitioned components could be theoretically independent. These findings are expected to deepen our understanding of the local community structure from the perspective of both spatial distribution and regional diversity patterns. The partitioning framework might have potential applications in field ecology and macroecology research.

Positive association between dietary manganese intake and new-onset hypertension: A nationwide cohort study in China.

BACKGROUND AND AIM: To date, few studies have investigated the association between dietary manganese intake and the risk of hypertension, so the prospective relationship of dietary manganese intake and new-onset hypertension remains uncertain. We aimed to investigate the association between dietary manganese intake and the risk of new-onset hypertension in the general Chinese population. METHODS AND RESULTS: This prospective cohort study included 12,177 participants who were free of hypertension at baseline from China Health and Nutrition Survey (CHNS). Dietary intake was measured by 3 consecutive 24-h dietary recalls combined with a household food inventory. The study outcome was new-onset hypertension, defined as systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg or diagnosed by a physician or under antihypertensive treatment during the follow-up. During a median follow-up duration of 6.1 years, 4269 (44.9 per 1000 person-years) participants developed new-onset hypertension. Overall, there was a positive association between dietary manganese intake and new-onset hypertension. The adjusted HRs (95%CIs) of new-onset hypertension were 1.00 (reference), 0.97 (0.87, 1.08), 1.24 (1.10, 1.39) and 1.75 (1.52, 2.01) across the quartiles of dietary manganese intake, respectively. Accordingly, a significantly higher risk of new-onset hypertension (HR, 1.38; 95%CI: 1.27, 1.50) was found in participants in quartiles 3-4 of dietary manganese intake (≥6.0 mg/day), compared with those in quartiles 1-2 (<6.0 mg/day). CONCLUSIONS: In the general Chinese population, dietary manganese intake was positively associated with the risk of new hypertension, independent of sodium intake and other important covariates.

A U-shaped association between dietary phosphorus intake and new-onset hypertension: a nationwide cohort study in China.

BACKGROUND: The association between dietary phosphorus intake and the risk of hypertension remains uncertain. We aimed to investigate the relation of dietary phosphorus intake with new-onset hypertension among Chinese adults. METHODS: A total of 12,177 participants who were free of hypertension at baseline from the China Health and Nutrition Survey (CHNS) were included. Dietary intake was measured by 3 consecutive 24-hour dietary recalls combined with a household food inventory. New-onset hypertension was defined as systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg or diagnosed by a physician or under antihypertensive treatment during the follow-up. RESULTS: During a median follow-up of 6.1 years, 4,269 participants developed new-onset hypertension. Overall, the association between dietary phosphorus intake and new-onset hypertension followed a U-shape (P for nonlinearity<.001). Consistently, when dietary phosphorus intake was assessed as quintiles, compared with those in the 3rd to 4th quintiles (912.0-<1089.5 mg/d), a significantly higher risk of new-onset hypertension was found in participants in the 1st to 2nd quintiles (<912.0 mg/d: HR, 1.23; 95% CI, 1.14-1.33), and the fifth quintile (≥1089.5 mg/d: HR, 1.21; 95% CI, 1.10-1.33). CONCLUSION: There was a U-shaped association between dietary phosphorus intake and new-onset hypertension in general Chinese adults.

Associations between visceral adiposity index and incident nephropathy outcomes in diabetic patients: Insights from the ACCORD trial.

