Frog Embryo Teratogenesis Assay

Davies, Wendy J.; Freeman, Stuart J.

doi:10.1385/0-89603-282-5:311

Cited by 6 publications

(3 citation statements)

References 5 publications

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“…A kit (DAB-M Kit) for staining HRP activity by the Ni(I1)-enhanced diaminobenzidine color reaction was purchased from Zymed Laboratories, Inc. (South San housed, fed, and bred a s previously described (Plowman et al, 1991;Sunderman et al, 19911, using albino adults to obtain nonpigmented progeny. Embryos were grown according to the FETAX protocol (Davies and Freeman, 1995). At 5 hr postfertilization, 12 groups of 25 albino embryos at midblastula stage (N/F stage 8, Nieuwkoop and Faber, 1967) were placed in six petri dishes that contained FETAX medium (controls) and six dishes that contained FETAX medium plus 300 pM NiClz (Ni-exposed embryos).…”

Section: Methodsmentioning

confidence: 99%

Characterization of pNiXa, a serpin of Xenopus laevis oocytes and embryos, and its histidine‐rich, Ni(II)‐binding domain

Sunderman¹,

Varghese²,

Kroftova³

et al. 1996

Mol. Reprod. Dev.

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A Ni(II)-binding serpin, pNiXa, is abundant in Xenopus oocytes and embryos. Kinetic assays show that purified pNiXa strongly inhibits bovine alpha-chymotrypsin (Ki = 3 mM), weakly inhibits porcine elastase (K1 = 0.5 microM), and does not inhibit bovine trypsin. The reversible, slow-binding inhibition of alpha-chymotrypsin by pNiXa is unaffected by Ni(II). Ovochymase in egg exudates is inhibited by pNiXa, but to a limited extent, even at high pNiXa concentrations. An octadecapeptide that models the His-rich domain (-HRHRHEQQGHHDSAKHGH-) of pNiXa forms six-coordinate, octahedral Ni(II)-complexes when the N-terminus is acetylated, and a square-planar Ni(II)-complex when the N-terminus is unblocked. Spectroscopy reveals two distinct types of octahedral Ni(II)-coordination to the N-acetylated octadecapeptide, involving, respectively, 3-4 and 5-6 imidazole nitrogens; the octadecapeptide undergoes partial, reversible precipitation in pH- and Ni(II)-dependent fashion, suggesting an insoluble, Ni(II)-coupled (Hx)n-dimer. Such (Hx)n-peptide interaction is confirmed by an enzyme-linked biotinavidin assay with N-biotin-KHRHRHE-amide and N-acetyl-KHRHRHE-resin beads, which become coupled after adding Ni(II) or Zn(II). H2O2 oxidation of 2'-deoxyguanosine to mutagenic 8-hydroxy-2'-deoxyguanosine is enhanced by the octahedral Ni(II)-octadecapeptide complex, although the effect is more intense with the square-planar Ni(II)-octadecapeptide complex. Immunoperoxidase staining of whole mounts with pNiXa antibody shows that pNiXa is distributed throughout gastrula-stage embryos and is localized during organogenesis in the brain, eye, spinal cord, myotomes, craniofacial tissues, and other sites of Ni(II)-induced anomalies. Patterns of pNiXa staining are similar in controls and Ni(II)-exposed embryos. Binding of Ni(II) to pNiXa may cause embryotoxicity by enhancing oxidative reactions that produce tissue injury and genotoxicity. Although the natural target proteinases for pNiXa inhibition have not been established, pNiXa may be an important regulator of proteolysis during embryonic development.

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Section: Methodsmentioning

confidence: 99%

Characterization of pNiXa, a serpin of Xenopus laevis oocytes and embryos, and its histidine‐rich, Ni(II)‐binding domain

Sunderman¹,

Varghese²,

Kroftova³

et al. 1996

Mol. Reprod. Dev.

