Xenopus laevis: model for cooperating to ecotoxicology studies

Ecotoxicology has emerged as a discipline that aims to identify and predict the effects caused by anthropogenic pollutants defined as emerging on ecosystems. Worrisome are engineered nanoparticles and microplastics found in many consumer products but also chemicals and drugs found in both marine and freshwater aquatic ecosystems. Although the in vitro study is supported by the authorities, continuing evidence indicates that in vivo testing is of extreme relevance in bioscience. X. laevis is a very relevant model for both environmental and biomedical studies (Carotenuto et al., 2016, 2020, 2021, 2022). It allows studies on gametogenesis and embryogenesis as well as on the juvenile and adult stages. Furthermore, compared to alternative models of invertebrates and vertebrates, it shows greater genetic homology and pathways that can be superimposed on mammals, including humans, so the data obtained can be easily translated (Takagi et al., 2013; Session et al., 2016; Tandon et al., 2017). The literature strongly suggests that Xenopus has all the characteristics required of a model organism for studies on bio-interactions and adverse effects of pollutants, also in the perspective of a safe development of new materials (Libralato et al., 2017). The use of this amphibian in the laboratory, offers some advantages: 1) eggs can be obtained almost all along the year by injecting females with gonadotropic hormones and in vitro fertilization is easy to perform; 2) the ease of manipulating of gametes, embryos and adult; 3) the direct visualization of organs morphogenesis; 4) the relative ease of manipulating of gene expression and genetic engineering (Takagi et al., 2013; De Marco et al., 2017) 5) the genome have been completely sequenced (Session et al., 2016) and has a high percentage of homology with that of humans; 6) the availability of Xenopus genetic and genomic data to study genes, gene families and gene networks, including ESTs (expressed sequence tags) (Sczyrba et al., 2005), 7) UniGene clusters continually update genomic sequences for the use of technologies as RNA-Seq (Amin et al., 2014) and quantitative proteomics (Sun et al., 2014). Furthermore, the National Xenopus Resource (NXR), the European Xenopus Resource Centre (EXRC), and other stock centers, have an increasing resource of transgenic lines; 8) the possibility to use techniques for modifying gene expression (morpholino) (Takagi et al., 2013; De Marco et al., 2017), and genome editing techniques like the CRISPR/Cas9 system (Naert et al., 2020). The possibilities offered by X.laevis are an excellent link to undertake cooperation in the study of one of the most challenging environmental aspects, the activity of pollutants on biota including humans.