Search Results (1,254)

S-adenosyl-L-homocysteine hydrolase (SAHH) is an evolutionarily conserved enzyme present in eukaryotes, bacteria, and archaea. As the rate-limiting enzyme in the methionine cycle, it catalyzes the reversible hydrolysis of S-adenosyl-L-homocysteine (SAH) to adenosine and homocysteine, thereby modulating the S-adenosylmethionine/SAH ratio and cellular methylation potential. Dysregulation of SAHH activity is causally linked to cancer, cardiovascular disorders, and neurodegenerative conditions. This review systematically examines the biological distribution, catalytic mechanisms, structural architecture, and regulation of SAHH across diverse species. We highlight lineage-specific adaptations—including C-terminal truncation, a 40-residue substrate-binding-domain insertion, and a His-Phe molecular gate—that fine-tune substrate preference, cofactor affinity, and thermostability, with metal ions and NAD⁺ serving as key modulators of activity and conformational dynamics. These variations exemplify an evolutionary trade-off between catalytic efficiency and structural rigidity, particularly pronounced in archaeal and thermophilic orthologs. Collectively, these insights underpin the enzyme’s multifaceted translational value: SAHH serves as a therapeutic target for diverse diseases (e.g., cancer, viral infections, tuberculosis), a source of diagnostic/prognostic biomarkers (e.g., plasma homocysteine and SAH/SAM ratio), and a versatile biocatalyst for synthesizing pharmaceutical-grade adenosine and its derivatives. By integrating mechanistic, structural, and evolutionary perspectives, this review establishes a unified framework that explains these functional adaptations and their translational implications. This framework guides the rational development of SAHH-targeted inhibitors, diagnostic tools, and engineered biocatalysts, with broad applications in precision medicine and biotechnology. Full article

Class I KNOX1 (KNOTTED1-like homeobox 1) transcription factors integrate gibberellin (GA), cytokinin (CK), and auxin (IAA) signaling to maintain shoot apical meristem identity and coordinate plant organogenesis. This review examines the structural conservation, evolutionary dynamics, and regulatory architecture of KNOX1 genes across horticultural crops, drawing essential mechanistic context from model species. We synthesize KNOX1 functions in six agronomic domains, including plant architecture and branching, leaf morphogenesis and ornamental traits, floral development and sex determination, fruit formation and quality, storage organ specification, and abiotic stress resilience. Particular attention is given to recent breakthroughs in cucurbit inferior ovary development, tomato chloroplast patterning, and potato tuber morphogenesis. We identify critical bottlenecks constraining translation, including fragmented regulatory networks, recalcitrant transformation systems in woody perennials, uneven taxonomic coverage favoring annual vegetables over ornamentals and medicinal species, and a near-complete absence of multi-environment field validation. We propose four strategic priorities to bridge this gap: (i) construction of spatiotemporal expression atlases using single-cell and spatial transcriptomics; (ii) tissue-specific and promoter-engineered CRISPR/Cas9 editing to circumvent pleiotropic penalties; (iii) cross-species comparative evo–devo analysis of lineage-specific innovations (compound leaves, inferior ovaries, tubers); and (iv) integrated field trials assessing genotype-by-environment interactions and trait stability. This framework aims to accelerate KNOX1-directed molecular design breeding in horticultural crops. Full article

The size of the mitogenome varies greatly in angiosperms from different species, but the causes of expansion remain unclear. Species from the Zingiberaceae family often carry exceptionally large mitogenomes, where this phenomenon can be readily studied. C. kwangsiensis is a medicinal plant that is native to Guangxi, China, and it is traditionally used to treat blood stasis and gynecological conditions. We assembled its complete mitogenome by using the Illumina and Nanopore reads obtained from its analysis. The genome comprises 12 circular contigs with a multi-branched structure, totaling 7.76 Mb. It contains 39 protein-coding genes, 30 tRNAs (transfer RNAs), three rRNAs (ribosomal RNAs), and 652 C-to-U RNA edited sites. Repeated analysis revealed that the dispersed repeats are the major contributors to genome expansion. Comparisons with two other Zingiberaceae mitogenomes suggested that the large genome arose in a common ancestor rather than from a whole-genome duplication, with little contribution from DNA transfers from the chloroplasts and nuclei. Thus, the exceptionally large mitogenome of Curcuma appears to result largely from repeated accumulation in the non-coding regions, such as nuclear genome expansion in angiosperms. This finding also highlights the conservation of core mitochondrial genes. Our work provides new insights into mitogenomic size variations and gene conservation in plant species, including Zingiberaceae. Full article

