Open Biology最新文献

The type III secretion system (T3SS) has traditionally been studied for its role in bacterial virulence. However, recent research emphasizes its dual role in beneficial interactions between bacteria and plants. This review examines the immunomodulatory functions of T3SS beyond pathogenicity and focuses on how T3SS effectors manipulate plant immune responses to promote symbioses. By comparing T3SS mechanisms in pathogenic and non-pathogenic bacteria, we aim to understand how this system enables beneficial microbes to colonize plants and improve plant growth and stress resilience. We also investigate the potential of T3SS to trigger induced systemic resistance in plants, a mechanism that could be utilized in agriculture to improve crop resistance to pathogens. The review concludes with an outlook on future research and emphasizes the need for comprehensive studies on T3SS effectors in non-pathogenic bacteria and their interactions with plant hosts.

Genomic data are lacking for most Antarctic marine invertebrates, predicating our ability to understand physiological adaptation and specific life-history traits, such as longevity. The environmental stress response of the Antarctic infaunal clam Laternula elliptica is much diminished in older adult animals compared with younger juvenile individuals. However, the mechanism underlying this reduced capacity is unknown. In this study, we describe and analyse the genome of L. elliptica and use it as a tool to understand transcriptomic responses to shell damage across different age cohorts. Gene expression data were combined with reduced representation enzymic methyl sequencing to identify if methylation was acting as an epigenetic mechanism driving age-dependent transcriptional profiles. Our transcriptomic results demonstrated a clear bipartite molecular response in L. elliptica, associated with a rapid growth phase in juveniles and a stabilization phase in reproductively mature adults. Genes active in the response to damage repair in juvenile animals are silent in adults but can be reactivated after several months following damage stimulus; however, these genes were not methylated. Hence, the trigger for this critical and imprinted change in physiological state is, as yet, unknown. While epigenetics is likely involved in this process, the mechanism is unlikely to be methylation.

Micronuclei exhibit defective proteomes rendering their chromatin vulnerable to fragmentation. This fragmentation process, known as chromothripsis, promotes tumorigenesis by catalysing the activation of oncogenes and the silencing of tumor suppressors. With this role in mind, micronuclei serve as promising targets for therapeutic intervention. This review will explore recent discoveries regarding how micronuclei form, their function in catalysing chromothripsis and how chromothripsis provides a selective advantage for cancer cells.

Centrosomes are intracellular organelles traditionally recognized as the primary microtubule (MT) organizing centres (MTOCs) in the cell, playing a crucial role in organizing the cytoskeleton and forming the MT-based spindle during cell division. However, it is now well established that centrosomes also function as central hubs for a wide range of signalling pathways. In non-dividing cells, they give rise to the primary cilium, a surface antenna that serves as a key structure for signalling. Neurons are highly specialized cells with a distinctive morphology, and most neurons have cilia. During brain development, cilia regulate the self-renewal of neural progenitors, as well as the differentiation, migration and synapse formation of newly generated neurons. As a consequence, defects in cilia result in various neurodevelopmental disorders. The role of centrosomes and cilia in neurodegeneration, or the progressive loss of neurons, is less understood. Centrosomes take part in several cellular processes that are often disrupted in neurodegenerative diseases (NDDs), and many proteins associated with these conditions have been found at centrosomes or cilia suggesting a link between these organelles and the underlying mechanisms that contribute to neuronal decline. Unravelling if and how centrosome dysfunction contributes to neurodegeneration could significantly deepen our understanding of the underlying biology of these disorders. Such insights may pave the way for new therapeutic approaches to address these debilitating conditions.

Novel and invasive diseases are a key threat to wildlife. The disease chytridiomycosis has had devastating global impacts, but some amphibian species can persist and even rebound after severe declines. Understanding how these species persist is critical to discovering management techniques for supporting declining species. Here, we explored the impacts of disease on reproduction in the threatened Litoria verreauxii alpina, investigating its effect on reproductive effort and success using a combination of laboratory-based clinical trials and field sampling through capture-mark-recapture surveys. We found that male frogs are increasing various facets of their breeding effort resulting in increased offspring. Infected male frogs (i) increased vocal sac coloration, (ii) increased sperm quality, and (iii) fathered more egg masses than uninfected males. Our research demonstrates that frogs can counteract high disease-caused mortality through enhanced breeding effort, which could lead to population persistence. Mitigation for wildlife diseases often aims to directly reduce mortality, such as through increasing host resistance or decreasing environmental suitability for the pathogen. Our work indicates that reproductive output is also important and should be considered when protecting our precious amphibians.

