1
|
Yang H, Xu Y, Yuan Y, Liu X, Zhang J, Li J, Zhang R, Cao J, Cheng T, Liu C. Identification and function of the Pax gene Bmgsb in the silk gland of Bombyx mori. INSECT MOLECULAR BIOLOGY 2024; 33:173-184. [PMID: 38238257 DOI: 10.1111/imb.12886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 11/29/2023] [Indexed: 05/08/2024]
Abstract
Paired box (Pax) genes are highly conserved throughout evolution, and the Pax protein is an important transcription factor of embryonic development. The Pax gene Bmgsb is expressed in the silk glands of silkworm, but its biological functions remain unclear. This study aimed to investigate the expression pattern of Bmgsb in the silk gland and explore its functions using RNA interference (RNAi). Here, we identified eight Pax genes in Bombyx mori. Phylogenetic analysis showed that the B. mori Pax genes were highly homologous to the Pax genes in other insects and highly evolutionarily conserved. The tissue expression profile showed that Bmgsb was expressed in the anterior silk gland and anterior part of the middle silk gland (AMSG). RNAi of Bmgsb resulted in defective development of the AMSG, and the larvae were mostly unable to cocoon in the wandering stage. RNA-seq analysis showed that the fibroin genes fib-l, fib-h and p25, cellular heat shock response-related genes and phenol oxidase genes were considerably upregulated upon Bmgsb knockdown. Furthermore, quantitative reverse transcription-PCR results showed that the fibroin genes and ubiquitin proteolytic enzyme-related genes were significantly upregulated in the AMSG after Bmgsb knockdown. This study provides a foundation for future research on the biological functions of B. mori Pax genes. In addition, it demonstrates the important roles of Bmgsb in the transcriptional regulation of fibroin genes and silk gland development.
Collapse
Affiliation(s)
- Hongguo Yang
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
| | - Yongping Xu
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
| | - Yutong Yuan
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
| | - Xuebing Liu
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
| | - Jikailang Zhang
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
| | - Jiaojiao Li
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
| | - Ran Zhang
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
| | - Jun Cao
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
| | - Tingcai Cheng
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
- Cancer Center, Medical Research Institute, Southwest University, Chongqing, China
- Jinfeng Laboratory, Chongqing, China
| | - Chun Liu
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
- Cancer Center, Medical Research Institute, Southwest University, Chongqing, China
- Jinfeng Laboratory, Chongqing, China
| |
Collapse
|
2
|
Baxi AB, Nemes P, Moody SA. Time-resolved quantitative proteomic analysis of the developing Xenopus otic vesicle reveals putative congenital hearing loss candidates. iScience 2023; 26:107665. [PMID: 37670778 PMCID: PMC10475516 DOI: 10.1016/j.isci.2023.107665] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 07/16/2023] [Accepted: 08/14/2023] [Indexed: 09/07/2023] Open
Abstract
Over 200 genes are known to underlie human congenital hearing loss (CHL). Although transcriptomic approaches have identified candidate regulators of otic development, little is known about the abundance of their protein products. We used a multiplexed quantitative mass spectrometry-based proteomic approach to determine protein abundances over key stages of Xenopus otic morphogenesis to reveal a dynamic expression of cytoskeletal, integrin signaling, and extracellular matrix proteins. We correlated these dynamically expressed proteins to previously published lists of putative downstream targets of human syndromic hearing loss genes: SIX1 (BOR syndrome), CHD7 (CHARGE syndrome), and SOX10 (Waardenburg syndrome). We identified transforming growth factor beta-induced (Tgfbi), an extracellular integrin-interacting protein, as a putative target of Six1 that is required for normal otic vesicle formation. Our findings demonstrate the application of this Xenopus dataset to understanding the dynamic regulation of proteins during otic development and to discovery of additional candidates for human CHL.
Collapse
Affiliation(s)
- Aparna B. Baxi
- Department of Anatomy and Cell Biology, The George Washington University School of Medicine and Health Sciences, Washington, DC 20052, USA
| | - Peter Nemes
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
| | - Sally A. Moody
- Department of Anatomy and Cell Biology, The George Washington University School of Medicine and Health Sciences, Washington, DC 20052, USA
| |
Collapse
|
3
|
Shiraki T, Hayashi T, Ozue J, Watanabe M. Appropriate Amounts and Activity of the Wilms' Tumor Suppressor Gene, wt1, Are Required for Normal Pronephros Development of Xenopus Embryos. J Dev Biol 2022; 10:jdb10040046. [PMID: 36412640 PMCID: PMC9680428 DOI: 10.3390/jdb10040046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 10/23/2022] [Accepted: 10/27/2022] [Indexed: 12/14/2022] Open
Abstract
The Wilms' tumor suppressor gene, wt1, encodes a zinc finger-containing transcription factor that binds to a GC-rich motif and regulates the transcription of target genes. wt1 was first identified as a tumor suppressor gene in Wilms' tumor, a pediatric kidney tumor, and has been implicated in normal kidney development. The WT1 protein has transcriptional activation and repression domains and acts as a transcriptional activator or repressor, depending on the target gene and context. In Xenopus, an ortholog of wt1 has been isolated and shown to be expressed in the developing embryonic pronephros. To investigate the role of wt1 in pronephros development in Xenopus embryos, we mutated wt1 by CRISPR/Cas9 and found that the expression of pronephros marker genes was reduced. In reporter assays in which known WT1 binding sequences were placed upstream of the luciferase gene, WT1 activated transcription of the luciferase gene. The injection of wild-type or artificially altered transcriptional activity of wt1 mRNA disrupted the expression of pronephros marker genes in the embryos. These results suggest that the appropriate amounts and activity of WT1 protein are required for normal pronephros development in Xenopus embryos.
Collapse
Affiliation(s)
- Taisei Shiraki
- Graduate School of Sciences and Technology for Innovation, Tokushima University, 1-1 Minamijosanjima-Cho, Tokushima 770-8054, Japan
| | - Takuma Hayashi
- Graduate School of Sciences and Technology for Innovation, Tokushima University, 1-1 Minamijosanjima-Cho, Tokushima 770-8054, Japan
| | - Jotaro Ozue
- Graduate School of Sciences and Technology for Innovation, Tokushima University, 1-1 Minamijosanjima-Cho, Tokushima 770-8054, Japan
| | - Minoru Watanabe
- Graduate School of Sciences and Technology for Innovation, Tokushima University, 1-1 Minamijosanjima-Cho, Tokushima 770-8054, Japan
- Institute of Liberal Arts and Sciences, Tokushima University, 1-1 Minamijosanjima-Cho, Tokushima 770-8054, Japan
- Correspondence: ; Tel.: +81-088-656-7253
| |
Collapse
|
4
|
Keer S, Cousin H, Jourdeuil K, Neilson KM, Tavares ALP, Alfandari D, Moody SA. Mcrs1 is required for branchial arch and cranial cartilage development. Dev Biol 2022; 489:62-75. [PMID: 35697116 PMCID: PMC10426812 DOI: 10.1016/j.ydbio.2022.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 06/06/2022] [Accepted: 06/08/2022] [Indexed: 11/22/2022]
Abstract
Mcrs1 is a multifunctional protein that is critical for many cellular processes in a wide range of cell types. Previously, we showed that Mcrs1 binds to the Six1 transcription factor and reduces the ability of the Six1-Eya1 complex to upregulate transcription, and that Mcrs1 loss-of-function leads to the expansion of several neural plate genes, reduction of neural border and pre-placodal ectoderm (PPR) genes, and pleiotropic effects on various neural crest (NC) genes. Because the affected embryonic structures give rise to several of the cranial tissues affected in Branchio-otic/Branchio-oto-renal (BOR) syndrome, herein we tested whether these gene expression changes subsequently alter the development of the proximate precursors of BOR affected structures - the otic vesicles (OV) and branchial arches (BA). We found that Mcrs1 is required for the expression of several OV genes involved in inner ear formation, patterning and otic capsule cartilage formation. Mcrs1 knockdown also reduced the expression domains of many genes expressed in the larval BA, derived from either NC or PPR, except for emx2, which was expanded. Reduced Mcrs1 also diminished the length of the expression domain of tbx1 in BA1 and BA2 and interfered with cranial NC migration from the dorsal neural tube; this subsequently resulted in defects in the morphology of lower jaw cartilages derived from BA1 and BA2, including the infrarostral, Meckel's, and ceratohyal as well as the otic capsule. These results demonstrate that Mcrs1 plays an important role in processes that lead to the formation of craniofacial cartilages and its loss results in phenotypes consistent with reduced Six1 activity associated with BOR.
Collapse
Affiliation(s)
- Stephanie Keer
- Department of Anatomy and Cell Biology, The George Washington University School of Medicine and Health Sciences, 2300 I (eye) Street, NW, Washington, DC, 20037, USA
| | - Helene Cousin
- Department of Animal Science, University of Massachusetts Amherst, Integrated Science Building, 661 N. Pleasant Street, Amherst, MA, 01003, USA
| | - Karyn Jourdeuil
- Department of Anatomy and Cell Biology, The George Washington University School of Medicine and Health Sciences, 2300 I (eye) Street, NW, Washington, DC, 20037, USA
| | - Karen M Neilson
- Department of Anatomy and Cell Biology, The George Washington University School of Medicine and Health Sciences, 2300 I (eye) Street, NW, Washington, DC, 20037, USA
| | - Andre L P Tavares
- Department of Anatomy and Cell Biology, The George Washington University School of Medicine and Health Sciences, 2300 I (eye) Street, NW, Washington, DC, 20037, USA
| | - Dominique Alfandari
- Department of Animal Science, University of Massachusetts Amherst, Integrated Science Building, 661 N. Pleasant Street, Amherst, MA, 01003, USA
| | - Sally A Moody
- Department of Anatomy and Cell Biology, The George Washington University School of Medicine and Health Sciences, 2300 I (eye) Street, NW, Washington, DC, 20037, USA.
| |
Collapse
|
5
|
Zahn N, James-Zorn C, Ponferrada VG, Adams DS, Grzymkowski J, Buchholz DR, Nascone-Yoder NM, Horb M, Moody SA, Vize PD, Zorn AM. Normal Table of Xenopus development: a new graphical resource. Development 2022; 149:dev200356. [PMID: 35833709 PMCID: PMC9445888 DOI: 10.1242/dev.200356] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 03/17/2022] [Indexed: 12/26/2022]
Abstract
Normal tables of development are essential for studies of embryogenesis, serving as an important resource for model organisms, including the frog Xenopus laevis. Xenopus has long been used to study developmental and cell biology, and is an increasingly important model for human birth defects and disease, genomics, proteomics and toxicology. Scientists utilize Nieuwkoop and Faber's classic 'Normal Table of Xenopus laevis (Daudin)' and accompanying illustrations to enable experimental reproducibility and reuse the illustrations in new publications and teaching. However, it is no longer possible to obtain permission for these copyrighted illustrations. We present 133 new, high-quality illustrations of X. laevis development from fertilization to metamorphosis, with additional views that were not available in the original collection. All the images are available on Xenbase, the Xenopus knowledgebase (http://www.xenbase.org/entry/zahn.do), for download and reuse under an attributable, non-commercial creative commons license. Additionally, we have compiled a 'Landmarks Table' of key morphological features and marker gene expression that can be used to distinguish stages quickly and reliably (https://www.xenbase.org/entry/landmarks-table.do). This new open-access resource will facilitate Xenopus research and teaching in the decades to come.
