Biology subjects

Martins, C.

Publications and source records attributed to Martins, C..

At least 19 recordsLinked to original sources

bioRxiv2026

Meiotic cohesin Rec8 imposes fitness costs on fission yeast gametesfavoring the evolution of parental bias in gene expression

Differences between partner gametes, which evolved repeatedly in eukaryotes, can contribute to the evolution of the sexes, sexual selection and non-Mendelian inheritance1- 4. Yet, the empirical evidence for how functional asymmetries arise between initially equivalent gametes is limited. Here, we combine theoretical and experimental approaches in the fission yeast Schizosaccharomyces pombe to show how selective pressures acting concurrently on gametes and zygotes drive the evolution of gamete differences. We find that despite being morphologically identical, P- and M-type partner gametes invest asymmetrically in zygotic development by contributing different amounts of conserved meiotic cohesins. P-gametes preferentially produce thve Rec85 cohesin that increases zygotic fitness but reduces gamete viability, revealing a trade-off between reproductive success and gamete survival. We demonstrate that this asymmetry is mediated by partner-specific communication and model its evolutionary dynamics using empirically determined parameters. Our results support classical theoretical predictions for the evolution of gamete differences and provide a mechanistic understanding of how molecular asymmetries between partners can originate from opposing selection pressures acting in species that lack morphologically distinct gametes.

evolutionary biology↗

bioRxiv2026

Metabolic Reprogramming of Human Macrophages Drives the Formation of Hybrid M1/M2 Pro-Regenerative Extracellular Vesicles

The coordinated activity of macrophages is essential for bone repair, with pro-inflammatory M1 macrophages driving early responses and anti-inflammatory M2 macrophages supporting later tissue remodeling. While both phenotypes are required, prolonged persistence of either subtype can impair healing, underscoring the correct transition between the two states. Macrophage polarization is closely linked to cellular metabolism, and human macrophages display distinct metabolic profiles. Macrophage-derived extracellular vesicles (EVs) carry bioactive cargo and reflect parental polarization, influencing recipient cell function. This raises critical questions about how metabolic regulation influences human macrophage function, their EVs and their effect on angiogenesis and osteogenesis. This study investigates EVs derived from polarized primary human macrophages and from macrophages exposed to DASA-58, a small molecule which activates the metabolic enzyme pyruvate kinase M2 (PKM2). Alterations in macrophage metabolism modifies the molecular cargo of their EVs, including microRNAs (miRNAs), to modulate regenerative activity. These findings demonstrate that human macrophage-derived EVs exert metabolically dependent effects on angiogenesis and osteogenesis, and that metabolic modulation enables the generation of EVs with hybrid pro-regenerative properties intermediate between M1 and M2. This establishes metabolic reprogramming within human macrophages using small molecules as a strategy to engineer novel phenotypes and EVs for bone repair.

immunology↗

bioRxiv2025

A Novel Stress Response Pathway Mediates Antibiotic Tolerance and Architecture in Pseudomonas aeruginosa Biofilms

Pseudomonas aeruginosa is a multidrug-resistant opportunistic pathogen, with chronic infections often associated with biofilm formation. Here, we investigate the previously uncharacterized gene PA3049, which is upregulated under biofilm conditions, to determine its role in infection, biofilm formation, and antimicrobial tolerance. We show that the small uncharacterised protein PA3049, renamed as Biofilm antibiotic tolerance Regulator (BatR), promotes biofilm establishment and enhances bacterial survival in sub-inhibitory concentrations of antibiotics. Proteomic analysis revealed that BatR influences the R2/F2 pyocin cluster, which drives explosive cell lysis and extracellular DNA (eDNA) release during biofilm development. We further identify a specific interaction between BatR and PA0486 (SrkA), an uncharacterised Ser/Thr protein kinase. We show that SrkA controls biofilm and pyocyanin production, and lysis-mediated eDNA release through regulation of the R2/F2 pyocin cluster and activation of bacteriophage Pf1. Our findings support a model in which SrkA directly regulates key biofilm-associated phenotypes, while BatR acts as a modulatory partner that tunes SrkA activity under specific conditions. Finally, BatR function was tested in high- validity infection models, including the ex vivo pig lung model of cystic fibrosis infection and a synthetic chronic-wound model. In these models, BatR contributes to biofilm architecture and antibiotic tolerance, and modulates pyocyanin production. Our study implicates the BatR/SrkA system in the response of P. aeruginosa biofilms to antibiotic challenge in lung infections.