Epimedium sagittatum is an important understory shade-tolerant medicinal plant native to China. However, assessments of its responses to climate change under multiple scenarios and time periods remain insufficient, particularly regarding the mitigation of model overfitting and the quantitative disentanglement of hydrothermal constraints. In this study, based on 269 valid occurrence records and 24 initial environmental variables (reduced to 13 after collinearity screening), we employed a parameter-optimized MaxEnt 3.4.4 model (RM = 3.5, FC = QHP) coupled with the BCC-CSM2-MR climate model to project the dynamics of potential suitable habitats under current (1970–2000) and future (2050s, 2070s, 2090s) scenarios (SSP126, SSP370, SSP585). The results showed that the optimized model substantially reduced the risk of overfitting compared with the default parameters (ΔAICc dropped from 82.16 to 0) and achieved an AUC of 0.934. Precipitation of the Driest Quarter (Bio14, 53.4% contribution) and Minimum Temperature of the Coldest Month (Bio6, 20.5% contribution) were identified as the dominant factors governing the species’ distribution, with optimum conditions of ≥1.58 mm and −8.34 °C to 13.61 °C, respectively. Under future climate scenarios, the centroid of suitable habitats shifted progressively southwestward, with a cumulative displacement of approximately 127.47 km under SSP585, and water availability, rather than temperature, dominated the direction of this shift. Under the high-emission scenario, suitable areas exhibited a spatial reorganization characterized by westward expansion and eastward contraction. Based on these findings, this study proposes a three-tier planning framework comprising in situ conservation, climate-smart introduction, and assisted migration, providing a scientific basis for the conservation of germplasm resources and the spatial planning of artificial cultivation of E. sagittatum. Full article

Urban pigeons (Columba livia) are widely distributed synanthropic birds closely associated with environments of intense human activity, raising interest in their role in urban microbial dynamics. Here, we characterized the fecal bacterial microbiota of urban pigeons from northern Mexico using 16S rRNA gene amplicon sequencing (V3–V4). A total of 1479 amplicon sequence variants (ASVs) were identified across five pooled samples. Alpha diversity varied among pools, with observed richness ranging from 228 to 514 ASVs. The bacterial community was dominated by Proteobacteria and Firmicutes, particularly Escherichia–Shigella and Enterococcus. PICRUSt2-based functional predictions suggested a predominance of predicted metabolic pathways related to carbohydrate degradation and energy acquisition. Conservative taxonomic screening identified 58 gut-associated taxa, including 15 bacteria previously reported in association with humans; however, only three (Clostridium perfringens, Enterococcus faecalis, and Proteus mirabilis) showed reported zoonotic associations, all at very low relative abundances (<0.07%). These findings indicate that the fecal bacterial communities characterized in this study were dominated by taxa commonly associated with the avian gastrointestinal tract, whereas taxa that could be conservatively linked to documented zoonotic reports represented only a minor fraction of the detected microbiota. Overall, the results contribute to a more ecologically informed understanding of urban pigeon-associated microbiota within a One Health framework. Full article

Systems Medicine aims to understand the dynamics of physiological systems and the differences between healthy and disease states, to then bring the latter back to health. To this aim, it is critical to identify the states that allow modifying the phenotype of a model system and are robust to perturbations. Indeed, for these changes to be sustained in time, the system’s robustness shall be investigated through various analyses and their emerging results. Lie symmetry analysis—a study of fixed variable relations in a differential equations model—uncovers the model’s hidden robustness through its conservation laws. The emerging conservation laws can then be used as a series of robust invariant characteristics of the system under a specific type of perturbations. Although it holds much predictive potential for robustness investigations, the application of Lie symmetry-based conservation law analysis to physiological systems is currently unexplored. Here, we propose a novel application of Lie symmetry-based conservation law analysis to identify the conservation laws—and their existence conditions—influencing the dynamics of a system towards robust remission or relapse. This methodology is used to analyse a minimal model of rheumatoid arthritis with the aim to: (i) investigate the existence and extent of robust disease characteristics as conservation laws of the model, (ii) clinically interpret their biological viability, and (iii) inform model plausibility, testing, and selection. This novel application of the Lie symmetry analysis can retrieve the robust characteristics of physiological conditions, thus providing a new analytical contribution to the Systems Medicine field. Full article

