1
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Cassidy RM, Flores EM, Trinh Nguyen AK, Cheruvu SS, Uribe RA, Krachler AM, Odem MA. Systematic analysis of proximal midgut- and anorectal-originating contractions in larval zebrafish using event feature detection and supervised machine learning algorithms. Neurogastroenterol Motil 2023; 35:e14675. [PMID: 37743702 PMCID: PMC10841157 DOI: 10.1111/nmo.14675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 07/16/2023] [Accepted: 08/28/2023] [Indexed: 09/26/2023]
Abstract
BACKGROUND Zebrafish larvae are translucent, allowing in vivo analysis of gut development and physiology, including gut motility. While recent progress has been made in measuring gut motility in larvae, challenges remain which can influence results, such as how data are interpreted, opportunities for technical user error, and inconsistencies in methods. METHODS To overcome these challenges, we noninvasively introduced Nile Red fluorescent dye to fill the intraluminal gut space in zebrafish larvae and collected serial confocal microscopic images of gut fluorescence. We automated the detection of fluorescent-contrasted contraction events against the median-subtracted signal and compared it to manually annotated gut contraction events across anatomically defined gut regions. Supervised machine learning (multiple logistic regression) was then used to discriminate between true contraction events and noise. To demonstrate, we analyzed motility in larvae under control and reserpine-treated conditions. We also used automated event detection analysis to compare unfed and fed larvae. KEY RESULTS Automated analysis retained event features for proximal midgut-originating retrograde and anterograde contractions and anorectal-originating retrograde contractions. While manual annotation showed reserpine disrupted gut motility, machine learning only achieved equivalent contraction discrimination in controls and failed to accurately identify contractions after reserpine due to insufficient intraluminal fluorescence. Automated analysis also showed feeding had no effect on the frequency of anorectal-originating contractions. CONCLUSIONS & INFERENCES Automated event detection analysis rapidly and accurately annotated contraction events, including the previously neglected phenomenon of anorectal contractions. However, challenges remain to discriminate contraction events based on intraluminal fluorescence under treatment conditions that disrupt functional motility.
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Affiliation(s)
- Ryan M. Cassidy
- Brown Foundation Institute of Molecular Medicine, McGovern
Medical School at UTHealth, Houston, TX 77030, USA
| | - Erika M. Flores
- Department of Microbiology and Molecular Genetics, McGovern
Medical School at UTHealth, Houston, TX 77030, USA
| | - Anh K. Trinh Nguyen
- Department of Microbiology and Molecular Genetics, McGovern
Medical School at UTHealth, Houston, TX 77030, USA
| | - Sai S. Cheruvu
- Department of Integrative Biology and Pharmacology,
McGovern Medical School at UTHealth, Houston, TX 77030, USA
| | - Rosa A. Uribe
- Department of Biosciences, Rice University, Houston, TX
77005, USA
| | - Anne Marie Krachler
- Department of Microbiology and Molecular Genetics, McGovern
Medical School at UTHealth, Houston, TX 77030, USA
| | - Max A. Odem
- Department of Microbiology and Molecular Genetics, McGovern
Medical School at UTHealth, Houston, TX 77030, USA
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2
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Nikaido M, Shirai A, Mizumaki Y, Shigenobu S, Ueno N, Hatta K. Intestinal expression patterns of transcription factors and markers for interstitial cells in the larval zebrafish. Dev Growth Differ 2023; 65:418-428. [PMID: 37452633 DOI: 10.1111/dgd.12878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 06/26/2023] [Accepted: 07/10/2023] [Indexed: 07/18/2023]
Abstract
For the digestion of food, it is important for the gut to be differentiated regionally and to have proper motor control. However, the number of transcription factors that regulate its development is still limited. Meanwhile, the interstitial cells of the gastrointestinal (GI) tract are necessary for intestinal motility in addition to the enteric nervous system. There are anoctamine1 (Ano1)-positive and platelet-derived growth factor receptor α (Pdgfra)-positive interstitial cells in mammal, but Pdgfra-positive cells have not been reported in the zebrafish. To identify new transcription factors involved in GI tract development, we used RNA sequencing comparing between larval and adult gut. We isolated 40 transcription factors that were more highly expressed in the larval gut. We demonstrated expression patterns of the 13 genes, 7 of which were newly found to be expressed in the zebrafish larval gut. Six of the 13 genes encode nuclear receptors. The osr2 is expressed in the anterior part, while foxP4 in its distal part. Also, we reported the expression pattern of pdgfra for the first time in the larval zebrafish gut. Our data provide fundamental knowledge for studying vertebrate gut regionalization and motility by live imaging using zebrafish.
