51
|
Emison ES, McCallion AS, Kashuk CS, Bush RT, Grice E, Lin S, Portnoy ME, Cutler DJ, Green ED, Chakravarti A. A common sex-dependent mutation in a RET enhancer underlies Hirschsprung disease risk. Nature 2005; 434:857-63. [PMID: 15829955 DOI: 10.1038/nature03467] [Citation(s) in RCA: 341] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2004] [Accepted: 02/15/2005] [Indexed: 12/20/2022]
Abstract
The identification of common variants that contribute to the genesis of human inherited disorders remains a significant challenge. Hirschsprung disease (HSCR) is a multifactorial, non-mendelian disorder in which rare high-penetrance coding sequence mutations in the receptor tyrosine kinase RET contribute to risk in combination with mutations at other genes. We have used family-based association studies to identify a disease interval, and integrated this with comparative and functional genomic analysis to prioritize conserved and functional elements within which mutations can be sought. We now show that a common non-coding RET variant within a conserved enhancer-like sequence in intron 1 is significantly associated with HSCR susceptibility and makes a 20-fold greater contribution to risk than rare alleles do. This mutation reduces in vitro enhancer activity markedly, has low penetrance, has different genetic effects in males and females, and explains several features of the complex inheritance pattern of HSCR. Thus, common low-penetrance variants, identified by association studies, can underlie both common and rare diseases.
Collapse
Affiliation(s)
- Eileen Sproat Emison
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
52
|
Elworthy S, Pinto JP, Pettifer A, Cancela ML, Kelsh RN. Phox2b function in the enteric nervous system is conserved in zebrafish and is sox10-dependent. Mech Dev 2005; 122:659-69. [PMID: 15817223 DOI: 10.1016/j.mod.2004.12.008] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2004] [Revised: 12/16/2004] [Accepted: 12/16/2004] [Indexed: 02/07/2023]
Abstract
Zebrafish lacking functional sox10 have defects in non-ectomesenchymal neural crest derivatives including the enteric nervous system (ENS) and as such provide an animal model for human Waardenburg Syndrome IV. Here, we characterize zebrafish phox2b as a functionally conserved marker of the developing ENS. We show that morpholino-mediated knockdown of Phox2b generates fish modeling Hirschsprung disease. Using markers, including phox2b, we investigate the ontogeny of the sox10 ENS phenotype. As previously shown for melanophore development, ENS progenitor fate specification fails in these mutant fish. However, in addition, we trace back the sox10 mutant ENS defect to an even earlier time point, finding that most neural crest cells fail to migrate ventrally to the gut primordium.
Collapse
Affiliation(s)
- Stone Elworthy
- Centre for Regenerative Medicine, Developmental Biology Programme, Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | | | | | | | | |
Collapse
|
53
|
Shepherd IT, Pietsch J, Elworthy S, Kelsh RN, Raible DW. Roles for GFRα1 receptors in zebrafish enteric nervous system development. Development 2004; 131:241-9. [PMID: 14660438 DOI: 10.1242/dev.00912] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Components of the zebrafish GDNF receptor complex are expressed very early in the development of enteric nervous system precursors, and are already present as these cells begin to enter the gut and migrate caudally along its length. Both gfra1a and gfra1b as well as ret are expressed at this time, while gfra2 expression, the receptor component that binds the GDNF-related ligand neurturin, is not detected until the precursors have migrated along the gut. Gfra genes are also expressed in regions of the zebrafish brain and peripheral ganglia, expression domains conserved with other species. Enteric neurons are eliminated after injection with antisense morpholino oligonucleotides against ret or against both Gfra1 orthologs, but are not affected by antisense oligonucleotides against gfra2. Blocking GDNF signaling prevents migration of enteric neuron precursors, which remain positioned at the anterior end of the gut. Phenotypes induced by injection of antisense morpholinos against both Gfra orthologs can be rescued by introduction of mRNA for gfra1a or for gfra2, suggesting that GFRα1 and GFRα2 are functionally equivalent.