Collapse
Affiliation(s)
| | - Christina James-Zorn
- Xenbase, Division of Developmental Biology, Cincinnati Children's Hospital Research Foundation, 3333 Burnet Ave, Cincinnati, OH 45229, USA
| | - Virgilio G. Ponferrada
- Xenbase, Division of Developmental Biology, Cincinnati Children's Hospital Research Foundation, 3333 Burnet Ave, Cincinnati, OH 45229, USA
| | - Dany S. Adams
- Lucell Diagnostics Inc, 16 Stearns Street, Cambridge, MA 02138, USA
| | - Julia Grzymkowski
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27695, USA
| | - Daniel R. Buchholz
- Department of Biology Sciences, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Nanette M. Nascone-Yoder
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27695, USA
| | - Marko Horb
- National Xenopus Resource, Marine Biological Laboratory, Woods Hole, MA 02543, USA
| | - Sally A. Moody
- Department of Anatomy and Cell Biology, George Washington University Medical Center, Washington, DC 20037, USA
| | - Peter D. Vize
- Xenbase, Department of Biological Science, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - Aaron M. Zorn
- Xenbase, Division of Developmental Biology, Cincinnati Children's Hospital Research Foundation, 3333 Burnet Ave, Cincinnati, OH 45229, USA
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| |
Collapse
|
6
|
Hidalgo-Sánchez M, Andreu-Cervera A, Villa-Carballar S, Echevarria D. An Update on the Molecular Mechanism of the Vertebrate Isthmic Organizer Development in the Context of the Neuromeric Model. Front Neuroanat 2022; 16:826976. [PMID: 35401126 PMCID: PMC8987131 DOI: 10.3389/fnana.2022.826976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 02/28/2022] [Indexed: 11/13/2022] Open
Abstract
A crucial event during the development of the central nervous system (CNS) is the early subdivision of the neural tube along its anterior-to-posterior axis to form neuromeres, morphogenetic units separated by transversal constrictions and programed for particular genetic cascades. The narrower portions observed in the developing neural tube are responsible for relevant cellular and molecular processes, such as clonal restrictions, expression of specific regulatory genes, and differential fate specification, as well as inductive activities. In this developmental context, the gradual formation of the midbrain-hindbrain (MH) constriction has been an excellent model to study the specification of two major subdivisions of the CNS containing the mesencephalic and isthmo-cerebellar primordia. This MH boundary is coincident with the common Otx2-(midbrain)/Gbx2-(hindbrain) expressing border. The early interactions between these two pre-specified areas confer positional identities and induce the generation of specific diffusible morphogenes at this interface, in particular FGF8 and WNT1. These signaling pathways are responsible for the gradual histogenetic specifications and cellular identity acquisitions with in the MH domain. This review is focused on the cellular and molecular mechanisms involved in the specification of the midbrain/hindbrain territory and the formation of the isthmic organizer. Emphasis will be placed on the chick/quail chimeric experiments leading to the acquisition of the first fate mapping and experimental data to, in this way, better understand pioneering morphological studies and innovative gain/loss-of-function analysis.
Collapse
Affiliation(s)
- Matías Hidalgo-Sánchez
- Departamento de Biología Celular, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain
- *Correspondence: Matías Hidalgo-Sánchez Diego Echevarria
| | - Abraham Andreu-Cervera
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Alicante, Spain
| | - Sergio Villa-Carballar
- Departamento de Biología Celular, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain
| | - Diego Echevarria
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Alicante, Spain
- *Correspondence: Matías Hidalgo-Sánchez Diego Echevarria
| |
Collapse
|
7
|
Coppenrath K, Tavares ALP, Shaidani NI, Wlizla M, Moody SA, Horb M. Generation of a new six1-null line in Xenopus tropicalis for study of development and congenital disease. Genesis 2021; 59:e23453. [PMID: 34664392 DOI: 10.1002/dvg.23453] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 09/02/2021] [Accepted: 09/04/2021] [Indexed: 12/15/2022]
Abstract
The vertebrate Six (Sine oculis homeobox) family of homeodomain transcription factors plays critical roles in the development of several organs. Six1 plays a central role in cranial placode development, including the precursor tissues of the inner ear, as well as other cranial sensory organs and the kidney. In humans, mutations in SIX1 underlie some cases of Branchio-oto-renal (BOR) syndrome, which is characterized by moderate-to-severe hearing loss. We utilized CRISPR/Cas9 technology to establish a six1 mutant line in Xenopus tropicalis that is available to the research community. We demonstrate that at larval stages, the six1-null animals show severe disruptions in gene expression of putative Six1 target genes in the otic vesicle, cranial ganglia, branchial arch, and neural tube. At tadpole stages, six1-null animals display dysmorphic Meckel's, ceratohyal, and otic capsule cartilage morphology. This mutant line will be of value for the study of the development of several organs as well as congenital syndromes that involve these tissues.
Collapse
Affiliation(s)
- Kelsey Coppenrath
- Eugene Bell Center for Regenerative Biology and Tissue Engineering and National Xenopus Resource, Marine Biological Laboratory, Woods Hole, Massachusetts, USA
| | - Andre L P Tavares
- Department of Anatomy and Cell Biology, George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, USA
| | - Nikko-Ideen Shaidani
- Eugene Bell Center for Regenerative Biology and Tissue Engineering and National Xenopus Resource, Marine Biological Laboratory, Woods Hole, Massachusetts, USA
| | - Marcin Wlizla
- Eugene Bell Center for Regenerative Biology and Tissue Engineering and National Xenopus Resource, Marine Biological Laboratory, Woods Hole, Massachusetts, USA.,Embryology Department, Charles River Laboratories, Wilmington, Massachusetts, USA
| | - Sally A Moody
- Department of Anatomy and Cell Biology, George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, USA
| | - Marko Horb
- Eugene Bell Center for Regenerative Biology and Tissue Engineering and National Xenopus Resource, Marine Biological Laboratory, Woods Hole, Massachusetts, USA
| |
Collapse
|
8
|
Lusk S, Kwan KM. Pax2a, but not pax2b, influences cell survival and periocular mesenchyme localization to facilitate zebrafish optic fissure closure. Dev Dyn 2021; 251:625-644. [PMID: 34535934 PMCID: PMC8930785 DOI: 10.1002/dvdy.422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/23/2021] [Accepted: 09/13/2021] [Indexed: 11/09/2022] Open
Abstract
Background Pax2 is required for optic fissure development in many organisms, including humans and zebrafish. Zebrafish loss‐of‐function mutations in pax2a display coloboma, yet the etiology of the morphogenetic defects is unclear. Further, pax2 is duplicated in zebrafish, and a role for pax2b in optic fissure development has not been examined. Results Using a combination of imaging and molecular genetics, we interrogated a potential role for pax2b and examined how loss of pax2 affects optic fissure development. Although optic fissure formation appears normal in pax2 mutants, an endothelial‐specific subset of periocular mesenchyme (POM) fails to initially localize within the optic fissure, yet both neural crest and endothelial‐derived POM ectopically accumulate at later stages in pax2a and pax2a; pax2b mutants. Apoptosis is not up‐regulated within the optic fissure in pax2 mutants, yet cell death is increased in tissues outside of the optic fissure, and when apoptosis is inhibited, coloboma is partially rescued. In contrast to pax2a, loss of pax2b does not appear to affect optic fissure morphogenesis. Conclusions Our results suggest that pax2a, but not pax2b, supports cell survival outside of the optic fissure and POM abundance within it to facilitate optic fissure closure. Zebrafish pax2a null mutants display a defect in optic fissure closure and coloboma Loss of pax2b does not affect optic fissure development An endothelial‐specific subset of periocular mesenchyme cells fails to initially localize to the optic fissure in pax2a mutants At a later stage of optic fissure development both neural crest and endothelial‐derived periocular mesenchyme ectopically accumulate within the optic fissure Pax2a mutants have increased apoptosis in surrounding tissues, but not within the optic fissure margin cells, and apoptosis in part underlies the coloboma phenotype
Collapse
Affiliation(s)
- Sarah Lusk
- Department of Human Genetics, University of Utah, Salt Lake City, Utah, USA
| | - Kristen M Kwan
- Department of Human Genetics, University of Utah, Salt Lake City, Utah, USA
| |
Collapse
|
9
|
Mechanical Brain Injury Increases Cells' Production of Cystathionine β-Synthase and Glutamine Synthetase, but Reduces Pax2 Expression in the Telencephalon of Juvenile Chum Salmon, Oncorhynchus keta. Int J Mol Sci 2021; 22:ijms22031279. [PMID: 33525421 PMCID: PMC7865298 DOI: 10.3390/ijms22031279] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 01/15/2021] [Accepted: 01/20/2021] [Indexed: 12/15/2022] Open
Abstract
The considerable post-traumatic brain recovery in fishes makes them a useful model for studying the mechanisms that provide reparative neurogenesis, which is poorly represented in mammals. After a mechanical injury to the telencephalon in adult fish, lost neurons are actively replaced due to the proliferative activity of neuroepithelial cells and radial glia in the neurogenic periventricular zone. However, it is not enough clear which signaling mechanisms are involved in the activation of adult neural stem cells (aNSC) after the injury (reactive proliferation) and in the production of new neurons (regenerative neurogenesis) from progenitor cells (NPC). In juvenile Pacific salmon, the predominant type of NSCs in the telencephalon are neuroepithelial cells corresponding to embryonic NSCs. Expression of glutamine synthetase (GS), a NSC molecular marker, was detected in the neuroepithelial cells of the pallium and subpallium of juvenile chum salmon, Oncorhynchus keta. At 3 days after a traumatic brain injury (TBI) in juvenile chum salmon, the GS expression was detected in the radial glia corresponding to aNSC in the pallium and subpallium. The maximum density of distribution of GS+ radial glia was found in the dorsal pallial region. Hydrogen sulfide (H2S) is a proneurogenic factor that reduces oxidative stress and excitotoxicity effects, along with the increased GS production in the brain cells of juvenile chum salmon. In the fish brain, H2S producing by cystathionine β-synthase in neurogenic zones may be involved in maintaining the microenvironment that provides optimal conditions for the functioning of neurogenic niches during constitutive neurogenesis. After injury, H2S can determine cell survivability, providing a neuroprotective effect in the area of injury and reducing the process of glutamate excitotoxicity, acting as a signaling molecule involved in changing the neurogenic environment, which leads to the reactivation of neurogenic niches and cell regeneration programs. The results of studies on the control of the expression of regulatory Sonic Hedgehog genes (Shh) and the transcription factors Paired Box2 (Pax2) regulated by them are still insufficient. A comparative analysis of Pax2 expression in the telencephalon of intact chum salmon showed the presence of constitutive patterns of Pax2 expression in neurogenic areas and non-neurogenic parenchymal zones of the pallium and subpallium. After mechanical injury, the patterns of Pax2 expression changed, and the amount of Pax2+ decreased (p < 0.05) in lateral (Dl), medial (Dm) zones of the pallium, and the lateral zone (Vl) of the subpallium compared to the control. We believe that the decrease in the expression of Pax2 may be caused by the inhibitory effect of the Pax6 transcription factor, whose expression in the juvenile salmon brain increases upon injury.
Collapse
|
10
|
de Bakker BS, van den Hoff MJB, Vize PD, Oostra RJ. The Pronephros; a Fresh Perspective. Integr Comp Biol 2019; 59:29-47. [PMID: 30649320 DOI: 10.1093/icb/icz001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Contemporary papers and book chapters on nephrology open with the assumption that human kidney development passes through three morphological stages: pronephros, mesonephros, and metanephros. Current knowledge of the human pronephros, however, appears to be based on only a hand full of human specimens. The ongoing use of variations in the definition of a pronephros hampers the interpretation of study results. Because of the increased interest in the anamniote pronephros as a genetic model for kidney organogenesis we aimed to provide an overview of the literature concerning kidney development and to clarify the existence of a pronephros in human embryos. We performed an extensive literature survey regarding vertebrate renal morphology and we investigated histological sections of human embryos between 2 and 8 weeks of development. To facilitate better understanding of the literature about kidney development, a referenced glossary with short definitions was composed. The most striking difference between pronephros versus meso- and metanephros is found in nephron architecture. The pronephros consists exclusively of non-integrated nephrons with external glomeruli, whereas meso- and metanephros are composed of integrated nephrons with internal glomeruli. Animals whose embryos have comparatively little yolk at their disposal and hence have a free-swimming larval stage do develop a pronephros that is dedicated to survival in aquatic environments. Species in which embryos do not have a free-swimming larval stage have embryos that are supplied with a large amount of yolk or that develop within the body of the parent. In those species the pronephros is usually absent, incompletely developed, and apparently functionless. Non-integrated nephrons were not identified in histological sections of human embryos. Therefore, we conclude that a true pronephros is not detectable in human embryos although the most cranial part of the amniote excretory organ is often confusingly referred to as pronephros. The term pronephros should be avoided in amniotes unless all elements for a functional pronephros are undeniably present.
