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PubMed2026

Prevalence of Theileria luwenshuni in goats (Capra hircus) on Tarama Island, Okinawa, Japan.

Caprine theileriosis is an economically important tick-borne disease caused by various Theileria species, particularly Theileria lestoquardi, Theileria luwenshuni, and Theileria uilenbergi, in goats (Capra hircus). Goat farming plays an economically and culturally important role on Tarama Island, Okinawa, Japan. Because goats on the island are mainly managed under an extensive grazing system, tick infestation is common. However, Theileria infections have not previously been investigated in goats on Tarama Island. To address this, archived DNA samples prepared from blood collected from 44 goats on Tarama Island were screened using a universal PCR assay targeting 18S rRNA sequences of Theileria and Babesia species. Two DNA samples were positive, and sequencing analysis of the amplicons identified T. luwenshuni. To further investigate the epidemiology of T. luwenshuni on Tarama Island, blood samples were subsequently collected from 96 goats across 19 farms. From each blood sample, a thin blood smear was prepared and genomic DNA was extracted. Microscopic examination of Diff-Quik-stained smears detected intraerythrocytic Theileria-like organisms in 35 (36.5%) goats. In addition, screening of DNA samples using a newly developed T. luwenshuni-specific PCR assay detected 77 (80.2%) positive goats, and the subsequent sequencing analysis confirmed the PCR results. Given that T. luwenshuni can cause severe disease in small ruminants, our findings highlight the importance of managing T. luwenshuni infection in goats on Tarama Island.

Animals↗

PubMed2026

Getting to the Core of the Matter-Assessing the Role of Replication in Metabarcoding-Based sedaDNA.

Replication is central to most experimental and sampling designs, increasing inferential power and capturing fine-scale data heterogeneity. However, its importance remains poorly evaluated in some ecological and evolutionary settings. This is the case of metabarcoding studies using DNA recovered from sedimentary archives, in which biological signals integrate ecological information through depositional and burial processes, yet are commonly inferred from a single sediment core per site. Here, we evaluated the effect of different types of replication using sedimentary DNA metabarcoding data from two genetic markers (mitochondrial COI and nuclear 18S) using a nested sampling design. The design included three intertidal sites, three spatially separated sediment cores per site (biological replicates), two sediment horizons per core, and eight PCR (technical) replicates per sediment sample. Variance partitioning showed that site identity and sediment age group together explained > 70% of the variation in beta diversity, indicating that among-site spatial and stratigraphic differences were the dominant drivers of community composition. PERMANOVA likewise identified non-significant effects of biological replication. Among PCR replicates from the same sediment sample, richness varied substantially, whereas Shannon diversity was more consistent. Despite this variability, differences in community composition among technical replicates remained smaller than those associated with biological replication or site identity, indicating a limited influence on broader ecological patterns. Community composition was highly similar among replicate cores within sites, consistent with stratigraphic coherence. These results indicate limited within-site heterogeneity and suggest that, under stratigraphically coherent conditions, increasing biological replication may provide little additional information, whereas enhancing technical replication and stratigraphic resolution can improve ecological inference from sedimentary DNA metabarcoding datasets.

DNA Barcoding, Taxonomic↗

PubMed2026

Metabolomics and genomics reveal high diversity and concentrations of cyanopeptides during a Microcystis bloom.

