The role of chorion around embryos in toxic effects of bisphenol AF exposure on embryonic zebrafish (Danio rerio) development

2020 ◽  
Vol 233 ◽  
pp. 106540 ◽  
Author(s):  
Yang Yang ◽  
Tian-Le Tang ◽  
Ya-Wen Chen ◽  
Wen-Hao Tang ◽  
Fei Yang
2012 ◽  
Vol 20 (2) ◽  
pp. 101-119
Author(s):  
Sahar El-Dakroory ◽  
Amal El-Bakary ◽  
Adel Zalata ◽  
Hussien Abd Elaziz

Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 2001
Author(s):  
Greta Baratti ◽  
Angelo Rizzo ◽  
Maria Elena Miletto Petrazzini ◽  
Valeria Anna Sovrano

Zebrafish spontaneously use distance and directional relationships among three-dimensional extended surfaces to reorient within a rectangular arena. However, they fail to take advantage of either an array of freestanding corners or an array of unequal-length surfaces to search for a no-longer-present goal under a spontaneous cued memory procedure, being unable to use the information supplied by corners and length without some kind of rewarded training. The present study aimed to tease apart the geometric components characterizing a rectangular enclosure under a procedure recruiting the reference memory, thus training zebrafish in fragmented layouts that provided differences in surface distance, corners, and length. Results showed that fish, besides the distance, easily learned to use both corners and length if subjected to a rewarded exit task over time, suggesting that they can represent all the geometrically informative parts of a rectangular arena when consistently exposed to them. Altogether, these findings highlight crucially important issues apropos the employment of different behavioral protocols (spontaneous choice versus training over time) to assess spatial abilities of zebrafish, further paving the way to deepen the role of visual and nonvisual encodings of isolated geometric components in relation to macrostructural boundaries.


2009 ◽  
Vol 297 (2) ◽  
pp. R412-R420 ◽  
Author(s):  
Shelby L. Steele ◽  
Kwok Hong Andy Lo ◽  
Vincent Wai Tsun Li ◽  
Shuk Han Cheng ◽  
Marc Ekker ◽  
...  

Fish exposed to hypoxia develop decreased heart rate, or bradycardia, the physiological significance of which remains unknown. The general muscarinic receptor antagonist atropine abolishes the development of this hypoxic bradycardia, suggesting the involvement of muscarinic receptors. In this study, we tested the hypothesis that the hypoxic bradycardia is mediated specifically by stimulation of the M2 muscarinic receptor, the most abundant subtype in the vertebrate heart. Zebrafish ( Danio rerio) were reared at two levels of hypoxia (30 and 40 Torr Po2) from the point of fertilization. In hypoxic fish, the heart rate was significantly lower than in normoxic controls from 2 to 10 days postfertilization (dpf). At the more severe level of hypoxia (30 Torr Po2), there were significant increases in the relative mRNA expression of M 2 and the cardiac type β-adrenergic receptors ( β1AR, β2aAR, and β2bAR) at 4 dpf. The hypoxic bradycardia was abolished (at 40 Torr Po2) or significantly attenuated (at 30 Torr Po2) in larvae experiencing M2 receptor knockdown (using morpholino antisense oligonucleotides). Sham-injected larvae exhibited typical hypoxic bradycardia in both hypoxic regimens. The expression of β1AR, β2aAR, β2bAR, and M 2 mRNA was altered at various stages between 1 and 4 dpf in larvae experiencing M2 receptor knockdown. Interestingly, M2 receptor knockdown revealed a cardioinhibitory role for the β2-adrenergic receptor. This is the first study to demonstrate a specific role of the M2 muscarinic receptor in the initiation of hypoxic bradycardia in fish.


Endocrinology ◽  
2013 ◽  
Vol 154 (11) ◽  
pp. 4158-4169 ◽  
Author(s):  
Lucinda B. Griffin ◽  
Kathleen E. January ◽  
Karen W. Ho ◽  
Kellie A. Cotter ◽  
Gloria V. Callard

Genetically distinct estrogen receptor (ER) subtypes (ERα and ERβ) play a major role in mediating estrogen actions in vertebrates, but their unique and overlapping functions are not entirely clear. Although mammals have 1 gene of each subtype (ESR1 and ESR2), teleost fish have a single esr1 (ERα) and 2 esr2 (ERβa and ERβb) genes. To determine the in vivo role of different ER isoforms in regulating estrogen-inducible transcription targets, zebrafish (Danio rerio) embryos were microinjected with esr-specific morpholino (MO) oligonucleotides to disrupt splicing of the exon III/intron III junction in the DNA-binding domain. Each MO knocked down its respective normal transcript and increased production of variants with a retained intron III (esr1 MO) or a deleted or mis-spliced exon III (esr2a and esr2b MOs). Both esr1 and esr2b MOs blocked estradiol induction of vitellogenin and ERα mRNAs, predominant hepatic genes, but esr2b was the only MO that blocked induction of cytochrome P450 aromatase B mRNA, a predominant brain gene. Knockdown of ERβa with the esr2a MO had no effect on estrogen induction of the 3 mRNAs but, when coinjected with esr1 MO, attenuated the effect of ERα knockdown. Results indicate that ERα and ERβb, acting separately or cooperatively on specific gene targets, are positive transcriptional regulators of estrogen action, but the role of ERβa, if any, is unclear. We conclude that MO technology in zebrafish embryos is an advantageous approach for investigating the interplay of ER subtypes in a true physiological context.


2018 ◽  
Vol 5 (1) ◽  
pp. 96-102 ◽  
Author(s):  
Carolyn M. Wilke ◽  
Jean-François Gaillard ◽  
Kimberly A. Gray

Light influences chemical interactions of engineered nanomaterials and their toxic effects. Under simulated solar irradiation, we observed that binary mixtures of n-Ag, n-Au, or n-Pt with n-TiO2cause synergistic toxic effects inE. colidue to photochemical interactions governed by metal nanoparticle stability and localized surface plasmon resonance.


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