Collapse
Affiliation(s)
- B S de Bakker
- Department of Medical Biology, Section Clinical Anatomy and Embryology, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
| | - M J B van den Hoff
- Department of Medical Biology, Section Clinical Anatomy and Embryology, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
| | - P D Vize
- Department of Biological Science, University of Calgary, Calgary, Alberta, Canada T2N 1N4
| | - R J Oostra
- Department of Medical Biology, Section Clinical Anatomy and Embryology, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
| |
Collapse
|
11
|
Suzuki N, Hirano K, Ogino H, Ochi H. Arid3a regulates nephric tubule regeneration via evolutionarily conserved regeneration signal-response enhancers. eLife 2019; 8:43186. [PMID: 30616715 PMCID: PMC6324879 DOI: 10.7554/elife.43186] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2018] [Accepted: 12/18/2018] [Indexed: 12/15/2022] Open
Abstract
Amphibians and fish have the ability to regenerate numerous tissues, whereas mammals have a limited regenerative capacity. Despite numerous developmental genes becoming reactivated during regeneration, an extensive analysis is yet to be performed on whether highly regenerative animals utilize unique cis-regulatory elements for the reactivation of genes during regeneration and how such cis-regulatory elements become activated. Here, we screened regeneration signal-response enhancers at the lhx1 locus using Xenopus and found that the noncoding elements conserved from fish to human function as enhancers in the regenerating nephric tubules. A DNA-binding motif of Arid3a, a component of H3K9me3 demethylases, was commonly found in RSREs. Arid3a binds to RSREs and reduces the H3K9me3 levels. It promotes cell cycle progression and causes the outgrowth of nephric tubules, whereas the conditional knockdown of arid3a using photo-morpholino inhibits regeneration. These results suggest that Arid3a contributes to the regeneration of nephric tubules by decreasing H3K9me3 on RSREs.
Collapse
Affiliation(s)
- Nanoka Suzuki
- Institute for Promotion of Medical Science Research, Yamagata University, Faculty of Medicine, Yamagata, Japan
| | - Kodai Hirano
- Institute for Promotion of Medical Science Research, Yamagata University, Faculty of Medicine, Yamagata, Japan
| | - Hajime Ogino
- Amphibian Research Center, Hiroshima University, Higashi-hiroshima, Japan
| | - Haruki Ochi
- Institute for Promotion of Medical Science Research, Yamagata University, Faculty of Medicine, Yamagata, Japan
| |
Collapse
|
12
|
Seigfried FA, Cizelsky W, Pfister AS, Dietmann P, Walther P, Kühl M, Kühl SJ. Frizzled 3 acts upstream of Alcam during embryonic eye development. Dev Biol 2017; 426:69-83. [PMID: 28427856 DOI: 10.1016/j.ydbio.2017.04.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 02/09/2017] [Accepted: 04/14/2017] [Indexed: 12/18/2022]
Abstract
Formation of a functional eye during vertebrate embryogenesis requires different processes such as cell differentiation, cell migration, cell-cell interactions as well as intracellular signalling processes. It was previously shown that the non-canonical Wnt receptor Frizzled 3 (Fzd3) is required for proper eye formation, however, the underlying mechanism is poorly understood. Here we demonstrate that loss of Fzd3 induces severe malformations of the developing eye and that this defect is phenocopied by loss of the activated leukocyte cell adhesion molecule (Alcam). Promoter analysis revealed the presence of a Fzd3 responsive element within the alcam promoter, which is responsible for alcam expression during anterior neural development. In-depth analysis identified the jun N-terminal protein kinase 1 (JNK1) and the transcription factor paired box 2 (Pax2) to be important for the activation of alcam expression. Altogether our study reveals that alcam is activated through non-canonical Wnt signalling during embryonic eye development in Xenopus laevis and shows that this pathway plays a similar role in different tissues.
Collapse
Affiliation(s)
- Franziska A Seigfried
- Institute of Biochemistry and Molecular Biology, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany; International Graduate School in Molecular Medicine Ulm, 89081 Ulm, Germany; Tissue Homeostasis Joint-PhD-Programme in Cooperation with the University of Oulu, Finland
| | - Wiebke Cizelsky
- Institute of Biochemistry and Molecular Biology, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany; International Graduate School in Molecular Medicine Ulm, 89081 Ulm, Germany
| | - Astrid S Pfister
- Institute of Biochemistry and Molecular Biology, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Petra Dietmann
- Institute of Biochemistry and Molecular Biology, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Paul Walther
- Central Facility for Electron Microscopy, Ulm University, Albert-Einstein-Allee 11, D-89081 Ulm, Germany
| | - Michael Kühl
- Institute of Biochemistry and Molecular Biology, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Susanne J Kühl
- Institute of Biochemistry and Molecular Biology, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany.
| |
Collapse
|
13
|
Krneta-Stankic V, DeLay BD, Miller RK. Xenopus: leaping forward in kidney organogenesis. Pediatr Nephrol 2017; 32:547-555. [PMID: 27099217 PMCID: PMC5074909 DOI: 10.1007/s00467-016-3372-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 03/08/2016] [Accepted: 03/09/2016] [Indexed: 12/17/2022]
Abstract
While kidney donations stagnate, the number of people in need of kidney transplants continues to grow. Although transplanting culture-grown organs is years away, pursuing the engineering of the kidney de novo is a valid means of closing the gap between the supply and demand of kidneys for transplantation. The structural organization of a mouse kidney is similar to that of humans. Therefore, mice have traditionally served as the primary model system for the study of kidney development. The mouse is an ideal model organism for understanding the complexity of the human kidney. Nonetheless, the elaborate structure of the mammalian kidney makes the discovery of new therapies based on de novo engineered kidneys more challenging. In contrast to mammals, amphibians have a kidney that is anatomically less complex and develops faster. Given that analogous genetic networks regulate the development of mammalian and amphibian nephric organs, using embryonic kidneys of Xenopus laevis (African clawed frog) to analyze inductive cell signaling events and morphogenesis has many advantages. Pioneering work that led to the ability to generate kidney organoids from embryonic cells was carried out in Xenopus. In this review, we discuss how Xenopus can be utilized to compliment the work performed in mammalian systems to understand kidney development.
Collapse
Affiliation(s)
- Vanja Krneta-Stankic
- Department of Pediatrics, Pediatric Research Center, University of Texas McGovern Medical School, 6431 Fannin Street, MSE R413, Houston, TX, 77030, USA
- Program in Genes and Development, University of Texas Graduate School of Biomedical Sciences, Houston, TX, USA
| | - Bridget D DeLay
- Department of Pediatrics, Pediatric Research Center, University of Texas McGovern Medical School, 6431 Fannin Street, MSE R413, Houston, TX, 77030, USA
| | - Rachel K Miller
- Department of Pediatrics, Pediatric Research Center, University of Texas McGovern Medical School, 6431 Fannin Street, MSE R413, Houston, TX, 77030, USA.
- Program in Genes and Development, University of Texas Graduate School of Biomedical Sciences, Houston, TX, USA.
- Program in Cell and Regulatory Biology, University of Texas Graduate School of Biomedical Sciences, Houston, TX, USA.
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX, USA.
| |
Collapse
|
14
|
Navet S, Buresi A, Baratte S, Andouche A, Bonnaud-Ponticelli L, Bassaglia Y. The Pax gene family: Highlights from cephalopods. PLoS One 2017; 12:e0172719. [PMID: 28253300 PMCID: PMC5333810 DOI: 10.1371/journal.pone.0172719] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 02/08/2017] [Indexed: 01/15/2023] Open
Abstract
Pax genes play important roles in Metazoan development. Their evolution has been extensively studied but Lophotrochozoa are usually omitted. We addressed the question of Pax paralog diversity in Lophotrochozoa by a thorough review of available databases. The existence of six Pax families (Pax1/9, Pax2/5/8, Pax3/7, Pax4/6, Paxβ, PoxNeuro) was confirmed and the lophotrochozoan Paxβ subfamily was further characterized. Contrary to the pattern reported in chordates, the Pax2/5/8 family is devoid of homeodomain in Lophotrochozoa. Expression patterns of the three main pax classes (pax2/5/8, pax3/7, pax4/6) during Sepia officinalis development showed that Pax roles taken as ancestral and common in metazoans are modified in S. officinalis, most likely due to either the morphological specificities of cephalopods or to their direct development. Some expected expression patterns were missing (e.g. pax6 in the developing retina), and some expressions in unexpected tissues have been found (e.g. pax2/5/8 in dermal tissue and in gills). This study underlines the diversity and functional plasticity of Pax genes and illustrates the difficulty of using probable gene homology as strict indicator of homology between biological structures.
Collapse
Affiliation(s)
- Sandra Navet
- UMR BOREA MNHN/CNRS7208/IRD207/UPMC/UCN/UA, Muséum National d'Histoire Naturelle, Sorbonne Universités, Paris, France
| | - Auxane Buresi
- UMR BOREA MNHN/CNRS7208/IRD207/UPMC/UCN/UA, Muséum National d'Histoire Naturelle, Sorbonne Universités, Paris, France
| | - Sébastien Baratte
- UMR BOREA MNHN/CNRS7208/IRD207/UPMC/UCN/UA, Muséum National d'Histoire Naturelle, Sorbonne Universités, Paris, France
- Univ. Paris Sorbonne-ESPE, Sorbonne Universités, Paris, France
| | - Aude Andouche
- UMR BOREA MNHN/CNRS7208/IRD207/UPMC/UCN/UA, Muséum National d'Histoire Naturelle, Sorbonne Universités, Paris, France
| | - Laure Bonnaud-Ponticelli
- UMR BOREA MNHN/CNRS7208/IRD207/UPMC/UCN/UA, Muséum National d'Histoire Naturelle, Sorbonne Universités, Paris, France
| | - Yann Bassaglia
- UMR BOREA MNHN/CNRS7208/IRD207/UPMC/UCN/UA, Muséum National d'Histoire Naturelle, Sorbonne Universités, Paris, France
- Univ. Paris Est Créteil-Val de Marne, Créteil, France
- * E-mail:
| |
Collapse
|
15
|
Abstract
The Xenopus genus includes several members of aquatic frogs native to Africa but is perhaps best known for the species Xenopus laevis and Xenopus tropicalis. These species were popularized as model organisms from as early as the 1800s and have been instrumental in expanding several biological fields including cell biology, environmental toxicology, regenerative biology, and developmental biology. In fact, much of what we know about the formation and maturation of the vertebrate renal system has been acquired by examining the intricate genetic and morphological patterns that epitomize nephrogenesis in Xenopus. From these numerous reports, we have learned that the process of kidney development is as unique among organs as it is conserved among vertebrates. While development of most organs involves increases in size at a single location, development of the kidney occurs through a series of three increasingly complex nephric structures that are temporally distinct from one another and which occupy discrete spatial locales within the body. These three renal systems all serve to provide homeostatic, osmoregulatory, and excretory functions in animals. Importantly, the kidneys in amphibians, such as Xenopus, are less complex and more easily accessed than those in mammals, and thus tadpoles and frogs provide useful models for understanding our own kidney development. Several descriptive and mechanistic studies conducted with the Xenopus model system have allowed us to elucidate the cellular and molecular mediators of renal patterning and have also laid the foundation for our current understanding of kidney repair mechanisms in vertebrates. While some species-specific responses to renal injury have been observed, we still recognize the advantage of the Xenopus system due to its distinctive similarity to mammalian wound healing, reparative, and regenerative responses. In addition, the first evidence of renal regeneration in an amphibian system was recently demonstrated in Xenopus laevis. As genetic and molecular tools continue to advance, our appreciation for and utilization of this amphibian model organism can only intensify and will certainly provide ample opportunities to further our understanding of renal development and repair.