microbiology↗

bioRxiv2025

Extracellular Vesicles-Mediated Crosstalk in Bone: miR-150-5p as a Mechanosensitive Inhibitor of Osteoclastogenesis

Bone is a dynamic tissue that is constantly remodelling via a tightly controlled balance between formation and resorption. However, when osteoclast-mediated resorption exceeds formation, it can lead to net bone loss and the development of osteoporosis. Osteoclastogenesis is regulated by local environmental cues, including paracrine factors released by resident cell populations. Extracellular vesicles (EVs) have recently emerged as key mediators of paracrine communication, though their role in osteoclastogenesis remains underexplored. Therefore, this study investigated how resident mesenchymal-derived bone cells and their secreted EVs modulate osteoclastogenesis, and delineate the signalling factors mediating this anti-catabolic communication. We demonstrate that the secretome of mesenchymal-derived bone cells inhibit osteoclast differentiation to differing degrees depending on the stage of lineage commitment and on the mechanical environment, and demonstrate that this inhibition is mediated via the release of EVs. In addition, we identified the terminally differentiated osteocyte as the optimal parent cell for the production of anti-catabolic EVs and demonstrated the importance EV dosage. Finally, we show that mechanosensitive miR-150-5p is packaged within osteocyte-derived EVs and inhibits osteoclast differentiation. Taken together, this study identifies mechanically-activated osteocyte derived EVs and miR-150-5p as key regulators of osteoclastogenesis and novel molecular therapies for skeletal pathologies.

bioengineering↗

bioRxiv2025

Genome Assembly of Astatotilapia latifasciata Uncovers B Chromosome Linked Chromatin Reorganization

B chromosomes (Bs) are supernumerary genomic elements found in many eukaryotes, yet their full sequence composition, functional potential, and regulatory impact on the host genome remain unclear. Here, we present a chromosome-level genome assembly of the cichlid fish Astatotilapia latifasciata, integrating PacBio long reads, Illumina short reads, and Hi-C chromatin contact maps to resolve both A and B chromosomes. The 0.93 Gb assembly (N50 = 36.2 Mb) includes a 34 Mb B chromosome containing 789 predicted protein-coding genes and a markedly higher density of transposable elements (TEs), especially long terminal repeats (LTR) retrotransposons. Transcriptome profiling revealed that B-linked genes are predominantly transcriptionally repressed relative to their A chromosome paralogs. Hi-C based chromatin modeling uncovered distinct 3D structural configurations associated with the B chromosome, including fewer topologically associating domains (TADs), reduced loop formation, and altered compartmentalization. These changes are linked to long-range chromatin interactions and genomic rearrangements, suggesting that the B chromosome reshapes the nuclear architecture of the host genome. Our study proposes a potential regulatory role of Bs in genome and provides a genomic resource for investigating chromosome evolution in cichlids.

genomics↗

bioRxiv2025

Mechanically activated bone cell derived extracellular vesicles regulate angiogenesis in a manner that is dependent on the stage of lineage commitment

Bone regeneration requires a finely tuned interplay between osteogenesis and angiogenesis. While current treatments such as auto/allografts, provide support, they often fail to promote adequate vascularisation necessary for complete repair. Extracellular vesicles (EVs), as mediators of intercellular communication, have emerged as promising acellular nanotechnologies for tissue regeneration due to their bioactive cargo and low immunogenicity. Mechanical stimulation, a known enhancer of bone cell function, can modulate EV cargo and potentially improve regenerative efficacy. In this study, we investigated how mechanical stimulation, and the stage of mesenchymal lineage commitment influence the angiogenic potential of secretomes and EVs derived from mesenchymal stromal/stem cells, osteoblasts, and osteocytes. Our findings reveal that both cell mechanical stimulation and their differentiation stage significantly modulate the angiogenic properties of the resulting EVs. Among the tested conditions, mechanically-stimulated osteocyte-derived EVs demonstrate superior angiogenesis, promoting endothelial cell migration, tube formation, and CD31 expression. These effects were further validated in a pre-clinical ex ovo chick chorioallantoic membrane assay, where robust neovascularisation was observed. This work highlights the critical role of both mechanical cues and cell differentiation stage in regulating the angiogenic capacity of EVs and proposes mechanically activated osteocyte-derived EVs as a novel pro-angiogenic nanotherapeutic for bone repair.

bioengineering↗

bioRxiv2025

Profile of the B cell receptor repertoire and antibody responses upon 17DD-YF vaccine boosting