AIMS: Visceral adiposity index (VAI) was a reliable marker for visceral adiposity accumulation and dysfunction. The association between VAI and nephropathy outcomes remains uncertain in patients with type 2 diabetes (T2DM). We aimed to evaluate the longitudinal relationships between VAI and incident nephropathy outcomes in T2DM patients. MATERIALS AND METHODS: Ten thousand one hundred and thirty two participants with T2DM from the ACCORD trial were included in the present study. Cumulative average VAI based on VAI measurements at baseline and follow-up was used to represent long-term VAI status. The primary outcome was the incident composite nephropathy outcome defined as: (1) serum creatinine doubling or >20 ml/min decrease in eGFR; or (2) development of macro-albuminuria; or (3) renal failure or end stage kidney disease (dialysis) or serum creatinine >3.3 mg/dl. RESULTS: During 26,168 person-years follow-up duration, 6094 (60.1%) participants developed the incident composite nephropathy outcome. When assessing cumulative average VAI as quartiles, compared with those in the 1-2 quartiles (<2.6), a significantly higher risk of incident composite nephropathy outcomes was observed among participants in the 3-4 quartiles (≥2.6, adjusted HR: 1.09, 95% CI: 1.01, 1.18). Moreover, the positive association was consistent in participants with or without single abnormal VAI components, including general obesity, abdominal obesity, elevated triglycerides, and low high-density lipoprotein cholesterol, or with different numbers of abnormal VAI components. Additionally, the positive association was stronger in participants with cumulative average systolic blood pressure <130 mmHg (vs. ≥130 mmHg; p-interaction < 0.001). CONCLUSIONS: In T2DM patients, higher cumulative average VAI was associated with a higher risk of incident composite nephropathy outcomes. CLINICAL TRIAL REGISTRATION: clinicaltrials.gov, identifier: NCT00000620.

A U-shaped association between dietary phosphorus intake and new-onset diabetes: A nationwide cohort study in China.

BACKGROUND AND AIMS: The association between dietary phosphorus intake and the risk of diabetes remains uncertain. We aimed to investigate the relation of dietary phosphorus intake with new-onset diabetes among Chinese adults. METHODS AND RESULTS: A total of 16,272 participants who were free of diabetes at baseline from the China Health and Nutrition Survey were included. Dietary intake was measured by 3 consecutive 24-h dietary recalls combined with a household food inventory. Participants with self-reported physician-diagnosed diabetes, or fasting glucose ≥7.0 mmol/L or glycated hemoglobin ≥6.5% during the follow-up were defined as having new-onset diabetes. During a median follow-up of 9.0years, 1101 participants developed new-onset diabetes. Overall, the association between dietary phosphorus intake with new-onset diabetes followed a U-shape (P for nonlinearity<0.001). The risk of new-onset diabetes significantly decreased with the increment of dietary phosphorus intake (per SD increment: HR, 0.64; 95%CI, 0.48-0.84) in participants with phosphorus intake <921.6 mg/day, and increased with the increment of dietary phosphorus intake (per SD increment: HR, 1.33; 95%CI, 1.16-1.53) in participants with phosphorus intake ≥921.6 mg/day. Consistently, when dietary phosphorus intake was assessed as quintiles, compared with those in the 3rd quintile (905.0-<975.4 mg/day), significantly higher risks of new-onset diabetes were found in participants in the 1st-2nd quintiles (<905.0 mg/day: HR, 1.59; 95%CI, 1.30-1.94), and 4th-5th quintiles (≥975.4 mg/day: HR, 1.46; 95%CI, 1.19-1.78). CONCLUSIONS: There was a U-shaped association between dietary phosphorus intake and new-onset diabetes in general Chinese adults, with an inflection point at 921.6 mg/day and a minimal risk at 905.0-975.4 mg/day of dietary phosphorus intake.

Identification of the prognostic value of Th1/Th2 ratio and a novel prognostic signature in basal-like breast cancer.