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“…Individual paired breeding was induced using diluted (1:12) Ovitrelle (Merck Serono; 250 µg per 0.5 ml choriogonadotropin alfa) following the protocol of Davies and Freeman (1995). Male X. laevis individuals were injected with 250 IU of human chorionic gonadotrophin (HCG) on the first, second and third day of breeding.…”

Section: Adult Breedingmentioning

confidence: 99%

Progeny ofXenopus laevisfrom altitudinal extremes display adaptive physiological performance

Wagener

Kruger

Measey

2021

Journal of Experimental Biology

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Environmental temperature variation generates adaptive phenotypic differentiation in widespread populations. We used a common garden experiment to determine whether offspring with varying parental origins display adaptive phenotypic variation related to different thermal conditions experienced in parental environments. We compared burst swimming performance and critical thermal limits of African clawed frog (Xenopus laevis) tadpoles bred from adults captured at high (∼ 2000 m above sea level) and low (∼ 5 m above sea level) altitudes. Maternal origin significantly affected swimming performance. Optimal swimming performance temperature had a >9°C difference between tadpoles with low altitude maternal origins (Topt: pure- and cross-bred 35.0°C) and high altitude maternal origins (Topt: pure-bred 25.5°C, cross-bred 25.9°C). Parental origin significantly affected critical thermal limits. Pure-bred tadpoles with low altitude parental origins had higher CTmax (37.8±0.8°C) than pure-bred tadpoles with high altitude parental origins and all cross-bred tadpoles (37.0±0.8 and 37.1±0.8°C). Pure-bred tadpoles with low altitude parental origins and all cross-bred tadpoles had higher CTmin (4.2±0.7 and 4.2±0.7°C) than pure-bred tadpoles with high altitude parental origins (2.5±0.6°C). Our study shows Xenopus laevis tadpoles’ varying thermal physiological traits is the result of adaptive responses to their parental thermal environments. This study is one of few demonstrating potential intraspecific evolution of critical thermal limits in a vertebrate species. Multi-generation common garden experiments and genetic analyses would be required to further tease apart the relative contribution of plastic and genetic effects to the adaptive phenotypic variation observed in these tadpoles.

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“…In addition, both zebrafish and Xenopus embryo bioassays have been deployed in environmental studies, especially for evaluation of aquatic toxins . For example, the Zebrafish Embryo Toxicity assay (FET) has been introduced as one of the most promising alternative approaches to acute fish toxicity tests , whereas the Frog Embryo Teratogenesis Assay‐ Xenopus (FETAX) is an established bioassay for ecotoxicity and teratogenicity screening . FETAX has also been applied in forward chemical genomic screening for compounds disrupting development .…”

mentioning

confidence: 99%

Fishing on chips: Up‐and‐coming technological advances in analysis of zebrafish and Xenopus embryos

et al. 2014

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Biotests performed on small vertebrate model organisms provide significant investigative advantages as compared with bioassays that employ cell lines, isolated primary cells, or tissue samples. The main advantage offered by whole-organism approaches is that the effects under study occur in the context of intact physiological milieu, with all its intercellular and multisystem interactions. The gap between the high-throughput cell-based in vitro assays and low-throughput, disproportionally expensive and ethically controversial mammal in vivo tests can be closed by small model organisms such as zebrafish or Xenopus. The optical transparency of their tissues, the ease of genetic manipulation and straightforward husbandry, explain the growing popularity of these model organisms. Nevertheless, despite the potential for miniaturization, automation and subsequent increase in throughput of experimental setups, the manipulation, dispensing and analysis of living fish and frog embryos remain labor-intensive. Recently, a new generation of miniaturized chip-based devices have been developed for zebrafish and Xenopus embryo on-chip culture and experimentation. In this work, we review the critical developments in the field of Lab-on-a-Chip devices designed to alleviate the limits of traditional platforms for studies on zebrafish and clawed frog embryo and larvae. V C 2014 International Society for Advancement of Cytometry

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Frog Embryo Teratogenesis Assay

Cited by 6 publications

References 5 publications

Characterization of pNiXa, a serpin of Xenopus laevis oocytes and embryos, and its histidine‐rich, Ni(II)‐binding domain

Characterization of pNiXa, a serpin of Xenopus laevis oocytes and embryos, and its histidine‐rich, Ni(II)‐binding domain

Progeny ofXenopus laevisfrom altitudinal extremes display adaptive physiological performance

Fishing on chips: Up‐and‐coming technological advances in analysis of zebrafish and Xenopus embryos

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