17 February 2022

Together with colleagues from Nizhny Novgorod Institute for Education Development, scientists from Immanuel Kant Baltic Federal University received a grant from the Russian Ministry of Education and Science. The grant is worth 318 million rubles and is aimed at fish genomic research. The project seeks to purify the domesticated species gene pool from small "breakages" that worsen animal health and cause great material losses in the long term. During the study, scientists will search for ways that can be used to cull these harmful genes out. When a human breeds new animals, all he thinks about is achieving goals: increasing milk yields in cows, making a dog's face flatter, increasing body size and stockiness. Artificial selection is based on developing particular characteristics, while others are neglected.

Konstantin Popadin, professor at the Immanuel Kant Baltic Federal University (Kaliningrad) and senior researcher at the Swiss Federal Institute of Technology of Lausanne (Switzerland):

"There is a constant accumulation of small genetic failures that reduce the body's adaptability and worsen its overall health. Of course, no one is going to release a cow into the mountains or a dog into the woods, but these small damaging mutations can affect, for example, an animal's resistance to infections or increase the risk of developing diseases. With each new generation, we get weaker and weaker individuals. As a result, all attempts to breed more fluffy and meaty species are coming to the point where the animal is simply unable to live long enough to recoup the resources spent on it"

Scientists from Immanuel Kant BFU and the Nizhny Novgorod Institute for Education Development call their project "100 Ways to Kill Fish" — on some level, they do plan to find these ways. The very essence of the work is to bring the altered artificial genomes of different fish species closer to the wild ones. And do that not by losing needed characteristics but by spreading the genes preserved in some individuals that ensure health and competitiveness in natural surroundings. "Killing" means to increase the burden of small harmful mutations to the point where individuals who have them do not survive. Then only the healthiest, strongest, and closest in characteristics to the wild ancestors will remain.


"Imagine that we have a few little men carrying sacks of stones — these stones would be an allusion to genetic mutations. If the stone is too big, then the breakage becomes very harmful and it will crush the man. But if the stones are small and the sack is not full — the man will be able to carry his cargo. Then we plan to add one more rather big stone to each man. There are several scenarios of what is going to be next: combined with the existing ones it will crush the man, or the man will endure. Another interesting scenario, which we mostly rely on — this stone can affect the existing small pebbles, and they start to get bigger. Basically, it is possible to selectively "kill" fish with specific small breakages", — adds Dr. Popadin.

For the moment, scientists plan to try two methods. The first one is temperature shock, i.e., "making the soup". In these conditions, the proteins of the cells will unfold, and then, at normal temperature, they will return to their normal state. To make this possible, the proteins need helpers — chaperones. If the latter ones are affected by small breakages, the fish egg will die. Another method of "killing" is quite traditional — inbreeding, that is, closely related crossbreeding. Its effectiveness has been proven many times. For example, we can have a look at the Habsburgs, whose inbreeding eventually led to the disablement and degeneration of the royal European dynasty. Researchers want to repeat their experience, but only with fish.

"We will test these two ideas on danio rerio, and then move on to the breeds used in fish farming. Of course, the approach will differ for the species and the conditions in which they live. The same heating will affect the heat-loving carp differently from the cold-loving salmon. We also need to develop techniques to determine that everything really worked — analysis of the activity of genes, proteins, behavior, and so on. You should understand that such cleansing will not provide long-term results: small breakdowns accumulate constantly, and the process must be repeated periodically. And even so, for business the cost of improving the gene pool will be very small compared to what it would take to treat fish with a lot of genomic errors," — sums up Konstantin Popadin.