1
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Xie S, Yang B, Li S, Ge L, Li M, Chen Q, Qing X, Zou J. Generation and application of a novel transgenic zebrafish line Tg(GAcyp1a:eGFP/Luc) as an in vivo assay to sensitive and specific monitoring of DLCs in the environment. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 264:115471. [PMID: 37729807 DOI: 10.1016/j.ecoenv.2023.115471] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 09/06/2023] [Accepted: 09/10/2023] [Indexed: 09/22/2023]
Abstract
CYP1A is the most commonly used biomarker and transgenic fish which carrying a cyp1a promoter to drive a reporter gene can be used as reliable way to monitor dioxin/dioxin-like compounds (DLCs) in the environment. Here, we cloned the cyp1a promoter of Gambusia affinis and this promoter showed stronger transcriptional activity than that of zebrafish. Then, a Tg(GAcyp1a:eGFP/Luc) transgenic zebrafish line was first constructed with the G. affinis cyp1a promoter driving eGFP expression using meganuclease I-SceI mediated transgenesis technology. The Tg(GAcyp1a:eGFP/Luc) larvae at 72 h post-fertilization (hpf) were tested by exposing to TCDD for 72 h, and induced GFP was mainly expressed in the liver with low background. The Tg(GAcyp1a:eGFP/Luc) zebrafish showed high sensitivity (limit of detection of 0.322 ng/L TCDD and 0.7 TEQ-ng/L PCDD/Fs) and specificity (insensitive to responses to PAHs and PCBs). In addition, the transgenic line showed a low detection concentration of the DLCs contaminated environmental samples (as low as 1.8 TEQ-ng/L), and the eGFP fluorescence intensity and the chemical-TEQ values were closely correlated. In conclusion, a sensitively and specifically transgenic zebrafish line was established to convenient and effective to detect DLCs in the environment.
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Affiliation(s)
- Shaolin Xie
- College of Marine Sciences, South China Agricultural University, Guangzhou, Guangdong 510642, China; Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou 510642, China
| | - Bing Yang
- College of Marine Sciences, South China Agricultural University, Guangzhou, Guangdong 510642, China; CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Siying Li
- College of Marine Sciences, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Liangjun Ge
- College of Marine Sciences, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Min Li
- College of Marine Sciences, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Qingshi Chen
- College of Marine Sciences, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Xian Qing
- South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510530, China.
| | - Jixing Zou
- College of Marine Sciences, South China Agricultural University, Guangzhou, Guangdong 510642, China; Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou 510642, China.
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2
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Choe CP, Choi SY, Kee Y, Kim MJ, Kim SH, Lee Y, Park HC, Ro H. Transgenic fluorescent zebrafish lines that have revolutionized biomedical research. Lab Anim Res 2021; 37:26. [PMID: 34496973 PMCID: PMC8424172 DOI: 10.1186/s42826-021-00103-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 08/26/2021] [Indexed: 12/22/2022] Open
Abstract
Since its debut in the biomedical research fields in 1981, zebrafish have been used as a vertebrate model organism in more than 40,000 biomedical research studies. Especially useful are zebrafish lines expressing fluorescent proteins in a molecule, intracellular organelle, cell or tissue specific manner because they allow the visualization and tracking of molecules, intracellular organelles, cells or tissues of interest in real time and in vivo. In this review, we summarize representative transgenic fluorescent zebrafish lines that have revolutionized biomedical research on signal transduction, the craniofacial skeletal system, the hematopoietic system, the nervous system, the urogenital system, the digestive system and intracellular organelles.
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Affiliation(s)
- Chong Pyo Choe
- Division of Life Science, Gyeongsang National University, Jinju, 52828, Republic of Korea.,Division of Applied Life Science, Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, 52828, Republic of Korea
| | - Seok-Yong Choi
- Department of Biomedical Sciences, Chonnam National University Medical School, Hwasun, 58128, Republic of Korea
| | - Yun Kee
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, Republic of Korea.
| | - Min Jung Kim
- Department of Biological Sciences, Sookmyung Women's University, Seoul, 04310, Republic of Korea
| | - Seok-Hyung Kim
- Department of Marine Life Sciences and Fish Vaccine Research Center, Jeju National University, Jeju, 63243, Republic of Korea
| | - Yoonsung Lee
- Center for Genomic Integrity, Institute for Basic Science (IBS), Ulsan, 44919, Republic of Korea
| | - Hae-Chul Park
- Department of Biomedical Sciences, College of Medicine, Korea University, Ansan, 15355, Republic of Korea
| | - Hyunju Ro
- Department of Biological Sciences, College of Bioscience and Biotechnology, Chungnam National University, Daejeon, 34134, Republic of Korea
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3
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Li C, Zhang Y, Ge Y, Qiu B, Zhang D, Wang X, Liu W, Tao H. Comparative transcriptome and microbiota analyses provide new insights into the adverse effects of industrial trans fatty acids on the small intestine of C57BL/6 mice. Eur J Nutr 2020; 60:975-987. [PMID: 32564148 DOI: 10.1007/s00394-020-02297-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 06/04/2020] [Indexed: 12/25/2022]
Abstract
PURPOSE To reveal the mechanism that links industrial trans fatty acids (iTFAs) to various chronic diseases, we examined the impact of iTFAs on the local microenvironment of the small intestine (duodenum, jejunum and ileum). METHODS Forty male 8-week-old mice were fed diets containing one of the following: (1) low soybean oil (LS); (2) high soybean oil (HS); (3) low partially hydrogenated oil (LH), and (4) high partially hydrogenated oil (HH). The analysis of microbiota from small intestinal content was performed by real-time qPCR. The fatty acid composition of small intestine mucosa was measured by GC/MS, and comparative transcriptome of the small intestinal mucosa was analyzed by RNA-sequencing. RESULTS The intake of iTFAs changed the fatty acid spectrum of the small intestine mucosa, especially the excessive accumulation of iTFA (mainly elaidic acid). For microbiota, the relative abundance of δ- and γ-proteobacteria, Lactobacillus, Desulfovibrio, Peptostreptococcus and Turicibacter were significantly different in the iTFA diet groups compared to the control group. Based on the identification of differently expressed genes(DEGs) and pathway annotation, comparative transcriptome analysis of the small intestine mucosa revealed obvious overexpression of genes involved in the extracellular matrix (ECM)-receptor interaction and the peroxisome proliferator-activated receptor signaling pathway, which suggests that ECM remodeling and abnormal lipid metabolism may have occurred with iTFA ingestion. CONCLUSION Our research demonstrated multiple adverse effects of iTFA that may have originated from the small intestine. This finding could be to facilitate the development of new strategies to suppress iTFA-related diseases by reversing the adverse effects of iTFA on intestinal health.
