1
|
Zuo JY, Chen HX, Yang Q, Liu ZG, He GW. Tetralogy of Fallot: variants of MYH6 gene promoter and cellular functional analyses. Pediatr Res 2024; 96:338-346. [PMID: 38135727 DOI: 10.1038/s41390-023-02955-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Revised: 11/10/2023] [Accepted: 11/18/2023] [Indexed: 12/24/2023]
Abstract
BACKGROUND Tetralogy of Fallot (TOF) is a common form of congenital heart disease. The MYH6 gene has important effects on cardiovascular growth and development. METHODS In 608 subjects, including 315 TOF patients, we investigated the MYH6 gene promoter variants and verified the effect on gene expression by using cellular functional experiments with three cell lines (HEK-293, HL-1, and H9C2 cells) and bioinformatics analysis. RESULTS In the MYH6 gene promoter, 12 variants were identified from 608 subjects. Five variants were found only in patients with TOF and two of them (g.3384G>T and g.4518T>C) were novel. Electrophoretic mobility shift assay with three cell lines (HEK-293, HL-1, and H9C2) showed significant changes in the transcription factors bound by the promoter variants compared to the wild-type. Dual luciferase reporter showed that four of the five variants reduced the transcriptional activity of the MYH6 gene promoter (p < 0.05). CONCLUSIONS This study is the first to test the cellular function of variants in the promoter region of the MYH6 gene in patients with TOF, which provides new insights into the genetic basis of TOF and provides a basis for further study of the mechanism of TOF formation. IMPACT DNA from 608 human subjects was sequenced for MYH6 gene promoter region variants with five variants found only in TOF patients and two were novel. EMSA and dual luciferase reporter experiments in three cell lines found these variants pathological. Prediction by JASPAR database indicated that these variants alter the transcription factor binding sites. The study, for the first time, confirmed that there are variants at the MYH6 gene promoter region and these variants alter the cellular function. The variants found in this study suggest the possible pathological role in the formation of TOF.
Collapse
Affiliation(s)
- Ji-Yang Zuo
- The Institute of Cardiovascular Diseases & Department of Cardiovascular Surgery, TEDA International Cardiovascular Hospital, Tianjin University & Chinese Academy of Medical Sciences, Tianjin, 300457, China
- Tianjin Key Laboratory of Molecular Regulation of Cardiovascular Diseases and Translational Medicine, Tianjin, 300457, China
- Clinical School of Cardiovascular Disease, Tianjin Medical University, Tianjin, China
| | - Huan-Xin Chen
- The Institute of Cardiovascular Diseases & Department of Cardiovascular Surgery, TEDA International Cardiovascular Hospital, Tianjin University & Chinese Academy of Medical Sciences, Tianjin, 300457, China
- Tianjin Key Laboratory of Molecular Regulation of Cardiovascular Diseases and Translational Medicine, Tianjin, 300457, China
| | - Qin Yang
- The Institute of Cardiovascular Diseases & Department of Cardiovascular Surgery, TEDA International Cardiovascular Hospital, Tianjin University & Chinese Academy of Medical Sciences, Tianjin, 300457, China
- Tianjin Key Laboratory of Molecular Regulation of Cardiovascular Diseases and Translational Medicine, Tianjin, 300457, China
| | - Zhi-Gang Liu
- The Institute of Cardiovascular Diseases & Department of Cardiovascular Surgery, TEDA International Cardiovascular Hospital, Tianjin University & Chinese Academy of Medical Sciences, Tianjin, 300457, China.
- Tianjin Key Laboratory of Molecular Regulation of Cardiovascular Diseases and Translational Medicine, Tianjin, 300457, China.
| | - Guo-Wei He
- The Institute of Cardiovascular Diseases & Department of Cardiovascular Surgery, TEDA International Cardiovascular Hospital, Tianjin University & Chinese Academy of Medical Sciences, Tianjin, 300457, China.
- Tianjin Key Laboratory of Molecular Regulation of Cardiovascular Diseases and Translational Medicine, Tianjin, 300457, China.
| |
Collapse
|
2
|
Kerner M, Flach H, Dietmann P, Kühl M, Kühl SJ. The impact of the insecticide acetamiprid on the embryogenesis of the aquatic model organism Xenopus laevis. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2023; 103:104278. [PMID: 37734584 DOI: 10.1016/j.etap.2023.104278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 09/13/2023] [Accepted: 09/18/2023] [Indexed: 09/23/2023]
Abstract
Acetamiprid (ACT) is used extensively in agriculture worldwide, although data on ACT concentrations in natural water bodies and its impact on aquatic organisms are limited. To study whether ACT influences the embryogenesis of the South African clawed frog Xenopus laevis, embryos were incubated in ACT solutions from 0.01 to 100 mg/L. The low concentrations were chosen on the basis of concentrations already found in nature. ACT treatment leads to shorter embryo lengths, intestine malformation and reduced eye areas. It also affects the cranial cartilage and cardiac development as well as the embryo's mobility. The expression of tissue-specific marker genes is affected as well. Thus, our study suggests that pesticides may lead to an increased mortality of non-target organisms and emphasizes the importance of regular testing for ACT concentrations in nature. Our study provides an overview of ACT effects and can therefore be used as a basis for an ACT risk assessment.
Collapse
Affiliation(s)
- Marlen Kerner
- Institute of Biochemistry and Molecular Biology, Ulm University, Albert-Einstein-Allee 11, Ulm 89081, Germany
| | - Hannah Flach
- Institute of Biochemistry and Molecular Biology, Ulm University, Albert-Einstein-Allee 11, Ulm 89081, Germany
| | - Petra Dietmann
- Institute of Biochemistry and Molecular Biology, Ulm University, Albert-Einstein-Allee 11, Ulm 89081, Germany
| | - Michael Kühl
- Institute of Biochemistry and Molecular Biology, Ulm University, Albert-Einstein-Allee 11, Ulm 89081, Germany
| | - Susanne J Kühl
- Institute of Biochemistry and Molecular Biology, Ulm University, Albert-Einstein-Allee 11, Ulm 89081, Germany.
| |
Collapse
|
3
|
Flach H, Geiß K, Lohse KA, Feickert M, Dietmann P, Pfeffer S, Kühl M, Kühl SJ. The neonicotinoid thiacloprid leads to multiple defects during early embryogenesis of the South African clawed frog (Xenopuslaevis). Food Chem Toxicol 2023; 176:113761. [PMID: 37028742 DOI: 10.1016/j.fct.2023.113761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 03/24/2023] [Accepted: 03/30/2023] [Indexed: 04/09/2023]
Abstract
There is increasing concern about the health effects of pesticides that pollute natural waters. In particular, the use of neonicotinoids, such as thiacloprid (THD), is causing unease. THD is considered non-toxic to non-target vertebrates. Studies classify THD as carcinogenic, toxic to reproduction, and therefore harmful to the environment. A detailed study of possible THD effects during the amphibian embryogenesis is needed because leaching can introduce THD into aquatic environments. We incubated stage 2 embryos of the South African clawed frog in various THD concentrations (0.1-100 mg/L) at 14 °C to study the potential effects of a one-time THD contamination of waters on the early embryogenesis. We showed that THD has, indeed, negative effects on the embryonic development of the X. laevis. A treatment with THD led to a reduced embryonic body length and mobility. Furthermore, a treatment with THD resulted in smaller cranial cartilages, eyes and brains, and the embryos had shorter cranial nerves and an impaired cardiogenesis. On a molecular basis, THD led to a reduced expression of the brain marker emx1 and the heart marker mhcα. Our results underly the importance of a strict and efficient monitoring of the regulatory levels and application areas of THD.
Collapse
Affiliation(s)
- Hannah Flach
- Institute of Biochemistry and Molecular Biology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Kristina Geiß
- Institute of Biochemistry and Molecular Biology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Kim-André Lohse
- Institute of Biochemistry and Molecular Biology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Manuel Feickert
- 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
| | - Sarah Pfeffer
- Institute of Neurobiology, Ulm University, Albert-Einstein-Allee 11, 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
|
4
|
Abu-Daya A, Godwin A. CRISPR/Cas9 Gene Disruption Studies in F 0 Xenopus Tadpoles: Understanding Development and Disease in the Frog. Methods Mol Biol 2023; 2633:111-130. [PMID: 36853461 DOI: 10.1007/978-1-0716-3004-4_10] [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] [Indexed: 03/01/2023]
Abstract
CRISPR/Cas9 has become the favorite method for gene knockouts in a range of vertebrate model organisms due to its ease of use and versatility. Gene-specific guide RNAs can be designed to a unique genomic sequence and used to target the Cas9 endonuclease, which causes a double-stranded break at the desired locus. Repair of the breaks through non-homologous end joining often results in the deletion or insertion of several nucleotides, which frequently result in nonsense mutations. Xenopus frogs have long been an excellent model organism in which to study gene function, and they have proven to be useful in gene-editing experiments, especially the diploid species, X. tropicalis. In this chapter, we present our protocols for gene disruption in Xenopus, which we regularly use to investigate developmental processes and model human genetic disease.