Understanding and treating disease depend upon our knowledge of how the body works. The biomedical approach to disease describes health purely in terms of biological factors, with a focus on the genome as the molecular basis for cellular function and dysfunction in disease. However, the eukaryotic cell has evolved as a partnership between prokaryotic cells with mitochondria being crucial to this relationship. Aside from their role as bioenergetic and biosynthetic hubs, mitochondria are also involved in cell signalling and cell fate pathways, playing a multifaceted role in cell function and health. Crucially, mitochondria are implicated in most diseases. Perhaps then, visualizing biomedical function on the backdrop of endosymbiosis may provide another viewpoint for explaining and treating disease.

Retroposition is a gene duplication mechanism that uses RNA molecules as intermediaries to generate new gene copies. Dinoflagellates are proposed as an ideal model for exploring this process due to the tagging of retrogenes with DNA-encoded remnants of the dinoflagellate-specific splice-leader motif at their 5' end. We conducted a comprehensive search for retrogenes in dinoflagellate transcriptomes to uncover their functional nature and the processes underlying their redundancy. We obtained a high-confidence set of hypothetical functional retrogenes widespread through the dinoflagellate lineage. Through annotations and gene ontology enrichment analysis, we found that the functional diversity of retrogenes reflects the most prevalent and active processes during stress periods, particularly those involving post-translational modifications and cell signalling pathways. Additionally, the significant presence of retrogenes linked to specific biological processes involved in symbiosis and toxin production underscores the role of retrogenes in adaptation. The expression profile and codon composition similar to protein-coding genes confirm the operational status of retrogenes and strengthen the idea that retrogenes recapitulate parental gene expression and function. This study provides new evidence supporting widespread gene retroposition across dinoflagellates and highlights the functional link of retrogenes with the core activity of the cell.

Global climate change is characterized by increased extreme temperatures affecting insects at all trophic levels. Zinc finger proteins (ZFPs) are key regulators of gene expression and cell differentiation in eukaryotes, essential for stress resistance in both animals and plants. Using CRISPR/Cas9 for gene deletion, this study predicted and examined the structure of ZFP320 in the diamondback moth (Plutella xylostella) and investigated its function in temperature stress response through a comprehensive age-stage, two-sex life table analysis. We found ZFP320 encodes a 387 amino acid protein (43 kDa) with no transmembrane domains, featuring a ZnF-C2H2 domain. Quantitative fluorescence analysis showed that ZFP320 expression increased under high temperatures. ZFP320 knockout altered antioxidant gene expression, resulting in higher levels of superoxide dismutase and catalase in mutant strains compared with wild-type strain. Life table analysis revealed that the mutant strains had shorter fecundity and oviposition periods under both normal and high temperatures. Additionally, mutant strains exhibited lower parameters (r, λ, R₀), as well as reduced survival rates and critical thermal maxima. Notably, PxZFP320 plays a crucial role in temperature adaptation, paving the way for future investigations on the significance of ZFPs in P. xylostella's temperature tolerance.

African trypanosomes are medically important parasites that cause sleeping sickness in humans and nagana in animals. In addition to their pathogenic role, they have emerged as valuable model organisms for studying fundamental biological processes. Protein tagging is a powerful tool for investigating protein localization and function. In a previous study, we developed two plasmids for rapid and reproducible polymerase chain reaction-based protein tagging in trypanosomes, which enabled the subcellular mapping of 89% of the trypanosome proteome. However, the limited selection of fluorescent protein tags and selectable markers restricted the flexibility of this approach. Here, we present an extended set of >100 plasmids that incorporate universal primer annealing sequences, enabling protein tagging with a range of fluorescent, biochemical and epitope tags, using five different selection markers. We evaluated the suitability of various fluorescent proteins for live and fixed cell imaging, fluorescent movies, and we demonstrate the use of tagging plasmids encoding tandem epitope tags to support expansion microscopy approaches. We show that this series of plasmids is functional in other trypanosomatid parasites, significantly increasing its value. Finally, we developed a new plasmid for tagging glycosylphosphatidylinositol-anchored proteins. We anticipate that this will be an important toolset for investigating trypanosomatid protein localization and function.