[The heavy metal content in the soft tissues and shells of specimens of 3 varieties of the Azov and Black Sea mussel Mytilus galloprovincialis].

In representatives of 15 micropopulations of the Black Sea mussels related to three varieties of Mytilus galloprovincialis var. dilatata, var. acrocyrta, var.

[Changes in the properties of the enzymes of energy allowance resulting from heat shock in lake frogs].

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.

[Correlations of the individual levels of the activity and heat resistance of energy-support enzymes in the lake frog].

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.

[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].

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].

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.

[Activity and thermal stability of the enzymes of energy support in the common frog].

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.

[Comparison of the heat resistance of ATP-hydrolyzing enzymes in 2 species of frogs].

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.

[Evaluation of the heritability of aldolase and actinomycin activity and heat resistance in the common frog].

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).

[Individual variability and an error in the method of determining protein thermostability].

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.

[Time of the action of genes controlling the activity of aldolase in embryonal development of groudling].

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.

[Heat resistance of aldolase of the hybrid embryos of sea urchins Strongylocentrotus droebachiensis and 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.

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.