The origin of cells that generate the blastema following appendage amputation has been a long-standing question in epimorphic regeneration studies. is thought to originate from either stem (or progenitor) or differentiated various tissues undergo dedifferentiation. Here, we investigate contribute zebrafish caudal fin skeletal elements. We provide evidence process lepidotrichia (bony rays) initiated as early 24 hours post-amputation and scleroblasts acquire proliferative state, detach...

Abstract Background The correct evaluation of mineralization is fundamental for the study skeletal development, maintenance, and regeneration. Current methods to visualize mineralized tissue in zebrafish rely on: 1) fixed specimens; 2) radiographic μCT techniques, that are ultimately limited resolution; or 3) vital stains with fluorochromes indistinguishable from signal green fluorescent protein (GFP)-labelled cells. Alizarin compounds, either form alizarin red S (ARS) complexone (ALC), have...

The presence of microplastics in the aquatic ecosystem represents a major issue for environment and human health. capacity organic pollutants to adsorb onto microplastic particles raises additional concerns, as it creates new route toxic compounds enter food web. Current knowledge on impact pristine and/or contaminated organisms remains insufficient, we provide here insights by evaluating their biological effects zebrafish (Danio rerio). Zebrafish larvae were raised ZEB316 stand-alone...

In chondrichthyans, basal osteichthyans and tetrapods, vertebral bodies have cartilaginous anlagen that subsequently mineralize (chondrichthyans) or ossify (osteichthyans). Chondrocytes form the centra derive from somites. teleost fish, centrum formation starts in absence of cartilage, through direct mineralization notochord sheath. a second step, is surrounded by somite-derived intramembranous bone. several small species, including zebrafish (Danio rerio), even haemal neural arches directly...

Zebrafish are able to regenerate many of its tissues and organs after damage. In amphibians this process is regulated by nerve fibres present at the site injury, which have been proposed release factors into amputated limbs/fins, promoting sustaining proliferation blastemal cells. Although some candidate mediate dependency regeneration, molecular mechanisms involved in remain unclear. We used zebrafish as a model system address role fin regeneration. developed protocol for pectoral...

Complex interplay between cardiac tissues is crucial for their integrity. The flow responsive transcription factor KLF2, which expressed in the endocardium, vital cardiovascular development but its exact role remains to be defined. To this end, we mutated both klf2 paralogues zebrafish, and while single mutants exhibit no obvious phenotype, double display a novel phenotype of cardiomyocyte extrusion towards abluminal side. This requires contractility correlates with mislocalization...

The transcription factor NFATC1 (nuclear of activated T-cell 1) has been implicated in cardiac valve formation humans and mice, but we know little about the underlying mechanisms. To gain mechanistic understanding at single-cell resolution insights into role this process, used zebrafish model as it offers unique attributes for live imaging facile genetics.To understand Nfatc1 formation.Using atrioventricular valve, focus on interstitial cells (VICs), which confer biomechanical strength to...

SUMMARY The vertebral column results from a controlled segmentation process associated with two main structures, the notochord and somites. Pathological fusion of bodies can result impaired during embryonic development or occur postnatally. Here, we explore formation subsequent caudalmost in zebrafish, where is normal process, mechanically required to support caudal fin. To reveal whether product on an evolutionary developmental scale, analyze mode bodies, identify transitory rudiments,...

Regeneration depends on the ability of mature cells at injury site to respond injury, generating tissue-specific progenitors that incorporate blastema and proliferate reconstitute original organ architecture. The metabolic microenvironment has been tightly connected cell function identity during development tumorigenesis. Yet, link between metabolism mechanistic level in a regenerative context remains unclear. adult zebrafish caudal fin, bone specifically, have crucial for understanding...

Osteoblast differentiation is a key process for bone homeostasis and repair. Multiple signalling pathways have been associated with osteoblast differentiation, yet much remains unknown on how this regulated in vivo Previous studies proposed that the Hippo pathway transcriptional co-activators YAP TAZ (also known as YAP1 WWTR1, respectively) maintain progenitor stemness inhibit terminal of osteoblasts, whereas others suggest they potentiate formation. Here, we use zebrafish caudal fin...

The development of the cardiac outflow tract (OFT), which connects heart to great arteries, relies on a complex crosstalk between endothelial (ECs) and smooth muscle (SMCs) cells. Defects in OFT can lead severe malformations, including aortic aneurysms, are frequently associated with impaired TGF-β signaling. To better understand role signaling formation, we generated zebrafish lacking receptor Alk5 found strikingly specific dilation OFT: alk5-/- OFTs exhibit increased EC numbers as well...