Collapse
Affiliation(s)
- Anita Abu-Daya
- European Xenopus Resource Centre, University of Portsmouth, Portsmouth, UK.
| | - Annie Godwin
- European Xenopus Resource Centre, University of Portsmouth, Portsmouth, UK.
| |
Collapse
|
5
|
Zuo JY, Chen HX, Liu ZG, Yang Q, He GW. Identification and functional analysis of variants of MYH6 gene promoter in isolated ventricular septal defects. BMC Med Genomics 2022; 15:213. [PMID: 36209093 PMCID: PMC9548206 DOI: 10.1186/s12920-022-01365-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 09/21/2022] [Indexed: 11/11/2022] Open
Abstract
Background Ventricular septal defect is the most common form of congenital heart diseases. MYH6 gene has a critical effect on the growth and development of the heart but the variants in the promoter of MYH6 is unknown. Patients and methods In 604 of the subjects (311 isolated and sporadic ventricular septal defect patients and 293 healthy controls), DNA was extracted from blood samples and MYH6 gene promoter region variants were analyzed by sequencing. Further functional verification was performed by cellular experiments using dual luciferase reporter gene analysis, electrophoretic mobility shift assays, and bioinformatics analysis. Results Nine variants were identified in the MYH6 gene promoter and two of those variants [g.4085G>C(rs1222539675) and g.4716G>A(rs377648095)] were only found in the ventricular septal defect patients. Cellular function experiments showed that these two variants reduced the transcriptional activity of the MYH6 gene promoter (p < 0.001). Further analysis with online JASPAR database suggests that these variants may alter a set of putative transcription factor binding sites that possibly lead to changes in myosin subunit expression and ventricular septal defect formation. Conclusions Our study for the first time identifies variants in the promoter region of the MYH6 gene in Chinese patients with isolated and sporadic ventricular septal defect. These variants significantly reduced MYH6 gene expression and affected transcription factor binding sites and therefore are pathogenic. The present study provides new insights in the role of the MYH6 gene promoter region to better understand the genetic basis of VSD formation. Supplementary Information The online version contains supplementary material available at 10.1186/s12920-022-01365-y.
Collapse
Affiliation(s)
- Ji-Yang Zuo
- Department of Cardiovascular Surgery, The Institute of Cardiovascular Diseases, TEDA International Cardiovascular Hospital, Tianjin University & Chinese Academy of Medical Sciences, No. 61, the 3rd Ave., Tianjin, 300457, China.,Clinical School of Cardiovascular Disease, Tianjin Medical University, Tianjin, China
| | - Huan-Xin Chen
- Department of Cardiovascular Surgery, The Institute of Cardiovascular Diseases, TEDA International Cardiovascular Hospital, Tianjin University & Chinese Academy of Medical Sciences, No. 61, the 3rd Ave., Tianjin, 300457, China
| | - Zhi-Gang Liu
- Department of Cardiovascular Surgery, The Institute of Cardiovascular Diseases, TEDA International Cardiovascular Hospital, Tianjin University & Chinese Academy of Medical Sciences, No. 61, the 3rd Ave., Tianjin, 300457, China
| | - Qin Yang
- Department of Cardiovascular Surgery, The Institute of Cardiovascular Diseases, TEDA International Cardiovascular Hospital, Tianjin University & Chinese Academy of Medical Sciences, No. 61, the 3rd Ave., Tianjin, 300457, China
| | - Guo-Wei He
- Department of Cardiovascular Surgery, The Institute of Cardiovascular Diseases, TEDA International Cardiovascular Hospital, Tianjin University & Chinese Academy of Medical Sciences, No. 61, the 3rd Ave., Tianjin, 300457, China.
| |
Collapse
|
6
|
Anfinson M, Fitts RH, Lough JW, James JM, Simpson PM, Handler SS, Mitchell ME, Tomita-Mitchell A. Significance of α-Myosin Heavy Chain ( MYH6) Variants in Hypoplastic Left Heart Syndrome and Related Cardiovascular Diseases. J Cardiovasc Dev Dis 2022; 9:144. [PMID: 35621855 PMCID: PMC9147009 DOI: 10.3390/jcdd9050144] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 04/27/2022] [Accepted: 04/29/2022] [Indexed: 02/04/2023] Open
Abstract
Hypoplastic left heart syndrome (HLHS) is a severe congenital heart disease (CHD) with complex genetic inheritance. HLHS segregates with other left ventricular outflow tract (LVOT) malformations in families, and can present as either an isolated phenotype or as a feature of a larger genetic disorder. The multifactorial etiology of HLHS makes it difficult to interpret the clinical significance of genetic variants. Specific genes have been implicated in HLHS, including rare, predicted damaging MYH6 variants that are present in >10% of HLHS patients, and which have been shown to be associated with decreased transplant-free survival in our previous studies. MYH6 (α-myosin heavy chain, α-MHC) variants have been reported in HLHS and numerous other CHDs, including LVOT malformations, and may provide a genetic link to these disorders. In this paper, we outline the MYH6 variants that have been identified, discuss how bioinformatic and functional studies can inform clinical decision making, and highlight the importance of genetic testing in HLHS.
Collapse
Affiliation(s)
- Melissa Anfinson
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA; (M.A.); (J.W.L.)
- Herma Heart Institute, Children’s Wisconsin, Milwaukee, WI 53226, USA; (S.S.H.); (M.E.M.)
| | - Robert H. Fitts
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53233, USA;
| | - John W. Lough
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA; (M.A.); (J.W.L.)
| | - Jeanne M. James
- Department of Pediatrics, Children’s Mercy, Kansas City, MO 64108, USA;
| | - Pippa M. Simpson
- Department of Pediatrics, Division of Quantitative Health Sciences, Medical College of Wisconsin, Milwaukee, WI 53226, USA;
| | - Stephanie S. Handler
- Herma Heart Institute, Children’s Wisconsin, Milwaukee, WI 53226, USA; (S.S.H.); (M.E.M.)
- Department of Pediatrics, Division of Pediatric Cardiology, Children’s Wisconsin, Milwaukee, WI 53226, USA
| | - Michael E. Mitchell
- Herma Heart Institute, Children’s Wisconsin, Milwaukee, WI 53226, USA; (S.S.H.); (M.E.M.)
- Department of Surgery, Division of Congenital Heart Surgery, Children’s Wisconsin, Milwaukee, WI 53226, USA
| | - Aoy Tomita-Mitchell
- Herma Heart Institute, Children’s Wisconsin, Milwaukee, WI 53226, USA; (S.S.H.); (M.E.M.)
- Department of Surgery, Division of Congenital Heart Surgery, Children’s Wisconsin, Milwaukee, WI 53226, USA
| |
Collapse
|
7
|
Eaton KM, Hallaj A, Stoeckel JA, Bernal MA. Ocean Warming Leads to Increases in Aerobic Demand and Changes to Gene Expression in the Pinfish (Lagodon rhomboides). Front Ecol Evol 2022. [DOI: 10.3389/fevo.2021.809375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Anthropogenic climate change is causing increases in the frequency, intensity, and duration of marine heatwaves (MHWs). These short-term warming events can last for days to weeks and can produce severe disruptions in marine ecosystems, as many aquatic species are poikilotherms that depend on the conditions of the environment for physiological processes. It is crucial to investigate the effects of these thermal fluctuations on species that play a disproportionate ecological role in marine ecosystems, such as the pinfish (Lagodon rhomboides) in the Gulf of Mexico and western Atlantic. In this study, we exposed pinfish to a simulated MHW in aquaria and examined the impacts of acute warming on two life stages (juvenile and adult), measuring oxygen consumption and gene expression in two relevant tissue types (liver and muscle). We saw significant increases in routine metabolic rate with increasing temperature in both juveniles (24.58 mgO2/kg/h increase per 1°C of warming) and adults (10.01 mgO2/kg/h increase per 1°C of warming). These results indicate that exposure to increased temperatures was more metabolically costly for juveniles than for adults, on a mass-specific basis. This was also observed in the molecular analyses, where the largest number of differentially expressed genes were observed in the juvenile pinfish. The analyses of gene expression suggest warming produces changes to immune function, cell proliferation, muscle contraction, nervous system function, and oxygen transport. These results indicate that this ecologically relevant species will be significantly impacted by projected increases in frequency and magnitude of MHWs, particularly in the juvenile stage.
Collapse
|
8
|
Ebrahimi N, Bradley C, Hunter P. An integrative multiscale view of early cardiac looping. WIREs Mech Dis 2022; 14:e1535. [PMID: 35023324 DOI: 10.1002/wsbm.1535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 06/20/2021] [Accepted: 06/21/2021] [Indexed: 11/12/2022]
Abstract
The heart is the first organ to form and function during the development of an embryo. Heart development consists of a series of events believed to be highly conserved in vertebrates. Development of heart begins with the formation of the cardiac fields followed by a linear heart tube formation. The straight heart tube then undergoes a ventral bending prior to further bending and helical torsion to form a looped heart. The looping phase is then followed by ballooning, septation, and valve formation giving rise to a four-chambered heart in avians and mammals. The looping phase plays a central role in heart development. Successful looping is essential for proper alignment of the future cardiac chambers and tracts. As aberrant looping results in various congenital heart diseases, the mechanisms of cardiac looping have been studied for several decades by various disciplines. Many groups have studied anatomy, biology, genetics, and mechanical processes during heart looping, and have proposed multiple mechanisms. Computational modeling approaches have been utilized to examine the proposed mechanisms of the looping process. Still, the exact underlying mechanism(s) controlling the looping phase remain poorly understood. Although further experimental measurements are obviously still required, the need for more integrative computational modeling approaches is also apparent in order to make sense of the vast amount of experimental data and the complexity of multiscale developmental systems. Indeed, there needs to be an iterative interaction between experimentation and modeling in order to properly find the gap in the existing data and to validate proposed hypotheses. This article is categorized under: Cardiovascular Diseases > Genetics/Genomics/Epigenetics Cardiovascular Diseases > Computational Models Cardiovascular Diseases > Molecular and Cellular Physiology.
