Veal in Ural
A calf was born in Yekaterinburg, obtained with the help of genetic engineering
Press center of FGBNU Urfanits UrO RAS
Outwardly, he is no different from his relatives, however, his birth was due to modern methods of genetic engineering.
A team of geneticists, embryologists, biologists and veterinarians has been working for 3 years to develop a unique technology for editing the genome of cattle in order to obtain an animal with the specified characteristics.
"The idea of the project is to combine advanced developments in embryology, molecular biology, genetic engineering, veterinary reproductology to create animals with improved traits not in 7-10 generations, but in a short time – by directly making small changes to the genome of Holstein black-and-white cows common in the Urals. Now the improvement of some characteristics of cows occurs traditionally, through breeding work, and this takes decades," explained Anna Sergeevna Krivonogova, project manager, leading researcher at the Laboratory of Biological Technologies of the Ural Research Institute of the Ural State Medical University Urfanits Ural Branch of the Russian Academy of Sciences, Doctor of Biological Sciences.
The main targets for scientists were DNA sites responsible for susceptibility to leukemia, earlessness (hornlessness) and the production of hypoallergenic milk. Leukemia is one of the most common infectious diseases of cattle in many countries of the world. It is forbidden to use milk from sick cows, and this directly affects the efficiency of any livestock enterprise. Comolost is an important point in commodity production: horned animals often injure each other and staff. To avoid this, calves have their horns removed in infancy. And the absence of allergenic protein in milk allows not only people with allergies to use it, but also to make baby formula and dietary products from it.
Genome editing is a jewelry and very complex process. First of all, scientists had to determine the DNA site where the desired gene is located, find a way to deliver an editing system to the cell in order to block the part of the genome that is not needed. To do this, they used CRISPR/Cas9 technology, which allows changing DNA fragments. For a living cell, any intervention is stressful. Therefore, many times scientists have faced a situation when a cell freezes and stops dividing.
"The development of a technique for transplanting an artificially grown embryo with gene correction to an animal is a large–scale and very time-consuming process. For several years, a huge amount of research work has been carried out on the selection of donor material, its preparation for editing, a serious bioinformatic analysis has been performed, a system for making changes to the genome based on CRISPR/Cas9 has been created, and its improved version packaged in an adeno-associated virus (AAV). At each stage, something didn't work out, didn't work, and we carefully searched for the reason. The key to the success of the project was a wonderful team – geneticists, embryologists, biologists and veterinarians involved in the study are highly qualified specialists," says Anna Sergeevna Krivonogova, project manager.
The project, unique in the country, is supervised by the Vice-President of the Russian Academy of Sciences I.M. Donnik. The project is being implemented at the Ural Federal Agrarian Research Center of the Ural Branch of the Russian Academy of Sciences together with the Center for High-Precision Editing and Genetic Technologies for Biomedicine of the Institute of Gene Biology of the Russian Academy of Sciences, leading medical embryologists and JSC Uralplemcenter.
Scientists have begun research on the first experienced calf. In the near future, they will have to lay the following experiments in order to bring the technology to perfection.
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