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Affiliation(s)
- Can Li
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan, 250353, China
| | - Yuhan Zhang
- Institute of Agro-Food Science and Technology, Shandong Academy of Agricultural Sciences, Jinan, 250100, China.,College of Life Science, Shandong Normal University, Jinan, 250014, China
| | - Yueting Ge
- Institute of Agro-Food Science and Technology, Shandong Academy of Agricultural Sciences, Jinan, 250100, China
| | - Bin Qiu
- Institute of Agro-Food Science and Technology, Shandong Academy of Agricultural Sciences, Jinan, 250100, China
| | - Di Zhang
- Qilu Hospital, Shandong University, Jinan, 250012, China
| | - Xianshu Wang
- Institute of Agro-Food Science and Technology, Shandong Academy of Agricultural Sciences, Jinan, 250100, China
| | - Wei Liu
- Institute of Agro-Food Science and Technology, Shandong Academy of Agricultural Sciences, Jinan, 250100, China.
| | - Haiteng Tao
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan, 250353, China.
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4
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Tay SS, Kuah MK, Shu-Chien AC. Transcriptional activation of zebrafish fads2 promoter and its transient transgene expression in yolk syncytial layer of zebrafish embryos. Sci Rep 2018; 8:3874. [PMID: 29497119 PMCID: PMC5832746 DOI: 10.1038/s41598-018-22157-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 02/16/2018] [Indexed: 12/12/2022] Open
Abstract
The front-end desaturases (Fads) are rate-limiting enzymes responsible for production of long-chain polyunsaturated fatty acids (LC-PUFA). The full spectrum of the transcriptional regulation of fads is still incomplete, as cloning of fads promoter is limited to a few species. Here, we described the cloning and characterisation of the zebrafish fads2 promoter. Using 5'-deletion and mutation analysis on this promoter, we identified a specific region containing the sterol regulatory element (SRE) which is responsible for the activation of the fads2 promoter. In tandem, two conserved CCAAT boxes were also present adjacent to the SRE and mutation of either of these binding sites attenuates the transcriptional activation of the fads2 promoter. An in vivo analysis employing GFP reporter gene in transiently transfected zebrafish embryos showed that this 1754 bp upstream region of the fads2 gene specifically directs GFP expression in the yolk syncytial layer (YSL) region. This indicates a role for LC-PUFA in the transport of yolk lipids through this tissue layer. In conclusion, besides identifying novel core elements for transcriptional activation in zebrafish fads2 promoter, we also reveal a potential role for fads2 or LC-PUFA in YSL during development.
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Affiliation(s)
- Shu-Shen Tay
- School of Biological Sciences, Universiti Sains Malaysia, 11800, Minden, Penang, Malaysia
| | - Meng-Kiat Kuah
- Centre for Chemical Biology, Universiti Sains Malaysia, Sains@USM, Block B No. 10, Persiaran Bukit Jambul, 11900, Bayan Lepas, Penang, Malaysia
| | - Alexander Chong Shu-Chien
- School of Biological Sciences, Universiti Sains Malaysia, 11800, Minden, Penang, Malaysia. .,Centre for Chemical Biology, Universiti Sains Malaysia, Sains@USM, Block B No. 10, Persiaran Bukit Jambul, 11900, Bayan Lepas, Penang, Malaysia.
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5
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Troll JV, Hamilton MK, Abel ML, Ganz J, Bates JM, Stephens WZ, Melancon E, van der Vaart M, Meijer AH, Distel M, Eisen JS, Guillemin K. Microbiota promote secretory cell determination in the intestinal epithelium by modulating host Notch signaling. Development 2018; 145:145/4/dev155317. [PMID: 29475973 DOI: 10.1242/dev.155317] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 01/19/2018] [Indexed: 12/15/2022]
Abstract
Resident microbes promote many aspects of host development, although the mechanisms by which microbiota influence host tissues remain unclear. We showed previously that the microbiota is required for allocation of appropriate numbers of secretory cells in the zebrafish intestinal epithelium. Because Notch signaling is crucial for secretory fate determination, we conducted epistasis experiments to establish whether the microbiota modulates host Notch signaling. We also investigated whether innate immune signaling transduces microbiota cues via the Myd88 adaptor protein. We provide the first evidence that microbiota-induced, Myd88-dependent signaling inhibits host Notch signaling in the intestinal epithelium, thereby promoting secretory cell fate determination. These results connect microbiota activity via innate immune signaling to the Notch pathway, which also plays crucial roles in intestinal homeostasis throughout life and when impaired can result in chronic inflammation and cancer.