Collapse
Affiliation(s)
- Nazanin Ebrahimi
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Christopher Bradley
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Peter Hunter
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| |
Collapse
|
9
|
Rafatian N, Vizely K, Al Asafen H, Korolj A, Radisic M. Drawing Inspiration from Developmental Biology for Cardiac Tissue Engineers. Adv Biol (Weinh) 2021; 5:e2000190. [PMID: 34008910 DOI: 10.1002/adbi.202000190] [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: 07/21/2020] [Revised: 12/21/2020] [Indexed: 12/17/2022]
Abstract
A sound understanding of developmental biology is part of the foundation of effective stem cell-derived tissue engineering. Here, the key concepts of cardiac development that are successfully applied in a bioinspired approach to growing engineered cardiac tissues, are reviewed. The native cardiac milieu is studied extensively from embryonic to adult phenotypes, as it provides a resource of factors, mechanisms, and protocols to consider when working toward establishing living tissues in vitro. It begins with the various cell types that constitute the cardiac tissue. It is discussed how myocytes interact with other cell types and their microenvironment and how they change over time from the embryonic to the adult states, with a view on how such changes affect the tissue function and may be used in engineered tissue models. Key embryonic signaling pathways that have been leveraged in the design of culture media and differentiation protocols are presented. The cellular microenvironment, from extracellular matrix chemical and physical properties, to the dynamic mechanical and electrical forces that are exerted on tissues is explored. It is shown that how such microenvironmental factors can inform the design of biomaterials, scaffolds, stimulation bioreactors, and maturation readouts, and suggest considerations for ongoing biomimetic advancement of engineered cardiac tissues and regeneration strategies for the future.
Collapse
Affiliation(s)
- Naimeh Rafatian
- Toronto General Research Institute, Toronto, Ontario, M5G 2C4, Canada
| | - Katrina Vizely
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, M5S 3E5, Canada
| | - Hadel Al Asafen
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, M5S 3E5, Canada
| | - Anastasia Korolj
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, M5S 3E5, Canada.,Institute of Biomaterials Engineering, University of Toronto, Toronto, Ontario, M5S 3G9, Canada
| | - Milica Radisic
- Toronto General Research Institute, Toronto, Ontario, M5G 2C4, Canada.,Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, M5S 3E5, Canada.,Institute of Biomaterials Engineering, University of Toronto, Toronto, Ontario, M5S 3G9, Canada
| |
Collapse
|
10
|
Dur AH, Tang T, Viviano S, Sekuri A, Willsey HR, Tagare HD, Kahle KT, Deniz E. In Xenopus ependymal cilia drive embryonic CSF circulation and brain development independently of cardiac pulsatile forces. Fluids Barriers CNS 2020; 17:72. [PMID: 33308296 PMCID: PMC7731788 DOI: 10.1186/s12987-020-00234-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 11/28/2020] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Hydrocephalus, the pathological expansion of the cerebrospinal fluid (CSF)-filled cerebral ventricles, is a common, deadly disease. In the adult, cardiac and respiratory forces are the main drivers of CSF flow within the brain ventricular system to remove waste and deliver nutrients. In contrast, the mechanics and functions of CSF circulation in the embryonic brain are poorly understood. This is primarily due to the lack of model systems and imaging technology to study these early time points. Here, we studied embryos of the vertebrate Xenopus with optical coherence tomography (OCT) imaging to investigate in vivo ventricular and neural development during the onset of CSF circulation. METHODS Optical coherence tomography (OCT), a cross-sectional imaging modality, was used to study developing Xenopus tadpole brains and to dynamically detect in vivo ventricular morphology and CSF circulation in real-time, at micrometer resolution. The effects of immobilizing cilia and cardiac ablation were investigated. RESULTS In Xenopus, using OCT imaging, we demonstrated that ventriculogenesis can be tracked throughout development until the beginning of metamorphosis. We found that during Xenopus embryogenesis, initially, CSF fills the primitive ventricular space and remains static, followed by the initiation of the cilia driven CSF circulation where ependymal cilia create a polarized CSF flow. No pulsatile flow was detected throughout these tailbud and early tadpole stages. As development progressed, despite the emergence of the choroid plexus in Xenopus, cardiac forces did not contribute to the CSF circulation, and ciliary flow remained the driver of the intercompartmental bidirectional flow as well as the near-wall flow. We finally showed that cilia driven flow is crucial for proper rostral development and regulated the spatial neural cell organization. CONCLUSIONS Our data support a paradigm in which Xenopus embryonic ventriculogenesis and rostral brain development are critically dependent on ependymal cilia-driven CSF flow currents that are generated independently of cardiac pulsatile forces. Our work suggests that the Xenopus ventricular system forms a complex cilia-driven CSF flow network which regulates neural cell organization. This work will redirect efforts to understand the molecular regulators of embryonic CSF flow by focusing attention on motile cilia rather than other forces relevant only to the adult.
Collapse
Affiliation(s)
- A H Dur
- Department of Pediatrics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06510, USA
- Acibadem Mehmet Ali Aydinlar University School of Medicine, Istanbul, Turkey
| | - T Tang
- Department of Radiology and Biomedical Imaging, Yale University, 300 Cedar St, New Haven, CT, 06510, USA
| | - S Viviano
- Department of Pediatrics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06510, USA
- Pediatric Genomics Discovery Program, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06510, USA
| | - A Sekuri
- Acibadem Mehmet Ali Aydinlar University School of Medicine, Istanbul, Turkey
| | - H R Willsey
- Department of Psychiatry and Behavioral Sciences, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, 94143, USA
| | - H D Tagare
- Department of Radiology and Biomedical Imaging, Yale University, 300 Cedar St, New Haven, CT, 06510, USA
| | - K T Kahle
- Department of Pediatrics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06510, USA
- Department of Neurosurgery and Cellular & Molecular Physiology, and Centers for Mendelian Genomics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06510, USA
| | - E Deniz
- Department of Pediatrics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06510, USA.
- Pediatric Genomics Discovery Program, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06510, USA.
| |
Collapse
|
11
|
Wang D, Zhang Y, Li J, Dahlgren RA, Wang X, Huang H, Wang H. Risk assessment of cardiotoxicity to zebrafish (Danio rerio) by environmental exposure to triclosan and its derivatives. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 265:114995. [PMID: 32554097 DOI: 10.1016/j.envpol.2020.114995] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 06/02/2020] [Accepted: 06/06/2020] [Indexed: 06/11/2023]
Abstract
Triclosan (TCS) and its two derivatives (2,4-dichlorophenol and 2,4,6-trichlorophenol) are priority pollutants that coexist in aquatic environments. Joint exposure of TCS, 2,4-dichlorophenol and 2,4,6-trichlorophenol, hereafter referred to as TCS-DT, contributes severe toxicity to aquatic organisms. There is currently a paucity of data regarding TCS-DT molecular toxicity, especially on cardiac diseases. We used zebrafish (Danio rerio) as a model organism, and evaluated the molecular-level cardiotoxicity induced by TCS-DT from embryonic to adult stages. TCS-DT exposure prominently led to phenotypic malformations, such as pericardial cysts, cardiac bleeding, increased SV-BA distance, decreased heart rate and reduced ejection fraction, as well as abnormal swimming behavior. Analyses of the GO and KEGG pathways revealed enrichment pathways related to cardiac development and screened for significantly down-regulated adrenaline signaling in cardiomyocytes. The cardiac marker genes (amhc, cmlc2, vmhc, and nkx2.5) were obtained through protein-protein interaction (PPI) networks, and expressed as down-regulation by WISH. After chronic exposure to TCS-DT from 30 to 90-dpf, both body mass and heart indexes prominently increased, showing myocardial hypertrophy, abnormal heart rate and histopathological injury. Heart tissue damage included disordered and ruptured myocardial fibers, broken and dissolved myofilaments, nuclear pyknosis, mitochondrial injury and inflammatory cell infiltration. Further, abnormal changes in a series of cardiac functions-related biomarkers, including superoxide dismutase, triglyceride, lactate dehydrogenase and creatinine kinase MB, provided evidence for cardiac pathological responses. These results highlight the molecular mechanisms involving TCS-DT induced cardiac toxicity, and provide theoretical data to guide prevention and treatment of pollutant-induced cardiac diseases.
Collapse
Affiliation(s)
- Danting Wang
- Zhejiang Provincial Key Laboratory of Medical Genetics, Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Yuhuan Zhang
- Zhejiang Provincial Key Laboratory of Medical Genetics, Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Jieyi Li
- Zhejiang Provincial Key Laboratory of Medical Genetics, Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Randy A Dahlgren
- Department of Land, Air and Water Resources, University of California, Davis, CA, 95616, USA
| | - Xuedong Wang
- National and Local Joint Engineering Laboratory of Municipal Sewage Resource Utilization Technology, School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, Jiangsu, 215009, China
| | - Haishan Huang
- Zhejiang Provincial Key Laboratory of Medical Genetics, Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Huili Wang
- Zhejiang Provincial Key Laboratory of Medical Genetics, Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China.
| |
Collapse
|
12
|
Lombardo VA, Heise M, Moghtadaei M, Bornhorst D, Männer J, Abdelilah-Seyfried S. Morphogenetic control of zebrafish cardiac looping by Bmp signaling. Development 2019; 146:dev.180091. [PMID: 31628109 DOI: 10.1242/dev.180091] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 10/15/2019] [Indexed: 12/23/2022]
Abstract
Cardiac looping is an essential and highly conserved morphogenetic process that places the different regions of the developing vertebrate heart tube into proximity of their final topographical positions. High-resolution 4D live imaging of mosaically labelled cardiomyocytes reveals distinct cardiomyocyte behaviors that contribute to the deformation of the entire heart tube. Cardiomyocytes acquire a conical cell shape, which is most pronounced at the superior wall of the atrioventricular canal and contributes to S-shaped bending. Torsional deformation close to the outflow tract contributes to a torque-like winding of the entire heart tube between its two poles. Anisotropic growth of cardiomyocytes based on their positions reinforces S-shaping of the heart. During cardiac looping, bone morphogenetic protein pathway signaling is strongest at the future superior wall of the atrioventricular canal. Upon pharmacological or genetic inhibition of bone morphogenetic protein signaling, myocardial cells at the superior wall of the atrioventricular canal maintain cuboidal cell shapes and S-shaped bending is impaired. This description of cellular rearrangements and cardiac looping regulation may also be relevant for understanding the etiology of human congenital heart defects.