Collapse
|
16
|
Macrì S, Simula L, Pellarin I, Pegoraro S, Onorati M, Sgarra R, Manfioletti G, Vignali R. Hmga2 is required for neural crest cell specification in Xenopus laevis. Dev Biol 2016; 411:25-37. [PMID: 26806704 DOI: 10.1016/j.ydbio.2016.01.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 12/23/2015] [Accepted: 01/20/2016] [Indexed: 12/12/2022]
Abstract
HMGA proteins are small nuclear proteins that bind DNA by conserved AT-hook motifs, modify chromatin architecture and assist in gene expression. Two HMGAs (HMGA1 and HMGA2), encoded by distinct genes, exist in mammals and are highly expressed during embryogenesis or reactivated in tumour progression. We here addressed the in vivo role of Xenopus hmga2 in the neural crest cells (NCCs). We show that hmga2 is required for normal NCC specification and development. hmga2 knockdown leads to severe disruption of major skeletal derivatives of anterior NCCs. We show that, within the NCC genetic network, hmga2 acts downstream of msx1, and is required for msx1, pax3 and snail2 activities, thus participating at different levels of the network. Because of hmga2 early effects in NCC specification, the subsequent epithelial-mesenchymal transition (EMT) and migration of NCCs towards the branchial pouches are also compromised. Strictly paralleling results on embryos, interfering with Hmga2 in a breast cancer cell model for EMT leads to molecular effects largely consistent with those observed on NCCs. These data indicate that Hmga2 is recruited in key molecular events that are shared by both NCCs and tumour cells.
Collapse
Affiliation(s)
- Simone Macrì
- Dipartimento di Biologia, Unità di Biologia Cellulare e dello Sviluppo, Università degli Studi di Pisa, SS12 Abetone e Brennero 4, 56127 Pisa, Italy
| | - Luca Simula
- Dipartimento di Biologia, Unità di Biologia Cellulare e dello Sviluppo, Università degli Studi di Pisa, SS12 Abetone e Brennero 4, 56127 Pisa, Italy
| | - Ilenia Pellarin
- Dipartimento di Scienze della Vita, Università degli Studi di Trieste, via Giorgieri 5, 34127 Trieste, Italy
| | - Silvia Pegoraro
- Dipartimento di Scienze della Vita, Università degli Studi di Trieste, via Giorgieri 5, 34127 Trieste, Italy
| | - Marco Onorati
- Dipartimento di Biologia, Unità di Biologia Cellulare e dello Sviluppo, Università degli Studi di Pisa, SS12 Abetone e Brennero 4, 56127 Pisa, Italy
| | - Riccardo Sgarra
- Dipartimento di Scienze della Vita, Università degli Studi di Trieste, via Giorgieri 5, 34127 Trieste, Italy
| | - Guidalberto Manfioletti
- Dipartimento di Scienze della Vita, Università degli Studi di Trieste, via Giorgieri 5, 34127 Trieste, Italy
| | - Robert Vignali
- Dipartimento di Biologia, Unità di Biologia Cellulare e dello Sviluppo, Università degli Studi di Pisa, SS12 Abetone e Brennero 4, 56127 Pisa, Italy.
| |
Collapse
|
17
|
Katada T, Sakurai H. Proper Notch activity is necessary for the establishment of proximal cells and differentiation of intermediate, distal, and connecting tubule in Xenopus pronephros development. Dev Dyn 2016; 245:472-82. [PMID: 26773453 DOI: 10.1002/dvdy.24386] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 12/11/2015] [Accepted: 01/05/2016] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Notch signaling in pronephros development has been shown to regulate establishment of glomus and proximal tubule, but how Notch signal works on competency of pronephric anlagen during the generation of pronephric components remains to be understood. RESULTS We investigated how components of pronephros (glomus, proximal tubule, intermediate tubule, distal tubule, and connecting tubule) were generated in Xenopus embryos by timed overactivation and suppression of Notch signaling. Notch activation resulted in expansion of the glomus and disruption of the proximal tubule formation. Inhibition of Notch signaling reduced expression of wt1 and XSMP-30. In addition, when Notch signaling was overactivated at stage 20 on, intermediate, distal, and connecting tubule markers, gremlin and clcnkb, were decreased while Notch down-regulation increased gremlin and clcnkb. Similar changes were observed with segmental markers, cldn19, cldn14, and rhcg on activation or inhibition of Notch. Although Notch did not affect the expression of pan-pronephric progenitor marker, pax2, its activation inhibited lumen formation in the pronephros. CONCLUSIONS Notch signal is essential for glomus and proximal tubule development and inhibition of Notch is critical for the differentiation of the intermediate, distal, and connecting tubule.
Collapse
Affiliation(s)
- Tomohisa Katada
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Tokyo, Japan
| | - Hiroyuki Sakurai
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Tokyo, Japan
| |
Collapse
|
18
|
Fabian P, Kozmikova I, Kozmik Z, Pantzartzi CN. Pax2/5/8 and Pax6 alternative splicing events in basal chordates and vertebrates: a focus on paired box domain. Front Genet 2015; 6:228. [PMID: 26191073 PMCID: PMC4488758 DOI: 10.3389/fgene.2015.00228] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 06/15/2015] [Indexed: 12/19/2022] Open
Abstract
Paired box transcription factors play important role in development and tissue morphogenesis. The number of Pax homologs varies among species studied so far, due to genome and gene duplications that have affected PAX family to a great extent. Based on sequence similarity and functional domains, four Pax classes have been identified in chordates, namely Pax1/9, Pax2/5/8, Pax3/7, and Pax4/6. Numerous splicing events have been reported mainly for Pax2/5/8 and Pax6 genes. Of significant interest are those events that lead to Pax proteins with presumed novel properties, such as altered DNA-binding or transcriptional activity. In the current study, a thorough analysis of Pax2/5/8 splicing events from cephalochordates and vertebrates was performed. We focused more on Pax2/5/8 and Pax6 splicing events in which the paired domain is involved. Three new splicing events were identified in Oryzias latipes, one of which seems to be conserved in Acanthomorphata. Using representatives from deuterostome and protostome phyla, a comparative analysis of the Pax6 exon-intron structure of the paired domain was performed, during an attempt to estimate the time of appearance of the Pax6(5a) mRNA isoform. As shown in our analysis, this splicing event is characteristic of Gnathostomata and is absent in the other chordate subphyla. Moreover, expression pattern of alternative spliced variants was compared between cephalochordates and fish species. In summary, our data indicate expansion of alternative mRNA variants in paired box region of Pax2/5/8 and Pax6 genes during the course of vertebrate evolution.
Collapse
Affiliation(s)
- Peter Fabian
- Department of Transcriptional Regulation, Institute of Molecular Genetics Prague, Czech Republic
| | - Iryna Kozmikova
- Department of Transcriptional Regulation, Institute of Molecular Genetics Prague, Czech Republic
| | - Zbynek Kozmik
- Department of Transcriptional Regulation, Institute of Molecular Genetics Prague, Czech Republic
| | - Chrysoula N Pantzartzi
- Department of Transcriptional Regulation, Institute of Molecular Genetics Prague, Czech Republic
| |
Collapse
|
19
|
Shi W, Xu G, Wang C, Sperber SM, Chen Y, Zhou Q, Deng Y, Zhao H. Heat shock 70-kDa protein 5 (Hspa5) is essential for pronephros formation by mediating retinoic acid signaling. J Biol Chem 2015; 290:577-89. [PMID: 25398881 PMCID: PMC4281759 DOI: 10.1074/jbc.m114.591628] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Revised: 11/09/2014] [Indexed: 12/17/2022] Open
Abstract
Heat shock 70-kDa protein 5 (Hspa5), also known as binding immunoglobulin protein (Bip) or glucose-regulated protein 78 (Grp78), belongs to the heat shock protein 70 kDa family. As a multifunctional protein, it participates in protein folding and calcium homeostasis and serves as an essential regulator of the endoplasmic reticulum (ER) stress response. It has also been implicated in signal transduction by acting as a receptor or co-receptor residing at the plasma membrane. Its function during embryonic development, however, remains largely elusive. In this study, we used morpholino antisense oligonucleotides (MOs) to knock down Hspa5 activity in Xenopus embryos. In Hspa5 morphants, pronephros formation was strongly inhibited with the reduction of pronephric marker genes Lim homeobox protein 1 (lhx1), pax2, and β1 subunit of Na/K-ATPase (atp1b1). Pronephros tissue was induced in vitro by treating animal caps with all-trans-retinoic acid and activin. Depletion of Hspa5 in animal caps, however, blocked the induction of pronephros as well as reduced the expression of retinoic acid (RA)-responsive genes, suggesting that knockdown of Hspa5 attenuated RA signaling. Knockdown of Hspa5 in animal caps resulted in decreased expression of lhx1, a transcription factor directly regulated by RA signaling and essential for pronephros specification. Co-injection of Hspa5MO with lhx1 mRNA partially rescued the phenotype induced by Hspa5MO. These results suggest that the RA-Lhx1 signaling cascade is involved in Hspa5MO-induced pronephros malformation. This study shows that Hspa5, a key regulator of the unfolded protein response, plays an essential role in pronephros formation, which is mediated in part through RA signaling during early embryonic development.
Collapse
Affiliation(s)
- Weili Shi
- From the Key Laboratory for Regenerative Medicine, Ministry of Education, School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong Special Administrative Region (SAR), China
| | - Gang Xu
- School of Chinese Medicine, Hong Kong Baptist University, 7 Baptist University Road, Kowloon Tong, Hong Kong SAR, China
| | - Chengdong Wang
- From the Key Laboratory for Regenerative Medicine, Ministry of Education, School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong Special Administrative Region (SAR), China, Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen 518057, China
| | - Steven M Sperber
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029-6574
| | - Yonglong Chen
- Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China, and
| | - Qin Zhou
- Division of Molecular Nephrology and Creative Training Center for Undergraduates, Ministry of Education Key Laboratory of Laboratory Medicine Diagnostics, College of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, China
| | - Yi Deng
- Department of Biology, South University of Science and Technology of China, Shenzhen 518055, China,
| | - Hui Zhao
- From the Key Laboratory for Regenerative Medicine, Ministry of Education, School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong Special Administrative Region (SAR), China, Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen 518057, China,
| |
Collapse
|
20
|
Pax8 and Pax2 are specifically required at different steps of Xenopus pronephros development. Dev Biol 2014; 397:175-90. [PMID: 25446030 DOI: 10.1016/j.ydbio.2014.10.022] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Revised: 10/07/2014] [Accepted: 10/26/2014] [Indexed: 11/23/2022]
Abstract
The respective role of Pax2 and Pax8 in early kidney development in vertebrates is poorly understood. In this report, we have studied the roles of Pax8 and Pax2 in Xenopus pronephros development using a loss-of-function approach. Our results highlight a differential requirement of these two transcription factors for proper pronephros formation. Pax8 is necessary for the earliest steps of pronephric development and its depletion leads to a complete absence of pronephric tubule. Pax2 is required after the establishment of the tubule pronephric anlage, for the expression of several terminal differentiation markers of the pronephric tubule. Neither Pax2 nor Pax8 is essential to glomus development. We further show that Pax8 controls hnf1b, but not lhx1 and Osr2, expression in the kidney field as soon as the mid-neurula stage. Pax8 is also required for cell proliferation of pronephric precursors in the kidney field. It may exert its action through the wnt/beta-catenin pathway since activation of this pathway can rescue MoPax8 induced proliferation defect and Pax8 regulates expression of the wnt pathway components, dvl1 and sfrp3. Finally, we observed that loss of pronephros in Pax8 morphants correlates with an expanded vascular/blood gene expression domain indicating that Pax8 function is important to delimit the blood/endothelial genes expression domain in the anterior part of the dorso-lateral plate.