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Affiliation(s)
| | - Ayaka Shirai
- School of Science, University of Hyogo, Ako-gun, Japan
| | | | - Shuji Shigenobu
- Trans-Scale Biology Center, National Institute for Basic Biology, Okazaki, Japan
| | - Naoto Ueno
- Trans-Scale Biology Center, National Institute for Basic Biology, Okazaki, Japan
- Unit of Quantitative and Imaging Biology, International Research Collaboration Center, National Institute of Natural Sciences, Okazaki, Japan
| | - Kohei Hatta
- Graduate School of Science, University of Hyogo, Ako-gun, Japan
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3
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Ganz J, Ratcliffe EM. Who's talking to whom: microbiome-enteric nervous system interactions in early life. Am J Physiol Gastrointest Liver Physiol 2023; 324:G196-G206. [PMID: 36625480 PMCID: PMC9988524 DOI: 10.1152/ajpgi.00166.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 12/22/2022] [Accepted: 01/04/2023] [Indexed: 01/11/2023]
Abstract
The enteric nervous system (ENS) is the intrinsic nervous system of the gastrointestinal tract (GI) and regulates important GI functions, including motility, nutrient uptake, and immune response. The development of the ENS begins during early organogenesis and continues to develop once feeding begins, with ongoing plasticity into adulthood. There has been increasing recognition that the intestinal microbiota and ENS interact during critical periods, with implications for normal development and potential disease pathogenesis. In this review, we focus on insights from mouse and zebrafish model systems to compare and contrast how each model can serve in elucidating the bidirectional communication between the ENS and the microbiome. At the end of this review, we further outline implications for human disease and highlight research innovations that can lead the field forward.
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Affiliation(s)
- Julia Ganz
- Department of Integrative Biology, Michigan State University, East Lansing, Michigan, United States
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4
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Xia H, Chen H, Cheng X, Yin M, Yao X, Ma J, Huang M, Chen G, Liu H. Zebrafish: an efficient vertebrate model for understanding role of gut microbiota. Mol Med 2022; 28:161. [PMID: 36564702 PMCID: PMC9789649 DOI: 10.1186/s10020-022-00579-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 11/21/2022] [Indexed: 12/24/2022] Open
Abstract
Gut microbiota plays a critical role in the maintenance of host health. As a low-cost and genetically tractable vertebrate model, zebrafish have been widely used for biological research. Zebrafish and humans share some similarities in intestinal physiology and function, and this allows zebrafish to be a surrogate model for investigating the crosstalk between the gut microbiota and host. Especially, zebrafish have features such as high fecundity, external fertilization, and early optical transparency. These enable the researchers to employ the fish to address questions not easily addressed in other animal models. In this review, we described the intestine structure of zebrafish. Also, we summarized the methods of generating a gnotobiotic zebrafish model, the factors affecting its intestinal flora, and the study progress of gut microbiota functions in zebrafish. Finally, we discussed the limitations and challenges of the zebrafish model for gut microbiota studies. In summary, this review established that zebrafish is an attractive research tool to understand mechanistic insights into host-microbe interaction.
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Affiliation(s)
- Hui Xia
- College of Basic Medicine, Hubei University of Chinese Medicine, Huangjiahu West Road 16, Hongshan Disctrict, Wuhan, 430065, China
| | - Huimin Chen
- College of Basic Medicine, Hubei University of Chinese Medicine, Huangjiahu West Road 16, Hongshan Disctrict, Wuhan, 430065, China
| | - Xue Cheng
- College of Basic Medicine, Hubei University of Chinese Medicine, Huangjiahu West Road 16, Hongshan Disctrict, Wuhan, 430065, China
| | - Mingzhu Yin
- College of Basic Medicine, Hubei University of Chinese Medicine, Huangjiahu West Road 16, Hongshan Disctrict, Wuhan, 430065, China
| | - Xiaowei Yao
- College of Basic Medicine, Hubei University of Chinese Medicine, Huangjiahu West Road 16, Hongshan Disctrict, Wuhan, 430065, China
| | - Jun Ma
- College of Basic Medicine, Hubei University of Chinese Medicine, Huangjiahu West Road 16, Hongshan Disctrict, Wuhan, 430065, China
| | - Mengzhen Huang
- College of Basic Medicine, Hubei University of Chinese Medicine, Huangjiahu West Road 16, Hongshan Disctrict, Wuhan, 430065, China
| | - Gang Chen
- Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan, 430061, China.
| | - Hongtao Liu
- College of Basic Medicine, Hubei University of Chinese Medicine, Huangjiahu West Road 16, Hongshan Disctrict, Wuhan, 430065, China.
