Defense of the dissertation of Корнилова Анна Александровна for the degree of Doctor of Philosophy (PhD) in the specialty «6D060700 - Биология»
L.N. Gumilyov Eurasian National University, a dissertation defense for the degree of Doctor of Philosophy (PhD) by Корнилова Анна Александровна on the topic «Genotoxic effect of non-utilized and prohibited pesticides on the organism of farm animals» in the field of «6D060700 – Биология».
The dissertation was carried out at the «» of L.N. Gumilyov Eurasian National University.
The language of defense is russian
Reviewers:
Какабаев Ануарбек Аязбаевич - Candidate of Science, Assistant Professor
Колумбаева Сауле Жанабаевна - Doctor of Science, Professor, professor
Temporary members of the Dissertation Committee:
Абилев Серикбай Каримович
Галкина Светлана Анатольевна
Абильдинова Гульшара Жусуповна - Doctor of Science, Head of Laboratory
Бигалиев Айтхажа Бигалиевич - Doctor of Science, Professor, professor
Academic Advisors:
Zhapbasov Rakhimbek
Sibatayev Anuarbek
The defense will take place on February 14, 2024, at 03:00 PM in the Dissertation Council for the training direction «8D051 – %!s(*string=0xc0011a5ce0)» in the specialty «6D060700 – Биология» of L.N. Gumilyov Eurasian National University. The defense meeting is planned to be held online.
Link: https://us06web.zoom.us/j/82994334102?pwd=6L3P7t6NcrbjZvI2Ce2TvxPgz6GpJb.1 Идентификатор конференции: 829 9433 4102 Код доступа: 252358
Address: Астана
Abstract (English): ANNOTATION dissertation of Kornilova Anna Alexandrovna on the topic "Genotoxic effect of non-utilized and prohibited pesticides on the organism of farm animals" for the degree of Doctor of Philosophy (PhD) in the specialty 6D060700 - Biology. General description of work. This work is devoted to the study of the genotoxic effect of non-utilized and banned pesticides on the body of farm animals. Relevance of the study: Currently, Kazakhstan is a major producer of agricultural products. The development of this powerful sector of the economy is impossible without the use of chemical plant and animal protection products. However, many of them have a whole range of negative effects on the body, including the ability to cause mutations, cancer, and congenital malformations. In this connection, the Decree of the Government of the Republic of Kazakhstan dated April 15, 1996 No. 439, in order to prevent pollution of the environment, agricultural products, as well as the harmful effects of pesticides on human health and wildlife, prohibited the use in the Republic of Kazakhstan of highly toxic pesticides with pronounced cumulative, carcinogenic, mutagenic , teratogenic, embryo- and gonadotoxic properties and having the ability to accumulate in plants, soil and aquatic environment. According to the same regulatory document, “pesticides recognized as prohibited for use on the territory of the Republic of Kazakhstan or that have become unusable are subject to mandatory disposal or destruction. At the same time, the burial of prohibited drugs or their destruction is carried out at the expense of their owner [1]. However, by now on the territory of Kazakhstan, there are a large number of unauthorized places of accumulation of non-utilized and prohibited pesticides, which permanently pollute the environment and negatively affect the viability of organisms. According to the Ministry of Energy of the Republic of Kazakhstan, as of April 2014, the total amount of obsolete pesticides stored at various facilities in Kazakhstan reached 1,617,637.75 kg and containers from them were more than 169,660 pieces. Compared to the data of 2008, in 2014 the amount of obsolete pesticides increased noticeably, which may be due to the discovery of new sites with obsolete pesticides and their containers [2]. The collapse of the USSR led to problems with the organization of pesticide storage sites, which led to large-scale changes in the agricultural system of countries, including Kazakhstan. The loss of centralized control over warehouses has led to the spontaneous accumulation of toxic substances in open spaces, their entry into groundwater and soil, and some of them border settlements and agricultural land [3]. As of 2010, in the Almaty region, 64 warehouses of chemical plant protection products were recorded, in which there were more than 68 tons of non-utilized pesticides belonging to different genotoxicity groups. The potential danger of pesticides for the environment lies, first of all, in the fact that the vast majority of them are synthetic chemicals that are not found in nature, they are deliberately introduced by humans into the biosphere, and on an ever-increasing scale, and are among the top ten pollutants [4]. Agricultural doses of a number of pesticides act like chemical mutagens, causing a negative genetic effect. So, when studying 407 pesticides for mutagenicity, 263 of them had mutagenic activity and represented a genetic hazard [5]. Numerous studies show a relationship between pesticide exposure and an increased risk of cancer, neurodegenerative diseases, respiratory disorders, and diabetes [6]. In the context of the problem of contamination of the territory of Kazakhstan with non-utilized and banned pesticides, which is currently very relevant, more regions of the country can be called “hot spots”, since they are centers of high toxicity and environmental pollution [7]. As a result of improper storage, the chemical structure of the active ingredients of pesticides changes. However, even in this case, their residual amount and their metabolites in the soil become dangerous for the environment. In connection with the current situation, a number of research works were carried out to study the degree of environmental pollution