Biology-Basel最新文献

Background: Plant citrate synthase (CSY) is involved in the iron deficiency (-Fe) response and aluminum (Al) detoxification. However, knowledge of CSY function in responding to excess iron (+Fe) or Al stress (+Al) is still limited.

Methods: The CDS and promoter of GmCSY3 were isolated from soybean and bioinformatically analyzed. The GmCSY3 expression was detected by qRT-PCR and GUS assay. The growth of GmCSY3 recombinant yeast under +Fe or +Al was detected. The phenotype, CSY activity, citric acid concentration, chlorophyll content, MDA, H₂O₂, O₂^- contents, GST, CAT, SOD, and POD activities were examined in GmCSY3 overexpressed and RNAi-suppressed soybean chimeras under +Fe or +Al. Perls and Hematoxylin stained the roots, and the FCR activity was determined.

Results: GmCSY3 was induced by +Fe or +Al, but not by -Fe. GmCSY3 enhanced yeast's acid production and resistance to +Fe or +Al. GmCSY3 overexpression in soybean significantly enhanced CSY activity, promoted growth, alleviated oxidative damage caused by +Fe or +Al, with less free Fe³⁺ and Al³⁺, and reduced FCR activity, while GmCSY3 RNAi-suppressed showed the opposite effect.

Conclusions: GmCSY3 promotes the process of citrate synthesis, chelates Fe³⁺ and Al³⁺, alleviates oxidative damage caused by +Fe or +Al, and modulates iron absorption in plants.

Foodborne pathogens remain a global public health concern, and antimicrobial resistance increases their impact. In mass-gathering cities such as Al-Madinah Al-Munawarah, contaminated ready-to-eat (RTE) fast foods can contribute to both local transmission and international spread. In this study, 300 RTE fast food samples, including shawarma, burgers, fried chicken, sandwiches, and salads, were collected from international franchises, local restaurants, and street vendors. Pathogens were identified using conventional culture combined with matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Antimicrobial susceptibility testing followed CLSI guidelines, and real-time PCR confirmed species identity and screened resistance determinants. Principal component analysis (PCA) and dendrogram clustering were used to assess diagnostic discrimination. Among the 300 samples, 129 (43.0%) were culture positive. The most common pathogens were Staphylococcus aureus (14.3%) and Escherichia coli (13.0%), followed by Salmonella spp. (9.0%) and Acinetobacter baumannii (6.7%). About 35% of S. aureus isolates were methicillin resistant (MRSA), and 85% of A. baumannii carried OXA-type carbapenemase genes. MALDI-TOF MS achieved 96.1% score-based identification and, with PCA, showed strong interspecies separation. PCR confirmed species identity and detected widespread resistance genes, with genotype-phenotype concordance of at least 80%. Overall, 60.5% of isolates were multidrug resistant. RTE fast foods in Al-Madinah represent reservoirs of MDR pathogens, including carbapenemase-producing A. baumannii. The combined use of MALDI-TOF MS and real-time PCR established a rapid and scalable workflow that provided reliable identification and resistance profiling in less than 24 h, compared with 48 to 72 h for conventional methods. This approach supports One Health surveillance in high-risk food settings and strengthens preparedness for mass gatherings.

Wildlife conservation and the management of biological resources face unprecedented challenges in the Anthropocene [...].

Niclosamide has been the primary molluscicide for schistosomiasis control for over 50 years, but its chronic effects on inter-organ interactions in non-target mollusks remain poorly understood. Cipangopaludina cathayensis, a dominant species in East Asian schistosomiasis-endemic regions, was chronically exposed to environmentally relevant concentrations of niclosamide to assess its toxic effects. Digestive glands accumulated more niclosamide than the foot tissues. Prolonged exposure was associated with metabolic impairment of the digestive glands, characterized by tubular atrophy, inflammatory reactions, and depletion of nutrient components. Foot tissues exhibited epithelial lesions and muscle fiber atrophy. Alterations in foot structure were associated with changes in digestive gland nutrient status. Niclosamide exposure may weaken the metabolic coupling between these organs, thereby impairing locomotor function. At the population level, persistent niclosamide exposure may destabilize mollusk trophic-level populations, ultimately leading to ecological consequences. Our findings demonstrate the toxicological risks of niclosamide to freshwater mollusks.