Cyanobacterial blooms are an immense global problem that release complex mixtures of poorly characterized biologically active cyanopeptides into freshwater. In this study, metabolomics and genomics were used to assess the diversity and concentrations of cyanopeptides during a dense Microcystis bloom during the late summer of 2023 in Lake Champlain, a large transboundary lake situated between Canada and the United States. Despite the relatively low genetic diversity of the bloom determined by 16S rRNA metabarcoding, 151 cyanopeptides were detected by non-targeted metabolomics. This represents the most recorded cyanopeptides from a single lake plankton bloom event to date. Fifty-two cyanopeptides were previously reported and 99 represent putative new structures. Standards from the microcystin, cyanopeptolin, microginin, and anabaenopeptin groups were used to either quantify or approximate respective cyanopeptide concentrations over the sampling period. Cyanopeptolins were the most diverse (n = 68) cyanopeptides and the second most abundant, reaching 12,892 μg/L. Microginins were the second most diverse (n = 24) and reached the highest concentrations (18,262 μg/L). Anabaenopeptins were the third most diverse (n = 17) cyanopeptides, reaching 4,818 μg/L. Only 8 microcystins were detected, reaching 4,935 μg/L, where MC-LR was the dominant congener. Target cyanopeptide biosynthesis genes for microcystins (mcyE), cyanopeptolins (mcnC), anabaenopeptins (apnD), microviridins (mdnC), and aeruginosins (aerA) were also quantified using digital droplet PCR (ddPCR). The gene copy numbers for mcyE, mcnC, and apnD were highly correlated with their corresponding cyanopeptide concentrations. Overall, the studied Microcystis bloom produced a very diverse cyanopeptide mixture with high cyanopeptide concentrations including non-microcystin groups.

Microcystis↗

PubMed2026

Efficient rDNA-mediated multi-copy integration of gene clusters in Aureobasidium melanogenum.

Aureobasidium melanogenum is a promising non-conventional yeast chassis for synthetic biology. However, techniques recombining large genetic fragments, such as gene clusters, are still unavailable, hindering further metabolic reprogramming in this chassis. To achieve multi-copy integration of genes, we employed highly repetitive ribosomal DNA (rDNA) sequences in A. melanogenum as homologous recombination sites for large genetic fragments. First, integration efficiency of three different regions of A. melanogenum rDNA were investigated: RNA polymerase I promoter region (rDNA1, 1.0 kb), partial 26S rDNA region (rDNA2, 1.0 kb), and RNA polymerase I terminator region (rDNA3, 1.0 kb). Our findings revealed that the highest copy numbers and expression stability were observed for the short heterologous green fluorescent protein gene (gfp, 0.7 kb) and the long native polyketide synthase gene (pks, 7.0 kb) after rDNA1-mediated integration. Specifically, the copy numbers reached 7.0 and 8.0 for gfp and pks, respectively, and they remained stably expressed in the genome after 120-h subculturing. Furthermore, an 11.0 kb gene cluster (comprising the native pks, phosphopantetheinyl transferase (npg1), and scytalone dehydratase genes (scd) responsible for melanin biosynthesis) was integrated at the rDNA1 site, resulting in stable recombination with 15.0 copies and an approximately 12-fold increase in melanin production. Overall, the convenience and efficiency of the proposed rDNA-mediated multi-copy insertion strategy will facilitate superior metabolic engineering of A. melanogenum chassis cells.

Multigene Family↗

PubMed2026

Insights into specific and nonspecific butyrate-producing pathways during the in vitro fecal fermentation of butyrylated starch.

Butyrylated starch is a special type-4 resistant starch with butyrate-carrying attribute. In this study, the unique butyrate-producing capability of butyrylated starch was deeply investigated by focusing on its specific and nonspecific butyrate-producing pathways, respectively, using specially designed substrates as controls. In vitro fermentation studies revealed that butyrylated and isobutyrylated starches generated high levels of butyrate and isobutyrate, respectively, highlighting the role of butyryl group metabolism in the specificity of butyrate production. Carboxylesterase assays have demonstrated that butyryl group metabolism is primarily facilitated by carbohydrate esterases expressed in the gut microbiota. Combined with 16S rRNA sequencing and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, it was found that butyrylated starch fermentation did not significantly enhance traditional butyrate synthesis pathways but modified the balance between the butyryl-CoA:acetyl-CoA transferase and butyrate kinase pathways by altering the gut microbiota composition, specifically by upregulating the relative abundance of indicator species such as Bacteroides, the Lachnospiraceae_NK4A136_group, and Parabacteroides. These insights offer theoretical guidance for designing butyrylated starch structures and regulating intestinal health.

