Training of Marta Blanes and Leonor Ferrão

 Between October 24th and November 26th, this year we had the pleasure of hosting Marta Blanes and Leonor Ferrão of the Group of Aquaculture and Biodiversity under the leadership of Prof. Juan F. Asturiano at the Polytechnical University of Valencia in Spain. Marta and Leonor were trained by Zoran in various techniques including isolation of germline stem cells (GSCs), treatment of embryos with  morpholinos to induce sterility as well as transplantation of GSCs into suitable recipents. Their work was part of the EELGONIA project funded by the Spanish Ministry of Science and Innovation. During their stay, Marta and Leonor have isolated GSCs from cryopreserved gonads of the European eel and transplanted them under Zoran's supervision into sterilized zebrafish and common carp larvae. The recipient larvae are currently grown in our facilities and we cannot wait to see what will happen to the transplanted cells.

Marta and Leonor with members of our team in front of our building

Aquaculture Europe 2021

 Zoran and Ákos attended the Aquaculture Europe 2021 meeting that was held on October 4-7 in Funchal, the capital city of the beautiful island of Madeira in Portugal. The meeting was organized by the European Aquaculture Society and attended by more than 1400 participants. The conference was of special interest for us because of the opportunity to meet our friends Juan F. Asturian of the Polytechnical University of Valencia (Spain) and Elsa Cabrita from CCMAR and University of Algarve (Portugal) who was also co-chairing the session on Reproduction. The conference was very well-organized with high-quality sessions and a large trade show. Regarding the cons, the e-poster session was virtually invisible and completely insignificant. A classical poster session with poster boards would have been much nicer. Nevertheless, we had a good time and will definitely come to EAS next year.

The posters presented were:

Á. Horváth, B. Pataki, G. Mészáros, Z. Marinović, N. Kitanović, B. Urbányi: Does sperm concentration matter in carp sperm cryopreservation?

Z. Marinović, J. Lujić, S. Sušnik Bajec, I. Djurdjevič, A. Snoj, B. Urbányi and Á. Horváth: Triploid rainbow trout Oncorhynchus mykiss as a recipient of brown trout germline stem cells.

Bernadett Pataki, Béla Urbányi, Tímea Kollár, Ákos Horváth: Inheritance of sperm cryoresistance in common carp (Cyprinus carpio)

Ákos with Elsa Cabrita (CCMAR, Faro, Portugal) and Juan F. Asturiano (Universitat Politècnica de València, Spain)

Conference in Croatia

Ákos and Betti along with our colleagues Dr. Balázs Kovács and Réka Balogh from the Department of Molecular Ecology have participated at the 56th Croatian and 16th International Symposium of Agriculture which was held between September 5-10th in Vodice, Croatia. Both Betti and Ákos presented the results of the group in several talks during the session on Fisheries, Game Management and Beekeeping. 

Prior to the meeting we also had the pleasure to visit the hatchery of the largest Croatian marine aquaculture company, Cromaris which is situated in the little coastal town of Nin. We had a guided tour of the hatchery by chief technologist Adelko Mihovilović and had the fortune of seeing a large-scale marine fish hatchery for the first time.

Visit to the hatchery of the marine aquaculture company Cromaris in Nin. Left to right: Ákos, Betti, chief technologist Adelko Mihovilović, Réka Balogh and Dr. Balázs Kovács

Betti giving her presentation

Ákos giving his presentation

Zoran's defense

 The long anticipated day has finally come: one of the core members of our team, Zoran Marinović has defended his PhD title. His dissertation was entitled: "Intra- and inter-specific transplantation of spermatogonial stem cells in freshwater fish". The defense was held online on 5th July, 2021 and it was a special pleasure to host Dr. Elsa Cabrita of CCMAR/University of Algarve from Faro, Portugal in Gödöllő as one of Zoran's reviewers. This was the first time in the history of the PhD school of Animal Biotechnology and Animal Sciences that a foreign reviewer has taken part in the work of the defense committee. The committee has evaluated Zoran's presentation, dissertation and debate to a score of 100%. We congatulate Zoran to his success and wish him all the best. 

Well done, Dr. Marinović!

The committee during Zoran's online defense

After a job well done a dinner in Budapest on the banks of the Danube

Ági's defense

 The alumna of our group, Ágnes Ősz has successfully defended her PhD thesis on 28th May, 2021. Her dissertation was entitled "Genetic analysis of Hungarian brown trout populations and development of a marker-assisted breeding system". Ági gave an impressive performance and the committee evaluated her presentation and discussion to a score of 97%. We wish Ági all the best and congratulate her to her new title.