Collapse
|
21
|
Cerqueira DM, Tran U, Romaker D, Abreu JG, Wessely O. Sterol carrier protein 2 regulates proximal tubule size in the Xenopus pronephric kidney by modulating lipid rafts. Dev Biol 2014; 394:54-64. [PMID: 25127994 DOI: 10.1016/j.ydbio.2014.07.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Revised: 05/29/2014] [Accepted: 07/30/2014] [Indexed: 11/29/2022]
Abstract
The kidney is a homeostatic organ required for waste excretion and reabsorption of water, salts and other macromolecules. To this end, a complex series of developmental steps ensures the formation of a correctly patterned and properly proportioned organ. While previous studies have mainly focused on the individual signaling pathways, the formation of higher order receptor complexes in lipid rafts is an equally important aspect. These membrane platforms are characterized by differences in local lipid and protein compositions. Indeed, the cells in the Xenopus pronephric kidney were positive for the lipid raft markers ganglioside GM1 and Caveolin-1. To specifically interfere with lipid raft function in vivo, we focused on the Sterol Carrier Protein 2 (scp2), a multifunctional protein that is an important player in remodeling lipid raft composition. In Xenopus, scp2 mRNA was strongly expressed in differentiated epithelial structures of the pronephric kidney. Knockdown of scp2 did not interfere with the patterning of the kidney along its proximo-distal axis, but dramatically decreased the size of the kidney, in particular the proximal tubules. This phenotype was accompanied by a reduction of lipid rafts, but was independent of the peroxisomal or transcriptional activities of scp2. Finally, disrupting lipid micro-domains by inhibiting cholesterol synthesis using Mevinolin phenocopied the defects seen in scp2 morphants. Together these data underscore the importance for localized signaling platforms in the proper formation of the Xenopus kidney.
Collapse
Affiliation(s)
- Débora M Cerqueira
- Cleveland Clinic Foundation, Lerner Research Institute, Department Cellular and Molecular Medicine, 9500 Euclid Avenue/NC10 Cleveland, OH 44195, USA; Universidade Federal do Rio de Janeiro, Instituto de Ciências Biomédicas-CCS, Av. Carlos Chagas Filho, 373 bloco F2 sala 15, Rio de Janeiro 21949-590, Brazil
| | - Uyen Tran
- Cleveland Clinic Foundation, Lerner Research Institute, Department Cellular and Molecular Medicine, 9500 Euclid Avenue/NC10 Cleveland, OH 44195, USA
| | - Daniel Romaker
- Cleveland Clinic Foundation, Lerner Research Institute, Department Cellular and Molecular Medicine, 9500 Euclid Avenue/NC10 Cleveland, OH 44195, USA
| | - José G Abreu
- Universidade Federal do Rio de Janeiro, Instituto de Ciências Biomédicas-CCS, Av. Carlos Chagas Filho, 373 bloco F2 sala 15, Rio de Janeiro 21949-590, Brazil
| | - Oliver Wessely
- Cleveland Clinic Foundation, Lerner Research Institute, Department Cellular and Molecular Medicine, 9500 Euclid Avenue/NC10 Cleveland, OH 44195, USA.
| |
Collapse
|
22
|
Hanotel J, Bessodes N, Thélie A, Hedderich M, Parain K, Van Driessche B, Brandão KDO, Kricha S, Jorgensen MC, Grapin-Botton A, Serup P, Van Lint C, Perron M, Pieler T, Henningfeld KA, Bellefroid EJ. The Prdm13 histone methyltransferase encoding gene is a Ptf1a-Rbpj downstream target that suppresses glutamatergic and promotes GABAergic neuronal fate in the dorsal neural tube. Dev Biol 2013; 386:340-57. [PMID: 24370451 DOI: 10.1016/j.ydbio.2013.12.024] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 11/19/2013] [Accepted: 12/17/2013] [Indexed: 12/01/2022]
Abstract
The basic helix-loop-helix (bHLH) transcriptional activator Ptf1a determines inhibitory GABAergic over excitatory glutamatergic neuronal cell fate in progenitors of the vertebrate dorsal spinal cord, cerebellum and retina. In an in situ hybridization expression survey of PR domain containing genes encoding putative chromatin-remodeling zinc finger transcription factors in Xenopus embryos, we identified Prdm13 as a histone methyltransferase belonging to the Ptf1a synexpression group. Gain and loss of Ptf1a function analyses in both frog and mice indicates that Prdm13 is positively regulated by Ptf1a and likely constitutes a direct transcriptional target. We also showed that this regulation requires the formation of the Ptf1a-Rbp-j complex. Prdm13 knockdown in Xenopus embryos and in Ptf1a overexpressing ectodermal explants lead to an upregulation of Tlx3/Hox11L2, which specifies a glutamatergic lineage and a reduction of the GABAergic neuronal marker Pax2. It also leads to an upregulation of Prdm13 transcription, suggesting an autonegative regulation. Conversely, in animal caps, Prdm13 blocks the ability of the bHLH factor Neurog2 to activate Tlx3. Additional gain of function experiments in the chick neural tube confirm that Prdm13 suppresses Tlx3(+)/glutamatergic and induces Pax2(+)/GABAergic neuronal fate. Thus, Prdm13 is a novel crucial component of the Ptf1a regulatory pathway that, by modulating the transcriptional activity of bHLH factors such as Neurog2, controls the balance between GABAergic and glutamatergic neuronal fate in the dorsal and caudal part of the vertebrate neural tube.
Collapse
Affiliation(s)
- Julie Hanotel
- Laboratory of Developmental Genetics, Université Libre de Bruxelles (ULB), Institute of Molecular Biology and Medicine, and ULB Neuroscience Institute, B-6041 Gosselies, Belgium
| | - Nathalie Bessodes
- Laboratory of Developmental Genetics, Université Libre de Bruxelles (ULB), Institute of Molecular Biology and Medicine, and ULB Neuroscience Institute, B-6041 Gosselies, Belgium
| | - Aurore Thélie
- Laboratory of Developmental Genetics, Université Libre de Bruxelles (ULB), Institute of Molecular Biology and Medicine, and ULB Neuroscience Institute, B-6041 Gosselies, Belgium
| | - Marie Hedderich
- Department of Developmental Biochemistry, Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), University of Goettingen, 37077 Goettingen, Germany
| | - Karine Parain
- UPR CNRS 3294 Neurobiology and Development, Université Paris Sud, 91405 Orsay Cedex, France
| | - Benoit Van Driessche
- Laboratory of Molecular Virology, Université Libre de Bruxelles (ULB), Institute of Molecular Biology and Medicine, B-6041 Gosselies, Belgium
| | - Karina De Oliveira Brandão
- Laboratory of Developmental Genetics, Université Libre de Bruxelles (ULB), Institute of Molecular Biology and Medicine, and ULB Neuroscience Institute, B-6041 Gosselies, Belgium
| | - Sadia Kricha
- Laboratory of Developmental Genetics, Université Libre de Bruxelles (ULB), Institute of Molecular Biology and Medicine, and ULB Neuroscience Institute, B-6041 Gosselies, Belgium
| | - Mette C Jorgensen
- DanStem, University of Copenhagen, 3B Blegdamsvej, DK-2200 Copenhagen N, Denmark
| | - Anne Grapin-Botton
- DanStem, University of Copenhagen, 3B Blegdamsvej, DK-2200 Copenhagen N, Denmark
| | - Palle Serup
- DanStem, University of Copenhagen, 3B Blegdamsvej, DK-2200 Copenhagen N, Denmark
| | - Carine Van Lint
- Laboratory of Molecular Virology, Université Libre de Bruxelles (ULB), Institute of Molecular Biology and Medicine, B-6041 Gosselies, Belgium
| | - Muriel Perron
- UPR CNRS 3294 Neurobiology and Development, Université Paris Sud, 91405 Orsay Cedex, France
| | - Tomas Pieler
- Department of Developmental Biochemistry, Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), University of Goettingen, 37077 Goettingen, Germany
| | - Kristine A Henningfeld
- Department of Developmental Biochemistry, Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), University of Goettingen, 37077 Goettingen, Germany
| | - Eric J Bellefroid
- Laboratory of Developmental Genetics, Université Libre de Bruxelles (ULB), Institute of Molecular Biology and Medicine, and ULB Neuroscience Institute, B-6041 Gosselies, Belgium.
| |
Collapse
|
23
|
MacMurray E, Barr M, Bruce A, Epp L, Zwollo P. Alternative splicing of the trout Pax5 gene and identification of novel B cell populations using Pax5 signatures. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2013; 41:270-81. [PMID: 23796789 PMCID: PMC3932526 DOI: 10.1016/j.dci.2013.06.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Revised: 06/11/2013] [Accepted: 06/15/2013] [Indexed: 05/21/2023]
Abstract
Pax5 is an alternatively spliced transcription factor that regulates B cell development and activation. The function of specific Pax5 isoforms is unknown. Here we report the existence of seven alternatively spliced isoforms of Pax5 in the rainbow trout. We hypothesized that B cells differentially express specific Pax5 isoforms as a means of modulating Pax5 activity during cell maturation. Flow cytometric analyses using Pax5-specific antibodies recognizing the paired domain, a central (exon 6-encoding) domain, or the C-terminus, revealed the existence of distinct Pax5-expressing cell populations in trout immune tissues. Additionally, using the transcription factor EBF, we show that Pax5 isoforms lacking a paired domain are already expressed at the earliest stages of trout (B) lymphopoiesis, and unexpectedly, that minor populations of such cells reside in blood and spleen. These data support use of differentially expressed Pax5 isoforms to identify novel B cell subsets in the form of Pax5 tissue signatures, and as such, provides new biomarkers for malignancy, infectious disease, and disease resistance in trout and humans.
Collapse
Affiliation(s)
- Elizabeth MacMurray
- Department of Biology, The College of William and Mary, Williamsburg, VA 23185
| | - Maggie Barr
- Department of Biology, The College of William and Mary, Williamsburg, VA 23185
| | - Amber Bruce
- Department of Biology, The College of William and Mary, Williamsburg, VA 23185
| | - Lidia Epp
- Department of Biology, The College of William and Mary, Williamsburg, VA 23185
| | - Patty Zwollo
- Department of Biology, The College of William and Mary, Williamsburg, VA 23185
- To whom correspondence should be addressed: Patty Zwollo, Department of Biology, The College of William and Mary, Williamsburg, VA 23185-8795, FAX: 757-221-6483; Phone: 757-221-1969;
| |
Collapse
|
24
|
Osman AHK, Farouk SM, Eidaroos H, Abbott LC, Ahmed AA. Prenatal metanephrogenesis of the camel: morphological evidence of epithelial-mesenchymal interaction. Anat Histol Embryol 2013; 43:141-52. [PMID: 23713903 DOI: 10.1111/ahe.12057] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Accepted: 03/03/2013] [Indexed: 11/30/2022]
Abstract
The present investigation examined histogenesis of epithelial, stromal and angiogenic elements of the prenatal camel permanent or metanephric kidney. The primitive metanephros was first observed at the 13-mm crown vertebral rump length (CVRL) stage as an ovoid structure composed of a centrally located epithelial ureteric bud and peripheral circumscribed masses of undifferentiated mesenchymal cells. The first morphological evidence of glomerulogenesis was observed at the 28-mm CVRL stage. Developing renal corpuscles became obvious at the 35-mm CVRL stage. At the 60-mm CVRL stage, the epithelial renal pelvis gave rise to tubular branches that extended towards the cortical zone. These branches represented the presumptive collecting ducts. Differentiation of renal tubules into the proximal and distal convoluted tubules was observed at the 95-mm CVRL stage. At the 130-mm CVRL stage, the renal medulla was clearly delineated into medullary pyramids, which in association with the corresponding cortical caps formed the morphological basis of the renal lobar formation. A gradual nephrogenic decline was noticed from the 940-mm CVRL on; however, the process of nephrogenesis persisted throughout all the studied foetal stages.
Collapse
Affiliation(s)
- A-H K Osman
- Department of Cytology and Histology, Faculty of Veterinary Medicine, Suez Canal University, Ismailia 41511, Egypt
| | | | | | | | | |
Collapse
|
25
|
Holland LZ. Evolution of new characters after whole genome duplications: insights from amphioxus. Semin Cell Dev Biol 2013; 24:101-9. [PMID: 23291260 DOI: 10.1016/j.semcdb.2012.12.007] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 12/25/2012] [Indexed: 12/31/2022]
Abstract
Additional copies of genes resulting from two whole genome duplications at the base of the vertebrates have been suggested as enabling the evolution of vertebrate-specific structures such as neural crest, a midbrain/hindbrain organizer and neurogenic placodes. These structures, however, did not evolve entirely de novo, but arose from tissues already present in an ancestral chordate. This review discusses the evolutionary history of co-option of old genes for new roles in vertebrate development as well as the relative contributions of changes in cis-regulation and in protein structure. Particular examples are the FoxD, FGF8/17/18 and Pax2/5/8 genes. Comparisons with invertebrate chordates (amphioxus and tunicates) paint a complex picture with co-option of genes into new structures occurring both after and before the whole genome duplications. In addition, while cis-regulatory changes are likely of primary importance in evolution of vertebrate-specific structures, changes in protein structure including alternative splicing are non-trivial.