BACKGROUND: Breast cancer is a heterogeneous group of diseases. The polarization of CD4+ T helper (Th) lymphocytes (mainly Th1 and Th2) may differ in breast cancers with different outcomes, but this has not been fully validated. METHODS: This study is a bioinformatic analysis, in which differentially expressed genes (DEGs) were identified in patients with low and high Th1/Th2 ratios. And then, DEG functions, hub genes and independent predictors were determined. RESULTS: Low Th1/Th2 ratio was associated with poor outcome in Luminal A and basal-like breast cancer (p < 0.05). GSEA and KEGG analysis of DEGs obtained from comparing low and high Th1/Th2 ratios illuminated downregulation of immune-related gene sets and pathways affecting Th1/Th2 balance toward Th2 polarization (p < 0.05). Survival and Cox analyses of all the DEGs confirmed CCL1 and MYH6 were independent protective factors and IFNK and SOAT2 were independent risk factors for basal-like breast cancer (95%CI: 1.06-2.5, p = 0.026). Then a four-gene signature was constructed and achieved a promising prognostic value (C-index = 0.82; AUC = 0.826). CONCLUSIONS: Low Th1/Th2 ratio predicts poor outcome in Luminal A and Basal-like breast cancer, and downregulation of immune-related gene sets and pathways contribute to Th1/Th2 balance toward Th2 polarization. CCL1, MYH6, IFNK, and SOAT2 have an independent prognostic value of survival outcome and might be novel markers in basal-like breast cancer.

Why Bufo gargarizans tadpoles grow bigger in Pb-contaminated environments? The gut microbiota matter.

The impacts of lead/Pb2+ on ecosystems have received widespread attention. Growth suppression is a major toxic effect of Pb compounds on aquatic animals, however, some studies have also reported their growth-promoting effects. These complex outcomes may be explained by anions that accompany Pb2+ or by the multiple toxic mechanisms/pathways of Pb2+. To examine these hypotheses, we tested how Bufo gargarizans tadpoles responded to Pb(NO3)2 (100 and 200 µg/L Pb2+) using transcriptomics and microbiomics, with NaNO3 and blank groups as controls. Tadpoles exposed to Pb(NO3)2 showed delayed development while increased somatic growth in a dose-dependent manner, which can be attributed to the effects of NO3- and Pb2+, respectively. Tadpole transcriptomics revealed that exposure to NO3- downregulated the MAPK pathway at transcriptional level, explaining the development-suppressing effect of NO3-; while Pb2+ upregulated the transcription of detoxification pathways (e.g., xenobiotics metabolism by cytochrome P450 and glutathione metabolism), indicating cellular stress and thus contradicting the growth advantage of Pb2+-exposed tadpoles. Pb2+ exposure changed the tadpole gut microbiota drastically, characterized by increased polysaccharides and carbohydrate utilization while decreased fatty acid and amino acid consumption according to microbial functional analysis. Similar gut microbial variations were observed in field-collected tadpoles from different Pb2+ environments. This metabolic shift in gut microbiota likely improved the overall food utilization efficiency and increased the allocation of fatty acids and amino acids to the host, explaining the growth advantage of Pb2+-exposed tadpoles. In summary, our results suggest multiple toxic pathways of Pb2+, and the gut microbiota may affect the pollution outcomes on animals.

Short-term outcomes of reduced-port laparoscopic surgery versus conventional laparoscopic surgery for total gastrectomy: a single-institute experience.

BACKGROUND: The efficacy of reduced-port laparoscopic surgery (RLS) for total gastrectomy remains unclear. This study focused on evaluating the short-term outcomes of RLS compared with conventional laparoscopic surgery (CLS) for total gastrectomy. METHODS: One hundred and ten patients who underwent completed laparoscopic total gastrectomy for gastric cancer between September 2018 and June 2022 were retrospectively collected and classified into two groups (65 CLS and 45 RLS) according to different operation approach. Twenty-four RLS cases underwent single-incision plus two ports laparoscopic surgery (SILS + 2) and twenty-one underwent single-incision plus one port laparoscopic surgery (SILS + 1). Surgical outcomes, pain intensity, cosmetic and postoperative morbidity, and mortality were compared between groups. RESULTS: The overall incidence of postoperative complications was similar between the CLS group and the RLS group (16.9% vs. 8.9%, P = 0.270). It was also comparable in the Clavien-Dindo classification (P = 0.774). However, compared with the CLS group, the RLS group had a significantly shorter total length of incision (5.6 ± 1.0 cm vs. 7.1 ± 0.7 cm, P = 0.000); shorter time to first ambulation (24.9 ± 5.9 h vs. 27.6 ± 5.0 h, P = 0.009), flatus (3.0 ± 0.8 d vs. 3.5 ± 1.0 d, P = 0.022) and oral intake (4.0 ± 1.6 d vs. 6.1 ± 5.1 d, P = 0.011); lower white blood cell count on the third day after the operation (9.8 ± 4.0*109/L vs. 11.6 ± 4.7*109/L, P = 0.037); and lower visual analogue scale score on postoperative days 1 and 3(3.0 ± 0.7 vs. 3.3 ± 0.7, P = 0.044 and 0.6 ± 0.7 vs. 1.6 ± 0.6, P = 0.000 respectively). On the other hand, it didn't find any difference in short-term outcomes between the SILS + 2 group and the SILS + 1 group (P > 0.05). But the proximal resection margin was longer in the SILS + 2 group than in the SILS + 1 group (2.6 ± 0.7 cm vs. 1.5 ± 0.9 cm, P = 0.046) in patients with adenocarcinoma of the esophagogastric junction (AEG). CONCLUSIONS: RLS for total gastrectomy is a feasible and safe technique when performed by an experienced laparoscopic surgeon. Moreover, compared with SILS + 1, SILS + 2 might have some advantages in AEG patients.