Although the 17DD-YF vaccine is highly effective in conferring long-term immunity, recent studies suggest that booster doses may be necessary in endemic areas. In this study, we characterized the dynamics of the B cell repertoire following 17DD-YF booster vaccination and examined its impact on antibody kinetics. Using a combined approach of serological analysis and B cell receptor (BCR) sequencing, we investigated molecular features of the antibody response in four vaccinated individuals from a YFV-endemic region. Our results indicate that the booster induces a transient antibody response, with limited effect on the neutralization capacity against DENV1-4 and ZIKV. Notably, we observed a rapid clonal expansion of B cells within 14 days post-vaccination, predominantly involving IgA and IgG isotypes. However, this expansion was short-lived, with reduced magnitude and persistence of these lineages by day 28. Interestingly, some of the expanded lineages shared sequence similarity with previously characterized anti-DENV and anti-ZIKV antibodies, although further validation is required to assess their functional relevance and presence in circulating serum. Together, these findings highlight the transient nature and isotype composition of the antibody response following YFV revaccination and provide insights into the complex interplay between pre-existing immunity and recall responses in individuals living in endemic regions.

immunology↗

bioRxiv2025

Extracellular redox sensors control the protein secretion stress response in Streptomyces

Streptomyces secondary metabolites account for over half of all clinically used antibiotics, as well as numerous antifungal agents, anticancer compounds, and immunosuppressants. Two-component systems, which are widespread in bacteria, are key regulators of antibiotic production in Streptomyces species, yet their activating signals remain poorly understood. CutRS was the first two-component system identified in the genus Streptomyces and deletion of cutRS in Streptomyces coelicolor was shown to enhance antibiotic production, although its CutR regulon does not include any biosynthetic genes. Here, we used Streptomyces venezuelae to further investigate CutRS function. We show that deletion of cutRS leads to an increase in growth rate and a reversal of the typical glucose-mediated carbon catabolite repression typically observed in Streptomyces species. We also demonstrate that CutR DNA binding is glucose-dependent, but CutR does not directly regulate genes involved in growth, antibiotic biosynthesis, or glucose metabolism. The only CutR targets conserved in both S. coelicolor and S. venezuelae are the foldase genes htrA3 and htrB, which are involved in the protein secretion stress response. Consistent with this, we show that CutS homologues all contain two conserved cysteine residues in their extracellular sensor domains and that changing these residues to serine constitutively activates S. venezuelae CutRS. We propose that failure of a disulfide bond to form between these cysteine residues indicates secretion stress and leads to activation of the CutRS system and the secretion stress response. IMPORTANCEStreptomyces bacteria are the primary source of clinically useful antibiotics. While many two-component systems have been linked to antibiotic biosynthesis in Streptomyces species, few have been well characterized. Here, we characterize a secretion stress sensing two-component system called CutRS and propose a model for how the sensor kinase detects extracellular protein misfolding via two highly conserved cysteine residues. Importantly, we also show that deletion of cutRS triggers antibiotic overproduction in the presence of glucose. Since glucose normally represses antibiotic biosynthesis in Streptomyces species through carbon catabolite repression, this finding reveals a simple genetic route to bypass this barrier. This has significant implications for antibiotic discovery pipelines and industrial production, where glucose-rich media are preferred for cost and scalability. Our results position CutRS as a key target for future strain improvement strategies.

microbiology↗

bioRxiv2025

Redox control of antibiotic biosynthesis

Streptomyces bacteria make diverse specialised metabolites that form the basis of [~]55% of clinically used antibiotics. Despite this, only 3% of their encoded specialised metabolites have been matched to molecules and understanding how their biosynthesis is controlled is essential to fully exploit their potential. Here we use Streptomyces formicae and the formicamycin biosynthetic pathway as a model to understand the complex regulation of specialised metabolism. We analysed all three pathway-specific regulators and found that biosynthesis is subject to negative feedback and redox control via two MarR-family proteins while activation of the pathway is dependent on a cytoplasmic two-component system. Like many Streptomyces antibiotics, formicamycins are only produced in solid culture and biosynthesis is switched off in aerated liquid cultures. Here, we demonstrate that a redox-sensitive repressor named ForJ senses oxygen via a single cysteine residue that is required to repress formicamycin biosynthesis in liquid cultures.

molecular biology↗

bioRxiv2025

External and Internal Load Profiles of Male and Female Participants during a Walking Football Practice