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Affiliation(s)
- Joshua V Troll
- Institute of Molecular Biology, Department of Biology, 1229 University of Oregon, Eugene, OR 97403, USA
| | - M Kristina Hamilton
- Institute of Neuroscience, Department of Biology, 1254 University of Oregon, Eugene, OR 97403, USA
| | - Melissa L Abel
- Institute of Molecular Biology, Department of Biology, 1229 University of Oregon, Eugene, OR 97403, USA
| | - Julia Ganz
- Institute of Neuroscience, Department of Biology, 1254 University of Oregon, Eugene, OR 97403, USA
| | - Jennifer M Bates
- Institute of Molecular Biology, Department of Biology, 1229 University of Oregon, Eugene, OR 97403, USA
| | - W Zac Stephens
- Institute of Molecular Biology, Department of Biology, 1229 University of Oregon, Eugene, OR 97403, USA
| | - Ellie Melancon
- Institute of Neuroscience, Department of Biology, 1254 University of Oregon, Eugene, OR 97403, USA
| | | | - Annemarie H Meijer
- Institute of Biology, Leiden University, 2300 RA Leiden, The Netherlands
| | - Martin Distel
- Children's Cancer Research Institute, 1090 Vienna, Austria
| | - Judith S Eisen
- Institute of Neuroscience, Department of Biology, 1254 University of Oregon, Eugene, OR 97403, USA
| | - Karen Guillemin
- Institute of Molecular Biology, Department of Biology, 1229 University of Oregon, Eugene, OR 97403, USA .,Humans and the Microbiome Program, Canadian Institute for Advanced Research, Toronto, Ontario, Canada M5G 1Z8
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6
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Innovative Disease Model: Zebrafish as an In Vivo Platform for Intestinal Disorder and Tumors. Biomedicines 2017; 5:biomedicines5040058. [PMID: 28961226 PMCID: PMC5744082 DOI: 10.3390/biomedicines5040058] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 09/26/2017] [Accepted: 09/29/2017] [Indexed: 12/12/2022] Open
Abstract
Colorectal cancer (CRC) is one of the world’s most common cancers and is the second leading cause of cancer deaths, causing more than 50,000 estimated deaths each year. Several risk factors are highly associated with CRC, including being overweight, eating a diet high in red meat and over-processed meat, having a history of inflammatory bowel disease, and smoking. Previous zebrafish studies have demonstrated that multiple oncogenes and tumor suppressor genes can be regulated through genetic or epigenetic alterations. Zebrafish research has also revealed that the activation of carcinogenesis-associated signal pathways plays an important role in CRC. The biology of cancer, intestinal disorders caused by carcinogens, and the morphological patterns of tumors have been found to be highly similar between zebrafish and humans. Therefore, the zebrafish has become an important animal model for translational medical research. Several zebrafish models have been developed to elucidate the characteristics of gastrointestinal diseases. This review article focuses on zebrafish models that have been used to study human intestinal disorders and tumors, including models involving mutant and transgenic fish. We also report on xenograft models and chemically-induced enterocolitis. This review demonstrates that excellent zebrafish models can provide novel insights into the pathogenesis of gastrointestinal diseases and help facilitate the evaluation of novel anti-tumor drugs.
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7
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Venkatachalam AB, Parmar MB, Wright JM. Evolution of the duplicated intracellular lipid-binding protein genes of teleost fishes. Mol Genet Genomics 2017; 292:699-727. [PMID: 28389698 DOI: 10.1007/s00438-017-1313-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 02/15/2017] [Indexed: 12/18/2022]
Abstract
Increasing organismal complexity during the evolution of life has been attributed to the duplication of genes and entire genomes. More recently, theoretical models have been proposed that postulate the fate of duplicated genes, among them the duplication-degeneration-complementation (DDC) model. In the DDC model, the common fate of a duplicated gene is lost from the genome owing to nonfunctionalization. Duplicated genes are retained in the genome either by subfunctionalization, where the functions of the ancestral gene are sub-divided between the sister duplicate genes, or by neofunctionalization, where one of the duplicate genes acquires a new function. Both processes occur either by loss or gain of regulatory elements in the promoters of duplicated genes. Here, we review the genomic organization, evolution, and transcriptional regulation of the multigene family of intracellular lipid-binding protein (iLBP) genes from teleost fishes. Teleost fishes possess many copies of iLBP genes owing to a whole genome duplication (WGD) early in the teleost fish radiation. Moreover, the retention of duplicated iLBP genes is substantially higher than the retention of all other genes duplicated in the teleost genome. The fatty acid-binding protein genes, a subfamily of the iLBP multigene family in zebrafish, are differentially regulated by peroxisome proliferator-activated receptor (PPAR) isoforms, which may account for the retention of iLBP genes in the zebrafish genome by the process of subfunctionalization of cis-acting regulatory elements in iLBP gene promoters.
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Affiliation(s)
- Ananda B Venkatachalam
- Department of Biology, Dalhousie University, 1355 Oxford Street, PO BOX 15000, Halifax, NS, B3H 4R2, Canada
| | - Manoj B Parmar
- Department of Biology, Dalhousie University, 1355 Oxford Street, PO BOX 15000, Halifax, NS, B3H 4R2, Canada
| | - Jonathan M Wright
- Department of Biology, Dalhousie University, 1355 Oxford Street, PO BOX 15000, Halifax, NS, B3H 4R2, Canada.
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8
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You MS, Jiang YJ, Yuh CH, Wang CM, Tang CH, Chuang YJ, Lin BH, Wu JL, Hwang SPL. A Sketch of the Taiwan Zebrafish Core Facility. Zebrafish 2016; 13 Suppl 1:S24-9. [PMID: 27267235 DOI: 10.1089/zeb.2015.1208] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
In the past three decades, the number of zebrafish laboratories has significantly increased in Taiwan. The Taiwan Zebrafish Core Facility (TZCF), a government-funded core facility, was launched to serve this growing community. The Core Facility was built on two sites, one located at the National Health Research Institutes (NHRI, called Taiwan Zebrafish Core Facility at NHRI or TZeNH) and the other is located at the Academia Sinica (Taiwan Zebrafish Core Facility at AS a.k.a. TZCAS). The total surface area of the TZCF is about 180 m(2) encompassing 2880 fish tanks. Each site has a separate quarantine room and centralized water recirculating systems, monitoring key water parameters. To prevent diseases, three main strategies have been implemented: (1) imported fish must be quarantined; (2) only bleached embryos are introduced into the main facilities; and (3) working practices were implemented to minimize pathogen transfer between stocks and facilities. Currently, there is no health program in place; however, a fourth measure for the health program, specific regular pathogen tests, is being planned. In March 2015, the TZCF at NHRI has been AAALAC accredited. It is our goal to ensure that we provide "disease-free" fish and embryos to the Taiwanese research community.