Flavonoids from Citrus paradise cv. Changshan-huyou exerts protective effect on ischemia-induced cerebral injury in mice via inhibiting RhoA-ROCK2 signaling pathway. / èƒ¡æŸšé»„é ®é€šè¿‡æŠ‘åˆ¶RhoA-ROCK2信号通路发挥脑缺血保护作用.

OBJECTIVES: To investigate the protective effect and mechanism of total flavonoids from Citrus paradise cv. Changshan-huyou extracts (TFC) on oxygen-glucose deprivation (OGD) of primary neurons and chronic ischemia-induced cerebral injury in mice. METHODS: Primary hippocampal neurons of 18-day fetal rats were isolated and cultured for 1 week, then treated with 0.25, 0.50 and 1.00 mg/mL TFC. After oxygen-glucose deprivation for 1 h, cells were reperfused for 6 and 24 h, respectively. The cytoskeleton was observed by phalloidin staining. In animal study, 6-week ICR male mice were randomly divided into sham operation group, model group, low-dose (10 mg/kg), medium-dose (25 mg/kg) and high-dose (50 mg/kg) TFC treatment groups, with 20 mice in each group. After 3 weeks, chronic cerebral ischemia was induced by unilateral common carotid artery ligation in all groups except sham operation group. Mice were treated with different concentrations of TFC in the three TFC treatment groups for 4 weeks. Open field test, novel object recognition test and Morris water maze test were used to evaluate anxiety, learning and memory of these mice. Nissl, HE and Golgi stainings were used to detect neuronal degeneration and dendritic spine changes in the cortex and the hippocampus. The expression levels of Rho-associated kinase (ROCK) 2, LIM kinase (LIMK) 1, cofilin and its phosphorylation, as well as the expression of globular actin (G-actin) and filamentous actin (F-actin) protein in hippocampus of mice were detected by Western blotting. RESULTS: Neurons subjected to OGD showed that neurites displayed shortening and breakage; while treatment with TFC reversed OGD-induced neurite injury, especially in the 0.50 mg/mL TFC group. Compared with the sham operation group, the mice in the model group showed a significant decline in anxiety and cognitive ability (P<0.01), whereas treatment with TFC significantly reversed anxiety and cognitive deficits (P<0.05). Improvement in the medium-dose TFC group was the most obvious. Histopathological analysis indicated that the number of Nissl bodies and dendritic spines in hippocampus and cortex were decreased in the model group (all P<0.01). However, after treatment with medium dose of TFC, the number of Nissl bodies and dendritic spines (all P<0.05) was significantly recovered. Compared with the sham operation group, the phosphorylation level of ROCK2 in the brain tissue of the model group was significantly increased (P<0.05), while the phosphorylation levels of LIMK1 and cofilin were significantly decreased (P<0.05), and the relative content ratio of G-actin/F-actin was significantly increased (P<0.05). After administration of TFC, the phosphorylation level of ROCK2 in brain tissue of each group was significantly decreased (P<0.05), while the phosphorylation levels of LIMK1 and cofilin were significantly up-regulated (P<0.05) and the relative content ratio of G-actin/F-actin was significantly decreased (P<0.05). CONCLUSIONS: TFC protects from ischemia-induced cytoskeletal damage, reduces neuronal dendritic spine injury and protects mice against chronic cerebral ischemia through RhoA-ROCK2 signaling pathway, indicating that TFC might be a potential candidate for treatment of chronic ischemic cerebral injury.