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5
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Bandla A, Melancon E, Taylor CR, Davidson AE, Eisen JS, Ganz J. A New Transgenic Tool to Study the Ret Signaling Pathway in the Enteric Nervous System. Int J Mol Sci 2022; 23:15667. [PMID: 36555308 PMCID: PMC9779438 DOI: 10.3390/ijms232415667] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 11/23/2022] [Accepted: 12/02/2022] [Indexed: 12/14/2022] Open
Abstract
The receptor tyrosine kinase Ret plays a critical role in regulating enteric nervous system (ENS) development. Ret is important for proliferation, migration, and survival of enteric progenitor cells (EPCs). Ret also promotes neuronal fate, but its role during neuronal differentiation and in the adult ENS is less well understood. Inactivating RET mutations are associated with ENS diseases, e.g., Hirschsprung Disease, in which distal bowel lacks ENS cells. Zebrafish is an established model system for studying ENS development and modeling human ENS diseases. One advantage of the zebrafish model system is that their embryos are transparent, allowing visualization of developmental phenotypes in live animals. However, we lack tools to monitor Ret expression in live zebrafish. Here, we developed a new BAC transgenic line that expresses GFP under the ret promoter. We find that EPCs and the majority of ENS neurons express ret:GFP during ENS development. In the adult ENS, GFP+ neurons are equally present in females and males. In homozygous mutants of ret and sox10-another important ENS developmental regulator gene-GFP+ ENS cells are absent. In summary, we characterize a ret:GFP transgenic line as a new tool to visualize and study the Ret signaling pathway from early development through adulthood.
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Affiliation(s)
- Ashoka Bandla
- Department of Integrative Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Ellie Melancon
- Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
| | - Charlotte R. Taylor
- Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
- Department of Biochemistry & Biophysics, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Ann E. Davidson
- Department of Integrative Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Judith S. Eisen
- Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
| | - Julia Ganz
- Department of Integrative Biology, Michigan State University, East Lansing, MI 48824, USA
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6
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Sun T, Ji C, Li F, Shan X, Wu H. The legacy effect of microplastics on aquatic animals in the depuration phase: Kinetic characteristics and recovery potential. ENVIRONMENT INTERNATIONAL 2022; 168:107467. [PMID: 35985106 DOI: 10.1016/j.envint.2022.107467] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 07/25/2022] [Accepted: 08/09/2022] [Indexed: 06/15/2023]
Abstract
The prevalence of microplastics (MPs) in global aquatic environments has received considerable attention. Currently, concerns have been raised regarding reports that the adverse effect of MPs on aquatic animals in the exposure phase may not be (completely) reversed in the depuration phase. In order to provide insights into the legacy effect of MPs from the depuration phase, this study evaluated the kinetic characteristics and recovery potential of aquatic animals after the exposure to MPs. More specifically, a total of 68 depuration kinetic curves were highly fitted to estimate the retention time of MPs. It was shown that the retention time ranged from 1.26 to 3.01 days, corresponding to the egestion of 90 % to 99 % of ingested MPs. The retention time decreased with the increased retention rate. Furthermore, variables potentially affecting the retention time were ranked by the decision tree-based eXtreme Gradient Boosting (XGBoost) algorithm, suggesting that the particle size and tested species were of great importance for explaining the difference in retention time of MPs. Moreover, a biomarker profile was recompiled to determine the toxic changes. Results indicated that the MPs-induced toxicity significantly reduced in the depuration phase, evidenced by the recovery of energy reserves and metabolism, hepatotoxicity, immunotoxicity, hematological parameters, neurotoxicity and oxidative stress. However, the continuous detoxification and remarkable genotoxicity implied that the toxicity was not completely alleviated. In addition, the current knowledge gaps are also highlighted, with recommendations proposed for future research.
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Affiliation(s)
- Tao Sun
- CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), Shandong Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai 264003, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Chenglong Ji
- CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), Shandong Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai 264003, PR China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, PR China; Center for Ocean Mega-Science, Chinese Academy of Sciences (CAS), Qingdao 266071, PR China
| | - Fei Li
- CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), Shandong Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai 264003, PR China; Center for Ocean Mega-Science, Chinese Academy of Sciences (CAS), Qingdao 266071, PR China
| | - Xiujuan Shan
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, PR China
| | - Huifeng Wu
- CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), Shandong Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai 264003, PR China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, PR China; Center for Ocean Mega-Science, Chinese Academy of Sciences (CAS), Qingdao 266071, PR China.
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7
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Rueckert H, Ganz J. How to Heal the Gut's Brain: Regeneration of the Enteric Nervous System. Int J Mol Sci 2022; 23:ijms23094799. [PMID: 35563190 PMCID: PMC9105052 DOI: 10.3390/ijms23094799] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/20/2022] [Accepted: 04/20/2022] [Indexed: 02/06/2023] Open
Abstract
The neural-crest-derived enteric nervous system (ENS) is the intrinsic nervous system of the gastrointestinal (GI) tract and controls all gut functions, including motility. Lack of ENS neurons causes various ENS disorders such as Hirschsprung Disease. One treatment option for ENS disorders includes the activation of resident stem cells to regenerate ENS neurons. Regeneration in the ENS has mainly been studied in mammalian species using surgical or chemically induced injury methods. These mammalian studies showed a variety of regenerative responses with generally limited regeneration of ENS neurons but (partial) regrowth and functional recovery of nerve fibers. Several aspects might contribute to the variety in regenerative responses, including observation time after injury, species, and gut region targeted. Zebrafish have recently emerged as a promising model system to study ENS regeneration as larvae possess the ability to generate new neurons after ablation. As the next steps in ENS regeneration research, we need a detailed understanding of how regeneration is regulated on a cellular and molecular level in animal models with both high and low regenerative capacity. Understanding the regulatory programs necessary for robust ENS regeneration will pave the way for using neural regeneration as a therapeutic approach to treating ENS disorders.
