Nodal induces ectopic goosecoid and lim1 expression and axis duplication in zebrafish

Development ◽  
1995 ◽  
Vol 121 (2) ◽  
pp. 383-391 ◽  
Author(s):  
R. Toyama ◽  
M.L. O'Connell ◽  
C.V. Wright ◽  
M.R. Kuehn ◽  
I.B. Dawid

One of the first intercellular signalling events in the vertebrate embryo leads to mesoderm formation and axis determination. In the mouse, a gene encoding a new member of the TGF-beta superfamily, nodal, is disrupted in a mutant deficient in mesoderm formation (Zhou et al., 1993, Nature 361, 543). nodal mRNA is found in prestreak mouse embryos, consistent with a role in the development of the dorsal axis. To examine the biological activities of nodal, we have studied the action of this factor in eliciting axis determination in the zebrafish, Danio rerio. Injection of nodal mRNA into zebrafish embryos caused the formation of ectopic axes that included notochord and somites. Axis duplication was preceded by the generation of an apparent ectopic shield (organizer equivalent) in nodal-injected embryos, as indicated by the appearance of a region over-expressing gsc and lim1; isolation and expression in the shield of the lim1 gene is reported here. These results suggest a role for a nodal-like factor in pattern formation in zebrafish.

Author(s):  
Ann-Kathrin Loerracher ◽  
Thomas Braunbeck

AbstractGiven the strong trend to implement zebrafish (Danio rerio) embryos as translational model not only in ecotoxicological, but also toxicological testing strategies, there is an increasing need for a better understanding of their capacity for xenobiotic biotransformation. With respect to the extrapolation of toxicological data from zebrafish embryos to other life stages or even other organisms, qualitative and quantitative differences in biotransformation pathways, above all in cytochrome P450-dependent (CYP) phase I biotransformation, may lead to over- or underestimation of the hazard and risk certain xenobiotic compounds may pose to later developmental stages or other species. This review provides a comprehensive state-of-the-art overview of the scientific knowledge on the development of the CYP1-4 families and corresponding phase I biotransformation and bioactivation capacities in zebrafish. A total of 68 publications dealing with spatiotemporal CYP mRNA expression patterns, activities towards mammalian CYP-probe substrates, bioactivation and detoxification activities, as well as metabolite profiling were analyzed and included in this review. The main results allow for the following conclusions: (1) Extensive work has been done to document mRNA expression of CYP isoforms from earliest embryonic stages of zebrafish, but juvenile and adult zebrafish have been largely neglected so far. (2) There is insufficient understanding of how sex- and developmental stage-related differences in expression levels of certain CYP isoforms may impact biotransformation and bioactivation capacities in the respective sexes and in different developmental stages of zebrafish. (3) Albeit qualitatively often identical, many studies revealed quantitative differences in metabolic activities of zebrafish embryos and later developmental stages. However, the actual relevance of age-related differences on the outcome of toxicological studies still needs to be clarified. (4) With respect to current remaining gaps, there is still an urgent need for further studies systematically assessing metabolic profiles and capacities of CYP isoforms in zebrafish. Given the increasing importance of Adverse Outcome Pathway (AOP) concepts, an improved understanding of CYP capacities appears essential for the interpretation and outcome of (eco)toxicological studies.


Genetics ◽  
2002 ◽  
Vol 161 (1) ◽  
pp. 259-267 ◽  
Author(s):  
Joachim Altschmied ◽  
Jacqueline Delfgaauw ◽  
Brigitta Wilde ◽  
Jutta Duschl ◽  
Laurence Bouneau ◽  
...  