Handroanthus chrysanthus (Jacq.) S.O. Grose is a Neotropical tree species highly valued for its ornamental beauty, durable timber, and medicinal properties. However, overexploitation and the recalcitrant nature of its seeds have constrained propagation and conservation efforts, and the species has been listed as Vulnerable on the IUCN Red List since 2020. In this study, a direct adventitious shoot regeneration system was developed for H. chrysanthus by systematically evaluating explant type, basal medium, plant growth regulator combination, and light quality. Hypocotyls were identified as the most responsive explants for shoot induction, and the highest adventitious shoot induction frequency, 51.79%, was obtained on Murashige and Skoog medium (MS) supplemented with 5 mg·L⁻¹ 6-benzylaminopurine, 0.5 mg·L⁻¹ indole-3-butyric acid, and 0.2 mg·L⁻¹ thidiazuron under white fluorescent light. The highest shoot multiplication coefficient, 3.27, was obtained on MS medium containing 4 mg·L⁻¹ 6-benzylaminopurine and 0.3 mg·L⁻¹ gibberellic acid. The maximum rooting frequency, 80%, was obtained on R14 medium after 30 days of culture. After acclimatization, 95% of the regenerated plantlets survived and grew vigorously under greenhouse conditions. To our knowledge, no direct adventitious shoot regeneration system has been reported for the Tabebuia alliance. This efficient regeneration protocol provides a practical platform for clonal propagation, germplasm conservation, and genetic improvement of H. chrysanthus and may also support regeneration and conservation in related endangered taxa within the Tabebuia alliance. Full article

Butterworts (Pinguicula spp.) are carnivorous plants often restricted to small, isolated populations in mountainous microclimates, making them vulnerable to inbreeding and demographic decline. In Mexico, the global hotspot for Pinguicula diversity (>50 species, 90% endemic), conservation is limited by scarce data on population biology, demography, and vulnerability. This study provides the first population size estimate for the endemic P. gracilis and evaluates how patch and population size influence biological fitness components across three localities in northeastern Mexico. Using a multi-component fitness framework and statistical models, we found that smaller populations and patches exhibit significantly reduced reproductive fitness, particularly in fruit set and seed quality. Patch size showed strong positive correlations with fruit production (r = 0.45–0.53), while isolation negatively affected seed output (r = −0.48). These results highlight the role of landscape structure in shaping fitness components, with patch size influencing reproductive effort and connectivity determining reproductive success. Our findings provide the first germplasm and population baseline for P. gracilis and a framework to identify vulnerable populations, prioritize conservation actions, and guide restoration strategies. Full article

Horses in Vietnam have a long historical presence and continue to hold economic, socio-cultural, and medicinal importance across diverse regions. Despite these roles, comprehensive scientific information on equine development, including health and disease patterns, reproductive performance, genetic resources, and biomedical applications, remains limited and fragmented. In this review, we summarize existing knowledge on equine populations, production systems, and their development in Vietnam, as well as their roles in cultural practices, livelihoods, and traditional medicine. We then identify major gaps in surveillance, genetic characterization, and coordinated research capacity by synthesizing evidence from breeding, health, reproduction, and emerging research areas. Finally, we highlight where current efforts fall short and outline key priorities for future work to strengthen equine science, support culturally relevant practices, and guide the sustainable development of Vietnam’s horse sector. Overall, the synthesis information shows (i) native Vietnamese horses belong to the Southeast Asian pony complex and include at least four recognized populations; (ii) the northern mountain provinces account for the substantial majority of the national herd; (iii) strongyle infections, Trypanosomiasis, haemorrhagic septicaemia and the recently confirmed equine piroplasmosis are the principal health challenges; and (iv) genetic characterization, reproductive management, welfare assessment, and capacity building are the four most critical research priorities identified. This information is important for prioritizing future research and conservation activities and enhancing the development of Vietnam’s horse population. Full article

Bovine-associated microbial communities play important roles in animal physiology, immune regulation, and mammary health. However, knowledge regarding bacterial populations associated with blood and milk remains limited in healthy dairy cattle exposed to different environmental conditions. In this study, we characterized and compared blood- and milk-associated bacterial communities from clinically healthy Holstein cows during summer and winter in an intensive commercial dairy production system located in northern Mexico using 16S rRNA metabarcoding. Significant differences in alpha and beta diversity metrics were observed according to sample type and season. Milk samples exhibited higher microbial richness and diversity than blood samples, and comparative analyses revealed significant differences in bacterial community composition between sample types and seasonal sampling periods. Bacterial communities were mainly dominated by Proteobacteria, Firmicutes, Actinobacteriota, and Bacteroidota. Differential abundance analyses identified genera associated with environmental exposure or opportunistic infections, including Staphylococcus, Streptococcus, Corynebacterium, Pseudomonas, and Acinetobacter. Overall, the observed bacterial community patterns varied according to sample type and seasonal environmental conditions, highlighting the complexity of host-associated microbial ecosystems in dairy cattle. Full article

