The PhD researcher Rubén Francisco Martínez López will defend his thesis on endocrine disruption in zebrafish. Language of the event: English
The PhD researcher Rubén Francisco Martínez López from the Environmental Toxicology group, will defend his thesis next 25th September 2020 at 16:00h.
Thesis will be live streamed on this link: https://meet.lync.com/ubarcelona-ub/ncarbo/TM2H4VI6
Title: Integrative analysis of endocrine disruption in zebrafish (Danio rerio)
Director: Dr. Benjamin Cayetano Piña Capó and Laia Navarro Martín
Abstract:
Understanding the mode of action of different pollutants and xenobiotics in human and wildlife is a key step in environmental risk assessment. Omic technologies allow the study of the global status at different biological levels (transcriptome, metabolome, lipidome…) from a holistic and integrative point of view. The omic data fusion and integration of the effects at these different levels is an extremely useful method to elucidate the mode of action (MoA) of the pollutants and to propose adverse outcome pathways (AOPs).
In this way, the aim of this thesis is to determine molecular and phenotypical signatures of exposure of several endocrine disrupting chemicals (EDCs) on zebrafish (Danio rerio) eleutheroembryos, which constitutes an excellent model for endocrine disruption.
Morphometric and transcriptomic (RNA-Sequencing) studies were carried out in individuals exposed to bisphenol A (BPA), perfluorooctanesulfonate (PFOS) and tributyltin (TBT). Further metabolic, epigenetic (DNA methylation and miRNAs) and lipidomic (thin layer chromatography and high performance liquid chromatography – mass spectrometry) studies were performed only in BPA-exposed individuals. Main effects of BPA included lipid metabolism disruption, yolk sac malabsorption syndrome and lipid retention (obesogenicity), visual system alteration, and estrogenicity. Some of its effects were long-term persistent and could be mediated by epigenetic mechanisms. PFOS had immunosuppressive and anorexic-like properties, it disrupted the transcription of genes related to cell adhesion molecules (CAMs), and the exposed eleutheroembryos presented muscle-skeletal alterations (scoliosis and kyphosis). Finally, TBT disrupted the transcription of genes related to steroid and cell cycle metabolism, and elicited a general developmental delay (diapause-arrest effect) in the exposed individuals.
Phenotypic observations were related to their transcriptomic alterations and their proposed molecular initiation event (MIE), allowing the design of an AOP for each of the studied EDCs. Overall, this thesis shows the usefulness of transcriptomics and of data integration at different biological levels to discern AOPs and MIE, therefore contributing to a deeper comprehension of the toxicity and the mode of action of BPA, PFOS and TBT. We consider that these results can be extrapolated to understand the toxic effects of these compounds in other animals, including humans.