Abstract The microphthalmia-associated transcription factor (MITF) exists in at least four isoforms. These are generated in higher vertebrates using alternative 5′ exons and promoters from a single gene. Two separate genes (mitf-m and mitf-b), however, are present in different teleost fish species including the poeciliid Xiphophorus, the pufferfishes Fugu rubripes and Tetraodon nigroviridis, and the zebrafish Danio rerio. Fish proteins MITF-m and MITF-b correspond at both the structural and the expression levels to one particular bird/mammalian MITF isoform. In the teleost lineage subfunctionalization of mitf genes after duplication at least 100 million years ago is associated with the degeneration of alternative exons and, probably, regulatory elements and promoters. For example, a remnant of the first exon specific for MITF-m is detected within the pufferfish gene encoding MITF-b. Retracing the evolutionary history of mitf genes in vertebrates uncovered the differential recruitment of new introns specific for either the teleost or the bird/mammalian lineage.


Development ◽  
1993 ◽  
Vol 117 (2) ◽  
pp. 807-822 ◽  
Author(s):  
K.A. Wharton ◽  
R.P. Ray ◽  
W.M. Gelbart

decapentaplegic (dpp) is a zygotically expressed gene encoding a TGF-beta-related ligand that is necessary for dorsal-ventral patterning in the Drosophila embryo. We show here that dpp is an integral part of a gradient that specifies many different cell fates via intercellular signalling. There is a graded requirement for dpp activity in the early embryo: high levels of dpp activity specify the amnioserosa, while progressively lower levels specify dorsal and lateral ectoderm. This potential for dpp to specify cell fate is highly dosage sensitive. In the wild-type embryo, increasing the gene dosage of dpp can shift cell fates along the dorsal-ventral axis. Furthermore, in mutant embryos, in which only a subset of the dorsal-ventral pattern elements are represented, increasing the gene dosage of dpp can specifically transform those pattern elements into more dorsal ones. We present evidence that the zygotic dpp gradient and the maternal dorsal gradient specify distinct, non-overlapping domains of the dorsal-ventral pattern.


2014 ◽  
Vol 33 (12) ◽  
pp. 2859-2868 ◽  
Author(s):  
Jing Hua ◽  
Martina G. Vijver ◽  
Michael K. Richardson ◽  
Farooq Ahmad ◽  
Willie J.G.M. Peijnenburg

Author(s):  
Noor Izati Abd Aziz ◽  
Vikneswari Perumal ◽  
Suganya Murugesu ◽  
Qamar Uddin Ahmed ◽  
Bisha Fathamah Uzir ◽  
...  

 The use of zebrafish vertebrate model in vivo analysis of the drug toxicity and efficacy, chemical toxicity, and safety is increasing in recent researches. Momordica charantia Linn (Cucurbitaceae) has been traditionally claimed for its many protective roles. However, the development of toxicity effect may cause morphological abnormalities by using an embryo of zebrafish (Danio Rerio) is unknown. Hence, this study was designed to determine the toxicity and teratogenic effect of hydroethanolic extract of M. charantia fruit using Zebrafish (Danio Rerio) embryos. The crude extract was prepared from the fruit of M. charantia using 80% hydroethanolic solvent. The zebrafish embryos were exposed to serial dilution of crude extract. The active constituent was analyzed using gas chromatography coupled with mass spectrophotometry (GC-MS) Momordica charantia Linn (Cucurbitaceae) has been widely commercialized based on traditional usage as an antidiabetic product. The current study has shown the toxic effects of the M.  charantia fruit extract on the developing zebrafish embryos, and the median lethal concentration (LC50) was calculated to be 725.90 mg/L at 48 hpt. The observed effects are dependent on the time of exposure and concentrations of the extract. At higher concentration, the extract causes some morphological defects such as less pigmentation, dented tail, spinal curvature, oedema, reduced hatchability, and growth retardation, that indicates the presence of toxicant(s). Based on the GC-MS profiling, some of the compounds identified in the hydroethanolic extract, such as propanedioic acid and glutamine, may have caused the teratogenic effects to the embryos. Further research on the M. charantia fruit's metabolites should be carried out prior to any nutraceutical or pharmaceutical application.