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Affiliation(s)
- Helen Rueckert
- Department of Integrative Biology, Michigan State University, East Lansing, MI 48824, USA;
- Department of Cell Biology, Duke University School of Medicine, Durham, NC 27710, USA
- Department of Orthopaedic Surgery, Duke University School of Medicine, Durham, NC 27710, USA
| | - Julia Ganz
- Department of Integrative Biology, Michigan State University, East Lansing, MI 48824, USA;
- Correspondence:
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8
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Vega NM, Ludington WB. From a parts list to assembly instructions and an operating manual: how small host models can re-write microbiome theory. Curr Opin Microbiol 2021; 64:146-151. [PMID: 34739919 DOI: 10.1016/j.mib.2021.10.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 08/10/2021] [Accepted: 10/08/2021] [Indexed: 10/20/2022]
Affiliation(s)
- Nic M Vega
- Biology Department, Emory University, Atlanta, GA, United States.
| | - William B Ludington
- Department of Embryology, Carnegie Institution of Washington, Baltimore, MD, United States
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9
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Jones BS, Keightley LJ, Harris JO, Wiklendt L, Spencer NJ, Dinning PG. Identification of neurogenic intestinal motility patterns in silver perch (Bidyanus bidyanus) that persist over wide temperature ranges. Neurogastroenterol Motil 2021; 33:e14037. [PMID: 33340207 DOI: 10.1111/nmo.14037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 10/28/2020] [Accepted: 10/30/2020] [Indexed: 02/08/2023]
Abstract
BACKGROUND Fish are increasingly being utilized as a model species for genetic manipulation studies related to gastrointestinal (GI) motility. Our aim was to identify whether patterns of GI motility in fish and the mechanisms underlying their generation are similar to those recorded from mammals (including humans). METHODS The entire intestine was removed from euthanized adult Silver Perch (n = 11) and lesioned at the midway point to obtain two equal lengths. Proximal and distal segments were studied separately in organ baths with oxygenated Krebs solution, maintained at either 15°C (n = 5) or 25°C (n = 6). Motility was analyzed during rest, after oral infusion of Krebs solution, and after application of hexamethonium (100 µM) and tetrodotoxin (TTX) (0.6 µM). KEY RESULTS Antegrade and retrograde propagating contractions (PC) were recorded in all preparations. In the proximal intestine, at 15 and 25°C, retrograde PCs occurred at 2.7 [1.7-4.5] and 3.1 [1.6-6.5] times the frequency of antegrade PCs, respectively. Colder temperatures did not inhibit PC frequency. Hexamethonium did not inhibit PC, and however, TTX abolished all contractile activity. CONCLUSIONS AND INFERENCES Both neurogenic antegrade and retrograde propagating contractions occur throughout the intestine of Silver Perch. However, unlike the mammalian colon, these motor patterns do not require enteric nicotinic transmission and they are not inhibited by cold temperatures (15°C). Therefore, while the GI motility patterns in Silver Perch resemble those recorded from the colon of mammals, there may be differences in the mechanisms that underlying their generation.
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Affiliation(s)
- Bradley S Jones
- College of Science & Engineering, Flinders University, Adelaide, SA, Australia
| | - Lauren J Keightley
- College of Medicine & Public Health, Flinders University, Adelaide, SA, Australia
| | - James O Harris
- College of Science & Engineering, Flinders University, Adelaide, SA, Australia
| | - Lukasz Wiklendt
- College of Medicine & Public Health, Flinders University, Adelaide, SA, Australia
| | - Nick J Spencer
- College of Medicine & Public Health, Flinders University, Adelaide, SA, Australia
| | - Phil G Dinning
- College of Medicine & Public Health, Flinders University, Adelaide, SA, Australia.,Department of Surgery and Gastroenterology, Flinders Medical Centre, Bedford Park, SA, Australia
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10
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Fujii K, Nakajo K, Egashira Y, Yamamoto Y, Kitada K, Taniguchi K, Kawai M, Tomiyama H, Kawakami K, Uchiyama K, Ono F. Gastrointestinal Neurons Expressing HCN4 Regulate Retrograde Peristalsis. Cell Rep 2021; 30:2879-2888.e3. [PMID: 32130893 DOI: 10.1016/j.celrep.2020.02.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 09/30/2019] [Accepted: 02/06/2020] [Indexed: 12/31/2022] Open
Abstract
Peristalsis is indispensable for physiological function of the gut. The enteric nervous system (ENS) plays an important role in regulating peristalsis. While the neural network regulating anterograde peristalsis, which migrates from the oral end to the anal end, is characterized to some extent, retrograde peristalsis remains unresolved with regards to its neural regulation. Using forward genetics in zebrafish, we reveal that a population of neurons expressing a hyperpolarization-activated nucleotide-gated channel HCN4 specifically regulates retrograde peristalsis. When HCN4 channels are blocked by an HCN channel inhibitor or morpholinos blocking the protein expression, retrograde peristalsis is specifically attenuated. Conversely, when HCN4(+) neurons expressing channelrhodopsin are activated by illumination, retrograde peristalsis is enhanced while anterograde peristalsis remains unchanged. We propose that HCN4(+) neurons in the ENS forward activating signals toward the oral end and simultaneously stimulate local circuits regulating the circular muscle.