Manganese (Mn) is a crucial micronutrient for plants. The impaired function of the oxygen-evolving complex in Photosystem II (PSII) due to Mn deficiency is believed to result in the overproduction of reactive oxygen species and the induction of an enzymatic antioxidant system. In our study, we investigated the effects of progressive Mn deficiency (the difference in Mn content between the needles of control and Mn-deficient plants increased from 17-fold at the beginning of the experiment to 59-fold at the end) on the activities of superoxide dismutase (SOD), catalase, ascorbate peroxidase, and guaiacol peroxidase in the roots and needles of Scots pine seedlings. We found that the soluble protein content in plant organs under Mn deficiency was maintained at a level comparable to that of the control. Regardless of the severity of Mn deficiency, the needles of the Mn-deficient plants presented twofold lower SOD activity than the needles of the control plants. These differences were observed even when Mn deficiency did not negatively affect plant growth. Additionally, the total SOD activity in the needles of both plant groups was determined solely by the activity of the Cu/Zn-containing SOD isozymes. Compared with the control plants, Mn deficiency did not result in an increase in any of the studied H₂O₂-degrading enzymes in the needles of the seedlings. In contrast, the needles of the Mn-deficient plants presented a lower level of guaiacol peroxidase activity. Despite the inhibition of root growth, Mn deficiency led to changes in the balance of the enzymatic antioxidant system in plant roots. The data obtained suggest that the lack of activation of SOD and other antioxidant enzymes in Scots pine seedlings against the background of progressive Mn deficiency is due to the reduced ability of PSII to generate ROS under these conditions.

The Kazakh horse is an outstanding dual-purpose dairy and meat breed in China, characterized by early maturity, tolerance to coarse feed, and strong stress resistance. Previous studies have examined gene expression patterns in the testicular tissues of Kazakh horses at different age stages, but the molecular mechanisms regulating testicular sexual maturation remain unclear. To address this gap, this study conducted HE staining and in-depth transcriptome sequencing analysis of Kazakh horse testicular tissue before and after sexual maturity. HE staining showed that the G3 group had well-formed seminiferous tubule lumens, dense interstitial cells, and visible early spermatocytes and spermatozoa, indicating structural maturation. (G1 group: pre-sexual maturity; G3 group: post-sexual maturity), with four biological replicates per group (n = 4). Differentially expressed genes (DEGs) were called using the criteria of |log₂(fold change)| ≥ 1.5 and adjusted p-value ≤ 0.05. A total of 3054 differentially expressed genes (DEGs), including CABS1, RPL10, PGAM2, TMSB4X, and CYP17A1, were identified in the G1 and G3 groups. Among these, 402 genes showed upregulation and 2652 genes showed downregulation. GO annotation and KEGG enrichment analysis of DEGs revealed their predominant enrichment in the following categories: signaling pathways such as Focal adhesion, Pathways in cancer, and the PI3K-Akt signaling pathway. RT-qPCR validation confirmed the accuracy of the transcriptomic sequencing data. This study further elucidates the differentially expressed genes and associated signaling pathways in Kazakh stallion testes tissue before and after sexual maturity, providing a theoretical foundation and data reference for enhancing reproductive efficiency in equids and promoting biological processes such as testes development and spermatogenesis.

Microalgae are an evolutionarily ancient and morphologically diverse group of photosynthetic eukaryotes, with taxonomic resolution complicated by environmentally driven phenotypic plasticity. This study merges deep learning and explainable artificial intelligence (XAI) to establish a transparent, reliable, and biologically meaningful framework for green microalgae (Chlorophyta) classification. Microscope images from three morphologically distinct algal species-Desmodesmus flavescens, Desmodesmus subspicatus, and Tetradesmus dimorphus representing the genera Desmodesmus and Tetradesmus within Chlorophyta-were analyzed using twelve convolutional neural networks, including EfficientNet-B0-B7, DenseNet201, NASNetLarge, Xception, and ResNet152V2. A curated dataset comprising 3624 microscopic images from three Chlorophyta species was used, split into training, validation, and test subsets. All models were trained using standardized preprocessing and data augmentation procedures, including grayscale conversion, CLAHE-based contrast enhancement, rotation, flipping, and brightness normalization. The model's performance was assessed using accuracy and loss metrics on independent test datasets, while interpretability was evaluated through saliency maps and Gradient-weighted Class Activation Mapping (Grad-CAM) visualizations. ResNet152V2 achieved the highest overall performance among all evaluated architectures, outperforming EfficientNet variants, NASNetLarge, and Xception in terms of macro F1-score. Visualization analysis showed that both Grad-CAM and saliency mapping consistently highlighted biologically relevant regions-including cell walls, surface ornamentation, and colony structures-confirming that the models relied on taxonomically meaningful features rather than background artifacts. The findings indicate that the integration of deep learning and XAI can attain consistently high test accuracy for microalgal species, even with constrained datasets. This approach enables automated taxonomy and supports biodiversity monitoring, ecological assessment, biomass optimization, and biodiesel production by integrating interpretability with high predictive accuracy.