Development ◽  
1997 ◽  
Vol 124 (2) ◽  
pp. 271-278 ◽  
Author(s):  
F. Pignoni ◽  
S.L. Zipursky

The Drosophila decapentaplegic (dpp) gene, encoding a secreted protein of the transforming growth factor-beta (TGF-beta) superfamily, controls proliferation and patterning in diverse tissues, including the eye imaginal disc. Pattern formation in this tissue is initiated at the posterior edge and moves anteriorly as a wave; the front of this wave is called the morphogenetic furrow (MF). Dpp is required for proliferation and initiation of pattern formation at the posterior edge of the eye disc. It has also been suggested that Dpp is the principal mediator of Hedgehog function in driving progression of the MF across the disc. In this paper, ectopic Dpp expression is shown to be sufficient to induce a duplicated eye disc with normal shape, MF progression, neuronal cluster formation and direction of axon outgrowth. Induction of ectopic eye development occurs preferentially along the anterior margin of the eye disc. Ectopic Dpp clones situated away from the margins induce neither proliferation nor patterning. The Dpp signalling pathway is shown to be under tight transcriptional and post-transcriptional control within different spatial domains in the developing eye disc. In addition, Dpp positively controls its own expression and suppresses wingless transcription. In contrast to the wing disc, Dpp does not appear to be the principal mediator of Hedgehog function in the eye.


2020 ◽  
Vol 15 (8) ◽  
pp. 1934578X2093717
Author(s):  
Chengniu Wang ◽  
Jie Hui ◽  
Xinhui Zhu ◽  
Shengyu Cui ◽  
Zhiming Cui ◽  
...  

Studies have shown that lobetyolin (LBT), a component of traditional Chinese herbal medicine, has many very good biological activities and functions. However, its side effects and toxicities have not been evaluated adequately. In this work, we investigated the effects of LBT in transgenic zebrafish. LBT treatments promoted angiogenesis and led to vascular morphological malformation in zebrafish embryos, although they were normal in appearance. Interestingly, our results indicated that LBT has a function of promoting nerve growth in the embryonic stage of zebrafish. We also treated the zebrafish with combretastatin A-4 (which resulted in neuronal apoptosis) and LBT simultaneously and found that LBT promoted nerve growth at higher concentrations. Taken together, our findings clearly display that LBT efficiently promotes angiogenesis, leading to vascular morphological malformation, has low toxicity, and notably promotes neuronal development in zebrafish.


2018 ◽  
Vol 634 ◽  
pp. 478-487 ◽  
Author(s):  
Le Qian ◽  
Feng Cui ◽  
Yang Yang ◽  
Yuan Liu ◽  
Suzhen Qi ◽  
...  

Development ◽  
2020 ◽  
Vol 147 (22) ◽  
pp. dev185298
Author(s):  
Zhi Ye ◽  
David Kimelman

ABSTRACTThe early vertebrate embryo extends from anterior to posterior due to the addition of neural and mesodermal cells from a neuromesodermal progenitor (NMp) population located at the most posterior end of the embryo. In order to produce mesoderm throughout this time, the NMps produce their own niche, which is high in Wnt and low in retinoic acid. Using a loss-of-function approach, we demonstrate here that the two most abundant Hox13 genes in zebrafish have a novel role in providing robustness to the NMp niche by working in concert with the niche-establishing factor Brachyury to allow mesoderm formation. Mutants lacking both hoxa13b and hoxd13a in combination with reduced Brachyury activity have synergistic posterior body defects, in the strongest case producing embryos with severe mesodermal defects that phenocopy brachyury null mutants. Our results provide a new way of understanding the essential role of the Hox13 genes in early vertebrate development.This article has an associated ‘The people behind the papers’ interview.


1993 ◽  
Vol 340 (1293) ◽  
pp. 287-296 ◽  

The mesoderm of amphibian embryos arises through an inductive interaction in which a signal from the vegetal hemisphere of the blastula-stage embryo acts on overlying equatorial cells. Strong candidates for endogenous mesoderm-inducing signals include members of the fibroblast growth factor (FGF) and activin families. In this paper we show that cells form different mesodermal cell types in response to different concentrations of these factors, and that graded distributions of activin and FGF can, in principle, provide sufficient positional information to generate the body plan of the Xenopus embryo.


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