Small HSPs molecular weights as new indication to the hypothesis of segregated status of thermophilic relict Gmelinoides fasciatus among baikal and palearctic amphipods

Among the great diverse of Baikal fauna of amphipods (more than 350 species and subspecies) Gmelinoides fasciatus (Stebbing 1899) takes the special place. It is characterized by a high morphological variability and wide thermal-adaptive possibilities. By common opinion G. fasciatus is a thermophilic relict segregated from other Baikal temperature sensitive amphipods' fauna. In present study we tested hypothesis of segregated status of G. fasciatus among some Baikal and some Palearctic amphipods using of heat-shock proteins’ (HSP) molecular weight as comparative biomarkers. We used heat-shock proteins (HSP) from two families: HSP70 and small HSP (sHSP) immunochemically related to α-crystalline. 15 species of Baikal amphipods from different genera and families and 2 Palearctic species from genus Gammarus were tested. It was shown, that molecular weights of HSP70 were the same in all investigated species and corresponds close to 70 kD. In the contrast, the molecular weights of sHSP in G. fasciatus was 37 kD and differed from all other species, in which molecular weights of sHSP were 35 kD. In sum, this study showed that sHSPs molecular weights may relate to evolutional differences between the close related species. Additionally, obtained data can be taken as new indication of segregated status of thermophilic relict G. fasciatus which linked with its phylogenetic history in Lake Baikal

The Estimation of Impact of Water-soluble Fraction Crude Oil to Deep-water Baikal Amphipod Ommatogammarus carneolus melanophthalmus

The purpose of current work was to assess the effect of water-soluble oil fractions on survival, lactate content and heat shock proteins HSP70 in the deep-water Baikal amphipod - Ommatogammarus carneolus melanophthalmus. Amphipods were exposed for two days in solutions of water-soluble oil fractions at a concentration of 50 μg/L. During exposition time mortality of amphipods was not observed. Significant deviations from the control values for the studied biochemical parameters of O. carneolus melanophthalmus, were not detected. It can be explained by reduction of activity of stress-response mechanisms in deep-water amphipods due to adaptation to stable environmental conditions

Global data set of long-term summertime vertical temperature profiles in 153 lakes

peer reviewedClimate change and other anthropogenic stressors have led to long-term changes in the thermal structure, including surface temperatures, deepwater temperatures, and vertical thermal gradients, in many lakes around the world. Though many studies highlight warming of surface water temperatures in lakes worldwide, less is known about long-term trends in full vertical thermal structure and deepwater temperatures, which have been changing less consistently in both direction and magnitude. Here, we present a globally-expansive data set of summertime in-situ vertical temperature profiles from 153 lakes, with one time series beginning as early as 1894. We also compiled lake geographic, morphometric, and water quality variables that can influence vertical thermal structure through a variety of potential mechanisms in these lakes. These long-term time series of vertical temperature profiles and corresponding lake characteristics serve as valuable data to help understand changes and drivers of lake thermal structure in a time of rapid global and ecological change. © 2021, The Author(s)

Sub-littoral and supra-littoral amphipods respond differently to acute thermal stress

Thermal tolerance was determined in two closely related amphipod species from contrasting environments (sub-littoral and supra-littoral zones of the sea) using HSP expression and the activity of antioxidant enzymes. The levels of HSP70 and small HSPs present in untreated control animals were higher in the supra-littoral Orchestia gammarellus than in the sub-littoral Gammarus oceanicus. Under the acute thermal stress, HSP levels increased less strongly in O. gammarellus than in G. oceanicus. Activities of antioxidant enzymes peroxidase, catalase and glutathione S-transferase, were more pronounced in the supra-littoral O. gammarellus then in the sub-littoral G. oceanicus. We conclude that the environmental temperature regime modifies key cellular defense mechanisms in amphipods. Higher levels of constitutive HSP synthesis and higher levels of antioxidant enzymes in the supra-littoral species likely reflects adaptation to this highly thermally variable environment

Injections of Encapsulated pH Sensor SNARF-1 do not Induce Apparent Stress Reaction in Larvae of Endemic Baikal Caddisflies Baicalina thamastoides

