Protoplasma最新文献

Mastigonemes on the anterior flagellum (AF) of flagellated Stramenopiles (which includes diverse organisms such as diatoms, brown algae, oomycetes and others) are tripartite tubular structures. We investigated the functions of mastigonemes in gametes of the brown alga Ectocarpus species 7 strain Ec32 using a mas1 mutant generated by CRISPR-Cas9. Loss of mastigonemes in the mas1 mutant gametes could be confirmed by immunofluorescence microscopy using a specific anti-MAS1 antibody and transmission electron microscopy, showing complete loss of mastigonemes from the AF. High-speed video analysis revealed a drastic reduction in swimming speed in the mas1 mutant gametes compared to wild type gametes, despite an increase in the AF beat frequency. Additionally, waveform analysis indicated larger AF double amplitudes in the mas1 mutant gametes. These results suggested that mastigonemes enhance the AF thrust. The mas1 mutant male gametes fertilized female gametes (wild type strain Ec25). A mas1 mutant female strain was established from the heterozygous sporophyte that developed from such a zygote. Both wild type and the mas1 mutant male gametes could fertilize the mas1 mutant female gametes. Mastigonemes are therefore dispensable for gamete recognition and fusion in the brown alga Ectocarpus.

Smooth muscle tissues exhibit significant functional diversity across various organ systems, but their cellular heterogeneity remains poorly understood. Recent ultrastructural investigations have identified two distinct populations of smooth muscle cells (SMCs), dark and light cells suggesting potential specialization in their roles. This study aims to comprehensively characterize these SMC subpopulations using a detailed morphological approach and histochemical techniques. This study characterizes two morphologically and functionally distinct smooth muscle cell (SMC) populations-light and dark cells-in avian intestinal and pulmonary tissues through comprehensive histochemical (H&E, Giemsa, Mallory/Crossmon's trichrome, silver stain, alcian blue, toluidine/methylene blue, PAS, Orange G) and ultrastructural (TEM) analyses. Light cells, identified by electron-lucent cytoplasm and secretory vesicles, and dark cells, marked by electron-dense cytoplasm and lysosomes, were consistently segregated within the intestinal muscular tunic and bronchovascular walls. Both subtypes contained dense bodies, confirming contractile capacity while suggesting specialized roles-light cells in secretory functions (e.g., extracellular matrix modulation) and dark cells in lysosome-mediated tissue remodeling. In pulmonary tissues, these cells populated the bronchial walls and the arterial tunica media, implicating subtype-specific contributions to airway resistance and vascular tone. The conserved presence of these populations across organs highlights their fundamental role in motility regulation, with clinical relevance to SMC pathologies: light cell dysfunction may underlie secretory disorders (e.g., mucus hypersecretion in asthma), while dark cell abnormalities could drive hypercontractile states (e.g., hypertension, achalasia). These findings establish avian models as powerful tools for investigating SMC heterogeneity, offering insights into phenotype-specific mechanisms in motility diseases and paving the way for targeted therapies that selectively modulate secretory or contractile SMC subpopulations to restore tissue homeostasis.

Fusarium wilt caused by Fusarium oxysporum poses a significant threat to tomato cultivation worldwide and requiring the development of sustainable and effective control measures. This study explored the potential of biologically synthesized iron oxide nanoparticles (IONPs) as an eco-friendly alternative to conventional fungicides and evaluated their antifungal efficacy along with plant health impact. The IONPs were synthesized using Trichoderma spp. metabolites and characterized using multiple analytical techniques. DLS and XRD analyses confirmed a uniform size distribution (80 nm hydrodynamic size and 16.83 nm crystallite size). SEM imaging showed agglomerated particles ranging from 30 to 50 nm, while EDX confirmed Fe and O as the primary elements. FTIR spectroscopy indicated the presence of protein capping agents and Fe-O bonds. In vitro studies demonstrated significant antifungal activity with 76.19% growth inhibition against F. oxysporum compared to commercial carbendazim (17.86%). Greenhouse experiments showed dose-dependent effects with 100 ppm IONPs treatment resulted in remarkable improvements in plant growth parameters: 143.1% increase in shoot length, 178.8% in root length, and 505.9% in wet weight. Disease incidence was reduced by 89.8% at a concentration of 100 ppm, whereas the disease severity index decreased by 60%. Plant physiological analysis revealed an enhanced chlorophyll content (237.3% increase at 100 ppm) and modulated stress enzyme (superoxide dismutase and peroxidase) activity. The soil dehydrogenase activity improved by 170% after treatment with 100 ppm. Furthermore, toxicity prediction indicated a low toxicity potential (LD50: 5000 mg/kg, class 4), supporting it's safe agricultural applications. This study highlights biosynthesized IONPs as an eco-friendly alternative for Fusarium wilt management, offering potential in sustainable agriculture.