Impairment of segmentation during embryonic development leads to congenital fusion vertebrae. Nevertheless, vertebral can also occur post-embryonic life. Fusion cause reduction in mobility and may be pathological, but it part normal mechanically required, such as the teleost caudal skeleton, or tetrapod sacrum. Using a series closely spaced ontogenetic stages zebrafish, stained for mineralized (Alizarin red) cartilaginous (Alcian blue) structures, we have characterized all fusions occurring...

The transcription factor Snai1, a well-known regulator of epithelial-to-mesenchymal transition, has been implicated in early cardiac morphogenesis as well valve formation. However, role for Snai1 regulating other aspects not reported. Using genetic, transcriptomic, and chimeric analyses zebrafish, we find that Snai1b is required cardiomyocytes myocardial wall integrity. Loss snai1b increases the frequency cardiomyocyte extrusion away from lumen. Extruding exhibit increased actomyosin...

Persistent and ubiquitous organic pollutants, such as the polycyclic aromatic hydrocarbon benzo[⍺]pyrene (BaP), represent a major threat to aquatic organisms human health. Beside some well-documented adverse effects on development reproduction of organisms, BaP was recently shown affect fish bone formation skeletal through mechanisms that remain poorly understood. In this work, zebrafish bone-related in vivo assays were used evaluate osteotoxic during regeneration. Acute exposure larvae from...

The shaping of bone structures relies on various cell types and signaling pathways. Here, we use the zebrafish bifurcating fin rays during regeneration to investigate patterning. We found that regenerating form via two mineralization fronts undergo an osteoblast-dependent fusion/stitching until branchpoint, bifurcation is not simply splitting one unit into two. identified tartrate-resistant acid phosphatase-positive osteolytic tubular at branchpoints, hereafter named tubules (OLTs). Chemical...

Lordosis and kyphosis are curvatures of the vertebral column that commonly affect Senegalese sole (Solea senegalensis) under intensive rearing conditions, constituting a problem for aquaculture industry by increasing labor operation costs consequently reducing profits. However, no studies have yet addressed microanatomical changes in curvature this species. We conducted histological analyses order to determine alterations at tissue cellular levels these deformities. Development an ectopic...

Tetrapod vertebrae are sclerotome-derived metameric structures. Cells from this tissue provide cartilage that surrounds the notochord and give rise to vertebral centrum as well arches. Eventually, later on, is remodeled into bone. Vertebral body development in teleost fish different, since mineralization of sheath first step formation no involved process. Thus, sclerotomal contribution early has been questioned. In contrast, arches often have cartilaginous precursors. short review we compare...

Abstract Aims Mammalian models have been instrumental in investigating adult heart function and human disease. However, electrophysiological differences with hearts high costs motivate the need for non-mammalian models. The zebrafish is a well-established genetic model to study cardiovascular development function; however, analysis of phenotypes specimens particularly challenging as they are opaque. Methods results Here, we optimized combined multiple imaging techniques including...

The development of organs composed by repeated functional units is, in many cases, accomplished the transition cells from a progenitor to differentiation domain, triggering reiterated developmental program. Yet, how these discrete fields are formed during is still largely unresolved question. posterior lateral line (pLL), sensory organ present fish and amphibians, develops primordium that migrates along flanks animal periodically depositing neuromasts, pLL units. In zebrafish (Danio rerio),...

Summary The zinc finger transcription factor Snai1 is a well-known regulator of epithelial-to-mesenchymal transition (EMT) 1, 2 ; it required for mesoderm ingression in flies 3 and neural crest delamination vertebrates 4 . During cardiac development, Snai1-regulated EMT necessary myocardial precursor migration valve formation 5, 6 However, role maturing cardiomyocytes (CMs) has not been reported. Here, using genetic, transcriptomic chimeric analyses zebrafish, we find that Snai1b wall...

Abstract Regeneration depends on the ability of mature cells at injury site to respond injury, generating tissue-specific progenitors that incorporate blastema and proliferate reconstitute original organ architecture. The metabolic microenvironment has been tightly connected cell function identity during development tumorigenesis. Yet, link between metabolism mechanistic level in a regenerative context remains unclear. adult zebrafish caudal fin, bone specifically, have crucial for...

Abstract Mammalian models have been instrumental to investigate adult heart function and human disease. However, electrophysiological differences with hearts high costs emphasize the need for additional models. The zebrafish is a well-established genetic model study cardiac development function; however, analysis of phenotypes in specimens particularly challenging as they are opaque. Here, we optimized combined multiple imaging techniques including echocardiography, magnetic resonance...