BACKGROUNDHigh levels of sedentary behavior among older adults highlight the importance of walking football (WF) in promoting physical activity for healthy aging. This study examines the external and internal load profiles of male and female participants during a WF tournament, addressing a gap in research on game demands and induced load. METHODSThe study involved 176 players aged 50+ participating in a 40-min, 5v5 WF tournament with unlimited substitutions. External load (total and categorized distances) was measured using Global Positioning System (GPS), while heart rate (HR) monitors assessed internal load, including absolute HR and intensity zones based on %HRmax. RESULTSThe proportion of male participants (n=123; 70.3%) was higher than females (n=52; 29.7%), p<.001. They were similar in age (61.6{+/-}8.6 and 60.8{+/-}6.9, respectively). Males covered a higher distance per minute than females, with sex showing a moderate effect (63.3{+/-}10.7 m/min vs. 54.7{+/-}15.8 m/min; p < .001; Cohens dunbiased = 0.69 [0.36; 1.03]), especially in fast walking (41.7{+/-}12.2 m/min vs. 32.6{+/-}16.7 m/min; p < .001; Cohens dunbiased = 0.66 [0.33; 1.00]). Males played more time than females (22:26{+/-}09:47 min:ss vs. 15:41{+/-}07:46 min:ss; p<.001), with moderate effect (Cohens dunbiased = 0.73 [0.40; 1.06]). However, no differences between sexes were identified in the internal load variables, such that the female average %HRmax was 80{+/-}11% and the male was 82{+/-}8% during the practice. CONCLUSIONSOverall, while males generally exhibit higher external loads in WF, both sexes experience similar internal load demands, highlighting WFs potential as a scalable, health-promoting intervention for aging populations.

physiology↗

bioRxiv2024

The conserved aphid saliva chemosensory protein effector Mp10 targets plant AMSH deubiquitinases at cellular membranes to suppress pattern-triggered immunity

Chemosensory proteins (CSPs) are a conserved family present in insects and other arthropods, recognized for their critical roles in both intra- and interspecies communication. However, the functional mechanisms of these proteins remain largely unexplored. In our previous research, we identified a CSP in aphid saliva, Mp10, from the peach-potato aphid Myzus persicae, which functions as an effector protein modulating host plant immunity. Mp10 suppresses pattern recognition receptor (PRR)-triggered immunity (PTI), the first layer of plant defence, while also inducing effector-triggered immunity (ETI). In this study, we elucidate the molecular mechanisms by which Mp10 suppresses PTI. Our findings reveal that Mp10 interacts with AMSH deubiquitinase enzymes in plants, as shown by yeast two-hybrid, co-immunoprecipitation (co-IP), and FRET-FLIM assays, with these interactions predominantly localized to intracellular membranes. Mp10 was found to modulate the dynamics of membrane-bound PRR receptor kinases in plant cells. Co-IP and mass spectrometry analyses demonstrated that Mp10 and AMSH2 associate with a range of PRR kinases, PRR-associated kinases, and proteins involved in the intracellular trafficking of membrane proteins. Mp10 reduces the accumulation of these kinases at the cell surface by promoting their internalization to internal membranes, thereby dampening PTI. Supporting this, a dominant-negative catalytically inactive variant of AMSH2 also inhibits PTI. Interestingly, Mp10 orthologues from other sap-feeding hemipteran insects exhibit similar immune-suppressive activities, and our findings show that their interaction with plant AMSH proteins is conserved, indicating this immune-suppression mechanism is evolutionarily ancient.

plant biology↗

bioRxiv2024

Three cytochrome P450 enzymes catalyse the formation of furanoclerodane precursors in Salvia spp.

Salvia species native to the Americas are rich in valuable bioactive furanoclerodanes, like the psychoactive salvinorin A found in Salvia divinorum, which is used in treatment of opioid addiction. However, there is relatively little known about their biosynthesis. To address this, we investigated the biosynthesis of salviarin, the simplest furanoclerodane structure in the ornamental sage Salvia splendens. Using a self-organizing map and mutual rank analysis of RNA-seq co-expression data, we identified three cytochrome P450 enzymes responsible for converting kolavenol into salviarin precursors, consecutively: annonene, hardwickiic acid and hautriwaic acid. As annonene and hardwickiic acid have also been proposed as intermediates in the biosynthesis of salvinorin A, and to examine our hypothesis for common evolutionary origin of the furanoclerodane pathway between the two Salvia species, we searched for homologous genes in available data for S. divinorum. The enzymes encoded by orthologous genes from S. divinorum displayed kolavenol synthase (SdKLS), annonene synthase (SdANS), and hardwickiic acid synthase (SdHDAS) activity respectively, supporting the view that these are intermediate steps in the biosynthesis of salvinorin A. We investigated the origin of annonene synthase and the role of gene duplication in the evolution of this specific activity. Our work shows how S. splendens can serve as a model species for studying furanoclerodanes biosynthesis in Salvia species, contributes to understanding the evolution of specialized metabolism in plants, and provides new tools to produce salvinorin A in biotechnological chassis.

