Biological monitoring of mouse-like rodents in the regions susceptible to anthropogenic pollution: evaluation of environmental conditions (1993) and trends of their alterations (2000)

Institute of Cytology and Genetics, SB RAS, Novosibirsk
Institute for Systematics and Ecology of Animals, SB RAS, Novosibirsk
Novosibirsk State University, Faculty of Natural Sciences,
Department of General Genetics

Head of the Institute:

Vladimir K. Shumny, Academician of the RAS
10 Acad. Lavrentyev Ave., Novosibirsk, 630090, Russia
Phone: (3832)333118, Fax: (3832)333118
email: shumny@bionet.nsc.ru

Principal researchers:

M.N.Bochkarev, Ph.D.
E.I.Karakin, Dr.Sci.
G.M.Ronichevskaya, Dr.Sci.
V.P.Nikolin, Ph.D.
T.A.Dupal, Ph.D.

Project objectives

The Project is aimed to study anthropogenic pollution in the regions studied and its influence on (i) the frequency of chromosomal aberration occurrence in mouse-like rodents; (ii) alteration in the leukocyte and erythrocyte number; (iii) general immune status of animals; (iv) frequencies of internal organ pathology; (v) embryonal mortality.

Background and significance of objectives

The suggested Project is directed to the studying of the most important biological characteristics of rodent species at the Altai territory that were subjected to exactly known dozes of radioactive (near the Semipalatinsk testing ground) and chemical pollutants.

The analysis of mouse-like rodent populations has some cogent advantages. Certainly, these animals are evolutionally closer to humans rather than insects, plants, or bacteria. In addition, rodent species (e.g., forest mice Apodemus sylvaticus and house mice Mus musculus) are characterised by a vast habitat. Due to this fact, it is possible to compare populations from the different, often very remote regions. The rodents are characterised by large-size populations and an enhanced rate of reproduction, this making possible to analyse extended samples of animals.

It is of common knowledge that chemical and radiation pollution (which may be considered as components of the general environmental pollution) leads to mutagenesis in somatic and germ cells. As a consequence, the relative frequencies of chromosomal aberrations increase.

As is known, mutagens of different origin cause definite dominant lethal mutations. In turn, they inevitably modify embryonal mortality.

As a measure of mutagen influence on the frequency of dominant lethal occurrence, it is proposed to apply the number of resorbed embryos of the pregnant females.

As a matter of fact, the summarised influence of mutagens and toxins on the organism of the animals from natural populations causes the decrease in total resistance to disease. The indicator of this process is the alteration of the total number of blood leukocytes and erythrocytes; variation in immunoglobulins quantities; expansion of pathologies in internal parts of the body; and, at last, merely an increase in the number of diseased animals. The elementary parameters described above are sufficient to a large extent to describe the state of mouse-like rodent populations in the studied regions.

The approaches described above were applied by our research group for studying natural populations of mouse-like rodents in some regions of the Altai district, which are variously polluted due to nuclear tests at the Semipalatinsk testing ground. The obtained data by the parameters given above are well correlating to the pollution extent at the territories analysed.

In particular, it was demonstrated that cytogenetic testing is the most informative measure of mutagenesis. The next by effectiveness are the blood parameters, then the general pathological alterations of internal parts of the body follow, including tumours (Karakin et al.,1993). In the course of expeditions and the subsequent laboratory studies, we have developed a complex biological test-system for evaluation of the anthropogenic influence on Rodentia wild populations. Besides, the basic scale of biological parameters was described for the animals of the 90-th generation after nuclear tests in 1949.

The results of the submitted Project of biomonitoring within the same territories in 2000 would reveal the trends in the natural rodent populations state.

Research plan: approaches and methods

The study of animal populations from nature is tightly related to expeditionary research conditions in which high-tech analyses are practically impossible to perform. Besides, large samples of animals necessary to support reliable conclusions make it impossible to transport live animals to the laboratory for further research. That is why we suggest applying of a series of elementary analytical methods that can be easily performed in expeditions and lead to results enabling to make the definite conclusions.

As is known, the most adequate results in calculating chromosomal aberrations frequency are revealed by G-banding staining. However, under expeditionary conditions and taking into account the large sampling sizes, this method is practically unpractised. That is why in our previous research we have applied the calculation of aberrations frequency in the anaphase chromosomes. This method allows analysing the occurrence of dicentric, acentric and ring chromosomes in the marrow bone cells. Thus, the application of this method leads to reliable conclusions within the framework of the research task.

The concentration of immunoglobulins in the blood is detected in agarose gels according to Manchini’s method. This method allows numerous dried or frozen blood samples delivered to the laboratory to b detected.

The total amount of blood leukocytes and erythrocytes is calculated by the standard medical procedure directly after the slaughter of animals.

Pathological alterations of internal parts of the body and embryonic mortality are detected visually during anatomization. Pathomorphological and oncological parameters of internal parts will be estimated histologically at the laboratory.

Expected results

Based on the experience obtained during the Project “Altai-93”, we suggest that the methods of monitoring suggested reveal the direct correlation of the state of wild rodent populations in 2000 in comparison to the same basic characteristics obtained in 1993 at the same territories.

The results obtained may be most comprehensively interpreted when compared to complete data on chemical and irradiation pollution of the territory.

According to the goals of the Project, the authors are in needed of financial support for:

ŕ) collection of biological material "Alta -2000" and the studies for obtaining results similar to "Altai-1993" data;

b) translation of the obtained results on "Altai-1993" and "Altai-2000" Programs into English;

c) creation of the databases "Altai-1993" and "Altai-2000" on biomonitoring of wild rodent populations that will be accessible via Internet;

d) publication of a monograph on the results of the project "Altai-1993".

List of publications of participants related of the project

Table 1. The frequency of chromosomal abberations in bone marrow cells in forest and house mice in various Altai regions differing by extent of anthropogenic pollution.

District

Number of the animals

Number of the anaphases

Anaphases with chromosome aberrations, in %

Mitotic activity,

in ‰

Loktevsky

148

36800

7,5

10,1

Tumentsevsky

114

28756

7,4

10,4

Uglovsky

148

36540

16,5

9,3

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