Starch↗

PubMed2026

Dynamics of antibiotic resistance genes co-occurrence with pathogenic and non-pathogenic bacteria throughout wastewater treatment processes.

Wastewater treatment plants (WWTPs) are recognized hotspots for antibiotic resistance genes (ARGs) and pathogenic bacteria. Despite advancements in treatment technologies, the persistence of ARGs and pathogenic bacteria remains a concern. In this study, we analyzed the dynamic changes in ARGs and bacterial communities throughout the treatment processes within an anaerobic-anoxic-oxic (AAO) WWTP over one week by using HT-qPCR coupled with 16S rRNA gene amplicon sequencing. The connectedness index, based on network analysis, showed that the dynamics of ARGs and mobile genetic elements (MGEs) were more strongly associated with potentially pathogenic bacteria than with non-pathogenic bacteria, suggesting that ARG immigration and dissemination in the WWTP were likely driven by potentially pathogenic taxa. The AAO treatment significantly reduced ARGs in final effluent (EF) (∼64 %) and residual sludge (RS) (∼81 %); however, potential hosts of ARGs such as Comamonas testosteroni and Clostridioides difficile persisted with minimal changes in relative abundance and remained detectable in EF and RS. Notably, the abundance of ARGs was lower in RS than in EF, and source tracking analysis identified influent as the primary source of ARGs and potentially pathogenic taxa in EF, underscoring the greater health risks associated with effluent discharge.

Wastewater↗

PubMed2026

Comparative analysis of gut microbiota in yaks under different feeding management strategies during cold seasons.

Yaks (Bos grunniens) are crucial for the livelihoods of pastoral communities in cold regions, where feed scarcity during the cold season poses challenges to their health and productivity, underscoring the necessity of understanding how dietary management influences the gut microbiota. In this study, 24 yak steers matched for body weight and health status were randomly allocated to four groups: natural grazing or indoor feeding with roughage-to-concentrate ratios of 50:50, 70:30, or 90:10. Fecal samples were collected for 16S rDNA sequencing and subsequent functional prediction of the microbiota. The results showed that Firmicutes and Bacteroidetes were the dominant phyla across all groups, and UCG-005 and Rikenellaceae_RC9_gut_group were the predominant genera. Concentrate supplementation during the cold season significantly enhanced microbial richness and diversity, with the 70:30 ratio exerting the most pronounced beneficial effects on microbiota structure and key taxa enrichment. These findings highlight the critical role of dietary management in shaping the yak gut microbiota during cold seasons and suggest that the 70:30 ratio optimally improves microbial community structure, thereby promoting yak health and productivity under harsh climatic conditions. Future research should explore the long-term implications of such dietary strategies.

Animals↗

PubMed2026

Enrichment of Lysobacter in a long-term organically managed agricultural field with low soilborne disease incidence.

Disease-suppressive soils, in which soilborne pathogens are naturally suppressed, offer a promising model for sustainable crop protection, particularly in organic farming systems where chemical disease control options are limited. Although disease suppression in these soils is considered to rely on biological control, the underlying mechanisms remain poorly understood. In this study, we investigated soil from a long-term organically managed field in Shiga Prefecture, Japan, where soilborne disease incidence has remained consistently low, to identify bacterial community features potentially associated with this field. The 16S rRNA gene amplicon sequencing indicated that this soil harbored a bacterial community distinct from those of nearby agricultural soils. Following the application of organic compounds, the genus Lysobacter, a taxon with known antagonistic activity against plant pathogens, was markedly enriched in response to proteinaceous organic inputs. This enrichment was consistent across sampling times and specific to certain proteinaceous organic inputs, whereas minimal effects were observed on chitin, N-acetyl-d-glucosamine, or cysteine. Broader soil surveys indicated that Lysobacter enrichment was not strictly associated with whether soils had been managed under organic or conventional farming practices. Stepwise multiple regression analysis identified 10 co-occurring bacterial genera that were strongly associated with Lysobacter abundance. These findings highlight condition-dependent Lysobacter enrichment as a characteristic microbial response to proteinaceous organic amendments in this low-disease-incidence field and provide microbial insights that may inform microbiome-based strategies for sustainable soil management.