Fast-twitch and slow-twitch muscle fibers not only differ in metabolic characteristics and physiological functions but also significantly influence the texture of livestock meat. RNA editing represents an important post-transcriptional regulatory process that can influence both gene expression and the resulting protein function. However, studies on RNA editing events in yak muscle remain limited. This study systematically identified RNA editing events in yak biceps femoris (BF, n = 3) and obliquus externus abdominis (OEA, n = 3) using transcriptomic data, discovering 17,713 unique editing sites, most located in non-coding regions. Within coding regions, 3350 sites were detected, with 1195 resulting in non-synonymous amino acid substitutions. Further analysis revealed that 785 sites potentially affected miRNA binding sites, suggesting RNA editing may participate in miRNA-mediated gene regulation. Tukey's post hoc test (p < 0.05) identified 242 sites (involving 170 genes) with significantly different editing levels between BF and OEA. KEGG pathway analysis indicated that genes with differential RNA editing were predominantly associated with pathways involved in muscle fiber type transitions, including the MAPK and calcium signaling pathways. Collectively, this study maps the RNA editing landscape in yak muscle tissue and identifies distinct, fiber-type-specific RNA editing patterns between oxidative and glycolytic muscle fibers, including differences in editing levels and site distributions, supporting a potential association between RNA editing and muscle fiber type transformation.

Chagas disease remains a major public health challenge due to the limited effectiveness and considerable side effects of existing treatments, particularly during the chronic stage. Açaí (Euterpe oleracea) seeds have gained increasing attention as a source of bioactive compounds with potential therapeutic applications. In this study, hydroalcoholic extracts and solvent fractions obtained from açaí seeds were chemically characterized by ESI/MS and HPLC-MS/MS and evaluated for their cytotoxicity and antiparasitic activity against different developmental stages of Trypanosoma cruzi (Y strain). Chemical profiling revealed a predominance of phenolic compounds, particularly catechins and procyanidins, which were identified as major constituents of the hydroalcoholic extract and the ethyl acetate fraction. Cytotoxicity assays performed on murine peritoneal macrophages demonstrated low toxicity, with CC₅₀ values exceeding 500 µg/mL for most samples, indicating a favorable in vitro safety profile. Antiparasitic assays showed weak activity against epimastigote forms; however, significant inhibitory effects were observed against bloodstream trypomastigotes, cell culture-derived trypomastigotes, and intracellular amastigotes. Notably, the hydroalcoholic extract exhibited the highest selectivity against intracellular amastigotes, with a selectivity index greater than 10, fulfilling key criteria proposed by the Drugs for Neglected Diseases initiative (DNDi) for early-stage hit compounds. Flow cytometry analysis showed that both the hydroalcoholic extract and the ethyl acetate fraction induced parasite cell death through late apoptosis-like and necrosis. Together, these findings highlight the antiparasitic potential of E. oleracea seed extracts, particularly against clinically relevant stages of T. cruzi, and support further investigation of these bioproducts as promising candidates for the development of new therapeutic strategies for Chagas disease.

Hepatocellular carcinoma (HCC) ranks among the top causes of cancer-related mortality worldwide, and its complex tumor microenvironment (TME) contributes to poor responses to immunotherapy. Although PD-1/PD-L1 blockade has emerged as an effective treatment strategy, therapeutic resistance frequently limits its clinical benefit. Here, we uncover a distinct macrophage population associated with anti-PD-1 resistance in HCC. Single-cell transcriptomic profiling reveals an NFKBIZ⁺ M0 macrophage subset predominantly present in non-responders. Notably, these macrophages exhibit a hypoxia-induced phenotype characterized by the secretion of VEGFA and HBEGF, which cooperatively enhance tumor angiogenesis, alongside an elevated expression of the inflammatory chemokines CXCL2, CXCL3, and CXCL8 that consolidate an immunosuppressive, pro-tumorigenic microenvironment. Transcriptional regulatory network analysis further identified FOSB-VEGFA and FOS-HBEGF axes as key drivers of this pathogenic macrophage phenotype. Our findings define a distinct NFKBIZ⁺ macrophage population that mechanistically links hypoxia, angiogenesis, and immune evasion to PD-1 blockade resistance. This work provides new insights into the cellular and molecular basis of immunotherapy failure in HCC and highlights potential targets for overcoming treatment resistance.