Good job, Dr. Ősz!

New paper published in Aquaculture

 A new paper describing the genetic diversity of brown trout broodstocks throughout Europe was published with Ákos as a coauthor. The main conclusion of the paper is that there exists an international strain of Atlantic lineage of the species that is distributed throughout the continent that could potentially contribute to the reduction of the genetic diversity in brown trout. Enjoy!

Patrick Berrebi, Ákos Horváth, Andrea Splendiani, Stefan Palm, Rafał Bernaś (2021) Genetic diversity of domestic brown trout stocks in Europe. Aquaculture, Volume 544, 15 November 2021, 737043

Abstract

Brown trout (Salmo trutta) is composed of numerous geographical forms in the wild and a multitude of stocks reared in hatcheries. Practices impacting this species are domestication and fish farming. Thousands of hatcheries are producing domestic trout which are frequently released in the wild without real knowledge of the origin and genetic composition of the strains and of the receiving populations. The present study contains an analysis of the genetic structure (using twelve microsatellites) of 26 hatchery strains from Europe (Sweden, Poland, Czech Republic, Slovakia, Hungary, France, Italy and Spain) and one from North America (Minnesota). Several new observations improved our knowledge on this domestic part of S. trutta. First, a cross-border commercial strain of the North Atlantic lineage occupies most of European hatcheries and the American one, as a probable consequence of intensive exchanges of broodstock materials over time. In addition to the common Europe-wide commercial Atlantic strain, local strains stemming from domesticated regional wild fish also occur. Second, the level of genetic polymorphism of most hatchery strains is high to very high, likely reflecting genetic admixture counteracting expected losses of diversity through random genetic drift and domestication. This study emphasizes the value of identifying the genetic composition of hatchery stocks used for releases. It further stresses the need for caution when stocking a common stock across the whole geographical range of a species, with risks for reducing the intraspecific genetic diversity and local adaptation.

Participation in an online workshop

Members of our team (Ákos, Nevena and Zoran) are participating in the 4th edition of the Workshop on Reproductive Biotechnology and Cryobanking in Aquatic Species organized by our colleagues from the Center of Marine Sciences (CCMAR) of the University of Algarve in Faro, Portugal. Ákos will give a talk on the principles of cryopreservation, and he will be joined by Nevena and Zoran in a video presentation of zebrafish gonad vitrification as well as transplantation of cells into suitable recipients. Registration is free and open until April 2nd. 

Institutional changes

As of February 1st, 2021 Szent István University no longer exists. Following a merger of SZIU with the University of Kaposvár, the Georgikon Faculty of Agriculture of the University of Pannonia and the Károly Róbert Campus of Eszterházy University on August 1st, 2020, a new merger took place last Monday when the National Agricultural Research and Innovation Centre (NAIK) was integrated into the university structure. 

The new university is called Hungarian University of Agriculture and Life Sciences (Magyar Agrár- és Élettudományi Egyetem – MATE). The university has five campuses: Buda (Budapest), Szent István (Gödöllő), Georgikon (Keszthely), Kaposvár (Kaposvár) and Károly Róbert (Gyöngyös) and instead of faculties, it is divided into 21 institutes. 

Our team belongs to the Institute of Aquaculture and Environmental Safety, one of the largest institutes of the new university with approximately 150 employees and PhD students at 3 campuses. One of the constituent institutes of the former NAIK, the Research Institute for Fisheries and Aquaculture (HAKI) also belongs to our Institute now (renamed as a research center). The new Institute consists of 6 departments and one research center. Our team belongs to the Department of Aquaculture of which Ákos is the designated chair.

To know more about the new university, please visit this site: https://uni-mate.hu/hu 

Sampling in Lillafüred

 On January 27th 2021, we went to Lillafüred to sample the triploid rainbow trout that were transplanted with brown trout spermatogonia three years ago as well as tiger trout that were transplanted with rainbow trout spermatogonia as adults. The triploids have grown to an enormous size, some females were close to 5 kg in weight. Results of the transplantation will be verified by histology as well as using molecular markers. 

A triploid rainbow trout female transplanted with brown trout spermatogonia

Gyuri, the owner of the farm has also shown us the fish that were the result of the first successful transplantation of rainbow trout spermatogonia into tiger trout recipients. Sperm stripped from one of the tigers was used to fertilize rainbow trout eggs and as the photos show, the progeny are completely normal rainbow trout. Many of the males are already sexually mature and produced sperm that was used for regular fertilization.

A fish hatched from rainbow trout eggs fertilized with sperm stripped from a tiger trout recipient