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Affiliation(s)
- May-Su You
- 1 Institute of Molecular and Genomic Medicine, National Health Research Institutes , Miaoli, Taiwan
| | - Yun-Jin Jiang
- 1 Institute of Molecular and Genomic Medicine, National Health Research Institutes , Miaoli, Taiwan
| | - Chiou-Hwa Yuh
- 1 Institute of Molecular and Genomic Medicine, National Health Research Institutes , Miaoli, Taiwan
| | - Chien-Ming Wang
- 1 Institute of Molecular and Genomic Medicine, National Health Research Institutes , Miaoli, Taiwan
| | - Chih-Hao Tang
- 1 Institute of Molecular and Genomic Medicine, National Health Research Institutes , Miaoli, Taiwan
| | - Yung-Jen Chuang
- 2 Department of Medical Science, National Tsing Hua University , Hsinchu, Taiwan
| | - Bo-Hung Lin
- 3 Institute of Cellular and Organismic Biology , Academia Sinica, Taipei, Taiwan
| | - Jen-Leih Wu
- 3 Institute of Cellular and Organismic Biology , Academia Sinica, Taipei, Taiwan
| | - Sheng-Ping L Hwang
- 3 Institute of Cellular and Organismic Biology , Academia Sinica, Taipei, Taiwan
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9
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Esteves A, Knoll-Gellida A, Canclini L, Silvarrey MC, André M, Babin PJ. Fatty acid binding proteins have the potential to channel dietary fatty acids into enterocyte nuclei. J Lipid Res 2015; 57:219-32. [PMID: 26658423 DOI: 10.1194/jlr.m062232] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Indexed: 12/13/2022] Open
Abstract
Intracellular lipid binding proteins, including fatty acid binding proteins (FABPs) 1 and 2, are highly expressed in tissues involved in the active lipid metabolism. A zebrafish model was used to demonstrate differential expression levels of fabp1b.1, fabp1b.2, and fabp2 transcripts in liver, anterior intestine, and brain. Transcription levels of fabp1b.1 and fabp2 in the anterior intestine were upregulated after feeding and modulated according to diet formulation. Immunofluorescence and electron microscopy immunodetection with gold particles localized these FABPs in the microvilli, cytosol, and nuclei of most enterocytes in the anterior intestinal mucosa. Nuclear localization was mostly in the interchromatin space outside the condensed chromatin clusters. Native PAGE binding assay of BODIPY-FL-labeled FAs demonstrated binding of BODIPY-FLC(12) but not BODIPY-FLC(5) to recombinant Fabp1b.1 and Fabp2. The binding of BODIPY-FLC(12) to Fabp1b.1 was fully displaced by oleic acid. In vivo experiments demonstrated, for the first time, that intestinal absorption of dietary BODIPY-FLC(12) was followed by colocalization of the labeled FA with Fabp1b and Fabp2 in the nuclei. These data suggest that dietary FAs complexed with FABPs are able to reach the enterocyte nucleus with the potential to modulate nuclear activity.
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Affiliation(s)
- Adriana Esteves
- Facultad de Ciencias, Universidad de la República, 11400 Montevideo, Uruguay
| | - Anja Knoll-Gellida
- University Bordeaux, Maladies Rares: Génétique et Métabolisme (MRGM), F-33615 Pessac, France INSERM, U1211, F-33076, Bordeaux, France
| | - Lucia Canclini
- Facultad de Ciencias, Universidad de la República, 11400 Montevideo, Uruguay
| | | | - Michèle André
- University Bordeaux, Maladies Rares: Génétique et Métabolisme (MRGM), F-33615 Pessac, France INSERM, U1211, F-33076, Bordeaux, France
| | - Patrick J Babin
- University Bordeaux, Maladies Rares: Génétique et Métabolisme (MRGM), F-33615 Pessac, France INSERM, U1211, F-33076, Bordeaux, France
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10
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Cruz-Garcia L, Schlegel A. Lxr-driven enterocyte lipid droplet formation delays transport of ingested lipids. J Lipid Res 2014; 55:1944-58. [PMID: 25030662 DOI: 10.1194/jlr.m052845] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Liver X receptors (Lxrs) are master regulators of cholesterol catabolism, driving the elimination of cholesterol from the periphery to the lumen of the intestine. Development of pharmacological agents to activate Lxrs has been hindered by synthetic Lxr agonists' induction of hepatic lipogenesis and hypertriglyceridemia. Elucidating the function of Lxrs in regulating enterocyte lipid handling might identify novel aspects of lipid metabolism that are pharmacologically amenable. We took a genetic approach centered on the single Lxr gene nr1h3 in zebrafish to study the role of Lxr in enterocyte lipid metabolism. Loss of nr1h3 function causes anticipated gene regulatory changes and cholesterol intolerance, collectively reflecting high evolutionary conservation of zebrafish Lxra function. Intestinal nr1h3 activation delays transport of absorbed neutral lipids, with accumulation of neutral lipids in enterocyte cytoplasmic droplets. This delay in transport of ingested neutral lipids protects animals from hypercholesterolemia and hepatic steatosis induced by a high-fat diet. On a gene regulatory level, Lxra induces expression of acsl3a, which encodes acyl-CoA synthetase long-chain family member 3a, a lipid droplet-anchored protein that directs fatty acyl chains into lipids. Forced overexpression of acls3a in enterocytes delays, in part, the appearance of neutral lipids in the vasculature of zebrafish larvae. Activation of Lxr in the intestine cell-autonomously regulates the rate of delivery of absorbed lipids by inducting a temporary lipid intestinal droplet storage depot.