Seasonal variation significantly influenced the stochasticity of community assembly of amphibian symbiotic bacteria.

Seasonal variation has been shown to influence symbiotic bacterial community composition and structure in amphibians. It is still unknown how the symbiotic bacterial community assembly changes during different seasons, especially for amphibians who are particularly sensitive to environmental change. We found significant differences in the composition and diversity (alpha and beta diversity) of amphibian skin and gut bacteria. Co-occurrences network analysis showed that seasonal variation reduced the microbial network complexity of amphibians from summer to autumn. The normalized stochastic ratio (NST) and phylogenetic bin-based null model analysis (iCAMP) models showed that the same result that stochastic processes was the major factor regulating the symbiotic bacterial community assembly mechanisms of amphibians. From summer to autumn, the symbiotic bacterial community assembly mechanisms declined in the contribution of stochastic processes, while increasing in the contribution of deterministic processes. Dispersal limitation was the dominant microbial assembly mechanism, followed by homogeneous selection, and then heterogeneous selection in the symbiotic bacterial community communities of amphibians between summer and autumn. Furthermore, higher niche width of the symbiotic bacterial community of amphibians was found in summer than autumn. Overall, these results demonstrated that seasonal variation influenced amphibian symbiotic bacterial community between summer and autumn.

Rising floor and dropping ceiling: organ heterogeneity in response to cold acclimation of the largest extant amphibian.

Low temperature imposes strong selective pressure on ectotherms. To maximize their overall fitness under cold conditions, the ectotherms may either try to maintain their physiological activities through metabolic compensation or enter into metabolic depression; however, some species adopt both strategies to cope with different degrees of cold. Nevertheless, how these two seemingly opposite strategies are coordinated has rarely been elucidated. Here, we investigated the molecular strategy underlying the cold acclimation of Andrias davidianus, the largest extant amphibian, using multi-organ metabolomics and transcriptomics. The results showed remarkable organ heterogeneity in response to cold. While most organs showed transcriptional upregulation of metabolic processes, the heart exhibited downregulation. This heterogeneity explained the adaptive reorganization in resource allocation, which compensates for metabolic maintenance by compromising growth. Importantly, the cardiac function might constitute a 'ceiling' to constrain the space for compensation, especially under colder conditions. Additionally, the opposite transcriptional regulation of oxidative phosphorylation and other pathways might also shape the overall metabolic capacity under cold conditions. The heterogeneity in cold responses may have directed a shift in cold adaptive strategy from compensation to depression with a drop in temperature. These results provide a novel insight into the regulatory mechanisms underlying cold survival strategies of ectotherms.

Multi-omics provide mechanistic insight into the Pb-induced changes in tadpole fitness-related traits and environmental water quality.

