The evaluation of the antioxidant enzyme’s activity and activity of anaerobic glycolysis’ enzymes under gradual temperature increase in Baikal amphipod species Eulimnogammаrus marituji, E. maackii and Gmelinoides fasciatus

The aim of present study was the evaluation of the antioxidant enzyme’s activity and activity of anaerobic glycolysis enzymes under gradual temperature increase in Baikal amphipods species Eulimnogammarus marituji (Baz., 1945), E. maackii (Gerstf, 1858) and Gmelinoides fasciatus (Stebb., 1899). In all species under gradual temperature increase exposition elevation of peroxidase’ activity was observed. Activities of catalase’, glutathione S – transferase’ and lactate dehydrogenase’ activity in E. marituji andE. maacki were differed from G. fasciatus. It was proposed that changes in the antioxidant enzyme’s activity and activity of anaerobic glycolysis enzymes in Baikal amphipods may contribute to increasing of glycolytic processes functional efficiency and keeping of energetic homeostasis in endemic organisms

MICROSPORIDIAN PARASITES OF SOME SPECIES ENDEMICK AMPHIPODS OF LAKE BAIKAL

With use universal microsporidian SSU rDNA primers were carry out PCR based screening of nine species endemic amphipods of lake Baikal. Six differ species microsporidian parasites were find out at two species of amphipods (P. cancel­lus and E. verrrucosus). Three parasites of uncovered microsporidian are endemick.Работа выполнена при частичной финансовой поддержке грантов ГЗ № 6.382.2014/К, РНФ 14-14-00400, Программы стратегического развития ФГБОУ ВПО «ИГУ» и совместной программы академических обменов DAAD – Минобрнауки РФ «М. Ломоносов» 2014–2015 гг

Salinity modulates thermotolerance, energy metabolism and stress response in amphipods Gammarus lacustris

Temperature and salinity are important abiotic factors for aquatic invertebrates. We investigated the influence of different salinity regimes on thermotolerance, energy metabolism and cellular stress defense mechanisms in amphipods Gammarus lacustris Sars from two populations. We exposed amphipods to different thermal scenarios and determined their survival as well as activity of major antioxidant enzymes (peroxidase, catalase, glutathione S-transferase) and parameters of energy metabolism (content of glucose, glycogen, ATP, ADP, AMP and lactate). Amphipods from a freshwater population were more sensitive to the thermal challenge, showing higher mortality during acute and gradual temperature change compared to their counterparts from a saline lake. A more thermotolerant population from a saline lake had high activity of antioxidant enzymes. The energy limitations of the freshwater population (indicated by low baseline glucose levels, downward shift of the critical temperature of aerobic metabolism and inability to maintain steady-state ATP levels during warming) was observed, possibly reflecting a trade-off between the energy demands for osmoregulation under the hypo-osmotic condition of a freshwater environment and protection against temperature stress

CHANGES IN ACTIVITY OF ANTIOXIDANT ENZYMES UNDER INCREASED SALINITY IN PALEARCTIC AMPHIPODS GAMMARUS LACUSTRIS SARS

The aim of the present study was to evaluate activity of antioxidant en­zymes (peroxidase, catalase, glutathione S-transferase) in Palearctic amphipod species Gammarus lacustris Sars under increased salinity. Activity of peroxidase and catalase was stable under combined influence of increased salinity and temperature. Opposite to this, activity of glutathione S-transferase decreased in the same conditions. Prob­ably, here we demonstrated possible participation of antioxidant enzymes in adaptation mechanisms to environmental changes in widespread amphipods G. lacustris

STRAINS OF ACTINOMYCETES, ISOLATED FROM THE BAIKAL MACROINVERTEBRATES, LIKE THE PROSPECTIVE SOURCE FOR SEARCHING OF BIOACTIVE SUBSTANCES