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Affiliation(s)
- Kensuke Fujii
- Department of General and Gastroenterological Surgery, Osaka Medical College, Takatsuki, Japan
| | - Koichi Nakajo
- Department of Physiology, Osaka Medical College, Takatsuki, Japan; Division of Integrative Physiology, Department of Physiology, Jichi Medical University, Shimotsuke, Japan
| | | | | | - Kazuya Kitada
- Department of General and Gastroenterological Surgery, Osaka Medical College, Takatsuki, Japan
| | - Kohei Taniguchi
- Department of General and Gastroenterological Surgery, Osaka Medical College, Takatsuki, Japan
| | - Masaru Kawai
- Department of General and Gastroenterological Surgery, Osaka Medical College, Takatsuki, Japan
| | - Hideki Tomiyama
- Department of General and Gastroenterological Surgery, Osaka Medical College, Takatsuki, Japan
| | - Koichi Kawakami
- Laboratory of Molecular and Developmental Biology, National Institute of Genetics and Department of Genetics, SOKENDAI (The Graduate University for Advanced Studies), Hayama, Japan
| | - Kazuhisa Uchiyama
- Department of General and Gastroenterological Surgery, Osaka Medical College, Takatsuki, Japan
| | - Fumihito Ono
- Department of Physiology, Osaka Medical College, Takatsuki, Japan.
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11
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Kuil LE, Chauhan RK, Cheng WW, Hofstra RMW, Alves MM. Zebrafish: A Model Organism for Studying Enteric Nervous System Development and Disease. Front Cell Dev Biol 2021; 8:629073. [PMID: 33553169 PMCID: PMC7859111 DOI: 10.3389/fcell.2020.629073] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 12/23/2020] [Indexed: 12/11/2022] Open
Abstract
The Enteric Nervous System (ENS) is a large network of enteric neurons and glia that regulates various processes in the gastrointestinal tract including motility, local blood flow, mucosal transport and secretion. The ENS is derived from stem cells coming from the neural crest that migrate into and along the primitive gut. Defects in ENS establishment cause enteric neuropathies, including Hirschsprung disease (HSCR), which is characterized by an absence of enteric neural crest cells in the distal part of the colon. In this review, we discuss the use of zebrafish as a model organism to study the development of the ENS. The accessibility of the rapidly developing gut in zebrafish embryos and larvae, enables in vivo visualization of ENS development, peristalsis and gut transit. These properties make the zebrafish a highly suitable model to bring new insights into ENS development, as well as in HSCR pathogenesis. Zebrafish have already proven fruitful in studying ENS functionality and in the validation of novel HSCR risk genes. With the rapid advancements in gene editing techniques and their unique properties, research using zebrafish as a disease model, will further increase our understanding on the genetics underlying HSCR, as well as possible treatment options for this disease.