Collapse
Affiliation(s)
- Verónica A Lombardo
- Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas and Universidad Nacional de Rosario, 2000 Rosario, Argentina .,Centro de Estudios Interdisciplinarios, Universidad Nacional de Rosario, 2000 Rosario, Argentina
| | - Melina Heise
- Institute of Molecular Biology, Hannover Medical School, D-30625 Hannover, Germany
| | - Motahareh Moghtadaei
- Institute of Molecular Biology, Hannover Medical School, D-30625 Hannover, Germany.,Institute of Biochemistry and Biology, Potsdam University, D-14476 Potsdam, Germany
| | - Dorothee Bornhorst
- Institute of Molecular Biology, Hannover Medical School, D-30625 Hannover, Germany.,Institute of Biochemistry and Biology, Potsdam University, D-14476 Potsdam, Germany
| | - Jörg Männer
- Institute of Anatomy and Embryology, UMG, Göttingen University, D-37075 Göttingen, Germany
| | - Salim Abdelilah-Seyfried
- Institute of Molecular Biology, Hannover Medical School, D-30625 Hannover, Germany .,Institute of Biochemistry and Biology, Potsdam University, D-14476 Potsdam, Germany
| |
Collapse
|
13
|
Deniz E, Jonas S, Khokha MK, Choma MA. Quantitative Phenotyping of Xenopus Embryonic Heart Pathophysiology Using Hemoglobin Contrast Subtraction Angiography to Screen Human Cardiomyopathies. Front Physiol 2019; 10:1197. [PMID: 31620018 PMCID: PMC6763566 DOI: 10.3389/fphys.2019.01197] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 09/03/2019] [Indexed: 01/09/2023] Open
Abstract
Congenital heart disease (CHD) is a significant cause of mortality in infants and adults. Currently human genomic analysis has identified a number of candidate genes in these patients. These genes span diverse categories of gene function suggesting that despite the similarity in cardiac lesion, the underlying pathophysiology may be different. In fact, patients with similar CHDs can have drastically different outcomes, including a dramatic decrease in myocardial function. To test these human candidate genes for their impact on myocardial function, we need efficient animals models of disease. For this purpose, we paired Xenopus tropicalis with our microangiography technique, hemoglobin contrast subtraction angiography (HCSA). To demonstrate the gene-teratogen-physiology relationship, we modeled human cardiomyopathy in tadpoles. First we depleted the sarcomeric protein myosin heavy chain 6 (myh6) expression using morpholino oligos. Next, we exposed developing embryos to the teratogen ethanol and in both conditions showed varying degrees of cardiac dysfunction. Our results demonstrate that HCSA can distinguish biomechanical phenotypes in the context of gene dysfunction or teratogen. This approach can be used to screen numerous candidate CHD genes or suspected teratogens for their effect on cardiac function.
Collapse
Affiliation(s)
- Engin Deniz
- Department of Pediatrics, Yale University, New Haven, CT, United States
| | - Stephan Jonas
- Department of Informatics, Technical University of Munich, Munich, Germany
| | - Mustafa K Khokha
- Department of Pediatrics, Yale University, New Haven, CT, United States.,Department of Genetics, Yale University, New Haven, CT, United States
| | - Michael A Choma
- Department of Pediatrics, Yale University, New Haven, CT, United States.,Department of Diagnostic Radiology, Yale University, New Haven, CT, United States.,Department of Biomedical Engineering, Yale University, New Haven, CT, United States.,Department of Applied Physics, Yale University, New Haven, CT, United States
| |
Collapse
|
14
|
Hwang WY, Marquez J, Khokha MK. Xenopus: Driving the Discovery of Novel Genes in Patient Disease and Their Underlying Pathological Mechanisms Relevant for Organogenesis. Front Physiol 2019; 10:953. [PMID: 31417417 PMCID: PMC6682594 DOI: 10.3389/fphys.2019.00953] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 07/09/2019] [Indexed: 12/16/2022] Open
Abstract
Frog model organisms have been appreciated for their utility in exploring physiological phenomena for nearly a century. Now, a vibrant community of biologists that utilize this model organism has poised Xenopus to serve as a high throughput vertebrate organism to model patient-driven genetic diseases. This has facilitated the investigation of effects of patient mutations on specific organs and signaling pathways. This approach promises a rapid investigation into novel mechanisms that disrupt normal organ morphology and function. Considering that many disease states are still interrogated in vitro to determine relevant biological processes for further study, the prospect of interrogating genetic disease in Xenopus in vivo is an attractive alternative. This model may more closely capture important aspects of the pathology under investigation such as cellular micro environments and local forces relevant to a specific organ's development and homeostasis. This review aims to highlight recent methodological advances that allow investigation of genetic disease in organ-specific contexts in Xenopus as well as provide examples of how these methods have led to the identification of novel mechanisms and pathways important for understanding human disease.
Collapse
Affiliation(s)
| | | | - Mustafa K. Khokha
- Department of Pediatrics and Genetics, The Pediatric Genomics Discovery Program, Yale University School of Medicine, New Haven, CT, United States
| |
Collapse
|
15
|
López-Unzu MA, Durán AC, Soto-Navarrete MT, Sans-Coma V, Fernández B. Differential expression of myosin heavy chain isoforms in cardiac segments of gnathostome vertebrates and its evolutionary implications. Front Zool 2019; 16:18. [PMID: 31198434 PMCID: PMC6558913 DOI: 10.1186/s12983-019-0318-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 05/20/2019] [Indexed: 01/18/2023] Open
Abstract
Background Immunohistochemical studies of hearts from the lesser spotted dogfish, Scyliorhinus canicula (Chondrichthyes) revealed that the pan-myosin heavy chain (pan-MyHC) antibody MF20 homogeneously labels all the myocardium, while the pan-MyHC antibody A4.1025 labels the myocardium of the inflow (sinus venosus and atrium) but not the outflow (ventricle and conus arteriosus) cardiac segments, as opposed to other vertebrates. We hypothesized that the conventional pattern of cardiac MyHC isoform distribution present in most vertebrates, i.e. MYH6 in the inflow and MYH7 in the outflow segments, has evolved from a primitive pattern that persists in Chondrichthyes. In order to test this hypothesis, we conducted protein detection techniques to identify the MyHC isoforms expressed in adult dogfish cardiac segments and to assess the pan-MyHC antibodies reactivity against the cardiac segments of representative species from different vertebrate groups. Results Western and slot blot results confirmed the specificity of MF20 and A4.1025 for MyHC in dogfish and their differential reactivity against distinct myocardial segments. HPLC-ESI-MS/MS and ESI-Quadrupole-Orbitrap revealed abundance of MYH6 and MYH2 in the inflow and of MYH7 and MYH7B in the outflow segments. Immunoprecipitation showed higher affinity of A4.1025 for MYH2 and MYH6 than for MYH7 and almost no affinity for MYH7B. Immunohistochemistry showed that A4.1025 signals are restricted to the inflow myocardial segments of elasmobranchs, homogeneous in all myocardial segments of teleosts and acipenseriforms, and low in the ventricle of polypteriforms. Conclusions The cardiac inflow and outflow segments of the dogfish show predominance of fast- and slow-twitch MyHC isoforms respectively, what can be considered a synapomorphy of gnathostomes. The myocardium of the dogfish contains two isomyosins (MYH2 and MYH7B) not expressed in the adult heart of other vertebrates. We propose that these isomyosins lost their function in cardiac contraction during the evolution of gnathostomes, the later acquiring a regulatory role in myogenesis through its intronic miRNA. Loss of MYH2 and MYH7B expression in the heart possibly occurred before the origin of Osteichthyes, being the latter reacquired in polypteriforms. We raise the hypothesis that the slow tonic MYH7B facilitates the peristaltic contraction of the conus arteriosus of fish with a primitive cardiac anatomical design and of the vertebrate embryo.