This article provides results of the screening and an analysis of biosynthetic potential of actinomycetes, isolated from the Baikal macroinvertebrates. An analysis of mass-spec chromatograms extracts, had demonstrated that percent of identified compounds amounted to 9% (n=14), while percent of unidentified compounds amounted to 91% (n=141). Some of these identified compounds, isolated from the biomass and culture broth of the strains, had recently discovered in macroinvertebrates.Работа выполнена при частичной финансовой поддержке проектной части ГЗ № 6.382.2014/K, грантов РФФИ № 14-04-00501_а, РНФ 14-14-00400 программы стратегического развития ФГБОУ ВПО «ИГУ», а также Немецкой службы академических обменов

Microsporidian Parasites Found in the Hemolymph of Four Baikalian Endemic Amphipods.

At present, approximately 187 genera and over 1300 species of Microsporidia have been described, among which almost half infect aquatic species and approximately 50 genera potentially infect aquatic arthropods. Lake Baikal is the deepest and one of the oldest lakes in the world, and it has a rich endemic fauna with a predominance of arthropods. Among the arthropods living in this lake, amphipods (Crustacea) are the most dominant group and are represented by more than 350 endemic species. Baikalian amphipods inhabit almost all depths and all types of substrates. The age and geographical isolation of this group creates excellent opportunities for studying the diversity, evolution and genetics of host-parasite relationships. However, despite more than 150 years of study, data investigating the microsporidia of Lake Baikal remain incomplete. In this study, we used molecular genetic analyses to detect microsporidia in the hemolymph of several endemic species of amphipods from Lake Baikal. We provide the first evidence that microsporidian species belonging to three genera (Microsporidium, Dictyocoela and Nosema) are present in the hemolymph of Baikalian endemic amphipods. In the hemolymph of Eulimnogammarus verrucosus, we detected SSU rDNA of microsporidia belonging to the genus Nozema. In the hemolymph of Pallasea cancellous, we found the DNA of Microsporidium sp. similar to that in other Baikalian endemic amphipods; Dictyocoela sp. was found in the hemolymph of Eulimnogammarus marituji and Acanthogammarus lappaceus longispinus

The SSU rDNA sequences of microsporidia used for phylogenetic analysis.

<p>‘*’—the species of microsporidia founds in endemic amphipod of Lake Baikal (GenBank data).</p><p>The SSU rDNA sequences of microsporidia used for phylogenetic analysis.</p

Determination of Lake Baikal endemic amphipod Eulimnogammarus verrucosus (Gerstf., 1858) thermal optima limits by changes in its metaboliс markers

In present study the determination of cellular metabolic markers under exposure of Lake Baikal endemic amphipod Eulimnogammarus verrucosus (Amphipoda, Crustacea) in a wide range of ambient temperatures was carried out. The metabolic data was compared with species termopreferendum data obtained in our previous studies. It was found that exposure of amphipods under increased temperatures resulted in increase of HSP70 content and lactate, activating of antioxidant enzymes (catalase and peroxidase), as well as reduction of lactate dehydrogenase and glutathione S-transferase activities. Exposure of E. verrucosus at low temperatures resulted in decrease of HSP70 content, increase of lactate level, peroxidase and lactate dehydrogenase activation, and reduction of glutathione S-transferase activity. It was noted that the most expressed changes of metabolism markers in the species observed when temperature threshold was exceeded 11°C or then temperature dropped below 4°C. The temperature range 4-11°C represented the area of ​​stability of cellular metabolic markers in E. verrucosus and correlated with a preferred temperature limits, previously obtained in behavioral experiments. Thus, for a first time with Lake Baikal amphipods we showed that the zone of stability of cellular metabolism in E. verrucosus closely related to their behavioral thermal preference zones and is likely to reflect thermal optima limits of the species

The SSU rDNA sequences of microsporidia used for phylogenetic analysis.

<p>‘*’—the species of microsporidia founds in endemic amphipod of Lake Baikal (GenBank data).</p><p>The SSU rDNA sequences of microsporidia used for phylogenetic analysis.</p