Did you mean: pronephri
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Pediatric Nephrology (Berlin, Germany) Feb 2017The nephron is the functional subunit of the vertebrate kidney and plays important osmoregulatory and excretory roles during embryonic development and in adulthood.... (Review)
Review
The nephron is the functional subunit of the vertebrate kidney and plays important osmoregulatory and excretory roles during embryonic development and in adulthood. Despite its central role in kidney function, surprisingly little is known about the molecular and cellular processes that control nephrogenesis. The zebrafish pronephric kidney, comprising two nephrons, provides a visually accessible and genetically tractable model system for a better understanding of nephron formation. Using this system, various developmental processes, including the commitment of mesoderm to a kidney fate, renal tubule proliferation, and migration, can be studied during nephrogenesis. Here, we discuss some of these processes in zebrafish with a focus on the pathways that influence renal tubule cell morphogenesis.
Topics: Animals; Kidney Tubules; Morphogenesis; Organogenesis; Zebrafish
PubMed: 26942753
DOI: 10.1007/s00467-016-3353-1 -
Developmental Dynamics : An Official... Jan 2003Initiation of excretory system development in all vertebrates requires (1) delamination of the pronephric and pronephric duct rudiments from intermediate mesoderm at the... (Review)
Review
Initiation of excretory system development in all vertebrates requires (1) delamination of the pronephric and pronephric duct rudiments from intermediate mesoderm at the ventral border of anterior somites, and (2) extension of the pronephric duct to the cloaca. Pronephric duct extension is the central event in nephric system development; the pronephric duct differentiates into the tubule that carries nephric filtrate out of the body and induces terminal differentiation of adult kidneys. Early studies concluded that pronephric ducts formed by means of in situ segregation of pronephric duct tissue from lateral mesoderm ventral to the forming somites; more recent studies highlight caudal migration of the pronephric duct as the major morphogenetic mechanism. The purpose of this review is to provide the historical background on studies of the mechanisms of amphibian pronephric duct extension, to review evidence showing that different amphibians perform pronephric duct morphogenesis in different ways, and to suggest future studies that may help illuminate the molecular basis of the mechanisms that have evolved in amphibians to extend the pronephric duct to the cloaca.
Topics: Ambystoma; Animals; Cell Movement; Embryo, Nonmammalian; In Situ Hybridization; Kidney; Models, Biological; Morphogenesis; Time Factors; Wolffian Ducts; Xenopus laevis
PubMed: 12508219
DOI: 10.1002/dvdy.10205 -
Current Topics in Developmental Biology 1999
Review
Topics: Animals; Body Patterning; Humans; Kidney; Kidney Glomerulus; Kidney Tubules
PubMed: 9891877
DOI: 10.1016/s0070-2153(08)60467-6 -
The International Journal of... 1999Kidney development is distinguished by the sequential formation of three structures of putatively equivalent function from the intermediate mesoderm, the pronephros,... (Review)
Review
Kidney development is distinguished by the sequential formation of three structures of putatively equivalent function from the intermediate mesoderm, the pronephros, mesonephros, and metanephros. While these organs differ morphologically, their basic structural organization exhibits important similarities. The earliest form of the kidney, the pronephros, is the primary blood filtration and osmoregulatory organ of fish and amphibian larvae. Simple organization and rapid formation render the Xenopus pronephric kidney an ideal model for research on the molecular and cellular mechanisms dictating early kidney organogenesis. A prerequisite for this is the identification of genes critical for pronephric kidney development. This review describes the emerging framework of genes that act to establish the basic components of the pronephric kidney: the corpuscle, tubules, and the duct. Systematic analysis of marker gene expression, in temporal and spatial resolution, has begun to reveal the molecular anatomy underlying pronephric kidney development. Furthermore, the emerging evidence indicates extensive conservation of gene expression between pronephric and metanephric kidneys, underscoring the importance of the Xenopus pronephric kidney as a simple model for nephrogenesis. Given that Xenopus embryos allow for easy testing of gene function, the pathways that direct cell fate decisions in the intermediate mesoderm to make the diverse spectrum of cell types of the pronephric kidney may become unraveled in the future.
Topics: Animals; Cell Differentiation; Cell Lineage; Embryo, Nonmammalian; Embryonic and Fetal Development; Gene Expression Regulation, Developmental; Hematopoiesis; Kidney; Mesoderm; Xenopus
PubMed: 10535314
DOI: No ID Found -
Journal of the American Society of... Sep 2011Canonical β-catenin-mediated Wnt signaling is essential for the induction of nephron development. Noncanonical Wnt/planar cell polarity (PCP) pathways contribute to...