Collapse
Affiliation(s)
- Miguel A López-Unzu
- 1Departamento de Biología Animal, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, España.,2Instituto de Biomedicina de Málaga (IBIMA), Málaga, Spain
| | - Ana Carmen Durán
- 1Departamento de Biología Animal, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, España.,2Instituto de Biomedicina de Málaga (IBIMA), Málaga, Spain
| | - María Teresa Soto-Navarrete
- 1Departamento de Biología Animal, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, España.,2Instituto de Biomedicina de Málaga (IBIMA), Málaga, Spain
| | - Valentín Sans-Coma
- 1Departamento de Biología Animal, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, España.,2Instituto de Biomedicina de Málaga (IBIMA), Málaga, Spain
| | - Borja Fernández
- 1Departamento de Biología Animal, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, España.,2Instituto de Biomedicina de Málaga (IBIMA), Málaga, Spain.,CIBERCV Enfermedades Cardiovasculares, Málaga, Spain
| |
Collapse
|
16
|
Gentsch GE, Spruce T, Monteiro RS, Owens NDL, Martin SR, Smith JC. Innate Immune Response and Off-Target Mis-splicing Are Common Morpholino-Induced Side Effects in Xenopus. Dev Cell 2018; 44:597-610.e10. [PMID: 29478923 PMCID: PMC5861998 DOI: 10.1016/j.devcel.2018.01.022] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 11/21/2017] [Accepted: 01/26/2018] [Indexed: 12/20/2022]
Abstract
Antisense morpholino oligomers (MOs) have been indispensable tools for developmental biologists to transiently knock down (KD) genes rather than to knock them out (KO). Here we report on the implications of genetic KO versus MO-mediated KD of the mesoderm-specifying Brachyury paralogs in the frog Xenopus tropicalis. While both KO and KD embryos fail to activate the same core gene regulatory network, resulting in virtually identical morphological defects, embryos injected with control or target MOs also show a systemic GC content-dependent immune response and many off-target splicing defects. Optimization of MO dosage and increasing incubation temperatures can mitigate, but not eliminate, these MO side effects, which are consistent with the high affinity measured between MO and off-target sequence in vitro. We conclude that while MOs can be useful to profile loss-of-function phenotypes at a molecular level, careful attention must be paid to their immunogenic and off-target side effects.
Collapse
Affiliation(s)
- George E Gentsch
- The Francis Crick Institute, Developmental Biology Laboratory, 1 Midland Road, London NW1 1AT, UK.
| | - Thomas Spruce
- The Francis Crick Institute, Developmental Biology Laboratory, 1 Midland Road, London NW1 1AT, UK
| | - Rita S Monteiro
- The Francis Crick Institute, Developmental Biology Laboratory, 1 Midland Road, London NW1 1AT, UK
| | - Nick D L Owens
- The Francis Crick Institute, Developmental Biology Laboratory, 1 Midland Road, London NW1 1AT, UK
| | - Stephen R Martin
- The Francis Crick Institute, Structural Biology Science Technology Platform, 1 Midland Road, London NW1 1AT, UK
| | - James C Smith
- The Francis Crick Institute, Developmental Biology Laboratory, 1 Midland Road, London NW1 1AT, UK.
| |
Collapse
|
17
|
Lawson TB, Scott-Drechsel DE, Chivukula VK, Rugonyi S, Thornburg KL, Hinds MT. Hyperglycemia Alters the Structure and Hemodynamics of the Developing Embryonic Heart. J Cardiovasc Dev Dis 2018; 5:jcdd5010013. [PMID: 29439517 PMCID: PMC5872361 DOI: 10.3390/jcdd5010013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Revised: 02/06/2018] [Accepted: 02/09/2018] [Indexed: 12/27/2022] Open
Abstract
Congenital heart defects (CHDs) represent the most common form of human birth defects; approximately one-third of heart defects involve malformations of the outflow tract (OFT). Maternal diabetes increases the risk of CHD by 3-5 fold. During heart organogenesis, little is known about the effects of hyperglycemia on hemodynamics, which are critical to normal heart development. Heart development prior to septation in the chick embryo was studied under hyperglycemic conditions. Sustained hyperglycemic conditions were induced, raising the average plasma glucose concentration from 70 mg/dL to 180 mg/dL, akin to the fasting plasma glucose of a patient with diabetes. The OFTs were assessed for structural and hemodynamic alterations using optical coherence tomography (OCT), confocal microscopy, and microcomputed tomography. In hyperglycemic embryos, the endocardial cushions of the proximal OFT were asymmetric, and the OFTs curvature and torsion were significantly altered. The blood flow velocity through the OFT of hyperglycemic embryos was significantly decreased, including flow reversal in 30% of the cardiac cycle. Thus, hyperglycemia at the onset of gestation results in asymmetric proximal endocardial cushions, abnormal OFT curvature, and altered hemodynamics in the developing heart. If present in humans, these results may identify early developmental alterations that contribute to the increased risk for cardiac malformations in babies from diabetic mothers.
Collapse
Affiliation(s)
- Taylor B Lawson
- Biomedical Engineering Department, Oregon Health & Science University, Portland, OR 97239, USA.
| | - Devon E Scott-Drechsel
- Biomedical Engineering Department, Oregon Health & Science University, Portland, OR 97239, USA.
| | - Venkat Keshav Chivukula
- Biomedical Engineering Department, Oregon Health & Science University, Portland, OR 97239, USA.
| | - Sandra Rugonyi
- Biomedical Engineering Department, Oregon Health & Science University, Portland, OR 97239, USA.
| | - Kent L Thornburg
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR 97239, USA.
| | - Monica T Hinds
- Biomedical Engineering Department, Oregon Health & Science University, Portland, OR 97239, USA.
| |
Collapse
|
18
|
Deniz E, Jonas S, Hooper M, N. Griffin J, Choma MA, Khokha MK. Analysis of Craniocardiac Malformations in Xenopus using Optical Coherence Tomography. Sci Rep 2017; 7:42506. [PMID: 28195132 PMCID: PMC5307353 DOI: 10.1038/srep42506] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 01/10/2017] [Indexed: 12/17/2022] Open
Abstract
Birth defects affect 3% of children in the United States. Among the birth defects, congenital heart disease and craniofacial malformations are major causes of mortality and morbidity. Unfortunately, the genetic mechanisms underlying craniocardiac malformations remain largely uncharacterized. To address this, human genomic studies are identifying sequence variations in patients, resulting in numerous candidate genes. However, the molecular mechanisms of pathogenesis for most candidate genes are unknown. Therefore, there is a need for functional analyses in rapid and efficient animal models of human disease. Here, we coupled the frog Xenopus tropicalis with Optical Coherence Tomography (OCT) to create a fast and efficient system for testing craniocardiac candidate genes. OCT can image cross-sections of microscopic structures in vivo at resolutions approaching histology. Here, we identify optimal OCT imaging planes to visualize and quantitate Xenopus heart and facial structures establishing normative data. Next we evaluate known human congenital heart diseases: cardiomyopathy and heterotaxy. Finally, we examine craniofacial defects by a known human teratogen, cyclopamine. We recapitulate human phenotypes readily and quantify the functional and structural defects. Using this approach, we can quickly test human craniocardiac candidate genes for phenocopy as a critical first step towards understanding disease mechanisms of the candidate genes.
Collapse
Affiliation(s)
- Engin Deniz
- Pediatric Genomics Discovery Program, Department of Pediatrics, Yale University, 333 Cedar Street, New Haven, CT 06510, USA
| | - Stephan Jonas
- Department of Medical Informatics, RWTH Aachen University, Pauwelsstraße 30, 52074 Aachen, Germany
| | - Michael Hooper
- Pediatric Genomics Discovery Program, Department of Pediatrics, Yale University, 333 Cedar Street, New Haven, CT 06510, USA
| | - John N. Griffin
- Pediatric Genomics Discovery Program, Department of Pediatrics, Yale University, 333 Cedar Street, New Haven, CT 06510, USA
| | - Michael A. Choma
- Department of Radiology and Biomedical Imaging, Department of Pediatrics, Yale University, 333 Cedar, Street New Haven, CT 06510, USA
- Department of Biomedical Engineering and Applied Physics, Yale University, 333 Cedar Street, New Haven, CT 06510, USA
| | - Mustafa K. Khokha
- Pediatric Genomics Discovery Program, Department of Pediatrics, Yale University, 333 Cedar Street, New Haven, CT 06510, USA
- Department of Genetics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
| |
Collapse
|
19
|
Pearl E, Morrow S, Noble A, Lerebours A, Horb M, Guille M. An optimized method for cryogenic storage of Xenopus sperm to maximise the effectiveness of research using genetically altered frogs. Theriogenology 2017; 92:149-155. [PMID: 28237331 PMCID: PMC5340284 DOI: 10.1016/j.theriogenology.2017.01.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 10/26/2016] [Accepted: 01/04/2017] [Indexed: 02/06/2023]
Abstract
Cryogenic storage of sperm from genetically altered Xenopus improves cost effectiveness and animal welfare associated with their use in research; currently it is routine for X. tropicalis but not reliable for X. laevis. Here we compare directly the three published protocols for Xenopus sperm freeze-thaw and determine whether sperm storage temperature, method of testes maceration and delays in the freezing protocols affect successful fertilisation and embryo development in X. laevis. We conclude that the protocol is robust and that the variability observed in fertilisation rates is due to differences between individuals. We show that the embryos made from the frozen-thawed sperm are normal and that the adults they develop into are reproductively indistinguishable from others in the colony. This opens the way for using cryopreserved sperm to distribute dominant genetically altered (GA) lines, potentially saving travel-induced stress to the male frogs, reducing their numbers used and making Xenopus experiments more cost effective. Xenopus cryopreservation is robust using an optimized method. Success is dependent on the quality of animals from which the sperm are taken. Frozen sperm may now be used to distribute lines and wild-type male gametes around the world.