Collapse
Affiliation(s)
- Iain T Shepherd
- Department of Biological Structure, University of Washington, Box 357420, Seattle, WA 98195, USA.
| | | | | | | | | |
Collapse
|
54
|
Affiliation(s)
- Iain A Drummond
- Department of Medicine, Harvard Medical School and Renal Unit, Massachusetts General Hospital, Charlestown, Massachusetts 02129, USA
| |
Collapse
|
55
|
Matsukawa T, Arai K, Koriyama Y, Liu Z, Kato S. Axonal Regeneration of Fish Optic Nerve after Injury. Biol Pharm Bull 2004; 27:445-51. [PMID: 15056844 DOI: 10.1248/bpb.27.445] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Since Sperry's work in the 1950s, it has been known that the central nervous system (CNS) neurons of lower vertebrates such as fish and amphibians can regenerate after axotomy, whereas the CNS neurons of mammals become apoptotic after axotomy. The goldfish optic nerve (ON) is one of the most studied animal models of CNS regeneration. Morphological changes in the goldfish retina and tectum after ON transection were first researched in the 1970s-1980s. Many biochemical studies of neurite outgrowth-promoting substances were then carried out in the 1980s-1990s. Many factors have been reported to be active substances that show increased levels during fish ON regeneration, as shown by using various protein chemistry techniques. However, there are very few molecular cloning techniques for studying ON regeneration after injury. In this review article, we summarize the neurite outgrowth-promoting factors reported by other researchers and describe our strategies for searching for ON regenerating molecules using a differential hybridization technique in the goldfish visual system. The process of goldfish ON regeneration after injury is very long. It takes about half a year from the start of axonal regrowth to complete restoration of vision. The process has been classified into three stages: early, middle and late. We screened for genes with increased expression during regeneration using axotomized goldfish retinal and tectal cDNA libraries and obtained stage-specific cDNA clones that were upregulated in the retina and tectum. We further discuss functional roles of these molecules in the regeneration processes of goldfish ON.
Collapse
Affiliation(s)
- Toru Matsukawa
- Department of Molecular Neurobiology, Graduate School of Medicine, Kanazawa University, 13-1 Takara-machi, Kanazawa, Ishikawa 920-8640, Japan
| | | | | | | | | |
Collapse
|
56
|
Hostetter CL, Sullivan-Brown JL, Burdine RD. Zebrafish pronephros: A model for understanding cystic kidney disease. Dev Dyn 2003; 228:514-22. [PMID: 14579389 DOI: 10.1002/dvdy.10371] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The embryonic kidney of the zebrafish is the pronephros. The ease of genetic analysis and experimentation in zebrafish, coupled with the simplicity of the pronephros, make the zebrafish an ideal model system for studying kidney development and function. Several mutations have been isolated in zebrafish genetic screens that result in cyst formation in the pronephros. Cloning and characterization of these mutations will provide insight into kidney development but may also provide understanding of the molecular basis of cystic kidney diseases. In this review, we focus on the zebrafish as a model for understanding cystic kidney disease and the links between cystic kidney disease and left-right patterning.
Collapse
Affiliation(s)
- Christine L Hostetter
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08540, USA
| | | | | |
Collapse
|
57
|
Boguslavsky D, Ierusalimsky V, Malyshev A, Balaban P, Belyavsky A. Selective blockade of gene expression in a single identified snail neuron. Neuroscience 2003; 119:15-8. [PMID: 12763064 DOI: 10.1016/s0306-4522(03)00075-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In the present study, the applicability of antisense morpholino oligos for loss-of-function experiments in neurobiology was investigated. The identified withdrawal interneurons of the parietal ganglia expressing helix command neuron-specific 2 (HCS2) gene were pressure injected with HCS2 antisense or control morpholino oligo solution at a final concentration 1-4 microM. No toxic or side effects for the neural functioning were noted immediately or several hours after injection. The changes in the concentration of HCS2-encoded protein in neurons after injection were monitored by two methods, Western blotting and immunostaining of the brain. The amount of the peptide immunoreactive with the HCS2 antibody started to decline in the injected cells at day 2 post-injection, decreased four- to five-fold at day 4, and stayed at this low level thereafter. Similar results obtained by both methods suggest significant selective blockade of production of the HCS2-encoded peptide. In contrast, no substantial decrease of the HCS2-encoded polypeptide was observed after injection with control oligos. Due to the high stability of the morpholino oligos in the cell, they represent a highly efficient tool for a specific long-term blockade of gene expression in molluscan neurons.