Gills are associated with a gland known as the cervical gill slit gland. Little is known regarding the composition, function, and nature of the secretion from the gill slit glands. The current work used semi-thin sections and transmission electron microscopy to analyze the morphological aspects of the gill or brachial gland in the apparently, three healthy silver carp (H. molitrix). The oil cells' basal zone had a flattened profile, a prominent nucleus with euchromatin and distinct nucleuses, and cytoplasm with relatively few lipid droplets and an indistinguishable smooth endoplasmic reticulum. The maturation zone takes on a polyhedral form, has pronounced SER, and accumulates various lipid droplets. They have a dilated smooth nuclear membrane and a dilated SER. Lipid droplets may be associated with the SER. The pyknotic nucleus identified damaged oil cells that had empty spaces and were involved in different stages of making lipids connected to the formation of small sacs. More studies should be done to explore the chemical properties of the secretion, and the tissue features of the secretory epithelium to gain a clearer understanding of the signal produced by the gill slit gland.

Epigenetic responses of in vitro-cultured plants to elicitation with salicylic acid (SA) and methyl jasmonate (MJ) have been little explored. This study addresses how pepper seedlings respond to incorporating SA (0 and 10 µM) and/or MJ (0 and 10 µM) into the culture medium at physiological and molecular levels. The individual application of MJ or SA enhanced root fresh weight by an average of 59.8%. However, the mixed treatment synergistically augmented the root biomass by 2.2-fold. SA was individually more effective than MJ in triggering changes in the DNA methylome profiles. The epigenetic cytosine methylation in the MJ + SA group differed from that of the individual treatments. The individual SA treatment led to severe DNA hypermethylation, which was modified with the MJ application. Moreover, MJ and/or SA-mediated upregulation of the histone deacetylase (HDA) gene also confirmed the epigenetic regulation at the histone modification level. The MJ elicitor showed greater effectiveness in influencing the transcription of the target genes than the SA one. The expression of the MAPK kinase and ethylene-responsive transcription factor (EREB) genes displayed a similar upward trend. Applying pepper seedlings with MJ and SA increased proline concentrations and catalase activities. The simultaneous application of MJ and SA supplements effectively stimulated secondary metabolism, indicated by increased soluble phenols and activity of the phenylalanine ammonia-lyase enzyme. This study presents novel comparative insights into the SA and MJ-mediated epigenetic modifications. These findings can be employed to design in vitro culture systems and implement large-scale projects.

Chlorella spp. live in mutual symbiosis with Paramecium bursaria. In the present study, we investigated the digestive processes of Chlorella variabilis isolated from P. bursaria ingested by P. multimicronucleatum, a species that does not have the ability to undergo endosymbiosis with algae. The digestion of algae within the digestive vacuole (DV) of P. multimicronucleatum began within 5 min, and complete digestion occurred within 12 h. The digested algae were retained in P. multimicronucleatum even after 72 h of incubation. Additionally, after 0.5 h, some single green alga appeared in the P. multimicronucleatum cytoplasm by budding from the DV membrane. Comparing the re-endosymbiosis process between P. bursaria and Chlorella sp., some algae exhibited temporary lysosomal enzyme resistance in P. multimicronucleatum DVs and appeared from the DVs by budding the DV membrane one cell at a time. However, the differentiation of the DV membrane surrounding a single green alga into a symbiosome membrane, called the perialgal vacuole membrane, localized beneath the P. bursaria cell cortex was not observed in P. multimicronucleatum. These findings provide insights into the digestive process of symbiotic algae in Paramecium species incapable of endosymbiosis and highlight the unique adaptations required for the establishment of endosymbiosis between P. bursaria and Chlorella spp.