Lysobacter↗

PubMed2026

Sea urchin co-culture boosts abalone growth by reducing environmental stress and remodeling gut microbiota.

Biofouling and microenvironmental deterioration are major bottlenecks restricting the intensive aquaculture of Pacific abalone (Haliotis discus hannai). While co-culturing offers an eco-friendly mitigation strategy, the underlying mechanisms promoting abalone growth remain poorly understood. This study evaluated the growth performance of H. d. hannai co-cultured with varying densities of the sea urchin (Strongylocentrotus intermedius). By employing transcriptome and 16S rRNA sequencing of the abalone gut, we investigated the synergistic responses of host gene expression and gut microbiota. Compared with the monoculture group, the co-culture groups showed significantly less biofouling and greater growth of abalone, with the co-culture (n = 15) exhibiting the best outcomes. Transcriptomic analysis revealed 1444, 760, and 508 DEGs in G5, G10, and G15, respectively, compared with G0. These DEGs were significantly enriched in metabolic pathways, including glycolysis and sterol metabolism, indicating a shift in intestinal energy metabolism from stress defense toward growth under co-culture conditions. Gut microbiota profiling identified Proteobacteria and Firmicutes as the dominant phyla, with specific functional taxa (e.g., Psychrilyobacter and Akkermansia) enriched in a density-dependent manner. Furthermore, correlation analysis demonstrated that growth traits positively correlated with growth-promoting taxa (e.g., the unclassified AB1 lineage), but negatively correlated with potentially opportunistic taxa (e.g., Tabrizicola). These findings provide insights into a potential synergistic mechanism of "environmental stress alleviation-metabolic reprogramming-microecological remodeling" driving abalone growth, providing a theoretical foundation for optimizing co-culture systems and developing growth-associated biomarkers.

Animals↗

PubMed2025

New insights into soil amendment: Impact of humic acid on typical antibiotic resistance in agricultural soil.

Humic acid (HA) addition can improve agricultural soil, but little is known about how it affects the soil resistome. In this study, we used selective agar plate combined with quantitative PCR (qPCR) and 16S rRNA gene sequencing to investigate how HA influences antibiotic resistant bacteria (ARB) and antibiotic resistant genes (ARGs) in soil contaminated with erythromycin and kanamycin. 0.1 % HA reduced the abundance of culturable erythromycin-resistant bacteria (ERB), while promoting the growth of kanamycin-resistant bacteria (KRB). Lysinibacillus and Paenibacillus were the dominant genera in ERB and KRB, respectively, governing the changes in their abundances. At this concentration, the Lysinibacillus abundance in ERB decreased from 96.74 % to 70.57 %. Meanwhile, that of Paenibacillus in KRB increased from 33.40 % to 77.44 %. The copy number of ermF decreased after HA addition, while that of ermB increased. Furthermore, 0.1 % HA significantly reduced the copy number and relative abundance of aadA1 and aac(6')-Ib (aka aacA4)-03 in the soil. Changes in these two types of ARB and ARGs were primarily driven by shifts in the microbial community structure. Soil physicochemical properties, particularly increased organic matter (OM), altered the absolute abundance of ermB. Meanwhile, changes in intI1 abundance determined the risk associated with aadA1 and aac(6')-Ib (aka aacA4)-03. These findings emphasize the dual role of HA in the dissemination of antibiotic resistance in agricultural soils and highlight the necessity of considering dose-dependent effects when applying HA as a soil amendment.