Collapse
Affiliation(s)
- D Boguslavsky
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Butlerova 5A, Moscow 117865, Russia
| | | | | | | | | |
Collapse
|
58
|
Homma S, Yaginuma H, Vinsant S, Seino M, Kawata M, Gould T, Shimada T, Kobayashi N, Oppenheim RW. Differential expression of the GDNF family receptors RET and GFRalpha1, 2, and 4 in subsets of motoneurons: a relationship between motoneuron birthdate and receptor expression. J Comp Neurol 2003; 456:245-59. [PMID: 12528189 DOI: 10.1002/cne.10529] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Previous studies have demonstrated the expression of specific members of the glial cell line-derived neurotrophic factor (GDNF) receptor family alpha (GFRalpha) in subsets of motoneurons (MNs) in the developing mouse spinal cord. We examined the expression pattern of GFRalpha and RET in the avian lumbar spinal cord during the period of programmed cell death (PCD) of MNs by using double labeling in situ hybridization and immunohistochemistry. In the lateral motor column (LMC) of the lumbar spinal cord, a laminar organization of GFRalpha expression was observed: GFRalpha1-positive MNs were located in the medial LMC; GFRalpha1-, 2-, and 4-positive MNs were situated in the lateral LMC; and GFRalpha4-positive MNs were located in the intermediate LMC. The species of GFRalpha receptor that was expressed in MNs was found to be related to their birthdates. The expression of subpopulation-specific transcriptional factors was also used to define MNs that express a specific pattern of GFRalpha. This analysis suggests that motor pools as defined by these transcriptional factors have unique expression patterns of GFRalpha receptor. Early limb bud ablation did not affect the expression of GFRalpha in the spinal cord, indicating that regulation of receptor expression is independent of target-derived signals. Finally, GDNF mRNA expression was found in the limb during the PCD period of MNs. In conclusion, these results indicate that time of withdrawal from the mitotic cycle may specify the expression pattern of GFRalpha in subsets of MNs and that GDNF may function as a target-derived neurotrophic factor for specific subpopulations of MNs.
Collapse
Affiliation(s)
- Shunsaku Homma
- Department of Anatomy, School of Medicine, Fukushima Medical University, Japan.
| | | | | | | | | | | | | | | | | |
Collapse
|
59
|
Spitsbergen JM, Kent ML. The state of the art of the zebrafish model for toxicology and toxicologic pathology research--advantages and current limitations. Toxicol Pathol 2003; 31 Suppl:62-87. [PMID: 12597434 PMCID: PMC1909756 DOI: 10.1080/01926230390174959] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The zebrafish (Danio rerio) is now the pre-eminent vertebrate model system for clarification of the roles of specific genes and signaling pathways in development. The zebrafish genome will be completely sequenced within the next 1-2 years. Together with the substantial historical database regarding basic developmental biology, toxicology, and gene transfer, the rich foundation of molecular genetic and genomic data makes zebrafish a powerful model system for clarifying mechanisms in toxicity. In contrast to the highly advanced knowledge base on molecular developmental genetics in zebrafish, our database regarding infectious and noninfectious diseases and pathologic lesions in zebrafish lags far behind the information available on most other domestic mammalian and avian species, particularly rodents. Currently, minimal data are available regarding spontaneous neoplasm rates or spontaneous aging lesions in any of the commonly used wild-type or mutant lines of zebrafish. Therefore, to fully utilize the potential of zebrafish as an animal model for understanding human development, disease, and toxicology we must greatly advance our knowledge on zebrafish diseases and pathology.