Water pollution from lead/Pb2+ poses a significant threat to aquatic ecosystems, and its repercussions on aquatic animals have received considerable attention. Although Pb2+ has been found to affect numerous aspects of animals, including individual fitness, metabolic status, and symbiotic microbiota, few studies have focused on the associations between Pb2+-induced variations in fitness, metabolome, symbiotic microbiome, and environmental parameters in the same system, limiting a comprehensive understanding of ecotoxicological mechanisms from a holistic perspective. Moreover, most ecotoxicological studies neglected the potential contributions of anions to the consequences generated by inorganic lead compounds. We investigated the effects of Pb(NO3)2 at environmentally relevant concentrations on the Rana omeimontis tadpoles and the water quality around them, using blank and NaNO3-treated groups as control. Results showed that Pb(NO3)2 not only induced a rise in water nitrite level, but exposure to this chemical also impaired tadpole fitness-related traits (e.g., growth and development). The impacts on tadpoles were most likely a combination of Pb2+ and NO3-. Tissue metabolomics revealed that Pb(NO3)2 exposure influenced animal substrate (i.e., carbohydrate, lipid, and amino acid) and prostaglandin metabolism. Pb(NO3)2 produced profound shifts in gut microbiota, with increased Proteobacteria impairing Firmicutes, resulting in higher aerobic and possibly pathogenic bacteria. NaNO3 also influenced tadpole metabolome and gut microbiome, in a manner different to that of Pb(NO3)2. The presence of NO3- seemed to counteract some changes caused by Pb2+, particularly on the microbiota. Piecewise structural equation model and correlation analyses demonstrated connections between tissue metabolome and gut microbiome, and the variations in tadpole phenotypic traits and water quality were linked to changes in tissue metabolome and gut microbiome. These findings emphasized the important roles of gut microbiome in mediating the effects of toxin on aquatic ecosystem. Moreover, it is suggested to consider the influences of anions in the risk assessment of heavy metal pollutions.

Association between serum advanced oxidation protein products and mortality risk in maintenance hemodialysis patients.

BACKGROUND: The association between serum advanced oxidation protein products (AOPP) and mortality risk remains equivocal. We aimed to assess the correlation of serum AOPP levels with the risk of all-cause mortality in hemodialysis (HD) patients. METHODS: A total of 1394 maintenance HD patients with complete data on AOPP and related parameters were included from China Collaborative Study on Dialysis (CCSD), a multi-center, prospective cohort study. The primary outcome was all-cause mortality, the secondary outcome was cardiovascular disease (CVD) mortality. RESULTS: During a median follow-up duration of 5.2 years (IQR, 2.1-5.4), all-cause mortality occurred in 492 (31.4%) participants. Overall, there was a reversed L-shaped association between serum AOPP and all-cause mortality in HD patients (P for nonlinearity = 0.04), with an inflection point at 87 µmol/L. Accordingly, there was no significant association between serum AOPP and all-cause mortality (per SD increment; HR, 0.94; 95%CI, 0.84, 1.05) in participants with AOPP < 87 µmol/L. However, there was a positive relationship of serum AOPP and all-cause mortality (per SD increment; HR, 1.24; 95%CI, 1.08, 1.42) in those with AOPP ≥ 87 µmol/L. Moreover, a similar trend was found for CVD mortality. CONCLUSIONS: Elevated serum AOPP levels were associated with higher risk of all-cause mortality in Chinese maintenance HD patients.

Comparative osteology of the hynobiid complex Liua-Protohynobius-Pseudohynobius (Amphibia, Urodela): â . Cranial anatomy of Pseudohynobius.

Hynobiidae are a clade of salamanders that diverged early within the crown radiation and that retain a considerable number of features plesiomorphic for the group. Their evolutionary history is informed by a fossil record that extends to the Middle Jurassic Bathonian time. Our understanding of the evolution within the total group of Hynobiidae has benefited considerably from recent discoveries of stem hynobiids but is constrained by inadequate anatomical knowledge of some extant forms. Pseudohynobius is a derived hynobiid clade consisting of five to seven extant species living endemic to southwestern China. Although this clade has been recognized for over 37 years, osteological details of these extant hynobiids remain elusive, which undoubtedly has contributed to taxonomic controversies over the hynobiid complex Liua-Protohynobius-Pseudohynobius. Here we provide a bone-by-bone study of the cranium in the five extant species of Pseudohynobius (Ps. flavomaculatus, Ps. guizhouensis, Ps. jinfo, Ps. kuankuoshuiensis and Ps. shuichengensis) based on x-ray computer tomography data for 18 specimens. Our results indicate that the cranium in each of these species has a combination of differences in morphology, proportions and articulation patterns in both dermal and endochondral bones. Our study establishes a range of intraspecific differences that will serve as organizing hypotheses for future studies as more extensive collections of these species become available. Morphological features in the cranium for terrestrial ecological adaptation in Hynobiidae are summarized. Based on the results, we also discuss the evolution and development of several potential synapomorphies of Hynobiidae, including features of the orbitosphenoid and articular.

