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Plasmodesmata (PD) are plasma membrane-lined cytoplasmic nanochannels that mediate cell-to-cell communication across the cell wall. A range of proteins are embedded in the PD plasma membrane and endoplasmic reticulum (ER), and function in regulating PD-mediated symplasmic trafficking. However, knowledge of the nature and function of the ER-embedded proteins in the intercellular movement of non-cell-autonomous proteins is limited. Here, we report the functional characterization of two ER luminal proteins, AtBiP1/2, and two ER integral membrane proteins, AtERdj2A/B, which are located within the PD. These PD proteins were identified as interacting proteins with cucumber mosaic virus (CMV) movement protein (MP) in co-immunoprecipitation studies using an Arabidopsis-derived plasmodesmal-enriched cell wall protein preparation (PECP). The AtBiP1/2 PD location was confirmed by TEM-based immunolocalization, and their AtBiP1/2 signal peptides (SPs) function in PD targeting. In vitro/in vivo pull-down assays revealed the association between AtBiP1/2 and CMV MP, mediated by AtERdj2A, through the formation of an AtBiP1/2-AtERdj2-CMV MP complex within PD. The role of this complex in CMV infection was established, as systemic infection was retarded in bip1/bip2w and erdj2b mutants. Our findings provide a model for a mechanism by which the CMV MP mediates cell-to-cell trafficking of its viral ribonucleoprotein complex.

In recent years, with the rapid development of life sciences, the use of laboratory fish in toxicology, genetics, developmental biology and medicine has increased dramatically, and they have gradually become important new model organisms. At the same time, the welfare of laboratory fish has also received increasing attention. Although the research level of experimental fish welfare is still in a relatively early stage compared to terrestrial experimental animals, developed regions such as Europe and America have established corresponding legal frameworks to safeguard the welfare of laboratory fish in research. This article elucidates the current developmental status of laboratory fish welfare, discusses the rationale behind the imperative to prioritize and enhance their welfare, deeply investigates factors influencing their welfare from the feeding stage and experimental stage. Moreover, it explores strategies for augmenting welfare standards, with the overarching aim of propelling the continual improvement of laboratory fish welfare in our country.

Objective To observe the fine structure of the trunk kidney in zebrafish, and to identify its secreted exosomes.Methods The microstructure and ultrastructure of the trunk kidney in zebrafish were observed by light microscopy and electron microscopy, and the particle size of exosomes was detected by nanoparticle tracking analysis (NTA).Results The trunk kidney was close and parallel to the spine in adult zebrafish. The nephron consisted of renal tubules and renal corpuscles. The renal tubules could be further divided into three types: proximal convoluted tubules, distal convoluted tubules, and cervical segments. The renal corpuscles were composed of glomerulus and renal capsules. The periodic acid-Schiff (PAS) staining results revealed that there were abundant glycogen granules in the proximal convoluted tubules, with brush-like outline in the apical surface of epithelial cells. Under transmission electron microscopy (TEM), there were exosomes distributed in the lumen of renal tubules, with numerous late endosomes and few number of multivesicular bodies (MVBs) in the cytoplasm of the epithelial cells concentrating on the apical side. Meanwhile, MVBs were also distributed in the apical regions of the renal tubules and the podocytes of the renal glomeruli. Immunohistochemical staining results showed that CD9, CD63 and TSG101 were strongly expressed in the lumen surface of the renal tubules, but weakly expressed in the corpuscles and lumen. NTA and TEM results showed that the exosomes isolated from zebrafish trunk kidney were saucer-like outline, and the particle size mode was 144.4 nm, which was consistent with the characteristics of morphological futures of exosome.Conclusion The zebrafish somatic kidney has the typical structure of the mammalian kidney and is the urinary organ in the body. The renal tubules have the ability to secrete exosomes, and their formation is a process of releasing poly-vesicles to the free surface of epithelial cells into the extracellular space. This study laid a morphological foundation for further study of exosomes in urinary function in aquatic experimental animals as well as the development and application of related models.

