[The heavy metal content in the soft tissues and shells of specimens of 3 varieties of the Azov and Black Sea mussel Mytilus galloprovincialis]. / Soderzhanie tiazhelykh metallov v miagkikh tkaniakh i rakovinakh osobei trekh varietetov azovsko-chernomorskoi midii Mytilus galloprovincialis.

In representatives of 15 micropopulations of the Black Sea mussels related to three varieties of Mytilus galloprovincialis var. dilatata, var. acrocyrta, var. frecviens the content of iron, zinc, lead, copper and cadmium in the soft tissues and shells has been determined with the use of atomic adsorption spectrophotometry. It has been found that of importance is the content of industrial wastes in the habitat of the micropopulation examined rather than its attribution to some or other variety. In representatives of all the varieties the accumulation of metals in soft tissues was higher than that is shells. By their concentration in tissues the metals examined can be aligned in the following row in decreasing order: iron, zinc, lead, copper and cadmium.

[Changes in the properties of the enzymes of energy allowance resulting from heat shock in lake frogs]. / Izmenenie svoistv fermentov énergoobespecheniia ozernykh liagushek v rezul'tate teplovogo shoka.

A study was made of the activity and heat resistance of preparations of Na, K-ATPase, Mg-ATPase and succinate dehydrogenase of the lake frog R. ridibunda caused by the heat shock of animals. A decrease in the activity and an increase in the heat resistance of all the three enzymes studied were observed. The level of individual correlations between these parameters remained unchanged. An increase in the heat resistance of Na, K-ATPase occurs at the expense of a higher threshold of its thermal inactivation without changes in the affinity of this enzyme to Na+ and K+. Under discussion is the question of the functional significance of the changes observed.

[Correlations of the individual levels of the activity and heat resistance of energy-support enzymes in the lake frog]. / Issledovanie korreliatsii individual'nykh urovnei aktivnosti i teploustoichivosti fermentov énergoobespecheniia ozernoi liagushki.

A study was made of the correlation between the levels of the activity and heat resistance of Na,K-ATPase, Mg-ATPase and succinate dehydrogenase (SDG) in Rana ridibunda. A correlation was observed between the activities of two ATPases, and between either of them and the activity of liver SDG. The correlation coefficient between the heat resistance levels was statistically significant only in SDG of liver and muscles. The question whether the criterion of T50% inactivation may be good for a comparative appraisal of the heat resistance of enzymes is under discussion.

[Properties of the enzymes of energy supply in the common frog under various physiological states. II. Changes in the heat resistance of adenosine triphosphatases and succinate dehydrogenase]. / Issledovanie svoistv fermentov énergoobespecheniia travianoi liagushki pri raznykh fiziologicheskikh sostoianiiakh organizma. II. Izmenenie teploustoichivosti adenozintrifosfataz i suktsinatdegidrogenazy.

The heat resistance of SDG, Na, K-ATPase and Mg-ATPase of the grass frog was determined in January, March and May, the number of animals examined being 30-40 in either experiment. It was found that the average level of the heat resistance of the enzymes studied shows significant, often differently directed changes, which depend on the physiological state of an organism. Negligible correlation between the thermal sensitivity of different enzymes of an organism during hibernation, completely disappear during the activity state.

[Properties of the energy-allowance enzymes of the common frog in different physiological body states. I. Adenosine triphosphatase and succinate dehydrogenase activities]. / Issledovanie svoistv fewrmentov énergoobespecheniia travianoi liagushki pri raznykh fiziologicheskikh sostoianiiakh organizma. I. Aktivnost' adenozintrifosfataz i suktsinatdegidrogenazy.

The activity of SDG, Na, K-ATPase and Mg-ATPase of the grass frog was determined in January, March and May, the number of animals examined being 30-40 in either series of experiments. In May (period of reproduction) the average activity of the above enzymes was higher than in January and March. This was observed both in males and females. A correlation between enzymatic activities of each single organism in March and May significantly increased. The role of these changes in the increase of viability of the organism is discussed.

[Activity and thermal stability of the enzymes of energy support in the common frog]. / Izuchenie aktivnosti i teploustoichivosti nekotorykh fermentov energoobespecheniia travianoi liagushki.

The activity and heat resistance of succinate dehydrogenase (SDG), Na, K-ATPase and Mg-ATPase of the grass frog (39 specimens) have been determined. No correlation was found between individual levels of heat resistance both of either enzyme examined and of the same enzyme but taken from different tissues (SDG of liver and muscles). The average level of heat resistance of SDG in liver is significantly higher than that in m. gastrocnemius. A statistically significant correlation was observed between individual levels of enzyme activity in the internal organs (SDG of liver, Na, K-ATPase and Mg-ATPase of kidney). The activity of SDG of muscles does not correlate with that of either partner.

[Comparison of the heat resistance of ATP-hydrolyzing enzymes in 2 species of frogs]. / Sravnenie teploustoichivosti ATF-gidrolizuiushchikh fermentov u dvukh vidov liagushek.

