Генетична структура роду Microcolpiа (Mollusca: Gastropoda: Melanopsidae)

Abstract

Здійснено дослідження генетичної структури популяцій трьох видів роду Microcolpia, що сумісно проживають в одному біотопі. Встановлено відсутність фіксованих генних відмінностей та достовірних відмінностей у частотах між цими вибірками. Виявлено повну відповідність очікуваного та наявного розподілу генотипів поліморфного локусу у сумісній виборці трьох видів роду Microcolpia.

Осуществлено исследование генетической структуры популяций совместно проживающих в одном биотопе трех видов рода Microcolpia. Установлено отсутствие фиксированных генных отличий и достоверных отличий в частотах между данными выборками. Выявлено полное соответствие ожидаемого и имеющегося распределения генотипов полиморфного локусу в совместимой виборке трех видов рода Microcolpia.

Nowadays the genetic methods of the systematic analysis get a great importance. It is connected with the objectivity of the results of genetic researches, which allow, relying on fixation of alternative allelic conditions, to draw definite conclusions about an evolutionary-genetic discretion of the group of individuals. It is therefore increasingly important in the practice of the systematic researches acquires the biological species concept, which treats the species as a genetic discontinuity, which appear only in the process of historical development and for a historically significant period of time. The application of the genetic methods is particularly important in groups, with traditionally contradictory systematics, when the researchers are inclined to interpret the status of the same forms in different ways. In such cases, the fixation of the alternative alleles in the different groups of individuals definitely gives a positive response to the availability of reproductive isolation. The last looks especially convincing in the case of simpatrical (simbiotopical) of the existence of the species. However in practice the importance of morphological characteristics as the criteria for identifying species in evolutionary concept did not lost its importance, but supplemented with an analysis of the signs at the molecular genetics level of the organizations, the manifestations of which does not depend on habitat and ontogenetic stages and individual variability at this level is strictly governed by the laws of heredity. It should be emphasized that in practice the taxonomy of the most groups of animals was, is and will be typological, inasmuch as the introduction of genetic methods, because of their complexity, it is advisable to realize only in researches of model groups, taxonomy of which is particular interesting. Exactly the results of genetic analysis are the criterion of truth in the last case. In the recent decades, namely genetic researchers allowed to establish the systematic structure of many groups of the mollusks. We realized biochemical genetic marking of the representatives of the available group of molluscs exactly for making more precise the systematic structure of the Microcolpia genus, confirmation or denial of the results of the conchological and kariological researches. The selections of the mollusks M. ucrainica, M. canaliculata, M. potamoctebia,, which live together and was gathered in the village Vylkove (Odessa region) were as the material for this work. The 20 copies of each species were studied by electrophoretic analysis. Was researched the next ferments: malate dehydrogenase, aspartate aminotransferase, nonspecific esterases and structural proteins of muscles. Electrophoretic analysis was carried out in 7.5% poliakrylamidnome gels and continuous system of the buffers. The 4 loci of the nonspecific esterase, one locus of the malate dehydrogenase (sMdh) and the aspartate aminotransferase (sAat) and 4-5 loci of the structural muscle proteins were totally identified. Electrophoretic separation was carried out in poliakrylamidnome gels in tris-EDTA buffer. Conditions of the electrophoretic separation and coloring of the ferments are typical. As a result of electrophoretic analysis of the researched ferments was found that all loci, except for sMdh, are invariant. Including extremely changing and as usually those that are highly species-specific, were the loci that are encoding of the nonspecific esterases. Only one locus (sMdh), which encodes a soluble form malate dehydrogenase was polymorphic. It is represented in the selections with two alleles, the frequency of which did not differ in the researched species. The conducted test for conformity of the distribution of the genotypes of the locus sMdh population panmixia model, indicates that the distribution of genotypes in mixed selection corresponds to the expected distribution. This is evidenced by the very low value of the χ2 criterion. This result can be obtained in two cases: in a situation of free interbreeding between the three predictable species, which in the practice of population-genetic researches are still not known, or in the case of a single population panmixia, individuals of which interbreed with each other without restrictions. Consequently researching of the genetic structure of species of the Microcolpia genus, which live together, was revealed the absence of the fixed genetic differences and reliable differences in the frequencies between the given selections. The full conformity with existing and anticipated distribution of genotypes of polymorphic loci in a joint selection of three species which was gathered in a biotope was established. This gives the reason to believe that the three predictable species are the morphological forms of the same species. To confirm this hypothesis in the future are necessary to see the actualization of the genetic studies of different populations Microcolpia.