Canonical β-catenin-mediated Wnt signaling is essential for the induction of nephron development. Noncanonical Wnt/planar cell polarity (PCP) pathways contribute to processes such as cell polarization and cytoskeletal modulation in several tissues. Although PCP components likely establish the plane of polarization in kidney tubulogenesis, whether PCP effectors directly modulate the actin cytoskeleton in tubulogenesis is unknown. Here, we investigated the roles of Wnt PCP components in cytoskeletal assembly during kidney tubule morphogenesis in Xenopus laevis and zebrafish. We found that during tubulogenesis, the developing pronephric anlagen expresses Daam1 and its interacting Rho-GEF (WGEF), which compose one PCP/noncanonical Wnt pathway branch. Knockdown of Daam1 resulted in reduced expression of late pronephric epithelial markers with no apparent effect upon early markers of patterning and determination. Inhibiting various points in the Daam1 signaling pathway significantly reduced pronephric tubulogenesis. These data indicate that pronephric tubulogenesis requires the Daam1/WGEF/Rho PCP pathway.
Topics: Adaptor Proteins, Signal Transducing; Animals; Apoptosis; Cell Polarity; Cell Proliferation; Cytoskeleton; Female; Guanine Nucleotide Exchange Factors; Kidney Tubules; Organogenesis; Wnt Proteins; Xenopus Proteins; Xenopus laevis; Zebrafish; Zebrafish Proteins
PubMed: 21804089
DOI: 10.1681/ASN.2010101086 -
Developmental Biology Mar 2016Mutations in the homeobox transcription factor MNX1 are the major cause of dominantly inherited sacral agenesis. Studies in model organisms revealed conserved mnx gene...
Mutations in the homeobox transcription factor MNX1 are the major cause of dominantly inherited sacral agenesis. Studies in model organisms revealed conserved mnx gene requirements in neuronal and pancreatic development while Mnx activities that could explain the caudal mesoderm specific agenesis phenotype remain elusive. Here we use the zebrafish pronephros as a simple yet genetically conserved model for kidney formation to uncover a novel role of Mnx factors in nephron morphogenesis. Pronephros formation can formally be divided in four stages, the specification of nephric mesoderm from the intermediate mesoderm (IM), growth and epithelialisation, segmentation and formation of the glomerular capillary tuft. Two of the three mnx genes in zebrafish are dynamically transcribed in caudal IM in a time window that proceeds segmentation. We show that expression of one mnx gene, mnx2b, is restricted to the pronephric lineage and that mnx2b knock-down causes proximal pronephric tubule dilation and impaired pronephric excretion. Using expression profiling of embryos transgenic for conditional activation and repression of Mnx regulated genes, we further identified irx1b as a direct target of Mnx factors. Consistent with a repression of irx1b by Mnx factors, the transcripts of irx1b and mnx genes are found in mutual exclusive regions in the IM, and blocking of Mnx functions results in a caudal expansion of the IM-specific irx1b expression. Finally, we find that knock-down of irx1b is sufficient to rescue proximal pronephric tubule dilation and impaired nephron function in mnx-morpholino injected embryos. Our data revealed a first caudal mesoderm specific requirement of Mnx factors in a non-human system and they demonstrate that Mnx-dependent restriction of IM-specific irx1b activation is required for the morphogenesis and function of the zebrafish pronephros.
Topics: Abnormalities, Multiple; Animals; Animals, Genetically Modified; Body Patterning; DNA-Binding Proteins; Enzyme Activation; Gene Expression Profiling; Gene Expression Regulation, Developmental; Gene Knockdown Techniques; Homeodomain Proteins; Kidney Tubules; Meningocele; Mesoderm; Models, Animal; Morpholinos; Organogenesis; Pronephros; Sacrococcygeal Region; Transcription Factors; Zebrafish; Zebrafish Proteins
PubMed: 26472045
DOI: 10.1016/j.ydbio.2015.10.014 -
Journal of Morphology Aug 2016The zebrafish pronephros is a valuable model for studying kidney development and diseases. Ultrastructural studies have revealed that zebrafish and mammals share...
The zebrafish pronephros is a valuable model for studying kidney development and diseases. Ultrastructural studies have revealed that zebrafish and mammals share similarities in nephron structures such as podocytes, slit diaphragms, glomerular basement membrane, and endothelium. However, the basic ultrastructural features of the pronephric glomerulus during glomerulogenesis have not been characterized. To understand these features, it is instructive to consider the developmental process of the pronephros glomerulus. Here, we describe the ultrastructural features of pronephric glomerulus in detail from 24 h hours post-fertilization (hpf) to 144 hpf, the period during which the pronephric glomerulus develops from initiation to its mature morphology. The pronephric glomerulus underwent progressive morphogenesis from 24 to 72 hpf, and presumptive glomerular cells were observed ventral to the aorta region at 24 hpf. The nascent glomerular basement membrane and initial lumen were formed at 36 hpf. A lumen was clearly visible in the region of the pronephros at 48 hpf. At 60 hpf, the pronephric glomerulus contained more patches of capillaries. After these transformations, the complex capillary vessel networks had formed inside the glomerulus, which was surrounded by podocyte bodies with elaborate foot processes as well as well-formed glomerular basement membrane by 72 hpf. The number of renal glomerular cells rapidly increased, and the glomerulus presented its delicate structural features by 96 hpf. Morphogenesis was completed at 120 hpf with the final formation of the pronephric glomerulus. J. Morphol. 277:1104-1112, 2016. © 2016 Wiley Periodicals, Inc.