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Affiliation(s)
- Laura E. Kuil
- Department of Clinical Genetics, Erasmus University Medical Centre, Rotterdam, Netherlands
| | - Rajendra K. Chauhan
- Department of Clinical Genetics, Erasmus University Medical Centre, Rotterdam, Netherlands
| | - William W. Cheng
- Department of Clinical Genetics, Erasmus University Medical Centre, Rotterdam, Netherlands
| | - Robert M. W. Hofstra
- Department of Clinical Genetics, Erasmus University Medical Centre, Rotterdam, Netherlands
- Stem Cells and Regenerative Medicine, University College London (UCL) Great Ormond Street Institute of Child Health, London, United Kingdom
| | - Maria M. Alves
- Department of Clinical Genetics, Erasmus University Medical Centre, Rotterdam, Netherlands
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12
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Ye L, Bae M, Cassilly CD, Jabba SV, Thorpe DW, Martin AM, Lu HY, Wang J, Thompson JD, Lickwar CR, Poss KD, Keating DJ, Jordt SE, Clardy J, Liddle RA, Rawls JF. Enteroendocrine cells sense bacterial tryptophan catabolites to activate enteric and vagal neuronal pathways. Cell Host Microbe 2020; 29:179-196.e9. [PMID: 33352109 DOI: 10.1016/j.chom.2020.11.011] [Citation(s) in RCA: 136] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 09/08/2020] [Accepted: 11/19/2020] [Indexed: 12/12/2022]
Abstract
The intestinal epithelium senses nutritional and microbial stimuli using epithelial sensory enteroendocrine cells (EEC). EECs communicate nutritional information to the nervous system, but whether they also relay signals from intestinal microbes remains unknown. Using in vivo real-time measurements of EEC and nervous system activity in zebrafish, we discovered that the bacteria Edwardsiella tarda activate EECs through the receptor transient receptor potential ankyrin A1 (Trpa1) and increase intestinal motility. Microbial, pharmacological, or optogenetic activation of Trpa1+EECs directly stimulates vagal sensory ganglia and activates cholinergic enteric neurons by secreting the neurotransmitter 5-hydroxytryptamine (5-HT). A subset of indole derivatives of tryptophan catabolism produced by E. tarda and other gut microbes activates zebrafish EEC Trpa1 signaling. These catabolites also directly stimulate human and mouse Trpa1 and intestinal 5-HT secretion. These results establish a molecular pathway by which EECs regulate enteric and vagal neuronal pathways in response to microbial signals.
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Affiliation(s)
- Lihua Ye
- Department of Molecular Genetics and Microbiology, Duke Microbiome Center, Duke University School of Medicine, Durham, NC 27710, USA; Division of Gastroenterology, Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
| | - Munhyung Bae
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Chelsi D Cassilly
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Sairam V Jabba
- Department of Anesthesiology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Daniel W Thorpe
- Flinders Medical Research Institute, College of Medicine and Public Health, Flinders University, Adelaide, Australia
| | - Alyce M Martin
- Flinders Medical Research Institute, College of Medicine and Public Health, Flinders University, Adelaide, Australia
| | - Hsiu-Yi Lu
- Department of Molecular Genetics and Microbiology, Duke Microbiome Center, Duke University School of Medicine, Durham, NC 27710, USA
| | - Jinhu Wang
- Division of Cardiology, School of Medicine, Emory University, Atlanta, GA 30322, USA
| | - John D Thompson
- Department of Cell Biology, Regeneration Next, Duke University School of Medicine, Durham, NC 27710, USA
| | - Colin R Lickwar
- Department of Molecular Genetics and Microbiology, Duke Microbiome Center, Duke University School of Medicine, Durham, NC 27710, USA; Division of Gastroenterology, Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
| | - Kenneth D Poss
- Department of Cell Biology, Regeneration Next, Duke University School of Medicine, Durham, NC 27710, USA
| | - Damien J Keating
- Flinders Medical Research Institute, College of Medicine and Public Health, Flinders University, Adelaide, Australia
| | - Sven-Eric Jordt
- Department of Anesthesiology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Jon Clardy
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Rodger A Liddle
- Division of Gastroenterology, Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA; Department of Veterans Affairs, Durham, NC 27705, USA
| | - John F Rawls
- Department of Molecular Genetics and Microbiology, Duke Microbiome Center, Duke University School of Medicine, Durham, NC 27710, USA; Division of Gastroenterology, Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA.
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13
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El-Nachef WN, Bronner ME. De novo enteric neurogenesis in post-embryonic zebrafish from Schwann cell precursors rather than resident cell types. Development 2020; 147:dev186619. [PMID: 32541008 PMCID: PMC7375481 DOI: 10.1242/dev.186619] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 06/03/2020] [Indexed: 12/12/2022]
Abstract
The enteric nervous system (ENS) is essential for normal gastrointestinal function. Although the embryonic origin of enteric neurons from the neural crest is well established, conflicting evidence exists regarding postnatal enteric neurogenesis. Here, we address this by examining the origin of de novo neurogenesis in the post-embryonic zebrafish ENS. Although new neurons are added during growth and after injury, the larval intestine appears to lack resident neurogenic precursors or classical glia marked by sox10, plp1a, gfap or s100 Rather, lineage tracing with lipophilic dye or inducible Sox10-Cre suggests that post-embryonic enteric neurons arise from trunk neural crest-derived Schwann cell precursors that migrate from the spinal cord into the intestine. Furthermore, the 5-HT4 receptor agonist prucalopride increases enteric neurogenesis in normal development and after injury. Taken together, the results suggest that despite the lack of resident progenitors in the gut, post-embryonic enteric neurogenesis occurs via gut-extrinsic Schwann cell precursors during development and injury, and is promoted by serotonin receptor agonists. The absence of classical glia in the ENS further suggests that neural crest-derived enteric glia might have evolved after the teleost lineage.This article has an associated 'The people behind the papers' interview.