Collapse
Affiliation(s)
- Jan M Spitsbergen
- Department of Environmental and Molecular Toxicology and Marine/Freshwater Biomedical Sciences Center, Oregon State University, Corvallis, Oregon 97333, USA.
| | | |
Collapse
|
60
|
Drapeau P, Saint-Amant L, Buss RR, Chong M, McDearmid JR, Brustein E. Development of the locomotor network in zebrafish. Prog Neurobiol 2002; 68:85-111. [PMID: 12450489 DOI: 10.1016/s0301-0082(02)00075-8] [Citation(s) in RCA: 260] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The zebrafish is a leading model for studies of vertebrate development and genetics. Its embryonic motor behaviors are easy to assess (e.g. for mutagenic screens), the embryos develop rapidly (hatching as larvae at 2 days) and are transparent, permitting calcium imaging and patch clamp recording in vivo. We review primarily the recent advances in understanding the cellular basis for the development of motor activities in the developing zebrafish. The motor activities are generated largely in the spinal cord and hindbrain. In the embryo these segmented structures possess a relatively small number of repeating sets of identifiable neurons. Many types of neurons as well as the two types of muscle cells have been classified based on their morphologies. Some of the molecular signals for cellular differentiation have been identified recently and mutations affecting cell development have been isolated. Embryonic motor behaviors appear in sequence and consist of an early period of transient spontaneous coiling contractions, followed by the emergence of twitching responses to touch, and later by the ability to swim. Coiling contractions are generated by an electrically coupled network of a subset of spinal neurons whereas a chemical (glutamatergic and glycinergic) synaptic drive underlies touch responses and swimming. Swimming becomes sustained in larvae once the neuromodulatory serotonergic system develops. These results indicate many similarities between developing zebrafish and other vertebrates in the properties of the synaptic drive underlying locomotion. Therefore, the zebrafish is a useful preparation for gaining new insights into the development of the neural control of vertebrate locomotion. As the types of neurons, transmitters, receptors and channels used in the locomotor network are being defined, this opens the possibility of combining cellular neurophysiology with forward and reverse molecular genetics to understand the principles of locomotor network assembly and function.
Collapse
Affiliation(s)
- Pierre Drapeau
- McGill Centre for Research in Neuroscience and Department of Biology, McGill University, Que., Montreal, Canada.
| | | | | | | | | | | |
Collapse
|
61
|
Newgreen D, Young HM. Enteric nervous system: development and developmental disturbances--part 2. Pediatr Dev Pathol 2002; 5:329-49. [PMID: 12016531 DOI: 10.1007/s10024-002-0002-4] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2001] [Accepted: 08/01/2001] [Indexed: 01/26/2023]
Abstract
This review, which is presented in two parts, summarizes and synthesizes current views on the genetic, molecular, and cell biological underpinnings of the early embryonic phases of enteric nervous system (ENS) formation and its defects. Accurate descriptions of the phenotype of ENS dysplasias, and knowledge of genes which, when mutated, give rise to the disorders (see Part 1 in the previous issue of this journal), are not sufficient to give a real understanding of how these abnormalities arise. The often indirect link between genotype and phenotype must be sought in the early embryonic development of the ENS. Therefore, in this, the second part, we provide a description of the development of the ENS, concentrating mainly on the origin of the ENS precursor cells and on the cell migration by which they become distributed throughout the gastrointestinal tract. This section also includes experimental evidence on the controls of ENS formation derived from classic embryological, cell culture, and molecular genetic approaches. In addition, for reasons of completeness, we also briefly describe the origins of the interstitial cells of Cajal, a cell population closely related anatomically and functionally to the ENS. Finally, a brief sketch is presented of current notions on the developmental processes between the genes and the morphogenesis of the ENS, and of the means by which the known genetic abnormalities might result in the ENS phenotype observed in Hirschsprung's disease.
Collapse
Affiliation(s)
- Donald Newgreen
- Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, 3052, Victoria, Australia.
| | | |
Collapse
|
62
|
Abstract
Since morpholino oligos were first introduced as a means to inhibit gene function in embryos, in the Spring of 2000, they have been tested in a range of model organisms, including sea urchin, ascidian, zebrafish, frog, chick, and mouse. This review surveys the results of these studies and examines the successes and limitations of the approach for targeting maternal and zygotic gene function. The evidence so far suggests that, with careful controls, morpholinos provide a relatively simple and rapid method to study gene function.