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Affiliation(s)
- Lourdes Cruz-Garcia
- University of Utah Molecular Medicine (U2M2) Program,University of Utah, Salt Lake City, UT 84112 Department of Internal Medicine, Division of Endocrinology, Metabolism, and Diabetes,University of Utah, Salt Lake City, UT 84112
| | - Amnon Schlegel
- University of Utah Molecular Medicine (U2M2) Program,University of Utah, Salt Lake City, UT 84112 Department of Internal Medicine, Division of Endocrinology, Metabolism, and Diabetes,University of Utah, Salt Lake City, UT 84112 Department of Biochemistry, School of Medicine, University of Utah, Salt Lake City, UT 84112
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11
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Hsu CC, Pai WY, Lai CY, Lu MW, Her GM. Genetic characterization and in vivo image analysis of novel zebrafish Danio rerio pigment mutants. JOURNAL OF FISH BIOLOGY 2013; 82:1671-1683. [PMID: 23639161 DOI: 10.1111/jfb.12109] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2012] [Accepted: 02/19/2013] [Indexed: 06/02/2023]
Abstract
This study reports the isolation and characterization of a new type of transparent zebrafish Danio rerio mutant called pinky (pk), which has been visually isolated from a spontaneous mutation in a D. rerio colony. The pk larvae possess complex mutations affecting pigmentation because of missing pigment cells or a dramatic reduction in the chromatophore number. The pk displays a totally colourless phenotype and adult body transplant with no other obvious external morphological abnormalities, except for a red retina. The molecular analysis results in several candidate genes, hps1, ap3m2 and rabggta, implicated in the Hermansky-Pudlak syndrome (HPS) genes associated with HPS in pk. To demonstrate its applications of deep-tissue imaging, this study examines green fluorescent protein alone or with other fluorescent proteins to investigate their capability for using multilabelling purposes in live adult pk. In this study, pk is particularly valuable for tissue cell labelling and internal organogenesis studies because of its optical clarity in the adult body.
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Affiliation(s)
- C C Hsu
- Department of Radiology, Buddhist Tzu Chi General Hospital, Taichung Branch, No. 66, Sec. 1, Fongsing Rd, Tanzih Township, Taichung County 427, Taiwan
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12
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Xia JH, Lin G, He X, Liu P, Liu F, Sun F, Tu R, Yue GH. Whole genome scanning and association mapping identified a significant association between growth and a SNP in the IFABP-a gene of the Asian seabass. BMC Genomics 2013; 14:295. [PMID: 23634810 PMCID: PMC3653795 DOI: 10.1186/1471-2164-14-295] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Accepted: 04/25/2013] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Aquaculture is the quickest growing sector in agriculture. However, QTL for important traits have been only identified in a few aquaculture species. We conducted QTL mapping for growth traits in an Asian seabass F(2) family with 359 individuals using 123 microsatellites and 22 SNPs, and performed association mapping in four populations with 881 individuals. RESULTS Twelve and nine significant QTL, as well as 14 and 10 suggestive QTL were detected for growth traits at six and nine months post hatch, respectively. These QTL explained 0.9-12.0% of the phenotypic variance. For body weight, two QTL intervals at two stages were overlapped while the others were mapped onto different positions. The IFABP-a gene located in a significant QTL interval for growth on LG5 was cloned and characterized. A SNP in exon 3 of the gene was significantly associated with growth traits in different populations. CONCLUSIONS The results of QTL mapping for growth traits suggest that growth at different stages was controlled by some common QTL and some different QTL. Positional candidate genes and association mapping suggest that the IFABP-a is a strong candidate gene for growth. Our data supply a basis for fine mapping QTL, marker-assisted selection and further detailed analysis of the functions of the IFABP-a gene in fish growth.
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Affiliation(s)
- Jun Hong Xia
- Molecular Population Genetics Group, Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, 117604 Singapore, Singapore
| | - Grace Lin
- Molecular Population Genetics Group, Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, 117604 Singapore, Singapore
| | - Xiaoping He
- Molecular Population Genetics Group, Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, 117604 Singapore, Singapore
| | - Peng Liu
- Molecular Population Genetics Group, Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, 117604 Singapore, Singapore
| | - Feng Liu
- Molecular Population Genetics Group, Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, 117604 Singapore, Singapore
| | - Fei Sun
- Molecular Population Genetics Group, Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, 117604 Singapore, Singapore
| | - Rongjian Tu
- Molecular Population Genetics Group, Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, 117604 Singapore, Singapore
| | - Gen Hua Yue
- Molecular Population Genetics Group, Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, 117604 Singapore, Singapore
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Venkatachalam AB, Sawler DL, Wright JM. Tissue-specific transcriptional modulation of fatty acid-binding protein genes, fabp2, fabp3 and fabp6, by fatty acids and the peroxisome proliferator, clofibrate, in zebrafish (Danio rerio). Gene 2013; 520:14-21. [PMID: 23466978 DOI: 10.1016/j.gene.2013.02.034] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Revised: 02/19/2013] [Accepted: 02/21/2013] [Indexed: 12/28/2022]
Abstract
All fabp genes, except fabp2, fabp3 and fabp6, exist as duplicates in the zebrafish genome owing to a whole genome duplication event ~230-400 million years ago. Transcription of some duplicated fabp genes is modulated by fatty acids (FAs) and/or clofibrate, a peroxisome proliferator-activated receptor (PPAR) agonist. We had also shown previously that the steady-state level of acyl-CoA oxidase 1 (acox1) mRNA, a marker of PPARα activation, was elevated in liver, intestine, heart and muscle of fish fed clofibrate demonstrating that zebrafish, unlike some fishes, is responsive to this drug. acox1 transcripts were not induced in the brain of fish fed clofibrate, which suggests this drug may not cross the blood brain barrier. Here, we investigated the effect of dietary FAs and clofibrate on the transcription of single copy fabp genes, fabp2, fabp3 and fabp6, in five tissues of inbred zebrafish. The steady-state level of fabp2 transcripts increased in intestine, while fabp3 mRNA increased in liver of fish fed diets differing in FA content. In fish fed clofibrate, fabp3 mRNA in intestine, and fabp6 mRNA in intestine and heart, were elevated. Based on these findings, modulation of fabp2, fabp3 and fabp6 transcription by FAs and/or clofibrate in zebrafish implicates control of these genes by PPAR interaction with peroxisome proliferator response elements (PPRE) most likely in fabp promoters. Moreover, transcriptional induction of these fabp genes by dietary FAs and/or clofibrate is over-ridden by a tissue-specific mechanism(s), e.g., transcriptional activator or repressor proteins.