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Affiliation(s)
- Wael Noor El-Nachef
- Department of Medicine, Vatche and Tamar Manoukian Division of Digestive Diseases, University of California Los Angeles, Los Angeles, CA 90095, USA
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Marianne E Bronner
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
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14
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Swimming motility of a gut bacterial symbiont promotes resistance to intestinal expulsion and enhances inflammation. PLoS Biol 2020; 18:e3000661. [PMID: 32196484 PMCID: PMC7112236 DOI: 10.1371/journal.pbio.3000661] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 04/01/2020] [Accepted: 02/24/2020] [Indexed: 01/07/2023] Open
Abstract
Some of the densest microbial ecosystems in nature thrive within the intestines of humans and other animals. To protect mucosal tissues and maintain immune tolerance, animal hosts actively sequester bacteria within the intestinal lumen. In response, numerous bacterial pathogens and pathobionts have evolved strategies to subvert spatial restrictions, thereby undermining immune homeostasis. However, in many cases, it is unclear how escaping host spatial control benefits gut bacteria and how changes in intestinal biogeography are connected to inflammation. A better understanding of these processes could uncover new targets for treating microbiome-mediated inflammatory diseases. To this end, we investigated the spatial organization and dynamics of bacterial populations within the intestine using larval zebrafish and live imaging. We discovered that a proinflammatory Vibrio symbiont native to zebrafish governs its own spatial organization using swimming motility and chemotaxis. Surprisingly, we found that Vibrio’s motile behavior does not enhance its growth rate but rather promotes its persistence by enabling it to counter intestinal flow. In contrast, Vibrio mutants lacking motility traits surrender to host spatial control, becoming aggregated and entrapped within the lumen. Consequently, nonmotile and nonchemotactic mutants are susceptible to intestinal expulsion and experience large fluctuations in absolute abundance. Further, we found that motile Vibrio cells induce expression of the proinflammatory cytokine tumor necrosis factor alpha (TNFα) in gut-associated macrophages and the liver. Using inducible genetic switches, we demonstrate that swimming motility can be manipulated in situ to modulate the spatial organization, persistence, and inflammatory activity of gut bacterial populations. Together, our findings suggest that host spatial control over resident microbiota plays a broader role in regulating the abundance and persistence of gut bacteria than simply protecting mucosal tissues. Moreover, we show that intestinal flow and bacterial motility are potential targets for therapeutically managing bacterial spatial organization and inflammatory activity within the gut. The use of live imaging and bacteria engineered to carry inducible genetic switches reveals how a gut symbiont uses swimming motility to escape the host's spatial control and persist within the physically dynamic confines of the intestine.
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15
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Schlomann BH, Wiles TJ, Wall ES, Guillemin K, Parthasarathy R. Sublethal antibiotics collapse gut bacterial populations by enhancing aggregation and expulsion. Proc Natl Acad Sci U S A 2019; 116:21392-21400. [PMID: 31591228 PMCID: PMC6815146 DOI: 10.1073/pnas.1907567116] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Antibiotics induce large and highly variable changes in the intestinal microbiome even at sublethal concentrations, through mechanisms that remain elusive. Using gnotobiotic zebrafish, which allow high-resolution examination of microbial dynamics, we found that sublethal doses of the common antibiotic ciprofloxacin cause severe drops in bacterial abundance. Contrary to conventional views of antimicrobial tolerance, disruption was more pronounced for slow-growing, aggregated bacteria than for fast-growing, planktonic species. Live imaging revealed that antibiotic treatment promoted bacterial aggregation and increased susceptibility to intestinal expulsion. Intestinal mechanics therefore amplify the effects of antibiotics on resident bacteria. Microbial dynamics are captured by a biophysical model that connects antibiotic-induced collapses to gelation phase transitions in soft materials, providing a framework for predicting the impact of antibiotics on the intestinal microbiome.