A comparison was made between the heat resistance levels of two enzymatic preparations: the actomyosinic and the transport ATPases of two species of frogs (grass and lake frogs) differing in their thermophilia. The interspecies differences in the heat resistance were found to be 6 degrees C for the actomyosinic and 3 degrees C for the transport ATPase in favour of the more thermophilic lake frog. In both species the myosinic ATPase is more sensitive to heat than the transport one. The high heat resistance of the transport ATPase is due to a higher threshold of its sensitivity to temperature.

[Evaluation of the heritability of aldolase and actinomycin activity and heat resistance in the common frog]. / Otsenka nasleduemosti aktivnosti i teploustoichivosti al'dolazy i aktomiozina travianoi liagushki.

The extent of heritability of activities and heat resistance of aldolase and actmyosin in the grass frog tadpoles and adults has been investigated. It has been found that for aldolase the heritability of heat resistance is rather high; almost half of the variability of the character falls on the genotype (h2=0.45). In the period of ontogenesis studied (42nd stage of metamorphosis) a distinct prevalence of the effect of the paternal heat resistance of aldolase was observed in tadpoles, whereas the maternal effect was negligible. The average heritability of actomyosin heat resistance for both the parents is close to that of aldolase, h2=0.43. The shares of the effect of each parent are similar. The heritability of actomyosin activity and that of aldolase is not statistically significant. It can be assumed that in some periods of ontogenesis, of major importance may be the paternal characters of heat resistance and enzyme activity, whereas in others--those of the maternal organism.

[Individual variability and an error in the method of determining protein thermostability]. / Individual'naia izmenchivost' i oshibka metoda opredeleniia teploustoichivosti belkov.

The individual variability of the heat resistance of two enzymes (aldolase and actomyosine) of the m. gastrochemius of the grass frog Rana temporaria has been quantitatively evaluated by means of analysis of variance. 37--41% of the total variability of the character may be due to errors in the methods of investigation, whereas 59--63% of the variability is due to phenotypic differences between individuals of the same population. The extent of error is primarily associated with the initial stages of the experiment, i. e. the isolation of the enzyme preparations. The individual variability of the heat resistance of proteins is lower than that of the cells or the organisms from which they are derived.

[Heat resistance of aldolase of the hybrid embryos of sea urchins Strongylocentrotus droebachiensis and S, intermedius]. / Teploustoichivost' al'dolazy gibridnykh zarodyshei morskikh azhei Strongylocentrotus droebachiensis i S. intermedius

The time of expression of the genes controlling aldolase has been studied in the hybrid embryos female Strongylocentrotus droebachiensis X male S. intermedius. The enzyme heat resistance estimated by the temperature of 50% inactivation following the exposition for 30 min (T50) was used as its genetic marker. T50 of aldolase of the psychrophilic maternal species suffered practically no changes from the stage of mesenchyme blastula till the stage of 11 days old pluteus and equated 35.3 degrees. T50 of aldolase of autumn- and spring-spawning populations of the thermophilic paternal species equaled 39.5 degrees at the stage of 11 days old pluteus. The heat resistance of aldolase of the hybrid embryos did not differ reliably from that of maternal enzyme during the first 4 days of development (at 8 degrees) till the late gastrula stage and attained the maximum (T50 =36.9 degrees) on the 8th day (stage of pluteus). The expression of the genes controlling aldolase appears to take place between these developmental stages.

[Time of the action of genes controlling the activity of aldolase in embryonal development of groudling]. / Vremia deistviia genov, kontroliruiushchikh aktivnost' al'dolazy v embrional'nom razvitii v'iuna

The time of action of the genes controlling the decrease of aldolase activity (21-23 hrs of development) and its subsequent increase (23-36 hrs) was determined by means of inactivation of the nuclei by actinomycin or heavy doses of irradiation at succesive developmental stages. There exist two distinct periods of gene activity; the former (15-18 hrs) determines the rapid fall of maternal aldolase activity and the latter (21-27 hrs) its subsequent replacement by embryonic aldolase. This result is confirmed by the data concerning the changes in aldolase heat resistance in the hybrids of the loach and tropical cyprinids. The genes controlling the synthesis of the new aldolase and the morphogenesis which takes place at the same developmental stages are functioning at different times, i.e. the biochemical and morphological differentiations may occur relatively independently.

Expression of aldolase-controlling genes in hybrid fish embryos. Use of thermostability as a genetic marker.

A new method based on differences in protein thermostability has been proposed for studying genetic control of protein synthesis during development. The effectiveness of this method was checked for aldolase, whose thermostability was established from the temperature required for 50% inactivation after heating for 30 min (T50%). Eggs from a relatively cryophilic species, the loach, were fertilized with sperm from warm-water aquarium fish: the danio, barb, rasbora, and goldfish. The T50% for aldolase from the hybrid embryos and fry was 1-4 degrees higher than for aldolase from the loach. The increase in T50% in the loach times danio and loach times rasbora hybrids was shown to be caused by functioning of the paternal aldolase-controlling genes, which began at the somite-formation stage and coincided with the increase in enzyme activity in the embryo. The value of T50% was increased to a greater extent and reached its maximum more rapidly in the somite tissues than in the cephalic tissues. A decrease in aldolase thermostability occurred in reciprocal danio times loach hybrids during the same developmental stages.