Microsurgical dissection methods for embryonic cloning of monozygotic twins

Abstract

To date, biotechnological methods for producing double grains play an important role in increasing the production of milk and meat. At the same time, monozygotic twins are of particular interest for assessing the heritability of quantitative traits, breeding value when studying the influence of the maternal effect on offspring and creating reserve genes with known properties. However, in cattle, the frequency of birth of twins is only 0.025%, and the appearance of identical twins is only 0.01%. The reasons for the separation of embryos in the process of ontogenesis are unknown, but their production became possible with the development of genetic engineering methods, which include embryonic cloning by microsurgery of early embryos (dissection). The results of research in this area are mostly not applied, which is due to the high cost of micromanipulation equipment and the complexity of the procedure due to the large number of micro-tools. Today, the development of simplified methods of microsurgical manipulations on embryos remains an urgent task. In this regard, the aim of the research was to study the possibility of simplifying the existing technology of microsurgical dissection of preimplantation embryos by developing appropriate tools. In connection with this goal, the tasks of developing a device for simplifying the dissection procedure and determining its effectiveness in comparison with the use of a micromanipulator with one tool were determined. The development of the device and its practical application were carried out in 2021-2023 at the Regional Research and Production Center for the Reproduction of Farm Animals of the Kalmyk State University named after B.B. Gorodovikov. The conducted studies showed the following results: the efficiency of using a micromanipulator with one microscalpel was 86.1%: as a result of dissection of 61 embryos, 105 full-fledged demiembryons out of 122 possible ones were obtained. The efficiency of the developed device was 10.2% higher – after separation, 27 embryos received 52 compacted demiembryons out of 54 possible (96.3%).