Szent Istvan University 3 articles published in JoVE Environment Using Tg(Vtg1:mcherry) Zebrafish Embryos to Test the Estrogenic Effects of Endocrine Disrupting Compounds Zsolt Csenki1, Ákos Horváth1, Illés Bock1, Edina Garai1, Flóra Kerekes1, Erna Vásárhelyi1, Balázs Kovács1, Béla Urbányi1, Ferenc Mueller2, Katalin Bakos1 1Department of Aquaculture, Institute of Aquaculture and Environmental Safety, Faculty of Agricultural and Environmental Sciences, Szent István University, 2Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham Present here is a detailed protocol for the use of zebrafish embryos Tg(vtg1: mCherry) for the detection of estrogenic effects. The protocol covers the propagation of the fish and treatment of embryos, and emphasizes the detection, documentation, and the evaluation of fluorescent signals induced by endocrine disrupting compounds (EDC). Biology Cryopreservation of Zebrafish Spermatogonia by Whole Testes Needle Immersed Ultra-Rapid Cooling Zoran Marinović1, Jelena Lujić1, Eszter Kása1, Zsolt Csenki1, Béla Urbányi1, Ákos Horváth1 1Department of Aquaculture, Szent István University The main purpose of this study was to adapt the needle immersed vitrification (NIV) procedure to cryopreserve whole zebrafish testes. Additionally, the repeatability of the method in five different zebrafish strains was tested. Developmental Biology Handling and Treatment of Male European Eels (Anguilla anguilla) for Hormonal Maturation and Sperm Cryopreservation Juan G. Herranz-Jusdado1, Eszter Kása2, Tímea Kollár2, Víctor Gallego1, David S. Peñaranda1, Christoffer Rozenfeld1, Luz Pérez1, Ákos Horváth2, Juan F. Asturiano1 1Grupo de Acuicultura y Biodiversidad, Instituto de Ciencia y Tecnología Animal, Universitat Politècnica de València, 2Department of Aquaculture, Institute of Aquaculture and Environmental Safety, Szent Istvan University Protocols for European eel maturation and sperm cryopreservation have been improved over the last years. This article describes the best protocol available using human chorionic gonadotropin (hCG) for inducing maturation and methanol as cryoprotectant.