Soil Microbiology↗

PubMed2026

Multi-omics analysis reveals stage-associated differences in gut immunity and microbiota between juvenile and adult common carp (Cyprinus carpio).

In vertebrates, the development of intestinal immunity is closely associated with dynamic changes in the gut microbiota. However, stage-associated differences in intestinal immunity and gut microbial communities remain poorly characterized in teleost fish. In this study, transcriptomic analysis combined with 16S rRNA gene sequencing was employed to characterize intestinal immunity and gut microbial communities in juvenile and adult common carp (Cyprinus carpio). Transcriptomic profiling revealed marked developmental differences in intestinal immune function. Juvenile carp exhibited a predominantly innate immune phenotype, characterized by elevated expression of pro-inflammatory cytokines, antimicrobial peptides, and lysozyme-related genes. This immune profile was accompanied by enhanced mucosal barrier function and a relatively pro-inflammatory intestinal environment. In contrast, adult carp displayed increased expression of genes associated with adaptive immunity, suggesting that adult common carp exhibit relatively stronger adaptive immune characteristics than juvenile fish. Gut microbiota analysis demonstrated significant stage-dependent differences in microbial diversity and community composition. Juvenile fish were enriched with bacterial taxa potentially associated with innate immune activation, whereas adult fish harbored distinct microbial communities linked to intestinal homeostasis and barrier maintenance. Furthermore, correlation analyses identified significant associations between specific microbial taxa and innate immune-related gene expression, suggesting a close association between gut microbiota composition and intestinal immune characteristics in juvenile and adult common carp. Collectively, these findings reveal stage-associated differences in intestinal immunity and gut microbial communities between juvenile and adult common carp, thereby providing insights into intestinal immune characteristics at different developmental stages in teleost fish.

Animals↗

PubMed2026

Routine methods misidentify Serratia spp.: Limitations of MALDI-TOF MS revealed by whole-genome sequencing.

Accurate species-level identification within the genus Serratia remains challenging due to extensive phenotypic overlap and high genomic relatedness among closely related and recently described taxa. This study presents an evaluation of routine and genome-based identification approaches applied to clinical Serratia isolates, integrating phenotypic assays, MALDI-TOF MS (Bruker Daltonics), 16S rRNA gene sequencing, and Whole-Genome Sequencing (WGS). A total of 103 isolates collected from a teaching hospital were analyzed. WGS was performed on a subset of isolates. Conventional biochemical methods classified all isolates as Serratia marcescens, whereas MALDI-TOF MS identified 60.1% as S. marcescens, 11.6% as S. ureilytica, and 28.1% just at the genus level. Peak analysis from MALDI-TOF MS revealed specific peaks associated with S. marcescens and S. ureilytica, but limited discriminatory power. WGS of six isolates initially identified as S. ureilytica by MALDI-TOF MS revealed reclassification as Serratia sarumanii (n = 5) and Serratia montpellierensis (n = 1), supported by Average Nucleotide Identity (ANI), Average Amino Acid Identity (AAI), and Digital DNA-DNA Hybridization (dDDH) thresholds. In contrast, 16S rRNA analysis showed limited species-level resolution. Phylogenomic and SNP-based analyses confirmed these classifications with strong support. Overall, this study underscores the critical role of high-resolution genomic approaches for precise species identification and highlights the need for continuous expansion and curation of MALDI-TOF MS reference databases to support reliable clinical diagnostics and epidemiological surveillance of emerging Serratia species.

Spectrometry, Mass, Matrix-Assisted Laser Desorpti↗

PubMed2026

Cross-kingdom dynamics of the subgingival bacteriome and mycobiome: A pilot study on the effects of a novel HA-H₂O₂-Glycine formulation to treat periodontitis.

