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Disruption of the folate pathway in zebrafish causes developmental defects

BACKGROUND: Folic acid supplementation reduces the risk of neural tube defects and congenital heart defects. The biological mechanisms through which folate prevents birth defects are not well understood. We explore the use of zebrafish as a model system to investigate the role of folate metabolism d...

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Autores principales: Lee, Marina S, Bonner, Jenna R, Bernard, David J, Sanchez, Erica L, Sause, Eric T, Prentice, R Reid, Burgess, Shawn M, Brody, Lawrence C
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2012
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3410756/
https://www.ncbi.nlm.nih.gov/pubmed/22480165
http://dx.doi.org/10.1186/1471-213X-12-12
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author Lee, Marina S
Bonner, Jenna R
Bernard, David J
Sanchez, Erica L
Sause, Eric T
Prentice, R Reid
Burgess, Shawn M
Brody, Lawrence C
author_facet Lee, Marina S
Bonner, Jenna R
Bernard, David J
Sanchez, Erica L
Sause, Eric T
Prentice, R Reid
Burgess, Shawn M
Brody, Lawrence C
author_sort Lee, Marina S
collection PubMed
description BACKGROUND: Folic acid supplementation reduces the risk of neural tube defects and congenital heart defects. The biological mechanisms through which folate prevents birth defects are not well understood. We explore the use of zebrafish as a model system to investigate the role of folate metabolism during development. RESULTS: We first identified zebrafish orthologs of 12 human folate metabolic genes. RT-PCR and in situ analysis indicated maternal transcripts supply the embryo with mRNA so that the embryo has an intact folate pathway. To perturb folate metabolism we exposed zebrafish embryos to methotrexate (MTX), a potent inhibitor of dihydrofolate reductase (Dhfr) an essential enzyme in the folate metabolic pathway. Embryos exposed to high doses of MTX exhibited developmental arrest prior to early segmentation. Lower doses of MTX resulted in embryos with a shortened anterior-posterior axis and cardiac defects: linear heart tubes or incomplete cardiac looping. Inhibition of dhfr mRNA with antisense morpholino oligonucleotides resulted in embryonic lethality. One function of the folate pathway is to provide essential one-carbon units for dTMP synthesis, a rate-limiting step of DNA synthesis. After 24 hours of exposure to high levels of MTX, mutant embryos continue to incorporate the thymidine analog BrdU. However, additional experiments indicate that these embryos have fewer mitotic cells, as assayed with phospho-histone H3 antibodies, and that treated embryos have perturbed cell cycles. CONCLUSIONS: Our studies demonstrate that human and zebrafish utilize similar one-carbon pathways. Our data indicate that folate metabolism is essential for early zebrafish development. Zebrafish studies of the folate pathway and its deficiencies could provide insight into the underlying etiology of human birth defects and the natural role of folate in development.
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spelling pubmed-34107562012-08-03 Disruption of the folate pathway in zebrafish causes developmental defects Lee, Marina S Bonner, Jenna R Bernard, David J Sanchez, Erica L Sause, Eric T Prentice, R Reid Burgess, Shawn M Brody, Lawrence C BMC Dev Biol Research Article BACKGROUND: Folic acid supplementation reduces the risk of neural tube defects and congenital heart defects. The biological mechanisms through which folate prevents birth defects are not well understood. We explore the use of zebrafish as a model system to investigate the role of folate metabolism during development. RESULTS: We first identified zebrafish orthologs of 12 human folate metabolic genes. RT-PCR and in situ analysis indicated maternal transcripts supply the embryo with mRNA so that the embryo has an intact folate pathway. To perturb folate metabolism we exposed zebrafish embryos to methotrexate (MTX), a potent inhibitor of dihydrofolate reductase (Dhfr) an essential enzyme in the folate metabolic pathway. Embryos exposed to high doses of MTX exhibited developmental arrest prior to early segmentation. Lower doses of MTX resulted in embryos with a shortened anterior-posterior axis and cardiac defects: linear heart tubes or incomplete cardiac looping. Inhibition of dhfr mRNA with antisense morpholino oligonucleotides resulted in embryonic lethality. One function of the folate pathway is to provide essential one-carbon units for dTMP synthesis, a rate-limiting step of DNA synthesis. After 24 hours of exposure to high levels of MTX, mutant embryos continue to incorporate the thymidine analog BrdU. However, additional experiments indicate that these embryos have fewer mitotic cells, as assayed with phospho-histone H3 antibodies, and that treated embryos have perturbed cell cycles. CONCLUSIONS: Our studies demonstrate that human and zebrafish utilize similar one-carbon pathways. Our data indicate that folate metabolism is essential for early zebrafish development. Zebrafish studies of the folate pathway and its deficiencies could provide insight into the underlying etiology of human birth defects and the natural role of folate in development. BioMed Central 2012-04-05 /pmc/articles/PMC3410756/ /pubmed/22480165 http://dx.doi.org/10.1186/1471-213X-12-12 Text en Copyright ©2012 Lee et al; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research Article
Lee, Marina S
Bonner, Jenna R
Bernard, David J
Sanchez, Erica L
Sause, Eric T
Prentice, R Reid
Burgess, Shawn M
Brody, Lawrence C
Disruption of the folate pathway in zebrafish causes developmental defects
title Disruption of the folate pathway in zebrafish causes developmental defects
title_full Disruption of the folate pathway in zebrafish causes developmental defects
title_fullStr Disruption of the folate pathway in zebrafish causes developmental defects
title_full_unstemmed Disruption of the folate pathway in zebrafish causes developmental defects
title_short Disruption of the folate pathway in zebrafish causes developmental defects
title_sort disruption of the folate pathway in zebrafish causes developmental defects
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3410756/
https://www.ncbi.nlm.nih.gov/pubmed/22480165
http://dx.doi.org/10.1186/1471-213X-12-12
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