New paper published in Aquaculture Reports

 A new paper with Betti and Ákos as coauthors was published in the journal Aquaculture Reports. Enjoy!

Ljubobratović, U., Péter, G., Demény, F., Kugyela, N., Horváth, Á., Pataki, B., Horváth, Z., Jakabné Sándor, Z. & Rónyai, A. (2020). Reproductive performance in virgin pikeperch (Sander lucioperca L.) females fed different dietary levels of arachidonic acid with respect to the duration of spawning induction. Aquaculture Reports, 18, 100430.

Abstract

Pikeperch (Sander lucioperca) is a species of significant importance for the further development of intensive aquaculture, what makes the total control over species’ reproductive cycle a high priority task. The present study aimed to assess the effect of arachidonic acid (AA) dietary enrichment on the reproductive performance in virgin females (two-years-old; individual weight 1.0 ± 0.2 kg) kept in fully controlled conditions with respect to different time of hormonal application. Two groups of breeders, ARA (fed AA enriched diet) and CTRL (fed control feed), were reared in two separated tanks of the recirculation system over the course of seven months. Five, six, and seven months after the start of trial, batches of five pairs of breeders (in total 15 pairs per each feeding group) from each group were hormonally treated. Ovulations occurred after six and seven months (oocyte diameter range 912−1030 μm), and samples of dry eggs were taken for the analysis of fatty acid profiles. Among the parameters of reproductive success, the embryo survival was significantly affected by the diet, while induction duration affected latency time only. The CTRL group females showed overall higher embryo survival across both reproduction occasions (p = 0.028) than group fed AA enriched diet (35.7 ± 17.1 % and 18.6 ± 13.6 % in CTRL and ARA group, respectively). A significant accumulation of AA was found in ARA group eggs in both reproduction batches. Virgin pikeperch breeders appear to keep at least one month plasticity towards the duration of spawning induction in controlled conditions and optimal oocyte diameter range for artificial reproduction is between 900−1000 μm. Levelling dietary AA with eicosapentaenoic acid during the entire photothermal protocol negatively altered the egg quality.

New paper published in Dose-Response

 A new paper with Ákos' coauthorship was published in the journal Dose-Response. Enjoy!

Kerekes, F., Kollár, T., Gazsi, G., Kása, E., Urbányi, B., Csenki-Bakos, Z., & Horváth, Á. (2020). Investigation of Fertilizing Capacity of Zebrafish (Danio rerio) Sperm Exposed to Heavy Metals. Dose-Response. https://doi.org/10.1177/1559325820919597 

Abstract

The objective of our study was to investigate the effects of heavy metals on the fertilizing capacity of exposed zebrafish sperm, on embryonic survival, and on occurrence of embryonic deformities following fertilization with exposed sperm. It is important to test heavy metals because they are well-known pollutants. Sperm of externally fertilizing species can get in contact with pollutants found in aquatic environment. Zebrafish sperm, despite its advantages, has seldom been used in in vitro toxicological studies and no reports are available regarding the fertilizing capacity of exposed sperm. Zebrafish sperm was stripped and exposed to concentrations of the tested heavy metals (Zn2+, Cd2+, Cr3+, Cu2+, Ni2+, Hg2+, As3+) for 30 or 120 minutes. Calculated half-maximal effective concentration (EC50) values do not differ significantly from those calculated for motility for any of the tested heavy metals, which means fertilization rate can indicate the toxicity of the given substance following exposure of sperm. Thus, its application as in vitro toxicological end point is reasonable. The survival of embryos and embryonic development have not been affected by the exposure of spermatozoa, which means all alterations in spermatozoa caused by heavy metals have been expressed before 24 hours post fertilization.

New paper published in JoVE

 A new paper with Ákos' coauthorship was published in the Journal of Visualized Experiments (JoVE). Enjoy!

Csenki, Z., Horváth, Á., Bock, I., Garai, E., Kerekes, F., Vásárhelyi, E., Kovács, B., Urbányi, B., Mueller, F., Bakos, K. Using Tg(Vtg1:mcherry) Zebrafish Embryos to Test the Estrogenic Effects of Endocrine Disrupting Compounds. J. Vis. Exp. (162), e60462, doi:10.3791/60462 (2020).

Summary

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).