OBJECTIVES: Traditional periodontal therapy primarily focuses on bacterial biofilm control; however, recent evidence also suggests a critical role for the oral mycobiome. This study evaluated the clinical and ecological impact of a novel mouthwash formulation containing hyaluronic acid (HA), hydrogen peroxide (H2O2), and glycine on periodontal patients METHODS: This prospective, randomized split-mouth trial included 13 adult participants with periodontitis treated with HA-H2O2-glycine formula (BMG0703A) used twice a day for seven days. Subgingival plaque samples were collected from periodontal pocket and healthy control sites at baseline (T0) and one-week post-treatment (T1). Microbial and fungal communities were characterized using Next-Generation Sequencing (NGS) of the 16S rRNA and ITS2 regions. Linear Mixed Models (LMM) and Spearman correlation were used to assess taxonomic shifts and cross-kingdom relationships. RESULTS: Sequencing revealed a promising ecological shift: the bacteriome shifted from anaerobic dominance (Olsenella, Peptostreptococcus) toward a health-associated aerobic profile, with Rothia near-doubling (11.91% to 22.68%). The mycobiome underwent a "normalization" effect: Candida abundance decreased significantly (22.8% to 9.1%), while fungal Shannon diversity in pockets returned to healthy-site levels. Inter-kingdom analysis identified antagonistic relationships between expanding commensal bacteria and opportunistic fungi, suggesting that the intervention may help re-establish a protective bacterial niche. CONCLUSIONS: The HA-H2O2-glycine formulation seems to facilitate a rapid, cross-kingdom modulation of the subgingival niche. By reducing anaerobic pathogens and normalizing the mycobiome it appear to induce short-term changes, suggesting potential as adjunctive strategy in periodontal management. CLINICAL SIGNIFICANCE: The present work underlines the possible cross-Kingdom effects of a novel compound.

Humans↗

PubMed2026

Microbial allies in a cotton pest: A descriptive account of associated microbiota dynamics in Dysdercus cingulatus across development.

BACKGROUND: Hemipteran insects harbour several symbiotic partners, mainly bacteria, which play pivotal roles for hosts like dietary provision, support overall physiology, xenobiotic degradation and manipulate/regulate behaviour. Most of these symbionts usually reside and operate from the digestive tracts of the animals. Cotton is one of the major cash crops in India and Dysdercus cingulatus (D. cingulatus) though a secondary pest, is causing significant destruction of cotton bolls, poor lint quality and reduce oil content of seeds. Premature opening of cotton bolls often leads to bacterial and fungal infections, thus resulting in extensive economic loss worldwide. D. cingulatus is a hemimetabolous insect that comprises of developmental stages like egg, nymph (5 instar stages), and adult. The present work explored the ontogeny specific diversity in the associated microbiota and predicted their probable functional inputs in D. cingulatus. RESULTS: The data obtained using 16S rRNA gene sequencing (NovaSeq 6000) revealed presence of members of Proteobacteria (65.83%), Firmicutes (24%), Actinobacteria (10%) phyla throughout the ontogeny of D. cingulatus. Highest alpha diversity of these symbiotic bacteria was recorded in the third instar nymphs in contrast to rest of the developmental stages. Among all the observed genera, Stenotrophomonas, Hungatella and Glutamicibacter were predominant from egg to adult stages. MicFunPred, a tool used for predicting the probable functional inputs of these symbionts, hinted at their probable stage specific contribution in crucial biochemical pathways such as polyketide biosynthesis, ascorbate/aldarate metabolism, pentose phosphate and glyoxylate cycles, steroid hormone and peptidoglycan biosynthesis, and glycolysis/pyruvate metabolism. CONCLUSIONS: The primary investigations on the ontogenetic composition and diversity of associated microbiota, suggest dynamic shifts in D. cingulatus, concurrent with their probable functions/roles in the host development and metabolism. To the best of our knowledge, this is the first report on symbiotic microbiota variation across the developmental stages of D. cingulatus that provides preliminary descriptive observations that may guide future functional and experimental investigations into microbiota-based pest management.