Collapse
Affiliation(s)
- Linda Z Holland
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093-0202, USA.
| |
Collapse
|
26
|
Short S, Kozmik Z, Holland LZ. The function and developmental expression of alternatively spliced isoforms of amphioxus and Xenopus laevis Pax2/5/8 genes: revealing divergence at the invertebrate to vertebrate transition. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2012; 318:555-71. [PMID: 22791613 DOI: 10.1002/jez.b.22460] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Revised: 05/07/2012] [Accepted: 05/28/2012] [Indexed: 01/14/2023]
Abstract
Pax genes encode highly conserved transcription factors vital for metazoan development. Pax transcripts, particularly those in Group II (Pax2/5/8), are extensively alternatively spliced. This study compares the transcriptional activation capacity and developmental stage-specific expression of major isoforms of Group II Pax proteins in amphioxus (Branchiostoma floridae) and in Xenopus laevis. The comparison reveals considerable divergence of splice forms between the lineages, with the X. laevis Group II Pax genes (Pax2, Pax5, and Pax8) possessing a greater repertoire of regulated and functionally distinct splice forms than the single amphioxus gene (Pax2/5/8). Surprisingly, some apparently conserved splice forms are expressed at quite different levels during development in the two organisms and present different capacities to activate transcription. However, despite this divergence, the combinatorial transcriptional activation capacity of the isoforms present in early X. laevis and amphioxus development are broadly similar. This suggests that the some of the conserved functional roles, implied by the expression of Group II Pax genes in homologous tissues of amphioxus and X. laevis embryos, may depend upon the combination of isoforms expressed in a particular tissue at a particular time in development. Thus, during early development, the evolutionary constraint on the net effect of several isoforms co-expressed in a given tissue may be more strict than that on specific isoforms. This flexibility may facilitate the appearance of new exons and splicing patterns in the vertebrate duplicates, leading to isoforms with subtly distinct functions critical to the subsequent development of vertebrate-specific cell types and structures.
Collapse
Affiliation(s)
- Stephen Short
- Institute of Marine Sciences, School of Biological Sciences, University of Portsmouth, Portsmouth, Hampshire, United Kingdom
| | | | | |
Collapse
|
27
|
Le Bouffant R, Wang JH, Futel M, Buisson I, Umbhauer M, Riou JF. Retinoic acid-dependent control of MAP kinase phosphatase-3 is necessary for early kidney development in Xenopus. Biol Cell 2012; 104:516-32. [DOI: 10.1111/boc.201200005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2012] [Accepted: 04/20/2012] [Indexed: 11/28/2022]
|
28
|
Barnett C, Yazgan O, Kuo HC, Malakar S, Thomas T, Fitzgerald A, Harbour W, Henry JJ, Krebs JE. Williams Syndrome Transcription Factor is critical for neural crest cell function in Xenopus laevis. Mech Dev 2012; 129:324-38. [PMID: 22691402 DOI: 10.1016/j.mod.2012.06.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Revised: 05/31/2012] [Accepted: 06/01/2012] [Indexed: 11/17/2022]
Abstract
Williams Syndrome Transcription Factor (WSTF) is one of ∼25 haplodeficient genes in patients with the complex developmental disorder Williams Syndrome (WS). WS results in visual/spatial processing defects, cognitive impairment, unique behavioral phenotypes, characteristic "elfin" facial features, low muscle tone and heart defects. WSTF exists in several chromatin remodeling complexes and has roles in transcription, replication, and repair. Chromatin remodeling is essential during embryogenesis, but WSTF's role in vertebrate development is poorly characterized. To investigate the developmental role of WSTF, we knocked down WSTF in Xenopus laevis embryos using a morpholino that targets WSTF mRNA. BMP4 shows markedly increased and spatially aberrant expression in WSTF-deficient embryos, while SHH, MRF4, PAX2, EPHA4 and SOX2 expression are severely reduced, coupled with defects in a number of developing embryonic structures and organs. WSTF-deficient embryos display defects in anterior neural development. Induction of the neural crest, measured by expression of the neural crest-specific genes SNAIL and SLUG, is unaffected by WSTF depletion. However, at subsequent stages WSTF knockdown results in a severe defect in neural crest migration and/or maintenance. Consistent with a maintenance defect, WSTF knockdowns display a specific pattern of increased apoptosis at the tailbud stage in regions corresponding to the path of cranial neural crest migration. Our work is the first to describe a role for WSTF in proper neural crest function, and suggests that neural crest defects resulting from WSTF haploinsufficiency may be a major contributor to the pathoembryology of WS.
Collapse
Affiliation(s)
- Chris Barnett
- Department of Biological Sciences, University of Alaska Anchorage, 3101 Science Circle, Anchorage, AK 99508, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Evolution of a tissue-specific silencer underlies divergence in the expression of pax2 and pax8 paralogues. Nat Commun 2012; 3:848. [DOI: 10.1038/ncomms1851] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Accepted: 04/18/2012] [Indexed: 12/24/2022] Open
|
30
|
Kim HT, Kim JW. Compartmentalization of vertebrate optic neuroephithelium: external cues and transcription factors. Mol Cells 2012; 33:317-24. [PMID: 22450691 PMCID: PMC3887801 DOI: 10.1007/s10059-012-0030-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Revised: 02/21/2012] [Accepted: 02/24/2012] [Indexed: 02/02/2023] Open
Abstract
The vertebrate eye is a laterally extended structure of the forebrain. It develops through a series of events, including specification and regionalization of the anterior neural plate, evagination of the optic vesicle (OV), and development of three distinct optic structures: the neural retina (NR), optic stalk (OS), and retinal pigment epithelium (RPE). Various external signals that act on the optic neuroepithelium in a spatial- and temporal-specific manner control the fates of OV subdomains by inducing localized expression of key transcription factors. Investigating the mechanisms underlying compartmentalization of these distinct optic neuroepithelium-derived tissues is therefore not only important from the standpoint of accounting for vertebrate eye morphogenesis, it is also helpful for understanding the fundamental basis of fate determination of other neuroectoderm- derived tissues. This review focuses on the molecular signatures of OV subdomains and the external factors that direct the development of tissues originating from the OV.
Collapse
Affiliation(s)
- Hyoung-Tai Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701,
Korea
| | - Jin Woo Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701,
Korea
| |
Collapse
|
31
|
Heat-shock mediated overexpression of HNF1β mutations has differential effects on gene expression in the Xenopus pronephric kidney. PLoS One 2012; 7:e33522. [PMID: 22438943 PMCID: PMC3305329 DOI: 10.1371/journal.pone.0033522] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Accepted: 02/15/2012] [Indexed: 02/07/2023] Open
Abstract
The transcription factor HNF1B, encoded by the TCF2 gene, plays an important role in the organogenesis of vertebrates. In humans, heterozygous mutations of HNF1B are associated with several diseases, such as pancreatic β-cell dysfunction leading to maturity-onset diabetes of the young (MODY5), defective kidney development, disturbed liver function, pancreas atrophy, and malformations of the genital tract. The African claw frog Xenopus laevis is an excellent model to study the processes involved in embryogenesis and organogenesis, as it can be manipulated easily with a series of methods. In the present study, we overexpressed HNF1β mutants in the developing Xenopus embryo to assess their roles during organogenesis, particularly in the developing pronephric kidney. Towards this goal, we developed a heat-shock inducible binary Cre/loxP system with activator and effector strains. Heat-shock activation of the mutant HNF1B variants P328L329del and A263insGG resulted in malformations of various organs and the affected larvae developed large edemas. Defects in the pronephros were primarily confined to malformed proximal tubules. Furthermore, the expression of the proximal tubule marker genes tmem27 and slc3a1, both involved in amino acid transport, was affected. Both P328L329del and A263insGG downregulated expression of slc3a1. In addition, P328L329del reduced tmem27 expression while A263insGG overexpression decreased expression of the chloride channel clcnk and the transcription factor pax2. Overexpression of two mutant HNF1B derivatives resulted in distinct phenotypes reflected by either a reduction or an enlargement of pronephros size. The expression of selected pronephric marker genes was differentially affected upon overexpression of HNF1B mutations. Based on our findings, we postulate that HNF1B mutations influence gene regulation upon overexpression in specific and distinct manners. Furthermore, our study demonstrates that the newly established Cre/loxP system for Xenopus embryos is an attractive alternative to examine the gene regulatory potential of transcription factors in developing pronephric kidney as exemplified here for HNF1B.
Collapse
|
32
|
Parrilla M, Lillo C, Herrero-Turrión MJ, Arévalo R, Aijón J, Lara JM, Velasco A. Characterization of Pax2 expression in the goldfish optic nerve head during retina regeneration. PLoS One 2012; 7:e32348. [PMID: 22384226 PMCID: PMC3288081 DOI: 10.1371/journal.pone.0032348] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Accepted: 01/26/2012] [Indexed: 01/09/2023] Open
Abstract
The Pax2 transcription factor plays a crucial role in axon-guidance and astrocyte differentiation in the optic nerve head (ONH) during vertebrate visual system development. However, little is known about its function during regeneration. The fish visual system is in continuous growth and can regenerate. Müller cells and astrocytes of the retina and ONH play an important role in these processes. We demonstrate that pax2a in goldfish is highly conserved and at least two pax2a transcripts are expressed in the optic nerve. Moreover, we show two different astrocyte populations in goldfish: Pax2+ astrocytes located in the ONH and S100+ astrocytes distributed throughout the retina and the ONH. After peripheral growth zone (PGZ) cryolesion, both Pax2+ and S100+ astrocytes have different responses. At 7 days after injury the number of Pax2+ cells is reduced and coincides with the absence of young axons. In contrast, there is an increase of S100+ astrocytes in the retina surrounding the ONH and S100+ processes in the ONH. At 15 days post injury, the PGZ starts to regenerate and the number of S100+ astrocytes increases in this region. Moreover, the regenerating axons reach the ONH and the pax2a gene expression levels and the number of Pax2+ cells increase. At the same time, S100+/GFAP+/GS+ astrocytes located in the posterior ONH react strongly. In the course of the regeneration, Müller cell vitreal processes surrounding the ONH are primarily disorganized and later increase in number. During the whole regenerative process we detect a source of Pax2+/PCNA+ astrocytes surrounding the posterior ONH. We demonstrate that pax2a expression and the Pax2+ astrocyte population in the ONH are modified during the PGZ regeneration, suggesting that they could play an important role in this process.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Almudena Velasco
- Institute of Neuroscience of Castilla y Leon, University of Salamanca, Salamanca, Spain
- * E-mail:
| |
Collapse
|
33
|
Pieper M, Ahrens K, Rink E, Peter A, Schlosser G. Differential distribution of competence for panplacodal and neural crest induction to non-neural and neural ectoderm. Development 2012; 139:1175-87. [PMID: 22318231 DOI: 10.1242/dev.074468] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
It is still controversial whether cranial placodes and neural crest cells arise from a common precursor at the neural plate border or whether placodes arise from non-neural ectoderm and neural crest from neural ectoderm. Using tissue grafting in embryos of Xenopus laevis, we show here that the competence for induction of neural plate, neural plate border and neural crest markers is confined to neural ectoderm, whereas competence for induction of panplacodal markers is confined to non-neural ectoderm. This differential distribution of competence is established during gastrulation paralleling the dorsal restriction of neural competence. We further show that Dlx3 and GATA2 are required cell-autonomously for panplacodal and epidermal marker expression in the non-neural ectoderm, while ectopic expression of Dlx3 or GATA2 in the neural plate suppresses neural plate, border and crest markers. Overexpression of Dlx3 (but not GATA2) in the neural plate is sufficient to induce different non-neural markers in a signaling-dependent manner, with epidermal markers being induced in the presence, and panplacodal markers in the absence, of BMP signaling. Taken together, these findings demonstrate a non-neural versus neural origin of placodes and neural crest, respectively, strongly implicate Dlx3 in the regulation of non-neural competence, and show that GATA2 contributes to non-neural competence but is not sufficient to promote it ectopically.