Osteological development of a small and fast metamorphic frog, Microhyla fissipes (Anura, Neobatrachia, Microhylidae).

Describing osteological development is of great importance for understanding vertebrate phenotypic variations, form-functional transitions and ecological adaptations. Anurans exhibit dramatic changes in their morphology, habitat preferences, diet and behaviour between the tadpole and frog stages. However, the anatomical details of their cranial and postcranial development have not been extensively studied, especially in Microhylidae. In this work, we studied the microhylid Microhyla fissipes, commonly known as the ornamented pygmy frog, a small-sized frog with fast metamorphosis. Its osteological development was comprehensively described based on 120 cleared and stained specimens, including six tadpoles for each stage between 28 and 45, six juveniles and six adults. Additionally, 22 osteological traits of these specimens involved in food acquisition, respiration, audition and locomotion were selected and measured to reflect the changes in tadpole ecological functions during metamorphosis. Our study provides the first detailed qualitative and quantitative developmental information about these structures. Our results have confirmed that skeletal elements (viz., neopalatines, omosternum, clavicles and procoracoids) absent in adults are not detected during development. Our data reveal that morphologically, radical transformations of the cranial structures related to feeding and breathing are completed within stages 42-45 (72 h), but the relative length and width of these skeletons have changed in earlier stages. The postcranial skeletons correlated with locomotion are well developed before stage 42 and approach the adult morphology at stage 45. Indeed, the relative length of the pectoral girdle and forelimb reaches the adult level at stage 42 and stage 45, respectively, whereas that of the vertebral column, pelvic girdle and hind limbs increases from their appearance until reaching adulthood. Based on published accounts of 19 species from Neobatrachia, Mesobatrachia and Archaeobatrachia, cranial elements are among the first ossified skeletons in most studied species, whereas sphenethmoids, neopalatines, quadratojugals, mentomeckelians, carpals and tarsals tend to ossify after metamorphosis. These results will help us to better understand the ecomorphological transformations of anurans from aquatic to terrestrial life. Meanwhile, detailed morphological and quantitative accounts of the osteological development of Microhyla fissipes will provide a foundation for further study.

Serum and Tissue Levels of Advanced Glycation End Products and Risk of Mortality in Patients on Maintenance Hemodialysis.

BACKGROUND: The relation of tissue and circulating advanced glycation end products (AGEs) with mortality in hemodialysis (HD) patients remains inconclusive. We aimed to investigate the association of serum AGEs (CML) and tissue AGEs estimated by skin autofluorescence (SAF) with all-cause and cardiovascular disease (CVD) mortality, and examine the possible modifiers for the association in HD patients with by far the largest sample size in any similar studies. METHODS: A total of 1,634 HD patients were included from the China Cooperative Study on Dialysis (CCSD), a multicenter prospective cohort study. The primary and secondary outcomes were all-cause mortality and CVD mortality, respectively. RESULTS: The median follow-up duration was 5.2 years. Overall, there was a positive relation of baseline SAF levels with the risk of all-cause mortality (per 1 AU increment, adjusted hazard ratio (HR), 1.30; 95% confidence interval (CI): 1.12, 1.50) and CVD mortality (per 1 AU increment, adjusted HR, 1.36; 95% CI: 1.14, 1.62). Moreover, a stronger positive association between baseline SAF (per 1 AU increment) and all-cause mortality was found in participants with shorter dialysis vintage, or lower C-reactive protein levels (Both p interactions <0.05). Nevertheless, there was no significant association between serum CML and the risk of mortality. CONCLUSIONS: In patients undergoing long-term HD, baseline SAF, but not serum CML, was significantly associated with the risk of all-cause and CVD death.