Animals↗

PubMed2026

Long-term microbiome and clinical effects of a microbiome-guided personalized diet versus low-FODMAP diet in irritable bowel syndrome: A 12-month follow-up randomized controlled trial.

Dietary therapy is central to irritable bowel syndrome (IBS) management, yet the long-term durability of the low-FODMAP diet (LFD), and of microbiome-guided personalization, remains unclear. We assessed the long-term clinical and gut-microbiome effects of a microbiome-guided personalized diet (PD) compared with a standard LFD in adults meeting Rome IV criteria for IBS. In this multicenter, open-label randomized controlled trial with blinded outcome assessment, participants who completed a 6-week dietary intervention (PD or LFD) were followed at 6 and 12 months without further dietary intervention. Outcomes included the IBS Severity Scoring System (IBS-SSS), IBS Quality of Life (IBS-QOL), and the Hospital Anxiety and Depression Scale (HADS); gut microbiota were profiled by 16S rRNA sequencing. Longitudinal changes were evaluated using linear mixed-effects models, responder analyses, PERMANOVA, and PERMDISP. Both diets reduced IBS-SSS at 6 weeks. PD maintained symptom improvement at 6 and 12 months (-82.0 and -78.3 points from baseline), whereas LFD benefits regressed by 12 months (+29.3 points; between-group p = 0.001). At 12 months, IBS-SSS responder rates were higher with PD than LFD (62.5% vs 34.5%; absolute risk difference +28.0%, 95% CI 4.2-47.7; Fisher p = 0.029), and IBS-QOL, HADS-anxiety, and HADS-depression showed more favourable trajectories with PD. PD was associated with sustained Shannon alpha-diversity gains (+0.488 at 6 weeks; +0.205 at 12 months; both p < 0.01). A modest between-group beta-diversity difference at 6 months (R2 = 0.035; p = 0.011) was not significant at 12 months. This hypothesis-generating follow-up suggests more durable benefit with PD; larger trials powered for long-term clinical and microbiome outcomes are warranted.

Humans↗

PubMed2026

ScRNA-seq analysis reveals the effects of nitrite stress on the endocrine system of the eyestalk in Litopenaeus vannamei.

Nitrite is a harmful substance generated in Litopenaeus vannamei farming systems, largely originating from the inadequate breakdown of surplus feed and shrimp feces. Its accumulation in the water can affect the growth and physiological functions of shrimp, damage the immune system, and even cause mass mortality, thus becoming a key environmental factor restricting the green development of the industry. Under nitrite stress, the eyestalk, as an important neuroendocrine regulatory center in crustaceans, participates in the stress adaptation of the organism and exerts a protective effect by regulating energy metabolism and immune function. However, the molecular regulatory mechanism of the eyestalk in response to nitrite stress remains unclear. In this study, single-cell RNA sequencing (scRNA-seq) technology was used to analyze the heterogeneity of eyestalk cells in L. vannamei under nitrite stress. A total of 18, 394 high-quality cells were obtained, and six major cell subpopulations, including Neurosecretory cell, Motor neuron, Sensory neuron, Interneuron, Neurogliocyte, and Support cell, were identified. Differential expression analysis identified 839 differentially expressed genes, and different cell types showed distinct specific responses to nitrite stress. Functional enrichment analysis indicated that pathways such as glycolysis, oxidative phosphorylation, ribosome function, and endoplasmic reticulum protein processing were significantly activated, while signal transduction and DNA repair-related pathways were inhibited. Further analysis revealed that nitrite stress could induce mitochondrial function changes and trigger oxidative stress, thereby affecting the neuroendocrine system function of the eyestalk. This study provided insights into transcriptomic responses of the eyestalk to nitrite stress at the single-cell level, laying a theoretical foundation for the management of aquaculture environments.

Animals↗

PubMed2026

Long-term heat exposure reshapes muscle molecular regulation and enhances thermal tolerance in Clarias fuscus.