Collapse
Affiliation(s)
- Janet Heasman
- Division of Developmental Biology, Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, Ohio 45229-3039, USA.
| |
Collapse
|
63
|
van der Sar AM, Zivković D, den Hertog J. Eye defects in receptor protein-tyrosine phosphatase alpha knock-down zebrafish. Dev Dyn 2002; 223:292-7. [PMID: 11836793 DOI: 10.1002/dvdy.10059] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Receptor protein-tyrosine phosphatase alpha (RPTP alpha) is highly expressed in the developing retina of different species, but little is known about its function there. Here, we report that injection of antisense morpholinos in zebrafish embryos reduced RPTP alpha expression to almost nondetectable levels up to 3 days postfertilization (dpf). RPTP alpha was detectable again from 4 dpf onward. RPTP alpha knock-down resulted in smaller eyes. Examination of sections of the retina at different developmental stages demonstrated that already at 28 hours postfertilization (hpf) fewer cells were present in the retina of RPTP alpha-morpholino-injected embryos. At 3 dpf, the layered organization of the retina was absent. In addition, the morphology and labeling with an axon specific antibody, acetylated tubulin, demonstrated that most cells appeared to be undifferentiated. Strikingly, at 5 dpf the lamination of the retina was partially restored, concomitant with re-expression of RPTP alpha protein. Although cells in the retina were now differentiated, the layering of the retina remained disrupted and significant gaps were observed in the amacrine cell layer. Therefore, knock-down of RPTP alpha protein provides evidence that RPTP alpha is essential for normal retinal development.
Collapse
Affiliation(s)
- Astrid M van der Sar
- Hubrecht Laboratory, Netherlands Institute for Developmental Biology, Utrecht, The Netherlands
| | | | | |
Collapse
|
64
|
Abstract
Many zebrafish mutants have specific defects in axon guidance or synaptogenesis, particularly in the retinotectal and motor systems. Several mutants have now been characterized in detail and/or cloned. A combination of genetic studies, in vivo imaging and new techniques for misexpressing genes or blocking their function promises to reveal the molecules and principles that govern wiring of the vertebrate nervous system.
Collapse
Affiliation(s)
- Lara D Hutson
- Department of Neurobiology and Anatomy, Room 401 Medical Research and Engineering Building, 20 North 1900 East, University of Utah Medical Center, Salt Lake City, Utah 84132, USA
| | | |
Collapse
|
65
|
Tucker RP. Abnormal neural crest cell migration after the in vivo knockdown of tenascin-C expression with morpholino antisense oligonucleotides. Dev Dyn 2001; 222:115-9. [PMID: 11507773 DOI: 10.1002/dvdy.1171] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A key feature of vertebrate development is the formation of the neural crest. In the trunk, neural crest cells delaminate from the neural tube shortly after the fusion of the neural folds and migrate ventrally along specific pathways to form the neurons and glia of the peripheral nervous system. As neural crest cells leave the neural tube during the initial stages of their migration, they express the extracellular matrix glycoprotein tenascin-C, which is also found in the stroma of many tumors. We have studied the possible role for tenascin-C during neural crest morphogenesis in vivo by microinjecting tenascin-C morpholino antisense oligonucleotides into the lumen of the avian neural tube in ovo and electroporating the morpholino antisense oligonucleotides into the precursors of the neural crest. After 24 hr, tenascin-C immunostaining is reduced around the dorsal neural tube in the experimental microinjected embryos (12 of 13) but not in embryos microinjected with control morpholino antisense oligonucleotides (n = 3) or subjected to electroporation only (n = 2). In each of the 12 tenascin-C knockdown embryos neural crest cells are seen ectopically in the lumen of the neural tube and in the neuroepithelium; cells that do leave the neural tube after the microinjection fail to disperse laterally from the surface of the neural tube into the somites. The observation that neural crest cells must express tenascin-C to migrate normally is consistent with a role for this glycoprotein in contributing to the invasive behavior of neural crest cells.
Collapse
Affiliation(s)
- R P Tucker
- Department of Cell Biology and Human Anatomy, University of California at Davis, Davis, California 95616, USA.
| |
Collapse
|