Collapse
Affiliation(s)
- Esther Pearl
- National Xenopus Resource, 7 MBL Street, Woods Hole, MA, 02543, USA
| | - Sean Morrow
- European Xenopus Resource Centre, Institute of Biomedical and Biomolecular Sciences, University of Portsmouth, Portsmouth, PO1 2DT, UK
| | - Anna Noble
- European Xenopus Resource Centre, Institute of Biomedical and Biomolecular Sciences, University of Portsmouth, Portsmouth, PO1 2DT, UK
| | - Adelaide Lerebours
- School of Biological Sciences, University of Portsmouth, Portsmouth, PO1 2DY, UK
| | - Marko Horb
- National Xenopus Resource, 7 MBL Street, Woods Hole, MA, 02543, USA
| | - Matthew Guille
- European Xenopus Resource Centre, Institute of Biomedical and Biomolecular Sciences, University of Portsmouth, Portsmouth, PO1 2DT, UK; School of Biological Sciences, University of Portsmouth, Portsmouth, PO1 2DY, UK.
| |
Collapse
|
20
|
Liu LS, Zhao LY, Wang SH, Jiang JP. Research proceedings on amphibian model organisms. DONG WU XUE YAN JIU = ZOOLOGICAL RESEARCH 2016; 37:237-45. [PMID: 27469255 PMCID: PMC4980064 DOI: 10.13918/j.issn.2095-8137.2016.4.237] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 03/20/2016] [Accepted: 06/10/2016] [Indexed: 12/26/2022]
Abstract
Model organisms have long been important in biology and medicine due to their specific characteristics. Amphibians, especially Xenopus, play key roles in answering fundamental questions on developmental biology, regeneration, genetics, and toxicology due to their large and abundant eggs, as well as their versatile embryos, which can be readily manipulated and developed in vivo. Furthermore, amphibians have also proven to be of considerable benefit in human disease research due to their conserved cellular developmental and genomic organization. This review gives a brief introduction on the progress and limitations of these animal models in biology and human disease research, and discusses the potential and challenge of Microhyla fissipes as a new model organism.
Collapse
Affiliation(s)
- Lu-Sha Liu
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China
| | - Lan-Ying Zhao
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China;University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shou-Hong Wang
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China;University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jian-Ping Jiang
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China.
| |
Collapse
|
21
|
Smith SJ, Towers N, Saldanha JW, Shang CA, Mahmood SR, Taylor WR, Mohun TJ. The cardiac-restricted protein ADP-ribosylhydrolase-like 1 is essential for heart chamber outgrowth and acts on muscle actin filament assembly. Dev Biol 2016; 416:373-88. [PMID: 27217161 PMCID: PMC4990356 DOI: 10.1016/j.ydbio.2016.05.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 04/29/2016] [Accepted: 05/06/2016] [Indexed: 12/22/2022]
Abstract
Adprhl1, a member of the ADP-ribosylhydrolase protein family, is expressed exclusively in the developing heart of all vertebrates. In the amphibian Xenopus laevis, distribution of its mRNA is biased towards actively growing chamber myocardium. Morpholino oligonucleotide-mediated knockdown of all Adprhl1 variants inhibits striated myofibril assembly and prevents outgrowth of the ventricle. The resulting ventricles retain normal electrical conduction and express markers of chamber muscle differentiation but are functionally inert. Using a cardiac-specific Gal4 binary expression system, we show that the abundance of Adprhl1 protein in tadpole hearts is tightly controlled through a negative regulatory mechanism targeting the 5′-coding sequence of Xenopus adprhl1. Over-expression of full length (40 kDa) Adprhl1 variants modified to escape such repression, also disrupts cardiac myofibrillogenesis. Disarrayed myofibrils persist that show extensive branching, with sarcomere division occurring at the actin-Z-disc boundary. Ultimately, Adprhl1-positive cells contain thin actin threads, connected to numerous circular branch points. Recombinant Adprhl1 can localize to stripes adjacent to the Z-disc, suggesting a direct role for Adprhl1 in modifying Z-disc and actin dynamics as heart chambers grow. Modelling the structure of Adprhl1 suggests this cardiac-specific protein is a pseudoenzyme, lacking key residues necessary for ADP-ribosylhydrolase catalytic activity. Adprhl1 is expressed exclusively in the heart of all vertebrates. Morpholino knockdown of Adprhl1 prevents outgrowth of the ventricle. Elevated 40 kDa Adprhl1 produces disarrayed myofibrils that show extensive branching. The 5′-coding sequence of Xenopus adprhl1 influences the synthesis of Adprhl1 protein. Two Adprhl1 proteins, 40+23 kDa exist in Xenopus embryos and are conserved in mouse.
Collapse
Affiliation(s)
- Stuart J Smith
- Heart Formation in Vertebrates Laboratory, The Francis Crick Institute - Mill Hill Laboratory, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - Norma Towers
- Heart Formation in Vertebrates Laboratory, The Francis Crick Institute - Mill Hill Laboratory, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - José W Saldanha
- Mathematical Biology Laboratory, The Francis Crick Institute - Mill Hill Laboratory, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - Catherine A Shang
- Heart Formation in Vertebrates Laboratory, The Francis Crick Institute - Mill Hill Laboratory, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - S Radma Mahmood
- Experimental Histopathology, The Francis Crick Institute - Mill Hill Laboratory, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - William R Taylor
- Mathematical Biology Laboratory, The Francis Crick Institute - Mill Hill Laboratory, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - Timothy J Mohun
- Heart Formation in Vertebrates Laboratory, The Francis Crick Institute - Mill Hill Laboratory, The Ridgeway, Mill Hill, London NW7 1AA, UK.
| |
Collapse
|
22
|
Geach TJ, Hirst EMA, Zimmerman LB. Contractile activity is required for Z-disc sarcomere maturation in vivo. Genesis 2015; 53:299-307. [PMID: 25845369 PMCID: PMC4676352 DOI: 10.1002/dvg.22851] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 03/30/2015] [Accepted: 03/31/2015] [Indexed: 01/16/2023]
Abstract
Sarcomere structure underpins structural integrity, signaling, and force transmission in the muscle. In embryos of the frog Xenopus tropicalis, muscle contraction begins even while sarcomerogenesis is ongoing. To determine whether contractile activity plays a role in sarcomere formation in vivo, chemical tools were used to block acto-myosin contraction in embryos of the frog X. tropicalis, and Z-disc assembly was characterized in the paralyzed dicky ticker mutant. Confocal and ultrastructure analysis of paralyzed embryos showed delayed Z-disc formation and defects in thick filament organization. These results suggest a previously undescribed role for contractility in sarcomere maturation in vivo. genesis 53:299–307, 2015. © 2015 The Authors. Genesis Published by Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Timothy J Geach
- Division of Developmental Biology, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London, United Kingdom
| | - Elizabeth M A Hirst
- Division of Developmental Biology, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London, United Kingdom
| | - Lyle B Zimmerman
- Division of Developmental Biology, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London, United Kingdom
| |
Collapse
|
23
|
|
24
|
Schmitt SM, Gull M, Brändli AW. Engineering Xenopus embryos for phenotypic drug discovery screening. Adv Drug Deliv Rev 2014; 69-70:225-46. [PMID: 24576445 DOI: 10.1016/j.addr.2014.02.004] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 02/13/2014] [Accepted: 02/14/2014] [Indexed: 02/08/2023]
Abstract
Many rare human inherited diseases remain untreatable despite the fact that the disease causing genes are known and adequate mouse disease models have been developed. In vivo phenotypic drug screening relies on isolating drug candidates by their ability to produce a desired therapeutic phenotype in whole organisms. Embryos of zebrafish and Xenopus frogs are abundant, small and free-living. They can be easily arrayed in multi-well dishes and treated with small organic molecules. With the development of novel genome modification tools, such a zinc-finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and CRISPR/Cas, it is now possible to efficiently engineer non-mammalian models of inherited human diseases. Here, we will review the rapid progress made in adapting these novel genome editing tools to Xenopus. The advantages of Xenopus embryos as in vivo models to study human inherited diseases will be presented and their utility for drug discovery screening will be discussed. Being a tetrapod, Xenopus complements zebrafish as an indispensable non-mammalian animal model for the study of human disease pathologies and the discovery of novel therapeutics for inherited diseases.
Collapse
|
25
|
del Viso F, Bhattacharya D, Kong Y, Gilchrist MJ, Khokha MK. Exon capture and bulk segregant analysis: rapid discovery of causative mutations using high-throughput sequencing. BMC Genomics 2012; 13:649. [PMID: 23171430 PMCID: PMC3526394 DOI: 10.1186/1471-2164-13-649] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Accepted: 11/15/2012] [Indexed: 11/21/2022] Open
Abstract
Background Exome sequencing has transformed human genetic analysis and may do the same for other vertebrate model systems. However, a major challenge is sifting through the large number of sequence variants to identify the causative mutation for a given phenotype. In models like Xenopus tropicalis, an incomplete and occasionally incorrect genome assembly compounds this problem. To facilitate cloning of X. tropicalis mutants identified in forward genetic screens, we sought to combine bulk segregant analysis and exome sequencing into a single step. Results Here we report the first use of exon capture sequencing to identify mutations in a non-mammalian, vertebrate model. We demonstrate that bulk segregant analysis coupled with exon capture sequencing is not only able to identify causative mutations but can also generate linkage information, facilitate the assembly of scaffolds, identify misassembles, and discover thousands of SNPs for fine mapping. Conclusion Exon capture sequencing and bulk segregant analysis is a rapid, inexpensive method to clone mutants identified in forward genetic screens. With sufficient meioses, this method can be generalized to any model system with a genome assembly, polished or unpolished, and in the latter case, it also provides many critical genomic resources.
Collapse
Affiliation(s)
- Florencia del Viso
- Department of Pediatrics and Genetics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | | | | | | | | |
Collapse
|
26
|
Nath K, Fisher C, Elinson RP. Expression of a cardiac myosin gene in non-heart tissues of developing frogs. Dev Genes Evol 2012; 223:189-93. [PMID: 23076351 DOI: 10.1007/s00427-012-0421-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Accepted: 10/03/2012] [Indexed: 02/02/2023]
Abstract
Direct developing frogs, like Eleutherodactylus coqui, provide opportunities to investigate limb early development in anuran amphibians that are less available in species with tadpoles. We have found that myosin heavy chain 6 (myh6), a myosin gene usually considered heart-specific in Xenopus and other animals, is expressed in limbs of E. coqui embryos. The gene for microRNA(miR)-208 is contained in an intron of the E. coqui myh6 gene as in mammals, and miR -208 was detected as a microRNA, more highly expressed in a microarray of E. coqui limb buds, compared to Xenopus laevis limb buds. Myh6 is also expressed in several muscles of tadpoles and froglets of Xenopus tropicalis. These connections raise the possibility of an involvement of myh6 and miR-208 in the thyroid dependent metamorphosis of anurans.