Collapse
Affiliation(s)
- Mareike Pieper
- Brain Research Institute, University of Bremen, FB2, PO Box 330440, 28334 Bremen, Germany
| | | | | | | | | |
Collapse
|
34
|
Origin and segregation of cranial placodes in Xenopus laevis. Dev Biol 2011; 360:257-75. [PMID: 21989028 DOI: 10.1016/j.ydbio.2011.09.024] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2011] [Revised: 08/31/2011] [Accepted: 09/01/2011] [Indexed: 11/23/2022]
Abstract
Cranial placodes are local thickenings of the vertebrate head ectoderm that contribute to the paired sense organs (olfactory epithelium, lens, inner ear, lateral line), cranial ganglia and the adenohypophysis. Here we use tissue grafting and dye injections to generated fate maps of the dorsal cranial part of the non-neural ectoderm for Xenopus embryos between neural plate and early tailbud stages. We show that all placodes arise from a crescent-shaped area located around the anterior neural plate, the pre-placodal ectoderm. In agreement with proposed roles of Six1 and Pax genes in the specification of a panplacodal primordium and different placodal areas, respectively, we show that Six1 is expressed uniformly throughout most of the pre-placodal ectoderm, while Pax6, Pax3, Pax8 and Pax2 each are confined to specific subregions encompassing the precursors of different subsets of placodes. However, the precursors of the vagal epibranchial and posterior lateral line placodes, which arise from the posteriormost pre-placodal ectoderm, upregulate Six1 and Pax8/Pax2 only at tailbud stages. Whereas our fate map suggests that regions of origin for different placodes overlap extensively with each other and with other ectodermal fates at neural plate stages, analysis of co-labeled placodes reveals that the actual degree of overlap is much smaller. Time lapse imaging of the pre-placodal ectoderm at single cell resolution demonstrates that no directed, large-scale cell rearrangements occur, when the pre-placodal region segregates into distinct placodes at subsequent stages. Our results indicate that individuation of placodes from the pre-placodal ectoderm does not involve large-scale cell sorting in Xenopus.
Collapse
|
35
|
Jung B, Köhler A, Schambony A, Wedlich D. PAPC and the Wnt5a/Ror2 pathway control the invagination of the otic placode in Xenopus. BMC DEVELOPMENTAL BIOLOGY 2011; 11:36. [PMID: 21663658 PMCID: PMC3127988 DOI: 10.1186/1471-213x-11-36] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Accepted: 06/10/2011] [Indexed: 01/16/2023]
Abstract
BACKGROUND Paraxial protocadherin (PAPC) plays a crucial role in morphogenetic movements during gastrulation and somitogenesis in mouse, zebrafish and Xenopus. PAPC influences cell-cell adhesion mediated by C-Cadherin. A putative direct adhesion activity of PAPC is discussed. PAPC also promotes cell elongation, tissue separation and coordinates cell mass movements. In these processes the signaling function of PAPC in activating RhoA/JNK and supporting Wnt-11/PCP by binding to frizzled 7 (fz7) is important. RESULTS Here we demonstrate by loss of function experiments in Xenopus embryos that PAPC regulates another type of morphogenetic movement, the invagination of the ear placode. Knockdown of PAPC by antisense morpholinos results in deformation of the otic vesicle without altering otocyst marker expression. Depletion of PAPC could be rescued by full-length PAPC, constitutive active RhoA and by the closely related PCNS but not by classical cadherins. Also the cytoplasmic deletion mutant M-PAPC, which influences cell adhesion, does not rescue the PAPC knockdown. Interestingly, depletion of Wnt5a or Ror2 which are also expressed in the otocyst phenocopies the PAPC morphant phenotype. CONCLUSIONS PAPC signaling via RhoA and Wnt5a/Ror2 activity are required to keep cells aligned in apical-basal orientation during invagination of the ear placode. Since neither the cytoplasmic deletion mutant M-PAPC nor a classical cadherin is able to rescue loss of PAPC we suggest that the signaling function of the protocadherin rather than its role as modulator of cell-cell adhesion is required during invagination of the ear placode.
Collapse
Affiliation(s)
- Barbara Jung
- Karlsruhe Institute of Technology, Department of Cell and Developmental Biology, Karlsruhe, Germany
| | | | | | | |
Collapse
|
36
|
Cho GS, Choi SC, Park EC, Han JK. Role of Tbx2 in defining the territory of the pronephric nephron. Development 2011; 138:465-74. [PMID: 21205791 DOI: 10.1242/dev.061234] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Despite extensive study of the development of the nephron, which is the functional unit of the kidney, the molecular mechanisms underlying the determination of nephron size remain largely unknown. Using the Xenopus pronephros, we demonstrate here that Tbx2, a T-box transcriptional repressor, functions to demarcate the territory of the pronephric nephron. Tbx2 is specifically expressed around three distinct components of the pronephric nephron: the tubule, duct and glomus. Gain of function of Tbx2 inhibits nephric mesoderm formation. Conversely, Tbx2 loss of function expands the boundary of each component of the pronephric nephron, resulting in an enlarged pronephros. BMP signals induce Tbx2 in the non-nephric mesoderm, which inhibits the expression of the nephric markers Hey1 and Gremlin. Importantly, these pronephric molecules repress Tbx2 expression by antagonizing BMP signals in the nephric mesoderm. These results suggest that the negative regulatory loops between BMP/Tbx2 and Gremlin or Hey1 are responsible for defining the territory of the pronephric nephron.
Collapse
Affiliation(s)
- Gun-Sik Cho
- Division of Molecular and Life Sciences, Pohang University of Science and Technology, San 31, Hyoja-dong, Nam-gu, Pohang, Kyungbuk, Republic of Korea
| | | | | | | |
Collapse
|
37
|
Dichmann DS, Harland RM. Nkx6 genes pattern the frog neural plate and Nkx6.1 is necessary for motoneuron axon projection. Dev Biol 2010; 349:378-86. [PMID: 21035438 DOI: 10.1016/j.ydbio.2010.10.030] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2010] [Revised: 10/20/2010] [Accepted: 10/20/2010] [Indexed: 12/28/2022]
Abstract
Neuronal subtypes originate from an undifferentiated neural epithelium that is progressively divided into progenitor domains by homeodomain transcription factors such as members of the Nkx family. Here we report the functional analysis of Nkx6.1 and Nkx6.2 in Xenopus. While Nkx6.2 is expressed early in a large region of the medial neural plate, Nkx6.1 is restricted to a region overlapping with the region of motor neuron formation. By mRNA injection we show that both can inhibit primary neurogenesis as well as expression of intermediate neural plate markers. However, they do not form auto-regulatory loops and fail to induce ectopic motor neurons as they do in the chick. Using morpholino-mediated knockdown in Xenopus laevis and Xenopus tropicalis we show that Nkx6.1 knockdown results in paralyzed tadpoles. Using DiI labeling and immunohistochemistry we show that the underlying mechanism is a failure of spinal motor neurons to extend axons to their targets. Analysis of neural pattern reveals that ventral Lhx3+ and Pax2+ interneurons are dependent on Nkx6.1 function, but overall neural patterning is not. This study illustrates that while important aspects of Nkx6 gene function are conserved in vertebrate neural patterning, others are not.
Collapse
Affiliation(s)
- Darwin S Dichmann
- Department of Molecular & Cell Biology, Center for Integrative Genomics, University of California, Berkeley, 571 Life Sciences Addition, #3200, Berkeley, CA 94720-3200, USA
| | | |
Collapse
|
38
|
Stanke J, Moose HE, El-Hodiri HM, Fischer AJ. Comparative study of Pax2 expression in glial cells in the retina and optic nerve of birds and mammals. J Comp Neurol 2010; 518:2316-33. [PMID: 20437530 DOI: 10.1002/cne.22335] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Little is known about the expression of Pax2 in mature retina or optic nerve. Here we probed for the expression of Pax2 in late stages of embryonic development and in mature chick retina. We find two distinct Pax2 isoforms expressed by cells within the retina and optic nerve. Surprisingly, Müller glia in central regions of the retina express Pax2, and levels of expression are decreased with increasing distance from the nerve head. In Müller glia, the expression levels of Pax2 are increased by acute retinal damage or treatment with growth factors. At the optic nerve, Pax2 is expressed by peripapillary glia, at the junction of the neural retina and optic nerve head and by glia within the optic nerve. In addition, we assayed for Pax2 expression in glial cells in mammalian retinas. In mammalian retinas, unlike the case in chick retina, the Müller glia do not express Pax2. Pax2-expressing cells are found in the optic nerve and astrocytes within the mouse retina. By comparison, Pax2-positive cells are not found within the guinea pig retina; Pax2-expressing glia are confined to the optic nerve. In dog and monkey (Macaca fascicularis), Pax2 is expressed by astrocytes that are scattered across inner retinal layers and by numerous glia within the optic nerve. Interestingly, Pax2-positive glial cells are found at the peripheral edge of the dog retina, but only in older animals. We conclude that the expression of Pax2 in the vertebrate eye is restricted to retinal astrocytes, peripapillary glia, and glia within the optic nerve.
Collapse
Affiliation(s)
- Jennifer Stanke
- Integrated Biomedical Science Graduate Program, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | | | | | | |
Collapse
|
39
|
Holland LZ, Short S. Alternative splicing in development and function of chordate endocrine systems: a focus on Pax genes. Integr Comp Biol 2010; 50:22-34. [PMID: 21558185 DOI: 10.1093/icb/icq048] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Genome sequencing has facilitated an understanding of gene networks but has also shown that they are only a small part of the answer to the question of how genes translate into a functional organism. Much of the answer lies in epigenetics-heritable traits not directly encoded by the genome. One such phenomenon is alternative splicing, which affects over 75% of protein coding genes and greatly amplifies the number of proteins. Although it was postulated that alternative splicing and gene duplication are inversely proportional and, therefore, have similar effects on the size of the proteome, for ancient duplications such as occurred in the Pax family of transcription factors, that is not necessarily so. The importance of alternative splicing in development and physiology is only just coming to light. However, several techniques for studying isoform functions both in vitro and in vivo have been recently developed. As examples of what is known and what is yet to be discovered, this review focuses on the evolution and roles of the Pax family of transcription factors in development and on alternative splicing of endocrine genes and the factors that regulate them.
Collapse
Affiliation(s)
- Linda Z Holland
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093-0202, USA.
| | | |
Collapse
|
40
|
Abstract
Whole genome duplication events are thought to have substantially contributed to organismal complexity, largely via divergent transcriptional regulation. Members of the vertebrate PAX2, PAX5 and PAX8 gene subfamily derived from an ancient class of paired box genes and arose from such whole genome duplication events. These genes are critical in establishing the midbrain-hindbrain boundary, specifying interneuron populations and for eye, ear and kidney development. Also PAX2 has adopted a unique role in pancreas development, whilst PAX5 is essential for early B-cell differentiation. The contribution of PAX258 genes to their collective role has diverged across paralogues and the animal lineages, resulting in a complex wealth of literature. It is now timely to provide a comprehensive comparative overview of these genes and their ancient and divergent roles. We also discuss their fundamental place within gene regulatory networks and the likely influence of cis-regulatory elements over their differential roles during early animal development.
Collapse
Affiliation(s)
- Debbie K Goode
- Queen Mary, University of London, School of Biological and Chemical Sciences, London, United Kingdom
| | | |
Collapse
|
41
|
Lee SJ, Kim S, Choi SC, Han JK. XPteg (Xenopus proximal tubules-expressed gene) is essential for pronephric mesoderm specification and tubulogenesis. Mech Dev 2009; 127:49-61. [PMID: 19909807 DOI: 10.1016/j.mod.2009.11.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Revised: 11/02/2009] [Accepted: 11/05/2009] [Indexed: 12/24/2022]
Abstract
Retinoic acid (RA) signaling is important for the early steps of nephrogenic cell fate specification. Here, we report a novel target gene of RA signaling named XPteg (Xenopus proximal tubules-expressed gene) which is critical for pronephric development. XPteg starts to be expressed at the earliest stage of embryonic kidney specification and was restricted to the pronephric proximal tubules during kidney development. Anti-sense morpholino (MO)-mediated knockdown of XPteg perturbed formation of pronephros as demonstrated by reduced expression of pronephric tubule markers. Conversely, overexpression of XPteg promoted endogenous and ectopic expression of those markers and expanded pronephric tubules. Treatment of retinoic acid induced the expression of XPteg in the pronephric field without protein synthesis. Furthermore, we found that the pronephric defects caused by a dominant negative RA receptor could be rescued by coexpression of XPteg. Taken together, these results suggest that XPteg functions as a direct transcriptional target of RA signaling to regulate pronephric tubulogenesis in Xenopus early development.