In the present study possibility of stress reaction of larvae of caddisflies Baicalina thamastoides Martynov, 1914 to injection of encapsulated sensors has been assessed. Activities of superoxide dismutase, non-specific esterases and glutathione S-transferase, which play important roles in functioning of organism defense systems, were used as biomarkers. Enzyme activities were measured after injections of empty microcapsules and microcapsules with fluorescent pH sensor SNARF-1, as well as after inlections of physiological saline solution and solution of the fluorescent sensor. Obtained results argue for nontoxicity and no apparent stress reaction of antioxidant and detoxification systems of B. thamastoides larvae to both types of microcapsules

Preliminary Analysis of Hemocyanins in Hemolymph Plasma of Baikal Endemic Amphipods

Two-dimensional electrophoresis of plasma hemolymph proteins of several endemic Baikal amphipod species showed that, as expected, hemocyanin is the main major protein in plasma of these species. Isoforms of hemocyanins form on the gels maximum 24 separate spots with slightly different molecular weight and vary by their isoelectric points. Analysis of transcript sequences of hemocyanin of Baikal amphipod Eulimnogammarus verrucosus revealed a broad heterogeneity of hemocyanin isoforms, which were divided into 2 distinct groups on their amino acid sequence and have different calculated molecular weight and isoelectric points. The β-type of hemocyanin has been described for percarid crustaceans for the first time

Repetitive Measurements of Physiological pH by Implantable Optical Sensors in Muscles of adult Danio rerio: Preliminary Results

Encapsulated optical sensors are promising tool for measurements of physiological parameters inside living organisms. In the present study we tested the possibility to apply encapsulated fluorescent sensors to measure pH in muscles of adult Danio rerio. Right after injection, the sensors detect slightly acidic pH, while after 3 h pH becomes significantly more alkaline. These fluctuations are probably related to cell damage during the injection and further wound repair. After 20 h pH of interstitial fluid was equal to 7,65, which is in between previously measured values and close to the blood pH known for other fishes

COMPARISON OF STRESS PROTEINS PARTICIPATION IN ADAPTATION MECHANISMS OF BAIKALIAN AND PALEARCTIC AMPHIPOD (AMPHIPODA; CRUSTACEA) SPECIES

The aim of the present study was a study of the influence different stressful factor on syntheses and activity of the stress proteins (HSP70, sHSP and peroxidase) of freshwater organism. Six freshwater amphipod species were investigated: Eulimnogammarus cyaneus (Dyb.), E verrucosus (Gerstf.), E vittatus (Dyb.) - endemic species from Lake Baikal which were compared with Palearctic species - Gammarus lacustris Sars., G tigrinus (Sexton), Chaetogammarus ischnus (Stebbins). It was shown expression of sHSP by heat and toxic stresses for all amphipods species. Oxidative stress induced HSP70 for Palearctic species G tigrinus and C ischnus but not for baikalian species. Heat stress did not caused the increase of HSP70 level for Baikalian species of amphipods. The activity of the peroxidase was decrease by heat and toxic stresses. Oxidative stress caused the increase of peroxidase activity for Palearctic species, and the decrease for Baikalian once

Estimation of experimental cohabitation between Holarctic and Baikal Endemic Amphipods Species: G. lacustris against G. fasciatus

The aim of the present study was to estimate the cohabitation effect of two invasive amphipods species (Gammarus lacustris and Gmelinoides fasciatus) by the cellular stress markers such as activity of antioxidant enzymes (peroxidase, catalase, glutathione S-transferase) and content of heat shock protein 70 (HSP70). Changes of antioxidant enzymes activity were shown in both amphipods species. It was observed that in G. lacustris cohabitation with other species led to the activation of all studied enzymes, whereas in G. fasciatus only peroxidase activity alteration was recorded. Notably, the activation of all studied enzymes was short-term. There were no changes of HSP70 content for both species. According to obtained data less sensitivity of G. fasciatus stress markers can be one of the key advantages for further successful distribution and adaptation to the new conditions