Collapse
Affiliation(s)
- Kimberly Nath
- Department of Biological Sciences, Duquesne University, 600 Forbes Avenue, Pittsburgh, PA 15282, USA
| | | | | |
Collapse
|
27
|
Heavy and light roles: myosin in the morphogenesis of the heart. Cell Mol Life Sci 2012; 70:1221-39. [PMID: 22955375 PMCID: PMC3602621 DOI: 10.1007/s00018-012-1131-1] [Citation(s) in RCA: 136] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Revised: 08/08/2012] [Accepted: 08/13/2012] [Indexed: 01/10/2023]
Abstract
Myosin is an essential component of cardiac muscle, from the onset of cardiogenesis through to the adult heart. Although traditionally known for its role in energy transduction and force development, recent studies suggest that both myosin heavy-chain and myosin light-chain proteins are required for a correctly formed heart. Myosins are structural proteins that are not only expressed from early stages of heart development, but when mutated in humans they may give rise to congenital heart defects. This review will discuss the roles of myosin, specifically with regards to the developing heart. The expression of each myosin protein will be described, and the effects that altering expression has on the heart in embryogenesis in different animal models will be discussed. The human molecular genetics of the myosins will also be reviewed.
Collapse
|
28
|
Goenezen S, Rennie MY, Rugonyi S. Biomechanics of early cardiac development. Biomech Model Mechanobiol 2012; 11:1187-204. [PMID: 22760547 DOI: 10.1007/s10237-012-0414-7] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Accepted: 06/20/2012] [Indexed: 12/31/2022]
Abstract
Biomechanics affect early cardiac development, from looping to the development of chambers and valves. Hemodynamic forces are essential for proper cardiac development, and their disruption leads to congenital heart defects. A wealth of information already exists on early cardiac adaptations to hemodynamic loading, and new technologies, including high-resolution imaging modalities and computational modeling, are enabling a more thorough understanding of relationships between hemodynamics and cardiac development. Imaging and modeling approaches, used in combination with biological data on cell behavior and adaptation, are paving the road for new discoveries on links between biomechanics and biology and their effect on cardiac development and fetal programming.
Collapse
Affiliation(s)
- Sevan Goenezen
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR 97239, USA.
| | | | | |
Collapse
|
29
|
Formation, contraction, and mechanotransduction of myofribrils in cardiac development: clues from genetics. Biochem Res Int 2012; 2012:504906. [PMID: 22720160 PMCID: PMC3376475 DOI: 10.1155/2012/504906] [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: 01/20/2012] [Revised: 04/11/2012] [Accepted: 04/15/2012] [Indexed: 01/24/2023] Open
Abstract
Congenital heart disease (CHD) is the most common birth defect in humans. It is a leading infant mortality factor worldwide, caused by defective cardiac development. Mutations in transcription factors, signalling and structural molecules have been shown to contribute to the genetic component of CHD. Recently, mutations in genes encoding myofibrillar proteins expressed in the embryonic heart have also emerged as an important genetic causative factor of the disease, which implies that the contraction of the early heart primordium contributes to its morphogenesis. This notion is supported by increasing evidence suggesting that not only contraction but also formation, mechanosensing, and mechanotransduction of the cardiac myofibrillar proteins influence heart development. In this paper, we summarize the genetic clues supporting this idea.
Collapse
|
30
|
Granados-Riveron JT, Brook JD. The impact of mechanical forces in heart morphogenesis. ACTA ACUST UNITED AC 2012; 5:132-42. [PMID: 22337926 DOI: 10.1161/circgenetics.111.961086] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Javier T Granados-Riveron
- Institute of Genetics, School of Biology, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom.
| | | |
Collapse
|
31
|
Khokha MK. Xenopuswhite papers and resources: Folding functional genomics and genetics into the frog. Genesis 2012; 50:133-42. [DOI: 10.1002/dvg.22015] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 01/13/2012] [Accepted: 01/15/2012] [Indexed: 02/04/2023]
|
32
|
Abu-Daya A, Khokha MK, Zimmerman LB. The hitchhiker's guide to Xenopus genetics. Genesis 2012; 50:164-75. [PMID: 22344745 DOI: 10.1002/dvg.22007] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Revised: 12/19/2011] [Accepted: 12/23/2011] [Indexed: 01/12/2023]
Abstract
A decade after the human genome sequence, most vertebrate gene functions remain poorly understood, limiting benefits to human health from rapidly advancing genomic technologies. Systematic in vivo functional analysis is ideally suited to the experimentally accessible Xenopus embryo, which combines embryological accessibility with a broad range of transgenic, biochemical, and gain-of-function assays. The diploid X. tropicalis adds loss-of-function genetics and enhanced genomics to this repertoire. In the last decade, diverse phenotypes have been recovered from genetic screens, mutations have been cloned, and reverse genetics in the form of TILLING and targeted gene editing have been established. Simple haploid genetics and gynogenesis and the very large number of embryos produced streamline screening and mapping. Improved genomic resources and the revolution in high-throughput sequencing are transforming mutation cloning and reverse genetic approaches. The combination of loss-of-function mutant backgrounds with the diverse array of conventional Xenopus assays offers a uniquely flexible platform for analysis of gene function in vertebrate development.
Collapse
Affiliation(s)
- Anita Abu-Daya
- Division of Developmental Biology, MRC-National Institute for Medical Research, Mill Hill, London, United Kingdom
| | | | | |
Collapse
|
33
|
Abstract
The pipid frog Xenopus tropicalis has emerged as a powerful new model system for combining genetic and genomic analysis of tetrapod development with robust embryological, molecular, and biochemical assays. Its early development closely resembles that of its well-understood relative X. laevis, from which techniques and reagents can be readily transferred. In contrast to the tetraploid X. laevis, X. tropicalis has a compact diploid genome with strong synteny to those of amniotes. Recently, advances in high-throughput sequencing together with solution-hybridization whole-exome enrichment technology offer powerful strategies for cloning novel mutations as well as reverse genetic identification of sequence lesions in specific genes of interest. Further advantages include the wide range of functional and molecular assays available, the large number of embryos/meioses produced, and the ease of haploid genetics and gynogenesis. The addition of these genetic tools to X. tropicalis provides a uniquely flexible platform for analysis of gene function in vertebrate development.
Collapse
Affiliation(s)
- Timothy J. Geach
- National Institute for Medical Research, The Ridgeway, Mill Hill, London, NW7 1AA United Kingdom
| | | | - Lyle B. Zimmerman
- National Institute for Medical Research, The Ridgeway, Mill Hill, London, NW7 1AA United Kingdom
| |
Collapse
|
34
|
Abstract
Xenopus tropicalis combine the advantages of X. laevis, for example using explants and targeted gain of function, with the ability to take classical genetics approaches to answering cell and developmental biology questions making it arguably the most versatile of the model organisms. Against this background, husbandry of X. tropicalis is less well developed than for its larger, more robust relative. Here we describe the methods used to keep and breed these frogs successfully.
Collapse
Affiliation(s)
- Alan Jafkins
- European Xenopus Resource Centre, School of Biological Sciences, University of Portsmouth, Portsmouth, England, UK
| | | | | | | | | |
Collapse
|
35
|
Abstract
Xenopus tropicalis was introduced as a model system for genetic, and then genomic research, in the early 1990s, complementing work on the widely used model organism Xenopus laevis. Its shorter generation time and diploid genome has facilitated a number of experimental approaches. It has permitted multigenerational experiments (e.g., preparation of transgenic lines and generation of mutant lines) that have added powerful approaches for research by the Xenopus community. As a diploid animal, its simpler genome was sequenced before X. laevis, and has provided a highly valuable resource indispensable for all Xenopus researchers. As more sophisticated transgenic technologies for manipulating gene expression are developed, and mutations, particularly null mutations, are identified in widely studied genes involved in critical cellular and developmental processes, researchers will increasingly turn to X. tropicalis for definitive analysis of complex genetic pathways. This chapter describes the historical and conceptual development of X. tropicalis as a genetic and genomic model system for higher vertebrate development.
Collapse
Affiliation(s)
- Robert M Grainger
- Department of Biology, University of Virginia, Charlottesville, VA, USA.
| |
Collapse
|
36
|
Harland RM, Grainger RM. Xenopus research: metamorphosed by genetics and genomics. Trends Genet 2011; 27:507-15. [PMID: 21963197 PMCID: PMC3601910 DOI: 10.1016/j.tig.2011.08.003] [Citation(s) in RCA: 133] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Revised: 08/25/2011] [Accepted: 08/25/2011] [Indexed: 01/18/2023]
Abstract
Research using Xenopus takes advantage of large, abundant eggs and readily manipulated embryos in addition to conserved cellular, developmental and genomic organization with mammals. Research on Xenopus has defined key principles of gene regulation and signal transduction, embryonic induction, morphogenesis and patterning as well as cell cycle regulation. Genomic and genetic advances in this system, including the development of Xenopus tropicalis as a genetically tractable complement to the widely used Xenopus laevis, capitalize on the classical strengths and wealth of achievements. These attributes provide the tools to tackle the complex biological problems of the new century, including cellular reprogramming, organogenesis, regeneration, gene regulatory networks and protein interactions controlling growth and development, all of which provide insights into a multitude of human diseases and their potential treatments.