plant biology↗

bioRxiv2024

Within-ejaculate haploid selection reduces disease biomarkers in human sperm

The germline is widely regarded as a checkpoint against the inheritance of damaged genomes, yet the mechanisms that could enact such filtering remain poorly resolved. Of the millions of sperm in a human ejaculate, only one fertilises the egg, creating a strong opportunity for selection among gametes. Combining within-ejaculate selection on sperm quality with whole-genome sequencing and proteomics in healthy donors, we find that this selection is biased against molecular signatures of age-related disease. The most reproducibly diverging genes are tumour suppressors, and genes diverging under sperm longevity-based selection are enriched for senescence-associated genes involved in genome maintenance and oxidative stress response. High-quality sperm are further depleted of inflammation- and cancer-associated proteins. This genomic signature is conserved in zebrafish, in which longer-lived sperm sire longer-lived offspring. We propose that within-ejaculate selection acts as a pre-fertilisation filter against age-related disease alleles, with implications for offspring lifespan and healthspan.

molecular biology↗

bioRxiv2024

LC-SRM combined with machine learning enables fast identification and quantification of bacterial pathogens in urinary tract infections

Urinary tract infections (UTIs) are a worldwide health problem. Fast and accurate detection of bacterial infection is essential to provide appropriate antibiotherapy to patients and to avoid the emergence of drug-resistant pathogens. While the gold standard requires 24h to 48h of bacteria culture prior MALDI-TOF species identification, we propose a culture-free workflow, enabling a bacterial identification and quantification in less than 4 hours using 1mL of urine. After a rapid and automatable sample preparation, a signature of 82 bacterial peptides, defined by machine learning, was monitored in LC-MS, to distinguish the 15 species causing 84% of the UTIs. The combination of the sensitivity of the SRM mode on a triple quadrupole TSQ Altis instrument and the robustness of capillary flow enabled us to analyze up to 75 samples per day, with 99.2% accuracy on bacterial inoculations of healthy urines. We have also shown our method can be used to quantify the spread of the infection, from 8x104 to 3x107 CFU/mL. Finally, the workflow was validated on 45 inoculated urines and on 84 UTI-positive urine from patients, with respectively 93.3% and 87.1% of agreement with the culture-MALDI procedure at a level above 1x105 CFU/mL corresponding to an infection requiring antibiotherapy. HIGHLIGHTS- LC-MS-SRM and machine learning to identify and quantify bacterial species of UTI - Fast sample preparation without bacterial culture and high-throughput MS analysis - Accurate quantification through calibration curves for 15 species of UTIs - Validation on inoculations (93% accuracy) and on patients specimens (87% accuracy)

microbiology↗

bioRxiv2024

Structural comparison of protein-RNA homologous interfaces reveals widespread overall conservation contrasted with versatility in polar contacts

Protein-RNA interactions play a critical role in many cellular processes and pathologies. However, experimental determination of protein-RNA structures is still challenging, therefore computational tools are needed for the prediction of protein-RNA interfaces. Although evolutionary pressures can be exploited for structural prediction of protein-protein interfaces, and recent deep learning methods using protein multiple sequence alignments have radically improved the performance of protein-protein interface structural prediction, protein-RNA structural prediction is lagging behind, due to the scarcity of structural data and the flexibility involved in these complexes. To study the evolution of protein-RNA interface structures, we first identified a large and diverse dataset of 2,022 pairs of structurally homologous interfaces (termed structural interologs). We leveraged this unique dataset to analyze the conservation of interface contacts among structural interologs based on the properties of involved amino acids and nucleotides. We uncovered that 73% of distance-based contacts and 68% of apolar contacts are conserved on average, and the strong conservation of these contacts occurs even in distant homologs with sequence identity below 20%. Distance-based contacts are also much more conserved compared to what we had found in a previous study of homologous protein-protein interfaces. In contrast, hydrogen bonds, salt bridges, and {pi}-stacking interactions are very versatile in pairs of protein-RNA interologs, even for close homologs with high interface sequence identity. We found that almost half of the non-conserved distance-based contacts are due to a small proportion of interface residues that no longer belong to the interface in the interolog, a phenomenon we term "interface switching out". We also examined possible recovery mechanisms for non-conserved hydrogen bonds and salt bridges, uncovering diverse scenarii of switching out, change in amino acid chemical nature, intermolecular and intramolecular compensations. Our findings provide insights for integrating evolutionary signals into predictive protein-RNA structural modeling methods.