The Zona Pellucida (ZP) and its structural analogs are evolutionarily ancient extracellular matrix components. These are essential for oocyte protection, species-specific gamete recognition, and prevention of polyspermy across Metazoa. Defined by the conserved ZP-domain—comprising ZP-N and ZP-C subdomains—these glycoproteins self-assemble into fibrillar matrices through tightly regulated polymerization. Mechanisms of the regulated polymerization involve furin cleavage, disulfide bonding, and hydrophobic interactions. Once considered a vertebrate innovation, the canonical ZP-domain—defined by its bipartite ZP-N/ZP-C architecture, eight conserved cysteine residues, and capacity for matrix polymerization—is now recognized as an ancient metazoan extracellular module, with homologs identified in basal lineages including Porifera, Cnidaria, and Placozoa. While ZP-like sequences have been reported in choanoflagellates such as Salpingoeca rosetta, these lack the complete canonical features and are considered distant structural relatives rather than true ZP-modules. There they function in cell adhesion and tissue integrity, suggesting an origin predating the evolution of specialized reproductive coats. Previous phylogenetic analyses across 97 metazoan species have revealed that vertebrate ZP genes arose from ancestral duplications of the canonical ZP-module. Accordingly, they give rise to eight subfamilies (ZP1–ZP4, ZPD, ZPAX, ZPX, ZPY), with lineage-specific expansions, losses, and pseudogenization reflecting adaptations to diverse reproductive strategies. Positive selection in sperm-binding regions of ZP2 and ZP3 drives a rapid adaptive evolution. It underscores coevolutionary arms races with sperm ligands, contributing to reproductive isolation and speciation. In invertebrates such as abalone and insects, ZP-domain proteins mediate analogous functions through lineage-specific elaborations, including tandem repeats and domain shuffling. Post-translational modifications, particularly glycosylation, fine-tune sperm receptor specificity and matrix stability. The functional transition from a general protective barrier in early metazoans to a sophisticated gamete recognition interface in vertebrates exemplifies modular evolution. This synthesis highlights the domain-level deep homology of ZP-domain proteins as a foundational element of metazoan extracellular matrices, repurposed through gene duplication, neofunctionalization, and selection to meet the demands of evolving reproductive modes. These insights bridge evolutionary biology, reproductive medicine, and developmental genetics. However, major gaps remain, including unresolved orthology between vertebrate and invertebrate ZP genes, the relative contribution of glycans versus protein backbone in sperm recognition, and the lack of functional evidence for canonical ZP-domain proteins in insects. Future studies integrating glycoproteomics, single-cell transcriptomics, and CRISPR-based models are needed to resolve these questions. Full article

Trillium camschatcense, a plant renowned for its ecological and medicinal value, is predominantly found in the temperate forests of East Asia. However, its habitat is increasingly threatened from climate change, habitat fragmentation, and intensified human activities. In this study, the Maxent (Maximum Entropy) model was used to assess the current ecological suitability of T. camschatcense based on historical climate data (1970–2000), and further simulate its potential distribution shifts under multiple future climate change scenarios to predict long-term habitat variation trends across northeast China. All modeling and spatial mapping analyses were performed using MaxEnt and ArcGIS 10.8.1 software. Drawing upon 93 known distribution points and 26 pertinent environmental variables covering climate, soil, and elevation, we built species distribution models for both present and future periods to pinpoint the crucial environmental factors influencing its distribution. Our findings revealed that elevation, soil nitrogen content, seasonal temperatures, annual precipitation, mean temperature during the coldest quarter, and mean diurnal temperature range were the primary factors influencing the distribution of T. camschatcense. Notably, highly suitable habitats were predominantly concentrated in Baishan City and the southwestern region of Yanbian Korean Autonomous Prefecture in Jilin Province. This insight offers valuable scientific guidance for the conservation planning, sustainable utilization, and potential introduction and cultivation of T. camschatcense. Furthermore, targeted conservation strategies can help identify climate refugia and protect climatically stable habitats for the long-term persistence and resilience of the species under continuous global warming. Full article

