Search

Microsatellite analysis was used to examine intraspecific polymorphism in two extensive continental isolates of the striped field mouse (Apodemus agrarius Pallas, 1771) separated by the Baikal disjunction. Striped field mice from the western isolate (from the European and Kazakh-Siberian parts of the range) and from the eastern isolate (from the territory of the Middle Amur Region and Coastal Territory of Far East) were tested. The analysis used 180 specimens collected from 33 localities and five microsatellite loci developed earlier for the genus Apodemus. The work was carried out based on the summation of local samples in each of the aforementioned geographical regions. It was shown that allelic diversity and the number of specific alleles were higher in the eastern isolate that may be the result of the longer habitation of the striped field mouse in the eastern part of the range. The limited number of specific alleles in the western isolate as compared to the eastern one can be determined by the founder effect and may reflect the direction of the historical migration of the species from east to west. Our results demonstrate no more than a population level of differentiation within the continental isolates of the striped field mouse and indicate no more than a subspecies level of differences between these isolated forms, i.e., the relatively recent penetration of A. agrarius to western Eurasia.

The composition of organic matter and fluctuations of thermodynamic parameters were investigated in the hydrothermal systems of the Kamchatka peninsula in the context of the origin of life. Organics were analyzed by gas-chromatography/mass spectrometry, and 111 organic compounds belonging to 14 homologous series (aromatic hydrocarbons, alkanes and isoalkanes, halogenated aromatic hydrocarbons, carboxylic acids, esters, etc.) were found in hot springs inhabited by Archaeal and Bacterial thermophiles. The organics detected in the sterile condensate of water-steam mixture taken from deep boreholes (temperature 108-175 °C) consisted of 69 compounds of 11 homologous series, with aromatic hydrocarbons and alkanes being prevalent. The organic material included important prebiotic components such as nitrogen-containing compounds and lipid precursors. A separate organic phase (oil) was discovered in the Uzon Caldera. A biogenic origin is supported by the presence of sterane and hopane biomarkers and the δ(13)C value of the bulk oil; its age determined by (14)C measurements was 1030 ± 40 years. Multilevel fluctuations of thermodynamic parameters proposed to be required for the origin of life were determined in the Mutnovsky and Pauzhetsky hydrothermal systems. The low-frequency component of the hydrothermal fluid pressure varied by up to 2 bars over periods of hours to days, while mid-frequency variations had regular micro-oscillations with periods of about 20 min; the high-frequency component displayed sharp changes of pressure and microfluctuations with periods less than 5 min. The correlation coefficient between pressure and temperature ranges from 0.89 to 0.99 (average 0.96). The natural regimes of pressure and temperature fluctuations in Kamchatka hydrothermal systems can guide future experiments on prebiotic chemistry under oscillating conditions.