As the incidence of male infertility has been increasing during recent years, it is urgent to reveal the pathogenesis of male infertility, as well as to develop the new drugs for treatment of male infertility, in order to solve the declining birth rate and aging problems. The construction and application of male infertile animal models is critical for drug development, which plays an important role in accurately evaluating the efficacy and mechanism of infertility treatment. A suitable infertility model not only can reduce the repeated drug efficacy evaluations, reduce animal usage and the cost of new drug development, but also has important reference value for subsequent clinical trial research. Male infertility laboratory animal models can be constructed through chemical, physical, endocrine, environmental estrogen, gene modification, and immune methods. This article mainly introduces the existing male infertility animal models available for drug development, and briefly introduces the application progress of each model to provide reference for the male infertility drug researchers.

This article, published in the New Phytologist journal, discusses the behavior and internalization of the AtRGS1 protein in response to different pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs) in Arabidopsis thaliana. The study found that AtRGS1 exhibits distinct behaviors and endocytic pathways depending on the type of PAMP/DAMP, and that its phosphorylation pattern contributes to its organization and endocytic model. The research provides insights into the mechanisms of plant immune responses. [Extracted from the article]

This article investigates the sampled‐data stabilization problem for a class of switched singular systems with aperiodic sampling. The asynchronous switching between the plant and the switched controller caused by sampling is considered. Unlike normal systems, the conventional zero‐order hold type sampled‐data control law may be inapplicable to singular systems. This is because under that control law, the algebraic equations of singular systems may have no solutions at sampling instants. To cope with this problem, a new hybrid control law composed of a mode‐dependent impulsive controller and a mode‐dependent sampled‐data state feedback controller is devised. The impulsive controller adjusts the values of differential substate at sampling instants so that the algebraic equations are solvable. Then, by constructing a novel piecewise sampling‐time‐dependent Lyapunov function and using the average dwell time method as well as convex technique, a sampling‐range‐dependent sufficient condition for exponential stability of the resulting closed‐loop system is established. Moreover, an optimization‐based method is proposed to solve the hybrid controller gains. Simulation results on two examples including a mechanical arm system show the effectiveness of the proposed control method. [ABSTRACT FROM AUTHOR]

Background: Intervertebral disc degeneration (IDD) is a significant cause of low back pain and poses a significant public health concern. Genetic factors play a crucial role in IDD, highlighting the need for a better understanding of the underlying mechanisms. Aim: The aim of this study was to identify potential IDD‐related biomarkers using a comprehensive bioinformatics approach and validate them in vitro. Materials and Methods: In this study, we employed several analytical approaches to identify the key genes involved in IDD. We utilized weighted gene coexpression network analysis (WGCNA), MCODE, LASSO algorithms, and ROC curves to identify the key genes. Additionally, immune infiltrating analysis and a single‐cell sequencing dataset were utilized to further explore the characteristics of the key genes. Finally, we conducted in vitro experiments on human disc tissues to validate the significance of these key genes in IDD. Results: we obtained gene expression profiles from the GEO database (GSE23130 and GSE15227) and identified 1015 DEGs associated with IDD. Using WGCNA, we identified the blue module as significantly related to IDD. Among the DEGs, we identified 47 hub genes that overlapped with the genes in the blue module, based on criteria of |logFC| ≥ 2.0 and p.adj <0.05. Further analysis using both MCODE and LASSO algorithms enabled us to identify five key genes, of which CKAP4 and SSR1 were validated by GSE70362, demonstrating significant diagnostic value for IDD. Additionally, immune infiltrating analysis revealed that monocytes were significantly correlated with the two key genes. We also analyzed a single‐cell sequencing dataset, GSE199866, which showed that both CKAP4 and SSR1 were highly expressed in fibrocartilage chondrocytes. Finally, we validated our findings in vitro by performing real time polymerase chain reaction (RT‐PCR) and immunohistochemistry (IHC) on 30 human disc samples. Our results showed that CKAP4 and SSR1 were upregulated in degenerated disc samples. Taken together, our findings suggest that CKAP4 and SSR1 have the potential to serve as disease biomarkers for IDD. [ABSTRACT FROM AUTHOR]