Topics: Animals; Cell Differentiation; Embryo, Nonmammalian; Fertilization; Glomerular Filtration Barrier; Kidney Glomerulus; Morphogenesis; Podocytes; Pronephros; Zebrafish
PubMed: 27185367
DOI: 10.1002/jmor.20560 -
Journal of the American Society of... Feb 2005Recent advances in techniques that are available to study the molecular development of the frog Xenopus make developmental studies using this amphibian amenable to... (Comparative Study)
Comparative Study Review
Recent advances in techniques that are available to study the molecular development of the frog Xenopus make developmental studies using this amphibian amenable to experimentation. This review outlines some of the attractive features of this model organism and describes how these techniques can be and are being used in studies on the organogenesis of the larval amphibian kidney, the pronephros. The roles of micromanipulation, grafting, and in vitro culturing of animal caps are discussed as tools in the analysis of kidney development and as a source of tissue for subtractive hybridization strategies. The importance of expression cloning and functional analysis of newly identified pronephros-specific genes are also described. Finally, transgenesis and electroporation are discussed as potentially new methods of gene delivery to the pronephros. These techniques can be used to help identify the gene networks that control organogenesis of this larval kidney form, which will undoubtedly have applicability to higher vertebrate kidney development.
Topics: Animals; Embryo, Nonmammalian; Embryonic Development; Gene Expression Regulation, Developmental; Gene Transfer Techniques; Kidney Tubules; Models, Animal; Nephrons; Organogenesis; Sensitivity and Specificity; Xenopus; Xenopus Proteins
PubMed: 15647339
DOI: 10.1681/ASN.2004070617 -
Development (Cambridge, England) Dec 2003The epidermis overlying the migrating axolotl pronephric duct is known to participate in duct guidance. This epidermis deposits an extracellular matrix onto the...
The epidermis overlying the migrating axolotl pronephric duct is known to participate in duct guidance. This epidermis deposits an extracellular matrix onto the migrating duct and its pathway that is a potential source of directional guidance cues. The role of this matrix in pronephric duct guidance was assayed by presenting matrix deposited on microcarriers directly to migrating pronephric ducts in situ. We found that reorientation of extracellular-matrix-bearing carriers prior to their presentation to migrating ducts caused a corresponding reorientation of pronephric duct migration. Subepidermal microinjection of function-blocking antibodies against alpha6 integrin, beta1 integrin or the laminin-1/E8 domain recognized by alpha6beta1 integrin, all of which were detected and localized here, inhibited pronephric duct migration. Moreover, pre-exposure to anti-laminin-1/E8 function-blocking antibody prevented reoriented carriers of epidermally deposited matrix from reorienting pronephric duct migration. These results are incorporated into an integrated model of pronephric duct guidance consistent with all present evidence, proposing roles for the previously implicated glial cell-line derived neurotrophic factor and its receptor as well as for laminin 1 and alpha6beta1 integrin.
Topics: Ambystoma; Animals; Antibodies; Cell Movement; Embryonic Structures; Extracellular Matrix; Integrin alpha6beta1; Kidney; Laminin; Morphogenesis
PubMed: 14522870
DOI: 10.1242/dev.00765 -
Mechanisms of Development Jul 1998We have examined the timing of specification of the pronephric tubules and duct in Xenopus laevis by explanting the presumptive pronephric rudiments into blastula...
We have examined the timing of specification of the pronephric tubules and duct in Xenopus laevis by explanting the presumptive pronephric rudiments into blastula ectodermal wraps. We have established the time point of specification using the monoclonal antibody markers 3G8 and 4A6 which recognize antigens in pronephric tubule and duct, respectively. We show that, by experimental analysis in explants, kidney tubules are specified by stage 12.5 in the pronephric anlagen whereas pronephric duct is specified later between stages 13 and 14. Furthermore we show that signals involved in tubulogenesis of the pronephric tubules are normally received between stage 12.5 and 13. These experiments unambiguously pinpoint the timing of pronephros specification analyzed by explant experimentation to a developmental stage prior to that demonstrated for urodele amphibia, and provide an essential biological backdrop to a search for the molecular nature of pronephric inducers.
Topics: Animals; Cell Lineage; Embryo, Nonmammalian; Embryonic Development; Kidney; Kidney Transplantation; Time Factors; Xenopus laevis
PubMed: 9739124
DOI: 10.1016/s0925-4773(98)00094-x