Collapse
Affiliation(s)
- Seung Joon Lee
- Department of Life Science, Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang, Kyungbuk, South Korea
| | | | | | | |
Collapse
|
42
|
Dichmann DS, Fletcher RB, Harland RM. Expression cloning in Xenopus identifies RNA-binding proteins as regulators of embryogenesis and Rbmx as necessary for neural and muscle development. Dev Dyn 2008; 237:1755-66. [PMID: 18521943 DOI: 10.1002/dvdy.21590] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We have performed an expression cloning screen in Xenopus laevis with the aim of isolating novel gene activities from the neural plate. Of 8,064 clones screened, we isolated 61 clones that affected either neural plate patterning or tadpole morphology. Of these, 20 clones encoded RNA binding proteins, and the majority of these are heterogeneous nuclear ribonucleoproteins (hnRNPs) or SR-proteins, which are associated with alternative splicing. All of these genes are expressed in the nervous system, and in several cases specific to neural tissue. Injecting mRNA encoding these proteins results in neural plate mispatterning and abnormal muscle segmentation. To initiate characterization of these proteins, we selected Rbmx as a candidate for deeper analysis. Using morpholino mediated knockdown, we show that Rbmx is necessary for normal anterior neural plate patterning, neurogenesis, neural crest development, and muscle segmentation.
Collapse
Affiliation(s)
- Darwin S Dichmann
- Department of Molecular & Cell Biology, Center for Integrative Genomics, University of California, Berkeley, California 94720-3200, USA
| | | | | |
Collapse
|
43
|
Koop D, Holland LZ. The basal chordate amphioxus as a simple model for elucidating developmental mechanisms in vertebrates. ACTA ACUST UNITED AC 2008; 84:175-87. [DOI: 10.1002/bdrc.20128] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
44
|
Bassham S, Cañestro C, Postlethwait JH. Evolution of developmental roles of Pax2/5/8 paralogs after independent duplication in urochordate and vertebrate lineages. BMC Biol 2008; 6:35. [PMID: 18721460 PMCID: PMC2532684 DOI: 10.1186/1741-7007-6-35] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2008] [Accepted: 08/22/2008] [Indexed: 12/02/2022] Open
Abstract
Background Gene duplication provides opportunities for lineage diversification and evolution of developmental novelties. Duplicated genes generally either disappear by accumulation of mutations (nonfunctionalization), or are preserved either by the origin of positively selected functions in one or both duplicates (neofunctionalization), or by the partitioning of original gene subfunctions between the duplicates (subfunctionalization). The Pax2/5/8 family of important developmental regulators has undergone parallel expansion among chordate groups. After the divergence of urochordate and vertebrate lineages, two rounds of independent gene duplications resulted in the Pax2, Pax5, and Pax8 genes of most vertebrates (the sister group of the urochordates), and an additional duplication provided the pax2a and pax2b duplicates in teleost fish. Separate from the vertebrate genome expansions, a duplication also created two Pax2/5/8 genes in the common ancestor of ascidian and larvacean urochordates. Results To better understand mechanisms underlying the evolution of duplicated genes, we investigated, in the larvacean urochordate Oikopleura dioica, the embryonic gene expression patterns of Pax2/5/8 paralogs. We compared the larvacean and ascidian expression patterns to infer modular subfunctions present in the single pre-duplication Pax2/5/8 gene of stem urochordates, and we compared vertebrate and urochordate expression to infer the suite of Pax2/5/8 gene subfunctions in the common ancestor of olfactores (vertebrates + urochordates). Expression pattern differences of larvacean and ascidian Pax2/5/8 orthologs in the endostyle, pharynx and hindgut suggest that some ancestral gene functions have been partitioned differently to the duplicates in the two urochordate lineages. Novel expression in the larvacean heart may have resulted from the neofunctionalization of a Pax2/5/8 gene in the urochordates. Expression of larvacean Pax2/5/8 in the endostyle, in sites of epithelial remodeling, and in sensory tissues evokes like functions of Pax2, Pax5 and Pax8 in vertebrate embryos, and may indicate ancient origins for these functions in the chordate common ancestor. Conclusion Comparative analysis of expression patterns of chordate Pax2/5/8 duplicates, rooted on the single-copy Pax2/5/8 gene of amphioxus, whose lineage diverged basally among chordates, provides new insights into the evolution and development of the heart, thyroid, pharynx, stomodeum and placodes in chordates; supports the controversial conclusion that the atrial siphon of ascidians and the otic placode in vertebrates are homologous; and backs the notion that Pax2/5/8 functioned in ancestral chordates to engineer epithelial fusions and perforations, including gill slit openings.
Collapse
Affiliation(s)
- Susan Bassham
- Center for Ecology and Evolutionary Biology, University of Oregon, Eugene, OR 97403, USA.
| | | | | |
Collapse
|
45
|
Colas A, Cartry J, Buisson I, Umbhauer M, Smith JC, Riou JF. Mix.1/2-dependent control of FGF availability during gastrulation is essential for pronephros development in Xenopus. Dev Biol 2008; 320:351-65. [DOI: 10.1016/j.ydbio.2008.05.547] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2007] [Revised: 04/30/2008] [Accepted: 05/20/2008] [Indexed: 10/22/2022]
|
46
|
Raciti D, Reggiani L, Geffers L, Jiang Q, Bacchion F, Subrizi AE, Clements D, Tindal C, Davidson DR, Kaissling B, Brändli AW. Organization of the pronephric kidney revealed by large-scale gene expression mapping. Genome Biol 2008; 9:R84. [PMID: 18492243 PMCID: PMC2441470 DOI: 10.1186/gb-2008-9-5-r84] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2008] [Revised: 03/19/2008] [Accepted: 05/20/2008] [Indexed: 11/28/2022] Open
Abstract
Gene expression mapping reveals 8 functionally distinct domains in the Xenopus pronephros. Interestingly, no structure equivalent to the mammalian collecting duct is identified. Background The pronephros, the simplest form of a vertebrate excretory organ, has recently become an important model of vertebrate kidney organogenesis. Here, we elucidated the nephron organization of the Xenopus pronephros and determined the similarities in segmentation with the metanephros, the adult kidney of mammals. Results We performed large-scale gene expression mapping of terminal differentiation markers to identify gene expression patterns that define distinct domains of the pronephric kidney. We analyzed the expression of over 240 genes, which included members of the solute carrier, claudin, and aquaporin gene families, as well as selected ion channels. The obtained expression patterns were deposited in the searchable European Renal Genome Project Xenopus Gene Expression Database. We found that 112 genes exhibited highly regionalized expression patterns that were adequate to define the segmental organization of the pronephric nephron. Eight functionally distinct domains were discovered that shared significant analogies in gene expression with the mammalian metanephric nephron. We therefore propose a new nomenclature, which is in line with the mammalian one. The Xenopus pronephric nephron is composed of four basic domains: proximal tubule, intermediate tubule, distal tubule, and connecting tubule. Each tubule may be further subdivided into distinct segments. Finally, we also provide compelling evidence that the expression of key genes underlying inherited renal diseases in humans has been evolutionarily conserved down to the level of the pronephric kidney. Conclusion The present study validates the Xenopus pronephros as a genuine model that may be used to elucidate the molecular basis of nephron segmentation and human renal disease.
Collapse
Affiliation(s)
- Daniela Raciti
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, ETH Zürich, Wolfgang-Pauli-Strasse 10, CH-8093 Zürich, Switzerland.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
47
|
The Evolution of Alternative Splicing in the Pax Family: The View from the Basal Chordate Amphioxus. J Mol Evol 2008; 66:605-20. [DOI: 10.1007/s00239-008-9113-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2008] [Revised: 04/16/2008] [Accepted: 04/22/2008] [Indexed: 10/22/2022]
|
48
|
Bello V, Sirour C, Moreau N, Denker E, Darribère T. A function for dystroglycan in pronephros development in Xenopus laevis. Dev Biol 2008; 317:106-20. [DOI: 10.1016/j.ydbio.2008.02.024] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2007] [Revised: 02/01/2008] [Accepted: 02/05/2008] [Indexed: 11/27/2022]
|
49
|
Reggiani L, Raciti D, Airik R, Kispert A, Brändli AW. The prepattern transcription factor Irx3 directs nephron segment identity. Genes Dev 2007; 21:2358-70. [PMID: 17875669 PMCID: PMC1973149 DOI: 10.1101/gad.450707] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The nephron, the basic structural and functional unit of the vertebrate kidney, is organized into discrete segments, which are composed of distinct renal epithelial cell types. Each cell type carries out highly specific physiological functions to regulate fluid balance, osmolarity, and metabolic waste excretion. To date, the genetic basis of regionalization of the nephron has remained largely unknown. Here we show that Irx3, a member of the Iroquois (Irx) gene family, acts as a master regulator of intermediate tubule fate. Comparative studies in Xenopus and mouse have identified Irx1, Irx2, and Irx3 as an evolutionary conserved subset of Irx genes, whose expression represents the earliest manifestation of intermediate compartment patterning in the developing vertebrate nephron discovered to date. Intermediate tubule progenitors will give rise to epithelia of Henle's loop in mammals. Loss-of-function studies indicate that irx1 and irx2 are dispensable, whereas irx3 is necessary for intermediate tubule formation in Xenopus. Furthermore, we demonstrate that misexpression of irx3 is sufficient to direct ectopic development of intermediate tubules in the Xenopus mesoderm. Taken together, irx3 is the first gene known to be necessary and sufficient to specify nephron segment fate in vivo.
Collapse
Affiliation(s)
- Luca Reggiani
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Daniela Raciti
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Rannar Airik
- Institute of Molecular Biology, Hannover Medical School, D-30625 Hannover, Germany
| | - Andreas Kispert
- Institute of Molecular Biology, Hannover Medical School, D-30625 Hannover, Germany
| | - André W. Brändli
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, ETH Zurich, CH-8093 Zurich, Switzerland
- Corresponding author.E-MAIL ; FAX 41-44-633-1358
| |
Collapse
|
50
|
Rorick AM, Mei W, Liette NL, Phiel C, El-Hodiri HM, Yang J. PP2A:B56ε is required for eye induction and eye field separation. Dev Biol 2007; 302:477-93. [PMID: 17074314 DOI: 10.1016/j.ydbio.2006.10.011] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2006] [Revised: 09/29/2006] [Accepted: 10/05/2006] [Indexed: 12/18/2022]
Abstract
Eye induction and eye field separation are the earliest events during vertebrate eye development. Both of these processes occur much earlier than the formation of optic vesicles. The insulin-like growth factor (IGF) pathway appears to be essential for eye induction, yet it remains unclear how IGF downstream pathways are involved in eye induction. As a consequence of eye induction, a single eye anlage is specified in the anterior neural plate. Subsequently, this single eye anlage is divided into two symmetric eye fields in response to Sonic Hedgehog (Shh) secreted from the prechordal mesoderm. Here, we report that B56epsilon regulatory subunit of protein phosphatase 2A (PP2A) is involved in Xenopus eye induction and subsequent eye field separation. We provide evidence that B56epsilon is required for the IGF/PI3K/Akt pathway and that interfering with the PI3K/Akt pathway inhibits eye induction. In addition, we show that B56epsilon regulates the Hedgehog (Hh) pathway during eye field separation. Thus, B56epsilon is involved in multiple signaling pathways and plays critical roles during early development.
Collapse
Affiliation(s)
- Anna M Rorick
- Columbus Children's Research Institute, Department of Pediatrics, The Ohio State University, Columbus, OH 43205, USA
| | | | | | | | | | | |
Collapse
|