With the intensification of global climate change and the increasing frequency of extreme weather events, medicinal plants are facing unprecedented challenges to their survival environments. Understanding the impacts of ecological threats on medicinal plants is crucial for formulating conservation strategies and ensuring the sustainable utilization of Traditional Chinese Medicine (TCM) resources. This study employed a scoping review methodology to systematically search databases including CNKI, Wanfang Data, and PubMed, incorporating both the Chinese and English literature. A conceptual map was constructed to analyze the response mechanisms, distribution changes, and conservation status of medicinal plants under ecological threats. The review synthesizes evidence from 65 articles retrieved from both the Chinese and international literature. Our mapping reveals that (1) ecological threats are extensively documented, with habitat loss and climate change being the primary drivers; (2) the responses of medicinal plants are mainly manifested as population decline, range shifts, and alterations in secondary metabolites; (3) current conservation efforts focus heavily on ex situ protection, while research on climate change adaptation management remains insufficient. This study systematically outlines the current research landscape regarding medicinal plants under ecological threats, revealing the characteristics and gaps in existing evidence. Future research should strengthen interdisciplinary collaboration, focusing on adaptive evolution and ecological restoration technologies to address the escalating environmental challenges. Full article

Geographic and ecological variations are frequently associated with differences in the microbiota of arthropod vectors, with potential implications for pathogen transmission and public health. This study characterized and compared the bacterial microbiota associated with the brown dog tick (Rhipicephalus sanguineus) across three ecologically contrasting regions of Mexico: Cancun (Quintana Roo), Comarca Lagunera (Durango–Coahuila), and Hermosillo (Sonora). Non-engorged ticks collected from stray dogs were analyzed using 16S rRNA gene (V3–V4) sequencing. Amplicon sequence variants (ASVs) generated in QIIME2 were used for taxonomic, diversity, and predictive functional analyses. Proteobacteria dominated all samples, with Coxiella-like bacteria tentatively assigned as Coxiella mudrowiae identified as a dominant taxon across all localities. Significant geographic differences were observed in alpha and beta diversity, with Comarca Lagunera showing the highest diversity and Hermosillo the lowest. Sequences tentatively assigned to Rickettsia rickettsii were detected exclusively in two pools from Hermosillo. Functional predictions revealed a conserved metabolic repertoire alongside geographic variation in pathway abundance. Overall, the results support the existence of a stable symbiotic component accompanied by a geographically variable bacterial fraction associated with ecologically contrasting regions. These findings highlight the importance of geographic context in shaping tick-associated bacterial communities. Full article

For over 3000 years, the perennial herb mugwort (Artemisia argyi) has served as a cornerstone of traditional Asian medicine. Its clinical efficacy is driven by a diverse array of specialized metabolites, most notably flavonoids and volatile oils. While B-box (BBX) transcription factors are known to dictate photomorphogenic development and secondary metabolic pathways in plants, this specific gene family has not yet been systematically analyzed in A. argyi. Leveraging a chromosome-level genomic assembly, we comprehensively identified and analyzed the complete repertoire of AarBBX genes, profiling their structural organization, physicochemical attributes, conserved motifs, promoter architecture, and spatial expression dynamics. The AarBBX family segregates into five distinct evolutionary clades and comprises 114 members, exceeding the gene counts in the diploid relatives Artemisia annua (27) and Arabidopsis thaliana (32), a numerical increase potentially attributable to the tetraploid genome architecture of A. argyi. Promoter scanning revealed a high density of cis-acting elements linked to light perception and environmental stress responses. Integrating RNA-seq transcriptomics with tissue-specific expression profiling, we identified prominent candidate light-responsive AarBBX genes that are highly active in green, photosynthetic tissues and acutely responsive to shifts in light conditions, providing a foundation for future exploration of their potential relationship with secondary metabolic pathways, including flavonoid and terpenoid biosynthesis. Furthermore, we validated the potential operational compartments and structural interactions of these proteins utilizing green fluorescent protein (GFP) subcellular localization and yeast two-hybrid (Y2H) screenings. Collectively, these findings provide new insights into the evolutionary trajectory and regulatory potential of the B-box (BBX) proteins in A. argyi, offering a prioritized candidate gene set for subsequent investigations into their potential roles in light-regulated secondary metabolism, including flavonoid and terpenoid pathways. Full article