Teaching in Pula and Zagreb, Croatia

On the invitation of our colleague Dr. Ana Gavrilović from the University of Zagreb in Croatia, Ákos has spent the period between May 23-27th in Pula and Zagreb. This included teaching the basics of cryobiology, fish sperm and germ cell cryopreservation and their transplantation to undergraduate students of the University of Pula and to graduate students in Zagreb. The trip was also a good opportunity for Ákos to practice his original qualification of a fisheries and aquaculture person as he joined a fishing expedition with Ana and her student Neven Iveša. As you see in the picture below, the catch was quite abundant and a real professional treat for Ákos.

Ákos giving a presentation in Pula

The catch of the day

New review paper published in Theriogenology

A new review paper with the co-authorship of Ákos has been published in Theriogenology. Enjoy!

Juan German Herranz-Jusdado, Victor Gallego, Marina Morini, Christoffer Rozenfeld, Luz Pérez, Tamás Müller, Ákos Horváth, Hiromi Ohta, Juan F. Asturiano: Eel sperm cryopreservation: An overview. Theriogenology, 133, 210-215. https://doi.org/10.1016/j.theriogenology.2019.03.033

The eels are teleost fishes from the order Anguilliformes that includes several species with high commercial value. Due to the high interest for aquaculture production of some eel species and for the need to restore eel species that are endangered, several research groups have directed their research toward developing protocols to cryopreserve the spermatozoa of Japanese eel (Anguilla japonica) and European eel (Anguilla anguilla). In this review, we provide an overview on the different protocols that have been developed so far. The first developed protocols used DMSO as cryoprotectant in both species with good success, obtaining sperm motilities of over 45% in Japanese eel and over 35% in European eel. Moreover, sperm cryopreserved using DMSO was successfully used in fertilization trials, although with low fertilization rates. However, recent studies show that DMSO produce epigenetic changes in eel sperm and therefore, the last developed protocols used methanol as cryoprotectant instead. Cryopreservation protocols using methanol as cryoprotectant, showed improved motility values in both Japanese and European eel. In addition, the latest protocols have been adapted to cryopreserve larger volumes of sperm of up to 5 mL, which is useful for larger scale fertilization trials.
The present study introduces the state of the art and future perspectives of the eel sperm cryopreservation to be applied in aquaculture and biological conservation programs.


New paper accepted in PlosOne

A new paper in collaboration with our colleagues from University of South Bohemia in Česke Budejovice, Faculty of Fisheries and Protection of Waters (Czech Republic) has been accepted for publication in PlosOne.

Franěk R., Marinović Z., Lujić J., Urbányi B., Fučíková M., Kašpar V., Pšenička M., Horváth Á. 2019. Cryopreservation and transplantation of common carp spermatogonia. PLoS One. 14(4):e0205481. DOI: 10.1371/journal.pone.0205481

Common carp (Cyprinus carpio) is one of the most cultured fish species over the world with many different breeds and plenty of published protocols for sperm cryopreservation. However, data regarding preservation of gonadal tissue and surrogate production is still missing. A protocol for freezing common carp spermatogonia was developed through varying different factors along a set of serial subsequent experiments. Among the six cryoprotectants tested, the best survival was achieved with dimethyl sulfoxide (Me2SO). In the next experiment, a wide range of cooling rates (0.5–10°C/min) and different concentrations of Me2SO were tested resulting in the highest survival achieved using 2 M Me2SO and cooling rate of -1°C/min. When testing different tissue sizes and incubation times in the cryomedia, the highest viability was observed when incubating 100 mg tissue fragments for 30 min. Finally, sugar supplementation did not yield significant differences. When testing different equilibration (ES) and vitrification solutions (VS) used for needle-immersed vitrification, no significant differences were observed between the tested groups. Additionally, varied exposure time to VS did not improve the vitrification outcome where the viability was 4-fold lower than that of freezing. The functionality of cryopreserved cells was tested by interspecific transplantation into sterilized goldfish recipients. The exogenous origin of the germ cells in gonads of goldfish recipient was confirmed by molecular markers and incorporation rate was over 40% at 3 months post-transplantation. Results of this study can serve for long-term preservation of germplasm in carp which can be recovered in a surrogate recipient.


Bilateral project with Serbia - second year

The second year of our bilateral project with Serbia and University of Novi Sad has started with the visit of our colleagues dr Nada Tokodi and dr Damjana Drobac. The spent one week working in our histological laboratory preparing samples of different fish tissues from Serbian and Hungarian lakes.
It was our pleasure to host you again.

Laboratory safety in the histology lab
Nevena and Damjana
Selfie time during a break
Happy host and happy guests


International Conference: Adriatic Biodiversity Protection – AdriBioPro2019

Jelena and Ilija participated at the International Conference: Adriatic Biodiversity Protection – AdriBioPro2019 organized by University of Montenegro and Institute for Marine Biology in the period between 7th and 10th April in Kotor, Montenegro. They presented their research in Freshwater biodiversity conservation section as oral presentations. 

- Ilija Šćekić, Jelena Lujić, Juan German Herranz-Jusdado, Zoran Marinović, Béla Urbányi, Tamás Müller, Juan F. Asturiano, Ákos Horváth. New strategy for conservation of European eel

- Jelena Lujić, Zoran Marinović, Ilija Šćekić, Béla Urbányi, Ákos Horváth. New strategy for ichthyofaunal conservation - cryopreservation and transplantation of early stage germ cells

Group photo for the beginning
We are ready
AdriBioPro2019 photo wall
Jelena`s presentation
Ilija`s presentation