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Venkatachalam AB, Lall SP, Denovan-Wright EM, Wright JM. Tissue-specific differential induction of duplicated fatty acid-binding protein genes by the peroxisome proliferator, clofibrate, in zebrafish (Danio rerio). BMC Evol Biol 2012; 12:112. [PMID: 22776158 PMCID: PMC3483278 DOI: 10.1186/1471-2148-12-112] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2012] [Accepted: 05/31/2012] [Indexed: 01/03/2023] Open
Abstract
Background Force, Lynch and Conery proposed the duplication-degeneration-complementation (DDC) model in which partitioning of ancestral functions (subfunctionalization) and acquisition of novel functions (neofunctionalization) were the two primary mechanisms for the retention of duplicated genes. The DDC model was tested by analyzing the transcriptional induction of the duplicated fatty acid-binding protein (fabp) genes by clofibrate in zebrafish. Clofibrate is a specific ligand of the peroxisome proliferator-activated receptor (PPAR); it activates PPAR which then binds to a peroxisome proliferator response element (PPRE) to induce the transcriptional initiation of genes primarily involved in lipid homeostasis. Zebrafish was chosen as our model organism as it has many duplicated genes owing to a whole genome duplication (WGD) event that occurred ~230-400 million years ago in the teleost fish lineage. We assayed the steady-state levels of fabp mRNA and heterogeneous nuclear RNA (hnRNA) transcripts in liver, intestine, muscle, brain and heart for four sets of duplicated fabp genes, fabp1a/fabp1b.1/fabp1b.2, fabp7a/fabp7b, fabp10a/fabp10b and fabp11a/fabp11b in zebrafish fed different concentrations of clofibrate. Result Electron microscopy showed an increase in the number of peroxisomes and mitochondria in liver and heart, respectively, in zebrafish fed clofibrate. Clofibrate also increased the steady-state level of acox1 mRNA and hnRNA transcripts in different tissues, a gene with a functional PPRE. These results demonstrate that zebrafish is responsive to clofibrate, unlike some other fishes. The levels of fabp mRNA and hnRNA transcripts for the four sets of duplicated fabp genes was determined by reverse transcription, quantitative polymerase chain reaction (RT-qPCR). The level of hnRNA coded by a gene is an indirect estimate of the rate of transcriptional initiation of that gene. Clofibrate increased the steady-state level of fabp mRNAs and hnRNAs for both the duplicated copies of fabp1a/fabp1b.1, and fabp7a/fabp7b, but in different tissues. Clofibrate also increased the steady-state level of fabp10a and fabp11a mRNAs and hnRNAs in liver, but not for fabp10b and fabp11b. Conclusion Some duplicated fabp genes have, most likely, retained PPREs, but induction by clofibrate is over-ridden by an, as yet, unknown tissue-specific mechanism(s). Regardless of the tissue-specific mechanism(s), transcriptional control of duplicated zebrafish fabp genes by clofibrate has markedly diverged since the WGD event.
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Abstract
The zebrafish provides an ideal model for the study of vertebrate organogenesis, including the formation of the digestive tract and its associated organs. Despite optical transparency of embryos, the internal position of the developing digestive system and its close juxtaposition with the yolk initially made morphological analysis relatively challenging, particularly during the first 3 d of development. However, methodologies have been successfully developed to address these problems and comprehensive morphologic analysis of the developing digestive system has now been achieved using a combination of light and fluorescence microscope approaches-including confocal analysis-to visualize wholemount and histological preparations of zebrafish embryos. Furthermore, the expanding number of antibodies that cross-react with zebrafish proteins and the generation of tissue-specific transgenic green fluorescent protein reporter lines that mark specific cell and tissue compartments have greatly enhanced our ability to successfully image the developing zebrafish digestive system.
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Affiliation(s)
- Andrew J Trotter
- Colon Molecular and Cell Biology Laboratory, Ludwig Institute for Cancer Research, Royal Melbourne Hospital, Parkville, VIC, Australia
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17
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Selected papers on zebrafish and other aquarium fish models. Zebrafish 2008; 1:165-72. [PMID: 18248227 DOI: 10.1089/zeb.2004.1.165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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18
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Belaguli NS, Zhang M, Rigi M, Aftab M, Berger DH. Cooperation between GATA4 and TGF-beta signaling regulates intestinal epithelial gene expression. Am J Physiol Gastrointest Liver Physiol 2007; 292:G1520-33. [PMID: 17290010 DOI: 10.1152/ajpgi.00236.2006] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Members of the transforming growth factor-beta (TGF-beta) family have been shown to play an important role in the regulation of gut epithelial gene expression. We have used the intestinal alkaline phosphatase (IAP) and intestinal fatty acid binding protein (IFABP) promoters to dissect the mechanisms by which TGF-beta1 signaling regulates gut epithelial gene expression. TGF-beta signaling alone was not sufficient for activation of IAP and IFABP promoters. However, TGF-beta signaling cooperated with the gut epithelial transcription factor GATA4 to synergistically activate IAP and IFABP promoters. Coexpression of GATA4 along with the TGF-beta1 signal transducing downstream effectors such as Smad2, 3, and 4 resulted in synergistic activation of both IAP and IFABP promoters. This synergistic activation was reduced by simultaneous expression of dominant-negative Smad4. -40 and -89 GATA binding sites in the IFABP promoter were required for the synergistic activation by Smad2, 3, and 4 and GATA4. GATA4 and Smad2, 3, and 4 physically associated with each other and this interaction was mediated through the MH2 domain of Smad2, 3, and 4 and the second zinc finger and the COOH-terminal basic domain of GATA4. The COOH-terminal activation domain and the Smad-interacting second zinc finger domain of GATA4 were required for the synergistic activation of the IFABP promoter. Naturally occurring oncogenic mutations within the GATA4-interacting MH2 domain of Smad2 reduced the coactivation of IFABP promoter by Smad2 and GATA4. Our results suggest that the TGF-beta signaling regulates gut epithelial gene expression by targeting GATA4.