Collapse
Affiliation(s)
- Richard M Harland
- Department of Molecular and Cell Biology, Center for Integrative Genomics, University of California Berkeley, CA 94720, USA
| | | |
Collapse
|
37
|
Kaltenbrun E, Tandon P, Amin NM, Waldron L, Showell C, Conlon FL. Xenopus: An emerging model for studying congenital heart disease. ACTA ACUST UNITED AC 2011; 91:495-510. [PMID: 21538812 DOI: 10.1002/bdra.20793] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2010] [Revised: 01/18/2011] [Accepted: 01/28/2011] [Indexed: 02/02/2023]
Abstract
Congenital heart defects affect nearly 1% of all newborns and are a significant cause of infant death. Clinical studies have identified a number of congenital heart syndromes associated with mutations in genes that are involved in the complex process of cardiogenesis. The African clawed frog, Xenopus, has been instrumental in studies of vertebrate heart development and provides a valuable tool to investigate the molecular mechanisms underlying human congenital heart diseases. In this review, we discuss the methodologies that make Xenopus an ideal model system to investigate heart development and disease. We also outline congenital heart conditions linked to cardiac genes that have been well studied in Xenopus and describe some emerging technologies that will further aid in the study of these complex syndromes.
Collapse
Affiliation(s)
- Erin Kaltenbrun
- University of North Carolina McAllister Heart Institute, Chapel Hill, NC 27599, USA
| | | | | | | | | | | |
Collapse
|
38
|
Wells DE, Gutierrez L, Xu Z, Krylov V, Macha J, Blankenburg KP, Hitchens M, Bellot LJ, Spivey M, Stemple DL, Kowis A, Ye Y, Pasternak S, Owen J, Tran T, Slavikova R, Tumova L, Tlapakova T, Seifertova E, Scherer SE, Sater AK. A genetic map of Xenopus tropicalis. Dev Biol 2011; 354:1-8. [PMID: 21458440 PMCID: PMC3098391 DOI: 10.1016/j.ydbio.2011.03.022] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2010] [Revised: 03/05/2011] [Accepted: 03/11/2011] [Indexed: 01/22/2023]
Abstract
We present a genetic map for Xenopus tropicalis, consisting of 2886 Simple Sequence Length Polymorphism (SSLP) markers. Using a bioinformatics-based strategy, we identified unique SSLPs within the X. tropicalis genome. Scaffolds from X. tropicalis genome assembly 2.0 (JGI) were scanned for Simple Sequence Repeats (SSRs); unique SSRs were then tested for amplification and polymorphisms using DNA from inbred Nigerian and Ivory Coast individuals. Thus identified, the SSLPs were genotyped against a mapping cross panel of DNA samples from 190 F2 individuals. Nearly 4000 SSLPs were genotyped, yielding a 2886-marker genetic map consisting of 10 major linkage groups between 73 and 132cM in length, and 4 smaller linkage groups between 7 and 40cM. The total effective size of the map is 1658cM, and the average intermarker distance for each linkage group ranged from 0.27 to 0.75cM. Fluorescence In Situ Hybridization (FISH) was carried out using probes for genes located on mapped scaffolds to assign linkage groups to chromosomes. Comparisons of this map with the X. tropicalis genome Assembly 4.1 (JGI) indicate that the map provides representation of a minimum of 66% of the X. tropicalis genome, incorporating 758 of the approximately 1300 scaffolds over 100,000bp. The genetic map and SSLP marker database constitute an essential resource for genetic and genomic analyses in X. tropicalis.
Collapse
Affiliation(s)
- Dan E Wells
- Department of Biology and Biochemistry, University of Houston, 4800 Calhoun Rd., Houston TX 77204-5001, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Abstract
The diploid pipid frog Xenopus tropicalis has recently emerged as a powerful new model system for combining genetic and genomic analysis of tetrapod development with embryological and biochemical assays. Its early development closely resembles that of its well-understood tetraploid relative Xenopus laevis, from which techniques and reagents can be readily transferred, but its compact genome is highly syntenic with those of amniotes. Genetic approaches are facilitated by the large number of embryos produced and the ease of haploid genetics and gynogenesis.
Collapse
|
40
|
Granados-Riveron JT, Ghosh TK, Pope M, Bu'Lock F, Thornborough C, Eason J, Kirk EP, Fatkin D, Feneley MP, Harvey RP, Armour JAL, David Brook J. Alpha-cardiac myosin heavy chain (MYH6) mutations affecting myofibril formation are associated with congenital heart defects. Hum Mol Genet 2010; 19:4007-16. [PMID: 20656787 DOI: 10.1093/hmg/ddq315] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Congenital heart defects (CHD) are collectively the most common form of congenital malformation. Studies of human cases and animal models have revealed that mutations in several genes are responsible for both familial and sporadic forms of CHD. We have previously shown that a mutation in MYH6 can cause an autosomal dominant form of atrial septal defect (ASD), whereas others have identified mutations of the same gene in patients with hypertrophic and dilated cardiomyopathy. In the present study, we report a mutation analysis of MYH6 in patients with a wide spectrum of sporadic CHD. The mutation analysis of MYH6 was performed in DNA samples from 470 cases of isolated CHD using denaturing high-performance liquid chromatography and sequence analysis to detect point mutations and small deletions or insertions, and multiplex amplifiable probe hybridization to detect partial or complete copy number variations. One non-sense mutation, one splicing site mutation and seven non-synonymous coding mutations were identified. Transfection of plasmids encoding mutant and non-mutant green fluorescent protein-MYH6 fusion proteins in mouse myoblasts revealed that the mutations A230P and A1366D significantly disrupt myofibril formation, whereas the H252Q mutation significantly enhances myofibril assembly in comparison with the non-mutant protein. Our data indicate that functional variants of MYH6 are associated with cardiac malformations in addition to ASD and provide a novel potential mechanism. Such phenotypic heterogeneity has been observed in other genes mutated in CHD.
Collapse
Affiliation(s)
- Javier T Granados-Riveron
- Institute of Genetics, School of Biology, Queen’s Medical Centre, University of Nottingham, Nottingham, UK
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Geach TJ, Zimmerman LB. Paralysis and delayed Z-disc formation in the Xenopus tropicalis unc45b mutant dicky ticker. BMC DEVELOPMENTAL BIOLOGY 2010; 10:75. [PMID: 20637071 PMCID: PMC2919470 DOI: 10.1186/1471-213x-10-75] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2010] [Accepted: 07/16/2010] [Indexed: 11/10/2022]
Abstract
Background The protein components of mature skeletal muscle have largely been characterized, but the mechanics and sequence of their assembly during normal development remain an active field of study. Chaperone proteins specific to sarcomeric myosins have been shown to be necessary in zebrafish and invertebrates for proper muscle assembly and function. Results The Xenopus tropicalis mutation dicky ticker results in disrupted skeletal muscle myofibrillogenesis, paralysis, and lack of heartbeat, and maps to a missense mutation in the muscle-specific chaperone unc45b. Unc45b is known to be required for folding the head domains of myosin heavy chains, and mutant embryos fail to incorporate muscle myosin into sarcomeres. Mutants also show delayed polymerization of α-actinin-rich Z-bodies into the Z-disks that flank the myosin-containing A-band. Conclusions The dicky ticker phenotype confirms that a requirement for myosin-specific chaperones is conserved in tetrapod sarcomerogenesis, and also suggests a novel role for myosin chaperone function in Z-body maturation.
Collapse
Affiliation(s)
- Timothy J Geach
- Division of Developmental Biology, MRC-National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | | |
Collapse
|
42
|
Hellsten U, Harland RM, Gilchrist MJ, Hendrix D, Jurka J, Kapitonov V, Ovcharenko I, Putnam NH, Shu S, Taher L, Blitz IL, Blumberg B, Dichmann DS, Dubchak I, Amaya E, Detter JC, Fletcher R, Gerhard DS, Goodstein D, Graves T, Grigoriev IV, Grimwood J, Kawashima T, Lindquist E, Lucas SM, Mead PE, Mitros T, Ogino H, Ohta Y, Poliakov AV, Pollet N, Robert J, Salamov A, Sater AK, Schmutz J, Terry A, Vize PD, Warren WC, Wells D, Wills A, Wilson RK, Zimmerman LB, Zorn AM, Grainger R, Grammer T, Khokha MK, Richardson PM, Rokhsar DS. The genome of the Western clawed frog Xenopus tropicalis. Science 2010; 328:633-6. [PMID: 20431018 PMCID: PMC2994648 DOI: 10.1126/science.1183670] [Citation(s) in RCA: 589] [Impact Index Per Article: 42.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The western clawed frog Xenopus tropicalis is an important model for vertebrate development that combines experimental advantages of the African clawed frog Xenopus laevis with more tractable genetics. Here we present a draft genome sequence assembly of X. tropicalis. This genome encodes more than 20,000 protein-coding genes, including orthologs of at least 1700 human disease genes. Over 1 million expressed sequence tags validated the annotation. More than one-third of the genome consists of transposable elements, with unusually prevalent DNA transposons. Like that of other tetrapods, the genome of X. tropicalis contains gene deserts enriched for conserved noncoding elements. The genome exhibits substantial shared synteny with human and chicken over major parts of large chromosomes, broken by lineage-specific chromosome fusions and fissions, mainly in the mammalian lineage.
Collapse
Affiliation(s)
- Uffe Hellsten
- Department of Energy Joint Genome Institute, Walnut Creek, CA 94598, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|