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Affiliation(s)
- Brandon H Schlomann
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403
- Department of Physics, University of Oregon, Eugene, OR 97403
- Materials Science Institute, University of Oregon, Eugene, OR 97403
| | - Travis J Wiles
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403
| | - Elena S Wall
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403
| | - Karen Guillemin
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403
- Humans and the Microbiome Program, CIFAR, Toronto, ON M5G 1Z8, Canada
| | - Raghuveer Parthasarathy
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403;
- Department of Physics, University of Oregon, Eugene, OR 97403
- Materials Science Institute, University of Oregon, Eugene, OR 97403
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16
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Kulkarni S, Ganz J, Bayrer J, Becker L, Bogunovic M, Rao M. Advances in Enteric Neurobiology: The "Brain" in the Gut in Health and Disease. J Neurosci 2018; 38:9346-9354. [PMID: 30381426 PMCID: PMC6209840 DOI: 10.1523/jneurosci.1663-18.2018] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 09/20/2018] [Accepted: 09/22/2018] [Indexed: 12/14/2022] Open
Abstract
The enteric nervous system (ENS) is a large, complex division of the peripheral nervous system that regulates many digestive, immune, hormonal, and metabolic functions. Recent advances have elucidated the dynamic nature of the mature ENS, as well as the complex, bidirectional interactions among enteric neurons, glia, and the many other cell types that are important for mediating gut behaviors. Here, we provide an overview of ENS development and maintenance, and focus on the latest insights gained from the use of novel model systems and live-imaging techniques. We discuss major advances in the understanding of enteric glia, and the functional interactions among enteric neurons, glia, and enteroendocrine cells, a large class of sensory epithelial cells. We conclude by highlighting recent work on muscularis macrophages, a group of immune cells that closely interact with the ENS in the gut wall, and the importance of neurological-immune system communication in digestive health and disease.
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Affiliation(s)
- Subhash Kulkarni
- Department of Medicine, The John Hopkins University School of Medicine, Baltimore, Maryland 21205,
| | - Julia Ganz
- Department of Integrative Biology, Michigan State University, East Lansing, Michigan 48824
| | - James Bayrer
- Department of Pediatrics, University of California, San Francisco, San Francisco, California 94143
| | - Laren Becker
- Department of Medicine, Stanford University, Stanford, California 94305
| | - Milena Bogunovic
- Department of Microbiology and Immunology, Penn State College of Medicine, Hershey, Pennsylvania 17033, and
| | - Meenakshi Rao
- Division of Gastroenterology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts 02115
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17
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Bacterial Cohesion Predicts Spatial Distribution in the Larval Zebrafish Intestine. Biophys J 2018; 115:2271-2277. [PMID: 30448038 DOI: 10.1016/j.bpj.2018.10.017] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 10/12/2018] [Accepted: 10/22/2018] [Indexed: 02/06/2023] Open
Abstract
Are there general biophysical relationships governing the spatial organization of the gut microbiome? Despite growing realization that spatial structure is important for population stability, interbacterial competition, and host functions, it is unclear in any animal gut whether such structure is subject to predictive, unifying rules or if it results from contextual, species-specific behaviors. To explore this, we used light sheet fluorescence microscopy to conduct a high-resolution comparative study of bacterial distribution patterns throughout the entire intestinal volume of live, larval zebrafish. Fluorescently tagged strains of seven bacterial symbionts, representing six different species native to zebrafish, were each separately monoassociated with animals that had been raised initially germ-free. The strains showed large differences in both cohesion-the degree to which they auto-aggregate-and spatial distribution. We uncovered a striking correlation between each strain's mean position and its cohesion, whether quantified as the fraction of cells existing as planktonic individuals, the average aggregate size, or the total number of aggregates. Moreover, these correlations held within species as well; aggregates of different sizes localized as predicted from the pan-species observations. Together, our findings indicate that bacteria within the zebrafish intestine are subject to generic processes that organize populations by their cohesive properties. The likely drivers of this relationship-peristaltic fluid flow, tubular anatomy, and bacterial growth and aggregation kinetics-are common throughout animals. We therefore suggest that the framework introduced here of biophysical links between bacterial cohesion and spatial organization should be useful for directing explorations in other host-microbe systems, formulating detailed models that can quantitatively map onto experimental data, and developing new tools that manipulate cohesion to engineer microbiome function.
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18
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Rich A. Improved Imaging of Zebrafish Motility. Neurogastroenterol Motil 2018; 30:e13435. [PMID: 30240125 PMCID: PMC6152886 DOI: 10.1111/nmo.13435] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 07/06/2018] [Accepted: 06/30/2018] [Indexed: 12/12/2022]
Abstract
Zebrafish larvae are transparent and the entire gastrointestinal (GI) tract is easily visualized. Application of a new image analysis technique is reported in this issue of Neurogastroenterology and Motility (Neurogastroenterol Motil., 2018, volume 30, e13351). The technique quantifies movement in images collected in a timed sequence, and characterizes smooth muscle contractions based on contraction distance and frequency. The technique also reports the contraction amplitude, or the distance moved. This technique, and current spatiotemporal mapping techniques, are essential tools enabling characterization of GI motility patterns in intact physiological settings. Advances and development of transgenic zebrafish that lack pigmentation, with calcium reporters expressed in specific cell types, or with inactivation of specific genes contribute to our understanding of the generation, and regulation of GI motility at the molecular, cellular, and systemic level. Finally, development of chambers that immobilize zebrafish larvae for long-duration imaging will contribute to our technique toolbox, and will provide an increased experimental throughput.
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Affiliation(s)
- Adam Rich
- The College at Brockport, SUNY, 350 New Campus Drive, Brockport, NY 14420 USA, Telephone: 585-395-5740
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