Rapid fluctuations in water temperature driven by global warming have become a major abiotic stressor affecting muscle function in teleost fish. This study examined the effects of long-term thermal conditions on heat tolerance in Clarias fuscus. Fish were maintained for 90 days at either a normal temperature group (NT, 26 °C) or a high-temperature group (HT, 34 °C). Subsequently, muscle histology, and transcriptomic profiles were observed following acute high-temperature exposure (34 °C) and after temperature recovery (26 °C). Histological analysis showed that fish from the NT under acute high-temperature stress exhibited severe muscle damage (atrophy, myofilament disruption, and myolysis), whereas fish from the HT displayed markedly reduced lesions. RNA-seq profiling revealed 5769 differentially expressed genes (DEGs) in the NT and 3292 DEGs in the HT following acute temperature challenges. Functional enrichment indicated that, in the HT, modulation of key cell cycle regulators (e.g., ccna, ccnb, cdk1, cdk2) contributed to alleviating muscle damage caused by temperature fluctuations. In the NT, genes associated with ribosome biogenesis (e.g., nop56, riok2, riok1) were up-regulated and then down-regulated during temperature fluctuation, whereas p53 in the cell cycle pathway showed the opposite expression pattern. These findings demonstrate long-term heat exposure reshapes molecular expression and regulatory mechanisms in the muscle of C. fuscus, thereby enhancing thermal tolerance and adaptability, and providing a theoretical basis for breeding heat-resistant, high-quality aquaculture strains.

Animals↗

PubMed2026

Mitochondrial dysfunction in muscle cells induced by snoring vibrations.

Snoring-related vibrations have been proposed as a pathogenic factor contributing to upper airway muscle dysfunction in patients with obstructive sleep apnea (OSA). To investigate whether exposure to snoring vibration is linked to muscle weakness, we used an in vitro vibration model to examine its effects on mitochondrial homeostasis in L6 muscle cells at 8, 12, 24, and 48 h. The findings were then compared with mitochondrial alterations in the upper airway muscles from snorers and patients with OSA. Proteomic analysis of L6 myoblasts revealed extensive remodeling of the mitochondrial proteome at 8 h, affecting pathways involved in oxidative phosphorylation, protein import, ribosome biogenesis, and RNA processing. Respiratory chain remodeling was subunit-specific, with increased abundance of selected components of Complexes I, IV, and V, including NDUFS4, COX5A, and ATP5PD. However, reductions in spliceosome-associated factors, such as SRSF2 and DDX46, along with alterations in mitochondrial ribosomal proteins, indicated impaired RNA processing and protein synthesis. Furthermore, both proteomic and transcriptomic analyses revealed activation of a mechanosensing-mechanotransduction axis, with early upregulation of integrin subunits and mechanosensitive ion channels, followed by transient activation of focal adhesion signaling. Despite transcriptional upregulation of selected Complex IV subunits Cox5a and Cox6a2, this response was accompanied by accumulation of unspliced pre-mRNA, indicating impaired RNA processing efficiency and a decoupling between transcript and protein levels. Real-time Seahorse assay revealed a collapse of mitochondrial respiration and glycolytic reserve at 8 h. Although mitochondrial oxygen consumption recovered after 48 h, the ability to dynamically upregulate glycolysis remained impaired. In patients, muscle capillarization was impaired, COX activity was reduced, and mitochondrial organization was disrupted. Moreover, transcription of Complex IV subunits COX5A and COX6A2 was, as in vibrated L6 cells, upregulated, suggesting a mismatch between transcript levels and protein expression. We conclude that snoring-induced vibrations are an unrecognized stressor that disrupts mitochondrial homeostasis in muscle by impairing RNA processing, protein synthesis, and mechanotransduction-driven mitochondrial remodeling, leading to transcript-protein uncoupling and likely muscle dysfunction.

Humans↗