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MESH Headings
- Activin Receptors, Type I/metabolism
- Alkaline Phosphatase
- Animals
- Antigens, Neoplasm/genetics
- Antigens, Neoplasm/metabolism
- Epithelial Cells/metabolism
- Epithelial Cells/pathology
- Fatty Acid-Binding Proteins/genetics
- Fatty Acid-Binding Proteins/metabolism
- GATA4 Transcription Factor/chemistry
- GATA4 Transcription Factor/genetics
- GATA4 Transcription Factor/metabolism
- GPI-Linked Proteins
- Gene Expression
- Genes, Reporter
- HCT116 Cells
- Haplorhini
- Humans
- Intestinal Mucosa/metabolism
- Intestinal Mucosa/pathology
- Luciferases
- Mutation
- Promoter Regions, Genetic
- Protein Binding
- Protein Serine-Threonine Kinases
- Protein Structure, Tertiary
- RNA Interference
- RNA, Small Interfering/genetics
- RNA, Small Interfering/metabolism
- Receptor, Transforming Growth Factor-beta Type I
- Receptors, Transforming Growth Factor beta/metabolism
- Signal Transduction/genetics
- Smad2 Protein/metabolism
- Smad3 Protein/metabolism
- Smad4 Protein/metabolism
- Transfection
- Transforming Growth Factor beta1/genetics
- Transforming Growth Factor beta1/metabolism
- Zinc Fingers
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Affiliation(s)
- Narasimhaswamy S Belaguli
- Michael E. DeBakey Dept. of Surgery, Michael E. DeBakey VA Medical Center, Baylor College of Medicine, 2002 Holcombe Blvd., Houston, Texas 77030, USA.
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19
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Development of the mammalian liver and ventral pancreas is dependent on GATA4. BMC DEVELOPMENTAL BIOLOGY 2007; 7:37. [PMID: 17451603 PMCID: PMC1877807 DOI: 10.1186/1471-213x-7-37] [Citation(s) in RCA: 155] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2007] [Accepted: 04/23/2007] [Indexed: 01/05/2023]
Abstract
BACKGROUND In the mouse, the parenchyma of both the liver and ventral pancreas is specified from adjacent domains of the ventral foregut endoderm. GATA4, a zinc finger transcription factor, is strongly expressed in these endodermal domains and molecular analyses have implicated GATA4 in potentiating liver gene expression during the onset of hepatogenesis. We therefore hypothesized that GATA4 has an integral role in controlling the early stages of pancreatic and liver development. RESULTS To determine whether GATA4 contributes to development of either the pancreas or liver we characterized the formation of pancreatic and hepatic tissues in embryos derived from Gata4-/- ES cells by tetraploid embryo complementation. In the absence of GATA4, development of the liver and ventral pancreas was disrupted. At embryonic day (E) 9.5, the liver bud failed to expand although, contrary to expectations, the hepatic endoderm was able to form a pseudo-stratified epithelial liver bud that expressed hepatic genes. Moreover, as we had shown previously, the embryos lacked septum transversum mesenchyme suggesting that liver defects may be cell non-autonomous. Analyses of pancreatic development revealed a complete absence of the ventral but not the dorsal pancreas in Gata4-/- embryos. Moreover, Gata6-/- embryos displayed a similar, although less dramatic phenotype, suggesting a critical role for multiple GATA factors at the earliest stages of ventral pancreas development. CONCLUSION This study defines integral roles for GATA factors in controlling early development of the mammalian liver and pancreas.
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20
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Klapper M, Böhme M, Nitz I, Döring F. Type 2 diabetes-associated fatty acid binding protein 2 promoter haplotypes are differentially regulated by GATA factors. Hum Mutat 2007; 29:142-9. [DOI: 10.1002/humu.20618] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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21
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Bates JM, Mittge E, Kuhlman J, Baden KN, Cheesman SE, Guillemin K. Distinct signals from the microbiota promote different aspects of zebrafish gut differentiation. Dev Biol 2006; 297:374-86. [PMID: 16781702 DOI: 10.1016/j.ydbio.2006.05.006] [Citation(s) in RCA: 357] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2006] [Revised: 05/02/2006] [Accepted: 05/03/2006] [Indexed: 11/19/2022]
Abstract
All animals exist in intimate associations with microorganisms that play important roles in the hosts' normal development and tissue physiology. In vertebrates, the most populous and complex community of microbes resides in the digestive tract. Here, we describe the establishment of the gut microbiota and its role in digestive tract differentiation in the zebrafish model vertebrate, Danio rerio. We find that in the absence of the microbiota, the gut epithelium is arrested in aspects of its differentiation, as revealed by the lack of brush border intestinal alkaline phosphatase activity, the maintenance of immature patterns of glycan expression and a paucity of goblet and enteroendocrine cells. In addition, germ-free intestines fail to take up protein macromolecules in the distal intestine and exhibit faster motility. Reintroduction of a complex microbiota at later stages of development or mono-association of germ-free larvae with individual constituents of the microbiota reverses all of these germ-free phenotypes. Exposure of germ-free zebrafish to heat-killed preparations of the microbiota or bacterial lipopolysaccharide is sufficient to restore alkaline phosphatase activity but not mature patterns of Gal alpha1,3Gal containing glycans, indicating that the host perceives and responds to its associated microbiota by at least two distinct pathways.