bioinformatics↗

bioRxiv2024

BatR: A novel regulator of antibiotic tolerance in Pseudomonas aeruginosa biofilms

Pseudomonas aeruginosa is a multidrug-resistant opportunistic human pathogen. Chronic infections are associated with biofilms, conferring resistance to antibiotics and complicating treatment strategies. This study focuses on understanding the role of the uncharacterized gene PA3049, upregulated under biofilm conditions. In the context of P. aeruginosa biofilms, PA3049 plays a role in withstanding antimicrobial challenges both in vitro and in clinically validated infection models. Under sub-inhibitory concentrations of antibiotic, the deletion of PA3049 resulted in reduced pyocyanin production and altered abundance of enzymes controlling denitrification, pyoverdine, and hydrogen cyanide biosynthesis. Notably, PA3049 directly interacts with two kinases implicated in stress response, inactivating their active sites. Renamed as the Biofilm antibiotic tolerance Regulator (BatR), PA3049 is a key player in P. aeruginosa biofilm maintenance and antimicrobial tolerance. These findings contribute to understanding the complex bacterial lifestyle in biofilms, shedding light on a previously uncharacterized gene with significant implications for combating multidrug-resistant infections. IMPORTANCEP. aeruginosa is a multidrug-resistant ESKAPE pathogen that causes chronic biofilm-based infections and is a leading cause of mortality in cystic fibrosis (CF) patients. Understanding the molecular mechanisms underlying P. aeruginosa biofilm resilience and antimicrobial resistance is crucial for developing effective therapeutic interventions. This study focuses on characterizing the gene PA3049, now known as the biofilm antibiotic tolerance Regulator (batR). BatR plays a central role within P. aeruginosa biofilms, orchestrating adaptive responses to antimicrobial challenges. Our work sheds light on the contribution of batR to biofilm biology and its relevance in lung infections, where subinhibitory antibiotic concentrations make BatR pivotal for bacterial survival. By advancing our understanding of P. aeruginosa biofilm regulation, this study holds significant promise for the development of innovative approaches against biofilm-associated infections to mitigate the growing threat of antimicrobial resistance.

microbiology↗

bioRxiv2023

Extended-depth of field random illumination microscopy, EDF-RIM, provides super-resolved projective imaging

The ultimate aim of fluorescence microscopy is to achieve high-resolution imaging of increasingly larger biological samples. Extended depth of field presents a potential solution to accelerate imaging of large samples when compression of information along the optical axis is not detrimental to the interpretation of images. We have implemented an Extended Depth of Field (EDF) approach in a Random Illumination Microscope (RIM). RIM uses multiple speckled illuminations and variance data processing to double the resolution. It is particularly adapted to the imaging of thick samples as it does not require the knowledge of illumination patterns. We demonstrate highly-resolved projective images of biological tissues and cells. Compared to a sequential scan of the imaged volume with conventional 2D-RIM, EDF-RIM allows an order of magnitude improvement in speed and light dose reduction, with comparable resolution. As the axial information is lost in an EDF modality, we propose a method to retrieve the sample topography for samples that are organized in cell sheets.

bioengineering↗

bioRxiv2023

Universal conditions for establish continuous cell cultures in ray-finned fishes

Ray-finned fishes represent the most diverse vertebrate lineage and show extensive variations in physiology, ways of life and adaptations to marine and freshwater environments. Actinopterygii are largely exploited for human consumption and several species have been established as biological models. The in vitro culture of cells is fundamental for several fields of biological research, being an alternative for studies that use animals, since it mimics the cellular homogeneity of the original organisms beyond the advantage of reducing the variability of responses observed under in vivo conditions. In the case of fish cell cultures, besides being an important biomedical tool, they can offer important contributions to aquaculture and fish conservation. Hundreds of fish cell lines have been established using specific methods for each cell type and species. Here we describe an optimized protocol for obtaining cell cultures from the caudal fin of a wide range of ray-finned fishes including marine and freshwater species. The proliferative potential of these cultures makes them useful for several applications and the minimally invasive feature of this protocol makes it suitable for use in conservation plans.

cell biology↗