Izvestiia Akademii nauk. Seriia biologicheskaia最新文献

Forty-six chiropteran specimens from seven species have been captured on the territory of Southern Siberia. From them, 676 ectoparasites of 16 species (gamasid mites and insects) were collected. The bat fly Basilia mongolensis mongolensis Theodor, 1966 was found in Russia for the first time. The gamasid mites Spinturnix maedai Uchikawa et Wada, 1979 and Macronyssus hosonoi Uchikawa, 1979 have not previously been registered in Siberia. Several species have been recorded on new hosts. Three species of gamasid mites out of the genus Macronyssus are, probably, new to science. New data on the ecology of low-abundant and understudied bat species belonging to the Siberian-Far Eastern complex have been provided.

Cellobiohydrolase activity (CBHA) of endosymbionts in the digestive tract of two African rodent species differing in its morphology and in feeding specialization--Arvicanthis niloticus and Otomys helleri--has been studied as a characteristic of their physiological and ecological adaptation to phytophagy A statistically significant correlation of CBHA with obesity has been revealed in A. niloticus, with the CBHA level being significantly higher in corpus ceci than in ampulla ceci. The possible morphophysiological and ecological significance of the observed features of symbiotic digestion are discussed.

The effect of intra- and interspecific competition on the spatial distribution of the biomass and mortmass of woody plant roots in mixed tree stands has been studied. It has been found that the mass of roots in the samples from tree pairs of different species is higher than in the samples from monospecific pairs. Species-specific differences in the vertical distribution of roots and the effect of intra- and interspecific competition on the spatial structure of biomass have been shown. It has been noted that the proportion of dead roots increases almost linearly with depth.

For the first time using laser confocal microscopy and histochemical and immunocytochemical methods (detection of F-actine, catecholamines, acetylcholintransferase, substances of P and FM RFamide) in combination with classical histological methods and electron microscopy of total preparations, the general structure and regularities of formation of the main organs and the nervous, muscular, and digestive systems in early postlarval development (2 to 4 months) in the opistobranch mollusk Cadlina laevis were studied. Heterochronies manifested in positive allometry of the sensory organs, ganglia of the central nervous system, and the pharyngeal region of the digestive system in relation to general body sizes in juvenile individuals compared to adult animals were detected.

It was observed that open growth systems of modular organisms provide for the organic unity of the processes of embryogenesis, morphogenesis, and reproduction and a wide distribution of vegetative propagation, and these peculiarities determine the topicality of detection of heterotopia in the development of structures associated with reproduction. It was established that homeotic transformations played a certain role in the development of new efficient reproductive strategies, and their wide distribution favored an increase in the reliability of reproductive systems of modular living beings.

Different effects of fasciation on the structure of blastozones and ultimately on the morphology of the plants of the two families investigated was detected. The results of this study demonstrate that in Arabidopsis thaliana phyllotaxis changes, leading to the formation of whorled leaf aestivation (two or four leaf in the whorl). We also demonstrated that in Pisum sativum the number of folioles of a compound leaf increased, the number of stipules also increased, and stipules can grow together and form a structure similar to the sheath of Gramineae. Our results demonstrated that a common manifestation of fasciations in Arabidopsis and Pisum is the formation of a flattened meristem, which extended along the same line (axes of fasciation).

Macrosmatic animals (dogs and mice) have been proved to be able to distinguish between the urine or feces of mice with transplanted hepatocellular carcinoma and those of healthy mice by odor. The chemical composition of animal excreta was found to change with tumor growth; however, it is not clear yet if this results from tumor growth itself, inflammation, or immune response. We suggested that the use of the ability of macrosmatic animals to compare odor mixtures combined with mouse cancer models is a promising trend in the search for new tumor markers.

Interdependence of parameters of shell growth in length and height during ontogeny has been studied in the freshwater pearl mussel M. margaritifera. It has been shown that the results of determining the height-to-length ratio depend on at least two factors: shell corrosion in the apical (umbo) zone and regular, rhythmic deviation of this ratio from values expected from linear regression equation. The first factor may be taken into account by applying an individual correction for each specimen, thereby making the ratio of linear dimensions independent of mussel age and size. The calculation error caused by biological rhythms may be reduced by measuring the greatest possible number of annual rings (> or = 18). Factors accounting for alternation between periods of prevalent shell growth in length or in height are discussed.

The lysosomal enzyme activities of the cestode Triaenophorus nodulosus and its host, the pike, in-aquatic bodies with different degrees of technogenic transformation (Northern Karelia, Russia) have been studied. As has been shown, iron-ore waste causes an increase in the acid phosphatase, nuclease, and beta-galactosidase activities of the host and a decrease in its beta-glucosidase and cathepsin D activities. As a rule, the changes in the same cestode enzyme activities are the opposite. With a decrease in the technogenic load, most of the studied characteristics display the trend of approaching the corresponding values observed in a clean lake. It is assumed that the host plays a leading role in the biochemical adaptation of the parasite and its host to mineral environmental pollution.