in places where prohibited pesticides are stored. Soil studies have shown a high level of contamination with metabolites. And they are highly toxic with a pronounced skin-resorptive reaction, they also have aneugenic, clastogenic, mutagenic, antimitotic and embryotoxic effects [5]. As is known, chemical mutagens are capable of causing negative consequences in a living organism in a much greater number of cases than, for example, physical or biological ones [8]. In this regard, it is important that even after several years, such toxic chemicals remain dangerous for nature, living organisms and humans. That is why the question of the degree of genotoxic effect of pesticides stored in improper conditions and creating a dangerous level of the ecological situation remains relevant. Modern science has established that in order to detect the genotoxicity of chemical agents, it is most rational to study the level of chromosomal aberrations and genomic mutations in the blood system. If xenobiotics in the form of genotoxic pesticides enter a living organism, there is also a violation of the DNA repair system at the molecular level and, as a result, malfunctions of the body's immune system [9]. There are studies by foreign authors devoted to the study of the cytotoxic and genotoxic effect of pesticides on the human body. Most of the studies were conducted on workers in the chemical industry or agriculture who are in direct contact with toxic chemicals. For example, the cytotoxic effect of benodanil on human blood lymphocytes has been established, which manifests itself in a decrease in the mitotic index [10]. In another work, the genotoxic effect of pesticides on the male body of agricultural workers was proved using the micronucleus test and the DNA comet method [11]. PON1 and GSTP1 genes involved in pesticide metabolism in pesticide-exposed women [12]. In the literature there are also works devoted to the study of the effect of pesticides on the organism of farm animals. Thus, it has been established that fungicides provoke the formation of reactive oxygen species in the body of cattle, a change in the normal chemical composition of the cell membrane, stimulate toxic stress of the cell, the appearance of double-stranded DNA breaks, which leads to an increase in the level of apoptosis in damaged cells. Atrazine herbicide causes a decrease in sperm fertility bovine, the pesticide doramectin induces genotoxic effects in bovine lymphocytes and cumulus cells in vitro [13-15]. However, all of these works are devoted to the study of the effect of pesticides permitted for use in agriculture, and the study of the genotoxicity of non-utilized and prohibited pesticides remains an open issue that needs a comprehensive study using modern advances in genetic science due to the need to protect the environment. Purpose and objectives of the study: Assessment of the genotoxic effect of non-utilized and prohibited pesticides on the body of farm animals (sheep and cattle) kept in areas adjacent to their accumulation areas. To achieve this goal, the following tasks were defined: 1. To study the frequency of occurrence of erythrocytes with micronuclei in sheep and cattle kept in areas adjacent to storage sites of unutilized and prohibited pesticides. 2. To study the frequency of occurrence of genomic mutations and chromosomal aberrations in sheep and cattle kept in areas adjacent to the storage sites of unutilized and prohibited pesticides. 3. To study the general level of cytogenetic instability in sheep and cattle kept in the territories adjacent to the storage sites of non-utilized and banned pesticides. Object of study: Sheep (Ovis aries L.) and cattle (Bos taurus L.) kept in grazing areas adjacent to places of accumulation of non-utilized and banned pesticides; control - animals kept in pasture areas, where there are no places of accumulation of prohibited and non-utilized pesticides. Research methods: micronucleus test, cell cultivation, analysis of metaphase chromosomes, statistical methods for processing experimental data. Scientific novelty of research. For the first time, the genotoxic consequences of exposure to the organism of farm animals (sheep and cattle) of non-utilized and prohibited pesticides have been studied. It has been determined that in animals kept in areas adjacent to accumulations of non-utilized and banned pesticides, the frequency of erythrocytes containing micronuclei increases by an average of 3.83 times compared to the control group. Genomic mutations appear in experimental animals on average in 21.041.83% of cases, and chromosomal aberrations - in 8.011.13%. The obtained scientific materials of the genetic study of farm animals are highly predictive for humans as well. These studies differ from existing similar works in that in numerous works on the study of the effect of pesticides on a living organism, peripheral blood of people who were in contact with pesticides was mainly used as an object, and from animals, mainly amphibians, birds or mouse-like rodents that live in such areas. However, the study of the genotoxic effect of non-utilized and banned pesticides should be carried out using farm animals, the production of which occupies a significant place in people's daily lives. Therefore, it is these animals that were examined by genetic methods in order to diagnose the genotoxicity of non-utilized and banned pesticides. Practical value The data obtained as a result of the work on the genotoxicity of banned and non-utilized pesticides formed the basis of guidelines for cytogenetic testing of farm animals for genotoxicity. They are also the basis for the development of remediation measures. The main provisions of the dissertation submitted for defense. 