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Affiliation(s)
- Jennifer M Bates
- Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
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22
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Ng ANY, de Jong-Curtain TA, Mawdsley DJ, White SJ, Shin J, Appel B, Dong PDS, Stainier DYR, Heath JK. Formation of the digestive system in zebrafish: III. Intestinal epithelium morphogenesis. Dev Biol 2005; 286:114-35. [PMID: 16125164 DOI: 10.1016/j.ydbio.2005.07.013] [Citation(s) in RCA: 281] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2004] [Revised: 06/30/2005] [Accepted: 07/18/2005] [Indexed: 02/08/2023]
Abstract
Recent analysis of a novel strain of transgenic zebrafish (gutGFP) has provided a detailed description of the early morphological events that occur during the development of the liver and pancreas. In this paper, we aim to complement these studies by providing an analysis of the morphological events that shape the zebrafish intestinal epithelium. One of our goals is to provide a framework for the future characterization of zebrafish mutant phenotypes in which intestinal epithelial morphogenesis has been disrupted. Our analysis encompasses the period between 26 and 126 h post-fertilization (hpf) and follows the growth, lumen formation and differentiation of a continuous layer of endoderm into a functional intestinal epithelium with three morphologically distinct segments: the intestinal bulb, mid-intestine and posterior intestine. Between 26 hpf and 76 hpf, the entire intestinal endoderm is a highly proliferative organ. To make a lumen, the zebrafish endoderm cells undergo apical membrane biogenesis, adopt a bilayer configuration and form small cavities that coalesce without cell death. Thereafter, the endoderm cells polarize and differentiate into distinct cell lineages. Enteroendocrine cells are distinguished first at 52 hpf in the caudal region of the intestine in a new stable transgenic line, Tg[nkx2.2a:mEGFP]. The differentiation of mucin-containing goblet cells is first evident at 100 hpf and is tightly restricted to a middle segment of the intestine, designated the mid-intestine, that is also demarcated by the presence of enterocytes with large supranuclear vacuoles. Meanwhile, striking expansion of the lumen in the rostral intestine forms the intestinal bulb. Here the epithelium elaborates folds and proliferating cells become progressively restricted to a basal compartment analogous to the crypts of Lieberkühn in mammals. At 126 hpf, the posterior intestine remains an unfolded monolayer of simple columnar epithelium.
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Affiliation(s)
- Annie N Y Ng
- Colon Molecular and Cell Biology Laboratory, Ludwig Institute for Cancer Research, Post Office Box 2008, Royal Melbourne Hospital, Parkville, Victoria 3050, Australia
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23
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Shin JT, Priest JR, Ovcharenko I, Ronco A, Moore RK, Burns CG, MacRae CA. Human-zebrafish non-coding conserved elements act in vivo to regulate transcription. Nucleic Acids Res 2005; 33:5437-45. [PMID: 16179648 PMCID: PMC1236720 DOI: 10.1093/nar/gki853] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Whole genome comparisons of distantly related species effectively predict biologically important sequences--core genes and cis-acting regulatory elements (REs)--but require experimentation to verify biological activity. To examine the efficacy of comparative genomics in identification of active REs from anonymous, non-coding (NC) sequences, we generated a novel alignment of the human and draft zebrafish genomes, and contrasted this set to existing human and fugu datasets. We tested the transcriptional regulatory potential of candidate sequences using two in vivo assays. Strict selection of non-genic elements which are deeply conserved in vertebrate evolution identifies 1744 core vertebrate REs in human and two fish genomes. We tested 16 elements in vivo for cis-acting gene regulatory properties using zebrafish transient transgenesis and found that 10 (63%) strongly modulate tissue-specific expression of a green fluorescent protein reporter vector. We also report a novel quantitative enhancer assay with potential for increased throughput based on normalized luciferase activity in vivo. This complementary system identified 11 (69%; including 9 of 10 GFP-confirmed elements) with cis-acting function. Together, these data support the utility of comparative genomics of distantly related vertebrate species to identify REs and provide a scaleable, in vivo quantitative assay to define functional activity of candidate REs.
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Affiliation(s)
- Jordan T Shin
- Cardiovascular Research Center and Cardiology Division, Massachusetts General Hospital and Harvard Medical School Charlestown, MA 02129, USA.
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Marza E, Barthe C, André M, Villeneuve L, Hélou C, Babin PJ. Developmental expression and nutritional regulation of a zebrafish gene homologous to mammalian microsomal triglyceride transfer protein large subunit. Dev Dyn 2005; 232:506-18. [PMID: 15614773 DOI: 10.1002/dvdy.20251] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The microsomal triglyceride transfer protein (MTP) large subunit is required for the assembly and secretion of apolipoprotein B-containing lipoproteins. We have found a zebrafish mtp homologous gene coding a protein with 54% identity with human MTP large subunit with the most conserved regions distributed in the corresponding predicted alpha-helical and C- and A-sheet domains. In situ hybridizations showed that zebrafish mtp transcripts were distributed in the yolk syncytial layer during early embryogenesis and in anterior intestine and liver from 48 hr postfertilization onward. Real-time quantitative RT-PCR confirmed the developmental regulation and tissue-specificity of mtp expression. A significant pretranslational up-regulation of mtp expression was observed in the anterior intestine after feeding. The nutritional regulation of zebrafish mtp expression observed in the anterior intestine supports the notion that this protein, similar to mammalian MTP large subunit, could be a factor implicated directly or indirectly in large lipid droplets accumulation observed in the fish enterocyte after feeding.
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Affiliation(s)
- Esther Marza
- Laboratoire Génomique et Physiologie des Poissons, UMR 1067 NUAGE INRA-IFREMER, Université Bordeaux 1, 33405 Talence Cedex, France
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25
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Abstract
We have developed a loss-of-function model for Gata4 in zebrafish, in order to examine broadly its requirement for organogenesis. We show that the function of Gata4 in zebrafish heart development is well conserved with that in mouse, and that, in addition, Gata4 is required for development of the intestine, liver, pancreas and swim bladder. Therefore, a single transcription factor regulates the formation of many organs. Gata6 is a closely related transcription factor with an overlapping expression pattern. We show that zebrafish depleted of Gata6 show defects in liver bud growth similar to mouse Gata6 mutants and zebrafish Gata4 morphants, and that zebrafish embryos depleted of both Gata4 and Gata6 display an earlier block in liver development, and thus completely lack liver buds. Therefore, Gata4 and Gata6 have distinct non-redundant functions in cardiac morphogenesis, but are redundant for an early step of liver development. In addition, both Gata4 and Gata6 are essential and non-redundant for liver growth following initial budding.
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Affiliation(s)
- Audrey Holtzinger
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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