Izvestiia Akademii nauk. Seriia biologicheskaia最新文献

Biosynthesis of metalloproteinase by the Proteus mirabilis 5127-1 strain on different media and the influence of glucose and urea on biosynthesis were studied. It was found that the P. mirabilis 5127-1 bacteria secretes metalloproteinase in the medium in two isoforms (52 and 50 kDa). It was established that proteinase synthesis is completely suppressed during the growth of bacteria on synthetic media, as well as in the presence of LB glucose in the medium. It was demonstrated that addition of urea in the medium results in an increase of the culture productivity in the proteinase synthesis. Maximal culture productivity in the proteinase synthesis was found in the medium with natural urine. During the growth of bacteria on artificial urine, proteinase appeared in the medium only after 12 hours of growth as a single isoform.

It has been demonstrated by the example of the crucian carp (Carassius carassius) that a 1-hour stay of fish in a combined magnetic field with resonance parameters for calcium ions decreases the proteolytic and amylolytic activities of their intestinal enzymes. It has been found that a 1-hour exposure to a combined magnetic field with resonance parameters for potassium ions has almost no effect on the activity of proteinases, but it decreases the amylolytic activity. It has been noted that the activity of proteases and glycosidases is lower under hypomagnetic conditions. Upon the inversion of the vertical component of the geomagnetic field, the proteolytic activity of the intestinal mucosa in C. carassius decreases, while the amylolytic activity becomes higher compared to the control. Possible effects of magnetic fields on the activity of digestive hydrolases in fish are discussed.

The diurnal dynamics of the content of thyroid and sex steroid hormones is investigated in the blood of the resident form of Black Sea trout in summer. The maximums and minimums of concentration of the investigated hormones do not coincide over 24 h, except for the decrease in the level of T3 and testosterone before dawn. The dynamics of the investigated hormones is controlled to a high extent by the sex of fish in the morning and in the daytime.

We found that selective inhibitors of neuronal and inducible NOS (7-nitroindazole and aminoguanidine) significantly enhance the protective effect of short-term adaptation to hypoxia on the development of stress lesions in rats Krushinsky-Molodkina.

The relationship between the cranial features and feeding types in the musk deer has been studied. According to the results of dispersion and cluster analyses, the six modern subspecies were divided into four trophic (mixed-feeders) subcategories--by the ratio of grass and leaves with a significant fraction of lichens (from 25 to 75%) in their diet. It was established that some morphological features of the skulls of subspecies forms correlate with their feeding specialization and habitat and can thus be useful in the reconstruction of adaptations of extinct Moschidae taxa.

The influence of salicylic (SA) and jasmonic (JA) acids as signaling systems mediators on the generation of H2O2 and expression of genes encoding protective proteins was studied in the leaves of wheat Triticum aestivum L. upon infection with the pathogen of septoriosis Septoria nodorum Berk. It was found that presowing treatment of seeds with SA and JA decreased the development of the fungus on the leaves of wheat and had a stimulating effect on the production of H2O2 in the area of infection. An increased expression of genes encoding oxalate oxidase AJ556991.1 and anionic peroxidase TC 151917 was shown in infected tissues with the method of polymerase chain reaction.

Fry of five species of salmonids are found in the lower reaches of the Ozernaya River. The most abundant are chum salmon and pink salmon which compose the bulk of fry which migrate downstream from the river to the sea. The dates and duration of migration of particular species differed according to the specific traits of their biology. Pink salmon is characterized by a simple migration strategy: it migrated downstream in a short time after emergence from theground. Chum salmon has two strategies of downstream migration: some fry start migration soon after emergence, and others remained in the river for several weeks. Downstream migration of pink salmon occurred mainly at night in contrast to that of chum salmon, over 24 h, the part of daytime increased with growth, of the fish. Migration of pink salmon was passive. Passive migration of chum salmon changed into active-passive with growth of the fish. The ratio of fish in the inshore zone and in the current was different in the course of 24 h. The number of fish in the inshore zone decreased in the period of intensive downstream migration.

Retinal pigment epithelium (RPE) cells that have the unique ability to reprogram retinal cells @in vivo@ were analyzed in the adult newt. Our own data and that available in the literature on the peculiarities of the biology of these cells (from morphology to molecular profile, which can be associated with the capability of phenotype change) were summarized: It was established that the molecular traits of specialized and poorly differentiated cells are combined in RPE of the adult newt. It was registered that persistent (at a low level) proliferation and rapid change of specific cytoskeleton proteins can contribute to the success of RPE cell reprogramming in the neuronal direction. Each of the considered factors of competence for reprogramming can be found for animal RPE, whose cells are not able @in vivo@ to change the phenotype to a neuronal one; however, their totality (supported by the epigenetic state permissive for conversion) is probably an internal property of only newt RPE.

The physicochemical, regulatory, and kinetic properties of malate dehydrogenase (EC 1.1.1.37) from haloalkaliphilic purple nonsulfur Rhodovulum steppense bacteria, strain A-20s, were studied. The malate dehydrogenase (MDH) preparation with a specific activity of 0.775 ± 0.113 U/mg protein was obtained in an electrophoretically homogeneous state using multistep purification. Using homogenous preparations, the molecular weight and the Michaelis constant of the enzyme were determined; the effects of metal ions, the temperature effect, and the thermal stability of the MDH were studied. The dimer structure of the enzyme was demonstrated by DS-Na-electrophoresis.

The ecology of the willow warbler in the north of Western Siberia is considered, and the adaptations that enable the spread of this species to the Subarctic are analyzed. It is established that one of the key factors that caused the change in the range of this species is the northward distribution of shrubs and, hence, the biomass of insects (available food items of these birds).