CHARACTERISTICS OF AUTOCHTHONOUS BREEDS OF RUSSIA AND KAZAKHSTAN BY MICRONUCLEAR TEST

Abstract

The article is devoted to the results of the micronucleus test in two well-known autochthonous sheep breeds of the Russian Federation and the Republic of Kazakhstan: Romanov and Edilbay. In Romanov sheep, the highest rates of micronucleus occurrence were found in lambs (8.7 ± 0.9 ‰), than in producing rams (5.6 ± 0.03 ‰) and ewes (4.8 ± 0.3 ‰). The Edilbay breed has the differences in micronucleus test results in erythrocytes are most pronounced between two intrabreed types: “Birlik” and “Suyunduk”. The breeding plant “Birlik” is located in the Ural, the West Kazakhstan region. “Suyunduk” type of Edilbay breed sheep are raised in the breeding plant “Makash” in the Atyrauz region of the Republic of Kazakhstan, located near the Azgir nuclear test site. The difference in the micronucleus test is due to the fact that sheep of the “Suyunduk” type are exposed to environmental stress factors due to the proximity of places with high levels of radionuclide contamination. The constant action of natural selection contributes to the reproduction of animals with increased resistance to environmental stress factors. This explains the low occurrence of cells with cytogenetic abnormalities in sheep of the “Suyunduk” Edilbay breed sheep type. This type has a higher potential for adaptation to adverse breeding conditions than the Birlik type of Edilbay breed sheep. The high level of micronucleus test indicators in sheep of the Romanov breed is associated with the peculiarities of gender and age groups, and also the environmental stress of climatic conditions in Central Russia. A classification of micronucleus is proposed. It is believed that large and medium-sized micronucleus are formed by the action of various mutagens on the body, causing a large in the division of individual chromosomes in metaphase and anaphase. Small micronucleuses indicate a decrease in potential cell viability.