1. The frequency of occurrence of erythrocytes with micronuclei in sheep and cattle kept in the territories adjacent to the places of storage of non-utilized and prohibited pesticides exceeds similar indicators in the control group of animals. 2. The frequency of occurrence of genomic mutations and chromosomal aberrations in sheep and cattle kept in areas adjacent to the storage sites of non-utilized and banned pesticides exceeds that in the control group of animals. 3. Indicators of cytogenetic instability (A, B, C) in two types of farm animals indicate that the overall increase in the number of chromosomal disorders occurs due to an increase in the number of cells in the blood with chromosomal aberrations and a polyploid set of chromosomes. Relationship of work with research programs. The dissertation work was carried out within the framework of the scientific project "Comprehensive assessment of the impact of non-utilized and prohibited pesticides on the genetic status and health of the population of the Almaty region" state registration number No. 0118rk00749 in 2017-2020. Research results. Farm animals from 5 experimental sites (Beskaynar village, Kyzylkairat village, Belbulak village, Enbekshi village, Basshi village) of Talgar and districts of Almaty region were studied. The sample consisted of 67 sheep and 57 cattle. Of these, as a control, cytogenetic materials were taken from 10 sheep and 10 cattle from the city of Usharal, and for the micronucleus test, 10 sheep and 10 cattle from the village of Karaoy. The level of cytogenetic instability was studied in 5935 sheep peripheral blood cells and 5947 cattle cells. 151244 sheep erythrocytes and 156304 cattle erythrocytes were examined for the presence of micronuclei. The frequency of occurrence of micronuclei in erythrocytes of cattle and sheep significantly exceeds that in the control group. The frequency of erythrocytes with micronuclei in sheep kept in the experimental plots was 2.430.16%, which is 3.47 times higher than in the control group. In cattle, cells with micronuclei were recorded in 3.30.20% of cases, significantly exceeding the data of the control group (by 4.7 times). In erythrocytes of cattle, the largest number of micronuclei was found in animals from the village. Basshi (3.680.20%) and Kyzylkairat (3.550.20%), and in erythrocytes of sheep in animals from the village of Belbulak (2.600.21%). Regularities in the frequency of occurrence of micronuclei in erythrocytes depending on the age of cattle and sheep were not found. The frequency of occurrence of genomic mutations in experimental animals averaged 23.411.95% in cattle and 18.661.72 in sheep. The main share is hypodiploid cells (up to 68.44% of genomic mutations). Hyperdiploid cells are found in 1.760.45% in cattle and 0.760.25% in sheep. The frequency of occurrence of polyploid cells was noted at 5.650.78% in cattle and 5.190.61% in sheep. Chromosomal aberrations were determined in 8.891.28% in cattle and in 7.130.98% in sheep. The ratio of the total amount of cells with hypodiploid, hyperdiploid, polyploid sets of chromosomes and cells with chromosome aberrations (A) to the sum of cells with only a hyperdiploid set of chromosomes and cells with chromosome aberrations (C) in sheep from the control group is 9.350,41% to 1.521,70%, while in sheep from the experimental plots - 25.62,07% to 7.831,01%. In cattle, these figures in the control group are 15.011,67% to 1.350,21%, and from the experimental plots 32.202,75% to 10.661,46%. These results of cytogenetic instability indices (A, C) in two types of farm animals show that the overall increase in the number of chromosomal disorders in them occurs mainly due to an increase in the number of cells in the blood with chromosomal aberrations and a polyploid set of chromosomes. In cattle, the frequency of occurrence of cells with a hyperdiploid set and chromosome aberration was higher than in sheep from the same areas. Therefore, it can be assumed that, taking into account the difference in the mass and duration of the economic use of animals, the body of cattle is most susceptible to the clastogenic and mutagenic effects of the chemical constituents of pesticides. Approbation of work. The main provisions and results of the dissertation are presented: in the collection of articles following the results of the International Scientific and Practical Conference “Theoretical and Practical Aspects of the Formation and Development of the New Science” (Omsk, 2022); in the collection of articles on the results of the International Scientific and Practical Conference "Problems and prospects for the implementation of interdisciplinary research" (Kaluga, 2022). Publications. Based on the materials of the dissertation, 7 scientific papers were published, including: 2 in collections of articles of international scientific and practical conferences 3 in the publication according to the list of the Committee for Control in the Sphere of Education and Science of the Ministry of Education and Science of the Republic of Kazakhstan 1 Guidelines for cytogenetic testing of farm animals for genotoxicity of non-utilized and prohibited pesticides in the Almaty region (catalogue of cells with genomic mutations and chromosome aberrations) 1 in publications included in the Scopus database (Contemporary Problems of Ecology, IF-0.771, percentile 40 The structure and scope of the dissertation. The dissertation consists of an introduction, a review of the literature, research materials and methods, results and their discussion, a conclusion and a list of sources used.
Conclusion of the Research Ethics Committee
Defense of the dissertation: https://www.youtube.com/watch?v=1bJvWt-oDxg&list=PLdGXS-MQBmwby2ZBKr9ZF-kA5InVB4MVc
